xref: /openbmc/linux/drivers/input/mouse/elantech.c (revision b34e08d5)
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/slab.h>
15 #include <linux/module.h>
16 #include <linux/input.h>
17 #include <linux/input/mt.h>
18 #include <linux/serio.h>
19 #include <linux/libps2.h>
20 #include "psmouse.h"
21 #include "elantech.h"
22 
23 #define elantech_debug(fmt, ...)					\
24 	do {								\
25 		if (etd->debug)						\
26 			psmouse_printk(KERN_DEBUG, psmouse,		\
27 					fmt, ##__VA_ARGS__);		\
28 	} while (0)
29 
30 /*
31  * Send a Synaptics style sliced query command
32  */
33 static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
34 				unsigned char *param)
35 {
36 	if (psmouse_sliced_command(psmouse, c) ||
37 	    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
38 		psmouse_err(psmouse, "%s query 0x%02x failed.\n", __func__, c);
39 		return -1;
40 	}
41 
42 	return 0;
43 }
44 
45 /*
46  * V3 and later support this fast command
47  */
48 static int elantech_send_cmd(struct psmouse *psmouse, unsigned char c,
49 				unsigned char *param)
50 {
51 	struct ps2dev *ps2dev = &psmouse->ps2dev;
52 
53 	if (ps2_command(ps2dev, NULL, ETP_PS2_CUSTOM_COMMAND) ||
54 	    ps2_command(ps2dev, NULL, c) ||
55 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
56 		psmouse_err(psmouse, "%s query 0x%02x failed.\n", __func__, c);
57 		return -1;
58 	}
59 
60 	return 0;
61 }
62 
63 /*
64  * A retrying version of ps2_command
65  */
66 static int elantech_ps2_command(struct psmouse *psmouse,
67 				unsigned char *param, int command)
68 {
69 	struct ps2dev *ps2dev = &psmouse->ps2dev;
70 	struct elantech_data *etd = psmouse->private;
71 	int rc;
72 	int tries = ETP_PS2_COMMAND_TRIES;
73 
74 	do {
75 		rc = ps2_command(ps2dev, param, command);
76 		if (rc == 0)
77 			break;
78 		tries--;
79 		elantech_debug("retrying ps2 command 0x%02x (%d).\n",
80 				command, tries);
81 		msleep(ETP_PS2_COMMAND_DELAY);
82 	} while (tries > 0);
83 
84 	if (rc)
85 		psmouse_err(psmouse, "ps2 command 0x%02x failed.\n", command);
86 
87 	return rc;
88 }
89 
90 /*
91  * Send an Elantech style special command to read a value from a register
92  */
93 static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
94 				unsigned char *val)
95 {
96 	struct elantech_data *etd = psmouse->private;
97 	unsigned char param[3];
98 	int rc = 0;
99 
100 	if (reg < 0x07 || reg > 0x26)
101 		return -1;
102 
103 	if (reg > 0x11 && reg < 0x20)
104 		return -1;
105 
106 	switch (etd->hw_version) {
107 	case 1:
108 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_READ) ||
109 		    psmouse_sliced_command(psmouse, reg) ||
110 		    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
111 			rc = -1;
112 		}
113 		break;
114 
115 	case 2:
116 		if (elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
117 		    elantech_ps2_command(psmouse,  NULL, ETP_REGISTER_READ) ||
118 		    elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
119 		    elantech_ps2_command(psmouse,  NULL, reg) ||
120 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
121 			rc = -1;
122 		}
123 		break;
124 
125 	case 3 ... 4:
126 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
127 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
128 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
129 		    elantech_ps2_command(psmouse, NULL, reg) ||
130 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
131 			rc = -1;
132 		}
133 		break;
134 	}
135 
136 	if (rc)
137 		psmouse_err(psmouse, "failed to read register 0x%02x.\n", reg);
138 	else if (etd->hw_version != 4)
139 		*val = param[0];
140 	else
141 		*val = param[1];
142 
143 	return rc;
144 }
145 
146 /*
147  * Send an Elantech style special command to write a register with a value
148  */
149 static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
150 				unsigned char val)
151 {
152 	struct elantech_data *etd = psmouse->private;
153 	int rc = 0;
154 
155 	if (reg < 0x07 || reg > 0x26)
156 		return -1;
157 
158 	if (reg > 0x11 && reg < 0x20)
159 		return -1;
160 
161 	switch (etd->hw_version) {
162 	case 1:
163 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_WRITE) ||
164 		    psmouse_sliced_command(psmouse, reg) ||
165 		    psmouse_sliced_command(psmouse, val) ||
166 		    ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
167 			rc = -1;
168 		}
169 		break;
170 
171 	case 2:
172 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
173 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
174 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
175 		    elantech_ps2_command(psmouse, NULL, reg) ||
176 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
177 		    elantech_ps2_command(psmouse, NULL, val) ||
178 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
179 			rc = -1;
180 		}
181 		break;
182 
183 	case 3:
184 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
185 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
186 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
187 		    elantech_ps2_command(psmouse, NULL, reg) ||
188 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
189 		    elantech_ps2_command(psmouse, NULL, val) ||
190 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
191 			rc = -1;
192 		}
193 		break;
194 
195 	case 4:
196 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
197 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
198 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
199 		    elantech_ps2_command(psmouse, NULL, reg) ||
200 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
201 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
202 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
203 		    elantech_ps2_command(psmouse, NULL, val) ||
204 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
205 			rc = -1;
206 		}
207 		break;
208 	}
209 
210 	if (rc)
211 		psmouse_err(psmouse,
212 			    "failed to write register 0x%02x with value 0x%02x.\n",
213 			    reg, val);
214 
215 	return rc;
216 }
217 
218 /*
219  * Dump a complete mouse movement packet to the syslog
220  */
221 static void elantech_packet_dump(struct psmouse *psmouse)
222 {
223 	int	i;
224 
225 	psmouse_printk(KERN_DEBUG, psmouse, "PS/2 packet [");
226 	for (i = 0; i < psmouse->pktsize; i++)
227 		printk("%s0x%02x ", i ? ", " : " ", psmouse->packet[i]);
228 	printk("]\n");
229 }
230 
231 /*
232  * Interpret complete data packets and report absolute mode input events for
233  * hardware version 1. (4 byte packets)
234  */
235 static void elantech_report_absolute_v1(struct psmouse *psmouse)
236 {
237 	struct input_dev *dev = psmouse->dev;
238 	struct elantech_data *etd = psmouse->private;
239 	unsigned char *packet = psmouse->packet;
240 	int fingers;
241 
242 	if (etd->fw_version < 0x020000) {
243 		/*
244 		 * byte 0:  D   U  p1  p2   1  p3   R   L
245 		 * byte 1:  f   0  th  tw  x9  x8  y9  y8
246 		 */
247 		fingers = ((packet[1] & 0x80) >> 7) +
248 				((packet[1] & 0x30) >> 4);
249 	} else {
250 		/*
251 		 * byte 0: n1  n0  p2  p1   1  p3   R   L
252 		 * byte 1:  0   0   0   0  x9  x8  y9  y8
253 		 */
254 		fingers = (packet[0] & 0xc0) >> 6;
255 	}
256 
257 	if (etd->jumpy_cursor) {
258 		if (fingers != 1) {
259 			etd->single_finger_reports = 0;
260 		} else if (etd->single_finger_reports < 2) {
261 			/* Discard first 2 reports of one finger, bogus */
262 			etd->single_finger_reports++;
263 			elantech_debug("discarding packet\n");
264 			return;
265 		}
266 	}
267 
268 	input_report_key(dev, BTN_TOUCH, fingers != 0);
269 
270 	/*
271 	 * byte 2: x7  x6  x5  x4  x3  x2  x1  x0
272 	 * byte 3: y7  y6  y5  y4  y3  y2  y1  y0
273 	 */
274 	if (fingers) {
275 		input_report_abs(dev, ABS_X,
276 			((packet[1] & 0x0c) << 6) | packet[2]);
277 		input_report_abs(dev, ABS_Y,
278 			etd->y_max - (((packet[1] & 0x03) << 8) | packet[3]));
279 	}
280 
281 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
282 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
283 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
284 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
285 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
286 
287 	if (etd->fw_version < 0x020000 &&
288 	    (etd->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
289 		/* rocker up */
290 		input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
291 		/* rocker down */
292 		input_report_key(dev, BTN_BACK, packet[0] & 0x80);
293 	}
294 
295 	input_sync(dev);
296 }
297 
298 static void elantech_set_slot(struct input_dev *dev, int slot, bool active,
299 			      unsigned int x, unsigned int y)
300 {
301 	input_mt_slot(dev, slot);
302 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
303 	if (active) {
304 		input_report_abs(dev, ABS_MT_POSITION_X, x);
305 		input_report_abs(dev, ABS_MT_POSITION_Y, y);
306 	}
307 }
308 
309 /* x1 < x2 and y1 < y2 when two fingers, x = y = 0 when not pressed */
310 static void elantech_report_semi_mt_data(struct input_dev *dev,
311 					 unsigned int num_fingers,
312 					 unsigned int x1, unsigned int y1,
313 					 unsigned int x2, unsigned int y2)
314 {
315 	elantech_set_slot(dev, 0, num_fingers != 0, x1, y1);
316 	elantech_set_slot(dev, 1, num_fingers == 2, x2, y2);
317 }
318 
319 /*
320  * Interpret complete data packets and report absolute mode input events for
321  * hardware version 2. (6 byte packets)
322  */
323 static void elantech_report_absolute_v2(struct psmouse *psmouse)
324 {
325 	struct elantech_data *etd = psmouse->private;
326 	struct input_dev *dev = psmouse->dev;
327 	unsigned char *packet = psmouse->packet;
328 	unsigned int fingers, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
329 	unsigned int width = 0, pres = 0;
330 
331 	/* byte 0: n1  n0   .   .   .   .   R   L */
332 	fingers = (packet[0] & 0xc0) >> 6;
333 
334 	switch (fingers) {
335 	case 3:
336 		/*
337 		 * Same as one finger, except report of more than 3 fingers:
338 		 * byte 3:  n4  .   w1  w0   .   .   .   .
339 		 */
340 		if (packet[3] & 0x80)
341 			fingers = 4;
342 		/* pass through... */
343 	case 1:
344 		/*
345 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
346 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
347 		 */
348 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
349 		/*
350 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
351 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
352 		 */
353 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
354 
355 		pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
356 		width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
357 		break;
358 
359 	case 2:
360 		/*
361 		 * The coordinate of each finger is reported separately
362 		 * with a lower resolution for two finger touches:
363 		 * byte 0:  .   .  ay8 ax8  .   .   .   .
364 		 * byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
365 		 */
366 		x1 = (((packet[0] & 0x10) << 4) | packet[1]) << 2;
367 		/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
368 		y1 = etd->y_max -
369 			((((packet[0] & 0x20) << 3) | packet[2]) << 2);
370 		/*
371 		 * byte 3:  .   .  by8 bx8  .   .   .   .
372 		 * byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
373 		 */
374 		x2 = (((packet[3] & 0x10) << 4) | packet[4]) << 2;
375 		/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
376 		y2 = etd->y_max -
377 			((((packet[3] & 0x20) << 3) | packet[5]) << 2);
378 
379 		/* Unknown so just report sensible values */
380 		pres = 127;
381 		width = 7;
382 		break;
383 	}
384 
385 	input_report_key(dev, BTN_TOUCH, fingers != 0);
386 	if (fingers != 0) {
387 		input_report_abs(dev, ABS_X, x1);
388 		input_report_abs(dev, ABS_Y, y1);
389 	}
390 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
391 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
392 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
393 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
394 	input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
395 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
396 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
397 	if (etd->reports_pressure) {
398 		input_report_abs(dev, ABS_PRESSURE, pres);
399 		input_report_abs(dev, ABS_TOOL_WIDTH, width);
400 	}
401 
402 	input_sync(dev);
403 }
404 
405 /*
406  * Interpret complete data packets and report absolute mode input events for
407  * hardware version 3. (12 byte packets for two fingers)
408  */
409 static void elantech_report_absolute_v3(struct psmouse *psmouse,
410 					int packet_type)
411 {
412 	struct input_dev *dev = psmouse->dev;
413 	struct elantech_data *etd = psmouse->private;
414 	unsigned char *packet = psmouse->packet;
415 	unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
416 	unsigned int width = 0, pres = 0;
417 
418 	/* byte 0: n1  n0   .   .   .   .   R   L */
419 	fingers = (packet[0] & 0xc0) >> 6;
420 
421 	switch (fingers) {
422 	case 3:
423 	case 1:
424 		/*
425 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
426 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
427 		 */
428 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
429 		/*
430 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
431 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
432 		 */
433 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
434 		break;
435 
436 	case 2:
437 		if (packet_type == PACKET_V3_HEAD) {
438 			/*
439 			 * byte 1:   .    .    .    .  ax11 ax10 ax9  ax8
440 			 * byte 2: ax7  ax6  ax5  ax4  ax3  ax2  ax1  ax0
441 			 */
442 			etd->mt[0].x = ((packet[1] & 0x0f) << 8) | packet[2];
443 			/*
444 			 * byte 4:   .    .    .    .  ay11 ay10 ay9  ay8
445 			 * byte 5: ay7  ay6  ay5  ay4  ay3  ay2  ay1  ay0
446 			 */
447 			etd->mt[0].y = etd->y_max -
448 				(((packet[4] & 0x0f) << 8) | packet[5]);
449 			/*
450 			 * wait for next packet
451 			 */
452 			return;
453 		}
454 
455 		/* packet_type == PACKET_V3_TAIL */
456 		x1 = etd->mt[0].x;
457 		y1 = etd->mt[0].y;
458 		x2 = ((packet[1] & 0x0f) << 8) | packet[2];
459 		y2 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
460 		break;
461 	}
462 
463 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
464 	width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
465 
466 	input_report_key(dev, BTN_TOUCH, fingers != 0);
467 	if (fingers != 0) {
468 		input_report_abs(dev, ABS_X, x1);
469 		input_report_abs(dev, ABS_Y, y1);
470 	}
471 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
472 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
473 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
474 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
475 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
476 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
477 	input_report_abs(dev, ABS_PRESSURE, pres);
478 	input_report_abs(dev, ABS_TOOL_WIDTH, width);
479 
480 	input_sync(dev);
481 }
482 
483 static void elantech_input_sync_v4(struct psmouse *psmouse)
484 {
485 	struct input_dev *dev = psmouse->dev;
486 	unsigned char *packet = psmouse->packet;
487 
488 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
489 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
490 	input_mt_report_pointer_emulation(dev, true);
491 	input_sync(dev);
492 }
493 
494 static void process_packet_status_v4(struct psmouse *psmouse)
495 {
496 	struct input_dev *dev = psmouse->dev;
497 	unsigned char *packet = psmouse->packet;
498 	unsigned fingers;
499 	int i;
500 
501 	/* notify finger state change */
502 	fingers = packet[1] & 0x1f;
503 	for (i = 0; i < ETP_MAX_FINGERS; i++) {
504 		if ((fingers & (1 << i)) == 0) {
505 			input_mt_slot(dev, i);
506 			input_mt_report_slot_state(dev, MT_TOOL_FINGER, false);
507 		}
508 	}
509 
510 	elantech_input_sync_v4(psmouse);
511 }
512 
513 static void process_packet_head_v4(struct psmouse *psmouse)
514 {
515 	struct input_dev *dev = psmouse->dev;
516 	struct elantech_data *etd = psmouse->private;
517 	unsigned char *packet = psmouse->packet;
518 	int id = ((packet[3] & 0xe0) >> 5) - 1;
519 	int pres, traces;
520 
521 	if (id < 0)
522 		return;
523 
524 	etd->mt[id].x = ((packet[1] & 0x0f) << 8) | packet[2];
525 	etd->mt[id].y = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
526 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
527 	traces = (packet[0] & 0xf0) >> 4;
528 
529 	input_mt_slot(dev, id);
530 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, true);
531 
532 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
533 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
534 	input_report_abs(dev, ABS_MT_PRESSURE, pres);
535 	input_report_abs(dev, ABS_MT_TOUCH_MAJOR, traces * etd->width);
536 	/* report this for backwards compatibility */
537 	input_report_abs(dev, ABS_TOOL_WIDTH, traces);
538 
539 	elantech_input_sync_v4(psmouse);
540 }
541 
542 static void process_packet_motion_v4(struct psmouse *psmouse)
543 {
544 	struct input_dev *dev = psmouse->dev;
545 	struct elantech_data *etd = psmouse->private;
546 	unsigned char *packet = psmouse->packet;
547 	int weight, delta_x1 = 0, delta_y1 = 0, delta_x2 = 0, delta_y2 = 0;
548 	int id, sid;
549 
550 	id = ((packet[0] & 0xe0) >> 5) - 1;
551 	if (id < 0)
552 		return;
553 
554 	sid = ((packet[3] & 0xe0) >> 5) - 1;
555 	weight = (packet[0] & 0x10) ? ETP_WEIGHT_VALUE : 1;
556 	/*
557 	 * Motion packets give us the delta of x, y values of specific fingers,
558 	 * but in two's complement. Let the compiler do the conversion for us.
559 	 * Also _enlarge_ the numbers to int, in case of overflow.
560 	 */
561 	delta_x1 = (signed char)packet[1];
562 	delta_y1 = (signed char)packet[2];
563 	delta_x2 = (signed char)packet[4];
564 	delta_y2 = (signed char)packet[5];
565 
566 	etd->mt[id].x += delta_x1 * weight;
567 	etd->mt[id].y -= delta_y1 * weight;
568 	input_mt_slot(dev, id);
569 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
570 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
571 
572 	if (sid >= 0) {
573 		etd->mt[sid].x += delta_x2 * weight;
574 		etd->mt[sid].y -= delta_y2 * weight;
575 		input_mt_slot(dev, sid);
576 		input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[sid].x);
577 		input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[sid].y);
578 	}
579 
580 	elantech_input_sync_v4(psmouse);
581 }
582 
583 static void elantech_report_absolute_v4(struct psmouse *psmouse,
584 					int packet_type)
585 {
586 	switch (packet_type) {
587 	case PACKET_V4_STATUS:
588 		process_packet_status_v4(psmouse);
589 		break;
590 
591 	case PACKET_V4_HEAD:
592 		process_packet_head_v4(psmouse);
593 		break;
594 
595 	case PACKET_V4_MOTION:
596 		process_packet_motion_v4(psmouse);
597 		break;
598 
599 	case PACKET_UNKNOWN:
600 	default:
601 		/* impossible to get here */
602 		break;
603 	}
604 }
605 
606 static int elantech_packet_check_v1(struct psmouse *psmouse)
607 {
608 	struct elantech_data *etd = psmouse->private;
609 	unsigned char *packet = psmouse->packet;
610 	unsigned char p1, p2, p3;
611 
612 	/* Parity bits are placed differently */
613 	if (etd->fw_version < 0x020000) {
614 		/* byte 0:  D   U  p1  p2   1  p3   R   L */
615 		p1 = (packet[0] & 0x20) >> 5;
616 		p2 = (packet[0] & 0x10) >> 4;
617 	} else {
618 		/* byte 0: n1  n0  p2  p1   1  p3   R   L */
619 		p1 = (packet[0] & 0x10) >> 4;
620 		p2 = (packet[0] & 0x20) >> 5;
621 	}
622 
623 	p3 = (packet[0] & 0x04) >> 2;
624 
625 	return etd->parity[packet[1]] == p1 &&
626 	       etd->parity[packet[2]] == p2 &&
627 	       etd->parity[packet[3]] == p3;
628 }
629 
630 static int elantech_debounce_check_v2(struct psmouse *psmouse)
631 {
632         /*
633          * When we encounter packet that matches this exactly, it means the
634          * hardware is in debounce status. Just ignore the whole packet.
635          */
636         const u8 debounce_packet[] = { 0x84, 0xff, 0xff, 0x02, 0xff, 0xff };
637         unsigned char *packet = psmouse->packet;
638 
639         return !memcmp(packet, debounce_packet, sizeof(debounce_packet));
640 }
641 
642 static int elantech_packet_check_v2(struct psmouse *psmouse)
643 {
644 	struct elantech_data *etd = psmouse->private;
645 	unsigned char *packet = psmouse->packet;
646 
647 	/*
648 	 * V2 hardware has two flavors. Older ones that do not report pressure,
649 	 * and newer ones that reports pressure and width. With newer ones, all
650 	 * packets (1, 2, 3 finger touch) have the same constant bits. With
651 	 * older ones, 1/3 finger touch packets and 2 finger touch packets
652 	 * have different constant bits.
653 	 * With all three cases, if the constant bits are not exactly what I
654 	 * expected, I consider them invalid.
655 	 */
656 	if (etd->reports_pressure)
657 		return (packet[0] & 0x0c) == 0x04 &&
658 		       (packet[3] & 0x0f) == 0x02;
659 
660 	if ((packet[0] & 0xc0) == 0x80)
661 		return (packet[0] & 0x0c) == 0x0c &&
662 		       (packet[3] & 0x0e) == 0x08;
663 
664 	return (packet[0] & 0x3c) == 0x3c &&
665 	       (packet[1] & 0xf0) == 0x00 &&
666 	       (packet[3] & 0x3e) == 0x38 &&
667 	       (packet[4] & 0xf0) == 0x00;
668 }
669 
670 /*
671  * We check the constant bits to determine what packet type we get,
672  * so packet checking is mandatory for v3 and later hardware.
673  */
674 static int elantech_packet_check_v3(struct psmouse *psmouse)
675 {
676 	struct elantech_data *etd = psmouse->private;
677 	const u8 debounce_packet[] = { 0xc4, 0xff, 0xff, 0x02, 0xff, 0xff };
678 	unsigned char *packet = psmouse->packet;
679 
680 	/*
681 	 * check debounce first, it has the same signature in byte 0
682 	 * and byte 3 as PACKET_V3_HEAD.
683 	 */
684 	if (!memcmp(packet, debounce_packet, sizeof(debounce_packet)))
685 		return PACKET_DEBOUNCE;
686 
687 	/*
688 	 * If the hardware flag 'crc_enabled' is set the packets have
689 	 * different signatures.
690 	 */
691 	if (etd->crc_enabled) {
692 		if ((packet[3] & 0x09) == 0x08)
693 			return PACKET_V3_HEAD;
694 
695 		if ((packet[3] & 0x09) == 0x09)
696 			return PACKET_V3_TAIL;
697 	} else {
698 		if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
699 			return PACKET_V3_HEAD;
700 
701 		if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
702 			return PACKET_V3_TAIL;
703 	}
704 
705 	return PACKET_UNKNOWN;
706 }
707 
708 static int elantech_packet_check_v4(struct psmouse *psmouse)
709 {
710 	struct elantech_data *etd = psmouse->private;
711 	unsigned char *packet = psmouse->packet;
712 	unsigned char packet_type = packet[3] & 0x03;
713 	bool sanity_check;
714 
715 	/*
716 	 * Sanity check based on the constant bits of a packet.
717 	 * The constant bits change depending on the value of
718 	 * the hardware flag 'crc_enabled' but are the same for
719 	 * every packet, regardless of the type.
720 	 */
721 	if (etd->crc_enabled)
722 		sanity_check = ((packet[3] & 0x08) == 0x00);
723 	else
724 		sanity_check = ((packet[0] & 0x0c) == 0x04 &&
725 				(packet[3] & 0x1c) == 0x10);
726 
727 	if (!sanity_check)
728 		return PACKET_UNKNOWN;
729 
730 	switch (packet_type) {
731 	case 0:
732 		return PACKET_V4_STATUS;
733 
734 	case 1:
735 		return PACKET_V4_HEAD;
736 
737 	case 2:
738 		return PACKET_V4_MOTION;
739 	}
740 
741 	return PACKET_UNKNOWN;
742 }
743 
744 /*
745  * Process byte stream from mouse and handle complete packets
746  */
747 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
748 {
749 	struct elantech_data *etd = psmouse->private;
750 	int packet_type;
751 
752 	if (psmouse->pktcnt < psmouse->pktsize)
753 		return PSMOUSE_GOOD_DATA;
754 
755 	if (etd->debug > 1)
756 		elantech_packet_dump(psmouse);
757 
758 	switch (etd->hw_version) {
759 	case 1:
760 		if (etd->paritycheck && !elantech_packet_check_v1(psmouse))
761 			return PSMOUSE_BAD_DATA;
762 
763 		elantech_report_absolute_v1(psmouse);
764 		break;
765 
766 	case 2:
767 		/* ignore debounce */
768 		if (elantech_debounce_check_v2(psmouse))
769 			return PSMOUSE_FULL_PACKET;
770 
771 		if (etd->paritycheck && !elantech_packet_check_v2(psmouse))
772 			return PSMOUSE_BAD_DATA;
773 
774 		elantech_report_absolute_v2(psmouse);
775 		break;
776 
777 	case 3:
778 		packet_type = elantech_packet_check_v3(psmouse);
779 		/* ignore debounce */
780 		if (packet_type == PACKET_DEBOUNCE)
781 			return PSMOUSE_FULL_PACKET;
782 
783 		if (packet_type == PACKET_UNKNOWN)
784 			return PSMOUSE_BAD_DATA;
785 
786 		elantech_report_absolute_v3(psmouse, packet_type);
787 		break;
788 
789 	case 4:
790 		packet_type = elantech_packet_check_v4(psmouse);
791 		if (packet_type == PACKET_UNKNOWN)
792 			return PSMOUSE_BAD_DATA;
793 
794 		elantech_report_absolute_v4(psmouse, packet_type);
795 		break;
796 	}
797 
798 	return PSMOUSE_FULL_PACKET;
799 }
800 
801 /*
802  * Put the touchpad into absolute mode
803  */
804 static int elantech_set_absolute_mode(struct psmouse *psmouse)
805 {
806 	struct elantech_data *etd = psmouse->private;
807 	unsigned char val;
808 	int tries = ETP_READ_BACK_TRIES;
809 	int rc = 0;
810 
811 	switch (etd->hw_version) {
812 	case 1:
813 		etd->reg_10 = 0x16;
814 		etd->reg_11 = 0x8f;
815 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
816 		    elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
817 			rc = -1;
818 		}
819 		break;
820 
821 	case 2:
822 					/* Windows driver values */
823 		etd->reg_10 = 0x54;
824 		etd->reg_11 = 0x88;	/* 0x8a */
825 		etd->reg_21 = 0x60;	/* 0x00 */
826 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
827 		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
828 		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
829 			rc = -1;
830 		}
831 		break;
832 
833 	case 3:
834 		etd->reg_10 = 0x0b;
835 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
836 			rc = -1;
837 
838 		break;
839 
840 	case 4:
841 		etd->reg_07 = 0x01;
842 		if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
843 			rc = -1;
844 
845 		goto skip_readback_reg_10; /* v4 has no reg 0x10 to read */
846 	}
847 
848 	if (rc == 0) {
849 		/*
850 		 * Read back reg 0x10. For hardware version 1 we must make
851 		 * sure the absolute mode bit is set. For hardware version 2
852 		 * the touchpad is probably initializing and not ready until
853 		 * we read back the value we just wrote.
854 		 */
855 		do {
856 			rc = elantech_read_reg(psmouse, 0x10, &val);
857 			if (rc == 0)
858 				break;
859 			tries--;
860 			elantech_debug("retrying read (%d).\n", tries);
861 			msleep(ETP_READ_BACK_DELAY);
862 		} while (tries > 0);
863 
864 		if (rc) {
865 			psmouse_err(psmouse,
866 				    "failed to read back register 0x10.\n");
867 		} else if (etd->hw_version == 1 &&
868 			   !(val & ETP_R10_ABSOLUTE_MODE)) {
869 			psmouse_err(psmouse,
870 				    "touchpad refuses to switch to absolute mode.\n");
871 			rc = -1;
872 		}
873 	}
874 
875  skip_readback_reg_10:
876 	if (rc)
877 		psmouse_err(psmouse, "failed to initialise registers.\n");
878 
879 	return rc;
880 }
881 
882 static int elantech_set_range(struct psmouse *psmouse,
883 			      unsigned int *x_min, unsigned int *y_min,
884 			      unsigned int *x_max, unsigned int *y_max,
885 			      unsigned int *width)
886 {
887 	struct elantech_data *etd = psmouse->private;
888 	unsigned char param[3];
889 	unsigned char traces;
890 
891 	switch (etd->hw_version) {
892 	case 1:
893 		*x_min = ETP_XMIN_V1;
894 		*y_min = ETP_YMIN_V1;
895 		*x_max = ETP_XMAX_V1;
896 		*y_max = ETP_YMAX_V1;
897 		break;
898 
899 	case 2:
900 		if (etd->fw_version == 0x020800 ||
901 		    etd->fw_version == 0x020b00 ||
902 		    etd->fw_version == 0x020030) {
903 			*x_min = ETP_XMIN_V2;
904 			*y_min = ETP_YMIN_V2;
905 			*x_max = ETP_XMAX_V2;
906 			*y_max = ETP_YMAX_V2;
907 		} else {
908 			int i;
909 			int fixed_dpi;
910 
911 			i = (etd->fw_version > 0x020800 &&
912 			     etd->fw_version < 0x020900) ? 1 : 2;
913 
914 			if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
915 				return -1;
916 
917 			fixed_dpi = param[1] & 0x10;
918 
919 			if (((etd->fw_version >> 16) == 0x14) && fixed_dpi) {
920 				if (etd->send_cmd(psmouse, ETP_SAMPLE_QUERY, param))
921 					return -1;
922 
923 				*x_max = (etd->capabilities[1] - i) * param[1] / 2;
924 				*y_max = (etd->capabilities[2] - i) * param[2] / 2;
925 			} else if (etd->fw_version == 0x040216) {
926 				*x_max = 819;
927 				*y_max = 405;
928 			} else if (etd->fw_version == 0x040219 || etd->fw_version == 0x040215) {
929 				*x_max = 900;
930 				*y_max = 500;
931 			} else {
932 				*x_max = (etd->capabilities[1] - i) * 64;
933 				*y_max = (etd->capabilities[2] - i) * 64;
934 			}
935 		}
936 		break;
937 
938 	case 3:
939 		if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
940 			return -1;
941 
942 		*x_max = (0x0f & param[0]) << 8 | param[1];
943 		*y_max = (0xf0 & param[0]) << 4 | param[2];
944 		break;
945 
946 	case 4:
947 		if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
948 			return -1;
949 
950 		*x_max = (0x0f & param[0]) << 8 | param[1];
951 		*y_max = (0xf0 & param[0]) << 4 | param[2];
952 		traces = etd->capabilities[1];
953 		if ((traces < 2) || (traces > *x_max))
954 			return -1;
955 
956 		*width = *x_max / (traces - 1);
957 		break;
958 	}
959 
960 	return 0;
961 }
962 
963 /*
964  * (value from firmware) * 10 + 790 = dpi
965  * we also have to convert dpi to dots/mm (*10/254 to avoid floating point)
966  */
967 static unsigned int elantech_convert_res(unsigned int val)
968 {
969 	return (val * 10 + 790) * 10 / 254;
970 }
971 
972 static int elantech_get_resolution_v4(struct psmouse *psmouse,
973 				      unsigned int *x_res,
974 				      unsigned int *y_res)
975 {
976 	unsigned char param[3];
977 
978 	if (elantech_send_cmd(psmouse, ETP_RESOLUTION_QUERY, param))
979 		return -1;
980 
981 	*x_res = elantech_convert_res(param[1] & 0x0f);
982 	*y_res = elantech_convert_res((param[1] & 0xf0) >> 4);
983 
984 	return 0;
985 }
986 
987 /*
988  * Advertise INPUT_PROP_BUTTONPAD for clickpads. The testing of bit 12 in
989  * fw_version for this is based on the following fw_version & caps table:
990  *
991  * Laptop-model:           fw_version:     caps:           buttons:
992  * Acer S3                 0x461f00        10, 13, 0e      clickpad
993  * Acer S7-392             0x581f01        50, 17, 0d      clickpad
994  * Acer V5-131             0x461f02        01, 16, 0c      clickpad
995  * Acer V5-551             0x461f00        ?               clickpad
996  * Asus K53SV              0x450f01        78, 15, 0c      2 hw buttons
997  * Asus G46VW              0x460f02        00, 18, 0c      2 hw buttons
998  * Asus G750JX             0x360f00        00, 16, 0c      2 hw buttons
999  * Asus UX31               0x361f00        20, 15, 0e      clickpad
1000  * Asus UX32VD             0x361f02        00, 15, 0e      clickpad
1001  * Avatar AVIU-145A2       0x361f00        ?               clickpad
1002  * Gigabyte U2442          0x450f01        58, 17, 0c      2 hw buttons
1003  * Lenovo L430             0x350f02        b9, 15, 0c      2 hw buttons (*)
1004  * Samsung NF210           0x150b00        78, 14, 0a      2 hw buttons
1005  * Samsung NP770Z5E        0x575f01        10, 15, 0f      clickpad
1006  * Samsung NP700Z5B        0x361f06        21, 15, 0f      clickpad
1007  * Samsung NP900X3E-A02    0x575f03        ?               clickpad
1008  * Samsung NP-QX410        0x851b00        19, 14, 0c      clickpad
1009  * Samsung RC512           0x450f00        08, 15, 0c      2 hw buttons
1010  * Samsung RF710           0x450f00        ?               2 hw buttons
1011  * System76 Pangolin       0x250f01        ?               2 hw buttons
1012  * (*) + 3 trackpoint buttons
1013  */
1014 static void elantech_set_buttonpad_prop(struct psmouse *psmouse)
1015 {
1016 	struct input_dev *dev = psmouse->dev;
1017 	struct elantech_data *etd = psmouse->private;
1018 
1019 	if (etd->fw_version & 0x001000) {
1020 		__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
1021 		__clear_bit(BTN_RIGHT, dev->keybit);
1022 	}
1023 }
1024 
1025 /*
1026  * Set the appropriate event bits for the input subsystem
1027  */
1028 static int elantech_set_input_params(struct psmouse *psmouse)
1029 {
1030 	struct input_dev *dev = psmouse->dev;
1031 	struct elantech_data *etd = psmouse->private;
1032 	unsigned int x_min = 0, y_min = 0, x_max = 0, y_max = 0, width = 0;
1033 	unsigned int x_res = 0, y_res = 0;
1034 
1035 	if (elantech_set_range(psmouse, &x_min, &y_min, &x_max, &y_max, &width))
1036 		return -1;
1037 
1038 	__set_bit(INPUT_PROP_POINTER, dev->propbit);
1039 	__set_bit(EV_KEY, dev->evbit);
1040 	__set_bit(EV_ABS, dev->evbit);
1041 	__clear_bit(EV_REL, dev->evbit);
1042 
1043 	__set_bit(BTN_LEFT, dev->keybit);
1044 	__set_bit(BTN_RIGHT, dev->keybit);
1045 
1046 	__set_bit(BTN_TOUCH, dev->keybit);
1047 	__set_bit(BTN_TOOL_FINGER, dev->keybit);
1048 	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
1049 	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
1050 
1051 	switch (etd->hw_version) {
1052 	case 1:
1053 		/* Rocker button */
1054 		if (etd->fw_version < 0x020000 &&
1055 		    (etd->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
1056 			__set_bit(BTN_FORWARD, dev->keybit);
1057 			__set_bit(BTN_BACK, dev->keybit);
1058 		}
1059 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1060 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1061 		break;
1062 
1063 	case 2:
1064 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1065 		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
1066 		/* fall through */
1067 	case 3:
1068 		if (etd->hw_version == 3)
1069 			elantech_set_buttonpad_prop(psmouse);
1070 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1071 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1072 		if (etd->reports_pressure) {
1073 			input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1074 					     ETP_PMAX_V2, 0, 0);
1075 			input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1076 					     ETP_WMAX_V2, 0, 0);
1077 		}
1078 		input_mt_init_slots(dev, 2, 0);
1079 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1080 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1081 		break;
1082 
1083 	case 4:
1084 		if (elantech_get_resolution_v4(psmouse, &x_res, &y_res)) {
1085 			/*
1086 			 * if query failed, print a warning and leave the values
1087 			 * zero to resemble synaptics.c behavior.
1088 			 */
1089 			psmouse_warn(psmouse, "couldn't query resolution data.\n");
1090 		}
1091 		elantech_set_buttonpad_prop(psmouse);
1092 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1093 		/* For X to recognize me as touchpad. */
1094 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1095 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1096 		input_abs_set_res(dev, ABS_X, x_res);
1097 		input_abs_set_res(dev, ABS_Y, y_res);
1098 		/*
1099 		 * range of pressure and width is the same as v2,
1100 		 * report ABS_PRESSURE, ABS_TOOL_WIDTH for compatibility.
1101 		 */
1102 		input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1103 				     ETP_PMAX_V2, 0, 0);
1104 		input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1105 				     ETP_WMAX_V2, 0, 0);
1106 		/* Multitouch capable pad, up to 5 fingers. */
1107 		input_mt_init_slots(dev, ETP_MAX_FINGERS, 0);
1108 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1109 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1110 		input_abs_set_res(dev, ABS_MT_POSITION_X, x_res);
1111 		input_abs_set_res(dev, ABS_MT_POSITION_Y, y_res);
1112 		input_set_abs_params(dev, ABS_MT_PRESSURE, ETP_PMIN_V2,
1113 				     ETP_PMAX_V2, 0, 0);
1114 		/*
1115 		 * The firmware reports how many trace lines the finger spans,
1116 		 * convert to surface unit as Protocol-B requires.
1117 		 */
1118 		input_set_abs_params(dev, ABS_MT_TOUCH_MAJOR, 0,
1119 				     ETP_WMAX_V2 * width, 0, 0);
1120 		break;
1121 	}
1122 
1123 	etd->y_max = y_max;
1124 	etd->width = width;
1125 
1126 	return 0;
1127 }
1128 
1129 struct elantech_attr_data {
1130 	size_t		field_offset;
1131 	unsigned char	reg;
1132 };
1133 
1134 /*
1135  * Display a register value by reading a sysfs entry
1136  */
1137 static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
1138 					char *buf)
1139 {
1140 	struct elantech_data *etd = psmouse->private;
1141 	struct elantech_attr_data *attr = data;
1142 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1143 	int rc = 0;
1144 
1145 	if (attr->reg)
1146 		rc = elantech_read_reg(psmouse, attr->reg, reg);
1147 
1148 	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
1149 }
1150 
1151 /*
1152  * Write a register value by writing a sysfs entry
1153  */
1154 static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
1155 				     void *data, const char *buf, size_t count)
1156 {
1157 	struct elantech_data *etd = psmouse->private;
1158 	struct elantech_attr_data *attr = data;
1159 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1160 	unsigned char value;
1161 	int err;
1162 
1163 	err = kstrtou8(buf, 16, &value);
1164 	if (err)
1165 		return err;
1166 
1167 	/* Do we need to preserve some bits for version 2 hardware too? */
1168 	if (etd->hw_version == 1) {
1169 		if (attr->reg == 0x10)
1170 			/* Force absolute mode always on */
1171 			value |= ETP_R10_ABSOLUTE_MODE;
1172 		else if (attr->reg == 0x11)
1173 			/* Force 4 byte mode always on */
1174 			value |= ETP_R11_4_BYTE_MODE;
1175 	}
1176 
1177 	if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
1178 		*reg = value;
1179 
1180 	return count;
1181 }
1182 
1183 #define ELANTECH_INT_ATTR(_name, _register)				\
1184 	static struct elantech_attr_data elantech_attr_##_name = {	\
1185 		.field_offset = offsetof(struct elantech_data, _name),	\
1186 		.reg = _register,					\
1187 	};								\
1188 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,			\
1189 			    &elantech_attr_##_name,			\
1190 			    elantech_show_int_attr,			\
1191 			    elantech_set_int_attr)
1192 
1193 ELANTECH_INT_ATTR(reg_07, 0x07);
1194 ELANTECH_INT_ATTR(reg_10, 0x10);
1195 ELANTECH_INT_ATTR(reg_11, 0x11);
1196 ELANTECH_INT_ATTR(reg_20, 0x20);
1197 ELANTECH_INT_ATTR(reg_21, 0x21);
1198 ELANTECH_INT_ATTR(reg_22, 0x22);
1199 ELANTECH_INT_ATTR(reg_23, 0x23);
1200 ELANTECH_INT_ATTR(reg_24, 0x24);
1201 ELANTECH_INT_ATTR(reg_25, 0x25);
1202 ELANTECH_INT_ATTR(reg_26, 0x26);
1203 ELANTECH_INT_ATTR(debug, 0);
1204 ELANTECH_INT_ATTR(paritycheck, 0);
1205 
1206 static struct attribute *elantech_attrs[] = {
1207 	&psmouse_attr_reg_07.dattr.attr,
1208 	&psmouse_attr_reg_10.dattr.attr,
1209 	&psmouse_attr_reg_11.dattr.attr,
1210 	&psmouse_attr_reg_20.dattr.attr,
1211 	&psmouse_attr_reg_21.dattr.attr,
1212 	&psmouse_attr_reg_22.dattr.attr,
1213 	&psmouse_attr_reg_23.dattr.attr,
1214 	&psmouse_attr_reg_24.dattr.attr,
1215 	&psmouse_attr_reg_25.dattr.attr,
1216 	&psmouse_attr_reg_26.dattr.attr,
1217 	&psmouse_attr_debug.dattr.attr,
1218 	&psmouse_attr_paritycheck.dattr.attr,
1219 	NULL
1220 };
1221 
1222 static struct attribute_group elantech_attr_group = {
1223 	.attrs = elantech_attrs,
1224 };
1225 
1226 static bool elantech_is_signature_valid(const unsigned char *param)
1227 {
1228 	static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10 };
1229 	int i;
1230 
1231 	if (param[0] == 0)
1232 		return false;
1233 
1234 	if (param[1] == 0)
1235 		return true;
1236 
1237 	for (i = 0; i < ARRAY_SIZE(rates); i++)
1238 		if (param[2] == rates[i])
1239 			return false;
1240 
1241 	return true;
1242 }
1243 
1244 /*
1245  * Use magic knock to detect Elantech touchpad
1246  */
1247 int elantech_detect(struct psmouse *psmouse, bool set_properties)
1248 {
1249 	struct ps2dev *ps2dev = &psmouse->ps2dev;
1250 	unsigned char param[3];
1251 
1252 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
1253 
1254 	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
1255 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1256 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1257 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1258 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
1259 		psmouse_dbg(psmouse, "sending Elantech magic knock failed.\n");
1260 		return -1;
1261 	}
1262 
1263 	/*
1264 	 * Report this in case there are Elantech models that use a different
1265 	 * set of magic numbers
1266 	 */
1267 	if (param[0] != 0x3c || param[1] != 0x03 ||
1268 	    (param[2] != 0xc8 && param[2] != 0x00)) {
1269 		psmouse_dbg(psmouse,
1270 			    "unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
1271 			    param[0], param[1], param[2]);
1272 		return -1;
1273 	}
1274 
1275 	/*
1276 	 * Query touchpad's firmware version and see if it reports known
1277 	 * value to avoid mis-detection. Logitech mice are known to respond
1278 	 * to Elantech magic knock and there might be more.
1279 	 */
1280 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1281 		psmouse_dbg(psmouse, "failed to query firmware version.\n");
1282 		return -1;
1283 	}
1284 
1285 	psmouse_dbg(psmouse,
1286 		    "Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
1287 		    param[0], param[1], param[2]);
1288 
1289 	if (!elantech_is_signature_valid(param)) {
1290 		psmouse_dbg(psmouse,
1291 			    "Probably not a real Elantech touchpad. Aborting.\n");
1292 		return -1;
1293 	}
1294 
1295 	if (set_properties) {
1296 		psmouse->vendor = "Elantech";
1297 		psmouse->name = "Touchpad";
1298 	}
1299 
1300 	return 0;
1301 }
1302 
1303 /*
1304  * Clean up sysfs entries when disconnecting
1305  */
1306 static void elantech_disconnect(struct psmouse *psmouse)
1307 {
1308 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
1309 			   &elantech_attr_group);
1310 	kfree(psmouse->private);
1311 	psmouse->private = NULL;
1312 }
1313 
1314 /*
1315  * Put the touchpad back into absolute mode when reconnecting
1316  */
1317 static int elantech_reconnect(struct psmouse *psmouse)
1318 {
1319 	psmouse_reset(psmouse);
1320 
1321 	if (elantech_detect(psmouse, 0))
1322 		return -1;
1323 
1324 	if (elantech_set_absolute_mode(psmouse)) {
1325 		psmouse_err(psmouse,
1326 			    "failed to put touchpad back into absolute mode.\n");
1327 		return -1;
1328 	}
1329 
1330 	return 0;
1331 }
1332 
1333 /*
1334  * determine hardware version and set some properties according to it.
1335  */
1336 static int elantech_set_properties(struct elantech_data *etd)
1337 {
1338 	/* This represents the version of IC body. */
1339 	int ver = (etd->fw_version & 0x0f0000) >> 16;
1340 
1341 	/* Early version of Elan touchpads doesn't obey the rule. */
1342 	if (etd->fw_version < 0x020030 || etd->fw_version == 0x020600)
1343 		etd->hw_version = 1;
1344 	else {
1345 		switch (ver) {
1346 		case 2:
1347 		case 4:
1348 			etd->hw_version = 2;
1349 			break;
1350 		case 5:
1351 			etd->hw_version = 3;
1352 			break;
1353 		case 6:
1354 		case 7:
1355 		case 8:
1356 			etd->hw_version = 4;
1357 			break;
1358 		default:
1359 			return -1;
1360 		}
1361 	}
1362 
1363 	/* decide which send_cmd we're gonna use early */
1364 	etd->send_cmd = etd->hw_version >= 3 ? elantech_send_cmd :
1365 					       synaptics_send_cmd;
1366 
1367 	/* Turn on packet checking by default */
1368 	etd->paritycheck = 1;
1369 
1370 	/*
1371 	 * This firmware suffers from misreporting coordinates when
1372 	 * a touch action starts causing the mouse cursor or scrolled page
1373 	 * to jump. Enable a workaround.
1374 	 */
1375 	etd->jumpy_cursor =
1376 		(etd->fw_version == 0x020022 || etd->fw_version == 0x020600);
1377 
1378 	if (etd->hw_version > 1) {
1379 		/* For now show extra debug information */
1380 		etd->debug = 1;
1381 
1382 		if (etd->fw_version >= 0x020800)
1383 			etd->reports_pressure = true;
1384 	}
1385 
1386 	/*
1387 	 * The signatures of v3 and v4 packets change depending on the
1388 	 * value of this hardware flag.
1389 	 */
1390 	etd->crc_enabled = ((etd->fw_version & 0x4000) == 0x4000);
1391 
1392 	return 0;
1393 }
1394 
1395 /*
1396  * Initialize the touchpad and create sysfs entries
1397  */
1398 int elantech_init(struct psmouse *psmouse)
1399 {
1400 	struct elantech_data *etd;
1401 	int i, error;
1402 	unsigned char param[3];
1403 
1404 	psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
1405 	if (!etd)
1406 		return -ENOMEM;
1407 
1408 	psmouse_reset(psmouse);
1409 
1410 	etd->parity[0] = 1;
1411 	for (i = 1; i < 256; i++)
1412 		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
1413 
1414 	/*
1415 	 * Do the version query again so we can store the result
1416 	 */
1417 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1418 		psmouse_err(psmouse, "failed to query firmware version.\n");
1419 		goto init_fail;
1420 	}
1421 	etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
1422 
1423 	if (elantech_set_properties(etd)) {
1424 		psmouse_err(psmouse, "unknown hardware version, aborting...\n");
1425 		goto init_fail;
1426 	}
1427 	psmouse_info(psmouse,
1428 		     "assuming hardware version %d (with firmware version 0x%02x%02x%02x)\n",
1429 		     etd->hw_version, param[0], param[1], param[2]);
1430 
1431 	if (etd->send_cmd(psmouse, ETP_CAPABILITIES_QUERY,
1432 	    etd->capabilities)) {
1433 		psmouse_err(psmouse, "failed to query capabilities.\n");
1434 		goto init_fail;
1435 	}
1436 	psmouse_info(psmouse,
1437 		     "Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
1438 		     etd->capabilities[0], etd->capabilities[1],
1439 		     etd->capabilities[2]);
1440 
1441 	if (elantech_set_absolute_mode(psmouse)) {
1442 		psmouse_err(psmouse,
1443 			    "failed to put touchpad into absolute mode.\n");
1444 		goto init_fail;
1445 	}
1446 
1447 	if (elantech_set_input_params(psmouse)) {
1448 		psmouse_err(psmouse, "failed to query touchpad range.\n");
1449 		goto init_fail;
1450 	}
1451 
1452 	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
1453 				   &elantech_attr_group);
1454 	if (error) {
1455 		psmouse_err(psmouse,
1456 			    "failed to create sysfs attributes, error: %d.\n",
1457 			    error);
1458 		goto init_fail;
1459 	}
1460 
1461 	psmouse->protocol_handler = elantech_process_byte;
1462 	psmouse->disconnect = elantech_disconnect;
1463 	psmouse->reconnect = elantech_reconnect;
1464 	psmouse->pktsize = etd->hw_version > 1 ? 6 : 4;
1465 
1466 	return 0;
1467 
1468  init_fail:
1469 	kfree(etd);
1470 	return -1;
1471 }
1472