Re: [PATCH] HID: kye: Change Device Usage from Puck to Mouse

From: Jiri Kosina
Date: Mon May 06 2024 - 17:30:41 EST


On Thu, 2 May 2024, David Yang wrote:

> Change device type because
> a. it is exactly a mouse, with left/right buttons and scroll wheel;
> b. it does not have visible marks or crosshairs, thus does not provide
> higher accuracy than stylus.

Let's CC Milan, who originally added all this in feb6faf1e5d46 ("HID: kye:
Fix report descriptor for Genius PenSketch M912") ... Milan, any concerns
about the below?

Thanks.

>
> Signed-off-by: David Yang <mmyangfl@xxxxxxxxx>
> ---
> drivers/hid/hid-kye.c | 75 +++++++++++++++++++++++++------------------
> 1 file changed, 44 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/hid/hid-kye.c b/drivers/hid/hid-kye.c
> index eb9bf2829937..70ceb9437332 100644
> --- a/drivers/hid/hid-kye.c
> +++ b/drivers/hid/hid-kye.c
> @@ -209,7 +209,7 @@ static const __u8 pensketch_t609a_control_rdesc[] = {
> 0xC0 /* End Collection */
> };
>
> -/* Fix indexes in kye_tablet_fixup if you change this */
> +/* Fix indexes in kye_tablet_fixup() if you change this */
> static const __u8 kye_tablet_rdesc[] = {
> 0x06, 0x00, 0xFF, /* Usage Page (FF00h), */
> 0x09, 0x01, /* Usage (01h), */
> @@ -262,12 +262,16 @@ static const __u8 kye_tablet_rdesc[] = {
> 0x27, 0xFF, 0x07, 0x00, 0x00, /* Logical Maximum (2047), */
> 0x81, 0x02, /* Input (Variable), */
> 0xC0, /* End Collection, */
> - 0xC0, /* End Collection, */
> - 0x05, 0x0D, /* Usage Page (Digitizer), */
> - 0x09, 0x21, /* Usage (Puck), */
> + 0xC0 /* End Collection, */
> +};
> +
> +/* Fix indexes in kye_tablet_fixup() if you change this */
> +static const __u8 kye_tablet_mouse_rdesc[] = {
> + 0x05, 0x01, /* Usage Page (Desktop), */
> + 0x09, 0x02, /* Usage (Mouse), */
> 0xA1, 0x01, /* Collection (Application), */
> 0x85, 0x11, /* Report ID (17), */
> - 0x09, 0x21, /* Usage (Puck), */
> + 0x09, 0x01, /* Usage (Pointer), */
> 0xA0, /* Collection (Physical), */
> 0x05, 0x09, /* Usage Page (Button), */
> 0x19, 0x01, /* Usage Minimum (01h), */
> @@ -280,7 +284,7 @@ static const __u8 kye_tablet_rdesc[] = {
> 0x95, 0x04, /* Report Count (4), */
> 0x81, 0x01, /* Input (Constant), */
> 0x05, 0x0D, /* Usage Page (Digitizer), */
> - 0x09, 0x32, /* Usage (In Range), */
> + 0x09, 0x37, /* Usage (Data Valid), */
> 0x95, 0x01, /* Report Count (1), */
> 0x81, 0x02, /* Input (Variable), */
> 0x05, 0x01, /* Usage Page (Desktop), */
> @@ -317,7 +321,7 @@ static const struct kye_tablet_info {
> __s32 y_physical_maximum;
> __s8 unit_exponent;
> __s8 unit;
> - bool has_punk;
> + bool has_mouse;
> unsigned int control_rsize;
> const __u8 *control_rdesc;
> } kye_tablets_info[] = {
> @@ -402,7 +406,7 @@ static __u8 *kye_consumer_control_fixup(struct hid_device *hdev, __u8 *rdesc,
> static __u8 *kye_tablet_fixup(struct hid_device *hdev, __u8 *rdesc, unsigned int *rsize)
> {
> const struct kye_tablet_info *info;
> - unsigned int newsize;
> + __u8 *newdesc = rdesc;
>
> if (*rsize < sizeof(kye_tablet_rdesc)) {
> hid_warn(hdev,
> @@ -420,36 +424,45 @@ static __u8 *kye_tablet_fixup(struct hid_device *hdev, __u8 *rdesc, unsigned int
> return rdesc;
> }
>
> - newsize = info->has_punk ? sizeof(kye_tablet_rdesc) : 112;
> - memcpy(rdesc, kye_tablet_rdesc, newsize);
> -
> - put_unaligned_le32(info->x_logical_maximum, rdesc + 66);
> - put_unaligned_le32(info->x_physical_maximum, rdesc + 72);
> - rdesc[77] = info->unit;
> - rdesc[79] = info->unit_exponent;
> - put_unaligned_le32(info->y_logical_maximum, rdesc + 87);
> - put_unaligned_le32(info->y_physical_maximum, rdesc + 92);
> - put_unaligned_le32(info->pressure_logical_maximum, rdesc + 104);
> -
> - if (info->has_punk) {
> - put_unaligned_le32(info->x_logical_maximum, rdesc + 156);
> - put_unaligned_le32(info->x_physical_maximum, rdesc + 162);
> - rdesc[167] = info->unit;
> - rdesc[169] = info->unit_exponent;
> - put_unaligned_le32(info->y_logical_maximum, rdesc + 177);
> - put_unaligned_le32(info->y_physical_maximum, rdesc + 182);
> + memcpy(newdesc, kye_tablet_rdesc, sizeof(kye_tablet_rdesc));
> +
> + put_unaligned_le32(info->x_logical_maximum, newdesc + 66);
> + put_unaligned_le32(info->x_physical_maximum, newdesc + 72);
> + newdesc[77] = info->unit;
> + newdesc[79] = info->unit_exponent;
> + put_unaligned_le32(info->y_logical_maximum, newdesc + 87);
> + put_unaligned_le32(info->y_physical_maximum, newdesc + 92);
> + put_unaligned_le32(info->pressure_logical_maximum, newdesc + 104);
> +
> + newdesc += sizeof(kye_tablet_rdesc);
> +
> + if (info->has_mouse) {
> + if (newdesc + sizeof(kye_tablet_mouse_rdesc) > rdesc + *rsize)
> + hid_err(hdev, "control desc unexpectedly large\n");
> + else {
> + memcpy(newdesc, kye_tablet_mouse_rdesc, sizeof(kye_tablet_mouse_rdesc));
> +
> + put_unaligned_le32(info->x_logical_maximum, newdesc + 44);
> + put_unaligned_le32(info->x_physical_maximum, newdesc + 50);
> + newdesc[55] = info->unit;
> + newdesc[57] = info->unit_exponent;
> + put_unaligned_le32(info->y_logical_maximum, newdesc + 65);
> + put_unaligned_le32(info->y_physical_maximum, newdesc + 70);
> +
> + newdesc += sizeof(kye_tablet_mouse_rdesc);
> + }
> }
>
> if (info->control_rsize) {
> - if (newsize + info->control_rsize > *rsize)
> - hid_err(hdev, "control rdesc unexpectedly large");
> + if (newdesc + info->control_rsize > rdesc + *rsize)
> + hid_err(hdev, "control desc unexpectedly large\n");
> else {
> - memcpy(rdesc + newsize, info->control_rdesc, info->control_rsize);
> - newsize += info->control_rsize;
> + memcpy(newdesc, info->control_rdesc, info->control_rsize);
> + newdesc += info->control_rsize;
> }
> }
>
> - *rsize = newsize;
> + *rsize = newdesc - rdesc;
> return rdesc;
> }
>
> --
> 2.43.0
>

--
Jiri Kosina
SUSE Labs