[PATCH v3 1/5] pwm-backlight: enable/disable the PWM before/after LCD enable toggle.

Enric Balletbo i Serra enric.balletbo at collabora.com
Mon Jul 17 14:28:07 PDT 2017


Before this patch the enable signal was set before the PWM signal and
vice-versa on power off. I guess that this sequence is wrong, at least,
it is on the different panels datasheets that I checked, so I inverted
the sequence to follow the specs.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo at collabora.com>
---
Changes since v2:
 - Add this as a separate patch (Thierry Reding)
Changes since v1:
 - None

 drivers/video/backlight/pwm_bl.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 002f1ce..909a686 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -54,10 +54,11 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
 	if (err < 0)
 		dev_err(pb->dev, "failed to enable power supply\n");
 
+	pwm_enable(pb->pwm);
+
 	if (pb->enable_gpio)
 		gpiod_set_value_cansleep(pb->enable_gpio, 1);
 
-	pwm_enable(pb->pwm);
 	pb->enabled = true;
 }
 
@@ -66,12 +67,12 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb)
 	if (!pb->enabled)
 		return;
 
-	pwm_config(pb->pwm, 0, pb->period);
-	pwm_disable(pb->pwm);
-
 	if (pb->enable_gpio)
 		gpiod_set_value_cansleep(pb->enable_gpio, 0);
 
+	pwm_config(pb->pwm, 0, pb->period);
+	pwm_disable(pb->pwm);
+
 	regulator_disable(pb->power_supply);
 	pb->enabled = false;
 }
-- 
2.9.3




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