[PATCH v2] backlight: pwm_bl: use gpiod_set_value_cansleep to fix warnings

[Steven Jackson <sj@oscode.net>]

This is the same issue and fix as 1581b088fc91cbb974ad2b98431a8ecabb48
(backlight: corgi_lcd: use gpio_set_value_cansleep() to avoid WARN_ON).

PWM backlights which use a SPI/I2C IO expander to control power will see
warnings when disabling and enabling the backlight, we should use
_cansleep variants of gpio set/get whenever the context can sleep.

Other backlight drivers such as corgi_bl.c and gpio_backlight.c are
using _cansleep variants in the same contexts.

Signed-off-by: Steven Jackson <sj@oscode.net>
---
  drivers/video/backlight/pwm_bl.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/backlight/pwm_bl.c 
b/drivers/video/backlight/pwm_bl.c
index b2b366b..1261400 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -55,7 +55,7 @@ static void pwm_backlight_power_on(struct pwm_bl_data 
*pb, int brightness)
  		dev_err(pb->dev, "failed to enable power supply\n");

  	if (pb->enable_gpio)
-		gpiod_set_value(pb->enable_gpio, 1);
+		gpiod_set_value_cansleep(pb->enable_gpio, 1);

  	pwm_enable(pb->pwm);
  	pb->enabled = true;
@@ -70,7 +70,7 @@ static void pwm_backlight_power_off(struct pwm_bl_data 
*pb)
  	pwm_disable(pb->pwm);

  	if (pb->enable_gpio)
-		gpiod_set_value(pb->enable_gpio, 0);
+		gpiod_set_value_cansleep(pb->enable_gpio, 0);

  	regulator_disable(pb->power_supply);
  	pb->enabled = false;
-- 
2.7.4