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pwm: vt8500: Implement .apply() callback

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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: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Uwe Kleine-König 2021-11-02 10:28:03 +01:00 committed by Thierry Reding
parent 0ee11b87c3
commit 14d8956548
1 changed files with 50 additions and 7 deletions
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57
drivers/pwm/pwm-vt8500.c
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@ -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,
};