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 
22 static 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  */
focaltech_detect(struct psmouse * psmouse,bool set_properties)35 int focaltech_detect(struct psmouse *psmouse, bool set_properties)
36 {
37 	if (!psmouse_matches_pnp_id(psmouse, 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  */
63 struct 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  */
88 struct 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 
110 struct focaltech_data {
111 	unsigned int x_max, y_max;
112 	struct focaltech_hw_state state;
113 };
114 
focaltech_report_state(struct psmouse * psmouse)115 static 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, 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, clamped_x);
138 			input_report_abs(dev, ABS_MT_POSITION_Y,
139 					 priv->y_max - clamped_y);
140 			input_report_abs(dev, ABS_TOOL_WIDTH, state->width);
141 		}
142 	}
143 	input_mt_report_pointer_emulation(dev, true);
144 
145 	input_report_key(dev, BTN_LEFT, state->pressed);
146 	input_sync(dev);
147 }
148 
focaltech_process_touch_packet(struct psmouse * psmouse,unsigned char * packet)149 static 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 
focaltech_process_abs_packet(struct psmouse * psmouse,unsigned char * packet)173 static 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 
focaltech_process_rel_packet(struct psmouse * psmouse,unsigned char * packet)195 static 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 += (char)packet[1];
206 		state->fingers[finger1].y += (char)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 += (char)packet[4];
222 		state->fingers[finger2].y += (char)packet[5];
223 	}
224 }
225 
focaltech_process_packet(struct psmouse * psmouse)226 static 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 
focaltech_process_byte(struct psmouse * psmouse)251 static 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 
focaltech_switch_protocol(struct psmouse * psmouse)265 static 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, 0x10f8))
272 		return -EIO;
273 
274 	if (ps2_command(ps2dev, param, 0x10f8))
275 		return -EIO;
276 
277 	if (ps2_command(ps2dev, param, 0x10f8))
278 		return -EIO;
279 
280 	param[0] = 1;
281 	if (ps2_command(ps2dev, param, 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 
focaltech_reset(struct psmouse * psmouse)293 static void focaltech_reset(struct psmouse *psmouse)
294 {
295 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
296 	psmouse_reset(psmouse);
297 }
298 
focaltech_disconnect(struct psmouse * psmouse)299 static void focaltech_disconnect(struct psmouse *psmouse)
300 {
301 	focaltech_reset(psmouse);
302 	kfree(psmouse->private);
303 	psmouse->private = NULL;
304 }
305 
focaltech_reconnect(struct psmouse * psmouse)306 static 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 
focaltech_set_input_params(struct psmouse * psmouse)321 static 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, 0, priv->x_max, 0, 0);
341 	input_set_abs_params(dev, ABS_MT_POSITION_Y, 0, priv->y_max, 0, 0);
342 	input_set_abs_params(dev, ABS_TOOL_WIDTH, 0, 15, 0, 0);
343 	input_mt_init_slots(dev, 5, INPUT_MT_POINTER);
344 	__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
345 }
346 
focaltech_read_register(struct ps2dev * ps2dev,int reg,unsigned char * param)347 static 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 
focaltech_read_size(struct psmouse * psmouse)373 static 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, 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 
focaltech_set_resolution(struct psmouse * psmouse,unsigned int resolution)389 static void focaltech_set_resolution(struct psmouse *psmouse,
390 				     unsigned int resolution)
391 {
392 	/* not supported yet */
393 }
394 
focaltech_set_rate(struct psmouse * psmouse,unsigned int rate)395 static void focaltech_set_rate(struct psmouse *psmouse, unsigned int rate)
396 {
397 	/* not supported yet */
398 }
399 
focaltech_set_scale(struct psmouse * psmouse,enum psmouse_scale scale)400 static void focaltech_set_scale(struct psmouse *psmouse,
401 				enum psmouse_scale scale)
402 {
403 	/* not supported yet */
404 }
405 
focaltech_init(struct psmouse * psmouse)406 int focaltech_init(struct psmouse *psmouse)
407 {
408 	struct focaltech_data *priv;
409 	int error;
410 
411 	psmouse->private = priv = kzalloc(sizeof(struct focaltech_data),
412 					  GFP_KERNEL);
413 	if (!priv)
414 		return -ENOMEM;
415 
416 	focaltech_reset(psmouse);
417 
418 	error = focaltech_read_size(psmouse);
419 	if (error) {
420 		psmouse_err(psmouse,
421 			    "Unable to read the size of the touchpad\n");
422 		goto fail;
423 	}
424 
425 	error = focaltech_switch_protocol(psmouse);
426 	if (error) {
427 		psmouse_err(psmouse, "Unable to initialize the device\n");
428 		goto fail;
429 	}
430 
431 	focaltech_set_input_params(psmouse);
432 
433 	psmouse->protocol_handler = focaltech_process_byte;
434 	psmouse->pktsize = 6;
435 	psmouse->disconnect = focaltech_disconnect;
436 	psmouse->reconnect = focaltech_reconnect;
437 	psmouse->cleanup = focaltech_reset;
438 	/* resync is not supported yet */
439 	psmouse->resync_time = 0;
440 	/*
441 	 * rate/resolution/scale changes are not supported yet, and
442 	 * the generic implementations of these functions seem to
443 	 * confuse some touchpads
444 	 */
445 	psmouse->set_resolution = focaltech_set_resolution;
446 	psmouse->set_rate = focaltech_set_rate;
447 	psmouse->set_scale = focaltech_set_scale;
448 
449 	return 0;
450 
451 fail:
452 	focaltech_reset(psmouse);
453 	kfree(priv);
454 	return error;
455 }
456 #endif /* CONFIG_MOUSE_PS2_FOCALTECH */
457