From acfdc2e1bdb4b148e7546fe8948d8f75bd2f9377 Mon Sep 17 00:00:00 2001 From: Alexander Stein Date: Wed, 5 Oct 2011 09:59:58 +0200 Subject: [PATCH] atmel_lcdfb: Use proper blanking on negative contrast polarity If used with negative polarity the PWM unit cannot be disabled. This would result in a full contrast screen. Instead let the PWM unit enabled using 0x0 as compare value which darkens the display. In result no power saving is possible if inverted contrast polarity is used. Signed-off-by: Alexander Stein Signed-off-by: Florian Tobias Schandinat --- drivers/video/atmel_lcdfb.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c index 7e66263b18c1..8bfee6aecc8b 100644 --- a/drivers/video/atmel_lcdfb.c +++ b/drivers/video/atmel_lcdfb.c @@ -99,8 +99,11 @@ static int atmel_bl_update_status(struct backlight_device *bl) brightness = 0; lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_VAL, brightness); - lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, + if (contrast_ctr & ATMEL_LCDC_POL_POSITIVE) + lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, brightness ? contrast_ctr : 0); + else + lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, contrast_ctr); bl->props.fb_blank = bl->props.power = sinfo->bl_power = power; -- 2.30.2