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 */
33static 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 */
48static 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 */
66static 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 */
93static 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 */
149static 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 */
221static 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 */
235static 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
298static 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 */
310static 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 */
323static 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 */
409static 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
483static 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_mt_report_pointer_emulation(dev, true);
490	input_sync(dev);
491}
492
493static void process_packet_status_v4(struct psmouse *psmouse)
494{
495	struct input_dev *dev = psmouse->dev;
496	unsigned char *packet = psmouse->packet;
497	unsigned fingers;
498	int i;
499
500	/* notify finger state change */
501	fingers = packet[1] & 0x1f;
502	for (i = 0; i < ETP_MAX_FINGERS; i++) {
503		if ((fingers & (1 << i)) == 0) {
504			input_mt_slot(dev, i);
505			input_mt_report_slot_state(dev, MT_TOOL_FINGER, false);
506		}
507	}
508
509	elantech_input_sync_v4(psmouse);
510}
511
512static void process_packet_head_v4(struct psmouse *psmouse)
513{
514	struct input_dev *dev = psmouse->dev;
515	struct elantech_data *etd = psmouse->private;
516	unsigned char *packet = psmouse->packet;
517	int id = ((packet[3] & 0xe0) >> 5) - 1;
518	int pres, traces;
519
520	if (id < 0)
521		return;
522
523	etd->mt[id].x = ((packet[1] & 0x0f) << 8) | packet[2];
524	etd->mt[id].y = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
525	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
526	traces = (packet[0] & 0xf0) >> 4;
527
528	input_mt_slot(dev, id);
529	input_mt_report_slot_state(dev, MT_TOOL_FINGER, true);
530
531	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
532	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
533	input_report_abs(dev, ABS_MT_PRESSURE, pres);
534	input_report_abs(dev, ABS_MT_TOUCH_MAJOR, traces * etd->width);
535	/* report this for backwards compatibility */
536	input_report_abs(dev, ABS_TOOL_WIDTH, traces);
537
538	elantech_input_sync_v4(psmouse);
539}
540
541static void process_packet_motion_v4(struct psmouse *psmouse)
542{
543	struct input_dev *dev = psmouse->dev;
544	struct elantech_data *etd = psmouse->private;
545	unsigned char *packet = psmouse->packet;
546	int weight, delta_x1 = 0, delta_y1 = 0, delta_x2 = 0, delta_y2 = 0;
547	int id, sid;
548
549	id = ((packet[0] & 0xe0) >> 5) - 1;
550	if (id < 0)
551		return;
552
553	sid = ((packet[3] & 0xe0) >> 5) - 1;
554	weight = (packet[0] & 0x10) ? ETP_WEIGHT_VALUE : 1;
555	/*
556	 * Motion packets give us the delta of x, y values of specific fingers,
557	 * but in two's complement. Let the compiler do the conversion for us.
558	 * Also _enlarge_ the numbers to int, in case of overflow.
559	 */
560	delta_x1 = (signed char)packet[1];
561	delta_y1 = (signed char)packet[2];
562	delta_x2 = (signed char)packet[4];
563	delta_y2 = (signed char)packet[5];
564
565	etd->mt[id].x += delta_x1 * weight;
566	etd->mt[id].y -= delta_y1 * weight;
567	input_mt_slot(dev, id);
568	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
569	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
570
571	if (sid >= 0) {
572		etd->mt[sid].x += delta_x2 * weight;
573		etd->mt[sid].y -= delta_y2 * weight;
574		input_mt_slot(dev, sid);
575		input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[sid].x);
576		input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[sid].y);
577	}
578
579	elantech_input_sync_v4(psmouse);
580}
581
582static void elantech_report_absolute_v4(struct psmouse *psmouse,
583					int packet_type)
584{
585	switch (packet_type) {
586	case PACKET_V4_STATUS:
587		process_packet_status_v4(psmouse);
588		break;
589
590	case PACKET_V4_HEAD:
591		process_packet_head_v4(psmouse);
592		break;
593
594	case PACKET_V4_MOTION:
595		process_packet_motion_v4(psmouse);
596		break;
597
598	case PACKET_UNKNOWN:
599	default:
600		/* impossible to get here */
601		break;
602	}
603}
604
605static int elantech_packet_check_v1(struct psmouse *psmouse)
606{
607	struct elantech_data *etd = psmouse->private;
608	unsigned char *packet = psmouse->packet;
609	unsigned char p1, p2, p3;
610
611	/* Parity bits are placed differently */
612	if (etd->fw_version < 0x020000) {
613		/* byte 0:  D   U  p1  p2   1  p3   R   L */
614		p1 = (packet[0] & 0x20) >> 5;
615		p2 = (packet[0] & 0x10) >> 4;
616	} else {
617		/* byte 0: n1  n0  p2  p1   1  p3   R   L */
618		p1 = (packet[0] & 0x10) >> 4;
619		p2 = (packet[0] & 0x20) >> 5;
620	}
621
622	p3 = (packet[0] & 0x04) >> 2;
623
624	return etd->parity[packet[1]] == p1 &&
625	       etd->parity[packet[2]] == p2 &&
626	       etd->parity[packet[3]] == p3;
627}
628
629static int elantech_debounce_check_v2(struct psmouse *psmouse)
630{
631        /*
632         * When we encounter packet that matches this exactly, it means the
633         * hardware is in debounce status. Just ignore the whole packet.
634         */
635        const u8 debounce_packet[] = { 0x84, 0xff, 0xff, 0x02, 0xff, 0xff };
636        unsigned char *packet = psmouse->packet;
637
638        return !memcmp(packet, debounce_packet, sizeof(debounce_packet));
639}
640
641static int elantech_packet_check_v2(struct psmouse *psmouse)
642{
643	struct elantech_data *etd = psmouse->private;
644	unsigned char *packet = psmouse->packet;
645
646	/*
647	 * V2 hardware has two flavors. Older ones that do not report pressure,
648	 * and newer ones that reports pressure and width. With newer ones, all
649	 * packets (1, 2, 3 finger touch) have the same constant bits. With
650	 * older ones, 1/3 finger touch packets and 2 finger touch packets
651	 * have different constant bits.
652	 * With all three cases, if the constant bits are not exactly what I
653	 * expected, I consider them invalid.
654	 */
655	if (etd->reports_pressure)
656		return (packet[0] & 0x0c) == 0x04 &&
657		       (packet[3] & 0x0f) == 0x02;
658
659	if ((packet[0] & 0xc0) == 0x80)
660		return (packet[0] & 0x0c) == 0x0c &&
661		       (packet[3] & 0x0e) == 0x08;
662
663	return (packet[0] & 0x3c) == 0x3c &&
664	       (packet[1] & 0xf0) == 0x00 &&
665	       (packet[3] & 0x3e) == 0x38 &&
666	       (packet[4] & 0xf0) == 0x00;
667}
668
669/*
670 * We check the constant bits to determine what packet type we get,
671 * so packet checking is mandatory for v3 and later hardware.
672 */
673static int elantech_packet_check_v3(struct psmouse *psmouse)
674{
675	const u8 debounce_packet[] = { 0xc4, 0xff, 0xff, 0x02, 0xff, 0xff };
676	unsigned char *packet = psmouse->packet;
677
678	/*
679	 * check debounce first, it has the same signature in byte 0
680	 * and byte 3 as PACKET_V3_HEAD.
681	 */
682	if (!memcmp(packet, debounce_packet, sizeof(debounce_packet)))
683		return PACKET_DEBOUNCE;
684
685	if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
686		return PACKET_V3_HEAD;
687
688	if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
689		return PACKET_V3_TAIL;
690
691	return PACKET_UNKNOWN;
692}
693
694static int elantech_packet_check_v4(struct psmouse *psmouse)
695{
696	unsigned char *packet = psmouse->packet;
697
698	if ((packet[0] & 0x0c) == 0x04 &&
699	    (packet[3] & 0x1f) == 0x11)
700		return PACKET_V4_HEAD;
701
702	if ((packet[0] & 0x0c) == 0x04 &&
703	    (packet[3] & 0x1f) == 0x12)
704		return PACKET_V4_MOTION;
705
706	if ((packet[0] & 0x0c) == 0x04 &&
707	    (packet[3] & 0x1f) == 0x10)
708		return PACKET_V4_STATUS;
709
710	return PACKET_UNKNOWN;
711}
712
713/*
714 * Process byte stream from mouse and handle complete packets
715 */
716static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
717{
718	struct elantech_data *etd = psmouse->private;
719	int packet_type;
720
721	if (psmouse->pktcnt < psmouse->pktsize)
722		return PSMOUSE_GOOD_DATA;
723
724	if (etd->debug > 1)
725		elantech_packet_dump(psmouse);
726
727	switch (etd->hw_version) {
728	case 1:
729		if (etd->paritycheck && !elantech_packet_check_v1(psmouse))
730			return PSMOUSE_BAD_DATA;
731
732		elantech_report_absolute_v1(psmouse);
733		break;
734
735	case 2:
736		/* ignore debounce */
737		if (elantech_debounce_check_v2(psmouse))
738			return PSMOUSE_FULL_PACKET;
739
740		if (etd->paritycheck && !elantech_packet_check_v2(psmouse))
741			return PSMOUSE_BAD_DATA;
742
743		elantech_report_absolute_v2(psmouse);
744		break;
745
746	case 3:
747		packet_type = elantech_packet_check_v3(psmouse);
748		/* ignore debounce */
749		if (packet_type == PACKET_DEBOUNCE)
750			return PSMOUSE_FULL_PACKET;
751
752		if (packet_type == PACKET_UNKNOWN)
753			return PSMOUSE_BAD_DATA;
754
755		elantech_report_absolute_v3(psmouse, packet_type);
756		break;
757
758	case 4:
759		packet_type = elantech_packet_check_v4(psmouse);
760		if (packet_type == PACKET_UNKNOWN)
761			return PSMOUSE_BAD_DATA;
762
763		elantech_report_absolute_v4(psmouse, packet_type);
764		break;
765	}
766
767	return PSMOUSE_FULL_PACKET;
768}
769
770/*
771 * Put the touchpad into absolute mode
772 */
773static int elantech_set_absolute_mode(struct psmouse *psmouse)
774{
775	struct elantech_data *etd = psmouse->private;
776	unsigned char val;
777	int tries = ETP_READ_BACK_TRIES;
778	int rc = 0;
779
780	switch (etd->hw_version) {
781	case 1:
782		etd->reg_10 = 0x16;
783		etd->reg_11 = 0x8f;
784		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
785		    elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
786			rc = -1;
787		}
788		break;
789
790	case 2:
791					/* Windows driver values */
792		etd->reg_10 = 0x54;
793		etd->reg_11 = 0x88;	/* 0x8a */
794		etd->reg_21 = 0x60;	/* 0x00 */
795		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
796		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
797		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
798			rc = -1;
799		}
800		break;
801
802	case 3:
803		etd->reg_10 = 0x0b;
804		if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
805			rc = -1;
806
807		break;
808
809	case 4:
810		etd->reg_07 = 0x01;
811		if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
812			rc = -1;
813
814		goto skip_readback_reg_10; /* v4 has no reg 0x10 to read */
815	}
816
817	if (rc == 0) {
818		/*
819		 * Read back reg 0x10. For hardware version 1 we must make
820		 * sure the absolute mode bit is set. For hardware version 2
821		 * the touchpad is probably initializing and not ready until
822		 * we read back the value we just wrote.
823		 */
824		do {
825			rc = elantech_read_reg(psmouse, 0x10, &val);
826			if (rc == 0)
827				break;
828			tries--;
829			elantech_debug("retrying read (%d).\n", tries);
830			msleep(ETP_READ_BACK_DELAY);
831		} while (tries > 0);
832
833		if (rc) {
834			psmouse_err(psmouse,
835				    "failed to read back register 0x10.\n");
836		} else if (etd->hw_version == 1 &&
837			   !(val & ETP_R10_ABSOLUTE_MODE)) {
838			psmouse_err(psmouse,
839				    "touchpad refuses to switch to absolute mode.\n");
840			rc = -1;
841		}
842	}
843
844 skip_readback_reg_10:
845	if (rc)
846		psmouse_err(psmouse, "failed to initialise registers.\n");
847
848	return rc;
849}
850
851static int elantech_set_range(struct psmouse *psmouse,
852			      unsigned int *x_min, unsigned int *y_min,
853			      unsigned int *x_max, unsigned int *y_max,
854			      unsigned int *width)
855{
856	struct elantech_data *etd = psmouse->private;
857	unsigned char param[3];
858	unsigned char traces;
859
860	switch (etd->hw_version) {
861	case 1:
862		*x_min = ETP_XMIN_V1;
863		*y_min = ETP_YMIN_V1;
864		*x_max = ETP_XMAX_V1;
865		*y_max = ETP_YMAX_V1;
866		break;
867
868	case 2:
869		if (etd->fw_version == 0x020800 ||
870		    etd->fw_version == 0x020b00 ||
871		    etd->fw_version == 0x020030) {
872			*x_min = ETP_XMIN_V2;
873			*y_min = ETP_YMIN_V2;
874			*x_max = ETP_XMAX_V2;
875			*y_max = ETP_YMAX_V2;
876		} else {
877			int i;
878			int fixed_dpi;
879
880			i = (etd->fw_version > 0x020800 &&
881			     etd->fw_version < 0x020900) ? 1 : 2;
882
883			if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
884				return -1;
885
886			fixed_dpi = param[1] & 0x10;
887
888			if (((etd->fw_version >> 16) == 0x14) && fixed_dpi) {
889				if (etd->send_cmd(psmouse, ETP_SAMPLE_QUERY, param))
890					return -1;
891
892				*x_max = (etd->capabilities[1] - i) * param[1] / 2;
893				*y_max = (etd->capabilities[2] - i) * param[2] / 2;
894			} else if (etd->fw_version == 0x040216) {
895				*x_max = 819;
896				*y_max = 405;
897			} else if (etd->fw_version == 0x040219 || etd->fw_version == 0x040215) {
898				*x_max = 900;
899				*y_max = 500;
900			} else {
901				*x_max = (etd->capabilities[1] - i) * 64;
902				*y_max = (etd->capabilities[2] - i) * 64;
903			}
904		}
905		break;
906
907	case 3:
908		if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
909			return -1;
910
911		*x_max = (0x0f & param[0]) << 8 | param[1];
912		*y_max = (0xf0 & param[0]) << 4 | param[2];
913		break;
914
915	case 4:
916		if (etd->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
917			return -1;
918
919		*x_max = (0x0f & param[0]) << 8 | param[1];
920		*y_max = (0xf0 & param[0]) << 4 | param[2];
921		traces = etd->capabilities[1];
922		if ((traces < 2) || (traces > *x_max))
923			return -1;
924
925		*width = *x_max / (traces - 1);
926		break;
927	}
928
929	return 0;
930}
931
932/*
933 * (value from firmware) * 10 + 790 = dpi
934 * we also have to convert dpi to dots/mm (*10/254 to avoid floating point)
935 */
936static unsigned int elantech_convert_res(unsigned int val)
937{
938	return (val * 10 + 790) * 10 / 254;
939}
940
941static int elantech_get_resolution_v4(struct psmouse *psmouse,
942				      unsigned int *x_res,
943				      unsigned int *y_res)
944{
945	unsigned char param[3];
946
947	if (elantech_send_cmd(psmouse, ETP_RESOLUTION_QUERY, param))
948		return -1;
949
950	*x_res = elantech_convert_res(param[1] & 0x0f);
951	*y_res = elantech_convert_res((param[1] & 0xf0) >> 4);
952
953	return 0;
954}
955
956/*
957 * Set the appropriate event bits for the input subsystem
958 */
959static int elantech_set_input_params(struct psmouse *psmouse)
960{
961	struct input_dev *dev = psmouse->dev;
962	struct elantech_data *etd = psmouse->private;
963	unsigned int x_min = 0, y_min = 0, x_max = 0, y_max = 0, width = 0;
964	unsigned int x_res = 0, y_res = 0;
965
966	if (elantech_set_range(psmouse, &x_min, &y_min, &x_max, &y_max, &width))
967		return -1;
968
969	__set_bit(INPUT_PROP_POINTER, dev->propbit);
970	__set_bit(EV_KEY, dev->evbit);
971	__set_bit(EV_ABS, dev->evbit);
972	__clear_bit(EV_REL, dev->evbit);
973
974	__set_bit(BTN_LEFT, dev->keybit);
975	__set_bit(BTN_RIGHT, dev->keybit);
976
977	__set_bit(BTN_TOUCH, dev->keybit);
978	__set_bit(BTN_TOOL_FINGER, dev->keybit);
979	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
980	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
981
982	switch (etd->hw_version) {
983	case 1:
984		/* Rocker button */
985		if (etd->fw_version < 0x020000 &&
986		    (etd->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
987			__set_bit(BTN_FORWARD, dev->keybit);
988			__set_bit(BTN_BACK, dev->keybit);
989		}
990		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
991		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
992		break;
993
994	case 2:
995		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
996		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
997		/* fall through */
998	case 3:
999		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1000		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1001		if (etd->reports_pressure) {
1002			input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1003					     ETP_PMAX_V2, 0, 0);
1004			input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1005					     ETP_WMAX_V2, 0, 0);
1006		}
1007		input_mt_init_slots(dev, 2);
1008		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1009		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1010		break;
1011
1012	case 4:
1013		if (elantech_get_resolution_v4(psmouse, &x_res, &y_res)) {
1014			/*
1015			 * if query failed, print a warning and leave the values
1016			 * zero to resemble synaptics.c behavior.
1017			 */
1018			psmouse_warn(psmouse, "couldn't query resolution data.\n");
1019		}
1020		/* v4 is clickpad, with only one button. */
1021		__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
1022		__clear_bit(BTN_RIGHT, dev->keybit);
1023		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1024		/* For X to recognize me as touchpad. */
1025		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1026		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1027		input_abs_set_res(dev, ABS_X, x_res);
1028		input_abs_set_res(dev, ABS_Y, y_res);
1029		/*
1030		 * range of pressure and width is the same as v2,
1031		 * report ABS_PRESSURE, ABS_TOOL_WIDTH for compatibility.
1032		 */
1033		input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1034				     ETP_PMAX_V2, 0, 0);
1035		input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1036				     ETP_WMAX_V2, 0, 0);
1037		/* Multitouch capable pad, up to 5 fingers. */
1038		input_mt_init_slots(dev, ETP_MAX_FINGERS);
1039		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1040		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1041		input_abs_set_res(dev, ABS_MT_POSITION_X, x_res);
1042		input_abs_set_res(dev, ABS_MT_POSITION_Y, y_res);
1043		input_set_abs_params(dev, ABS_MT_PRESSURE, ETP_PMIN_V2,
1044				     ETP_PMAX_V2, 0, 0);
1045		/*
1046		 * The firmware reports how many trace lines the finger spans,
1047		 * convert to surface unit as Protocol-B requires.
1048		 */
1049		input_set_abs_params(dev, ABS_MT_TOUCH_MAJOR, 0,
1050				     ETP_WMAX_V2 * width, 0, 0);
1051		break;
1052	}
1053
1054	etd->y_max = y_max;
1055	etd->width = width;
1056
1057	return 0;
1058}
1059
1060struct elantech_attr_data {
1061	size_t		field_offset;
1062	unsigned char	reg;
1063};
1064
1065/*
1066 * Display a register value by reading a sysfs entry
1067 */
1068static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
1069					char *buf)
1070{
1071	struct elantech_data *etd = psmouse->private;
1072	struct elantech_attr_data *attr = data;
1073	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1074	int rc = 0;
1075
1076	if (attr->reg)
1077		rc = elantech_read_reg(psmouse, attr->reg, reg);
1078
1079	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
1080}
1081
1082/*
1083 * Write a register value by writing a sysfs entry
1084 */
1085static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
1086				     void *data, const char *buf, size_t count)
1087{
1088	struct elantech_data *etd = psmouse->private;
1089	struct elantech_attr_data *attr = data;
1090	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1091	unsigned char value;
1092	int err;
1093
1094	err = kstrtou8(buf, 16, &value);
1095	if (err)
1096		return err;
1097
1098	/* Do we need to preserve some bits for version 2 hardware too? */
1099	if (etd->hw_version == 1) {
1100		if (attr->reg == 0x10)
1101			/* Force absolute mode always on */
1102			value |= ETP_R10_ABSOLUTE_MODE;
1103		else if (attr->reg == 0x11)
1104			/* Force 4 byte mode always on */
1105			value |= ETP_R11_4_BYTE_MODE;
1106	}
1107
1108	if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
1109		*reg = value;
1110
1111	return count;
1112}
1113
1114#define ELANTECH_INT_ATTR(_name, _register)				\
1115	static struct elantech_attr_data elantech_attr_##_name = {	\
1116		.field_offset = offsetof(struct elantech_data, _name),	\
1117		.reg = _register,					\
1118	};								\
1119	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,			\
1120			    &elantech_attr_##_name,			\
1121			    elantech_show_int_attr,			\
1122			    elantech_set_int_attr)
1123
1124ELANTECH_INT_ATTR(reg_07, 0x07);
1125ELANTECH_INT_ATTR(reg_10, 0x10);
1126ELANTECH_INT_ATTR(reg_11, 0x11);
1127ELANTECH_INT_ATTR(reg_20, 0x20);
1128ELANTECH_INT_ATTR(reg_21, 0x21);
1129ELANTECH_INT_ATTR(reg_22, 0x22);
1130ELANTECH_INT_ATTR(reg_23, 0x23);
1131ELANTECH_INT_ATTR(reg_24, 0x24);
1132ELANTECH_INT_ATTR(reg_25, 0x25);
1133ELANTECH_INT_ATTR(reg_26, 0x26);
1134ELANTECH_INT_ATTR(debug, 0);
1135ELANTECH_INT_ATTR(paritycheck, 0);
1136
1137static struct attribute *elantech_attrs[] = {
1138	&psmouse_attr_reg_07.dattr.attr,
1139	&psmouse_attr_reg_10.dattr.attr,
1140	&psmouse_attr_reg_11.dattr.attr,
1141	&psmouse_attr_reg_20.dattr.attr,
1142	&psmouse_attr_reg_21.dattr.attr,
1143	&psmouse_attr_reg_22.dattr.attr,
1144	&psmouse_attr_reg_23.dattr.attr,
1145	&psmouse_attr_reg_24.dattr.attr,
1146	&psmouse_attr_reg_25.dattr.attr,
1147	&psmouse_attr_reg_26.dattr.attr,
1148	&psmouse_attr_debug.dattr.attr,
1149	&psmouse_attr_paritycheck.dattr.attr,
1150	NULL
1151};
1152
1153static struct attribute_group elantech_attr_group = {
1154	.attrs = elantech_attrs,
1155};
1156
1157static bool elantech_is_signature_valid(const unsigned char *param)
1158{
1159	static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10 };
1160	int i;
1161
1162	if (param[0] == 0)
1163		return false;
1164
1165	if (param[1] == 0)
1166		return true;
1167
1168	for (i = 0; i < ARRAY_SIZE(rates); i++)
1169		if (param[2] == rates[i])
1170			return false;
1171
1172	return true;
1173}
1174
1175/*
1176 * Use magic knock to detect Elantech touchpad
1177 */
1178int elantech_detect(struct psmouse *psmouse, bool set_properties)
1179{
1180	struct ps2dev *ps2dev = &psmouse->ps2dev;
1181	unsigned char param[3];
1182
1183	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
1184
1185	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
1186	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1187	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1188	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1189	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
1190		psmouse_dbg(psmouse, "sending Elantech magic knock failed.\n");
1191		return -1;
1192	}
1193
1194	/*
1195	 * Report this in case there are Elantech models that use a different
1196	 * set of magic numbers
1197	 */
1198	if (param[0] != 0x3c || param[1] != 0x03 ||
1199	    (param[2] != 0xc8 && param[2] != 0x00)) {
1200		psmouse_dbg(psmouse,
1201			    "unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
1202			    param[0], param[1], param[2]);
1203		return -1;
1204	}
1205
1206	/*
1207	 * Query touchpad's firmware version and see if it reports known
1208	 * value to avoid mis-detection. Logitech mice are known to respond
1209	 * to Elantech magic knock and there might be more.
1210	 */
1211	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1212		psmouse_dbg(psmouse, "failed to query firmware version.\n");
1213		return -1;
1214	}
1215
1216	psmouse_dbg(psmouse,
1217		    "Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
1218		    param[0], param[1], param[2]);
1219
1220	if (!elantech_is_signature_valid(param)) {
1221		psmouse_dbg(psmouse,
1222			    "Probably not a real Elantech touchpad. Aborting.\n");
1223		return -1;
1224	}
1225
1226	if (set_properties) {
1227		psmouse->vendor = "Elantech";
1228		psmouse->name = "Touchpad";
1229	}
1230
1231	return 0;
1232}
1233
1234/*
1235 * Clean up sysfs entries when disconnecting
1236 */
1237static void elantech_disconnect(struct psmouse *psmouse)
1238{
1239	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
1240			   &elantech_attr_group);
1241	kfree(psmouse->private);
1242	psmouse->private = NULL;
1243}
1244
1245/*
1246 * Put the touchpad back into absolute mode when reconnecting
1247 */
1248static int elantech_reconnect(struct psmouse *psmouse)
1249{
1250	psmouse_reset(psmouse);
1251
1252	if (elantech_detect(psmouse, 0))
1253		return -1;
1254
1255	if (elantech_set_absolute_mode(psmouse)) {
1256		psmouse_err(psmouse,
1257			    "failed to put touchpad back into absolute mode.\n");
1258		return -1;
1259	}
1260
1261	return 0;
1262}
1263
1264/*
1265 * determine hardware version and set some properties according to it.
1266 */
1267static int elantech_set_properties(struct elantech_data *etd)
1268{
1269	/* This represents the version of IC body. */
1270	int ver = (etd->fw_version & 0x0f0000) >> 16;
1271
1272	/* Early version of Elan touchpads doesn't obey the rule. */
1273	if (etd->fw_version < 0x020030 || etd->fw_version == 0x020600)
1274		etd->hw_version = 1;
1275	else {
1276		switch (ver) {
1277		case 2:
1278		case 4:
1279			etd->hw_version = 2;
1280			break;
1281		case 5:
1282			etd->hw_version = 3;
1283			break;
1284		case 6:
1285			etd->hw_version = 4;
1286			break;
1287		default:
1288			return -1;
1289		}
1290	}
1291
1292	/* decide which send_cmd we're gonna use early */
1293	etd->send_cmd = etd->hw_version >= 3 ? elantech_send_cmd :
1294					       synaptics_send_cmd;
1295
1296	/* Turn on packet checking by default */
1297	etd->paritycheck = 1;
1298
1299	/*
1300	 * This firmware suffers from misreporting coordinates when
1301	 * a touch action starts causing the mouse cursor or scrolled page
1302	 * to jump. Enable a workaround.
1303	 */
1304	etd->jumpy_cursor =
1305		(etd->fw_version == 0x020022 || etd->fw_version == 0x020600);
1306
1307	if (etd->hw_version > 1) {
1308		/* For now show extra debug information */
1309		etd->debug = 1;
1310
1311		if (etd->fw_version >= 0x020800)
1312			etd->reports_pressure = true;
1313	}
1314
1315	return 0;
1316}
1317
1318/*
1319 * Initialize the touchpad and create sysfs entries
1320 */
1321int elantech_init(struct psmouse *psmouse)
1322{
1323	struct elantech_data *etd;
1324	int i, error;
1325	unsigned char param[3];
1326
1327	psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
1328	if (!etd)
1329		return -ENOMEM;
1330
1331	psmouse_reset(psmouse);
1332
1333	etd->parity[0] = 1;
1334	for (i = 1; i < 256; i++)
1335		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
1336
1337	/*
1338	 * Do the version query again so we can store the result
1339	 */
1340	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1341		psmouse_err(psmouse, "failed to query firmware version.\n");
1342		goto init_fail;
1343	}
1344	etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
1345
1346	if (elantech_set_properties(etd)) {
1347		psmouse_err(psmouse, "unknown hardware version, aborting...\n");
1348		goto init_fail;
1349	}
1350	psmouse_info(psmouse,
1351		     "assuming hardware version %d (with firmware version 0x%02x%02x%02x)\n",
1352		     etd->hw_version, param[0], param[1], param[2]);
1353
1354	if (etd->send_cmd(psmouse, ETP_CAPABILITIES_QUERY,
1355	    etd->capabilities)) {
1356		psmouse_err(psmouse, "failed to query capabilities.\n");
1357		goto init_fail;
1358	}
1359	psmouse_info(psmouse,
1360		     "Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
1361		     etd->capabilities[0], etd->capabilities[1],
1362		     etd->capabilities[2]);
1363
1364	if (elantech_set_absolute_mode(psmouse)) {
1365		psmouse_err(psmouse,
1366			    "failed to put touchpad into absolute mode.\n");
1367		goto init_fail;
1368	}
1369
1370	if (elantech_set_input_params(psmouse)) {
1371		psmouse_err(psmouse, "failed to query touchpad range.\n");
1372		goto init_fail;
1373	}
1374
1375	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
1376				   &elantech_attr_group);
1377	if (error) {
1378		psmouse_err(psmouse,
1379			    "failed to create sysfs attributes, error: %d.\n",
1380			    error);
1381		goto init_fail;
1382	}
1383
1384	psmouse->protocol_handler = elantech_process_byte;
1385	psmouse->disconnect = elantech_disconnect;
1386	psmouse->reconnect = elantech_reconnect;
1387	psmouse->pktsize = etd->hw_version > 1 ? 6 : 4;
1388
1389	return 0;
1390
1391 init_fail:
1392	kfree(etd);
1393	return -1;
1394}
1395