pwm: Make .get_state() callback return an error code

.get_state() might fail in some cases. To make it possible that a driver
signals such a failure change the prototype of .get_state() to return an
error code.

This patch was created using coccinelle and the following semantic patch:

@p1@
identifier getstatefunc;
identifier driver;
@@
 struct pwm_ops driver = {
        ...,
        .get_state = getstatefunc
        ,...
 };

@p2@
identifier p1.getstatefunc;
identifier chip, pwm, state;
@@
-void
+int
 getstatefunc(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state)
 {
   ...
-  return;
+  return 0;
   ...
 }

plus the actual change of the prototype in include/linux/pwm.h (plus some
manual fixing of indentions and empty lines).

So for now all drivers return success unconditionally. They are adapted
in the following patches to make the changes easier reviewable.

Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Acked-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221130152148.2769768-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index 1bb317b8dcce..91a4232ee58c 100644
--- a/drivers/gpio/gpio-mvebu.c
+++ b/drivers/gpio/gpio-mvebu.c
@@ -657,9 +657,10 @@ static void mvebu_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 	spin_unlock_irqrestore(&mvpwm->lock, flags);
 }
 
-static void mvebu_pwm_get_state(struct pwm_chip *chip,
-				struct pwm_device *pwm,
-				struct pwm_state *state) {
+static int mvebu_pwm_get_state(struct pwm_chip *chip,
+			       struct pwm_device *pwm,
+			       struct pwm_state *state)
+{
 
 	struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
 	struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
@@ -693,6 +694,8 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip,
 		state->enabled = false;
 
 	spin_unlock_irqrestore(&mvpwm->lock, flags);
+
+	return 0;
 }
 
 static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,