xref: /openbmc/linux/drivers/input/mouse/elantech.c (revision dc6a81c3)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Elantech Touchpad driver (v6)
4  *
5  * Copyright (C) 2007-2009 Arjan Opmeer <arjan@opmeer.net>
6  *
7  * Trademarks are the property of their respective owners.
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/dmi.h>
12 #include <linux/slab.h>
13 #include <linux/module.h>
14 #include <linux/i2c.h>
15 #include <linux/input.h>
16 #include <linux/input/mt.h>
17 #include <linux/platform_device.h>
18 #include <linux/serio.h>
19 #include <linux/libps2.h>
20 #include <asm/unaligned.h>
21 #include "psmouse.h"
22 #include "elantech.h"
23 #include "elan_i2c.h"
24 
25 #define elantech_debug(fmt, ...)					\
26 	do {								\
27 		if (etd->info.debug)					\
28 			psmouse_printk(KERN_DEBUG, psmouse,		\
29 					fmt, ##__VA_ARGS__);		\
30 	} while (0)
31 
32 /*
33  * Send a Synaptics style sliced query command
34  */
35 static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
36 				unsigned char *param)
37 {
38 	if (ps2_sliced_command(&psmouse->ps2dev, c) ||
39 	    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
40 		psmouse_err(psmouse, "%s query 0x%02x failed.\n", __func__, c);
41 		return -1;
42 	}
43 
44 	return 0;
45 }
46 
47 /*
48  * V3 and later support this fast command
49  */
50 static int elantech_send_cmd(struct psmouse *psmouse, unsigned char c,
51 				unsigned char *param)
52 {
53 	struct ps2dev *ps2dev = &psmouse->ps2dev;
54 
55 	if (ps2_command(ps2dev, NULL, ETP_PS2_CUSTOM_COMMAND) ||
56 	    ps2_command(ps2dev, NULL, c) ||
57 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
58 		psmouse_err(psmouse, "%s query 0x%02x failed.\n", __func__, c);
59 		return -1;
60 	}
61 
62 	return 0;
63 }
64 
65 /*
66  * A retrying version of ps2_command
67  */
68 static int elantech_ps2_command(struct psmouse *psmouse,
69 				unsigned char *param, int command)
70 {
71 	struct ps2dev *ps2dev = &psmouse->ps2dev;
72 	struct elantech_data *etd = psmouse->private;
73 	int rc;
74 	int tries = ETP_PS2_COMMAND_TRIES;
75 
76 	do {
77 		rc = ps2_command(ps2dev, param, command);
78 		if (rc == 0)
79 			break;
80 		tries--;
81 		elantech_debug("retrying ps2 command 0x%02x (%d).\n",
82 				command, tries);
83 		msleep(ETP_PS2_COMMAND_DELAY);
84 	} while (tries > 0);
85 
86 	if (rc)
87 		psmouse_err(psmouse, "ps2 command 0x%02x failed.\n", command);
88 
89 	return rc;
90 }
91 
92 /*
93  * Send an Elantech style special command to read a value from a register
94  */
95 static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
96 				unsigned char *val)
97 {
98 	struct elantech_data *etd = psmouse->private;
99 	unsigned char param[3];
100 	int rc = 0;
101 
102 	if (reg < 0x07 || reg > 0x26)
103 		return -1;
104 
105 	if (reg > 0x11 && reg < 0x20)
106 		return -1;
107 
108 	switch (etd->info.hw_version) {
109 	case 1:
110 		if (ps2_sliced_command(&psmouse->ps2dev, ETP_REGISTER_READ) ||
111 		    ps2_sliced_command(&psmouse->ps2dev, reg) ||
112 		    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
113 			rc = -1;
114 		}
115 		break;
116 
117 	case 2:
118 		if (elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
119 		    elantech_ps2_command(psmouse,  NULL, ETP_REGISTER_READ) ||
120 		    elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
121 		    elantech_ps2_command(psmouse,  NULL, reg) ||
122 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
123 			rc = -1;
124 		}
125 		break;
126 
127 	case 3 ... 4:
128 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
129 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
130 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
131 		    elantech_ps2_command(psmouse, NULL, reg) ||
132 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
133 			rc = -1;
134 		}
135 		break;
136 	}
137 
138 	if (rc)
139 		psmouse_err(psmouse, "failed to read register 0x%02x.\n", reg);
140 	else if (etd->info.hw_version != 4)
141 		*val = param[0];
142 	else
143 		*val = param[1];
144 
145 	return rc;
146 }
147 
148 /*
149  * Send an Elantech style special command to write a register with a value
150  */
151 static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
152 				unsigned char val)
153 {
154 	struct elantech_data *etd = psmouse->private;
155 	int rc = 0;
156 
157 	if (reg < 0x07 || reg > 0x26)
158 		return -1;
159 
160 	if (reg > 0x11 && reg < 0x20)
161 		return -1;
162 
163 	switch (etd->info.hw_version) {
164 	case 1:
165 		if (ps2_sliced_command(&psmouse->ps2dev, ETP_REGISTER_WRITE) ||
166 		    ps2_sliced_command(&psmouse->ps2dev, reg) ||
167 		    ps2_sliced_command(&psmouse->ps2dev, val) ||
168 		    ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
169 			rc = -1;
170 		}
171 		break;
172 
173 	case 2:
174 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
175 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
176 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
177 		    elantech_ps2_command(psmouse, NULL, reg) ||
178 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
179 		    elantech_ps2_command(psmouse, NULL, val) ||
180 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
181 			rc = -1;
182 		}
183 		break;
184 
185 	case 3:
186 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
187 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
188 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
189 		    elantech_ps2_command(psmouse, NULL, reg) ||
190 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
191 		    elantech_ps2_command(psmouse, NULL, val) ||
192 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
193 			rc = -1;
194 		}
195 		break;
196 
197 	case 4:
198 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
199 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
200 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
201 		    elantech_ps2_command(psmouse, NULL, reg) ||
202 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
203 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
204 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
205 		    elantech_ps2_command(psmouse, NULL, val) ||
206 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
207 			rc = -1;
208 		}
209 		break;
210 	}
211 
212 	if (rc)
213 		psmouse_err(psmouse,
214 			    "failed to write register 0x%02x with value 0x%02x.\n",
215 			    reg, val);
216 
217 	return rc;
218 }
219 
220 /*
221  * Dump a complete mouse movement packet to the syslog
222  */
223 static void elantech_packet_dump(struct psmouse *psmouse)
224 {
225 	psmouse_printk(KERN_DEBUG, psmouse, "PS/2 packet [%*ph]\n",
226 		       psmouse->pktsize, psmouse->packet);
227 }
228 
229 /*
230  * Advertise INPUT_PROP_BUTTONPAD for clickpads. The testing of bit 12 in
231  * fw_version for this is based on the following fw_version & caps table:
232  *
233  * Laptop-model:           fw_version:     caps:           buttons:
234  * Acer S3                 0x461f00        10, 13, 0e      clickpad
235  * Acer S7-392             0x581f01        50, 17, 0d      clickpad
236  * Acer V5-131             0x461f02        01, 16, 0c      clickpad
237  * Acer V5-551             0x461f00        ?               clickpad
238  * Asus K53SV              0x450f01        78, 15, 0c      2 hw buttons
239  * Asus G46VW              0x460f02        00, 18, 0c      2 hw buttons
240  * Asus G750JX             0x360f00        00, 16, 0c      2 hw buttons
241  * Asus TP500LN            0x381f17        10, 14, 0e      clickpad
242  * Asus X750JN             0x381f17        10, 14, 0e      clickpad
243  * Asus UX31               0x361f00        20, 15, 0e      clickpad
244  * Asus UX32VD             0x361f02        00, 15, 0e      clickpad
245  * Avatar AVIU-145A2       0x361f00        ?               clickpad
246  * Fujitsu CELSIUS H760    0x570f02        40, 14, 0c      3 hw buttons (**)
247  * Fujitsu CELSIUS H780    0x5d0f02        41, 16, 0d      3 hw buttons (**)
248  * Fujitsu LIFEBOOK E544   0x470f00        d0, 12, 09      2 hw buttons
249  * Fujitsu LIFEBOOK E546   0x470f00        50, 12, 09      2 hw buttons
250  * Fujitsu LIFEBOOK E547   0x470f00        50, 12, 09      2 hw buttons
251  * Fujitsu LIFEBOOK E554   0x570f01        40, 14, 0c      2 hw buttons
252  * Fujitsu LIFEBOOK E557   0x570f01        40, 14, 0c      2 hw buttons
253  * Fujitsu T725            0x470f01        05, 12, 09      2 hw buttons
254  * Fujitsu H730            0x570f00        c0, 14, 0c      3 hw buttons (**)
255  * Gigabyte U2442          0x450f01        58, 17, 0c      2 hw buttons
256  * Lenovo L430             0x350f02        b9, 15, 0c      2 hw buttons (*)
257  * Lenovo L530             0x350f02        b9, 15, 0c      2 hw buttons (*)
258  * Samsung NF210           0x150b00        78, 14, 0a      2 hw buttons
259  * Samsung NP770Z5E        0x575f01        10, 15, 0f      clickpad
260  * Samsung NP700Z5B        0x361f06        21, 15, 0f      clickpad
261  * Samsung NP900X3E-A02    0x575f03        ?               clickpad
262  * Samsung NP-QX410        0x851b00        19, 14, 0c      clickpad
263  * Samsung RC512           0x450f00        08, 15, 0c      2 hw buttons
264  * Samsung RF710           0x450f00        ?               2 hw buttons
265  * System76 Pangolin       0x250f01        ?               2 hw buttons
266  * (*) + 3 trackpoint buttons
267  * (**) + 0 trackpoint buttons
268  * Note: Lenovo L430 and Lenovo L530 have the same fw_version/caps
269  */
270 static inline int elantech_is_buttonpad(struct elantech_device_info *info)
271 {
272 	return info->fw_version & 0x001000;
273 }
274 
275 /*
276  * Interpret complete data packets and report absolute mode input events for
277  * hardware version 1. (4 byte packets)
278  */
279 static void elantech_report_absolute_v1(struct psmouse *psmouse)
280 {
281 	struct input_dev *dev = psmouse->dev;
282 	struct elantech_data *etd = psmouse->private;
283 	unsigned char *packet = psmouse->packet;
284 	int fingers;
285 
286 	if (etd->info.fw_version < 0x020000) {
287 		/*
288 		 * byte 0:  D   U  p1  p2   1  p3   R   L
289 		 * byte 1:  f   0  th  tw  x9  x8  y9  y8
290 		 */
291 		fingers = ((packet[1] & 0x80) >> 7) +
292 				((packet[1] & 0x30) >> 4);
293 	} else {
294 		/*
295 		 * byte 0: n1  n0  p2  p1   1  p3   R   L
296 		 * byte 1:  0   0   0   0  x9  x8  y9  y8
297 		 */
298 		fingers = (packet[0] & 0xc0) >> 6;
299 	}
300 
301 	if (etd->info.jumpy_cursor) {
302 		if (fingers != 1) {
303 			etd->single_finger_reports = 0;
304 		} else if (etd->single_finger_reports < 2) {
305 			/* Discard first 2 reports of one finger, bogus */
306 			etd->single_finger_reports++;
307 			elantech_debug("discarding packet\n");
308 			return;
309 		}
310 	}
311 
312 	input_report_key(dev, BTN_TOUCH, fingers != 0);
313 
314 	/*
315 	 * byte 2: x7  x6  x5  x4  x3  x2  x1  x0
316 	 * byte 3: y7  y6  y5  y4  y3  y2  y1  y0
317 	 */
318 	if (fingers) {
319 		input_report_abs(dev, ABS_X,
320 			((packet[1] & 0x0c) << 6) | packet[2]);
321 		input_report_abs(dev, ABS_Y,
322 			etd->y_max - (((packet[1] & 0x03) << 8) | packet[3]));
323 	}
324 
325 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
326 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
327 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
328 
329 	psmouse_report_standard_buttons(dev, packet[0]);
330 
331 	if (etd->info.fw_version < 0x020000 &&
332 	    (etd->info.capabilities[0] & ETP_CAP_HAS_ROCKER)) {
333 		/* rocker up */
334 		input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
335 		/* rocker down */
336 		input_report_key(dev, BTN_BACK, packet[0] & 0x80);
337 	}
338 
339 	input_sync(dev);
340 }
341 
342 static void elantech_set_slot(struct input_dev *dev, int slot, bool active,
343 			      unsigned int x, unsigned int y)
344 {
345 	input_mt_slot(dev, slot);
346 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
347 	if (active) {
348 		input_report_abs(dev, ABS_MT_POSITION_X, x);
349 		input_report_abs(dev, ABS_MT_POSITION_Y, y);
350 	}
351 }
352 
353 /* x1 < x2 and y1 < y2 when two fingers, x = y = 0 when not pressed */
354 static void elantech_report_semi_mt_data(struct input_dev *dev,
355 					 unsigned int num_fingers,
356 					 unsigned int x1, unsigned int y1,
357 					 unsigned int x2, unsigned int y2)
358 {
359 	elantech_set_slot(dev, 0, num_fingers != 0, x1, y1);
360 	elantech_set_slot(dev, 1, num_fingers >= 2, x2, y2);
361 }
362 
363 /*
364  * Interpret complete data packets and report absolute mode input events for
365  * hardware version 2. (6 byte packets)
366  */
367 static void elantech_report_absolute_v2(struct psmouse *psmouse)
368 {
369 	struct elantech_data *etd = psmouse->private;
370 	struct input_dev *dev = psmouse->dev;
371 	unsigned char *packet = psmouse->packet;
372 	unsigned int fingers, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
373 	unsigned int width = 0, pres = 0;
374 
375 	/* byte 0: n1  n0   .   .   .   .   R   L */
376 	fingers = (packet[0] & 0xc0) >> 6;
377 
378 	switch (fingers) {
379 	case 3:
380 		/*
381 		 * Same as one finger, except report of more than 3 fingers:
382 		 * byte 3:  n4  .   w1  w0   .   .   .   .
383 		 */
384 		if (packet[3] & 0x80)
385 			fingers = 4;
386 		/* fall through */
387 	case 1:
388 		/*
389 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
390 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
391 		 */
392 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
393 		/*
394 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
395 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
396 		 */
397 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
398 
399 		pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
400 		width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
401 		break;
402 
403 	case 2:
404 		/*
405 		 * The coordinate of each finger is reported separately
406 		 * with a lower resolution for two finger touches:
407 		 * byte 0:  .   .  ay8 ax8  .   .   .   .
408 		 * byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
409 		 */
410 		x1 = (((packet[0] & 0x10) << 4) | packet[1]) << 2;
411 		/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
412 		y1 = etd->y_max -
413 			((((packet[0] & 0x20) << 3) | packet[2]) << 2);
414 		/*
415 		 * byte 3:  .   .  by8 bx8  .   .   .   .
416 		 * byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
417 		 */
418 		x2 = (((packet[3] & 0x10) << 4) | packet[4]) << 2;
419 		/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
420 		y2 = etd->y_max -
421 			((((packet[3] & 0x20) << 3) | packet[5]) << 2);
422 
423 		/* Unknown so just report sensible values */
424 		pres = 127;
425 		width = 7;
426 		break;
427 	}
428 
429 	input_report_key(dev, BTN_TOUCH, fingers != 0);
430 	if (fingers != 0) {
431 		input_report_abs(dev, ABS_X, x1);
432 		input_report_abs(dev, ABS_Y, y1);
433 	}
434 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
435 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
436 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
437 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
438 	input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
439 	psmouse_report_standard_buttons(dev, packet[0]);
440 	if (etd->info.reports_pressure) {
441 		input_report_abs(dev, ABS_PRESSURE, pres);
442 		input_report_abs(dev, ABS_TOOL_WIDTH, width);
443 	}
444 
445 	input_sync(dev);
446 }
447 
448 static void elantech_report_trackpoint(struct psmouse *psmouse,
449 				       int packet_type)
450 {
451 	/*
452 	 * byte 0:  0   0  sx  sy   0   M   R   L
453 	 * byte 1:~sx   0   0   0   0   0   0   0
454 	 * byte 2:~sy   0   0   0   0   0   0   0
455 	 * byte 3:  0   0 ~sy ~sx   0   1   1   0
456 	 * byte 4: x7  x6  x5  x4  x3  x2  x1  x0
457 	 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
458 	 *
459 	 * x and y are written in two's complement spread
460 	 * over 9 bits with sx/sy the relative top bit and
461 	 * x7..x0 and y7..y0 the lower bits.
462 	 * The sign of y is opposite to what the input driver
463 	 * expects for a relative movement
464 	 */
465 
466 	struct elantech_data *etd = psmouse->private;
467 	struct input_dev *tp_dev = etd->tp_dev;
468 	unsigned char *packet = psmouse->packet;
469 	int x, y;
470 	u32 t;
471 
472 	t = get_unaligned_le32(&packet[0]);
473 
474 	switch (t & ~7U) {
475 	case 0x06000030U:
476 	case 0x16008020U:
477 	case 0x26800010U:
478 	case 0x36808000U:
479 		x = packet[4] - (int)((packet[1]^0x80) << 1);
480 		y = (int)((packet[2]^0x80) << 1) - packet[5];
481 
482 		psmouse_report_standard_buttons(tp_dev, packet[0]);
483 
484 		input_report_rel(tp_dev, REL_X, x);
485 		input_report_rel(tp_dev, REL_Y, y);
486 
487 		input_sync(tp_dev);
488 
489 		break;
490 
491 	default:
492 		/* Dump unexpected packet sequences if debug=1 (default) */
493 		if (etd->info.debug == 1)
494 			elantech_packet_dump(psmouse);
495 
496 		break;
497 	}
498 }
499 
500 /*
501  * Interpret complete data packets and report absolute mode input events for
502  * hardware version 3. (12 byte packets for two fingers)
503  */
504 static void elantech_report_absolute_v3(struct psmouse *psmouse,
505 					int packet_type)
506 {
507 	struct input_dev *dev = psmouse->dev;
508 	struct elantech_data *etd = psmouse->private;
509 	unsigned char *packet = psmouse->packet;
510 	unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
511 	unsigned int width = 0, pres = 0;
512 
513 	/* byte 0: n1  n0   .   .   .   .   R   L */
514 	fingers = (packet[0] & 0xc0) >> 6;
515 
516 	switch (fingers) {
517 	case 3:
518 	case 1:
519 		/*
520 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
521 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
522 		 */
523 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
524 		/*
525 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
526 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
527 		 */
528 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
529 		break;
530 
531 	case 2:
532 		if (packet_type == PACKET_V3_HEAD) {
533 			/*
534 			 * byte 1:   .    .    .    .  ax11 ax10 ax9  ax8
535 			 * byte 2: ax7  ax6  ax5  ax4  ax3  ax2  ax1  ax0
536 			 */
537 			etd->mt[0].x = ((packet[1] & 0x0f) << 8) | packet[2];
538 			/*
539 			 * byte 4:   .    .    .    .  ay11 ay10 ay9  ay8
540 			 * byte 5: ay7  ay6  ay5  ay4  ay3  ay2  ay1  ay0
541 			 */
542 			etd->mt[0].y = etd->y_max -
543 				(((packet[4] & 0x0f) << 8) | packet[5]);
544 			/*
545 			 * wait for next packet
546 			 */
547 			return;
548 		}
549 
550 		/* packet_type == PACKET_V3_TAIL */
551 		x1 = etd->mt[0].x;
552 		y1 = etd->mt[0].y;
553 		x2 = ((packet[1] & 0x0f) << 8) | packet[2];
554 		y2 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
555 		break;
556 	}
557 
558 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
559 	width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
560 
561 	input_report_key(dev, BTN_TOUCH, fingers != 0);
562 	if (fingers != 0) {
563 		input_report_abs(dev, ABS_X, x1);
564 		input_report_abs(dev, ABS_Y, y1);
565 	}
566 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
567 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
568 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
569 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
570 
571 	/* For clickpads map both buttons to BTN_LEFT */
572 	if (elantech_is_buttonpad(&etd->info))
573 		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
574 	else
575 		psmouse_report_standard_buttons(dev, packet[0]);
576 
577 	input_report_abs(dev, ABS_PRESSURE, pres);
578 	input_report_abs(dev, ABS_TOOL_WIDTH, width);
579 
580 	input_sync(dev);
581 }
582 
583 static void elantech_input_sync_v4(struct psmouse *psmouse)
584 {
585 	struct input_dev *dev = psmouse->dev;
586 	struct elantech_data *etd = psmouse->private;
587 	unsigned char *packet = psmouse->packet;
588 
589 	/* For clickpads map both buttons to BTN_LEFT */
590 	if (elantech_is_buttonpad(&etd->info))
591 		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
592 	else
593 		psmouse_report_standard_buttons(dev, packet[0]);
594 
595 	input_mt_report_pointer_emulation(dev, true);
596 	input_sync(dev);
597 }
598 
599 static void process_packet_status_v4(struct psmouse *psmouse)
600 {
601 	struct input_dev *dev = psmouse->dev;
602 	unsigned char *packet = psmouse->packet;
603 	unsigned fingers;
604 	int i;
605 
606 	/* notify finger state change */
607 	fingers = packet[1] & 0x1f;
608 	for (i = 0; i < ETP_MAX_FINGERS; i++) {
609 		if ((fingers & (1 << i)) == 0) {
610 			input_mt_slot(dev, i);
611 			input_mt_report_slot_state(dev, MT_TOOL_FINGER, false);
612 		}
613 	}
614 
615 	elantech_input_sync_v4(psmouse);
616 }
617 
618 static void process_packet_head_v4(struct psmouse *psmouse)
619 {
620 	struct input_dev *dev = psmouse->dev;
621 	struct elantech_data *etd = psmouse->private;
622 	unsigned char *packet = psmouse->packet;
623 	int id = ((packet[3] & 0xe0) >> 5) - 1;
624 	int pres, traces;
625 
626 	if (id < 0)
627 		return;
628 
629 	etd->mt[id].x = ((packet[1] & 0x0f) << 8) | packet[2];
630 	etd->mt[id].y = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
631 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
632 	traces = (packet[0] & 0xf0) >> 4;
633 
634 	input_mt_slot(dev, id);
635 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, true);
636 
637 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
638 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
639 	input_report_abs(dev, ABS_MT_PRESSURE, pres);
640 	input_report_abs(dev, ABS_MT_TOUCH_MAJOR, traces * etd->width);
641 	/* report this for backwards compatibility */
642 	input_report_abs(dev, ABS_TOOL_WIDTH, traces);
643 
644 	elantech_input_sync_v4(psmouse);
645 }
646 
647 static void process_packet_motion_v4(struct psmouse *psmouse)
648 {
649 	struct input_dev *dev = psmouse->dev;
650 	struct elantech_data *etd = psmouse->private;
651 	unsigned char *packet = psmouse->packet;
652 	int weight, delta_x1 = 0, delta_y1 = 0, delta_x2 = 0, delta_y2 = 0;
653 	int id, sid;
654 
655 	id = ((packet[0] & 0xe0) >> 5) - 1;
656 	if (id < 0)
657 		return;
658 
659 	sid = ((packet[3] & 0xe0) >> 5) - 1;
660 	weight = (packet[0] & 0x10) ? ETP_WEIGHT_VALUE : 1;
661 	/*
662 	 * Motion packets give us the delta of x, y values of specific fingers,
663 	 * but in two's complement. Let the compiler do the conversion for us.
664 	 * Also _enlarge_ the numbers to int, in case of overflow.
665 	 */
666 	delta_x1 = (signed char)packet[1];
667 	delta_y1 = (signed char)packet[2];
668 	delta_x2 = (signed char)packet[4];
669 	delta_y2 = (signed char)packet[5];
670 
671 	etd->mt[id].x += delta_x1 * weight;
672 	etd->mt[id].y -= delta_y1 * weight;
673 	input_mt_slot(dev, id);
674 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
675 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
676 
677 	if (sid >= 0) {
678 		etd->mt[sid].x += delta_x2 * weight;
679 		etd->mt[sid].y -= delta_y2 * weight;
680 		input_mt_slot(dev, sid);
681 		input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[sid].x);
682 		input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[sid].y);
683 	}
684 
685 	elantech_input_sync_v4(psmouse);
686 }
687 
688 static void elantech_report_absolute_v4(struct psmouse *psmouse,
689 					int packet_type)
690 {
691 	switch (packet_type) {
692 	case PACKET_V4_STATUS:
693 		process_packet_status_v4(psmouse);
694 		break;
695 
696 	case PACKET_V4_HEAD:
697 		process_packet_head_v4(psmouse);
698 		break;
699 
700 	case PACKET_V4_MOTION:
701 		process_packet_motion_v4(psmouse);
702 		break;
703 
704 	case PACKET_UNKNOWN:
705 	default:
706 		/* impossible to get here */
707 		break;
708 	}
709 }
710 
711 static int elantech_packet_check_v1(struct psmouse *psmouse)
712 {
713 	struct elantech_data *etd = psmouse->private;
714 	unsigned char *packet = psmouse->packet;
715 	unsigned char p1, p2, p3;
716 
717 	/* Parity bits are placed differently */
718 	if (etd->info.fw_version < 0x020000) {
719 		/* byte 0:  D   U  p1  p2   1  p3   R   L */
720 		p1 = (packet[0] & 0x20) >> 5;
721 		p2 = (packet[0] & 0x10) >> 4;
722 	} else {
723 		/* byte 0: n1  n0  p2  p1   1  p3   R   L */
724 		p1 = (packet[0] & 0x10) >> 4;
725 		p2 = (packet[0] & 0x20) >> 5;
726 	}
727 
728 	p3 = (packet[0] & 0x04) >> 2;
729 
730 	return etd->parity[packet[1]] == p1 &&
731 	       etd->parity[packet[2]] == p2 &&
732 	       etd->parity[packet[3]] == p3;
733 }
734 
735 static int elantech_debounce_check_v2(struct psmouse *psmouse)
736 {
737         /*
738          * When we encounter packet that matches this exactly, it means the
739          * hardware is in debounce status. Just ignore the whole packet.
740          */
741 	static const u8 debounce_packet[] = {
742 		0x84, 0xff, 0xff, 0x02, 0xff, 0xff
743 	};
744         unsigned char *packet = psmouse->packet;
745 
746         return !memcmp(packet, debounce_packet, sizeof(debounce_packet));
747 }
748 
749 static int elantech_packet_check_v2(struct psmouse *psmouse)
750 {
751 	struct elantech_data *etd = psmouse->private;
752 	unsigned char *packet = psmouse->packet;
753 
754 	/*
755 	 * V2 hardware has two flavors. Older ones that do not report pressure,
756 	 * and newer ones that reports pressure and width. With newer ones, all
757 	 * packets (1, 2, 3 finger touch) have the same constant bits. With
758 	 * older ones, 1/3 finger touch packets and 2 finger touch packets
759 	 * have different constant bits.
760 	 * With all three cases, if the constant bits are not exactly what I
761 	 * expected, I consider them invalid.
762 	 */
763 	if (etd->info.reports_pressure)
764 		return (packet[0] & 0x0c) == 0x04 &&
765 		       (packet[3] & 0x0f) == 0x02;
766 
767 	if ((packet[0] & 0xc0) == 0x80)
768 		return (packet[0] & 0x0c) == 0x0c &&
769 		       (packet[3] & 0x0e) == 0x08;
770 
771 	return (packet[0] & 0x3c) == 0x3c &&
772 	       (packet[1] & 0xf0) == 0x00 &&
773 	       (packet[3] & 0x3e) == 0x38 &&
774 	       (packet[4] & 0xf0) == 0x00;
775 }
776 
777 /*
778  * We check the constant bits to determine what packet type we get,
779  * so packet checking is mandatory for v3 and later hardware.
780  */
781 static int elantech_packet_check_v3(struct psmouse *psmouse)
782 {
783 	struct elantech_data *etd = psmouse->private;
784 	static const u8 debounce_packet[] = {
785 		0xc4, 0xff, 0xff, 0x02, 0xff, 0xff
786 	};
787 	unsigned char *packet = psmouse->packet;
788 
789 	/*
790 	 * check debounce first, it has the same signature in byte 0
791 	 * and byte 3 as PACKET_V3_HEAD.
792 	 */
793 	if (!memcmp(packet, debounce_packet, sizeof(debounce_packet)))
794 		return PACKET_DEBOUNCE;
795 
796 	/*
797 	 * If the hardware flag 'crc_enabled' is set the packets have
798 	 * different signatures.
799 	 */
800 	if (etd->info.crc_enabled) {
801 		if ((packet[3] & 0x09) == 0x08)
802 			return PACKET_V3_HEAD;
803 
804 		if ((packet[3] & 0x09) == 0x09)
805 			return PACKET_V3_TAIL;
806 	} else {
807 		if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
808 			return PACKET_V3_HEAD;
809 
810 		if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
811 			return PACKET_V3_TAIL;
812 		if ((packet[3] & 0x0f) == 0x06)
813 			return PACKET_TRACKPOINT;
814 	}
815 
816 	return PACKET_UNKNOWN;
817 }
818 
819 static int elantech_packet_check_v4(struct psmouse *psmouse)
820 {
821 	struct elantech_data *etd = psmouse->private;
822 	unsigned char *packet = psmouse->packet;
823 	unsigned char packet_type = packet[3] & 0x03;
824 	unsigned int ic_version;
825 	bool sanity_check;
826 
827 	if (etd->tp_dev && (packet[3] & 0x0f) == 0x06)
828 		return PACKET_TRACKPOINT;
829 
830 	/* This represents the version of IC body. */
831 	ic_version = (etd->info.fw_version & 0x0f0000) >> 16;
832 
833 	/*
834 	 * Sanity check based on the constant bits of a packet.
835 	 * The constant bits change depending on the value of
836 	 * the hardware flag 'crc_enabled' and the version of
837 	 * the IC body, but are the same for every packet,
838 	 * regardless of the type.
839 	 */
840 	if (etd->info.crc_enabled)
841 		sanity_check = ((packet[3] & 0x08) == 0x00);
842 	else if (ic_version == 7 && etd->info.samples[1] == 0x2A)
843 		sanity_check = ((packet[3] & 0x1c) == 0x10);
844 	else
845 		sanity_check = ((packet[0] & 0x08) == 0x00 &&
846 				(packet[3] & 0x1c) == 0x10);
847 
848 	if (!sanity_check)
849 		return PACKET_UNKNOWN;
850 
851 	switch (packet_type) {
852 	case 0:
853 		return PACKET_V4_STATUS;
854 
855 	case 1:
856 		return PACKET_V4_HEAD;
857 
858 	case 2:
859 		return PACKET_V4_MOTION;
860 	}
861 
862 	return PACKET_UNKNOWN;
863 }
864 
865 /*
866  * Process byte stream from mouse and handle complete packets
867  */
868 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
869 {
870 	struct elantech_data *etd = psmouse->private;
871 	int packet_type;
872 
873 	if (psmouse->pktcnt < psmouse->pktsize)
874 		return PSMOUSE_GOOD_DATA;
875 
876 	if (etd->info.debug > 1)
877 		elantech_packet_dump(psmouse);
878 
879 	switch (etd->info.hw_version) {
880 	case 1:
881 		if (etd->info.paritycheck && !elantech_packet_check_v1(psmouse))
882 			return PSMOUSE_BAD_DATA;
883 
884 		elantech_report_absolute_v1(psmouse);
885 		break;
886 
887 	case 2:
888 		/* ignore debounce */
889 		if (elantech_debounce_check_v2(psmouse))
890 			return PSMOUSE_FULL_PACKET;
891 
892 		if (etd->info.paritycheck && !elantech_packet_check_v2(psmouse))
893 			return PSMOUSE_BAD_DATA;
894 
895 		elantech_report_absolute_v2(psmouse);
896 		break;
897 
898 	case 3:
899 		packet_type = elantech_packet_check_v3(psmouse);
900 		switch (packet_type) {
901 		case PACKET_UNKNOWN:
902 			return PSMOUSE_BAD_DATA;
903 
904 		case PACKET_DEBOUNCE:
905 			/* ignore debounce */
906 			break;
907 
908 		case PACKET_TRACKPOINT:
909 			elantech_report_trackpoint(psmouse, packet_type);
910 			break;
911 
912 		default:
913 			elantech_report_absolute_v3(psmouse, packet_type);
914 			break;
915 		}
916 
917 		break;
918 
919 	case 4:
920 		packet_type = elantech_packet_check_v4(psmouse);
921 		switch (packet_type) {
922 		case PACKET_UNKNOWN:
923 			return PSMOUSE_BAD_DATA;
924 
925 		case PACKET_TRACKPOINT:
926 			elantech_report_trackpoint(psmouse, packet_type);
927 			break;
928 
929 		default:
930 			elantech_report_absolute_v4(psmouse, packet_type);
931 			break;
932 		}
933 
934 		break;
935 	}
936 
937 	return PSMOUSE_FULL_PACKET;
938 }
939 
940 /*
941  * This writes the reg_07 value again to the hardware at the end of every
942  * set_rate call because the register loses its value. reg_07 allows setting
943  * absolute mode on v4 hardware
944  */
945 static void elantech_set_rate_restore_reg_07(struct psmouse *psmouse,
946 		unsigned int rate)
947 {
948 	struct elantech_data *etd = psmouse->private;
949 
950 	etd->original_set_rate(psmouse, rate);
951 	if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
952 		psmouse_err(psmouse, "restoring reg_07 failed\n");
953 }
954 
955 /*
956  * Put the touchpad into absolute mode
957  */
958 static int elantech_set_absolute_mode(struct psmouse *psmouse)
959 {
960 	struct elantech_data *etd = psmouse->private;
961 	unsigned char val;
962 	int tries = ETP_READ_BACK_TRIES;
963 	int rc = 0;
964 
965 	switch (etd->info.hw_version) {
966 	case 1:
967 		etd->reg_10 = 0x16;
968 		etd->reg_11 = 0x8f;
969 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
970 		    elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
971 			rc = -1;
972 		}
973 		break;
974 
975 	case 2:
976 					/* Windows driver values */
977 		etd->reg_10 = 0x54;
978 		etd->reg_11 = 0x88;	/* 0x8a */
979 		etd->reg_21 = 0x60;	/* 0x00 */
980 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
981 		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
982 		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
983 			rc = -1;
984 		}
985 		break;
986 
987 	case 3:
988 		if (etd->info.set_hw_resolution)
989 			etd->reg_10 = 0x0b;
990 		else
991 			etd->reg_10 = 0x01;
992 
993 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
994 			rc = -1;
995 
996 		break;
997 
998 	case 4:
999 		etd->reg_07 = 0x01;
1000 		if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
1001 			rc = -1;
1002 
1003 		goto skip_readback_reg_10; /* v4 has no reg 0x10 to read */
1004 	}
1005 
1006 	if (rc == 0) {
1007 		/*
1008 		 * Read back reg 0x10. For hardware version 1 we must make
1009 		 * sure the absolute mode bit is set. For hardware version 2
1010 		 * the touchpad is probably initializing and not ready until
1011 		 * we read back the value we just wrote.
1012 		 */
1013 		do {
1014 			rc = elantech_read_reg(psmouse, 0x10, &val);
1015 			if (rc == 0)
1016 				break;
1017 			tries--;
1018 			elantech_debug("retrying read (%d).\n", tries);
1019 			msleep(ETP_READ_BACK_DELAY);
1020 		} while (tries > 0);
1021 
1022 		if (rc) {
1023 			psmouse_err(psmouse,
1024 				    "failed to read back register 0x10.\n");
1025 		} else if (etd->info.hw_version == 1 &&
1026 			   !(val & ETP_R10_ABSOLUTE_MODE)) {
1027 			psmouse_err(psmouse,
1028 				    "touchpad refuses to switch to absolute mode.\n");
1029 			rc = -1;
1030 		}
1031 	}
1032 
1033  skip_readback_reg_10:
1034 	if (rc)
1035 		psmouse_err(psmouse, "failed to initialise registers.\n");
1036 
1037 	return rc;
1038 }
1039 
1040 /*
1041  * (value from firmware) * 10 + 790 = dpi
1042  * we also have to convert dpi to dots/mm (*10/254 to avoid floating point)
1043  */
1044 static unsigned int elantech_convert_res(unsigned int val)
1045 {
1046 	return (val * 10 + 790) * 10 / 254;
1047 }
1048 
1049 static int elantech_get_resolution_v4(struct psmouse *psmouse,
1050 				      unsigned int *x_res,
1051 				      unsigned int *y_res,
1052 				      unsigned int *bus)
1053 {
1054 	unsigned char param[3];
1055 
1056 	if (elantech_send_cmd(psmouse, ETP_RESOLUTION_QUERY, param))
1057 		return -1;
1058 
1059 	*x_res = elantech_convert_res(param[1] & 0x0f);
1060 	*y_res = elantech_convert_res((param[1] & 0xf0) >> 4);
1061 	*bus = param[2];
1062 
1063 	return 0;
1064 }
1065 
1066 static void elantech_set_buttonpad_prop(struct psmouse *psmouse)
1067 {
1068 	struct input_dev *dev = psmouse->dev;
1069 	struct elantech_data *etd = psmouse->private;
1070 
1071 	if (elantech_is_buttonpad(&etd->info)) {
1072 		__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
1073 		__clear_bit(BTN_RIGHT, dev->keybit);
1074 	}
1075 }
1076 
1077 /*
1078  * Some hw_version 4 models do have a middle button
1079  */
1080 static const struct dmi_system_id elantech_dmi_has_middle_button[] = {
1081 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1082 	{
1083 		/* Fujitsu H730 has a middle button */
1084 		.matches = {
1085 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1086 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H730"),
1087 		},
1088 	},
1089 	{
1090 		/* Fujitsu H760 also has a middle button */
1091 		.matches = {
1092 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1093 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H760"),
1094 		},
1095 	},
1096 	{
1097 		/* Fujitsu H780 also has a middle button */
1098 		.matches = {
1099 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1100 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H780"),
1101 		},
1102 	},
1103 #endif
1104 	{ }
1105 };
1106 
1107 /*
1108  * Set the appropriate event bits for the input subsystem
1109  */
1110 static int elantech_set_input_params(struct psmouse *psmouse)
1111 {
1112 	struct input_dev *dev = psmouse->dev;
1113 	struct elantech_data *etd = psmouse->private;
1114 	struct elantech_device_info *info = &etd->info;
1115 	unsigned int x_min = info->x_min, y_min = info->y_min,
1116 		     x_max = info->x_max, y_max = info->y_max,
1117 		     width = info->width;
1118 
1119 	__set_bit(INPUT_PROP_POINTER, dev->propbit);
1120 	__set_bit(EV_KEY, dev->evbit);
1121 	__set_bit(EV_ABS, dev->evbit);
1122 	__clear_bit(EV_REL, dev->evbit);
1123 
1124 	__set_bit(BTN_LEFT, dev->keybit);
1125 	if (info->has_middle_button)
1126 		__set_bit(BTN_MIDDLE, dev->keybit);
1127 	__set_bit(BTN_RIGHT, dev->keybit);
1128 
1129 	__set_bit(BTN_TOUCH, dev->keybit);
1130 	__set_bit(BTN_TOOL_FINGER, dev->keybit);
1131 	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
1132 	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
1133 
1134 	switch (info->hw_version) {
1135 	case 1:
1136 		/* Rocker button */
1137 		if (info->fw_version < 0x020000 &&
1138 		    (info->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
1139 			__set_bit(BTN_FORWARD, dev->keybit);
1140 			__set_bit(BTN_BACK, dev->keybit);
1141 		}
1142 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1143 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1144 		break;
1145 
1146 	case 2:
1147 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1148 		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
1149 		/* fall through */
1150 	case 3:
1151 		if (info->hw_version == 3)
1152 			elantech_set_buttonpad_prop(psmouse);
1153 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1154 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1155 		if (info->reports_pressure) {
1156 			input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1157 					     ETP_PMAX_V2, 0, 0);
1158 			input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1159 					     ETP_WMAX_V2, 0, 0);
1160 		}
1161 		input_mt_init_slots(dev, 2, INPUT_MT_SEMI_MT);
1162 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1163 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1164 		break;
1165 
1166 	case 4:
1167 		elantech_set_buttonpad_prop(psmouse);
1168 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1169 		/* For X to recognize me as touchpad. */
1170 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1171 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1172 		/*
1173 		 * range of pressure and width is the same as v2,
1174 		 * report ABS_PRESSURE, ABS_TOOL_WIDTH for compatibility.
1175 		 */
1176 		input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1177 				     ETP_PMAX_V2, 0, 0);
1178 		input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1179 				     ETP_WMAX_V2, 0, 0);
1180 		/* Multitouch capable pad, up to 5 fingers. */
1181 		input_mt_init_slots(dev, ETP_MAX_FINGERS, 0);
1182 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1183 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1184 		input_set_abs_params(dev, ABS_MT_PRESSURE, ETP_PMIN_V2,
1185 				     ETP_PMAX_V2, 0, 0);
1186 		/*
1187 		 * The firmware reports how many trace lines the finger spans,
1188 		 * convert to surface unit as Protocol-B requires.
1189 		 */
1190 		input_set_abs_params(dev, ABS_MT_TOUCH_MAJOR, 0,
1191 				     ETP_WMAX_V2 * width, 0, 0);
1192 		break;
1193 	}
1194 
1195 	input_abs_set_res(dev, ABS_X, info->x_res);
1196 	input_abs_set_res(dev, ABS_Y, info->y_res);
1197 	if (info->hw_version > 1) {
1198 		input_abs_set_res(dev, ABS_MT_POSITION_X, info->x_res);
1199 		input_abs_set_res(dev, ABS_MT_POSITION_Y, info->y_res);
1200 	}
1201 
1202 	etd->y_max = y_max;
1203 	etd->width = width;
1204 
1205 	return 0;
1206 }
1207 
1208 struct elantech_attr_data {
1209 	size_t		field_offset;
1210 	unsigned char	reg;
1211 };
1212 
1213 /*
1214  * Display a register value by reading a sysfs entry
1215  */
1216 static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
1217 					char *buf)
1218 {
1219 	struct elantech_data *etd = psmouse->private;
1220 	struct elantech_attr_data *attr = data;
1221 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1222 	int rc = 0;
1223 
1224 	if (attr->reg)
1225 		rc = elantech_read_reg(psmouse, attr->reg, reg);
1226 
1227 	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
1228 }
1229 
1230 /*
1231  * Write a register value by writing a sysfs entry
1232  */
1233 static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
1234 				     void *data, const char *buf, size_t count)
1235 {
1236 	struct elantech_data *etd = psmouse->private;
1237 	struct elantech_attr_data *attr = data;
1238 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1239 	unsigned char value;
1240 	int err;
1241 
1242 	err = kstrtou8(buf, 16, &value);
1243 	if (err)
1244 		return err;
1245 
1246 	/* Do we need to preserve some bits for version 2 hardware too? */
1247 	if (etd->info.hw_version == 1) {
1248 		if (attr->reg == 0x10)
1249 			/* Force absolute mode always on */
1250 			value |= ETP_R10_ABSOLUTE_MODE;
1251 		else if (attr->reg == 0x11)
1252 			/* Force 4 byte mode always on */
1253 			value |= ETP_R11_4_BYTE_MODE;
1254 	}
1255 
1256 	if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
1257 		*reg = value;
1258 
1259 	return count;
1260 }
1261 
1262 #define ELANTECH_INT_ATTR(_name, _register)				\
1263 	static struct elantech_attr_data elantech_attr_##_name = {	\
1264 		.field_offset = offsetof(struct elantech_data, _name),	\
1265 		.reg = _register,					\
1266 	};								\
1267 	PSMOUSE_DEFINE_ATTR(_name, 0644,				\
1268 			    &elantech_attr_##_name,			\
1269 			    elantech_show_int_attr,			\
1270 			    elantech_set_int_attr)
1271 
1272 #define ELANTECH_INFO_ATTR(_name)					       \
1273 	static struct elantech_attr_data elantech_attr_##_name = {	       \
1274 		.field_offset = offsetof(struct elantech_data, info) +	       \
1275 				offsetof(struct elantech_device_info, _name),  \
1276 		.reg = 0,						       \
1277 	};								       \
1278 	PSMOUSE_DEFINE_ATTR(_name, 0644,				       \
1279 			    &elantech_attr_##_name,			       \
1280 			    elantech_show_int_attr,			       \
1281 			    elantech_set_int_attr)
1282 
1283 ELANTECH_INT_ATTR(reg_07, 0x07);
1284 ELANTECH_INT_ATTR(reg_10, 0x10);
1285 ELANTECH_INT_ATTR(reg_11, 0x11);
1286 ELANTECH_INT_ATTR(reg_20, 0x20);
1287 ELANTECH_INT_ATTR(reg_21, 0x21);
1288 ELANTECH_INT_ATTR(reg_22, 0x22);
1289 ELANTECH_INT_ATTR(reg_23, 0x23);
1290 ELANTECH_INT_ATTR(reg_24, 0x24);
1291 ELANTECH_INT_ATTR(reg_25, 0x25);
1292 ELANTECH_INT_ATTR(reg_26, 0x26);
1293 ELANTECH_INFO_ATTR(debug);
1294 ELANTECH_INFO_ATTR(paritycheck);
1295 ELANTECH_INFO_ATTR(crc_enabled);
1296 
1297 static struct attribute *elantech_attrs[] = {
1298 	&psmouse_attr_reg_07.dattr.attr,
1299 	&psmouse_attr_reg_10.dattr.attr,
1300 	&psmouse_attr_reg_11.dattr.attr,
1301 	&psmouse_attr_reg_20.dattr.attr,
1302 	&psmouse_attr_reg_21.dattr.attr,
1303 	&psmouse_attr_reg_22.dattr.attr,
1304 	&psmouse_attr_reg_23.dattr.attr,
1305 	&psmouse_attr_reg_24.dattr.attr,
1306 	&psmouse_attr_reg_25.dattr.attr,
1307 	&psmouse_attr_reg_26.dattr.attr,
1308 	&psmouse_attr_debug.dattr.attr,
1309 	&psmouse_attr_paritycheck.dattr.attr,
1310 	&psmouse_attr_crc_enabled.dattr.attr,
1311 	NULL
1312 };
1313 
1314 static const struct attribute_group elantech_attr_group = {
1315 	.attrs = elantech_attrs,
1316 };
1317 
1318 static bool elantech_is_signature_valid(const unsigned char *param)
1319 {
1320 	static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10 };
1321 	int i;
1322 
1323 	if (param[0] == 0)
1324 		return false;
1325 
1326 	if (param[1] == 0)
1327 		return true;
1328 
1329 	/*
1330 	 * Some hw_version >= 4 models have a revision higher then 20. Meaning
1331 	 * that param[2] may be 10 or 20, skip the rates check for these.
1332 	 */
1333 	if ((param[0] & 0x0f) >= 0x06 && (param[1] & 0xaf) == 0x0f &&
1334 	    param[2] < 40)
1335 		return true;
1336 
1337 	for (i = 0; i < ARRAY_SIZE(rates); i++)
1338 		if (param[2] == rates[i])
1339 			return false;
1340 
1341 	return true;
1342 }
1343 
1344 /*
1345  * Use magic knock to detect Elantech touchpad
1346  */
1347 int elantech_detect(struct psmouse *psmouse, bool set_properties)
1348 {
1349 	struct ps2dev *ps2dev = &psmouse->ps2dev;
1350 	unsigned char param[3];
1351 
1352 	ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
1353 
1354 	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
1355 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1356 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1357 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1358 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
1359 		psmouse_dbg(psmouse, "sending Elantech magic knock failed.\n");
1360 		return -1;
1361 	}
1362 
1363 	/*
1364 	 * Report this in case there are Elantech models that use a different
1365 	 * set of magic numbers
1366 	 */
1367 	if (param[0] != 0x3c || param[1] != 0x03 ||
1368 	    (param[2] != 0xc8 && param[2] != 0x00)) {
1369 		psmouse_dbg(psmouse,
1370 			    "unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
1371 			    param[0], param[1], param[2]);
1372 		return -1;
1373 	}
1374 
1375 	/*
1376 	 * Query touchpad's firmware version and see if it reports known
1377 	 * value to avoid mis-detection. Logitech mice are known to respond
1378 	 * to Elantech magic knock and there might be more.
1379 	 */
1380 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1381 		psmouse_dbg(psmouse, "failed to query firmware version.\n");
1382 		return -1;
1383 	}
1384 
1385 	psmouse_dbg(psmouse,
1386 		    "Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
1387 		    param[0], param[1], param[2]);
1388 
1389 	if (!elantech_is_signature_valid(param)) {
1390 		psmouse_dbg(psmouse,
1391 			    "Probably not a real Elantech touchpad. Aborting.\n");
1392 		return -1;
1393 	}
1394 
1395 	if (set_properties) {
1396 		psmouse->vendor = "Elantech";
1397 		psmouse->name = "Touchpad";
1398 	}
1399 
1400 	return 0;
1401 }
1402 
1403 /*
1404  * Clean up sysfs entries when disconnecting
1405  */
1406 static void elantech_disconnect(struct psmouse *psmouse)
1407 {
1408 	struct elantech_data *etd = psmouse->private;
1409 
1410 	/*
1411 	 * We might have left a breadcrumb when trying to
1412 	 * set up SMbus companion.
1413 	 */
1414 	psmouse_smbus_cleanup(psmouse);
1415 
1416 	if (etd->tp_dev)
1417 		input_unregister_device(etd->tp_dev);
1418 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
1419 			   &elantech_attr_group);
1420 	kfree(psmouse->private);
1421 	psmouse->private = NULL;
1422 }
1423 
1424 /*
1425  * Put the touchpad back into absolute mode when reconnecting
1426  */
1427 static int elantech_reconnect(struct psmouse *psmouse)
1428 {
1429 	psmouse_reset(psmouse);
1430 
1431 	if (elantech_detect(psmouse, 0))
1432 		return -1;
1433 
1434 	if (elantech_set_absolute_mode(psmouse)) {
1435 		psmouse_err(psmouse,
1436 			    "failed to put touchpad back into absolute mode.\n");
1437 		return -1;
1438 	}
1439 
1440 	return 0;
1441 }
1442 
1443 /*
1444  * Some hw_version 4 models do not work with crc_disabled
1445  */
1446 static const struct dmi_system_id elantech_dmi_force_crc_enabled[] = {
1447 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1448 	{
1449 		/* Fujitsu H730 does not work with crc_enabled == 0 */
1450 		.matches = {
1451 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1452 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H730"),
1453 		},
1454 	},
1455 	{
1456 		/* Fujitsu H760 does not work with crc_enabled == 0 */
1457 		.matches = {
1458 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1459 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H760"),
1460 		},
1461 	},
1462 	{
1463 		/* Fujitsu LIFEBOOK E544  does not work with crc_enabled == 0 */
1464 		.matches = {
1465 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1466 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E544"),
1467 		},
1468 	},
1469 	{
1470 		/* Fujitsu LIFEBOOK E546  does not work with crc_enabled == 0 */
1471 		.matches = {
1472 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1473 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E546"),
1474 		},
1475 	},
1476 	{
1477 		/* Fujitsu LIFEBOOK E547 does not work with crc_enabled == 0 */
1478 		.matches = {
1479 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1480 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E547"),
1481 		},
1482 	},
1483 	{
1484 		/* Fujitsu LIFEBOOK E554  does not work with crc_enabled == 0 */
1485 		.matches = {
1486 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1487 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E554"),
1488 		},
1489 	},
1490 	{
1491 		/* Fujitsu LIFEBOOK E556 does not work with crc_enabled == 0 */
1492 		.matches = {
1493 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1494 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E556"),
1495 		},
1496 	},
1497 	{
1498 		/* Fujitsu LIFEBOOK E557 does not work with crc_enabled == 0 */
1499 		.matches = {
1500 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1501 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E557"),
1502 		},
1503 	},
1504 	{
1505 		/* Fujitsu LIFEBOOK U745 does not work with crc_enabled == 0 */
1506 		.matches = {
1507 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1508 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK U745"),
1509 		},
1510 	},
1511 #endif
1512 	{ }
1513 };
1514 
1515 /*
1516  * Some hw_version 3 models go into error state when we try to set
1517  * bit 3 and/or bit 1 of r10.
1518  */
1519 static const struct dmi_system_id no_hw_res_dmi_table[] = {
1520 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1521 	{
1522 		/* Gigabyte U2442 */
1523 		.matches = {
1524 			DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
1525 			DMI_MATCH(DMI_PRODUCT_NAME, "U2442"),
1526 		},
1527 	},
1528 #endif
1529 	{ }
1530 };
1531 
1532 /*
1533  * determine hardware version and set some properties according to it.
1534  */
1535 static int elantech_set_properties(struct elantech_device_info *info)
1536 {
1537 	/* This represents the version of IC body. */
1538 	int ver = (info->fw_version & 0x0f0000) >> 16;
1539 
1540 	/* Early version of Elan touchpads doesn't obey the rule. */
1541 	if (info->fw_version < 0x020030 || info->fw_version == 0x020600)
1542 		info->hw_version = 1;
1543 	else {
1544 		switch (ver) {
1545 		case 2:
1546 		case 4:
1547 			info->hw_version = 2;
1548 			break;
1549 		case 5:
1550 			info->hw_version = 3;
1551 			break;
1552 		case 6 ... 15:
1553 			info->hw_version = 4;
1554 			break;
1555 		default:
1556 			return -1;
1557 		}
1558 	}
1559 
1560 	/* decide which send_cmd we're gonna use early */
1561 	info->send_cmd = info->hw_version >= 3 ? elantech_send_cmd :
1562 						 synaptics_send_cmd;
1563 
1564 	/* Turn on packet checking by default */
1565 	info->paritycheck = 1;
1566 
1567 	/*
1568 	 * This firmware suffers from misreporting coordinates when
1569 	 * a touch action starts causing the mouse cursor or scrolled page
1570 	 * to jump. Enable a workaround.
1571 	 */
1572 	info->jumpy_cursor =
1573 		(info->fw_version == 0x020022 || info->fw_version == 0x020600);
1574 
1575 	if (info->hw_version > 1) {
1576 		/* For now show extra debug information */
1577 		info->debug = 1;
1578 
1579 		if (info->fw_version >= 0x020800)
1580 			info->reports_pressure = true;
1581 	}
1582 
1583 	/*
1584 	 * The signatures of v3 and v4 packets change depending on the
1585 	 * value of this hardware flag.
1586 	 */
1587 	info->crc_enabled = (info->fw_version & 0x4000) == 0x4000 ||
1588 			     dmi_check_system(elantech_dmi_force_crc_enabled);
1589 
1590 	/* Enable real hardware resolution on hw_version 3 ? */
1591 	info->set_hw_resolution = !dmi_check_system(no_hw_res_dmi_table);
1592 
1593 	return 0;
1594 }
1595 
1596 static int elantech_query_info(struct psmouse *psmouse,
1597 			       struct elantech_device_info *info)
1598 {
1599 	unsigned char param[3];
1600 	unsigned char traces;
1601 
1602 	memset(info, 0, sizeof(*info));
1603 
1604 	/*
1605 	 * Do the version query again so we can store the result
1606 	 */
1607 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1608 		psmouse_err(psmouse, "failed to query firmware version.\n");
1609 		return -EINVAL;
1610 	}
1611 	info->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
1612 
1613 	if (elantech_set_properties(info)) {
1614 		psmouse_err(psmouse, "unknown hardware version, aborting...\n");
1615 		return -EINVAL;
1616 	}
1617 	psmouse_info(psmouse,
1618 		     "assuming hardware version %d (with firmware version 0x%02x%02x%02x)\n",
1619 		     info->hw_version, param[0], param[1], param[2]);
1620 
1621 	if (info->send_cmd(psmouse, ETP_CAPABILITIES_QUERY,
1622 	    info->capabilities)) {
1623 		psmouse_err(psmouse, "failed to query capabilities.\n");
1624 		return -EINVAL;
1625 	}
1626 	psmouse_info(psmouse,
1627 		     "Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
1628 		     info->capabilities[0], info->capabilities[1],
1629 		     info->capabilities[2]);
1630 
1631 	if (info->hw_version != 1) {
1632 		if (info->send_cmd(psmouse, ETP_SAMPLE_QUERY, info->samples)) {
1633 			psmouse_err(psmouse, "failed to query sample data\n");
1634 			return -EINVAL;
1635 		}
1636 		psmouse_info(psmouse,
1637 			     "Elan sample query result %02x, %02x, %02x\n",
1638 			     info->samples[0],
1639 			     info->samples[1],
1640 			     info->samples[2]);
1641 	}
1642 
1643 	if (info->samples[1] == 0x74 && info->hw_version == 0x03) {
1644 		/*
1645 		 * This module has a bug which makes absolute mode
1646 		 * unusable, so let's abort so we'll be using standard
1647 		 * PS/2 protocol.
1648 		 */
1649 		psmouse_info(psmouse,
1650 			     "absolute mode broken, forcing standard PS/2 protocol\n");
1651 		return -ENODEV;
1652 	}
1653 
1654 	/* The MSB indicates the presence of the trackpoint */
1655 	info->has_trackpoint = (info->capabilities[0] & 0x80) == 0x80;
1656 
1657 	info->x_res = 31;
1658 	info->y_res = 31;
1659 	if (info->hw_version == 4) {
1660 		if (elantech_get_resolution_v4(psmouse,
1661 					       &info->x_res,
1662 					       &info->y_res,
1663 					       &info->bus)) {
1664 			psmouse_warn(psmouse,
1665 				     "failed to query resolution data.\n");
1666 		}
1667 	}
1668 
1669 	/* query range information */
1670 	switch (info->hw_version) {
1671 	case 1:
1672 		info->x_min = ETP_XMIN_V1;
1673 		info->y_min = ETP_YMIN_V1;
1674 		info->x_max = ETP_XMAX_V1;
1675 		info->y_max = ETP_YMAX_V1;
1676 		break;
1677 
1678 	case 2:
1679 		if (info->fw_version == 0x020800 ||
1680 		    info->fw_version == 0x020b00 ||
1681 		    info->fw_version == 0x020030) {
1682 			info->x_min = ETP_XMIN_V2;
1683 			info->y_min = ETP_YMIN_V2;
1684 			info->x_max = ETP_XMAX_V2;
1685 			info->y_max = ETP_YMAX_V2;
1686 		} else {
1687 			int i;
1688 			int fixed_dpi;
1689 
1690 			i = (info->fw_version > 0x020800 &&
1691 			     info->fw_version < 0x020900) ? 1 : 2;
1692 
1693 			if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1694 				return -EINVAL;
1695 
1696 			fixed_dpi = param[1] & 0x10;
1697 
1698 			if (((info->fw_version >> 16) == 0x14) && fixed_dpi) {
1699 				if (info->send_cmd(psmouse, ETP_SAMPLE_QUERY, param))
1700 					return -EINVAL;
1701 
1702 				info->x_max = (info->capabilities[1] - i) * param[1] / 2;
1703 				info->y_max = (info->capabilities[2] - i) * param[2] / 2;
1704 			} else if (info->fw_version == 0x040216) {
1705 				info->x_max = 819;
1706 				info->y_max = 405;
1707 			} else if (info->fw_version == 0x040219 || info->fw_version == 0x040215) {
1708 				info->x_max = 900;
1709 				info->y_max = 500;
1710 			} else {
1711 				info->x_max = (info->capabilities[1] - i) * 64;
1712 				info->y_max = (info->capabilities[2] - i) * 64;
1713 			}
1714 		}
1715 		break;
1716 
1717 	case 3:
1718 		if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1719 			return -EINVAL;
1720 
1721 		info->x_max = (0x0f & param[0]) << 8 | param[1];
1722 		info->y_max = (0xf0 & param[0]) << 4 | param[2];
1723 		break;
1724 
1725 	case 4:
1726 		if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1727 			return -EINVAL;
1728 
1729 		info->x_max = (0x0f & param[0]) << 8 | param[1];
1730 		info->y_max = (0xf0 & param[0]) << 4 | param[2];
1731 		traces = info->capabilities[1];
1732 		if ((traces < 2) || (traces > info->x_max))
1733 			return -EINVAL;
1734 
1735 		info->width = info->x_max / (traces - 1);
1736 
1737 		/* column number of traces */
1738 		info->x_traces = traces;
1739 
1740 		/* row number of traces */
1741 		traces = info->capabilities[2];
1742 		if ((traces >= 2) && (traces <= info->y_max))
1743 			info->y_traces = traces;
1744 
1745 		break;
1746 	}
1747 
1748 	/* check for the middle button: DMI matching or new v4 firmwares */
1749 	info->has_middle_button = dmi_check_system(elantech_dmi_has_middle_button) ||
1750 				  (ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version) &&
1751 				   !elantech_is_buttonpad(info));
1752 
1753 	return 0;
1754 }
1755 
1756 #if defined(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)
1757 
1758 /*
1759  * The newest Elantech device can use a secondary bus (over SMBus) which
1760  * provides a better bandwidth and allow a better control of the touchpads.
1761  * This is used to decide if we need to use this bus or not.
1762  */
1763 enum {
1764 	ELANTECH_SMBUS_NOT_SET = -1,
1765 	ELANTECH_SMBUS_OFF,
1766 	ELANTECH_SMBUS_ON,
1767 };
1768 
1769 static int elantech_smbus = IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) ?
1770 		ELANTECH_SMBUS_NOT_SET : ELANTECH_SMBUS_OFF;
1771 module_param_named(elantech_smbus, elantech_smbus, int, 0644);
1772 MODULE_PARM_DESC(elantech_smbus, "Use a secondary bus for the Elantech device.");
1773 
1774 static const char * const i2c_blacklist_pnp_ids[] = {
1775 	/*
1776 	 * These are known to not be working properly as bits are missing
1777 	 * in elan_i2c.
1778 	 */
1779 	NULL
1780 };
1781 
1782 static int elantech_create_smbus(struct psmouse *psmouse,
1783 				 struct elantech_device_info *info,
1784 				 bool leave_breadcrumbs)
1785 {
1786 	struct property_entry i2c_props[11] = {};
1787 	struct i2c_board_info smbus_board = {
1788 		I2C_BOARD_INFO("elan_i2c", 0x15),
1789 		.flags = I2C_CLIENT_HOST_NOTIFY,
1790 	};
1791 	unsigned int idx = 0;
1792 
1793 	smbus_board.properties = i2c_props;
1794 
1795 	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-size-x",
1796 						   info->x_max + 1);
1797 	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-size-y",
1798 						   info->y_max + 1);
1799 	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-min-x",
1800 						   info->x_min);
1801 	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-min-y",
1802 						   info->y_min);
1803 	if (info->x_res)
1804 		i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-x-mm",
1805 						      (info->x_max + 1) / info->x_res);
1806 	if (info->y_res)
1807 		i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-y-mm",
1808 						      (info->y_max + 1) / info->y_res);
1809 
1810 	if (info->has_trackpoint)
1811 		i2c_props[idx++] = PROPERTY_ENTRY_BOOL("elan,trackpoint");
1812 
1813 	if (info->has_middle_button)
1814 		i2c_props[idx++] = PROPERTY_ENTRY_BOOL("elan,middle-button");
1815 
1816 	if (info->x_traces)
1817 		i2c_props[idx++] = PROPERTY_ENTRY_U32("elan,x_traces",
1818 						      info->x_traces);
1819 	if (info->y_traces)
1820 		i2c_props[idx++] = PROPERTY_ENTRY_U32("elan,y_traces",
1821 						      info->y_traces);
1822 
1823 	if (elantech_is_buttonpad(info))
1824 		i2c_props[idx++] = PROPERTY_ENTRY_BOOL("elan,clickpad");
1825 
1826 	return psmouse_smbus_init(psmouse, &smbus_board, NULL, 0, false,
1827 				  leave_breadcrumbs);
1828 }
1829 
1830 /**
1831  * elantech_setup_smbus - called once the PS/2 devices are enumerated
1832  * and decides to instantiate a SMBus InterTouch device.
1833  */
1834 static int elantech_setup_smbus(struct psmouse *psmouse,
1835 				struct elantech_device_info *info,
1836 				bool leave_breadcrumbs)
1837 {
1838 	int error;
1839 
1840 	if (elantech_smbus == ELANTECH_SMBUS_OFF)
1841 		return -ENXIO;
1842 
1843 	if (elantech_smbus == ELANTECH_SMBUS_NOT_SET) {
1844 		/*
1845 		 * New ICs are enabled by default, unless mentioned in
1846 		 * i2c_blacklist_pnp_ids.
1847 		 * Old ICs are up to the user to decide.
1848 		 */
1849 		if (!ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version) ||
1850 		    psmouse_matches_pnp_id(psmouse, i2c_blacklist_pnp_ids))
1851 			return -ENXIO;
1852 	}
1853 
1854 	psmouse_info(psmouse, "Trying to set up SMBus access\n");
1855 
1856 	error = elantech_create_smbus(psmouse, info, leave_breadcrumbs);
1857 	if (error) {
1858 		if (error == -EAGAIN)
1859 			psmouse_info(psmouse, "SMbus companion is not ready yet\n");
1860 		else
1861 			psmouse_err(psmouse, "unable to create intertouch device\n");
1862 
1863 		return error;
1864 	}
1865 
1866 	return 0;
1867 }
1868 
1869 static bool elantech_use_host_notify(struct psmouse *psmouse,
1870 				     struct elantech_device_info *info)
1871 {
1872 	if (ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version))
1873 		return true;
1874 
1875 	switch (info->bus) {
1876 	case ETP_BUS_PS2_ONLY:
1877 		/* expected case */
1878 		break;
1879 	case ETP_BUS_SMB_ALERT_ONLY:
1880 		/* fall-through  */
1881 	case ETP_BUS_PS2_SMB_ALERT:
1882 		psmouse_dbg(psmouse, "Ignoring SMBus provider through alert protocol.\n");
1883 		break;
1884 	case ETP_BUS_SMB_HST_NTFY_ONLY:
1885 		/* fall-through  */
1886 	case ETP_BUS_PS2_SMB_HST_NTFY:
1887 		return true;
1888 	default:
1889 		psmouse_dbg(psmouse,
1890 			    "Ignoring SMBus bus provider %d.\n",
1891 			    info->bus);
1892 	}
1893 
1894 	return false;
1895 }
1896 
1897 int elantech_init_smbus(struct psmouse *psmouse)
1898 {
1899 	struct elantech_device_info info;
1900 	int error = -EINVAL;
1901 
1902 	psmouse_reset(psmouse);
1903 
1904 	error = elantech_query_info(psmouse, &info);
1905 	if (error)
1906 		goto init_fail;
1907 
1908 	if (info.hw_version < 4) {
1909 		error = -ENXIO;
1910 		goto init_fail;
1911 	}
1912 
1913 	return elantech_create_smbus(psmouse, &info, false);
1914  init_fail:
1915 	psmouse_reset(psmouse);
1916 	return error;
1917 }
1918 #endif /* CONFIG_MOUSE_PS2_ELANTECH_SMBUS */
1919 
1920 /*
1921  * Initialize the touchpad and create sysfs entries
1922  */
1923 static int elantech_setup_ps2(struct psmouse *psmouse,
1924 			      struct elantech_device_info *info)
1925 {
1926 	struct elantech_data *etd;
1927 	int i;
1928 	int error = -EINVAL;
1929 	struct input_dev *tp_dev;
1930 
1931 	psmouse->private = etd = kzalloc(sizeof(*etd), GFP_KERNEL);
1932 	if (!etd)
1933 		return -ENOMEM;
1934 
1935 	etd->info = *info;
1936 
1937 	etd->parity[0] = 1;
1938 	for (i = 1; i < 256; i++)
1939 		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
1940 
1941 	if (elantech_set_absolute_mode(psmouse)) {
1942 		psmouse_err(psmouse,
1943 			    "failed to put touchpad into absolute mode.\n");
1944 		goto init_fail;
1945 	}
1946 
1947 	if (info->fw_version == 0x381f17) {
1948 		etd->original_set_rate = psmouse->set_rate;
1949 		psmouse->set_rate = elantech_set_rate_restore_reg_07;
1950 	}
1951 
1952 	if (elantech_set_input_params(psmouse)) {
1953 		psmouse_err(psmouse, "failed to query touchpad range.\n");
1954 		goto init_fail;
1955 	}
1956 
1957 	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
1958 				   &elantech_attr_group);
1959 	if (error) {
1960 		psmouse_err(psmouse,
1961 			    "failed to create sysfs attributes, error: %d.\n",
1962 			    error);
1963 		goto init_fail;
1964 	}
1965 
1966 	if (info->has_trackpoint) {
1967 		tp_dev = input_allocate_device();
1968 
1969 		if (!tp_dev) {
1970 			error = -ENOMEM;
1971 			goto init_fail_tp_alloc;
1972 		}
1973 
1974 		etd->tp_dev = tp_dev;
1975 		snprintf(etd->tp_phys, sizeof(etd->tp_phys), "%s/input1",
1976 			psmouse->ps2dev.serio->phys);
1977 		tp_dev->phys = etd->tp_phys;
1978 		tp_dev->name = "ETPS/2 Elantech TrackPoint";
1979 		tp_dev->id.bustype = BUS_I8042;
1980 		tp_dev->id.vendor  = 0x0002;
1981 		tp_dev->id.product = PSMOUSE_ELANTECH;
1982 		tp_dev->id.version = 0x0000;
1983 		tp_dev->dev.parent = &psmouse->ps2dev.serio->dev;
1984 		tp_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
1985 		tp_dev->relbit[BIT_WORD(REL_X)] =
1986 			BIT_MASK(REL_X) | BIT_MASK(REL_Y);
1987 		tp_dev->keybit[BIT_WORD(BTN_LEFT)] =
1988 			BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_MIDDLE) |
1989 			BIT_MASK(BTN_RIGHT);
1990 
1991 		__set_bit(INPUT_PROP_POINTER, tp_dev->propbit);
1992 		__set_bit(INPUT_PROP_POINTING_STICK, tp_dev->propbit);
1993 
1994 		error = input_register_device(etd->tp_dev);
1995 		if (error < 0)
1996 			goto init_fail_tp_reg;
1997 	}
1998 
1999 	psmouse->protocol_handler = elantech_process_byte;
2000 	psmouse->disconnect = elantech_disconnect;
2001 	psmouse->reconnect = elantech_reconnect;
2002 	psmouse->pktsize = info->hw_version > 1 ? 6 : 4;
2003 
2004 	return 0;
2005  init_fail_tp_reg:
2006 	input_free_device(tp_dev);
2007  init_fail_tp_alloc:
2008 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
2009 			   &elantech_attr_group);
2010  init_fail:
2011 	kfree(etd);
2012 	return error;
2013 }
2014 
2015 int elantech_init_ps2(struct psmouse *psmouse)
2016 {
2017 	struct elantech_device_info info;
2018 	int error = -EINVAL;
2019 
2020 	psmouse_reset(psmouse);
2021 
2022 	error = elantech_query_info(psmouse, &info);
2023 	if (error)
2024 		goto init_fail;
2025 
2026 	error = elantech_setup_ps2(psmouse, &info);
2027 	if (error)
2028 		goto init_fail;
2029 
2030 	return 0;
2031  init_fail:
2032 	psmouse_reset(psmouse);
2033 	return error;
2034 }
2035 
2036 int elantech_init(struct psmouse *psmouse)
2037 {
2038 	struct elantech_device_info info;
2039 	int error = -EINVAL;
2040 
2041 	psmouse_reset(psmouse);
2042 
2043 	error = elantech_query_info(psmouse, &info);
2044 	if (error)
2045 		goto init_fail;
2046 
2047 #if defined(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)
2048 
2049 	if (elantech_use_host_notify(psmouse, &info)) {
2050 		if (!IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) ||
2051 		    !IS_ENABLED(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)) {
2052 			psmouse_warn(psmouse,
2053 				     "The touchpad can support a better bus than the too old PS/2 protocol. "
2054 				     "Make sure MOUSE_PS2_ELANTECH_SMBUS and MOUSE_ELAN_I2C_SMBUS are enabled to get a better touchpad experience.\n");
2055 		}
2056 		error = elantech_setup_smbus(psmouse, &info, true);
2057 		if (!error)
2058 			return PSMOUSE_ELANTECH_SMBUS;
2059 	}
2060 
2061 #endif /* CONFIG_MOUSE_PS2_ELANTECH_SMBUS */
2062 
2063 	error = elantech_setup_ps2(psmouse, &info);
2064 	if (error < 0) {
2065 		/*
2066 		 * Not using any flavor of Elantech support, so clean up
2067 		 * SMbus breadcrumbs, if any.
2068 		 */
2069 		psmouse_smbus_cleanup(psmouse);
2070 		goto init_fail;
2071 	}
2072 
2073 	return PSMOUSE_ELANTECH;
2074  init_fail:
2075 	psmouse_reset(psmouse);
2076 	return error;
2077 }
2078