Commit d4b9f10a authored by José Expósito's avatar José Expósito Committed by Jiri Kosina
Browse files

HID: magicmouse: enable high-resolution scroll 



The Magic Mouse, generations 1 and 2, doesn't have a physical scroll
wheel, instead, the REL_WHEEL and REL_HWHEEL events are emulated
when sliding a finger on the surface of the mouse.
However, the smooth movement of the finger is transformed into a step
based scroll on the screen, leading to a suboptimal user experience.

Emulate high-resolution scroll by sending REL_WHEEL_HI_RES and
REL_HWHEEL_HI_RES events so the scroll on the screen is closer to the
finger movement.

Signed-off-by: default avatarJosé Expósito <jose.exposito89@gmail.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent df04fbe8

drivers/hid/hid-magicmouse.c

+31 −0
Original line number Diff line number Diff line
@@ -68,6 +68,9 @@ MODULE_PARM_DESC(report_undeciphered, "Report undeciphered multi-touch state fie 
#define TOUCH_STATE_START 0x30

#define TOUCH_STATE_DRAG  0x40



/* Number of high-resolution events for each low-resolution detent. */

#define SCROLL_HR_STEPS 10

#define SCROLL_HR_MULT (120 / SCROLL_HR_STEPS)

#define SCROLL_ACCEL_DEFAULT 7



/* Touch surface information. Dimension is in hundredths of a mm, min and max
@@ -126,6 +129,8 @@ struct magicmouse_sc { 
		short y;

		short scroll_x;

		short scroll_y;

		short scroll_x_hr;

		short scroll_y_hr;

		u8 size;

	} touches[16];

	int tracking_ids[16];
@@ -248,12 +253,18 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda 
		unsigned long now = jiffies;

		int step_x = msc->touches[id].scroll_x - x;

		int step_y = msc->touches[id].scroll_y - y;

		int step_hr = ((64 - (int)scroll_speed) * msc->scroll_accel) /

			      SCROLL_HR_STEPS;

		int step_x_hr = msc->touches[id].scroll_x_hr - x;

		int step_y_hr = msc->touches[id].scroll_y_hr - y;



		/* Calculate and apply the scroll motion. */

		switch (state) {

		case TOUCH_STATE_START:

			msc->touches[id].scroll_x = x;

			msc->touches[id].scroll_y = y;

			msc->touches[id].scroll_x_hr = x;

			msc->touches[id].scroll_y_hr = y;



			/* Reset acceleration after half a second. */

			if (scroll_acceleration && time_before(now,
@@ -280,6 +291,24 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda 
				msc->scroll_jiffies = now;

				input_report_rel(input, REL_WHEEL, step_y);

			}



			step_x_hr /= step_hr;

			if (step_x_hr != 0) {

				msc->touches[id].scroll_x_hr -= step_x_hr *

					step_hr;

				input_report_rel(input,

						 REL_HWHEEL_HI_RES,

						 -step_x_hr * SCROLL_HR_MULT);

			}



			step_y_hr /= step_hr;

			if (step_y_hr != 0) {

				msc->touches[id].scroll_y_hr -= step_y_hr *

					step_hr;

				input_report_rel(input,

						 REL_WHEEL_HI_RES,

						 step_y_hr * SCROLL_HR_MULT);

			}

			break;

		}

	}
@@ -481,6 +510,8 @@ static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hd 
		if (emulate_scroll_wheel) {

			__set_bit(REL_WHEEL, input->relbit);

			__set_bit(REL_HWHEEL, input->relbit);

			__set_bit(REL_WHEEL_HI_RES, input->relbit);

			__set_bit(REL_HWHEEL_HI_RES, input->relbit);

		}

	} else if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {

		/* setting the device name to ensure the same driver settings