[PATCH] ARM: dts: qcom: msm8960: expressatt Add PWM vibrator

[PATCH] ARM: dts: qcom: msm8960: expressatt Add PWM vibrator

[Rudraksha Gupta via B4 Relay]

From: Rudraksha Gupta <guptarud@gmail.com>

Add a pwm-vibrator to expressatt. Currently this vibrates only at 100%

Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
---
Add a pwm-vibrator to expressatt. Currently this vibrates only at 100%

Link:
- https://github.com/LineageOS/android_kernel_samsung_d2/blob/stable/cm-12.0-YNG4N/arch/arm/mach-msm/board-express.c#L1767
- https://github.com/LineageOS/android_kernel_samsung_d2/blob/stable/cm-12.0-YNG4N/drivers/motor/Makefile#L5

Test:
=====================
samsung-expressatt:~$ dmesg | grep vibra
[   79.892226] input: pwm-vibrator as /devices/platform/vibrator/input/input4
samsung-expressatt:~$ fftest /dev/input/event4 
Force feedback test program.
HOLD FIRMLY YOUR WHEEL OR JOYSTICK TO PREVENT DAMAGES

Device /dev/input/event4 opened
Features:
  * Absolute axes: 
    [00 00 00 00 00 00 00 00 ]
  * Relative axes: 
    [00 00 ]
  * Force feedback effects types: Periodic, Rumble, Gain, 
    Force feedback periodic effects: Square, Triangle, Sine, 
    [00 00 00 00 00 00 00 00 00 00 03 07 01 00 00 00 ]
  * Number of simultaneous effects: 16

Setting master gain to 75% ... OK
Uploading effect #0 (Periodic sinusoidal) ... OK (id 0)
Uploading effect #1 (Constant) ... Error: Invalid argument
Uploading effect #2 (Spring) ... Error: Invalid argument
Uploading effect #3 (Damper) ... Error: Invalid argument
Uploading effect #4 (Strong rumble, with heavy motor) ... OK (id 1)
Uploading effect #5 (Weak rumble, with light motor) ... OK (id 2)
Enter effect number, -1 to exit
0
Now Playing: Sine vibration
Enter effect number, -1 to exit
[  157.967092] pwm-vibrator vibrator: failed to apply pwm state: -16
[  158.017952] pwm-vibrator vibrator: failed to apply pwm state: -16

Note: This patch was assisted with Claude and cleaned up by me.
---
 .../dts/qcom/qcom-msm8960-samsung-expressatt.dts   | 44 ++++++++++++++++++++++
 1 file changed, 44 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 c4b98af6955d..09443df0fdce 100644
--- a/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
+++ b/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
@@ -87,6 +87,35 @@ touchkey@20 {
 			linux,keycodes = <KEY_MENU KEY_BACK>;
 		};
 	};
+
+	gp1_pwm: pwm {
+		compatible = "clk-pwm";
+		#pwm-cells = <2>;
+		clocks = <&gcc GP1_CLK>;
+	};
+
+	/* TODO: Vary the frequency besides being 0% or 100% */
+	vibrator {
+		compatible = "pwm-vibrator";
+		pwms = <&gp1_pwm 0 54347 0>;  /* ~18.4 kHz */
+		pwm-names = "enable";
+		enable-gpios = <&pm8921_gpio 4 GPIO_ACTIVE_HIGH>;
+		vcc-supply = <&vdd_haptics>;
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&vib_pwm_gpio>;
+	};
+
+	vdd_haptics: vdd-haptics-regulator {
+		compatible = "regulator-fixed";
+		regulator-name = "vdd_haptics";
+		gpio = <&tlmm 47 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+		regulator-boot-on;
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&haptics_pwr_en>;
+	};
 };
 
 &gsbi2 {
@@ -241,6 +270,21 @@ touchkey_i2c_pins: touchkey-i2c-state {
 		bias-disable;
 	};
 
+	haptics_pwr_en: haptics-pwr-en-state {
+		pins = "gpio47";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-disable;
+		output-low;
+	};
+
+	vib_pwm_gpio: vib-pwm-gpio-state {
+		pins = "gpio70";
+		function = "gp_clk_1b";
+		drive-strength = <2>;
+		bias-disable;
+	};
+
 	touchkey_irq_pin: touchkey-irq-state {
 		pins = "gpio52";
 		function = "gpio";

---
base-commit: b066d7751f99fabaa07939006233781536ab16e5
change-id: 20251211-expressatt-vibrator-de557aa8f7d4
prerequisite-message-id: <20251205-expressatt-touchkey-v1-1-1444b927c9f3@gmail.com>
prerequisite-patch-id: 8de4de7909722ccaf385c4224f25a623eaa72c28

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

Re: [PATCH] ARM: dts: qcom: msm8960: expressatt Add PWM vibrator

[Konrad Dybcio]

On 12/11/25 11:23 AM, Rudraksha Gupta via B4 Relay wrote:
> From: Rudraksha Gupta <guptarud@gmail.com>
> 
> Add a pwm-vibrator to expressatt. Currently this vibrates only at 100%
> 
> Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
> ---
> Add a pwm-vibrator to expressatt. Currently this vibrates only at 100%
> 
> Link:
> - https://github.com/LineageOS/android_kernel_samsung_d2/blob/stable/cm-12.0-YNG4N/arch/arm/mach-msm/board-express.c#L1767
> - https://github.com/LineageOS/android_kernel_samsung_d2/blob/stable/cm-12.0-YNG4N/drivers/motor/Makefile#L5
> 
> Test:
> =====================
> samsung-expressatt:~$ dmesg | grep vibra
> [   79.892226] input: pwm-vibrator as /devices/platform/vibrator/input/input4
> samsung-expressatt:~$ fftest /dev/input/event4 
> Force feedback test program.
> HOLD FIRMLY YOUR WHEEL OR JOYSTICK TO PREVENT DAMAGES
> 
> Device /dev/input/event4 opened
> Features:
>   * Absolute axes: 
>     [00 00 00 00 00 00 00 00 ]
>   * Relative axes: 
>     [00 00 ]
>   * Force feedback effects types: Periodic, Rumble, Gain, 
>     Force feedback periodic effects: Square, Triangle, Sine, 
>     [00 00 00 00 00 00 00 00 00 00 03 07 01 00 00 00 ]
>   * Number of simultaneous effects: 16
> 
> Setting master gain to 75% ... OK
> Uploading effect #0 (Periodic sinusoidal) ... OK (id 0)
> Uploading effect #1 (Constant) ... Error: Invalid argument
> Uploading effect #2 (Spring) ... Error: Invalid argument
> Uploading effect #3 (Damper) ... Error: Invalid argument

Looks like this is because GP1_CLK does not implement .set_duty_cycle..

The downstream driver you linked to does so in a terribly hacky way
(from the vibrator driver and not the clock driver):

https://github.com/LineageOS/android_kernel_samsung_d2/blob/cm-14.1/drivers/motor/immvibespi.c#L53

Upstream, we have an implementation for clk_rcg*2*_ops, whereas 8960
uses clk_rcg_ops.

They look very similar though, perhaps you can hack it up..

One thing to note is that you're passing GP1_CLK to the clk-pwm (as
you should), but we need to do clk_set_duty_cycle on its parent,
GP1_CLK*_SRC*. The framework will take care of this:

```
--- drivers/clk/clk.c
	if (!core->ops->get_duty_cycle)
		return clk_core_update_duty_cycle_parent_nolock(core);
```

so long as you add CLK_DUTY_CYCLE_PARENT to the child

[...]
> +	/* TODO: Vary the frequency besides being 0% or 100% */
> +	vibrator {
> +		compatible = "pwm-vibrator";
> +		pwms = <&gp1_pwm 0 54347 0>;  /* ~18.4 kHz */
> +		pwm-names = "enable";
> +		enable-gpios = <&pm8921_gpio 4 GPIO_ACTIVE_HIGH>;
> +		vcc-supply = <&vdd_haptics>;
> +
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&vib_pwm_gpio>;

pinctrl-n
pinctrl-names

please, both occurences

> +	};
> +
> +	vdd_haptics: vdd-haptics-regulator {
> +		compatible = "regulator-fixed";
> +		regulator-name = "vdd_haptics";
> +		gpio = <&tlmm 47 GPIO_ACTIVE_HIGH>;
> +		enable-active-high;
> +		regulator-boot-on;
> +
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&haptics_pwr_en>;
> +	};
>  };
>  
>  &gsbi2 {
> @@ -241,6 +270,21 @@ touchkey_i2c_pins: touchkey-i2c-state {
>  		bias-disable;
>  	};
>  
> +	haptics_pwr_en: haptics-pwr-en-state {
> +		pins = "gpio47";
> +		function = "gpio";
> +		drive-strength = <2>;
> +		bias-disable;
> +		output-low;

Drop output-low, the driver should take care of setting the state

Konrad