xref: /openbmc/linux/drivers/input/mouse/elantech.c (revision 7dd65feb)
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/module.h>
15 #include <linux/input.h>
16 #include <linux/serio.h>
17 #include <linux/libps2.h>
18 #include "psmouse.h"
19 #include "elantech.h"
20 
21 #define elantech_debug(format, arg...)				\
22 	do {							\
23 		if (etd->debug)					\
24 			printk(KERN_DEBUG format, ##arg);	\
25 	} while (0)
26 
27 /*
28  * Send a Synaptics style sliced query command
29  */
30 static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
31 				unsigned char *param)
32 {
33 	if (psmouse_sliced_command(psmouse, c) ||
34 	    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
35 		pr_err("elantech.c: synaptics_send_cmd query 0x%02x failed.\n", c);
36 		return -1;
37 	}
38 
39 	return 0;
40 }
41 
42 /*
43  * A retrying version of ps2_command
44  */
45 static int elantech_ps2_command(struct psmouse *psmouse,
46 				unsigned char *param, int command)
47 {
48 	struct ps2dev *ps2dev = &psmouse->ps2dev;
49 	struct elantech_data *etd = psmouse->private;
50 	int rc;
51 	int tries = ETP_PS2_COMMAND_TRIES;
52 
53 	do {
54 		rc = ps2_command(ps2dev, param, command);
55 		if (rc == 0)
56 			break;
57 		tries--;
58 		elantech_debug("elantech.c: retrying ps2 command 0x%02x (%d).\n",
59 			command, tries);
60 		msleep(ETP_PS2_COMMAND_DELAY);
61 	} while (tries > 0);
62 
63 	if (rc)
64 		pr_err("elantech.c: ps2 command 0x%02x failed.\n", command);
65 
66 	return rc;
67 }
68 
69 /*
70  * Send an Elantech style special command to read a value from a register
71  */
72 static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
73 				unsigned char *val)
74 {
75 	struct elantech_data *etd = psmouse->private;
76 	unsigned char param[3];
77 	int rc = 0;
78 
79 	if (reg < 0x10 || reg > 0x26)
80 		return -1;
81 
82 	if (reg > 0x11 && reg < 0x20)
83 		return -1;
84 
85 	switch (etd->hw_version) {
86 	case 1:
87 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_READ) ||
88 		    psmouse_sliced_command(psmouse, reg) ||
89 		    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
90 			rc = -1;
91 		}
92 		break;
93 
94 	case 2:
95 		if (elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
96 		    elantech_ps2_command(psmouse,  NULL, ETP_REGISTER_READ) ||
97 		    elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
98 		    elantech_ps2_command(psmouse,  NULL, reg) ||
99 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
100 			rc = -1;
101 		}
102 		break;
103 	}
104 
105 	if (rc)
106 		pr_err("elantech.c: failed to read register 0x%02x.\n", reg);
107 	else
108 		*val = param[0];
109 
110 	return rc;
111 }
112 
113 /*
114  * Send an Elantech style special command to write a register with a value
115  */
116 static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
117 				unsigned char val)
118 {
119 	struct elantech_data *etd = psmouse->private;
120 	int rc = 0;
121 
122 	if (reg < 0x10 || reg > 0x26)
123 		return -1;
124 
125 	if (reg > 0x11 && reg < 0x20)
126 		return -1;
127 
128 	switch (etd->hw_version) {
129 	case 1:
130 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_WRITE) ||
131 		    psmouse_sliced_command(psmouse, reg) ||
132 		    psmouse_sliced_command(psmouse, val) ||
133 		    ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
134 			rc = -1;
135 		}
136 		break;
137 
138 	case 2:
139 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
140 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
141 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
142 		    elantech_ps2_command(psmouse, NULL, reg) ||
143 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
144 		    elantech_ps2_command(psmouse, NULL, val) ||
145 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
146 			rc = -1;
147 		}
148 		break;
149 	}
150 
151 	if (rc)
152 		pr_err("elantech.c: failed to write register 0x%02x with value 0x%02x.\n",
153 			reg, val);
154 
155 	return rc;
156 }
157 
158 /*
159  * Dump a complete mouse movement packet to the syslog
160  */
161 static void elantech_packet_dump(unsigned char *packet, int size)
162 {
163 	int	i;
164 
165 	printk(KERN_DEBUG "elantech.c: PS/2 packet [");
166 	for (i = 0; i < size; i++)
167 		printk("%s0x%02x ", (i) ? ", " : " ", packet[i]);
168 	printk("]\n");
169 }
170 
171 /*
172  * Interpret complete data packets and report absolute mode input events for
173  * hardware version 1. (4 byte packets)
174  */
175 static void elantech_report_absolute_v1(struct psmouse *psmouse)
176 {
177 	struct input_dev *dev = psmouse->dev;
178 	struct elantech_data *etd = psmouse->private;
179 	unsigned char *packet = psmouse->packet;
180 	int fingers;
181 	static int old_fingers;
182 
183 	if (etd->fw_version_maj == 0x01) {
184 		/* byte 0:  D   U  p1  p2   1  p3   R   L
185 		   byte 1:  f   0  th  tw  x9  x8  y9  y8 */
186 		fingers = ((packet[1] & 0x80) >> 7) +
187 				((packet[1] & 0x30) >> 4);
188 	} else {
189 		/* byte 0: n1  n0  p2  p1   1  p3   R   L
190 		   byte 1:  0   0   0   0  x9  x8  y9  y8 */
191 		fingers = (packet[0] & 0xc0) >> 6;
192 	}
193 
194 	if (etd->jumpy_cursor) {
195 		/* Discard packets that are likely to have bogus coordinates */
196 		if (fingers > old_fingers) {
197 			elantech_debug("elantech.c: discarding packet\n");
198 			goto discard_packet_v1;
199 		}
200 	}
201 
202 	input_report_key(dev, BTN_TOUCH, fingers != 0);
203 
204 	/* byte 2: x7  x6  x5  x4  x3  x2  x1  x0
205 	   byte 3: y7  y6  y5  y4  y3  y2  y1  y0 */
206 	if (fingers) {
207 		input_report_abs(dev, ABS_X,
208 			((packet[1] & 0x0c) << 6) | packet[2]);
209 		input_report_abs(dev, ABS_Y, ETP_YMAX_V1 -
210 			(((packet[1] & 0x03) << 8) | packet[3]));
211 	}
212 
213 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
214 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
215 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
216 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
217 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
218 
219 	if ((etd->fw_version_maj == 0x01) &&
220 	    (etd->capabilities & ETP_CAP_HAS_ROCKER)) {
221 		/* rocker up */
222 		input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
223 		/* rocker down */
224 		input_report_key(dev, BTN_BACK, packet[0] & 0x80);
225 	}
226 
227 	input_sync(dev);
228 
229  discard_packet_v1:
230 	old_fingers = fingers;
231 }
232 
233 /*
234  * Interpret complete data packets and report absolute mode input events for
235  * hardware version 2. (6 byte packets)
236  */
237 static void elantech_report_absolute_v2(struct psmouse *psmouse)
238 {
239 	struct input_dev *dev = psmouse->dev;
240 	unsigned char *packet = psmouse->packet;
241 	int fingers, x1, y1, x2, y2;
242 
243 	/* byte 0: n1  n0   .   .   .   .   R   L */
244 	fingers = (packet[0] & 0xc0) >> 6;
245 	input_report_key(dev, BTN_TOUCH, fingers != 0);
246 
247 	switch (fingers) {
248 	case 1:
249 		/* byte 1: x15 x14 x13 x12 x11 x10 x9  x8
250 		   byte 2: x7  x6  x5  x4  x4  x2  x1  x0 */
251 		input_report_abs(dev, ABS_X, (packet[1] << 8) | packet[2]);
252 		/* byte 4: y15 y14 y13 y12 y11 y10 y8  y8
253 		   byte 5: y7  y6  y5  y4  y3  y2  y1  y0 */
254 		input_report_abs(dev, ABS_Y, ETP_YMAX_V2 -
255 			((packet[4] << 8) | packet[5]));
256 		break;
257 
258 	case 2:
259 		/* The coordinate of each finger is reported separately with
260 		   a lower resolution for two finger touches */
261 		/* byte 0:  .   .  ay8 ax8  .   .   .   .
262 		   byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0 */
263 		x1 = ((packet[0] & 0x10) << 4) | packet[1];
264 		/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
265 		y1 = ETP_2FT_YMAX - (((packet[0] & 0x20) << 3) | packet[2]);
266 		/* byte 3:  .   .  by8 bx8  .   .   .   .
267 		   byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0 */
268 		x2 = ((packet[3] & 0x10) << 4) | packet[4];
269 		/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
270 		y2 = ETP_2FT_YMAX - (((packet[3] & 0x20) << 3) | packet[5]);
271 		/* For compatibility with the X Synaptics driver scale up one
272 		   coordinate and report as ordinary mouse movent */
273 		input_report_abs(dev, ABS_X, x1 << 2);
274 		input_report_abs(dev, ABS_Y, y1 << 2);
275 		/* For compatibility with the proprietary X Elantech driver
276 		   report both coordinates as hat coordinates */
277 		input_report_abs(dev, ABS_HAT0X, x1);
278 		input_report_abs(dev, ABS_HAT0Y, y1);
279 		input_report_abs(dev, ABS_HAT1X, x2);
280 		input_report_abs(dev, ABS_HAT1Y, y2);
281 		break;
282 	}
283 
284 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
285 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
286 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
287 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
288 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
289 
290 	input_sync(dev);
291 }
292 
293 static int elantech_check_parity_v1(struct psmouse *psmouse)
294 {
295 	struct elantech_data *etd = psmouse->private;
296 	unsigned char *packet = psmouse->packet;
297 	unsigned char p1, p2, p3;
298 
299 	/* Parity bits are placed differently */
300 	if (etd->fw_version_maj == 0x01) {
301 		/* byte 0:  D   U  p1  p2   1  p3   R   L */
302 		p1 = (packet[0] & 0x20) >> 5;
303 		p2 = (packet[0] & 0x10) >> 4;
304 	} else {
305 		/* byte 0: n1  n0  p2  p1   1  p3   R   L */
306 		p1 = (packet[0] & 0x10) >> 4;
307 		p2 = (packet[0] & 0x20) >> 5;
308 	}
309 
310 	p3 = (packet[0] & 0x04) >> 2;
311 
312 	return etd->parity[packet[1]] == p1 &&
313 	       etd->parity[packet[2]] == p2 &&
314 	       etd->parity[packet[3]] == p3;
315 }
316 
317 /*
318  * Process byte stream from mouse and handle complete packets
319  */
320 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
321 {
322 	struct elantech_data *etd = psmouse->private;
323 
324 	if (psmouse->pktcnt < psmouse->pktsize)
325 		return PSMOUSE_GOOD_DATA;
326 
327 	if (etd->debug > 1)
328 		elantech_packet_dump(psmouse->packet, psmouse->pktsize);
329 
330 	switch (etd->hw_version) {
331 	case 1:
332 		if (etd->paritycheck && !elantech_check_parity_v1(psmouse))
333 			return PSMOUSE_BAD_DATA;
334 
335 		elantech_report_absolute_v1(psmouse);
336 		break;
337 
338 	case 2:
339 		/* We don't know how to check parity in protocol v2 */
340 		elantech_report_absolute_v2(psmouse);
341 		break;
342 	}
343 
344 	return PSMOUSE_FULL_PACKET;
345 }
346 
347 /*
348  * Put the touchpad into absolute mode
349  */
350 static int elantech_set_absolute_mode(struct psmouse *psmouse)
351 {
352 	struct elantech_data *etd = psmouse->private;
353 	unsigned char val;
354 	int tries = ETP_READ_BACK_TRIES;
355 	int rc = 0;
356 
357 	switch (etd->hw_version) {
358 	case 1:
359 		etd->reg_10 = 0x16;
360 		etd->reg_11 = 0x8f;
361 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
362 		    elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
363 			rc = -1;
364 		}
365 		break;
366 
367 	case 2:
368 					/* Windows driver values */
369 		etd->reg_10 = 0x54;
370 		etd->reg_11 = 0x88;	/* 0x8a */
371 		etd->reg_21 = 0x60;	/* 0x00 */
372 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
373 		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
374 		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
375 			rc = -1;
376 			break;
377 		}
378 	}
379 
380 	if (rc == 0) {
381 		/*
382 		 * Read back reg 0x10. For hardware version 1 we must make
383 		 * sure the absolute mode bit is set. For hardware version 2
384 		 * the touchpad is probably initalising and not ready until
385 		 * we read back the value we just wrote.
386 		 */
387 		do {
388 			rc = elantech_read_reg(psmouse, 0x10, &val);
389 			if (rc == 0)
390 				break;
391 			tries--;
392 			elantech_debug("elantech.c: retrying read (%d).\n",
393 					tries);
394 			msleep(ETP_READ_BACK_DELAY);
395 		} while (tries > 0);
396 
397 		if (rc) {
398 			pr_err("elantech.c: failed to read back register 0x10.\n");
399 		} else if (etd->hw_version == 1 &&
400 			   !(val & ETP_R10_ABSOLUTE_MODE)) {
401 			pr_err("elantech.c: touchpad refuses "
402 				"to switch to absolute mode.\n");
403 			rc = -1;
404 		}
405 	}
406 
407 	if (rc)
408 		pr_err("elantech.c: failed to initialise registers.\n");
409 
410 	return rc;
411 }
412 
413 /*
414  * Set the appropriate event bits for the input subsystem
415  */
416 static void elantech_set_input_params(struct psmouse *psmouse)
417 {
418 	struct input_dev *dev = psmouse->dev;
419 	struct elantech_data *etd = psmouse->private;
420 
421 	__set_bit(EV_KEY, dev->evbit);
422 	__set_bit(EV_ABS, dev->evbit);
423 	__clear_bit(EV_REL, dev->evbit);
424 
425 	__set_bit(BTN_LEFT, dev->keybit);
426 	__set_bit(BTN_RIGHT, dev->keybit);
427 
428 	__set_bit(BTN_TOUCH, dev->keybit);
429 	__set_bit(BTN_TOOL_FINGER, dev->keybit);
430 	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
431 	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
432 
433 	switch (etd->hw_version) {
434 	case 1:
435 		/* Rocker button */
436 		if ((etd->fw_version_maj == 0x01) &&
437 		    (etd->capabilities & ETP_CAP_HAS_ROCKER)) {
438 			__set_bit(BTN_FORWARD, dev->keybit);
439 			__set_bit(BTN_BACK, dev->keybit);
440 		}
441 		input_set_abs_params(dev, ABS_X, ETP_XMIN_V1, ETP_XMAX_V1, 0, 0);
442 		input_set_abs_params(dev, ABS_Y, ETP_YMIN_V1, ETP_YMAX_V1, 0, 0);
443 		break;
444 
445 	case 2:
446 		input_set_abs_params(dev, ABS_X, ETP_XMIN_V2, ETP_XMAX_V2, 0, 0);
447 		input_set_abs_params(dev, ABS_Y, ETP_YMIN_V2, ETP_YMAX_V2, 0, 0);
448 		input_set_abs_params(dev, ABS_HAT0X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
449 		input_set_abs_params(dev, ABS_HAT0Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
450 		input_set_abs_params(dev, ABS_HAT1X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
451 		input_set_abs_params(dev, ABS_HAT1Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
452 		break;
453 	}
454 }
455 
456 struct elantech_attr_data {
457 	size_t		field_offset;
458 	unsigned char	reg;
459 };
460 
461 /*
462  * Display a register value by reading a sysfs entry
463  */
464 static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
465 					char *buf)
466 {
467 	struct elantech_data *etd = psmouse->private;
468 	struct elantech_attr_data *attr = data;
469 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
470 	int rc = 0;
471 
472 	if (attr->reg)
473 		rc = elantech_read_reg(psmouse, attr->reg, reg);
474 
475 	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
476 }
477 
478 /*
479  * Write a register value by writing a sysfs entry
480  */
481 static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
482 				     void *data, const char *buf, size_t count)
483 {
484 	struct elantech_data *etd = psmouse->private;
485 	struct elantech_attr_data *attr = data;
486 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
487 	unsigned long value;
488 	int err;
489 
490 	err = strict_strtoul(buf, 16, &value);
491 	if (err)
492 		return err;
493 
494 	if (value > 0xff)
495 		return -EINVAL;
496 
497 	/* Do we need to preserve some bits for version 2 hardware too? */
498 	if (etd->hw_version == 1) {
499 		if (attr->reg == 0x10)
500 			/* Force absolute mode always on */
501 			value |= ETP_R10_ABSOLUTE_MODE;
502 		else if (attr->reg == 0x11)
503 			/* Force 4 byte mode always on */
504 			value |= ETP_R11_4_BYTE_MODE;
505 	}
506 
507 	if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
508 		*reg = value;
509 
510 	return count;
511 }
512 
513 #define ELANTECH_INT_ATTR(_name, _register)				\
514 	static struct elantech_attr_data elantech_attr_##_name = {	\
515 		.field_offset = offsetof(struct elantech_data, _name),	\
516 		.reg = _register,					\
517 	};								\
518 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,			\
519 			    &elantech_attr_##_name,			\
520 			    elantech_show_int_attr,			\
521 			    elantech_set_int_attr)
522 
523 ELANTECH_INT_ATTR(reg_10, 0x10);
524 ELANTECH_INT_ATTR(reg_11, 0x11);
525 ELANTECH_INT_ATTR(reg_20, 0x20);
526 ELANTECH_INT_ATTR(reg_21, 0x21);
527 ELANTECH_INT_ATTR(reg_22, 0x22);
528 ELANTECH_INT_ATTR(reg_23, 0x23);
529 ELANTECH_INT_ATTR(reg_24, 0x24);
530 ELANTECH_INT_ATTR(reg_25, 0x25);
531 ELANTECH_INT_ATTR(reg_26, 0x26);
532 ELANTECH_INT_ATTR(debug, 0);
533 ELANTECH_INT_ATTR(paritycheck, 0);
534 
535 static struct attribute *elantech_attrs[] = {
536 	&psmouse_attr_reg_10.dattr.attr,
537 	&psmouse_attr_reg_11.dattr.attr,
538 	&psmouse_attr_reg_20.dattr.attr,
539 	&psmouse_attr_reg_21.dattr.attr,
540 	&psmouse_attr_reg_22.dattr.attr,
541 	&psmouse_attr_reg_23.dattr.attr,
542 	&psmouse_attr_reg_24.dattr.attr,
543 	&psmouse_attr_reg_25.dattr.attr,
544 	&psmouse_attr_reg_26.dattr.attr,
545 	&psmouse_attr_debug.dattr.attr,
546 	&psmouse_attr_paritycheck.dattr.attr,
547 	NULL
548 };
549 
550 static struct attribute_group elantech_attr_group = {
551 	.attrs = elantech_attrs,
552 };
553 
554 /*
555  * Use magic knock to detect Elantech touchpad
556  */
557 int elantech_detect(struct psmouse *psmouse, bool set_properties)
558 {
559 	struct ps2dev *ps2dev = &psmouse->ps2dev;
560 	unsigned char param[3];
561 
562 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
563 
564 	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
565 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
566 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
567 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
568 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
569 		pr_debug("elantech.c: sending Elantech magic knock failed.\n");
570 		return -1;
571 	}
572 
573 	/*
574 	 * Report this in case there are Elantech models that use a different
575 	 * set of magic numbers
576 	 */
577 	if (param[0] != 0x3c || param[1] != 0x03 || param[2] != 0xc8) {
578 		pr_debug("elantech.c: "
579 			 "unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
580 			 param[0], param[1], param[2]);
581 		return -1;
582 	}
583 
584 	/*
585 	 * Query touchpad's firmware version and see if it reports known
586 	 * value to avoid mis-detection. Logitech mice are known to respond
587 	 * to Elantech magic knock and there might be more.
588 	 */
589 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
590 		pr_debug("elantech.c: failed to query firmware version.\n");
591 		return -1;
592 	}
593 
594 	pr_debug("elantech.c: Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
595 		 param[0], param[1], param[2]);
596 
597 	if (param[0] == 0 || param[1] != 0) {
598 		pr_debug("elantech.c: Probably not a real Elantech touchpad. Aborting.\n");
599 		return -1;
600 	}
601 
602 	if (set_properties) {
603 		psmouse->vendor = "Elantech";
604 		psmouse->name = "Touchpad";
605 	}
606 
607 	return 0;
608 }
609 
610 /*
611  * Clean up sysfs entries when disconnecting
612  */
613 static void elantech_disconnect(struct psmouse *psmouse)
614 {
615 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
616 			   &elantech_attr_group);
617 	kfree(psmouse->private);
618 	psmouse->private = NULL;
619 }
620 
621 /*
622  * Put the touchpad back into absolute mode when reconnecting
623  */
624 static int elantech_reconnect(struct psmouse *psmouse)
625 {
626 	if (elantech_detect(psmouse, 0))
627 		return -1;
628 
629 	if (elantech_set_absolute_mode(psmouse)) {
630 		pr_err("elantech.c: failed to put touchpad back into absolute mode.\n");
631 		return -1;
632 	}
633 
634 	return 0;
635 }
636 
637 /*
638  * Initialize the touchpad and create sysfs entries
639  */
640 int elantech_init(struct psmouse *psmouse)
641 {
642 	struct elantech_data *etd;
643 	int i, error;
644 	unsigned char param[3];
645 
646 	psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
647 	if (!etd)
648 		return -1;
649 
650 	etd->parity[0] = 1;
651 	for (i = 1; i < 256; i++)
652 		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
653 
654 	/*
655 	 * Do the version query again so we can store the result
656 	 */
657 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
658 		pr_err("elantech.c: failed to query firmware version.\n");
659 		goto init_fail;
660 	}
661 	etd->fw_version_maj = param[0];
662 	etd->fw_version_min = param[2];
663 
664 	/*
665 	 * Assume every version greater than this is new EeePC style
666 	 * hardware with 6 byte packets
667 	 */
668 	if (etd->fw_version_maj >= 0x02 && etd->fw_version_min >= 0x30) {
669 		etd->hw_version = 2;
670 		/* For now show extra debug information */
671 		etd->debug = 1;
672 		/* Don't know how to do parity checking for version 2 */
673 		etd->paritycheck = 0;
674 	} else {
675 		etd->hw_version = 1;
676 		etd->paritycheck = 1;
677 	}
678 	pr_info("elantech.c: assuming hardware version %d, firmware version %d.%d\n",
679 		etd->hw_version, etd->fw_version_maj, etd->fw_version_min);
680 
681 	if (synaptics_send_cmd(psmouse, ETP_CAPABILITIES_QUERY, param)) {
682 		pr_err("elantech.c: failed to query capabilities.\n");
683 		goto init_fail;
684 	}
685 	pr_info("elantech.c: Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
686 		param[0], param[1], param[2]);
687 	etd->capabilities = param[0];
688 
689 	/*
690 	 * This firmware seems to suffer from misreporting coordinates when
691 	 * a touch action starts causing the mouse cursor or scrolled page
692 	 * to jump. Enable a workaround.
693 	 */
694 	if (etd->fw_version_maj == 0x02 && etd->fw_version_min == 0x22) {
695 		pr_info("elantech.c: firmware version 2.34 detected, "
696 			"enabling jumpy cursor workaround\n");
697 		etd->jumpy_cursor = 1;
698 	}
699 
700 	if (elantech_set_absolute_mode(psmouse)) {
701 		pr_err("elantech.c: failed to put touchpad into absolute mode.\n");
702 		goto init_fail;
703 	}
704 
705 	elantech_set_input_params(psmouse);
706 
707 	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
708 				   &elantech_attr_group);
709 	if (error) {
710 		pr_err("elantech.c: failed to create sysfs attributes, error: %d.\n",
711 			error);
712 		goto init_fail;
713 	}
714 
715 	psmouse->protocol_handler = elantech_process_byte;
716 	psmouse->disconnect = elantech_disconnect;
717 	psmouse->reconnect = elantech_reconnect;
718 	psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;
719 
720 	return 0;
721 
722  init_fail:
723 	kfree(etd);
724 	return -1;
725 }
726