diff mbox series

[7/7] arm64: dts: qcom: sc7280: Hook up the touchscreen IO rail on evoker

Message ID 20230206184744.7.I2d960ed7f2445db0cf3d227fde985fbd740f3c4d@changeid
State New
Headers
Series arm: qcom: Fix touchscreen voltage for sc7280-herobrine boards |

Commit Message

Doug Anderson Feb. 7, 2023, 2:48 a.m. UTC 
  On older revisions of evoker, the touchscreen was either
non-functional or needed special hardware magic to get it talking
properly. It's been decided that the proper way going forward is to
use L3C to power some buffers on the QCard and then configure the
touchscreens for 1.8V. Let's do that.

Note that this is safe to do even on older revs even if it might not
make the touchscreen work there (because they didn't have a properly
stuffed QCard). As talked about in the patch ("arm64: dts: qcom:
sc7280: On QCard, regulator L3C should be 1.8V") the L3C regulator
didn't go anywhere at all on older revs.

This patch relies on the patch ("HID: i2c-hid: goodix: Add
mainboard-vddio-supply") in order to function properly. Without that
patch this one won't do any harm but it won't actually accomplish its
goal.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
I haven't yet received real hardware to test this on, but it's a very
simple patch and, in the very least, highly unlikely to make anything
worse. No real users have these boards yet.

 arch/arm64/boot/dts/qcom/sc7280-herobrine-evoker.dtsi | 1 +
 1 file changed, 1 insertion(+)

Comments

Matthias Kaehlcke Feb. 7, 2023, 6:47 p.m. UTC | #1 
On Mon, Feb 06, 2023 at 06:48:16PM -0800, Douglas Anderson wrote:
> On older revisions of evoker, the touchscreen was either
> non-functional or needed special hardware magic to get it talking
> properly. It's been decided that the proper way going forward is to
> use L3C to power some buffers on the QCard and then configure the
> touchscreens for 1.8V. Let's do that.
> 
> Note that this is safe to do even on older revs even if it might not
> make the touchscreen work there (because they didn't have a properly
> stuffed QCard). As talked about in the patch ("arm64: dts: qcom:
> sc7280: On QCard, regulator L3C should be 1.8V") the L3C regulator
> didn't go anywhere at all on older revs.
> 
> This patch relies on the patch ("HID: i2c-hid: goodix: Add
> mainboard-vddio-supply") in order to function properly. Without that
> patch this one won't do any harm but it won't actually accomplish its
> goal.
> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/qcom/sc7280-herobrine-evoker.dtsi b/arch/arm64/boot/dts/qcom/sc7280-herobrine-evoker.dtsi
index 3d639c70a06e..0add7a2a099c 100644
--- a/arch/arm64/boot/dts/qcom/sc7280-herobrine-evoker.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7280-herobrine-evoker.dtsi
@@ -55,6 +55,7 @@  ap_ts: touchscreen@5d {
 		reset-gpios = <&tlmm 54 GPIO_ACTIVE_LOW>;
 
 		vdd-supply = <&ts_avdd>;
+		mainboard-vddio-supply = <&ts_avccio>;
 	};
 };