xref: /openbmc/linux/drivers/input/mouse/elantech.c (revision 97e6f135)
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 3 bytes from a register
94  */
95 static int elantech_read_reg_params(struct psmouse *psmouse, u8 reg, u8 *param)
96 {
97 	if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
98 	    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
99 	    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
100 	    elantech_ps2_command(psmouse, NULL, reg) ||
101 	    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
102 		psmouse_err(psmouse,
103 			    "failed to read register %#02x\n", reg);
104 		return -EIO;
105 	}
106 
107 	return 0;
108 }
109 
110 /*
111  * Send an Elantech style special command to write a register with a parameter
112  */
113 static int elantech_write_reg_params(struct psmouse *psmouse, u8 reg, u8 *param)
114 {
115 	if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
116 	    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
117 	    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
118 	    elantech_ps2_command(psmouse, NULL, reg) ||
119 	    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
120 	    elantech_ps2_command(psmouse, NULL, param[0]) ||
121 	    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
122 	    elantech_ps2_command(psmouse, NULL, param[1]) ||
123 	    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
124 		psmouse_err(psmouse,
125 			    "failed to write register %#02x with value %#02x%#02x\n",
126 			    reg, param[0], param[1]);
127 		return -EIO;
128 	}
129 
130 	return 0;
131 }
132 
133 /*
134  * Send an Elantech style special command to read a value from a register
135  */
136 static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
137 				unsigned char *val)
138 {
139 	struct elantech_data *etd = psmouse->private;
140 	unsigned char param[3];
141 	int rc = 0;
142 
143 	if (reg < 0x07 || reg > 0x26)
144 		return -1;
145 
146 	if (reg > 0x11 && reg < 0x20)
147 		return -1;
148 
149 	switch (etd->info.hw_version) {
150 	case 1:
151 		if (ps2_sliced_command(&psmouse->ps2dev, ETP_REGISTER_READ) ||
152 		    ps2_sliced_command(&psmouse->ps2dev, reg) ||
153 		    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
154 			rc = -1;
155 		}
156 		break;
157 
158 	case 2:
159 		if (elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
160 		    elantech_ps2_command(psmouse,  NULL, ETP_REGISTER_READ) ||
161 		    elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
162 		    elantech_ps2_command(psmouse,  NULL, reg) ||
163 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
164 			rc = -1;
165 		}
166 		break;
167 
168 	case 3 ... 4:
169 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
170 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
171 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
172 		    elantech_ps2_command(psmouse, NULL, reg) ||
173 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
174 			rc = -1;
175 		}
176 		break;
177 	}
178 
179 	if (rc)
180 		psmouse_err(psmouse, "failed to read register 0x%02x.\n", reg);
181 	else if (etd->info.hw_version != 4)
182 		*val = param[0];
183 	else
184 		*val = param[1];
185 
186 	return rc;
187 }
188 
189 /*
190  * Send an Elantech style special command to write a register with a value
191  */
192 static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
193 				unsigned char val)
194 {
195 	struct elantech_data *etd = psmouse->private;
196 	int rc = 0;
197 
198 	if (reg < 0x07 || reg > 0x26)
199 		return -1;
200 
201 	if (reg > 0x11 && reg < 0x20)
202 		return -1;
203 
204 	switch (etd->info.hw_version) {
205 	case 1:
206 		if (ps2_sliced_command(&psmouse->ps2dev, ETP_REGISTER_WRITE) ||
207 		    ps2_sliced_command(&psmouse->ps2dev, reg) ||
208 		    ps2_sliced_command(&psmouse->ps2dev, val) ||
209 		    ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
210 			rc = -1;
211 		}
212 		break;
213 
214 	case 2:
215 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
216 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
217 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
218 		    elantech_ps2_command(psmouse, NULL, reg) ||
219 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
220 		    elantech_ps2_command(psmouse, NULL, val) ||
221 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
222 			rc = -1;
223 		}
224 		break;
225 
226 	case 3:
227 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
228 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
229 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
230 		    elantech_ps2_command(psmouse, NULL, reg) ||
231 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
232 		    elantech_ps2_command(psmouse, NULL, val) ||
233 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
234 			rc = -1;
235 		}
236 		break;
237 
238 	case 4:
239 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
240 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
241 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
242 		    elantech_ps2_command(psmouse, NULL, reg) ||
243 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
244 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
245 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
246 		    elantech_ps2_command(psmouse, NULL, val) ||
247 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
248 			rc = -1;
249 		}
250 		break;
251 	}
252 
253 	if (rc)
254 		psmouse_err(psmouse,
255 			    "failed to write register 0x%02x with value 0x%02x.\n",
256 			    reg, val);
257 
258 	return rc;
259 }
260 
261 /*
262  * Dump a complete mouse movement packet to the syslog
263  */
264 static void elantech_packet_dump(struct psmouse *psmouse)
265 {
266 	psmouse_printk(KERN_DEBUG, psmouse, "PS/2 packet [%*ph]\n",
267 		       psmouse->pktsize, psmouse->packet);
268 }
269 
270 /*
271  * Advertise INPUT_PROP_BUTTONPAD for clickpads. The testing of bit 12 in
272  * fw_version for this is based on the following fw_version & caps table:
273  *
274  * Laptop-model:           fw_version:     caps:           buttons:
275  * Acer S3                 0x461f00        10, 13, 0e      clickpad
276  * Acer S7-392             0x581f01        50, 17, 0d      clickpad
277  * Acer V5-131             0x461f02        01, 16, 0c      clickpad
278  * Acer V5-551             0x461f00        ?               clickpad
279  * Asus K53SV              0x450f01        78, 15, 0c      2 hw buttons
280  * Asus G46VW              0x460f02        00, 18, 0c      2 hw buttons
281  * Asus G750JX             0x360f00        00, 16, 0c      2 hw buttons
282  * Asus TP500LN            0x381f17        10, 14, 0e      clickpad
283  * Asus X750JN             0x381f17        10, 14, 0e      clickpad
284  * Asus UX31               0x361f00        20, 15, 0e      clickpad
285  * Asus UX32VD             0x361f02        00, 15, 0e      clickpad
286  * Avatar AVIU-145A2       0x361f00        ?               clickpad
287  * Fujitsu CELSIUS H760    0x570f02        40, 14, 0c      3 hw buttons (**)
288  * Fujitsu CELSIUS H780    0x5d0f02        41, 16, 0d      3 hw buttons (**)
289  * Fujitsu LIFEBOOK E544   0x470f00        d0, 12, 09      2 hw buttons
290  * Fujitsu LIFEBOOK E546   0x470f00        50, 12, 09      2 hw buttons
291  * Fujitsu LIFEBOOK E547   0x470f00        50, 12, 09      2 hw buttons
292  * Fujitsu LIFEBOOK E554   0x570f01        40, 14, 0c      2 hw buttons
293  * Fujitsu LIFEBOOK E557   0x570f01        40, 14, 0c      2 hw buttons
294  * Fujitsu T725            0x470f01        05, 12, 09      2 hw buttons
295  * Fujitsu H730            0x570f00        c0, 14, 0c      3 hw buttons (**)
296  * Gigabyte U2442          0x450f01        58, 17, 0c      2 hw buttons
297  * Lenovo L430             0x350f02        b9, 15, 0c      2 hw buttons (*)
298  * Lenovo L530             0x350f02        b9, 15, 0c      2 hw buttons (*)
299  * Samsung NF210           0x150b00        78, 14, 0a      2 hw buttons
300  * Samsung NP770Z5E        0x575f01        10, 15, 0f      clickpad
301  * Samsung NP700Z5B        0x361f06        21, 15, 0f      clickpad
302  * Samsung NP900X3E-A02    0x575f03        ?               clickpad
303  * Samsung NP-QX410        0x851b00        19, 14, 0c      clickpad
304  * Samsung RC512           0x450f00        08, 15, 0c      2 hw buttons
305  * Samsung RF710           0x450f00        ?               2 hw buttons
306  * System76 Pangolin       0x250f01        ?               2 hw buttons
307  * (*) + 3 trackpoint buttons
308  * (**) + 0 trackpoint buttons
309  * Note: Lenovo L430 and Lenovo L530 have the same fw_version/caps
310  */
311 static inline int elantech_is_buttonpad(struct elantech_device_info *info)
312 {
313 	return info->fw_version & 0x001000;
314 }
315 
316 /*
317  * Interpret complete data packets and report absolute mode input events for
318  * hardware version 1. (4 byte packets)
319  */
320 static void elantech_report_absolute_v1(struct psmouse *psmouse)
321 {
322 	struct input_dev *dev = psmouse->dev;
323 	struct elantech_data *etd = psmouse->private;
324 	unsigned char *packet = psmouse->packet;
325 	int fingers;
326 
327 	if (etd->info.fw_version < 0x020000) {
328 		/*
329 		 * byte 0:  D   U  p1  p2   1  p3   R   L
330 		 * byte 1:  f   0  th  tw  x9  x8  y9  y8
331 		 */
332 		fingers = ((packet[1] & 0x80) >> 7) +
333 				((packet[1] & 0x30) >> 4);
334 	} else {
335 		/*
336 		 * byte 0: n1  n0  p2  p1   1  p3   R   L
337 		 * byte 1:  0   0   0   0  x9  x8  y9  y8
338 		 */
339 		fingers = (packet[0] & 0xc0) >> 6;
340 	}
341 
342 	if (etd->info.jumpy_cursor) {
343 		if (fingers != 1) {
344 			etd->single_finger_reports = 0;
345 		} else if (etd->single_finger_reports < 2) {
346 			/* Discard first 2 reports of one finger, bogus */
347 			etd->single_finger_reports++;
348 			elantech_debug("discarding packet\n");
349 			return;
350 		}
351 	}
352 
353 	input_report_key(dev, BTN_TOUCH, fingers != 0);
354 
355 	/*
356 	 * byte 2: x7  x6  x5  x4  x3  x2  x1  x0
357 	 * byte 3: y7  y6  y5  y4  y3  y2  y1  y0
358 	 */
359 	if (fingers) {
360 		input_report_abs(dev, ABS_X,
361 			((packet[1] & 0x0c) << 6) | packet[2]);
362 		input_report_abs(dev, ABS_Y,
363 			etd->y_max - (((packet[1] & 0x03) << 8) | packet[3]));
364 	}
365 
366 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
367 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
368 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
369 
370 	psmouse_report_standard_buttons(dev, packet[0]);
371 
372 	if (etd->info.fw_version < 0x020000 &&
373 	    (etd->info.capabilities[0] & ETP_CAP_HAS_ROCKER)) {
374 		/* rocker up */
375 		input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
376 		/* rocker down */
377 		input_report_key(dev, BTN_BACK, packet[0] & 0x80);
378 	}
379 
380 	input_sync(dev);
381 }
382 
383 static void elantech_set_slot(struct input_dev *dev, int slot, bool active,
384 			      unsigned int x, unsigned int y)
385 {
386 	input_mt_slot(dev, slot);
387 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
388 	if (active) {
389 		input_report_abs(dev, ABS_MT_POSITION_X, x);
390 		input_report_abs(dev, ABS_MT_POSITION_Y, y);
391 	}
392 }
393 
394 /* x1 < x2 and y1 < y2 when two fingers, x = y = 0 when not pressed */
395 static void elantech_report_semi_mt_data(struct input_dev *dev,
396 					 unsigned int num_fingers,
397 					 unsigned int x1, unsigned int y1,
398 					 unsigned int x2, unsigned int y2)
399 {
400 	elantech_set_slot(dev, 0, num_fingers != 0, x1, y1);
401 	elantech_set_slot(dev, 1, num_fingers >= 2, x2, y2);
402 }
403 
404 /*
405  * Interpret complete data packets and report absolute mode input events for
406  * hardware version 2. (6 byte packets)
407  */
408 static void elantech_report_absolute_v2(struct psmouse *psmouse)
409 {
410 	struct elantech_data *etd = psmouse->private;
411 	struct input_dev *dev = psmouse->dev;
412 	unsigned char *packet = psmouse->packet;
413 	unsigned int fingers, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
414 	unsigned int width = 0, pres = 0;
415 
416 	/* byte 0: n1  n0   .   .   .   .   R   L */
417 	fingers = (packet[0] & 0xc0) >> 6;
418 
419 	switch (fingers) {
420 	case 3:
421 		/*
422 		 * Same as one finger, except report of more than 3 fingers:
423 		 * byte 3:  n4  .   w1  w0   .   .   .   .
424 		 */
425 		if (packet[3] & 0x80)
426 			fingers = 4;
427 		fallthrough;
428 	case 1:
429 		/*
430 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
431 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
432 		 */
433 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
434 		/*
435 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
436 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
437 		 */
438 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
439 
440 		pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
441 		width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
442 		break;
443 
444 	case 2:
445 		/*
446 		 * The coordinate of each finger is reported separately
447 		 * with a lower resolution for two finger touches:
448 		 * byte 0:  .   .  ay8 ax8  .   .   .   .
449 		 * byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
450 		 */
451 		x1 = (((packet[0] & 0x10) << 4) | packet[1]) << 2;
452 		/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
453 		y1 = etd->y_max -
454 			((((packet[0] & 0x20) << 3) | packet[2]) << 2);
455 		/*
456 		 * byte 3:  .   .  by8 bx8  .   .   .   .
457 		 * byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
458 		 */
459 		x2 = (((packet[3] & 0x10) << 4) | packet[4]) << 2;
460 		/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
461 		y2 = etd->y_max -
462 			((((packet[3] & 0x20) << 3) | packet[5]) << 2);
463 
464 		/* Unknown so just report sensible values */
465 		pres = 127;
466 		width = 7;
467 		break;
468 	}
469 
470 	input_report_key(dev, BTN_TOUCH, fingers != 0);
471 	if (fingers != 0) {
472 		input_report_abs(dev, ABS_X, x1);
473 		input_report_abs(dev, ABS_Y, y1);
474 	}
475 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
476 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
477 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
478 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
479 	input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
480 	psmouse_report_standard_buttons(dev, packet[0]);
481 	if (etd->info.reports_pressure) {
482 		input_report_abs(dev, ABS_PRESSURE, pres);
483 		input_report_abs(dev, ABS_TOOL_WIDTH, width);
484 	}
485 
486 	input_sync(dev);
487 }
488 
489 static void elantech_report_trackpoint(struct psmouse *psmouse,
490 				       int packet_type)
491 {
492 	/*
493 	 * byte 0:  0   0  sx  sy   0   M   R   L
494 	 * byte 1:~sx   0   0   0   0   0   0   0
495 	 * byte 2:~sy   0   0   0   0   0   0   0
496 	 * byte 3:  0   0 ~sy ~sx   0   1   1   0
497 	 * byte 4: x7  x6  x5  x4  x3  x2  x1  x0
498 	 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
499 	 *
500 	 * x and y are written in two's complement spread
501 	 * over 9 bits with sx/sy the relative top bit and
502 	 * x7..x0 and y7..y0 the lower bits.
503 	 * The sign of y is opposite to what the input driver
504 	 * expects for a relative movement
505 	 */
506 
507 	struct elantech_data *etd = psmouse->private;
508 	struct input_dev *tp_dev = etd->tp_dev;
509 	unsigned char *packet = psmouse->packet;
510 	int x, y;
511 	u32 t;
512 
513 	t = get_unaligned_le32(&packet[0]);
514 
515 	switch (t & ~7U) {
516 	case 0x06000030U:
517 	case 0x16008020U:
518 	case 0x26800010U:
519 	case 0x36808000U:
520 
521 		/*
522 		 * This firmware misreport coordinates for trackpoint
523 		 * occasionally. Discard packets outside of [-127, 127] range
524 		 * to prevent cursor jumps.
525 		 */
526 		if (packet[4] == 0x80 || packet[5] == 0x80 ||
527 		    packet[1] >> 7 == packet[4] >> 7 ||
528 		    packet[2] >> 7 == packet[5] >> 7) {
529 			elantech_debug("discarding packet [%6ph]\n", packet);
530 			break;
531 
532 		}
533 		x = packet[4] - (int)((packet[1]^0x80) << 1);
534 		y = (int)((packet[2]^0x80) << 1) - packet[5];
535 
536 		psmouse_report_standard_buttons(tp_dev, packet[0]);
537 
538 		input_report_rel(tp_dev, REL_X, x);
539 		input_report_rel(tp_dev, REL_Y, y);
540 
541 		input_sync(tp_dev);
542 
543 		break;
544 
545 	default:
546 		/* Dump unexpected packet sequences if debug=1 (default) */
547 		if (etd->info.debug == 1)
548 			elantech_packet_dump(psmouse);
549 
550 		break;
551 	}
552 }
553 
554 /*
555  * Interpret complete data packets and report absolute mode input events for
556  * hardware version 3. (12 byte packets for two fingers)
557  */
558 static void elantech_report_absolute_v3(struct psmouse *psmouse,
559 					int packet_type)
560 {
561 	struct input_dev *dev = psmouse->dev;
562 	struct elantech_data *etd = psmouse->private;
563 	unsigned char *packet = psmouse->packet;
564 	unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
565 	unsigned int width = 0, pres = 0;
566 
567 	/* byte 0: n1  n0   .   .   .   .   R   L */
568 	fingers = (packet[0] & 0xc0) >> 6;
569 
570 	switch (fingers) {
571 	case 3:
572 	case 1:
573 		/*
574 		 * byte 1:  .   .   .   .  x11 x10 x9  x8
575 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
576 		 */
577 		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
578 		/*
579 		 * byte 4:  .   .   .   .  y11 y10 y9  y8
580 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
581 		 */
582 		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
583 		break;
584 
585 	case 2:
586 		if (packet_type == PACKET_V3_HEAD) {
587 			/*
588 			 * byte 1:   .    .    .    .  ax11 ax10 ax9  ax8
589 			 * byte 2: ax7  ax6  ax5  ax4  ax3  ax2  ax1  ax0
590 			 */
591 			etd->mt[0].x = ((packet[1] & 0x0f) << 8) | packet[2];
592 			/*
593 			 * byte 4:   .    .    .    .  ay11 ay10 ay9  ay8
594 			 * byte 5: ay7  ay6  ay5  ay4  ay3  ay2  ay1  ay0
595 			 */
596 			etd->mt[0].y = etd->y_max -
597 				(((packet[4] & 0x0f) << 8) | packet[5]);
598 			/*
599 			 * wait for next packet
600 			 */
601 			return;
602 		}
603 
604 		/* packet_type == PACKET_V3_TAIL */
605 		x1 = etd->mt[0].x;
606 		y1 = etd->mt[0].y;
607 		x2 = ((packet[1] & 0x0f) << 8) | packet[2];
608 		y2 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
609 		break;
610 	}
611 
612 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
613 	width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
614 
615 	input_report_key(dev, BTN_TOUCH, fingers != 0);
616 	if (fingers != 0) {
617 		input_report_abs(dev, ABS_X, x1);
618 		input_report_abs(dev, ABS_Y, y1);
619 	}
620 	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
621 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
622 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
623 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
624 
625 	/* For clickpads map both buttons to BTN_LEFT */
626 	if (elantech_is_buttonpad(&etd->info))
627 		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
628 	else
629 		psmouse_report_standard_buttons(dev, packet[0]);
630 
631 	input_report_abs(dev, ABS_PRESSURE, pres);
632 	input_report_abs(dev, ABS_TOOL_WIDTH, width);
633 
634 	input_sync(dev);
635 }
636 
637 static void elantech_input_sync_v4(struct psmouse *psmouse)
638 {
639 	struct input_dev *dev = psmouse->dev;
640 	struct elantech_data *etd = psmouse->private;
641 	unsigned char *packet = psmouse->packet;
642 
643 	/* For clickpads map both buttons to BTN_LEFT */
644 	if (elantech_is_buttonpad(&etd->info))
645 		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
646 	else
647 		psmouse_report_standard_buttons(dev, packet[0]);
648 
649 	input_mt_report_pointer_emulation(dev, true);
650 	input_sync(dev);
651 }
652 
653 static void process_packet_status_v4(struct psmouse *psmouse)
654 {
655 	struct input_dev *dev = psmouse->dev;
656 	unsigned char *packet = psmouse->packet;
657 	unsigned fingers;
658 	int i;
659 
660 	/* notify finger state change */
661 	fingers = packet[1] & 0x1f;
662 	for (i = 0; i < ETP_MAX_FINGERS; i++) {
663 		if ((fingers & (1 << i)) == 0) {
664 			input_mt_slot(dev, i);
665 			input_mt_report_slot_state(dev, MT_TOOL_FINGER, false);
666 		}
667 	}
668 
669 	elantech_input_sync_v4(psmouse);
670 }
671 
672 static void process_packet_head_v4(struct psmouse *psmouse)
673 {
674 	struct input_dev *dev = psmouse->dev;
675 	struct elantech_data *etd = psmouse->private;
676 	unsigned char *packet = psmouse->packet;
677 	int id;
678 	int pres, traces;
679 
680 	id = ((packet[3] & 0xe0) >> 5) - 1;
681 	if (id < 0 || id >= ETP_MAX_FINGERS)
682 		return;
683 
684 	etd->mt[id].x = ((packet[1] & 0x0f) << 8) | packet[2];
685 	etd->mt[id].y = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
686 	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
687 	traces = (packet[0] & 0xf0) >> 4;
688 
689 	input_mt_slot(dev, id);
690 	input_mt_report_slot_state(dev, MT_TOOL_FINGER, true);
691 
692 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
693 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
694 	input_report_abs(dev, ABS_MT_PRESSURE, pres);
695 	input_report_abs(dev, ABS_MT_TOUCH_MAJOR, traces * etd->width);
696 	/* report this for backwards compatibility */
697 	input_report_abs(dev, ABS_TOOL_WIDTH, traces);
698 
699 	elantech_input_sync_v4(psmouse);
700 }
701 
702 static void process_packet_motion_v4(struct psmouse *psmouse)
703 {
704 	struct input_dev *dev = psmouse->dev;
705 	struct elantech_data *etd = psmouse->private;
706 	unsigned char *packet = psmouse->packet;
707 	int weight, delta_x1 = 0, delta_y1 = 0, delta_x2 = 0, delta_y2 = 0;
708 	int id, sid;
709 
710 	id = ((packet[0] & 0xe0) >> 5) - 1;
711 	if (id < 0 || id >= ETP_MAX_FINGERS)
712 		return;
713 
714 	sid = ((packet[3] & 0xe0) >> 5) - 1;
715 	weight = (packet[0] & 0x10) ? ETP_WEIGHT_VALUE : 1;
716 	/*
717 	 * Motion packets give us the delta of x, y values of specific fingers,
718 	 * but in two's complement. Let the compiler do the conversion for us.
719 	 * Also _enlarge_ the numbers to int, in case of overflow.
720 	 */
721 	delta_x1 = (signed char)packet[1];
722 	delta_y1 = (signed char)packet[2];
723 	delta_x2 = (signed char)packet[4];
724 	delta_y2 = (signed char)packet[5];
725 
726 	etd->mt[id].x += delta_x1 * weight;
727 	etd->mt[id].y -= delta_y1 * weight;
728 	input_mt_slot(dev, id);
729 	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
730 	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
731 
732 	if (sid >= 0 && sid < ETP_MAX_FINGERS) {
733 		etd->mt[sid].x += delta_x2 * weight;
734 		etd->mt[sid].y -= delta_y2 * weight;
735 		input_mt_slot(dev, sid);
736 		input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[sid].x);
737 		input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[sid].y);
738 	}
739 
740 	elantech_input_sync_v4(psmouse);
741 }
742 
743 static void elantech_report_absolute_v4(struct psmouse *psmouse,
744 					int packet_type)
745 {
746 	switch (packet_type) {
747 	case PACKET_V4_STATUS:
748 		process_packet_status_v4(psmouse);
749 		break;
750 
751 	case PACKET_V4_HEAD:
752 		process_packet_head_v4(psmouse);
753 		break;
754 
755 	case PACKET_V4_MOTION:
756 		process_packet_motion_v4(psmouse);
757 		break;
758 
759 	case PACKET_UNKNOWN:
760 	default:
761 		/* impossible to get here */
762 		break;
763 	}
764 }
765 
766 static int elantech_packet_check_v1(struct psmouse *psmouse)
767 {
768 	struct elantech_data *etd = psmouse->private;
769 	unsigned char *packet = psmouse->packet;
770 	unsigned char p1, p2, p3;
771 
772 	/* Parity bits are placed differently */
773 	if (etd->info.fw_version < 0x020000) {
774 		/* byte 0:  D   U  p1  p2   1  p3   R   L */
775 		p1 = (packet[0] & 0x20) >> 5;
776 		p2 = (packet[0] & 0x10) >> 4;
777 	} else {
778 		/* byte 0: n1  n0  p2  p1   1  p3   R   L */
779 		p1 = (packet[0] & 0x10) >> 4;
780 		p2 = (packet[0] & 0x20) >> 5;
781 	}
782 
783 	p3 = (packet[0] & 0x04) >> 2;
784 
785 	return etd->parity[packet[1]] == p1 &&
786 	       etd->parity[packet[2]] == p2 &&
787 	       etd->parity[packet[3]] == p3;
788 }
789 
790 static int elantech_debounce_check_v2(struct psmouse *psmouse)
791 {
792         /*
793          * When we encounter packet that matches this exactly, it means the
794          * hardware is in debounce status. Just ignore the whole packet.
795          */
796 	static const u8 debounce_packet[] = {
797 		0x84, 0xff, 0xff, 0x02, 0xff, 0xff
798 	};
799         unsigned char *packet = psmouse->packet;
800 
801         return !memcmp(packet, debounce_packet, sizeof(debounce_packet));
802 }
803 
804 static int elantech_packet_check_v2(struct psmouse *psmouse)
805 {
806 	struct elantech_data *etd = psmouse->private;
807 	unsigned char *packet = psmouse->packet;
808 
809 	/*
810 	 * V2 hardware has two flavors. Older ones that do not report pressure,
811 	 * and newer ones that reports pressure and width. With newer ones, all
812 	 * packets (1, 2, 3 finger touch) have the same constant bits. With
813 	 * older ones, 1/3 finger touch packets and 2 finger touch packets
814 	 * have different constant bits.
815 	 * With all three cases, if the constant bits are not exactly what I
816 	 * expected, I consider them invalid.
817 	 */
818 	if (etd->info.reports_pressure)
819 		return (packet[0] & 0x0c) == 0x04 &&
820 		       (packet[3] & 0x0f) == 0x02;
821 
822 	if ((packet[0] & 0xc0) == 0x80)
823 		return (packet[0] & 0x0c) == 0x0c &&
824 		       (packet[3] & 0x0e) == 0x08;
825 
826 	return (packet[0] & 0x3c) == 0x3c &&
827 	       (packet[1] & 0xf0) == 0x00 &&
828 	       (packet[3] & 0x3e) == 0x38 &&
829 	       (packet[4] & 0xf0) == 0x00;
830 }
831 
832 /*
833  * We check the constant bits to determine what packet type we get,
834  * so packet checking is mandatory for v3 and later hardware.
835  */
836 static int elantech_packet_check_v3(struct psmouse *psmouse)
837 {
838 	struct elantech_data *etd = psmouse->private;
839 	static const u8 debounce_packet[] = {
840 		0xc4, 0xff, 0xff, 0x02, 0xff, 0xff
841 	};
842 	unsigned char *packet = psmouse->packet;
843 
844 	/*
845 	 * check debounce first, it has the same signature in byte 0
846 	 * and byte 3 as PACKET_V3_HEAD.
847 	 */
848 	if (!memcmp(packet, debounce_packet, sizeof(debounce_packet)))
849 		return PACKET_DEBOUNCE;
850 
851 	/*
852 	 * If the hardware flag 'crc_enabled' is set the packets have
853 	 * different signatures.
854 	 */
855 	if (etd->info.crc_enabled) {
856 		if ((packet[3] & 0x09) == 0x08)
857 			return PACKET_V3_HEAD;
858 
859 		if ((packet[3] & 0x09) == 0x09)
860 			return PACKET_V3_TAIL;
861 	} else {
862 		if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
863 			return PACKET_V3_HEAD;
864 
865 		if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
866 			return PACKET_V3_TAIL;
867 		if ((packet[3] & 0x0f) == 0x06)
868 			return PACKET_TRACKPOINT;
869 	}
870 
871 	return PACKET_UNKNOWN;
872 }
873 
874 static int elantech_packet_check_v4(struct psmouse *psmouse)
875 {
876 	struct elantech_data *etd = psmouse->private;
877 	unsigned char *packet = psmouse->packet;
878 	unsigned char packet_type = packet[3] & 0x03;
879 	unsigned int ic_version;
880 	bool sanity_check;
881 
882 	if (etd->tp_dev && (packet[3] & 0x0f) == 0x06)
883 		return PACKET_TRACKPOINT;
884 
885 	/* This represents the version of IC body. */
886 	ic_version = (etd->info.fw_version & 0x0f0000) >> 16;
887 
888 	/*
889 	 * Sanity check based on the constant bits of a packet.
890 	 * The constant bits change depending on the value of
891 	 * the hardware flag 'crc_enabled' and the version of
892 	 * the IC body, but are the same for every packet,
893 	 * regardless of the type.
894 	 */
895 	if (etd->info.crc_enabled)
896 		sanity_check = ((packet[3] & 0x08) == 0x00);
897 	else if (ic_version == 7 && etd->info.samples[1] == 0x2A)
898 		sanity_check = ((packet[3] & 0x1c) == 0x10);
899 	else
900 		sanity_check = ((packet[0] & 0x08) == 0x00 &&
901 				(packet[3] & 0x1c) == 0x10);
902 
903 	if (!sanity_check)
904 		return PACKET_UNKNOWN;
905 
906 	switch (packet_type) {
907 	case 0:
908 		return PACKET_V4_STATUS;
909 
910 	case 1:
911 		return PACKET_V4_HEAD;
912 
913 	case 2:
914 		return PACKET_V4_MOTION;
915 	}
916 
917 	return PACKET_UNKNOWN;
918 }
919 
920 /*
921  * Process byte stream from mouse and handle complete packets
922  */
923 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
924 {
925 	struct elantech_data *etd = psmouse->private;
926 	int packet_type;
927 
928 	if (psmouse->pktcnt < psmouse->pktsize)
929 		return PSMOUSE_GOOD_DATA;
930 
931 	if (etd->info.debug > 1)
932 		elantech_packet_dump(psmouse);
933 
934 	switch (etd->info.hw_version) {
935 	case 1:
936 		if (etd->info.paritycheck && !elantech_packet_check_v1(psmouse))
937 			return PSMOUSE_BAD_DATA;
938 
939 		elantech_report_absolute_v1(psmouse);
940 		break;
941 
942 	case 2:
943 		/* ignore debounce */
944 		if (elantech_debounce_check_v2(psmouse))
945 			return PSMOUSE_FULL_PACKET;
946 
947 		if (etd->info.paritycheck && !elantech_packet_check_v2(psmouse))
948 			return PSMOUSE_BAD_DATA;
949 
950 		elantech_report_absolute_v2(psmouse);
951 		break;
952 
953 	case 3:
954 		packet_type = elantech_packet_check_v3(psmouse);
955 		switch (packet_type) {
956 		case PACKET_UNKNOWN:
957 			return PSMOUSE_BAD_DATA;
958 
959 		case PACKET_DEBOUNCE:
960 			/* ignore debounce */
961 			break;
962 
963 		case PACKET_TRACKPOINT:
964 			elantech_report_trackpoint(psmouse, packet_type);
965 			break;
966 
967 		default:
968 			elantech_report_absolute_v3(psmouse, packet_type);
969 			break;
970 		}
971 
972 		break;
973 
974 	case 4:
975 		packet_type = elantech_packet_check_v4(psmouse);
976 		switch (packet_type) {
977 		case PACKET_UNKNOWN:
978 			return PSMOUSE_BAD_DATA;
979 
980 		case PACKET_TRACKPOINT:
981 			elantech_report_trackpoint(psmouse, packet_type);
982 			break;
983 
984 		default:
985 			elantech_report_absolute_v4(psmouse, packet_type);
986 			break;
987 		}
988 
989 		break;
990 	}
991 
992 	return PSMOUSE_FULL_PACKET;
993 }
994 
995 /*
996  * This writes the reg_07 value again to the hardware at the end of every
997  * set_rate call because the register loses its value. reg_07 allows setting
998  * absolute mode on v4 hardware
999  */
1000 static void elantech_set_rate_restore_reg_07(struct psmouse *psmouse,
1001 		unsigned int rate)
1002 {
1003 	struct elantech_data *etd = psmouse->private;
1004 
1005 	etd->original_set_rate(psmouse, rate);
1006 	if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
1007 		psmouse_err(psmouse, "restoring reg_07 failed\n");
1008 }
1009 
1010 /*
1011  * Put the touchpad into absolute mode
1012  */
1013 static int elantech_set_absolute_mode(struct psmouse *psmouse)
1014 {
1015 	struct elantech_data *etd = psmouse->private;
1016 	unsigned char val;
1017 	int tries = ETP_READ_BACK_TRIES;
1018 	int rc = 0;
1019 
1020 	switch (etd->info.hw_version) {
1021 	case 1:
1022 		etd->reg_10 = 0x16;
1023 		etd->reg_11 = 0x8f;
1024 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
1025 		    elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
1026 			rc = -1;
1027 		}
1028 		break;
1029 
1030 	case 2:
1031 					/* Windows driver values */
1032 		etd->reg_10 = 0x54;
1033 		etd->reg_11 = 0x88;	/* 0x8a */
1034 		etd->reg_21 = 0x60;	/* 0x00 */
1035 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
1036 		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
1037 		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
1038 			rc = -1;
1039 		}
1040 		break;
1041 
1042 	case 3:
1043 		if (etd->info.set_hw_resolution)
1044 			etd->reg_10 = 0x0b;
1045 		else
1046 			etd->reg_10 = 0x01;
1047 
1048 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
1049 			rc = -1;
1050 
1051 		break;
1052 
1053 	case 4:
1054 		etd->reg_07 = 0x01;
1055 		if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
1056 			rc = -1;
1057 
1058 		goto skip_readback_reg_10; /* v4 has no reg 0x10 to read */
1059 	}
1060 
1061 	if (rc == 0) {
1062 		/*
1063 		 * Read back reg 0x10. For hardware version 1 we must make
1064 		 * sure the absolute mode bit is set. For hardware version 2
1065 		 * the touchpad is probably initializing and not ready until
1066 		 * we read back the value we just wrote.
1067 		 */
1068 		do {
1069 			rc = elantech_read_reg(psmouse, 0x10, &val);
1070 			if (rc == 0)
1071 				break;
1072 			tries--;
1073 			elantech_debug("retrying read (%d).\n", tries);
1074 			msleep(ETP_READ_BACK_DELAY);
1075 		} while (tries > 0);
1076 
1077 		if (rc) {
1078 			psmouse_err(psmouse,
1079 				    "failed to read back register 0x10.\n");
1080 		} else if (etd->info.hw_version == 1 &&
1081 			   !(val & ETP_R10_ABSOLUTE_MODE)) {
1082 			psmouse_err(psmouse,
1083 				    "touchpad refuses to switch to absolute mode.\n");
1084 			rc = -1;
1085 		}
1086 	}
1087 
1088  skip_readback_reg_10:
1089 	if (rc)
1090 		psmouse_err(psmouse, "failed to initialise registers.\n");
1091 
1092 	return rc;
1093 }
1094 
1095 /*
1096  * (value from firmware) * 10 + 790 = dpi
1097  * we also have to convert dpi to dots/mm (*10/254 to avoid floating point)
1098  */
1099 static unsigned int elantech_convert_res(unsigned int val)
1100 {
1101 	return (val * 10 + 790) * 10 / 254;
1102 }
1103 
1104 static int elantech_get_resolution_v4(struct psmouse *psmouse,
1105 				      unsigned int *x_res,
1106 				      unsigned int *y_res,
1107 				      unsigned int *bus)
1108 {
1109 	unsigned char param[3];
1110 
1111 	if (elantech_send_cmd(psmouse, ETP_RESOLUTION_QUERY, param))
1112 		return -1;
1113 
1114 	*x_res = elantech_convert_res(param[1] & 0x0f);
1115 	*y_res = elantech_convert_res((param[1] & 0xf0) >> 4);
1116 	*bus = param[2];
1117 
1118 	return 0;
1119 }
1120 
1121 static void elantech_set_buttonpad_prop(struct psmouse *psmouse)
1122 {
1123 	struct input_dev *dev = psmouse->dev;
1124 	struct elantech_data *etd = psmouse->private;
1125 
1126 	if (elantech_is_buttonpad(&etd->info)) {
1127 		__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
1128 		__clear_bit(BTN_RIGHT, dev->keybit);
1129 	}
1130 }
1131 
1132 /*
1133  * Some hw_version 4 models do have a middle button
1134  */
1135 static const struct dmi_system_id elantech_dmi_has_middle_button[] = {
1136 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1137 	{
1138 		/* Fujitsu H730 has a middle button */
1139 		.matches = {
1140 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1141 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H730"),
1142 		},
1143 	},
1144 	{
1145 		/* Fujitsu H760 also has a middle button */
1146 		.matches = {
1147 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1148 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H760"),
1149 		},
1150 	},
1151 	{
1152 		/* Fujitsu H780 also has a middle button */
1153 		.matches = {
1154 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1155 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H780"),
1156 		},
1157 	},
1158 #endif
1159 	{ }
1160 };
1161 
1162 /*
1163  * Set the appropriate event bits for the input subsystem
1164  */
1165 static int elantech_set_input_params(struct psmouse *psmouse)
1166 {
1167 	struct input_dev *dev = psmouse->dev;
1168 	struct elantech_data *etd = psmouse->private;
1169 	struct elantech_device_info *info = &etd->info;
1170 	unsigned int x_min = info->x_min, y_min = info->y_min,
1171 		     x_max = info->x_max, y_max = info->y_max,
1172 		     width = info->width;
1173 
1174 	__set_bit(INPUT_PROP_POINTER, dev->propbit);
1175 	__set_bit(EV_KEY, dev->evbit);
1176 	__set_bit(EV_ABS, dev->evbit);
1177 	__clear_bit(EV_REL, dev->evbit);
1178 
1179 	__set_bit(BTN_LEFT, dev->keybit);
1180 	if (info->has_middle_button)
1181 		__set_bit(BTN_MIDDLE, dev->keybit);
1182 	__set_bit(BTN_RIGHT, dev->keybit);
1183 
1184 	__set_bit(BTN_TOUCH, dev->keybit);
1185 	__set_bit(BTN_TOOL_FINGER, dev->keybit);
1186 	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
1187 	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
1188 
1189 	switch (info->hw_version) {
1190 	case 1:
1191 		/* Rocker button */
1192 		if (info->fw_version < 0x020000 &&
1193 		    (info->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
1194 			__set_bit(BTN_FORWARD, dev->keybit);
1195 			__set_bit(BTN_BACK, dev->keybit);
1196 		}
1197 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1198 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1199 		break;
1200 
1201 	case 2:
1202 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1203 		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
1204 		fallthrough;
1205 	case 3:
1206 		if (info->hw_version == 3)
1207 			elantech_set_buttonpad_prop(psmouse);
1208 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1209 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1210 		if (info->reports_pressure) {
1211 			input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1212 					     ETP_PMAX_V2, 0, 0);
1213 			input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1214 					     ETP_WMAX_V2, 0, 0);
1215 		}
1216 		input_mt_init_slots(dev, 2, INPUT_MT_SEMI_MT);
1217 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1218 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1219 		break;
1220 
1221 	case 4:
1222 		elantech_set_buttonpad_prop(psmouse);
1223 		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
1224 		/* For X to recognize me as touchpad. */
1225 		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
1226 		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
1227 		/*
1228 		 * range of pressure and width is the same as v2,
1229 		 * report ABS_PRESSURE, ABS_TOOL_WIDTH for compatibility.
1230 		 */
1231 		input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
1232 				     ETP_PMAX_V2, 0, 0);
1233 		input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
1234 				     ETP_WMAX_V2, 0, 0);
1235 		/* Multitouch capable pad, up to 5 fingers. */
1236 		input_mt_init_slots(dev, ETP_MAX_FINGERS, 0);
1237 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
1238 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
1239 		input_set_abs_params(dev, ABS_MT_PRESSURE, ETP_PMIN_V2,
1240 				     ETP_PMAX_V2, 0, 0);
1241 		/*
1242 		 * The firmware reports how many trace lines the finger spans,
1243 		 * convert to surface unit as Protocol-B requires.
1244 		 */
1245 		input_set_abs_params(dev, ABS_MT_TOUCH_MAJOR, 0,
1246 				     ETP_WMAX_V2 * width, 0, 0);
1247 		break;
1248 	}
1249 
1250 	input_abs_set_res(dev, ABS_X, info->x_res);
1251 	input_abs_set_res(dev, ABS_Y, info->y_res);
1252 	if (info->hw_version > 1) {
1253 		input_abs_set_res(dev, ABS_MT_POSITION_X, info->x_res);
1254 		input_abs_set_res(dev, ABS_MT_POSITION_Y, info->y_res);
1255 	}
1256 
1257 	etd->y_max = y_max;
1258 	etd->width = width;
1259 
1260 	return 0;
1261 }
1262 
1263 struct elantech_attr_data {
1264 	size_t		field_offset;
1265 	unsigned char	reg;
1266 };
1267 
1268 /*
1269  * Display a register value by reading a sysfs entry
1270  */
1271 static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
1272 					char *buf)
1273 {
1274 	struct elantech_data *etd = psmouse->private;
1275 	struct elantech_attr_data *attr = data;
1276 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1277 	int rc = 0;
1278 
1279 	if (attr->reg)
1280 		rc = elantech_read_reg(psmouse, attr->reg, reg);
1281 
1282 	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
1283 }
1284 
1285 /*
1286  * Write a register value by writing a sysfs entry
1287  */
1288 static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
1289 				     void *data, const char *buf, size_t count)
1290 {
1291 	struct elantech_data *etd = psmouse->private;
1292 	struct elantech_attr_data *attr = data;
1293 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
1294 	unsigned char value;
1295 	int err;
1296 
1297 	err = kstrtou8(buf, 16, &value);
1298 	if (err)
1299 		return err;
1300 
1301 	/* Do we need to preserve some bits for version 2 hardware too? */
1302 	if (etd->info.hw_version == 1) {
1303 		if (attr->reg == 0x10)
1304 			/* Force absolute mode always on */
1305 			value |= ETP_R10_ABSOLUTE_MODE;
1306 		else if (attr->reg == 0x11)
1307 			/* Force 4 byte mode always on */
1308 			value |= ETP_R11_4_BYTE_MODE;
1309 	}
1310 
1311 	if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
1312 		*reg = value;
1313 
1314 	return count;
1315 }
1316 
1317 #define ELANTECH_INT_ATTR(_name, _register)				\
1318 	static struct elantech_attr_data elantech_attr_##_name = {	\
1319 		.field_offset = offsetof(struct elantech_data, _name),	\
1320 		.reg = _register,					\
1321 	};								\
1322 	PSMOUSE_DEFINE_ATTR(_name, 0644,				\
1323 			    &elantech_attr_##_name,			\
1324 			    elantech_show_int_attr,			\
1325 			    elantech_set_int_attr)
1326 
1327 #define ELANTECH_INFO_ATTR(_name)					       \
1328 	static struct elantech_attr_data elantech_attr_##_name = {	       \
1329 		.field_offset = offsetof(struct elantech_data, info) +	       \
1330 				offsetof(struct elantech_device_info, _name),  \
1331 		.reg = 0,						       \
1332 	};								       \
1333 	PSMOUSE_DEFINE_ATTR(_name, 0644,				       \
1334 			    &elantech_attr_##_name,			       \
1335 			    elantech_show_int_attr,			       \
1336 			    elantech_set_int_attr)
1337 
1338 ELANTECH_INT_ATTR(reg_07, 0x07);
1339 ELANTECH_INT_ATTR(reg_10, 0x10);
1340 ELANTECH_INT_ATTR(reg_11, 0x11);
1341 ELANTECH_INT_ATTR(reg_20, 0x20);
1342 ELANTECH_INT_ATTR(reg_21, 0x21);
1343 ELANTECH_INT_ATTR(reg_22, 0x22);
1344 ELANTECH_INT_ATTR(reg_23, 0x23);
1345 ELANTECH_INT_ATTR(reg_24, 0x24);
1346 ELANTECH_INT_ATTR(reg_25, 0x25);
1347 ELANTECH_INT_ATTR(reg_26, 0x26);
1348 ELANTECH_INFO_ATTR(debug);
1349 ELANTECH_INFO_ATTR(paritycheck);
1350 ELANTECH_INFO_ATTR(crc_enabled);
1351 
1352 static struct attribute *elantech_attrs[] = {
1353 	&psmouse_attr_reg_07.dattr.attr,
1354 	&psmouse_attr_reg_10.dattr.attr,
1355 	&psmouse_attr_reg_11.dattr.attr,
1356 	&psmouse_attr_reg_20.dattr.attr,
1357 	&psmouse_attr_reg_21.dattr.attr,
1358 	&psmouse_attr_reg_22.dattr.attr,
1359 	&psmouse_attr_reg_23.dattr.attr,
1360 	&psmouse_attr_reg_24.dattr.attr,
1361 	&psmouse_attr_reg_25.dattr.attr,
1362 	&psmouse_attr_reg_26.dattr.attr,
1363 	&psmouse_attr_debug.dattr.attr,
1364 	&psmouse_attr_paritycheck.dattr.attr,
1365 	&psmouse_attr_crc_enabled.dattr.attr,
1366 	NULL
1367 };
1368 
1369 static const struct attribute_group elantech_attr_group = {
1370 	.attrs = elantech_attrs,
1371 };
1372 
1373 static bool elantech_is_signature_valid(const unsigned char *param)
1374 {
1375 	static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10 };
1376 	int i;
1377 
1378 	if (param[0] == 0)
1379 		return false;
1380 
1381 	if (param[1] == 0)
1382 		return true;
1383 
1384 	/*
1385 	 * Some hw_version >= 4 models have a revision higher then 20. Meaning
1386 	 * that param[2] may be 10 or 20, skip the rates check for these.
1387 	 */
1388 	if ((param[0] & 0x0f) >= 0x06 && (param[1] & 0xaf) == 0x0f &&
1389 	    param[2] < 40)
1390 		return true;
1391 
1392 	for (i = 0; i < ARRAY_SIZE(rates); i++)
1393 		if (param[2] == rates[i])
1394 			return false;
1395 
1396 	return true;
1397 }
1398 
1399 /*
1400  * Use magic knock to detect Elantech touchpad
1401  */
1402 int elantech_detect(struct psmouse *psmouse, bool set_properties)
1403 {
1404 	struct ps2dev *ps2dev = &psmouse->ps2dev;
1405 	unsigned char param[3];
1406 
1407 	ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
1408 
1409 	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
1410 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1411 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1412 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
1413 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
1414 		psmouse_dbg(psmouse, "sending Elantech magic knock failed.\n");
1415 		return -1;
1416 	}
1417 
1418 	/*
1419 	 * Report this in case there are Elantech models that use a different
1420 	 * set of magic numbers
1421 	 */
1422 	if (param[0] != 0x3c || param[1] != 0x03 ||
1423 	    (param[2] != 0xc8 && param[2] != 0x00)) {
1424 		psmouse_dbg(psmouse,
1425 			    "unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
1426 			    param[0], param[1], param[2]);
1427 		return -1;
1428 	}
1429 
1430 	/*
1431 	 * Query touchpad's firmware version and see if it reports known
1432 	 * value to avoid mis-detection. Logitech mice are known to respond
1433 	 * to Elantech magic knock and there might be more.
1434 	 */
1435 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1436 		psmouse_dbg(psmouse, "failed to query firmware version.\n");
1437 		return -1;
1438 	}
1439 
1440 	psmouse_dbg(psmouse,
1441 		    "Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
1442 		    param[0], param[1], param[2]);
1443 
1444 	if (!elantech_is_signature_valid(param)) {
1445 		psmouse_dbg(psmouse,
1446 			    "Probably not a real Elantech touchpad. Aborting.\n");
1447 		return -1;
1448 	}
1449 
1450 	if (set_properties) {
1451 		psmouse->vendor = "Elantech";
1452 		psmouse->name = "Touchpad";
1453 	}
1454 
1455 	return 0;
1456 }
1457 
1458 /*
1459  * Clean up sysfs entries when disconnecting
1460  */
1461 static void elantech_disconnect(struct psmouse *psmouse)
1462 {
1463 	struct elantech_data *etd = psmouse->private;
1464 
1465 	/*
1466 	 * We might have left a breadcrumb when trying to
1467 	 * set up SMbus companion.
1468 	 */
1469 	psmouse_smbus_cleanup(psmouse);
1470 
1471 	if (etd->tp_dev)
1472 		input_unregister_device(etd->tp_dev);
1473 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
1474 			   &elantech_attr_group);
1475 	kfree(psmouse->private);
1476 	psmouse->private = NULL;
1477 }
1478 
1479 /*
1480  * Put the touchpad back into absolute mode when reconnecting
1481  */
1482 static int elantech_reconnect(struct psmouse *psmouse)
1483 {
1484 	psmouse_reset(psmouse);
1485 
1486 	if (elantech_detect(psmouse, 0))
1487 		return -1;
1488 
1489 	if (elantech_set_absolute_mode(psmouse)) {
1490 		psmouse_err(psmouse,
1491 			    "failed to put touchpad back into absolute mode.\n");
1492 		return -1;
1493 	}
1494 
1495 	return 0;
1496 }
1497 
1498 /*
1499  * Some hw_version 4 models do not work with crc_disabled
1500  */
1501 static const struct dmi_system_id elantech_dmi_force_crc_enabled[] = {
1502 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1503 	{
1504 		/* Fujitsu H730 does not work with crc_enabled == 0 */
1505 		.matches = {
1506 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1507 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H730"),
1508 		},
1509 	},
1510 	{
1511 		/* Fujitsu H760 does not work with crc_enabled == 0 */
1512 		.matches = {
1513 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1514 			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H760"),
1515 		},
1516 	},
1517 	{
1518 		/* Fujitsu LIFEBOOK E544  does not work with crc_enabled == 0 */
1519 		.matches = {
1520 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1521 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E544"),
1522 		},
1523 	},
1524 	{
1525 		/* Fujitsu LIFEBOOK E546  does not work with crc_enabled == 0 */
1526 		.matches = {
1527 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1528 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E546"),
1529 		},
1530 	},
1531 	{
1532 		/* Fujitsu LIFEBOOK E547 does not work with crc_enabled == 0 */
1533 		.matches = {
1534 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1535 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E547"),
1536 		},
1537 	},
1538 	{
1539 		/* Fujitsu LIFEBOOK E554  does not work with crc_enabled == 0 */
1540 		.matches = {
1541 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1542 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E554"),
1543 		},
1544 	},
1545 	{
1546 		/* Fujitsu LIFEBOOK E556 does not work with crc_enabled == 0 */
1547 		.matches = {
1548 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1549 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E556"),
1550 		},
1551 	},
1552 	{
1553 		/* Fujitsu LIFEBOOK E557 does not work with crc_enabled == 0 */
1554 		.matches = {
1555 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1556 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E557"),
1557 		},
1558 	},
1559 	{
1560 		/* Fujitsu LIFEBOOK U745 does not work with crc_enabled == 0 */
1561 		.matches = {
1562 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
1563 			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK U745"),
1564 		},
1565 	},
1566 #endif
1567 	{ }
1568 };
1569 
1570 /*
1571  * Some hw_version 3 models go into error state when we try to set
1572  * bit 3 and/or bit 1 of r10.
1573  */
1574 static const struct dmi_system_id no_hw_res_dmi_table[] = {
1575 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
1576 	{
1577 		/* Gigabyte U2442 */
1578 		.matches = {
1579 			DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
1580 			DMI_MATCH(DMI_PRODUCT_NAME, "U2442"),
1581 		},
1582 	},
1583 #endif
1584 	{ }
1585 };
1586 
1587 /*
1588  * Change Report id 0x5E to 0x5F.
1589  */
1590 static int elantech_change_report_id(struct psmouse *psmouse)
1591 {
1592 	/*
1593 	 * NOTE: the code is expecting to receive param[] as an array of 3
1594 	 * items (see __ps2_command()), even if in this case only 2 are
1595 	 * actually needed. Make sure the array size is 3 to avoid potential
1596 	 * stack out-of-bound accesses.
1597 	 */
1598 	unsigned char param[3] = { 0x10, 0x03 };
1599 
1600 	if (elantech_write_reg_params(psmouse, 0x7, param) ||
1601 	    elantech_read_reg_params(psmouse, 0x7, param) ||
1602 	    param[0] != 0x10 || param[1] != 0x03) {
1603 		psmouse_err(psmouse, "Unable to change report ID to 0x5f.\n");
1604 		return -EIO;
1605 	}
1606 
1607 	return 0;
1608 }
1609 /*
1610  * determine hardware version and set some properties according to it.
1611  */
1612 static int elantech_set_properties(struct elantech_device_info *info)
1613 {
1614 	/* This represents the version of IC body. */
1615 	info->ic_version = (info->fw_version & 0x0f0000) >> 16;
1616 
1617 	/* Early version of Elan touchpads doesn't obey the rule. */
1618 	if (info->fw_version < 0x020030 || info->fw_version == 0x020600)
1619 		info->hw_version = 1;
1620 	else {
1621 		switch (info->ic_version) {
1622 		case 2:
1623 		case 4:
1624 			info->hw_version = 2;
1625 			break;
1626 		case 5:
1627 			info->hw_version = 3;
1628 			break;
1629 		case 6 ... 15:
1630 			info->hw_version = 4;
1631 			break;
1632 		default:
1633 			return -1;
1634 		}
1635 	}
1636 
1637 	/* Get information pattern for hw_version 4 */
1638 	info->pattern = 0x00;
1639 	if (info->ic_version == 0x0f && (info->fw_version & 0xff) <= 0x02)
1640 		info->pattern = info->fw_version & 0xff;
1641 
1642 	/* decide which send_cmd we're gonna use early */
1643 	info->send_cmd = info->hw_version >= 3 ? elantech_send_cmd :
1644 						 synaptics_send_cmd;
1645 
1646 	/* Turn on packet checking by default */
1647 	info->paritycheck = 1;
1648 
1649 	/*
1650 	 * This firmware suffers from misreporting coordinates when
1651 	 * a touch action starts causing the mouse cursor or scrolled page
1652 	 * to jump. Enable a workaround.
1653 	 */
1654 	info->jumpy_cursor =
1655 		(info->fw_version == 0x020022 || info->fw_version == 0x020600);
1656 
1657 	if (info->hw_version > 1) {
1658 		/* For now show extra debug information */
1659 		info->debug = 1;
1660 
1661 		if (info->fw_version >= 0x020800)
1662 			info->reports_pressure = true;
1663 	}
1664 
1665 	/*
1666 	 * The signatures of v3 and v4 packets change depending on the
1667 	 * value of this hardware flag.
1668 	 */
1669 	info->crc_enabled = (info->fw_version & 0x4000) == 0x4000 ||
1670 			     dmi_check_system(elantech_dmi_force_crc_enabled);
1671 
1672 	/* Enable real hardware resolution on hw_version 3 ? */
1673 	info->set_hw_resolution = !dmi_check_system(no_hw_res_dmi_table);
1674 
1675 	return 0;
1676 }
1677 
1678 static int elantech_query_info(struct psmouse *psmouse,
1679 			       struct elantech_device_info *info)
1680 {
1681 	unsigned char param[3];
1682 	unsigned char traces;
1683 	unsigned char ic_body[3];
1684 
1685 	memset(info, 0, sizeof(*info));
1686 
1687 	/*
1688 	 * Do the version query again so we can store the result
1689 	 */
1690 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
1691 		psmouse_err(psmouse, "failed to query firmware version.\n");
1692 		return -EINVAL;
1693 	}
1694 	info->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
1695 
1696 	if (elantech_set_properties(info)) {
1697 		psmouse_err(psmouse, "unknown hardware version, aborting...\n");
1698 		return -EINVAL;
1699 	}
1700 	psmouse_info(psmouse,
1701 		     "assuming hardware version %d (with firmware version 0x%02x%02x%02x)\n",
1702 		     info->hw_version, param[0], param[1], param[2]);
1703 
1704 	if (info->send_cmd(psmouse, ETP_CAPABILITIES_QUERY,
1705 	    info->capabilities)) {
1706 		psmouse_err(psmouse, "failed to query capabilities.\n");
1707 		return -EINVAL;
1708 	}
1709 	psmouse_info(psmouse,
1710 		     "Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
1711 		     info->capabilities[0], info->capabilities[1],
1712 		     info->capabilities[2]);
1713 
1714 	if (info->hw_version != 1) {
1715 		if (info->send_cmd(psmouse, ETP_SAMPLE_QUERY, info->samples)) {
1716 			psmouse_err(psmouse, "failed to query sample data\n");
1717 			return -EINVAL;
1718 		}
1719 		psmouse_info(psmouse,
1720 			     "Elan sample query result %02x, %02x, %02x\n",
1721 			     info->samples[0],
1722 			     info->samples[1],
1723 			     info->samples[2]);
1724 	}
1725 
1726 	if (info->pattern > 0x00 && info->ic_version == 0xf) {
1727 		if (info->send_cmd(psmouse, ETP_ICBODY_QUERY, ic_body)) {
1728 			psmouse_err(psmouse, "failed to query ic body\n");
1729 			return -EINVAL;
1730 		}
1731 		info->ic_version = be16_to_cpup((__be16 *)ic_body);
1732 		psmouse_info(psmouse,
1733 			     "Elan ic body: %#04x, current fw version: %#02x\n",
1734 			     info->ic_version, ic_body[2]);
1735 	}
1736 
1737 	info->product_id = be16_to_cpup((__be16 *)info->samples);
1738 	if (info->pattern == 0x00)
1739 		info->product_id &= 0xff;
1740 
1741 	if (info->samples[1] == 0x74 && info->hw_version == 0x03) {
1742 		/*
1743 		 * This module has a bug which makes absolute mode
1744 		 * unusable, so let's abort so we'll be using standard
1745 		 * PS/2 protocol.
1746 		 */
1747 		psmouse_info(psmouse,
1748 			     "absolute mode broken, forcing standard PS/2 protocol\n");
1749 		return -ENODEV;
1750 	}
1751 
1752 	/* The MSB indicates the presence of the trackpoint */
1753 	info->has_trackpoint = (info->capabilities[0] & 0x80) == 0x80;
1754 
1755 	if (info->has_trackpoint && info->ic_version == 0x0011 &&
1756 	    (info->product_id == 0x08 || info->product_id == 0x09 ||
1757 	     info->product_id == 0x0d || info->product_id == 0x0e)) {
1758 		/*
1759 		 * This module has a bug which makes trackpoint in SMBus
1760 		 * mode return invalid data unless trackpoint is switched
1761 		 * from using 0x5e reports to 0x5f. If we are not able to
1762 		 * make the switch, let's abort initialization so we'll be
1763 		 * using standard PS/2 protocol.
1764 		 */
1765 		if (elantech_change_report_id(psmouse)) {
1766 			psmouse_info(psmouse,
1767 				     "Trackpoint report is broken, forcing standard PS/2 protocol\n");
1768 			return -ENODEV;
1769 		}
1770 	}
1771 
1772 	info->x_res = 31;
1773 	info->y_res = 31;
1774 	if (info->hw_version == 4) {
1775 		if (elantech_get_resolution_v4(psmouse,
1776 					       &info->x_res,
1777 					       &info->y_res,
1778 					       &info->bus)) {
1779 			psmouse_warn(psmouse,
1780 				     "failed to query resolution data.\n");
1781 		}
1782 	}
1783 
1784 	/* query range information */
1785 	switch (info->hw_version) {
1786 	case 1:
1787 		info->x_min = ETP_XMIN_V1;
1788 		info->y_min = ETP_YMIN_V1;
1789 		info->x_max = ETP_XMAX_V1;
1790 		info->y_max = ETP_YMAX_V1;
1791 		break;
1792 
1793 	case 2:
1794 		if (info->fw_version == 0x020800 ||
1795 		    info->fw_version == 0x020b00 ||
1796 		    info->fw_version == 0x020030) {
1797 			info->x_min = ETP_XMIN_V2;
1798 			info->y_min = ETP_YMIN_V2;
1799 			info->x_max = ETP_XMAX_V2;
1800 			info->y_max = ETP_YMAX_V2;
1801 		} else {
1802 			int i;
1803 			int fixed_dpi;
1804 
1805 			i = (info->fw_version > 0x020800 &&
1806 			     info->fw_version < 0x020900) ? 1 : 2;
1807 
1808 			if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1809 				return -EINVAL;
1810 
1811 			fixed_dpi = param[1] & 0x10;
1812 
1813 			if (((info->fw_version >> 16) == 0x14) && fixed_dpi) {
1814 				if (info->send_cmd(psmouse, ETP_SAMPLE_QUERY, param))
1815 					return -EINVAL;
1816 
1817 				info->x_max = (info->capabilities[1] - i) * param[1] / 2;
1818 				info->y_max = (info->capabilities[2] - i) * param[2] / 2;
1819 			} else if (info->fw_version == 0x040216) {
1820 				info->x_max = 819;
1821 				info->y_max = 405;
1822 			} else if (info->fw_version == 0x040219 || info->fw_version == 0x040215) {
1823 				info->x_max = 900;
1824 				info->y_max = 500;
1825 			} else {
1826 				info->x_max = (info->capabilities[1] - i) * 64;
1827 				info->y_max = (info->capabilities[2] - i) * 64;
1828 			}
1829 		}
1830 		break;
1831 
1832 	case 3:
1833 		if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1834 			return -EINVAL;
1835 
1836 		info->x_max = (0x0f & param[0]) << 8 | param[1];
1837 		info->y_max = (0xf0 & param[0]) << 4 | param[2];
1838 		break;
1839 
1840 	case 4:
1841 		if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
1842 			return -EINVAL;
1843 
1844 		info->x_max = (0x0f & param[0]) << 8 | param[1];
1845 		info->y_max = (0xf0 & param[0]) << 4 | param[2];
1846 		traces = info->capabilities[1];
1847 		if ((traces < 2) || (traces > info->x_max))
1848 			return -EINVAL;
1849 
1850 		info->width = info->x_max / (traces - 1);
1851 
1852 		/* column number of traces */
1853 		info->x_traces = traces;
1854 
1855 		/* row number of traces */
1856 		traces = info->capabilities[2];
1857 		if ((traces >= 2) && (traces <= info->y_max))
1858 			info->y_traces = traces;
1859 
1860 		break;
1861 	}
1862 
1863 	/* check for the middle button: DMI matching or new v4 firmwares */
1864 	info->has_middle_button = dmi_check_system(elantech_dmi_has_middle_button) ||
1865 				  (ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version) &&
1866 				   !elantech_is_buttonpad(info));
1867 
1868 	return 0;
1869 }
1870 
1871 #if defined(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)
1872 
1873 /*
1874  * The newest Elantech device can use a secondary bus (over SMBus) which
1875  * provides a better bandwidth and allow a better control of the touchpads.
1876  * This is used to decide if we need to use this bus or not.
1877  */
1878 enum {
1879 	ELANTECH_SMBUS_NOT_SET = -1,
1880 	ELANTECH_SMBUS_OFF,
1881 	ELANTECH_SMBUS_ON,
1882 };
1883 
1884 static int elantech_smbus = IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) ?
1885 		ELANTECH_SMBUS_NOT_SET : ELANTECH_SMBUS_OFF;
1886 module_param_named(elantech_smbus, elantech_smbus, int, 0644);
1887 MODULE_PARM_DESC(elantech_smbus, "Use a secondary bus for the Elantech device.");
1888 
1889 static const char * const i2c_blacklist_pnp_ids[] = {
1890 	/*
1891 	 * These are known to not be working properly as bits are missing
1892 	 * in elan_i2c.
1893 	 */
1894 	NULL
1895 };
1896 
1897 static int elantech_create_smbus(struct psmouse *psmouse,
1898 				 struct elantech_device_info *info,
1899 				 bool leave_breadcrumbs)
1900 {
1901 	struct property_entry i2c_props[11] = {};
1902 	struct i2c_board_info smbus_board = {
1903 		I2C_BOARD_INFO("elan_i2c", 0x15),
1904 		.flags = I2C_CLIENT_HOST_NOTIFY,
1905 	};
1906 	unsigned int idx = 0;
1907 
1908 	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-size-x",
1909 						   info->x_max + 1);
1910 	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-size-y",
1911 						   info->y_max + 1);
1912 	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-min-x",
1913 						   info->x_min);
1914 	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-min-y",
1915 						   info->y_min);
1916 	if (info->x_res)
1917 		i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-x-mm",
1918 						      (info->x_max + 1) / info->x_res);
1919 	if (info->y_res)
1920 		i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-y-mm",
1921 						      (info->y_max + 1) / info->y_res);
1922 
1923 	if (info->has_trackpoint)
1924 		i2c_props[idx++] = PROPERTY_ENTRY_BOOL("elan,trackpoint");
1925 
1926 	if (info->has_middle_button)
1927 		i2c_props[idx++] = PROPERTY_ENTRY_BOOL("elan,middle-button");
1928 
1929 	if (info->x_traces)
1930 		i2c_props[idx++] = PROPERTY_ENTRY_U32("elan,x_traces",
1931 						      info->x_traces);
1932 	if (info->y_traces)
1933 		i2c_props[idx++] = PROPERTY_ENTRY_U32("elan,y_traces",
1934 						      info->y_traces);
1935 
1936 	if (elantech_is_buttonpad(info))
1937 		i2c_props[idx++] = PROPERTY_ENTRY_BOOL("elan,clickpad");
1938 
1939 	smbus_board.fwnode = fwnode_create_software_node(i2c_props, NULL);
1940 	if (IS_ERR(smbus_board.fwnode))
1941 		return PTR_ERR(smbus_board.fwnode);
1942 
1943 	return psmouse_smbus_init(psmouse, &smbus_board, NULL, 0, false,
1944 				  leave_breadcrumbs);
1945 }
1946 
1947 /*
1948  * elantech_setup_smbus - called once the PS/2 devices are enumerated
1949  * and decides to instantiate a SMBus InterTouch device.
1950  */
1951 static int elantech_setup_smbus(struct psmouse *psmouse,
1952 				struct elantech_device_info *info,
1953 				bool leave_breadcrumbs)
1954 {
1955 	int error;
1956 
1957 	if (elantech_smbus == ELANTECH_SMBUS_OFF)
1958 		return -ENXIO;
1959 
1960 	if (elantech_smbus == ELANTECH_SMBUS_NOT_SET) {
1961 		/*
1962 		 * New ICs are enabled by default, unless mentioned in
1963 		 * i2c_blacklist_pnp_ids.
1964 		 * Old ICs are up to the user to decide.
1965 		 */
1966 		if (!ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version) ||
1967 		    psmouse_matches_pnp_id(psmouse, i2c_blacklist_pnp_ids))
1968 			return -ENXIO;
1969 	}
1970 
1971 	psmouse_info(psmouse, "Trying to set up SMBus access\n");
1972 
1973 	error = elantech_create_smbus(psmouse, info, leave_breadcrumbs);
1974 	if (error) {
1975 		if (error == -EAGAIN)
1976 			psmouse_info(psmouse, "SMbus companion is not ready yet\n");
1977 		else
1978 			psmouse_err(psmouse, "unable to create intertouch device\n");
1979 
1980 		return error;
1981 	}
1982 
1983 	return 0;
1984 }
1985 
1986 static bool elantech_use_host_notify(struct psmouse *psmouse,
1987 				     struct elantech_device_info *info)
1988 {
1989 	if (ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version))
1990 		return true;
1991 
1992 	switch (info->bus) {
1993 	case ETP_BUS_PS2_ONLY:
1994 		/* expected case */
1995 		break;
1996 	case ETP_BUS_SMB_ALERT_ONLY:
1997 	case ETP_BUS_PS2_SMB_ALERT:
1998 		psmouse_dbg(psmouse, "Ignoring SMBus provider through alert protocol.\n");
1999 		break;
2000 	case ETP_BUS_SMB_HST_NTFY_ONLY:
2001 	case ETP_BUS_PS2_SMB_HST_NTFY:
2002 		return true;
2003 	default:
2004 		psmouse_dbg(psmouse,
2005 			    "Ignoring SMBus bus provider %d.\n",
2006 			    info->bus);
2007 	}
2008 
2009 	return false;
2010 }
2011 
2012 int elantech_init_smbus(struct psmouse *psmouse)
2013 {
2014 	struct elantech_device_info info;
2015 	int error;
2016 
2017 	psmouse_reset(psmouse);
2018 
2019 	error = elantech_query_info(psmouse, &info);
2020 	if (error)
2021 		goto init_fail;
2022 
2023 	if (info.hw_version < 4) {
2024 		error = -ENXIO;
2025 		goto init_fail;
2026 	}
2027 
2028 	return elantech_create_smbus(psmouse, &info, false);
2029  init_fail:
2030 	psmouse_reset(psmouse);
2031 	return error;
2032 }
2033 #endif /* CONFIG_MOUSE_PS2_ELANTECH_SMBUS */
2034 
2035 /*
2036  * Initialize the touchpad and create sysfs entries
2037  */
2038 static int elantech_setup_ps2(struct psmouse *psmouse,
2039 			      struct elantech_device_info *info)
2040 {
2041 	struct elantech_data *etd;
2042 	int i;
2043 	int error = -EINVAL;
2044 	struct input_dev *tp_dev;
2045 
2046 	psmouse->private = etd = kzalloc(sizeof(*etd), GFP_KERNEL);
2047 	if (!etd)
2048 		return -ENOMEM;
2049 
2050 	etd->info = *info;
2051 
2052 	etd->parity[0] = 1;
2053 	for (i = 1; i < 256; i++)
2054 		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
2055 
2056 	if (elantech_set_absolute_mode(psmouse)) {
2057 		psmouse_err(psmouse,
2058 			    "failed to put touchpad into absolute mode.\n");
2059 		goto init_fail;
2060 	}
2061 
2062 	if (info->fw_version == 0x381f17) {
2063 		etd->original_set_rate = psmouse->set_rate;
2064 		psmouse->set_rate = elantech_set_rate_restore_reg_07;
2065 	}
2066 
2067 	if (elantech_set_input_params(psmouse)) {
2068 		psmouse_err(psmouse, "failed to query touchpad range.\n");
2069 		goto init_fail;
2070 	}
2071 
2072 	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
2073 				   &elantech_attr_group);
2074 	if (error) {
2075 		psmouse_err(psmouse,
2076 			    "failed to create sysfs attributes, error: %d.\n",
2077 			    error);
2078 		goto init_fail;
2079 	}
2080 
2081 	if (info->has_trackpoint) {
2082 		tp_dev = input_allocate_device();
2083 
2084 		if (!tp_dev) {
2085 			error = -ENOMEM;
2086 			goto init_fail_tp_alloc;
2087 		}
2088 
2089 		etd->tp_dev = tp_dev;
2090 		snprintf(etd->tp_phys, sizeof(etd->tp_phys), "%s/input1",
2091 			psmouse->ps2dev.serio->phys);
2092 		tp_dev->phys = etd->tp_phys;
2093 		tp_dev->name = "ETPS/2 Elantech TrackPoint";
2094 		tp_dev->id.bustype = BUS_I8042;
2095 		tp_dev->id.vendor  = 0x0002;
2096 		tp_dev->id.product = PSMOUSE_ELANTECH;
2097 		tp_dev->id.version = 0x0000;
2098 		tp_dev->dev.parent = &psmouse->ps2dev.serio->dev;
2099 		tp_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
2100 		tp_dev->relbit[BIT_WORD(REL_X)] =
2101 			BIT_MASK(REL_X) | BIT_MASK(REL_Y);
2102 		tp_dev->keybit[BIT_WORD(BTN_LEFT)] =
2103 			BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_MIDDLE) |
2104 			BIT_MASK(BTN_RIGHT);
2105 
2106 		__set_bit(INPUT_PROP_POINTER, tp_dev->propbit);
2107 		__set_bit(INPUT_PROP_POINTING_STICK, tp_dev->propbit);
2108 
2109 		error = input_register_device(etd->tp_dev);
2110 		if (error < 0)
2111 			goto init_fail_tp_reg;
2112 	}
2113 
2114 	psmouse->protocol_handler = elantech_process_byte;
2115 	psmouse->disconnect = elantech_disconnect;
2116 	psmouse->reconnect = elantech_reconnect;
2117 	psmouse->pktsize = info->hw_version > 1 ? 6 : 4;
2118 
2119 	return 0;
2120  init_fail_tp_reg:
2121 	input_free_device(tp_dev);
2122  init_fail_tp_alloc:
2123 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
2124 			   &elantech_attr_group);
2125  init_fail:
2126 	kfree(etd);
2127 	return error;
2128 }
2129 
2130 int elantech_init_ps2(struct psmouse *psmouse)
2131 {
2132 	struct elantech_device_info info;
2133 	int error;
2134 
2135 	psmouse_reset(psmouse);
2136 
2137 	error = elantech_query_info(psmouse, &info);
2138 	if (error)
2139 		goto init_fail;
2140 
2141 	error = elantech_setup_ps2(psmouse, &info);
2142 	if (error)
2143 		goto init_fail;
2144 
2145 	return 0;
2146  init_fail:
2147 	psmouse_reset(psmouse);
2148 	return error;
2149 }
2150 
2151 int elantech_init(struct psmouse *psmouse)
2152 {
2153 	struct elantech_device_info info;
2154 	int error;
2155 
2156 	psmouse_reset(psmouse);
2157 
2158 	error = elantech_query_info(psmouse, &info);
2159 	if (error)
2160 		goto init_fail;
2161 
2162 #if defined(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)
2163 
2164 	if (elantech_use_host_notify(psmouse, &info)) {
2165 		if (!IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) ||
2166 		    !IS_ENABLED(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)) {
2167 			psmouse_warn(psmouse,
2168 				     "The touchpad can support a better bus than the too old PS/2 protocol. "
2169 				     "Make sure MOUSE_PS2_ELANTECH_SMBUS and MOUSE_ELAN_I2C_SMBUS are enabled to get a better touchpad experience.\n");
2170 		}
2171 		error = elantech_setup_smbus(psmouse, &info, true);
2172 		if (!error)
2173 			return PSMOUSE_ELANTECH_SMBUS;
2174 	}
2175 
2176 #endif /* CONFIG_MOUSE_PS2_ELANTECH_SMBUS */
2177 
2178 	error = elantech_setup_ps2(psmouse, &info);
2179 	if (error < 0) {
2180 		/*
2181 		 * Not using any flavor of Elantech support, so clean up
2182 		 * SMbus breadcrumbs, if any.
2183 		 */
2184 		psmouse_smbus_cleanup(psmouse);
2185 		goto init_fail;
2186 	}
2187 
2188 	return PSMOUSE_ELANTECH;
2189  init_fail:
2190 	psmouse_reset(psmouse);
2191 	return error;
2192 }
2193