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Commit 3ac36d15 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Jiri Kosina
Browse files

HID: hid-multitouch: fix wrong protocol detection 



The previous implementation introduced a randomness in the splitting
of the different touches reported by the device. This version is more
robust as we don't rely on hi->input->absbit, but on our own structure.

This also prepares hid-multitouch to better support Win8 devices.

[Jiri Kosina <jkosina@suse.cz>: fix build]

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 16b79bb8

drivers/hid/hid-multitouch.c

+46 −12
Original line number Diff line number Diff line
@@ -70,9 +70,16 @@ struct mt_class { 
	bool is_indirect;	/* true for touchpads */

};



struct mt_fields {

	unsigned usages[HID_MAX_FIELDS];

	unsigned int length;

};



struct mt_device {

	struct mt_slot curdata;	/* placeholder of incoming data */

	struct mt_class mtclass;	/* our mt device class */

	struct mt_fields *fields;	/* temporary placeholder for storing the

					   multitouch fields */

	unsigned last_field_index;	/* last field index of the report */

	unsigned last_slot_field;	/* the last field of a slot */

	__s8 inputmode;		/* InputMode HID feature, -1 if non-existent */
@@ -278,11 +285,15 @@ static void set_abs(struct input_dev *input, unsigned int code, 
	input_set_abs_params(input, code, fmin, fmax, fuzz, 0);

}



static void set_last_slot_field(struct hid_usage *usage, struct mt_device *td,

static void mt_store_field(struct hid_usage *usage, struct mt_device *td,

		struct hid_input *hi)

{

	if (!test_bit(usage->hid, hi->input->absbit))

		td->last_slot_field = usage->hid;

	struct mt_fields *f = td->fields;



	if (f->length >= HID_MAX_FIELDS)

		return;



	f->usages[f->length++] = usage->hid;

}



static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
@@ -333,7 +344,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi, 
				cls->sn_move);

			/* touchscreen emulation */

			set_abs(hi->input, ABS_X, field, cls->sn_move);

			set_last_slot_field(usage, td, hi);

			mt_store_field(usage, td, hi);

			td->last_field_index = field->index;

			return 1;

		case HID_GD_Y:
@@ -343,7 +354,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi, 
				cls->sn_move);

			/* touchscreen emulation */

			set_abs(hi->input, ABS_Y, field, cls->sn_move);

			set_last_slot_field(usage, td, hi);

			mt_store_field(usage, td, hi);

			td->last_field_index = field->index;

			return 1;

		}
@@ -352,24 +363,24 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi, 
	case HID_UP_DIGITIZER:

		switch (usage->hid) {

		case HID_DG_INRANGE:

			set_last_slot_field(usage, td, hi);

			mt_store_field(usage, td, hi);

			td->last_field_index = field->index;

			return 1;

		case HID_DG_CONFIDENCE:

			set_last_slot_field(usage, td, hi);

			mt_store_field(usage, td, hi);

			td->last_field_index = field->index;

			return 1;

		case HID_DG_TIPSWITCH:

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

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

			set_last_slot_field(usage, td, hi);

			mt_store_field(usage, td, hi);

			td->last_field_index = field->index;

			return 1;

		case HID_DG_CONTACTID:

			if (!td->maxcontacts)

				td->maxcontacts = MT_DEFAULT_MAXCONTACT;

			input_mt_init_slots(hi->input, td->maxcontacts);

			td->last_slot_field = usage->hid;

			mt_store_field(usage, td, hi);

			td->last_field_index = field->index;

			td->touches_by_report++;

			return 1;
@@ -378,7 +389,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi, 
					EV_ABS, ABS_MT_TOUCH_MAJOR);

			set_abs(hi->input, ABS_MT_TOUCH_MAJOR, field,

				cls->sn_width);

			set_last_slot_field(usage, td, hi);

			mt_store_field(usage, td, hi);

			td->last_field_index = field->index;

			return 1;

		case HID_DG_HEIGHT:
@@ -388,7 +399,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi, 
				cls->sn_height);

			input_set_abs_params(hi->input,

					ABS_MT_ORIENTATION, 0, 1, 0, 0);

			set_last_slot_field(usage, td, hi);

			mt_store_field(usage, td, hi);

			td->last_field_index = field->index;

			return 1;

		case HID_DG_TIPPRESSURE:
@@ -399,7 +410,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi, 
			/* touchscreen emulation */

			set_abs(hi->input, ABS_PRESSURE, field,

				cls->sn_pressure);

			set_last_slot_field(usage, td, hi);

			mt_store_field(usage, td, hi);

			td->last_field_index = field->index;

			return 1;

		case HID_DG_CONTACTCOUNT:
@@ -653,6 +664,16 @@ static void mt_post_parse_default_settings(struct mt_device *td) 
	td->mtclass.quirks = quirks;

}



static void mt_post_parse(struct mt_device *td)

{

	struct mt_fields *f = td->fields;



	if (td->touches_by_report > 0) {

		int field_count_per_touch = f->length / td->touches_by_report;

		td->last_slot_field = f->usages[field_count_per_touch - 1];

	}

}



static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)

{

	int ret, i;
@@ -683,6 +704,13 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id) 
	td->maxcontact_report_id = -1;

	hid_set_drvdata(hdev, td);



	td->fields = kzalloc(sizeof(struct mt_fields), GFP_KERNEL);

	if (!td->fields) {

		dev_err(&hdev->dev, "cannot allocate multitouch fields data\n");

		ret = -ENOMEM;

		goto fail;

	}



	ret = hid_parse(hdev);

	if (ret != 0)

		goto fail;
@@ -691,6 +719,8 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id) 
	if (ret)

		goto fail;



	mt_post_parse(td);



	if (id->vendor == HID_ANY_ID && id->product == HID_ANY_ID)

		mt_post_parse_default_settings(td);
@@ -708,9 +738,13 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id) 
	mt_set_maxcontacts(hdev);

	mt_set_input_mode(hdev);



	kfree(td->fields);

	td->fields = NULL;



	return 0;



fail:

	kfree(td->fields);

	kfree(td);

	return ret;

}