xref: /openbmc/linux/drivers/input/mouse/focaltech.c (revision a2cce7a9) 
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 
26 static 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  */
39 int 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 
52 static 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  */
73 struct 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  */
98 struct 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 
120 struct focaltech_data {
121 	unsigned int x_max, y_max;
122 	struct focaltech_hw_state state;
123 };
124 
125 static 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 
159 static 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 
183 static 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 
205 static 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 
236 static 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 
261 static 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 
275 static 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 
303 static void focaltech_disconnect(struct psmouse *psmouse)
304 {
305 	focaltech_reset(psmouse);
306 	kfree(psmouse->private);
307 	psmouse->private = NULL;
308 }
309 
310 static 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 
325 static 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 
351 static 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 
377 static 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 
393 void focaltech_set_resolution(struct psmouse *psmouse, unsigned int resolution)
394 {
395 	/* not supported yet */
396 }
397 
398 static void focaltech_set_rate(struct psmouse *psmouse, unsigned int rate)
399 {
400 	/* not supported yet */
401 }
402 
403 static void focaltech_set_scale(struct psmouse *psmouse,
404 				enum psmouse_scale scale)
405 {
406 	/* not supported yet */
407 }
408 
409 int 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 
454 fail:
455 	focaltech_reset(psmouse);
456 	kfree(priv);
457 	return error;
458 }
459 
460 #else /* CONFIG_MOUSE_PS2_FOCALTECH */
461 
462 int focaltech_init(struct psmouse *psmouse)
463 {
464 	focaltech_reset(psmouse);
465 
466 	return 0;
467 }
468 
469 #endif /* CONFIG_MOUSE_PS2_FOCALTECH */
470