xref: /openbmc/linux/drivers/input/mouse/focaltech.c (revision e3b9f1e8)
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 = "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  */
67 struct 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  */
92 struct 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 
114 struct focaltech_data {
115 	unsigned int x_max, y_max;
116 	struct focaltech_hw_state state;
117 };
118 
119 static 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 
153 static 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 
177 static 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 
199 static 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 
230 static 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 
255 static 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 
269 static 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 
297 static void focaltech_reset(struct psmouse *psmouse)
298 {
299 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
300 	psmouse_reset(psmouse);
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 static void focaltech_set_resolution(struct psmouse *psmouse,
394 				     unsigned int resolution)
395 {
396 	/* not supported yet */
397 }
398 
399 static void focaltech_set_rate(struct psmouse *psmouse, unsigned int rate)
400 {
401 	/* not supported yet */
402 }
403 
404 static void focaltech_set_scale(struct psmouse *psmouse,
405 				enum psmouse_scale scale)
406 {
407 	/* not supported yet */
408 }
409 
410 int 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 
455 fail:
456 	focaltech_reset(psmouse);
457 	kfree(priv);
458 	return error;
459 }
460 #endif /* CONFIG_MOUSE_PS2_FOCALTECH */
461