pwm-backlight: retrieve configured PWM period

The PWM core is now able to initialize the PWM period from a lookup
table defined by board files. Use it if available and fallback to the
value supplied in pwm_period_ns.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index cc49347bbcc0..38ca88bc5c3e 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -296,12 +296,15 @@ static int pwm_backlight_probe(struct platform_device *pdev)
         /*
          * 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.
+         * set the period from platform data if it has not already been set
+         * via the PWM lookup table.
          */
-        if (data->pwm_period_ns > 0)
+        pb->period = pwm_get_period(pb->pwm);
+        if (!pb->period && (data->pwm_period_ns > 0)) {
+                pb->period = data->pwm_period_ns;
                 pwm_set_period(pb->pwm, data->pwm_period_ns);
+        }
 
-        pb->period = pwm_get_period(pb->pwm);
         pb->lth_brightness = data->lth_brightness * (pb->period / pb->scale);
 
         memset(&props, 0, sizeof(struct backlight_properties));