Commit Graph

748 Commits

Author SHA1 Message Date
Uwe Kleine-König
bca900829d pwm: rcar: Drop useless call to pwm_get_state()
pwm_get_state has no side effects and the resulting pwm_state is unused.
So drop the call to pwm_get_state() and the local variable from
rcar_pwm_apply().

The call was introduced in commit 7f68ce8287 ("pwm: rcar: Add support
"atomic" API") and already then was useless.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 12:21:49 +01:00
Krzysztof Kozlowski
f24e564129 pwm: Fix minor Kconfig whitespace issues
Remove double whitespace after "config" keyword.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:56:02 +01:00
Uwe Kleine-König
651b510a74 pwm: atmel: Implement .get_state()
This function reads back the configured parameters from the hardware. As
.apply() rounds down (mostly) I'm rounding up in .get_state() to achieve
that applying a state just read from hardware is a no-op.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:47:46 +01:00
Uwe Kleine-König
02afb811e0 pwm: atmel: Use register accessors for channels
This makes it a bit easier when instrumenting register access to only
have to add code in one place.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:44:51 +01:00
Uwe Kleine-König
998d189a81 pwm: atmel: Document known weaknesses of both hardware and software
This documents the my findings while reading through the driver and the
reference manual.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:44:08 +01:00
Uwe Kleine-König
2101c878f7 pwm: atmel: Replace loop in prescale calculation by ad-hoc calculation
The calculated values are the same with the modified algorithm. The only
difference is that the calculation is a bit more efficient.

Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:43:39 +01:00
Uwe Kleine-König
ff55e7a314 pwm: atmel: Use a constant for maximum prescale value
The maximal prescale value is 10 for all supported variants. So drop the
member in the variant description and introduce a global constant
instead.

This reduces the size of the variant descriptions and the .apply()
callback can be compiled a bit more effectively.

Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:43:00 +01:00
Uwe Kleine-König
3c269ba6d8 pwm: atmel: Add a hint where to find hardware documentation
Most Microchip (formerly Atmel) chips have publicly available manuals.
A comprehensive list is already contained in the documentation folder.
Reference this list in the header of the driver to allow reviewers to
find the relevant manuals.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:42:40 +01:00
Rasmus Villemoes
3c64ed74d6 pwm: mxs: Avoid a division in mxs_pwm_apply()
Since the divisor is not a compile-time constant (unless gcc somehow
decided to unroll the loop PERIOD_CDIV_MAX times), this does a
somewhat expensive 32/32 division. Replace that with a right shift.

We still have a 64/32 division just below, but at least in that
case the divisor is compile-time constant.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:35:12 +01:00
Rasmus Villemoes
2cf0f6fece pwm: mxs: Add support for inverse polarity
If I'm reading of_pwm_xlate_with_flags() right, existing device trees
that set #pwm-cells = 2 will continue to work.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:33:37 +01:00
Rasmus Villemoes
ebbfb1592c pwm: mxs: Remove legacy methods
Since we now have ->apply(), these are no longer relevant.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:33:11 +01:00
Rasmus Villemoes
bf29c2ff82 pwm: mxs: Implement ->apply()
In preparation for supporting setting the polarity, switch the driver
to support the ->apply() method.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 13:32:47 +01:00
Jernej Skrabec
fdd2c12e37 pwm: sun4i: Add support for H6 PWM
Now that sun4i PWM driver supports deasserting reset line and enabling
bus clock, support for H6 PWM can be added.

Note that while H6 PWM has two channels, only first one is wired to
output pin. Second channel is used as a clock source to companion AC200
chip which is bundled into same package.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:50:42 +01:00
Jernej Skrabec
9f28e95b52 pwm: sun4i: Add support to output source clock directly
PWM core has an option to bypass whole logic and output unchanged source
clock as PWM output. This is achieved by enabling bypass bit.

Note that when bypass is enabled, no other setting has any meaning, not
even enable bit.

This mode of operation is needed to achieve high enough frequency to
serve as clock source for AC200 chip which is integrated into same
package as H6 SoC.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:50:41 +01:00
Clément Péron
fa4d817846 pwm: sun4i: Always calculate params when applying new parameters
Bypass mode will require to be re-calculated when the pwm state
is changed.

Remove the condition so pwm_sun4i_calculate is always called.

Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:48:33 +01:00
Jernej Skrabec
5b090b430d pwm: sun4i: Add an optional probe for bus clock
H6 PWM core needs bus clock to be enabled in order to work.

Add an optional probe for it.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:48:19 +01:00
Clément Péron
b8d74644f3 pwm: sun4i: Prefer "mod" clock to unnamed
New device tree bindings called the source clock of the module
"mod" when several clocks are defined.

Try to get a clock called "mod" if nothing is found try to get
an unnamed clock.

Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:48:05 +01:00
Jernej Skrabec
a7fe985633 pwm: sun4i: Add an optional probe for reset line
H6 PWM core needs deasserted reset line in order to work.

Add an optional probe for it.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:47:26 +01:00
Thierry Reding
bd88d319ab pwm: imx27: Unconditionally write state to hardware
The i.MX driver currently uses a shortcut and doesn't write all of the
state through to the hardware when the PWM is disabled. This causes an
inconsistent state to be read back by consumers with the result of them
malfunctioning.

Fix this by always writing the full state through to the hardware
registers so that the correct state can always be read back.

Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Tested-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-12-09 10:05:46 +01:00
Thierry Reding
a3597d6c89 pwm: imx27: Cache duty cycle register value
The hardware register containing the duty cycle value cannot be accessed
when the PWM is disabled. This causes the ->get_state() callback to read
back a duty cycle value of 0, which can confuse consumer drivers.

Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Tested-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-12-09 10:05:43 +01:00
Thierry Reding
1db37f9561 pwm: cros-ec: Cache duty cycle value
The ChromeOS embedded controller doesn't differentiate between disabled
and duty cycle being 0. In order not to potentially confuse consumers,
cache the duty cycle and return the cached value instead of the real
value when the PWM is disabled.

Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-12-09 10:05:42 +01:00
Thierry Reding
cfc4c189bc pwm: Read initial hardware state at request time
Drivers that support reading the hardware state (using ->get_state())
may want to rely on per-PWM data to do so. Defer reading the hardware
state for the first time until the PWM has been requested and after
drivers have had a chance to allocate per-PWM data.

Conceptually this is also a more natural place to read the hardware
state because the PWM core doesn't need to know the hardware state of a
PWM unless there is a user for it. This also ensures that the state is
read everytime a user requests a PWM. If the PWM changes between users
for some reason, the PWM core will reload the state from hardware and
keep its copy of the state up-to-date.

Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-12-09 10:05:41 +01:00
Linus Torvalds
d9e48dc2a7 pwm: Changes for v5.5-rc1
Various changes and minor fixes across a couple of drivers.
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Merge tag 'pwm/for-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "Various changes and minor fixes across a couple of drivers"

* tag 'pwm/for-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: stm32: Pass breakinput instead of its values
  pwm: stm32: Remove clutter from ternary operator
  pwm: stm32: Validate breakinput data from DT
  pwm: Update comment on struct pwm_ops::apply
  pwm: sun4i: Fix incorrect calculation of duty_cycle/period
  pwm: stm32: Add power management support
  pwm: stm32: Split breakinput apply routine to ease PM support
  dt-bindings: pwm-stm32: Document pinctrl sleep state
  pwm: sun4i: Drop redundant assignment to variable pval
  dt-bindings: pwm: mediatek: Remove gratuitous compatible string for MT7629
2019-12-05 11:28:14 -08:00
Greg Kroah-Hartman
f0cb9b5dfd Merge 5.4-rc7 into staging-next
We want the staging fixes in here, and it resolves some merge issues.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-11 06:23:37 +01:00
Uwe Kleine-König
24906a41ee pwm: bcm-iproc: Prevent unloading the driver module while in use
The owner member of struct pwm_ops must be set to THIS_MODULE to
increase the reference count of the module such that the module cannot
be removed while its code is in use.

Fixes: daa5abc41c ("pwm: Add support for Broadcom iProc PWM controller")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-11-08 18:38:06 +01:00
Thierry Reding
9e1b4999a1 pwm: stm32: Pass breakinput instead of its values
Instead of passing the individual values of the breakpoint, pass a
pointer to the breakpoint.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:05 +02:00
Thierry Reding
8e53622594 pwm: stm32: Remove clutter from ternary operator
Remove usage of the ternary operator to assign values for register
fields. Instead, parameterize the register and field offset macros
and pass the index to them.

This removes clutter and improves readability.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:05 +02:00
Thierry Reding
8dfa620e3d pwm: stm32: Validate breakinput data from DT
Both index and level can only be either 0 or 1 and the filter value is
limited to values between (and including) 0 and 15. Validate that the
device tree node contains values that are within these ranges.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:04 +02:00
Ondrej Jirman
50cc7e3e4f pwm: sun4i: Fix incorrect calculation of duty_cycle/period
Since 5.4-rc1, pwm_apply_state calls ->get_state after ->apply
if available, and this revealed an issue with integer precision
when calculating duty_cycle and period for the currently set
state in ->get_state callback.

This issue manifested in broken backlight on several Allwinner
based devices.

Previously this worked, because ->apply updated the passed state
directly.

Fixes: deb9c462f4 ("pwm: sun4i: Don't update the state for the caller of pwm_apply_state")
Signed-off-by: Ondrej Jirman <megous@megous.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:02 +02:00
Fabrice Gasnier
2d3aa06b5d pwm: stm32: Add power management support
Add suspend/resume PM sleep ops. When going to low power, enforce the PWM
channel isn't active. Let the PWM consumers disable it during their own
suspend sequence, see [1]. So, perform a check here, and handle the
pinctrl states. Also restore the break inputs upon resume, as registers
content may be lost when going to low power mode.

[1] https://lkml.org/lkml/2019/2/5/770

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:01 +02:00
Fabrice Gasnier
0f9d2ecba8 pwm: stm32: Split breakinput apply routine to ease PM support
Split breakinput routine that configures STM32 timers 'break' safety
feature upon probe, into two routines:
- stm32_pwm_apply_breakinputs() sets all the break inputs into registers.
- stm32_pwm_probe_breakinputs() probes the device tree break input settings
  before calling stm32_pwm_apply_breakinputs()

This is a precursor patch to ease PM support. Registers content may get
lost during low power. So, break input settings applied upon probe need
to be restored upon resume (e.g. by calling stm32_pwm_apply_breakinputs()).

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:00 +02:00
Colin Ian King
1b98ad3b3b pwm: sun4i: Drop redundant assignment to variable pval
Variable pval is being assigned a value that is never read. The
assignment is redundant and hence can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:49:58 +02:00
Thierry Reding
40a6b9a009 Revert "pwm: Let pwm_get_state() return the last implemented state"
It turns out that commit 01ccf903ed ("pwm: Let pwm_get_state() return
the last implemented state") causes backlight failures on a number of
boards. The reason is that some of the drivers do not write the full
state through to the hardware registers, which means that ->get_state()
subsequently does not return the correct state. Consumers which rely on
pwm_get_state() returning the current state will therefore get confused
and subsequently try to program a bad state.

Before this change can be made, existing drivers need to be more
carefully audited and fixed to behave as the framework expects. Until
then, keep the original behaviour of returning the software state that
was applied rather than reading the state back from hardware.

Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:48:52 +02:00
David Lechner
7cabf9251a bus/ti-pwmss: move TI PWMSS driver from PWM to bus subsystem
The TI PWMSS driver is a simple bus driver for providing power
power management for the PWM peripherals on TI AM33xx SoCs, namely
eCAP, eHRPWM and eQEP. The eQEP is a counter rather than a PWM, so
it does not make sense to have the bus driver in the PWM subsystem
since the PWMSS is not exclusive to PWM devices.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-10-17 21:17:42 +01:00
Linus Torvalds
e37e3bc7e2 pwm: Changes for v5.4-rc1
Besides one new driver being added for the PWM controller found in
 various Spreadtrum SoCs, this series of changes brings a slew of, mostly
 minor, fixes and cleanups for existing drivers, as well as some
 enhancements to the core code.
 
 Lastly, Uwe is added to the PWM subsystem entry of the MAINTAINERS file,
 making official his role as a reviewer.
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Merge tag 'pwm/for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "Besides one new driver being added for the PWM controller found in
  various Spreadtrum SoCs, this series of changes brings a slew of,
  mostly minor, fixes and cleanups for existing drivers, as well as some
  enhancements to the core code.

  Lastly, Uwe is added to the PWM subsystem entry of the MAINTAINERS
  file, making official his role as a reviewer"

* tag 'pwm/for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (34 commits)
  MAINTAINERS: Add myself as reviewer for the PWM subsystem
  MAINTAINERS: Add patchwork link for PWM entry
  MAINTAINERS: Add a selection of PWM related keywords to the PWM entry
  pwm: mediatek: Add MT7629 compatible string
  dt-bindings: pwm: Update bindings for MT7629 SoC
  pwm: mediatek: Update license and switch to SPDX tag
  pwm: mediatek: Use pwm_mediatek as common prefix
  pwm: mediatek: Allocate the clks array dynamically
  pwm: mediatek: Remove the has_clks field
  pwm: mediatek: Drop the check for of_device_get_match_data()
  pwm: atmel: Consolidate driver data initialization
  pwm: atmel: Remove unneeded check for match data
  pwm: atmel: Remove platform_device_id and use only dt bindings
  pwm: stm32-lp: Add check in case requested period cannot be achieved
  pwm: Ensure pwm_apply_state() doesn't modify the state argument
  pwm: fsl-ftm: Don't update the state for the caller of pwm_apply_state()
  pwm: sun4i: Don't update the state for the caller of pwm_apply_state()
  pwm: rockchip: Don't update the state for the caller of pwm_apply_state()
  pwm: Let pwm_get_state() return the last implemented state
  pwm: Introduce local struct pwm_chip in pwm_apply_state()
  ...
2019-09-27 12:19:47 -07:00
Sam Shih
715d14da67 pwm: mediatek: Add MT7629 compatible string
This adds pwm support for MT7629, and separate mt7629 compatible string
from mt7622

Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-26 13:27:50 +02:00
Sam Shih
4bea6dd5be pwm: mediatek: Update license and switch to SPDX tag
Add SPDX identifiers to pwm-mediatek.c. Update MODULE_LICENSE to
correctly reflect the GNU General Public License v2.0.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-25 09:49:15 +02:00
Sam Shih
2503781c97 pwm: mediatek: Use pwm_mediatek as common prefix
Use pwm_mediatek as common prefix to match the filename. No functional
change intended.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-25 09:49:15 +02:00
Sam Shih
efecdeb82f pwm: mediatek: Allocate the clks array dynamically
Instead of using fixed size of arrays, allocate the memory for them
based on the number of PWMs specified for each SoC generation.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-25 09:49:15 +02:00
Sam Shih
61aa258ab1 pwm: mediatek: Remove the has_clks field
We can use fixed clocks to repair mt7628 PWM during configure from
userspace. The SoC is legacy MIPS and has no complex clock tree. Because
we can get the clock frequency for period calculation from fixed clocks
specified in DT, we can remove the has_clock field, and directly use
devm_clk_get() and clk_get_rate().

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-25 09:48:58 +02:00
Sam Shih
e6c7c258f0 pwm: mediatek: Drop the check for of_device_get_match_data()
This patch drop the check for of_device_get_match_data. Due to the only
way call driver probe is compatible match. The data pointer which points
to the SoC specify data is directly set by driver, and it should not be
NULL in our case. We can safety remove the check for the result of
of_device_get_match_data().

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:11 +02:00
Thierry Reding
9193c16e5a pwm: atmel: Consolidate driver data initialization
This helps readability by separating the driver-specific bits from the
PWM framework bits.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:11 +02:00
Thierry Reding
d85b9ce198 pwm: atmel: Remove unneeded check for match data
Since the driver is now exclusively DT, it only binds if it finds a
match in the of_device_id table. But in that case the associated data
can never be NULL, so drop the unnecessary check.

While at it, drop the extra local variable and store the pointer to
this per-SoC data in the driver data directly.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:11 +02:00
Kamel Bouhara
3d4d85741a pwm: atmel: Remove platform_device_id and use only dt bindings
Since commit 26202873bb ("avr32: remove support for AVR32
architecture") there is no more user of platform_device_id and we
should only use dt bindings

Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:10 +02:00
Fabrice Gasnier
c91e3234c6 pwm: stm32-lp: Add check in case requested period cannot be achieved
LPTimer can use a 32KHz clock for counting. It depends on clock tree
configuration. In such a case, PWM output frequency range is limited.
Although unlikely, nothing prevents user from requesting a PWM frequency
above counting clock (32KHz for instance):
- This causes (prd - 1) = 0xffff to be written in ARR register later in
the apply() routine.
This results in badly configured PWM period (and also duty_cycle).
Add a check to report an error is such a case.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:10 +02:00
Uwe Kleine-König
71523d1812 pwm: Ensure pwm_apply_state() doesn't modify the state argument
It is surprising for a PWM consumer when the variable holding the
requested state is modified by pwm_apply_state(). Consider for example a
driver doing:

        #define PERIOD 5000000
        #define DUTY_LITTLE 10
        ...
        struct pwm_state state = {
                .period = PERIOD,
                .duty_cycle = DUTY_LITTLE,
                .polarity = PWM_POLARITY_NORMAL,
                .enabled = true,
        };

        pwm_apply_state(mypwm, &state);
        ...
        state.duty_cycle = PERIOD / 2;
        pwm_apply_state(mypwm, &state);

For sure the second call to pwm_apply_state() should still have
state.period = PERIOD and not something the hardware driver chose for a
reason that doesn't necessarily apply to the second call.

So declare the state argument as a pointer to a const type and adapt all
drivers' .apply callbacks.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:10 +02:00
Uwe Kleine-König
c9675829ba pwm: fsl-ftm: Don't update the state for the caller of pwm_apply_state()
The pwm-fsl-ftm driver is one of only three PWM drivers which updates
the state for the caller of pwm_apply_state(). This might have
surprising results if the caller reuses the values expecting them to
still represent the same state.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 01:48:55 +02:00
Uwe Kleine-König
deb9c462f4 pwm: sun4i: Don't update the state for the caller of pwm_apply_state()
The pwm-sun4i driver is one of only three PWM drivers which updates the
state for the caller of pwm_apply_state(). This might have surprising
results if the caller reuses the values expecting them to still
represent the same state.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 01:48:55 +02:00
Uwe Kleine-König
797a5ebc26 pwm: rockchip: Don't update the state for the caller of pwm_apply_state()
The pwm-rockchip driver is one of only three PWM drivers which updates
the state for the caller of pwm_apply_state(). This might have
surprising results if the caller reuses the values expecting them to
still represent the same state.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 01:48:55 +02:00
Uwe Kleine-König
01ccf903ed pwm: Let pwm_get_state() return the last implemented state
When pwm_apply_state() is called the lowlevel driver usually has to
apply some rounding because the hardware doesn't support nanosecond
resolution. So let pwm_get_state() return the actually implemented state
instead of the last applied one if possible.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 01:48:54 +02:00