Commit 14d89565 authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Thierry Reding
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pwm: vt8500: Implement .apply() callback 



To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply(). This just pushes down a slightly
optimized variant of how legacy drivers are handled in the core.

Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent 0ee11b87

drivers/pwm/pwm-vt8500.c

+50 −7
Original line number Diff line number Diff line
@@ -70,7 +70,7 @@ static inline void vt8500_pwm_busy_wait(struct vt8500_chip *vt8500, int nr, u8 b 
}



static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,

		int duty_ns, int period_ns)

		u64 duty_ns, u64 period_ns)

{

	struct vt8500_chip *vt8500 = to_vt8500_chip(chip);

	unsigned long long c;
@@ -102,8 +102,8 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, 
	}



	c = (unsigned long long)pv * duty_ns;

	do_div(c, period_ns);

	dc = c;



	dc = div64_u64(c, period_ns);



	writel(prescale, vt8500->base + REG_SCALAR(pwm->hwpwm));

	vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_SCALAR_UPDATE);
@@ -176,11 +176,54 @@ static int vt8500_pwm_set_polarity(struct pwm_chip *chip, 
	return 0;

}



static int vt8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,

			    const struct pwm_state *state)

{

	int err;

	bool enabled = pwm->state.enabled;



	if (state->polarity != pwm->state.polarity) {

		/*

		 * Changing the polarity of a running PWM is only allowed when

		 * the PWM driver implements ->apply().

		 */

		if (enabled) {

			vt8500_pwm_disable(chip, pwm);



			enabled = false;

		}



		err = vt8500_pwm_set_polarity(chip, pwm, state->polarity);

		if (err)

			return err;

	}



	if (!state->enabled) {

		if (enabled)

			vt8500_pwm_disable(chip, pwm);



		return 0;

	}



	/*

	 * We cannot skip calling ->config even if state->period ==

	 * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle

	 * because we might have exited early in the last call to

	 * pwm_apply_state because of !state->enabled and so the two values in

	 * pwm->state might not be configured in hardware.

	 */

	err = vt8500_pwm_config(pwm->chip, pwm, state->duty_cycle, state->period);

	if (err)

		return err;



	if (!enabled)

		err = vt8500_pwm_enable(chip, pwm);



	return err;

}



static const struct pwm_ops vt8500_pwm_ops = {

	.enable = vt8500_pwm_enable,

	.disable = vt8500_pwm_disable,

	.config = vt8500_pwm_config,

	.set_polarity = vt8500_pwm_set_polarity,

	.apply = vt8500_pwm_apply,

	.owner = THIS_MODULE,

};