From a98e892c694284256296465a78d11072e2c5419f Mon Sep 17 00:00:00 2001 From: Werner Sembach Date: Tue, 11 Feb 2025 14:39:05 +0100 Subject: [PATCH 1/2] HID: core: Add functions for HID drivers to react on first open and last close call Adds a new function to the hid_driver struct that is called when the userspace starts using the device, and another one that is called when userspace stop using the device. With this a hid driver can implement special suspend handling for devices currently not in use. Signed-off-by: Werner Sembach Link: https://patch.msgid.link/20250211133950.422232-1-wse@tuxedocomputers.com Signed-off-by: Benjamin Tissoires --- drivers/hid/hid-core.c | 9 ++++++++- include/linux/hid.h | 4 ++++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 4741ff626771..b348d0464314 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2396,6 +2396,9 @@ int hid_hw_open(struct hid_device *hdev) ret = hdev->ll_driver->open(hdev); if (ret) hdev->ll_open_count--; + + if (hdev->driver->on_hid_hw_open) + hdev->driver->on_hid_hw_open(hdev); } mutex_unlock(&hdev->ll_open_lock); @@ -2415,8 +2418,12 @@ EXPORT_SYMBOL_GPL(hid_hw_open); void hid_hw_close(struct hid_device *hdev) { mutex_lock(&hdev->ll_open_lock); - if (!--hdev->ll_open_count) + if (!--hdev->ll_open_count) { hdev->ll_driver->close(hdev); + + if (hdev->driver->on_hid_hw_close) + hdev->driver->on_hid_hw_close(hdev); + } mutex_unlock(&hdev->ll_open_lock); } EXPORT_SYMBOL_GPL(hid_hw_close); diff --git a/include/linux/hid.h b/include/linux/hid.h index a1305210b2fd..568a9d8c749b 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -795,6 +795,8 @@ struct hid_usage_id { * @suspend: invoked on suspend (NULL means nop) * @resume: invoked on resume if device was not reset (NULL means nop) * @reset_resume: invoked on resume if device was reset (NULL means nop) + * @on_hid_hw_open: invoked when hid core opens first instance (NULL means nop) + * @on_hid_hw_close: invoked when hid core closes last instance (NULL means nop) * * probe should return -errno on error, or 0 on success. During probe, * input will not be passed to raw_event unless hid_device_io_start is @@ -850,6 +852,8 @@ struct hid_driver { int (*suspend)(struct hid_device *hdev, pm_message_t message); int (*resume)(struct hid_device *hdev); int (*reset_resume)(struct hid_device *hdev); + void (*on_hid_hw_open)(struct hid_device *hdev); + void (*on_hid_hw_close)(struct hid_device *hdev); /* private: */ struct device_driver driver; From 6a9e76f75c1a8fffbf45d4665daaf24e7d30095f Mon Sep 17 00:00:00 2001 From: Werner Sembach Date: Tue, 11 Feb 2025 14:39:06 +0100 Subject: [PATCH 2/2] HID: multitouch: 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 Link: https://patch.msgid.link/20250211133950.422232-2-wse@tuxedocomputers.com Signed-off-by: Benjamin Tissoires --- 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 e50887a6d22c..a8d0ef04d5aa 100644 --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -1887,6 +1887,16 @@ 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 @@ -2354,5 +2364,7 @@ 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);