Commit 0b778e76 authored by Chase Douglas's avatar Chase Douglas Committed by Jiri Kosina
Browse files

HID: magicmouse: add param for scroll speed 



The new scroll_speed param takes an integer value from 0 to 63, where 0
is slowest and 63 is fastest. The default of 32 remains the same. This
parameter also affects scroll acceleration linearly.

A second part of this change is a tightly coupled modification to the
scroll acceleration. Previously, scroll acceleration could be reset
without lifting the scroll finger. This is rather unintuitive and hard
to control in the case where a user wants faster scrolling, but wants to
hold the scroll touch for longer than a moment.

Note that scroll acceleration levels are now 1-7, where 7 is slowest. In
the previous implementation, there were 8 levels defined, but it was
impossible to start at the slowest level. In order to keep the default
scroll speed unchanged, only 7 levels are used now.

Signed-off-by: default avatarChase Douglas <chase.douglas@canonical.com>
Acked-by: default avatarMichael Poole <mdpoole@troilus.org>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 8d93efb2

drivers/hid/hid-magicmouse.c

+28 −15
Original line number Diff line number Diff line
@@ -30,6 +30,17 @@ static bool emulate_scroll_wheel = true; 
module_param(emulate_scroll_wheel, bool, 0644);

MODULE_PARM_DESC(emulate_scroll_wheel, "Emulate a scroll wheel");



static unsigned int scroll_speed = 32;

static int param_set_scroll_speed(const char *val, struct kernel_param *kp) {

	unsigned long speed;

	if (!val || strict_strtoul(val, 0, &speed) || speed > 63)

		return -EINVAL;

	scroll_speed = speed;

	return 0;

}

module_param_call(scroll_speed, param_set_scroll_speed, param_get_uint, &scroll_speed, 0644);

MODULE_PARM_DESC(scroll_speed, "Scroll speed, value from 0 (slow) to 63 (fast)");



static bool scroll_acceleration = false;

module_param(scroll_acceleration, bool, 0644);

MODULE_PARM_DESC(scroll_acceleration, "Accelerate sequential scroll events");
@@ -54,6 +65,8 @@ MODULE_PARM_DESC(report_undeciphered, "Report undeciphered multi-touch state fie 
#define TOUCH_STATE_START 0x30

#define TOUCH_STATE_DRAG  0x40



#define SCROLL_ACCEL_DEFAULT 7



/**

 * struct magicmouse_sc - Tracks Magic Mouse-specific data.

 * @input: Input device through which we report events.
@@ -145,7 +158,7 @@ static void magicmouse_emit_buttons(struct magicmouse_sc *msc, int state) 
	input_report_key(msc->input, BTN_RIGHT, state & 2);



	if (state != last_state)

		msc->scroll_accel = 0;

		msc->scroll_accel = SCROLL_ACCEL_DEFAULT;

}



static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tdata)
@@ -167,30 +180,28 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda 
	 * vertical touch motions.

	 */

	if (emulate_scroll_wheel) {

		static const int accel_profile[] = {

			256, 228, 192, 160, 128, 96, 64, 32,

		};

		unsigned long now = jiffies;

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



		/* Reset acceleration after half a second. */

		if (time_after(now, msc->scroll_jiffies + HZ / 2))

			msc->scroll_accel = 0;



		/* Calculate and apply the scroll motion. */

		switch (tdata[7] & TOUCH_STATE_MASK) {

		case TOUCH_STATE_START:

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

			if (scroll_acceleration)

				msc->scroll_accel = min_t(int,

						msc->scroll_accel + 1,

						ARRAY_SIZE(accel_profile) - 1);



			/* Reset acceleration after half a second. */

			if (scroll_acceleration && time_before(now,

						msc->scroll_jiffies + HZ / 2))

				msc->scroll_accel = max_t(int,

						msc->scroll_accel - 1, 1);

			else

				msc->scroll_accel = SCROLL_ACCEL_DEFAULT;



			break;

		case TOUCH_STATE_DRAG:

			step = step / accel_profile[msc->scroll_accel];

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

			if (step != 0) {

				msc->touches[id].scroll_y -=

					step * accel_profile[msc->scroll_accel];

				msc->touches[id].scroll_y -= step *

					(64 - scroll_speed) * msc->scroll_accel;

				msc->scroll_jiffies = now;

				input_report_rel(input, REL_WHEEL, step);

			}
@@ -351,6 +362,8 @@ static int magicmouse_probe(struct hid_device *hdev, 
		return -ENOMEM;

	}



	msc->scroll_accel = SCROLL_ACCEL_DEFAULT;



	msc->quirks = id->driver_data;

	hid_set_drvdata(hdev, msc);

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