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video: backlight: Parse PWM polarity cell 

This patch enables the reading of the polarity cell from a PWM
phandle and calls pwm_set_invert().

Not all platforms have polarity cell, so skip if it's not pressent.

Signed-off-by: Stefan Mavrodiev <stefan@olimex.com>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
This commit is contained in:
Stefan Mavrodiev 2019-04-12 08:56:27 +03:00 committed by Anatolij Gustschin
parent cf5eebeb18
commit 57e7775413
1 changed files with 11 additions and 0 deletions
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11
drivers/video/pwm_backlight.c
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@ -39,6 +39,12 @@ struct pwm_backlight_priv {
struct udevice *pwm; struct udevice *pwm;
uint channel; uint channel;
uint period_ns; uint period_ns;
/*
* the polarity of one PWM
* 0: normal polarity
* 1: inverted polarity
*/
bool polarity;
u32 *levels; u32 *levels;
int num_levels; int num_levels;
uint default_level; uint default_level;
@ -57,7 +63,10 @@ static int set_pwm(struct pwm_backlight_priv *priv)
(priv->max_level - priv->min_level + 1); (priv->max_level - priv->min_level + 1);
ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns, ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns,
duty_cycle); duty_cycle);
if (ret)
return log_ret(ret);
ret = pwm_set_invert(priv->pwm, priv->channel, priv->polarity);
return log_ret(ret); return log_ret(ret);
} }
@ -202,6 +211,8 @@ static int pwm_backlight_ofdata_to_platdata(struct udevice *dev)
return log_msg_ret("Not enough arguments to pwm\n", -EINVAL); return log_msg_ret("Not enough arguments to pwm\n", -EINVAL);
priv->channel = args.args[0]; priv->channel = args.args[0];
priv->period_ns = args.args[1]; priv->period_ns = args.args[1];
if (args.args_count > 2)
priv->polarity = args.args[2];
index = dev_read_u32_default(dev, "default-brightness-level", 255); index = dev_read_u32_default(dev, "default-brightness-level", 255);
cell = dev_read_prop(dev, "brightness-levels", &len); cell = dev_read_prop(dev, "brightness-levels", &len);