From 57e0d7b7f8663d0a3a5facc83c445ffc9802ad65 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 26 Jan 2021 22:32:00 +0100 Subject: backlight: ktd253: Bring up in a known state The KTD253 backlight might already be on when the driver is probed: then we don't really know what the current ratio is and all light intensity settings will be off relative to what it was at boot. To fix this, bring up the backlight OFF then move it to the default backlight from there so we know the state. Signed-off-by: Linus Walleij Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones --- drivers/video/backlight/ktd253-backlight.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) (limited to 'drivers/video') diff --git a/drivers/video/backlight/ktd253-backlight.c b/drivers/video/backlight/ktd253-backlight.c index e3fee3f1f582..d7b287cffd5c 100644 --- a/drivers/video/backlight/ktd253-backlight.c +++ b/drivers/video/backlight/ktd253-backlight.c @@ -137,15 +137,7 @@ static int ktd253_backlight_probe(struct platform_device *pdev) brightness = max_brightness; } - if (brightness) - /* This will be the default ratio when the KTD253 is enabled */ - ktd253->ratio = KTD253_MAX_RATIO; - else - ktd253->ratio = 0; - - ktd253->gpiod = devm_gpiod_get(dev, "enable", - brightness ? GPIOD_OUT_HIGH : - GPIOD_OUT_LOW); + ktd253->gpiod = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW); if (IS_ERR(ktd253->gpiod)) { ret = PTR_ERR(ktd253->gpiod); if (ret != -EPROBE_DEFER) @@ -153,6 +145,8 @@ static int ktd253_backlight_probe(struct platform_device *pdev) return ret; } gpiod_set_consumer_name(ktd253->gpiod, dev_name(dev)); + /* Bring backlight to a known off state */ + msleep(KTD253_T_OFF_MS); bl = devm_backlight_device_register(dev, dev_name(dev), dev, ktd253, &ktd253_backlight_ops, NULL); -- cgit v1.2.3