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: Benjamin Tissoires <benjamin.tissoires@enac.fr> Acked-by: Henrik Rydberg <rydberg@euromail.se> Signed-off-by: Jiri Kosina <jkosina@suse.cz>

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: Benjamin Tissoires <benjamin.tissoires@enac.fr> Acked-by: Henrik Rydberg <rydberg@euromail.se> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Benjamin Tissoires · Jiri Kosina
1 parent 16b79bb8ec
Showing 1 changed file with 46 additions and 12 deletions Side-by-side Diff
drivers/hid/hid-multitouch.c
@@ -70,9 +70,16 @@
 	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 @@
 	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 @@
 				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 @@
 				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 @@
 	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 @@
 					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 @@
 				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 @@
 			/* 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 @@
 	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 @@
 	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 @@
 	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 @@
 	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;
 }
...	...	@@ -70,9 +70,16 @@
70	70	bool is_indirect; /* true for touchpads */
71	71	};
72	72
	73	+struct mt_fields {
	74	+ unsigned usages[HID_MAX_FIELDS];
	75	+ unsigned int length;
	76	+};
	77	+
73	78	struct mt_device {
74	79	struct mt_slot curdata; /* placeholder of incoming data */
75	80	struct mt_class mtclass; /* our mt device class */
	81	+ struct mt_fields fields; / temporary placeholder for storing the
	82	+ multitouch fields */
76	83	unsigned last_field_index; /* last field index of the report */
77	84	unsigned last_slot_field; /* the last field of a slot */
78	85	__s8 inputmode; /* InputMode HID feature, -1 if non-existent */
79	86
...	...	@@ -278,11 +285,15 @@
278	285	input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
279	286	}
280	287
281		-static void set_last_slot_field(struct hid_usage usage, struct mt_device td,
	288	+static void mt_store_field(struct hid_usage usage, struct mt_device td,
282	289	struct hid_input *hi)
283	290	{
284		- if (!test_bit(usage->hid, hi->input->absbit))
285		- td->last_slot_field = usage->hid;
	291	+ struct mt_fields *f = td->fields;
	292	+
	293	+ if (f->length >= HID_MAX_FIELDS)
	294	+ return;
	295	+
	296	+ f->usages[f->length++] = usage->hid;
286	297	}
287	298
288	299	static int mt_input_mapping(struct hid_device hdev, struct hid_input hi,
...	...	@@ -333,7 +344,7 @@
333	344	cls->sn_move);
334	345	/* touchscreen emulation */
335	346	set_abs(hi->input, ABS_X, field, cls->sn_move);
336		- set_last_slot_field(usage, td, hi);
	347	+ mt_store_field(usage, td, hi);
337	348	td->last_field_index = field->index;
338	349	return 1;
339	350	case HID_GD_Y:
...	...	@@ -343,7 +354,7 @@
343	354	cls->sn_move);
344	355	/* touchscreen emulation */
345	356	set_abs(hi->input, ABS_Y, field, cls->sn_move);
346		- set_last_slot_field(usage, td, hi);
	357	+ mt_store_field(usage, td, hi);
347	358	td->last_field_index = field->index;
348	359	return 1;
349	360	}
350	361
351	362
352	363
...	...	@@ -352,24 +363,24 @@
352	363	case HID_UP_DIGITIZER:
353	364	switch (usage->hid) {
354	365	case HID_DG_INRANGE:
355		- set_last_slot_field(usage, td, hi);
	366	+ mt_store_field(usage, td, hi);
356	367	td->last_field_index = field->index;
357	368	return 1;
358	369	case HID_DG_CONFIDENCE:
359		- set_last_slot_field(usage, td, hi);
	370	+ mt_store_field(usage, td, hi);
360	371	td->last_field_index = field->index;
361	372	return 1;
362	373	case HID_DG_TIPSWITCH:
363	374	hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
364	375	input_set_capability(hi->input, EV_KEY, BTN_TOUCH);
365		- set_last_slot_field(usage, td, hi);
	376	+ mt_store_field(usage, td, hi);
366	377	td->last_field_index = field->index;
367	378	return 1;
368	379	case HID_DG_CONTACTID:
369	380	if (!td->maxcontacts)
370	381	td->maxcontacts = MT_DEFAULT_MAXCONTACT;
371	382	input_mt_init_slots(hi->input, td->maxcontacts);
372		- td->last_slot_field = usage->hid;
	383	+ mt_store_field(usage, td, hi);
373	384	td->last_field_index = field->index;
374	385	td->touches_by_report++;
375	386	return 1;
...	...	@@ -378,7 +389,7 @@
378	389	EV_ABS, ABS_MT_TOUCH_MAJOR);
379	390	set_abs(hi->input, ABS_MT_TOUCH_MAJOR, field,
380	391	cls->sn_width);
381		- set_last_slot_field(usage, td, hi);
	392	+ mt_store_field(usage, td, hi);
382	393	td->last_field_index = field->index;
383	394	return 1;
384	395	case HID_DG_HEIGHT:
...	...	@@ -388,7 +399,7 @@
388	399	cls->sn_height);
389	400	input_set_abs_params(hi->input,
390	401	ABS_MT_ORIENTATION, 0, 1, 0, 0);
391		- set_last_slot_field(usage, td, hi);
	402	+ mt_store_field(usage, td, hi);
392	403	td->last_field_index = field->index;
393	404	return 1;
394	405	case HID_DG_TIPPRESSURE:
...	...	@@ -399,7 +410,7 @@
399	410	/* touchscreen emulation */
400	411	set_abs(hi->input, ABS_PRESSURE, field,
401	412	cls->sn_pressure);
402		- set_last_slot_field(usage, td, hi);
	413	+ mt_store_field(usage, td, hi);
403	414	td->last_field_index = field->index;
404	415	return 1;
405	416	case HID_DG_CONTACTCOUNT:
...	...	@@ -653,6 +664,16 @@
653	664	td->mtclass.quirks = quirks;
654	665	}
655	666
	667	+static void mt_post_parse(struct mt_device *td)
	668	+{
	669	+ struct mt_fields *f = td->fields;
	670	+
	671	+ if (td->touches_by_report > 0) {
	672	+ int field_count_per_touch = f->length / td->touches_by_report;
	673	+ td->last_slot_field = f->usages[field_count_per_touch - 1];
	674	+ }
	675	+}
	676	+
656	677	static int mt_probe(struct hid_device hdev, const struct hid_device_id id)
657	678	{
658	679	int ret, i;
...	...	@@ -683,6 +704,13 @@
683	704	td->maxcontact_report_id = -1;
684	705	hid_set_drvdata(hdev, td);
685	706
	707	+ td->fields = kzalloc(sizeof(struct mt_fields), GFP_KERNEL);
	708	+ if (!td->fields) {
	709	+ dev_err(&hdev->dev, "cannot allocate multitouch fields data\n");
	710	+ ret = -ENOMEM;
	711	+ goto fail;
	712	+ }
	713	+
686	714	ret = hid_parse(hdev);
687	715	if (ret != 0)
688	716	goto fail;
...	...	@@ -691,6 +719,8 @@
691	719	if (ret)
692	720	goto fail;
693	721
	722	+ mt_post_parse(td);
	723	+
694	724	if (id->vendor == HID_ANY_ID && id->product == HID_ANY_ID)
695	725	mt_post_parse_default_settings(td);
696	726
697	727
...	...	@@ -708,9 +738,13 @@
708	738	mt_set_maxcontacts(hdev);
709	739	mt_set_input_mode(hdev);
710	740
	741	+ kfree(td->fields);
	742	+ td->fields = NULL;
	743	+
711	744	return 0;
712	745
713	746	fail:
	747	+ kfree(td->fields);
714	748	kfree(td);
715	749	return ret;
716	750	}