pwm: meson: Don't cache struct pwm_state internally

The PWM core already caches the "current struct pwm_state" as the
"current state of the hardware registers" inside struct pwm_device.

Drop the struct pwm_state from struct meson_pwm_channel in favour of the
struct pwm_state in struct pwm_device. While here also drop any checks
based on the pwm_state because the PWM core already takes care of this.

No functional changes intended.
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-meson.c

@@ -68,8 +68,6 @@ struct meson_pwm_channel {
 	unsigned int lo;
 	u8 pre_div;
 
-	struct pwm_state state;
-
 	struct clk *clk_parent;
 	struct clk_mux mux;
 	struct clk *clk;
@@ -127,8 +125,6 @@ static int meson_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 		return err;
 	}
 
-	chip->ops->get_state(chip, pwm, &channel->state);
-
 	return pwm_set_chip_data(pwm, channel);
 }
 
@@ -153,10 +149,6 @@ static int meson_pwm_calc(struct meson_pwm *meson, struct pwm_device *pwm,
 	if (state->polarity == PWM_POLARITY_INVERSED)
 		duty = period - duty;
 
-	if (period == channel->state.period &&
-	    duty == channel->state.duty_cycle)
-		return 0;
-
 	fin_freq = clk_get_rate(channel->clk);
 	if (fin_freq == 0) {
 		dev_err(meson->chip.dev, "invalid source clock frequency\n");
@@ -253,7 +245,6 @@ static void meson_pwm_disable(struct meson_pwm *meson, struct pwm_device *pwm)
 static int meson_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			   struct pwm_state *state)
 {
-	struct meson_pwm_channel *channel = pwm_get_chip_data(pwm);
 	struct meson_pwm *meson = to_meson_pwm(chip);
 	int err = 0;
 
@@ -262,26 +253,12 @@ static int meson_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	if (!state->enabled) {
 		meson_pwm_disable(meson, pwm);
-		channel->state.enabled = false;
-
-		return 0;
-	}
-
-	if (state->period != channel->state.period ||
-	    state->duty_cycle != channel->state.duty_cycle ||
-	    state->polarity != channel->state.polarity) {
+	} else {
 		err = meson_pwm_calc(meson, pwm, state);
 		if (err < 0)
 			return err;
 
-		channel->state.polarity = state->polarity;
-		channel->state.period = state->period;
-		channel->state.duty_cycle = state->duty_cycle;
-	}
-
-	if (state->enabled && !channel->state.enabled) {
 		meson_pwm_enable(meson, pwm);
-		channel->state.enabled = true;
 	}
 
 	return 0;