1/*
2 * Focaltech TouchPad PS/2 mouse driver
3 *
4 * Copyright (c) 2014 Red Hat Inc.
5 * Copyright (c) 2014 Mathias Gottschlag <mgottschlag@gmail.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * Red Hat authors:
13 *
14 * Hans de Goede <hdegoede@redhat.com>
15 */
16
17
18#include <linux/device.h>
19#include <linux/libps2.h>
20#include <linux/input/mt.h>
21#include <linux/serio.h>
22#include <linux/slab.h>
23#include "psmouse.h"
24#include "focaltech.h"
25
26static const char * const focaltech_pnp_ids[] = {
27	"FLT0101",
28	"FLT0102",
29	"FLT0103",
30	NULL
31};
32
33/*
34 * Even if the kernel is built without support for Focaltech PS/2 touchpads (or
35 * when the real driver fails to recognize the device), we still have to detect
36 * them in order to avoid further detection attempts confusing the touchpad.
37 * This way it at least works in PS/2 mouse compatibility mode.
38 */
39int focaltech_detect(struct psmouse *psmouse, bool set_properties)
40{
41	if (!psmouse_matches_pnp_id(psmouse, focaltech_pnp_ids))
42		return -ENODEV;
43
44	if (set_properties) {
45		psmouse->vendor = "FocalTech";
46		psmouse->name = "FocalTech Touchpad";
47	}
48
49	return 0;
50}
51
52static void focaltech_reset(struct psmouse *psmouse)
53{
54	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
55	psmouse_reset(psmouse);
56}
57
58#ifdef CONFIG_MOUSE_PS2_FOCALTECH
59
60/*
61 * Packet types - the numbers are not consecutive, so we might be missing
62 * something here.
63 */
64#define FOC_TOUCH 0x3 /* bitmap of active fingers */
65#define FOC_ABS 0x6 /* absolute position of one finger */
66#define FOC_REL 0x9 /* relative position of 1-2 fingers */
67
68#define FOC_MAX_FINGERS 5
69
70/*
71 * Current state of a single finger on the touchpad.
72 */
73struct focaltech_finger_state {
74	/* The touchpad has generated a touch event for the finger */
75	bool active;
76
77	/*
78	 * The touchpad has sent position data for the finger. The
79	 * flag is 0 when the finger is not active, and there is a
80	 * time between the first touch event for the finger and the
81	 * following absolute position packet for the finger where the
82	 * touchpad has declared the finger to be valid, but we do not
83	 * have any valid position yet.
84	 */
85	bool valid;
86
87	/*
88	 * Absolute position (from the bottom left corner) of the
89	 * finger.
90	 */
91	unsigned int x;
92	unsigned int y;
93};
94
95/*
96 * Description of the current state of the touchpad hardware.
97 */
98struct focaltech_hw_state {
99	/*
100	 * The touchpad tracks the positions of the fingers for us,
101	 * the array indices correspond to the finger indices returned
102	 * in the report packages.
103	 */
104	struct focaltech_finger_state fingers[FOC_MAX_FINGERS];
105
106	/* True if the clickpad has been pressed. */
107	bool pressed;
108};
109
110struct focaltech_data {
111	unsigned int x_max, y_max;
112	struct focaltech_hw_state state;
113};
114
115static void focaltech_report_state(struct psmouse *psmouse)
116{
117	struct focaltech_data *priv = psmouse->private;
118	struct focaltech_hw_state *state = &priv->state;
119	struct input_dev *dev = psmouse->dev;
120	int i;
121
122	for (i = 0; i < FOC_MAX_FINGERS; i++) {
123		struct focaltech_finger_state *finger = &state->fingers[i];
124		bool active = finger->active && finger->valid;
125
126		input_mt_slot(dev, i);
127		input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
128		if (active) {
129			unsigned int clamped_x, clamped_y;
130			/*
131			 * The touchpad might report invalid data, so we clamp
132			 * the resulting values so that we do not confuse
133			 * userspace.
134			 */
135			clamped_x = clamp(finger->x, 0U, priv->x_max);
136			clamped_y = clamp(finger->y, 0U, priv->y_max);
137			input_report_abs(dev, ABS_MT_POSITION_X, clamped_x);
138			input_report_abs(dev, ABS_MT_POSITION_Y,
139					 priv->y_max - clamped_y);
140		}
141	}
142	input_mt_report_pointer_emulation(dev, true);
143
144	input_report_key(psmouse->dev, BTN_LEFT, state->pressed);
145	input_sync(psmouse->dev);
146}
147
148static void focaltech_process_touch_packet(struct psmouse *psmouse,
149					   unsigned char *packet)
150{
151	struct focaltech_data *priv = psmouse->private;
152	struct focaltech_hw_state *state = &priv->state;
153	unsigned char fingers = packet[1];
154	int i;
155
156	state->pressed = (packet[0] >> 4) & 1;
157
158	/* the second byte contains a bitmap of all fingers touching the pad */
159	for (i = 0; i < FOC_MAX_FINGERS; i++) {
160		state->fingers[i].active = fingers & 0x1;
161		if (!state->fingers[i].active) {
162			/*
163			 * Even when the finger becomes active again, we still
164			 * will have to wait for the first valid position.
165			 */
166			state->fingers[i].valid = false;
167		}
168		fingers >>= 1;
169	}
170}
171
172static void focaltech_process_abs_packet(struct psmouse *psmouse,
173					 unsigned char *packet)
174{
175	struct focaltech_data *priv = psmouse->private;
176	struct focaltech_hw_state *state = &priv->state;
177	unsigned int finger;
178
179	finger = (packet[1] >> 4) - 1;
180	if (finger >= FOC_MAX_FINGERS) {
181		psmouse_err(psmouse, "Invalid finger in abs packet: %d\n",
182			    finger);
183		return;
184	}
185
186	state->pressed = (packet[0] >> 4) & 1;
187
188	state->fingers[finger].x = ((packet[1] & 0xf) << 8) | packet[2];
189	state->fingers[finger].y = (packet[3] << 8) | packet[4];
190	state->fingers[finger].valid = true;
191}
192
193static void focaltech_process_rel_packet(struct psmouse *psmouse,
194					 unsigned char *packet)
195{
196	struct focaltech_data *priv = psmouse->private;
197	struct focaltech_hw_state *state = &priv->state;
198	int finger1, finger2;
199
200	state->pressed = packet[0] >> 7;
201	finger1 = ((packet[0] >> 4) & 0x7) - 1;
202	if (finger1 < FOC_MAX_FINGERS) {
203		state->fingers[finger1].x += (char)packet[1];
204		state->fingers[finger1].y += (char)packet[2];
205	} else {
206		psmouse_err(psmouse, "First finger in rel packet invalid: %d\n",
207			    finger1);
208	}
209
210	/*
211	 * If there is an odd number of fingers, the last relative
212	 * packet only contains one finger. In this case, the second
213	 * finger index in the packet is 0 (we subtract 1 in the lines
214	 * above to create array indices, so the finger will overflow
215	 * and be above FOC_MAX_FINGERS).
216	 */
217	finger2 = ((packet[3] >> 4) & 0x7) - 1;
218	if (finger2 < FOC_MAX_FINGERS) {
219		state->fingers[finger2].x += (char)packet[4];
220		state->fingers[finger2].y += (char)packet[5];
221	}
222}
223
224static void focaltech_process_packet(struct psmouse *psmouse)
225{
226	unsigned char *packet = psmouse->packet;
227
228	switch (packet[0] & 0xf) {
229	case FOC_TOUCH:
230		focaltech_process_touch_packet(psmouse, packet);
231		break;
232
233	case FOC_ABS:
234		focaltech_process_abs_packet(psmouse, packet);
235		break;
236
237	case FOC_REL:
238		focaltech_process_rel_packet(psmouse, packet);
239		break;
240
241	default:
242		psmouse_err(psmouse, "Unknown packet type: %02x\n", packet[0]);
243		break;
244	}
245
246	focaltech_report_state(psmouse);
247}
248
249static psmouse_ret_t focaltech_process_byte(struct psmouse *psmouse)
250{
251	if (psmouse->pktcnt >= 6) { /* Full packet received */
252		focaltech_process_packet(psmouse);
253		return PSMOUSE_FULL_PACKET;
254	}
255
256	/*
257	 * We might want to do some validation of the data here, but
258	 * we do not know the protocol well enough
259	 */
260	return PSMOUSE_GOOD_DATA;
261}
262
263static int focaltech_switch_protocol(struct psmouse *psmouse)
264{
265	struct ps2dev *ps2dev = &psmouse->ps2dev;
266	unsigned char param[3];
267
268	param[0] = 0;
269	if (ps2_command(ps2dev, param, 0x10f8))
270		return -EIO;
271
272	if (ps2_command(ps2dev, param, 0x10f8))
273		return -EIO;
274
275	if (ps2_command(ps2dev, param, 0x10f8))
276		return -EIO;
277
278	param[0] = 1;
279	if (ps2_command(ps2dev, param, 0x10f8))
280		return -EIO;
281
282	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11))
283		return -EIO;
284
285	if (ps2_command(ps2dev, param, PSMOUSE_CMD_ENABLE))
286		return -EIO;
287
288	return 0;
289}
290
291static void focaltech_disconnect(struct psmouse *psmouse)
292{
293	focaltech_reset(psmouse);
294	kfree(psmouse->private);
295	psmouse->private = NULL;
296}
297
298static int focaltech_reconnect(struct psmouse *psmouse)
299{
300	int error;
301
302	focaltech_reset(psmouse);
303
304	error = focaltech_switch_protocol(psmouse);
305	if (error) {
306		psmouse_err(psmouse, "Unable to initialize the device\n");
307		return error;
308	}
309
310	return 0;
311}
312
313static void focaltech_set_input_params(struct psmouse *psmouse)
314{
315	struct input_dev *dev = psmouse->dev;
316	struct focaltech_data *priv = psmouse->private;
317
318	/*
319	 * Undo part of setup done for us by psmouse core since touchpad
320	 * is not a relative device.
321	 */
322	__clear_bit(EV_REL, dev->evbit);
323	__clear_bit(REL_X, dev->relbit);
324	__clear_bit(REL_Y, dev->relbit);
325	__clear_bit(BTN_RIGHT, dev->keybit);
326	__clear_bit(BTN_MIDDLE, dev->keybit);
327
328	/*
329	 * Now set up our capabilities.
330	 */
331	__set_bit(EV_ABS, dev->evbit);
332	input_set_abs_params(dev, ABS_MT_POSITION_X, 0, priv->x_max, 0, 0);
333	input_set_abs_params(dev, ABS_MT_POSITION_Y, 0, priv->y_max, 0, 0);
334	input_mt_init_slots(dev, 5, INPUT_MT_POINTER);
335	__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
336}
337
338static int focaltech_read_register(struct ps2dev *ps2dev, int reg,
339				   unsigned char *param)
340{
341	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11))
342		return -EIO;
343
344	param[0] = 0;
345	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
346		return -EIO;
347
348	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
349		return -EIO;
350
351	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
352		return -EIO;
353
354	param[0] = reg;
355	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
356		return -EIO;
357
358	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
359		return -EIO;
360
361	return 0;
362}
363
364static int focaltech_read_size(struct psmouse *psmouse)
365{
366	struct ps2dev *ps2dev = &psmouse->ps2dev;
367	struct focaltech_data *priv = psmouse->private;
368	char param[3];
369
370	if (focaltech_read_register(ps2dev, 2, param))
371		return -EIO;
372
373	/* not sure whether this is 100% correct */
374	priv->x_max = (unsigned char)param[1] * 128;
375	priv->y_max = (unsigned char)param[2] * 128;
376
377	return 0;
378}
379
380void focaltech_set_resolution(struct psmouse *psmouse, unsigned int resolution)
381{
382	/* not supported yet */
383}
384
385static void focaltech_set_rate(struct psmouse *psmouse, unsigned int rate)
386{
387	/* not supported yet */
388}
389
390static void focaltech_set_scale(struct psmouse *psmouse,
391				enum psmouse_scale scale)
392{
393	/* not supported yet */
394}
395
396int focaltech_init(struct psmouse *psmouse)
397{
398	struct focaltech_data *priv;
399	int error;
400
401	psmouse->private = priv = kzalloc(sizeof(struct focaltech_data),
402					  GFP_KERNEL);
403	if (!priv)
404		return -ENOMEM;
405
406	focaltech_reset(psmouse);
407
408	error = focaltech_read_size(psmouse);
409	if (error) {
410		psmouse_err(psmouse,
411			    "Unable to read the size of the touchpad\n");
412		goto fail;
413	}
414
415	error = focaltech_switch_protocol(psmouse);
416	if (error) {
417		psmouse_err(psmouse, "Unable to initialize the device\n");
418		goto fail;
419	}
420
421	focaltech_set_input_params(psmouse);
422
423	psmouse->protocol_handler = focaltech_process_byte;
424	psmouse->pktsize = 6;
425	psmouse->disconnect = focaltech_disconnect;
426	psmouse->reconnect = focaltech_reconnect;
427	psmouse->cleanup = focaltech_reset;
428	/* resync is not supported yet */
429	psmouse->resync_time = 0;
430	/*
431	 * rate/resolution/scale changes are not supported yet, and
432	 * the generic implementations of these functions seem to
433	 * confuse some touchpads
434	 */
435	psmouse->set_resolution = focaltech_set_resolution;
436	psmouse->set_rate = focaltech_set_rate;
437	psmouse->set_scale = focaltech_set_scale;
438
439	return 0;
440
441fail:
442	focaltech_reset(psmouse);
443	kfree(priv);
444	return error;
445}
446
447#else /* CONFIG_MOUSE_PS2_FOCALTECH */
448
449int focaltech_init(struct psmouse *psmouse)
450{
451	focaltech_reset(psmouse);
452
453	return 0;
454}
455
456#endif /* CONFIG_MOUSE_PS2_FOCALTECH */
457