pwm: crc: Implement apply() method to support the new atomic PWM API

Replace the enable, disable and config pwm_ops with an apply op,
to support the new atomic PWM API.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-13-hdegoede@redhat.com

drivers/pwm/pwm-crc.c

@@ -51,59 +51,78 @@ 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));
+	struct crystalcove_pwm *crc_pwm = to_crc_pwm(chip);
+	struct device *dev = crc_pwm->chip.dev;
+	int err;
 
-	regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, div | PWM_OUTPUT_ENABLE);
-	regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 1);
+	if (state->period > PWM_MAX_PERIOD_NS) {
+		dev_err(dev, "un-supported period_ns\n");
+		return -EINVAL;
+	}
 
-	return 0;
-}
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -EOPNOTSUPP;
 
-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));
+	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;
+		}
+	}
 
-	regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0);
-	regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, div);
-}
+	if (pwm_get_duty_cycle(pwm) != state->duty_cycle ||
+	    pwm_get_period(pwm) != state->period) {
+		u64 level = state->duty_cycle * PWM_MAX_LEVEL;
 
-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 device *dev = crc_pwm->chip.dev;
-	int level;
+		do_div(level, state->period);
 
-	if (period_ns > PWM_MAX_PERIOD_NS) {
-		dev_err(dev, "un-supported period_ns\n");
-		return -EINVAL;
+		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_get_period(pwm) != period_ns) {
-		int clk_div = crc_pwm_calc_clk_div(period_ns);
-
+	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)