Re: [PATCH 2/2] HID: logitech-hidpp: enable reprogrammable buttons on Signature M650

[Bastien Nocera <hadess@hadess.net>]

Hey Elliot,

I have an m650 on hand on with which I should be able to test your
patch next week, once we've gone through a first round of reviews.

Benjamin, is there something I can capture locally that could make it
into the HID tests for this feature?

Inline comments below

On Sat, 2026-06-13 at 10:51 -0700, Elliot Douglas wrote:
> The Bluetooth Signature M650 exposes its side buttons through the
> normal
> mouse report, but the observed events are short click-like events
> emitted
> around release rather than physical press/release state.
> 
> The device appears to use the held side-button state for its built-in
> gesture and side-button + wheel horizontal-scroll mode. As a result,
> holding a side button long enough can prevent the normal mouse report
> from
> emitting a usable button event at all.
> 
> HID++ REPROG_CONTROLS_V4 diversion for control IDs 0x0053 and 0x0056
> provides real press and release timing for those same controls.
> Logitech
> documents the Signature M650 side buttons as Back/Forward buttons, so
> report the diverted controls as BTN_BACK and BTN_FORWARD.
> 
> Link:
> https://support.logi.com/hc/en-nz/articles/4414473810583-Getting-Started-Signature-M650
> 
> Signed-off-by: Elliot Douglas <edouglas7358@gmail.com>
> ---
>  drivers/hid/hid-logitech-hidpp.c | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-
> logitech-hidpp.c
> index 24c9cfaa4f37..80108778ee80 100644
> --- a/drivers/hid/hid-logitech-hidpp.c
> +++ b/drivers/hid/hid-logitech-hidpp.c
> @@ -3621,6 +3621,9 @@ static int
> hidpp10_extra_mouse_buttons_raw_event(struct hidpp_device *hidpp,
>  
>  #define HIDPP_REPROG_CONTROLS_EVENT_DIVERTED		0x00
>  
> +#define HIDPP_REPROG_CONTROL_M650_BACK			0x0053
> +#define HIDPP_REPROG_CONTROL_M650_FORWARD		0x0056

I read through the 0x1b04 docs, and I'm trying to understand whether
those CID numbers change in different hardware, or if they're hardcoded
(a back button will always have the 83/0x53 value).

Seems to me that it's the latter? The back button is listed in the
Example Control ID table in the 0x1b04 docs.

> +
>  struct hidpp_reprog_control_mapping {
>  	u16 control;
>  	u16 code;
> @@ -3631,9 +3634,24 @@ struct hidpp_reprog_controls_profile {
>  	unsigned int mapping_count;
>  };
>  
> +static const struct hidpp_reprog_control_mapping
> m650_reprog_control_mappings[] = {
> +	{ HIDPP_REPROG_CONTROL_M650_BACK, BTN_BACK },
> +	{ HIDPP_REPROG_CONTROL_M650_FORWARD, BTN_FORWARD },
> +};
> +
> +static const struct hidpp_reprog_controls_profile
> m650_reprog_controls_profile = {
> +	.mappings = m650_reprog_control_mappings,
> +	.mapping_count = ARRAY_SIZE(m650_reprog_control_mappings),
> +};
> +
>  static const struct hidpp_reprog_controls_profile *
>  hidpp20_reprog_controls_get_profile(struct hidpp_device *hidpp)
>  {
> +	switch (hidpp->hid_dev->product) {
> +	case 0xb02a:

You probably want a define for that constant.

> +		return &m650_reprog_controls_profile;
> +	}
> +
>  	return NULL;
>  }
>  
> @@ -4921,7 +4939,8 @@ static const struct hid_device_id
> hidpp_devices[] = {
>  	{ /* MX Vertical mouse over Bluetooth */
>  	  HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH, 0xb020) },
>  	{ /* Signature M650 over Bluetooth */
> -	  HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH, 0xb02a) },
> +	  HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH, 0xb02a),
> +	  .driver_data = HIDPP_QUIRK_HIDPP_REPROG_CONTROLS_BTNS },
>  	{ /* MX Master 3 mouse over Bluetooth */
>  	  HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH, 0xb023) },
>  	{ /* MX Anywhere 3 mouse over Bluetooth */