[PATCH v3 10/15] pwm: crc: Implement apply() method to support the new atomic PWM API

Hans de Goede
2020-06-20T12:19:14Z

Replace the enable, disable and config pwm_ops with an apply op,
to support the new atomic PWM API.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v3:
- Keep crc_pwm_calc_clk_div() helper to avoid needless churn
---
drivers/pwm/pwm-crc.c | 89 ++++++++++++++++++++++++++-----------------
1 file changed, 53 insertions(+), 36 deletions(-)

diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c
index b72008c9b072..8a7f4707279c 100644
--- a/drivers/pwm/pwm-crc.c
+++ b/drivers/pwm/pwm-crc.c
@@ -51,59 +51,76 @@ static int crc_pwm_calc_clk_div(int period_ns)
return clk_div;
}

-static int crc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm)
+static int crc_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
{
- struct crystalcove_pwm *crc_pwm = to_crc_pwm(c);
- int div = crc_pwm_calc_clk_div(pwm_get_period(pwm));
-
- regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, div | PWM_OUTPUT_ENABLE);
- regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 1);
-
- return 0;
-}
-
-static void crc_pwm_disable(struct pwm_chip *c, struct pwm_device *pwm)
-{
- struct crystalcove_pwm *crc_pwm = to_crc_pwm(c);
- int div = crc_pwm_calc_clk_div(pwm_get_period(pwm));
-
- regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0);
- regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, div);
-}
-
-static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm,
- int duty_ns, int period_ns)
-{
- struct crystalcove_pwm *crc_pwm = to_crc_pwm(c);
+ struct crystalcove_pwm *crc_pwm = to_crc_pwm(chip);
struct device *dev = crc_pwm->chip.dev;
- int level;
+ int err;

- if (period_ns > PWM_MAX_PERIOD_NS) {
+ if (state->period > PWM_MAX_PERIOD_NS) {
dev_err(dev, "un-supported period_ns\n");
return -EINVAL;
}

- if (pwm_get_period(pwm) != period_ns) {
- int clk_div = crc_pwm_calc_clk_div(period_ns);
+ if (state->polarity != PWM_POLARITY_NORMAL)
+ return -EOPNOTSUPP;
+
+ if (pwm_is_enabled(pwm) && !state->enabled) {
+ err = regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0);
+ if (err) {
+ dev_err(dev, "Error writing BACKLIGHT_EN %d\n", err);
+ return err;
+ }
+ }
+
+ if (pwm_get_duty_cycle(pwm) != state->duty_cycle ||
+ pwm_get_period(pwm) != state->period) {
+ int level = state->duty_cycle * PWM_MAX_LEVEL / state->period;

+ err = regmap_write(crc_pwm->regmap, PWM0_DUTY_CYCLE, level);
+ if (err) {
+ dev_err(dev, "Error writing PWM0_DUTY_CYCLE %d\n", err);
+ return err;
+ }
+ }
+
+ if (pwm_is_enabled(pwm) && state->enabled &&
+ pwm_get_period(pwm) != state->period) {
/* changing the clk divisor, clear PWM_OUTPUT_ENABLE first */
- regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, 0);
+ err = regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, 0);
+ if (err) {
+ dev_err(dev, "Error writing PWM0_CLK_DIV %d\n", err);
+ return err;
+ }
+ }

- regmap_write(crc_pwm->regmap, PWM0_CLK_DIV,
- clk_div | PWM_OUTPUT_ENABLE);
+ if (pwm_get_period(pwm) != state->period ||
+ pwm_is_enabled(pwm) != state->enabled) {
+ int clk_div = crc_pwm_calc_clk_div(state->period);
+ int pwm_output_enable = state->enabled ? PWM_OUTPUT_ENABLE : 0;
+
+ err = regmap_write(crc_pwm->regmap, PWM0_CLK_DIV,
+ clk_div | pwm_output_enable);
+ if (err) {
+ dev_err(dev, "Error writing PWM0_CLK_DIV %d\n", err);
+ return err;
+ }
}

- /* change the pwm duty cycle */
- level = duty_ns * PWM_MAX_LEVEL / period_ns;
- regmap_write(crc_pwm->regmap, PWM0_DUTY_CYCLE, level);
+ if (!pwm_is_enabled(pwm) && state->enabled) {
+ err = regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 1);
+ if (err) {
+ dev_err(dev, "Error writing BACKLIGHT_EN %d\n", err);
+ return err;
+ }
+ }

return 0;
}

static const struct pwm_ops crc_pwm_ops = {
- .config = crc_pwm_config,
- .enable = crc_pwm_enable,
- .disable = crc_pwm_disable,
+ .apply = crc_pwm_apply,
};

static int crystalcove_pwm_probe(struct platform_device *pdev)
--
2.26.2