linux-kernel - [PATCH 5.11 176/775] drm/panel: s6e63m0: Support max-brightness

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210301161210.327472163@linuxfoundation.org>
Date:   Mon,  1 Mar 2021 17:05:44 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Stephan Gerhold <stephan@...hold.net>,
        Linus Walleij <linus.walleij@...aro.org>,
        Sam Ravnborg <sam@...nborg.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.11 176/775] drm/panel: s6e63m0: Support max-brightness

From: Linus Walleij <linus.walleij@...aro.org>

[ Upstream commit 1f20bf5921de420071fdb1d55cda7550ae137bcd ]

The "max-brightness" is a standard backlight property that
we need to support for the Samsung GT-I8190 Golden because
the display will go black if we crank up the brightness
too high.

As the platform needs this ability to give picture this is
a regression fix along with the addition of the property
to the GT-I8190 device tree.

Cc: Stephan Gerhold <stephan@...hold.net>
Fixes: 9c3f0a0dd6a1 ("drm/panel: s6e63m0: Implement 28 backlight levels")
Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
Reviewed-by: Sam Ravnborg <sam@...nborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201214222210.238081-1-linus.walleij@linaro.org
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpu/drm/panel/panel-samsung-s6e63m0.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c b/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c
index bf6d704d4d272..603c5dfe87682 100644
--- a/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c
+++ b/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c
@@ -692,12 +692,12 @@ static const struct backlight_ops s6e63m0_backlight_ops = {
 	.update_status	= s6e63m0_set_brightness,
 };
 
-static int s6e63m0_backlight_register(struct s6e63m0 *ctx)
+static int s6e63m0_backlight_register(struct s6e63m0 *ctx, u32 max_brightness)
 {
 	struct backlight_properties props = {
 		.type		= BACKLIGHT_RAW,
-		.brightness	= MAX_BRIGHTNESS,
-		.max_brightness = MAX_BRIGHTNESS
+		.brightness	= max_brightness,
+		.max_brightness = max_brightness,
 	};
 	struct device *dev = ctx->dev;
 	int ret = 0;
@@ -719,6 +719,7 @@ int s6e63m0_probe(struct device *dev,
 		  bool dsi_mode)
 {
 	struct s6e63m0 *ctx;
+	u32 max_brightness;
 	int ret;
 
 	ctx = devm_kzalloc(dev, sizeof(struct s6e63m0), GFP_KERNEL);
@@ -734,6 +735,14 @@ int s6e63m0_probe(struct device *dev,
 	ctx->enabled = false;
 	ctx->prepared = false;
 
+	ret = device_property_read_u32(dev, "max-brightness", &max_brightness);
+	if (ret)
+		max_brightness = MAX_BRIGHTNESS;
+	if (max_brightness > MAX_BRIGHTNESS) {
+		dev_err(dev, "illegal max brightness specified\n");
+		max_brightness = MAX_BRIGHTNESS;
+	}
+
 	ctx->supplies[0].supply = "vdd3";
 	ctx->supplies[1].supply = "vci";
 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),
@@ -753,7 +762,7 @@ int s6e63m0_probe(struct device *dev,
 		       dsi_mode ? DRM_MODE_CONNECTOR_DSI :
 		       DRM_MODE_CONNECTOR_DPI);
 
-	ret = s6e63m0_backlight_register(ctx);
+	ret = s6e63m0_backlight_register(ctx, max_brightness);
 	if (ret < 0)
 		return ret;
 
-- 
2.27.0