When I got my clock parenting slightly wrong I ended up with a crash
that looked like this:
Unable to handle kernel NULL pointer dereference at virtual
address 0000000000000000
...
pc : clk_hw_get_rate+0x14/0x44
...
Call trace:
clk_hw_get_rate+0x14/0x44
_freq_tbl_determine_rate+0x94/0xfc
clk_rcg2_determine_rate+0x2c/0x38
clk_core_determine_round_nolock+0x4c/0x88
clk_core_round_rate_nolock+0x6c/0xa8
clk_core_round_rate_nolock+0x9c/0xa8
clk_core_set_rate_nolock+0x70/0x180
clk_set_rate+0x3c/0x6c
of_clk_set_defaults+0x254/0x360
platform_drv_probe+0x28/0xb0
really_probe+0x120/0x2dc
driver_probe_device+0x64/0xfc
device_driver_attach+0x4c/0x6c
__driver_attach+0xac/0xc0
bus_for_each_dev+0x84/0xcc
driver_attach+0x2c/0x38
bus_add_driver+0xfc/0x1d0
driver_register+0x64/0xf8
__platform_driver_register+0x4c/0x58
msm_drm_register+0x5c/0x60
...
It turned out that clk_hw_get_parent_by_index() was returning NULL and
we weren't checking. Let's check it so that we don't crash.
Fixes: ac269395cd ("clk: qcom: Convert to clk_hw based provider APIs")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lkml.kernel.org/r/20200203103049.v4.1.I7487325fe8e701a68a07d3be8a6a4b571eca9cfa@changeid
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The DFS frequency table logic overwrites 'cfg' while detecting the
parent clk and then later on in clk_rcg2_dfs_populate_freq() we use that
same variable to figure out the mode of the clk, either MND or not. Add
a new variable to hold the parent clk bit so that 'cfg' is left
untouched for use later.
This fixes problems in detecting the supported frequencies for any clks
in DFS mode.
Fixes: cc4f6944d0 ("clk: qcom: Add support for RCG to register for DFS")
Reported-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lkml.kernel.org/r/20200128193329.45635-1-sboyd@kernel.org
Tested-by: Rajendra Nayak <rnayak@codeaurora.org>
Some RCGs (the gfx_3d_src_clk in msm8998 for example) are basically just
some constant ratio from the input across the entire frequency range. It
would be great if we could specify the frequency table as a single entry
constant ratio instead of a long list, ie:
{ .src = P_GPUPLL0_OUT_EVEN, .pre_div = 3 },
{ }
So, lets support that.
We need to fix a corner case in qcom_find_freq() where if the freq table
is non-null, but has no frequencies, we end up returning an "entry" before
the table array, which is bad. Then, we need ignore the freq from the
table, and instead base everything on the requested freq.
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Link: https://lkml.kernel.org/r/20191031185715.15504-1-jeffrey.l.hugo@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
These aren't useful and they reference the init structure name. Let's
just drop them.
Cc: Taniya Das <tdas@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lkml.kernel.org/r/20190815160020.183334-5-sboyd@kernel.org
Acked-by: Taniya Das <tdas@codeaurora.org>
The RCG CFG/M/N/D register base could be at a different offset than
the CMD register, so introduce a cfg_offset to identify the offset
with respect to the CMD RCGR register.
Signed-off-by: Taniya Das <tdas@codeaurora.org>
Signed-off-by: Anu Ramanathan <anur@codeaurora.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The table allocated in clk_rcg2_dfs_populate_freq_table() is
eventually iterated over by qcom_find_freq() which assumes that the
table is NULL terminated. Allocate one extra space in the array for
the NULL termination. Initting of the NULL termination is implicit
due to kcalloc().
Fixes: cc4f6944d0 ("clk: qcom: Add support for RCG to register for DFS")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Dynamic Frequency switch is a feature of clock controller by which request
from peripherals allows automatic switching frequency of input clock
without SW intervention. There are various performance levels associated
with a root clock. When the input performance state changes, the source
clocks and division ratios of the new performance state are loaded on to
RCG via HW and the RCG switches to new clock frequency when the RCG is in
DFS HW enabled mode.
Register the root clock generators(RCG) to switch to use the dfs clock ops
in the cases where DFS is enabled. The clk_round_rate() called by the clock
consumer would invoke the dfs determine clock ops and would read the DFS
performance level registers to identify all the frequencies supported and
update the frequency table. The DFS clock consumers would maintain these
frequency mapping and request the desired performance levels.
Signed-off-by: Taniya Das <tdas@codeaurora.org>
[sboyd@kernel.org: Rework registration logic to stop copying, change
recalc_rate() to index directly into the table if possible and fallback
to calculating on the fly with an assumed correct parent]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
* clk-qcom-sdm845:
clk: qcom: Export clk_fabia_pll_configure()
clk: qcom: Add video clock controller driver for SDM845
dt-bindings: clock: Introduce QCOM Video clock bindings
clk: qcom: Add Global Clock controller (GCC) driver for SDM845
clk: qcom: Add DT bindings for SDM845 gcc clock controller
clk: qcom: Configure the RCGs to a safe source as needed
clk: qcom: Add support for BRANCH_HALT_SKIP flag for branch clocks
clk: qcom: Simplify gdsc status checking logic
clk: qcom: gdsc: Add support to poll CFG register to check GDSC state
clk: qcom: gdsc: Add support to poll for higher timeout value
clk: qcom: gdsc: Add support to reset AON and block reset logic
clk: qcom: Add support for controlling Fabia PLL
clk: qcom: Clear hardware clock control bit of RCG
Also fixup the Kconfig mess where SDM845 GCC has msm8998 in the
description and also the video Kconfig says things slightly differently
from the GCC one so just make it the same.
_freq_tbl_determine_rate uses the pre_div found in the clock plan
multiplied by the requested rate from the caller to determine the
best parent rate to set. If the requested rate is not exactly equal
to the rate that was found in the clock plan, then using the requested
rate in parent rate calculations is incorrect. For instance, if 150MHz
was requested, but 200MHz was the match found, and that plan had a
pre_div of 3, then the parent should be set to 600MHz, not 450MHz.
Signed-off-by: Evan Green <evgreen@chromium.org>
Fixes: bcd61c0f53 ("clk: qcom: Add support for root clock generators (RCGs)")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
For some root clock generators, there could be child branches which are
controlled by an entity other than application processor subsystem. For
such RCGs, as per application processor subsystem clock driver, all of
its downstream clocks are disabled and RCG is in disabled state but in
reality downstream clocks can be left enabled before.
So in this scenario, when RCG is disabled as per clock driver's point of
view and when rate scaling request comes before downstream clock enable
request, then RCG fails to update its configuration because in reality
RCG is on and it expects its new source to already be in enable state but
in reality new source is off. In order to avoid having the RCG to go into
an invalid state, add support to update the CFG, M, N and D registers
during set_rate() without configuration update and defer the actual RCG
configuration update to be done during clk_enable() as at this point of
time, both its new parent and safe source will be already enabled and RCG
can safely switch to new parent.
During clk_disable() request, configure it to safe source as both its
parents, safe source and current parent will be enabled and RCG can
safely execute a switch.
Signed-off-by: Taniya Das <tdas@codeaurora.org>
Signed-off-by: Amit Nischal <anischal@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
For upcoming targets like sdm845, POR value of the hardware clock control
bit is set for most of root clocks which needs to be cleared for software
to be able to control. For older targets like MSM8996, this bit is reserved
bit and having POR value as 0 so this patch will work for the older targets
too. So update the configuration mask to take care of the same to clear
hardware clock control bit.
Signed-off-by: Amit Nischal <anischal@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The RCGs ops for shared branches are not used now, so remove it.
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
The default behaviour with clk_rcg2_ops is for the
clk_round_rate()/clk_set_rate() to return/set a ceil clock
rate closest to the requested rate by looking up the corresponding
frequency table.
However, we do have some instances (mainly sdcc on various platforms)
of clients expecting a clk_set_rate() to set a floor value instead.
Add a new clk_rcg2_floor_ops to handle this for such specific
rcg instances
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
The GPU clocks on msm8996 have three dedicated PLLs, MMPLL2,
MMPLL8, and MMPLL9. We leave MMPLL9 at the maximum speed (624
MHz), and we use MMPLL2 and MMPLL8 for the other frequencies. To
make switching frequencies faster, we ping-pong between MMPLL2
and MMPLL8 when we're switching between frequencies that aren't
the maximum. Implement custom rcg clk ops for this type of
frequency switching.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Some root clock generators may have child branches that are controlled
by different CPUs. These RCGs require some special operations:
- some enable bits have to be toggled when we set the rate;
- if RCG is disabled we only cache the rate and set it later when enabled;
- when the RCG is disabled, the mux is set to the safe source;
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
[sboyd@codeaurora.org: Simplify recalc_rate implementation]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Sometimes the display driver may want to change the parent PLL of
the display clocks (byte and pixel clocks) depending on the
use-case. Currently the parent is fixed by means of having a
frequency table with one entry that chooses a particular parent.
Remove this restriction and use the parent the clock is
configured for in the hardware during clk_set_rate(). This
requires consumers to rely on the default parent or to configure
the parent with clk_set_parent()/assigned-clock-parents on the
clocks before calling clk_set_rate().
Tested-by: Archit Taneja <architt@codeaurora.org>
Cc: Hai Li <hali@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
We're removing struct clk from the clk provider API, so switch
this code to using the clk_hw based provider APIs.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Mostly converted with the following snippet:
@@
struct clk_hw *E;
@@
-__clk_get_flags(E->clk)
+clk_hw_get_flags(E)
Acked-by: Tero Kristo <t-kristo@ti.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Coquelin <mcoquelin.stm32@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
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>
Since the parent rate has been recalculated, pixel RCG clock
should rely on it to find the correct M/N values during set_rate,
instead of calling __clk_round_rate() to its parent again.
Signed-off-by: Hai Li <hali@codeaurora.org>
Tested-by: Archit Taneja <architt@codeaurora.org>
Fixes: 99cbd064b0 ("clk: qcom: Support display RCG clocks")
[sboyd@codeaurora.org: Silenced unused parent variable warning]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
When we introduced the parent_map tables, we missed to update
some of the functions where mapping is translated. Fix this.
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Tested-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
In the current parent mapping code, we can get duplicate or inconsistent
indexes, which leads to discrepancy between the number of elements in the
array and the number of parents. Until now, this was solved with some
reordering but this is not always possible.
This patch introduces index tables that are used to define the relations
between the PLL source and the hardware mux configuration value.
To accomplish this, here we do the following:
- Define a parent_map struct to map the relations between PLL source index
and register configuration value.
- Add a qcom_find_src_index() function for finding the index of a clock
matching the specific PLL configuration.
- Update the {set,get}_parent RCG functions use the newly introduced
parent_map struct.
- Convert all existing drivers to the new parent_map tables.
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
According to the common clock framework API, the clk_get_parent() function
should return u8. Currently we are returning negative values on error. Fix
this and use the default parent in case of an error.
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Currently, a RCG's M/N counter (used for fraction division) is
set to either 'bypass' (counter disabled) or 'dual edge' (counter
enabled) based on whether the corresponding rcg struct has a mnd
field specified and a non-zero N.
In the case where M and N are the same value, the M/N counter is
still enabled by code even though no division takes place.
Leaving the RCG in such a state can result in improper behavior.
This was observed with the DSI pixel clock RCG when M and N were
both set to 1.
Add an additional check (M != N) to enable the M/N counter only
when it's needed for fraction division.
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Fixes: bcd61c0f53 (clk: qcom: Add support for root clock
generators (RCGs))
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
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]
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>
There are two find_freq() functions in clk-rcg.c and clk-rcg2.c
that are almost exactly the same. Consolidate them into one
function to save on some code space.
Cc: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Add support for the DSI/EDP/HDMI RCG clocks. With the proper
display driver in place this should allow us to support display
clocks on msm8974 based devices.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Some drivers may want to call clk_set_rate() with a very large
number to force the clock to go as fast as it possibly can
without having to know the range between the highest rate and
second highest rate. Add support for this by defaulting to the
highest rate in the frequency table if we can't find a frequency
greater than what is requested.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
If the bit is set the clock is off so we should be checking for
a clear bit, not a set bit. Invert the logic.
Fixes: bcd61c0f53 (clk: qcom: Add support for root clock generators (RCGs))
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Add support for the root clock generators on Qualcomm devices.
RCGs are highly customizable mux/divider/counter clocks that can
be used to generate almost any rate desired given some input
source that is faster than the desired rate.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Douglas Anderson