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path: root/drivers/leds/leds-pwm.c
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Diffstat (limited to 'drivers/leds/leds-pwm.c')
-rw-r--r--drivers/leds/leds-pwm.c49
1 files changed, 43 insertions, 6 deletions
diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
index d71e9fa5c8de..6832180c1c54 100644
--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -17,10 +17,12 @@
#include <linux/err.h>
#include <linux/pwm.h>
#include <linux/slab.h>
+#include "leds.h"
struct led_pwm {
const char *name;
u8 active_low;
+ u8 default_state;
unsigned int max_brightness;
};
@@ -77,7 +79,38 @@ static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
led_data->cdev.brightness_set_blocking = led_pwm_set;
- pwm_init_state(led_data->pwm, &led_data->pwmstate);
+ /* init PWM state */
+ switch (led->default_state) {
+ case LEDS_DEFSTATE_KEEP:
+ pwm_get_state(led_data->pwm, &led_data->pwmstate);
+ if (led_data->pwmstate.period)
+ break;
+ led->default_state = LEDS_DEFSTATE_OFF;
+ dev_warn(dev,
+ "failed to read period for %s, default to off",
+ led->name);
+ fallthrough;
+ default:
+ pwm_init_state(led_data->pwm, &led_data->pwmstate);
+ break;
+ }
+
+ /* set brightness */
+ switch (led->default_state) {
+ case LEDS_DEFSTATE_ON:
+ led_data->cdev.brightness = led->max_brightness;
+ break;
+ case LEDS_DEFSTATE_KEEP:
+ {
+ uint64_t brightness;
+
+ brightness = led->max_brightness;
+ brightness *= led_data->pwmstate.duty_cycle;
+ do_div(brightness, led_data->pwmstate.period);
+ led_data->cdev.brightness = brightness;
+ }
+ break;
+ }
ret = devm_led_classdev_register_ext(dev, &led_data->cdev, &init_data);
if (ret) {
@@ -86,11 +119,13 @@ static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
return ret;
}
- ret = led_pwm_set(&led_data->cdev, led_data->cdev.brightness);
- if (ret) {
- dev_err(dev, "failed to set led PWM value for %s: %d",
- led->name, ret);
- return ret;
+ if (led->default_state != LEDS_DEFSTATE_KEEP) {
+ ret = led_pwm_set(&led_data->cdev, led_data->cdev.brightness);
+ if (ret) {
+ dev_err(dev, "failed to set led PWM value for %s: %d",
+ led->name, ret);
+ return ret;
+ }
}
priv->num_leds++;
@@ -120,6 +155,8 @@ static int led_pwm_create_fwnode(struct device *dev, struct led_pwm_priv *priv)
fwnode_property_read_u32(fwnode, "max-brightness",
&led.max_brightness);
+ led.default_state = led_init_default_state_get(fwnode);
+
ret = led_pwm_add(dev, priv, &led, fwnode);
if (ret)
goto err_child_out;