xref: /openbmc/linux/drivers/input/mouse/elantech.c (revision 1a4e39c2e5ca2eb494a53ecd73055562f690bca0)
1 /*
2  * Elantech Touchpad driver (v6)
3  *
4  * Copyright (C) 2007-2009 Arjan Opmeer <arjan@opmeer.net>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 as published
8  * by the Free Software Foundation.
9  *
10  * Trademarks are the property of their respective owners.
11  */
12 
13 #include <linux/delay.h>
14 #include <linux/dmi.h>
15 #include <linux/slab.h>
16 #include <linux/module.h>
17 #include <linux/input.h>
18 #include <linux/input/mt.h>
19 #include <linux/serio.h>
20 #include <linux/libps2.h>
21 #include <asm/unaligned.h>
22 #include "psmouse.h"
23 #include "elantech.h"
24 
25 #define elantech_debug(fmt, ...)					\
26 	do {								\
27 		if (etd->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 (psmouse_sliced_command(psmouse, 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->hw_version) {
109 	case 1:
110 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_READ) ||
111 		    psmouse_sliced_command(psmouse, 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->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->hw_version) {
164 	case 1:
165 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_WRITE) ||
166 		    psmouse_sliced_command(psmouse, reg) ||
167 		    psmouse_sliced_command(psmouse, 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 	int	i;
226 
227 	psmouse_printk(KERN_DEBUG, psmouse, "PS/2 packet [");
228 	for (i = 0; i < psmouse->pktsize; i++)
229 		printk("%s0x%02x ", i ? ", " : " ", psmouse->packet[i]);
230 	printk("]\n");
231 }
232 
233 /*
234  * Interpret complete data packets and report absolute mode input events for
235  * hardware version 1. (4 byte packets)
236  */
237 static void elantech_report_absolute_v1(struct psmouse *psmouse)
238 {
239 	struct input_dev *dev = psmouse->dev;
240 	struct elantech_data *etd = psmouse->private;
241 	unsigned char *packet = psmouse->packet;
242 	int fingers;
243 
244 	if (etd->fw_version < 0x020000) {
245 		/*
246 		 * byte 0:  D   U  p1  p2   1  p3   R   L
247 		 * byte 1:  f   0  th  tw  x9  x8  y9  y8
248 		 */
249 		fingers = ((packet[1] & 0x80) >> 7) +
250 				((packet[1] & 0x30) >> 4);
251 	} else {
252 		/*
253 		 * byte 0: n1  n0  p2  p1   1  p3   R   L
254 		 * byte 1:  0   0   0   0  x9  x8  y9  y8
255 		 */
256 		fingers = (packet[0] & 0xc0) >> 6;
257 	}
258 
259 	if (etd->jumpy_cursor) {
260 		if (fingers != 1) {
261 			etd->single_finger_reports = 0;
262 		} else if (etd->single_finger_reports < 2) {
263 			/* Discard first 2 reports of one finger, bogus */
264 			etd->single_finger_reports++;
265 			elantech_debug("discarding packet\n");
266 			return;
267 		}
268 	}
269 
270 	input_report_key(dev, BTN_TOUCH, fingers != 0);
271 
272 	/*
273 	 * byte 2: x7  x6  x5  x4  x3  x2  x1  x0
274 	 * byte 3: y7  y6  y5  y4  y3  y2  y1  y0
275 	 */
276 	if (fingers) {
277 		input_report_abs(dev, ABS_X,
278 			((packet[1] & 0x0c) << 6) | packet[2]);
279 		input_report_abs(dev, ABS_Y,
280 			etd->y_max - (((packet[1] & 0x03) << 8) | packet[3]));
281 	}
282 
283 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
284 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
285 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
286 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
287 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
288 
289 	if (etd->fw_version < 0x020000 &&
290 	    (etd->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
291 		/* rocker up */
292 		input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
293 		/* rocker down */
294 		input_report_key(dev, BTN_BACK, packet[0] & 0x80);
295 	}
296 
297 	input_sync(dev);
298 }
299 
300 static void elantech_set_slot(struct input_dev *dev, int slot, bool active,
301 			      unsigned int x, unsigned int y)
302 {
303 	input_mt_slot(dev, slot);
304 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
305 	if (active) {
306 		input_report_abs(dev, ABS_MT_POSITION_X, x);
307 		input_report_abs(dev, ABS_MT_POSITION_Y, y);
308 	}
309 }
310 
311 /* x1 < x2 and y1 < y2 when two fingers, x = y = 0 when not pressed */
312 static void elantech_report_semi_mt_data(struct input_dev *dev,
313 					 unsigned int num_fingers,
314 					 unsigned int x1, unsigned int y1,
315 					 unsigned int x2, unsigned int y2)
316 {
317 	elantech_set_slot(dev, 0, num_fingers != 0, x1, y1);
318 	elantech_set_slot(dev, 1, num_fingers == 2, x2, y2);
319 }
320 
321 /*
322  * Interpret complete data packets and report absolute mode input events for
323  * hardware version 2. (6 byte packets)
324  */
325 static void elantech_report_absolute_v2(struct psmouse *psmouse)
326 {
327 	struct elantech_data *etd = psmouse->private;
328 	struct input_dev *dev = psmouse->dev;
329 	unsigned char *packet = psmouse->packet;
330 	unsigned int fingers, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
331 	unsigned int width = 0, pres = 0;
332 
333 	/* byte 0: n1  n0   .   .   .   .   R   L */
334 	fingers = (packet[0] & 0xc0) >> 6;
335 
336 	switch (fingers) {
337 	case 3:
338 		/*
339 		 * Same as one finger, except report of more than 3 fingers:
340 		 * byte 3:  n4  .   w1  w0   .   .   .   .
341 		 */
342 		if (packet[3] & 0x80)
343 			fingers = 4;
344 		/* pass through... */
345 	case 1:
346 		/*
347 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
348 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
349 		 */
350 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
351 		/*
352 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
353 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
354 		 */
355 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
356 
357 		pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
358 		width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
359 		break;
360 
361 	case 2:
362 		/*
363 		 * The coordinate of each finger is reported separately
364 		 * with a lower resolution for two finger touches:
365 		 * byte 0:  .   .  ay8 ax8  .   .   .   .
366 		 * byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
367 		 */
368 		x1 = (((packet[0] & 0x10) << 4) | packet[1]) << 2;
369 		/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
370 		y1 = etd->y_max -
371 			((((packet[0] & 0x20) << 3) | packet[2]) << 2);
372 		/*
373 		 * byte 3:  .   .  by8 bx8  .   .   .   .
374 		 * byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
375 		 */
376 		x2 = (((packet[3] & 0x10) << 4) | packet[4]) << 2;
377 		/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
378 		y2 = etd->y_max -
379 			((((packet[3] & 0x20) << 3) | packet[5]) << 2);
380 
381 		/* Unknown so just report sensible values */
382 		pres = 127;
383 		width = 7;
384 		break;
385 	}
386 
387 	input_report_key(dev, BTN_TOUCH, fingers != 0);
388 	if (fingers != 0) {
389 		input_report_abs(dev, ABS_X, x1);
390 		input_report_abs(dev, ABS_Y, y1);
391 	}
392 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
393 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
394 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
395 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
396 	input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
397 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
398 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
399 	if (etd->reports_pressure) {
400 		input_report_abs(dev, ABS_PRESSURE, pres);
401 		input_report_abs(dev, ABS_TOOL_WIDTH, width);
402 	}
403 
404 	input_sync(dev);
405 }
406 
407 static void elantech_report_trackpoint(struct psmouse *psmouse,
408 				       int packet_type)
409 {
410 	/*
411 	 * byte 0:  0   0  sx  sy   0   M   R   L
412 	 * byte 1:~sx   0   0   0   0   0   0   0
413 	 * byte 2:~sy   0   0   0   0   0   0   0
414 	 * byte 3:  0   0 ~sy ~sx   0   1   1   0
415 	 * byte 4: x7  x6  x5  x4  x3  x2  x1  x0
416 	 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
417 	 *
418 	 * x and y are written in two's complement spread
419 	 * over 9 bits with sx/sy the relative top bit and
420 	 * x7..x0 and y7..y0 the lower bits.
421 	 * The sign of y is opposite to what the input driver
422 	 * expects for a relative movement
423 	 */
424 
425 	struct elantech_data *etd = psmouse->private;
426 	struct input_dev *tp_dev = etd->tp_dev;
427 	unsigned char *packet = psmouse->packet;
428 	int x, y;
429 	u32 t;
430 
431 	if (dev_WARN_ONCE(&psmouse->ps2dev.serio->dev,
432 			  !tp_dev,
433 			  psmouse_fmt("Unexpected trackpoint message\n"))) {
434 		if (etd->debug == 1)
435 			elantech_packet_dump(psmouse);
436 		return;
437 	}
438 
439 	t = get_unaligned_le32(&packet[0]);
440 
441 	switch (t & ~7U) {
442 	case 0x06000030U:
443 	case 0x16008020U:
444 	case 0x26800010U:
445 	case 0x36808000U:
446 		x = packet[4] - (int)((packet[1]^0x80) << 1);
447 		y = (int)((packet[2]^0x80) << 1) - packet[5];
448 
449 		input_report_key(tp_dev, BTN_LEFT, packet[0] & 0x01);
450 		input_report_key(tp_dev, BTN_RIGHT, packet[0] & 0x02);
451 		input_report_key(tp_dev, BTN_MIDDLE, packet[0] & 0x04);
452 
453 		input_report_rel(tp_dev, REL_X, x);
454 		input_report_rel(tp_dev, REL_Y, y);
455 
456 		input_sync(tp_dev);
457 
458 		break;
459 
460 	default:
461 		/* Dump unexpected packet sequences if debug=1 (default) */
462 		if (etd->debug == 1)
463 			elantech_packet_dump(psmouse);
464 
465 		break;
466 	}
467 }
468 
469 /*
470  * Interpret complete data packets and report absolute mode input events for
471  * hardware version 3. (12 byte packets for two fingers)
472  */
473 static void elantech_report_absolute_v3(struct psmouse *psmouse,
474 					int packet_type)
475 {
476 	struct input_dev *dev = psmouse->dev;
477 	struct elantech_data *etd = psmouse->private;
478 	unsigned char *packet = psmouse->packet;
479 	unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
480 	unsigned int width = 0, pres = 0;
481 
482 	/* byte 0: n1  n0   .   .   .   .   R   L */
483 	fingers = (packet[0] & 0xc0) >> 6;
484 
485 	switch (fingers) {
486 	case 3:
487 	case 1:
488 		/*
489 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
490 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
491 		 */
492 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
493 		/*
494 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
495 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
496 		 */
497 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
498 		break;
499 
500 	case 2:
501 		if (packet_type == PACKET_V3_HEAD) {
502 			/*
503 			 * byte 1:   .    .    .    .  ax11 ax10 ax9  ax8
504 			 * byte 2: ax7  ax6  ax5  ax4  ax3  ax2  ax1  ax0
505 			 */
506 			etd->mt[0].x = ((packet[1] & 0x0f) << 8) | packet[2];
507 			/*
508 			 * byte 4:   .    .    .    .  ay11 ay10 ay9  ay8
509 			 * byte 5: ay7  ay6  ay5  ay4  ay3  ay2  ay1  ay0
510 			 */
511 			etd->mt[0].y = etd->y_max -
512 				(((packet[4] & 0x0f) << 8) | packet[5]);
513 			/*
514 			 * wait for next packet
515 			 */
516 			return;
517 		}
518 
519 		/* packet_type == PACKET_V3_TAIL */
520 		x1 = etd->mt[0].x;
521 		y1 = etd->mt[0].y;
522 		x2 = ((packet[1] & 0x0f) << 8) | packet[2];
523 		y2 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
524 		break;
525 	}
526 
527 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
528 	width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
529 
530 	input_report_key(dev, BTN_TOUCH, fingers != 0);
531 	if (fingers != 0) {
532 		input_report_abs(dev, ABS_X, x1);
533 		input_report_abs(dev, ABS_Y, y1);
534 	}
535 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
536 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
537 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
538 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
539 
540 	/* For clickpads map both buttons to BTN_LEFT */
541 	if (etd->fw_version & 0x001000) {
542 		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
543 	} else {
544 		input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
545 		input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
546 	}
547 
548 	input_report_abs(dev, ABS_PRESSURE, pres);
549 	input_report_abs(dev, ABS_TOOL_WIDTH, width);
550 
551 	input_sync(dev);
552 }
553 
554 static void elantech_input_sync_v4(struct psmouse *psmouse)
555 {
556 	struct input_dev *dev = psmouse->dev;
557 	struct elantech_data *etd = psmouse->private;
558 	unsigned char *packet = psmouse->packet;
559 
560 	/* For clickpads map both buttons to BTN_LEFT */
561 	if (etd->fw_version & 0x001000) {
562 		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
563 	} else {
564 		input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
565 		input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
566 		input_report_key(dev, BTN_MIDDLE, packet[0] & 0x04);
567 	}
568 
569 	input_mt_report_pointer_emulation(dev, true);
570 	input_sync(dev);
571 }
572 
573 static void process_packet_status_v4(struct psmouse *psmouse)
574 {
575 	struct input_dev *dev = psmouse->dev;
576 	unsigned char *packet = psmouse->packet;
577 	unsigned fingers;
578 	int i;
579 
580 	/* notify finger state change */
581 	fingers = packet[1] & 0x1f;
582 	for (i = 0; i < ETP_MAX_FINGERS; i++) {
583 		if ((fingers & (1 << i)) == 0) {
584 			input_mt_slot(dev, i);
585 			input_mt_report_slot_state(dev, MT_TOOL_FINGER, false);
586 		}
587 	}
588 
589 	elantech_input_sync_v4(psmouse);
590 }
591 
592 static void process_packet_head_v4(struct psmouse *psmouse)
593 {
594 	struct input_dev *dev = psmouse->dev;
595 	struct elantech_data *etd = psmouse->private;
596 	unsigned char *packet = psmouse->packet;
597 	int id = ((packet[3] & 0xe0) >> 5) - 1;
598 	int pres, traces;
599 
600 	if (id < 0)
601 		return;
602 
603 	etd->mt[id].x = ((packet[1] & 0x0f) << 8) | packet[2];
604 	etd->mt[id].y = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
605 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
606 	traces = (packet[0] & 0xf0) >> 4;
607 
608 	input_mt_slot(dev, id);
609 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, true);
610 
611 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
612 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
613 	input_report_abs(dev, ABS_MT_PRESSURE, pres);
614 	input_report_abs(dev, ABS_MT_TOUCH_MAJOR, traces * etd->width);
615 	/* report this for backwards compatibility */
616 	input_report_abs(dev, ABS_TOOL_WIDTH, traces);
617 
618 	elantech_input_sync_v4(psmouse);
619 }
620 
621 static void process_packet_motion_v4(struct psmouse *psmouse)
622 {
623 	struct input_dev *dev = psmouse->dev;
624 	struct elantech_data *etd = psmouse->private;
625 	unsigned char *packet = psmouse->packet;
626 	int weight, delta_x1 = 0, delta_y1 = 0, delta_x2 = 0, delta_y2 = 0;
627 	int id, sid;
628 
629 	id = ((packet[0] & 0xe0) >> 5) - 1;
630 	if (id < 0)
631 		return;
632 
633 	sid = ((packet[3] & 0xe0) >> 5) - 1;
634 	weight = (packet[0] & 0x10) ? ETP_WEIGHT_VALUE : 1;
635 	/*
636 	 * Motion packets give us the delta of x, y values of specific fingers,
637 	 * but in two's complement. Let the compiler do the conversion for us.
638 	 * Also _enlarge_ the numbers to int, in case of overflow.
639 	 */
640 	delta_x1 = (signed char)packet[1];
641 	delta_y1 = (signed char)packet[2];
642 	delta_x2 = (signed char)packet[4];
643 	delta_y2 = (signed char)packet[5];
644 
645 	etd->mt[id].x += delta_x1 * weight;
646 	etd->mt[id].y -= delta_y1 * weight;
647 	input_mt_slot(dev, id);
648 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
649 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
650 
651 	if (sid >= 0) {
652 		etd->mt[sid].x += delta_x2 * weight;
653 		etd->mt[sid].y -= delta_y2 * weight;
654 		input_mt_slot(dev, sid);
655 		input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[sid].x);
656 		input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[sid].y);
657 	}
658 
659 	elantech_input_sync_v4(psmouse);
660 }
661 
662 static void elantech_report_absolute_v4(struct psmouse *psmouse,
663 					int packet_type)
664 {
665 	switch (packet_type) {
666 	case PACKET_V4_STATUS:
667 		process_packet_status_v4(psmouse);
668 		break;
669 
670 	case PACKET_V4_HEAD:
671 		process_packet_head_v4(psmouse);
672 		break;
673 
674 	case PACKET_V4_MOTION:
675 		process_packet_motion_v4(psmouse);
676 		break;
677 
678 	case PACKET_UNKNOWN:
679 	default:
680 		/* impossible to get here */
681 		break;
682 	}
683 }
684 
685 static int elantech_packet_check_v1(struct psmouse *psmouse)
686 {
687 	struct elantech_data *etd = psmouse->private;
688 	unsigned char *packet = psmouse->packet;
689 	unsigned char p1, p2, p3;
690 
691 	/* Parity bits are placed differently */
692 	if (etd->fw_version < 0x020000) {
693 		/* byte 0:  D   U  p1  p2   1  p3   R   L */
694 		p1 = (packet[0] & 0x20) >> 5;
695 		p2 = (packet[0] & 0x10) >> 4;
696 	} else {
697 		/* byte 0: n1  n0  p2  p1   1  p3   R   L */
698 		p1 = (packet[0] & 0x10) >> 4;
699 		p2 = (packet[0] & 0x20) >> 5;
700 	}
701 
702 	p3 = (packet[0] & 0x04) >> 2;
703 
704 	return etd->parity[packet[1]] == p1 &&
705 	       etd->parity[packet[2]] == p2 &&
706 	       etd->parity[packet[3]] == p3;
707 }
708 
709 static int elantech_debounce_check_v2(struct psmouse *psmouse)
710 {
711         /*
712          * When we encounter packet that matches this exactly, it means the
713          * hardware is in debounce status. Just ignore the whole packet.
714          */
715         const u8 debounce_packet[] = { 0x84, 0xff, 0xff, 0x02, 0xff, 0xff };
716         unsigned char *packet = psmouse->packet;
717 
718         return !memcmp(packet, debounce_packet, sizeof(debounce_packet));
719 }
720 
721 static int elantech_packet_check_v2(struct psmouse *psmouse)
722 {
723 	struct elantech_data *etd = psmouse->private;
724 	unsigned char *packet = psmouse->packet;
725 
726 	/*
727 	 * V2 hardware has two flavors. Older ones that do not report pressure,
728 	 * and newer ones that reports pressure and width. With newer ones, all
729 	 * packets (1, 2, 3 finger touch) have the same constant bits. With
730 	 * older ones, 1/3 finger touch packets and 2 finger touch packets
731 	 * have different constant bits.
732 	 * With all three cases, if the constant bits are not exactly what I
733 	 * expected, I consider them invalid.
734 	 */
735 	if (etd->reports_pressure)
736 		return (packet[0] & 0x0c) == 0x04 &&
737 		       (packet[3] & 0x0f) == 0x02;
738 
739 	if ((packet[0] & 0xc0) == 0x80)
740 		return (packet[0] & 0x0c) == 0x0c &&
741 		       (packet[3] & 0x0e) == 0x08;
742 
743 	return (packet[0] & 0x3c) == 0x3c &&
744 	       (packet[1] & 0xf0) == 0x00 &&
745 	       (packet[3] & 0x3e) == 0x38 &&
746 	       (packet[4] & 0xf0) == 0x00;
747 }
748 
749 /*
750  * We check the constant bits to determine what packet type we get,
751  * so packet checking is mandatory for v3 and later hardware.
752  */
753 static int elantech_packet_check_v3(struct psmouse *psmouse)
754 {
755 	struct elantech_data *etd = psmouse->private;
756 	const u8 debounce_packet[] = { 0xc4, 0xff, 0xff, 0x02, 0xff, 0xff };
757 	unsigned char *packet = psmouse->packet;
758 
759 	/*
760 	 * check debounce first, it has the same signature in byte 0
761 	 * and byte 3 as PACKET_V3_HEAD.
762 	 */
763 	if (!memcmp(packet, debounce_packet, sizeof(debounce_packet)))
764 		return PACKET_DEBOUNCE;
765 
766 	/*
767 	 * If the hardware flag 'crc_enabled' is set the packets have
768 	 * different signatures.
769 	 */
770 	if (etd->crc_enabled) {
771 		if ((packet[3] & 0x09) == 0x08)
772 			return PACKET_V3_HEAD;
773 
774 		if ((packet[3] & 0x09) == 0x09)
775 			return PACKET_V3_TAIL;
776 	} else {
777 		if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
778 			return PACKET_V3_HEAD;
779 
780 		if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
781 			return PACKET_V3_TAIL;
782 		if ((packet[3] & 0x0f) == 0x06)
783 			return PACKET_TRACKPOINT;
784 	}
785 
786 	return PACKET_UNKNOWN;
787 }
788 
789 static int elantech_packet_check_v4(struct psmouse *psmouse)
790 {
791 	struct elantech_data *etd = psmouse->private;
792 	unsigned char *packet = psmouse->packet;
793 	unsigned char packet_type = packet[3] & 0x03;
794 	bool sanity_check;
795 
796 	if ((packet[3] & 0x0f) == 0x06)
797 		return PACKET_TRACKPOINT;
798 
799 	/*
800 	 * Sanity check based on the constant bits of a packet.
801 	 * The constant bits change depending on the value of
802 	 * the hardware flag 'crc_enabled' but are the same for
803 	 * every packet, regardless of the type.
804 	 */
805 	if (etd->crc_enabled)
806 		sanity_check = ((packet[3] & 0x08) == 0x00);
807 	else
808 		sanity_check = ((packet[0] & 0x0c) == 0x04 &&
809 				(packet[3] & 0x1c) == 0x10);
810 
811 	if (!sanity_check)
812 		return PACKET_UNKNOWN;
813 
814 	switch (packet_type) {
815 	case 0:
816 		return PACKET_V4_STATUS;
817 
818 	case 1:
819 		return PACKET_V4_HEAD;
820 
821 	case 2:
822 		return PACKET_V4_MOTION;
823 	}
824 
825 	return PACKET_UNKNOWN;
826 }
827 
828 /*
829  * Process byte stream from mouse and handle complete packets
830  */
831 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
832 {
833 	struct elantech_data *etd = psmouse->private;
834 	int packet_type;
835 
836 	if (psmouse->pktcnt < psmouse->pktsize)
837 		return PSMOUSE_GOOD_DATA;
838 
839 	if (etd->debug > 1)
840 		elantech_packet_dump(psmouse);
841 
842 	switch (etd->hw_version) {
843 	case 1:
844 		if (etd->paritycheck && !elantech_packet_check_v1(psmouse))
845 			return PSMOUSE_BAD_DATA;
846 
847 		elantech_report_absolute_v1(psmouse);
848 		break;
849 
850 	case 2:
851 		/* ignore debounce */
852 		if (elantech_debounce_check_v2(psmouse))
853 			return PSMOUSE_FULL_PACKET;
854 
855 		if (etd->paritycheck && !elantech_packet_check_v2(psmouse))
856 			return PSMOUSE_BAD_DATA;
857 
858 		elantech_report_absolute_v2(psmouse);
859 		break;
860 
861 	case 3:
862 		packet_type = elantech_packet_check_v3(psmouse);
863 		switch (packet_type) {
864 		case PACKET_UNKNOWN:
865 			return PSMOUSE_BAD_DATA;
866 
867 		case PACKET_DEBOUNCE:
868 			/* ignore debounce */
869 			break;
870 
871 		case PACKET_TRACKPOINT:
872 			elantech_report_trackpoint(psmouse, packet_type);
873 			break;
874 
875 		default:
876 			elantech_report_absolute_v3(psmouse, packet_type);
877 			break;
878 		}
879 
880 		break;
881 
882 	case 4:
883 		packet_type = elantech_packet_check_v4(psmouse);
884 		switch (packet_type) {
885 		case PACKET_UNKNOWN:
886 			return PSMOUSE_BAD_DATA;
887 
888 		case PACKET_TRACKPOINT:
889 			elantech_report_trackpoint(psmouse, packet_type);
890 			break;
891 
892 		default:
893 			elantech_report_absolute_v4(psmouse, packet_type);
894 			break;
895 		}
896 
897 		break;
898 	}
899 
900 	return PSMOUSE_FULL_PACKET;
901 }
902 
903 /*
904  * Put the touchpad into absolute mode
905  */
906 static int elantech_set_absolute_mode(struct psmouse *psmouse)
907 {
908 	struct elantech_data *etd = psmouse->private;
909 	unsigned char val;
910 	int tries = ETP_READ_BACK_TRIES;
911 	int rc = 0;
912 
913 	switch (etd->hw_version) {
914 	case 1:
915 		etd->reg_10 = 0x16;
916 		etd->reg_11 = 0x8f;
917 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
918 		    elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
919 			rc = -1;
920 		}
921 		break;
922 
923 	case 2:
924 					/* Windows driver values */
925 		etd->reg_10 = 0x54;
926 		etd->reg_11 = 0x88;	/* 0x8a */
927 		etd->reg_21 = 0x60;	/* 0x00 */
928 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
929 		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
930 		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
931 			rc = -1;
932 		}
933 		break;
934 
935 	case 3:
936 		if (etd->set_hw_resolution)
937 			etd->reg_10 = 0x0b;
938 		else
939 			etd->reg_10 = 0x01;
940 
941 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
942 			rc = -1;
943 
944 		break;
945 
946 	case 4:
947 		etd->reg_07 = 0x01;
948 		if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
949 			rc = -1;
950 
951 		goto skip_readback_reg_10; /* v4 has no reg 0x10 to read */
952 	}
953 
954 	if (rc == 0) {
955 		/*
956 		 * Read back reg 0x10. For hardware version 1 we must make
957 		 * sure the absolute mode bit is set. For hardware version 2
958 		 * the touchpad is probably initializing and not ready until
959 		 * we read back the value we just wrote.
960 		 */
961 		do {
962 			rc = elantech_read_reg(psmouse, 0x10, &val);
963 			if (rc == 0)
964 				break;
965 			tries--;
966 			elantech_debug("retrying read (%d).\n", tries);
967 			msleep(ETP_READ_BACK_DELAY);
968 		} while (tries > 0);
969 
970 		if (rc) {
971 			psmouse_err(psmouse,
972 				    "failed to read back register 0x10.\n");
973 		} else if (etd->hw_version == 1 &&
974 			   !(val & ETP_R10_ABSOLUTE_MODE)) {
975 			psmouse_err(psmouse,
976 				    "touchpad refuses to switch to absolute mode.\n");
977 			rc = -1;
978 		}
979 	}
980 
981  skip_readback_reg_10:
982 	if (rc)
983 		psmouse_err(psmouse, "failed to initialise registers.\n");
984 
985 	return rc;
986 }
987 
988 static int elantech_set_range(struct psmouse *psmouse,
989 			      unsigned int *x_min, unsigned int *y_min,
990 			      unsigned int *x_max, unsigned int *y_max,
991 			      unsigned int *width)
992 {
993 	struct elantech_data *etd = psmouse->private;
994 	unsigned char param[3];
995 	unsigned char traces;
996 
997 	switch (etd->hw_version) {
998 	case 1:
999 		*x_min = ETP_XMIN_V1;
1000 		*y_min = ETP_YMIN_V1;
1001 		*x_max = ETP_XMAX_V1;
1002 		*y_max = ETP_YMAX_V1;
1003 		break;
1004 
1005 	case 2:
1006 		if (etd->fw_version == 0x020800 ||
1007 		    etd->fw_version == 0x020b00 ||
1008 		    etd->fw_version == 0x020030) {
1009 			*x_min = ETP_XMIN_V2;
1010 			*y_min = ETP_YMIN_V2;
1011 			*x_max = ETP_XMAX_V2;
1012 			*y_max = ETP_YMAX_V2;
1013 		} else {
1014 			int i;
1015 			int fixed_dpi;
1016 
1017 			i = (etd->fw_version > 0x020800 &&
1018 			     etd->fw_version < 0x020900) ? 1 : 2;
1019 
1020 			if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1021 				return -1;
1022 
1023 			fixed_dpi = param[1] & 0x10;
1024 
1025 			if (((etd->fw_version >> 16) == 0x14) && fixed_dpi) {
1026 				if (etd->send_cmd(psmouse, ETP_SAMPLE_QUERY, param))
1027 					return -1;
1028 
1029 				*x_max = (etd->capabilities[1] - i) * param[1] / 2;
1030 				*y_max = (etd->capabilities[2] - i) * param[2] / 2;
1031 			} else if (etd->fw_version == 0x040216) {
1032 				*x_max = 819;
1033 				*y_max = 405;
1034 			} else if (etd->fw_version == 0x040219 || etd->fw_version == 0x040215) {
1035 				*x_max = 900;
1036 				*y_max = 500;
1037 			} else {
1038 				*x_max = (etd->capabilities[1] - i) * 64;
1039 				*y_max = (etd->capabilities[2] - i) * 64;
1040 			}
1041 		}
1042 		break;
1043 
1044 	case 3:
1045 		if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1046 			return -1;
1047 
1048 		*x_max = (0x0f & param[0]) << 8 | param[1];
1049 		*y_max = (0xf0 & param[0]) << 4 | param[2];
1050 		break;
1051 
1052 	case 4:
1053 		if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1054 			return -1;
1055 
1056 		*x_max = (0x0f & param[0]) << 8 | param[1];
1057 		*y_max = (0xf0 & param[0]) << 4 | param[2];
1058 		traces = etd->capabilities[1];
1059 		if ((traces < 2) || (traces > *x_max))
1060 			return -1;
1061 
1062 		*width = *x_max / (traces - 1);
1063 		break;
1064 	}
1065 
1066 	return 0;
1067 }
1068 
1069 /*
1070  * (value from firmware) * 10 + 790 = dpi
1071  * we also have to convert dpi to dots/mm (*10/254 to avoid floating point)
1072  */
1073 static unsigned int elantech_convert_res(unsigned int val)
1074 {
1075 	return (val * 10 + 790) * 10 / 254;
1076 }
1077 
1078 static int elantech_get_resolution_v4(struct psmouse *psmouse,
1079 				      unsigned int *x_res,
1080 				      unsigned int *y_res)
1081 {
1082 	unsigned char param[3];
1083 
1084 	if (elantech_send_cmd(psmouse, ETP_RESOLUTION_QUERY, param))
1085 		return -1;
1086 
1087 	*x_res = elantech_convert_res(param[1] & 0x0f);
1088 	*y_res = elantech_convert_res((param[1] & 0xf0) >> 4);
1089 
1090 	return 0;
1091 }
1092 
1093 /*
1094  * Advertise INPUT_PROP_BUTTONPAD for clickpads. The testing of bit 12 in
1095  * fw_version for this is based on the following fw_version & caps table:
1096  *
1097  * Laptop-model:           fw_version:     caps:           buttons:
1098  * Acer S3                 0x461f00        10, 13, 0e      clickpad
1099  * Acer S7-392             0x581f01        50, 17, 0d      clickpad
1100  * Acer V5-131             0x461f02        01, 16, 0c      clickpad
1101  * Acer V5-551             0x461f00        ?               clickpad
1102  * Asus K53SV              0x450f01        78, 15, 0c      2 hw buttons
1103  * Asus G46VW              0x460f02        00, 18, 0c      2 hw buttons
1104  * Asus G750JX             0x360f00        00, 16, 0c      2 hw buttons
1105  * Asus UX31               0x361f00        20, 15, 0e      clickpad
1106  * Asus UX32VD             0x361f02        00, 15, 0e      clickpad
1107  * Avatar AVIU-145A2       0x361f00        ?               clickpad
1108  * Fujitsu H730            0x570f00        c0, 14, 0c      3 hw buttons (**)
1109  * Gigabyte U2442          0x450f01        58, 17, 0c      2 hw buttons
1110  * Lenovo L430             0x350f02        b9, 15, 0c      2 hw buttons (*)
1111  * Lenovo L530             0x350f02        b9, 15, 0c      2 hw buttons (*)
1112  * Samsung NF210           0x150b00        78, 14, 0a      2 hw buttons
1113  * Samsung NP770Z5E        0x575f01        10, 15, 0f      clickpad
1114  * Samsung NP700Z5B        0x361f06        21, 15, 0f      clickpad
1115  * Samsung NP900X3E-A02    0x575f03        ?               clickpad
1116  * Samsung NP-QX410        0x851b00        19, 14, 0c      clickpad
1117  * Samsung RC512           0x450f00        08, 15, 0c      2 hw buttons
1118  * Samsung RF710           0x450f00        ?               2 hw buttons
1119  * System76 Pangolin       0x250f01        ?               2 hw buttons
1120  * (*) + 3 trackpoint buttons
1121  * (**) + 0 trackpoint buttons
1122  * Note: Lenovo L430 and Lenovo L430 have the same fw_version/caps
1123  */
1124 static void elantech_set_buttonpad_prop(struct psmouse *psmouse)
1125 {
1126 	struct input_dev *dev = psmouse->dev;
1127 	struct elantech_data *etd = psmouse->private;
1128 
1129 	if (etd->fw_version & 0x001000) {
1130 		__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
1131 		__clear_bit(BTN_RIGHT, dev->keybit);
1132 	}
1133 }
1134 
1135 /*
1136  * Some hw_version 4 models do have a middle button
1137  */
1138 static const struct dmi_system_id elantech_dmi_has_middle_button[] = {
1139 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1140 	{
1141 		/* Fujitsu H730 has a middle button */
1142 		.matches = {
1143 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1144 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H730"),
1145 		},
1146 	},
1147 #endif
1148 	{ }
1149 };
1150 
1151 /*
1152  * Set the appropriate event bits for the input subsystem
1153  */
1154 static int elantech_set_input_params(struct psmouse *psmouse)
1155 {
1156 	struct input_dev *dev = psmouse->dev;
1157 	struct elantech_data *etd = psmouse->private;
1158 	unsigned int x_min = 0, y_min = 0, x_max = 0, y_max = 0, width = 0;
1159 	unsigned int x_res = 0, y_res = 0;
1160 
1161 	if (elantech_set_range(psmouse, &x_min, &y_min, &x_max, &y_max, &width))
1162 		return -1;
1163 
1164 	__set_bit(INPUT_PROP_POINTER, dev->propbit);
1165 	__set_bit(EV_KEY, dev->evbit);
1166 	__set_bit(EV_ABS, dev->evbit);
1167 	__clear_bit(EV_REL, dev->evbit);
1168 
1169 	__set_bit(BTN_LEFT, dev->keybit);
1170 	if (dmi_check_system(elantech_dmi_has_middle_button))
1171 		__set_bit(BTN_MIDDLE, dev->keybit);
1172 	__set_bit(BTN_RIGHT, dev->keybit);
1173 
1174 	__set_bit(BTN_TOUCH, dev->keybit);
1175 	__set_bit(BTN_TOOL_FINGER, dev->keybit);
1176 	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
1177 	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
1178 
1179 	switch (etd->hw_version) {
1180 	case 1:
1181 		/* Rocker button */
1182 		if (etd->fw_version < 0x020000 &&
1183 		    (etd->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
1184 			__set_bit(BTN_FORWARD, dev->keybit);
1185 			__set_bit(BTN_BACK, dev->keybit);
1186 		}
1187 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1188 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1189 		break;
1190 
1191 	case 2:
1192 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1193 		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
1194 		/* fall through */
1195 	case 3:
1196 		if (etd->hw_version == 3)
1197 			elantech_set_buttonpad_prop(psmouse);
1198 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1199 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1200 		if (etd->reports_pressure) {
1201 			input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1202 					     ETP_PMAX_V2, 0, 0);
1203 			input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1204 					     ETP_WMAX_V2, 0, 0);
1205 		}
1206 		input_mt_init_slots(dev, 2, 0);
1207 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1208 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1209 		break;
1210 
1211 	case 4:
1212 		if (elantech_get_resolution_v4(psmouse, &x_res, &y_res)) {
1213 			/*
1214 			 * if query failed, print a warning and leave the values
1215 			 * zero to resemble synaptics.c behavior.
1216 			 */
1217 			psmouse_warn(psmouse, "couldn't query resolution data.\n");
1218 		}
1219 		elantech_set_buttonpad_prop(psmouse);
1220 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1221 		/* For X to recognize me as touchpad. */
1222 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1223 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1224 		input_abs_set_res(dev, ABS_X, x_res);
1225 		input_abs_set_res(dev, ABS_Y, y_res);
1226 		/*
1227 		 * range of pressure and width is the same as v2,
1228 		 * report ABS_PRESSURE, ABS_TOOL_WIDTH for compatibility.
1229 		 */
1230 		input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1231 				     ETP_PMAX_V2, 0, 0);
1232 		input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1233 				     ETP_WMAX_V2, 0, 0);
1234 		/* Multitouch capable pad, up to 5 fingers. */
1235 		input_mt_init_slots(dev, ETP_MAX_FINGERS, 0);
1236 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1237 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1238 		input_abs_set_res(dev, ABS_MT_POSITION_X, x_res);
1239 		input_abs_set_res(dev, ABS_MT_POSITION_Y, y_res);
1240 		input_set_abs_params(dev, ABS_MT_PRESSURE, ETP_PMIN_V2,
1241 				     ETP_PMAX_V2, 0, 0);
1242 		/*
1243 		 * The firmware reports how many trace lines the finger spans,
1244 		 * convert to surface unit as Protocol-B requires.
1245 		 */
1246 		input_set_abs_params(dev, ABS_MT_TOUCH_MAJOR, 0,
1247 				     ETP_WMAX_V2 * width, 0, 0);
1248 		break;
1249 	}
1250 
1251 	etd->y_max = y_max;
1252 	etd->width = width;
1253 
1254 	return 0;
1255 }
1256 
1257 struct elantech_attr_data {
1258 	size_t		field_offset;
1259 	unsigned char	reg;
1260 };
1261 
1262 /*
1263  * Display a register value by reading a sysfs entry
1264  */
1265 static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
1266 					char *buf)
1267 {
1268 	struct elantech_data *etd = psmouse->private;
1269 	struct elantech_attr_data *attr = data;
1270 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1271 	int rc = 0;
1272 
1273 	if (attr->reg)
1274 		rc = elantech_read_reg(psmouse, attr->reg, reg);
1275 
1276 	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
1277 }
1278 
1279 /*
1280  * Write a register value by writing a sysfs entry
1281  */
1282 static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
1283 				     void *data, const char *buf, size_t count)
1284 {
1285 	struct elantech_data *etd = psmouse->private;
1286 	struct elantech_attr_data *attr = data;
1287 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1288 	unsigned char value;
1289 	int err;
1290 
1291 	err = kstrtou8(buf, 16, &value);
1292 	if (err)
1293 		return err;
1294 
1295 	/* Do we need to preserve some bits for version 2 hardware too? */
1296 	if (etd->hw_version == 1) {
1297 		if (attr->reg == 0x10)
1298 			/* Force absolute mode always on */
1299 			value |= ETP_R10_ABSOLUTE_MODE;
1300 		else if (attr->reg == 0x11)
1301 			/* Force 4 byte mode always on */
1302 			value |= ETP_R11_4_BYTE_MODE;
1303 	}
1304 
1305 	if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
1306 		*reg = value;
1307 
1308 	return count;
1309 }
1310 
1311 #define ELANTECH_INT_ATTR(_name, _register)				\
1312 	static struct elantech_attr_data elantech_attr_##_name = {	\
1313 		.field_offset = offsetof(struct elantech_data, _name),	\
1314 		.reg = _register,					\
1315 	};								\
1316 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,			\
1317 			    &elantech_attr_##_name,			\
1318 			    elantech_show_int_attr,			\
1319 			    elantech_set_int_attr)
1320 
1321 ELANTECH_INT_ATTR(reg_07, 0x07);
1322 ELANTECH_INT_ATTR(reg_10, 0x10);
1323 ELANTECH_INT_ATTR(reg_11, 0x11);
1324 ELANTECH_INT_ATTR(reg_20, 0x20);
1325 ELANTECH_INT_ATTR(reg_21, 0x21);
1326 ELANTECH_INT_ATTR(reg_22, 0x22);
1327 ELANTECH_INT_ATTR(reg_23, 0x23);
1328 ELANTECH_INT_ATTR(reg_24, 0x24);
1329 ELANTECH_INT_ATTR(reg_25, 0x25);
1330 ELANTECH_INT_ATTR(reg_26, 0x26);
1331 ELANTECH_INT_ATTR(debug, 0);
1332 ELANTECH_INT_ATTR(paritycheck, 0);
1333 ELANTECH_INT_ATTR(crc_enabled, 0);
1334 
1335 static struct attribute *elantech_attrs[] = {
1336 	&psmouse_attr_reg_07.dattr.attr,
1337 	&psmouse_attr_reg_10.dattr.attr,
1338 	&psmouse_attr_reg_11.dattr.attr,
1339 	&psmouse_attr_reg_20.dattr.attr,
1340 	&psmouse_attr_reg_21.dattr.attr,
1341 	&psmouse_attr_reg_22.dattr.attr,
1342 	&psmouse_attr_reg_23.dattr.attr,
1343 	&psmouse_attr_reg_24.dattr.attr,
1344 	&psmouse_attr_reg_25.dattr.attr,
1345 	&psmouse_attr_reg_26.dattr.attr,
1346 	&psmouse_attr_debug.dattr.attr,
1347 	&psmouse_attr_paritycheck.dattr.attr,
1348 	&psmouse_attr_crc_enabled.dattr.attr,
1349 	NULL
1350 };
1351 
1352 static struct attribute_group elantech_attr_group = {
1353 	.attrs = elantech_attrs,
1354 };
1355 
1356 static bool elantech_is_signature_valid(const unsigned char *param)
1357 {
1358 	static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10 };
1359 	int i;
1360 
1361 	if (param[0] == 0)
1362 		return false;
1363 
1364 	if (param[1] == 0)
1365 		return true;
1366 
1367 	/*
1368 	 * Some models have a revision higher then 20. Meaning param[2] may
1369 	 * be 10 or 20, skip the rates check for these.
1370 	 */
1371 	if (param[0] == 0x46 && (param[1] & 0xef) == 0x0f && param[2] < 40)
1372 		return true;
1373 
1374 	for (i = 0; i < ARRAY_SIZE(rates); i++)
1375 		if (param[2] == rates[i])
1376 			return false;
1377 
1378 	return true;
1379 }
1380 
1381 /*
1382  * Use magic knock to detect Elantech touchpad
1383  */
1384 int elantech_detect(struct psmouse *psmouse, bool set_properties)
1385 {
1386 	struct ps2dev *ps2dev = &psmouse->ps2dev;
1387 	unsigned char param[3];
1388 
1389 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
1390 
1391 	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
1392 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1393 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1394 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1395 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
1396 		psmouse_dbg(psmouse, "sending Elantech magic knock failed.\n");
1397 		return -1;
1398 	}
1399 
1400 	/*
1401 	 * Report this in case there are Elantech models that use a different
1402 	 * set of magic numbers
1403 	 */
1404 	if (param[0] != 0x3c || param[1] != 0x03 ||
1405 	    (param[2] != 0xc8 && param[2] != 0x00)) {
1406 		psmouse_dbg(psmouse,
1407 			    "unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
1408 			    param[0], param[1], param[2]);
1409 		return -1;
1410 	}
1411 
1412 	/*
1413 	 * Query touchpad's firmware version and see if it reports known
1414 	 * value to avoid mis-detection. Logitech mice are known to respond
1415 	 * to Elantech magic knock and there might be more.
1416 	 */
1417 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1418 		psmouse_dbg(psmouse, "failed to query firmware version.\n");
1419 		return -1;
1420 	}
1421 
1422 	psmouse_dbg(psmouse,
1423 		    "Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
1424 		    param[0], param[1], param[2]);
1425 
1426 	if (!elantech_is_signature_valid(param)) {
1427 		psmouse_dbg(psmouse,
1428 			    "Probably not a real Elantech touchpad. Aborting.\n");
1429 		return -1;
1430 	}
1431 
1432 	if (set_properties) {
1433 		psmouse->vendor = "Elantech";
1434 		psmouse->name = "Touchpad";
1435 	}
1436 
1437 	return 0;
1438 }
1439 
1440 /*
1441  * Clean up sysfs entries when disconnecting
1442  */
1443 static void elantech_disconnect(struct psmouse *psmouse)
1444 {
1445 	struct elantech_data *etd = psmouse->private;
1446 
1447 	if (etd->tp_dev)
1448 		input_unregister_device(etd->tp_dev);
1449 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
1450 			   &elantech_attr_group);
1451 	kfree(psmouse->private);
1452 	psmouse->private = NULL;
1453 }
1454 
1455 /*
1456  * Put the touchpad back into absolute mode when reconnecting
1457  */
1458 static int elantech_reconnect(struct psmouse *psmouse)
1459 {
1460 	psmouse_reset(psmouse);
1461 
1462 	if (elantech_detect(psmouse, 0))
1463 		return -1;
1464 
1465 	if (elantech_set_absolute_mode(psmouse)) {
1466 		psmouse_err(psmouse,
1467 			    "failed to put touchpad back into absolute mode.\n");
1468 		return -1;
1469 	}
1470 
1471 	return 0;
1472 }
1473 
1474 /*
1475  * Some hw_version 4 models do not work with crc_disabled
1476  */
1477 static const struct dmi_system_id elantech_dmi_force_crc_enabled[] = {
1478 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1479 	{
1480 		/* Fujitsu H730 does not work with crc_enabled == 0 */
1481 		.matches = {
1482 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1483 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H730"),
1484 		},
1485 	},
1486 #endif
1487 	{ }
1488 };
1489 
1490 /*
1491  * Some hw_version 3 models go into error state when we try to set
1492  * bit 3 and/or bit 1 of r10.
1493  */
1494 static const struct dmi_system_id no_hw_res_dmi_table[] = {
1495 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1496 	{
1497 		/* Gigabyte U2442 */
1498 		.matches = {
1499 			DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
1500 			DMI_MATCH(DMI_PRODUCT_NAME, "U2442"),
1501 		},
1502 	},
1503 #endif
1504 	{ }
1505 };
1506 
1507 /*
1508  * determine hardware version and set some properties according to it.
1509  */
1510 static int elantech_set_properties(struct elantech_data *etd)
1511 {
1512 	/* This represents the version of IC body. */
1513 	int ver = (etd->fw_version & 0x0f0000) >> 16;
1514 
1515 	/* Early version of Elan touchpads doesn't obey the rule. */
1516 	if (etd->fw_version < 0x020030 || etd->fw_version == 0x020600)
1517 		etd->hw_version = 1;
1518 	else {
1519 		switch (ver) {
1520 		case 2:
1521 		case 4:
1522 			etd->hw_version = 2;
1523 			break;
1524 		case 5:
1525 			etd->hw_version = 3;
1526 			break;
1527 		case 6:
1528 		case 7:
1529 		case 8:
1530 		case 9:
1531 			etd->hw_version = 4;
1532 			break;
1533 		default:
1534 			return -1;
1535 		}
1536 	}
1537 
1538 	/* decide which send_cmd we're gonna use early */
1539 	etd->send_cmd = etd->hw_version >= 3 ? elantech_send_cmd :
1540 					       synaptics_send_cmd;
1541 
1542 	/* Turn on packet checking by default */
1543 	etd->paritycheck = 1;
1544 
1545 	/*
1546 	 * This firmware suffers from misreporting coordinates when
1547 	 * a touch action starts causing the mouse cursor or scrolled page
1548 	 * to jump. Enable a workaround.
1549 	 */
1550 	etd->jumpy_cursor =
1551 		(etd->fw_version == 0x020022 || etd->fw_version == 0x020600);
1552 
1553 	if (etd->hw_version > 1) {
1554 		/* For now show extra debug information */
1555 		etd->debug = 1;
1556 
1557 		if (etd->fw_version >= 0x020800)
1558 			etd->reports_pressure = true;
1559 	}
1560 
1561 	/*
1562 	 * The signatures of v3 and v4 packets change depending on the
1563 	 * value of this hardware flag.
1564 	 */
1565 	etd->crc_enabled = (etd->fw_version & 0x4000) == 0x4000 ||
1566 			   dmi_check_system(elantech_dmi_force_crc_enabled);
1567 
1568 	/* Enable real hardware resolution on hw_version 3 ? */
1569 	etd->set_hw_resolution = !dmi_check_system(no_hw_res_dmi_table);
1570 
1571 	return 0;
1572 }
1573 
1574 /*
1575  * Initialize the touchpad and create sysfs entries
1576  */
1577 int elantech_init(struct psmouse *psmouse)
1578 {
1579 	struct elantech_data *etd;
1580 	int i;
1581 	int error = -EINVAL;
1582 	unsigned char param[3];
1583 	struct input_dev *tp_dev;
1584 
1585 	psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
1586 	if (!etd)
1587 		return -ENOMEM;
1588 
1589 	psmouse_reset(psmouse);
1590 
1591 	etd->parity[0] = 1;
1592 	for (i = 1; i < 256; i++)
1593 		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
1594 
1595 	/*
1596 	 * Do the version query again so we can store the result
1597 	 */
1598 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1599 		psmouse_err(psmouse, "failed to query firmware version.\n");
1600 		goto init_fail;
1601 	}
1602 	etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
1603 
1604 	if (elantech_set_properties(etd)) {
1605 		psmouse_err(psmouse, "unknown hardware version, aborting...\n");
1606 		goto init_fail;
1607 	}
1608 	psmouse_info(psmouse,
1609 		     "assuming hardware version %d (with firmware version 0x%02x%02x%02x)\n",
1610 		     etd->hw_version, param[0], param[1], param[2]);
1611 
1612 	if (etd->send_cmd(psmouse, ETP_CAPABILITIES_QUERY,
1613 	    etd->capabilities)) {
1614 		psmouse_err(psmouse, "failed to query capabilities.\n");
1615 		goto init_fail;
1616 	}
1617 	psmouse_info(psmouse,
1618 		     "Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
1619 		     etd->capabilities[0], etd->capabilities[1],
1620 		     etd->capabilities[2]);
1621 
1622 	if (elantech_set_absolute_mode(psmouse)) {
1623 		psmouse_err(psmouse,
1624 			    "failed to put touchpad into absolute mode.\n");
1625 		goto init_fail;
1626 	}
1627 
1628 	if (elantech_set_input_params(psmouse)) {
1629 		psmouse_err(psmouse, "failed to query touchpad range.\n");
1630 		goto init_fail;
1631 	}
1632 
1633 	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
1634 				   &elantech_attr_group);
1635 	if (error) {
1636 		psmouse_err(psmouse,
1637 			    "failed to create sysfs attributes, error: %d.\n",
1638 			    error);
1639 		goto init_fail;
1640 	}
1641 
1642 	/* The MSB indicates the presence of the trackpoint */
1643 	if ((etd->capabilities[0] & 0x80) == 0x80) {
1644 		tp_dev = input_allocate_device();
1645 
1646 		if (!tp_dev) {
1647 			error = -ENOMEM;
1648 			goto init_fail_tp_alloc;
1649 		}
1650 
1651 		etd->tp_dev = tp_dev;
1652 		snprintf(etd->tp_phys, sizeof(etd->tp_phys), "%s/input1",
1653 			psmouse->ps2dev.serio->phys);
1654 		tp_dev->phys = etd->tp_phys;
1655 		tp_dev->name = "Elantech PS/2 TrackPoint";
1656 		tp_dev->id.bustype = BUS_I8042;
1657 		tp_dev->id.vendor  = 0x0002;
1658 		tp_dev->id.product = PSMOUSE_ELANTECH;
1659 		tp_dev->id.version = 0x0000;
1660 		tp_dev->dev.parent = &psmouse->ps2dev.serio->dev;
1661 		tp_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
1662 		tp_dev->relbit[BIT_WORD(REL_X)] =
1663 			BIT_MASK(REL_X) | BIT_MASK(REL_Y);
1664 		tp_dev->keybit[BIT_WORD(BTN_LEFT)] =
1665 			BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_MIDDLE) |
1666 			BIT_MASK(BTN_RIGHT);
1667 
1668 		__set_bit(INPUT_PROP_POINTER, tp_dev->propbit);
1669 		__set_bit(INPUT_PROP_POINTING_STICK, tp_dev->propbit);
1670 
1671 		error = input_register_device(etd->tp_dev);
1672 		if (error < 0)
1673 			goto init_fail_tp_reg;
1674 	}
1675 
1676 	psmouse->protocol_handler = elantech_process_byte;
1677 	psmouse->disconnect = elantech_disconnect;
1678 	psmouse->reconnect = elantech_reconnect;
1679 	psmouse->pktsize = etd->hw_version > 1 ? 6 : 4;
1680 
1681 	return 0;
1682  init_fail_tp_reg:
1683 	input_free_device(tp_dev);
1684  init_fail_tp_alloc:
1685 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
1686 			   &elantech_attr_group);
1687  init_fail:
1688 	psmouse_reset(psmouse);
1689 	kfree(etd);
1690 	return error;
1691 }
1692