pwm-pca9685: Fix several driver bugs (4a627b52) · Commits · 戴 / test

Problems: - When duty_ns == period_ns, the full OFF bit was not cleared and the PWM output of the PCA9685 stayed off. - When duty_ns == period_ns and the catch-all channel was used, the ALL_LED_OFF_L register was not cleared. - The full ON bit was not cleared when setting the OFF time, therefore the exact OFF time was ignored when setting a duty_ns < period_ns Solution: Clear both OFF registers when setting full ON and clear the full ON bit when changing the OFF registers. Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Steffen Trumtrar <s.trumtrar@pengutronix.de> Signed-off-by:

Clemens Gruber <clemens.gruber@pqgruber.com> Signed-off-by:

Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-pca9685.c

+24 −0

Original line number	Diff line number	Diff line
		@@ -85,6 +85,22 @@ static int pca9685_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
		}

		if (duty_ns == period_ns) {
		/* Clear both OFF registers */
		if (pwm->hwpwm >= PCA9685_MAXCHAN)
		reg = PCA9685_ALL_LED_OFF_L;
		else
		reg = LED_N_OFF_L(pwm->hwpwm);

		regmap_write(pca->regmap, reg, 0x0);

		if (pwm->hwpwm >= PCA9685_MAXCHAN)
		reg = PCA9685_ALL_LED_OFF_H;
		else
		reg = LED_N_OFF_H(pwm->hwpwm);

		regmap_write(pca->regmap, reg, 0x0);

		/* Set the full ON bit */
		if (pwm->hwpwm >= PCA9685_MAXCHAN)
		reg = PCA9685_ALL_LED_ON_H;
		else
		@@ -112,6 +128,14 @@ static int pca9685_pwm_config(struct pwm_chip chip, struct pwm_device pwm,

		regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf);

		/* Clear the full ON bit, otherwise the set OFF time has no effect */
		if (pwm->hwpwm >= PCA9685_MAXCHAN)
		reg = PCA9685_ALL_LED_ON_H;
		else
		reg = LED_N_ON_H(pwm->hwpwm);

		regmap_write(pca->regmap, reg, 0);

		return 0;
		}

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