1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * PS/2 mouse driver
4  *
5  * Copyright (c) 1999-2002 Vojtech Pavlik
6  * Copyright (c) 2003-2004 Dmitry Torokhov
7  */
8 
9 
10 #define pr_fmt(fmt)		KBUILD_MODNAME ": " fmt
11 #define psmouse_fmt(fmt)	fmt
12 
13 #include <linux/bitops.h>
14 #include <linux/delay.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/interrupt.h>
18 #include <linux/input.h>
19 #include <linux/serio.h>
20 #include <linux/init.h>
21 #include <linux/libps2.h>
22 #include <linux/mutex.h>
23 #include <linux/types.h>
24 
25 #include "psmouse.h"
26 #include "synaptics.h"
27 #include "logips2pp.h"
28 #include "alps.h"
29 #include "hgpk.h"
30 #include "lifebook.h"
31 #include "trackpoint.h"
32 #include "touchkit_ps2.h"
33 #include "elantech.h"
34 #include "sentelic.h"
35 #include "cypress_ps2.h"
36 #include "focaltech.h"
37 #include "vmmouse.h"
38 #include "byd.h"
39 
40 #define DRIVER_DESC	"PS/2 mouse driver"
41 
42 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
43 MODULE_DESCRIPTION(DRIVER_DESC);
44 MODULE_LICENSE("GPL");
45 
46 static unsigned int psmouse_max_proto = PSMOUSE_AUTO;
47 static int psmouse_set_maxproto(const char *val, const struct kernel_param *);
48 static int psmouse_get_maxproto(char *buffer, const struct kernel_param *kp);
49 static const struct kernel_param_ops param_ops_proto_abbrev = {
50 	.set = psmouse_set_maxproto,
51 	.get = psmouse_get_maxproto,
52 };
53 #define param_check_proto_abbrev(name, p)	__param_check(name, p, unsigned int)
54 module_param_named(proto, psmouse_max_proto, proto_abbrev, 0644);
55 MODULE_PARM_DESC(proto, "Highest protocol extension to probe (bare, imps, exps, any). Useful for KVM switches.");
56 
57 static unsigned int psmouse_resolution = 200;
58 module_param_named(resolution, psmouse_resolution, uint, 0644);
59 MODULE_PARM_DESC(resolution, "Resolution, in dpi.");
60 
61 static unsigned int psmouse_rate = 100;
62 module_param_named(rate, psmouse_rate, uint, 0644);
63 MODULE_PARM_DESC(rate, "Report rate, in reports per second.");
64 
65 static bool psmouse_smartscroll = true;
66 module_param_named(smartscroll, psmouse_smartscroll, bool, 0644);
67 MODULE_PARM_DESC(smartscroll, "Logitech Smartscroll autorepeat, 1 = enabled (default), 0 = disabled.");
68 
69 static bool psmouse_a4tech_2wheels;
70 module_param_named(a4tech_workaround, psmouse_a4tech_2wheels, bool, 0644);
71 MODULE_PARM_DESC(a4tech_workaround, "A4Tech second scroll wheel workaround, 1 = enabled, 0 = disabled (default).");
72 
73 static unsigned int psmouse_resetafter = 5;
74 module_param_named(resetafter, psmouse_resetafter, uint, 0644);
75 MODULE_PARM_DESC(resetafter, "Reset device after so many bad packets (0 = never).");
76 
77 static unsigned int psmouse_resync_time;
78 module_param_named(resync_time, psmouse_resync_time, uint, 0644);
79 MODULE_PARM_DESC(resync_time, "How long can mouse stay idle before forcing resync (in seconds, 0 = never).");
80 
81 PSMOUSE_DEFINE_ATTR(protocol, S_IWUSR | S_IRUGO,
82 			NULL,
83 			psmouse_attr_show_protocol, psmouse_attr_set_protocol);
84 PSMOUSE_DEFINE_ATTR(rate, S_IWUSR | S_IRUGO,
85 			(void *) offsetof(struct psmouse, rate),
86 			psmouse_show_int_attr, psmouse_attr_set_rate);
87 PSMOUSE_DEFINE_ATTR(resolution, S_IWUSR | S_IRUGO,
88 			(void *) offsetof(struct psmouse, resolution),
89 			psmouse_show_int_attr, psmouse_attr_set_resolution);
90 PSMOUSE_DEFINE_ATTR(resetafter, S_IWUSR | S_IRUGO,
91 			(void *) offsetof(struct psmouse, resetafter),
92 			psmouse_show_int_attr, psmouse_set_int_attr);
93 PSMOUSE_DEFINE_ATTR(resync_time, S_IWUSR | S_IRUGO,
94 			(void *) offsetof(struct psmouse, resync_time),
95 			psmouse_show_int_attr, psmouse_set_int_attr);
96 
97 static struct attribute *psmouse_attributes[] = {
98 	&psmouse_attr_protocol.dattr.attr,
99 	&psmouse_attr_rate.dattr.attr,
100 	&psmouse_attr_resolution.dattr.attr,
101 	&psmouse_attr_resetafter.dattr.attr,
102 	&psmouse_attr_resync_time.dattr.attr,
103 	NULL
104 };
105 
106 static const struct attribute_group psmouse_attribute_group = {
107 	.attrs	= psmouse_attributes,
108 };
109 
110 /*
111  * psmouse_mutex protects all operations changing state of mouse
112  * (connecting, disconnecting, changing rate or resolution via
113  * sysfs). We could use a per-device semaphore but since there
114  * rarely more than one PS/2 mouse connected and since semaphore
115  * is taken in "slow" paths it is not worth it.
116  */
117 static DEFINE_MUTEX(psmouse_mutex);
118 
119 static struct workqueue_struct *kpsmoused_wq;
120 
121 void psmouse_report_standard_buttons(struct input_dev *dev, u8 buttons)
122 {
123 	input_report_key(dev, BTN_LEFT,   buttons & BIT(0));
124 	input_report_key(dev, BTN_MIDDLE, buttons & BIT(2));
125 	input_report_key(dev, BTN_RIGHT,  buttons & BIT(1));
126 }
127 
128 void psmouse_report_standard_motion(struct input_dev *dev, u8 *packet)
129 {
130 	int x, y;
131 
132 	x = packet[1] ? packet[1] - ((packet[0] << 4) & 0x100) : 0;
133 	y = packet[2] ? packet[2] - ((packet[0] << 3) & 0x100) : 0;
134 
135 	input_report_rel(dev, REL_X, x);
136 	input_report_rel(dev, REL_Y, -y);
137 }
138 
139 void psmouse_report_standard_packet(struct input_dev *dev, u8 *packet)
140 {
141 	psmouse_report_standard_buttons(dev, packet[0]);
142 	psmouse_report_standard_motion(dev, packet);
143 }
144 
145 /*
146  * psmouse_process_byte() analyzes the PS/2 data stream and reports
147  * relevant events to the input module once full packet has arrived.
148  */
149 psmouse_ret_t psmouse_process_byte(struct psmouse *psmouse)
150 {
151 	struct input_dev *dev = psmouse->dev;
152 	u8 *packet = psmouse->packet;
153 	int wheel;
154 
155 	if (psmouse->pktcnt < psmouse->pktsize)
156 		return PSMOUSE_GOOD_DATA;
157 
158 	/* Full packet accumulated, process it */
159 
160 	switch (psmouse->protocol->type) {
161 	case PSMOUSE_IMPS:
162 		/* IntelliMouse has scroll wheel */
163 		input_report_rel(dev, REL_WHEEL, -(s8) packet[3]);
164 		break;
165 
166 	case PSMOUSE_IMEX:
167 		/* Scroll wheel and buttons on IntelliMouse Explorer */
168 		switch (packet[3] & 0xC0) {
169 		case 0x80: /* vertical scroll on IntelliMouse Explorer 4.0 */
170 			input_report_rel(dev, REL_WHEEL,
171 					 -sign_extend32(packet[3], 5));
172 			break;
173 		case 0x40: /* horizontal scroll on IntelliMouse Explorer 4.0 */
174 			input_report_rel(dev, REL_HWHEEL,
175 					 -sign_extend32(packet[3], 5));
176 			break;
177 		case 0x00:
178 		case 0xC0:
179 			wheel = sign_extend32(packet[3], 3);
180 
181 			/*
182 			 * Some A4Tech mice have two scroll wheels, with first
183 			 * one reporting +/-1 in the lower nibble, and second
184 			 * one reporting +/-2.
185 			 */
186 			if (psmouse_a4tech_2wheels && abs(wheel) > 1)
187 				input_report_rel(dev, REL_HWHEEL, wheel / 2);
188 			else
189 				input_report_rel(dev, REL_WHEEL, -wheel);
190 
191 			input_report_key(dev, BTN_SIDE,  packet[3] & BIT(4));
192 			input_report_key(dev, BTN_EXTRA, packet[3] & BIT(5));
193 			break;
194 		}
195 		break;
196 
197 	case PSMOUSE_GENPS:
198 		/* Report scroll buttons on NetMice */
199 		input_report_rel(dev, REL_WHEEL, -(s8) packet[3]);
200 
201 		/* Extra buttons on Genius NewNet 3D */
202 		input_report_key(dev, BTN_SIDE,  packet[0] & BIT(6));
203 		input_report_key(dev, BTN_EXTRA, packet[0] & BIT(7));
204 		break;
205 
206 	case PSMOUSE_THINKPS:
207 		/* Extra button on ThinkingMouse */
208 		input_report_key(dev, BTN_EXTRA, packet[0] & BIT(3));
209 
210 		/*
211 		 * Without this bit of weirdness moving up gives wildly
212 		 * high Y changes.
213 		 */
214 		packet[1] |= (packet[0] & 0x40) << 1;
215 		break;
216 
217 	case PSMOUSE_CORTRON:
218 		/*
219 		 * Cortron PS2 Trackball reports SIDE button in the
220 		 * 4th bit of the first byte.
221 		 */
222 		input_report_key(dev, BTN_SIDE, packet[0] & BIT(3));
223 		packet[0] |= BIT(3);
224 		break;
225 
226 	default:
227 		break;
228 	}
229 
230 	/* Generic PS/2 Mouse */
231 	packet[0] |= psmouse->extra_buttons;
232 	psmouse_report_standard_packet(dev, packet);
233 
234 	input_sync(dev);
235 
236 	return PSMOUSE_FULL_PACKET;
237 }
238 
239 void psmouse_queue_work(struct psmouse *psmouse, struct delayed_work *work,
240 		unsigned long delay)
241 {
242 	queue_delayed_work(kpsmoused_wq, work, delay);
243 }
244 
245 /*
246  * __psmouse_set_state() sets new psmouse state and resets all flags.
247  */
248 static inline void __psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state)
249 {
250 	psmouse->state = new_state;
251 	psmouse->pktcnt = psmouse->out_of_sync_cnt = 0;
252 	psmouse->ps2dev.flags = 0;
253 	psmouse->last = jiffies;
254 }
255 
256 /*
257  * psmouse_set_state() sets new psmouse state and resets all flags and
258  * counters while holding serio lock so fighting with interrupt handler
259  * is not a concern.
260  */
261 void psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state)
262 {
263 	serio_pause_rx(psmouse->ps2dev.serio);
264 	__psmouse_set_state(psmouse, new_state);
265 	serio_continue_rx(psmouse->ps2dev.serio);
266 }
267 
268 /*
269  * psmouse_handle_byte() processes one byte of the input data stream
270  * by calling corresponding protocol handler.
271  */
272 static int psmouse_handle_byte(struct psmouse *psmouse)
273 {
274 	psmouse_ret_t rc = psmouse->protocol_handler(psmouse);
275 
276 	switch (rc) {
277 	case PSMOUSE_BAD_DATA:
278 		if (psmouse->state == PSMOUSE_ACTIVATED) {
279 			psmouse_warn(psmouse,
280 				     "%s at %s lost sync at byte %d\n",
281 				     psmouse->name, psmouse->phys,
282 				     psmouse->pktcnt);
283 			if (++psmouse->out_of_sync_cnt == psmouse->resetafter) {
284 				__psmouse_set_state(psmouse, PSMOUSE_IGNORE);
285 				psmouse_notice(psmouse,
286 						"issuing reconnect request\n");
287 				serio_reconnect(psmouse->ps2dev.serio);
288 				return -EIO;
289 			}
290 		}
291 		psmouse->pktcnt = 0;
292 		break;
293 
294 	case PSMOUSE_FULL_PACKET:
295 		psmouse->pktcnt = 0;
296 		if (psmouse->out_of_sync_cnt) {
297 			psmouse->out_of_sync_cnt = 0;
298 			psmouse_notice(psmouse,
299 					"%s at %s - driver resynced.\n",
300 					psmouse->name, psmouse->phys);
301 		}
302 		break;
303 
304 	case PSMOUSE_GOOD_DATA:
305 		break;
306 	}
307 	return 0;
308 }
309 
310 static void psmouse_handle_oob_data(struct psmouse *psmouse, u8 data)
311 {
312 	switch (psmouse->oob_data_type) {
313 	case PSMOUSE_OOB_NONE:
314 		psmouse->oob_data_type = data;
315 		break;
316 
317 	case PSMOUSE_OOB_EXTRA_BTNS:
318 		psmouse_report_standard_buttons(psmouse->dev, data);
319 		input_sync(psmouse->dev);
320 
321 		psmouse->extra_buttons = data;
322 		psmouse->oob_data_type = PSMOUSE_OOB_NONE;
323 		break;
324 
325 	default:
326 		psmouse_warn(psmouse,
327 			     "unknown OOB_DATA type: 0x%02x\n",
328 			     psmouse->oob_data_type);
329 		psmouse->oob_data_type = PSMOUSE_OOB_NONE;
330 		break;
331 	}
332 }
333 
334 /*
335  * psmouse_interrupt() handles incoming characters, either passing them
336  * for normal processing or gathering them as command response.
337  */
338 static irqreturn_t psmouse_interrupt(struct serio *serio,
339 				     u8 data, unsigned int flags)
340 {
341 	struct psmouse *psmouse = serio_get_drvdata(serio);
342 
343 	if (psmouse->state == PSMOUSE_IGNORE)
344 		goto out;
345 
346 	if (unlikely((flags & SERIO_TIMEOUT) ||
347 		     ((flags & SERIO_PARITY) &&
348 		      !psmouse->protocol->ignore_parity))) {
349 
350 		if (psmouse->state == PSMOUSE_ACTIVATED)
351 			psmouse_warn(psmouse,
352 				     "bad data from KBC -%s%s\n",
353 				     flags & SERIO_TIMEOUT ? " timeout" : "",
354 				     flags & SERIO_PARITY ? " bad parity" : "");
355 		ps2_cmd_aborted(&psmouse->ps2dev);
356 		goto out;
357 	}
358 
359 	if (flags & SERIO_OOB_DATA) {
360 		psmouse_handle_oob_data(psmouse, data);
361 		goto out;
362 	}
363 
364 	if (unlikely(psmouse->ps2dev.flags & PS2_FLAG_ACK))
365 		if  (ps2_handle_ack(&psmouse->ps2dev, data))
366 			goto out;
367 
368 	if (unlikely(psmouse->ps2dev.flags & PS2_FLAG_CMD))
369 		if  (ps2_handle_response(&psmouse->ps2dev, data))
370 			goto out;
371 
372 	pm_wakeup_event(&serio->dev, 0);
373 
374 	if (psmouse->state <= PSMOUSE_RESYNCING)
375 		goto out;
376 
377 	if (psmouse->state == PSMOUSE_ACTIVATED &&
378 	    psmouse->pktcnt && time_after(jiffies, psmouse->last + HZ/2)) {
379 		psmouse_info(psmouse, "%s at %s lost synchronization, throwing %d bytes away.\n",
380 			     psmouse->name, psmouse->phys, psmouse->pktcnt);
381 		psmouse->badbyte = psmouse->packet[0];
382 		__psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
383 		psmouse_queue_work(psmouse, &psmouse->resync_work, 0);
384 		goto out;
385 	}
386 
387 	psmouse->packet[psmouse->pktcnt++] = data;
388 
389 	/* Check if this is a new device announcement (0xAA 0x00) */
390 	if (unlikely(psmouse->packet[0] == PSMOUSE_RET_BAT && psmouse->pktcnt <= 2)) {
391 		if (psmouse->pktcnt == 1) {
392 			psmouse->last = jiffies;
393 			goto out;
394 		}
395 
396 		if (psmouse->packet[1] == PSMOUSE_RET_ID ||
397 		    (psmouse->protocol->type == PSMOUSE_HGPK &&
398 		     psmouse->packet[1] == PSMOUSE_RET_BAT)) {
399 			__psmouse_set_state(psmouse, PSMOUSE_IGNORE);
400 			serio_reconnect(serio);
401 			goto out;
402 		}
403 
404 		/* Not a new device, try processing first byte normally */
405 		psmouse->pktcnt = 1;
406 		if (psmouse_handle_byte(psmouse))
407 			goto out;
408 
409 		psmouse->packet[psmouse->pktcnt++] = data;
410 	}
411 
412 	/*
413 	 * See if we need to force resync because mouse was idle for
414 	 * too long.
415 	 */
416 	if (psmouse->state == PSMOUSE_ACTIVATED &&
417 	    psmouse->pktcnt == 1 && psmouse->resync_time &&
418 	    time_after(jiffies, psmouse->last + psmouse->resync_time * HZ)) {
419 		psmouse->badbyte = psmouse->packet[0];
420 		__psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
421 		psmouse_queue_work(psmouse, &psmouse->resync_work, 0);
422 		goto out;
423 	}
424 
425 	psmouse->last = jiffies;
426 	psmouse_handle_byte(psmouse);
427 
428  out:
429 	return IRQ_HANDLED;
430 }
431 
432 /*
433  * psmouse_reset() resets the mouse into power-on state.
434  */
435 int psmouse_reset(struct psmouse *psmouse)
436 {
437 	u8 param[2];
438 	int error;
439 
440 	error = ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_RESET_BAT);
441 	if (error)
442 		return error;
443 
444 	if (param[0] != PSMOUSE_RET_BAT && param[1] != PSMOUSE_RET_ID)
445 		return -EIO;
446 
447 	return 0;
448 }
449 
450 /*
451  * Here we set the mouse resolution.
452  */
453 void psmouse_set_resolution(struct psmouse *psmouse, unsigned int resolution)
454 {
455 	static const u8 params[] = { 0, 1, 2, 2, 3 };
456 	u8 p;
457 
458 	if (resolution == 0 || resolution > 200)
459 		resolution = 200;
460 
461 	p = params[resolution / 50];
462 	ps2_command(&psmouse->ps2dev, &p, PSMOUSE_CMD_SETRES);
463 	psmouse->resolution = 25 << p;
464 }
465 
466 /*
467  * Here we set the mouse report rate.
468  */
469 static void psmouse_set_rate(struct psmouse *psmouse, unsigned int rate)
470 {
471 	static const u8 rates[] = { 200, 100, 80, 60, 40, 20, 10, 0 };
472 	u8 r;
473 	int i = 0;
474 
475 	while (rates[i] > rate)
476 		i++;
477 	r = rates[i];
478 	ps2_command(&psmouse->ps2dev, &r, PSMOUSE_CMD_SETRATE);
479 	psmouse->rate = r;
480 }
481 
482 /*
483  * Here we set the mouse scaling.
484  */
485 static void psmouse_set_scale(struct psmouse *psmouse, enum psmouse_scale scale)
486 {
487 	ps2_command(&psmouse->ps2dev, NULL,
488 		    scale == PSMOUSE_SCALE21 ? PSMOUSE_CMD_SETSCALE21 :
489 					       PSMOUSE_CMD_SETSCALE11);
490 }
491 
492 /*
493  * psmouse_poll() - default poll handler. Everyone except for ALPS uses it.
494  */
495 static int psmouse_poll(struct psmouse *psmouse)
496 {
497 	return ps2_command(&psmouse->ps2dev, psmouse->packet,
498 			   PSMOUSE_CMD_POLL | (psmouse->pktsize << 8));
499 }
500 
501 static bool psmouse_check_pnp_id(const char *id, const char * const ids[])
502 {
503 	int i;
504 
505 	for (i = 0; ids[i]; i++)
506 		if (!strcasecmp(id, ids[i]))
507 			return true;
508 
509 	return false;
510 }
511 
512 /*
513  * psmouse_matches_pnp_id - check if psmouse matches one of the passed in ids.
514  */
515 bool psmouse_matches_pnp_id(struct psmouse *psmouse, const char * const ids[])
516 {
517 	struct serio *serio = psmouse->ps2dev.serio;
518 	char *p, *fw_id_copy, *save_ptr;
519 	bool found = false;
520 
521 	if (strncmp(serio->firmware_id, "PNP: ", 5))
522 		return false;
523 
524 	fw_id_copy = kstrndup(&serio->firmware_id[5],
525 			      sizeof(serio->firmware_id) - 5,
526 			      GFP_KERNEL);
527 	if (!fw_id_copy)
528 		return false;
529 
530 	save_ptr = fw_id_copy;
531 	while ((p = strsep(&fw_id_copy, " ")) != NULL) {
532 		if (psmouse_check_pnp_id(p, ids)) {
533 			found = true;
534 			break;
535 		}
536 	}
537 
538 	kfree(save_ptr);
539 	return found;
540 }
541 
542 /*
543  * Genius NetMouse magic init.
544  */
545 static int genius_detect(struct psmouse *psmouse, bool set_properties)
546 {
547 	struct ps2dev *ps2dev = &psmouse->ps2dev;
548 	u8 param[4];
549 
550 	param[0] = 3;
551 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
552 	ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11);
553 	ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11);
554 	ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11);
555 	ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO);
556 
557 	if (param[0] != 0x00 || param[1] != 0x33 || param[2] != 0x55)
558 		return -ENODEV;
559 
560 	if (set_properties) {
561 		__set_bit(BTN_MIDDLE, psmouse->dev->keybit);
562 		__set_bit(BTN_EXTRA, psmouse->dev->keybit);
563 		__set_bit(BTN_SIDE, psmouse->dev->keybit);
564 		__set_bit(REL_WHEEL, psmouse->dev->relbit);
565 
566 		psmouse->vendor = "Genius";
567 		psmouse->name = "Mouse";
568 		psmouse->pktsize = 4;
569 	}
570 
571 	return 0;
572 }
573 
574 /*
575  * IntelliMouse magic init.
576  */
577 static int intellimouse_detect(struct psmouse *psmouse, bool set_properties)
578 {
579 	struct ps2dev *ps2dev = &psmouse->ps2dev;
580 	u8 param[2];
581 
582 	param[0] = 200;
583 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
584 	param[0] = 100;
585 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
586 	param[0] =  80;
587 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
588 	ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);
589 
590 	if (param[0] != 3)
591 		return -ENODEV;
592 
593 	if (set_properties) {
594 		__set_bit(BTN_MIDDLE, psmouse->dev->keybit);
595 		__set_bit(REL_WHEEL, psmouse->dev->relbit);
596 
597 		if (!psmouse->vendor)
598 			psmouse->vendor = "Generic";
599 		if (!psmouse->name)
600 			psmouse->name = "Wheel Mouse";
601 		psmouse->pktsize = 4;
602 	}
603 
604 	return 0;
605 }
606 
607 /*
608  * Try IntelliMouse/Explorer magic init.
609  */
610 static int im_explorer_detect(struct psmouse *psmouse, bool set_properties)
611 {
612 	struct ps2dev *ps2dev = &psmouse->ps2dev;
613 	u8 param[2];
614 
615 	intellimouse_detect(psmouse, 0);
616 
617 	param[0] = 200;
618 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
619 	param[0] = 200;
620 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
621 	param[0] =  80;
622 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
623 	ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);
624 
625 	if (param[0] != 4)
626 		return -ENODEV;
627 
628 	/* Magic to enable horizontal scrolling on IntelliMouse 4.0 */
629 	param[0] = 200;
630 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
631 	param[0] =  80;
632 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
633 	param[0] =  40;
634 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
635 
636 	if (set_properties) {
637 		__set_bit(BTN_MIDDLE, psmouse->dev->keybit);
638 		__set_bit(REL_WHEEL, psmouse->dev->relbit);
639 		__set_bit(REL_HWHEEL, psmouse->dev->relbit);
640 		__set_bit(BTN_SIDE, psmouse->dev->keybit);
641 		__set_bit(BTN_EXTRA, psmouse->dev->keybit);
642 
643 		if (!psmouse->vendor)
644 			psmouse->vendor = "Generic";
645 		if (!psmouse->name)
646 			psmouse->name = "Explorer Mouse";
647 		psmouse->pktsize = 4;
648 	}
649 
650 	return 0;
651 }
652 
653 /*
654  * Kensington ThinkingMouse / ExpertMouse magic init.
655  */
656 static int thinking_detect(struct psmouse *psmouse, bool set_properties)
657 {
658 	struct ps2dev *ps2dev = &psmouse->ps2dev;
659 	u8 param[2];
660 	static const u8 seq[] = { 20, 60, 40, 20, 20, 60, 40, 20, 20 };
661 	int i;
662 
663 	param[0] = 10;
664 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
665 	param[0] = 0;
666 	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
667 	for (i = 0; i < ARRAY_SIZE(seq); i++) {
668 		param[0] = seq[i];
669 		ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
670 	}
671 	ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);
672 
673 	if (param[0] != 2)
674 		return -ENODEV;
675 
676 	if (set_properties) {
677 		__set_bit(BTN_MIDDLE, psmouse->dev->keybit);
678 		__set_bit(BTN_EXTRA, psmouse->dev->keybit);
679 
680 		psmouse->vendor = "Kensington";
681 		psmouse->name = "ThinkingMouse";
682 	}
683 
684 	return 0;
685 }
686 
687 /*
688  * Bare PS/2 protocol "detection". Always succeeds.
689  */
690 static int ps2bare_detect(struct psmouse *psmouse, bool set_properties)
691 {
692 	if (set_properties) {
693 		if (!psmouse->vendor)
694 			psmouse->vendor = "Generic";
695 		if (!psmouse->name)
696 			psmouse->name = "Mouse";
697 
698 		/*
699 		 * We have no way of figuring true number of buttons so let's
700 		 * assume that the device has 3.
701 		 */
702 		input_set_capability(psmouse->dev, EV_KEY, BTN_MIDDLE);
703 	}
704 
705 	return 0;
706 }
707 
708 /*
709  * Cortron PS/2 protocol detection. There's no special way to detect it, so it
710  * must be forced by sysfs protocol writing.
711  */
712 static int cortron_detect(struct psmouse *psmouse, bool set_properties)
713 {
714 	if (set_properties) {
715 		psmouse->vendor = "Cortron";
716 		psmouse->name = "PS/2 Trackball";
717 
718 		__set_bit(BTN_MIDDLE, psmouse->dev->keybit);
719 		__set_bit(BTN_SIDE, psmouse->dev->keybit);
720 	}
721 
722 	return 0;
723 }
724 
725 static const struct psmouse_protocol psmouse_protocols[] = {
726 	{
727 		.type		= PSMOUSE_PS2,
728 		.name		= "PS/2",
729 		.alias		= "bare",
730 		.maxproto	= true,
731 		.ignore_parity	= true,
732 		.detect		= ps2bare_detect,
733 		.try_passthru	= true,
734 	},
735 #ifdef CONFIG_MOUSE_PS2_LOGIPS2PP
736 	{
737 		.type		= PSMOUSE_PS2PP,
738 		.name		= "PS2++",
739 		.alias		= "logitech",
740 		.detect		= ps2pp_detect,
741 	},
742 #endif
743 	{
744 		.type		= PSMOUSE_THINKPS,
745 		.name		= "ThinkPS/2",
746 		.alias		= "thinkps",
747 		.detect		= thinking_detect,
748 	},
749 #ifdef CONFIG_MOUSE_PS2_CYPRESS
750 	{
751 		.type		= PSMOUSE_CYPRESS,
752 		.name		= "CyPS/2",
753 		.alias		= "cypress",
754 		.detect		= cypress_detect,
755 		.init		= cypress_init,
756 	},
757 #endif
758 	{
759 		.type		= PSMOUSE_GENPS,
760 		.name		= "GenPS/2",
761 		.alias		= "genius",
762 		.detect		= genius_detect,
763 	},
764 	{
765 		.type		= PSMOUSE_IMPS,
766 		.name		= "ImPS/2",
767 		.alias		= "imps",
768 		.maxproto	= true,
769 		.ignore_parity	= true,
770 		.detect		= intellimouse_detect,
771 		.try_passthru	= true,
772 	},
773 	{
774 		.type		= PSMOUSE_IMEX,
775 		.name		= "ImExPS/2",
776 		.alias		= "exps",
777 		.maxproto	= true,
778 		.ignore_parity	= true,
779 		.detect		= im_explorer_detect,
780 		.try_passthru	= true,
781 	},
782 #ifdef CONFIG_MOUSE_PS2_SYNAPTICS
783 	{
784 		.type		= PSMOUSE_SYNAPTICS,
785 		.name		= "SynPS/2",
786 		.alias		= "synaptics",
787 		.detect		= synaptics_detect,
788 		.init		= synaptics_init_absolute,
789 	},
790 	{
791 		.type		= PSMOUSE_SYNAPTICS_RELATIVE,
792 		.name		= "SynRelPS/2",
793 		.alias		= "synaptics-relative",
794 		.detect		= synaptics_detect,
795 		.init		= synaptics_init_relative,
796 	},
797 #endif
798 #ifdef CONFIG_MOUSE_PS2_SYNAPTICS_SMBUS
799 	{
800 		.type		= PSMOUSE_SYNAPTICS_SMBUS,
801 		.name		= "SynSMBus",
802 		.alias		= "synaptics-smbus",
803 		.detect		= synaptics_detect,
804 		.init		= synaptics_init_smbus,
805 		.smbus_companion = true,
806 	},
807 #endif
808 #ifdef CONFIG_MOUSE_PS2_ALPS
809 	{
810 		.type		= PSMOUSE_ALPS,
811 		.name		= "AlpsPS/2",
812 		.alias		= "alps",
813 		.detect		= alps_detect,
814 		.init		= alps_init,
815 	},
816 #endif
817 #ifdef CONFIG_MOUSE_PS2_LIFEBOOK
818 	{
819 		.type		= PSMOUSE_LIFEBOOK,
820 		.name		= "LBPS/2",
821 		.alias		= "lifebook",
822 		.detect		= lifebook_detect,
823 		.init		= lifebook_init,
824 	},
825 #endif
826 #ifdef CONFIG_MOUSE_PS2_TRACKPOINT
827 	{
828 		.type		= PSMOUSE_TRACKPOINT,
829 		.name		= "TPPS/2",
830 		.alias		= "trackpoint",
831 		.detect		= trackpoint_detect,
832 		.try_passthru	= true,
833 	},
834 #endif
835 #ifdef CONFIG_MOUSE_PS2_TOUCHKIT
836 	{
837 		.type		= PSMOUSE_TOUCHKIT_PS2,
838 		.name		= "touchkitPS/2",
839 		.alias		= "touchkit",
840 		.detect		= touchkit_ps2_detect,
841 	},
842 #endif
843 #ifdef CONFIG_MOUSE_PS2_OLPC
844 	{
845 		.type		= PSMOUSE_HGPK,
846 		.name		= "OLPC HGPK",
847 		.alias		= "hgpk",
848 		.detect		= hgpk_detect,
849 	},
850 #endif
851 #ifdef CONFIG_MOUSE_PS2_ELANTECH
852 	{
853 		.type		= PSMOUSE_ELANTECH,
854 		.name		= "ETPS/2",
855 		.alias		= "elantech",
856 		.detect		= elantech_detect,
857 		.init		= elantech_init_ps2,
858 	},
859 #endif
860 #ifdef CONFIG_MOUSE_PS2_ELANTECH_SMBUS
861 	{
862 		.type		= PSMOUSE_ELANTECH_SMBUS,
863 		.name		= "ETSMBus",
864 		.alias		= "elantech-smbus",
865 		.detect		= elantech_detect,
866 		.init		= elantech_init_smbus,
867 		.smbus_companion = true,
868 	},
869 #endif
870 #ifdef CONFIG_MOUSE_PS2_SENTELIC
871 	{
872 		.type		= PSMOUSE_FSP,
873 		.name		= "FSPPS/2",
874 		.alias		= "fsp",
875 		.detect		= fsp_detect,
876 		.init		= fsp_init,
877 	},
878 #endif
879 	{
880 		.type		= PSMOUSE_CORTRON,
881 		.name		= "CortronPS/2",
882 		.alias		= "cortps",
883 		.detect		= cortron_detect,
884 	},
885 #ifdef CONFIG_MOUSE_PS2_FOCALTECH
886 	{
887 		.type		= PSMOUSE_FOCALTECH,
888 		.name		= "FocalTechPS/2",
889 		.alias		= "focaltech",
890 		.detect		= focaltech_detect,
891 		.init		= focaltech_init,
892 	},
893 #endif
894 #ifdef CONFIG_MOUSE_PS2_VMMOUSE
895 	{
896 		.type		= PSMOUSE_VMMOUSE,
897 		.name		= VMMOUSE_PSNAME,
898 		.alias		= "vmmouse",
899 		.detect		= vmmouse_detect,
900 		.init		= vmmouse_init,
901 	},
902 #endif
903 #ifdef CONFIG_MOUSE_PS2_BYD
904 	{
905 		.type		= PSMOUSE_BYD,
906 		.name		= "BYDPS/2",
907 		.alias		= "byd",
908 		.detect		= byd_detect,
909 		.init		= byd_init,
910 	},
911 #endif
912 	{
913 		.type		= PSMOUSE_AUTO,
914 		.name		= "auto",
915 		.alias		= "any",
916 		.maxproto	= true,
917 	},
918 };
919 
920 static const struct psmouse_protocol *__psmouse_protocol_by_type(enum psmouse_type type)
921 {
922 	int i;
923 
924 	for (i = 0; i < ARRAY_SIZE(psmouse_protocols); i++)
925 		if (psmouse_protocols[i].type == type)
926 			return &psmouse_protocols[i];
927 
928 	return NULL;
929 }
930 
931 static const struct psmouse_protocol *psmouse_protocol_by_type(enum psmouse_type type)
932 {
933 	const struct psmouse_protocol *proto;
934 
935 	proto = __psmouse_protocol_by_type(type);
936 	if (proto)
937 		return proto;
938 
939 	WARN_ON(1);
940 	return &psmouse_protocols[0];
941 }
942 
943 static const struct psmouse_protocol *psmouse_protocol_by_name(const char *name, size_t len)
944 {
945 	const struct psmouse_protocol *p;
946 	int i;
947 
948 	for (i = 0; i < ARRAY_SIZE(psmouse_protocols); i++) {
949 		p = &psmouse_protocols[i];
950 
951 		if ((strlen(p->name) == len && !strncmp(p->name, name, len)) ||
952 		    (strlen(p->alias) == len && !strncmp(p->alias, name, len)))
953 			return &psmouse_protocols[i];
954 	}
955 
956 	return NULL;
957 }
958 
959 /*
960  * Apply default settings to the psmouse structure. Most of them will
961  * be overridden by individual protocol initialization routines.
962  */
963 static void psmouse_apply_defaults(struct psmouse *psmouse)
964 {
965 	struct input_dev *input_dev = psmouse->dev;
966 
967 	bitmap_zero(input_dev->evbit, EV_CNT);
968 	bitmap_zero(input_dev->keybit, KEY_CNT);
969 	bitmap_zero(input_dev->relbit, REL_CNT);
970 	bitmap_zero(input_dev->absbit, ABS_CNT);
971 	bitmap_zero(input_dev->mscbit, MSC_CNT);
972 
973 	input_set_capability(input_dev, EV_KEY, BTN_LEFT);
974 	input_set_capability(input_dev, EV_KEY, BTN_RIGHT);
975 
976 	input_set_capability(input_dev, EV_REL, REL_X);
977 	input_set_capability(input_dev, EV_REL, REL_Y);
978 
979 	__set_bit(INPUT_PROP_POINTER, input_dev->propbit);
980 
981 	psmouse->protocol = &psmouse_protocols[0];
982 
983 	psmouse->set_rate = psmouse_set_rate;
984 	psmouse->set_resolution = psmouse_set_resolution;
985 	psmouse->set_scale = psmouse_set_scale;
986 	psmouse->poll = psmouse_poll;
987 	psmouse->protocol_handler = psmouse_process_byte;
988 	psmouse->pktsize = 3;
989 	psmouse->reconnect = NULL;
990 	psmouse->fast_reconnect = NULL;
991 	psmouse->disconnect = NULL;
992 	psmouse->cleanup = NULL;
993 	psmouse->pt_activate = NULL;
994 	psmouse->pt_deactivate = NULL;
995 }
996 
997 static bool psmouse_do_detect(int (*detect)(struct psmouse *, bool),
998 			      struct psmouse *psmouse, bool allow_passthrough,
999 			      bool set_properties)
1000 {
1001 	if (psmouse->ps2dev.serio->id.type == SERIO_PS_PSTHRU &&
1002 	    !allow_passthrough) {
1003 		return false;
1004 	}
1005 
1006 	if (set_properties)
1007 		psmouse_apply_defaults(psmouse);
1008 
1009 	return detect(psmouse, set_properties) == 0;
1010 }
1011 
1012 static bool psmouse_try_protocol(struct psmouse *psmouse,
1013 				 enum psmouse_type type,
1014 				 unsigned int *max_proto,
1015 				 bool set_properties, bool init_allowed)
1016 {
1017 	const struct psmouse_protocol *proto;
1018 
1019 	proto = __psmouse_protocol_by_type(type);
1020 	if (!proto)
1021 		return false;
1022 
1023 	if (!psmouse_do_detect(proto->detect, psmouse, proto->try_passthru,
1024 			       set_properties))
1025 		return false;
1026 
1027 	if (set_properties && proto->init && init_allowed) {
1028 		if (proto->init(psmouse) != 0) {
1029 			/*
1030 			 * We detected device, but init failed. Adjust
1031 			 * max_proto so we only try standard protocols.
1032 			 */
1033 			if (*max_proto > PSMOUSE_IMEX)
1034 				*max_proto = PSMOUSE_IMEX;
1035 
1036 			return false;
1037 		}
1038 	}
1039 
1040 	return true;
1041 }
1042 
1043 /*
1044  * psmouse_extensions() probes for any extensions to the basic PS/2 protocol
1045  * the mouse may have.
1046  */
1047 static int psmouse_extensions(struct psmouse *psmouse,
1048 			      unsigned int max_proto, bool set_properties)
1049 {
1050 	bool synaptics_hardware = false;
1051 	int ret;
1052 
1053 	/*
1054 	 * Always check for focaltech, this is safe as it uses pnp-id
1055 	 * matching.
1056 	 */
1057 	if (psmouse_do_detect(focaltech_detect,
1058 			      psmouse, false, set_properties)) {
1059 		if (max_proto > PSMOUSE_IMEX &&
1060 		    IS_ENABLED(CONFIG_MOUSE_PS2_FOCALTECH) &&
1061 		    (!set_properties || focaltech_init(psmouse) == 0)) {
1062 			return PSMOUSE_FOCALTECH;
1063 		}
1064 		/*
1065 		 * Restrict psmouse_max_proto so that psmouse_initialize()
1066 		 * does not try to reset rate and resolution, because even
1067 		 * that upsets the device.
1068 		 * This also causes us to basically fall through to basic
1069 		 * protocol detection, where we fully reset the mouse,
1070 		 * and set it up as bare PS/2 protocol device.
1071 		 */
1072 		psmouse_max_proto = max_proto = PSMOUSE_PS2;
1073 	}
1074 
1075 	/*
1076 	 * We always check for LifeBook because it does not disturb mouse
1077 	 * (it only checks DMI information).
1078 	 */
1079 	if (psmouse_try_protocol(psmouse, PSMOUSE_LIFEBOOK, &max_proto,
1080 				 set_properties, max_proto > PSMOUSE_IMEX))
1081 		return PSMOUSE_LIFEBOOK;
1082 
1083 	if (psmouse_try_protocol(psmouse, PSMOUSE_VMMOUSE, &max_proto,
1084 				 set_properties, max_proto > PSMOUSE_IMEX))
1085 		return PSMOUSE_VMMOUSE;
1086 
1087 	/*
1088 	 * Try Kensington ThinkingMouse (we try first, because Synaptics
1089 	 * probe upsets the ThinkingMouse).
1090 	 */
1091 	if (max_proto > PSMOUSE_IMEX &&
1092 	    psmouse_try_protocol(psmouse, PSMOUSE_THINKPS, &max_proto,
1093 				 set_properties, true)) {
1094 		return PSMOUSE_THINKPS;
1095 	}
1096 
1097 	/*
1098 	 * Try Synaptics TouchPad. Note that probing is done even if
1099 	 * Synaptics protocol support is disabled in config - we need to
1100 	 * know if it is Synaptics so we can reset it properly after
1101 	 * probing for IntelliMouse.
1102 	 */
1103 	if (max_proto > PSMOUSE_PS2 &&
1104 	    psmouse_do_detect(synaptics_detect,
1105 			      psmouse, false, set_properties)) {
1106 		synaptics_hardware = true;
1107 
1108 		if (max_proto > PSMOUSE_IMEX) {
1109 			/*
1110 			 * Try activating protocol, but check if support is
1111 			 * enabled first, since we try detecting Synaptics
1112 			 * even when protocol is disabled.
1113 			 */
1114 			if (IS_ENABLED(CONFIG_MOUSE_PS2_SYNAPTICS) ||
1115 			    IS_ENABLED(CONFIG_MOUSE_PS2_SYNAPTICS_SMBUS)) {
1116 				if (!set_properties)
1117 					return PSMOUSE_SYNAPTICS;
1118 
1119 				ret = synaptics_init(psmouse);
1120 				if (ret >= 0)
1121 					return ret;
1122 			}
1123 
1124 			/*
1125 			 * Some Synaptics touchpads can emulate extended
1126 			 * protocols (like IMPS/2).  Unfortunately
1127 			 * Logitech/Genius probes confuse some firmware
1128 			 * versions so we'll have to skip them.
1129 			 */
1130 			max_proto = PSMOUSE_IMEX;
1131 		}
1132 
1133 		/*
1134 		 * Make sure that touchpad is in relative mode, gestures
1135 		 * (taps) are enabled.
1136 		 */
1137 		synaptics_reset(psmouse);
1138 	}
1139 
1140 	/*
1141 	 * Try Cypress Trackpad. We must try it before Finger Sensing Pad
1142 	 * because Finger Sensing Pad probe upsets some modules of Cypress
1143 	 * Trackpads.
1144 	 */
1145 	if (max_proto > PSMOUSE_IMEX &&
1146 	    psmouse_try_protocol(psmouse, PSMOUSE_CYPRESS, &max_proto,
1147 				 set_properties, true)) {
1148 		return PSMOUSE_CYPRESS;
1149 	}
1150 
1151 	/* Try ALPS TouchPad */
1152 	if (max_proto > PSMOUSE_IMEX) {
1153 		ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
1154 		if (psmouse_try_protocol(psmouse, PSMOUSE_ALPS,
1155 					 &max_proto, set_properties, true))
1156 			return PSMOUSE_ALPS;
1157 	}
1158 
1159 	/* Try OLPC HGPK touchpad */
1160 	if (max_proto > PSMOUSE_IMEX &&
1161 	    psmouse_try_protocol(psmouse, PSMOUSE_HGPK, &max_proto,
1162 				 set_properties, true)) {
1163 		return PSMOUSE_HGPK;
1164 	}
1165 
1166 	/* Try Elantech touchpad */
1167 	if (max_proto > PSMOUSE_IMEX &&
1168 	    psmouse_try_protocol(psmouse, PSMOUSE_ELANTECH,
1169 				 &max_proto, set_properties, false)) {
1170 		if (!set_properties)
1171 			return PSMOUSE_ELANTECH;
1172 
1173 		ret = elantech_init(psmouse);
1174 		if (ret >= 0)
1175 			return ret;
1176 	}
1177 
1178 	if (max_proto > PSMOUSE_IMEX) {
1179 		if (psmouse_try_protocol(psmouse, PSMOUSE_GENPS,
1180 					 &max_proto, set_properties, true))
1181 			return PSMOUSE_GENPS;
1182 
1183 		if (psmouse_try_protocol(psmouse, PSMOUSE_PS2PP,
1184 					 &max_proto, set_properties, true))
1185 			return PSMOUSE_PS2PP;
1186 
1187 		if (psmouse_try_protocol(psmouse, PSMOUSE_TRACKPOINT,
1188 					 &max_proto, set_properties, true))
1189 			return PSMOUSE_TRACKPOINT;
1190 
1191 		if (psmouse_try_protocol(psmouse, PSMOUSE_TOUCHKIT_PS2,
1192 					 &max_proto, set_properties, true))
1193 			return PSMOUSE_TOUCHKIT_PS2;
1194 	}
1195 
1196 	/*
1197 	 * Try Finger Sensing Pad. We do it here because its probe upsets
1198 	 * Trackpoint devices (causing TP_READ_ID command to time out).
1199 	 */
1200 	if (max_proto > PSMOUSE_IMEX &&
1201 	    psmouse_try_protocol(psmouse, PSMOUSE_FSP,
1202 				 &max_proto, set_properties, true)) {
1203 		return PSMOUSE_FSP;
1204 	}
1205 
1206 	/*
1207 	 * Reset to defaults in case the device got confused by extended
1208 	 * protocol probes. Note that we follow up with full reset because
1209 	 * some mice put themselves to sleep when they see PSMOUSE_RESET_DIS.
1210 	 */
1211 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
1212 	psmouse_reset(psmouse);
1213 
1214 	if (max_proto >= PSMOUSE_IMEX &&
1215 	    psmouse_try_protocol(psmouse, PSMOUSE_IMEX,
1216 				 &max_proto, set_properties, true)) {
1217 		return PSMOUSE_IMEX;
1218 	}
1219 
1220 	if (max_proto >= PSMOUSE_IMPS &&
1221 	    psmouse_try_protocol(psmouse, PSMOUSE_IMPS,
1222 				 &max_proto, set_properties, true)) {
1223 		return PSMOUSE_IMPS;
1224 	}
1225 
1226 	/*
1227 	 * Okay, all failed, we have a standard mouse here. The number of
1228 	 * the buttons is still a question, though. We assume 3.
1229 	 */
1230 	psmouse_try_protocol(psmouse, PSMOUSE_PS2,
1231 			     &max_proto, set_properties, true);
1232 
1233 	if (synaptics_hardware) {
1234 		/*
1235 		 * We detected Synaptics hardware but it did not respond to
1236 		 * IMPS/2 probes.  We need to reset the touchpad because if
1237 		 * there is a track point on the pass through port it could
1238 		 * get disabled while probing for protocol extensions.
1239 		 */
1240 		psmouse_reset(psmouse);
1241 	}
1242 
1243 	return PSMOUSE_PS2;
1244 }
1245 
1246 /*
1247  * psmouse_probe() probes for a PS/2 mouse.
1248  */
1249 static int psmouse_probe(struct psmouse *psmouse)
1250 {
1251 	struct ps2dev *ps2dev = &psmouse->ps2dev;
1252 	u8 param[2];
1253 	int error;
1254 
1255 	/*
1256 	 * First, we check if it's a mouse. It should send 0x00 or 0x03 in
1257 	 * case of an IntelliMouse in 4-byte mode or 0x04 for IM Explorer.
1258 	 * Sunrex K8561 IR Keyboard/Mouse reports 0xff on second and
1259 	 * subsequent ID queries, probably due to a firmware bug.
1260 	 */
1261 	param[0] = 0xa5;
1262 	error = ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);
1263 	if (error)
1264 		return error;
1265 
1266 	if (param[0] != 0x00 && param[0] != 0x03 &&
1267 	    param[0] != 0x04 && param[0] != 0xff)
1268 		return -ENODEV;
1269 
1270 	/*
1271 	 * Then we reset and disable the mouse so that it doesn't generate
1272 	 * events.
1273 	 */
1274 	error = ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
1275 	if (error)
1276 		psmouse_warn(psmouse, "Failed to reset mouse on %s: %d\n",
1277 			     ps2dev->serio->phys, error);
1278 
1279 	return 0;
1280 }
1281 
1282 /*
1283  * psmouse_initialize() initializes the mouse to a sane state.
1284  */
1285 static void psmouse_initialize(struct psmouse *psmouse)
1286 {
1287 	/*
1288 	 * We set the mouse report rate, resolution and scaling.
1289 	 */
1290 	if (psmouse_max_proto != PSMOUSE_PS2) {
1291 		psmouse->set_rate(psmouse, psmouse->rate);
1292 		psmouse->set_resolution(psmouse, psmouse->resolution);
1293 		psmouse->set_scale(psmouse, PSMOUSE_SCALE11);
1294 	}
1295 }
1296 
1297 /*
1298  * psmouse_activate() enables the mouse so that we get motion reports from it.
1299  */
1300 int psmouse_activate(struct psmouse *psmouse)
1301 {
1302 	if (ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE)) {
1303 		psmouse_warn(psmouse, "Failed to enable mouse on %s\n",
1304 			     psmouse->ps2dev.serio->phys);
1305 		return -1;
1306 	}
1307 
1308 	psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
1309 	return 0;
1310 }
1311 
1312 /*
1313  * psmouse_deactivate() puts the mouse into poll mode so that we don't get
1314  * motion reports from it unless we explicitly request it.
1315  */
1316 int psmouse_deactivate(struct psmouse *psmouse)
1317 {
1318 	int error;
1319 
1320 	error = ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_DISABLE);
1321 	if (error) {
1322 		psmouse_warn(psmouse, "Failed to deactivate mouse on %s: %d\n",
1323 			     psmouse->ps2dev.serio->phys, error);
1324 		return error;
1325 	}
1326 
1327 	psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
1328 	return 0;
1329 }
1330 
1331 /*
1332  * psmouse_resync() attempts to re-validate current protocol.
1333  */
1334 static void psmouse_resync(struct work_struct *work)
1335 {
1336 	struct psmouse *parent = NULL, *psmouse =
1337 		container_of(work, struct psmouse, resync_work.work);
1338 	struct serio *serio = psmouse->ps2dev.serio;
1339 	psmouse_ret_t rc = PSMOUSE_GOOD_DATA;
1340 	bool failed = false, enabled = false;
1341 	int i;
1342 
1343 	mutex_lock(&psmouse_mutex);
1344 
1345 	if (psmouse->state != PSMOUSE_RESYNCING)
1346 		goto out;
1347 
1348 	if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
1349 		parent = serio_get_drvdata(serio->parent);
1350 		psmouse_deactivate(parent);
1351 	}
1352 
1353 	/*
1354 	 * Some mice don't ACK commands sent while they are in the middle of
1355 	 * transmitting motion packet. To avoid delay we use ps2_sendbyte()
1356 	 * instead of ps2_command() which would wait for 200ms for an ACK
1357 	 * that may never come.
1358 	 * As an additional quirk ALPS touchpads may not only forget to ACK
1359 	 * disable command but will stop reporting taps, so if we see that
1360 	 * mouse at least once ACKs disable we will do full reconnect if ACK
1361 	 * is missing.
1362 	 */
1363 	psmouse->num_resyncs++;
1364 
1365 	if (ps2_sendbyte(&psmouse->ps2dev, PSMOUSE_CMD_DISABLE, 20)) {
1366 		if (psmouse->num_resyncs < 3 || psmouse->acks_disable_command)
1367 			failed = true;
1368 	} else
1369 		psmouse->acks_disable_command = true;
1370 
1371 	/*
1372 	 * Poll the mouse. If it was reset the packet will be shorter than
1373 	 * psmouse->pktsize and ps2_command will fail. We do not expect and
1374 	 * do not handle scenario when mouse "upgrades" its protocol while
1375 	 * disconnected since it would require additional delay. If we ever
1376 	 * see a mouse that does it we'll adjust the code.
1377 	 */
1378 	if (!failed) {
1379 		if (psmouse->poll(psmouse))
1380 			failed = true;
1381 		else {
1382 			psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
1383 			for (i = 0; i < psmouse->pktsize; i++) {
1384 				psmouse->pktcnt++;
1385 				rc = psmouse->protocol_handler(psmouse);
1386 				if (rc != PSMOUSE_GOOD_DATA)
1387 					break;
1388 			}
1389 			if (rc != PSMOUSE_FULL_PACKET)
1390 				failed = true;
1391 			psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
1392 		}
1393 	}
1394 
1395 	/*
1396 	 * Now try to enable mouse. We try to do that even if poll failed
1397 	 * and also repeat our attempts 5 times, otherwise we may be left
1398 	 * out with disabled mouse.
1399 	 */
1400 	for (i = 0; i < 5; i++) {
1401 		if (!ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE)) {
1402 			enabled = true;
1403 			break;
1404 		}
1405 		msleep(200);
1406 	}
1407 
1408 	if (!enabled) {
1409 		psmouse_warn(psmouse, "failed to re-enable mouse on %s\n",
1410 			     psmouse->ps2dev.serio->phys);
1411 		failed = true;
1412 	}
1413 
1414 	if (failed) {
1415 		psmouse_set_state(psmouse, PSMOUSE_IGNORE);
1416 		psmouse_info(psmouse,
1417 			     "resync failed, issuing reconnect request\n");
1418 		serio_reconnect(serio);
1419 	} else
1420 		psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
1421 
1422 	if (parent)
1423 		psmouse_activate(parent);
1424  out:
1425 	mutex_unlock(&psmouse_mutex);
1426 }
1427 
1428 /*
1429  * psmouse_cleanup() resets the mouse into power-on state.
1430  */
1431 static void psmouse_cleanup(struct serio *serio)
1432 {
1433 	struct psmouse *psmouse = serio_get_drvdata(serio);
1434 	struct psmouse *parent = NULL;
1435 
1436 	mutex_lock(&psmouse_mutex);
1437 
1438 	if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
1439 		parent = serio_get_drvdata(serio->parent);
1440 		psmouse_deactivate(parent);
1441 	}
1442 
1443 	psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
1444 
1445 	/*
1446 	 * Disable stream mode so cleanup routine can proceed undisturbed.
1447 	 */
1448 	if (ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_DISABLE))
1449 		psmouse_warn(psmouse, "Failed to disable mouse on %s\n",
1450 			     psmouse->ps2dev.serio->phys);
1451 
1452 	if (psmouse->cleanup)
1453 		psmouse->cleanup(psmouse);
1454 
1455 	/*
1456 	 * Reset the mouse to defaults (bare PS/2 protocol).
1457 	 */
1458 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
1459 
1460 	/*
1461 	 * Some boxes, such as HP nx7400, get terribly confused if mouse
1462 	 * is not fully enabled before suspending/shutting down.
1463 	 */
1464 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE);
1465 
1466 	if (parent) {
1467 		if (parent->pt_deactivate)
1468 			parent->pt_deactivate(parent);
1469 
1470 		psmouse_activate(parent);
1471 	}
1472 
1473 	mutex_unlock(&psmouse_mutex);
1474 }
1475 
1476 /*
1477  * psmouse_disconnect() closes and frees.
1478  */
1479 static void psmouse_disconnect(struct serio *serio)
1480 {
1481 	struct psmouse *psmouse = serio_get_drvdata(serio);
1482 	struct psmouse *parent = NULL;
1483 
1484 	sysfs_remove_group(&serio->dev.kobj, &psmouse_attribute_group);
1485 
1486 	mutex_lock(&psmouse_mutex);
1487 
1488 	psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
1489 
1490 	/* make sure we don't have a resync in progress */
1491 	mutex_unlock(&psmouse_mutex);
1492 	flush_workqueue(kpsmoused_wq);
1493 	mutex_lock(&psmouse_mutex);
1494 
1495 	if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
1496 		parent = serio_get_drvdata(serio->parent);
1497 		psmouse_deactivate(parent);
1498 	}
1499 
1500 	if (psmouse->disconnect)
1501 		psmouse->disconnect(psmouse);
1502 
1503 	if (parent && parent->pt_deactivate)
1504 		parent->pt_deactivate(parent);
1505 
1506 	psmouse_set_state(psmouse, PSMOUSE_IGNORE);
1507 
1508 	serio_close(serio);
1509 	serio_set_drvdata(serio, NULL);
1510 
1511 	if (psmouse->dev)
1512 		input_unregister_device(psmouse->dev);
1513 
1514 	kfree(psmouse);
1515 
1516 	if (parent)
1517 		psmouse_activate(parent);
1518 
1519 	mutex_unlock(&psmouse_mutex);
1520 }
1521 
1522 static int psmouse_switch_protocol(struct psmouse *psmouse,
1523 				   const struct psmouse_protocol *proto)
1524 {
1525 	const struct psmouse_protocol *selected_proto;
1526 	struct input_dev *input_dev = psmouse->dev;
1527 	enum psmouse_type type;
1528 
1529 	input_dev->dev.parent = &psmouse->ps2dev.serio->dev;
1530 
1531 	if (proto && (proto->detect || proto->init)) {
1532 		psmouse_apply_defaults(psmouse);
1533 
1534 		if (proto->detect && proto->detect(psmouse, true) < 0)
1535 			return -1;
1536 
1537 		if (proto->init && proto->init(psmouse) < 0)
1538 			return -1;
1539 
1540 		selected_proto = proto;
1541 	} else {
1542 		type = psmouse_extensions(psmouse, psmouse_max_proto, true);
1543 		selected_proto = psmouse_protocol_by_type(type);
1544 	}
1545 
1546 	psmouse->protocol = selected_proto;
1547 
1548 	/*
1549 	 * If mouse's packet size is 3 there is no point in polling the
1550 	 * device in hopes to detect protocol reset - we won't get less
1551 	 * than 3 bytes response anyhow.
1552 	 */
1553 	if (psmouse->pktsize == 3)
1554 		psmouse->resync_time = 0;
1555 
1556 	/*
1557 	 * Some smart KVMs fake response to POLL command returning just
1558 	 * 3 bytes and messing up our resync logic, so if initial poll
1559 	 * fails we won't try polling the device anymore. Hopefully
1560 	 * such KVM will maintain initially selected protocol.
1561 	 */
1562 	if (psmouse->resync_time && psmouse->poll(psmouse))
1563 		psmouse->resync_time = 0;
1564 
1565 	snprintf(psmouse->devname, sizeof(psmouse->devname), "%s %s %s",
1566 		 selected_proto->name, psmouse->vendor, psmouse->name);
1567 
1568 	input_dev->name = psmouse->devname;
1569 	input_dev->phys = psmouse->phys;
1570 	input_dev->id.bustype = BUS_I8042;
1571 	input_dev->id.vendor = 0x0002;
1572 	input_dev->id.product = psmouse->protocol->type;
1573 	input_dev->id.version = psmouse->model;
1574 
1575 	return 0;
1576 }
1577 
1578 /*
1579  * psmouse_connect() is a callback from the serio module when
1580  * an unhandled serio port is found.
1581  */
1582 static int psmouse_connect(struct serio *serio, struct serio_driver *drv)
1583 {
1584 	struct psmouse *psmouse, *parent = NULL;
1585 	struct input_dev *input_dev;
1586 	int retval = 0, error = -ENOMEM;
1587 
1588 	mutex_lock(&psmouse_mutex);
1589 
1590 	/*
1591 	 * If this is a pass-through port deactivate parent so the device
1592 	 * connected to this port can be successfully identified
1593 	 */
1594 	if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
1595 		parent = serio_get_drvdata(serio->parent);
1596 		psmouse_deactivate(parent);
1597 	}
1598 
1599 	psmouse = kzalloc(sizeof(struct psmouse), GFP_KERNEL);
1600 	input_dev = input_allocate_device();
1601 	if (!psmouse || !input_dev)
1602 		goto err_free;
1603 
1604 	ps2_init(&psmouse->ps2dev, serio);
1605 	INIT_DELAYED_WORK(&psmouse->resync_work, psmouse_resync);
1606 	psmouse->dev = input_dev;
1607 	snprintf(psmouse->phys, sizeof(psmouse->phys), "%s/input0", serio->phys);
1608 
1609 	psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
1610 
1611 	serio_set_drvdata(serio, psmouse);
1612 
1613 	error = serio_open(serio, drv);
1614 	if (error)
1615 		goto err_clear_drvdata;
1616 
1617 	/* give PT device some time to settle down before probing */
1618 	if (serio->id.type == SERIO_PS_PSTHRU)
1619 		usleep_range(10000, 15000);
1620 
1621 	if (psmouse_probe(psmouse) < 0) {
1622 		error = -ENODEV;
1623 		goto err_close_serio;
1624 	}
1625 
1626 	psmouse->rate = psmouse_rate;
1627 	psmouse->resolution = psmouse_resolution;
1628 	psmouse->resetafter = psmouse_resetafter;
1629 	psmouse->resync_time = parent ? 0 : psmouse_resync_time;
1630 	psmouse->smartscroll = psmouse_smartscroll;
1631 
1632 	psmouse_switch_protocol(psmouse, NULL);
1633 
1634 	if (!psmouse->protocol->smbus_companion) {
1635 		psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
1636 		psmouse_initialize(psmouse);
1637 
1638 		error = input_register_device(input_dev);
1639 		if (error)
1640 			goto err_protocol_disconnect;
1641 	} else {
1642 		/* Smbus companion will be reporting events, not us. */
1643 		input_free_device(input_dev);
1644 		psmouse->dev = input_dev = NULL;
1645 	}
1646 
1647 	if (parent && parent->pt_activate)
1648 		parent->pt_activate(parent);
1649 
1650 	error = sysfs_create_group(&serio->dev.kobj, &psmouse_attribute_group);
1651 	if (error)
1652 		goto err_pt_deactivate;
1653 
1654 	/*
1655 	 * PS/2 devices having SMBus companions should stay disabled
1656 	 * on PS/2 side, in order to have SMBus part operable.
1657 	 */
1658 	if (!psmouse->protocol->smbus_companion)
1659 		psmouse_activate(psmouse);
1660 
1661  out:
1662 	/* If this is a pass-through port the parent needs to be re-activated */
1663 	if (parent)
1664 		psmouse_activate(parent);
1665 
1666 	mutex_unlock(&psmouse_mutex);
1667 	return retval;
1668 
1669  err_pt_deactivate:
1670 	if (parent && parent->pt_deactivate)
1671 		parent->pt_deactivate(parent);
1672 	if (input_dev) {
1673 		input_unregister_device(input_dev);
1674 		input_dev = NULL; /* so we don't try to free it below */
1675 	}
1676  err_protocol_disconnect:
1677 	if (psmouse->disconnect)
1678 		psmouse->disconnect(psmouse);
1679 	psmouse_set_state(psmouse, PSMOUSE_IGNORE);
1680  err_close_serio:
1681 	serio_close(serio);
1682  err_clear_drvdata:
1683 	serio_set_drvdata(serio, NULL);
1684  err_free:
1685 	input_free_device(input_dev);
1686 	kfree(psmouse);
1687 
1688 	retval = error;
1689 	goto out;
1690 }
1691 
1692 static int __psmouse_reconnect(struct serio *serio, bool fast_reconnect)
1693 {
1694 	struct psmouse *psmouse = serio_get_drvdata(serio);
1695 	struct psmouse *parent = NULL;
1696 	int (*reconnect_handler)(struct psmouse *);
1697 	enum psmouse_type type;
1698 	int rc = -1;
1699 
1700 	mutex_lock(&psmouse_mutex);
1701 
1702 	if (fast_reconnect) {
1703 		reconnect_handler = psmouse->fast_reconnect;
1704 		if (!reconnect_handler) {
1705 			rc = -ENOENT;
1706 			goto out_unlock;
1707 		}
1708 	} else {
1709 		reconnect_handler = psmouse->reconnect;
1710 	}
1711 
1712 	if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
1713 		parent = serio_get_drvdata(serio->parent);
1714 		psmouse_deactivate(parent);
1715 	}
1716 
1717 	psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
1718 
1719 	if (reconnect_handler) {
1720 		if (reconnect_handler(psmouse))
1721 			goto out;
1722 	} else {
1723 		psmouse_reset(psmouse);
1724 
1725 		if (psmouse_probe(psmouse) < 0)
1726 			goto out;
1727 
1728 		type = psmouse_extensions(psmouse, psmouse_max_proto, false);
1729 		if (psmouse->protocol->type != type)
1730 			goto out;
1731 	}
1732 
1733 	/*
1734 	 * OK, the device type (and capabilities) match the old one,
1735 	 * we can continue using it, complete initialization
1736 	 */
1737 	if (!psmouse->protocol->smbus_companion) {
1738 		psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
1739 		psmouse_initialize(psmouse);
1740 	}
1741 
1742 	if (parent && parent->pt_activate)
1743 		parent->pt_activate(parent);
1744 
1745 	/*
1746 	 * PS/2 devices having SMBus companions should stay disabled
1747 	 * on PS/2 side, in order to have SMBus part operable.
1748 	 */
1749 	if (!psmouse->protocol->smbus_companion)
1750 		psmouse_activate(psmouse);
1751 
1752 	rc = 0;
1753 
1754 out:
1755 	/* If this is a pass-through port the parent waits to be activated */
1756 	if (parent)
1757 		psmouse_activate(parent);
1758 
1759 out_unlock:
1760 	mutex_unlock(&psmouse_mutex);
1761 	return rc;
1762 }
1763 
1764 static int psmouse_reconnect(struct serio *serio)
1765 {
1766 	return __psmouse_reconnect(serio, false);
1767 }
1768 
1769 static int psmouse_fast_reconnect(struct serio *serio)
1770 {
1771 	return __psmouse_reconnect(serio, true);
1772 }
1773 
1774 static struct serio_device_id psmouse_serio_ids[] = {
1775 	{
1776 		.type	= SERIO_8042,
1777 		.proto	= SERIO_ANY,
1778 		.id	= SERIO_ANY,
1779 		.extra	= SERIO_ANY,
1780 	},
1781 	{
1782 		.type	= SERIO_PS_PSTHRU,
1783 		.proto	= SERIO_ANY,
1784 		.id	= SERIO_ANY,
1785 		.extra	= SERIO_ANY,
1786 	},
1787 	{ 0 }
1788 };
1789 
1790 MODULE_DEVICE_TABLE(serio, psmouse_serio_ids);
1791 
1792 static struct serio_driver psmouse_drv = {
1793 	.driver		= {
1794 		.name	= "psmouse",
1795 	},
1796 	.description	= DRIVER_DESC,
1797 	.id_table	= psmouse_serio_ids,
1798 	.interrupt	= psmouse_interrupt,
1799 	.connect	= psmouse_connect,
1800 	.reconnect	= psmouse_reconnect,
1801 	.fast_reconnect	= psmouse_fast_reconnect,
1802 	.disconnect	= psmouse_disconnect,
1803 	.cleanup	= psmouse_cleanup,
1804 };
1805 
1806 ssize_t psmouse_attr_show_helper(struct device *dev, struct device_attribute *devattr,
1807 				 char *buf)
1808 {
1809 	struct serio *serio = to_serio_port(dev);
1810 	struct psmouse_attribute *attr = to_psmouse_attr(devattr);
1811 	struct psmouse *psmouse = serio_get_drvdata(serio);
1812 
1813 	if (psmouse->protocol->smbus_companion &&
1814 			devattr != &psmouse_attr_protocol.dattr)
1815 		return -ENOENT;
1816 
1817 	return attr->show(psmouse, attr->data, buf);
1818 }
1819 
1820 ssize_t psmouse_attr_set_helper(struct device *dev, struct device_attribute *devattr,
1821 				const char *buf, size_t count)
1822 {
1823 	struct serio *serio = to_serio_port(dev);
1824 	struct psmouse_attribute *attr = to_psmouse_attr(devattr);
1825 	struct psmouse *psmouse, *parent = NULL;
1826 	int retval;
1827 
1828 	retval = mutex_lock_interruptible(&psmouse_mutex);
1829 	if (retval)
1830 		goto out;
1831 
1832 	psmouse = serio_get_drvdata(serio);
1833 
1834 	if (psmouse->protocol->smbus_companion &&
1835 			devattr != &psmouse_attr_protocol.dattr) {
1836 		retval = -ENOENT;
1837 		goto out_unlock;
1838 	}
1839 
1840 	if (attr->protect) {
1841 		if (psmouse->state == PSMOUSE_IGNORE) {
1842 			retval = -ENODEV;
1843 			goto out_unlock;
1844 		}
1845 
1846 		if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
1847 			parent = serio_get_drvdata(serio->parent);
1848 			psmouse_deactivate(parent);
1849 		}
1850 
1851 		if (!psmouse->protocol->smbus_companion)
1852 			psmouse_deactivate(psmouse);
1853 	}
1854 
1855 	retval = attr->set(psmouse, attr->data, buf, count);
1856 
1857 	if (attr->protect) {
1858 		if (retval != -ENODEV && !psmouse->protocol->smbus_companion)
1859 			psmouse_activate(psmouse);
1860 
1861 		if (parent)
1862 			psmouse_activate(parent);
1863 	}
1864 
1865  out_unlock:
1866 	mutex_unlock(&psmouse_mutex);
1867  out:
1868 	return retval;
1869 }
1870 
1871 static ssize_t psmouse_show_int_attr(struct psmouse *psmouse, void *offset, char *buf)
1872 {
1873 	unsigned int *field = (unsigned int *)((char *)psmouse + (size_t)offset);
1874 
1875 	return sprintf(buf, "%u\n", *field);
1876 }
1877 
1878 static ssize_t psmouse_set_int_attr(struct psmouse *psmouse, void *offset, const char *buf, size_t count)
1879 {
1880 	unsigned int *field = (unsigned int *)((char *)psmouse + (size_t)offset);
1881 	unsigned int value;
1882 	int err;
1883 
1884 	err = kstrtouint(buf, 10, &value);
1885 	if (err)
1886 		return err;
1887 
1888 	*field = value;
1889 
1890 	return count;
1891 }
1892 
1893 static ssize_t psmouse_attr_show_protocol(struct psmouse *psmouse, void *data, char *buf)
1894 {
1895 	return sprintf(buf, "%s\n", psmouse->protocol->name);
1896 }
1897 
1898 static ssize_t psmouse_attr_set_protocol(struct psmouse *psmouse, void *data, const char *buf, size_t count)
1899 {
1900 	struct serio *serio = psmouse->ps2dev.serio;
1901 	struct psmouse *parent = NULL;
1902 	struct input_dev *old_dev, *new_dev;
1903 	const struct psmouse_protocol *proto, *old_proto;
1904 	int error;
1905 	int retry = 0;
1906 
1907 	proto = psmouse_protocol_by_name(buf, count);
1908 	if (!proto)
1909 		return -EINVAL;
1910 
1911 	if (psmouse->protocol == proto)
1912 		return count;
1913 
1914 	new_dev = input_allocate_device();
1915 	if (!new_dev)
1916 		return -ENOMEM;
1917 
1918 	while (!list_empty(&serio->children)) {
1919 		if (++retry > 3) {
1920 			psmouse_warn(psmouse,
1921 				     "failed to destroy children ports, protocol change aborted.\n");
1922 			input_free_device(new_dev);
1923 			return -EIO;
1924 		}
1925 
1926 		mutex_unlock(&psmouse_mutex);
1927 		serio_unregister_child_port(serio);
1928 		mutex_lock(&psmouse_mutex);
1929 
1930 		if (serio->drv != &psmouse_drv) {
1931 			input_free_device(new_dev);
1932 			return -ENODEV;
1933 		}
1934 
1935 		if (psmouse->protocol == proto) {
1936 			input_free_device(new_dev);
1937 			return count; /* switched by other thread */
1938 		}
1939 	}
1940 
1941 	if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
1942 		parent = serio_get_drvdata(serio->parent);
1943 		if (parent->pt_deactivate)
1944 			parent->pt_deactivate(parent);
1945 	}
1946 
1947 	old_dev = psmouse->dev;
1948 	old_proto = psmouse->protocol;
1949 
1950 	if (psmouse->disconnect)
1951 		psmouse->disconnect(psmouse);
1952 
1953 	psmouse_set_state(psmouse, PSMOUSE_IGNORE);
1954 
1955 	psmouse->dev = new_dev;
1956 	psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
1957 
1958 	if (psmouse_switch_protocol(psmouse, proto) < 0) {
1959 		psmouse_reset(psmouse);
1960 		/* default to PSMOUSE_PS2 */
1961 		psmouse_switch_protocol(psmouse, &psmouse_protocols[0]);
1962 	}
1963 
1964 	psmouse_initialize(psmouse);
1965 	psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
1966 
1967 	if (psmouse->protocol->smbus_companion) {
1968 		input_free_device(psmouse->dev);
1969 		psmouse->dev = NULL;
1970 	} else {
1971 		error = input_register_device(psmouse->dev);
1972 		if (error) {
1973 			if (psmouse->disconnect)
1974 				psmouse->disconnect(psmouse);
1975 
1976 			psmouse_set_state(psmouse, PSMOUSE_IGNORE);
1977 			input_free_device(new_dev);
1978 			psmouse->dev = old_dev;
1979 			psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
1980 			psmouse_switch_protocol(psmouse, old_proto);
1981 			psmouse_initialize(psmouse);
1982 			psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
1983 
1984 			return error;
1985 		}
1986 	}
1987 
1988 	if (old_dev)
1989 		input_unregister_device(old_dev);
1990 
1991 	if (parent && parent->pt_activate)
1992 		parent->pt_activate(parent);
1993 
1994 	return count;
1995 }
1996 
1997 static ssize_t psmouse_attr_set_rate(struct psmouse *psmouse, void *data, const char *buf, size_t count)
1998 {
1999 	unsigned int value;
2000 	int err;
2001 
2002 	err = kstrtouint(buf, 10, &value);
2003 	if (err)
2004 		return err;
2005 
2006 	psmouse->set_rate(psmouse, value);
2007 	return count;
2008 }
2009 
2010 static ssize_t psmouse_attr_set_resolution(struct psmouse *psmouse, void *data, const char *buf, size_t count)
2011 {
2012 	unsigned int value;
2013 	int err;
2014 
2015 	err = kstrtouint(buf, 10, &value);
2016 	if (err)
2017 		return err;
2018 
2019 	psmouse->set_resolution(psmouse, value);
2020 	return count;
2021 }
2022 
2023 
2024 static int psmouse_set_maxproto(const char *val, const struct kernel_param *kp)
2025 {
2026 	const struct psmouse_protocol *proto;
2027 
2028 	if (!val)
2029 		return -EINVAL;
2030 
2031 	proto = psmouse_protocol_by_name(val, strlen(val));
2032 
2033 	if (!proto || !proto->maxproto)
2034 		return -EINVAL;
2035 
2036 	*((unsigned int *)kp->arg) = proto->type;
2037 
2038 	return 0;
2039 }
2040 
2041 static int psmouse_get_maxproto(char *buffer, const struct kernel_param *kp)
2042 {
2043 	int type = *((unsigned int *)kp->arg);
2044 
2045 	return sprintf(buffer, "%s", psmouse_protocol_by_type(type)->name);
2046 }
2047 
2048 static int __init psmouse_init(void)
2049 {
2050 	int err;
2051 
2052 	lifebook_module_init();
2053 	synaptics_module_init();
2054 	hgpk_module_init();
2055 
2056 	err = psmouse_smbus_module_init();
2057 	if (err)
2058 		return err;
2059 
2060 	kpsmoused_wq = alloc_ordered_workqueue("kpsmoused", 0);
2061 	if (!kpsmoused_wq) {
2062 		pr_err("failed to create kpsmoused workqueue\n");
2063 		err = -ENOMEM;
2064 		goto err_smbus_exit;
2065 	}
2066 
2067 	err = serio_register_driver(&psmouse_drv);
2068 	if (err)
2069 		goto err_destroy_wq;
2070 
2071 	return 0;
2072 
2073 err_destroy_wq:
2074 	destroy_workqueue(kpsmoused_wq);
2075 err_smbus_exit:
2076 	psmouse_smbus_module_exit();
2077 	return err;
2078 }
2079 
2080 static void __exit psmouse_exit(void)
2081 {
2082 	serio_unregister_driver(&psmouse_drv);
2083 	destroy_workqueue(kpsmoused_wq);
2084 	psmouse_smbus_module_exit();
2085 }
2086 
2087 module_init(psmouse_init);
2088 module_exit(psmouse_exit);
2089