Commit Graph

484 Commits

Author SHA1 Message Date
Viresh Kumar
b0ec094286 OPP: Migrate set-regulators API to use set-config helpers
Now that we have a central API to handle all OPP table configurations,
migrate the set-regulators family of helpers to use the new
infrastructure.

The return type and parameter to the APIs change a bit due to this,
update the current users as well in the same commit in order to avoid
breaking builds.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:33 +05:30
Viresh Kumar
87686cc845 OPP: Make dev_pm_opp_set_regulators() accept NULL terminated list
Make dev_pm_opp_set_regulators() accept a NULL terminated list of names
instead of making the callers keep the two parameters in sync, which
creates an opportunity for bugs to get in.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Steven Price <steven.price@arm.com> # panfrost
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:26:44 +05:30
Christian Marangi
c8934e4e34 PM / devfreq: exynos-bus: Fix NULL pointer dereference
Fix exynos-bus NULL pointer dereference by correctly using the local
generated freq_table to output the debug values instead of using the
profile freq_table that is not used in the driver.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: b5d281f6c1 ("PM / devfreq: Rework freq_table to be local to devfreq struct")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-07-08 04:32:26 +09:00
Lukas Bulwahn
f08fe6fcbe PM / devfreq: passive: revert an editing accident in SPDX-License line
Commit 26984d9d58 ("PM / devfreq: passive: Keep cpufreq_policy for
possible cpus") reworked governor_passive.c, and accidently added a
tab in the first line, i.e., the SPDX-License-Identifier line.

The checkpatch script warns with the SPDX_LICENSE_TAG warning, and hence
pointed this issue out while investigating checkpatch warnings.

Revert this editing accident. No functional change.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-06-30 05:11:17 +09:00
Christian Marangi
82c66d2bbb PM / devfreq: Fix kernel warning with cpufreq passive register fail
Remove cpufreq_passive_unregister_notifier from
cpufreq_passive_register_notifier in case of error as devfreq core
already call unregister on GOV_START fail.

This fix the kernel always printing a WARN on governor PROBE_DEFER as
cpufreq_passive_unregister_notifier is called two times and return
error on the second call as the cpufreq is already unregistered.

Fixes: a03dacb031 ("PM / devfreq: Add cpu based scaling support to passive governor")
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-06-30 05:11:17 +09:00
Christian Marangi
b5d281f6c1 PM / devfreq: Rework freq_table to be local to devfreq struct
On a devfreq PROBE_DEFER, the freq_table in the driver profile struct,
is never reset and may be leaved in an undefined state.

This comes from the fact that we store the freq_table in the driver
profile struct that is commonly defined as static and not reset on
PROBE_DEFER.
We currently skip the reinit of the freq_table if we found
it's already defined since a driver may declare his own freq_table.

This logic is flawed in the case devfreq core generate a freq_table, set
it in the profile struct and then PROBE_DEFER, freeing the freq_table.
In this case devfreq will found a NOT NULL freq_table that has been
freed, skip the freq_table generation and probe the driver based on the
wrong table.

To fix this and correctly handle PROBE_DEFER, use a local freq_table and
max_state in the devfreq struct and never modify the freq_table present
in the profile struct if it does provide it.

Fixes: 0ec09ac2ce ("PM / devfreq: Set the freq_table of devfreq device")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-06-30 05:11:17 +09:00
Miaoqian Lin
f44b799603 PM / devfreq: exynos-ppmu: Fix refcount leak in of_get_devfreq_events
of_get_child_by_name() returns a node pointer with refcount
incremented, we should use of_node_put() on it when done.
This function only calls of_node_put() in normal path,
missing it in error paths.
Add missing of_node_put() to avoid refcount leak.

Fixes: f262f28c14 ("PM / devfreq: event: Add devfreq_event class")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-06-30 05:11:17 +09:00
Yicong Yang
20e6c3cc90 PM / devfreq: passive: Use HZ_PER_KHZ macro in units.h
HZ macros has been centralized in units.h since [1]. Use it to avoid
duplicated definition.

[1] commit e2c77032fc ("units: add the HZ macros")

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-06-30 05:11:17 +09:00
Christian 'Ansuel' Marangi
0cca7e8dcf PM / devfreq: Fix cpufreq passive unregister erroring on PROBE_DEFER
With the passive governor, the cpu based scaling can PROBE_DEFER due to
the fact that CPU policy are not ready.
The cpufreq passive unregister notifier is called both from the
GOV_START errors and for the GOV_STOP and assume the notifier is
successfully registred every time. With GOV_START failing it's wrong to
loop over each possible CPU since the register path has failed for
some CPU policy not ready. Change the logic and unregister the notifer
based on the current allocated parent_cpu_data list to correctly handle
errors and the governor unregister path.

Fixes: a03dacb031 ("PM / devfreq: Add cpu based scaling support to passive governor")
Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-06-30 05:11:17 +09:00
Christian 'Ansuel' Marangi
e52b045fe0 PM / devfreq: Mute warning on governor PROBE_DEFER
Don't print warning when a governor PROBE_DEFER as it's not a real
GOV_START fail.

Fixes: a03dacb031 ("PM / devfreq: Add cpu based scaling support to passive governor")
Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-06-30 05:11:17 +09:00
Christian 'Ansuel' Marangi
57e00b4003 PM / devfreq: Fix kernel panic with cpu based scaling to passive gov
The cpufreq passive register notifier can PROBE_DEFER and the devfreq
struct is freed and then reallocaed on probe retry.
The current logic assume that the code can't PROBE_DEFER so the devfreq
struct in the this variable in devfreq_passive_data is assumed to be
(if already set) always correct.
This cause kernel panic as the code try to access the wrong address.
To correctly handle this, update the this variable in
devfreq_passive_data to the devfreq reallocated struct.

Fixes: a03dacb031 ("PM / devfreq: Add cpu based scaling support to passive governor")
Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-06-30 05:11:17 +09:00
Chanwoo Choi
42d2607d91 PM / devfreq: passive: Return non-error when not-supported event is required
Each devfreq governor specifies the supported governor event
such as GOV_START and GOV_STOP. When not-supported event is required,
just return non-error. But, commit ce9a0d88d97a ("PM / devfreq: Add
cpu based scaling support to passive governor") returned the error
value. So that return non-error value when not-supported event is required.

Fixes: ce9a0d88d97a ("PM / devfreq: Add cpu based scaling support to passive governor")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-05-19 19:32:19 +02:00
Chanwoo Choi
26984d9d58 PM / devfreq: passive: Keep cpufreq_policy for possible cpus
The passive governor requires the cpu data to get the next target frequency
of devfreq device if depending on cpu. In order to reduce the unnecessary
memory data, keep cpufreq_policy data for possible cpus instead of NR_CPU.

Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Johnson Wang <johnson.wang@mediatek.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-05-17 18:24:39 +09:00
Chanwoo Choi
05723e7123 PM / devfreq: passive: Reduce duplicate code when passive_devfreq case
In order to keep the consistent coding style between passive_devfreq
and passive_cpufreq, use common code for handling required opp property.
Also remove the unneed conditional statement and unify the comment
of both passive_devfreq and passive_cpufreq when getting the target frequency.

Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Johnson Wang <johnson.wang@mediatek.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-05-17 18:24:39 +09:00
Saravana Kannan
a03dacb031 PM / devfreq: Add cpu based scaling support to passive governor
Many CPU architectures have caches that can scale independent of the
CPUs. Frequency scaling of the caches is necessary to make sure that the
cache is not a performance bottleneck that leads to poor performance and
power. The same idea applies for RAM/DDR.

To achieve this, this patch adds support for cpu based scaling to the
passive governor. This is accomplished by taking the current frequency
of each CPU frequency domain and then adjust the frequency of the cache
(or any devfreq device) based on the frequency of the CPUs. It listens
to CPU frequency transition notifiers to keep itself up to date on the
current CPU frequency.

To decide the frequency of the device, the governor does one of the
following:
* Derives the optimal devfreq device opp from required-opps property of
  the parent cpu opp_table.

* Scales the device frequency in proportion to the CPU frequency. So, if
  the CPUs are running at their max frequency, the device runs at its
  max frequency. If the CPUs are running at their min frequency, the
  device runs at its min frequency. It is interpolated for frequencies
  in between.

Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Johnson Wang <johnson.wang@mediatek.com>
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
[Sibi: Integrated cpu-freqmap governor into passive_governor]
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
[Chanwoo: Fix conflict with latest code and cleanup code]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-05-17 18:24:39 +09:00
Chanwoo Choi
713472e53e PM / devfreq: Export devfreq_get_freq_range symbol within devfreq
In order to get frequency range within devfreq governors,
export devfreq_get_freq_range symbol within devfreq.

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Johnson Wang <johnson.wang@mediatek.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-05-17 18:24:39 +09:00
Brian Norris
2e691421a2 PM / devfreq: rk3399_dmc: Block PMU during transitions
See the previous patch ("soc: rockchip: power-domain: Manage resource
conflicts with firmware") for a thorough explanation of the conflicts.
While ARM Trusted Firmware may be modifying memory controller and
power-domain states, we need to block the kernel's power-domain driver.

If the power-domain driver is disabled, there is no resource conflict
and this becomes a no-op.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-05-09 03:38:07 +09:00
Brian Norris
5d521a3075 PM / devfreq: rk3399_dmc: Avoid static (reused) profile
This static struct can get reused if the device gets removed/reprobed,
and that causes use-after-free in its ->freq_table.

Let's just move the struct to our dynamic allocation.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-04-14 07:18:12 +09:00
Brian Norris
cb178a9585 PM / devfreq: rk3399_dmc: Use devm_pm_opp_of_add_table()
This simplifies error-cleanup and remove().

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-04-14 07:18:12 +09:00
Brian Norris
2fccf9e605 PM / devfreq: rk3399_dmc: Disable edev on remove()
Otherwise we hit an unablanced enable-count when unbinding the DFI
device:

[ 1279.659119] ------------[ cut here ]------------
[ 1279.659179] WARNING: CPU: 2 PID: 5638 at drivers/devfreq/devfreq-event.c:360 devfreq_event_remove_edev+0x84/0x8c
...
[ 1279.659352] Hardware name: Google Kevin (DT)
[ 1279.659363] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO BTYPE=--)
[ 1279.659371] pc : devfreq_event_remove_edev+0x84/0x8c
[ 1279.659380] lr : devm_devfreq_event_release+0x1c/0x28
...
[ 1279.659571] Call trace:
[ 1279.659582]  devfreq_event_remove_edev+0x84/0x8c
[ 1279.659590]  devm_devfreq_event_release+0x1c/0x28
[ 1279.659602]  release_nodes+0x1cc/0x244
[ 1279.659611]  devres_release_all+0x44/0x60
[ 1279.659621]  device_release_driver_internal+0x11c/0x1ac
[ 1279.659629]  device_driver_detach+0x20/0x2c
[ 1279.659641]  unbind_store+0x7c/0xb0
[ 1279.659650]  drv_attr_store+0x2c/0x40
[ 1279.659663]  sysfs_kf_write+0x44/0x58
[ 1279.659672]  kernfs_fop_write_iter+0xf4/0x190
[ 1279.659684]  vfs_write+0x2b0/0x2e4
[ 1279.659693]  ksys_write+0x80/0xec
[ 1279.659701]  __arm64_sys_write+0x24/0x30
[ 1279.659714]  el0_svc_common+0xf0/0x1d8
[ 1279.659724]  do_el0_svc_compat+0x28/0x3c
[ 1279.659738]  el0_svc_compat+0x10/0x1c
[ 1279.659746]  el0_sync_compat_handler+0xa8/0xcc
[ 1279.659758]  el0_sync_compat+0x188/0x1c0
[ 1279.659768] ---[ end trace cec200e5094155b4 ]---

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-04-14 07:18:12 +09:00
Brian Norris
fd5b8479ef PM / devfreq: rk3399_dmc: Support new *-ns properties
We want to keep the idle time fixed, so compute based on the current DDR
frequency.

The old properties were deprecated and never used, so we can safely drop
them from the driver.

This is a rewritten version of work by Lin Huang <hl@rock-chips.com>.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-04-14 07:18:12 +09:00
Brian Norris
e442172191 PM / devfreq: rk3399_dmc: Support new disable-freq properties
Implement the newly-defined properties to allow disabling certain
power-saving-at-idle features at higher frequencies.

This is a rewritten version of work by Lin Huang <hl@rock-chips.com>.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-04-14 07:18:12 +09:00
Brian Norris
a5ca18540d PM / devfreq: rk3399_dmc: Use bitfield macro definitions for ODT_PD
We're going to add new usages, and it's cleaner to work with macros
instead of comments and magic numbers.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-04-14 07:18:12 +09:00
Brian Norris
b82acf8215 PM / devfreq: rk3399_dmc: Drop excess timing properties
All of these properties are initialized by ARM Trusted Firmware, and
have been since the early days of this chip. It's redundant (and
possibly wrong) to do this here now. What's more, there seems to be some
confusion about the units and some of the definitions of this timing
struct: the DT docs say MHz for many of these, but downstream users were
in Hz (and therefore, the ATF interface was Hz). Also, the in-driver
usage for some of these (e.g., for comparing to target frequency) were
in Hz too. So doubly wrong.

We can avoid thinking about who got the right units by dropping the
unnecessary code and properties. They are marked deprecated in the
binding schema.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-04-14 07:18:11 +09:00
Brian Norris
5f50c52f13 PM / devfreq: rk3399_dmc: Drop undocumented ondemand DT props
These properties are:

* undocumented
* directly representing software properties, not hardware properties
* unused (no in-tree users, yet; this IP block has so far only been used
  in downstream kernels)

Let's just stick the values that downstream users have been using
directly in the driver and call it a day.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-04-14 07:18:11 +09:00
Tzung-Bi Shih
4667431419 PM / devfreq: Reduce log severity for informative message
Suppose devfreq_update_status() failure in devfreq_set_target() is not a
critical error, reduces the log severity.

Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-12-16 11:29:54 +09:00
Arnd Bergmann
a4b3c62fd0 PM / devfreq: sun8i: addd COMMON_CLK dependency
Compile-testing the driver without CONFIG_COMMON_CLK causes
a link failure:

arm-linux-gnueabi-ld: drivers/devfreq/sun8i-a33-mbus.o: in function `sun8i_a33_mbus_remove':
sun8i-a33-mbus.c:(.text+0x450): undefined reference to `clk_rate_exclusive_put'
arm-linux-gnueabi-ld: sun8i-a33-mbus.c:(.text+0x460): undefined reference to `clk_rate_exclusive_put'
arm-linux-gnueabi-ld: drivers/devfreq/sun8i-a33-mbus.o: in function `sun8i_a33_mbus_probe':
sun8i-a33-mbus.c:(.text+0x85c): undefined reference to `clk_rate_exclusive_get'
arm-linux-gnueabi-ld: sun8i-a33-mbus.c:(.text+0x878): undefined reference to `clk_rate_exclusive_get'

Fixes: 8bfd4858b4 ("PM / devfreq: Add a driver for the sun8i/sun50i MBUS")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-12-16 11:19:34 +09:00
Samuel Holland
8bfd4858b4 PM / devfreq: Add a driver for the sun8i/sun50i MBUS
This driver works by adjusting the divider on the DRAM controller's
module clock. Thus there is no fixed set of OPPs, only "full speed" down
to "quarter speed" (or whatever the maximum divider is on that variant).

It makes use of the MDFS hardware in the MBUS, in "DFS" mode, which
takes care of updating registers during the critical section while DRAM
is inaccessible.

This driver should support several sunxi SoCs, starting with the A33,
which have a DesignWare DDR3 controller with merged PHY register space
and the matching MBUS register layout (so not A63 or later). However,
the driver has only been tested on the A64/H5, so those are the only
compatibles enabled for now.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-12-10 15:56:07 +09:00
Rafael J. Wysocki
dcc0b6f2e6 Merge branches 'pm-opp' and 'pm-cpufreq'
Merge operating performance points (OPP) framework updates for and
intel_pstate driver fixes for 5.16-rc1.

* pm-opp:
  dt-bindings: opp: Allow multi-worded OPP entry name
  opp: Fix return in _opp_add_static_v2()
  PM / devfreq: tegra30: Check whether clk_round_rate() returns zero rate
  PM / devfreq: tegra30: Use resource-managed helpers
  PM / devfreq: Add devm_devfreq_add_governor()
  opp: Add more resource-managed variants of dev_pm_opp_of_add_table()
  opp: Change type of dev_pm_opp_attach_genpd(names) argument
  opp: Fix required-opps phandle array count check

* pm-cpufreq:
  cpufreq: intel_pstate: Clear HWP Status during HWP Interrupt enable
  cpufreq: intel_pstate: Fix unchecked MSR 0x773 access
  cpufreq: intel_pstate: Clear HWP desired on suspend/shutdown and offline
2021-11-10 14:06:51 +01:00
Samuel Holland
5cf79c2938 PM / devfreq: Strengthen check for freq_table
Since commit ea572f8160 ("PM / devfreq: Change return type of
devfreq_set_freq_table()"), all devfreq devices are expected to have a
valid freq_table. The devfreq core unconditionally dereferences
freq_table in the sysfs code and in get_freq_range().

Therefore, we need to ensure that freq_table is both non-null and
non-empty (length is > 0). If either check fails, replace the table
using set_freq_table() or return the error.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-10-27 14:22:12 +09:00
Krzysztof Kozlowski
14714135a8 devfreq: exynos-ppmu: simplify parsing event-type from DT
When parsing devicetree, the function of_get_devfreq_events(), for each
device child node, iterates over array of possible events "ppmu_events"
till it finds one matching by node name.  When match is found the
ppmu_events[i] points to element having both the name of the event and
the counters ID.

Each PPMU device child node might have an "event-name" property with the
name of the event, however due to the design of devfreq it must be the
same as the device node name.  If it is not the same, the devfreq client
won't be able to use it via devfreq_event_get_edev_by_phandle().

Since PPMU device child node name must be equal to the "event-name"
property (event-name == ppmu_events[i].name), there is no need to find
the counters ID by the "event-name".  Instead use ppmu_events[i].id
which must be equal to it.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-10-27 14:22:12 +09:00
Krzysztof Kozlowski
28d7f0f3f1 devfreq: exynos-ppmu: use node names with hyphens
Devicetree naming convention requires device node names to use hyphens
instead of underscore, so Exynos5422 devfreq event name
"ppmu-event3-dmc0_0" should be "ppmu-event3-dmc0-0".  Newly introduced
dtschema enforces this, however the driver still expects old name with
an underscore.

Add new events for Exynos5422 while still accepting old name for
backwards compatibility.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-10-27 14:22:11 +09:00
Dmitry Osipenko
4844bdbe91 PM / devfreq: tegra30: Check whether clk_round_rate() returns zero rate
EMC clock is always-on and can't be zero. Check whether clk_round_rate()
returns zero rate and error out if it does. It can return zero if clock
tree isn't initialized properly.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-10-05 09:54:39 +05:30
Dmitry Osipenko
68b79f2855 PM / devfreq: tegra30: Use resource-managed helpers
Use resource-managed API helpers to simplify driver's probe() function,
making code cleaner.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-10-05 09:54:38 +05:30
Dmitry Osipenko
1cc55204b0 PM / devfreq: Add devm_devfreq_add_governor()
Add resource-managed variant of devfreq_add_governor().

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-10-05 09:54:38 +05:30
Daniel Lezcano
04c8984ae3 devfreq: use HZ macros
HZ unit conversion macros are available in units.h, use them and remove
the duplicate definition.

The new macro has an unsigned long type.

All the code is dealing with unsigned long and the code using the macro is
doing a coercitive cast to unsigned long.

Link: https://lkml.kernel.org/r/20210816114732.1834145-5-daniel.lezcano@linaro.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Christian Eggers <ceggers@arri.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Lukasz Luba <lukasz.luba@arm.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-08 11:50:26 -07:00
Chanwoo Choi
8c37d01e1a PM / devfreq: passive: Fix get_target_freq when not using required-opp
The 86ad9a24f2 ("PM / devfreq: Add required OPPs support to passive governor")
supported the required-opp property for using devfreq passive governor.
But, 86ad9a24f2 has caused the problem on use-case when required-opp
is not used such as exynos-bus.c devfreq driver. So that fix the
get_target_freq of passive governor for supporting the case of when
required-opp is not used.

Fixes: 86ad9a24f2 ("PM / devfreq: Add required OPPs support to passive governor")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-06-24 10:37:35 +09:00
YueHaibing
1ad4f329fc PM / devfreq: userspace: Use DEVICE_ATTR_RW macro
Use DEVICE_ATTR_RW helper instead of plain DEVICE_ATTR,
which makes the code a bit shorter and easier to read.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-06-17 17:08:46 +09:00
Dong Aisheng
a15fc9aa5b PM / devfreq: imx8m-ddrc: Remove DEVFREQ_GOV_SIMPLE_ONDEMAND dependency
The driver can't support simple ondemand governor due to missing
.get_dev_status() capability.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-05-21 13:16:21 +09:00
Dmitry Osipenko
5e480ab94d PM / devfreq: tegra30: Support thermal cooling
Expose ACTMON devfreq device as a cooling device in order to throttle
memory freq on overheat. Throttling of memory freq has a significant
cooling effect on NVIDIA Tegra SoCs since higher memory freqs require
higher SoC core voltage which is one of the main causes of the heating.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-05-21 13:16:10 +09:00
Dong Aisheng
7dbc0d2468 PM / devfreq: imx-bus: Remove imx_bus_get_dev_status
Current driver actually does not support simple ondemand governor
as it's unable to provide device load information. So removing
the unnecessary callback to avoid confusing.
Right now the driver is using userspace governor by default.

polling_ms was also dropped as it's not needed for non-ondemand
governor.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-05-21 13:16:10 +09:00
YueHaibing
18b380ed61 PM / devfreq: Add missing error code in devfreq_add_device()
Set err code in the error path before jumping to the end of the function.

Fixes: 4dc3bab868 ("PM / devfreq: Add support delayed timer for polling mode")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-05-20 12:16:41 +09:00
Fabio Estevam
0a7dc8318c PM / devfreq: imx8m-ddrc: Remove unneeded of_match_ptr()
i.MX is a DT-only platform, so of_match_ptr() can be safely
removed.

Remove the unneeded of_match_ptr().

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-04-08 13:14:51 +09:00
Fabio Estevam
ca948312e0 PM / devfreq: imx-bus: Remove unneeded of_match_ptr()
i.MX is a DT-only platform, so of_match_ptr() can be safely
removed.

Remove the unneeded of_match_ptr().

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-04-08 13:14:51 +09:00
Dong Aisheng
6c4b264c70 PM / devfreq: imx8m-ddrc: Remove imx8m_ddrc_get_dev_status
Current driver actually does not support simple ondemand governor
as it's unable to provide device load information. So removing
the unnecessary callback to avoid confusing.
Right now the driver is using userspace governor by default.

polling_ms was also dropped as it's not needed for non-ondemand
governor.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-04-08 13:14:51 +09:00
Dong Aisheng
05f15314f0 PM / devfreq: Remove the invalid description for get_target_freq
First of all, no_central_polling was removed since
commit 7e6fdd4bad ("PM / devfreq: Core updates to support devices
which can idle")
Secondly, get_target_freq() is not only called only with update_devfreq()
notified by OPP now, but also min/max freq qos notifier.

So remove this invalid description now to avoid confusing.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-04-08 13:14:51 +09:00
Dong Aisheng
b19e13463a PM / devfreq: Check get_dev_status in devfreq_update_stats
Check .get_dev_status() in devfreq_update_stats in case it's abused
when a device does not provide it.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-04-08 13:14:51 +09:00
Dong Aisheng
5f104f9fc1 PM / devfreq: Fix the wrong set_freq path for userspace governor in Kconfig
Fix the wrong set_freq path for userspace governor in Kconfig.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-04-08 13:14:50 +09:00
Krzysztof Kozlowski
fbf821ec63 PM / devfreq: rk3399_dmc: Simplify with dev_err_probe()
Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and the error value gets printed.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-04-08 13:14:50 +09:00
Dong Aisheng
62453f1ba5 PM / devfreq: Use more accurate returned new_freq as resume_freq
Use the more accurate returned new_freq as resume_freq.
It's the same as how devfreq->previous_freq was updated.

Fixes: 83f8ca45af ("PM / devfreq: add support for suspend/resume of a devfreq device")
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-04-08 13:14:45 +09:00
Lukasz Luba
8b50a79957 PM / devfreq: Unlock mutex and free devfreq struct in error path
The devfreq->lock is held for time of setup. Release the lock in the
error path, before jumping to the end of the function.

Change the goto destination which frees the allocated memory.

Cc: v5.9+ <stable@vger.kernel.org> # v5.9+
Fixes: 4dc3bab868 ("PM / devfreq: Add support delayed timer for polling mode")
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-04-08 13:14:45 +09:00
Daniel Lezcano
1224451bb6 PM / devfreq: Register devfreq as a cooling device on demand
Currently the default behavior is to manually having the devfreq
backend to register themselves as a devfreq cooling device.

Instead of adding the code in the drivers for the thermal cooling
device registering, let's provide a flag in the devfreq's profile to
tell the common devfreq code to register the newly created devfreq as
a cooling device.

Suggested-by: Chanwoo Choi <cwchoi00@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-03-09 15:40:16 +09:00
Rafael J. Wysocki
332fd9005b Merge branches 'pm-devfreq' and 'pm-tools'
* pm-devfreq:
  PM / devfreq: rk3399_dmc: Remove unneeded semicolon
  PM / devfreq: Replace devfreq->dev.parent as dev in devfreq_add_device
  PM / devfreq: Correct spelling in a comment

* pm-tools:
  cpupower: Add cpuid cap flag for MSR_AMD_HWCR support
  cpupower: Remove family arg to decode_pstates()
  cpupower: Condense pstate enabled bit checks in decode_pstates()
  cpupower: Update family checks when decoding HW pstates
  cpupower: Remove unused pscur variable.
  cpupower: Add CPUPOWER_CAP_AMD_HW_PSTATE cpuid caps flag
  cpupower: Correct macro name for CPB caps flag
  cpupower: Update msr_pstate union struct naming
  cpupower: add Makefile dependencies for install targets
2021-02-15 17:02:04 +01:00
Saravana Kannan
86ad9a24f2 PM / devfreq: Add required OPPs support to passive governor
Look at the required OPPs of the "parent" device to determine the OPP that
is required from the slave device managed by the passive governor. This
allows having mappings between a parent device and a slave device even when
they don't have the same number of OPPs.

While at it do a minor spell-fix and remove out label.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
[ Viresh: Rearranged code and clean error paths ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-02-04 16:48:16 +05:30
Saravana Kannan
26f9c7cc42 PM / devfreq: Cache OPP table reference in devfreq
The OPP table can be used often in devfreq. Trying to get it each time can
be expensive, so cache it in the devfreq struct.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
[ Viresh: Added a blank line ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-02-04 16:36:28 +05:30
Yang Li
fc1745c0e4 PM / devfreq: rk3399_dmc: Remove unneeded semicolon
Eliminate the following coccicheck warning:
./drivers/devfreq/rk3399_dmc.c:403:2-3: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-02-02 16:17:27 +09:00
Viresh Kumar
c7f142190d devfreq: tegra30: Migrate to dev_pm_opp_set_opp()
dev_pm_opp_set_bw() is getting removed and dev_pm_opp_set_opp() should
be used instead. Migrate to the new API.

We don't want the OPP core to manage the clk for this driver, migrate to
dev_pm_opp_of_add_table_noclk() to make sure dev_pm_opp_set_opp()
doesn't have any side effects.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
2021-02-02 10:30:53 +05:30
pierre Kuo
ec894883de PM / devfreq: Replace devfreq->dev.parent as dev in devfreq_add_device
In devfreq_add_device, replace devfreq->dev.parent
as dev to keep code simple.

Signed-off-by: pierre Kuo <vichy.kuo@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-01-05 10:05:41 +09:00
Lukasz Luba
f40d81231b PM / devfreq: Correct spelling in a comment
The device attribute exposed in sysfs is called 'polling_interval'. Align
the comment.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-01-05 10:04:25 +09:00
Rafael J. Wysocki
b3fac81783 Merge branches 'pm-devfreq' and 'pm-tools'
* pm-devfreq:
  PM / devfreq: tegra30: Separate configurations per-SoC generation
  PM / devfreq: tegra30: Support interconnect and OPPs from device-tree
  PM / devfreq: tegra20: Deprecate in a favor of emc-stat based driver
  PM / devfreq: exynos-bus: Add registration of interconnect child device
  dt-bindings: devfreq: Add documentation for the interconnect properties
  soc/tegra: fuse: Add stub for tegra_sku_info
  soc/tegra: fuse: Export tegra_read_ram_code()
  clk: tegra: Export Tegra20 EMC kernel symbols
  PM / devfreq: tegra30: Silence deferred probe error
  PM / devfreq: tegra20: Relax Kconfig dependency
  PM / devfreq: tegra20: Silence deferred probe error
  PM / devfreq: Remove redundant governor_name from struct devfreq
  PM / devfreq: Add governor attribute flag for specifc sysfs nodes
  PM / devfreq: Add governor feature flag
  PM / devfreq: Add tracepoint for frequency changes
  PM / devfreq: Unify frequency change to devfreq_update_target func
  trace: events: devfreq: Use fixed indentation size to improve readability

* pm-tools:
  pm-graph v5.8
  cpupower: Provide online and offline CPU information
2020-12-15 15:27:16 +01:00
Viresh Kumar
8145687283 PM / devfreq: exynos: dev_pm_opp_put_*() accepts NULL argument
The dev_pm_opp_put_*() APIs now accepts a NULL opp_table pointer and so
there is no need for us to carry the extra check. Drop them.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-12-09 11:21:12 +05:30
Dmitry Osipenko
6a575e84f1 PM / devfreq: tegra30: Separate configurations per-SoC generation
Previously we were using count-weight of the T124 for T30 in order to
get EMC clock rate that was reasonable for T30. In fact the count-weight
should be x2 times smaller on T30, but then devfreq was producing a bit
too low EMC clock rate for ISO memory clients, like display controller
for example.

Now both Tegra ACTMON and Tegra DRM display drivers support interconnect
framework and display driver tells to ICC what a minimum memory bandwidth
is needed, preventing FIFO underflows. Thus, now we can use a proper
count-weight value for Tegra30 and MC_ALL device config needs a bit more
aggressive boosting.

Add a separate ACTMON driver configuration that is specific to Tegra30.

Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Nicolas Chauvet <kwizart@gmail.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-12-07 10:25:51 +09:00
Dmitry Osipenko
16e8b2a7cb PM / devfreq: tegra30: Support interconnect and OPPs from device-tree
This patch moves ACTMON driver away from generating OPP table by itself,
transitioning it to use the table which comes from device-tree. This
change breaks compatibility with older device-trees and brings support
for the interconnect framework to the driver. This is a mandatory change
which needs to be done in order to implement interconnect-based memory
DVFS, i.e. device-trees need to be updated. Now ACTMON issues a memory
bandwidth requests using dev_pm_opp_set_bw() instead of driving EMC clock
rate directly.

Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Nicolas Chauvet <kwizart@gmail.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-12-07 10:25:51 +09:00
Dmitry Osipenko
98fd9972ed PM / devfreq: tegra20: Deprecate in a favor of emc-stat based driver
Remove tegra20-devfreq in order to replace it with a EMC_STAT based
devfreq driver. Previously we were going to use MC_STAT based
tegra20-devfreq driver because EMC_STAT wasn't working properly, but
now that problem is resolved. This resolves complications imposed by
the removed driver since it was depending on both EMC and MC drivers
simultaneously.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-11-23 16:01:13 +09:00
Sylwester Nawrocki
404d59c57b PM / devfreq: exynos-bus: Add registration of interconnect child device
This patch adds registration of a child platform device for the exynos
interconnect driver. It is assumed that the interconnect provider will
only be needed when #interconnect-cells property is present in the bus
DT node, hence the child device will be created only when such a property
is present.

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-11-13 18:10:42 +09:00
Dmitry Osipenko
09d56d92ad PM / devfreq: tegra30: Silence deferred probe error
Tegra EMC driver was turned into a regular kernel driver, meaning that it
could be compiled as a loadable kernel module now. Hence EMC clock isn't
guaranteed to be available and clk_get("emc") may return -EPROBE_DEFER.
Let's silence the deferred probe error.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 12:16:05 +09:00
Dmitry Osipenko
cc2a4e8361 PM / devfreq: tegra20: Relax Kconfig dependency
The Tegra EMC driver now could be compiled as a loadable kernel module.
Currently devfreq driver depends on the EMC/MC drivers in Kconfig, and
thus, devfreq is forced to be a kernel module if EMC is compiled as a
module. This build dependency could be relaxed since devfreq driver
checks MC/EMC presence on probe, allowing kernel configuration where
devfreq is a built-in driver and EMC driver is a loadable module.
This change puts Tegra20 devfreq Kconfig entry on a par with the Tegra30
devfreq entry.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 12:15:43 +09:00
Dmitry Osipenko
9a93386bf6 PM / devfreq: tegra20: Silence deferred probe error
Tegra EMC driver was turned into a regular kernel driver, meaning that it
could be compiled as a loadable kernel module now. Hence EMC clock isn't
guaranteed to be available and clk_get("emc") may return -EPROBE_DEFER.
Let's silence the deferred probe error.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 12:15:43 +09:00
Chanwoo Choi
96ffcdf239 PM / devfreq: Remove redundant governor_name from struct devfreq
The devfreq structure instance contains the governor_name and a governor
instance. When need to show the governor name, better to use the name
of devfreq_governor structure. So, governor_name variable in struct devfreq
is a redundant and unneeded variable. Remove the redundant governor_name
of struct devfreq and then use the name of devfreq_governor instance.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 11:50:51 +09:00
Chanwoo Choi
5f1a9066fc PM / devfreq: Add governor attribute flag for specifc sysfs nodes
DEVFREQ supports the default governors like performance, simple_ondemand and
also allows the devfreq driver to add their own governor like tegra30-devfreq.c
according to their requirement. In result, some sysfs attributes are useful
or not useful. Prior to that the user can access all sysfs attributes
regardless of the available attributes.

So, clarify the access permission of sysfs attributes according to governor.
When adding the devfreq governor, can specify the available attribute
information by using DEVFREQ_GOV_ATTR_* constant variable. The user can
read or write the sysfs attributes in accordance to the specified attributes.

When adding the governor, can add the following attributes
according to the governor feature.

[Definition for speific sysfs attributes]
- DEVFREQ_GOV_ATTR_POLLING_INTERVAL to update polling interval for timer.
  : /sys/class/devfreq/[devfreq dev name]/polling_interval
- DEVFREQ_GOV_ATTR_TIMER to change the type of timer on either deferrable
  or dealyed timer.
  : /sys/class/devfreq/[devfreq dev name]/timer

And all devfreq governors have to support the following common attributes.
The common attributes are added to devfreq class by default.
- governor
- available_governors
- available_frequencies
- cur_freq
- target_freq
- min_freq
- max_freq
- trans_stat

[Table of governor attribute flags for devfreq governors]
------------------------------------------------------------------------------
                      | simple    | perfor | power | user | passive | tegra30
		      | ondemand  | mance  | save  | space|         |
------------------------------------------------------------------------------
governor              | O         | O      | O     | O    | O       | O
available_governors   | O         | O      | O     | O    | O       | O
available_frequencies | O         | O      | O     | O    | O       | O
cur_freq              | O         | O      | O     | O    | O       | O
target_freq           | O         | O      | O     | O    | O       | O
min_freq              | O         | O      | O     | O    | O       | O
max_freq              | O         | O      | O     | O    | O       | O
trans_stat            | O         | O      | O     | O    | O       | O
                      --------------------------------------------------------
polling_interval      | O         | X      | X     | X    | X       | O
timer                 | O         | X      | X     | X    | X       | X
------------------------------------------------------------------------------

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 11:46:54 +09:00
Chanwoo Choi
0dd25a0d12 PM / devfreq: Add governor feature flag
The devfreq governor is able to have the specific flag as follows
in order to implement the specific feature. For example, devfreq allows
user to change the governors on runtime via sysfs interface.
But, if devfreq device uses 'passive' governor, don't allow user to change
the governor. For this case, define the DEVFREQ_GOV_FLAG_IMMUTABLE
and set it to flag of passive governor.

[Definition for governor flag]
- DEVFREQ_GOV_FLAG_IMMUTABLE
  : If immutable flag is set, governor is never changeable to other governors.
- DEVFREQ_GOV_FLAG_IRQ_DRIVEN
  : Devfreq core won't schedule polling work for this governor if value is set.

[Table of governor flag for devfreq governors]
------------------------------------------------------------------------------
                      | simple    | perfor | power | user | passive | tegra30
		      | ondemand  | mance  | save  | space|         |
------------------------------------------------------------------------------
immutable             | X         | X      | X     | X    | O       | O
interrupt_driven      | X(polling)| X      | X     | X    | X       | O (irq)
------------------------------------------------------------------------------

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 10:54:41 +09:00
Matthias Kaehlcke
cab477d0d4 PM / devfreq: Add tracepoint for frequency changes
Add a tracepoint for frequency changes of devfreq devices and
use it.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
[cw00.choi: Move print position of tracepoint and add more information]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 10:52:37 +09:00
Chanwoo Choi
b4365423bb PM / devfreq: Unify frequency change to devfreq_update_target func
The update_devfreq() and update_passive_devfreq() have the duplicate
code when changing the target frequency on final stage. So, unify
frequency change code to devfreq_update_target() to remove the
duplicate code and to centralize the frequency change code.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-10-26 10:52:37 +09:00
Dmitry Osipenko
d353d1202b PM / devfreq: tegra30: Improve initial hardware resetting
It's safe to enable the ACTMON clock at any time during driver probing,
even if we don't know the state of hardware, because it's used only for
collecting and processing stats, and interrupt is kept disabled. This
allows us to slightly improve code which performs initial hardware
resetting by making use of a single reset_control_reset() instead of
assert/deassert pair. Secondly, a potential error of the reset-control
API is handled nicely now.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-09-29 17:50:10 +09:00
Chanwoo Choi
02bdbf7d09 PM / devfreq: event: Change prototype of devfreq_event_get_edev_by_phandle function
Previously, devfreq core support 'devfreq-events' property in order to get
the devfreq-event device by phandle. But, 'devfreq-events' property name is
not proper on devicetree binding because this name doesn't mean
the any h/w attribute.

The devfreq-event core hand over the rights to decide the property name
for getting the devfreq-event device on devicetree. Each devfreq-event driver
will decide the property name on devicetree binding and then pass
the their own property name to devfreq_event_get_edev_by_phandle function.

And change the prototype of devfreq_event_get_edev_count function
because of used deprecated 'devfreq-events' property.

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-09-29 17:50:10 +09:00
Chanwoo Choi
86d90fd95b PM / devfreq: Change prototype of devfreq_get_devfreq_by_phandle function
Previously, devfreq core support 'devfreq' property in order to get
the devfreq device by phandle. But, 'devfreq' property name is not proper
on devicetree binding because this name doesn't mean the any h/w attribute.

The devfreq core hand over the right to decide the property name
for getting the devfreq device on devicetree. Each devfreq driver
will decide the property name on devicetree binding and pass
the their own property name to devfreq_get_devfreq_by_phandle function.

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-09-29 17:50:10 +09:00
Leonard Crestez
7b38b7b042 PM / devfreq: Add devfreq_get_devfreq_by_node function
Split off part of devfreq_get_devfreq_by_phandle into a separate
function. This allows callers to fetch devfreq instances by enumerating
devicetree instead of explicit phandles.

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
[cw00.choi: Export devfreq_get_devfreq_by_node function and
 add function to devfreq.h when CONFIG_PM_DEVFREQ is enabled.]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-09-29 17:50:09 +09:00
Dan Carpenter
6bf560766a PM / devfreq: tegra30: Disable clock on error in probe
This error path needs to call clk_disable_unprepare().

Fixes: 7296443b90 ("PM / devfreq: tegra30: Handle possible round-rate error")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-09-23 13:35:58 +09:00
Chanwoo Choi
0c309ed17c PM / devfreq: Add timer type to devfreq_summary debugfs
The commit 4dc3bab868 ("PM / devfreq: Add support delayed timer for
polling mode") supports the delayed timer but this commit missed
the adding the timer type to devfreq_summary debugfs node.
Add the timer type to devfreq_summary debugfs.

Fixes: 4dc3bab868 ("PM / devfreq: Add support delayed timer for polling mode")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-09-23 13:35:58 +09:00
Chanwoo Choi
27a6971445 PM / devfreq: Fix the wrong end with semicolon
Fix the wrong grammar at the end of code line by using semicolon.

Cc: stable vger.kernel.org
Fixes: 490a421bc5 ("PM / devfreq: Add debugfs support with devfreq_summary file")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-07-30 17:22:58 +09:00
Chanwoo Choi
0aae11bcde PM / devfreq: Fix indentaion of devfreq_summary debugfs node
The commit 66d0e797bf ("Revert "PM / devfreq: Modify the device name
as devfreq(X) for sysfs"") roll back the device name from 'devfreqX'
to device name explained in DT. After applied commit 66d0e797bf,
the indentation of devfreq_summary debugfs node was broken.

So, fix indentaion of devfreq_summary debugfs node as following:

For example on Exynos5422-based Odroid-XU3 board,
$ cat /sys/kernel/debug/devfreq/devfreq_summary
dev                            parent_dev                     governor        polling_ms  cur_freq_Hz  min_freq_Hz  max_freq_Hz
------------------------------ ------------------------------ --------------- ---------- ------------ ------------ ------------
10c20000.memory-controller     null                           simple_ondemand          0    413000000    165000000    825000000
soc:bus_wcore                  null                           simple_ondemand         50     88700000     88700000    532000000
soc:bus_noc                    soc:bus_wcore                  passive                  0     66600000     66600000    111000000
soc:bus_fsys_apb               soc:bus_wcore                  passive                  0    111000000    111000000    222000000
soc:bus_fsys                   soc:bus_wcore                  passive                  0     75000000     75000000    200000000
soc:bus_fsys2                  soc:bus_wcore                  passive                  0     75000000     75000000    200000000
soc:bus_mfc                    soc:bus_wcore                  passive                  0     83250000     83250000    333000000
soc:bus_gen                    soc:bus_wcore                  passive                  0     88700000     88700000    266000000
soc:bus_peri                   soc:bus_wcore                  passive                  0     66600000     66600000     66600000
soc:bus_g2d                    soc:bus_wcore                  passive                  0     83250000     83250000    333000000
soc:bus_g2d_acp                soc:bus_wcore                  passive                  0            0     66500000    266000000
soc:bus_jpeg                   soc:bus_wcore                  passive                  0            0     75000000    300000000
soc:bus_jpeg_apb               soc:bus_wcore                  passive                  0            0     83250000    166500000
soc:bus_disp1_fimd             soc:bus_wcore                  passive                  0            0    120000000    200000000
soc:bus_disp1                  soc:bus_wcore                  passive                  0            0    120000000    300000000
soc:bus_gscl_scaler            soc:bus_wcore                  passive                  0            0    150000000    300000000
soc:bus_mscl                   soc:bus_wcore                  passive                  0            0     84000000    666000000

Cc: stable@vger.kernel.org
Fixes: 66d0e797bf ("Revert "PM / devfreq: Modify the device name as devfreq(X) for sysfs"")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-07-30 17:22:58 +09:00
Chanwoo Choi
483d557ee9 PM / devfreq: Clean up the devfreq instance name in sysfs attr
The sysfs attr interface used eithere 'df' or 'devfreq' for devfreq instance
name. In order to keep the consistency and to improve the readabilty,
unify the instance name as 'df'. Add add the missing conditional statement
to prevent the fault.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-07-30 17:22:57 +09:00
Chanwoo Choi
4dc3bab868 PM / devfreq: Add support delayed timer for polling mode
Until now, the devfreq driver using polling mode like simple_ondemand
governor have used only deferrable timer for reducing the redundant
power consumption. It reduces the CPU wake-up from idle due to polling mode
which check the status of Non-CPU device.

But, it has a problem for Non-CPU device like DMC device with DMA operation.
Some Non-CPU device need to do monitor continuously regardless of CPU state
in order to decide the proper next status of Non-CPU device.

So, add support the delayed timer for polling mode to support
the repetitive monitoring. The devfreq driver and user can select
the kind of timer on either deferrable and delayed timer.

For example, change the timer type of DMC device
based on Exynos5422-based Odroid-XU3 as following:

- If want to use deferrable timer as following:
echo deferrable > /sys/class/devfreq/10c20000.memory-controller/timer

- If want to use delayed timer as following:
echo delayed > /sys/class/devfreq/10c20000.memory-controller/timer

Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-07-30 17:22:57 +09:00
Kieran Bingham
ada795966a PM / devfreq: event: Fix trivial spelling
The word 'descriptor' is misspelled throughout the tree.

Fix it up accordingly:
    decriptors -> descriptors

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-07-30 17:22:57 +09:00
Marc Zyngier
63ef91f24f PM / devfreq: rk3399_dmc: Fix kernel oops when rockchip,pmu is absent
Booting a recent kernel on a rk3399-based system (nanopc-t4),
equipped with a recent u-boot and ATF results in an Oops due
to a NULL pointer dereference.

This turns out to be due to the rk3399-dmc driver looking for
an *undocumented* property (rockchip,pmu), and happily using
a NULL pointer when the property isn't there.

Instead, make most of what was brought in with 9173c5ceb0
("PM / devfreq: rk3399_dmc: Pass ODT and auto power down parameters
to TF-A.") conditioned on finding this property in the device-tree,
preventing the driver from exploding.

Cc: stable@vger.kernel.org
Fixes: 9173c5ceb0 ("PM / devfreq: rk3399_dmc: Pass ODT and auto power down parameters to TF-A.")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-07-30 17:22:57 +09:00
Krzysztof Kozlowski
8fc0e48e0f PM / devfreq: Use lockdep asserts instead of manual checks for locked mutex
Instead of warning when mutex_is_locked(), just use the lockdep
framework.  The code is smaller and checks could be disabled for
production environments (it is useful only during development).

Put asserts at beginning of function, even before validating arguments.

The behavior of update_devfreq() is now changed because lockdep assert
will only print a warning, not return with EINVAL.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-05-28 18:02:40 +09:00
Gustavo A. R. Silva
48bbf63751 PM / devfreq: imx-bus: Fix inconsistent IS_ERR and PTR_ERR
Fix inconsistent IS_ERR and PTR_ERR in imx_bus_init_icc().

The proper pointer to be passed as argument to PTR_ERR() is
priv->icc_pdev.

This bug was detected with the help of Coccinelle.

Fixes: 16c1d2f1b0bd ("PM / devfreq: imx: Register interconnect device")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
[cw00.choi: Edit the patch title from 'imx' to 'imx-bus']
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-05-28 18:02:40 +09:00
Dmitry Osipenko
a316b5ca9e PM / devfreq: Replace strncpy with strscpy
GCC produces this warning when kernel compiled using `make W=1`:

  warning: ‘strncpy’ specified bound 16 equals destination size [-Wstringop-truncation]
  772 |  strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);

The strncpy doesn't take care of NULL-termination of the destination
buffer, while the strscpy does.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-05-28 18:02:39 +09:00
Leonard Crestez
02355216b4 PM / devfreq: imx: Register interconnect device
There is no single device which can represent the imx interconnect.
Instead of adding a virtual one just make the main &noc act as the
global interconnect provider.

The imx interconnect provider driver will scale the NOC and DDRC based
on bandwidth request. More scalable nodes can be added in the future,
for example for audio/display/vpu/gpu NICs.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Tested-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-05-28 18:02:39 +09:00
Leonard Crestez
5173a9756c PM / devfreq: Add generic imx bus scaling driver
Add initial support for dynamic frequency switching on pieces of the imx
interconnect fabric.

All this driver does is set a clk rate based on an opp table, it does
not map register areas.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Tested-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-05-28 18:02:39 +09:00
Markus Elfring
0716f9fdb3 PM / devfreq: tegra30: Delete an error message in tegra_devfreq_probe()
The function “platform_get_irq” can log an error already.
Thus omit a redundant message for the exception handling in the
calling function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-05-28 18:02:39 +09:00
Dmitry Osipenko
d2216ba3eb PM / devfreq: tegra30: Make CPUFreq notifier to take into account boosting
We're taking into account both HW memory-accesses + CPU activity based on
current CPU's frequency. For memory-accesses there is a kind of hysteresis
in a form of "boosting" which is managed by the tegra30-devfreq driver.
If current HW memory activity is higher than activity judged based of the
CPU's frequency, then there is no need to schedule cpufreq_update_work
because the result of the work will be a NO-OP. And thus,
tegra_actmon_cpufreq_contribution() should return 0, meaning that at the
moment CPU frequency doesn't contribute anything to the final decision
about required memory clock rate.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-05-28 18:02:39 +09:00
Leonard Crestez
4c6abef7b4 PM / devfreq: Fix handling dev_pm_qos_remove_request result
The dev_pm_qos_remove_request function can return 1 if
"aggregated constraint value has changed" so only negative values should
be reported as errors.

Fixes: 27dbc542f6 ("PM / devfreq: Use PM QoS for sysfs min/max_freq")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-03-25 08:35:03 +09:00
Christophe JAILLET
3bb5ee9aaa PM / devfreq: Fix a typo in a comment
'govenror' was used in place of 'governor'

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-03-25 08:35:03 +09:00
Chanwoo Choi
3a1ec2e8d8 PM / devfreq: Change to DEVFREQ_GOV_UPDATE_INTERVAL event name
DEVFREQ_GOV_INTERVAL event indicates that update the interval
for polling mode of devfreq device. But, this event name doesn't
specify exactly what to do.

Change DEVFREQ_GOV_INTERVAL event name to DEVFREQ_GOV_UPDATE_INTERVAL
which specifies what to do by event name.

And modify the function name to DEVFREQ_GOV_UPDATE_INTERVAL
with 'devfreq_' prefix + verb + object as following:
- devfreq_interval_update -> devfreq_updatee_interval

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-03-25 08:35:03 +09:00
Chanwoo Choi
6d7434931a PM / devfreq: Remove unneeded extern keyword
Remove unneeded extern keyword from devfreq-related header file
and adjust the indentation of function parameter to keep the
consistency in header file

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-03-25 08:35:03 +09:00
pierre Kuo
4bb1faaccf PM / devfreq: Use constant name of userspace governor
Based on commit aa7c352f98 ("PM / devfreq: Define the constant governor
name"), use constant name for userspace governor.

Signed-off-by: pierre Kuo <vichy.kuo@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-03-25 08:35:03 +09:00
Orson Zhai
66d0e797bf Revert "PM / devfreq: Modify the device name as devfreq(X) for sysfs"
This reverts commit 4585fbcb53.

The name changing as devfreq(X) breaks some user space applications,
such as Android HAL from Unisoc and Hikey [1].
The device name will be changed unexpectly after every boot depending
on module init sequence. It will make trouble to setup some system
configuration like selinux for Android.

So we'd like to revert it back to old naming rule before any better
way being found.

[1] https://lkml.org/lkml/2018/5/8/1042

Cc: John Stultz <john.stultz@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: Orson Zhai <orson.unisoc@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-02-24 11:14:29 +09:00
Chanwoo Choi
490a421bc5 PM / devfreq: Add debugfs support with devfreq_summary file
Add debugfs interface to provide debugging information of devfreq device.
It contains 'devfreq_summary' entry to show the summary of registered
devfreq devices as following and the additional debugfs file will be added.
- /sys/kernel/debug/devfreq/devfreq_summary

[Detailed description of each field of 'devfreq_summary' debugfs file]
- dev_name	: Device name of h/w
- dev		: Device name made by devfreq core
- parent_dev	: If devfreq device uses the passive governor,
		  show parent devfreq device name. Otherwise, show 'null'.
- governor	: Devfreq governor name
- polling_ms	: If devfreq device uses the simple_ondemand governor,
		  polling_ms is necessary for the period. (unit: millisecond)
- cur_freq_Hz	: Current frequency (unit: Hz)
- min_freq_Hz	: Minimum frequency (unit: Hz)
- max_freq_Hz	: Maximum frequency (unit: Hz)

[For example on Exynos5422-based Odroid-XU3 board]
$ cat /sys/kernel/debug/devfreq/devfreq_summary
dev_name                       dev        parent_dev governor        polling_ms  cur_freq_Hz  min_freq_Hz  max_freq_Hz
------------------------------ ---------- ---------- --------------- ---------- ------------ ------------ ------------
10c20000.memory-controller     devfreq0   null       simple_ondemand          0    165000000    165000000    825000000
soc:bus_wcore                  devfreq1   null       simple_ondemand         50    532000000     88700000    532000000
soc:bus_noc                    devfreq2   devfreq1   passive                  0    111000000     66600000    111000000
soc:bus_fsys_apb               devfreq3   devfreq1   passive                  0    222000000    111000000    222000000
soc:bus_fsys                   devfreq4   devfreq1   passive                  0    200000000     75000000    200000000
soc:bus_fsys2                  devfreq5   devfreq1   passive                  0    200000000     75000000    200000000
soc:bus_mfc                    devfreq6   devfreq1   passive                  0    333000000     83250000    333000000
soc:bus_gen                    devfreq7   devfreq1   passive                  0    266000000     88700000    266000000
soc:bus_peri                   devfreq8   devfreq1   passive                  0     66600000     66600000     66600000
soc:bus_g2d                    devfreq9   devfreq1   passive                  0    333000000     83250000    333000000
soc:bus_g2d_acp                devfreq10  devfreq1   passive                  0    266000000     66500000    266000000
soc:bus_jpeg                   devfreq11  devfreq1   passive                  0    300000000     75000000    300000000
soc:bus_jpeg_apb               devfreq12  devfreq1   passive                  0    166500000     83250000    166500000
soc:bus_disp1_fimd             devfreq13  devfreq1   passive                  0    200000000    120000000    200000000
soc:bus_disp1                  devfreq14  devfreq1   passive                  0    300000000    120000000    300000000
soc:bus_gscl_scaler            devfreq15  devfreq1   passive                  0    300000000    150000000    300000000
soc:bus_mscl                   devfreq16  devfreq1   passive                  0    666000000     84000000    666000000

[lkp: Reported the build error]
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-01-16 19:14:49 +09:00
Krzysztof Kozlowski
91d7f3f8f1 PM / devfreq: exynos: Rename Exynos to lowercase
Fix up inconsistent usage of upper and lowercase letters in "Exynos"
name.

"EXYNOS" is not an abbreviation but a regular trademarked name.
Therefore it should be written with lowercase letters starting with
capital letter.

The lowercase "Exynos" name is promoted by its manufacturer Samsung
Electronics Co., Ltd., in advertisement materials and on website.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2020-01-06 10:50:09 +09:00