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 = "Touchpad";
47 }
48
49 return 0;
50}
51
52#ifdef CONFIG_MOUSE_PS2_FOCALTECH
53
54/*
55 * Packet types - the numbers are not consecutive, so we might be missing
56 * something here.
57 */
58#define FOC_TOUCH 0x3 /* bitmap of active fingers */
59#define FOC_ABS 0x6 /* absolute position of one finger */
60#define FOC_REL 0x9 /* relative position of 1-2 fingers */
61
62#define FOC_MAX_FINGERS 5
63
64/*
65 * Current state of a single finger on the touchpad.
66 */
67struct focaltech_finger_state {
68 /* The touchpad has generated a touch event for the finger */
69 bool active;
70
71 /*
72 * The touchpad has sent position data for the finger. The
73 * flag is 0 when the finger is not active, and there is a
74 * time between the first touch event for the finger and the
75 * following absolute position packet for the finger where the
76 * touchpad has declared the finger to be valid, but we do not
77 * have any valid position yet.
78 */
79 bool valid;
80
81 /*
82 * Absolute position (from the bottom left corner) of the
83 * finger.
84 */
85 unsigned int x;
86 unsigned int y;
87};
88
89/*
90 * Description of the current state of the touchpad hardware.
91 */
92struct focaltech_hw_state {
93 /*
94 * The touchpad tracks the positions of the fingers for us,
95 * the array indices correspond to the finger indices returned
96 * in the report packages.
97 */
98 struct focaltech_finger_state fingers[FOC_MAX_FINGERS];
99
100 /*
101 * Finger width 0-7 and 15 for a very big contact area.
102 * 15 value stays until the finger is released.
103 * Width is reported only in absolute packets.
104 * Since hardware reports width only for last touching finger,
105 * there is no need to store width for every specific finger,
106 * so we keep only last value reported.
107 */
108 unsigned int width;
109
110 /* True if the clickpad has been pressed. */
111 bool pressed;
112};
113
114struct focaltech_data {
115 unsigned int x_max, y_max;
116 struct focaltech_hw_state state;
117};
118
119static void focaltech_report_state(struct psmouse *psmouse)
120{
121 struct focaltech_data *priv = psmouse->private;
122 struct focaltech_hw_state *state = &priv->state;
123 struct input_dev *dev = psmouse->dev;
124 int i;
125
126 for (i = 0; i < FOC_MAX_FINGERS; i++) {
127 struct focaltech_finger_state *finger = &state->fingers[i];
128 bool active = finger->active && finger->valid;
129
130 input_mt_slot(dev, i);
131 input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
132 if (active) {
133 unsigned int clamped_x, clamped_y;
134 /*
135 * The touchpad might report invalid data, so we clamp
136 * the resulting values so that we do not confuse
137 * userspace.
138 */
139 clamped_x = clamp(finger->x, 0U, priv->x_max);
140 clamped_y = clamp(finger->y, 0U, priv->y_max);
141 input_report_abs(dev, ABS_MT_POSITION_X, clamped_x);
142 input_report_abs(dev, ABS_MT_POSITION_Y,
143 priv->y_max - clamped_y);
144 input_report_abs(dev, ABS_TOOL_WIDTH, state->width);
145 }
146 }
147 input_mt_report_pointer_emulation(dev, true);
148
149 input_report_key(dev, BTN_LEFT, state->pressed);
150 input_sync(dev);
151}
152
153static void focaltech_process_touch_packet(struct psmouse *psmouse,
154 unsigned char *packet)
155{
156 struct focaltech_data *priv = psmouse->private;
157 struct focaltech_hw_state *state = &priv->state;
158 unsigned char fingers = packet[1];
159 int i;
160
161 state->pressed = (packet[0] >> 4) & 1;
162
163 /* the second byte contains a bitmap of all fingers touching the pad */
164 for (i = 0; i < FOC_MAX_FINGERS; i++) {
165 state->fingers[i].active = fingers & 0x1;
166 if (!state->fingers[i].active) {
167 /*
168 * Even when the finger becomes active again, we still
169 * will have to wait for the first valid position.
170 */
171 state->fingers[i].valid = false;
172 }
173 fingers >>= 1;
174 }
175}
176
177static void focaltech_process_abs_packet(struct psmouse *psmouse,
178 unsigned char *packet)
179{
180 struct focaltech_data *priv = psmouse->private;
181 struct focaltech_hw_state *state = &priv->state;
182 unsigned int finger;
183
184 finger = (packet[1] >> 4) - 1;
185 if (finger >= FOC_MAX_FINGERS) {
186 psmouse_err(psmouse, "Invalid finger in abs packet: %d\n",
187 finger);
188 return;
189 }
190
191 state->pressed = (packet[0] >> 4) & 1;
192
193 state->fingers[finger].x = ((packet[1] & 0xf) << 8) | packet[2];
194 state->fingers[finger].y = (packet[3] << 8) | packet[4];
195 state->width = packet[5] >> 4;
196 state->fingers[finger].valid = true;
197}
198
199static void focaltech_process_rel_packet(struct psmouse *psmouse,
200 unsigned char *packet)
201{
202 struct focaltech_data *priv = psmouse->private;
203 struct focaltech_hw_state *state = &priv->state;
204 int finger1, finger2;
205
206 state->pressed = packet[0] >> 7;
207 finger1 = ((packet[0] >> 4) & 0x7) - 1;
208 if (finger1 < FOC_MAX_FINGERS) {
209 state->fingers[finger1].x += (char)packet[1];
210 state->fingers[finger1].y += (char)packet[2];
211 } else {
212 psmouse_err(psmouse, "First finger in rel packet invalid: %d\n",
213 finger1);
214 }
215
216 /*
217 * If there is an odd number of fingers, the last relative
218 * packet only contains one finger. In this case, the second
219 * finger index in the packet is 0 (we subtract 1 in the lines
220 * above to create array indices, so the finger will overflow
221 * and be above FOC_MAX_FINGERS).
222 */
223 finger2 = ((packet[3] >> 4) & 0x7) - 1;
224 if (finger2 < FOC_MAX_FINGERS) {
225 state->fingers[finger2].x += (char)packet[4];
226 state->fingers[finger2].y += (char)packet[5];
227 }
228}
229
230static void focaltech_process_packet(struct psmouse *psmouse)
231{
232 unsigned char *packet = psmouse->packet;
233
234 switch (packet[0] & 0xf) {
235 case FOC_TOUCH:
236 focaltech_process_touch_packet(psmouse, packet);
237 break;
238
239 case FOC_ABS:
240 focaltech_process_abs_packet(psmouse, packet);
241 break;
242
243 case FOC_REL:
244 focaltech_process_rel_packet(psmouse, packet);
245 break;
246
247 default:
248 psmouse_err(psmouse, "Unknown packet type: %02x\n", packet[0]);
249 break;
250 }
251
252 focaltech_report_state(psmouse);
253}
254
255static psmouse_ret_t focaltech_process_byte(struct psmouse *psmouse)
256{
257 if (psmouse->pktcnt >= 6) { /* Full packet received */
258 focaltech_process_packet(psmouse);
259 return PSMOUSE_FULL_PACKET;
260 }
261
262 /*
263 * We might want to do some validation of the data here, but
264 * we do not know the protocol well enough
265 */
266 return PSMOUSE_GOOD_DATA;
267}
268
269static int focaltech_switch_protocol(struct psmouse *psmouse)
270{
271 struct ps2dev *ps2dev = &psmouse->ps2dev;
272 unsigned char param[3];
273
274 param[0] = 0;
275 if (ps2_command(ps2dev, param, 0x10f8))
276 return -EIO;
277
278 if (ps2_command(ps2dev, param, 0x10f8))
279 return -EIO;
280
281 if (ps2_command(ps2dev, param, 0x10f8))
282 return -EIO;
283
284 param[0] = 1;
285 if (ps2_command(ps2dev, param, 0x10f8))
286 return -EIO;
287
288 if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11))
289 return -EIO;
290
291 if (ps2_command(ps2dev, param, PSMOUSE_CMD_ENABLE))
292 return -EIO;
293
294 return 0;
295}
296
297static void focaltech_reset(struct psmouse *psmouse)
298{
299 ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
300 psmouse_reset(psmouse);
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
393static void focaltech_set_resolution(struct psmouse *psmouse,
394 unsigned int resolution)
395{
396 /* not supported yet */
397}
398
399static void focaltech_set_rate(struct psmouse *psmouse, unsigned int rate)
400{
401 /* not supported yet */
402}
403
404static void focaltech_set_scale(struct psmouse *psmouse,
405 enum psmouse_scale scale)
406{
407 /* not supported yet */
408}
409
410int focaltech_init(struct psmouse *psmouse)
411{
412 struct focaltech_data *priv;
413 int error;
414
415 psmouse->private = priv = kzalloc(sizeof(struct focaltech_data),
416 GFP_KERNEL);
417 if (!priv)
418 return -ENOMEM;
419
420 focaltech_reset(psmouse);
421
422 error = focaltech_read_size(psmouse);
423 if (error) {
424 psmouse_err(psmouse,
425 "Unable to read the size of the touchpad\n");
426 goto fail;
427 }
428
429 error = focaltech_switch_protocol(psmouse);
430 if (error) {
431 psmouse_err(psmouse, "Unable to initialize the device\n");
432 goto fail;
433 }
434
435 focaltech_set_input_params(psmouse);
436
437 psmouse->protocol_handler = focaltech_process_byte;
438 psmouse->pktsize = 6;
439 psmouse->disconnect = focaltech_disconnect;
440 psmouse->reconnect = focaltech_reconnect;
441 psmouse->cleanup = focaltech_reset;
442 /* resync is not supported yet */
443 psmouse->resync_time = 0;
444 /*
445 * rate/resolution/scale changes are not supported yet, and
446 * the generic implementations of these functions seem to
447 * confuse some touchpads
448 */
449 psmouse->set_resolution = focaltech_set_resolution;
450 psmouse->set_rate = focaltech_set_rate;
451 psmouse->set_scale = focaltech_set_scale;
452
453 return 0;
454
455fail:
456 focaltech_reset(psmouse);
457 kfree(priv);
458 return error;
459}
460#endif /* CONFIG_MOUSE_PS2_FOCALTECH */
461