[PATCH v6 0/2] Add support for OLED panel used on Snapdragon Lenovo T14s Gen6

[PATCH v6 0/2] Add support for OLED panel used on Snapdragon Lenovo T14s Gen6

[Christopher Obbard]

The Snapdragon Lenovo T14s Gen6 can be bought with a number of different
panels. This patch series adds support for the OLED model which has a
Samsung ATNA40YK20 panel.

With this patch series the backlight of the OLED eDP panel does not
illuminate since the brightness is incorrectly read from the eDP panel
as (to be clear this is not a regression). This is fixed in [0].

[0]: https://lore.kernel.org/all/20250330-wip-obbardc-qcom-t14s-oled-panel-brightness-v6-1-84ad1cd1078a@linaro.org/

Signed-off-by: Christopher Obbard <christopher.obbard@linaro.org>
---
Changes in v6:
- Squash patches adding "edp_hpd_active" node & its user (Johan).
- Sort new pinctrl node correctly by name (Johan).
- Use correct function "edp0_hot" instead of "edp_hot" (Johan).
- Drop review tags.
- Link to v5: https://lore.kernel.org/r/20250402-wip-obbardc-qcom-t14s-oled-panel-v5-0-ff33f4d0020f@linaro.org

Changes in v5:
- Move edp_hpd_active from T14s DTS into SoC DTSI (Dmitry).
- Link to v4: https://lore.kernel.org/r/20250402-wip-obbardc-qcom-t14s-oled-panel-v4-0-41ba3f3739d0@linaro.org

Changes in v4:
- Rework HPD GPIO into eDP device rather than panel (Johan).
- Drop review tags for HPD GPIO patch.
- Link to v3: https://lore.kernel.org/r/20250327-wip-obbardc-qcom-t14s-oled-panel-v3-0-45d5f2747398@linaro.org

Changes in v3:
- Added review trailers from v2.
- Dropped dt-binding documentation patch (applied by Douglas Anderson into
  drm-misc-next).
- Dropped eDP maximum brightness patch (will be sent in separate
  series).
- Removed duplicate nodes in T14s OLED device tree.
- Reworked WIP comments from commit messages.
- Link to v2: https://lore.kernel.org/r/20250325-wip-obbardc-qcom-t14s-oled-panel-v2-0-e9bc7c9d30cc@linaro.org

Changes in v2:
- Use the existing atna33xc20 driver rather than panel-edp.
- Add eDP panel into OLED devicetree.
- Add patch to read the correct maximum brightness from the eDP panel.
- Link to v1: https://lore.kernel.org/r/20250320-wip-obbardc-qcom-t14s-oled-panel-v1-1-05bc4bdcd82a@linaro.org

---
Christopher Obbard (2):
      arm64: dts: qcom: x1e78100-t14s: add hpd gpio to dp controller
      arm64: dts: qcom: x1e78100-t14s-oled: add edp panel

 arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s-oled.dts | 8 ++++++++
 arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi     | 3 +++
 arch/arm64/boot/dts/qcom/x1e80100.dtsi                          | 5 +++++
 3 files changed, 16 insertions(+)
---
base-commit: ba94ec807b071becbed7377f8c84308f1b6ccd51
change-id: 20250320-wip-obbardc-qcom-t14s-oled-panel-b74fed21d600

Best regards,
-- 
Christopher Obbard <christopher.obbard@linaro.org>

[PATCH v6 1/2] arm64: dts: qcom: x1e78100-t14s: add hpd gpio to dp controller

[Christopher Obbard]

The eDP controller has an HPD GPIO. Describe it in the device tree
for the generic T14s model, as the HPD GPIO is used in both the
OLED and LCD models which inherit this device tree.

Signed-off-by: Christopher Obbard <christopher.obbard@linaro.org>
---
 arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi | 3 +++
 arch/arm64/boot/dts/qcom/x1e80100.dtsi                      | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi
index ac1dddf27da30e6a9f7e1d1ecbd5192bf2d0671e..c33dce6fec6746cc7fe2f7a1ab5e9f99feea5535 100644
--- a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi
+++ b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi
@@ -1008,6 +1008,9 @@ &mdss_dp1_out {
 &mdss_dp3 {
 	/delete-property/ #sound-dai-cells;
 
+	pinctrl-names = "default";
+	pinctrl-0 = <&edp_hpd_active>;
+
 	status = "okay";
 
 	aux-bus {
diff --git a/arch/arm64/boot/dts/qcom/x1e80100.dtsi b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
index 5e9a8fa3cf96468b12775f91192cbd779d5ce946..8efd045af778beb30831f3af5ad2b901a72d87d7 100644
--- a/arch/arm64/boot/dts/qcom/x1e80100.dtsi
+++ b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
@@ -5779,6 +5779,11 @@ tlmm: pinctrl@f100000 {
 			gpio-ranges = <&tlmm 0 0 239>;
 			wakeup-parent = <&pdc>;
 
+			edp_hpd_active: edp-hpd-active-state {
+				pins = "gpio119";
+				function = "edp0_hot";
+			};
+
 			qup_i2c0_data_clk: qup-i2c0-data-clk-state {
 				/* SDA, SCL */
 				pins = "gpio0", "gpio1";

-- 
2.50.1

Re: [PATCH v6 1/2] arm64: dts: qcom: x1e78100-t14s: add hpd gpio to dp controller

[Johan Hovold]

On Thu, Jul 31, 2025 at 09:51:26PM +0100, Christopher Obbard wrote:
> The eDP controller has an HPD GPIO. Describe it in the device tree
> for the generic T14s model, as the HPD GPIO is used in both the
> OLED and LCD models which inherit this device tree.

> @@ -5779,6 +5779,11 @@ tlmm: pinctrl@f100000 {
>  			gpio-ranges = <&tlmm 0 0 239>;
>  			wakeup-parent = <&pdc>;
>  
> +			edp_hpd_active: edp-hpd-active-state {

The node name and label needs an index as this SoC has two edp hpd pins
as I already pointed out.

> +				pins = "gpio119";
> +				function = "edp0_hot";

And you also need to configure the bias somewhere as you should not rely
on the firmware having configured things for you (as I also pointed out
before).

On my T14s the internal pull-up has been disabled.

> +			};

Johan

Re: [PATCH v6 1/2] arm64: dts: qcom: x1e78100-t14s: add hpd gpio to dp controller

[Christopher Obbard]

Hi Johan,


On Mon, 4 Aug 2025 at 14:13, Johan Hovold <johan@kernel.org> wrote:
>
> On Thu, Jul 31, 2025 at 09:51:26PM +0100, Christopher Obbard wrote:
> > The eDP controller has an HPD GPIO. Describe it in the device tree
> > for the generic T14s model, as the HPD GPIO is used in both the
> > OLED and LCD models which inherit this device tree.
>
> > @@ -5779,6 +5779,11 @@ tlmm: pinctrl@f100000 {
> >                       gpio-ranges = <&tlmm 0 0 239>;
> >                       wakeup-parent = <&pdc>;
> >
> > +                     edp_hpd_active: edp-hpd-active-state {
>
> The node name and label needs an index as this SoC has two edp hpd pins
> as I already pointed out.

Sure. After looking at the schematics this should be called
edp0_hpd_active. I will fix this in the next revision.


> > +                             pins = "gpio119";
> > +                             function = "edp0_hot";
>
> And you also need to configure the bias somewhere as you should not rely
> on the firmware having configured things for you (as I also pointed out
> before).
>
> On my T14s the internal pull-up has been disabled.

I am still unsure of what else needs to be set here. Can you help me
with the correct settings?

Thanks,
Chris

Re: [PATCH v6 1/2] arm64: dts: qcom: x1e78100-t14s: add hpd gpio to dp controller

[Neil Armstrong]

On 09/08/2025 00:28, Christopher Obbard wrote:
> Hi Johan,
> 
> 
> On Mon, 4 Aug 2025 at 14:13, Johan Hovold <johan@kernel.org> wrote:
>>
>> On Thu, Jul 31, 2025 at 09:51:26PM +0100, Christopher Obbard wrote:
>>> The eDP controller has an HPD GPIO. Describe it in the device tree
>>> for the generic T14s model, as the HPD GPIO is used in both the
>>> OLED and LCD models which inherit this device tree.
>>
>>> @@ -5779,6 +5779,11 @@ tlmm: pinctrl@f100000 {
>>>                        gpio-ranges = <&tlmm 0 0 239>;
>>>                        wakeup-parent = <&pdc>;
>>>
>>> +                     edp_hpd_active: edp-hpd-active-state {
>>
>> The node name and label needs an index as this SoC has two edp hpd pins
>> as I already pointed out.
> 
> Sure. After looking at the schematics this should be called
> edp0_hpd_active. I will fix this in the next revision.
> 
> 
>>> +                             pins = "gpio119";
>>> +                             function = "edp0_hot";
>>
>> And you also need to configure the bias somewhere as you should not rely
>> on the firmware having configured things for you (as I also pointed out
>> before).
>>
>> On my T14s the internal pull-up has been disabled.
> 
> I am still unsure of what else needs to be set here. Can you help me
> with the correct settings?

Just add bias-disable;

Neil

> 
> Thanks,
> Chris

Re: [PATCH v6 1/2] arm64: dts: qcom: x1e78100-t14s: add hpd gpio to dp controller

[Stephan Gerhold]

On Thu, Aug 14, 2025 at 04:21:09PM +0200, Neil Armstrong wrote:
> On 09/08/2025 00:28, Christopher Obbard wrote:
> > On Mon, 4 Aug 2025 at 14:13, Johan Hovold <johan@kernel.org> wrote:
> > > 
> > > On Thu, Jul 31, 2025 at 09:51:26PM +0100, Christopher Obbard wrote:
> > > > The eDP controller has an HPD GPIO. Describe it in the device tree
> > > > for the generic T14s model, as the HPD GPIO is used in both the
> > > > OLED and LCD models which inherit this device tree.
> > > 
> > > > @@ -5779,6 +5779,11 @@ tlmm: pinctrl@f100000 {
> > > >                        gpio-ranges = <&tlmm 0 0 239>;
> > > >                        wakeup-parent = <&pdc>;
> > > > 
> > > > +                     edp_hpd_active: edp-hpd-active-state {
> > > 
> > > The node name and label needs an index as this SoC has two edp hpd pins
> > > as I already pointed out.
> > 
> > Sure. After looking at the schematics this should be called
> > edp0_hpd_active. I will fix this in the next revision.
> > 
> > 
> > > > +                             pins = "gpio119";
> > > > +                             function = "edp0_hot";
> > > 
> > > And you also need to configure the bias somewhere as you should not rely
> > > on the firmware having configured things for you (as I also pointed out
> > > before).
> > > 
> > > On my T14s the internal pull-up has been disabled.
> > 
> > I am still unsure of what else needs to be set here. Can you help me
> > with the correct settings?
> 
> Just add bias-disable;
> 

I sent a patch fixing this for all the X1 devices upstream earlier [1],
so you could also just send v7 with just the second patch of your
series.

The bias-disable is really somewhat device-specific (what if there is no
pull down on the device side and someone disconnects the panel
entirely?), so I put it into each board DT separately like Johan
requested on v5. We have the same for the PCIe pinctrl.

Thanks,
Stephan

[1]: https://lore.kernel.org/linux-arm-msm/20250814-x1e80100-add-edp-hpd-v1-0-a52804db53f6@linaro.org/T/

Re: [PATCH v6 1/2] arm64: dts: qcom: x1e78100-t14s: add hpd gpio to dp controller

[Christopher Obbard]

Hi Stephan,

On Thu, 14 Aug 2025 at 15:47, Stephan Gerhold
<stephan.gerhold@linaro.org> wrote:
>
> On Thu, Aug 14, 2025 at 04:21:09PM +0200, Neil Armstrong wrote:
> > On 09/08/2025 00:28, Christopher Obbard wrote:
> > > On Mon, 4 Aug 2025 at 14:13, Johan Hovold <johan@kernel.org> wrote:
> > > >
> > > > On Thu, Jul 31, 2025 at 09:51:26PM +0100, Christopher Obbard wrote:
> > > > > The eDP controller has an HPD GPIO. Describe it in the device tree
> > > > > for the generic T14s model, as the HPD GPIO is used in both the
> > > > > OLED and LCD models which inherit this device tree.
> > > >
> > > > > @@ -5779,6 +5779,11 @@ tlmm: pinctrl@f100000 {
> > > > >                        gpio-ranges = <&tlmm 0 0 239>;
> > > > >                        wakeup-parent = <&pdc>;
> > > > >
> > > > > +                     edp_hpd_active: edp-hpd-active-state {
> > > >
> > > > The node name and label needs an index as this SoC has two edp hpd pins
> > > > as I already pointed out.
> > >
> > > Sure. After looking at the schematics this should be called
> > > edp0_hpd_active. I will fix this in the next revision.
> > >
> > >
> > > > > +                             pins = "gpio119";
> > > > > +                             function = "edp0_hot";
> > > >
> > > > And you also need to configure the bias somewhere as you should not rely
> > > > on the firmware having configured things for you (as I also pointed out
> > > > before).
> > > >
> > > > On my T14s the internal pull-up has been disabled.
> > >
> > > I am still unsure of what else needs to be set here. Can you help me
> > > with the correct settings?
> >
> > Just add bias-disable;
> >
>
> I sent a patch fixing this for all the X1 devices upstream earlier [1],
> so you could also just send v7 with just the second patch of your
> series.

Sure. I will do so and base my next version on your patchset.


> The bias-disable is really somewhat device-specific (what if there is no
> pull down on the device side and someone disconnects the panel
> entirely?), so I put it into each board DT separately like Johan
> requested on v5. We have the same for the PCIe pinctrl.
>
> Thanks,
> Stephan
>
> [1]: https://lore.kernel.org/linux-arm-msm/20250814-x1e80100-add-edp-hpd-v1-0-a52804db53f6@linaro.org/T/

[PATCH v6 2/2] arm64: dts: qcom: x1e78100-t14s-oled: add edp panel

[Christopher Obbard]

Add the Samsung ATNA40YK20 eDP panel to the device tree for the
Snapdragon T14s OLED model.

Signed-off-by: Christopher Obbard <christopher.obbard@linaro.org>
---
 arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s-oled.dts | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s-oled.dts b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s-oled.dts
index be65fafafa736a0401a5872c40f69cb20cfbbd90..d524afa12d19b2a6f22a24b9bed6b6b40248375f 100644
--- a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s-oled.dts
+++ b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s-oled.dts
@@ -10,3 +10,11 @@ / {
 	compatible = "lenovo,thinkpad-t14s-oled", "lenovo,thinkpad-t14s",
 		     "qcom,x1e78100", "qcom,x1e80100";
 };
+
+&panel {
+	compatible = "samsung,atna40yk20", "samsung,atna33xc20";
+	enable-gpios = <&pmc8380_3_gpios 4 GPIO_ACTIVE_HIGH>;
+
+	pinctrl-0 = <&edp_bl_en>;
+	pinctrl-names = "default";
+};

-- 
2.50.1