pwm: Move the enabled/disabled info into pwm_state

Prepare the transition to PWM atomic update by moving the enabled and
disabled state into the pwm_state struct. This way we can easily update
the whole PWM state by copying the new state in the ->state field.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index f3f91e7..c240b54 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -499,10 +499,10 @@
 	if (!pwm)
 		return -EINVAL;
 
-	if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) {
+	if (!pwm_is_enabled(pwm)) {
 		err = pwm->chip->ops->enable(pwm->chip, pwm);
-		if (err)
-			clear_bit(PWMF_ENABLED, &pwm->flags);
+		if (!err)
+			pwm->state.enabled = true;
 	}
 
 	return err;
@@ -515,8 +515,13 @@
  */
 void pwm_disable(struct pwm_device *pwm)
 {
-	if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
+	if (!pwm)
+		return;
+
+	if (pwm_is_enabled(pwm)) {
 		pwm->chip->ops->disable(pwm->chip, pwm);
+		pwm->state.enabled = false;
+	}
 }
 EXPORT_SYMBOL_GPL(pwm_disable);