Commit Graph

376 Commits

Author SHA1 Message Date
Stephen Boyd e7df6f6e21 clk: Constify clk_hw argument to provider APIs
We don't modify the clk_hw argument in these functions, so it's
safe to mark it as const.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:49:11 -07:00
Stephen Boyd fc4a05d4b0 clk: Remove unused provider APIs
Remove these APIs now that we've converted all users to the
replacement struct clk_hw based versions.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:49:02 -07:00
Stephen Boyd 1a9c069cb2 clk: Add clk_hw_*() APIs for use by clk providers
clk providers shouldn't need to use the consumer APIs (clk.h).
Add provider APIs to replace the __clk_*() APIs that take a
struct clk_hw as their first argument instead of a struct clk.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:48:42 -07:00
Heiko Stuebner e6500344ed clk: track the orphan status of clocks and their children
While children of orphan clocks are not carried in the orphan-list itself,
they're nevertheless orphans in their own right as they also don't have an
input-rate available. To ease tracking if a clock is an orphan or has an
orphan in its parent path introduce an orphan field into struct clk and
update it and the fields in child-clocks when a clock gets added or removed
from the orphan-list.

Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Alex Elder <elder@linaro.org>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: kernel@pengutronix.de
Cc: Zhangfei Gao <zhangfei.gao@linaro.org>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: Chao Xie <chao.xie@marvell.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Georgi Djakov <georgi.djakov@linaro.org>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Barry Song <baohua@kernel.org>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Viresh Kumar <viresh.linux@gmail.com>
Cc: Gabriel FERNANDEZ <gabriel.fernandez@st.com>
Cc: emilio@elopez.com.ar
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Michal Simek <michal.simek@xilinx.com>
[sboyd@codeaurora.org: s/clk/core/ in new function]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-12 00:59:18 -07:00
Stephen Boyd a57aa18539 clk: Silence warnings about lock imbalances
The recursive spinlock implementation trips up sparse and it
complains that these functions have lock imbalances. That isn't
really true though, so add some __acquires() and __releases()
information so that sparse is quiet.

drivers/clk/clk.c:116:22: warning: context imbalance in 'clk_enable_lock' - wrong count at exit
drivers/clk/clk.c:141:9: warning: context imbalance in 'clk_enable_unlock' - unexpected unlock

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28 11:59:30 -07:00
Stephen Boyd 9cfad9bc47 Merge branch 'cleanup-clk-h-includes' into clk-next
* cleanup-clk-h-includes: (62 commits)
  clk: Remove clk.h from clk-provider.h
  clk: h8300: Remove clk.h and clkdev.h includes
  clk: at91: Include clk.h and slab.h
  clk: ti: Switch clk-provider.h include to clk.h
  clk: pistachio: Include clk.h
  clk: ingenic: Include clk.h
  clk: si570: Include clk.h
  clk: moxart: Include clk.h
  clk: cdce925: Include clk.h
  clk: Include clk.h in clk.c
  clk: zynq: Include clk.h
  clk: ti: Include clk.h
  clk: sunxi: Include clk.h and remove unused clkdev.h includes
  clk: st: Include clk.h
  clk: qcom: Include clk.h
  clk: highbank: Include clk.h
  clk: bcm: Include clk.h
  clk: versatile: Remove clk.h and clkdev.h includes
  clk: ux500: Remove clk.h and clkdev.h includes
  clk: tegra: Properly include clk.h
  ...
2015-07-28 11:59:09 -07:00
Stephen Boyd 9783c0d985 clk: Allow providers to configure min/max rates
clk providers are using the consumer APIs to set min/max rates on
the clock they're providing. To encourage clk providers to move
away from the consumer APIs, add a provider API to set the
min/max rate of a clock. The assumption is that this is done
before the clock can be requested via clk_get() and that the
clock rate is already within the boundaries of the min/max that's
configured.

Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28 11:58:50 -07:00
Stephen Boyd 19aab27308 Merge branch 'clk-determine-rate-struct' into clk-next
* clk-determine-rate-struct:
  clk: fix some determine_rate implementations
  clk: change clk_ops' ->determine_rate() prototype
2015-07-28 11:51:30 -07:00
Boris Brezillon 57d866e606 clk: fix some determine_rate implementations
Some determine_rate implementations are not returning an error
when they failed to adapt the rate according to the rate request.
Fix them so that they return an error instead of silently
returning 0.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
CC: Jonathan Corbet <corbet@lwn.net>
CC: Tony Lindgren <tony@atomide.com>
CC: Ralf Baechle <ralf@linux-mips.org>
CC: "Emilio López" <emilio@elopez.com.ar>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Tero Kristo <t-kristo@ti.com>
CC: Peter De Schrijver <pdeschrijver@nvidia.com>
CC: Prashant Gaikwad <pgaikwad@nvidia.com>
CC: Stephen Warren <swarren@wwwdotorg.org>
CC: Thierry Reding <thierry.reding@gmail.com>
CC: Alexandre Courbot <gnurou@gmail.com>
CC: linux-doc@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-arm-kernel@lists.infradead.org
CC: linux-omap@vger.kernel.org
CC: linux-mips@linux-mips.org
CC: linux-tegra@vger.kernel.org
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-27 18:13:32 -07:00
Boris Brezillon 0817b62cc0 clk: change clk_ops' ->determine_rate() prototype
Clock rates are stored in an unsigned long field, but ->determine_rate()
(which returns a rounded rate from a requested one) returns a long
value (errors are reported using negative error codes), which can lead
to long overflow if the clock rate exceed 2Ghz.

Change ->determine_rate() prototype to return 0 or an error code, and pass
a pointer to a clk_rate_request structure containing the expected target
rate and the rate constraints imposed by clk users.

The clk_rate_request structure might be extended in the future to contain
other kind of constraints like the rounding policy, the maximum clock
inaccuracy or other things that are not yet supported by the CCF
(power consumption constraints ?).

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
CC: Jonathan Corbet <corbet@lwn.net>
CC: Tony Lindgren <tony@atomide.com>
CC: Ralf Baechle <ralf@linux-mips.org>
CC: "Emilio López" <emilio@elopez.com.ar>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Tero Kristo <t-kristo@ti.com>
CC: Peter De Schrijver <pdeschrijver@nvidia.com>
CC: Prashant Gaikwad <pgaikwad@nvidia.com>
CC: Stephen Warren <swarren@wwwdotorg.org>
CC: Thierry Reding <thierry.reding@gmail.com>
CC: Alexandre Courbot <gnurou@gmail.com>
CC: linux-doc@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-arm-kernel@lists.infradead.org
CC: linux-omap@vger.kernel.org
CC: linux-mips@linux-mips.org
CC: linux-tegra@vger.kernel.org
[sboyd@codeaurora.org: Fix parent dereference problem in
__clk_determine_rate()]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Romain Perier <romain.perier@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
[sboyd@codeaurora.org: Folded in fix from Heiko for fixed-rate
clocks without parents or a rate determining op]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-27 18:12:01 -07:00
Stephen Boyd 3c37311730 clk: Include clk.h in clk.c
This file implements the clk API and so it should include clk.h
directly instead of indirectly including it through
clk-provider.h.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-20 11:11:30 -07:00
Stephen Boyd 2573a02aa5 clk: Move clk_provider_list to scope of function using it
The list isn't used after of_clk_init() is called, so we don't
need to keep an empty list around after init. Put the list on the
stack.

Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-07 17:20:05 -07:00
Stephen Boyd 2e3b19f137 clk: Check for allocation errors in of_clk_init()
Dan Carpenter reports that we don't check the allocation here for
failure. Add a failure check and free any previously allocated
providers from the clk_provider_list.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-07 17:20:03 -07:00
Michael Turquette 2cd7b04328 clk: tegra: Changes for v4.2-rc1
This contains the EMC clock driver that's been exhaustively reviewed and
 tested. It also includes a change to the clock core that allows a clock
 provider to perform low-level reparenting of clocks. This is required by
 the EMC clock driver because the reparenting needs to be done at a very
 specific point in time during the EMC frequency switch.
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Merge tag 'tegra-for-4.2-clk' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into clk-next

clk: tegra: Changes for v4.2-rc1

This contains the EMC clock driver that's been exhaustively reviewed and
tested. It also includes a change to the clock core that allows a clock
provider to perform low-level reparenting of clocks. This is required by
the EMC clock driver because the reparenting needs to be done at a very
specific point in time during the EMC frequency switch.
2015-06-20 13:29:48 -07:00
Michael Turquette 85e88fab13 Merge branch 'clk-exynos-cpu-clk' into clk-next
Folded into this merge commit is a build error fix: s/clk/core in
clk_change_rate due to the new struct clk_core
2015-06-20 13:26:40 -07:00
Bartlomiej Zolnierkiewicz d8d919879e clk: add CLK_RECALC_NEW_RATES clock flag for Exynos cpu clock support
This flag is needed to fix the issue with wrong dividers being setup
by Common Clock Framework when using the new Exynos cpu clock support.

The issue happens because clk_core_set_rate_nolock()  calls
clk_calc_new_rates(clk, rate) before both pre/post clock notifiers have
a chance to run.  In case of Exynos cpu clock support pre/post clock
notifiers are registered for mout_apll clock which is a parent of armclk
cpu clock and dividers are modified in both pre and post clock notifier.
This results in wrong dividers values being later programmed by
clk_change_rate(top).  To workaround the problem CLK_RECALC_NEW_RATES
flag is added and it is set for mout_apll clock later so the correct
divider values are re-calculated after both pre and post clock notifiers
had run.

For example when using "performance" governor on Exynos4210 Origen board
the cpufreq-dt driver requests to change the frequency from 1000MHz to
1200MHz and after the change state of the relevant clocks is following:

Without use of CLK_GET_RATE_NOCACHE flag:

 fout_apll rate: 1200000000
         fout_apll_div_2 rate: 600000000
                 mout_clkout_cpu rate: 600000000
                         div_clkout_cpu rate: 600000000
                                 clkout_cpu rate: 600000000
         mout_apll rate: 1200000000
                 armclk rate: 1200000000
                 mout_hpm rate: 1200000000
                         div_copy rate: 300000000
                                 div_hpm rate: 300000000
                 mout_core rate: 1200000000
                         div_core rate: 1200000000
                                 div_core2 rate: 1200000000
                                         arm_clk_div_2 rate: 600000000
                                         div_corem0 rate: 300000000
                                         div_corem1 rate: 150000000
                                         div_periph rate: 300000000
                         div_atb rate: 300000000
                                 div_pclk_dbg rate: 150000000
                 sclk_apll rate: 1200000000
                         sclk_apll_div_2 rate: 600000000

With use of CLK_GET_RATE_NOCACHE flag:

 fout_apll rate: 1200000000
         fout_apll_div_2 rate: 600000000
                 mout_clkout_cpu rate: 600000000
                         div_clkout_cpu rate: 600000000
                                 clkout_cpu rate: 600000000
         mout_apll rate: 1200000000
                 armclk rate: 1200000000
                 mout_hpm rate: 1200000000
                         div_copy rate: 200000000
                                 div_hpm rate: 200000000
                 mout_core rate: 1200000000
                         div_core rate: 1200000000
                                 div_core2 rate: 1200000000
                                         arm_clk_div_2 rate: 600000000
                                         div_corem0 rate: 300000000
                                         div_corem1 rate: 150000000
                                         div_periph rate: 300000000
                         div_atb rate: 240000000
                                 div_pclk_dbg rate: 120000000
                 sclk_apll rate: 150000000
                         sclk_apll_div_2 rate: 75000000

Without this change cpufreq-dt driver showed ~10 mA larger energy
consumption when compared to cpufreq-exynos one when "performance"
cpufreq governor was used on Exynos4210 SoC based Origen board.

This issue was probably meant to be workarounded by use of
CLK_GET_RATE_NOCACHE and CLK_DIVIDER_READ_ONLY clock flags in
the original Exynos cpu clock patchset (in "[PATCH v12 6/6] clk:
samsung: remove unused clock aliases and update clock flags" patch)
but usage of these flags is not sufficient to fix the issue observed.

Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-06-20 12:17:41 -07:00
Maxime Coquelin 8c9a8a8f71 clk: Move debug_node field under DEBUG_FS flag in struct clk_core
The debug_node field is only used when DEBUG_FS config is selected,
so declare it only if DEBUG_FS is selected.

Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-06-10 14:21:22 -07:00
Dinh Nguyen 2e61dfb360 clk: of: helper for filling parent clock array and return num of parents
Sprinkled all through the platform clock drivers are code like this to
fill the clock parent array:

for (i = 0; i < num_parents; ++i)
	parent_names[i] = of_clk_get_parent_name(np, i);

The of_clk_parent_fill() will do the same as the code above, and while
at it, return the number of parents as well since the logic of the
function is to the walk the clock node to look for the parent.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
[sboyd@codeaurora.org: Fixed kernel-doc]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-06-05 18:10:33 -07:00
Shailendra Verma a59a516398 clk: Fix typo in clk_register() comment
Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-20 15:44:32 -07:00
Stephen Boyd 562ef0b098 clk: Silence sparse warnings about __clk_{get,put}()
drivers/clk/clk.c:2700:5: warning: symbol '__clk_get' was not declared. Should it be static?
drivers/clk/clk.c:2713:6: warning: symbol '__clk_put' was not declared. Should it be static?

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-14 17:11:17 -07:00
Tomeu Vizoso 42c86547f4 clk: Expose clk_hw_reparent() to providers
To be used by clock implementations for switching to a new parent during
rate change.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2015-05-13 15:17:08 +02:00
Stephen Boyd a633472519 clk: Add some more lockdep assertions
We don't check to make sure the enable_lock is held across
enable/disable and we don't check if the prepare_lock is held
across prepare/unprepare. Add some asserts to catch any future
locking problems.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-07 11:32:54 -07:00
Stephen Boyd 18e70efe3e Merge branch 'clk-fixes' into clk-next 2015-05-07 11:32:49 -07:00
Felipe Balbi 70e9f4dde0 clk: add newline character after dumping all clocks
clk_dump() will dump data about all clocks in JSON
format, but it misses a newline character at the
end of the JSON string. This patch adds that missing
newline character.

Signed-off-by: Felipe Balbi <balbi@ti.com>
[sboyd@codeaurora.org: Squelch checkpatch with seq_puts()]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-07 11:32:37 -07:00
Dong Aisheng d2a5d46b16 clk: add missing lock when call clk_core_enable in clk_set_parent
Before commit 035a61c314 ("clk: Make clk API return per-user
struct clk instances") we acquired the enable_lock in
__clk_set_parent_{before,after}() by means of calling
clk_enable(). After commit 035a61c314 we use clk_core_enable()
in place of the clk_enable(), and clk_core_enable() doesn't
acquire the enable_lock. This opens up a race condition between
clk_set_parent() and clk_enable(). Fix it.

Fixes: 035a61c314 ("clk: Make clk API return per-user struct clk instances")
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Dong Aisheng <aisheng.dong@freescale.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-06 16:58:53 -07:00
Stefan Wahren 7cb81136d2 clk: Fix JSON output in debugfs
key/value pairs in a JSON object must be separated by a comma.
After adding the properties "accuracy" and "phase" the JSON output
of /sys/kernel/debug/clk/clk_dump is invalid.

So add the missing commas to fix it.

Fixes: 5279fc402a ("clk: add clk accuracy retrieval support")
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
[sboyd@codeaurora.org: Added comment in function]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-01 18:25:08 -07:00
Stephen Boyd 6e5ab41b10 clk: Update some comments to reflect reality
The debugfs clk directory no longer expresses a clk tree. Update
the comments around that apporiately. Also drop comments about
prepare locks needing to be held as we have the proper
annotations with lockdep_assert_held().

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:41 -07:00
Stephen Boyd 4dff95dc94 clk: Remove forward declared function prototypes
Move the code around so that we don't need to declare function
prototypes at the start of the file. Simplify
clk_core_is_prepared() and clk_core_is_enabled() too to make the
diff easier to read.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:39 -07:00
Stephen Boyd 1f3e198342 clk: Remove impossible if condition in clk_core_get_phase()
This condition can't ever be true because this function is static
and it's always called with a non-NULL pointer.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:37 -07:00
Stephen Boyd d7d131512b clk: Drop unnecessary OOM prints
We don't need to print error messages when allocations fail.
We'll get a nice backtrace in such situations anyway.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:35 -07:00
Dong Aisheng 864e160ae5 clk: Squash __clk_{enable,disable}() into callers
These functions are only used in one place. Let's squash them
into their respective callers to save some lines.

Signed-off-by: Dong Aisheng <aisheng.dong@freescale.com>
[sboyd@codeaurora.org: Redo commit text, add NULL check in
clk_enable()]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:33 -07:00
Stephen Boyd d6968fca78 clk: s/clk/core/ for struct clk_core
While introducing struct clk_core we tried to minimize the diff
by changing the type of 'clk' variables from struct clk to struct
clk_core without changing the names of the variables. Now that
the split is complete, the code is slightly confusing when it
mixes variables called 'clk' and variables called 'core' that are
of the same type struct clk_core. Let's be consistent and use
'core' everywhere we have a struct clk_core pointer and 'clk'
when we have a struct clk pointer.

Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-04-30 16:28:24 -07:00
Boris Brezillon 03bc10ab5b clk: check ->determine/round_rate() return value in clk_calc_new_rates
->determine_rate() and ->round_rate() can return the closest rate to the
requested one or an error code.
clk_calc_new_rates is assuming these functions can't return a negative
value, which leads to a undefined behavior when the clk implementation
returns such an error code.
Fix this by returning NULL in case ->determine_rate() or ->round_rate()
returned an error code.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-04-12 21:09:49 -07:00
Stephen Boyd 5cf065f556 Merge branch 'clk-fixes' into clk-next 2015-03-12 12:20:36 -07:00
Stephen Boyd 306c342f9c clk: Replace of_clk_get_by_clkspec() with of_clk_get_from_provider()
of_clk_get_by_clkspec() has the same function signature as
of_clk_get_from_provider()

 struct clk *of_clk_get_by_clkspec(struct of_phandle_args
 *clkspec)
 struct clk *of_clk_get_from_provider(struct of_phandle_args
 *clkspec)

except of_clk_get_by_clkspec() checks to make sure clkspec is not
NULL. Let's remove of_clk_get_by_clkspec() and replace the
callers of it (clkconf.c) with of_clk_get_from_provider().

Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-12 12:20:34 -07:00
Stephen Boyd 50595f8b9e clk: Rename child_node to clks_node to avoid confusion
The child_node member of struct clk is named the same as the
child_node member of struct clk_core. Let's rename the struct
clk's member to clks_node to avoid getting confused with the
child_node member of struct clk_core and to match the name of the
list head, clks.

Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Alban Browaeys <alban.browaeys@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-12 12:20:32 -07:00
Stephen Boyd b61c43c09f clk: clk_set_parent() with current parent shouldn't fail
If a driver calls clk_set_parent(clk, parent) and parent is the
current parent of clk we shouldn't fail in any case.
Unfortunately if clk is a read-only mux we return -ENOSYS
because we think we can't change the parent, except for in this
special case where we don't actually need to change the parent at
all. Return 0 in such a situation.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12 12:18:53 -07:00
Stephen Boyd dfc202ead3 clk: Add tracepoints for hardware operations
It's useful to have tracepoints around operations that change the
hardware state so that we can debug clock hardware performance
and operations. Four basic types of events are supported: on/off
events for enable, disable, prepare, unprepare that only record
an event and a clock name, rate changing events for
clk_set_{min_,max_}rate{_range}(), phase changing events for
clk_set_phase() and parent changing events for clk_set_parent().

Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12 12:18:51 -07:00
Stephen Boyd 08b9575660 clk: Missing set_phase op is an error
If a clock's clk_ops doesn't have the set_phase op set we should
return an error from clk_set_phase(). This way clock consumers
know that when they tried to set a phase it didn't work, as
opposed to the current behavior where the return value is 0
meaning success.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12 12:18:49 -07:00
Krzysztof Kozlowski 496eadf821 clk: Use lockdep asserts to find missing hold of prepare_lock
Add lockdep asserts for holding the prepare_lock to all functions
marking this as a requirement in description. Add this to private and
exported functions so all locking misuse could be detected during
debugging.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12 12:18:45 -07:00
Michael Turquette 3d3801effd clk: introduce clk_is_match
Some drivers compare struct clk pointers as a means of knowing
if the two pointers reference the same clock hardware. This behavior is
dubious (drivers must not dereference struct clk), but did not cause any
regressions until the per-user struct clk patch was merged. Now the test
for matching clk's will always fail with per-user struct clk's.

clk_is_match is introduced to fix the regression and prevent drivers
from comparing the pointers manually.

Fixes: 035a61c314 ("clk: Make clk API return per-user struct clk instances")
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[arnd@arndb.de: Fix COMMON_CLK=N && HAS_CLK=Y config]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[sboyd@codeaurora.org: const arguments to clk_is_match() and
remove unnecessary ternary operation]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-11 15:56:59 -07:00
Julia Lawall f55ac0655a clk: don't export static symbol
The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
type T;
identifier f;
@@

static T f (...) { ... }

@@
identifier r.f;
declarer name EXPORT_SYMBOL_GPL;
@@

-EXPORT_SYMBOL_GPL(f);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Fixes: 035a61c314 "clk: Make clk API return per-user struct clk instances"
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-11 15:53:18 -07:00
Linus Torvalds 18a8d49973 The clock framework changes for 3.20 contain the usual driver additions,
enhancements and fixes mostly for ARM32, ARM64, MIPS and Power-based
 devices. Additionaly the framework core underwent a bit of surgery with
 two major changes. The boundary between the clock core and clock
 providers (e.g clock drivers) is now more well defined with dedicated
 provider helper functions. struct clk no longer maps 1:1 with the
 hardware clock but is a true per-user cookie which helps us tracker
 users of hardware clocks and debug bad behavior. The second major change
 is the addition of rate constraints for clocks. Rate ranges are now
 supported which are analogous to the voltage ranges in the regulator
 framework. Unfortunately these changes to the core created some
 breakeage. We think we fixed it all up but for this reason there are
 lots of last minute commits trying to undo the damage.
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Merge tag 'clk-for-linus-3.20' of git://git.linaro.org/people/mike.turquette/linux

Pull clock framework updates from Mike Turquette:
 "The clock framework changes contain the usual driver additions,
  enhancements and fixes mostly for ARM32, ARM64, MIPS and Power-based
  devices.

  Additionally the framework core underwent a bit of surgery with two
  major changes:

   - The boundary between the clock core and clock providers (e.g clock
     drivers) is now more well defined with dedicated provider helper
     functions.  struct clk no longer maps 1:1 with the hardware clock
     but is a true per-user cookie which helps us tracker users of
     hardware clocks and debug bad behavior.

   - The addition of rate constraints for clocks.  Rate ranges are now
     supported which are analogous to the voltage ranges in the
     regulator framework.

  Unfortunately these changes to the core created some breakeage.  We
  think we fixed it all up but for this reason there are lots of last
  minute commits trying to undo the damage"

* tag 'clk-for-linus-3.20' of git://git.linaro.org/people/mike.turquette/linux: (113 commits)
  clk: Only recalculate the rate if needed
  Revert "clk: mxs: Fix invalid 32-bit access to frac registers"
  clk: qoriq: Add support for the platform PLL
  powerpc/corenet: Enable CLK_QORIQ
  clk: Replace explicit clk assignment with __clk_hw_set_clk
  clk: Add __clk_hw_set_clk helper function
  clk: Don't dereference parent clock if is NULL
  MIPS: Alchemy: Remove bogus args from alchemy_clk_fgcs_detr
  clkdev: Always allocate a struct clk and call __clk_get() w/ CCF
  clk: shmobile: div6: Avoid division by zero in .round_rate()
  clk: mxs: Fix invalid 32-bit access to frac registers
  clk: omap: compile legacy omap3 clocks conditionally
  clkdev: Export clk_register_clkdev
  clk: Add rate constraints to clocks
  clk: remove clk-private.h
  pci: xgene: do not use clk-private.h
  arm: omap2+ remove dead clock code
  clk: Make clk API return per-user struct clk instances
  clk: tegra: Define PLLD_DSI and remove dsia(b)_mux
  clk: tegra: Add support for the Tegra132 CAR IP block
  ...
2015-02-21 12:30:30 -08:00
Tomeu Vizoso ec02ace8ca clk: Only recalculate the rate if needed
We don't really need to recalculate the effective rate of a clock when a
per-user clock is removed, if the constraints of the later aren't
limiting the requested rate.

This was causing problems with clocks that never had a rate set before,
as rate_req would be zero. Though this could be considered a bug in the
implementation of those clocks, this should be checked somewhere else.

Fixes: 1c8e600440 ("clk: Add rate constraints to clocks")
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-19 19:29:19 -08:00
Javier Martinez Canillas 9e0ad7d28a clk: Don't dereference parent clock if is NULL
The clock passed as an argument to clk_mux_determine_rate_flags()
has the CLK_SET_RATE_PARENT flag set but it has no parent, then a
NULL pointer will tried to be dereferenced.

This shouldn't happen since setting that flag for a clock with no
parent is a bug but the core should be robust to handle that case.

Fixes: 035a61c314 ("clk: Make clk API return per-user struct clk instances")
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-18 09:40:01 -08:00
Andrzej Hajda 612936f212 clk: convert clock name allocations to kstrdup_const
Clock subsystem frequently performs duplication of strings located in
read-only memory section.  Replacing kstrdup by kstrdup_const allows to
avoid such operations.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:36 -08:00
Stephen Boyd 73e0e496af clkdev: Always allocate a struct clk and call __clk_get() w/ CCF
of_clk_get_by_clkspec() returns a struct clk pointer but it
doesn't create a new handle for the consumers when we're using
the common clock framework. Instead it just returns whatever the
clk provider hands out. When the consumers go to call clk_put()
we get an Oops.

Unable to handle kernel paging request at virtual address 00200200
pgd = c0004000
[00200200] *pgd=00000000
Internal error: Oops: 805 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.19.0-rc1-00104-ga251361a-dirty #992
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
task: ee00b000 ti: ee088000 task.ti: ee088000
PC is at __clk_put+0x24/0xd0
LR is at clk_prepare_lock+0xc/0xec
pc : [<c03eef38>]    lr : [<c03ec1f4>]    psr: 20000153
sp : ee089de8  ip : 00000000  fp : 00000000
r10: ee02f480  r9 : 00000001  r8 : 00000000
r7 : ee031cc0  r6 : ee089e08  r5 : 00000000  r4 : ee02f480
r3 : 00100100  r2 : 00200200  r1 : 0000091e  r0 : 00000001
Flags: nzCv  IRQs on  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
Control: 10c5387d  Table: 4000404a  DAC: 00000015
Process swapper/0 (pid: 1, stack limit = 0xee088238)
Stack: (0xee089de8 to 0xee08a000)
9de0:                   ee7c8f14 c03f0ec8 ee089e08 00000000 c0718dc8 00000001
9e00: 00000000 c04ee0f0 ee7e0844 00000001 00000181 c04edb58 ee2bd320 00000000
9e20: 00000000 c011dc5c ee16a1e0 00000000 00000000 c0718dc8 ee16a1e0 ee2bd1e0
9e40: c0641740 ee16a1e0 00000000 ee2bd320 c0718dc8 ee1d3e10 ee1d3e10 00000000
9e60: c0769a88 00000000 c0718dc8 00000000 00000000 c02c3124 c02c310c ee1d3e10
9e80: c07b4eec 00000000 c0769a88 c02c1d0c ee1d3e10 c0769a88 ee1d3e44 00000000
9ea0: c07091dc c02c1eb8 00000000 c0769a88 c02c1e2c c02c0544 ee005478 ee1676c0
9ec0: c0769a88 ee3a4e80 c0760ce8 c02c150c c0669b90 c0769a88 c0746cd8 c0769a88
9ee0: c0746cd8 ee2bc4c0 c0778c00 c02c24e0 00000000 c0746cd8 c0746cd8 c07091f0
9f00: 00000000 c0008944 c04f405c 00000025 ee00b000 60000153 c074ab00 00000000
9f20: 00000000 c074ab90 60000153 00000000 ef7fca5d c050860c 000000b6 c0036b88
9f40: c065ecc4 c06bc728 00000006 00000006 c074ab30 ef7fca40 c0739bdc 00000006
9f60: c0718dbc c0778c00 000000b6 c0718dc8 c06ed598 c06edd64 00000006 00000006
9f80: c06ed598 c003b438 00000000 c04e64f4 00000000 00000000 00000000 00000000
9fa0: 00000000 c04e64fc 00000000 c000e838 00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 c0c0c0c0 c0c0c0c0
[<c03eef38>] (__clk_put) from [<c03f0ec8>] (of_clk_set_defaults+0xe0/0x2c0)
[<c03f0ec8>] (of_clk_set_defaults) from [<c02c3124>] (platform_drv_probe+0x18/0xa4)
[<c02c3124>] (platform_drv_probe) from [<c02c1d0c>] (driver_probe_device+0x10c/0x22c)
[<c02c1d0c>] (driver_probe_device) from [<c02c1eb8>] (__driver_attach+0x8c/0x90)
[<c02c1eb8>] (__driver_attach) from [<c02c0544>] (bus_for_each_dev+0x54/0x88)
[<c02c0544>] (bus_for_each_dev) from [<c02c150c>] (bus_add_driver+0xd4/0x1d0)
[<c02c150c>] (bus_add_driver) from [<c02c24e0>] (driver_register+0x78/0xf4)
[<c02c24e0>] (driver_register) from [<c07091f0>] (fimc_md_init+0x14/0x30)
[<c07091f0>] (fimc_md_init) from [<c0008944>] (do_one_initcall+0x80/0x1d0)
[<c0008944>] (do_one_initcall) from [<c06edd64>] (kernel_init_freeable+0x108/0x1d4)
[<c06edd64>] (kernel_init_freeable) from [<c04e64fc>] (kernel_init+0x8/0xec)
[<c04e64fc>] (kernel_init) from [<c000e838>] (ret_from_fork+0x14/0x3c)
Code: ebfff4ae e5943014 e5942018 e3530000 (e5823000)

Let's create a per-user handle here so that clk_put() can
properly unlink it and free the handle. Now that we allocate a
clk structure here we need to free it if __clk_get() fails so
bury the __clk_get() call in __of_clk_get_from_provider(). We
need to handle the same problem in clk_get_sys() so export
__clk_free_clk() to clkdev.c and do the same thing, except let's
use a union to make this code #ifdef free.

This fixes the above crash, properly calls __clk_get() when
of_clk_get_from_provider() is called, and cleans up the clk
structure on the error path of clk_get_sys().

Fixes: 035a61c314 "clk: Make clk API return per-user struct clk instances"
Reported-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reported-by: Alban Browaeys <alban.browaeys@gmail.com>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Alban Browaeys <prahal@yahoo.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-06 17:53:20 -08:00
Tomeu Vizoso 1c8e600440 clk: Add rate constraints to clocks
Adds a way for clock consumers to set maximum and minimum rates. This
can be used for thermal drivers to set minimum rates, or by misc.
drivers to set maximum rates to assure a minimum performance level.

Changes the signature of the determine_rate callback by adding the
parameters min_rate and max_rate.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
[sboyd@codeaurora.org: set req_rate in __clk_init]
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: min/max rate for sun6i_ahb1_clk_determine_rate
                        migrated clk-private.h changes to clk.c]
2015-02-02 14:23:42 -08:00
Michael Turquette b09d6d9910 clk: remove clk-private.h
Private clock framework data structures should be private, surprisingly.

Now that all platforms and drivers have been updated to remove static
initializations of struct clk and struct clk_core objects and all
references to clk-private.h have been removed we can move the
definitions of these structures into drivers/clk/clk.c and delete the
header.

Additionally the ugly DEFINE_CLK macros have been removed. Those were
used for static definitions of struct clk objects. That practice is no
longer allowed.

Finally __clk_init is staticized as it is no longer declared in any
header.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-02 14:23:41 -08:00
Tomeu Vizoso 035a61c314 clk: Make clk API return per-user struct clk instances
Moves clock state to struct clk_core, but takes care to change as little API as
possible.

struct clk_hw still has a pointer to a struct clk, which is the
implementation's per-user clk instance, for backwards compatibility.

The struct clk that clk_get_parent() returns isn't owned by the caller, but by
the clock implementation, so the former shouldn't call clk_put() on it.

Because some boards in mach-omap2 still register clocks statically, their clock
registration had to be updated to take into account that the clock information
is stored in struct clk_core now.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: adapted clk_has_parent to struct clk_core
                        applied OMAP3+ DPLL fix from Tero & Tony]
2015-02-02 14:22:19 -08:00
Tomeu Vizoso af0f349b29 clk: Remove __clk_register
As it has never been used.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-28 10:40:18 -08:00
Tomeu Vizoso c440525cb9 clk: Remove unneeded NULL checks
As clk_unprepare_unused_subtree and clk_disable_unused_subtree are
always called with a valid struct clk.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-28 10:40:18 -08:00
Maxime Ripard 9767b04fe6 clk: Export phase functions
The phase setter and getter were not exported until now, which was causing
build breakages when callers were compiled as module. Export these two
functions.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-27 11:52:43 -08:00
Stephen Boyd 15a02c1f6d clk: Add __clk_mux_determine_rate_closest
Some clock drivers want to find the closest rate on the input of
a mux instead of a rate that's less than or equal to the desired
rate. Add a generic mux function to support this.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Kenneth Westfield <kwestfie@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-27 11:48:39 -08:00
Srinivas Kandagatla 52bba9809a clk: Fix debugfs clk removal before inited
Some of the clks can be registered & unregistered before the clk related debugfs
entries are initialized at late_initcall. In the unregister path checking for only
dentry before clk_debug_init() would lead dangling pointers in the debug clk list,
because the list is already populated in register path and the clk pointer freed in
unregister path.
The side effect of not removing it from the list is either a null pointer
dereference or if lucky to boot the system, the number of clk entries in
debugfs disappear.

We could add more checks like if (inited && !clk->dentry) but just removing
the check for dentry made more sense as debugfs_remove_recursive() seems to be
safe with null pointers. This will ensure that the unregistering clk would be
removed from the debug list in all the code paths.

Without this patch kernel would crash with log:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c0204000
[00000000] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Modules linked in:
CPU: 1 PID: 1 Comm: swapper/0 Tainted: G    B          3.19.0-rc3-00007-g412f9ba-dirty #840
Hardware name: Qualcomm (Flattened Device Tree)
task: ed948000 ti: ed944000 task.ti: ed944000
PC is at strlen+0xc/0x40
LR is at __create_file+0x64/0x1dc
pc : [<c04ee604>]    lr : [<c049f1c4>]    psr: 60000013
sp : ed945e40  ip : ed945e50  fp : ed945e4c
r10: 00000000  r9 : c1006094  r8 : 00000000
r7 : 000041ed  r6 : 00000000  r5 : ed4af998  r4 : c11b5e28
r3 : 00000000  r2 : ed945e38  r1 : a0000013  r0 : 00000000
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: 10c5787d  Table: 8020406a  DAC: 00000015
Process swapper/0 (pid: 1, stack limit = 0xed944248)
Stack: (0xed945e40 to 0xed946000)
5e40: ed945e7c ed945e50 c049f1c4 c04ee604 c0fc2fa4 00000000 ecb748c0 c11c2b80
5e60: c0beec04 0000011c c0fc2fa4 00000000 ed945e94 ed945e80 c049f3e0 c049f16c
5e80: 00000000 00000000 ed945eac ed945e98 c08cbc50 c049f3c0 ecb748c0 c11c2b80
5ea0: ed945ed4 ed945eb0 c0fc3080 c08cbc30 c0beec04 c107e1d8 ecdf0600 c107e1d8
5ec0: c107e1d8 ecdf0600 ed945f54 ed945ed8 c0208ed4 c0fc2fb0 c026a784 c04ee628
5ee0: ed945f0c ed945ef0 c0f5d600 c04ee604 c0f5d5ec ef7fcc7d c0b40ecc 0000011c
5f00: ed945f54 ed945f10 c026a994 c0f5d5f8 c04ecc00 00000007 ef7fcc95 00000007
5f20: c0e90744 c0dd0884 ed945f54 c106cde0 00000007 c117f8c0 0000011c c0f5d5ec
5f40: c1006094 c100609c ed945f94 ed945f58 c0f5de34 c0208e50 00000007 00000007
5f60: c0f5d5ec be9b5ae0 00000000 c117f8c0 c0af1680 00000000 00000000 00000000
5f80: 00000000 00000000 ed945fac ed945f98 c0af169c c0f5dd2c ed944000 00000000
5fa0: 00000000 ed945fb0 c020f298 c0af168c 00000000 00000000 00000000 00000000
5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 ebcc6d33 bfffca73
[<c04ee604>] (strlen) from [<c049f1c4>] (__create_file+0x64/0x1dc)
[<c049f1c4>] (__create_file) from [<c049f3e0>] (debugfs_create_dir+0x2c/0x34)
[<c049f3e0>] (debugfs_create_dir) from [<c08cbc50>] (clk_debug_create_one+0x2c/0x16c)
[<c08cbc50>] (clk_debug_create_one) from [<c0fc3080>] (clk_debug_init+0xdc/0x144)
[<c0fc3080>] (clk_debug_init) from [<c0208ed4>] (do_one_initcall+0x90/0x1e0)
[<c0208ed4>] (do_one_initcall) from [<c0f5de34>] (kernel_init_freeable+0x114/0x1e0)
[<c0f5de34>] (kernel_init_freeable) from [<c0af169c>] (kernel_init+0x1c/0xfc)
[<c0af169c>] (kernel_init) from [<c020f298>] (ret_from_fork+0x14/0x3c)
Code: c0b40ecc e1a0c00d e92dd800 e24cb004 (e5d02000)
---[ end trace b940e45b5e25c1e7 ]---

Fixes: 6314b6796e "clk: Don't hold prepare_lock across debugfs creation"
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-27 11:45:53 -08:00
Michael Turquette 57386798f7 Merge branch 'clk-has-parent' into clk-next 2015-01-24 16:58:40 -08:00
Thierry Reding 4e88f3de89 clk: Introduce clk_has_parent()
This new function is similar to clk_set_parent(), except that it doesn't
actually change the parent. It merely checks that the given parent clock
can be a parent for the given clock.

A situation where this is useful is to check that a particular setup is
valid before switching to it. One specific use-case for this is atomic
modesetting in the DRM framework where setting a mode is divided into a
check phase where a given configuration is validated before applying
changes to the hardware.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-24 16:56:55 -08:00
Stephen Boyd 4526e7b857 clk: Skip fetching index for single parent clocks
We don't need to fetch the parent index for clocks if they only
have one parent. Doing this also avoid an unnecessary allocation
for the parent cache.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-20 10:09:06 -08:00
Stanimir Varbanov c7662fc59c clk: fix possible null pointer dereference
The commit 646cafc6 (clk: Change clk_ops->determine_rate to
return a clk_hw as the best parent) opens a possibility for
null pointer dereference, fix this.

Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-17 11:33:57 -08:00
Stephen Boyd 89f7e9de59 clk: Really fix deadlock with mmap_sem
Commit 6314b6796e (clk: Don't hold prepare_lock across debugfs
creation, 2014-09-04) forgot to update one place where we hold
the prepare_lock while creating debugfs directories. This means
we still have the chance of a deadlock that the commit was trying
to fix. Actually fix it by moving the debugfs creation outside
the prepare_lock.

Cc: <stable@vger.kernel.org> # 3.18
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fixes: 6314b6796e "clk: Don't hold prepare_lock across debugfs creation"
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removed lockdep_assert]
2014-12-15 17:02:06 -08:00
Tomeu Vizoso 646cafc6aa clk: Change clk_ops->determine_rate to return a clk_hw as the best parent
This is in preparation for clock providers to not have to deal with struct clk.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-12-03 16:21:37 -08:00
Tomeu Vizoso 61c7cddfad clk: change clk_debugfs_add_file to take a struct clk_hw
Instead of struct clk, as this should be only used by providers.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-12-03 15:15:35 -08:00
Tomeu Vizoso 920f1c7472 clk: Don't expose __clk_get_accuracy
As it's only used internally, in drivers/clk/clk.c.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-12-03 15:15:34 -08:00
Tomeu Vizoso 10cdfe54da clk: Don't try to use a struct clk* after it could have been freed
As __clk_release could call kfree on clk and then we wouldn't have a safe way
of getting the module that owns the clock.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Fixes: fcb0ee6a3d ("clk: Implement clk_unregister")
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-12-03 15:15:34 -08:00
Tomeu Vizoso 4afbe1760d clk: Remove unused function __clk_get_prepare_count
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-12-03 15:15:34 -08:00
Zhen Lei 40ba3f0ff2 clk: delete a local variable's repeated assignment
It's the same to the next statement, "ret = clk->parent". I think compiler will
optimize it, it's just not looking well.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-11-19 11:41:18 -08:00
Mike Turquette 4dc7ed32f3 Allwinner Clocks Additions for 3.18
The most important part of this serie is the addition of the phase API to
 handle the MMC clocks in the Allwinner SoCs.
 
 Apart from that, the A23 gained a new mbus driver, and there's a fix for a
 incorrect divider table on the APB0 clock.
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Merge tag 'sunxi-clocks-for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux into clk-next

Allwinner Clocks Additions for 3.18

The most important part of this serie is the addition of the phase API to
handle the MMC clocks in the Allwinner SoCs.

Apart from that, the A23 gained a new mbus driver, and there's a fix for a
incorrect divider table on the APB0 clock.
2014-09-27 12:52:33 -07:00
Maxime Ripard 9824cf73c3 clk: Add a function to retrieve phase
The current phase API doesn't look into the actual hardware to get the phase
value, but will rather get it from a variable only set by the set_phase
function.

This will cause issue when the client driver will never call the set_phase
function, where we can end up having a reported phase that will not match what
the hardware has been programmed to by the bootloader or what phase is
programmed out of reset.

Add a new get_phase function for the drivers to implement so that we can get
this value.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
2014-09-27 08:57:51 +02:00
Mike Turquette e59c5371fb clk: introduce clk_set_phase function & callback
A common operation for a clock signal generator is to shift the phase of
that signal. This patch introduces a new function to the clk.h API to
dynamically adjust the phase of a clock signal. Additionally this patch
introduces support for the new function in the common clock framework
via the .set_phase call back in struct clk_ops.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
2014-09-27 08:57:38 +02:00
Mike Turquette a52ae5a755 Merge branch 'clk-fixes' into clk-next 2014-09-17 11:47:56 -07:00
Stephen Boyd 6314b6796e clk: Don't hold prepare_lock across debugfs creation
Rob Clark reports a lockdep splat that involves the prepare_lock
chained with the mmap semaphore.

======================================================
[ INFO: possible circular locking dependency detected ]
3.17.0-rc1-00050-g07a489b #802 Tainted: G        W
-------------------------------------------------------
Xorg.bin/5413 is trying to acquire lock:
 (prepare_lock){+.+.+.}, at: [<c0781280>] clk_prepare_lock+0x88/0xfc

but task is already holding lock:
 (qcom_iommu_lock){+.+...}, at: [<c079f664>] qcom_iommu_unmap+0x1c/0x1f0

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #4 (qcom_iommu_lock){+.+...}:
       [<c079f860>] qcom_iommu_map+0x28/0x450
       [<c079eb50>] iommu_map+0xc8/0x12c
       [<c056c1fc>] msm_iommu_map+0xb4/0x130
       [<c05697bc>] msm_gem_get_iova_locked+0x9c/0xe8
       [<c0569854>] msm_gem_get_iova+0x4c/0x64
       [<c0562208>] mdp4_kms_init+0x4c4/0x6c0
       [<c056881c>] msm_load+0x2ac/0x34c
       [<c0545724>] drm_dev_register+0xac/0x108
       [<c0547510>] drm_platform_init+0x50/0xf0
       [<c0578a60>] try_to_bring_up_master.part.3+0xc8/0x108
       [<c0578b48>] component_master_add_with_match+0xa8/0x104
       [<c0568294>] msm_pdev_probe+0x64/0x70
       [<c057e704>] platform_drv_probe+0x2c/0x60
       [<c057cff8>] driver_probe_device+0x108/0x234
       [<c057b65c>] bus_for_each_drv+0x64/0x98
       [<c057cec0>] device_attach+0x78/0x8c
       [<c057c590>] bus_probe_device+0x88/0xac
       [<c057c9b8>] deferred_probe_work_func+0x68/0x9c
       [<c0259db4>] process_one_work+0x1a0/0x40c
       [<c025a710>] worker_thread+0x44/0x4d8
       [<c025ec54>] kthread+0xd8/0xec
       [<c020e9a8>] ret_from_fork+0x14/0x2c

-> #3 (&dev->struct_mutex){+.+.+.}:
       [<c0541188>] drm_gem_mmap+0x38/0xd0
       [<c05695b8>] msm_gem_mmap+0xc/0x5c
       [<c02f0b6c>] mmap_region+0x35c/0x6c8
       [<c02f11ec>] do_mmap_pgoff+0x314/0x398
       [<c02de1e0>] vm_mmap_pgoff+0x84/0xb4
       [<c02ef83c>] SyS_mmap_pgoff+0x94/0xbc
       [<c020e8e0>] ret_fast_syscall+0x0/0x48

-> #2 (&mm->mmap_sem){++++++}:
       [<c0321138>] filldir64+0x68/0x180
       [<c0333fe0>] dcache_readdir+0x188/0x22c
       [<c0320ed0>] iterate_dir+0x9c/0x11c
       [<c03213b0>] SyS_getdents64+0x78/0xe8
       [<c020e8e0>] ret_fast_syscall+0x0/0x48

-> #1 (&sb->s_type->i_mutex_key#3){+.+.+.}:
       [<c03fc544>] __create_file+0x58/0x1dc
       [<c03fc70c>] debugfs_create_dir+0x1c/0x24
       [<c0781c7c>] clk_debug_create_subtree+0x20/0x170
       [<c0be2af8>] clk_debug_init+0xec/0x14c
       [<c0208c70>] do_one_initcall+0x8c/0x1c8
       [<c0b9cce4>] kernel_init_freeable+0x13c/0x1dc
       [<c0877bc4>] kernel_init+0x8/0xe8
       [<c020e9a8>] ret_from_fork+0x14/0x2c

-> #0 (prepare_lock){+.+.+.}:
       [<c087c408>] mutex_lock_nested+0x70/0x3e8
       [<c0781280>] clk_prepare_lock+0x88/0xfc
       [<c0782c50>] clk_prepare+0xc/0x24
       [<c079f474>] __enable_clocks.isra.4+0x18/0xa4
       [<c079f614>] __flush_iotlb_va+0xe0/0x114
       [<c079f6f4>] qcom_iommu_unmap+0xac/0x1f0
       [<c079ea3c>] iommu_unmap+0x9c/0xe8
       [<c056c2fc>] msm_iommu_unmap+0x64/0x84
       [<c0569da4>] msm_gem_free_object+0x11c/0x338
       [<c05413ec>] drm_gem_object_handle_unreference_unlocked+0xfc/0x130
       [<c0541604>] drm_gem_object_release_handle+0x50/0x68
       [<c0447a98>] idr_for_each+0xa8/0xdc
       [<c0541c10>] drm_gem_release+0x1c/0x28
       [<c0540b3c>] drm_release+0x370/0x428
       [<c031105c>] __fput+0x98/0x1e8
       [<c025d73c>] task_work_run+0xb0/0xfc
       [<c02477ec>] do_exit+0x2ec/0x948
       [<c0247ec0>] do_group_exit+0x4c/0xb8
       [<c025180c>] get_signal+0x28c/0x6ac
       [<c0211204>] do_signal+0xc4/0x3e4
       [<c02116cc>] do_work_pending+0xb4/0xc4
       [<c020e938>] work_pending+0xc/0x20

other info that might help us debug this:

Chain exists of:
  prepare_lock --> &dev->struct_mutex --> qcom_iommu_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(qcom_iommu_lock);
                               lock(&dev->struct_mutex);
                               lock(qcom_iommu_lock);
  lock(prepare_lock);

 *** DEADLOCK ***

3 locks held by Xorg.bin/5413:
 #0:  (drm_global_mutex){+.+.+.}, at: [<c0540800>] drm_release+0x34/0x428
 #1:  (&dev->struct_mutex){+.+.+.}, at: [<c05413bc>] drm_gem_object_handle_unreference_unlocked+0xcc/0x130
 #2:  (qcom_iommu_lock){+.+...}, at: [<c079f664>] qcom_iommu_unmap+0x1c/0x1f0

stack backtrace:
CPU: 1 PID: 5413 Comm: Xorg.bin Tainted: G        W      3.17.0-rc1-00050-g07a489b #802
[<c0216290>] (unwind_backtrace) from [<c0211d8c>] (show_stack+0x10/0x14)
[<c0211d8c>] (show_stack) from [<c087a078>] (dump_stack+0x98/0xb8)
[<c087a078>] (dump_stack) from [<c027f024>] (print_circular_bug+0x218/0x340)
[<c027f024>] (print_circular_bug) from [<c0283e08>] (__lock_acquire+0x1d24/0x20b8)
[<c0283e08>] (__lock_acquire) from [<c0284774>] (lock_acquire+0x9c/0xbc)
[<c0284774>] (lock_acquire) from [<c087c408>] (mutex_lock_nested+0x70/0x3e8)
[<c087c408>] (mutex_lock_nested) from [<c0781280>] (clk_prepare_lock+0x88/0xfc)
[<c0781280>] (clk_prepare_lock) from [<c0782c50>] (clk_prepare+0xc/0x24)
[<c0782c50>] (clk_prepare) from [<c079f474>] (__enable_clocks.isra.4+0x18/0xa4)
[<c079f474>] (__enable_clocks.isra.4) from [<c079f614>] (__flush_iotlb_va+0xe0/0x114)
[<c079f614>] (__flush_iotlb_va) from [<c079f6f4>] (qcom_iommu_unmap+0xac/0x1f0)
[<c079f6f4>] (qcom_iommu_unmap) from [<c079ea3c>] (iommu_unmap+0x9c/0xe8)
[<c079ea3c>] (iommu_unmap) from [<c056c2fc>] (msm_iommu_unmap+0x64/0x84)
[<c056c2fc>] (msm_iommu_unmap) from [<c0569da4>] (msm_gem_free_object+0x11c/0x338)
[<c0569da4>] (msm_gem_free_object) from [<c05413ec>] (drm_gem_object_handle_unreference_unlocked+0xfc/0x130)
[<c05413ec>] (drm_gem_object_handle_unreference_unlocked) from [<c0541604>] (drm_gem_object_release_handle+0x50/0x68)
[<c0541604>] (drm_gem_object_release_handle) from [<c0447a98>] (idr_for_each+0xa8/0xdc)
[<c0447a98>] (idr_for_each) from [<c0541c10>] (drm_gem_release+0x1c/0x28)
[<c0541c10>] (drm_gem_release) from [<c0540b3c>] (drm_release+0x370/0x428)
[<c0540b3c>] (drm_release) from [<c031105c>] (__fput+0x98/0x1e8)
[<c031105c>] (__fput) from [<c025d73c>] (task_work_run+0xb0/0xfc)
[<c025d73c>] (task_work_run) from [<c02477ec>] (do_exit+0x2ec/0x948)
[<c02477ec>] (do_exit) from [<c0247ec0>] (do_group_exit+0x4c/0xb8)
[<c0247ec0>] (do_group_exit) from [<c025180c>] (get_signal+0x28c/0x6ac)
[<c025180c>] (get_signal) from [<c0211204>] (do_signal+0xc4/0x3e4)
[<c0211204>] (do_signal) from [<c02116cc>] (do_work_pending+0xb4/0xc4)
[<c02116cc>] (do_work_pending) from [<c020e938>] (work_pending+0xc/0x20)

We can break this chain if we don't hold the prepare_lock while
creating debugfs directories. We only hold the prepare_lock right
now because we're traversing the clock tree recursively and we
don't want the hierarchy to change during the traversal.
Replacing this traversal with a simple linked list walk allows us
to only grab a list lock instead of the prepare_lock, thus
breaking the lock chain.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-09-10 14:36:20 -07:00
Tero Kristo 067bb1741c clk: prevent erronous parsing of children during rate change
In some cases, clocks can switch their parent with clk_set_rate, for
example clk_mux can do this in some cases. Current implementation of
clk_change_rate uses un-safe list iteration on the clock children, which
will cause wrong clocks to be parsed in case any of the clock children
change their parents during the change rate operation. Fixed by using
the safe list iterator instead.

The problem was detected due to some divide by zero errors generated
by clock init on dra7-evm board, see discussion under
http://article.gmane.org/gmane.linux.ports.arm.kernel/349180 for details.

Fixes: 71472c0c06 ("clk: add support for clock reparent on set_rate")
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reported-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-09-03 12:09:14 -07:00
Chris Brand abeab450bf clk: Propagate any error return from debug_init()
If the .debug_init op is provided, it will be called by
clk_debug_create_one(). If debug_init() returns an error code,
clk_debug_create_one() will return -ENOMEM, regardless of the
value returned from debug_init(). Tweak the code to return
the actual value returned by debug_init() instead.

Signed-off-by: Chris Brand <chris.brand@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-07-29 17:13:48 -07:00
Sylwester Nawrocki 86be408bfb clk: Support for clock parents and rates assigned from device tree
This patch adds helper functions to configure clock parents and rates
as specified through 'assigned-clock-parents', 'assigned-clock-rates'
DT properties for a clock provider or clock consumer device.
The helpers are now being called by the bus code for the platform, I2C
and SPI busses, before the driver probing and also in the clock core
after registration of a clock provider.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-07-25 15:16:27 -07:00
Peter De Schrijver fb2b3c9f68 clk: define and export clk_debugs_add_file
Define and export a new function clk_debugs_add_file which adds a file
to a existing clock's debugfs directory. This can be used by clock
providers to add debugfs entries which are not related to a specific clock
type. Examples include the ability to measure the rate of a clock. It can
also be used by modules to create new debugfs entries. This is useful if you
want to expose features for testing which can potentially cause system
instability such as allowing to change a clock's rate from userspace.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-07-02 16:15:55 -07:00
Sachin Kamat 6b44c854b0 clk: Fix build warnings
‘all_lists’ and ‘orphan_list’ is accessed only when DEBUG_FS is defined.
Thus, make their compilation conditional to fix the below warnings introduced
by commit 27b8d5f723 ("clk: flatten clk tree in debugfs"):
drivers/clk/clk.c:40:27: warning: ‘all_lists’ defined but not used [-Wunused-variable]
drivers/clk/clk.c:46:27: warning: ‘orphan_list’ defined but not used [-Wunused-variable]

Signed-off-by: Sachin Kamat <sachin.kamat@samsung.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-07-01 20:20:36 -07:00
Peter De Schrijver 27b8d5f723 clk: flatten clk tree in debugfs
This patch flattens the clk tree in CCF debugfs. Instead of representing the
clocks and their hierarchy as a directory structure under
/sys/kernel/debug/clk, each clock gets a single directory directly under
/sys/kernel/debug/clk. The orphans directory is replaced by a file called
clk_orphan_summary.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-06-26 12:55:04 -07:00
Arnd Bergmann 1cdf8ee2f8 clk: export __clk_round_rate for providers
Commit 99cbd064b0 ("clk: qcom: Support display RCG clocks") adds
a use of the __clk_round_rate in a clock provided that can be built
as a loadable module.

This exports the symbol to avoid the build error from compiling
the qcom clock as a module.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-06-03 10:38:16 -07:00
Geert Uytterhoeven fb8abb7aef clk: Neaten clk_summary output
- Limit ruler to 80 characters (was: 81),
  - Widen rate column by 1 for nicer spacing,
  - Right-align numbers and their column headers,
  - Move a newline to reduce the number of seq_printf() calls,
  - Use set_puts() for fixed strings.

Before:

   clock                        enable_cnt  prepare_cnt  rate        accuracy
---------------------------------------------------------------------------------
 extal                          2           2            20000000   0
    thermal                     1           1            20000000   0
    cp                          0           0            10000000   0
       tpu0                     0           0            10000000   0
       tmu0                     0           0            10000000   0
    main                        1           1            20000000   0
       pll3                     0           0            1600000000 0
          ddr                   0           0            200000000  0
          zb3d2                 0           0            200000000  0
          zb3                   0           0            400000000  0
       pll1                     4           4            1560000000 0
          oscclk                0           0            126953     0
          rclk                  1           1            31738      0
             cmt1               0           0            31738      0
             cmt0               1           1            31738      0
          imp                   0           0            390000000  0

After:

   clock                         enable_cnt  prepare_cnt        rate   accuracy
--------------------------------------------------------------------------------
 extal                                    2            2    20000000          0
    thermal                               1            1    20000000          0
    cp                                    0            0    10000000          0
       tpu0                               0            0    10000000          0
       tmu0                               0            0    10000000          0
    main                                  1            1    20000000          0
       pll3                               0            0  1600000000          0
          ddr                             0            0   200000000          0
          zb3d2                           0            0   200000000          0
          zb3                             0            0   400000000          0
       pll1                               4            4  1560000000          0
          oscclk                          0            0      126953          0
          rclk                            1            1       31738          0
             cmt1                         0            0       31738          0
             cmt0                         1            1       31738          0
          imp                             0            0   390000000          0

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-05-23 14:10:59 -07:00
Stephen Boyd 63589e92c2 clk: Ignore error and NULL pointers passed to clk_{unprepare, disable}()
This simplifies error paths in drivers that use optional clocks
by allowing the NULL or error pointer to be passed
unconditionally.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-04-30 11:51:50 -07:00
Stephen Boyd 8f2c2db132 clk: Consolidate recalc rate logic
The same if-else statement exists four times to recalculate the
rate of a clock. Consolidate this logic into a single function to
save some lines.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-04-30 11:51:48 -07:00
Stephen Boyd 86a612349f clk: Don't check for missing ops in clk_set_parent()
We dereference clk->ops during clock registration so this check
for NULL ops can't possibly ever be true.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-04-30 11:51:47 -07:00
Stephen Boyd 874f224cc5 clk: Fix slab corruption in clk_unregister()
When a clock is unregsitered, we iterate over the list of
children and reparent them to NULL (i.e. orphan list). While
iterating the list, we should use the safe iterators because the
children list for this clock is changing when we reparent the
children to NULL. Failure to iterate safely can lead to slab
corruption like this:

=============================================================================
BUG kmalloc-128 (Not tainted): Poison overwritten
-----------------------------------------------------------------------------

Disabling lock debugging due to kernel taint
INFO: 0xed0c4900-0xed0c4903. First byte 0x0 instead of 0x6b
INFO: Allocated in clk_register+0x20/0x1bc age=297 cpu=2 pid=70
 __slab_alloc.isra.39.constprop.42+0x410/0x454
 kmem_cache_alloc_trace+0x200/0x24c
 clk_register+0x20/0x1bc
 devm_clk_register+0x34/0x68
 0xbf0000f0
 platform_drv_probe+0x18/0x48
 driver_probe_device+0x94/0x360
 __driver_attach+0x94/0x98
 bus_for_each_dev+0x54/0x88
 bus_add_driver+0xe8/0x204
 driver_register+0x78/0xf4
 do_one_initcall+0xc4/0x17c
 load_module+0x19ac/0x2294
 SyS_init_module+0xa4/0x110
 ret_fast_syscall+0x0/0x48
INFO: Freed in clk_unregister+0xd4/0x140 age=23 cpu=2 pid=73
 __slab_free+0x38/0x41c
 clk_unregister+0xd4/0x140
 release_nodes+0x164/0x1d8
 __device_release_driver+0x60/0xb0
 driver_detach+0xb4/0xb8
 bus_remove_driver+0x5c/0xc4
 SyS_delete_module+0x148/0x1d8
 ret_fast_syscall+0x0/0x48
INFO: Slab 0xeec50b90 objects=25 used=0 fp=0xed0c5400 flags=0x4080
INFO: Object 0xed0c48c0 @offset=2240 fp=0xed0c4a00

Bytes b4 ed0c48b0: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
Object ed0c48c0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c48d0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c48e0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c48f0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c4900: 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  ....kkkkkkkkkkkk
Object ed0c4910: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c4920: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c4930: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5  kkkkkkkkkkkkkkk.
Redzone ed0c4940: bb bb bb bb                                      ....
Padding ed0c49e8: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
Padding ed0c49f8: 5a 5a 5a 5a 5a 5a 5a 5a                          ZZZZZZZZ
CPU: 3 PID: 75 Comm: mdev Tainted: G    B         3.14.0-11033-g2054ba5ca781 #35
[<c0014be0>] (unwind_backtrace) from [<c0012240>] (show_stack+0x10/0x14)
[<c0012240>] (show_stack) from [<c04b74a0>] (dump_stack+0x70/0xbc)
[<c04b74a0>] (dump_stack) from [<c00f7a78>] (check_bytes_and_report+0xbc/0x100)
[<c00f7a78>] (check_bytes_and_report) from [<c00f7c48>] (check_object+0x18c/0x218)
[<c00f7c48>] (check_object) from [<c00f7efc>] (__free_slab+0x104/0x144)
[<c00f7efc>] (__free_slab) from [<c04b6668>] (__slab_free+0x3dc/0x41c)
[<c04b6668>] (__slab_free) from [<c014c008>] (load_elf_binary+0x88/0x12b4)
[<c014c008>] (load_elf_binary) from [<c0105a44>] (search_binary_handler+0x78/0x18c)
[<c0105a44>] (search_binary_handler) from [<c0106fc0>] (do_execve+0x490/0x5dc)
[<c0106fc0>] (do_execve) from [<c0036b8c>] (____call_usermodehelper+0x134/0x168)
[<c0036b8c>] (____call_usermodehelper) from [<c000f048>] (ret_from_fork+0x14/0x2c)
FIX kmalloc-128: Restoring 0xed0c4900-0xed0c4903=0x6b

Fixes: fcb0ee6a3d (clk: Implement clk_unregister)
Cc: Jiada Wang <jiada_wang@mentor.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: stable@vger.kernel.org
2014-04-30 11:44:05 -07:00
Stephen Boyd 293ba3b4a4 clk: Fix double free due to devm_clk_register()
Now that clk_unregister() frees the struct clk we're
unregistering we'll free memory twice: first we'll call kfree()
in __clk_release() with an address kmalloc doesn't know about and
second we'll call kfree() in the devres layer. Remove the
allocation of struct clk in devm_clk_register() and let
clk_release() handle it. This fixes slab errors like:

=============================================================================
BUG kmalloc-128 (Not tainted): Invalid object pointer 0xed08e8d0
-----------------------------------------------------------------------------

Disabling lock debugging due to kernel taint
INFO: Slab 0xeec503f8 objects=25 used=15 fp=0xed08ea00 flags=0x4081
CPU: 2 PID: 73 Comm: rmmod Tainted: G    B         3.14.0-11032-g526e9c764381 #34
[<c0014be0>] (unwind_backtrace) from [<c0012240>] (show_stack+0x10/0x14)
[<c0012240>] (show_stack) from [<c04b74dc>] (dump_stack+0x70/0xbc)
[<c04b74dc>] (dump_stack) from [<c00f6778>] (slab_err+0x74/0x84)
[<c00f6778>] (slab_err) from [<c04b6278>] (free_debug_processing+0x2cc/0x31c)
[<c04b6278>] (free_debug_processing) from [<c04b6300>] (__slab_free+0x38/0x41c)
[<c04b6300>] (__slab_free) from [<c03931bc>] (clk_unregister+0xd4/0x140)
[<c03931bc>] (clk_unregister) from [<c02fb774>] (release_nodes+0x164/0x1d8)
[<c02fb774>] (release_nodes) from [<c02f8698>] (__device_release_driver+0x60/0xb0)
[<c02f8698>] (__device_release_driver) from [<c02f9080>] (driver_detach+0xb4/0xb8)
[<c02f9080>] (driver_detach) from [<c02f8480>] (bus_remove_driver+0x5c/0xc4)
[<c02f8480>] (bus_remove_driver) from [<c008c9b8>] (SyS_delete_module+0x148/0x1d8)
[<c008c9b8>] (SyS_delete_module) from [<c000ef80>] (ret_fast_syscall+0x0/0x48)
FIX kmalloc-128: Object at 0xed08e8d0 not freed

Fixes: fcb0ee6a3d (clk: Implement clk_unregister)
Cc: Jiada Wang <jiada_wang@mentor.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: stable@vger.kernel.org
2014-04-30 11:44:04 -07:00
Sylwester Nawrocki e5ca8fb4cc clk: Fix minor errors in of_clk_init() function comments
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-03-27 16:48:14 -07:00
Sylwester Nawrocki 3f6d439f20 clk: reverse default clk provider initialization order in of_clk_init()
This restores the default clocks registration order as parsed from
devicetree, i.e. as before commit 1771b10d60
"clk: respect the clock dependencies in of_clk_init", for when there
is no explicit parent clock dependencies between clock providers
specified in the device tree.

It prevents regressions (boot failure, division by 0 errors) on
imx and exynos platforms.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-03-27 16:48:06 -07:00
Alex Elder c646cbf10f clk: support hardware-specific debugfs entries
Add a new clk_ops->debug_init method to allow a clock hardware
driver to populate the clock's debugfs directory with entries
beyond those common for every clock.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-03-24 17:10:07 -07:00
Sascha Hauer f736386160 clk: turn rate change failed warning into pr_debug
If a rate change failed it's the opportunity of the caller to handle
this. Do not spam the log with a message.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-03-20 14:44:47 -07:00
Gregory CLEMENT 1771b10d60 clk: respect the clock dependencies in of_clk_init
Until now the clock providers were initialized in the order found in
the device tree. This led to have the dependencies between the clocks
not respected: children clocks could be initialized before their
parent clocks.

Instead of forcing each platform to manage its own initialization order,
this patch adds this work inside the framework itself.

Using the data of the device tree the of_clk_init function now delayed
the initialization of a clock provider if its parent provider was not
ready yet.

The strict dependency check (all parents of a given clk must be
initialized) was added by Boris BREZILLON

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-03-19 17:15:29 -07:00
Mike Turquette ad077ceb8a Merge branch 'clk-fixes' into clk-next 2014-02-24 23:07:53 -08:00
Sylwester Nawrocki 00efcb1c8e clk: Correct handling of NULL clk in __clk_{get, put}
Ensure clk->kref is dereferenced only when clk is not NULL.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-02-24 21:58:38 -08:00
Jean-Francois Moine a34cd4666f clk: return probe defer when DT clock not yet ready
At probe time, a clock device may not be ready when some other device
wants to use it.

This patch lets the functions clk_get/devm_clk_get return a probe defer
when the clock is defined in the DT but not yet available.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-02-24 17:14:56 -08:00
Mike Turquette 86bcfa2e87 clk: add pr_debug & kerneldoc around clk notifiers
Both the pr_err and the additional kerneldoc aim to help when debugging
errors thrown from within a clock rate-change notifier callback.

Reported-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-02-24 17:13:55 -08:00
Ben Dooks 7a0fc1a3df clk: add clock-indices support
Add a property called clock-indices to allow clock-output-names
to be used where the index used to lookup a clock is not a 1:1
mapping to the array position in the clock-output-names

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-02-23 12:40:20 -08:00
Soren Brinkmann 5324fda79e clk: Fix notifier documentation
Contradicting to documenation, the notifier callbacks do receive
the original clock rate in struct clk_notifier_data.old_rate and the new
frequency struct clk_notifier_data.new_rate, independent of the
notification reason.

This behavior also seems to make more sense, since callbacks can use the
same code to deterimine whether clocks are scaled up or down. Something
which would not even possible in the post-rate-change case if the
behavior was as documented.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-02-18 14:08:05 -08:00
Stephen Boyd 0b7f04b868 clk: Export more clk-provider functions
Allow drivers to be compiled as modules by exporting more clock
provider functions.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-01-27 11:43:19 -08:00
Tero Kristo 819b4861c1 CLK: ti: add init support for clock IP blocks
ti_dt_clk_init_provider() can now be used to initialize the contents of
a single clock IP block. This parses all the clocks under the IP block
and calls the corresponding init function for them.

This patch also introduces a helper function for the TI clock drivers
to get register info from DT and append the master IP info to this.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-01-17 12:34:52 -08:00
Stephen Boyd 3fa2252b7a clk: Add set_rate_and_parent() op
Some of Qualcomm's clocks can change their parent and rate at the
same time with a single register write. Add support for this
hardware to the common clock framework by adding a new
set_rate_and_parent() op. When the clock framework determines
that both the parent and the rate are going to change during
clk_set_rate() it will call the .set_rate_and_parent() op if
available and fall back to calling .set_parent() followed by
.set_rate() otherwise.

Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-01-16 12:00:57 -08:00
Mike Turquette dbdf6ff51e Merge branch 'clk-next-unregister' into clk-next
Conflicts:
	drivers/clk/clk.c
2013-12-31 11:35:12 -08:00
Mike Turquette ea72dc2cf9 clk: remove CONFIG_COMMON_CLK_DEBUG
Populate ${DEBUGS_MOUNT_POINT}/clk if CONFIG_DEBUG_FS is set. This
eliminates the extra (annoying) step of enabling the config option
manually.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-12-27 17:45:08 -08:00
Boris BREZILLON 5279fc402a clk: add clk accuracy retrieval support
The clock accuracy is expressed in ppb (parts per billion) and represents
the possible clock drift.
Say you have a clock (e.g. an oscillator) which provides a fixed clock of
20MHz with an accuracy of +- 20Hz. This accuracy expressed in ppb is
20Hz/20MHz = 1000 ppb (or 1 ppm).

Clock users may need the clock accuracy information in order to choose
the best clock (the one with the best accuracy) across several available
clocks.

This patch adds clk accuracy retrieval support for common clk framework by
means of a new function called clk_get_accuracy.
This function returns the given clock accuracy expressed in ppb.

In order to get the clock accuracy, this implementation adds one callback
called recalc_accuracy to the clk_ops structure.
This callback is given the parent clock accuracy (if the clock is not a
root clock) and should recalculate the given clock accuracy.

This callback is optional and may be implemented if the clock is not
a perfect clock (accuracy != 0 ppb).

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-12-22 23:14:27 -08:00
Stephen Boyd 3a5aec246f clk: Fix debugfs reparenting NULL pointer dereference
Adding clocks from a kernel module can cause a NULL pointer
dereference if the parent of a clock is added after the clock is
added. This happens because __clk_init() iterates over the list
of orphans and reparents the orphans to the clock being
registered before creating the debugfs entry for the clock.
Create the debugfs entry first before reparenting the orphans.

Unable to handle kernel NULL pointer dereference at virtual address 00000028
pgd = ef3e4000
[00000028] *pgd=bf810831
Internal error: Oops: 17 [#1] PREEMPT SMP ARM
Modules linked in: mmcc_8960(+)
CPU: 0 PID: 52 Comm: modprobe Not tainted 3.12.0-rc2-00023-g1021a28-dirty #659
task: ef319200 ti: ef3a6000 task.ti: ef3a6000
PC is at lock_rename+0x24/0xc4
LR is at debugfs_rename+0x34/0x208
pc : [<c0317238>]    lr : [<c047dfe4>]    psr: 00000013
sp : ef3a7b88  ip : ef3a7ba8  fp : ef3a7ba4
r10: ef3d51cc  r9 : ef3bc680  r8 : ef3d5210
r7 : ef3bc640  r6 : eee287e0  r5 : eee287e0  r4 : 00000000
r3 : ef3bc640  r2 : 00000000  r1 : eee287e0  r0 : 00000000
Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 10c5787d  Table: af3e406a  DAC: 00000015
Process modprobe (pid: 52, stack limit = 0xef3a6240)
Stack: (0xef3a7b88 to 0xef3a8000)
7b80:                   ef3bc640 ee4047e0 00000000 eee287e0 ef3a7bec ef3a7ba8
7ba0: c047dfe4 c0317220 ef3bc680 ef3d51cc ef3a7bdc ef3a7bc0 c06e29d0 c0268784
7bc0: c08946e8 ef3d5210 00000000 ef3bc700 ef3d5290 ef3d5210 ef3bc680 ef3d51cc
7be0: ef3a7c0c ef3a7bf0 c05b9e9c c047dfbc 00000000 00000000 ef3d5210 ef3d5290
7c00: ef3a7c24 ef3a7c10 c05baebc c05b9e30 00000001 00000001 ef3a7c64 ef3a7c28
7c20: c05bb124 c05bae9c bf000cd8 ef3bc7c0 000000d0 c0ff129c bf001774 00000002
7c40: ef3bc740 ef3d5290 ef0f9a10 bf001774 bf00042c 00000061 ef3a7c8c ef3a7c68
7c60: c05bb480 c05baed8 bf001774 ef3d5290 ef0f9a10 bf001774 ef38bc10 ef0f9a00
7c80: ef3a7cac ef3a7c90 c05bb5a8 c05bb3a0 bf001774 00000062 ef0f9a10 ef38bc18
7ca0: ef3a7cec ef3a7cb0 bf00010c c05bb56c 00000000 ef38ba00 00000000 ef3d60d0
7cc0: ef3a7cdc c0fefc24 ef0f9a10 c0a091c0 bf000d24 00000000 bf0029f0 bf006000
7ce0: ef3a7cfc ef3a7cf0 c05156c0 bf000040 ef3a7d2c ef3a7d00 c0513f5c c05156a8
7d00: ef3a7d2c ef0f9a10 ef0f9a10 bf000d24 ef0f9a44 c09ca588 00000000 bf006000
7d20: ef3a7d4c ef3a7d30 c05142b8 c0513ecc ef0fd25c 00000000 bf000d24 c0514214
7d40: ef3a7d74 ef3a7d50 c0512030 c0514220 ef0050a8 ef0fd250 ef0050f8 bf000d24
7d60: ef37c100 c09ed150 ef3a7d84 ef3a7d78 c05139c8 c0511fd8 ef3a7
7d80: c051344c c05139a8 bf000864 c09ca588 ef3a7db4 bf000d24 bf002
7da0: c09ca588 00000000 ef3a7dcc ef3a7db8 c05149dc c0513360 ef3a7
7dc0: ef3a7ddc ef3a7dd0 c0515914 c0514960 ef3a7dec ef3a7de0 bf006
7de0: ef3a7e74 ef3a7df0 c0208800 bf00600c ef3a7e1c ef3a7e00 c04c5
7e00: ffffffff c09d46c4 00000000 bf0029a8 ef3a7e34 ef3a7e20 c024c
7e20: ffffffff c09d46c4 ef3a7e5c ef3a7e38 c024e2fc c024ce40 00000
7e40: ef3a7f48 bf0029b4 bf0029a8 271aeb1c ef3a7f48 bf0029a8 00000001 ef383c00
7e60: bf0029f0 00000001 ef3a7f3c ef3a7e78 c028fac4 c0208718 bf0029b4 00007fff
7e80: c028cd58 000000d2 f0065000 00000000 ef3a7ebc 00000000 00000000 bf0029b4
7ea0: 00000000 bf0029ac bf0029b4 ef3a6000 ef3a7efc c08bf128 00000000 00000000
7ec0: 00000000 00000000 00000000 00000000 6e72656b 00006c65 00000000 00000000
7ee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7f00: 00000000 00000000 00000000 271aeb1c ef3a7f2c 00016376 b6f38008 001d3774
7f20: 00000080 c020f968 ef3a6000 00000000 ef3a7fa4 ef3a7f40 c02904dc c028e178
7f40: c020f898 010ccfa8 f0065000 00016376 f0073f60 f0073d7d f007a1e8 00002b24
7f60: 000039e4 00000000 00000000 00000000 0000002f 00000030 00000019 00000016
7f80: 00000012 00000000 00000000 010de1b2 b6f38008 010ccfa8 00000000 ef3a7fa8
7fa0: c020f6c0 c0290434 010de1b2 b6f38008 b6f38008 00016376 001d3774 00000000
7fc0: 010de1b2 b6f38008 010ccfa8 00000080 010de1b2 bedb6f90 010de1c9 0001d8dc
7fe0: 0000000c bedb674c 0001ce30 000094c4 60000010 b6f38008 00000008 0000001d
[<c0317238>] (lock_rename+0x24/0xc4) from [<c047dfe4>] (debugfs_rename+0x34/0x208)
[<c047dfe4>] (debugfs_rename+0x34/0x208) from [<c05b9e9c>] (clk_debug_reparent+0x78/0xc0)
[<c05baebc>] (__clk_reparent+0x2c/0x3c) from [<c05bb124>] (__clk_init+0x258/0x4c8)
[<c05bb124>] (__clk_init+0x258/0x4c8) from [<c05bb480>] (_clk_register+0xec/0x1cc)
[<c05bb480>] (_clk_register+0xec/0x1cc) from [<c05bb5a8>] (devm_clk_register+0x48/0x7c)
[<c05bb5a8>] (devm_clk_register+0x48/0x7c) from [<bf00010c>] (msm_mmcc_8960_probe+0xd8/0x190 [mmcc_8960])
[<bf00010c>] (msm_mmcc_8960_probe+0xd8/0x190 [mmcc_8960]) from [<c05156c0>] (platform_drv_probe+0x24/0x28)
[<c05156c0>] (platform_drv_probe+0x24/0x28) from [<c0513f5c>] (driver_probe_device+0x9c/0x354)
[<c0513f5c>] (driver_probe_device+0x9c/0x354) from [<c05142b8>] (__driver_attach+0xa4/0xa8)
[<c05142b8>] (__driver_attach+0xa4/0xa8) from [<c0512030>] (bus_for_each_dev+0x64/0x98)
[<c0512030>] (bus_for_each_dev+0x64/0x98) from [<c05139c8>] (driver_attach+0x2c/0x30)
[<c05139c8>] (driver_attach+0x2c/0x30) from [<c051344c>] (bus_add_driver+0xf8/0x2a8)
[<c051344c>] (bus_add_driver+0xf8/0x2a8) from [<c05149dc>] (driver_register+0x88/0x104)
[<c05149dc>] (driver_register+0x88/0x104) from [<c0515914>] (__platform_driver_register+0x58/0x6c)
[<c0515914>] (__platform_driver_register+0x58/0x6c) from [<bf006018>] (msm_mmcc_8960_driver_init+0x18/0x24 [mmcc_8960])
[<bf006018>] (msm_mmcc_8960_driver_init+0x18/0x24 [mmcc_8960]) from [<c0208800>] (do_one_initcall+0xf4/0x1b8)
[<c0208800>] (do_one_initcall+0xf4/0x1b8) from [<c028fac4>] (load_module+0x1958/0x22bc)
[<c028fac4>] (load_module+0x1958/0x22bc) from [<c02904dc>] (SyS_init_module+0xb4/0x120)
[<c02904dc>] (SyS_init_module+0xb4/0x120) from [<c020f6c0>] (ret_fast_syscall+0x0/0x48)
Code: e1500001 e1a04000 e1a05001 0a000021 (e5903028)

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-12-14 19:23:52 -08:00
Sylwester Nawrocki fcb0ee6a3d clk: Implement clk_unregister
clk_unregister() is currently not implemented and it is required when
a clock provider module needs to be unloaded.

Normally the clock supplier module is prevented to be unloaded by
taking reference on the module in clk_get().

For cases when the clock supplier module deinitializes despite the
consumers of its clocks holding a reference on the module, e.g. when
the driver is unbound through "unbind" sysfs attribute, there are
empty clock ops added. These ops are assigned temporarily to struct
clk and used until all consumers release the clock, to avoid invoking
callbacks from the module which just got removed.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
2013-12-04 17:19:52 +01:00
Sylwester Nawrocki ac2df527fb clk: Add common __clk_get(), __clk_put() implementations
This patch adds common __clk_get(), __clk_put() clkdev helpers that
replace their platform specific counterparts when the common clock
API is used.

The owner module pointer field is added to struct clk so a reference
to the clock supplier module can be taken by the clock consumers.

The owner module is assigned while the clock is being registered,
in functions _clk_register() and __clk_register().

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-12-04 17:19:44 +01:00
Sylwester Nawrocki d6782c2636 clk: Provide not locked variant of of_clk_get_from_provider()
Add helper functions for the of_clk_providers list locking and
an unlocked variant of of_clk_get_from_provider().
These functions are intended to be used in the clkdev to avoid
race condition in the device tree based clock look up in clk_get().

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-12-04 17:19:30 +01:00
Alex Elder b5f98e65c0 clk: clean up everything on debugfs error
[Maybe the third time will be the charm. -Alex]

If CONFIG_COMMON_CLK_DEBUG is defined, clk_debug_create_one() is
called to populate a debugfs directory with a few entries that are
common for all clock types.

If an error happens after creating the first one debugfs_remove() is
called on the clock's directory.  The problem with this is that no
cleanup is done on the debugfs files already created in that
directory, so the directory never actually gets removed.   This
problem is silently ignored.

Fix this by calling debugfs_remove_recursive() instead.  Reset the
clk->dentry field to null afterward, to ensure it can't be mistaken
as a valid pointer.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-11-27 12:48:21 -08:00
Mike Turquette f61027426a clk: of: helper for determining number of parent clocks
Walks the "clocks" array of parent clock phandles and returns the
number.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-10-07 23:13:33 -07:00
Tomasz Figa da0f0b2c3a clk: Correct lookup logic in clk_fetch_parent_index()
This function is supposed to iterate over all parents of given child
clock to find the index of given parent clock in its parent list,
using parent cache if possible and falling back to string compare
otherwise. However currently the logic falls back to string compare in
every iteration in which clock cache entry does not match given parent,
due to wrong check conditions.

This patch corrects the logic to continue the loop if parent cache entry
is present and does not match requested parent clock. In addition,
redundant checks for parent cache array presence are removed, because it
is always allocated in the beginning of the function.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-10-01 18:40:17 -07:00
Tomasz Figa 96a7ed9079 clk: Use kcalloc() to allocate arrays
Instead of calculating sizes of arrays manually, kcalloc() can be used
to allocate arrays of elements with defined size. This is just a cleanup
patch without any functional changes.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-10-01 18:40:16 -07:00
Tomasz Figa f1c8b2edf9 clk: Add error handling to clk_fetch_parent_index()
There are at least two different error cases that can happen in
clk_fetch_parent_index() function:
 - allocation failure,
 - parent clock lookup failure,
however it returns only an u8, which is supposed to contain parent clock
index.

This patch modified the function to return full int instead allowing
positive clock indices and negative error codes to be returned. All
users of this function are adjusted as well to handle the return value
correctly.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-10-01 18:40:16 -07:00
Alex Elder 12d298865e clk: only call get_parent if there is one
In __clk_init(), after a clock is mostly initialized, a scan is done
of the orphan clocks to see if the clock being registered is the
parent of any of them.

This code assumes that any clock that provides a get_parent method
actually has at least one parent, and that's not a valid assumption.

As a result, an orphan clock with no parent can return *something*
as the parent index, and that value is blindly used to dereference
the orphan's parent_names[] array (which will be ZERO_SIZE_PTR or
NULL).

Fix this by ensuring get_parent is only called for orphans with at
least one parent.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-09-09 14:10:10 -07:00
Thierry Reding b05c683637 clk: Move symbol export to proper location
The __clk_get_flags() symbol is exported immediately following the
clk_unprepare_unused_subtree() function. This is unusual, since a symbol
export typically follows body of the function that it exports.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-09-03 13:41:29 -07:00
James Hogan 903efc553f clk: fix new_parent dereference before null check
Commit 71472c0 (clk: add support for clock reparent on set_rate) added a
dereference of the new_parent pointer in clk_reparent(), but as detected
by smatch clk_reparent() later checks whether new_parent is NULL.

The dereference was in order to clear the new parent's new_child pointer
to avoid duplicate POST_RATE_CHANGE notifications, so clearly isn't
necessary if the new parent is NULL, so move it inside the "if
(new_parent)" block.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-08-30 12:52:01 -07:00
Alex Elder 7f7ed584d1 clk: get matching entry under lock in of_clk_init()
Currently of_clk_init() finds a matching device node while holding
the device tree spinlock.  When a matching device node is found, the
lock is dropped and then re-acquired in order to get a reference
to the matching device id structure.

Acquiring the spinlock twice is unnecessary (and it opens a
vulnerable window that could conceivably lead to errors).

There already exists an interface for both finding and taking a
reference to a device id under lock, so use it.

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Christian Daudt <csd@broadcom.com>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-08-27 16:05:39 -07:00
Mike Turquette 89ac8d7ae1 clk: handle NULL struct clk gracefully
At some point changes to clk_set_rate and clk_set_parent introduced a
bug whereby NULL struct clk pointers were treated as an error. This is
in violation of the API in include/linux/clk.h. Reintroduce graceful
handling of NULL clk's by bailing from clk_set_rate and clk_set_parent
with return codes of zero.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-08-21 23:58:09 -07:00
James Hogan e366fdd725 clk: clk-mux: implement remuxing on set_rate
Implement clk-mux remuxing if the CLK_SET_RATE_NO_REPARENT flag isn't
set. This implements determine_rate for clk-mux to propagate to each
parent and to choose the best one (like clk-divider this chooses the
parent which provides the fastest rate <= the requested rate).

The determine_rate op is implemented as a core helper function so that
it can be easily used by more complex clocks which incorporate muxes.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-08-19 12:27:18 -07:00
James Hogan 71472c0c06 clk: add support for clock reparent on set_rate
Add core support to allow clock implementations to select the best
parent clock when rounding a rate, e.g. the one which can provide the
closest clock rate to that requested. This is by way of adding a new
clock op, determine_rate(), which is like round_rate() but has an extra
parameter to allow the clock implementation to optionally select a
different parent clock. The core then takes care of reparenting the
clock when setting the rate.

The parent change takes place with the help of some new private data
members. struct clk::new_parent specifies a clock's new parent (NULL
indicates no change), and struct clk::new_child specifies a clock's new
child (whose new_parent member points back to it). The purpose of these
are to allow correct walking of the future tree for notifications prior
to actually reparenting any clocks, specifically to skip child clocks
who are being reparented to another clock (they will be notified via the
new parent), and to include any new child clock. These pointers are set
by clk_calc_subtree(), and the new_child pointer gets cleared when a
child is actually reparented to avoid duplicate POST_RATE_CHANGE
notifications.

Each place where round_rate() is called, determine_rate() is checked
first and called in preference. This restructures a few of the call
sites to simplify the logic into if/else blocks.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-08-19 12:27:17 -07:00
James Hogan 4935b22c46 clk: move some parent related functions upwards
Move some parent related functions up in clk.c so they can be used by
the modifications in the following patch which enables clock reparenting
during set_rate. No other changes are made so this patch makes no
functional difference in isolation. This is separate from the following
patch primarily to ease readability of that patch.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-08-19 12:27:16 -07:00
James Hogan 7ef3dcc814 clk: abstract parent cache
Abstract access to the clock parent cache by defining
clk_get_parent_by_index(clk, index). This allows access to parent
clocks from clock drivers.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-08-19 12:27:15 -07:00
Peter Meerwald 24ee1a083c clk: fix typos
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-07-25 14:06:11 -07:00
Linus Torvalds 92295f632c The common clock framework changes for 3.11 include new clock drivers
across several different platforms and architectures, fixes to existing
 drivers, a MAINTAINERS file fix and improvements to the basic clock
 types that allow them to be of use to more platforms than before. Only a
 few fixes to the core framework are included with most all of the
 changes landing in the various clock drivers themselves.
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Merge tag 'clk-for-linus-3.11' of git://git.linaro.org/people/mturquette/linux

Pull clock framework updates from Mike Turquette:
 "The common clock framework changes for 3.11 include new clock drivers
  across several different platforms and architectures, fixes to
  existing drivers, a MAINTAINERS file fix and improvements to the basic
  clock types that allow them to be of use to more platforms than before.

  Only a few fixes to the core framework are included with most all of
  the changes landing in the various clock drivers themselves."

* tag 'clk-for-linus-3.11' of git://git.linaro.org/people/mturquette/linux: (55 commits)
  clk: tegra: fix ifdef for tegra_periph_reset_assert inline
  clk: tegra: provide tegra_periph_reset_assert alternative
  clk: exynos4: Fix clock aliases for cpufreq related clocks
  clk: samsung: Add MUX_FA macro to pass flag and alias
  clk: add support for Rockchip gate clocks
  clk: vexpress: Make the clock drivers directly available for arm64
  clk: vexpress: Use full node name to identify individual clocks
  clk: tegra: T114: add DFLL DVCO reset control
  clk: tegra: T114: add DFLL source clocks
  clk: tegra: T114: add FCPU clock shaper programming, needed by the DFLL
  clk: gate: add CLK_GATE_HIWORD_MASK
  clk: divider: add CLK_DIVIDER_HIWORD_MASK flag
  clk: mux: add CLK_MUX_HIWORD_MASK
  clk: Always notify whole subtree when reparenting
  MAINTAINERS: make drivers/clk entry match subdirs
  clk: honor CLK_GET_RATE_NOCACHE in clk_set_rate
  clk: use clk_get_rate() for debugfs
  clk: tegra: Use override bits when needed
  clk: tegra: override bits for Tegra30 PLLM
  clk: tegra: override bits for Tegra114 PLLM
  ...
2013-07-03 11:54:50 -07:00
Soren Brinkmann f3aab5d614 clk: Always notify whole subtree when reparenting
A clock's notifier count only reflects notifiers which are registered
directly for that clock. A reparent operation though affects the whole
subtree because of a potential rate change.
When issuing the pre rate change notifications only the notifier count
for the clock to be changed is considered and notifiers for subclocks
may never be called. Resulting in clocks in the subtree which have
registered notifiers, may receive a POST_- or ABORT_RATE_CHANGE
notification, without a PRE_RATE_CHANGE_NOTIFICATION.
Therefore always traverse the whole subtree when issueing pre rate
change notifications during a reparent operation.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-15 14:34:41 -07:00
Peter De Schrijver 34e452a152 clk: honor CLK_GET_RATE_NOCACHE in clk_set_rate
clk_set_rate() uses clk->rate directly. This causes problems if the clock
is marked as CLK_GET_RATE_NOCACHE. Hence call clk_get_rate() to get the
current rate.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-11 18:04:08 -07:00
Peter De Schrijver 670decdd95 clk: use clk_get_rate() for debugfs
debugfs uses the rate field directly. However this ignores the
CLK_GET_RATE_NOCACHE flag. Call clk_get_rate() instead.

Tested-by: Mark Zhang <markz@nvidia.com>
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-11 18:03:54 -07:00
Lai Jiangshan 72b5322f11 clk: remove notifier from list before freeing it
The @cn is stay in @clk_notifier_list after it is freed, it cause
memory corruption.

Example, if @clk is registered(first), unregistered(first),
registered(second), unregistered(second).

The freed @cn will be used when @clk is registered(second),
and the bug will be happened when @clk is unregistered(second):

[  517.040000] clk_notif_dbg clk_notif_dbg.1: clk_notifier_unregister()
[  517.040000] Unable to handle kernel paging request at virtual address 00df3008
[  517.050000] pgd = ed858000
[  517.050000] [00df3008] *pgd=00000000
[  517.060000] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
[  517.060000] Modules linked in: clk_notif_dbg(O-) [last unloaded: clk_notif_dbg]
[  517.060000] CPU: 1 PID: 499 Comm: modprobe Tainted: G           O 3.10.0-rc3-00119-ga93cb29-dirty #85
[  517.060000] task: ee1e0180 ti: ee3e6000 task.ti: ee3e6000
[  517.060000] PC is at srcu_readers_seq_idx+0x48/0x84
[  517.060000] LR is at srcu_readers_seq_idx+0x60/0x84
[  517.060000] pc : [<c0052720>]    lr : [<c0052738>]    psr: 80070013
[  517.060000] sp : ee3e7d48  ip : 00000000  fp : ee3e7d6c
[  517.060000] r10: 00000000  r9 : ee3e6000  r8 : 00000000
[  517.060000] r7 : ed84fe4c  r6 : c068ec90  r5 : c068e430  r4 : 00000000
[  517.060000] r3 : 00df3000  r2 : 00000000  r1 : 00000002  r0 : 00000000
[  517.060000] Flags: Nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[  517.060000] Control: 18c5387d  Table: 2d85804a  DAC: 00000015
[  517.060000] Process modprobe (pid: 499, stack limit = 0xee3e6238)
[  517.060000] Stack: (0xee3e7d48 to 0xee3e8000)
....
[  517.060000] [<c0052720>] (srcu_readers_seq_idx+0x48/0x84) from [<c0052790>] (try_check_zero+0x34/0xfc)
[  517.060000] [<c0052790>] (try_check_zero+0x34/0xfc) from [<c00528b0>] (srcu_advance_batches+0x58/0x114)
[  517.060000] [<c00528b0>] (srcu_advance_batches+0x58/0x114) from [<c0052c30>] (__synchronize_srcu+0x114/0x1ac)
[  517.060000] [<c0052c30>] (__synchronize_srcu+0x114/0x1ac) from [<c0052d14>] (synchronize_srcu+0x2c/0x34)
[  517.060000] [<c0052d14>] (synchronize_srcu+0x2c/0x34) from [<c0053a08>] (srcu_notifier_chain_unregister+0x68/0x74)
[  517.060000] [<c0053a08>] (srcu_notifier_chain_unregister+0x68/0x74) from [<c0375a78>] (clk_notifier_unregister+0x7c/0xc0)
[  517.060000] [<c0375a78>] (clk_notifier_unregister+0x7c/0xc0) from [<bf008034>] (clk_notif_dbg_remove+0x34/0x9c [clk_notif_dbg])
[  517.060000] [<bf008034>] (clk_notif_dbg_remove+0x34/0x9c [clk_notif_dbg]) from [<c02bb974>] (platform_drv_remove+0x24/0x28)
[  517.060000] [<c02bb974>] (platform_drv_remove+0x24/0x28) from [<c02b9bf8>] (__device_release_driver+0x8c/0xd4)
[  517.060000] [<c02b9bf8>] (__device_release_driver+0x8c/0xd4) from [<c02ba680>] (driver_detach+0x9c/0xc4)
[  517.060000] [<c02ba680>] (driver_detach+0x9c/0xc4) from [<c02b99c4>] (bus_remove_driver+0xcc/0xfc)
[  517.060000] [<c02b99c4>] (bus_remove_driver+0xcc/0xfc) from [<c02bace4>] (driver_unregister+0x54/0x78)
[  517.060000] [<c02bace4>] (driver_unregister+0x54/0x78) from [<c02bbb44>] (platform_driver_unregister+0x1c/0x20)
[  517.060000] [<c02bbb44>] (platform_driver_unregister+0x1c/0x20) from [<bf0081f8>] (clk_notif_dbg_driver_exit+0x14/0x1c [clk_notif_dbg])
[  517.060000] [<bf0081f8>] (clk_notif_dbg_driver_exit+0x14/0x1c [clk_notif_dbg]) from [<c00835e4>] (SyS_delete_module+0x200/0x28c)
[  517.060000] [<c00835e4>] (SyS_delete_module+0x200/0x28c) from [<c000edc0>] (ret_fast_syscall+0x0/0x48)
[  517.060000] Code: e5973004 e7911102 e0833001 e2881002 (e7933101)

Cc: stable@kernel.org
Reported-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Tested-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: shortened $SUBJECT]
2013-06-06 18:22:52 -07:00
Saravana Kannan d41d580587 clk: Disable unused clocks after deferred probing is done
With deferred probing, late_initcall() is too soon to declare a clock as
unused. Wait for deferred probing to finish before declaring a clock as
unused. Since deferred probing is done in late_initcall(), do the unused
check to late_initcall_sync.

Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-29 00:52:20 -07:00
Saravana Kannan f8aa0bd5c9 clk: Fix race condition between clk_set_parent and clk_enable()
Without this patch, the following race condition is possible.
* clk-A has two parents - clk-X and clk-Y.
* All three are disabled and clk-X is current parent.
* Thread A: clk_set_parent(clk-A, clk-Y).
* Thread A: <snip execution flow>
* Thread A: Grabs enable lock.
* Thread A: Sees enable count of clk-A is 0, so doesn't enable clk-Y.
* Thread A: Updates clk-A SW parent to clk-Y
* Thread A: Releases enable lock.
* Thread B: clk_enable(clk-A).
* Thread B: clk_enable() enables clk-Y, then enabled clk-A and returns.

clk-A is now enabled in software, but not clocking in hardware since the
hardware parent is still clk-X.

The only way to avoid race conditions between clk_set_parent() and
clk_enable/disable() is to ensure that clk_enable/disable() calls don't
require changes to hardware enable state between changes to software clock
topology and hardware clock topology.

The options to achieve the above are:
1. Grab the enable lock before changing software/hardware topology and
   release it afterwards.
2. Keep the clock enabled for the duration of software/hardware topology
   change so that any additional enable/disable calls don't try to change
   the hardware state. Once the topology change is complete, the clock can
   be put back in its original enable state.

Option (1) is not an acceptable solution since the set_parent() ops might
need to sleep.

Therefore, this patch implements option (2).

This patch doesn't violate any API semantics. clk_disable() doesn't
guarantee that the clock is actually disabled. So, no clients of a clock
can assume that a clock is disabled after their last call to clk_disable().
So, enabling the clock during a parent change is not a violation of any API
semantics.

This also has the nice side effect of simplifying the error handling code.

Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up whitespace issue]
2013-05-28 22:50:32 -07:00
Olof Johansson 1e435256d6 clk: add clk_ignore_unused option to keep boot clocks on
This is primarily useful when there's a driver that doesn't claim clocks
properly, but the bootloader leaves them on. It's not expected to be used
in normal cases, but for bringup and debug it's very useful to have the
option to not gate unclaimed clocks that are still on.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up trivial merge issue]
2013-04-27 23:03:43 -07:00
Sebastian Hesselbarth 496620ccf8 clk: export __clk_get_flags for modular clock providers
The common clock api provides some helpers for clk-providers but does
not export these helpers. This hinders clk-providers to be built as modules.
This patch adds __clk_get_flags() to the list of exported symbols.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-04-15 14:50:17 -07:00
Soren Brinkmann fb72a0590b clk: Properly handle notifier return values
Notifiers may return NOTIFY_(OK|DONE|STOP|BAD). The CCF uses an
inconsistent mix of checking against NOTIFY_STOP or NOTIFY_BAD.
This inconsistency leaves errors undetected in some cases:
clk_set_parent() calls __clk_speculate_rates(), which stops when it
hits a NOTIFIER_BAD (STOP is ignored), and passes this value back to the
caller.
clk_set_parent() compares this return value against NOTIFY_STOP only,
ignoring NOTIFY_BAD returns.

Use NOTIFY_STOP_MASK to detect a negative notifier return value and
document all four return value options.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-04-10 16:33:53 -07:00
Ulf Hansson a68de8e4ab clk: Fixup locking issues for clk_set_parent
Updating the clock tree topology must be protected with the spinlock
when doing clk_set_parent, otherwise we can not handle the migration
of the enable_count in a safe manner.

While issuing the .set_parent callback to make the clk-hw perform the
switch to the new parent, we can not hold the spinlock since it is must
be allowed to be slow path. This complicates error handling, but is still
possible to achieve.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-04-08 18:19:40 -07:00
Ulf Hansson 031dcc9bd4 clk: Fixup errorhandling for clk_set_parent
Fixup the broken feature of allowing reparent of a clk to the
orhpan list and vice verse. When operating on a single-parent
clk, the .set_parent callback for the clk hw is optional to
implement, but for a multi-parent clk it is mandatory.

Moreover improve the errorhandling by verifying the prerequisites
before triggering clk notifiers. This will prevent unnecessary
rollback with ABORT_RATE_CHANGE.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-04-08 18:19:32 -07:00
Ulf Hansson b33d212f49 clk: Restructure code for __clk_reparent
Split __clk_reparent into three pieces, one for doing the actual
reparent for updating the clock tree topology, one for the
COMMON_CLK_DEBUG code and one for doing the rate recalculation.

This patch also makes it possible to hold the spinlock over the
update of the clock tree topology, which could not be done before
when both debugfs updates and clock rate updates was done within
the same function.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-04-08 18:19:15 -07:00
Mike Turquette 533ddeb1e8 clk: allow reentrant calls into the clk framework
Reentrancy into the clock framework is necessary for clock operations
that result in nested calls to the clk api.  A common example is a clock
that is prepared via an i2c transaction, such as a clock inside of a
discrete audio chip or a power management IC.  The i2c subsystem itself
will use the clk api resulting in a deadlock:

clk_prepare(audio_clk)
	i2c_transfer(..)
		clk_prepare(i2c_controller_clk)

The ability to reenter the clock framework prevents this deadlock.

Other use cases exist such as allowing .set_rate callbacks to call
clk_set_parent to achieve the best rate, or to save power in certain
configurations.  Yet another example is performing pinctrl operations
from a clk_ops callback.  Calls into the pinctrl subsystem may call
clk_{un}prepare on an unrelated clock.  Allowing for nested calls to
reenter the clock framework enables both of these use cases.

Reentrancy is implemented by two global pointers that track the owner
currently holding a global lock.  One pointer tracks the owner during
sleepable, mutex-protected operations and the other one tracks the owner
during non-interruptible, spinlock-protected operations.

When the clk framework is entered we try to hold the global lock.  If it
is held we compare the current task against the current owner; a match
implies a nested call and we reenter.  If the values do not match then
we block on the lock until it is released.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2013-04-02 10:23:41 -07:00
Mike Turquette eab89f690e clk: abstract locking out into helper functions
Create locking helpers for the global mutex and global spinlock.  The
definitions of these helpers will be expanded upon in the next patch
which introduces reentrancy into the locking scheme.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2013-04-02 10:23:08 -07:00
Sachin Kamat 5fda6858a4 clk: Fix incorrect return type in clk.c
Return type of function clk_propagate_rate_change is a pointer.
But 0 was being returned. Change it to NULL.
Silences the following warning:
drivers/clk/clk.c:977:24: warning: Using plain integer as NULL pointer

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Reviewed-by: Pankaj Jangra <jangra.pankaj9@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-03-22 15:18:18 -07:00
Ulf Hansson 3cc8247f1d clk: Introduce optional unprepare_unused callback
An unprepare_unused callback is introduced due to the same reasons to
why the disable_unused callback was added.

During the clk_disable_unused sequence, those clk_hw that needs specific
treatment with regards to being unprepared, shall implement the
unprepare_unused callback.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-03-19 12:58:43 -07:00
Ulf Hansson 1c155b3dfe clk: Unprepare the unused prepared slow clocks at late init
The unused ungated fast clocks are already being disabled from
clk_disable_unused at late init. This patch extend this sequence
to the slow unused prepared clocks to be unprepared.

Unless the optional .is_prepared callback is implemented by a
clk_hw the clk_disable_unused sequence will not unprepare any
unused clocks, since it will fall back to use the software
prepare counter.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed hlist accessors per b67bfe0d]
2013-03-19 12:58:42 -07:00
Ulf Hansson 3d6ee287a3 clk: Introduce optional is_prepared callback
To reflect whether a clk_hw is prepared the clk_hw may implement
the optional is_prepared callback. If not implemented we fall back
to use the software prepare counter.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-03-19 12:58:42 -07:00
Sasha Levin b67bfe0d42 hlist: drop the node parameter from iterators
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:24 -08:00
Prashant Gaikwad f2f6c2556d clk: add common of_clk_init() function
Modify of_clk_init function so that it will determine which
driver to initialize based on device tree instead of each driver
registering to it.

Based on a similar patch for drivers/irqchip by Thomas Petazzoni and
drivers/clocksource by Stephen Warren.

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Tested-by: Tony Prisk <linux@prisktech.co.nz>
Tested-by: Pawel Moll <pawel.moll@arm.com>
Tested-by: Rob Herring <rob.herring@calxeda.com>
Tested-by: Josh Cartwright <josh.cartwright@ni.com>
Reviewed-by: Josh Cartwright <josh.cartwright@ni.com>
Acked-by: Maxime Ripard <maxime.ripard@anandra.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: merge conflict from missing CLKSRC_OF_TABLES()]

Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-01-24 11:09:28 -08:00
Nestor Ovroy 4cfe54e579 clk: Deduplicate exit code in clk_set_rate
On non-out case 'return ret;' is equivalent to 'return 0;' as the ret
variable is initialized at 0 and never changed.

Signed-off-by: Nestor Ovroy <novroy@riseup.net>
2013-01-21 14:29:11 -08:00
Prashant Gaikwad bddca8944a clk: JSON debugfs clock tree summary
Clock information is dumped in JSON format which is easy
for machines to parse.

Each clock is represented as an object which has same name as
clock and following properties
	- enable_count
	- prepare_count
	- rate

Output is verified using online JSON editor.

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-01-11 19:49:23 -08:00
Prashant Gaikwad 1af599df6b clk: human-readable debugfs clock tree summary
Adds debug file "clk_summary" in /sys/kernel/debug/clk dir.
It helps to view all the clock registered in human-readable format.

For example:
   clock                        enable_cnt  prepare_cnt  rate
---------------------------------------------------------------------
 i2s0_sync                      0           0            24000000
 spdif_in_sync                  0           0            24000000
    spdif_mux                   0           0            24000000
       spdif                    0           0            24000000
          spdif_doubler         0           0            48000000
             spdif_div          0           0            48000000
                spdif_2x        0           0            48000000
 clk_32k                        2           2            32768
    blink_override              1           1            32768
       blink                    1           1            32768
 clk_m                          2           2            12000000
    clk_out_3_mux               0           0            12000000
       clk_out_3                0           0            12000000
    pll_ref                     3           3            12000000
       pll_e_mux                0           0            12000000
          pll_e                 0           0            100000000
             cml0               0           0            100000000
             cml1               0           0            100000000
             pciex              0           0            100000000
       pll_d2                   0           0            1000000
          pll_d2_out0           0           0            500000
       pll_d                    0           0            1000000
          pll_d_out0            0           0            500000
             dsib_mux           0           0            500000
                dsib            0           0            500000
             dsia               0           0            500000

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-01-11 19:46:32 -08:00
Niels de Vos 4895084c87 clk: export __clk_get_name for re-use in imx-ipu-v3 and others
This fixes the following error when building for arm-imx:
> ERROR: "__clk_get_name" [drivers/staging/imx-drm/ipu-v3/imx-ipu-v3.ko] undefined!
> make[1]: *** [__modpost] Error 1
> make: *** [modules] Error 2

There are valid usecases to get the name of a clock, be it for debugging
purposes or to register a children of a clock like done in this IPU driver.
Therefore exporting __clk_get_name() and make it available for others makes
sense.

Reported-by: Peter Robinson <pbrobinson@gmail.com>
CC: Sascha Hauer <s.hauer@pengutronix.de>
CC: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removal of inline made redundant by 65800b2]
2013-01-11 18:34:14 -08:00
Russ Dill 65800b2c40 clk: Don't mark shared helper functions as inline
The helper functions that access the opaque struct clk should
not be marked inline since they are contained in clk.c, but expected
to be used by other compilation units. This causes compile errors
under gcc-4.7

In file included from arch/arm/mach-omap2/clockdomain.c:25:0:
arch/arm/mach-omap2/clockdomain.c: In function ‘clkdm_clk_disable’:
include/linux/clk-provider.h:338:12: error: inlining failed in call to always_inline ‘__clk_get_enable_count’: function body not available
arch/arm/mach-omap2/clockdomain.c:1001:28: error: called from here
make[1]: *** [arch/arm/mach-omap2/clockdomain.o] Error 1
make: *** [arch/arm/mach-omap2] Error 2

Signed-off-by: Russ Dill <Russ.Dill@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removed fixes made redundant by commit 93532c8a]
[mturquette@linaro.org: improved $SUBJECT]
2013-01-11 16:32:41 -08:00
Mike Turquette 7c045a55c9 clk: introduce optional disable_unused callback
Some gate clocks have special needs which must be handled during the
disable-unused clocks sequence.  These needs might be driven by software
due to the fact that we're disabling a clock outside of the normal
clk_disable path and a clk's enable_count will not be accurate.  On the
other hand a specific hardware programming sequence might need to be
followed for this corner case.

This change is needed for the upcoming OMAP port to the common clock
framework.  Specifically, it is undesirable to treat the disable-unused
path identically to the normal clk_disable path since other software
layers are involved.  In this case OMAP's clockdomain code throws WARNs
and bails early due to the clock's enable_count being set to zero.  A
custom callback mitigates this problem nicely.

Cc: Paul Walmsley <paul@pwsan.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-12-10 22:35:02 -08:00
Martin Fuzzey 1f61e5f143 clk: clock multiplexers may register out of order
When a clock, C is initialised any orphan clocks listing C as
a possible parent are reparented to it regardless of the
parent requested by the orphan's get_parent() operation.

This means that multiplexers registered before their parents
are reparented to the first parent subsequently declared,
regardless of the selection made by the hardware registers.

For example:
	static const char *sel[] = { "srcA", "srcB", "dummy", "srcC" };

	child = clk_register_mux(NULL, "child",  sel, ARRAY_SIZE(sel), ...);
	clk_register_fixed(NULL, "dummy", ...);
	clk_register_fixed(NULL, "srcA", ...);
	clk_register_fixed(NULL, "srcB", ...);
	clk_register_fixed(NULL, "srcC", ...);

Causes child's parent to always be "dummy".

To fix this, when an orphanned clock has a get_parent() operation,
only reparent to the clock indicated by get_parent().

Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: improve $SUBJECT]
2012-11-26 11:14:45 -08:00
Stephen Boyd 46c8773a58 clk: Add devm_clk_{register,unregister}()
Some clock drivers can be simplified if devres takes care of
unregistering any registered clocks along error paths. Introduce
devm_clk_register() so that clock drivers get unregistration for
free along with simplified error paths.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-10-29 11:12:46 -07:00
Stephen Boyd 2ac6b1f50a clk: Don't return negative numbers for unsigned values with !clk
Some of the helper functions return negative error codes if
passed a NULL clock. This can lead to confusing behavior when the
expected return value is unsigned. Fix up these accessors so that
they return unsigned values (or bool in the case of is_enabled).
This way we can't interpret NULL clocks as having valid and
interesting values.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-10-29 11:05:03 -07:00
Shawn Guo 494bfec999 clk: add of_clk_src_onecell_get() support
For those SoCs that have hundreds of clock outputs, their clock
DT bindings could reasonably define #clock-cells as 1 and require
the client device specify the index of the clock it consumes in the
cell of its "clocks" phandle.

Add a generic of_clk_src_onecell_get() function for this purpose.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-09-07 18:30:19 -07:00
Ulf Hansson a093bde2b4 clk: Provide option for clk_get_rate to issue hw for new rate
By using CLK_GET_RATE_NOCACHE flag, we tell the clk_get_rate API to
issue the hw for an updated clock rate. This can be used for a clock
which rate may be updated without a client necessary modifying it.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-09-06 17:56:22 -07:00
Fengguang Wu e47c6a3408 clk: validate pointer in __clk_disable()
clk_get() returns -ENOENT on error and some careless caller might
dereference it without error checking:

In mxc_rnga_remove():

        struct clk *clk = clk_get(&pdev->dev, "rng");

	// ...

        clk_disable(clk);

Since it's insane to audit the lots of existing and future clk users,
let's add a check in the callee to avoid kernel panic and warn about
any buggy user.

Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
Cc: viresh kumar <viresh.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:13 -07:00
Grant Likely 766e6a4ec6 clk: add DT clock binding support
Based on work 1st by Ben Herrenschmidt and Jeremy Kerr, then by Grant
Likely, this patch adds support to clk_get to allow drivers to retrieve
clock data from the device tree.

Platforms scan for clocks in DT with of_clk_init and a match table, and
the register a provider through of_clk_add_provider. The provider's
clk_src_get function will be called when a device references the
provider's OF node for a clock reference.

v6 (Rob Herring):
    - Return error values instead of NULL to match clock framework
      expectations

v5 (Rob Herring):
    - Move from drivers/of into common clock subsystem
    - Squashed "dt/clock: add a simple provider get function" and
      "dt/clock: add function to get parent clock name"
    - Rebase to 3.4-rc1
    - Drop CONFIG_OF_CLOCK and just use CONFIG_OF
    - Add missing EXPORT_SYMBOL to various functions
    - s/clock-output-name/clock-output-names/
    - Define that fixed-clock binding is a single output

v4 (Rob Herring):
    - Rework for common clk subsystem
    - Add of_clk_get_parent_name function

v3: - Clarified documentation

v2: - fixed errant ';' causing compile error
    - Editorial fixes from Shawn Guo
    - merged in adding lookup to clkdev
    - changed property names to match established convention. After
      working with the binding a bit it really made more sense to follow the
      lead of 'reg', 'gpios' and 'interrupts' by making the input simply
      'clocks' & 'clock-names' instead of 'clock-input-*', and to only use
      clock-output* for the producer nodes. (Sorry Shawn, this will mean
      you need to change some code, but it should be trivial)
    - Add ability to inherit clocks from parent nodes by using an empty
      'clock-ranges' property.  Useful for busses.  I could use some feedback
      on the new property name, 'clock-ranges' doesn't feel right to me.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Shawn Guo <shawn.guo@freescale.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-07-11 17:58:45 -07:00
Rajendra Nayak 9ca1c5a4bf clk: cache parent clocks only for muxes
caching parent clocks makes sense only when a clock has more
than one parent (mux clocks).
Avoid doing this for every other clock.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
[mturquette@linaro.org: removed extra parentheses]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-07-11 15:36:45 -07:00
Rajendra Nayak 863b13271f clk: fix parent validation in __clk_set_parent()
The below commit introduced a bug in __clk_set_parent()
which could cause it to *skip* the parent validation
which makes sure the parent passed to the api is a valid
one.

    commit 7975059db5
    Author: Rajendra Nayak <rnayak@ti.com>
    Date:   Wed Jun 6 14:41:31 2012 +0530

        clk: Allow late cache allocation for clk->parents

This was identified by the following compiler warning..

    drivers/clk/clk.c: In function '__clk_set_parent':
    drivers/clk/clk.c:1083:5: warning: 'i' may be used uninitialized in this function [-Wuninitialized]

.. as reported by Marc Kleine-Budde.

There were various options discussed on how to fix this, one
being initing 'i' to clk->num_parents, but the below approach
was found to be more appropriate as it also makes the 'parent
validation' code simpler to read.

Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: stable@kernel.org
2012-07-03 12:05:14 -07:00
Pawel Moll bf47b4fd8f clk: Check parent for NULL in clk_change_rate
clk_change_rate() is accessing parent's rate without checking
if the parent exists at all. In case of root clocks this will
cause NULL pointer dereference.

This patch follows what clk_calc_new_rates() does in such
situation.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: stable@kernel.org
2012-06-25 16:51:48 -07:00
Rajendra Nayak 7975059db5 clk: Allow late cache allocation for clk->parents
Parent clocks for muxes are cached in clk->parents to
avoid frequent lookups, however the cache allocation happens
only during clock registeration and later clk_set_parent()
assumes a cache space available and allocated.

This is not entirely true for platforms which do early clock
registerations wherein the cache allocation using kzalloc
could fail during clock registeration.

Allow cache allocation to happen later as part of clk_set_parent()
to help such cases and avoid crashes assuming a cache being
available.

While here also replace existing kmalloc() with kzalloc()
in the file.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: stable@kernel.org
2012-06-25 16:51:47 -07:00
Saravana Kannan 7e0fa1b5fa clk: Fix CLK_SET_RATE_GATE flag validation in clk_set_rate().
The clk_set_rate() code shouldn't check the clock's enable count when
validating CLK_SET_RATE_GATE flag since the enable count could change after
the validation. Similar to clk_set_parent(), it should instead check the
prepare count. The prepare count should go to zero only when the end user
expects the clock to not be enabled in the future. Since the code already
grabs the prepare count before validation, it's not possible for prepare
count to change after validation and by association not possible for a well
behaving end user to enable the clock while the set rate is in progress.

Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Reviewed-by: Richard Zhao <richard.zhao@freescale.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-05-15 22:42:10 -07:00
Mark Brown 1df5c939f6 clk: Provide dummy clk_unregister()
While there's no actual implementation behind it having the call to use
in drivers makes them feel neater from a driver author point of view. An
actual implementation can wait for someone who needs to use the function
in a real system.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
[mturquette@linaro.org: void return type instead of int -EINVAL]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-05-15 12:02:39 -07:00
Mike Turquette d269b974e3 clk: remove COMMON_CLK_DISABLE_UNUSED
Exposing this option generates confusion and incorrect behavior for
single-image builds across platforms.  Enable this behavior permanently.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
2012-05-08 14:12:42 -07:00
Mike Turquette 63f5c3b2b1 clk: prevent spurious parent rate propagation
Patch 'clk: always pass parent_rate into .round_rate' made a subtle
change to the semantics of .round_rate.  It is now expected for the
parent's rate to always be passed in, simplifying the implemenation of
various .round_rate callback definitions.

However the patch also introduced a bug in clk_calc_new_rates whereby a
clock without the CLK_SET_RATE_PARENT flag set could still propagate a
rate change up to a parent clock if the the .round_rate callback
modified the &best_parent_rate value in any way.

This patch fixes the issue at the framework level (in
clk_calc_new_rates) by specifically handling the case where the
CLK_SET_RATE_PARENT flag is not set.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-05-08 14:11:53 -07:00
Viresh Kumar 0e1c030175 clk: clk_set_rate() must fail if CLK_SET_RATE_GATE is set and clk is enabled
This is well documented but isn't implemented. clk_set_rate() must check if
flags have CLK_SET_RATE_GATE bit set and is enabled too.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-05-01 18:13:38 -07:00
Saravana Kannan 0197b3ea0f clk: Use a separate struct for holding init data.
Create a struct clk_init_data to hold all data that needs to be passed from
the platfrom specific driver to the common clock framework during clock
registration. Add a pointer to this struct inside clk_hw.

This has several advantages:
* Completely hides struct clk from many clock platform drivers and static
  clock initialization code that don't care for static initialization of
  the struct clks.
* For platforms that want to do complete static initialization, it removed
  the need to directly mess with the struct clk's fields while still
  allowing to statically allocate struct clk. This keeps the code more
  future proof even if they include clk-private.h.
* Simplifies the generic clk_register() function and allows adding optional
  fields in the future without modifying the function signature.
* Simplifies the static initialization of clocks on all platforms by
  removing the need for forward delcarations or convoluted macros.

Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
[mturquette@linaro.org: kept DEFINE_CLK_* macros and __clk_init]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Jamie Iles <jamie@jamieiles.com>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: Deepak Saxena <dsaxena@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
2012-05-01 18:13:20 -07:00
Viresh Kumar 1b2f99037a clk: Don't set clk->new_rate twice
if (!clk->ops->round_rate && (clk->flags & CLK_SET_RATE_PARENT)) is true, then
we don't need to set clk->new_rate here, as we will call clk_calc_subtree()
afterwards and it also sets clk->new_rate.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24 16:37:41 -07:00
Shawn Guo f4d8af2e5a clk: propagate round_rate for CLK_SET_RATE_PARENT case
Need to propagate round_rate call for the clk that has no .round_rate
operation but with flag CLK_SET_RATE_PARENT set.

For example, clk_mux is a clk with no .round_rate operation.  However,
it could likely be in a clk_set_rate propagation path, saying it has
parent clk who has .round_rate and .set_rate operations.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24 16:37:40 -07:00
Shawn Guo 1c0035d710 clk: pass parent_rate into .set_rate
For most of .set_rate implementation, parent_rate will be used, so just
like passing parent_rate into .recalc_rate, let's pass parent_rate into
.set_rate too.

It also updates the kernel doc for .set_rate ops.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24 16:37:40 -07:00
Shawn Guo 81536e072b clk: always pass parent_rate into .round_rate
The parent_rate will likely be used by most .round_rate implementation
no matter whether flag CLK_SET_RATE_PARENT is set or not, so let's
always pass parent_rate into .round_rate.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24 16:37:39 -07:00
Mike Turquette d1302a36a7 clk: core: copy parent_names & return error codes
This patch cleans up clk_register and solves a few bugs by teaching
clk_register and __clk_init to return error codes (instead of just NULL)
to better align with the existing clk.h api.

Along with that change this patch also introduces a new behavior whereby
clk_register copies the parent_names array, thus allowing platforms to
declare their parent_names arrays as __initdata.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24 16:37:39 -07:00
Mark Brown d305fb78f3 clk: Constify parent name arrays
Drivers should be able to declare their arrays of parent names as const
so the APIs need to accept const arguments.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
[mturquette@linaro.org: constified gate]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24 16:37:39 -07:00
Rajendra Nayak 34e44fe874 clk: Make clk_get_rate() return 0 on error
Most users of clk_get_rate() actually assume a non zero
return value as a valid rate returned. Returing -EINVAL
might confuse such users, so make it instead return zero
on error.

Besides the return value of clk_get_rate seems to be
'unsigned long'.

Signed-off-by: Rajendra nayak <rnayak@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24 16:37:39 -07:00
Mike Turquette d4d7e3ddc7 clk: core: enforce clk_ops consistency
Documentation/clk.txt has some handsome ASCII art outlining which
clk_ops are mandatory for a given clock, given the capability of the
hardware.  Enforce those mandates with sanity checks in __clk_init.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24 16:37:38 -07:00
Mike Turquette 7452b2191c clk: core: clk_calc_new_rates handles NULL parents
It is possible to call clk_set_rate on a clock with a NULL parent.  One
such example is an adjustable-rate root clock.  Ensure that
clk_calc_new_rates does not dereference parent without checking first
and also handle the corner cases gracefully.

Reported-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24 16:37:37 -07:00
Mike Turquette 70d347e6cd clk: core: remove dead code paths
Some static inline dummy functions were left over from before the clock
core was consolidated from several C files down to one.  Remove them.

Reported-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24 16:37:37 -07:00
Mike Turquette 5654dc94f8 clk: core: correct clk_set_rate kerneldoc
Remove old and misleading documentation from the previous clk_set_rate
implementaion.

Reported-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24 16:37:37 -07:00
Mike Turquette b2476490ef clk: introduce the common clock framework
The common clock framework defines a common struct clk useful across
most platforms as well as an implementation of the clk api that drivers
can use safely for managing clocks.

The net result is consolidation of many different struct clk definitions
and platform-specific clock framework implementations.

This patch introduces the common struct clk, struct clk_ops and an
implementation of the well-known clock api in include/clk/clk.h.
Platforms may define their own hardware-specific clock structure and
their own clock operation callbacks, so long as it wraps an instance of
struct clk_hw.

See Documentation/clk.txt for more details.

This patch is based on the work of Jeremy Kerr, which in turn was based
on the work of Ben Herrenschmidt.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Mike Turquette <mturquette@ti.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Rob Herring <rob.herring <at> calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: Deepak Saxena <dsaxena@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2012-03-16 20:35:01 +00:00