1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Focaltech TouchPad PS/2 mouse driver
4 *
5 * Copyright (c) 2014 Red Hat Inc.
6 * Copyright (c) 2014 Mathias Gottschlag <mgottschlag@gmail.com>
7 *
8 * Red Hat authors:
9 *
10 * Hans de Goede <hdegoede@redhat.com>
11 */
12
13
14#include <linux/device.h>
15#include <linux/libps2.h>
16#include <linux/input/mt.h>
17#include <linux/serio.h>
18#include <linux/slab.h>
19#include "psmouse.h"
20#include "focaltech.h"
21
22static const char * const focaltech_pnp_ids[] = {
23 "FLT0101",
24 "FLT0102",
25 "FLT0103",
26 NULL
27};
28
29/*
30 * Even if the kernel is built without support for Focaltech PS/2 touchpads (or
31 * when the real driver fails to recognize the device), we still have to detect
32 * them in order to avoid further detection attempts confusing the touchpad.
33 * This way it at least works in PS/2 mouse compatibility mode.
34 */
35int focaltech_detect(struct psmouse *psmouse, bool set_properties)
36{
37 if (!psmouse_matches_pnp_id(psmouse, ids: focaltech_pnp_ids))
38 return -ENODEV;
39
40 if (set_properties) {
41 psmouse->vendor = "FocalTech";
42 psmouse->name = "Touchpad";
43 }
44
45 return 0;
46}
47
48#ifdef CONFIG_MOUSE_PS2_FOCALTECH
49
50/*
51 * Packet types - the numbers are not consecutive, so we might be missing
52 * something here.
53 */
54#define FOC_TOUCH 0x3 /* bitmap of active fingers */
55#define FOC_ABS 0x6 /* absolute position of one finger */
56#define FOC_REL 0x9 /* relative position of 1-2 fingers */
57
58#define FOC_MAX_FINGERS 5
59
60/*
61 * Current state of a single finger on the touchpad.
62 */
63struct focaltech_finger_state {
64 /* The touchpad has generated a touch event for the finger */
65 bool active;
66
67 /*
68 * The touchpad has sent position data for the finger. The
69 * flag is 0 when the finger is not active, and there is a
70 * time between the first touch event for the finger and the
71 * following absolute position packet for the finger where the
72 * touchpad has declared the finger to be valid, but we do not
73 * have any valid position yet.
74 */
75 bool valid;
76
77 /*
78 * Absolute position (from the bottom left corner) of the
79 * finger.
80 */
81 unsigned int x;
82 unsigned int y;
83};
84
85/*
86 * Description of the current state of the touchpad hardware.
87 */
88struct focaltech_hw_state {
89 /*
90 * The touchpad tracks the positions of the fingers for us,
91 * the array indices correspond to the finger indices returned
92 * in the report packages.
93 */
94 struct focaltech_finger_state fingers[FOC_MAX_FINGERS];
95
96 /*
97 * Finger width 0-7 and 15 for a very big contact area.
98 * 15 value stays until the finger is released.
99 * Width is reported only in absolute packets.
100 * Since hardware reports width only for last touching finger,
101 * there is no need to store width for every specific finger,
102 * so we keep only last value reported.
103 */
104 unsigned int width;
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, slot: 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, value: clamped_x);
138 input_report_abs(dev, ABS_MT_POSITION_Y,
139 value: priv->y_max - clamped_y);
140 input_report_abs(dev, ABS_TOOL_WIDTH, value: state->width);
141 }
142 }
143 input_mt_report_pointer_emulation(dev, use_count: true);
144
145 input_report_key(dev, BTN_LEFT, value: state->pressed);
146 input_sync(dev);
147}
148
149static void focaltech_process_touch_packet(struct psmouse *psmouse,
150 unsigned char *packet)
151{
152 struct focaltech_data *priv = psmouse->private;
153 struct focaltech_hw_state *state = &priv->state;
154 unsigned char fingers = packet[1];
155 int i;
156
157 state->pressed = (packet[0] >> 4) & 1;
158
159 /* the second byte contains a bitmap of all fingers touching the pad */
160 for (i = 0; i < FOC_MAX_FINGERS; i++) {
161 state->fingers[i].active = fingers & 0x1;
162 if (!state->fingers[i].active) {
163 /*
164 * Even when the finger becomes active again, we still
165 * will have to wait for the first valid position.
166 */
167 state->fingers[i].valid = false;
168 }
169 fingers >>= 1;
170 }
171}
172
173static void focaltech_process_abs_packet(struct psmouse *psmouse,
174 unsigned char *packet)
175{
176 struct focaltech_data *priv = psmouse->private;
177 struct focaltech_hw_state *state = &priv->state;
178 unsigned int finger;
179
180 finger = (packet[1] >> 4) - 1;
181 if (finger >= FOC_MAX_FINGERS) {
182 psmouse_err(psmouse, "Invalid finger in abs packet: %d\n",
183 finger);
184 return;
185 }
186
187 state->pressed = (packet[0] >> 4) & 1;
188
189 state->fingers[finger].x = ((packet[1] & 0xf) << 8) | packet[2];
190 state->fingers[finger].y = (packet[3] << 8) | packet[4];
191 state->width = packet[5] >> 4;
192 state->fingers[finger].valid = true;
193}
194
195static void focaltech_process_rel_packet(struct psmouse *psmouse,
196 unsigned char *packet)
197{
198 struct focaltech_data *priv = psmouse->private;
199 struct focaltech_hw_state *state = &priv->state;
200 int finger1, finger2;
201
202 state->pressed = packet[0] >> 7;
203 finger1 = ((packet[0] >> 4) & 0x7) - 1;
204 if (finger1 < FOC_MAX_FINGERS) {
205 state->fingers[finger1].x += (s8)packet[1];
206 state->fingers[finger1].y += (s8)packet[2];
207 } else {
208 psmouse_err(psmouse, "First finger in rel packet invalid: %d\n",
209 finger1);
210 }
211
212 /*
213 * If there is an odd number of fingers, the last relative
214 * packet only contains one finger. In this case, the second
215 * finger index in the packet is 0 (we subtract 1 in the lines
216 * above to create array indices, so the finger will overflow
217 * and be above FOC_MAX_FINGERS).
218 */
219 finger2 = ((packet[3] >> 4) & 0x7) - 1;
220 if (finger2 < FOC_MAX_FINGERS) {
221 state->fingers[finger2].x += (s8)packet[4];
222 state->fingers[finger2].y += (s8)packet[5];
223 }
224}
225
226static void focaltech_process_packet(struct psmouse *psmouse)
227{
228 unsigned char *packet = psmouse->packet;
229
230 switch (packet[0] & 0xf) {
231 case FOC_TOUCH:
232 focaltech_process_touch_packet(psmouse, packet);
233 break;
234
235 case FOC_ABS:
236 focaltech_process_abs_packet(psmouse, packet);
237 break;
238
239 case FOC_REL:
240 focaltech_process_rel_packet(psmouse, packet);
241 break;
242
243 default:
244 psmouse_err(psmouse, "Unknown packet type: %02x\n", packet[0]);
245 break;
246 }
247
248 focaltech_report_state(psmouse);
249}
250
251static psmouse_ret_t focaltech_process_byte(struct psmouse *psmouse)
252{
253 if (psmouse->pktcnt >= 6) { /* Full packet received */
254 focaltech_process_packet(psmouse);
255 return PSMOUSE_FULL_PACKET;
256 }
257
258 /*
259 * We might want to do some validation of the data here, but
260 * we do not know the protocol well enough
261 */
262 return PSMOUSE_GOOD_DATA;
263}
264
265static int focaltech_switch_protocol(struct psmouse *psmouse)
266{
267 struct ps2dev *ps2dev = &psmouse->ps2dev;
268 unsigned char param[3];
269
270 param[0] = 0;
271 if (ps2_command(ps2dev, param, command: 0x10f8))
272 return -EIO;
273
274 if (ps2_command(ps2dev, param, command: 0x10f8))
275 return -EIO;
276
277 if (ps2_command(ps2dev, param, command: 0x10f8))
278 return -EIO;
279
280 param[0] = 1;
281 if (ps2_command(ps2dev, param, command: 0x10f8))
282 return -EIO;
283
284 if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11))
285 return -EIO;
286
287 if (ps2_command(ps2dev, param, PSMOUSE_CMD_ENABLE))
288 return -EIO;
289
290 return 0;
291}
292
293static void focaltech_reset(struct psmouse *psmouse)
294{
295 ps2_command(ps2dev: &psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
296 psmouse_reset(psmouse);
297}
298
299static void focaltech_disconnect(struct psmouse *psmouse)
300{
301 focaltech_reset(psmouse);
302 kfree(objp: psmouse->private);
303 psmouse->private = NULL;
304}
305
306static int focaltech_reconnect(struct psmouse *psmouse)
307{
308 int error;
309
310 focaltech_reset(psmouse);
311
312 error = focaltech_switch_protocol(psmouse);
313 if (error) {
314 psmouse_err(psmouse, "Unable to initialize the device\n");
315 return error;
316 }
317
318 return 0;
319}
320
321static void focaltech_set_input_params(struct psmouse *psmouse)
322{
323 struct input_dev *dev = psmouse->dev;
324 struct focaltech_data *priv = psmouse->private;
325
326 /*
327 * Undo part of setup done for us by psmouse core since touchpad
328 * is not a relative device.
329 */
330 __clear_bit(EV_REL, dev->evbit);
331 __clear_bit(REL_X, dev->relbit);
332 __clear_bit(REL_Y, dev->relbit);
333 __clear_bit(BTN_RIGHT, dev->keybit);
334 __clear_bit(BTN_MIDDLE, dev->keybit);
335
336 /*
337 * Now set up our capabilities.
338 */
339 __set_bit(EV_ABS, dev->evbit);
340 input_set_abs_params(dev, ABS_MT_POSITION_X, min: 0, max: priv->x_max, fuzz: 0, flat: 0);
341 input_set_abs_params(dev, ABS_MT_POSITION_Y, min: 0, max: priv->y_max, fuzz: 0, flat: 0);
342 input_set_abs_params(dev, ABS_TOOL_WIDTH, min: 0, max: 15, fuzz: 0, flat: 0);
343 input_mt_init_slots(dev, num_slots: 5, INPUT_MT_POINTER);
344 __set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
345}
346
347static int focaltech_read_register(struct ps2dev *ps2dev, int reg,
348 unsigned char *param)
349{
350 if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11))
351 return -EIO;
352
353 param[0] = 0;
354 if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
355 return -EIO;
356
357 if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
358 return -EIO;
359
360 if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
361 return -EIO;
362
363 param[0] = reg;
364 if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
365 return -EIO;
366
367 if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
368 return -EIO;
369
370 return 0;
371}
372
373static int focaltech_read_size(struct psmouse *psmouse)
374{
375 struct ps2dev *ps2dev = &psmouse->ps2dev;
376 struct focaltech_data *priv = psmouse->private;
377 char param[3];
378
379 if (focaltech_read_register(ps2dev, reg: 2, param))
380 return -EIO;
381
382 /* not sure whether this is 100% correct */
383 priv->x_max = (unsigned char)param[1] * 128;
384 priv->y_max = (unsigned char)param[2] * 128;
385
386 return 0;
387}
388
389static void focaltech_set_resolution(struct psmouse *psmouse,
390 unsigned int resolution)
391{
392 /* not supported yet */
393}
394
395static void focaltech_set_rate(struct psmouse *psmouse, unsigned int rate)
396{
397 /* not supported yet */
398}
399
400static void focaltech_set_scale(struct psmouse *psmouse,
401 enum psmouse_scale scale)
402{
403 /* not supported yet */
404}
405
406int focaltech_init(struct psmouse *psmouse)
407{
408 struct focaltech_data *priv;
409 int error;
410
411 psmouse->private = priv = kzalloc(sizeof(*priv), GFP_KERNEL);
412 if (!priv)
413 return -ENOMEM;
414
415 focaltech_reset(psmouse);
416
417 error = focaltech_read_size(psmouse);
418 if (error) {
419 psmouse_err(psmouse,
420 "Unable to read the size of the touchpad\n");
421 goto fail;
422 }
423
424 error = focaltech_switch_protocol(psmouse);
425 if (error) {
426 psmouse_err(psmouse, "Unable to initialize the device\n");
427 goto fail;
428 }
429
430 focaltech_set_input_params(psmouse);
431
432 psmouse->protocol_handler = focaltech_process_byte;
433 psmouse->pktsize = 6;
434 psmouse->disconnect = focaltech_disconnect;
435 psmouse->reconnect = focaltech_reconnect;
436 psmouse->cleanup = focaltech_reset;
437 /* resync is not supported yet */
438 psmouse->resync_time = 0;
439 /*
440 * rate/resolution/scale changes are not supported yet, and
441 * the generic implementations of these functions seem to
442 * confuse some touchpads
443 */
444 psmouse->set_resolution = focaltech_set_resolution;
445 psmouse->set_rate = focaltech_set_rate;
446 psmouse->set_scale = focaltech_set_scale;
447
448 return 0;
449
450fail:
451 focaltech_reset(psmouse);
452 kfree(objp: priv);
453 return error;
454}
455#endif /* CONFIG_MOUSE_PS2_FOCALTECH */
456