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	/*
107	 * Finger width 0-7 and 15 for a very big contact area.
108	 * 15 value stays until the finger is released.
109	 * Width is reported only in absolute packets.
110	 * Since hardware reports width only for last touching finger,
111	 * there is no need to store width for every specific finger,
112	 * so we keep only last value reported.
113	 */
114	unsigned int width;
115
116	/* True if the clickpad has been pressed. */
117	bool pressed;
118};
119
120struct focaltech_data {
121	unsigned int x_max, y_max;
122	struct focaltech_hw_state state;
123};
124
125static void focaltech_report_state(struct psmouse *psmouse)
126{
127	struct focaltech_data *priv = psmouse->private;
128	struct focaltech_hw_state *state = &priv->state;
129	struct input_dev *dev = psmouse->dev;
130	int i;
131
132	for (i = 0; i < FOC_MAX_FINGERS; i++) {
133		struct focaltech_finger_state *finger = &state->fingers[i];
134		bool active = finger->active && finger->valid;
135
136		input_mt_slot(dev, i);
137		input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
138		if (active) {
139			unsigned int clamped_x, clamped_y;
140			/*
141			 * The touchpad might report invalid data, so we clamp
142			 * the resulting values so that we do not confuse
143			 * userspace.
144			 */
145			clamped_x = clamp(finger->x, 0U, priv->x_max);
146			clamped_y = clamp(finger->y, 0U, priv->y_max);
147			input_report_abs(dev, ABS_MT_POSITION_X, clamped_x);
148			input_report_abs(dev, ABS_MT_POSITION_Y,
149					 priv->y_max - clamped_y);
150			input_report_abs(dev, ABS_TOOL_WIDTH, state->width);
151		}
152	}
153	input_mt_report_pointer_emulation(dev, true);
154
155	input_report_key(psmouse->dev, BTN_LEFT, state->pressed);
156	input_sync(psmouse->dev);
157}
158
159static void focaltech_process_touch_packet(struct psmouse *psmouse,
160					   unsigned char *packet)
161{
162	struct focaltech_data *priv = psmouse->private;
163	struct focaltech_hw_state *state = &priv->state;
164	unsigned char fingers = packet[1];
165	int i;
166
167	state->pressed = (packet[0] >> 4) & 1;
168
169	/* the second byte contains a bitmap of all fingers touching the pad */
170	for (i = 0; i < FOC_MAX_FINGERS; i++) {
171		state->fingers[i].active = fingers & 0x1;
172		if (!state->fingers[i].active) {
173			/*
174			 * Even when the finger becomes active again, we still
175			 * will have to wait for the first valid position.
176			 */
177			state->fingers[i].valid = false;
178		}
179		fingers >>= 1;
180	}
181}
182
183static void focaltech_process_abs_packet(struct psmouse *psmouse,
184					 unsigned char *packet)
185{
186	struct focaltech_data *priv = psmouse->private;
187	struct focaltech_hw_state *state = &priv->state;
188	unsigned int finger;
189
190	finger = (packet[1] >> 4) - 1;
191	if (finger >= FOC_MAX_FINGERS) {
192		psmouse_err(psmouse, "Invalid finger in abs packet: %d\n",
193			    finger);
194		return;
195	}
196
197	state->pressed = (packet[0] >> 4) & 1;
198
199	state->fingers[finger].x = ((packet[1] & 0xf) << 8) | packet[2];
200	state->fingers[finger].y = (packet[3] << 8) | packet[4];
201	state->width = packet[5] >> 4;
202	state->fingers[finger].valid = true;
203}
204
205static void focaltech_process_rel_packet(struct psmouse *psmouse,
206					 unsigned char *packet)
207{
208	struct focaltech_data *priv = psmouse->private;
209	struct focaltech_hw_state *state = &priv->state;
210	int finger1, finger2;
211
212	state->pressed = packet[0] >> 7;
213	finger1 = ((packet[0] >> 4) & 0x7) - 1;
214	if (finger1 < FOC_MAX_FINGERS) {
215		state->fingers[finger1].x += (char)packet[1];
216		state->fingers[finger1].y += (char)packet[2];
217	} else {
218		psmouse_err(psmouse, "First finger in rel packet invalid: %d\n",
219			    finger1);
220	}
221
222	/*
223	 * If there is an odd number of fingers, the last relative
224	 * packet only contains one finger. In this case, the second
225	 * finger index in the packet is 0 (we subtract 1 in the lines
226	 * above to create array indices, so the finger will overflow
227	 * and be above FOC_MAX_FINGERS).
228	 */
229	finger2 = ((packet[3] >> 4) & 0x7) - 1;
230	if (finger2 < FOC_MAX_FINGERS) {
231		state->fingers[finger2].x += (char)packet[4];
232		state->fingers[finger2].y += (char)packet[5];
233	}
234}
235
236static void focaltech_process_packet(struct psmouse *psmouse)
237{
238	unsigned char *packet = psmouse->packet;
239
240	switch (packet[0] & 0xf) {
241	case FOC_TOUCH:
242		focaltech_process_touch_packet(psmouse, packet);
243		break;
244
245	case FOC_ABS:
246		focaltech_process_abs_packet(psmouse, packet);
247		break;
248
249	case FOC_REL:
250		focaltech_process_rel_packet(psmouse, packet);
251		break;
252
253	default:
254		psmouse_err(psmouse, "Unknown packet type: %02x\n", packet[0]);
255		break;
256	}
257
258	focaltech_report_state(psmouse);
259}
260
261static psmouse_ret_t focaltech_process_byte(struct psmouse *psmouse)
262{
263	if (psmouse->pktcnt >= 6) { /* Full packet received */
264		focaltech_process_packet(psmouse);
265		return PSMOUSE_FULL_PACKET;
266	}
267
268	/*
269	 * We might want to do some validation of the data here, but
270	 * we do not know the protocol well enough
271	 */
272	return PSMOUSE_GOOD_DATA;
273}
274
275static int focaltech_switch_protocol(struct psmouse *psmouse)
276{
277	struct ps2dev *ps2dev = &psmouse->ps2dev;
278	unsigned char param[3];
279
280	param[0] = 0;
281	if (ps2_command(ps2dev, param, 0x10f8))
282		return -EIO;
283
284	if (ps2_command(ps2dev, param, 0x10f8))
285		return -EIO;
286
287	if (ps2_command(ps2dev, param, 0x10f8))
288		return -EIO;
289
290	param[0] = 1;
291	if (ps2_command(ps2dev, param, 0x10f8))
292		return -EIO;
293
294	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11))
295		return -EIO;
296
297	if (ps2_command(ps2dev, param, PSMOUSE_CMD_ENABLE))
298		return -EIO;
299
300	return 0;
301}
302
303static void focaltech_disconnect(struct psmouse *psmouse)
304{
305	focaltech_reset(psmouse);
306	kfree(psmouse->private);
307	psmouse->private = NULL;
308}
309
310static int focaltech_reconnect(struct psmouse *psmouse)
311{
312	int error;
313
314	focaltech_reset(psmouse);
315
316	error = focaltech_switch_protocol(psmouse);
317	if (error) {
318		psmouse_err(psmouse, "Unable to initialize the device\n");
319		return error;
320	}
321
322	return 0;
323}
324
325static void focaltech_set_input_params(struct psmouse *psmouse)
326{
327	struct input_dev *dev = psmouse->dev;
328	struct focaltech_data *priv = psmouse->private;
329
330	/*
331	 * Undo part of setup done for us by psmouse core since touchpad
332	 * is not a relative device.
333	 */
334	__clear_bit(EV_REL, dev->evbit);
335	__clear_bit(REL_X, dev->relbit);
336	__clear_bit(REL_Y, dev->relbit);
337	__clear_bit(BTN_RIGHT, dev->keybit);
338	__clear_bit(BTN_MIDDLE, dev->keybit);
339
340	/*
341	 * Now set up our capabilities.
342	 */
343	__set_bit(EV_ABS, dev->evbit);
344	input_set_abs_params(dev, ABS_MT_POSITION_X, 0, priv->x_max, 0, 0);
345	input_set_abs_params(dev, ABS_MT_POSITION_Y, 0, priv->y_max, 0, 0);
346	input_set_abs_params(dev, ABS_TOOL_WIDTH, 0, 15, 0, 0);
347	input_mt_init_slots(dev, 5, INPUT_MT_POINTER);
348	__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
349}
350
351static int focaltech_read_register(struct ps2dev *ps2dev, int reg,
352				   unsigned char *param)
353{
354	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11))
355		return -EIO;
356
357	param[0] = 0;
358	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
359		return -EIO;
360
361	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
362		return -EIO;
363
364	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
365		return -EIO;
366
367	param[0] = reg;
368	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
369		return -EIO;
370
371	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
372		return -EIO;
373
374	return 0;
375}
376
377static int focaltech_read_size(struct psmouse *psmouse)
378{
379	struct ps2dev *ps2dev = &psmouse->ps2dev;
380	struct focaltech_data *priv = psmouse->private;
381	char param[3];
382
383	if (focaltech_read_register(ps2dev, 2, param))
384		return -EIO;
385
386	/* not sure whether this is 100% correct */
387	priv->x_max = (unsigned char)param[1] * 128;
388	priv->y_max = (unsigned char)param[2] * 128;
389
390	return 0;
391}
392
393void focaltech_set_resolution(struct psmouse *psmouse, unsigned int resolution)
394{
395	/* not supported yet */
396}
397
398static void focaltech_set_rate(struct psmouse *psmouse, unsigned int rate)
399{
400	/* not supported yet */
401}
402
403static void focaltech_set_scale(struct psmouse *psmouse,
404				enum psmouse_scale scale)
405{
406	/* not supported yet */
407}
408
409int focaltech_init(struct psmouse *psmouse)
410{
411	struct focaltech_data *priv;
412	int error;
413
414	psmouse->private = priv = kzalloc(sizeof(struct focaltech_data),
415					  GFP_KERNEL);
416	if (!priv)
417		return -ENOMEM;
418
419	focaltech_reset(psmouse);
420
421	error = focaltech_read_size(psmouse);
422	if (error) {
423		psmouse_err(psmouse,
424			    "Unable to read the size of the touchpad\n");
425		goto fail;
426	}
427
428	error = focaltech_switch_protocol(psmouse);
429	if (error) {
430		psmouse_err(psmouse, "Unable to initialize the device\n");
431		goto fail;
432	}
433
434	focaltech_set_input_params(psmouse);
435
436	psmouse->protocol_handler = focaltech_process_byte;
437	psmouse->pktsize = 6;
438	psmouse->disconnect = focaltech_disconnect;
439	psmouse->reconnect = focaltech_reconnect;
440	psmouse->cleanup = focaltech_reset;
441	/* resync is not supported yet */
442	psmouse->resync_time = 0;
443	/*
444	 * rate/resolution/scale changes are not supported yet, and
445	 * the generic implementations of these functions seem to
446	 * confuse some touchpads
447	 */
448	psmouse->set_resolution = focaltech_set_resolution;
449	psmouse->set_rate = focaltech_set_rate;
450	psmouse->set_scale = focaltech_set_scale;
451
452	return 0;
453
454fail:
455	focaltech_reset(psmouse);
456	kfree(priv);
457	return error;
458}
459
460#else /* CONFIG_MOUSE_PS2_FOCALTECH */
461
462int focaltech_init(struct psmouse *psmouse)
463{
464	focaltech_reset(psmouse);
465
466	return 0;
467}
468
469#endif /* CONFIG_MOUSE_PS2_FOCALTECH */
470