linux-kernel - [PATCH 01/15] video: fbdev: atmel_lcdfb: Rework backlight handling

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Message-Id: <20230107-sam-video-backlight-drop-fb_blank-v1-1-1bd9bafb351f@ravnborg.org>
Date:   Sat, 07 Jan 2023 19:26:15 +0100
From:   Sam Ravnborg via B4 Submission Endpoint 
        <devnull+sam.ravnborg.org@...nel.org>
To:     Nicolas Ferre <nicolas.ferre@...rochip.com>,
        Helge Deller <deller@....de>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Claudiu Beznea <claudiu.beznea@...rochip.com>,
        Antonino Daplas <adaplas@...il.com>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Robin van der Gracht <robin@...tonic.nl>,
        Miguel Ojeda <ojeda@...nel.org>, Lee Jones <lee@...nel.org>,
        Daniel Thompson <daniel.thompson@...aro.org>,
        Jingoo Han <jingoohan1@...il.com>
Cc:     linux-fbdev@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-omap@...r.kernel.org, linux-staging@...ts.linux.dev,
        linuxppc-dev@...ts.ozlabs.org, Stephen Kitt <steve@....org>,
        Sam Ravnborg <sam@...nborg.org>,
        Ludovic Desroches <ludovic.desroches@...rochip.com>
Subject: [PATCH 01/15] video: fbdev: atmel_lcdfb: Rework backlight handling

From: Sam Ravnborg <sam@...nborg.org>

The atmel_lcdfb had code to save/restore power state.
This is not needed so drop it.

Introduce backlight_is_brightness() to make logic simpler.

Signed-off-by: Sam Ravnborg <sam@...nborg.org>
Cc: Nicolas Ferre <nicolas.ferre@...rochip.com>
Cc: Alexandre Belloni <alexandre.belloni@...tlin.com>
Cc: Ludovic Desroches <ludovic.desroches@...rochip.com>
Cc: linux-fbdev@...r.kernel.org
Cc: linux-arm-kernel@...ts.infradead.org
---
 drivers/video/fbdev/atmel_lcdfb.c | 24 +++---------------------
 1 file changed, 3 insertions(+), 21 deletions(-)

diff --git a/drivers/video/fbdev/atmel_lcdfb.c b/drivers/video/fbdev/atmel_lcdfb.c
index 1fc8de4ecbeb..d297b3892637 100644
--- a/drivers/video/fbdev/atmel_lcdfb.c
+++ b/drivers/video/fbdev/atmel_lcdfb.c
@@ -49,7 +49,6 @@ struct atmel_lcdfb_info {
 	struct clk		*lcdc_clk;
 
 	struct backlight_device	*backlight;
-	u8			bl_power;
 	u8			saved_lcdcon;
 
 	u32			pseudo_palette[16];
@@ -109,32 +108,18 @@ static u32 contrast_ctr = ATMEL_LCDC_PS_DIV8
 static int atmel_bl_update_status(struct backlight_device *bl)
 {
 	struct atmel_lcdfb_info *sinfo = bl_get_data(bl);
-	int			power = sinfo->bl_power;
-	int			brightness = bl->props.brightness;
+	int brightness;
 
-	/* REVISIT there may be a meaningful difference between
-	 * fb_blank and power ... there seem to be some cases
-	 * this doesn't handle correctly.
-	 */
-	if (bl->props.fb_blank != sinfo->bl_power)
-		power = bl->props.fb_blank;
-	else if (bl->props.power != sinfo->bl_power)
-		power = bl->props.power;
-
-	if (brightness < 0 && power == FB_BLANK_UNBLANK)
-		brightness = lcdc_readl(sinfo, ATMEL_LCDC_CONTRAST_VAL);
-	else if (power != FB_BLANK_UNBLANK)
-		brightness = 0;
+	brightness = backlight_get_brightness(bl);
 
 	lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_VAL, brightness);
+
 	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;
-
 	return 0;
 }
 
@@ -155,8 +140,6 @@ static void init_backlight(struct atmel_lcdfb_info *sinfo)
 	struct backlight_properties props;
 	struct backlight_device	*bl;
 
-	sinfo->bl_power = FB_BLANK_UNBLANK;
-
 	if (sinfo->backlight)
 		return;
 
@@ -173,7 +156,6 @@ static void init_backlight(struct atmel_lcdfb_info *sinfo)
 	sinfo->backlight = bl;
 
 	bl->props.power = FB_BLANK_UNBLANK;
-	bl->props.fb_blank = FB_BLANK_UNBLANK;
 	bl->props.brightness = atmel_bl_get_brightness(bl);
 }
 

-- 
2.34.1