Commit Graph

15 Commits

Author SHA1 Message Date
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
Yoshihiro Shimoda
c79468b895 pwm: rcar: Remove a redundant condition in rcar_pwm_apply()
Since the rcar_pwm_apply() has already checked whether state->enabled
is set or not, this patch removes a redundant condition.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 01:21:58 +02:00
Yoshihiro Shimoda
4a5fa56cc0 pwm: rcar: Remove suspend/resume support
According to the Documentation/pwm.txt, all PWM consumers should
implement power management instead of the PWM driver. So, this
patch removes suspend/resume support.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26 11:39:11 +02:00
Yoshihiro Shimoda
b4f9a7268d pwm: rcar: Improve calculation of divider
The rcar_pwm_get_clock_division() has a loop to calculate the divider,
but the value of div should be calculatable without a loop. So, this
patch improves it.

This algorithm is suggested by Uwe Kleine-König and Laurent Pinchart.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-03-04 12:14:21 +01:00
Yoshihiro Shimoda
8cc2b97039 pwm: rcar: Remove legacy APIs
This patch removes legacy APIs. Since rcar_pwm_{en,dis}able() functions
are reused on "atomic" API, this patch changes the arguments of these
functions. No change in behavior.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-03-04 12:14:07 +01:00
Yoshihiro Shimoda
87f50ce981 pwm: rcar: Use "atomic" API on rcar_pwm_resume()
To remove legacy API related functions in the future, this patch
uses "atomic" related function instead. No change in behavior.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-03-04 12:14:06 +01:00
Yoshihiro Shimoda
7f68ce8287 pwm: rcar: Add support "atomic" API
This patch adds support for "atomic" API. This behavior differs with
legacy APIs a little.

 Legacy APIs:
  The PWMCNT register will be updated in rcar_pwm_config() even if
  the PWM state is disabled.

 Atomic API:
  The PWMCNT register will be updated in rcar_pwm_apply() only if
  the PWM state is enabled. Otherwize, if a PWM runs with 30% duty
  cycles and the pwm_apply_state() is called with state->enabled = 0,
  ->duty_cycle = 60 and ->period = 100, this is possible to output
  a 60% duty cycle.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-03-04 12:14:05 +01:00
Wolfram Sang
e4ab5172ea pwm: Use SPDX identifier for Renesas drivers
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-10-12 13:35:45 +02:00
Wolfram Sang
692099cdcf pwm: simplify getting .drvdata
We should get drvdata from struct device directly. Going via
platform_device is an unneeded step back and forth.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-04-30 10:40:57 +02:00
Yoshihiro Shimoda
6873842235 pwm: rcar: Add suspend/resume support
This patch adds suspend/resume support for Renesas PWM driver.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-03-28 01:27:10 +02:00
Hien Dang
f2e6142cdc pwm: rcar: Use PM Runtime to control module clock
Runtime PM API (pm_runtime_get_sync/pm_runtime_put) should be used
to control module clock instead of clk_prepare_enable and
clk_disable_unprepare.

Signed-off-by: Hien Dang <hien.dang.eb@renesas.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-03-28 01:26:15 +02:00
Ryo Kodama
6225f9c64b pwm: rcar: Fix a condition to prevent mismatch value setting to duty
This patch fixes an issue that is possible to set mismatch value to duty
for R-Car PWM if we input the following commands:

 # cd /sys/class/pwm/<pwmchip>/
 # echo 0 > export
 # cd pwm0
 # echo 30 > period
 # echo 30 > duty_cycle
 # echo 0 > duty_cycle
 # cat duty_cycle
 0
 # echo 1 > enable
 --> Then, the actual duty_cycle is 30, not 0.

So, this patch adds a condition into rcar_pwm_config() to fix this
issue.

Signed-off-by: Ryo Kodama <ryo.kodama.vz@renesas.com>
[shimoda: revise the commit log and add Fixes and Cc tags]
Fixes: ed6c1476bf ("pwm: Add support for R-Car PWM Timer")
Cc: Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-03-28 01:20:13 +02:00
Boris BREZILLON
3587c26090 pwm: rcar: Make use of pwm_is_enabled()
Commit 5c31252c4a ("pwm: Add the pwm_is_enabled() helper") introduced
a new function to test whether a PWM device is enabled or not without
manipulating PWM internal fields.

Hiding this is necessary if we want to smoothly move to the atomic PWM
config approach without impacting PWM drivers. Fix this driver to use
pwm_is_enabled() instead of directly accessing the ->flags field.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17 14:44:57 +02:00
Ryo Kodama
72c16a9f98 pwm: rcar: Improve accuracy of frequency division setting
From: Ryo Kodama <ryo.kodama.vz@renesas.com>

When period_ns is set to the same value of RCAR_PWM_MAX_CYCLE in
rcar_pwm_get_clock_division(), this function should allow such value
for improving accuracy of frequency division setting.

Signed-off-by: Ryo Kodama <ryo.kodama.vz@renesas.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16 17:02:14 +01:00
Yoshihiro Shimoda
ed6c1476bf pwm: Add support for R-Car PWM Timer
This patch adds support for R-Car SoCs PWM Timer. The PWM timer of
R-Car H2 has 7 channels. So, we can use the channels if we describe
device tree nodes.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-10-06 09:40:46 +02:00