xref: /linux/drivers/input/mouse/elantech.c (revision 492c826b9facefa84995f4dea917e301b5ee0884)
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 #define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
14 
15 #include <linux/delay.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18 #include <linux/input.h>
19 #include <linux/input/mt.h>
20 #include <linux/serio.h>
21 #include <linux/libps2.h>
22 #include "psmouse.h"
23 #include "elantech.h"
24 
25 #define elantech_debug(fmt, ...)					\
26 	do {								\
27 		if (etd->debug)						\
28 			printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__);	\
29 	} while (0)
30 
31 static bool force_elantech;
32 module_param_named(force_elantech, force_elantech, bool, 0644);
33 MODULE_PARM_DESC(force_elantech, "Force the Elantech PS/2 protocol extension to be used, 1 = enabled, 0 = disabled (default).");
34 
35 /*
36  * Send a Synaptics style sliced query command
37  */
38 static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
39 				unsigned char *param)
40 {
41 	if (psmouse_sliced_command(psmouse, c) ||
42 	    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
43 		pr_err("synaptics_send_cmd query 0x%02x failed.\n", c);
44 		return -1;
45 	}
46 
47 	return 0;
48 }
49 
50 /*
51  * A retrying version of ps2_command
52  */
53 static int elantech_ps2_command(struct psmouse *psmouse,
54 				unsigned char *param, int command)
55 {
56 	struct ps2dev *ps2dev = &psmouse->ps2dev;
57 	struct elantech_data *etd = psmouse->private;
58 	int rc;
59 	int tries = ETP_PS2_COMMAND_TRIES;
60 
61 	do {
62 		rc = ps2_command(ps2dev, param, command);
63 		if (rc == 0)
64 			break;
65 		tries--;
66 		elantech_debug("retrying ps2 command 0x%02x (%d).\n",
67 				command, tries);
68 		msleep(ETP_PS2_COMMAND_DELAY);
69 	} while (tries > 0);
70 
71 	if (rc)
72 		pr_err("ps2 command 0x%02x failed.\n", command);
73 
74 	return rc;
75 }
76 
77 /*
78  * Send an Elantech style special command to read a value from a register
79  */
80 static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
81 				unsigned char *val)
82 {
83 	struct elantech_data *etd = psmouse->private;
84 	unsigned char param[3];
85 	int rc = 0;
86 
87 	if (reg < 0x10 || reg > 0x26)
88 		return -1;
89 
90 	if (reg > 0x11 && reg < 0x20)
91 		return -1;
92 
93 	switch (etd->hw_version) {
94 	case 1:
95 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_READ) ||
96 		    psmouse_sliced_command(psmouse, reg) ||
97 		    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
98 			rc = -1;
99 		}
100 		break;
101 
102 	case 2:
103 		if (elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
104 		    elantech_ps2_command(psmouse,  NULL, ETP_REGISTER_READ) ||
105 		    elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
106 		    elantech_ps2_command(psmouse,  NULL, reg) ||
107 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
108 			rc = -1;
109 		}
110 		break;
111 	}
112 
113 	if (rc)
114 		pr_err("failed to read register 0x%02x.\n", reg);
115 	else
116 		*val = param[0];
117 
118 	return rc;
119 }
120 
121 /*
122  * Send an Elantech style special command to write a register with a value
123  */
124 static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
125 				unsigned char val)
126 {
127 	struct elantech_data *etd = psmouse->private;
128 	int rc = 0;
129 
130 	if (reg < 0x10 || reg > 0x26)
131 		return -1;
132 
133 	if (reg > 0x11 && reg < 0x20)
134 		return -1;
135 
136 	switch (etd->hw_version) {
137 	case 1:
138 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_WRITE) ||
139 		    psmouse_sliced_command(psmouse, reg) ||
140 		    psmouse_sliced_command(psmouse, val) ||
141 		    ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
142 			rc = -1;
143 		}
144 		break;
145 
146 	case 2:
147 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
148 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
149 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
150 		    elantech_ps2_command(psmouse, NULL, reg) ||
151 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
152 		    elantech_ps2_command(psmouse, NULL, val) ||
153 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
154 			rc = -1;
155 		}
156 		break;
157 	}
158 
159 	if (rc)
160 		pr_err("failed to write register 0x%02x with value 0x%02x.\n",
161 			reg, val);
162 
163 	return rc;
164 }
165 
166 /*
167  * Dump a complete mouse movement packet to the syslog
168  */
169 static void elantech_packet_dump(unsigned char *packet, int size)
170 {
171 	int	i;
172 
173 	printk(KERN_DEBUG pr_fmt("PS/2 packet ["));
174 	for (i = 0; i < size; i++)
175 		printk("%s0x%02x ", (i) ? ", " : " ", packet[i]);
176 	printk("]\n");
177 }
178 
179 /*
180  * Interpret complete data packets and report absolute mode input events for
181  * hardware version 1. (4 byte packets)
182  */
183 static void elantech_report_absolute_v1(struct psmouse *psmouse)
184 {
185 	struct input_dev *dev = psmouse->dev;
186 	struct elantech_data *etd = psmouse->private;
187 	unsigned char *packet = psmouse->packet;
188 	int fingers;
189 
190 	if (etd->fw_version < 0x020000) {
191 		/*
192 		 * byte 0:  D   U  p1  p2   1  p3   R   L
193 		 * byte 1:  f   0  th  tw  x9  x8  y9  y8
194 		 */
195 		fingers = ((packet[1] & 0x80) >> 7) +
196 				((packet[1] & 0x30) >> 4);
197 	} else {
198 		/*
199 		 * byte 0: n1  n0  p2  p1   1  p3   R   L
200 		 * byte 1:  0   0   0   0  x9  x8  y9  y8
201 		 */
202 		fingers = (packet[0] & 0xc0) >> 6;
203 	}
204 
205 	if (etd->jumpy_cursor) {
206 		if (fingers != 1) {
207 			etd->single_finger_reports = 0;
208 		} else if (etd->single_finger_reports < 2) {
209 			/* Discard first 2 reports of one finger, bogus */
210 			etd->single_finger_reports++;
211 			elantech_debug("discarding packet\n");
212 			return;
213 		}
214 	}
215 
216 	input_report_key(dev, BTN_TOUCH, fingers != 0);
217 
218 	/*
219 	 * byte 2: x7  x6  x5  x4  x3  x2  x1  x0
220 	 * byte 3: y7  y6  y5  y4  y3  y2  y1  y0
221 	 */
222 	if (fingers) {
223 		input_report_abs(dev, ABS_X,
224 			((packet[1] & 0x0c) << 6) | packet[2]);
225 		input_report_abs(dev, ABS_Y,
226 			ETP_YMAX_V1 - (((packet[1] & 0x03) << 8) | packet[3]));
227 	}
228 
229 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
230 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
231 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
232 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
233 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
234 
235 	if (etd->fw_version < 0x020000 &&
236 	    (etd->capabilities & ETP_CAP_HAS_ROCKER)) {
237 		/* rocker up */
238 		input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
239 		/* rocker down */
240 		input_report_key(dev, BTN_BACK, packet[0] & 0x80);
241 	}
242 
243 	input_sync(dev);
244 }
245 
246 static void elantech_set_slot(struct input_dev *dev, int slot, bool active,
247 			      unsigned int x, unsigned int y)
248 {
249 	input_mt_slot(dev, slot);
250 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
251 	if (active) {
252 		input_report_abs(dev, ABS_MT_POSITION_X, x);
253 		input_report_abs(dev, ABS_MT_POSITION_Y, y);
254 	}
255 }
256 
257 /* x1 < x2 and y1 < y2 when two fingers, x = y = 0 when not pressed */
258 static void elantech_report_semi_mt_data(struct input_dev *dev,
259 					 unsigned int num_fingers,
260 					 unsigned int x1, unsigned int y1,
261 					 unsigned int x2, unsigned int y2)
262 {
263 	elantech_set_slot(dev, 0, num_fingers != 0, x1, y1);
264 	elantech_set_slot(dev, 1, num_fingers == 2, x2, y2);
265 }
266 
267 /*
268  * Interpret complete data packets and report absolute mode input events for
269  * hardware version 2. (6 byte packets)
270  */
271 static void elantech_report_absolute_v2(struct psmouse *psmouse)
272 {
273 	struct elantech_data *etd = psmouse->private;
274 	struct input_dev *dev = psmouse->dev;
275 	unsigned char *packet = psmouse->packet;
276 	unsigned int fingers, x1 = 0, y1 = 0, x2 = 0, y2 = 0, width = 0, pres = 0;
277 
278 	/* byte 0: n1  n0   .   .   .   .   R   L */
279 	fingers = (packet[0] & 0xc0) >> 6;
280 	input_report_key(dev, BTN_TOUCH, fingers != 0);
281 
282 	switch (fingers) {
283 	case 3:
284 		/*
285 		 * Same as one finger, except report of more than 3 fingers:
286 		 * byte 3:  n4  .   w1  w0   .   .   .   .
287 		 */
288 		if (packet[3] & 0x80)
289 			fingers = 4;
290 		/* pass through... */
291 	case 1:
292 		/*
293 		 * byte 1:  .   .   .   .   .  x10 x9  x8
294 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
295 		 */
296 		x1 = ((packet[1] & 0x07) << 8) | packet[2];
297 		/*
298 		 * byte 4:  .   .   .   .   .   .  y9  y8
299 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
300 		 */
301 		y1 = ETP_YMAX_V2 - (((packet[4] & 0x03) << 8) | packet[5]);
302 
303 		input_report_abs(dev, ABS_X, x1);
304 		input_report_abs(dev, ABS_Y, y1);
305 
306 		pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
307 		width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
308 		break;
309 
310 	case 2:
311 		/*
312 		 * The coordinate of each finger is reported separately
313 		 * with a lower resolution for two finger touches:
314 		 * byte 0:  .   .  ay8 ax8  .   .   .   .
315 		 * byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
316 		 */
317 		x1 = ((packet[0] & 0x10) << 4) | packet[1];
318 		/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
319 		y1 = ETP_2FT_YMAX - (((packet[0] & 0x20) << 3) | packet[2]);
320 		/*
321 		 * byte 3:  .   .  by8 bx8  .   .   .   .
322 		 * byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
323 		 */
324 		x2 = ((packet[3] & 0x10) << 4) | packet[4];
325 		/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
326 		y2 = ETP_2FT_YMAX - (((packet[3] & 0x20) << 3) | packet[5]);
327 		/*
328 		 * For compatibility with the X Synaptics driver scale up
329 		 * one coordinate and report as ordinary mouse movent
330 		 */
331 		input_report_abs(dev, ABS_X, x1 << 2);
332 		input_report_abs(dev, ABS_Y, y1 << 2);
333 
334 		/* Unknown so just report sensible values */
335 		pres = 127;
336 		width = 7;
337 		break;
338 	}
339 
340 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
341 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
342 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
343 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
344 	input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
345 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
346 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
347 	if (etd->reports_pressure) {
348 		input_report_abs(dev, ABS_PRESSURE, pres);
349 		input_report_abs(dev, ABS_TOOL_WIDTH, width);
350 	}
351 
352 	input_sync(dev);
353 }
354 
355 static int elantech_check_parity_v1(struct psmouse *psmouse)
356 {
357 	struct elantech_data *etd = psmouse->private;
358 	unsigned char *packet = psmouse->packet;
359 	unsigned char p1, p2, p3;
360 
361 	/* Parity bits are placed differently */
362 	if (etd->fw_version < 0x020000) {
363 		/* byte 0:  D   U  p1  p2   1  p3   R   L */
364 		p1 = (packet[0] & 0x20) >> 5;
365 		p2 = (packet[0] & 0x10) >> 4;
366 	} else {
367 		/* byte 0: n1  n0  p2  p1   1  p3   R   L */
368 		p1 = (packet[0] & 0x10) >> 4;
369 		p2 = (packet[0] & 0x20) >> 5;
370 	}
371 
372 	p3 = (packet[0] & 0x04) >> 2;
373 
374 	return etd->parity[packet[1]] == p1 &&
375 	       etd->parity[packet[2]] == p2 &&
376 	       etd->parity[packet[3]] == p3;
377 }
378 
379 /*
380  * Process byte stream from mouse and handle complete packets
381  */
382 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
383 {
384 	struct elantech_data *etd = psmouse->private;
385 
386 	if (psmouse->pktcnt < psmouse->pktsize)
387 		return PSMOUSE_GOOD_DATA;
388 
389 	if (etd->debug > 1)
390 		elantech_packet_dump(psmouse->packet, psmouse->pktsize);
391 
392 	switch (etd->hw_version) {
393 	case 1:
394 		if (etd->paritycheck && !elantech_check_parity_v1(psmouse))
395 			return PSMOUSE_BAD_DATA;
396 
397 		elantech_report_absolute_v1(psmouse);
398 		break;
399 
400 	case 2:
401 		/* We don't know how to check parity in protocol v2 */
402 		elantech_report_absolute_v2(psmouse);
403 		break;
404 	}
405 
406 	return PSMOUSE_FULL_PACKET;
407 }
408 
409 /*
410  * Put the touchpad into absolute mode
411  */
412 static int elantech_set_absolute_mode(struct psmouse *psmouse)
413 {
414 	struct elantech_data *etd = psmouse->private;
415 	unsigned char val;
416 	int tries = ETP_READ_BACK_TRIES;
417 	int rc = 0;
418 
419 	switch (etd->hw_version) {
420 	case 1:
421 		etd->reg_10 = 0x16;
422 		etd->reg_11 = 0x8f;
423 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
424 		    elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
425 			rc = -1;
426 		}
427 		break;
428 
429 	case 2:
430 					/* Windows driver values */
431 		etd->reg_10 = 0x54;
432 		etd->reg_11 = 0x88;	/* 0x8a */
433 		etd->reg_21 = 0x60;	/* 0x00 */
434 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
435 		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
436 		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
437 			rc = -1;
438 			break;
439 		}
440 	}
441 
442 	if (rc == 0) {
443 		/*
444 		 * Read back reg 0x10. For hardware version 1 we must make
445 		 * sure the absolute mode bit is set. For hardware version 2
446 		 * the touchpad is probably initalising and not ready until
447 		 * we read back the value we just wrote.
448 		 */
449 		do {
450 			rc = elantech_read_reg(psmouse, 0x10, &val);
451 			if (rc == 0)
452 				break;
453 			tries--;
454 			elantech_debug("retrying read (%d).\n", tries);
455 			msleep(ETP_READ_BACK_DELAY);
456 		} while (tries > 0);
457 
458 		if (rc) {
459 			pr_err("failed to read back register 0x10.\n");
460 		} else if (etd->hw_version == 1 &&
461 			   !(val & ETP_R10_ABSOLUTE_MODE)) {
462 			pr_err("touchpad refuses to switch to absolute mode.\n");
463 			rc = -1;
464 		}
465 	}
466 
467 	if (rc)
468 		pr_err("failed to initialise registers.\n");
469 
470 	return rc;
471 }
472 
473 /*
474  * Set the appropriate event bits for the input subsystem
475  */
476 static void elantech_set_input_params(struct psmouse *psmouse)
477 {
478 	struct input_dev *dev = psmouse->dev;
479 	struct elantech_data *etd = psmouse->private;
480 
481 	__set_bit(EV_KEY, dev->evbit);
482 	__set_bit(EV_ABS, dev->evbit);
483 	__clear_bit(EV_REL, dev->evbit);
484 
485 	__set_bit(BTN_LEFT, dev->keybit);
486 	__set_bit(BTN_RIGHT, dev->keybit);
487 
488 	__set_bit(BTN_TOUCH, dev->keybit);
489 	__set_bit(BTN_TOOL_FINGER, dev->keybit);
490 	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
491 	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
492 
493 	switch (etd->hw_version) {
494 	case 1:
495 		/* Rocker button */
496 		if (etd->fw_version < 0x020000 &&
497 		    (etd->capabilities & ETP_CAP_HAS_ROCKER)) {
498 			__set_bit(BTN_FORWARD, dev->keybit);
499 			__set_bit(BTN_BACK, dev->keybit);
500 		}
501 		input_set_abs_params(dev, ABS_X, ETP_XMIN_V1, ETP_XMAX_V1, 0, 0);
502 		input_set_abs_params(dev, ABS_Y, ETP_YMIN_V1, ETP_YMAX_V1, 0, 0);
503 		break;
504 
505 	case 2:
506 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
507 		input_set_abs_params(dev, ABS_X, ETP_XMIN_V2, ETP_XMAX_V2, 0, 0);
508 		input_set_abs_params(dev, ABS_Y, ETP_YMIN_V2, ETP_YMAX_V2, 0, 0);
509 		if (etd->reports_pressure) {
510 			input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
511 					     ETP_PMAX_V2, 0, 0);
512 			input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
513 					     ETP_WMAX_V2, 0, 0);
514 		}
515 		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
516 		input_mt_init_slots(dev, 2);
517 		input_set_abs_params(dev, ABS_MT_POSITION_X, ETP_XMIN_V2, ETP_XMAX_V2, 0, 0);
518 		input_set_abs_params(dev, ABS_MT_POSITION_Y, ETP_YMIN_V2, ETP_YMAX_V2, 0, 0);
519 		break;
520 	}
521 }
522 
523 struct elantech_attr_data {
524 	size_t		field_offset;
525 	unsigned char	reg;
526 };
527 
528 /*
529  * Display a register value by reading a sysfs entry
530  */
531 static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
532 					char *buf)
533 {
534 	struct elantech_data *etd = psmouse->private;
535 	struct elantech_attr_data *attr = data;
536 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
537 	int rc = 0;
538 
539 	if (attr->reg)
540 		rc = elantech_read_reg(psmouse, attr->reg, reg);
541 
542 	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
543 }
544 
545 /*
546  * Write a register value by writing a sysfs entry
547  */
548 static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
549 				     void *data, const char *buf, size_t count)
550 {
551 	struct elantech_data *etd = psmouse->private;
552 	struct elantech_attr_data *attr = data;
553 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
554 	unsigned long value;
555 	int err;
556 
557 	err = strict_strtoul(buf, 16, &value);
558 	if (err)
559 		return err;
560 
561 	if (value > 0xff)
562 		return -EINVAL;
563 
564 	/* Do we need to preserve some bits for version 2 hardware too? */
565 	if (etd->hw_version == 1) {
566 		if (attr->reg == 0x10)
567 			/* Force absolute mode always on */
568 			value |= ETP_R10_ABSOLUTE_MODE;
569 		else if (attr->reg == 0x11)
570 			/* Force 4 byte mode always on */
571 			value |= ETP_R11_4_BYTE_MODE;
572 	}
573 
574 	if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
575 		*reg = value;
576 
577 	return count;
578 }
579 
580 #define ELANTECH_INT_ATTR(_name, _register)				\
581 	static struct elantech_attr_data elantech_attr_##_name = {	\
582 		.field_offset = offsetof(struct elantech_data, _name),	\
583 		.reg = _register,					\
584 	};								\
585 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,			\
586 			    &elantech_attr_##_name,			\
587 			    elantech_show_int_attr,			\
588 			    elantech_set_int_attr)
589 
590 ELANTECH_INT_ATTR(reg_10, 0x10);
591 ELANTECH_INT_ATTR(reg_11, 0x11);
592 ELANTECH_INT_ATTR(reg_20, 0x20);
593 ELANTECH_INT_ATTR(reg_21, 0x21);
594 ELANTECH_INT_ATTR(reg_22, 0x22);
595 ELANTECH_INT_ATTR(reg_23, 0x23);
596 ELANTECH_INT_ATTR(reg_24, 0x24);
597 ELANTECH_INT_ATTR(reg_25, 0x25);
598 ELANTECH_INT_ATTR(reg_26, 0x26);
599 ELANTECH_INT_ATTR(debug, 0);
600 ELANTECH_INT_ATTR(paritycheck, 0);
601 
602 static struct attribute *elantech_attrs[] = {
603 	&psmouse_attr_reg_10.dattr.attr,
604 	&psmouse_attr_reg_11.dattr.attr,
605 	&psmouse_attr_reg_20.dattr.attr,
606 	&psmouse_attr_reg_21.dattr.attr,
607 	&psmouse_attr_reg_22.dattr.attr,
608 	&psmouse_attr_reg_23.dattr.attr,
609 	&psmouse_attr_reg_24.dattr.attr,
610 	&psmouse_attr_reg_25.dattr.attr,
611 	&psmouse_attr_reg_26.dattr.attr,
612 	&psmouse_attr_debug.dattr.attr,
613 	&psmouse_attr_paritycheck.dattr.attr,
614 	NULL
615 };
616 
617 static struct attribute_group elantech_attr_group = {
618 	.attrs = elantech_attrs,
619 };
620 
621 static bool elantech_is_signature_valid(const unsigned char *param)
622 {
623 	static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10 };
624 	int i;
625 
626 	if (param[0] == 0)
627 		return false;
628 
629 	if (param[1] == 0)
630 		return true;
631 
632 	for (i = 0; i < ARRAY_SIZE(rates); i++)
633 		if (param[2] == rates[i])
634 			return false;
635 
636 	return true;
637 }
638 
639 /*
640  * Use magic knock to detect Elantech touchpad
641  */
642 int elantech_detect(struct psmouse *psmouse, bool set_properties)
643 {
644 	struct ps2dev *ps2dev = &psmouse->ps2dev;
645 	unsigned char param[3];
646 
647 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
648 
649 	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
650 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
651 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
652 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
653 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
654 		pr_debug("sending Elantech magic knock failed.\n");
655 		return -1;
656 	}
657 
658 	/*
659 	 * Report this in case there are Elantech models that use a different
660 	 * set of magic numbers
661 	 */
662 	if (param[0] != 0x3c || param[1] != 0x03 || param[2] != 0xc8) {
663 		pr_debug("unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
664 			 param[0], param[1], param[2]);
665 		return -1;
666 	}
667 
668 	/*
669 	 * Query touchpad's firmware version and see if it reports known
670 	 * value to avoid mis-detection. Logitech mice are known to respond
671 	 * to Elantech magic knock and there might be more.
672 	 */
673 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
674 		pr_debug("failed to query firmware version.\n");
675 		return -1;
676 	}
677 
678 	pr_debug("Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
679 		 param[0], param[1], param[2]);
680 
681 	if (!elantech_is_signature_valid(param)) {
682 		if (!force_elantech) {
683 			pr_debug("Probably not a real Elantech touchpad. Aborting.\n");
684 			return -1;
685 		}
686 
687 		pr_debug("Probably not a real Elantech touchpad. Enabling anyway due to force_elantech.\n");
688 	}
689 
690 	if (set_properties) {
691 		psmouse->vendor = "Elantech";
692 		psmouse->name = "Touchpad";
693 	}
694 
695 	return 0;
696 }
697 
698 /*
699  * Clean up sysfs entries when disconnecting
700  */
701 static void elantech_disconnect(struct psmouse *psmouse)
702 {
703 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
704 			   &elantech_attr_group);
705 	kfree(psmouse->private);
706 	psmouse->private = NULL;
707 }
708 
709 /*
710  * Put the touchpad back into absolute mode when reconnecting
711  */
712 static int elantech_reconnect(struct psmouse *psmouse)
713 {
714 	if (elantech_detect(psmouse, 0))
715 		return -1;
716 
717 	if (elantech_set_absolute_mode(psmouse)) {
718 		pr_err("failed to put touchpad back into absolute mode.\n");
719 		return -1;
720 	}
721 
722 	return 0;
723 }
724 
725 /*
726  * Initialize the touchpad and create sysfs entries
727  */
728 int elantech_init(struct psmouse *psmouse)
729 {
730 	struct elantech_data *etd;
731 	int i, error;
732 	unsigned char param[3];
733 
734 	psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
735 	if (!etd)
736 		return -ENOMEM;
737 
738 	etd->parity[0] = 1;
739 	for (i = 1; i < 256; i++)
740 		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
741 
742 	/*
743 	 * Do the version query again so we can store the result
744 	 */
745 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
746 		pr_err("failed to query firmware version.\n");
747 		goto init_fail;
748 	}
749 
750 	etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
751 
752 	/*
753 	 * Assume every version greater than this is new EeePC style
754 	 * hardware with 6 byte packets
755 	 */
756 	if (etd->fw_version >= 0x020030) {
757 		etd->hw_version = 2;
758 		/* For now show extra debug information */
759 		etd->debug = 1;
760 		/* Don't know how to do parity checking for version 2 */
761 		etd->paritycheck = 0;
762 
763 		if (etd->fw_version >= 0x020800)
764 			etd->reports_pressure = true;
765 
766 	} else {
767 		etd->hw_version = 1;
768 		etd->paritycheck = 1;
769 	}
770 
771 	pr_info("assuming hardware version %d, firmware version %d.%d.%d\n",
772 		etd->hw_version, param[0], param[1], param[2]);
773 
774 	if (synaptics_send_cmd(psmouse, ETP_CAPABILITIES_QUERY, param)) {
775 		pr_err("failed to query capabilities.\n");
776 		goto init_fail;
777 	}
778 	pr_info("Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
779 		param[0], param[1], param[2]);
780 	etd->capabilities = param[0];
781 
782 	/*
783 	 * This firmware suffers from misreporting coordinates when
784 	 * a touch action starts causing the mouse cursor or scrolled page
785 	 * to jump. Enable a workaround.
786 	 */
787 	if (etd->fw_version == 0x020022 || etd->fw_version == 0x020600) {
788 		pr_info("firmware version 2.0.34/2.6.0 detected, enabling jumpy cursor workaround\n");
789 		etd->jumpy_cursor = true;
790 	}
791 
792 	if (elantech_set_absolute_mode(psmouse)) {
793 		pr_err("failed to put touchpad into absolute mode.\n");
794 		goto init_fail;
795 	}
796 
797 	elantech_set_input_params(psmouse);
798 
799 	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
800 				   &elantech_attr_group);
801 	if (error) {
802 		pr_err("failed to create sysfs attributes, error: %d.\n", error);
803 		goto init_fail;
804 	}
805 
806 	psmouse->protocol_handler = elantech_process_byte;
807 	psmouse->disconnect = elantech_disconnect;
808 	psmouse->reconnect = elantech_reconnect;
809 	psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;
810 
811 	return 0;
812 
813  init_fail:
814 	kfree(etd);
815 	return -1;
816 }
817