If we try to determine the rate of a pass-through clock (a clock which
does not implement .round_rate() nor .determine_rate()),
clk_core_round_rate_nolock() will directly forward the call to the
parent clock. In the particular case where the pass-through actually
does not have a parent, clk_core_round_rate_nolock() will directly
return 0 with the requested rate still set to the initial request
structure. This is interpreted as if the rate could be exactly achieved
while it actually cannot be adjusted.
This become a real problem when this particular pass-through clock is
the parent of a mux with the flag CLK_SET_RATE_PARENT set. The
pass-through clock will always report an exact match, get picked and
finally error when the rate is actually getting set.
This is fixed by setting the rate inside the req to 0 when core is NULL
in clk_core_round_rate_nolock() (same as in __clk_determine_rate() when
hw is NULL)
Fixes: 0f6cc2b8e9 ("clk: rework calls to round and determine rate callbacks")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The orphan clocks reparents should migrate any existing count from the
orphan clock to its new acestor clocks, otherwise we may have
inconsistent counts in the tree and end-up with gated critical clocks
Assuming we have two clocks, A and B.
* Clock A has CLK_IS_CRITICAL flag set.
* Clock B is an ancestor of A which can gate. Clock B gate is left
enabled by the bootloader.
Step 1: Clock A is registered. Since it is a critical clock, it is
enabled. The clock being still an orphan, no parent are enabled.
Step 2: Clock B is registered and reparented to clock A (potentially
through several other clocks). We are now in situation where the enable
count of clock A is 1 while the enable count of its ancestors is 0, which
is not good.
Step 3: in lateinit, clk_disable_unused() is called, the enable_count of
clock B being 0, clock B is gated and and critical clock A actually gets
disabled.
This situation was found while adding fdiv_clk gates to the meson8b
platform. These clocks parent clk81 critical clock, which is the mother
of all peripheral clocks in this system. Because of the issue described
here, the system is crashing when clk_disable_unused() is called.
The situation is solved by reverting
commit f8f8f1d044 ("clk: Don't touch hardware when reparenting during registration").
To avoid breaking again the situation described in this commit
description, enabling critical clock should be done before walking the
orphan list. This way, a parent critical clock may not be accidentally
disabled due to the CLK_OPS_PARENT_ENABLE mechanism.
Fixes: f8f8f1d044 ("clk: Don't touch hardware when reparenting during registration")
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
It's found that the final phase set by driver doesn't match that of
the output from clk_summary:
dwmmc_rockchip fe310000.dwmmc: Successfully tuned phase to 346
mmc0: new ultra high speed SDR104 SDIO card at address 0001
cat /sys/kernel/debug/clk/clk_summary | grep sdio_sample
sdio_sample 0 1 0 50000000 0 0
It seems the cached core->phase isn't updated after the clk was
registered. So fix this issue by updating the core->phase if setting
phase successfully.
Fixes: 9e4d04adeb ("clk: add clk_core_set_phase_nolock function")
Cc: Stable <stable@vger.kernel.org>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Tested-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
to the clk rate protection support added by Jerome Brunet. This feature
will allow consumers to lock in a certain rate on the output of a clk so
that things like audio playback don't hear pops when the clk frequency
changes due to shared parent clks changing rates. Currently the clk
API doesn't guarantee the rate of a clk stays at the rate you request
after clk_set_rate() is called, so this new API will allow drivers
to express that requirement. Beyond this, the core got some debugfs
pretty printing patches and a couple minor non-critical fixes.
Looking outside of the core framework diff we have some new driver
additions and the removal of a legacy TI clk driver. Both of these hit
high in the dirstat. Also, the removal of the asm-generic/clkdev.h file
causes small one-liners in all the architecture Kbuild files. Overall, the
driver diff seems to be the normal stuff that comes all the time to
fix little problems here and there and to support new hardware.
Core:
- Clk rate protection
- Symbolic clk flags in debugfs output
- Clk registration enabled clks while doing bookkeeping updates
New Drivers:
- Spreadtrum SC9860
- HiSilicon hi3660 stub
- Qualcomm A53 PLL, SPMI clkdiv, and MSM8916 APCS
- Amlogic Meson-AXG
- ASPEED BMC
Removed Drivers:
- TI OMAP 3xxx legacy clk (non-DT) support
- asm*/clkdev.h got removed (not really a driver)
Updates:
- Renesas FDP1-0 module clock on R-Car M3-W
- Renesas LVDS module clock on R-Car V3M
- Misc fixes to pr_err() prints
- Qualcomm MSM8916 audio fixes
- Qualcomm IPQ8074 rounded out support for more peripherals
- Qualcomm Alpha PLL variants
- Divider code was using container_of() on bad pointers
- Allwinner DE2 clks on H3
- Amlogic minor data fixes and dropping of CLK_IGNORE_UNUSED
- Mediatek clk driver compile test support
- AT91 PMC clk suspend/resume restoration support
- PLL issues fixed on si5351
- Broadcom IProc PLL calculation updates
- DVFS support for Armada mvebu CPU clks
- Allwinner fixed post-divider support
- TI clkctrl fixes and support for newer SoCs
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Merge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk updates from Stephen Boyd:
"The core framework has a handful of patches this time around, mostly
due to the clk rate protection support added by Jerome Brunet.
This feature will allow consumers to lock in a certain rate on the
output of a clk so that things like audio playback don't hear pops
when the clk frequency changes due to shared parent clks changing
rates. Currently the clk API doesn't guarantee the rate of a clk stays
at the rate you request after clk_set_rate() is called, so this new
API will allow drivers to express that requirement.
Beyond this, the core got some debugfs pretty printing patches and a
couple minor non-critical fixes.
Looking outside of the core framework diff we have some new driver
additions and the removal of a legacy TI clk driver. Both of these hit
high in the dirstat. Also, the removal of the asm-generic/clkdev.h
file causes small one-liners in all the architecture Kbuild files.
Overall, the driver diff seems to be the normal stuff that comes all
the time to fix little problems here and there and to support new
hardware.
Summary:
Core:
- Clk rate protection
- Symbolic clk flags in debugfs output
- Clk registration enabled clks while doing bookkeeping updates
New Drivers:
- Spreadtrum SC9860
- HiSilicon hi3660 stub
- Qualcomm A53 PLL, SPMI clkdiv, and MSM8916 APCS
- Amlogic Meson-AXG
- ASPEED BMC
Removed Drivers:
- TI OMAP 3xxx legacy clk (non-DT) support
- asm*/clkdev.h got removed (not really a driver)
Updates:
- Renesas FDP1-0 module clock on R-Car M3-W
- Renesas LVDS module clock on R-Car V3M
- Misc fixes to pr_err() prints
- Qualcomm MSM8916 audio fixes
- Qualcomm IPQ8074 rounded out support for more peripherals
- Qualcomm Alpha PLL variants
- Divider code was using container_of() on bad pointers
- Allwinner DE2 clks on H3
- Amlogic minor data fixes and dropping of CLK_IGNORE_UNUSED
- Mediatek clk driver compile test support
- AT91 PMC clk suspend/resume restoration support
- PLL issues fixed on si5351
- Broadcom IProc PLL calculation updates
- DVFS support for Armada mvebu CPU clks
- Allwinner fixed post-divider support
- TI clkctrl fixes and support for newer SoCs"
* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (125 commits)
clk: aspeed: Handle inverse polarity of USB port 1 clock gate
clk: aspeed: Fix return value check in aspeed_cc_init()
clk: aspeed: Add reset controller
clk: aspeed: Register gated clocks
clk: aspeed: Add platform driver and register PLLs
clk: aspeed: Register core clocks
clk: Add clock driver for ASPEED BMC SoCs
clk: mediatek: adjust dependency of reset.c to avoid unexpectedly being built
clk: fix reentrancy of clk_enable() on UP systems
clk: meson-axg: fix potential NULL dereference in axg_clkc_probe()
clk: Simplify debugfs registration
clk: Fix debugfs_create_*() usage
clk: Show symbolic clock flags in debugfs
clk: renesas: r8a7796: Add FDP clock
clk: Move __clk_{get,put}() into private clk.h API
clk: sunxi: Use CLK_IS_CRITICAL flag for critical clks
clk: Improve flags doc for of_clk_detect_critical()
arch: Remove clkdev.h asm-generic from Kbuild
clk: sunxi-ng: a83t: Add M divider to TCON1 clock
clk: Prepare to remove asm-generic/clkdev.h
...
* clk-aspeed:
clk: aspeed: Handle inverse polarity of USB port 1 clock gate
clk: aspeed: Fix return value check in aspeed_cc_init()
clk: aspeed: Add reset controller
clk: aspeed: Register gated clocks
clk: aspeed: Add platform driver and register PLLs
clk: aspeed: Register core clocks
clk: Add clock driver for ASPEED BMC SoCs
dt-bindings: clock: Add ASPEED constants
* clk-lock-UP:
clk: fix reentrancy of clk_enable() on UP systems
* clk-mediatek:
clk: mediatek: adjust dependency of reset.c to avoid unexpectedly being built
clk: mediatek: Fix all warnings for missing struct clk_onecell_data
clk: mediatek: fixup test-building of MediaTek clock drivers
clk: mediatek: group drivers under indpendent menu
* clk-allwinner:
clk: sunxi-ng: a83t: Add M divider to TCON1 clock
clk: sunxi-ng: fix the A64/H5 clock description of DE2 CCU
clk: sunxi-ng: add support for Allwinner H3 DE2 CCU
dt-bindings: fix the binding of Allwinner DE2 CCU of A83T and H3
clk: sunxi-ng: sun8i: a83t: Use sigma-delta modulation for audio PLL
clk: sunxi-ng: sun8i: a83t: Add /2 fixed post divider to audio PLL
clk: sunxi-ng: Support fixed post-dividers on NM style clocks
clk: sunxi-ng: sun50i: a64: Add 2x fixed post-divider to MMC module clocks
clk: sunxi-ng: Support fixed post-dividers on MP style clocks
clk: sunxi: Use PTR_ERR_OR_ZERO()
* clk-remove-asm-clkdev:
clk: Move __clk_{get,put}() into private clk.h API
clk: sunxi: Use CLK_IS_CRITICAL flag for critical clks
arch: Remove clkdev.h asm-generic from Kbuild
clk: Prepare to remove asm-generic/clkdev.h
blackfin: Use generic clkdev.h header
* clk-debugfs-fixes:
clk: Simplify debugfs registration
clk: Fix debugfs_create_*() usage
clk: Show symbolic clock flags in debugfs
clk: Improve flags doc for of_clk_detect_critical()
* clk-renesas:
clk: renesas: r8a7796: Add FDP clock
clk: renesas: cpg-mssr: Keep wakeup sources active during system suspend
clk: renesas: mstp: Keep wakeup sources active during system suspend
clk: renesas: r8a77970: Add LVDS clock
* clk-meson:
clk: meson-axg: fix potential NULL dereference in axg_clkc_probe()
clk: meson-axg: make local symbol axg_gp0_params_table static
clk: meson-axg: fix return value check in axg_clkc_probe()
clk: meson: mpll: use 64-bit maths in params_from_rate
clk: meson-axg: add clock controller drivers
clk: meson-axg: add clocks dt-bindings required header
dt-bindings: clock: add compatible variant for the Meson-AXG
clk: meson: make the spinlock naming more specific
clk: meson: gxbb: remove IGNORE_UNUSED from mmc clocks
clk: meson: gxbb: fix wrong clock for SARADC/SANA
* clk-at91:
clk: at91: pmc: Support backup for programmable clocks
clk: at91: pmc: Save SCSR during suspend
clk: at91: pmc: Wait for clocks when resuming
* clk-imx7ulp:
clk: Don't touch hardware when reparenting during registration
* clk-axigen:
clk: axi-clkgen: Round closest in round_rate() and recalc_rate()
clk: axi-clkgen: Correctly handle nocount bit in recalc_rate()
* clk-si5351:
clk: si5351: _si5351_clkout_reset_pll() can be static
clk: si5351: Do not enable parent clocks on probe
clk: si5351: Rename internal plls to avoid name collisions
clk: si5351: Apply PLL soft reset before enabling the outputs
clk: si5351: Add DT property to enable PLL reset
clk: si5351: implement remove handler
* clk-pxa:
clk: pxa: unbreak lookup of CLK_POUT
* clk-qcom-alpha-pll:
clk: qcom: add read-only alpha pll post divider operations
clk: qcom: support for 2 bit PLL post divider
clk: qcom: support Brammo type Alpha PLL
clk: qcom: support Huayra type Alpha PLL
clk: qcom: support for dynamic updating the PLL
clk: qcom: support for alpha mode configuration
clk: qcom: flag for 64 bit CONFIG_CTL
clk: qcom: fix 16 bit alpha support calculation
clk: qcom: support for alpha pll properties
* clk-check-ops-ptr:
clk: check ops pointer on clock register
* clk-protect-rate:
clk: fix set_rate_range when current rate is out of range
clk: add clk_rate_exclusive api
clk: cosmetic changes to clk_summary debugfs entry
clk: add clock protection mechanism to clk core
clk: use round rate to bail out early in set_rate
clk: rework calls to round and determine rate callbacks
clk: add clk_core_set_phase_nolock function
clk: take the prepare lock out of clk_core_set_parent
clk: fix incorrect usage of ENOSYS
* clk-omap:
clk: ti: Drop legacy clk-3xxx-legacy code
Reentrant calls to clk_enable() are not working on UP systems. This is
caused by the fact spin_trylock_irqsave() always returns true when
CONFIG_SMP=n (and CONFIG_DEBUG_SPINLOCK=n) which causes the reference
counting to not work correctly when clk_enable_lock() is called twice
before clk_enable_unlock() is called (this happens when clk_enable()
is called from within another clk_enable()).
This fixes the problem by skipping the call to spin_trylock_irqsave() on UP
systems and relying solely on reference counting. We also make sure to set
flags in this case so that we are not returning an uninitialized value.
Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
When exposing data access through debugfs, the correct
debugfs_create_*() functions must be used, matching the data
types.
Remove all casts from data pointers passed to debugfs_create_*()
functions, as such casts prevent the compiler from flagging bugs.
clk_core.rate and .accuracy are "unsigned long", hence casting
their addresses to "u32 *" exposed the wrong halves on big-endian
64-bit systems. Fix this by using debugfs_create_ulong() instead.
Octal permissions are preferred, as they are easier to read than
symbolic permissions. Hence replace "S_IRUGO" by "0444"
throughout.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
[sboyd@codeaurora.org: Squash the octal change in too]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Currently the virtual "clk_flags" file in debugfs shows the numeric
value of the top-level framework flags for the specified clock.
Hence the user must manually interpret these values.
Moreover, on big-endian 64-bit systems, the wrong half of the value is
shown, due to the cast from "unsigned long *" to "u32 *".
Fix both issues by showing the symbolic flag names instead.
Any non-standard flags are shown as a hex number.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
The "flags" parameter passed to of_clk_detect_critical() cannot be a
pointer to a real clk_core.flags field, as clk_core is private to the
clock framework internals.
Change the comment to refer to top-level framework flags instead.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Current clk_pm_runtime_put is using pm_runtime_put_sync which
is not safe to be called in clk_core_is_enabled as it should
be able to run in atomic context.
Thus use pm_runtime_put instead which is atomic safe.
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: 9a34b45397 ("clk: Add support for runtime PM")
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
The orphan clocks reparent operation shouldn't touch the hardware
if clocks are enabled, otherwise it may get a chance to disable a
newly registered critical clock which triggers the warning below.
Assuming we have two clocks: A and B, B is the parent of A.
Clock A has flag: CLK_OPS_PARENT_ENABLE
Clock B has flag: CLK_IS_CRITICAL
Step 1:
Clock A is registered, then it becomes orphan.
Step 2:
Clock B is registered. Before clock B reach the critical clock enable
operation, orphan A will find the newly registered parent B and do
reparent operation, then parent B will be finally disabled in
__clk_set_parent_after() due to CLK_OPS_PARENT_ENABLE flag as there's
still no users of B which will then trigger the following warning.
WARNING: CPU: 0 PID: 0 at drivers/clk/clk.c:597 clk_core_disable+0xb4/0xe0
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1-00056-gdff1f66-dirty #1373
Hardware name: Generic DT based system
Backtrace:
[<c010c4bc>] (dump_backtrace) from [<c010c764>] (show_stack+0x18/0x1c)
r6:600000d3 r5:00000000 r4:c0e26358 r3:00000000
[<c010c74c>] (show_stack) from [<c040599c>] (dump_stack+0xb4/0xe8)
[<c04058e8>] (dump_stack) from [<c0125c94>] (__warn+0xd8/0x104)
r10:c0c21cd0 r9:c048aa78 r8:00000255 r7:00000009 r6:c0c1cd90 r5:00000000
r4:00000000 r3:c0e01d34
[<c0125bbc>] (__warn) from [<c0125d74>] (warn_slowpath_null+0x28/0x30)
r9:00000000 r8:ef00bf80 r7:c165ac4c r6:ef00bf80 r5:ef00bf80 r4:ef00bf80
[<c0125d4c>] (warn_slowpath_null) from [<c048aa78>] (clk_core_disable+0xb4/0xe0)
[<c048a9c4>] (clk_core_disable) from [<c048be88>] (clk_core_disable_lock+0x20/0x2c)
r4:000000d3 r3:c0e0af00
[<c048be68>] (clk_core_disable_lock) from [<c048c224>] (clk_core_disable_unprepare+0x14/0x28)
r5:00000000 r4:ef00bf80
[<c048c210>] (clk_core_disable_unprepare) from [<c048c270>] (__clk_set_parent_after+0x38/0x54)
r4:ef00bd80 r3:000010a0
[<c048c238>] (__clk_set_parent_after) from [<c048daa8>] (clk_register+0x4d0/0x648)
r6:ef00d500 r5:ef00bf80 r4:ef00bd80 r3:ef00bfd4
[<c048d5d8>] (clk_register) from [<c048dc30>] (clk_hw_register+0x10/0x1c)
r9:00000000 r8:00000003 r7:00000000 r6:00000824 r5:00000001 r4:ef00d500
[<c048dc20>] (clk_hw_register) from [<c048e698>] (_register_divider+0xcc/0x120)
[<c048e5cc>] (_register_divider) from [<c048e730>] (clk_register_divider+0x44/0x54)
r10:00000004 r9:00000003 r8:00000001 r7:00000000 r6:00000003 r5:00000001
r4:f0810030
[<c048e6ec>] (clk_register_divider) from [<c0d3ff58>] (imx7ulp_clocks_init+0x558/0xe98)
r7:c0e296f8 r6:c165c808 r5:00000000 r4:c165c808
[<c0d3fa00>] (imx7ulp_clocks_init) from [<c0d24db0>] (of_clk_init+0x118/0x1e0)
r10:00000001 r9:c0e01f68 r8:00000000 r7:c0e01f60 r6:ef7f8974 r5:ef0035c0
r4:00000006
[<c0d24c98>] (of_clk_init) from [<c0d04a50>] (time_init+0x2c/0x38)
r10:efffed40 r9:c0d61a48 r8:c0e78000 r7:c0e07900 r6:ffffffff r5:c0e78000
r4:00000000
[<c0d04a24>] (time_init) from [<c0d00b8c>] (start_kernel+0x218/0x394)
[<c0d00974>] (start_kernel) from [<6000807c>] (0x6000807c)
r10:00000000 r9:410fc075 r8:6000406a r7:c0e0c930 r6:c0d61a44 r5:c0e07918
r4:c0e78294
We know that the clk isn't enabled with any sort of prepare_count
here so we don't need to enable anything to prevent a race. And
we're holding the prepare mutex so set_rate/set_parent can't race
here either. Based on an earlier patch by Dong Aisheng.
Fixes: fc8726a2c0 ("clk: core: support clocks which requires parents enable (part 2)")
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Reported-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Calling clk_core_set_rate() with core->req_rate is basically a no-op
because of the early bail-out mechanism.
This may leave the clock in inconsistent state if the rate is out the
requested range. Calling clk_core_set_rate() with the closest rate
limit could solve the problem but:
- The underlying determine_rate() callback needs to account for this
corner case (rounding within the range, if possible)
- if only round_rate() is available, we rely on luck unfortunately.
Fixes: 1c8e600440 ("clk: Add rate constraints to clocks")
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-11-jbrunet@baylibre.com
Using clock rate protection, we can now provide a way for clock consumer
to claim exclusive control over the rate of a producer
So far, rate change operations have been a "last write wins" affair. This
changes allows drivers to explicitly protect against this behavior, if
required.
Of course, if exclusivity over a producer is claimed more than once, the
rate is effectively locked as exclusivity cannot be preempted
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-10-jbrunet@baylibre.com
The patch adds clk_core_protect and clk_core_unprotect to the internal
CCF API. These functions allow to set a new constraint along the clock
tree to prevent any change, even indirect, which may result in rate
change or glitch.
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-7-jbrunet@baylibre.com
The current implementation of clk_core_set_rate_nolock() bails out early
if the requested rate is exactly the same as the one set. It should bail
out if the request would not result in a rate a change. This is important
when the rate is not exactly what is requested, which is fairly common
with PLLs.
Ex: provider able to give any rate with steps of 100Hz
- 1st consumer request 48000Hz and gets it.
- 2nd consumer request 48010Hz as well. If we were to perform the usual
mechanism, we would get 48000Hz as well. The clock would not change so
there is no point performing any checks to make sure the clock can
change, we know it won't.
This is important to prepare the addition of the clock protection
mechanism
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-6-jbrunet@baylibre.com
Rework the way the callbacks round_rate() and determine_rate() are called.
The goal is to do this at a single point and make it easier to add
conditions before calling them.
Because of this factorization, rate returned by determine_rate() is also
checked against the min and max rate values
This rework is done to ease the integration of "protected" clock
functionality.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-5-jbrunet@baylibre.com
Create a core function for set_phase, as it is done for set_rate and
set_parent.
This rework is done to ease the integration of "protected" clock
functionality.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-4-jbrunet@baylibre.com
Rework set_parent core function so it can be called when the prepare lock
is already held by the caller.
This rework is done to ease the integration of the "protected" clock
functionality.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-3-jbrunet@baylibre.com
ENOSYS is special and should only be used for incorrect syscall number.
It does not seem to be the case here.
Reported by checkpatch.pl while working on clock protection.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-2-jbrunet@baylibre.com
Nothing really prevents a provider from (trying to) register a clock
without providing the clock ops structure.
We do check the individual fields before using them, but not the
structure pointer itself. This may have the usual nasty consequences when
the pointer is dereferenced, most likely when checking one the field
during the initialization.
This is fixed by returning an error on clock register if the ops pointer
is NULL.
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171219083329.24746-1-jbrunet@baylibre.com
Sometimes we only have one of_clk_del_provider() call in driver
error and remove paths, because we're missing a
devm_of_clk_add_hw_provider() API. Introduce the API so we can
convert drivers to use this and potentially reduce the amount of
code needed to remove providers in drivers.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
* clk-pm-runtime:
clk: samsung: exynos-audss: Add support for runtime PM
clk: samsung: exynos-audss: Use local variable for controller's device
clk: samsung: exynos5433: Add support for runtime PM
clk: samsung: Add support for runtime PM
clk: Add support for runtime PM
Registers for some clocks might be located in the SOC area, which are under the
power domain. To enable access to those registers respective domain has to be
turned on. Additionally, registers for such clocks will usually loose its
contents when power domain is turned off, so additional saving and restoring of
them might be needed in the clock controller driver.
This patch adds basic infrastructure in the clocks core to allow implementing
driver for such clocks under power domains. Clock provider can supply a
struct device pointer, which is the used by clock core for tracking and managing
clock's controller runtime pm state. Each clk_prepare() operation
will first call pm_runtime_get_sync() on the supplied device, while
clk_unprepare() will do pm_runtime_put_sync() at the end.
Additional calls to pm_runtime_get/put functions are required to ensure that any
register access (like calculating/changing clock rates and unpreparing/disabling
unused clocks on boot) will be done with clock controller in runtime resumend
state.
When one wants to register clock controller, which make use of this feature, he
has to:
1. Provide a struct device to the core when registering the provider.
2. Ensure to enable runtime PM for that device before registering clocks.
3. Make sure that the runtime PM status of the controller device reflects
the HW state.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/1503302703-13801-2-git-send-email-m.szyprowski@samsung.com
Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: "Emilio López" <emilio@elopez.com.ar>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Prashant Gaikwad <pgaikwad@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: linux-clk@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: James Liao <jamesjj.liao@mediatek.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Replace the specification of two data structures by pointer dereferences
as the parameter for the operator "sizeof" to make the corresponding size
determination a bit safer according to the Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Four single characters should be put into a sequence.
Thus use the corresponding function "seq_putc".
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
In case there are multiple notify chains for the same clocks (because they
were registered by different users), we need to propagate potential failure
of any single one of them to the caller. Otherwise we eg risk violating the
V/f curve when a notifier is used for DVFS.
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
For validation purposes, it's often useful to be able to retrieve the list
of possible parents in userspace. Add a debugfs file for every clock which
has more than 1 possible parent.
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Reviewed-by: Jon Mayo <jmayo@nvidia.com>
[sboyd@codeaurora.org: Remove useless cast from void and extra
newline]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Some drivers use sprintf to build clk connection id names but the clk
core will save those strings and occasionally print them back. Duplicate
the con_id strings instead of fixing all the users.
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
This patch reverts commit 023bd7166b ("clk: skip unnecessary
set_phase if nothing to do"), fixing two problems:
* in some SoCs, the hardware phase delay depends on the rate ratio of
the clock and its parent. So, changing this ratio may imply to set
new hardware values, even if the logical delay is the same.
* when the delay was the same as previously, an error was returned.
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Fixes: 023bd7166b ("clk: skip unnecessary set_phase if nothing to do")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
__of_clk_get_hw_from_provider() is confusing because it will
return EPROBE_DEFER if there isn't a ->get() or ->get_hw()
function pointer in a provider. That's just a bug though, and we
used to NULL pointer exception when ->get() was missing anyway,
so let's make this more obvious that they're not optional. The
assumption is that most providers will implement ->get_hw() so we
only fallback to the ->get() function if necessary. This
clarifies the intent and removes any possibility of probe defer
happening if clk providers are buggy.
Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Before commit 0861e5b8cf (clk: Add clk_hw OF clk providers,
2016-02-05) __of_clk_get_from_provider() would return an error
pointer of the provider's choosing if there was a provider
registered and EPROBE_DEFER otherwise. After that commit, it
would return EPROBE_DEFER regardless of whether or not the
provider returned an error. This is odd and can lead to behavior
where clk consumers keep probe deferring when they should be
seeing some other error.
Let's restore the previous behavior where we only return
EPROBE_DEFER when there isn't a provider in our of_clk_providers
list. Otherwise, return the error from the last provider we find
that matches the node.
Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Fixes: 0861e5b8cf ("clk: Add clk_hw OF clk providers")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
This code is clear enough, but the intention will be even clearer
with this.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Some clock providers can be initialized via of_clk_init() and also via
platform device probe.
Avoid double initialization of them by setting the OF_POPULATED flag.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
It's always nice to see families reunited, and this is equally true when
talking about parent clocks and their children. However, if the orphan
clk had a positive prepare_count or enable_count, then we would not
migrate those counts up the parent chain correctly.
This has manifested with the recent critical clocks feature, which often
enables clocks very early, before their parents have been registered.
Fixed by replacing the call to clk_core_reparent with calls to
__clk_set_parent_{before,after}.
Cc: James Liao <jamesjj.liao@mediatek.com>
Cc: Erin Lo <erin.lo@mediatek.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
[sboyd@codeaurora.org: Recalc accuracies and rates too]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
On Freescale i.MX7D platform, all clocks operations, including
enable/disable, rate change and re-parent, requires its parent clock on.
Current clock core can not support it well.
This patch adding flag CLK_OPS_PARENT_ENABLE to handle this special case in
clock core that enable its parent clock firstly for each operation and
disable it later after operation complete.
The patch part 2 fixes set clock rate and set parent while its parent
is off. The most special case is for set_parent() operation which requires
all parents including both old and new one to be enabled at the same time
during the operation.
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
[sboyd@codeaurora.org: Move set_rate tracepoint after prepare_enable]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
On Freescale i.MX7D platform, all clocks operations, including
enable/disable, rate change and re-parent, requires its parent
clock enable. Current clock core can not support it well.
This patch introduce a new flag CLK_OPS_PARENT_ENABLE to handle this
special case in clock core that enable its parent clock firstly for
each operation and disable it later after operation complete.
The patch part 1 fixes the possible disabling clocks while its parent
is off during kernel booting phase in clk_disable_unused_subtree().
Before the completion of kernel booting, clock tree is still not built
completely, there may be a case that the child clock is on but its
parent is off which could be caused by either HW initial reset state
or bootloader initialization.
Taking bootloader as an example, we may enable all clocks in HW by default.
And during kernel booting time, the parent clock could be disabled in its
driver probe due to calling clk_prepare_enable and clk_disable_unprepare.
Because it's child clock is only enabled in HW while its SW usecount
in clock tree is still 0, so clk_disable of parent clock will gate
the parent clock in both HW and SW usecount ultimately. Then there will
be a child clock is still on in HW but its parent is already off.
Later in clk_disable_unused(), this clock disable accessing while its
parent off will cause system hang due to the limitation of HW which
must require its parent on.
This patch simply enables the parent clock first before disabling
if flag CLK_OPS_PARENT_ENABLE is set in clk_disable_unused_subtree().
This is a simple solution and only affects booting time.
After kernel booting up the clock tree is already created, there will
be no case that child is off but its parent is off.
So no need do this checking for normal clk_disable() later.
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
No function level change, just moving code place.
clk_disable_unused function will need to call clk_core_prepare_enable/
clk_core_disable_unprepare when adding CLK_OPS_PARENT_ENABLE features.
So move it after clk_core_disable_unprepare to avoid adding forward
declared functions later.
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
This can be useful when clock core wants to enable/disable clocks.
Then we don't have to convert the struct clk_core to struct clk to call
clk_enable/clk_disable which is a bit un-align with exist using.
And after introduce clk_core_{enable|disable}_lock, we can refine
clk_enable and clk_disable a bit.
As well as clk_core_{enable|disable}_lock, we also added
clk_core_{prepare|unprepare}_lock and clk_core_prepare_enable/
clk_core_unprepare_disable for clock core to easily use.
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Correct comments for __clk_determine_rate.
Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Stephen Boyd