[PATCH v3 0/5] ARM: dts: qcom: msm8960: expressatt: Add more peripherals

[PATCH v3 0/5] ARM: dts: qcom: msm8960: expressatt: Add more peripherals

[Rudraksha Gupta via B4 Relay]

Intro:
=================
The following is now working on the Samsung Galaxy Express SGH-I437, an
old 2012 Android phone:
- Light Sensor
    - Proximity is currently floating, even though it matches downstream
      GPIO pin
- Magnetometer
    - Regardless of orientation:
        - X axis seems to always be negative
        - Y and Z axis seems to always be positive
- NFC
- Accelerometer

Tests:
=================
Light Sensor
=================
// no external light on sensor
/sys/bus/iio/devices/iio:device2 # cat in_intensity0_raw && cat \
in_intensity1_raw
0
0

// external light shining on sensor
samsung-expressatt:/sys/bus/iio/devices/iio:device2$ cat \
in_intensity0_raw in_intensity1_raw
915
163

=================
NFC
=================
samsung-expressatt:~$ sudo nfctool -d nfc0 -1 -p
doas (user@samsung-expressatt) password: 
nfc0:
          Tags: [ ]
          Devices: [ ]
          Protocols: [ Felica MIFARE Jewel ISO-DEP NFC-DEP ]
          Powered: Yes
          RF Mode: None
          lto: 150
          rw: 15
          miux: 2047

Start polling on nfc0 as initiator

Targets found for nfc0
  Tags: [ tag0 ]
  Devices: [ ]

=================
Magnetometer
=================
// no matter the orientation x is always negative and y and z are always
// positive. The values seem to be changing during rotation, but for some
// reason the magnitude is extremely large
/sys/bus/iio/devices/iio:device1 # cat in_magn_x_raw && cat \
in_magn_y_raw && cat in_magn_z_raw
-441672
1223706
3275580

=================
Accelerometer
=================
I believe it follows the mount matrix guide located in the kernel:
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/mount-matrix.txt

// phone is vertical with charger port closest to the ground and the
// camera closest to the sky. result: +y
samsung-expressatt:/sys/bus/iio/devices/iio:device0$ cat in_accel_x_raw \
in_accel_y_raw in_accel_z_raw
4
488
-47

// phone is flat on the ground with the back of the phone closest to the
// ground and the screen closest to the sky. result: +z
samsung-expressatt:/sys/bus/iio/devices/iio:device0$ cat in_accel_x_raw \
in_accel_y_raw in_accel_z_raw
-4
2
496

// start with phone flat on the ground and the back of the phone
// closest to the ground and the screen closest to the sky. then rotate the
// phone so the charger is closest to you
// next, tilt the phone onto it's left edge. in this case, it would be
// the side with the volume buttons. result: +x
samsung-expressatt:/sys/bus/iio/devices/iio:device0$ cat in_accel_x_raw \
in_accel_y_raw in_accel_z_raw
499
-5
8

More Information:
=================
- Device page:
https://wiki.postmarketos.org/wiki/Samsung_Galaxy_Express_SGH-I437_(samsung-expressatt)
- Downstream kernel (uses board files):
https://github.com/LineageOS/android_kernel_samsung_d2/blob/stable/cm-12.0-YNG4N/arch/arm/mach-msm/board-express.c

Note: These patches were assisted with AI (specifically Claude) as it
was easily able to translate the old board file into a DTS format that
mainline understands.

Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
---
Changes in v3:
- More formatting changes
- Remove output-low on nfc_enable
- Resolved TODO mount matrix for accelerometer. My tests are above.
- Will try to eventually solve the following problems:
    - Couldn't figure out the mount matrix for magnetometer
    - Proximity is a floating value even though the downstream kernel
      matches the GPIO pin
- Link to v2: https://lore.kernel.org/r/20251121-expressatt_nfc_accel_magn_light-v2-0-54ce493cc6cf@gmail.com

Changes in v2:
- Fixed formatting issues
- Use GSBI instead of i2c-gpio
- Remove regulator-always-on
- Link to v1: https://lore.kernel.org/r/20251119-expressatt_nfc_accel_magn_light-v1-0-636f16f05cf4@gmail.com

---
Rudraksha Gupta (5):
      ARM: dts: qcom: msm8960: Add GSBI2 & GSBI7
      ARM: dts: qcom: msm8960: expressatt: Add Light/Proximity Sensor
      ARM: dts: qcom: msm8960: expressatt: Add NFC
      ARM: dts: qcom: msm8960: expressatt: Add Magnetometer
      ARM: dts: qcom: msm8960: expressatt: Add Accelerometer

 .../dts/qcom/qcom-msm8960-samsung-expressatt.dts   | 105 +++++++++++++++++++++
 arch/arm/boot/dts/qcom/qcom-msm8960.dtsi           |  96 +++++++++++++++++++
 2 files changed, 201 insertions(+)
---
base-commit: a771210bab42017434c91411e16694ac4fd7afc2
change-id: 20251119-expressatt_nfc_accel_magn_light-f78e02897186
prerequisite-message-id: <176210698639.937813.643585209118839199.b4-ty@kernel.org>
prerequisite-patch-id: befdfe1948c2fbfb867597a6de917c8067fd57be
prerequisite-patch-id: 70a2b0837b9846d8a775f464295da73ca8ff26b4
prerequisite-patch-id: 20e005aa4312c3525e1b90f33a398189b9e2b3b7
prerequisite-patch-id: 970e0eb8af1736e4565fc37830576a67bf7b3227
prerequisite-patch-id: babd3b55d9ff28f19dbc3f7978742c58ef436aee

Best regards,
-- 
Rudraksha Gupta <guptarud@gmail.com>

[PATCH v3 1/5] ARM: dts: qcom: msm8960: Add GSBI2 & GSBI7

[Rudraksha Gupta via B4 Relay]

From: Rudraksha Gupta <guptarud@gmail.com>

Add the GSBI2 & GSBI7 Node, which is similar to the
other GSBI nodes in this file.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
---
 arch/arm/boot/dts/qcom/qcom-msm8960.dtsi | 96 ++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

diff --git a/arch/arm/boot/dts/qcom/qcom-msm8960.dtsi b/arch/arm/boot/dts/qcom/qcom-msm8960.dtsi
index 38bd4fd8dda5..fd28401cebb5 100644
--- a/arch/arm/boot/dts/qcom/qcom-msm8960.dtsi
+++ b/arch/arm/boot/dts/qcom/qcom-msm8960.dtsi
@@ -149,6 +149,24 @@ i2c1-pins {
 				};
 			};
 
+			i2c2_default_state: i2c2-default-state {
+				i2c2-pins {
+					pins = "gpio12", "gpio13";
+					function = "gsbi2";
+					drive-strength = <8>;
+					bias-disable;
+				};
+			};
+
+			i2c2_sleep_state: i2c2-sleep-state {
+				i2c2-pins {
+					pins = "gpio12", "gpio13";
+					function = "gpio";
+					drive-strength = <2>;
+					bias-bus-hold;
+				};
+			};
+
 			i2c3_default_state: i2c3-default-state {
 				i2c3-pins {
 					pins = "gpio16", "gpio17";
@@ -167,6 +185,24 @@ i2c3-pins {
 				};
 			};
 
+			i2c7_default_state: i2c7-default-state {
+				i2c7-pins {
+					pins = "gpio32", "gpio33";
+					function = "gsbi7";
+					drive-strength = <8>;
+					bias-disable;
+				};
+			};
+
+			i2c7_sleep_state: i2c7-sleep-state {
+				i2c7-pins {
+					pins = "gpio32", "gpio33";
+					function = "gpio";
+					drive-strength = <2>;
+					bias-bus-hold;
+				};
+			};
+
 			i2c8_default_state: i2c8-default-state {
 				i2c8-pins {
 					pins = "gpio36", "gpio37";
@@ -543,6 +579,36 @@ gsbi1_spi: spi@16080000 {
 			};
 		};
 
+		gsbi2: gsbi@16100000 {
+			compatible = "qcom,gsbi-v1.0.0";
+			reg = <0x16100000 0x100>;
+			ranges;
+			cell-index = <2>;
+			clocks = <&gcc GSBI2_H_CLK>;
+			clock-names = "iface";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			status = "disabled";
+
+			gsbi2_i2c: i2c@16180000 {
+				compatible = "qcom,i2c-qup-v1.1.1";
+				reg = <0x16180000 0x1000>;
+				pinctrl-0 = <&i2c2_default_state>;
+				pinctrl-1 = <&i2c2_sleep_state>;
+				pinctrl-names = "default", "sleep";
+				interrupts = <GIC_SPI 149 IRQ_TYPE_LEVEL_HIGH>;
+				clocks = <&gcc GSBI2_QUP_CLK>,
+					 <&gcc GSBI2_H_CLK>;
+				clock-names = "core",
+					      "iface";
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				status = "disabled";
+			};
+		};
+
 		gsbi3: gsbi@16200000 {
 			compatible = "qcom,gsbi-v1.0.0";
 			reg = <0x16200000 0x100>;
@@ -600,6 +666,36 @@ gsbi5_serial: serial@16440000 {
 			};
 		};
 
+		gsbi7: gsbi@16600000 {
+			compatible = "qcom,gsbi-v1.0.0";
+			reg = <0x16600000 0x100>;
+			ranges;
+			cell-index = <7>;
+			clocks = <&gcc GSBI7_H_CLK>;
+			clock-names = "iface";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			status = "disabled";
+
+			gsbi7_i2c: i2c@16680000 {
+				compatible = "qcom,i2c-qup-v1.1.1";
+				reg = <0x16680000 0x1000>;
+				pinctrl-0 = <&i2c7_default_state>;
+				pinctrl-1 = <&i2c7_sleep_state>;
+				pinctrl-names = "default", "sleep";
+				interrupts = <GIC_SPI 159 IRQ_TYPE_LEVEL_HIGH>;
+				clocks = <&gcc GSBI7_QUP_CLK>,
+					 <&gcc GSBI7_H_CLK>;
+				clock-names = "core",
+					      "iface";
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				status = "disabled";
+			};
+		};
+
 		gsbi8: gsbi@1a000000 {
 			compatible = "qcom,gsbi-v1.0.0";
 			reg = <0x1a000000 0x100>;

-- 
2.52.0

[PATCH v3 2/5] ARM: dts: qcom: msm8960: expressatt: Add Light/Proximity Sensor

[Rudraksha Gupta via B4 Relay]

From: Rudraksha Gupta <guptarud@gmail.com>

Currently the Proximity Sensor doesn't work, but light sensor does.
Left the proximity sensor as a TODO for later.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
---
 .../dts/qcom/qcom-msm8960-samsung-expressatt.dts   | 34 ++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts b/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
index 5ee919dce75b..8d75ebd7976c 100644
--- a/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
+++ b/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
@@ -54,6 +54,31 @@ key-volume-down {
 	};
 };
 
+&gsbi2 {
+	qcom,mode = <GSBI_PROT_I2C>;
+
+	status = "okay";
+};
+
+&gsbi2_i2c {
+	status = "okay";
+
+	light-sensor@39 {
+		compatible = "amstaos,tmd2772";
+		reg = <0x39>;
+		interrupts-extended = <&pm8921_gpio 6 IRQ_TYPE_EDGE_FALLING>;
+		vdd-supply = <&pm8921_l9>;
+		vddio-supply = <&pm8921_lvs4>;
+
+		/* TODO: Proximity doesn't work */
+		amstaos,proximity-diodes = <0>;
+		led-max-microamp = <100000>;
+
+		pinctrl-0 = <&prox_sensor_int>;
+		pinctrl-names = "default";
+	};
+};
+
 &gsbi5 {
 	qcom,mode = <GSBI_PROT_I2C_UART>;
 	status = "okay";
@@ -163,6 +188,15 @@ &pm8921 {
 	interrupts-extended = <&tlmm 104 IRQ_TYPE_LEVEL_LOW>;
 };
 
+&pm8921_gpio {
+	prox_sensor_int: prox-sensor-int-state {
+		pins = "gpio6";
+		function = "normal";
+		input-enable;
+		bias-disable;
+	};
+};
+
 &rpm {
 	regulators {
 		compatible = "qcom,rpm-pm8921-regulators";

-- 
2.52.0

[PATCH v3 3/5] ARM: dts: qcom: msm8960: expressatt: Add NFC

[Rudraksha Gupta via B4 Relay]

From: Rudraksha Gupta <guptarud@gmail.com>

Add pn544 NFC chip

Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
---
 .../dts/qcom/qcom-msm8960-samsung-expressatt.dts   | 45 ++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts b/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
index 8d75ebd7976c..4f9b59db7bc3 100644
--- a/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
+++ b/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
@@ -182,6 +182,22 @@ touchscreen: touchscreen-int-state {
 		bias-disable;
 		drive-strength = <2>;
 	};
+
+	nfc_default: nfc-default-state {
+		irq-pins {
+			pins = "gpio106";
+			function = "gpio";
+			drive-strength = <2>;
+			bias-pull-down;
+		};
+
+		firmware-pins {
+			pins = "gpio92";
+			function = "gpio";
+			drive-strength = <2>;
+			bias-disable;
+		};
+	};
 };
 
 &pm8921 {
@@ -195,6 +211,14 @@ prox_sensor_int: prox-sensor-int-state {
 		input-enable;
 		bias-disable;
 	};
+
+	nfc_enable: nfc-enable-state {
+		pins = "gpio21";
+		function = "normal";
+		bias-disable;
+		qcom,drive-strength = <PMIC_GPIO_STRENGTH_LOW>;
+		power-source = <PM8921_GPIO_S4>;
+	};
 };
 
 &rpm {
@@ -442,3 +466,24 @@ &usb1 {
 	dr_mode = "otg";
 	status = "okay";
 };
+
+&gsbi7 {
+	qcom,mode = <GSBI_PROT_I2C>;
+
+	status = "okay";
+};
+
+&gsbi7_i2c {
+	status = "okay";
+
+	nfc@2b {
+		compatible = "nxp,pn544-i2c";
+		reg = <0x2b>;
+		interrupts-extended = <&tlmm 106 IRQ_TYPE_EDGE_RISING>;
+		enable-gpios = <&pm8921_gpio 21 GPIO_ACTIVE_HIGH>;
+		firmware-gpios = <&tlmm 92 GPIO_ACTIVE_HIGH>;
+
+		pinctrl-0 = <&nfc_default &nfc_enable>;
+		pinctrl-names = "default";
+	};
+};

-- 
2.52.0

[PATCH v3 4/5] ARM: dts: qcom: msm8960: expressatt: Add Magnetometer

[Rudraksha Gupta via B4 Relay]

From: Rudraksha Gupta <guptarud@gmail.com>

Add the Yamaha magnetometer. Mount Matrix is left as a TODO.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
---
 .../boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts b/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
index 4f9b59db7bc3..d32461fc58e9 100644
--- a/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
+++ b/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
@@ -487,3 +487,22 @@ nfc@2b {
 		pinctrl-names = "default";
 	};
 };
+
+&gsbi12 {
+	qcom,mode = <GSBI_PROT_I2C>;
+
+	status = "okay";
+};
+
+&gsbi12_i2c {
+	status = "okay";
+
+	magnetometer@2e {
+		compatible = "yamaha,yas532";
+		reg = <0x2e>;
+		vdd-supply = <&pm8921_l9>;
+		iovdd-supply = <&pm8921_lvs4>;
+
+		/* TODO: Figure out Mount Matrix */
+	};
+};

-- 
2.52.0

[PATCH v3 5/5] ARM: dts: qcom: msm8960: expressatt: Add Accelerometer

[Rudraksha Gupta via B4 Relay]

From: Rudraksha Gupta <guptarud@gmail.com>

Add the Bosch Accelerometer.

Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
---
 arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts b/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
index d32461fc58e9..cb7b56283f15 100644
--- a/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
+++ b/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
@@ -497,6 +497,13 @@ &gsbi12 {
 &gsbi12_i2c {
 	status = "okay";
 
+	accelerometer@18 {
+		compatible = "bosch,bma254";
+		reg = <0x18>;
+		vdd-supply = <&pm8921_l9>;
+		vddio-supply = <&pm8921_lvs4>;
+	};
+
 	magnetometer@2e {
 		compatible = "yamaha,yas532";
 		reg = <0x2e>;

-- 
2.52.0

Re: [PATCH v3 5/5] ARM: dts: qcom: msm8960: expressatt: Add Accelerometer

[Konrad Dybcio]

On 11/23/25 7:44 AM, Rudraksha Gupta via B4 Relay wrote:
> From: Rudraksha Gupta <guptarud@gmail.com>
> 
> Add the Bosch Accelerometer.
> 
> Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
> ---

I'm assuming this essentially means "the default settings (no
mount matrix) work out fine"

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad

Re: [PATCH v3 3/5] ARM: dts: qcom: msm8960: expressatt: Add NFC

[Konrad Dybcio]

On 11/23/25 7:44 AM, Rudraksha Gupta via B4 Relay wrote:
> From: Rudraksha Gupta <guptarud@gmail.com>
> 
> Add pn544 NFC chip
> 
> Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad

Re: [PATCH v3 5/5] ARM: dts: qcom: msm8960: expressatt: Add Accelerometer

[Rudraksha Gupta]

On 11/24/25 02:31, Konrad Dybcio wrote:
> On 11/23/25 7:44 AM, Rudraksha Gupta via B4 Relay wrote:
>> From: Rudraksha Gupta <guptarud@gmail.com>
>>
>> Add the Bosch Accelerometer.
>>
>> Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
>> ---
> I'm assuming this essentially means "the default settings (no
> mount matrix) work out fine"

I initially thought so... but I recently discovered monitor-sensor:

https://gitlab.freedesktop.org/hadess/iio-sensor-proxy


And it turns out that my testing is wrong. Will send another revision 
with the updated mount-matrix and fixing a driver nullptr bug.


>
> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
>
> Konrad