xref: /openbmc/linux/drivers/input/mouse/elantech.c (revision 588b48ca)
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 "psmouse.h"
22 #include "elantech.h"
23 
24 #define elantech_debug(fmt, ...)					\
25 	do {								\
26 		if (etd->debug)						\
27 			psmouse_printk(KERN_DEBUG, psmouse,		\
28 					fmt, ##__VA_ARGS__);		\
29 	} while (0)
30 
31 /*
32  * Send a Synaptics style sliced query command
33  */
34 static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
35 				unsigned char *param)
36 {
37 	if (psmouse_sliced_command(psmouse, c) ||
38 	    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
39 		psmouse_err(psmouse, "%s query 0x%02x failed.\n", __func__, c);
40 		return -1;
41 	}
42 
43 	return 0;
44 }
45 
46 /*
47  * V3 and later support this fast command
48  */
49 static int elantech_send_cmd(struct psmouse *psmouse, unsigned char c,
50 				unsigned char *param)
51 {
52 	struct ps2dev *ps2dev = &psmouse->ps2dev;
53 
54 	if (ps2_command(ps2dev, NULL, ETP_PS2_CUSTOM_COMMAND) ||
55 	    ps2_command(ps2dev, NULL, c) ||
56 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
57 		psmouse_err(psmouse, "%s query 0x%02x failed.\n", __func__, c);
58 		return -1;
59 	}
60 
61 	return 0;
62 }
63 
64 /*
65  * A retrying version of ps2_command
66  */
67 static int elantech_ps2_command(struct psmouse *psmouse,
68 				unsigned char *param, int command)
69 {
70 	struct ps2dev *ps2dev = &psmouse->ps2dev;
71 	struct elantech_data *etd = psmouse->private;
72 	int rc;
73 	int tries = ETP_PS2_COMMAND_TRIES;
74 
75 	do {
76 		rc = ps2_command(ps2dev, param, command);
77 		if (rc == 0)
78 			break;
79 		tries--;
80 		elantech_debug("retrying ps2 command 0x%02x (%d).\n",
81 				command, tries);
82 		msleep(ETP_PS2_COMMAND_DELAY);
83 	} while (tries > 0);
84 
85 	if (rc)
86 		psmouse_err(psmouse, "ps2 command 0x%02x failed.\n", command);
87 
88 	return rc;
89 }
90 
91 /*
92  * Send an Elantech style special command to read a value from a register
93  */
94 static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
95 				unsigned char *val)
96 {
97 	struct elantech_data *etd = psmouse->private;
98 	unsigned char param[3];
99 	int rc = 0;
100 
101 	if (reg < 0x07 || reg > 0x26)
102 		return -1;
103 
104 	if (reg > 0x11 && reg < 0x20)
105 		return -1;
106 
107 	switch (etd->hw_version) {
108 	case 1:
109 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_READ) ||
110 		    psmouse_sliced_command(psmouse, reg) ||
111 		    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
112 			rc = -1;
113 		}
114 		break;
115 
116 	case 2:
117 		if (elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
118 		    elantech_ps2_command(psmouse,  NULL, ETP_REGISTER_READ) ||
119 		    elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
120 		    elantech_ps2_command(psmouse,  NULL, reg) ||
121 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
122 			rc = -1;
123 		}
124 		break;
125 
126 	case 3 ... 4:
127 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
128 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
129 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
130 		    elantech_ps2_command(psmouse, NULL, reg) ||
131 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
132 			rc = -1;
133 		}
134 		break;
135 	}
136 
137 	if (rc)
138 		psmouse_err(psmouse, "failed to read register 0x%02x.\n", reg);
139 	else if (etd->hw_version != 4)
140 		*val = param[0];
141 	else
142 		*val = param[1];
143 
144 	return rc;
145 }
146 
147 /*
148  * Send an Elantech style special command to write a register with a value
149  */
150 static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
151 				unsigned char val)
152 {
153 	struct elantech_data *etd = psmouse->private;
154 	int rc = 0;
155 
156 	if (reg < 0x07 || reg > 0x26)
157 		return -1;
158 
159 	if (reg > 0x11 && reg < 0x20)
160 		return -1;
161 
162 	switch (etd->hw_version) {
163 	case 1:
164 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_WRITE) ||
165 		    psmouse_sliced_command(psmouse, reg) ||
166 		    psmouse_sliced_command(psmouse, val) ||
167 		    ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
168 			rc = -1;
169 		}
170 		break;
171 
172 	case 2:
173 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
174 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
175 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
176 		    elantech_ps2_command(psmouse, NULL, reg) ||
177 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
178 		    elantech_ps2_command(psmouse, NULL, val) ||
179 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
180 			rc = -1;
181 		}
182 		break;
183 
184 	case 3:
185 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
186 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
187 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
188 		    elantech_ps2_command(psmouse, NULL, reg) ||
189 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
190 		    elantech_ps2_command(psmouse, NULL, val) ||
191 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
192 			rc = -1;
193 		}
194 		break;
195 
196 	case 4:
197 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
198 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
199 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
200 		    elantech_ps2_command(psmouse, NULL, reg) ||
201 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
202 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
203 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
204 		    elantech_ps2_command(psmouse, NULL, val) ||
205 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
206 			rc = -1;
207 		}
208 		break;
209 	}
210 
211 	if (rc)
212 		psmouse_err(psmouse,
213 			    "failed to write register 0x%02x with value 0x%02x.\n",
214 			    reg, val);
215 
216 	return rc;
217 }
218 
219 /*
220  * Dump a complete mouse movement packet to the syslog
221  */
222 static void elantech_packet_dump(struct psmouse *psmouse)
223 {
224 	int	i;
225 
226 	psmouse_printk(KERN_DEBUG, psmouse, "PS/2 packet [");
227 	for (i = 0; i < psmouse->pktsize; i++)
228 		printk("%s0x%02x ", i ? ", " : " ", psmouse->packet[i]);
229 	printk("]\n");
230 }
231 
232 /*
233  * Interpret complete data packets and report absolute mode input events for
234  * hardware version 1. (4 byte packets)
235  */
236 static void elantech_report_absolute_v1(struct psmouse *psmouse)
237 {
238 	struct input_dev *dev = psmouse->dev;
239 	struct elantech_data *etd = psmouse->private;
240 	unsigned char *packet = psmouse->packet;
241 	int fingers;
242 
243 	if (etd->fw_version < 0x020000) {
244 		/*
245 		 * byte 0:  D   U  p1  p2   1  p3   R   L
246 		 * byte 1:  f   0  th  tw  x9  x8  y9  y8
247 		 */
248 		fingers = ((packet[1] & 0x80) >> 7) +
249 				((packet[1] & 0x30) >> 4);
250 	} else {
251 		/*
252 		 * byte 0: n1  n0  p2  p1   1  p3   R   L
253 		 * byte 1:  0   0   0   0  x9  x8  y9  y8
254 		 */
255 		fingers = (packet[0] & 0xc0) >> 6;
256 	}
257 
258 	if (etd->jumpy_cursor) {
259 		if (fingers != 1) {
260 			etd->single_finger_reports = 0;
261 		} else if (etd->single_finger_reports < 2) {
262 			/* Discard first 2 reports of one finger, bogus */
263 			etd->single_finger_reports++;
264 			elantech_debug("discarding packet\n");
265 			return;
266 		}
267 	}
268 
269 	input_report_key(dev, BTN_TOUCH, fingers != 0);
270 
271 	/*
272 	 * byte 2: x7  x6  x5  x4  x3  x2  x1  x0
273 	 * byte 3: y7  y6  y5  y4  y3  y2  y1  y0
274 	 */
275 	if (fingers) {
276 		input_report_abs(dev, ABS_X,
277 			((packet[1] & 0x0c) << 6) | packet[2]);
278 		input_report_abs(dev, ABS_Y,
279 			etd->y_max - (((packet[1] & 0x03) << 8) | packet[3]));
280 	}
281 
282 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
283 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
284 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
285 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
286 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
287 
288 	if (etd->fw_version < 0x020000 &&
289 	    (etd->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
290 		/* rocker up */
291 		input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
292 		/* rocker down */
293 		input_report_key(dev, BTN_BACK, packet[0] & 0x80);
294 	}
295 
296 	input_sync(dev);
297 }
298 
299 static void elantech_set_slot(struct input_dev *dev, int slot, bool active,
300 			      unsigned int x, unsigned int y)
301 {
302 	input_mt_slot(dev, slot);
303 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
304 	if (active) {
305 		input_report_abs(dev, ABS_MT_POSITION_X, x);
306 		input_report_abs(dev, ABS_MT_POSITION_Y, y);
307 	}
308 }
309 
310 /* x1 < x2 and y1 < y2 when two fingers, x = y = 0 when not pressed */
311 static void elantech_report_semi_mt_data(struct input_dev *dev,
312 					 unsigned int num_fingers,
313 					 unsigned int x1, unsigned int y1,
314 					 unsigned int x2, unsigned int y2)
315 {
316 	elantech_set_slot(dev, 0, num_fingers != 0, x1, y1);
317 	elantech_set_slot(dev, 1, num_fingers == 2, x2, y2);
318 }
319 
320 /*
321  * Interpret complete data packets and report absolute mode input events for
322  * hardware version 2. (6 byte packets)
323  */
324 static void elantech_report_absolute_v2(struct psmouse *psmouse)
325 {
326 	struct elantech_data *etd = psmouse->private;
327 	struct input_dev *dev = psmouse->dev;
328 	unsigned char *packet = psmouse->packet;
329 	unsigned int fingers, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
330 	unsigned int width = 0, pres = 0;
331 
332 	/* byte 0: n1  n0   .   .   .   .   R   L */
333 	fingers = (packet[0] & 0xc0) >> 6;
334 
335 	switch (fingers) {
336 	case 3:
337 		/*
338 		 * Same as one finger, except report of more than 3 fingers:
339 		 * byte 3:  n4  .   w1  w0   .   .   .   .
340 		 */
341 		if (packet[3] & 0x80)
342 			fingers = 4;
343 		/* pass through... */
344 	case 1:
345 		/*
346 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
347 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
348 		 */
349 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
350 		/*
351 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
352 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
353 		 */
354 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
355 
356 		pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
357 		width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
358 		break;
359 
360 	case 2:
361 		/*
362 		 * The coordinate of each finger is reported separately
363 		 * with a lower resolution for two finger touches:
364 		 * byte 0:  .   .  ay8 ax8  .   .   .   .
365 		 * byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
366 		 */
367 		x1 = (((packet[0] & 0x10) << 4) | packet[1]) << 2;
368 		/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
369 		y1 = etd->y_max -
370 			((((packet[0] & 0x20) << 3) | packet[2]) << 2);
371 		/*
372 		 * byte 3:  .   .  by8 bx8  .   .   .   .
373 		 * byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
374 		 */
375 		x2 = (((packet[3] & 0x10) << 4) | packet[4]) << 2;
376 		/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
377 		y2 = etd->y_max -
378 			((((packet[3] & 0x20) << 3) | packet[5]) << 2);
379 
380 		/* Unknown so just report sensible values */
381 		pres = 127;
382 		width = 7;
383 		break;
384 	}
385 
386 	input_report_key(dev, BTN_TOUCH, fingers != 0);
387 	if (fingers != 0) {
388 		input_report_abs(dev, ABS_X, x1);
389 		input_report_abs(dev, ABS_Y, y1);
390 	}
391 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
392 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
393 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
394 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
395 	input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
396 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
397 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
398 	if (etd->reports_pressure) {
399 		input_report_abs(dev, ABS_PRESSURE, pres);
400 		input_report_abs(dev, ABS_TOOL_WIDTH, width);
401 	}
402 
403 	input_sync(dev);
404 }
405 
406 /*
407  * Interpret complete data packets and report absolute mode input events for
408  * hardware version 3. (12 byte packets for two fingers)
409  */
410 static void elantech_report_absolute_v3(struct psmouse *psmouse,
411 					int packet_type)
412 {
413 	struct input_dev *dev = psmouse->dev;
414 	struct elantech_data *etd = psmouse->private;
415 	unsigned char *packet = psmouse->packet;
416 	unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
417 	unsigned int width = 0, pres = 0;
418 
419 	/* byte 0: n1  n0   .   .   .   .   R   L */
420 	fingers = (packet[0] & 0xc0) >> 6;
421 
422 	switch (fingers) {
423 	case 3:
424 	case 1:
425 		/*
426 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
427 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
428 		 */
429 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
430 		/*
431 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
432 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
433 		 */
434 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
435 		break;
436 
437 	case 2:
438 		if (packet_type == PACKET_V3_HEAD) {
439 			/*
440 			 * byte 1:   .    .    .    .  ax11 ax10 ax9  ax8
441 			 * byte 2: ax7  ax6  ax5  ax4  ax3  ax2  ax1  ax0
442 			 */
443 			etd->mt[0].x = ((packet[1] & 0x0f) << 8) | packet[2];
444 			/*
445 			 * byte 4:   .    .    .    .  ay11 ay10 ay9  ay8
446 			 * byte 5: ay7  ay6  ay5  ay4  ay3  ay2  ay1  ay0
447 			 */
448 			etd->mt[0].y = etd->y_max -
449 				(((packet[4] & 0x0f) << 8) | packet[5]);
450 			/*
451 			 * wait for next packet
452 			 */
453 			return;
454 		}
455 
456 		/* packet_type == PACKET_V3_TAIL */
457 		x1 = etd->mt[0].x;
458 		y1 = etd->mt[0].y;
459 		x2 = ((packet[1] & 0x0f) << 8) | packet[2];
460 		y2 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
461 		break;
462 	}
463 
464 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
465 	width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
466 
467 	input_report_key(dev, BTN_TOUCH, fingers != 0);
468 	if (fingers != 0) {
469 		input_report_abs(dev, ABS_X, x1);
470 		input_report_abs(dev, ABS_Y, y1);
471 	}
472 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
473 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
474 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
475 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
476 
477 	/* For clickpads map both buttons to BTN_LEFT */
478 	if (etd->fw_version & 0x001000) {
479 		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
480 	} else {
481 		input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
482 		input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
483 	}
484 
485 	input_report_abs(dev, ABS_PRESSURE, pres);
486 	input_report_abs(dev, ABS_TOOL_WIDTH, width);
487 
488 	input_sync(dev);
489 }
490 
491 static void elantech_input_sync_v4(struct psmouse *psmouse)
492 {
493 	struct input_dev *dev = psmouse->dev;
494 	struct elantech_data *etd = psmouse->private;
495 	unsigned char *packet = psmouse->packet;
496 
497 	/* For clickpads map both buttons to BTN_LEFT */
498 	if (etd->fw_version & 0x001000) {
499 		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
500 	} else {
501 		input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
502 		input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
503 	}
504 
505 	input_mt_report_pointer_emulation(dev, true);
506 	input_sync(dev);
507 }
508 
509 static void process_packet_status_v4(struct psmouse *psmouse)
510 {
511 	struct input_dev *dev = psmouse->dev;
512 	unsigned char *packet = psmouse->packet;
513 	unsigned fingers;
514 	int i;
515 
516 	/* notify finger state change */
517 	fingers = packet[1] & 0x1f;
518 	for (i = 0; i < ETP_MAX_FINGERS; i++) {
519 		if ((fingers & (1 << i)) == 0) {
520 			input_mt_slot(dev, i);
521 			input_mt_report_slot_state(dev, MT_TOOL_FINGER, false);
522 		}
523 	}
524 
525 	elantech_input_sync_v4(psmouse);
526 }
527 
528 static void process_packet_head_v4(struct psmouse *psmouse)
529 {
530 	struct input_dev *dev = psmouse->dev;
531 	struct elantech_data *etd = psmouse->private;
532 	unsigned char *packet = psmouse->packet;
533 	int id = ((packet[3] & 0xe0) >> 5) - 1;
534 	int pres, traces;
535 
536 	if (id < 0)
537 		return;
538 
539 	etd->mt[id].x = ((packet[1] & 0x0f) << 8) | packet[2];
540 	etd->mt[id].y = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
541 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
542 	traces = (packet[0] & 0xf0) >> 4;
543 
544 	input_mt_slot(dev, id);
545 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, true);
546 
547 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
548 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
549 	input_report_abs(dev, ABS_MT_PRESSURE, pres);
550 	input_report_abs(dev, ABS_MT_TOUCH_MAJOR, traces * etd->width);
551 	/* report this for backwards compatibility */
552 	input_report_abs(dev, ABS_TOOL_WIDTH, traces);
553 
554 	elantech_input_sync_v4(psmouse);
555 }
556 
557 static void process_packet_motion_v4(struct psmouse *psmouse)
558 {
559 	struct input_dev *dev = psmouse->dev;
560 	struct elantech_data *etd = psmouse->private;
561 	unsigned char *packet = psmouse->packet;
562 	int weight, delta_x1 = 0, delta_y1 = 0, delta_x2 = 0, delta_y2 = 0;
563 	int id, sid;
564 
565 	id = ((packet[0] & 0xe0) >> 5) - 1;
566 	if (id < 0)
567 		return;
568 
569 	sid = ((packet[3] & 0xe0) >> 5) - 1;
570 	weight = (packet[0] & 0x10) ? ETP_WEIGHT_VALUE : 1;
571 	/*
572 	 * Motion packets give us the delta of x, y values of specific fingers,
573 	 * but in two's complement. Let the compiler do the conversion for us.
574 	 * Also _enlarge_ the numbers to int, in case of overflow.
575 	 */
576 	delta_x1 = (signed char)packet[1];
577 	delta_y1 = (signed char)packet[2];
578 	delta_x2 = (signed char)packet[4];
579 	delta_y2 = (signed char)packet[5];
580 
581 	etd->mt[id].x += delta_x1 * weight;
582 	etd->mt[id].y -= delta_y1 * weight;
583 	input_mt_slot(dev, id);
584 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
585 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
586 
587 	if (sid >= 0) {
588 		etd->mt[sid].x += delta_x2 * weight;
589 		etd->mt[sid].y -= delta_y2 * weight;
590 		input_mt_slot(dev, sid);
591 		input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[sid].x);
592 		input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[sid].y);
593 	}
594 
595 	elantech_input_sync_v4(psmouse);
596 }
597 
598 static void elantech_report_absolute_v4(struct psmouse *psmouse,
599 					int packet_type)
600 {
601 	switch (packet_type) {
602 	case PACKET_V4_STATUS:
603 		process_packet_status_v4(psmouse);
604 		break;
605 
606 	case PACKET_V4_HEAD:
607 		process_packet_head_v4(psmouse);
608 		break;
609 
610 	case PACKET_V4_MOTION:
611 		process_packet_motion_v4(psmouse);
612 		break;
613 
614 	case PACKET_UNKNOWN:
615 	default:
616 		/* impossible to get here */
617 		break;
618 	}
619 }
620 
621 static int elantech_packet_check_v1(struct psmouse *psmouse)
622 {
623 	struct elantech_data *etd = psmouse->private;
624 	unsigned char *packet = psmouse->packet;
625 	unsigned char p1, p2, p3;
626 
627 	/* Parity bits are placed differently */
628 	if (etd->fw_version < 0x020000) {
629 		/* byte 0:  D   U  p1  p2   1  p3   R   L */
630 		p1 = (packet[0] & 0x20) >> 5;
631 		p2 = (packet[0] & 0x10) >> 4;
632 	} else {
633 		/* byte 0: n1  n0  p2  p1   1  p3   R   L */
634 		p1 = (packet[0] & 0x10) >> 4;
635 		p2 = (packet[0] & 0x20) >> 5;
636 	}
637 
638 	p3 = (packet[0] & 0x04) >> 2;
639 
640 	return etd->parity[packet[1]] == p1 &&
641 	       etd->parity[packet[2]] == p2 &&
642 	       etd->parity[packet[3]] == p3;
643 }
644 
645 static int elantech_debounce_check_v2(struct psmouse *psmouse)
646 {
647         /*
648          * When we encounter packet that matches this exactly, it means the
649          * hardware is in debounce status. Just ignore the whole packet.
650          */
651         const u8 debounce_packet[] = { 0x84, 0xff, 0xff, 0x02, 0xff, 0xff };
652         unsigned char *packet = psmouse->packet;
653 
654         return !memcmp(packet, debounce_packet, sizeof(debounce_packet));
655 }
656 
657 static int elantech_packet_check_v2(struct psmouse *psmouse)
658 {
659 	struct elantech_data *etd = psmouse->private;
660 	unsigned char *packet = psmouse->packet;
661 
662 	/*
663 	 * V2 hardware has two flavors. Older ones that do not report pressure,
664 	 * and newer ones that reports pressure and width. With newer ones, all
665 	 * packets (1, 2, 3 finger touch) have the same constant bits. With
666 	 * older ones, 1/3 finger touch packets and 2 finger touch packets
667 	 * have different constant bits.
668 	 * With all three cases, if the constant bits are not exactly what I
669 	 * expected, I consider them invalid.
670 	 */
671 	if (etd->reports_pressure)
672 		return (packet[0] & 0x0c) == 0x04 &&
673 		       (packet[3] & 0x0f) == 0x02;
674 
675 	if ((packet[0] & 0xc0) == 0x80)
676 		return (packet[0] & 0x0c) == 0x0c &&
677 		       (packet[3] & 0x0e) == 0x08;
678 
679 	return (packet[0] & 0x3c) == 0x3c &&
680 	       (packet[1] & 0xf0) == 0x00 &&
681 	       (packet[3] & 0x3e) == 0x38 &&
682 	       (packet[4] & 0xf0) == 0x00;
683 }
684 
685 /*
686  * We check the constant bits to determine what packet type we get,
687  * so packet checking is mandatory for v3 and later hardware.
688  */
689 static int elantech_packet_check_v3(struct psmouse *psmouse)
690 {
691 	struct elantech_data *etd = psmouse->private;
692 	const u8 debounce_packet[] = { 0xc4, 0xff, 0xff, 0x02, 0xff, 0xff };
693 	unsigned char *packet = psmouse->packet;
694 
695 	/*
696 	 * check debounce first, it has the same signature in byte 0
697 	 * and byte 3 as PACKET_V3_HEAD.
698 	 */
699 	if (!memcmp(packet, debounce_packet, sizeof(debounce_packet)))
700 		return PACKET_DEBOUNCE;
701 
702 	/*
703 	 * If the hardware flag 'crc_enabled' is set the packets have
704 	 * different signatures.
705 	 */
706 	if (etd->crc_enabled) {
707 		if ((packet[3] & 0x09) == 0x08)
708 			return PACKET_V3_HEAD;
709 
710 		if ((packet[3] & 0x09) == 0x09)
711 			return PACKET_V3_TAIL;
712 	} else {
713 		if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
714 			return PACKET_V3_HEAD;
715 
716 		if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
717 			return PACKET_V3_TAIL;
718 	}
719 
720 	return PACKET_UNKNOWN;
721 }
722 
723 static int elantech_packet_check_v4(struct psmouse *psmouse)
724 {
725 	struct elantech_data *etd = psmouse->private;
726 	unsigned char *packet = psmouse->packet;
727 	unsigned char packet_type = packet[3] & 0x03;
728 	bool sanity_check;
729 
730 	/*
731 	 * Sanity check based on the constant bits of a packet.
732 	 * The constant bits change depending on the value of
733 	 * the hardware flag 'crc_enabled' but are the same for
734 	 * every packet, regardless of the type.
735 	 */
736 	if (etd->crc_enabled)
737 		sanity_check = ((packet[3] & 0x08) == 0x00);
738 	else
739 		sanity_check = ((packet[0] & 0x0c) == 0x04 &&
740 				(packet[3] & 0x1c) == 0x10);
741 
742 	if (!sanity_check)
743 		return PACKET_UNKNOWN;
744 
745 	switch (packet_type) {
746 	case 0:
747 		return PACKET_V4_STATUS;
748 
749 	case 1:
750 		return PACKET_V4_HEAD;
751 
752 	case 2:
753 		return PACKET_V4_MOTION;
754 	}
755 
756 	return PACKET_UNKNOWN;
757 }
758 
759 /*
760  * Process byte stream from mouse and handle complete packets
761  */
762 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
763 {
764 	struct elantech_data *etd = psmouse->private;
765 	int packet_type;
766 
767 	if (psmouse->pktcnt < psmouse->pktsize)
768 		return PSMOUSE_GOOD_DATA;
769 
770 	if (etd->debug > 1)
771 		elantech_packet_dump(psmouse);
772 
773 	switch (etd->hw_version) {
774 	case 1:
775 		if (etd->paritycheck && !elantech_packet_check_v1(psmouse))
776 			return PSMOUSE_BAD_DATA;
777 
778 		elantech_report_absolute_v1(psmouse);
779 		break;
780 
781 	case 2:
782 		/* ignore debounce */
783 		if (elantech_debounce_check_v2(psmouse))
784 			return PSMOUSE_FULL_PACKET;
785 
786 		if (etd->paritycheck && !elantech_packet_check_v2(psmouse))
787 			return PSMOUSE_BAD_DATA;
788 
789 		elantech_report_absolute_v2(psmouse);
790 		break;
791 
792 	case 3:
793 		packet_type = elantech_packet_check_v3(psmouse);
794 		/* ignore debounce */
795 		if (packet_type == PACKET_DEBOUNCE)
796 			return PSMOUSE_FULL_PACKET;
797 
798 		if (packet_type == PACKET_UNKNOWN)
799 			return PSMOUSE_BAD_DATA;
800 
801 		elantech_report_absolute_v3(psmouse, packet_type);
802 		break;
803 
804 	case 4:
805 		packet_type = elantech_packet_check_v4(psmouse);
806 		if (packet_type == PACKET_UNKNOWN)
807 			return PSMOUSE_BAD_DATA;
808 
809 		elantech_report_absolute_v4(psmouse, packet_type);
810 		break;
811 	}
812 
813 	return PSMOUSE_FULL_PACKET;
814 }
815 
816 /*
817  * Put the touchpad into absolute mode
818  */
819 static int elantech_set_absolute_mode(struct psmouse *psmouse)
820 {
821 	struct elantech_data *etd = psmouse->private;
822 	unsigned char val;
823 	int tries = ETP_READ_BACK_TRIES;
824 	int rc = 0;
825 
826 	switch (etd->hw_version) {
827 	case 1:
828 		etd->reg_10 = 0x16;
829 		etd->reg_11 = 0x8f;
830 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
831 		    elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
832 			rc = -1;
833 		}
834 		break;
835 
836 	case 2:
837 					/* Windows driver values */
838 		etd->reg_10 = 0x54;
839 		etd->reg_11 = 0x88;	/* 0x8a */
840 		etd->reg_21 = 0x60;	/* 0x00 */
841 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
842 		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
843 		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
844 			rc = -1;
845 		}
846 		break;
847 
848 	case 3:
849 		if (etd->set_hw_resolution)
850 			etd->reg_10 = 0x0b;
851 		else
852 			etd->reg_10 = 0x01;
853 
854 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
855 			rc = -1;
856 
857 		break;
858 
859 	case 4:
860 		etd->reg_07 = 0x01;
861 		if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
862 			rc = -1;
863 
864 		goto skip_readback_reg_10; /* v4 has no reg 0x10 to read */
865 	}
866 
867 	if (rc == 0) {
868 		/*
869 		 * Read back reg 0x10. For hardware version 1 we must make
870 		 * sure the absolute mode bit is set. For hardware version 2
871 		 * the touchpad is probably initializing and not ready until
872 		 * we read back the value we just wrote.
873 		 */
874 		do {
875 			rc = elantech_read_reg(psmouse, 0x10, &val);
876 			if (rc == 0)
877 				break;
878 			tries--;
879 			elantech_debug("retrying read (%d).\n", tries);
880 			msleep(ETP_READ_BACK_DELAY);
881 		} while (tries > 0);
882 
883 		if (rc) {
884 			psmouse_err(psmouse,
885 				    "failed to read back register 0x10.\n");
886 		} else if (etd->hw_version == 1 &&
887 			   !(val & ETP_R10_ABSOLUTE_MODE)) {
888 			psmouse_err(psmouse,
889 				    "touchpad refuses to switch to absolute mode.\n");
890 			rc = -1;
891 		}
892 	}
893 
894  skip_readback_reg_10:
895 	if (rc)
896 		psmouse_err(psmouse, "failed to initialise registers.\n");
897 
898 	return rc;
899 }
900 
901 static int elantech_set_range(struct psmouse *psmouse,
902 			      unsigned int *x_min, unsigned int *y_min,
903 			      unsigned int *x_max, unsigned int *y_max,
904 			      unsigned int *width)
905 {
906 	struct elantech_data *etd = psmouse->private;
907 	unsigned char param[3];
908 	unsigned char traces;
909 
910 	switch (etd->hw_version) {
911 	case 1:
912 		*x_min = ETP_XMIN_V1;
913 		*y_min = ETP_YMIN_V1;
914 		*x_max = ETP_XMAX_V1;
915 		*y_max = ETP_YMAX_V1;
916 		break;
917 
918 	case 2:
919 		if (etd->fw_version == 0x020800 ||
920 		    etd->fw_version == 0x020b00 ||
921 		    etd->fw_version == 0x020030) {
922 			*x_min = ETP_XMIN_V2;
923 			*y_min = ETP_YMIN_V2;
924 			*x_max = ETP_XMAX_V2;
925 			*y_max = ETP_YMAX_V2;
926 		} else {
927 			int i;
928 			int fixed_dpi;
929 
930 			i = (etd->fw_version > 0x020800 &&
931 			     etd->fw_version < 0x020900) ? 1 : 2;
932 
933 			if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
934 				return -1;
935 
936 			fixed_dpi = param[1] & 0x10;
937 
938 			if (((etd->fw_version >> 16) == 0x14) && fixed_dpi) {
939 				if (etd->send_cmd(psmouse, ETP_SAMPLE_QUERY, param))
940 					return -1;
941 
942 				*x_max = (etd->capabilities[1] - i) * param[1] / 2;
943 				*y_max = (etd->capabilities[2] - i) * param[2] / 2;
944 			} else if (etd->fw_version == 0x040216) {
945 				*x_max = 819;
946 				*y_max = 405;
947 			} else if (etd->fw_version == 0x040219 || etd->fw_version == 0x040215) {
948 				*x_max = 900;
949 				*y_max = 500;
950 			} else {
951 				*x_max = (etd->capabilities[1] - i) * 64;
952 				*y_max = (etd->capabilities[2] - i) * 64;
953 			}
954 		}
955 		break;
956 
957 	case 3:
958 		if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
959 			return -1;
960 
961 		*x_max = (0x0f & param[0]) << 8 | param[1];
962 		*y_max = (0xf0 & param[0]) << 4 | param[2];
963 		break;
964 
965 	case 4:
966 		if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
967 			return -1;
968 
969 		*x_max = (0x0f & param[0]) << 8 | param[1];
970 		*y_max = (0xf0 & param[0]) << 4 | param[2];
971 		traces = etd->capabilities[1];
972 		if ((traces < 2) || (traces > *x_max))
973 			return -1;
974 
975 		*width = *x_max / (traces - 1);
976 		break;
977 	}
978 
979 	return 0;
980 }
981 
982 /*
983  * (value from firmware) * 10 + 790 = dpi
984  * we also have to convert dpi to dots/mm (*10/254 to avoid floating point)
985  */
986 static unsigned int elantech_convert_res(unsigned int val)
987 {
988 	return (val * 10 + 790) * 10 / 254;
989 }
990 
991 static int elantech_get_resolution_v4(struct psmouse *psmouse,
992 				      unsigned int *x_res,
993 				      unsigned int *y_res)
994 {
995 	unsigned char param[3];
996 
997 	if (elantech_send_cmd(psmouse, ETP_RESOLUTION_QUERY, param))
998 		return -1;
999 
1000 	*x_res = elantech_convert_res(param[1] & 0x0f);
1001 	*y_res = elantech_convert_res((param[1] & 0xf0) >> 4);
1002 
1003 	return 0;
1004 }
1005 
1006 /*
1007  * Advertise INPUT_PROP_BUTTONPAD for clickpads. The testing of bit 12 in
1008  * fw_version for this is based on the following fw_version & caps table:
1009  *
1010  * Laptop-model:           fw_version:     caps:           buttons:
1011  * Acer S3                 0x461f00        10, 13, 0e      clickpad
1012  * Acer S7-392             0x581f01        50, 17, 0d      clickpad
1013  * Acer V5-131             0x461f02        01, 16, 0c      clickpad
1014  * Acer V5-551             0x461f00        ?               clickpad
1015  * Asus K53SV              0x450f01        78, 15, 0c      2 hw buttons
1016  * Asus G46VW              0x460f02        00, 18, 0c      2 hw buttons
1017  * Asus G750JX             0x360f00        00, 16, 0c      2 hw buttons
1018  * Asus UX31               0x361f00        20, 15, 0e      clickpad
1019  * Asus UX32VD             0x361f02        00, 15, 0e      clickpad
1020  * Avatar AVIU-145A2       0x361f00        ?               clickpad
1021  * Gigabyte U2442          0x450f01        58, 17, 0c      2 hw buttons
1022  * Lenovo L430             0x350f02        b9, 15, 0c      2 hw buttons (*)
1023  * Samsung NF210           0x150b00        78, 14, 0a      2 hw buttons
1024  * Samsung NP770Z5E        0x575f01        10, 15, 0f      clickpad
1025  * Samsung NP700Z5B        0x361f06        21, 15, 0f      clickpad
1026  * Samsung NP900X3E-A02    0x575f03        ?               clickpad
1027  * Samsung NP-QX410        0x851b00        19, 14, 0c      clickpad
1028  * Samsung RC512           0x450f00        08, 15, 0c      2 hw buttons
1029  * Samsung RF710           0x450f00        ?               2 hw buttons
1030  * System76 Pangolin       0x250f01        ?               2 hw buttons
1031  * (*) + 3 trackpoint buttons
1032  */
1033 static void elantech_set_buttonpad_prop(struct psmouse *psmouse)
1034 {
1035 	struct input_dev *dev = psmouse->dev;
1036 	struct elantech_data *etd = psmouse->private;
1037 
1038 	if (etd->fw_version & 0x001000) {
1039 		__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
1040 		__clear_bit(BTN_RIGHT, dev->keybit);
1041 	}
1042 }
1043 
1044 /*
1045  * Set the appropriate event bits for the input subsystem
1046  */
1047 static int elantech_set_input_params(struct psmouse *psmouse)
1048 {
1049 	struct input_dev *dev = psmouse->dev;
1050 	struct elantech_data *etd = psmouse->private;
1051 	unsigned int x_min = 0, y_min = 0, x_max = 0, y_max = 0, width = 0;
1052 	unsigned int x_res = 0, y_res = 0;
1053 
1054 	if (elantech_set_range(psmouse, &x_min, &y_min, &x_max, &y_max, &width))
1055 		return -1;
1056 
1057 	__set_bit(INPUT_PROP_POINTER, dev->propbit);
1058 	__set_bit(EV_KEY, dev->evbit);
1059 	__set_bit(EV_ABS, dev->evbit);
1060 	__clear_bit(EV_REL, dev->evbit);
1061 
1062 	__set_bit(BTN_LEFT, dev->keybit);
1063 	__set_bit(BTN_RIGHT, dev->keybit);
1064 
1065 	__set_bit(BTN_TOUCH, dev->keybit);
1066 	__set_bit(BTN_TOOL_FINGER, dev->keybit);
1067 	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
1068 	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
1069 
1070 	switch (etd->hw_version) {
1071 	case 1:
1072 		/* Rocker button */
1073 		if (etd->fw_version < 0x020000 &&
1074 		    (etd->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
1075 			__set_bit(BTN_FORWARD, dev->keybit);
1076 			__set_bit(BTN_BACK, dev->keybit);
1077 		}
1078 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1079 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1080 		break;
1081 
1082 	case 2:
1083 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1084 		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
1085 		/* fall through */
1086 	case 3:
1087 		if (etd->hw_version == 3)
1088 			elantech_set_buttonpad_prop(psmouse);
1089 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1090 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1091 		if (etd->reports_pressure) {
1092 			input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1093 					     ETP_PMAX_V2, 0, 0);
1094 			input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1095 					     ETP_WMAX_V2, 0, 0);
1096 		}
1097 		input_mt_init_slots(dev, 2, 0);
1098 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1099 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1100 		break;
1101 
1102 	case 4:
1103 		if (elantech_get_resolution_v4(psmouse, &x_res, &y_res)) {
1104 			/*
1105 			 * if query failed, print a warning and leave the values
1106 			 * zero to resemble synaptics.c behavior.
1107 			 */
1108 			psmouse_warn(psmouse, "couldn't query resolution data.\n");
1109 		}
1110 		elantech_set_buttonpad_prop(psmouse);
1111 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1112 		/* For X to recognize me as touchpad. */
1113 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1114 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1115 		input_abs_set_res(dev, ABS_X, x_res);
1116 		input_abs_set_res(dev, ABS_Y, y_res);
1117 		/*
1118 		 * range of pressure and width is the same as v2,
1119 		 * report ABS_PRESSURE, ABS_TOOL_WIDTH for compatibility.
1120 		 */
1121 		input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1122 				     ETP_PMAX_V2, 0, 0);
1123 		input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1124 				     ETP_WMAX_V2, 0, 0);
1125 		/* Multitouch capable pad, up to 5 fingers. */
1126 		input_mt_init_slots(dev, ETP_MAX_FINGERS, 0);
1127 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1128 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1129 		input_abs_set_res(dev, ABS_MT_POSITION_X, x_res);
1130 		input_abs_set_res(dev, ABS_MT_POSITION_Y, y_res);
1131 		input_set_abs_params(dev, ABS_MT_PRESSURE, ETP_PMIN_V2,
1132 				     ETP_PMAX_V2, 0, 0);
1133 		/*
1134 		 * The firmware reports how many trace lines the finger spans,
1135 		 * convert to surface unit as Protocol-B requires.
1136 		 */
1137 		input_set_abs_params(dev, ABS_MT_TOUCH_MAJOR, 0,
1138 				     ETP_WMAX_V2 * width, 0, 0);
1139 		break;
1140 	}
1141 
1142 	etd->y_max = y_max;
1143 	etd->width = width;
1144 
1145 	return 0;
1146 }
1147 
1148 struct elantech_attr_data {
1149 	size_t		field_offset;
1150 	unsigned char	reg;
1151 };
1152 
1153 /*
1154  * Display a register value by reading a sysfs entry
1155  */
1156 static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
1157 					char *buf)
1158 {
1159 	struct elantech_data *etd = psmouse->private;
1160 	struct elantech_attr_data *attr = data;
1161 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1162 	int rc = 0;
1163 
1164 	if (attr->reg)
1165 		rc = elantech_read_reg(psmouse, attr->reg, reg);
1166 
1167 	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
1168 }
1169 
1170 /*
1171  * Write a register value by writing a sysfs entry
1172  */
1173 static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
1174 				     void *data, const char *buf, size_t count)
1175 {
1176 	struct elantech_data *etd = psmouse->private;
1177 	struct elantech_attr_data *attr = data;
1178 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1179 	unsigned char value;
1180 	int err;
1181 
1182 	err = kstrtou8(buf, 16, &value);
1183 	if (err)
1184 		return err;
1185 
1186 	/* Do we need to preserve some bits for version 2 hardware too? */
1187 	if (etd->hw_version == 1) {
1188 		if (attr->reg == 0x10)
1189 			/* Force absolute mode always on */
1190 			value |= ETP_R10_ABSOLUTE_MODE;
1191 		else if (attr->reg == 0x11)
1192 			/* Force 4 byte mode always on */
1193 			value |= ETP_R11_4_BYTE_MODE;
1194 	}
1195 
1196 	if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
1197 		*reg = value;
1198 
1199 	return count;
1200 }
1201 
1202 #define ELANTECH_INT_ATTR(_name, _register)				\
1203 	static struct elantech_attr_data elantech_attr_##_name = {	\
1204 		.field_offset = offsetof(struct elantech_data, _name),	\
1205 		.reg = _register,					\
1206 	};								\
1207 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,			\
1208 			    &elantech_attr_##_name,			\
1209 			    elantech_show_int_attr,			\
1210 			    elantech_set_int_attr)
1211 
1212 ELANTECH_INT_ATTR(reg_07, 0x07);
1213 ELANTECH_INT_ATTR(reg_10, 0x10);
1214 ELANTECH_INT_ATTR(reg_11, 0x11);
1215 ELANTECH_INT_ATTR(reg_20, 0x20);
1216 ELANTECH_INT_ATTR(reg_21, 0x21);
1217 ELANTECH_INT_ATTR(reg_22, 0x22);
1218 ELANTECH_INT_ATTR(reg_23, 0x23);
1219 ELANTECH_INT_ATTR(reg_24, 0x24);
1220 ELANTECH_INT_ATTR(reg_25, 0x25);
1221 ELANTECH_INT_ATTR(reg_26, 0x26);
1222 ELANTECH_INT_ATTR(debug, 0);
1223 ELANTECH_INT_ATTR(paritycheck, 0);
1224 
1225 static struct attribute *elantech_attrs[] = {
1226 	&psmouse_attr_reg_07.dattr.attr,
1227 	&psmouse_attr_reg_10.dattr.attr,
1228 	&psmouse_attr_reg_11.dattr.attr,
1229 	&psmouse_attr_reg_20.dattr.attr,
1230 	&psmouse_attr_reg_21.dattr.attr,
1231 	&psmouse_attr_reg_22.dattr.attr,
1232 	&psmouse_attr_reg_23.dattr.attr,
1233 	&psmouse_attr_reg_24.dattr.attr,
1234 	&psmouse_attr_reg_25.dattr.attr,
1235 	&psmouse_attr_reg_26.dattr.attr,
1236 	&psmouse_attr_debug.dattr.attr,
1237 	&psmouse_attr_paritycheck.dattr.attr,
1238 	NULL
1239 };
1240 
1241 static struct attribute_group elantech_attr_group = {
1242 	.attrs = elantech_attrs,
1243 };
1244 
1245 static bool elantech_is_signature_valid(const unsigned char *param)
1246 {
1247 	static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10 };
1248 	int i;
1249 
1250 	if (param[0] == 0)
1251 		return false;
1252 
1253 	if (param[1] == 0)
1254 		return true;
1255 
1256 	for (i = 0; i < ARRAY_SIZE(rates); i++)
1257 		if (param[2] == rates[i])
1258 			return false;
1259 
1260 	return true;
1261 }
1262 
1263 /*
1264  * Use magic knock to detect Elantech touchpad
1265  */
1266 int elantech_detect(struct psmouse *psmouse, bool set_properties)
1267 {
1268 	struct ps2dev *ps2dev = &psmouse->ps2dev;
1269 	unsigned char param[3];
1270 
1271 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
1272 
1273 	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
1274 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1275 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1276 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1277 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
1278 		psmouse_dbg(psmouse, "sending Elantech magic knock failed.\n");
1279 		return -1;
1280 	}
1281 
1282 	/*
1283 	 * Report this in case there are Elantech models that use a different
1284 	 * set of magic numbers
1285 	 */
1286 	if (param[0] != 0x3c || param[1] != 0x03 ||
1287 	    (param[2] != 0xc8 && param[2] != 0x00)) {
1288 		psmouse_dbg(psmouse,
1289 			    "unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
1290 			    param[0], param[1], param[2]);
1291 		return -1;
1292 	}
1293 
1294 	/*
1295 	 * Query touchpad's firmware version and see if it reports known
1296 	 * value to avoid mis-detection. Logitech mice are known to respond
1297 	 * to Elantech magic knock and there might be more.
1298 	 */
1299 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1300 		psmouse_dbg(psmouse, "failed to query firmware version.\n");
1301 		return -1;
1302 	}
1303 
1304 	psmouse_dbg(psmouse,
1305 		    "Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
1306 		    param[0], param[1], param[2]);
1307 
1308 	if (!elantech_is_signature_valid(param)) {
1309 		psmouse_dbg(psmouse,
1310 			    "Probably not a real Elantech touchpad. Aborting.\n");
1311 		return -1;
1312 	}
1313 
1314 	if (set_properties) {
1315 		psmouse->vendor = "Elantech";
1316 		psmouse->name = "Touchpad";
1317 	}
1318 
1319 	return 0;
1320 }
1321 
1322 /*
1323  * Clean up sysfs entries when disconnecting
1324  */
1325 static void elantech_disconnect(struct psmouse *psmouse)
1326 {
1327 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
1328 			   &elantech_attr_group);
1329 	kfree(psmouse->private);
1330 	psmouse->private = NULL;
1331 }
1332 
1333 /*
1334  * Put the touchpad back into absolute mode when reconnecting
1335  */
1336 static int elantech_reconnect(struct psmouse *psmouse)
1337 {
1338 	psmouse_reset(psmouse);
1339 
1340 	if (elantech_detect(psmouse, 0))
1341 		return -1;
1342 
1343 	if (elantech_set_absolute_mode(psmouse)) {
1344 		psmouse_err(psmouse,
1345 			    "failed to put touchpad back into absolute mode.\n");
1346 		return -1;
1347 	}
1348 
1349 	return 0;
1350 }
1351 
1352 /*
1353  * Some hw_version 3 models go into error state when we try to set
1354  * bit 3 and/or bit 1 of r10.
1355  */
1356 static const struct dmi_system_id no_hw_res_dmi_table[] = {
1357 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1358 	{
1359 		/* Gigabyte U2442 */
1360 		.matches = {
1361 			DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
1362 			DMI_MATCH(DMI_PRODUCT_NAME, "U2442"),
1363 		},
1364 	},
1365 #endif
1366 	{ }
1367 };
1368 
1369 /*
1370  * determine hardware version and set some properties according to it.
1371  */
1372 static int elantech_set_properties(struct elantech_data *etd)
1373 {
1374 	/* This represents the version of IC body. */
1375 	int ver = (etd->fw_version & 0x0f0000) >> 16;
1376 
1377 	/* Early version of Elan touchpads doesn't obey the rule. */
1378 	if (etd->fw_version < 0x020030 || etd->fw_version == 0x020600)
1379 		etd->hw_version = 1;
1380 	else {
1381 		switch (ver) {
1382 		case 2:
1383 		case 4:
1384 			etd->hw_version = 2;
1385 			break;
1386 		case 5:
1387 			etd->hw_version = 3;
1388 			break;
1389 		case 6:
1390 		case 7:
1391 		case 8:
1392 		case 9:
1393 			etd->hw_version = 4;
1394 			break;
1395 		default:
1396 			return -1;
1397 		}
1398 	}
1399 
1400 	/* decide which send_cmd we're gonna use early */
1401 	etd->send_cmd = etd->hw_version >= 3 ? elantech_send_cmd :
1402 					       synaptics_send_cmd;
1403 
1404 	/* Turn on packet checking by default */
1405 	etd->paritycheck = 1;
1406 
1407 	/*
1408 	 * This firmware suffers from misreporting coordinates when
1409 	 * a touch action starts causing the mouse cursor or scrolled page
1410 	 * to jump. Enable a workaround.
1411 	 */
1412 	etd->jumpy_cursor =
1413 		(etd->fw_version == 0x020022 || etd->fw_version == 0x020600);
1414 
1415 	if (etd->hw_version > 1) {
1416 		/* For now show extra debug information */
1417 		etd->debug = 1;
1418 
1419 		if (etd->fw_version >= 0x020800)
1420 			etd->reports_pressure = true;
1421 	}
1422 
1423 	/*
1424 	 * The signatures of v3 and v4 packets change depending on the
1425 	 * value of this hardware flag.
1426 	 */
1427 	etd->crc_enabled = ((etd->fw_version & 0x4000) == 0x4000);
1428 
1429 	/* Enable real hardware resolution on hw_version 3 ? */
1430 	etd->set_hw_resolution = !dmi_check_system(no_hw_res_dmi_table);
1431 
1432 	return 0;
1433 }
1434 
1435 /*
1436  * Initialize the touchpad and create sysfs entries
1437  */
1438 int elantech_init(struct psmouse *psmouse)
1439 {
1440 	struct elantech_data *etd;
1441 	int i, error;
1442 	unsigned char param[3];
1443 
1444 	psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
1445 	if (!etd)
1446 		return -ENOMEM;
1447 
1448 	psmouse_reset(psmouse);
1449 
1450 	etd->parity[0] = 1;
1451 	for (i = 1; i < 256; i++)
1452 		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
1453 
1454 	/*
1455 	 * Do the version query again so we can store the result
1456 	 */
1457 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1458 		psmouse_err(psmouse, "failed to query firmware version.\n");
1459 		goto init_fail;
1460 	}
1461 	etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
1462 
1463 	if (elantech_set_properties(etd)) {
1464 		psmouse_err(psmouse, "unknown hardware version, aborting...\n");
1465 		goto init_fail;
1466 	}
1467 	psmouse_info(psmouse,
1468 		     "assuming hardware version %d (with firmware version 0x%02x%02x%02x)\n",
1469 		     etd->hw_version, param[0], param[1], param[2]);
1470 
1471 	if (etd->send_cmd(psmouse, ETP_CAPABILITIES_QUERY,
1472 	    etd->capabilities)) {
1473 		psmouse_err(psmouse, "failed to query capabilities.\n");
1474 		goto init_fail;
1475 	}
1476 	psmouse_info(psmouse,
1477 		     "Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
1478 		     etd->capabilities[0], etd->capabilities[1],
1479 		     etd->capabilities[2]);
1480 
1481 	if (elantech_set_absolute_mode(psmouse)) {
1482 		psmouse_err(psmouse,
1483 			    "failed to put touchpad into absolute mode.\n");
1484 		goto init_fail;
1485 	}
1486 
1487 	if (elantech_set_input_params(psmouse)) {
1488 		psmouse_err(psmouse, "failed to query touchpad range.\n");
1489 		goto init_fail;
1490 	}
1491 
1492 	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
1493 				   &elantech_attr_group);
1494 	if (error) {
1495 		psmouse_err(psmouse,
1496 			    "failed to create sysfs attributes, error: %d.\n",
1497 			    error);
1498 		goto init_fail;
1499 	}
1500 
1501 	psmouse->protocol_handler = elantech_process_byte;
1502 	psmouse->disconnect = elantech_disconnect;
1503 	psmouse->reconnect = elantech_reconnect;
1504 	psmouse->pktsize = etd->hw_version > 1 ? 6 : 4;
1505 
1506 	return 0;
1507 
1508  init_fail:
1509 	kfree(etd);
1510 	return -1;
1511 }
1512