Hi Benjamin,
> Win 8 digitizer devices provides the actual scan time computed by the
> hardware itself. The value is global to the frame and is not specific
> to the multitouch protocol (though only touch, not pen, should use it
> according to the specification).
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxx>
> ---
> Documentation/input/event-codes.txt | 7 +++++++
> drivers/hid/hid-input.c | 4 ++++
> drivers/hid/hid-multitouch.c | 11 +++++++++--
> include/linux/hid.h | 1 +
> include/linux/input.h | 1 +
> 5 files changed, 22 insertions(+), 2 deletions(-)
This is a nice feature, useful in many other contexts. As such, I
think it should be defined in the context of the input subsystem, with
a more specific definition added to the documentation. For instance,
is 100us suitable? When should it start at zero, at BTN_TOUCH? Or
should it perhaps wrap around on unsigned integer instead? Or display
the difference from the last event?
> diff --git a/Documentation/input/event-codes.txt b/Documentation/input/event-codes.txt
> index 53305bd..8f8c908 100644
> --- a/Documentation/input/event-codes.txt
> +++ b/Documentation/input/event-codes.txt
> @@ -174,6 +174,13 @@ A few EV_ABS codes have special meanings:
> the input device may be used freely in three dimensions, consider ABS_Z
> instead.
>
> +* ABS_SCAN_TIME:
> + - Used when the device provides a timestamp for each frame. The unit must be
> + 100us, and may be reset when the device don't send any events for a
> + period of time. The values increment at each frame and thus, it can roll
> + back to 0 when reach logical_max. If the device does not provide this
> + information, the driver must not provide it to the user space.
> +
> * ABS_MT_<name>:
> - Used to describe multitouch input events. Please see
> multi-touch-protocol.txt for details.
> diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
> index 16cc89a..5fe7bd3 100644
> --- a/drivers/hid/hid-input.c
> +++ b/drivers/hid/hid-input.c
> @@ -675,6 +675,10 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
> map_key_clear(BTN_STYLUS2);
> break;
>
> + case 0x56: /* Scan Time */
> + map_abs(ABS_SCAN_TIME);
> + break;
> +
Is it not enough to map it in the case below? Or you mean this is
picked up by hid core?
> default: goto unknown;
> }
> break;
> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> index c0ab1c6..21a120b 100644
> --- a/drivers/hid/hid-multitouch.c
> +++ b/drivers/hid/hid-multitouch.c
> @@ -447,12 +447,19 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
> mt_store_field(usage, td, hi);
> td->last_field_index = field->index;
> return 1;
> + case HID_DG_SCANTIME:
> + hid_map_usage(hi, usage, bit, max,
> + EV_ABS, ABS_SCAN_TIME);
> + set_abs(hi->input, ABS_SCAN_TIME, field, 0);
> + td->last_field_index = field->index;
> + return 1;
> case HID_DG_CONTACTCOUNT:
> td->last_field_index = field->index;
> return 1;
> case HID_DG_CONTACTMAX:
> - /* we don't set td->last_slot_field as contactcount and
> - * contact max are global to the report */
> + /* we don't set td->last_slot_field as scan time,
> + * contactcount and contact max are global to the
> + * report */
> td->last_field_index = field->index;
> return -1;
> case HID_DG_TOUCH:
> diff --git a/include/linux/hid.h b/include/linux/hid.h
> index 6216529..99a6418 100644
> --- a/include/linux/hid.h
> +++ b/include/linux/hid.h
> @@ -279,6 +279,7 @@ struct hid_item {
> #define HID_DG_DEVICEINDEX 0x000d0053
> #define HID_DG_CONTACTCOUNT 0x000d0054
> #define HID_DG_CONTACTMAX 0x000d0055
> +#define HID_DG_SCANTIME 0x000d0056
>
> /*
> * HID report types --- Ouch! HID spec says 1 2 3!
> diff --git a/include/linux/input.h b/include/linux/input.h
> index ba48743..73c3a96 100644
> --- a/include/linux/input.h
> +++ b/include/linux/input.h
> @@ -796,6 +796,7 @@ struct input_keymap_entry {
> #define ABS_TILT_X 0x1a
> #define ABS_TILT_Y 0x1b
> #define ABS_TOOL_WIDTH 0x1c
> +#define ABS_SCAN_TIME 0x1d
>
> #define ABS_VOLUME 0x20
>
> --
> 1.7.11.7
>
Thanks,
Henrik
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
