Commit c2ef8f21 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Jiri Kosina
Browse files

HID: multitouch: add support for trackpads 



* some multitouch trackpads present the touch usage. This needs to be
filtered as it will conflict with mt-implementation.
* trackpads send BTN_TOOL_* to notify how many fingers are present
(this is used by xorg to use synaptics instead of generic evdev)
* trackpads like Perixx 701 are not different from a hid point of view
from a touchscreen, and we need to manually set them as touchpad.

Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@enac.fr>
Acked-by: default avatarHenrik Rydberg <rydberg@euromail.se>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 7c7ed8ec

drivers/hid/hid-multitouch.c

+34 −6
Original line number Diff line number Diff line 
/*

 *  HID driver for multitouch panels

 *

 *  Copyright (c) 2010-2011 Stephane Chatty <chatty@enac.fr>

 *  Copyright (c) 2010-2011 Benjamin Tissoires <benjamin.tissoires@gmail.com>

 *  Copyright (c) 2010-2011 Ecole Nationale de l'Aviation Civile, France

 *  Copyright (c) 2010-2012 Stephane Chatty <chatty@enac.fr>

 *  Copyright (c) 2010-2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>

 *  Copyright (c) 2010-2012 Ecole Nationale de l'Aviation Civile, France

 *

 *  This code is partly based on hid-egalax.c:

 *
@@ -67,6 +67,7 @@ struct mt_class { 
	__s32 sn_height;	/* Signal/noise ratio for height events */

	__s32 sn_pressure;	/* Signal/noise ratio for pressure events */

	__u8 maxcontacts;

	bool is_indirect;	/* true for touchpads */

};



struct mt_device {
@@ -265,17 +266,31 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi, 
{

	struct mt_device *td = hid_get_drvdata(hdev);

	struct mt_class *cls = &td->mtclass;

	int code;



	/* Only map fields from TouchScreen or TouchPad collections.

         * We need to ignore fields that belong to other collections

         * such as Mouse that might have the same GenericDesktop usages. */

	if (field->application == HID_DG_TOUCHSCREEN)

		set_bit(INPUT_PROP_DIRECT, hi->input->propbit);

	else if (field->application == HID_DG_TOUCHPAD)

		set_bit(INPUT_PROP_POINTER, hi->input->propbit);

	else

	else if (field->application != HID_DG_TOUCHPAD)

		return 0;



	/* In case of an indirect device (touchpad), we need to add

	 * specific BTN_TOOL_* to be handled by the synaptics xorg

	 * driver.

	 * We also consider that touchscreens providing buttons are touchpads.

	 */

	if (field->application == HID_DG_TOUCHPAD ||

	    (usage->hid & HID_USAGE_PAGE) == HID_UP_BUTTON ||

	    cls->is_indirect) {

		set_bit(INPUT_PROP_POINTER, hi->input->propbit);

		set_bit(BTN_TOOL_FINGER, hi->input->keybit);

		set_bit(BTN_TOOL_DOUBLETAP, hi->input->keybit);

		set_bit(BTN_TOOL_TRIPLETAP, hi->input->keybit);

		set_bit(BTN_TOOL_QUADTAP, hi->input->keybit);

	}



	/* eGalax devices provide a Digitizer.Stylus input which overrides

	 * the correct Digitizers.Finger X/Y ranges.

	 * Let's just ignore this input. */
@@ -389,9 +404,19 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi, 
				td->last_field_index = field->index;

			return -1;

		}

		case HID_DG_TOUCH:

			/* Legacy devices use TIPSWITCH and not TOUCH.

			 * Let's just ignore this field. */

			return -1;

		/* let hid-input decide for the others */

		return 0;



	case HID_UP_BUTTON:

		code = BTN_MOUSE + ((usage->hid - 1) & HID_USAGE);

		hid_map_usage(hi, usage, bit, max, EV_KEY, code);

		input_set_capability(hi->input, EV_KEY, code);

		return 1;



	case 0xff000000:

		/* we do not want to map these: no input-oriented meaning */

		return -1;
@@ -538,6 +563,9 @@ static int mt_event(struct hid_device *hid, struct hid_field *field, 
			if (value)

				td->num_expected = value;

			break;

		case HID_DG_TOUCH:

			/* do nothing */

			break;



		default:

			/* fallback to the generic hidinput handling */

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