linux-kernel - [PATCH 2/2] Disable touchpad on firmware level while not in use

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Message-ID: <20250211133950.422232-2-wse@tuxedocomputers.com>
Date: Tue, 11 Feb 2025 14:39:06 +0100
From: Werner Sembach <wse@...edocomputers.com>
To: Jiri Kosina <jikos@...nel.org>,
	Benjamin Tissoires <bentiss@...nel.org>
Cc: Werner Sembach <wse@...edocomputers.com>,
	linux-input@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] Disable touchpad on firmware level while not in use

Using the new on_hid_hw_open and on_hid_hw_close functions to disable the
touchpad on firmware level while not being in use.

This safes some battery and triggers touchpad-disabled-leds hardwired to
the touchpads firmware, that exist for example on some TongFang barebones.

For a lengthy discussion with all the details see
https://gitlab.freedesktop.org/libinput/libinput/-/issues/558

Signed-off-by: Werner Sembach <wse@...edocomputers.com>
---
 drivers/hid/hid-multitouch.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 82900857bfd87..7289c04f47f17 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -1884,6 +1884,16 @@ static void mt_remove(struct hid_device *hdev)
 	hid_hw_stop(hdev);
 }
 
+static void mt_on_hid_hw_open(struct hid_device *hdev)
+{
+	mt_set_modes(hdev, HID_LATENCY_NORMAL, TOUCHPAD_REPORT_ALL);
+}
+
+static void mt_on_hid_hw_close(struct hid_device *hdev)
+{
+	mt_set_modes(hdev, HID_LATENCY_HIGH, TOUCHPAD_REPORT_NONE);
+}
+
 /*
  * This list contains only:
  * - VID/PID of products not working with the default multitouch handling
@@ -2351,5 +2361,7 @@ static struct hid_driver mt_driver = {
 	.suspend = pm_ptr(mt_suspend),
 	.reset_resume = pm_ptr(mt_reset_resume),
 	.resume = pm_ptr(mt_resume),
+	.on_hid_hw_open = mt_on_hid_hw_open,
+	.on_hid_hw_close = mt_on_hid_hw_close,
 };
 module_hid_driver(mt_driver);
-- 
2.43.0