xref: /openbmc/linux/drivers/input/mouse/elantech.c (revision 7f904d7e1f3ec7c2de47c024a5a5c30988b54703)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Elantech Touchpad driver (v6)
4  *
5  * Copyright (C) 2007-2009 Arjan Opmeer <arjan@opmeer.net>
6  *
7  * Trademarks are the property of their respective owners.
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/dmi.h>
12 #include <linux/slab.h>
13 #include <linux/module.h>
14 #include <linux/i2c.h>
15 #include <linux/input.h>
16 #include <linux/input/mt.h>
17 #include <linux/platform_device.h>
18 #include <linux/serio.h>
19 #include <linux/libps2.h>
20 #include <asm/unaligned.h>
21 #include "psmouse.h"
22 #include "elantech.h"
23 #include "elan_i2c.h"
24 
25 #define elantech_debug(fmt, ...)					\
26 	do {								\
27 		if (etd->info.debug)					\
28 			psmouse_printk(KERN_DEBUG, psmouse,		\
29 					fmt, ##__VA_ARGS__);		\
30 	} while (0)
31 
32 /*
33  * Send a Synaptics style sliced query command
34  */
35 static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
36 				unsigned char *param)
37 {
38 	if (ps2_sliced_command(&psmouse->ps2dev, c) ||
39 	    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
40 		psmouse_err(psmouse, "%s query 0x%02x failed.\n", __func__, c);
41 		return -1;
42 	}
43 
44 	return 0;
45 }
46 
47 /*
48  * V3 and later support this fast command
49  */
50 static int elantech_send_cmd(struct psmouse *psmouse, unsigned char c,
51 				unsigned char *param)
52 {
53 	struct ps2dev *ps2dev = &psmouse->ps2dev;
54 
55 	if (ps2_command(ps2dev, NULL, ETP_PS2_CUSTOM_COMMAND) ||
56 	    ps2_command(ps2dev, NULL, c) ||
57 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
58 		psmouse_err(psmouse, "%s query 0x%02x failed.\n", __func__, c);
59 		return -1;
60 	}
61 
62 	return 0;
63 }
64 
65 /*
66  * A retrying version of ps2_command
67  */
68 static int elantech_ps2_command(struct psmouse *psmouse,
69 				unsigned char *param, int command)
70 {
71 	struct ps2dev *ps2dev = &psmouse->ps2dev;
72 	struct elantech_data *etd = psmouse->private;
73 	int rc;
74 	int tries = ETP_PS2_COMMAND_TRIES;
75 
76 	do {
77 		rc = ps2_command(ps2dev, param, command);
78 		if (rc == 0)
79 			break;
80 		tries--;
81 		elantech_debug("retrying ps2 command 0x%02x (%d).\n",
82 				command, tries);
83 		msleep(ETP_PS2_COMMAND_DELAY);
84 	} while (tries > 0);
85 
86 	if (rc)
87 		psmouse_err(psmouse, "ps2 command 0x%02x failed.\n", command);
88 
89 	return rc;
90 }
91 
92 /*
93  * Send an Elantech style special command to read a value from a register
94  */
95 static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
96 				unsigned char *val)
97 {
98 	struct elantech_data *etd = psmouse->private;
99 	unsigned char param[3];
100 	int rc = 0;
101 
102 	if (reg < 0x07 || reg > 0x26)
103 		return -1;
104 
105 	if (reg > 0x11 && reg < 0x20)
106 		return -1;
107 
108 	switch (etd->info.hw_version) {
109 	case 1:
110 		if (ps2_sliced_command(&psmouse->ps2dev, ETP_REGISTER_READ) ||
111 		    ps2_sliced_command(&psmouse->ps2dev, reg) ||
112 		    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
113 			rc = -1;
114 		}
115 		break;
116 
117 	case 2:
118 		if (elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
119 		    elantech_ps2_command(psmouse,  NULL, ETP_REGISTER_READ) ||
120 		    elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
121 		    elantech_ps2_command(psmouse,  NULL, reg) ||
122 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
123 			rc = -1;
124 		}
125 		break;
126 
127 	case 3 ... 4:
128 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
129 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
130 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
131 		    elantech_ps2_command(psmouse, NULL, reg) ||
132 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
133 			rc = -1;
134 		}
135 		break;
136 	}
137 
138 	if (rc)
139 		psmouse_err(psmouse, "failed to read register 0x%02x.\n", reg);
140 	else if (etd->info.hw_version != 4)
141 		*val = param[0];
142 	else
143 		*val = param[1];
144 
145 	return rc;
146 }
147 
148 /*
149  * Send an Elantech style special command to write a register with a value
150  */
151 static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
152 				unsigned char val)
153 {
154 	struct elantech_data *etd = psmouse->private;
155 	int rc = 0;
156 
157 	if (reg < 0x07 || reg > 0x26)
158 		return -1;
159 
160 	if (reg > 0x11 && reg < 0x20)
161 		return -1;
162 
163 	switch (etd->info.hw_version) {
164 	case 1:
165 		if (ps2_sliced_command(&psmouse->ps2dev, ETP_REGISTER_WRITE) ||
166 		    ps2_sliced_command(&psmouse->ps2dev, reg) ||
167 		    ps2_sliced_command(&psmouse->ps2dev, val) ||
168 		    ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
169 			rc = -1;
170 		}
171 		break;
172 
173 	case 2:
174 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
175 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
176 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
177 		    elantech_ps2_command(psmouse, NULL, reg) ||
178 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
179 		    elantech_ps2_command(psmouse, NULL, val) ||
180 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
181 			rc = -1;
182 		}
183 		break;
184 
185 	case 3:
186 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
187 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
188 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
189 		    elantech_ps2_command(psmouse, NULL, reg) ||
190 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
191 		    elantech_ps2_command(psmouse, NULL, val) ||
192 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
193 			rc = -1;
194 		}
195 		break;
196 
197 	case 4:
198 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
199 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
200 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
201 		    elantech_ps2_command(psmouse, NULL, reg) ||
202 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
203 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
204 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
205 		    elantech_ps2_command(psmouse, NULL, val) ||
206 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
207 			rc = -1;
208 		}
209 		break;
210 	}
211 
212 	if (rc)
213 		psmouse_err(psmouse,
214 			    "failed to write register 0x%02x with value 0x%02x.\n",
215 			    reg, val);
216 
217 	return rc;
218 }
219 
220 /*
221  * Dump a complete mouse movement packet to the syslog
222  */
223 static void elantech_packet_dump(struct psmouse *psmouse)
224 {
225 	psmouse_printk(KERN_DEBUG, psmouse, "PS/2 packet [%*ph]\n",
226 		       psmouse->pktsize, psmouse->packet);
227 }
228 
229 /*
230  * Interpret complete data packets and report absolute mode input events for
231  * hardware version 1. (4 byte packets)
232  */
233 static void elantech_report_absolute_v1(struct psmouse *psmouse)
234 {
235 	struct input_dev *dev = psmouse->dev;
236 	struct elantech_data *etd = psmouse->private;
237 	unsigned char *packet = psmouse->packet;
238 	int fingers;
239 
240 	if (etd->info.fw_version < 0x020000) {
241 		/*
242 		 * byte 0:  D   U  p1  p2   1  p3   R   L
243 		 * byte 1:  f   0  th  tw  x9  x8  y9  y8
244 		 */
245 		fingers = ((packet[1] & 0x80) >> 7) +
246 				((packet[1] & 0x30) >> 4);
247 	} else {
248 		/*
249 		 * byte 0: n1  n0  p2  p1   1  p3   R   L
250 		 * byte 1:  0   0   0   0  x9  x8  y9  y8
251 		 */
252 		fingers = (packet[0] & 0xc0) >> 6;
253 	}
254 
255 	if (etd->info.jumpy_cursor) {
256 		if (fingers != 1) {
257 			etd->single_finger_reports = 0;
258 		} else if (etd->single_finger_reports < 2) {
259 			/* Discard first 2 reports of one finger, bogus */
260 			etd->single_finger_reports++;
261 			elantech_debug("discarding packet\n");
262 			return;
263 		}
264 	}
265 
266 	input_report_key(dev, BTN_TOUCH, fingers != 0);
267 
268 	/*
269 	 * byte 2: x7  x6  x5  x4  x3  x2  x1  x0
270 	 * byte 3: y7  y6  y5  y4  y3  y2  y1  y0
271 	 */
272 	if (fingers) {
273 		input_report_abs(dev, ABS_X,
274 			((packet[1] & 0x0c) << 6) | packet[2]);
275 		input_report_abs(dev, ABS_Y,
276 			etd->y_max - (((packet[1] & 0x03) << 8) | packet[3]));
277 	}
278 
279 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
280 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
281 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
282 
283 	psmouse_report_standard_buttons(dev, packet[0]);
284 
285 	if (etd->info.fw_version < 0x020000 &&
286 	    (etd->info.capabilities[0] & ETP_CAP_HAS_ROCKER)) {
287 		/* rocker up */
288 		input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
289 		/* rocker down */
290 		input_report_key(dev, BTN_BACK, packet[0] & 0x80);
291 	}
292 
293 	input_sync(dev);
294 }
295 
296 static void elantech_set_slot(struct input_dev *dev, int slot, bool active,
297 			      unsigned int x, unsigned int y)
298 {
299 	input_mt_slot(dev, slot);
300 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
301 	if (active) {
302 		input_report_abs(dev, ABS_MT_POSITION_X, x);
303 		input_report_abs(dev, ABS_MT_POSITION_Y, y);
304 	}
305 }
306 
307 /* x1 < x2 and y1 < y2 when two fingers, x = y = 0 when not pressed */
308 static void elantech_report_semi_mt_data(struct input_dev *dev,
309 					 unsigned int num_fingers,
310 					 unsigned int x1, unsigned int y1,
311 					 unsigned int x2, unsigned int y2)
312 {
313 	elantech_set_slot(dev, 0, num_fingers != 0, x1, y1);
314 	elantech_set_slot(dev, 1, num_fingers >= 2, x2, y2);
315 }
316 
317 /*
318  * Interpret complete data packets and report absolute mode input events for
319  * hardware version 2. (6 byte packets)
320  */
321 static void elantech_report_absolute_v2(struct psmouse *psmouse)
322 {
323 	struct elantech_data *etd = psmouse->private;
324 	struct input_dev *dev = psmouse->dev;
325 	unsigned char *packet = psmouse->packet;
326 	unsigned int fingers, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
327 	unsigned int width = 0, pres = 0;
328 
329 	/* byte 0: n1  n0   .   .   .   .   R   L */
330 	fingers = (packet[0] & 0xc0) >> 6;
331 
332 	switch (fingers) {
333 	case 3:
334 		/*
335 		 * Same as one finger, except report of more than 3 fingers:
336 		 * byte 3:  n4  .   w1  w0   .   .   .   .
337 		 */
338 		if (packet[3] & 0x80)
339 			fingers = 4;
340 		/* fall through */
341 	case 1:
342 		/*
343 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
344 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
345 		 */
346 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
347 		/*
348 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
349 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
350 		 */
351 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
352 
353 		pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
354 		width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
355 		break;
356 
357 	case 2:
358 		/*
359 		 * The coordinate of each finger is reported separately
360 		 * with a lower resolution for two finger touches:
361 		 * byte 0:  .   .  ay8 ax8  .   .   .   .
362 		 * byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
363 		 */
364 		x1 = (((packet[0] & 0x10) << 4) | packet[1]) << 2;
365 		/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
366 		y1 = etd->y_max -
367 			((((packet[0] & 0x20) << 3) | packet[2]) << 2);
368 		/*
369 		 * byte 3:  .   .  by8 bx8  .   .   .   .
370 		 * byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
371 		 */
372 		x2 = (((packet[3] & 0x10) << 4) | packet[4]) << 2;
373 		/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
374 		y2 = etd->y_max -
375 			((((packet[3] & 0x20) << 3) | packet[5]) << 2);
376 
377 		/* Unknown so just report sensible values */
378 		pres = 127;
379 		width = 7;
380 		break;
381 	}
382 
383 	input_report_key(dev, BTN_TOUCH, fingers != 0);
384 	if (fingers != 0) {
385 		input_report_abs(dev, ABS_X, x1);
386 		input_report_abs(dev, ABS_Y, y1);
387 	}
388 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
389 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
390 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
391 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
392 	input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
393 	psmouse_report_standard_buttons(dev, packet[0]);
394 	if (etd->info.reports_pressure) {
395 		input_report_abs(dev, ABS_PRESSURE, pres);
396 		input_report_abs(dev, ABS_TOOL_WIDTH, width);
397 	}
398 
399 	input_sync(dev);
400 }
401 
402 static void elantech_report_trackpoint(struct psmouse *psmouse,
403 				       int packet_type)
404 {
405 	/*
406 	 * byte 0:  0   0  sx  sy   0   M   R   L
407 	 * byte 1:~sx   0   0   0   0   0   0   0
408 	 * byte 2:~sy   0   0   0   0   0   0   0
409 	 * byte 3:  0   0 ~sy ~sx   0   1   1   0
410 	 * byte 4: x7  x6  x5  x4  x3  x2  x1  x0
411 	 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
412 	 *
413 	 * x and y are written in two's complement spread
414 	 * over 9 bits with sx/sy the relative top bit and
415 	 * x7..x0 and y7..y0 the lower bits.
416 	 * The sign of y is opposite to what the input driver
417 	 * expects for a relative movement
418 	 */
419 
420 	struct elantech_data *etd = psmouse->private;
421 	struct input_dev *tp_dev = etd->tp_dev;
422 	unsigned char *packet = psmouse->packet;
423 	int x, y;
424 	u32 t;
425 
426 	t = get_unaligned_le32(&packet[0]);
427 
428 	switch (t & ~7U) {
429 	case 0x06000030U:
430 	case 0x16008020U:
431 	case 0x26800010U:
432 	case 0x36808000U:
433 		x = packet[4] - (int)((packet[1]^0x80) << 1);
434 		y = (int)((packet[2]^0x80) << 1) - packet[5];
435 
436 		psmouse_report_standard_buttons(tp_dev, packet[0]);
437 
438 		input_report_rel(tp_dev, REL_X, x);
439 		input_report_rel(tp_dev, REL_Y, y);
440 
441 		input_sync(tp_dev);
442 
443 		break;
444 
445 	default:
446 		/* Dump unexpected packet sequences if debug=1 (default) */
447 		if (etd->info.debug == 1)
448 			elantech_packet_dump(psmouse);
449 
450 		break;
451 	}
452 }
453 
454 /*
455  * Interpret complete data packets and report absolute mode input events for
456  * hardware version 3. (12 byte packets for two fingers)
457  */
458 static void elantech_report_absolute_v3(struct psmouse *psmouse,
459 					int packet_type)
460 {
461 	struct input_dev *dev = psmouse->dev;
462 	struct elantech_data *etd = psmouse->private;
463 	unsigned char *packet = psmouse->packet;
464 	unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
465 	unsigned int width = 0, pres = 0;
466 
467 	/* byte 0: n1  n0   .   .   .   .   R   L */
468 	fingers = (packet[0] & 0xc0) >> 6;
469 
470 	switch (fingers) {
471 	case 3:
472 	case 1:
473 		/*
474 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
475 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
476 		 */
477 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
478 		/*
479 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
480 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
481 		 */
482 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
483 		break;
484 
485 	case 2:
486 		if (packet_type == PACKET_V3_HEAD) {
487 			/*
488 			 * byte 1:   .    .    .    .  ax11 ax10 ax9  ax8
489 			 * byte 2: ax7  ax6  ax5  ax4  ax3  ax2  ax1  ax0
490 			 */
491 			etd->mt[0].x = ((packet[1] & 0x0f) << 8) | packet[2];
492 			/*
493 			 * byte 4:   .    .    .    .  ay11 ay10 ay9  ay8
494 			 * byte 5: ay7  ay6  ay5  ay4  ay3  ay2  ay1  ay0
495 			 */
496 			etd->mt[0].y = etd->y_max -
497 				(((packet[4] & 0x0f) << 8) | packet[5]);
498 			/*
499 			 * wait for next packet
500 			 */
501 			return;
502 		}
503 
504 		/* packet_type == PACKET_V3_TAIL */
505 		x1 = etd->mt[0].x;
506 		y1 = etd->mt[0].y;
507 		x2 = ((packet[1] & 0x0f) << 8) | packet[2];
508 		y2 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
509 		break;
510 	}
511 
512 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
513 	width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
514 
515 	input_report_key(dev, BTN_TOUCH, fingers != 0);
516 	if (fingers != 0) {
517 		input_report_abs(dev, ABS_X, x1);
518 		input_report_abs(dev, ABS_Y, y1);
519 	}
520 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
521 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
522 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
523 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
524 
525 	/* For clickpads map both buttons to BTN_LEFT */
526 	if (etd->info.fw_version & 0x001000)
527 		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
528 	else
529 		psmouse_report_standard_buttons(dev, packet[0]);
530 
531 	input_report_abs(dev, ABS_PRESSURE, pres);
532 	input_report_abs(dev, ABS_TOOL_WIDTH, width);
533 
534 	input_sync(dev);
535 }
536 
537 static void elantech_input_sync_v4(struct psmouse *psmouse)
538 {
539 	struct input_dev *dev = psmouse->dev;
540 	struct elantech_data *etd = psmouse->private;
541 	unsigned char *packet = psmouse->packet;
542 
543 	/* For clickpads map both buttons to BTN_LEFT */
544 	if (etd->info.fw_version & 0x001000)
545 		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
546 	else
547 		psmouse_report_standard_buttons(dev, packet[0]);
548 
549 	input_mt_report_pointer_emulation(dev, true);
550 	input_sync(dev);
551 }
552 
553 static void process_packet_status_v4(struct psmouse *psmouse)
554 {
555 	struct input_dev *dev = psmouse->dev;
556 	unsigned char *packet = psmouse->packet;
557 	unsigned fingers;
558 	int i;
559 
560 	/* notify finger state change */
561 	fingers = packet[1] & 0x1f;
562 	for (i = 0; i < ETP_MAX_FINGERS; i++) {
563 		if ((fingers & (1 << i)) == 0) {
564 			input_mt_slot(dev, i);
565 			input_mt_report_slot_state(dev, MT_TOOL_FINGER, false);
566 		}
567 	}
568 
569 	elantech_input_sync_v4(psmouse);
570 }
571 
572 static void process_packet_head_v4(struct psmouse *psmouse)
573 {
574 	struct input_dev *dev = psmouse->dev;
575 	struct elantech_data *etd = psmouse->private;
576 	unsigned char *packet = psmouse->packet;
577 	int id = ((packet[3] & 0xe0) >> 5) - 1;
578 	int pres, traces;
579 
580 	if (id < 0)
581 		return;
582 
583 	etd->mt[id].x = ((packet[1] & 0x0f) << 8) | packet[2];
584 	etd->mt[id].y = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
585 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
586 	traces = (packet[0] & 0xf0) >> 4;
587 
588 	input_mt_slot(dev, id);
589 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, true);
590 
591 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
592 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
593 	input_report_abs(dev, ABS_MT_PRESSURE, pres);
594 	input_report_abs(dev, ABS_MT_TOUCH_MAJOR, traces * etd->width);
595 	/* report this for backwards compatibility */
596 	input_report_abs(dev, ABS_TOOL_WIDTH, traces);
597 
598 	elantech_input_sync_v4(psmouse);
599 }
600 
601 static void process_packet_motion_v4(struct psmouse *psmouse)
602 {
603 	struct input_dev *dev = psmouse->dev;
604 	struct elantech_data *etd = psmouse->private;
605 	unsigned char *packet = psmouse->packet;
606 	int weight, delta_x1 = 0, delta_y1 = 0, delta_x2 = 0, delta_y2 = 0;
607 	int id, sid;
608 
609 	id = ((packet[0] & 0xe0) >> 5) - 1;
610 	if (id < 0)
611 		return;
612 
613 	sid = ((packet[3] & 0xe0) >> 5) - 1;
614 	weight = (packet[0] & 0x10) ? ETP_WEIGHT_VALUE : 1;
615 	/*
616 	 * Motion packets give us the delta of x, y values of specific fingers,
617 	 * but in two's complement. Let the compiler do the conversion for us.
618 	 * Also _enlarge_ the numbers to int, in case of overflow.
619 	 */
620 	delta_x1 = (signed char)packet[1];
621 	delta_y1 = (signed char)packet[2];
622 	delta_x2 = (signed char)packet[4];
623 	delta_y2 = (signed char)packet[5];
624 
625 	etd->mt[id].x += delta_x1 * weight;
626 	etd->mt[id].y -= delta_y1 * weight;
627 	input_mt_slot(dev, id);
628 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
629 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
630 
631 	if (sid >= 0) {
632 		etd->mt[sid].x += delta_x2 * weight;
633 		etd->mt[sid].y -= delta_y2 * weight;
634 		input_mt_slot(dev, sid);
635 		input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[sid].x);
636 		input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[sid].y);
637 	}
638 
639 	elantech_input_sync_v4(psmouse);
640 }
641 
642 static void elantech_report_absolute_v4(struct psmouse *psmouse,
643 					int packet_type)
644 {
645 	switch (packet_type) {
646 	case PACKET_V4_STATUS:
647 		process_packet_status_v4(psmouse);
648 		break;
649 
650 	case PACKET_V4_HEAD:
651 		process_packet_head_v4(psmouse);
652 		break;
653 
654 	case PACKET_V4_MOTION:
655 		process_packet_motion_v4(psmouse);
656 		break;
657 
658 	case PACKET_UNKNOWN:
659 	default:
660 		/* impossible to get here */
661 		break;
662 	}
663 }
664 
665 static int elantech_packet_check_v1(struct psmouse *psmouse)
666 {
667 	struct elantech_data *etd = psmouse->private;
668 	unsigned char *packet = psmouse->packet;
669 	unsigned char p1, p2, p3;
670 
671 	/* Parity bits are placed differently */
672 	if (etd->info.fw_version < 0x020000) {
673 		/* byte 0:  D   U  p1  p2   1  p3   R   L */
674 		p1 = (packet[0] & 0x20) >> 5;
675 		p2 = (packet[0] & 0x10) >> 4;
676 	} else {
677 		/* byte 0: n1  n0  p2  p1   1  p3   R   L */
678 		p1 = (packet[0] & 0x10) >> 4;
679 		p2 = (packet[0] & 0x20) >> 5;
680 	}
681 
682 	p3 = (packet[0] & 0x04) >> 2;
683 
684 	return etd->parity[packet[1]] == p1 &&
685 	       etd->parity[packet[2]] == p2 &&
686 	       etd->parity[packet[3]] == p3;
687 }
688 
689 static int elantech_debounce_check_v2(struct psmouse *psmouse)
690 {
691         /*
692          * When we encounter packet that matches this exactly, it means the
693          * hardware is in debounce status. Just ignore the whole packet.
694          */
695 	static const u8 debounce_packet[] = {
696 		0x84, 0xff, 0xff, 0x02, 0xff, 0xff
697 	};
698         unsigned char *packet = psmouse->packet;
699 
700         return !memcmp(packet, debounce_packet, sizeof(debounce_packet));
701 }
702 
703 static int elantech_packet_check_v2(struct psmouse *psmouse)
704 {
705 	struct elantech_data *etd = psmouse->private;
706 	unsigned char *packet = psmouse->packet;
707 
708 	/*
709 	 * V2 hardware has two flavors. Older ones that do not report pressure,
710 	 * and newer ones that reports pressure and width. With newer ones, all
711 	 * packets (1, 2, 3 finger touch) have the same constant bits. With
712 	 * older ones, 1/3 finger touch packets and 2 finger touch packets
713 	 * have different constant bits.
714 	 * With all three cases, if the constant bits are not exactly what I
715 	 * expected, I consider them invalid.
716 	 */
717 	if (etd->info.reports_pressure)
718 		return (packet[0] & 0x0c) == 0x04 &&
719 		       (packet[3] & 0x0f) == 0x02;
720 
721 	if ((packet[0] & 0xc0) == 0x80)
722 		return (packet[0] & 0x0c) == 0x0c &&
723 		       (packet[3] & 0x0e) == 0x08;
724 
725 	return (packet[0] & 0x3c) == 0x3c &&
726 	       (packet[1] & 0xf0) == 0x00 &&
727 	       (packet[3] & 0x3e) == 0x38 &&
728 	       (packet[4] & 0xf0) == 0x00;
729 }
730 
731 /*
732  * We check the constant bits to determine what packet type we get,
733  * so packet checking is mandatory for v3 and later hardware.
734  */
735 static int elantech_packet_check_v3(struct psmouse *psmouse)
736 {
737 	struct elantech_data *etd = psmouse->private;
738 	static const u8 debounce_packet[] = {
739 		0xc4, 0xff, 0xff, 0x02, 0xff, 0xff
740 	};
741 	unsigned char *packet = psmouse->packet;
742 
743 	/*
744 	 * check debounce first, it has the same signature in byte 0
745 	 * and byte 3 as PACKET_V3_HEAD.
746 	 */
747 	if (!memcmp(packet, debounce_packet, sizeof(debounce_packet)))
748 		return PACKET_DEBOUNCE;
749 
750 	/*
751 	 * If the hardware flag 'crc_enabled' is set the packets have
752 	 * different signatures.
753 	 */
754 	if (etd->info.crc_enabled) {
755 		if ((packet[3] & 0x09) == 0x08)
756 			return PACKET_V3_HEAD;
757 
758 		if ((packet[3] & 0x09) == 0x09)
759 			return PACKET_V3_TAIL;
760 	} else {
761 		if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
762 			return PACKET_V3_HEAD;
763 
764 		if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
765 			return PACKET_V3_TAIL;
766 		if ((packet[3] & 0x0f) == 0x06)
767 			return PACKET_TRACKPOINT;
768 	}
769 
770 	return PACKET_UNKNOWN;
771 }
772 
773 static int elantech_packet_check_v4(struct psmouse *psmouse)
774 {
775 	struct elantech_data *etd = psmouse->private;
776 	unsigned char *packet = psmouse->packet;
777 	unsigned char packet_type = packet[3] & 0x03;
778 	unsigned int ic_version;
779 	bool sanity_check;
780 
781 	if (etd->tp_dev && (packet[3] & 0x0f) == 0x06)
782 		return PACKET_TRACKPOINT;
783 
784 	/* This represents the version of IC body. */
785 	ic_version = (etd->info.fw_version & 0x0f0000) >> 16;
786 
787 	/*
788 	 * Sanity check based on the constant bits of a packet.
789 	 * The constant bits change depending on the value of
790 	 * the hardware flag 'crc_enabled' and the version of
791 	 * the IC body, but are the same for every packet,
792 	 * regardless of the type.
793 	 */
794 	if (etd->info.crc_enabled)
795 		sanity_check = ((packet[3] & 0x08) == 0x00);
796 	else if (ic_version == 7 && etd->info.samples[1] == 0x2A)
797 		sanity_check = ((packet[3] & 0x1c) == 0x10);
798 	else
799 		sanity_check = ((packet[0] & 0x08) == 0x00 &&
800 				(packet[3] & 0x1c) == 0x10);
801 
802 	if (!sanity_check)
803 		return PACKET_UNKNOWN;
804 
805 	switch (packet_type) {
806 	case 0:
807 		return PACKET_V4_STATUS;
808 
809 	case 1:
810 		return PACKET_V4_HEAD;
811 
812 	case 2:
813 		return PACKET_V4_MOTION;
814 	}
815 
816 	return PACKET_UNKNOWN;
817 }
818 
819 /*
820  * Process byte stream from mouse and handle complete packets
821  */
822 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
823 {
824 	struct elantech_data *etd = psmouse->private;
825 	int packet_type;
826 
827 	if (psmouse->pktcnt < psmouse->pktsize)
828 		return PSMOUSE_GOOD_DATA;
829 
830 	if (etd->info.debug > 1)
831 		elantech_packet_dump(psmouse);
832 
833 	switch (etd->info.hw_version) {
834 	case 1:
835 		if (etd->info.paritycheck && !elantech_packet_check_v1(psmouse))
836 			return PSMOUSE_BAD_DATA;
837 
838 		elantech_report_absolute_v1(psmouse);
839 		break;
840 
841 	case 2:
842 		/* ignore debounce */
843 		if (elantech_debounce_check_v2(psmouse))
844 			return PSMOUSE_FULL_PACKET;
845 
846 		if (etd->info.paritycheck && !elantech_packet_check_v2(psmouse))
847 			return PSMOUSE_BAD_DATA;
848 
849 		elantech_report_absolute_v2(psmouse);
850 		break;
851 
852 	case 3:
853 		packet_type = elantech_packet_check_v3(psmouse);
854 		switch (packet_type) {
855 		case PACKET_UNKNOWN:
856 			return PSMOUSE_BAD_DATA;
857 
858 		case PACKET_DEBOUNCE:
859 			/* ignore debounce */
860 			break;
861 
862 		case PACKET_TRACKPOINT:
863 			elantech_report_trackpoint(psmouse, packet_type);
864 			break;
865 
866 		default:
867 			elantech_report_absolute_v3(psmouse, packet_type);
868 			break;
869 		}
870 
871 		break;
872 
873 	case 4:
874 		packet_type = elantech_packet_check_v4(psmouse);
875 		switch (packet_type) {
876 		case PACKET_UNKNOWN:
877 			return PSMOUSE_BAD_DATA;
878 
879 		case PACKET_TRACKPOINT:
880 			elantech_report_trackpoint(psmouse, packet_type);
881 			break;
882 
883 		default:
884 			elantech_report_absolute_v4(psmouse, packet_type);
885 			break;
886 		}
887 
888 		break;
889 	}
890 
891 	return PSMOUSE_FULL_PACKET;
892 }
893 
894 /*
895  * This writes the reg_07 value again to the hardware at the end of every
896  * set_rate call because the register loses its value. reg_07 allows setting
897  * absolute mode on v4 hardware
898  */
899 static void elantech_set_rate_restore_reg_07(struct psmouse *psmouse,
900 		unsigned int rate)
901 {
902 	struct elantech_data *etd = psmouse->private;
903 
904 	etd->original_set_rate(psmouse, rate);
905 	if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
906 		psmouse_err(psmouse, "restoring reg_07 failed\n");
907 }
908 
909 /*
910  * Put the touchpad into absolute mode
911  */
912 static int elantech_set_absolute_mode(struct psmouse *psmouse)
913 {
914 	struct elantech_data *etd = psmouse->private;
915 	unsigned char val;
916 	int tries = ETP_READ_BACK_TRIES;
917 	int rc = 0;
918 
919 	switch (etd->info.hw_version) {
920 	case 1:
921 		etd->reg_10 = 0x16;
922 		etd->reg_11 = 0x8f;
923 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
924 		    elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
925 			rc = -1;
926 		}
927 		break;
928 
929 	case 2:
930 					/* Windows driver values */
931 		etd->reg_10 = 0x54;
932 		etd->reg_11 = 0x88;	/* 0x8a */
933 		etd->reg_21 = 0x60;	/* 0x00 */
934 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
935 		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
936 		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
937 			rc = -1;
938 		}
939 		break;
940 
941 	case 3:
942 		if (etd->info.set_hw_resolution)
943 			etd->reg_10 = 0x0b;
944 		else
945 			etd->reg_10 = 0x01;
946 
947 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
948 			rc = -1;
949 
950 		break;
951 
952 	case 4:
953 		etd->reg_07 = 0x01;
954 		if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
955 			rc = -1;
956 
957 		goto skip_readback_reg_10; /* v4 has no reg 0x10 to read */
958 	}
959 
960 	if (rc == 0) {
961 		/*
962 		 * Read back reg 0x10. For hardware version 1 we must make
963 		 * sure the absolute mode bit is set. For hardware version 2
964 		 * the touchpad is probably initializing and not ready until
965 		 * we read back the value we just wrote.
966 		 */
967 		do {
968 			rc = elantech_read_reg(psmouse, 0x10, &val);
969 			if (rc == 0)
970 				break;
971 			tries--;
972 			elantech_debug("retrying read (%d).\n", tries);
973 			msleep(ETP_READ_BACK_DELAY);
974 		} while (tries > 0);
975 
976 		if (rc) {
977 			psmouse_err(psmouse,
978 				    "failed to read back register 0x10.\n");
979 		} else if (etd->info.hw_version == 1 &&
980 			   !(val & ETP_R10_ABSOLUTE_MODE)) {
981 			psmouse_err(psmouse,
982 				    "touchpad refuses to switch to absolute mode.\n");
983 			rc = -1;
984 		}
985 	}
986 
987  skip_readback_reg_10:
988 	if (rc)
989 		psmouse_err(psmouse, "failed to initialise registers.\n");
990 
991 	return rc;
992 }
993 
994 static int elantech_set_range(struct psmouse *psmouse,
995 			      unsigned int *x_min, unsigned int *y_min,
996 			      unsigned int *x_max, unsigned int *y_max,
997 			      unsigned int *width)
998 {
999 	struct elantech_data *etd = psmouse->private;
1000 	struct elantech_device_info *info = &etd->info;
1001 	unsigned char param[3];
1002 	unsigned char traces;
1003 
1004 	switch (info->hw_version) {
1005 	case 1:
1006 		*x_min = ETP_XMIN_V1;
1007 		*y_min = ETP_YMIN_V1;
1008 		*x_max = ETP_XMAX_V1;
1009 		*y_max = ETP_YMAX_V1;
1010 		break;
1011 
1012 	case 2:
1013 		if (info->fw_version == 0x020800 ||
1014 		    info->fw_version == 0x020b00 ||
1015 		    info->fw_version == 0x020030) {
1016 			*x_min = ETP_XMIN_V2;
1017 			*y_min = ETP_YMIN_V2;
1018 			*x_max = ETP_XMAX_V2;
1019 			*y_max = ETP_YMAX_V2;
1020 		} else {
1021 			int i;
1022 			int fixed_dpi;
1023 
1024 			i = (info->fw_version > 0x020800 &&
1025 			     info->fw_version < 0x020900) ? 1 : 2;
1026 
1027 			if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1028 				return -1;
1029 
1030 			fixed_dpi = param[1] & 0x10;
1031 
1032 			if (((info->fw_version >> 16) == 0x14) && fixed_dpi) {
1033 				if (info->send_cmd(psmouse, ETP_SAMPLE_QUERY, param))
1034 					return -1;
1035 
1036 				*x_max = (info->capabilities[1] - i) * param[1] / 2;
1037 				*y_max = (info->capabilities[2] - i) * param[2] / 2;
1038 			} else if (info->fw_version == 0x040216) {
1039 				*x_max = 819;
1040 				*y_max = 405;
1041 			} else if (info->fw_version == 0x040219 || info->fw_version == 0x040215) {
1042 				*x_max = 900;
1043 				*y_max = 500;
1044 			} else {
1045 				*x_max = (info->capabilities[1] - i) * 64;
1046 				*y_max = (info->capabilities[2] - i) * 64;
1047 			}
1048 		}
1049 		break;
1050 
1051 	case 3:
1052 		if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1053 			return -1;
1054 
1055 		*x_max = (0x0f & param[0]) << 8 | param[1];
1056 		*y_max = (0xf0 & param[0]) << 4 | param[2];
1057 		break;
1058 
1059 	case 4:
1060 		if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1061 			return -1;
1062 
1063 		*x_max = (0x0f & param[0]) << 8 | param[1];
1064 		*y_max = (0xf0 & param[0]) << 4 | param[2];
1065 		traces = info->capabilities[1];
1066 		if ((traces < 2) || (traces > *x_max))
1067 			return -1;
1068 
1069 		*width = *x_max / (traces - 1);
1070 		break;
1071 	}
1072 
1073 	return 0;
1074 }
1075 
1076 /*
1077  * (value from firmware) * 10 + 790 = dpi
1078  * we also have to convert dpi to dots/mm (*10/254 to avoid floating point)
1079  */
1080 static unsigned int elantech_convert_res(unsigned int val)
1081 {
1082 	return (val * 10 + 790) * 10 / 254;
1083 }
1084 
1085 static int elantech_get_resolution_v4(struct psmouse *psmouse,
1086 				      unsigned int *x_res,
1087 				      unsigned int *y_res,
1088 				      unsigned int *bus)
1089 {
1090 	unsigned char param[3];
1091 
1092 	if (elantech_send_cmd(psmouse, ETP_RESOLUTION_QUERY, param))
1093 		return -1;
1094 
1095 	*x_res = elantech_convert_res(param[1] & 0x0f);
1096 	*y_res = elantech_convert_res((param[1] & 0xf0) >> 4);
1097 	*bus = param[2];
1098 
1099 	return 0;
1100 }
1101 
1102 /*
1103  * Advertise INPUT_PROP_BUTTONPAD for clickpads. The testing of bit 12 in
1104  * fw_version for this is based on the following fw_version & caps table:
1105  *
1106  * Laptop-model:           fw_version:     caps:           buttons:
1107  * Acer S3                 0x461f00        10, 13, 0e      clickpad
1108  * Acer S7-392             0x581f01        50, 17, 0d      clickpad
1109  * Acer V5-131             0x461f02        01, 16, 0c      clickpad
1110  * Acer V5-551             0x461f00        ?               clickpad
1111  * Asus K53SV              0x450f01        78, 15, 0c      2 hw buttons
1112  * Asus G46VW              0x460f02        00, 18, 0c      2 hw buttons
1113  * Asus G750JX             0x360f00        00, 16, 0c      2 hw buttons
1114  * Asus TP500LN            0x381f17        10, 14, 0e      clickpad
1115  * Asus X750JN             0x381f17        10, 14, 0e      clickpad
1116  * Asus UX31               0x361f00        20, 15, 0e      clickpad
1117  * Asus UX32VD             0x361f02        00, 15, 0e      clickpad
1118  * Avatar AVIU-145A2       0x361f00        ?               clickpad
1119  * Fujitsu CELSIUS H760    0x570f02        40, 14, 0c      3 hw buttons (**)
1120  * Fujitsu CELSIUS H780    0x5d0f02        41, 16, 0d      3 hw buttons (**)
1121  * Fujitsu LIFEBOOK E544   0x470f00        d0, 12, 09      2 hw buttons
1122  * Fujitsu LIFEBOOK E546   0x470f00        50, 12, 09      2 hw buttons
1123  * Fujitsu LIFEBOOK E547   0x470f00        50, 12, 09      2 hw buttons
1124  * Fujitsu LIFEBOOK E554   0x570f01        40, 14, 0c      2 hw buttons
1125  * Fujitsu LIFEBOOK E557   0x570f01        40, 14, 0c      2 hw buttons
1126  * Fujitsu T725            0x470f01        05, 12, 09      2 hw buttons
1127  * Fujitsu H730            0x570f00        c0, 14, 0c      3 hw buttons (**)
1128  * Gigabyte U2442          0x450f01        58, 17, 0c      2 hw buttons
1129  * Lenovo L430             0x350f02        b9, 15, 0c      2 hw buttons (*)
1130  * Lenovo L530             0x350f02        b9, 15, 0c      2 hw buttons (*)
1131  * Samsung NF210           0x150b00        78, 14, 0a      2 hw buttons
1132  * Samsung NP770Z5E        0x575f01        10, 15, 0f      clickpad
1133  * Samsung NP700Z5B        0x361f06        21, 15, 0f      clickpad
1134  * Samsung NP900X3E-A02    0x575f03        ?               clickpad
1135  * Samsung NP-QX410        0x851b00        19, 14, 0c      clickpad
1136  * Samsung RC512           0x450f00        08, 15, 0c      2 hw buttons
1137  * Samsung RF710           0x450f00        ?               2 hw buttons
1138  * System76 Pangolin       0x250f01        ?               2 hw buttons
1139  * (*) + 3 trackpoint buttons
1140  * (**) + 0 trackpoint buttons
1141  * Note: Lenovo L430 and Lenovo L530 have the same fw_version/caps
1142  */
1143 static void elantech_set_buttonpad_prop(struct psmouse *psmouse)
1144 {
1145 	struct input_dev *dev = psmouse->dev;
1146 	struct elantech_data *etd = psmouse->private;
1147 
1148 	if (etd->info.fw_version & 0x001000) {
1149 		__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
1150 		__clear_bit(BTN_RIGHT, dev->keybit);
1151 	}
1152 }
1153 
1154 /*
1155  * Some hw_version 4 models do have a middle button
1156  */
1157 static const struct dmi_system_id elantech_dmi_has_middle_button[] = {
1158 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1159 	{
1160 		/* Fujitsu H730 has a middle button */
1161 		.matches = {
1162 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1163 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H730"),
1164 		},
1165 	},
1166 	{
1167 		/* Fujitsu H760 also has a middle button */
1168 		.matches = {
1169 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1170 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H760"),
1171 		},
1172 	},
1173 	{
1174 		/* Fujitsu H780 also has a middle button */
1175 		.matches = {
1176 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1177 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H780"),
1178 		},
1179 	},
1180 #endif
1181 	{ }
1182 };
1183 
1184 static const char * const middle_button_pnp_ids[] = {
1185 	"LEN2131", /* ThinkPad P52 w/ NFC */
1186 	"LEN2132", /* ThinkPad P52 */
1187 	"LEN2133", /* ThinkPad P72 w/ NFC */
1188 	"LEN2134", /* ThinkPad P72 */
1189 	NULL
1190 };
1191 
1192 /*
1193  * Set the appropriate event bits for the input subsystem
1194  */
1195 static int elantech_set_input_params(struct psmouse *psmouse)
1196 {
1197 	struct input_dev *dev = psmouse->dev;
1198 	struct elantech_data *etd = psmouse->private;
1199 	struct elantech_device_info *info = &etd->info;
1200 	unsigned int x_min = 0, y_min = 0, x_max = 0, y_max = 0, width = 0;
1201 
1202 	if (elantech_set_range(psmouse, &x_min, &y_min, &x_max, &y_max, &width))
1203 		return -1;
1204 
1205 	__set_bit(INPUT_PROP_POINTER, dev->propbit);
1206 	__set_bit(EV_KEY, dev->evbit);
1207 	__set_bit(EV_ABS, dev->evbit);
1208 	__clear_bit(EV_REL, dev->evbit);
1209 
1210 	__set_bit(BTN_LEFT, dev->keybit);
1211 	if (dmi_check_system(elantech_dmi_has_middle_button) ||
1212 			psmouse_matches_pnp_id(psmouse, middle_button_pnp_ids))
1213 		__set_bit(BTN_MIDDLE, dev->keybit);
1214 	__set_bit(BTN_RIGHT, dev->keybit);
1215 
1216 	__set_bit(BTN_TOUCH, dev->keybit);
1217 	__set_bit(BTN_TOOL_FINGER, dev->keybit);
1218 	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
1219 	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
1220 
1221 	switch (info->hw_version) {
1222 	case 1:
1223 		/* Rocker button */
1224 		if (info->fw_version < 0x020000 &&
1225 		    (info->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
1226 			__set_bit(BTN_FORWARD, dev->keybit);
1227 			__set_bit(BTN_BACK, dev->keybit);
1228 		}
1229 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1230 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1231 		break;
1232 
1233 	case 2:
1234 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1235 		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
1236 		/* fall through */
1237 	case 3:
1238 		if (info->hw_version == 3)
1239 			elantech_set_buttonpad_prop(psmouse);
1240 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1241 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1242 		if (info->reports_pressure) {
1243 			input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1244 					     ETP_PMAX_V2, 0, 0);
1245 			input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1246 					     ETP_WMAX_V2, 0, 0);
1247 		}
1248 		input_mt_init_slots(dev, 2, INPUT_MT_SEMI_MT);
1249 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1250 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1251 		break;
1252 
1253 	case 4:
1254 		elantech_set_buttonpad_prop(psmouse);
1255 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1256 		/* For X to recognize me as touchpad. */
1257 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1258 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1259 		/*
1260 		 * range of pressure and width is the same as v2,
1261 		 * report ABS_PRESSURE, ABS_TOOL_WIDTH for compatibility.
1262 		 */
1263 		input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1264 				     ETP_PMAX_V2, 0, 0);
1265 		input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1266 				     ETP_WMAX_V2, 0, 0);
1267 		/* Multitouch capable pad, up to 5 fingers. */
1268 		input_mt_init_slots(dev, ETP_MAX_FINGERS, 0);
1269 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1270 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1271 		input_set_abs_params(dev, ABS_MT_PRESSURE, ETP_PMIN_V2,
1272 				     ETP_PMAX_V2, 0, 0);
1273 		/*
1274 		 * The firmware reports how many trace lines the finger spans,
1275 		 * convert to surface unit as Protocol-B requires.
1276 		 */
1277 		input_set_abs_params(dev, ABS_MT_TOUCH_MAJOR, 0,
1278 				     ETP_WMAX_V2 * width, 0, 0);
1279 		break;
1280 	}
1281 
1282 	input_abs_set_res(dev, ABS_X, info->x_res);
1283 	input_abs_set_res(dev, ABS_Y, info->y_res);
1284 	if (info->hw_version > 1) {
1285 		input_abs_set_res(dev, ABS_MT_POSITION_X, info->x_res);
1286 		input_abs_set_res(dev, ABS_MT_POSITION_Y, info->y_res);
1287 	}
1288 
1289 	etd->y_max = y_max;
1290 	etd->width = width;
1291 
1292 	return 0;
1293 }
1294 
1295 struct elantech_attr_data {
1296 	size_t		field_offset;
1297 	unsigned char	reg;
1298 };
1299 
1300 /*
1301  * Display a register value by reading a sysfs entry
1302  */
1303 static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
1304 					char *buf)
1305 {
1306 	struct elantech_data *etd = psmouse->private;
1307 	struct elantech_attr_data *attr = data;
1308 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1309 	int rc = 0;
1310 
1311 	if (attr->reg)
1312 		rc = elantech_read_reg(psmouse, attr->reg, reg);
1313 
1314 	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
1315 }
1316 
1317 /*
1318  * Write a register value by writing a sysfs entry
1319  */
1320 static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
1321 				     void *data, const char *buf, size_t count)
1322 {
1323 	struct elantech_data *etd = psmouse->private;
1324 	struct elantech_attr_data *attr = data;
1325 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1326 	unsigned char value;
1327 	int err;
1328 
1329 	err = kstrtou8(buf, 16, &value);
1330 	if (err)
1331 		return err;
1332 
1333 	/* Do we need to preserve some bits for version 2 hardware too? */
1334 	if (etd->info.hw_version == 1) {
1335 		if (attr->reg == 0x10)
1336 			/* Force absolute mode always on */
1337 			value |= ETP_R10_ABSOLUTE_MODE;
1338 		else if (attr->reg == 0x11)
1339 			/* Force 4 byte mode always on */
1340 			value |= ETP_R11_4_BYTE_MODE;
1341 	}
1342 
1343 	if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
1344 		*reg = value;
1345 
1346 	return count;
1347 }
1348 
1349 #define ELANTECH_INT_ATTR(_name, _register)				\
1350 	static struct elantech_attr_data elantech_attr_##_name = {	\
1351 		.field_offset = offsetof(struct elantech_data, _name),	\
1352 		.reg = _register,					\
1353 	};								\
1354 	PSMOUSE_DEFINE_ATTR(_name, 0644,				\
1355 			    &elantech_attr_##_name,			\
1356 			    elantech_show_int_attr,			\
1357 			    elantech_set_int_attr)
1358 
1359 #define ELANTECH_INFO_ATTR(_name)					       \
1360 	static struct elantech_attr_data elantech_attr_##_name = {	       \
1361 		.field_offset = offsetof(struct elantech_data, info) +	       \
1362 				offsetof(struct elantech_device_info, _name),  \
1363 		.reg = 0,						       \
1364 	};								       \
1365 	PSMOUSE_DEFINE_ATTR(_name, 0644,				       \
1366 			    &elantech_attr_##_name,			       \
1367 			    elantech_show_int_attr,			       \
1368 			    elantech_set_int_attr)
1369 
1370 ELANTECH_INT_ATTR(reg_07, 0x07);
1371 ELANTECH_INT_ATTR(reg_10, 0x10);
1372 ELANTECH_INT_ATTR(reg_11, 0x11);
1373 ELANTECH_INT_ATTR(reg_20, 0x20);
1374 ELANTECH_INT_ATTR(reg_21, 0x21);
1375 ELANTECH_INT_ATTR(reg_22, 0x22);
1376 ELANTECH_INT_ATTR(reg_23, 0x23);
1377 ELANTECH_INT_ATTR(reg_24, 0x24);
1378 ELANTECH_INT_ATTR(reg_25, 0x25);
1379 ELANTECH_INT_ATTR(reg_26, 0x26);
1380 ELANTECH_INFO_ATTR(debug);
1381 ELANTECH_INFO_ATTR(paritycheck);
1382 ELANTECH_INFO_ATTR(crc_enabled);
1383 
1384 static struct attribute *elantech_attrs[] = {
1385 	&psmouse_attr_reg_07.dattr.attr,
1386 	&psmouse_attr_reg_10.dattr.attr,
1387 	&psmouse_attr_reg_11.dattr.attr,
1388 	&psmouse_attr_reg_20.dattr.attr,
1389 	&psmouse_attr_reg_21.dattr.attr,
1390 	&psmouse_attr_reg_22.dattr.attr,
1391 	&psmouse_attr_reg_23.dattr.attr,
1392 	&psmouse_attr_reg_24.dattr.attr,
1393 	&psmouse_attr_reg_25.dattr.attr,
1394 	&psmouse_attr_reg_26.dattr.attr,
1395 	&psmouse_attr_debug.dattr.attr,
1396 	&psmouse_attr_paritycheck.dattr.attr,
1397 	&psmouse_attr_crc_enabled.dattr.attr,
1398 	NULL
1399 };
1400 
1401 static const struct attribute_group elantech_attr_group = {
1402 	.attrs = elantech_attrs,
1403 };
1404 
1405 static bool elantech_is_signature_valid(const unsigned char *param)
1406 {
1407 	static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10 };
1408 	int i;
1409 
1410 	if (param[0] == 0)
1411 		return false;
1412 
1413 	if (param[1] == 0)
1414 		return true;
1415 
1416 	/*
1417 	 * Some hw_version >= 4 models have a revision higher then 20. Meaning
1418 	 * that param[2] may be 10 or 20, skip the rates check for these.
1419 	 */
1420 	if ((param[0] & 0x0f) >= 0x06 && (param[1] & 0xaf) == 0x0f &&
1421 	    param[2] < 40)
1422 		return true;
1423 
1424 	for (i = 0; i < ARRAY_SIZE(rates); i++)
1425 		if (param[2] == rates[i])
1426 			return false;
1427 
1428 	return true;
1429 }
1430 
1431 /*
1432  * Use magic knock to detect Elantech touchpad
1433  */
1434 int elantech_detect(struct psmouse *psmouse, bool set_properties)
1435 {
1436 	struct ps2dev *ps2dev = &psmouse->ps2dev;
1437 	unsigned char param[3];
1438 
1439 	ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
1440 
1441 	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
1442 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1443 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1444 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1445 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
1446 		psmouse_dbg(psmouse, "sending Elantech magic knock failed.\n");
1447 		return -1;
1448 	}
1449 
1450 	/*
1451 	 * Report this in case there are Elantech models that use a different
1452 	 * set of magic numbers
1453 	 */
1454 	if (param[0] != 0x3c || param[1] != 0x03 ||
1455 	    (param[2] != 0xc8 && param[2] != 0x00)) {
1456 		psmouse_dbg(psmouse,
1457 			    "unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
1458 			    param[0], param[1], param[2]);
1459 		return -1;
1460 	}
1461 
1462 	/*
1463 	 * Query touchpad's firmware version and see if it reports known
1464 	 * value to avoid mis-detection. Logitech mice are known to respond
1465 	 * to Elantech magic knock and there might be more.
1466 	 */
1467 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1468 		psmouse_dbg(psmouse, "failed to query firmware version.\n");
1469 		return -1;
1470 	}
1471 
1472 	psmouse_dbg(psmouse,
1473 		    "Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
1474 		    param[0], param[1], param[2]);
1475 
1476 	if (!elantech_is_signature_valid(param)) {
1477 		psmouse_dbg(psmouse,
1478 			    "Probably not a real Elantech touchpad. Aborting.\n");
1479 		return -1;
1480 	}
1481 
1482 	if (set_properties) {
1483 		psmouse->vendor = "Elantech";
1484 		psmouse->name = "Touchpad";
1485 	}
1486 
1487 	return 0;
1488 }
1489 
1490 /*
1491  * Clean up sysfs entries when disconnecting
1492  */
1493 static void elantech_disconnect(struct psmouse *psmouse)
1494 {
1495 	struct elantech_data *etd = psmouse->private;
1496 
1497 	/*
1498 	 * We might have left a breadcrumb when trying to
1499 	 * set up SMbus companion.
1500 	 */
1501 	psmouse_smbus_cleanup(psmouse);
1502 
1503 	if (etd->tp_dev)
1504 		input_unregister_device(etd->tp_dev);
1505 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
1506 			   &elantech_attr_group);
1507 	kfree(psmouse->private);
1508 	psmouse->private = NULL;
1509 }
1510 
1511 /*
1512  * Put the touchpad back into absolute mode when reconnecting
1513  */
1514 static int elantech_reconnect(struct psmouse *psmouse)
1515 {
1516 	psmouse_reset(psmouse);
1517 
1518 	if (elantech_detect(psmouse, 0))
1519 		return -1;
1520 
1521 	if (elantech_set_absolute_mode(psmouse)) {
1522 		psmouse_err(psmouse,
1523 			    "failed to put touchpad back into absolute mode.\n");
1524 		return -1;
1525 	}
1526 
1527 	return 0;
1528 }
1529 
1530 /*
1531  * Some hw_version 4 models do not work with crc_disabled
1532  */
1533 static const struct dmi_system_id elantech_dmi_force_crc_enabled[] = {
1534 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1535 	{
1536 		/* Fujitsu H730 does not work with crc_enabled == 0 */
1537 		.matches = {
1538 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1539 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H730"),
1540 		},
1541 	},
1542 	{
1543 		/* Fujitsu H760 does not work with crc_enabled == 0 */
1544 		.matches = {
1545 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1546 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H760"),
1547 		},
1548 	},
1549 	{
1550 		/* Fujitsu LIFEBOOK E544  does not work with crc_enabled == 0 */
1551 		.matches = {
1552 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1553 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E544"),
1554 		},
1555 	},
1556 	{
1557 		/* Fujitsu LIFEBOOK E546  does not work with crc_enabled == 0 */
1558 		.matches = {
1559 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1560 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E546"),
1561 		},
1562 	},
1563 	{
1564 		/* Fujitsu LIFEBOOK E547 does not work with crc_enabled == 0 */
1565 		.matches = {
1566 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1567 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E547"),
1568 		},
1569 	},
1570 	{
1571 		/* Fujitsu LIFEBOOK E554  does not work with crc_enabled == 0 */
1572 		.matches = {
1573 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1574 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E554"),
1575 		},
1576 	},
1577 	{
1578 		/* Fujitsu LIFEBOOK E556 does not work with crc_enabled == 0 */
1579 		.matches = {
1580 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1581 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E556"),
1582 		},
1583 	},
1584 	{
1585 		/* Fujitsu LIFEBOOK E557 does not work with crc_enabled == 0 */
1586 		.matches = {
1587 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1588 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E557"),
1589 		},
1590 	},
1591 	{
1592 		/* Fujitsu LIFEBOOK U745 does not work with crc_enabled == 0 */
1593 		.matches = {
1594 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1595 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK U745"),
1596 		},
1597 	},
1598 #endif
1599 	{ }
1600 };
1601 
1602 /*
1603  * Some hw_version 3 models go into error state when we try to set
1604  * bit 3 and/or bit 1 of r10.
1605  */
1606 static const struct dmi_system_id no_hw_res_dmi_table[] = {
1607 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1608 	{
1609 		/* Gigabyte U2442 */
1610 		.matches = {
1611 			DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
1612 			DMI_MATCH(DMI_PRODUCT_NAME, "U2442"),
1613 		},
1614 	},
1615 #endif
1616 	{ }
1617 };
1618 
1619 /*
1620  * determine hardware version and set some properties according to it.
1621  */
1622 static int elantech_set_properties(struct elantech_device_info *info)
1623 {
1624 	/* This represents the version of IC body. */
1625 	int ver = (info->fw_version & 0x0f0000) >> 16;
1626 
1627 	/* Early version of Elan touchpads doesn't obey the rule. */
1628 	if (info->fw_version < 0x020030 || info->fw_version == 0x020600)
1629 		info->hw_version = 1;
1630 	else {
1631 		switch (ver) {
1632 		case 2:
1633 		case 4:
1634 			info->hw_version = 2;
1635 			break;
1636 		case 5:
1637 			info->hw_version = 3;
1638 			break;
1639 		case 6 ... 15:
1640 			info->hw_version = 4;
1641 			break;
1642 		default:
1643 			return -1;
1644 		}
1645 	}
1646 
1647 	/* decide which send_cmd we're gonna use early */
1648 	info->send_cmd = info->hw_version >= 3 ? elantech_send_cmd :
1649 						 synaptics_send_cmd;
1650 
1651 	/* Turn on packet checking by default */
1652 	info->paritycheck = 1;
1653 
1654 	/*
1655 	 * This firmware suffers from misreporting coordinates when
1656 	 * a touch action starts causing the mouse cursor or scrolled page
1657 	 * to jump. Enable a workaround.
1658 	 */
1659 	info->jumpy_cursor =
1660 		(info->fw_version == 0x020022 || info->fw_version == 0x020600);
1661 
1662 	if (info->hw_version > 1) {
1663 		/* For now show extra debug information */
1664 		info->debug = 1;
1665 
1666 		if (info->fw_version >= 0x020800)
1667 			info->reports_pressure = true;
1668 	}
1669 
1670 	/*
1671 	 * The signatures of v3 and v4 packets change depending on the
1672 	 * value of this hardware flag.
1673 	 */
1674 	info->crc_enabled = (info->fw_version & 0x4000) == 0x4000 ||
1675 			     dmi_check_system(elantech_dmi_force_crc_enabled);
1676 
1677 	/* Enable real hardware resolution on hw_version 3 ? */
1678 	info->set_hw_resolution = !dmi_check_system(no_hw_res_dmi_table);
1679 
1680 	return 0;
1681 }
1682 
1683 static int elantech_query_info(struct psmouse *psmouse,
1684 			       struct elantech_device_info *info)
1685 {
1686 	unsigned char param[3];
1687 
1688 	memset(info, 0, sizeof(*info));
1689 
1690 	/*
1691 	 * Do the version query again so we can store the result
1692 	 */
1693 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1694 		psmouse_err(psmouse, "failed to query firmware version.\n");
1695 		return -EINVAL;
1696 	}
1697 	info->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
1698 
1699 	if (elantech_set_properties(info)) {
1700 		psmouse_err(psmouse, "unknown hardware version, aborting...\n");
1701 		return -EINVAL;
1702 	}
1703 	psmouse_info(psmouse,
1704 		     "assuming hardware version %d (with firmware version 0x%02x%02x%02x)\n",
1705 		     info->hw_version, param[0], param[1], param[2]);
1706 
1707 	if (info->send_cmd(psmouse, ETP_CAPABILITIES_QUERY,
1708 	    info->capabilities)) {
1709 		psmouse_err(psmouse, "failed to query capabilities.\n");
1710 		return -EINVAL;
1711 	}
1712 	psmouse_info(psmouse,
1713 		     "Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
1714 		     info->capabilities[0], info->capabilities[1],
1715 		     info->capabilities[2]);
1716 
1717 	if (info->hw_version != 1) {
1718 		if (info->send_cmd(psmouse, ETP_SAMPLE_QUERY, info->samples)) {
1719 			psmouse_err(psmouse, "failed to query sample data\n");
1720 			return -EINVAL;
1721 		}
1722 		psmouse_info(psmouse,
1723 			     "Elan sample query result %02x, %02x, %02x\n",
1724 			     info->samples[0],
1725 			     info->samples[1],
1726 			     info->samples[2]);
1727 	}
1728 
1729 	if (info->samples[1] == 0x74 && info->hw_version == 0x03) {
1730 		/*
1731 		 * This module has a bug which makes absolute mode
1732 		 * unusable, so let's abort so we'll be using standard
1733 		 * PS/2 protocol.
1734 		 */
1735 		psmouse_info(psmouse,
1736 			     "absolute mode broken, forcing standard PS/2 protocol\n");
1737 		return -ENODEV;
1738 	}
1739 
1740 	/* The MSB indicates the presence of the trackpoint */
1741 	info->has_trackpoint = (info->capabilities[0] & 0x80) == 0x80;
1742 
1743 	info->x_res = 31;
1744 	info->y_res = 31;
1745 	if (info->hw_version == 4) {
1746 		if (elantech_get_resolution_v4(psmouse,
1747 					       &info->x_res,
1748 					       &info->y_res,
1749 					       &info->bus)) {
1750 			psmouse_warn(psmouse,
1751 				     "failed to query resolution data.\n");
1752 		}
1753 	}
1754 
1755 	return 0;
1756 }
1757 
1758 #if defined(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)
1759 
1760 /*
1761  * The newest Elantech device can use a secondary bus (over SMBus) which
1762  * provides a better bandwidth and allow a better control of the touchpads.
1763  * This is used to decide if we need to use this bus or not.
1764  */
1765 enum {
1766 	ELANTECH_SMBUS_NOT_SET = -1,
1767 	ELANTECH_SMBUS_OFF,
1768 	ELANTECH_SMBUS_ON,
1769 };
1770 
1771 static int elantech_smbus = IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) ?
1772 		ELANTECH_SMBUS_NOT_SET : ELANTECH_SMBUS_OFF;
1773 module_param_named(elantech_smbus, elantech_smbus, int, 0644);
1774 MODULE_PARM_DESC(elantech_smbus, "Use a secondary bus for the Elantech device.");
1775 
1776 static const char * const i2c_blacklist_pnp_ids[] = {
1777 	/*
1778 	 * These are known to not be working properly as bits are missing
1779 	 * in elan_i2c.
1780 	 */
1781 	"LEN2131", /* ThinkPad P52 w/ NFC */
1782 	"LEN2132", /* ThinkPad P52 */
1783 	"LEN2133", /* ThinkPad P72 w/ NFC */
1784 	"LEN2134", /* ThinkPad P72 */
1785 	NULL
1786 };
1787 
1788 static int elantech_create_smbus(struct psmouse *psmouse,
1789 				 struct elantech_device_info *info,
1790 				 bool leave_breadcrumbs)
1791 {
1792 	const struct property_entry i2c_properties[] = {
1793 		PROPERTY_ENTRY_BOOL("elan,trackpoint"),
1794 		{ },
1795 	};
1796 	struct i2c_board_info smbus_board = {
1797 		I2C_BOARD_INFO("elan_i2c", 0x15),
1798 		.flags = I2C_CLIENT_HOST_NOTIFY,
1799 	};
1800 
1801 	if (info->has_trackpoint)
1802 		smbus_board.properties = i2c_properties;
1803 
1804 	return psmouse_smbus_init(psmouse, &smbus_board, NULL, 0, false,
1805 				  leave_breadcrumbs);
1806 }
1807 
1808 /**
1809  * elantech_setup_smbus - called once the PS/2 devices are enumerated
1810  * and decides to instantiate a SMBus InterTouch device.
1811  */
1812 static int elantech_setup_smbus(struct psmouse *psmouse,
1813 				struct elantech_device_info *info,
1814 				bool leave_breadcrumbs)
1815 {
1816 	int error;
1817 
1818 	if (elantech_smbus == ELANTECH_SMBUS_OFF)
1819 		return -ENXIO;
1820 
1821 	if (elantech_smbus == ELANTECH_SMBUS_NOT_SET) {
1822 		/*
1823 		 * New ICs are enabled by default, unless mentioned in
1824 		 * i2c_blacklist_pnp_ids.
1825 		 * Old ICs are up to the user to decide.
1826 		 */
1827 		if (!ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version) ||
1828 		    psmouse_matches_pnp_id(psmouse, i2c_blacklist_pnp_ids))
1829 			return -ENXIO;
1830 	}
1831 
1832 	psmouse_info(psmouse, "Trying to set up SMBus access\n");
1833 
1834 	error = elantech_create_smbus(psmouse, info, leave_breadcrumbs);
1835 	if (error) {
1836 		if (error == -EAGAIN)
1837 			psmouse_info(psmouse, "SMbus companion is not ready yet\n");
1838 		else
1839 			psmouse_err(psmouse, "unable to create intertouch device\n");
1840 
1841 		return error;
1842 	}
1843 
1844 	return 0;
1845 }
1846 
1847 static bool elantech_use_host_notify(struct psmouse *psmouse,
1848 				     struct elantech_device_info *info)
1849 {
1850 	if (ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version))
1851 		return true;
1852 
1853 	switch (info->bus) {
1854 	case ETP_BUS_PS2_ONLY:
1855 		/* expected case */
1856 		break;
1857 	case ETP_BUS_SMB_ALERT_ONLY:
1858 		/* fall-through  */
1859 	case ETP_BUS_PS2_SMB_ALERT:
1860 		psmouse_dbg(psmouse, "Ignoring SMBus provider through alert protocol.\n");
1861 		break;
1862 	case ETP_BUS_SMB_HST_NTFY_ONLY:
1863 		/* fall-through  */
1864 	case ETP_BUS_PS2_SMB_HST_NTFY:
1865 		return true;
1866 	default:
1867 		psmouse_dbg(psmouse,
1868 			    "Ignoring SMBus bus provider %d.\n",
1869 			    info->bus);
1870 	}
1871 
1872 	return false;
1873 }
1874 
1875 int elantech_init_smbus(struct psmouse *psmouse)
1876 {
1877 	struct elantech_device_info info;
1878 	int error = -EINVAL;
1879 
1880 	psmouse_reset(psmouse);
1881 
1882 	error = elantech_query_info(psmouse, &info);
1883 	if (error)
1884 		goto init_fail;
1885 
1886 	if (info.hw_version < 4) {
1887 		error = -ENXIO;
1888 		goto init_fail;
1889 	}
1890 
1891 	return elantech_create_smbus(psmouse, &info, false);
1892  init_fail:
1893 	psmouse_reset(psmouse);
1894 	return error;
1895 }
1896 #endif /* CONFIG_MOUSE_PS2_ELANTECH_SMBUS */
1897 
1898 /*
1899  * Initialize the touchpad and create sysfs entries
1900  */
1901 static int elantech_setup_ps2(struct psmouse *psmouse,
1902 			      struct elantech_device_info *info)
1903 {
1904 	struct elantech_data *etd;
1905 	int i;
1906 	int error = -EINVAL;
1907 	struct input_dev *tp_dev;
1908 
1909 	psmouse->private = etd = kzalloc(sizeof(*etd), GFP_KERNEL);
1910 	if (!etd)
1911 		return -ENOMEM;
1912 
1913 	etd->info = *info;
1914 
1915 	etd->parity[0] = 1;
1916 	for (i = 1; i < 256; i++)
1917 		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
1918 
1919 	if (elantech_set_absolute_mode(psmouse)) {
1920 		psmouse_err(psmouse,
1921 			    "failed to put touchpad into absolute mode.\n");
1922 		goto init_fail;
1923 	}
1924 
1925 	if (info->fw_version == 0x381f17) {
1926 		etd->original_set_rate = psmouse->set_rate;
1927 		psmouse->set_rate = elantech_set_rate_restore_reg_07;
1928 	}
1929 
1930 	if (elantech_set_input_params(psmouse)) {
1931 		psmouse_err(psmouse, "failed to query touchpad range.\n");
1932 		goto init_fail;
1933 	}
1934 
1935 	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
1936 				   &elantech_attr_group);
1937 	if (error) {
1938 		psmouse_err(psmouse,
1939 			    "failed to create sysfs attributes, error: %d.\n",
1940 			    error);
1941 		goto init_fail;
1942 	}
1943 
1944 	if (info->has_trackpoint) {
1945 		tp_dev = input_allocate_device();
1946 
1947 		if (!tp_dev) {
1948 			error = -ENOMEM;
1949 			goto init_fail_tp_alloc;
1950 		}
1951 
1952 		etd->tp_dev = tp_dev;
1953 		snprintf(etd->tp_phys, sizeof(etd->tp_phys), "%s/input1",
1954 			psmouse->ps2dev.serio->phys);
1955 		tp_dev->phys = etd->tp_phys;
1956 		tp_dev->name = "ETPS/2 Elantech TrackPoint";
1957 		tp_dev->id.bustype = BUS_I8042;
1958 		tp_dev->id.vendor  = 0x0002;
1959 		tp_dev->id.product = PSMOUSE_ELANTECH;
1960 		tp_dev->id.version = 0x0000;
1961 		tp_dev->dev.parent = &psmouse->ps2dev.serio->dev;
1962 		tp_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
1963 		tp_dev->relbit[BIT_WORD(REL_X)] =
1964 			BIT_MASK(REL_X) | BIT_MASK(REL_Y);
1965 		tp_dev->keybit[BIT_WORD(BTN_LEFT)] =
1966 			BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_MIDDLE) |
1967 			BIT_MASK(BTN_RIGHT);
1968 
1969 		__set_bit(INPUT_PROP_POINTER, tp_dev->propbit);
1970 		__set_bit(INPUT_PROP_POINTING_STICK, tp_dev->propbit);
1971 
1972 		error = input_register_device(etd->tp_dev);
1973 		if (error < 0)
1974 			goto init_fail_tp_reg;
1975 	}
1976 
1977 	psmouse->protocol_handler = elantech_process_byte;
1978 	psmouse->disconnect = elantech_disconnect;
1979 	psmouse->reconnect = elantech_reconnect;
1980 	psmouse->pktsize = info->hw_version > 1 ? 6 : 4;
1981 
1982 	return 0;
1983  init_fail_tp_reg:
1984 	input_free_device(tp_dev);
1985  init_fail_tp_alloc:
1986 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
1987 			   &elantech_attr_group);
1988  init_fail:
1989 	kfree(etd);
1990 	return error;
1991 }
1992 
1993 int elantech_init_ps2(struct psmouse *psmouse)
1994 {
1995 	struct elantech_device_info info;
1996 	int error = -EINVAL;
1997 
1998 	psmouse_reset(psmouse);
1999 
2000 	error = elantech_query_info(psmouse, &info);
2001 	if (error)
2002 		goto init_fail;
2003 
2004 	error = elantech_setup_ps2(psmouse, &info);
2005 	if (error)
2006 		goto init_fail;
2007 
2008 	return 0;
2009  init_fail:
2010 	psmouse_reset(psmouse);
2011 	return error;
2012 }
2013 
2014 int elantech_init(struct psmouse *psmouse)
2015 {
2016 	struct elantech_device_info info;
2017 	int error = -EINVAL;
2018 
2019 	psmouse_reset(psmouse);
2020 
2021 	error = elantech_query_info(psmouse, &info);
2022 	if (error)
2023 		goto init_fail;
2024 
2025 #if defined(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)
2026 
2027 	if (elantech_use_host_notify(psmouse, &info)) {
2028 		if (!IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) ||
2029 		    !IS_ENABLED(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)) {
2030 			psmouse_warn(psmouse,
2031 				     "The touchpad can support a better bus than the too old PS/2 protocol. "
2032 				     "Make sure MOUSE_PS2_ELANTECH_SMBUS and MOUSE_ELAN_I2C_SMBUS are enabled to get a better touchpad experience.\n");
2033 		}
2034 		error = elantech_setup_smbus(psmouse, &info, true);
2035 		if (!error)
2036 			return PSMOUSE_ELANTECH_SMBUS;
2037 	}
2038 
2039 #endif /* CONFIG_MOUSE_PS2_ELANTECH_SMBUS */
2040 
2041 	error = elantech_setup_ps2(psmouse, &info);
2042 	if (error < 0) {
2043 		/*
2044 		 * Not using any flavor of Elantech support, so clean up
2045 		 * SMbus breadcrumbs, if any.
2046 		 */
2047 		psmouse_smbus_cleanup(psmouse);
2048 		goto init_fail;
2049 	}
2050 
2051 	return PSMOUSE_ELANTECH;
2052  init_fail:
2053 	psmouse_reset(psmouse);
2054 	return error;
2055 }
2056