[v3] HID: Implement haptic touchpad support

[PATCH v3 03/11] Input: add INPUT_PROP_HAPTIC_TOUCHPAD

Posted by Jonathan Denose 1 month, 2 weeks ago

From: Angela Czubak <aczubak@google.com>

INPUT_PROP_HAPTIC_TOUCHPAD property is to be set for a device with simple
haptic capabilities.

Signed-off-by: Angela Czubak <aczubak@google.com>
Co-developed-by: Jonathan Denose <jdenose@google.com>
Signed-off-by: Jonathan Denose <jdenose@google.com>
---
 Documentation/input/event-codes.rst    | 14 ++++++++++++++
 include/uapi/linux/input-event-codes.h |  1 +
 2 files changed, 15 insertions(+)

diff --git a/Documentation/input/event-codes.rst b/Documentation/input/event-codes.rst
index b4557462edd7b3fef9e9cd6c2c3cb2d05bb531ab..1ead9bb8d9c6451a81426665baab643f9e50216a 100644
--- a/Documentation/input/event-codes.rst
+++ b/Documentation/input/event-codes.rst
@@ -400,6 +400,20 @@ can report through the rotational axes (absolute and/or relative rx, ry, rz).
 All other axes retain their meaning. A device must not mix
 regular directional axes and accelerometer axes on the same event node.
 
+INPUT_PROP_HAPTIC_TOUCHPAD
+--------------------------
+
+The INPUT_PROP_HAPTIC_TOUCHPAD property indicates that device:
+- supports simple haptic auto and manual triggering
+- can differentiate between at least 5 fingers
+- uses correct resolution for the X/Y (units and value)
+- reports correct force per touch, and correct units for them (newtons or grams)
+- follows the MT protocol type B
+
+Summing up, such devices follow the MS spec for input devices in
+Win8 and Win8.1, and in addition support the Simple haptic controller HID table,
+and report correct units for the pressure.
+
 Guidelines
 ==========
 
diff --git a/include/uapi/linux/input-event-codes.h b/include/uapi/linux/input-event-codes.h
index 3b2524e4b667d1e7cc02ff5cb674e7c2ac069a66..efe8c36d4ee9a938ffb1b0dd0ddd0ec6a3fcb8fe 100644
--- a/include/uapi/linux/input-event-codes.h
+++ b/include/uapi/linux/input-event-codes.h
@@ -27,6 +27,7 @@
 #define INPUT_PROP_TOPBUTTONPAD		0x04	/* softbuttons at top of pad */
 #define INPUT_PROP_POINTING_STICK	0x05	/* is a pointing stick */
 #define INPUT_PROP_ACCELEROMETER	0x06	/* has accelerometer */
+#define INPUT_PROP_HAPTIC_TOUCHPAD	0x07	/* is a haptic touchpad */
 
 #define INPUT_PROP_MAX			0x1f
 #define INPUT_PROP_CNT			(INPUT_PROP_MAX + 1)

-- 
2.51.0.rc1.193.gad69d77794-goog

Re: [PATCH v3 03/11] Input: add INPUT_PROP_HAPTIC_TOUCHPAD

Posted by Dmitry Torokhov 2 weeks, 6 days ago

On Mon, Aug 18, 2025 at 11:08:44PM +0000, Jonathan Denose wrote:
> From: Angela Czubak <aczubak@google.com>
> 
> INPUT_PROP_HAPTIC_TOUCHPAD property is to be set for a device with simple
> haptic capabilities.
> 
> Signed-off-by: Angela Czubak <aczubak@google.com>
> Co-developed-by: Jonathan Denose <jdenose@google.com>
> Signed-off-by: Jonathan Denose <jdenose@google.com>

Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Thanks.

-- 
Dmitry

Re: [PATCH v3 03/11] Input: add INPUT_PROP_HAPTIC_TOUCHPAD

Posted by Randy Dunlap 1 month, 2 weeks ago


On 8/18/25 4:08 PM, Jonathan Denose wrote:
> From: Angela Czubak <aczubak@google.com>
> 
> INPUT_PROP_HAPTIC_TOUCHPAD property is to be set for a device with simple
> haptic capabilities.
> 
> Signed-off-by: Angela Czubak <aczubak@google.com>
> Co-developed-by: Jonathan Denose <jdenose@google.com>
> Signed-off-by: Jonathan Denose <jdenose@google.com>

Reviewed-by: Randy Dunlap <rdunlap@infradead.org>

Thanks.

> ---
>  Documentation/input/event-codes.rst    | 14 ++++++++++++++
>  include/uapi/linux/input-event-codes.h |  1 +
>  2 files changed, 15 insertions(+)
-- 
~Randy