[PATCH v2] arm64: dts: qcom: x1e80100-dell-xps13-9345: enable onboard accelerometers

[Aleksandrs Vinarskis]

Particular laptop comes with two sets of sensors:
1. Motherboard: accelerometer
2. Display/Camera module: accelerometer, ambient ligth (and more)
   sensor

Both i2c busses are bound to Snapdragon Sensor Core (SSC) and are
typically controlled by (A)DSP thus allowing for great power
efficiency. This however requires DSP libraries matching ADSP firmware,
sensors descriptions (must be extracted from Windows) and other
potentially closed-source libraries. Opensource tooling includes
`libssc` and `hexagonrpcd`, but they were not verified to be working.

Until SSC support for X1E lands, bitbang both i2c busses to enable
accelerometer functionality. In the future if/when sensors on this
platform can be used from DSP directly, this commit can be reverted.

Both accelerometers were tested individually via `monitor-sensor`.
Display accelerometer is defined first, as it appears automatic
screen rotation tools simply pick the 1st iio device.

Signed-off-by: Aleksandrs Vinarskis <alex@xxxxxxxxxxxxx>
---
Enable two accelerometers, one on the motherboard, one in display.
In combination with userland screen rotation tools such as Gnome's
'screen rotate' [1] this allows for automatic screen rotation depending
on device orientation.

There appears to be an ALS, a "True Color Sensor with Flicker Detection"
AMS TCS3530 at 0x39. Out-of-tree driver from OSRAM is available [2].
Document bus, address, IRQ such that it could be added in the future.

There is an issue with st_sensors which prevents initializing two
sensors at the time, fix submitted [3]. It is not blocking this series,
as without it, 2nd currently unused accelerometer on the motherboard
will simply fail to probe.

[1] https://extensions.gnome.org/extension/5389/screen-rotate
[2] https://ams-osram.com/support/download-center?search=TCS3530&type=software&subtype=driver
[3] https://lore.kernel.org/all/20260228-st-iio-trigger-v1-1-abf5909e547f@xxxxxxxxxxxxx/
---
Changes in v2:
- Fixed i2c node names to pass dtbs_check
- Updated commit description to reflect discussions of v1
- Link to v1: https://lore.kernel.org/r/20260228-dell-xps-9345-accel-v1-1-daf9e3b3b5ee@xxxxxxxxxxxxx
---
 .../boot/dts/qcom/x1e80100-dell-xps13-9345.dts     | 94 ++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/x1e80100-dell-xps13-9345.dts b/arch/arm64/boot/dts/qcom/x1e80100-dell-xps13-9345.dts
index ce7b10ea89b6dcb2a4a65c114037f4c90a4b0c6d..bde88655c36889cc4865a109370a9d2cd0166a00 100644
--- a/arch/arm64/boot/dts/qcom/x1e80100-dell-xps13-9345.dts
+++ b/arch/arm64/boot/dts/qcom/x1e80100-dell-xps13-9345.dts
@@ -40,6 +40,67 @@ switch-lid {
 		};
 	};
 
+	/* Display-mounted sensors */
+	i2c-sensors1 {
+		compatible = "i2c-gpio";
+		i2c-gpio,delay-us = <2>;
+
+		scl-gpios = <&tlmm 232 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+		sda-gpios = <&tlmm 231 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+
+		pinctrl-0 = <&sensors_i2c_display_default>;
+		pinctrl-names = "default";
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		accelerometer@18 {
+			compatible = "st,lis2dw12";
+			reg = <0x18>;
+
+			interrupts-extended = <&tlmm 29 IRQ_TYPE_LEVEL_LOW>;
+			pinctrl-0 = <&acc_display_int_n_default>;
+			pinctrl-names = "default";
+
+			mount-matrix = "-1", "0", "0",
+				       "0", "1", "0",
+				       "0", "0", "-1";
+		};
+
+		/* AMS TCS3530 @ 0x39, IRQ 93 */
+	};
+
+	/* Motherboard-mounted sensors */
+	i2c-sensors2 {
+		compatible = "i2c-gpio";
+		i2c-gpio,delay-us = <2>;
+
+		scl-gpios = <&tlmm 216 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+		sda-gpios = <&tlmm 215 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+
+		pinctrl-0 = <&sensors_i2c_mobo_default>;
+		pinctrl-names = "default";
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		accelerometer@18 {
+			compatible = "st,lis2dw12";
+			reg = <0x18>;
+
+			interrupts-extended = <&tlmm 28 IRQ_TYPE_LEVEL_LOW>;
+			pinctrl-0 = <&acc_mobo_int_n_default>;
+			pinctrl-names = "default";
+
+			vdd-supply = <&vreg_l10b_1p8>;
+			vddio-supply = <&vreg_l10b_1p8>;
+
+			mount-matrix = "0", "1", "0",
+				       "0", "0", "1",
+				       "1", "0", "0";
+		};
+	};
+
 	leds {
 		compatible = "gpio-leds";
 
@@ -450,6 +511,13 @@ vreg_l9b_2p9: ldo9 {
 			regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
 		};
 
+		vreg_l10b_1p8: ldo10 {
+			regulator-name = "vreg_l10b_1p8";
+			regulator-min-microvolt = <1800000>;
+			regulator-max-microvolt = <1800000>;
+			regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
+		};
+
 		vreg_l12b_1p2: ldo12 {
 			regulator-name = "vreg_l12b_1p2";
 			regulator-min-microvolt = <1200000>;
@@ -1074,6 +1142,18 @@ &tlmm {
 			       <76 4>,  /* SPI19 (TZ Protected) */
 			       <238 1>; /* UFS Reset */
 
+	acc_display_int_n_default: acc-display-int-n-state {
+		pins = "gpio29";
+		function = "gpio";
+		bias-pull-up;
+	};
+
+	acc_mobo_int_n_default: acc-mobo-int-n-state {
+		pins = "gpio28";
+		function = "gpio";
+		bias-pull-up;
+	};
+
 	cam_indicator_en: cam-indicator-en-state {
 		pins = "gpio110";
 		function = "gpio";
@@ -1197,6 +1277,20 @@ rtmr1_default: rtmr1-reset-n-active-state {
 		bias-disable;
 	};
 
+	sensors_i2c_display_default: sensors-i2c-display-state {
+		pins = "gpio231", "gpio232";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-disable;
+	};
+
+	sensors_i2c_mobo_default: sensors-i2c-mobo-state {
+		pins = "gpio215", "gpio216";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-disable;
+	};
+
 	tpad_default: tpad-default-state {
 		disable-pins {
 			pins = "gpio38";

---
base-commit: 3b058d1aeeeff27a7289529c4944291613b364e9
change-id: 20260228-dell-xps-9345-accel-4ab40ed9c827

Best regards,
-- 
Aleksandrs Vinarskis <alex@xxxxxxxxxxxxx>