diff mbox series

[v2,3/4] arm64: dts: qcom: x1e80100-crd: Fix backlight

Message ID 20240715-x1e80100-crd-backlight-v2-3-31b7f2f658a3@linaro.org (mailing list archive)
State Accepted
Commit 55d71c9f53335fac6a9949a1e1f9871cf2bac9a5
Headers show
Series drm/panel: atna33xc20: Fix the Samsung ATNA45AF01 panel | expand

Commit Message

Stephan Gerhold July 15, 2024, 12:15 p.m. UTC
The backlight does not work correctly with the current display panel
configuration: It works after boot, but once the display gets disabled it
is not possible to get it back on. It turns out that the ATNA45AF01 panel
needs exactly the same non-standard power sequence as implemented by the
panel-samsung-atna33xc20 driver for sc7180-trogdor-homestar.

Switch the panel in the DT to the new compatible and make two more changes
to make it work correctly:

 1. Add the missing GPIO for the panel EL_ON3 line (EDP_BL_EN on CRD and
    enable-gpios in the DT).
 2. Drop the regulator-always-on for the panel regulator. The panel does
    not seem to power off properly if the regulator stays on.

Fixes: d7e03cce0400 ("arm64: dts: qcom: x1e80100-crd: Enable more support")
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
---
This can be applied as fix for 6.11 since the driver works as-is with the
fallback compatible. If so, the defconfig patch should ideally also go
there to ensure people actually have the driver enabled.
---
 arch/arm64/boot/dts/qcom/x1e80100-crd.dts | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

Comments

Johan Hovold July 15, 2024, 12:33 p.m. UTC | #1
On Mon, Jul 15, 2024 at 02:15:39PM +0200, Stephan Gerhold wrote:
> The backlight does not work correctly with the current display panel
> configuration: It works after boot, but once the display gets disabled it
> is not possible to get it back on. It turns out that the ATNA45AF01 panel
> needs exactly the same non-standard power sequence as implemented by the
> panel-samsung-atna33xc20 driver for sc7180-trogdor-homestar.
> 
> Switch the panel in the DT to the new compatible and make two more changes
> to make it work correctly:
> 
>  1. Add the missing GPIO for the panel EL_ON3 line (EDP_BL_EN on CRD and
>     enable-gpios in the DT).
>  2. Drop the regulator-always-on for the panel regulator. The panel does
>     not seem to power off properly if the regulator stays on.
> 
> Fixes: d7e03cce0400 ("arm64: dts: qcom: x1e80100-crd: Enable more support")
> Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
> ---
> This can be applied as fix for 6.11 since the driver works as-is with the
> fallback compatible. If so, the defconfig patch should ideally also go
> there to ensure people actually have the driver enabled.

Verified that I can change the brightness setting and that the backlight
comes on again after being turned off (e.g. at suspend):

Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/qcom/x1e80100-crd.dts b/arch/arm64/boot/dts/qcom/x1e80100-crd.dts
index 6152bcd0bc1f..4a4eb7211e69 100644
--- a/arch/arm64/boot/dts/qcom/x1e80100-crd.dts
+++ b/arch/arm64/boot/dts/qcom/x1e80100-crd.dts
@@ -268,7 +268,6 @@  vreg_edp_3p3: regulator-edp-3p3 {
 		pinctrl-0 = <&edp_reg_en>;
 		pinctrl-names = "default";
 
-		regulator-always-on;
 		regulator-boot-on;
 	};
 
@@ -724,9 +723,13 @@  &mdss_dp3 {
 
 	aux-bus {
 		panel {
-			compatible = "edp-panel";
+			compatible = "samsung,atna45af01", "samsung,atna33xc20";
+			enable-gpios = <&pmc8380_3_gpios 4 GPIO_ACTIVE_HIGH>;
 			power-supply = <&vreg_edp_3p3>;
 
+			pinctrl-0 = <&edp_bl_en>;
+			pinctrl-names = "default";
+
 			port {
 				edp_panel_in: endpoint {
 					remote-endpoint = <&mdss_dp3_out>;
@@ -785,6 +788,16 @@  &pcie6a_phy {
 	status = "okay";
 };
 
+&pmc8380_3_gpios {
+	edp_bl_en: edp-bl-en-state {
+		pins = "gpio4";
+		function = "normal";
+		power-source = <1>; /* 1.8V */
+		input-disable;
+		output-enable;
+	};
+};
+
 &qupv3_0 {
 	status = "okay";
 };