[PATCH v2] pwm-backlight: fix the panel power sequence

YH Huang
2015-10-16T09:17:40Z

In order to match the panel power sequence, disable the enable_gpio
in the probe function. Also, reorder the code in the power_on and
power_off function to match the timing.

Signed-off-by: YH Huang <yh.huang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
Change in v2:
Fix the build error.
---
drivers/video/backlight/pwm_bl.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index eff379b..d8c9c62 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(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(pb->enable_gpio, 0);

+ pwm_config(pb->pwm, 0, pb->period);
+ pwm_disable(pb->pwm);
+
regulator_disable(pb->power_supply);
pb->enabled = false;
}
@@ -242,7 +243,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
pb->enabled = false;

pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
- GPIOD_OUT_HIGH);
+ GPIOD_ASIS);
if (IS_ERR(pb->enable_gpio)) {
ret = PTR_ERR(pb->enable_gpio);
goto err_alloc;
@@ -264,6 +265,9 @@ static int pwm_backlight_probe(struct platform_device *pdev)
pb->enable_gpio = gpio_to_desc(data->enable_gpio);
}

+ if (pb->enable_gpio)
+ gpiod_direction_output(pb->enable_gpio, 0);
+
pb->power_supply = devm_regulator_get(&pdev->dev, "power");
if (IS_ERR(pb->power_supply)) {
ret = PTR_ERR(pb->power_supply);
--
1.7.9.5