pwm: Clear chip_data in pwm_put()

BugLink: https://bugs.launchpad.net/bugs/1855313

commit e926b12c upstream.

After a PWM is disposed by its user the per chip data becomes invalid.
Clear the data in common code instead of the device drivers to get
consistent behaviour. Before this patch only three of nine drivers
cleaned up here.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/pwm/core.c

@@ -781,6 +781,7 @@ void pwm_put(struct pwm_device *pwm)
 	if (pwm->chip->ops->free)
 		pwm->chip->ops->free(pwm->chip, pwm);
 
+	pwm_set_chip_data(pwm, NULL);
 	pwm->label = NULL;
 
 	module_put(pwm->chip->ops->owner);

drivers/pwm/pwm-samsung.c

@@ -226,7 +226,6 @@ static int pwm_samsung_request(struct pwm_chip *chip, struct pwm_device *pwm)
 static void pwm_samsung_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	devm_kfree(chip->dev, pwm_get_chip_data(pwm));
-	pwm_set_chip_data(pwm, NULL);
 }
 
 static int pwm_samsung_enable(struct pwm_chip *chip, struct pwm_device *pwm)