Commit 7ca234e3 authored by Jason Gerecke's avatar Jason Gerecke Committed by Jiri Kosina
Browse files

HID: wacom: Add preliminary support for high-resolution wheel scrolling 



Modern userspace (i.e. libinput) will make use of high-resolution
scrolling if supported. Hardware does not currently set a resolution
multiplier needed for effective high-res scrolling, but we can still
write code to support it in the future.

Signed-off-by: default avatarJason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.com>
parent 7525a0bd

drivers/hid/wacom_wac.c

+20 −4
Original line number Diff line number Diff line
@@ -2046,10 +2046,12 @@ static void wacom_wac_pad_usage_mapping(struct hid_device *hdev, 
		features->device_type |= WACOM_DEVICETYPE_PAD;

		break;

	case WACOM_HID_WD_TOUCHRING:

		if (field->flags & HID_MAIN_ITEM_RELATIVE)

			wacom_map_usage(input, usage, field, EV_REL, REL_WHEEL, 0);

		else

		if (field->flags & HID_MAIN_ITEM_RELATIVE) {

			wacom_map_usage(input, usage, field, EV_REL, REL_WHEEL_HI_RES, 0);

			set_bit(REL_WHEEL, input->relbit);

		} else {

			wacom_map_usage(input, usage, field, EV_ABS, ABS_WHEEL, 0);

		}

		features->device_type |= WACOM_DEVICETYPE_PAD;

		break;

	case WACOM_HID_WD_TOUCHRINGSTATUS:
@@ -2177,7 +2179,21 @@ static void wacom_wac_pad_event(struct hid_device *hdev, struct hid_field *field 
			 * userspace treats positive REL_WHEEL as a

			 * scroll *up*!

			 */

			value = -value;

			int hires_value = -value * 120 / usage->resolution_multiplier;

			int *ring_value = &wacom_wac->hid_data.ring_value;



			value = hires_value;

			*ring_value += hires_value;



			/* Emulate a legacy wheel click for every 120

			 * units of hi-res travel.

			 */

			if (*ring_value >= 120 || *ring_value <= -120) {

				int clicks = *ring_value / 120;



				input_event(input, usage->type, REL_WHEEL, clicks);

				*ring_value -= clicks * 120;

			}

		}

		else {

			value = wacom_offset_rotation(input, usage, value, 1, 4);

drivers/hid/wacom_wac.h

+1 −0
Original line number Diff line number Diff line
@@ -312,6 +312,7 @@ struct hid_data { 
	int width;

	int height;

	int id;

	int ring_value;

	int cc_report;

	int cc_index;

	int cc_value_index;