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pwm: jz4740: Apply configuration atomically 

This is cleaner, more future-proof, and incidentally it also fixes the
PWM resetting its config when stopped/started several times.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Paul Cercueil 2019-06-07 17:44:07 +02:00 committed by Thierry Reding
parent 93808aca34
commit 1ac99c58bd
1 changed files with 12 additions and 25 deletions
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37
drivers/pwm/pwm-jz4740.c
View File

@ -83,17 +83,16 @@ static void jz4740_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
jz4740_timer_disable(pwm->hwpwm);
}
static int jz4740_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
static int jz4740_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
struct pwm_state *state)
{
struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip);
unsigned long long tmp;
unsigned long period, duty;
unsigned int prescaler = 0;
uint16_t ctrl;
bool is_enabled;
tmp = (unsigned long long)clk_get_rate(jz4740->clk) * period_ns;
tmp = (unsigned long long)clk_get_rate(jz4740->clk) * state->period;
do_div(tmp, 1000000000);
period = tmp;
@ -105,16 +104,14 @@ static int jz4740_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
if (prescaler == 6)
return -EINVAL;
tmp = (unsigned long long)period * duty_ns;
do_div(tmp, period_ns);
tmp = (unsigned long long)period * state->duty_cycle;
do_div(tmp, state->period);
duty = period - tmp;
if (duty >= period)
duty = period - 1;
is_enabled = jz4740_timer_is_enabled(pwm->hwpwm);
if (is_enabled)
jz4740_pwm_disable(chip, pwm);
jz4740_pwm_disable(chip, pwm);
jz4740_timer_set_count(pwm->hwpwm, 0);
jz4740_timer_set_duty(pwm->hwpwm, duty);
@ -125,18 +122,7 @@ static int jz4740_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
if (is_enabled)
jz4740_pwm_enable(chip, pwm);
return 0;
}
static int jz4740_pwm_set_polarity(struct pwm_chip *chip,
struct pwm_device *pwm, enum pwm_polarity polarity)
{
uint32_t ctrl = jz4740_timer_get_ctrl(pwm->pwm);
switch (polarity) {
switch (state->polarity) {
case PWM_POLARITY_NORMAL:
ctrl &= ~JZ_TIMER_CTRL_PWM_ACTIVE_LOW;
break;
@ -146,16 +132,17 @@ static int jz4740_pwm_set_polarity(struct pwm_chip *chip,
}
jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
if (state->enabled)
jz4740_pwm_enable(chip, pwm);
return 0;
}
static const struct pwm_ops jz4740_pwm_ops = {
.request = jz4740_pwm_request,
.free = jz4740_pwm_free,
.config = jz4740_pwm_config,
.set_polarity = jz4740_pwm_set_polarity,
.enable = jz4740_pwm_enable,
.disable = jz4740_pwm_disable,
.apply = jz4740_pwm_apply,
.owner = THIS_MODULE,
};