Commit 48ca7f30 authored by Bastien Curutchet's avatar Bastien Curutchet Committed by Lee Jones
Browse files

leds: pca9532: Use PWM1 for hardware blinking 



PSC0/PWM0 are used by all LEDs for brightness and blinking. This causes
conflicts when you set a brightness of a new LED while an other one is
already using PWM0 for blinking.

Use PSC1/PWM1 for blinking.
Check that no other LED is already blinking with a different PSC1/PWM1
configuration to avoid conflict.

Signed-off-by: default avatarBastien Curutchet <bastien.curutchet@bootlin.com>
Link: https://lore.kernel.org/r/20240617143910.154546-3-bastien.curutchet@bootlin.com


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent 0e69c906

drivers/leds/leds-pca9532.c

+43 −10
Original line number Diff line number Diff line
@@ -29,6 +29,9 @@ 
#define LED_SHIFT(led)		(LED_NUM(led) * 2)

#define LED_MASK(led)		(0x3 << LED_SHIFT(led))



#define PCA9532_PWM_PERIOD_DIV	152

#define PCA9532_PWM_DUTY_DIV	256



#define ldev_to_led(c)       container_of(c, struct pca9532_led, ldev)



struct pca9532_chip_info {
@@ -194,29 +197,59 @@ static int pca9532_set_brightness(struct led_classdev *led_cdev, 
	return err;

}



static int pca9532_update_hw_blink(struct pca9532_led *led,

				   unsigned long delay_on, unsigned long delay_off)

{

	struct pca9532_data *data = i2c_get_clientdata(led->client);

	unsigned int psc;

	int i;



	/* Look for others LEDs that already use PWM1 */

	for (i = 0; i < data->chip_info->num_leds; i++) {

		struct pca9532_led *other = &data->leds[i];



		if (other == led)

			continue;



		if (other->state == PCA9532_PWM1) {

			if (other->ldev.blink_delay_on != delay_on ||

			    other->ldev.blink_delay_off != delay_off) {

				dev_err(&led->client->dev,

					"HW can handle only one blink configuration at a time\n");

				return -EINVAL;

			}

		}

	}



	psc = ((delay_on + delay_off) * PCA9532_PWM_PERIOD_DIV - 1) / 1000;

	if (psc > U8_MAX) {

		dev_err(&led->client->dev, "Blink period too long to be handled by hardware\n");

		return -EINVAL;

	}



	led->state = PCA9532_PWM1;

	data->psc[PCA9532_PWM_ID_1] = psc;

	data->pwm[PCA9532_PWM_ID_1] = (delay_on * PCA9532_PWM_DUTY_DIV) / (delay_on + delay_off);



	return pca9532_setpwm(data->client, PCA9532_PWM_ID_1);

}



static int pca9532_set_blink(struct led_classdev *led_cdev,

	unsigned long *delay_on, unsigned long *delay_off)

{

	struct pca9532_led *led = ldev_to_led(led_cdev);

	struct i2c_client *client = led->client;

	int psc;

	int err = 0;

	int err;



	if (*delay_on == 0 && *delay_off == 0) {

		/* led subsystem ask us for a blink rate */

		*delay_on = 1000;

		*delay_off = 1000;

	}

	if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)

		return -EINVAL;



	/* Thecus specific: only use PSC/PWM 0 */

	psc = (*delay_on * 152-1)/1000;

	err = pca9532_calcpwm(client, PCA9532_PWM_ID_0, psc, led_cdev->brightness);

	err = pca9532_update_hw_blink(led, *delay_on, *delay_off);

	if (err)

		return err;

	if (led->state == PCA9532_PWM0)

		pca9532_setpwm(led->client, PCA9532_PWM_ID_0);



	pca9532_setled(led);



	return 0;