backlight: pwm_bl: Use pwm_get_args() where appropriate

The PWM framework has clarified the concept of reference PWM config (the
platform dependent config retrieved from the DT or the PWM lookup table)
and real PWM state.

Use pwm_get_args() when the PWM user wants to retrieve this reference
config and not the current state.

This is part of the rework allowing the PWM framework to support
hardware readout and expose real PWM state even when the PWM has just
been requested (before the user calls pwm_config/enable/disable()).

Signed-off-by: Boris Brezillon <[e-mail]>
Signed-off-by: Thierry Reding <[e-mail]>

drivers/video/backlight/pwm_bl.c

···
 	struct device_node *node = pdev->dev.of_node;
 	struct pwm_bl_data *pb;
 	int initial_blank = FB_BLANK_UNBLANK;
+	struct pwm_args pargs;
 	int ret;
 
 	if (!data) {
···
 	dev_dbg(&pdev->dev, "got pwm for backlight\n");
 
 	/*
+	 * FIXME: pwm_apply_args() should be removed when switching to
+	 * the atomic PWM API.
+	 */
+	pwm_apply_args(pb->pwm);
+
+	/*
 	 * The DT case will set the pwm_period_ns field to 0 and store the
 	 * period, parsed from the DT, in the PWM device. For the non-DT case,
 	 * set the period from platform data if it has not already been set
 	 * via the PWM lookup table.
 	 */
-	pb->period = pwm_get_period(pb->pwm);
+	pwm_get_args(pb->pwm, &pargs);
+	pb->period = pargs.period;
 	if (!pb->period && (data->pwm_period_ns > 0))
 		pb->period = data->pwm_period_ns;