xref: /linux/drivers/input/serio/i8042.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  i8042 keyboard and mouse controller driver for Linux
4  *
5  *  Copyright (c) 1999-2004 Vojtech Pavlik
6  */
7 
8 
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <linux/types.h>
12 #include <linux/delay.h>
13 #include <linux/module.h>
14 #include <linux/interrupt.h>
15 #include <linux/ioport.h>
16 #include <linux/init.h>
17 #include <linux/serio.h>
18 #include <linux/err.h>
19 #include <linux/rcupdate.h>
20 #include <linux/platform_device.h>
21 #include <linux/i8042.h>
22 #include <linux/slab.h>
23 #include <linux/suspend.h>
24 #include <linux/property.h>
25 
26 #include <asm/io.h>
27 
28 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
29 MODULE_DESCRIPTION("i8042 keyboard and mouse controller driver");
30 MODULE_LICENSE("GPL");
31 
32 static bool i8042_nokbd;
33 module_param_named(nokbd, i8042_nokbd, bool, 0);
34 MODULE_PARM_DESC(nokbd, "Do not probe or use KBD port.");
35 
36 static bool i8042_noaux;
37 module_param_named(noaux, i8042_noaux, bool, 0);
38 MODULE_PARM_DESC(noaux, "Do not probe or use AUX (mouse) port.");
39 
40 static bool i8042_nomux;
41 module_param_named(nomux, i8042_nomux, bool, 0);
42 MODULE_PARM_DESC(nomux, "Do not check whether an active multiplexing controller is present.");
43 
44 static bool i8042_unlock;
45 module_param_named(unlock, i8042_unlock, bool, 0);
46 MODULE_PARM_DESC(unlock, "Ignore keyboard lock.");
47 
48 static bool i8042_probe_defer;
49 module_param_named(probe_defer, i8042_probe_defer, bool, 0);
50 MODULE_PARM_DESC(probe_defer, "Allow deferred probing.");
51 
52 enum i8042_controller_reset_mode {
53 	I8042_RESET_NEVER,
54 	I8042_RESET_ALWAYS,
55 	I8042_RESET_ON_S2RAM,
56 #define I8042_RESET_DEFAULT	I8042_RESET_ON_S2RAM
57 };
58 static enum i8042_controller_reset_mode i8042_reset = I8042_RESET_DEFAULT;
59 static int i8042_set_reset(const char *val, const struct kernel_param *kp)
60 {
61 	enum i8042_controller_reset_mode *arg = kp->arg;
62 	int error;
63 	bool reset;
64 
65 	if (val) {
66 		error = kstrtobool(val, &reset);
67 		if (error)
68 			return error;
69 	} else {
70 		reset = true;
71 	}
72 
73 	*arg = reset ? I8042_RESET_ALWAYS : I8042_RESET_NEVER;
74 	return 0;
75 }
76 
77 static const struct kernel_param_ops param_ops_reset_param = {
78 	.flags = KERNEL_PARAM_OPS_FL_NOARG,
79 	.set = i8042_set_reset,
80 };
81 #define param_check_reset_param(name, p)	\
82 	__param_check(name, p, enum i8042_controller_reset_mode)
83 module_param_named(reset, i8042_reset, reset_param, 0);
84 MODULE_PARM_DESC(reset, "Reset controller on resume, cleanup or both");
85 
86 static bool i8042_direct;
87 module_param_named(direct, i8042_direct, bool, 0);
88 MODULE_PARM_DESC(direct, "Put keyboard port into non-translated mode.");
89 
90 static bool i8042_dumbkbd;
91 module_param_named(dumbkbd, i8042_dumbkbd, bool, 0);
92 MODULE_PARM_DESC(dumbkbd, "Pretend that controller can only read data from keyboard");
93 
94 static bool i8042_noloop;
95 module_param_named(noloop, i8042_noloop, bool, 0);
96 MODULE_PARM_DESC(noloop, "Disable the AUX Loopback command while probing for the AUX port");
97 
98 static bool i8042_notimeout;
99 module_param_named(notimeout, i8042_notimeout, bool, 0);
100 MODULE_PARM_DESC(notimeout, "Ignore timeouts signalled by i8042");
101 
102 static bool i8042_kbdreset;
103 module_param_named(kbdreset, i8042_kbdreset, bool, 0);
104 MODULE_PARM_DESC(kbdreset, "Reset device connected to KBD port");
105 
106 #ifdef CONFIG_X86
107 static bool i8042_dritek;
108 module_param_named(dritek, i8042_dritek, bool, 0);
109 MODULE_PARM_DESC(dritek, "Force enable the Dritek keyboard extension");
110 #endif
111 
112 #ifdef CONFIG_PNP
113 static bool i8042_nopnp;
114 module_param_named(nopnp, i8042_nopnp, bool, 0);
115 MODULE_PARM_DESC(nopnp, "Do not use PNP to detect controller settings");
116 #endif
117 
118 static bool i8042_forcenorestore;
119 module_param_named(forcenorestore, i8042_forcenorestore, bool, 0);
120 MODULE_PARM_DESC(forcenorestore, "Force no restore on s3 resume, copying s2idle behaviour");
121 
122 #define DEBUG
123 #ifdef DEBUG
124 static bool i8042_debug;
125 module_param_named(debug, i8042_debug, bool, 0600);
126 MODULE_PARM_DESC(debug, "Turn i8042 debugging mode on and off");
127 
128 static bool i8042_unmask_kbd_data;
129 module_param_named(unmask_kbd_data, i8042_unmask_kbd_data, bool, 0600);
130 MODULE_PARM_DESC(unmask_kbd_data, "Unconditional enable (may reveal sensitive data) of normally sanitize-filtered kbd data traffic debug log [pre-condition: i8042.debug=1 enabled]");
131 #endif
132 
133 static bool i8042_present;
134 static bool i8042_bypass_aux_irq_test;
135 static char i8042_kbd_firmware_id[128];
136 static char i8042_aux_firmware_id[128];
137 static struct fwnode_handle *i8042_kbd_fwnode;
138 
139 #include "i8042.h"
140 
141 /*
142  * i8042_lock protects serialization between i8042_command and
143  * the interrupt handler.
144  */
145 static DEFINE_SPINLOCK(i8042_lock);
146 
147 /*
148  * Writers to AUX and KBD ports as well as users issuing i8042_command
149  * directly should acquire i8042_mutex (by means of calling
150  * i8042_lock_chip() and i8042_unlock_chip() helpers) to ensure that
151  * they do not disturb each other (unfortunately in many i8042
152  * implementations write to one of the ports will immediately abort
153  * command that is being processed by another port).
154  */
155 static DEFINE_MUTEX(i8042_mutex);
156 
157 struct i8042_port {
158 	struct serio *serio;
159 	int irq;
160 	bool exists;
161 	bool driver_bound;
162 	signed char mux;
163 };
164 
165 #define I8042_KBD_PORT_NO	0
166 #define I8042_AUX_PORT_NO	1
167 #define I8042_MUX_PORT_NO	2
168 #define I8042_NUM_PORTS		(I8042_NUM_MUX_PORTS + 2)
169 
170 static struct i8042_port i8042_ports[I8042_NUM_PORTS];
171 
172 static unsigned char i8042_initial_ctr;
173 static unsigned char i8042_ctr;
174 static bool i8042_mux_present;
175 static bool i8042_kbd_irq_registered;
176 static bool i8042_aux_irq_registered;
177 static unsigned char i8042_suppress_kbd_ack;
178 static struct platform_device *i8042_platform_device;
179 static struct notifier_block i8042_kbd_bind_notifier_block;
180 
181 static bool i8042_handle_data(int irq);
182 static bool (*i8042_platform_filter)(unsigned char data, unsigned char str,
183 				     struct serio *serio);
184 
185 void i8042_lock_chip(void)
186 {
187 	mutex_lock(&i8042_mutex);
188 }
189 EXPORT_SYMBOL(i8042_lock_chip);
190 
191 void i8042_unlock_chip(void)
192 {
193 	mutex_unlock(&i8042_mutex);
194 }
195 EXPORT_SYMBOL(i8042_unlock_chip);
196 
197 int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str,
198 					struct serio *serio))
199 {
200 	guard(spinlock_irqsave)(&i8042_lock);
201 
202 	if (i8042_platform_filter)
203 		return -EBUSY;
204 
205 	i8042_platform_filter = filter;
206 	return 0;
207 }
208 EXPORT_SYMBOL(i8042_install_filter);
209 
210 int i8042_remove_filter(bool (*filter)(unsigned char data, unsigned char str,
211 				       struct serio *port))
212 {
213 	guard(spinlock_irqsave)(&i8042_lock);
214 
215 	if (i8042_platform_filter != filter)
216 		return -EINVAL;
217 
218 	i8042_platform_filter = NULL;
219 	return 0;
220 }
221 EXPORT_SYMBOL(i8042_remove_filter);
222 
223 /*
224  * The i8042_wait_read() and i8042_wait_write functions wait for the i8042 to
225  * be ready for reading values from it / writing values to it.
226  * Called always with i8042_lock held.
227  */
228 
229 static int i8042_wait_read(void)
230 {
231 	int i = 0;
232 
233 	while ((~i8042_read_status() & I8042_STR_OBF) && (i < I8042_CTL_TIMEOUT)) {
234 		udelay(50);
235 		i++;
236 	}
237 	return -(i == I8042_CTL_TIMEOUT);
238 }
239 
240 static int i8042_wait_write(void)
241 {
242 	int i = 0;
243 
244 	while ((i8042_read_status() & I8042_STR_IBF) && (i < I8042_CTL_TIMEOUT)) {
245 		udelay(50);
246 		i++;
247 	}
248 	return -(i == I8042_CTL_TIMEOUT);
249 }
250 
251 /*
252  * i8042_flush() flushes all data that may be in the keyboard and mouse buffers
253  * of the i8042 down the toilet.
254  */
255 
256 static int i8042_flush(void)
257 {
258 	unsigned char data, str;
259 	int count = 0;
260 
261 	guard(spinlock_irqsave)(&i8042_lock);
262 
263 	while ((str = i8042_read_status()) & I8042_STR_OBF) {
264 		if (count++ >= I8042_BUFFER_SIZE)
265 			return -EIO;
266 
267 		udelay(50);
268 		data = i8042_read_data();
269 		dbg("%02x <- i8042 (flush, %s)\n",
270 		    data, str & I8042_STR_AUXDATA ? "aux" : "kbd");
271 	}
272 
273 	return 0;
274 }
275 
276 /*
277  * i8042_command() executes a command on the i8042. It also sends the input
278  * parameter(s) of the commands to it, and receives the output value(s). The
279  * parameters are to be stored in the param array, and the output is placed
280  * into the same array. The number of the parameters and output values is
281  * encoded in bits 8-11 of the command number.
282  */
283 
284 static int __i8042_command(unsigned char *param, int command)
285 {
286 	int i, error;
287 
288 	if (i8042_noloop && command == I8042_CMD_AUX_LOOP)
289 		return -1;
290 
291 	error = i8042_wait_write();
292 	if (error)
293 		return error;
294 
295 	dbg("%02x -> i8042 (command)\n", command & 0xff);
296 	i8042_write_command(command & 0xff);
297 
298 	for (i = 0; i < ((command >> 12) & 0xf); i++) {
299 		error = i8042_wait_write();
300 		if (error) {
301 			dbg("     -- i8042 (wait write timeout)\n");
302 			return error;
303 		}
304 		dbg("%02x -> i8042 (parameter)\n", param[i]);
305 		i8042_write_data(param[i]);
306 	}
307 
308 	for (i = 0; i < ((command >> 8) & 0xf); i++) {
309 		error = i8042_wait_read();
310 		if (error) {
311 			dbg("     -- i8042 (wait read timeout)\n");
312 			return error;
313 		}
314 
315 		if (command == I8042_CMD_AUX_LOOP &&
316 		    !(i8042_read_status() & I8042_STR_AUXDATA)) {
317 			dbg("     -- i8042 (auxerr)\n");
318 			return -1;
319 		}
320 
321 		param[i] = i8042_read_data();
322 		dbg("%02x <- i8042 (return)\n", param[i]);
323 	}
324 
325 	return 0;
326 }
327 
328 int i8042_command(unsigned char *param, int command)
329 {
330 	if (!i8042_present)
331 		return -1;
332 
333 	guard(spinlock_irqsave)(&i8042_lock);
334 
335 	return __i8042_command(param, command);
336 }
337 EXPORT_SYMBOL(i8042_command);
338 
339 /*
340  * i8042_kbd_write() sends a byte out through the keyboard interface.
341  */
342 
343 static int i8042_kbd_write(struct serio *port, unsigned char c)
344 {
345 	int error;
346 
347 	guard(spinlock_irqsave)(&i8042_lock);
348 
349 	error = i8042_wait_write();
350 	if (error)
351 		return error;
352 
353 	dbg("%02x -> i8042 (kbd-data)\n", c);
354 	i8042_write_data(c);
355 
356 	return 0;
357 }
358 
359 /*
360  * i8042_aux_write() sends a byte out through the aux interface.
361  */
362 
363 static int i8042_aux_write(struct serio *serio, unsigned char c)
364 {
365 	struct i8042_port *port = serio->port_data;
366 
367 	return i8042_command(&c, port->mux == -1 ?
368 					I8042_CMD_AUX_SEND :
369 					I8042_CMD_MUX_SEND + port->mux);
370 }
371 
372 
373 /*
374  * i8042_port_close attempts to clear AUX or KBD port state by disabling
375  * and then re-enabling it.
376  */
377 
378 static void i8042_port_close(struct serio *serio)
379 {
380 	int irq_bit;
381 	int disable_bit;
382 	const char *port_name;
383 
384 	if (serio == i8042_ports[I8042_AUX_PORT_NO].serio) {
385 		irq_bit = I8042_CTR_AUXINT;
386 		disable_bit = I8042_CTR_AUXDIS;
387 		port_name = "AUX";
388 	} else {
389 		irq_bit = I8042_CTR_KBDINT;
390 		disable_bit = I8042_CTR_KBDDIS;
391 		port_name = "KBD";
392 	}
393 
394 	i8042_ctr &= ~irq_bit;
395 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR))
396 		pr_warn("Can't write CTR while closing %s port\n", port_name);
397 
398 	udelay(50);
399 
400 	i8042_ctr &= ~disable_bit;
401 	i8042_ctr |= irq_bit;
402 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR))
403 		pr_err("Can't reactivate %s port\n", port_name);
404 
405 	/*
406 	 * See if there is any data appeared while we were messing with
407 	 * port state.
408 	 */
409 	i8042_handle_data(0);
410 }
411 
412 /*
413  * i8042_start() is called by serio core when port is about to finish
414  * registering. It will mark port as existing so i8042_interrupt can
415  * start sending data through it.
416  */
417 static int i8042_start(struct serio *serio)
418 {
419 	struct i8042_port *port = serio->port_data;
420 
421 	device_set_wakeup_capable(&serio->dev, true);
422 
423 	/*
424 	 * On platforms using suspend-to-idle, allow the keyboard to
425 	 * wake up the system from sleep by enabling keyboard wakeups
426 	 * by default.  This is consistent with keyboard wakeup
427 	 * behavior on many platforms using suspend-to-RAM (ACPI S3)
428 	 * by default.
429 	 */
430 	if (pm_suspend_default_s2idle() &&
431 	    serio == i8042_ports[I8042_KBD_PORT_NO].serio) {
432 		device_set_wakeup_enable(&serio->dev, true);
433 	}
434 
435 	guard(spinlock_irq)(&i8042_lock);
436 	port->exists = true;
437 
438 	return 0;
439 }
440 
441 /*
442  * i8042_stop() marks serio port as non-existing so i8042_interrupt
443  * will not try to send data to the port that is about to go away.
444  * The function is called by serio core as part of unregister procedure.
445  */
446 static void i8042_stop(struct serio *serio)
447 {
448 	struct i8042_port *port = serio->port_data;
449 
450 	scoped_guard(spinlock_irq, &i8042_lock) {
451 		port->exists = false;
452 		port->serio = NULL;
453 	}
454 
455 	/*
456 	 * We need to make sure that interrupt handler finishes using
457 	 * our serio port before we return from this function.
458 	 * We synchronize with both AUX and KBD IRQs because there is
459 	 * a (very unlikely) chance that AUX IRQ is raised for KBD port
460 	 * and vice versa.
461 	 */
462 	synchronize_irq(I8042_AUX_IRQ);
463 	synchronize_irq(I8042_KBD_IRQ);
464 }
465 
466 /*
467  * i8042_filter() filters out unwanted bytes from the input data stream.
468  * It is called from i8042_interrupt and thus is running with interrupts
469  * off and i8042_lock held.
470  */
471 static bool i8042_filter(unsigned char data, unsigned char str,
472 			 struct serio *serio)
473 {
474 	if (unlikely(i8042_suppress_kbd_ack)) {
475 		if ((~str & I8042_STR_AUXDATA) &&
476 		    (data == 0xfa || data == 0xfe)) {
477 			i8042_suppress_kbd_ack--;
478 			dbg("Extra keyboard ACK - filtered out\n");
479 			return true;
480 		}
481 	}
482 
483 	if (i8042_platform_filter && i8042_platform_filter(data, str, serio)) {
484 		dbg("Filtered out by platform filter\n");
485 		return true;
486 	}
487 
488 	return false;
489 }
490 
491 /*
492  * i8042_handle_mux() handles case when data is coming from one of
493  * the multiplexed ports. It would be simple if not for quirks with
494  * handling errors:
495  *
496  * When MUXERR condition is signalled the data register can only contain
497  * 0xfd, 0xfe or 0xff if implementation follows the spec. Unfortunately
498  * it is not always the case. Some KBCs also report 0xfc when there is
499  * nothing connected to the port while others sometimes get confused which
500  * port the data came from and signal error leaving the data intact. They
501  * _do not_ revert to legacy mode (actually I've never seen KBC reverting
502  * to legacy mode yet, when we see one we'll add proper handling).
503  * Anyway, we process 0xfc, 0xfd, 0xfe and 0xff as timeouts, and for the
504  * rest assume that the data came from the same serio last byte
505  * was transmitted (if transmission happened not too long ago).
506  */
507 static int i8042_handle_mux(u8 str, u8 *data, unsigned int *dfl)
508 {
509 	static unsigned long last_transmit;
510 	static unsigned long last_port;
511 	unsigned int mux_port;
512 
513 	mux_port = (str >> 6) & 3;
514 	*dfl = 0;
515 
516 	if (str & I8042_STR_MUXERR) {
517 		dbg("MUX error, status is %02x, data is %02x\n",
518 		    str, *data);
519 
520 		switch (*data) {
521 		default:
522 			if (time_before(jiffies, last_transmit + HZ/10)) {
523 				mux_port = last_port;
524 				break;
525 			}
526 			fallthrough;	/* report timeout */
527 		case 0xfc:
528 		case 0xfd:
529 		case 0xfe:
530 			*dfl = SERIO_TIMEOUT;
531 			*data = 0xfe;
532 			break;
533 		case 0xff:
534 			*dfl = SERIO_PARITY;
535 			*data = 0xfe;
536 			break;
537 		}
538 	}
539 
540 	last_port = mux_port;
541 	last_transmit = jiffies;
542 
543 	return I8042_MUX_PORT_NO + mux_port;
544 }
545 
546 /*
547  * i8042_handle_data() is the most important function in this driver -
548  * it reads the data from the i8042, determines its destination serio
549  * port, and sends received byte to the upper layers.
550  *
551  * Returns true if there was data waiting, false otherwise.
552  */
553 static bool i8042_handle_data(int irq)
554 {
555 	struct i8042_port *port;
556 	struct serio *serio;
557 	unsigned char str, data;
558 	unsigned int dfl;
559 	unsigned int port_no;
560 	bool filtered;
561 
562 	scoped_guard(spinlock_irqsave, &i8042_lock) {
563 		str = i8042_read_status();
564 		if (unlikely(~str & I8042_STR_OBF))
565 			return false;
566 
567 		data = i8042_read_data();
568 
569 		if (i8042_mux_present && (str & I8042_STR_AUXDATA)) {
570 			port_no = i8042_handle_mux(str, &data, &dfl);
571 		} else {
572 
573 			dfl = (str & I8042_STR_PARITY) ? SERIO_PARITY : 0;
574 			if ((str & I8042_STR_TIMEOUT) && !i8042_notimeout)
575 				dfl |= SERIO_TIMEOUT;
576 
577 			port_no = (str & I8042_STR_AUXDATA) ?
578 					I8042_AUX_PORT_NO : I8042_KBD_PORT_NO;
579 		}
580 
581 		port = &i8042_ports[port_no];
582 		serio = port->exists ? port->serio : NULL;
583 
584 		filter_dbg(port->driver_bound,
585 			   data, "<- i8042 (interrupt, %d, %d%s%s)\n",
586 			   port_no, irq,
587 			   dfl & SERIO_PARITY ? ", bad parity" : "",
588 			   dfl & SERIO_TIMEOUT ? ", timeout" : "");
589 
590 		filtered = i8042_filter(data, str, serio);
591 	}
592 
593 	if (likely(serio && !filtered))
594 		serio_interrupt(serio, data, dfl);
595 
596 	return true;
597 }
598 
599 static irqreturn_t i8042_interrupt(int irq, void *dev_id)
600 {
601 	if (unlikely(!i8042_handle_data(irq))) {
602 		dbg("Interrupt %d, without any data\n", irq);
603 		return IRQ_NONE;
604 	}
605 
606 	return IRQ_HANDLED;
607 }
608 
609 /*
610  * i8042_enable_kbd_port enables keyboard port on chip
611  */
612 
613 static int i8042_enable_kbd_port(void)
614 {
615 	i8042_ctr &= ~I8042_CTR_KBDDIS;
616 	i8042_ctr |= I8042_CTR_KBDINT;
617 
618 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
619 		i8042_ctr &= ~I8042_CTR_KBDINT;
620 		i8042_ctr |= I8042_CTR_KBDDIS;
621 		pr_err("Failed to enable KBD port\n");
622 		return -EIO;
623 	}
624 
625 	return 0;
626 }
627 
628 /*
629  * i8042_enable_aux_port enables AUX (mouse) port on chip
630  */
631 
632 static int i8042_enable_aux_port(void)
633 {
634 	i8042_ctr &= ~I8042_CTR_AUXDIS;
635 	i8042_ctr |= I8042_CTR_AUXINT;
636 
637 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
638 		i8042_ctr &= ~I8042_CTR_AUXINT;
639 		i8042_ctr |= I8042_CTR_AUXDIS;
640 		pr_err("Failed to enable AUX port\n");
641 		return -EIO;
642 	}
643 
644 	return 0;
645 }
646 
647 /*
648  * i8042_enable_mux_ports enables 4 individual AUX ports after
649  * the controller has been switched into Multiplexed mode
650  */
651 
652 static int i8042_enable_mux_ports(void)
653 {
654 	unsigned char param;
655 	int i;
656 
657 	for (i = 0; i < I8042_NUM_MUX_PORTS; i++) {
658 		i8042_command(&param, I8042_CMD_MUX_PFX + i);
659 		i8042_command(&param, I8042_CMD_AUX_ENABLE);
660 	}
661 
662 	return i8042_enable_aux_port();
663 }
664 
665 /*
666  * i8042_set_mux_mode checks whether the controller has an
667  * active multiplexor and puts the chip into Multiplexed (true)
668  * or Legacy (false) mode.
669  */
670 
671 static int i8042_set_mux_mode(bool multiplex, unsigned char *mux_version)
672 {
673 
674 	unsigned char param, val;
675 /*
676  * Get rid of bytes in the queue.
677  */
678 
679 	i8042_flush();
680 
681 /*
682  * Internal loopback test - send three bytes, they should come back from the
683  * mouse interface, the last should be version.
684  */
685 
686 	param = val = 0xf0;
687 	if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param != val)
688 		return -1;
689 	param = val = multiplex ? 0x56 : 0xf6;
690 	if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param != val)
691 		return -1;
692 	param = val = multiplex ? 0xa4 : 0xa5;
693 	if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param == val)
694 		return -1;
695 
696 /*
697  * Workaround for interference with USB Legacy emulation
698  * that causes a v10.12 MUX to be found.
699  */
700 	if (param == 0xac)
701 		return -1;
702 
703 	if (mux_version)
704 		*mux_version = param;
705 
706 	return 0;
707 }
708 
709 /*
710  * i8042_check_mux() checks whether the controller supports the PS/2 Active
711  * Multiplexing specification by Synaptics, Phoenix, Insyde and
712  * LCS/Telegraphics.
713  */
714 
715 static int i8042_check_mux(void)
716 {
717 	unsigned char mux_version;
718 
719 	if (i8042_set_mux_mode(true, &mux_version))
720 		return -1;
721 
722 	pr_info("Detected active multiplexing controller, rev %d.%d\n",
723 		(mux_version >> 4) & 0xf, mux_version & 0xf);
724 
725 /*
726  * Disable all muxed ports by disabling AUX.
727  */
728 	i8042_ctr |= I8042_CTR_AUXDIS;
729 	i8042_ctr &= ~I8042_CTR_AUXINT;
730 
731 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
732 		pr_err("Failed to disable AUX port, can't use MUX\n");
733 		return -EIO;
734 	}
735 
736 	i8042_mux_present = true;
737 
738 	return 0;
739 }
740 
741 /*
742  * The following is used to test AUX IRQ delivery.
743  */
744 static struct completion i8042_aux_irq_delivered;
745 static bool i8042_irq_being_tested;
746 
747 static irqreturn_t i8042_aux_test_irq(int irq, void *dev_id)
748 {
749 	unsigned char str, data;
750 
751 	guard(spinlock_irqsave)(&i8042_lock);
752 
753 	str = i8042_read_status();
754 	if (!(str & I8042_STR_OBF))
755 		return IRQ_NONE;
756 
757 	data = i8042_read_data();
758 	dbg("%02x <- i8042 (aux_test_irq, %s)\n",
759 	    data, str & I8042_STR_AUXDATA ? "aux" : "kbd");
760 
761 	if (i8042_irq_being_tested && data == 0xa5 && (str & I8042_STR_AUXDATA))
762 		complete(&i8042_aux_irq_delivered);
763 
764 	return IRQ_HANDLED;
765 }
766 
767 /*
768  * i8042_toggle_aux - enables or disables AUX port on i8042 via command and
769  * verifies success by readinng CTR. Used when testing for presence of AUX
770  * port.
771  */
772 static int i8042_toggle_aux(bool on)
773 {
774 	unsigned char param;
775 	int i;
776 
777 	if (i8042_command(&param,
778 			on ? I8042_CMD_AUX_ENABLE : I8042_CMD_AUX_DISABLE))
779 		return -1;
780 
781 	/* some chips need some time to set the I8042_CTR_AUXDIS bit */
782 	for (i = 0; i < 100; i++) {
783 		udelay(50);
784 
785 		if (i8042_command(&param, I8042_CMD_CTL_RCTR))
786 			return -1;
787 
788 		if (!(param & I8042_CTR_AUXDIS) == on)
789 			return 0;
790 	}
791 
792 	return -1;
793 }
794 
795 /*
796  * i8042_check_aux() applies as much paranoia as it can at detecting
797  * the presence of an AUX interface.
798  */
799 
800 static int i8042_check_aux(void)
801 {
802 	int retval = -1;
803 	bool irq_registered = false;
804 	bool aux_loop_broken = false;
805 	unsigned char param;
806 
807 /*
808  * Get rid of bytes in the queue.
809  */
810 
811 	i8042_flush();
812 
813 /*
814  * Internal loopback test - filters out AT-type i8042's. Unfortunately
815  * SiS screwed up and their 5597 doesn't support the LOOP command even
816  * though it has an AUX port.
817  */
818 
819 	param = 0x5a;
820 	retval = i8042_command(&param, I8042_CMD_AUX_LOOP);
821 	if (retval || param != 0x5a) {
822 
823 /*
824  * External connection test - filters out AT-soldered PS/2 i8042's
825  * 0x00 - no error, 0x01-0x03 - clock/data stuck, 0xff - general error
826  * 0xfa - no error on some notebooks which ignore the spec
827  * Because it's common for chipsets to return error on perfectly functioning
828  * AUX ports, we test for this only when the LOOP command failed.
829  */
830 
831 		if (i8042_command(&param, I8042_CMD_AUX_TEST) ||
832 		    (param && param != 0xfa && param != 0xff))
833 			return -1;
834 
835 /*
836  * If AUX_LOOP completed without error but returned unexpected data
837  * mark it as broken
838  */
839 		if (!retval)
840 			aux_loop_broken = true;
841 	}
842 
843 /*
844  * Bit assignment test - filters out PS/2 i8042's in AT mode
845  */
846 
847 	if (i8042_toggle_aux(false)) {
848 		pr_warn("Failed to disable AUX port, but continuing anyway... Is this a SiS?\n");
849 		pr_warn("If AUX port is really absent please use the 'i8042.noaux' option\n");
850 	}
851 
852 	if (i8042_toggle_aux(true))
853 		return -1;
854 
855 /*
856  * Reset keyboard (needed on some laptops to successfully detect
857  * touchpad, e.g., some Gigabyte laptop models with Elantech
858  * touchpads).
859  */
860 	if (i8042_kbdreset) {
861 		pr_warn("Attempting to reset device connected to KBD port\n");
862 		i8042_kbd_write(NULL, (unsigned char) 0xff);
863 	}
864 
865 /*
866  * Test AUX IRQ delivery to make sure BIOS did not grab the IRQ and
867  * used it for a PCI card or somethig else.
868  */
869 
870 	if (i8042_noloop || i8042_bypass_aux_irq_test || aux_loop_broken) {
871 /*
872  * Without LOOP command we can't test AUX IRQ delivery. Assume the port
873  * is working and hope we are right.
874  */
875 		retval = 0;
876 		goto out;
877 	}
878 
879 	if (request_irq(I8042_AUX_IRQ, i8042_aux_test_irq, IRQF_SHARED,
880 			"i8042", i8042_platform_device))
881 		goto out;
882 
883 	irq_registered = true;
884 
885 	if (i8042_enable_aux_port())
886 		goto out;
887 
888 	scoped_guard(spinlock_irqsave, &i8042_lock) {
889 		init_completion(&i8042_aux_irq_delivered);
890 		i8042_irq_being_tested = true;
891 
892 		param = 0xa5;
893 		retval = __i8042_command(&param, I8042_CMD_AUX_LOOP & 0xf0ff);
894 		if (retval)
895 			goto out;
896 	}
897 
898 	if (wait_for_completion_timeout(&i8042_aux_irq_delivered,
899 					msecs_to_jiffies(250)) == 0) {
900 /*
901  * AUX IRQ was never delivered so we need to flush the controller to
902  * get rid of the byte we put there; otherwise keyboard may not work.
903  */
904 		dbg("     -- i8042 (aux irq test timeout)\n");
905 		i8042_flush();
906 		retval = -1;
907 	}
908 
909  out:
910 
911 /*
912  * Disable the interface.
913  */
914 
915 	i8042_ctr |= I8042_CTR_AUXDIS;
916 	i8042_ctr &= ~I8042_CTR_AUXINT;
917 
918 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR))
919 		retval = -1;
920 
921 	if (irq_registered)
922 		free_irq(I8042_AUX_IRQ, i8042_platform_device);
923 
924 	return retval;
925 }
926 
927 static int i8042_controller_check(void)
928 {
929 	if (i8042_flush()) {
930 		pr_info("No controller found\n");
931 		return -ENODEV;
932 	}
933 
934 	return 0;
935 }
936 
937 static int i8042_controller_selftest(void)
938 {
939 	unsigned char param;
940 	int i = 0;
941 
942 	/*
943 	 * We try this 5 times; on some really fragile systems this does not
944 	 * take the first time...
945 	 */
946 	do {
947 
948 		if (i8042_command(&param, I8042_CMD_CTL_TEST)) {
949 			pr_err("i8042 controller selftest timeout\n");
950 			return -ENODEV;
951 		}
952 
953 		if (param == I8042_RET_CTL_TEST)
954 			return 0;
955 
956 		dbg("i8042 controller selftest: %#x != %#x\n",
957 		    param, I8042_RET_CTL_TEST);
958 		msleep(50);
959 	} while (i++ < 5);
960 
961 #ifdef CONFIG_X86
962 	/*
963 	 * On x86, we don't fail entire i8042 initialization if controller
964 	 * reset fails in hopes that keyboard port will still be functional
965 	 * and user will still get a working keyboard. This is especially
966 	 * important on netbooks. On other arches we trust hardware more.
967 	 */
968 	pr_info("giving up on controller selftest, continuing anyway...\n");
969 	return 0;
970 #else
971 	pr_err("i8042 controller selftest failed\n");
972 	return -EIO;
973 #endif
974 }
975 
976 /*
977  * i8042_controller_init initializes the i8042 controller, and,
978  * most importantly, sets it into non-xlated mode if that's
979  * desired.
980  */
981 
982 static int i8042_controller_init(void)
983 {
984 	int n = 0;
985 	unsigned char ctr[2];
986 
987 /*
988  * Save the CTR for restore on unload / reboot.
989  */
990 
991 	do {
992 		if (n >= 10) {
993 			pr_err("Unable to get stable CTR read\n");
994 			return -EIO;
995 		}
996 
997 		if (n != 0)
998 			udelay(50);
999 
1000 		if (i8042_command(&ctr[n++ % 2], I8042_CMD_CTL_RCTR)) {
1001 			pr_err("Can't read CTR while initializing i8042\n");
1002 			return i8042_probe_defer ? -EPROBE_DEFER : -EIO;
1003 		}
1004 
1005 	} while (n < 2 || ctr[0] != ctr[1]);
1006 
1007 	i8042_initial_ctr = i8042_ctr = ctr[0];
1008 
1009 /*
1010  * Disable the keyboard interface and interrupt.
1011  */
1012 
1013 	i8042_ctr |= I8042_CTR_KBDDIS;
1014 	i8042_ctr &= ~I8042_CTR_KBDINT;
1015 
1016 /*
1017  * Handle keylock.
1018  */
1019 
1020 	scoped_guard(spinlock_irqsave, &i8042_lock) {
1021 		if (~i8042_read_status() & I8042_STR_KEYLOCK) {
1022 			if (i8042_unlock)
1023 				i8042_ctr |= I8042_CTR_IGNKEYLOCK;
1024 			else
1025 				pr_warn("Warning: Keylock active\n");
1026 		}
1027 	}
1028 
1029 /*
1030  * If the chip is configured into nontranslated mode by the BIOS, don't
1031  * bother enabling translating and be happy.
1032  */
1033 
1034 	if (~i8042_ctr & I8042_CTR_XLATE)
1035 		i8042_direct = true;
1036 
1037 /*
1038  * Set nontranslated mode for the kbd interface if requested by an option.
1039  * After this the kbd interface becomes a simple serial in/out, like the aux
1040  * interface is. We don't do this by default, since it can confuse notebook
1041  * BIOSes.
1042  */
1043 
1044 	if (i8042_direct)
1045 		i8042_ctr &= ~I8042_CTR_XLATE;
1046 
1047 /*
1048  * Write CTR back.
1049  */
1050 
1051 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
1052 		pr_err("Can't write CTR while initializing i8042\n");
1053 		return -EIO;
1054 	}
1055 
1056 /*
1057  * Flush whatever accumulated while we were disabling keyboard port.
1058  */
1059 
1060 	i8042_flush();
1061 
1062 	return 0;
1063 }
1064 
1065 
1066 /*
1067  * Reset the controller and reset CRT to the original value set by BIOS.
1068  */
1069 
1070 static void i8042_controller_reset(bool s2r_wants_reset)
1071 {
1072 	i8042_flush();
1073 
1074 /*
1075  * Disable both KBD and AUX interfaces so they don't get in the way
1076  */
1077 
1078 	i8042_ctr |= I8042_CTR_KBDDIS | I8042_CTR_AUXDIS;
1079 	i8042_ctr &= ~(I8042_CTR_KBDINT | I8042_CTR_AUXINT);
1080 
1081 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR))
1082 		pr_warn("Can't write CTR while resetting\n");
1083 
1084 /*
1085  * Disable MUX mode if present.
1086  */
1087 
1088 	if (i8042_mux_present)
1089 		i8042_set_mux_mode(false, NULL);
1090 
1091 /*
1092  * Reset the controller if requested.
1093  */
1094 
1095 	if (i8042_reset == I8042_RESET_ALWAYS ||
1096 	    (i8042_reset == I8042_RESET_ON_S2RAM && s2r_wants_reset)) {
1097 		i8042_controller_selftest();
1098 	}
1099 
1100 /*
1101  * Restore the original control register setting.
1102  */
1103 
1104 	if (i8042_command(&i8042_initial_ctr, I8042_CMD_CTL_WCTR))
1105 		pr_warn("Can't restore CTR\n");
1106 }
1107 
1108 
1109 /*
1110  * i8042_panic_blink() will turn the keyboard LEDs on or off and is called
1111  * when kernel panics. Flashing LEDs is useful for users running X who may
1112  * not see the console and will help distinguishing panics from "real"
1113  * lockups.
1114  *
1115  * Note that DELAY has a limit of 10ms so we will not get stuck here
1116  * waiting for KBC to free up even if KBD interrupt is off
1117  */
1118 
1119 #define DELAY do { mdelay(1); if (++delay > 10) return delay; } while(0)
1120 
1121 static long i8042_panic_blink(int state)
1122 {
1123 	long delay = 0;
1124 	char led;
1125 
1126 	led = (state) ? 0x01 | 0x04 : 0;
1127 	while (i8042_read_status() & I8042_STR_IBF)
1128 		DELAY;
1129 	dbg("%02x -> i8042 (panic blink)\n", 0xed);
1130 	i8042_suppress_kbd_ack = 2;
1131 	i8042_write_data(0xed); /* set leds */
1132 	DELAY;
1133 	while (i8042_read_status() & I8042_STR_IBF)
1134 		DELAY;
1135 	DELAY;
1136 	dbg("%02x -> i8042 (panic blink)\n", led);
1137 	i8042_write_data(led);
1138 	DELAY;
1139 	return delay;
1140 }
1141 
1142 #undef DELAY
1143 
1144 #ifdef CONFIG_X86
1145 static void i8042_dritek_enable(void)
1146 {
1147 	unsigned char param = 0x90;
1148 	int error;
1149 
1150 	error = i8042_command(&param, 0x1059);
1151 	if (error)
1152 		pr_warn("Failed to enable DRITEK extension: %d\n", error);
1153 }
1154 #endif
1155 
1156 #ifdef CONFIG_PM
1157 
1158 /*
1159  * Here we try to reset everything back to a state we had
1160  * before suspending.
1161  */
1162 
1163 static int i8042_controller_resume(bool s2r_wants_reset)
1164 {
1165 	int error;
1166 
1167 	error = i8042_controller_check();
1168 	if (error)
1169 		return error;
1170 
1171 	if (i8042_reset == I8042_RESET_ALWAYS ||
1172 	    (i8042_reset == I8042_RESET_ON_S2RAM && s2r_wants_reset)) {
1173 		error = i8042_controller_selftest();
1174 		if (error)
1175 			return error;
1176 	}
1177 
1178 /*
1179  * Restore original CTR value and disable all ports
1180  */
1181 
1182 	i8042_ctr = i8042_initial_ctr;
1183 	if (i8042_direct)
1184 		i8042_ctr &= ~I8042_CTR_XLATE;
1185 	i8042_ctr |= I8042_CTR_AUXDIS | I8042_CTR_KBDDIS;
1186 	i8042_ctr &= ~(I8042_CTR_AUXINT | I8042_CTR_KBDINT);
1187 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
1188 		pr_warn("Can't write CTR to resume, retrying...\n");
1189 		msleep(50);
1190 		if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
1191 			pr_err("CTR write retry failed\n");
1192 			return -EIO;
1193 		}
1194 	}
1195 
1196 
1197 #ifdef CONFIG_X86
1198 	if (i8042_dritek)
1199 		i8042_dritek_enable();
1200 #endif
1201 
1202 	if (i8042_mux_present) {
1203 		if (i8042_set_mux_mode(true, NULL) || i8042_enable_mux_ports())
1204 			pr_warn("failed to resume active multiplexor, mouse won't work\n");
1205 	} else if (i8042_ports[I8042_AUX_PORT_NO].serio) {
1206 		i8042_enable_aux_port();
1207 	}
1208 
1209 	if (i8042_ports[I8042_KBD_PORT_NO].serio)
1210 		i8042_enable_kbd_port();
1211 
1212 	i8042_handle_data(0);
1213 
1214 	return 0;
1215 }
1216 
1217 /*
1218  * Here we try to restore the original BIOS settings to avoid
1219  * upsetting it.
1220  */
1221 
1222 static int i8042_pm_suspend(struct device *dev)
1223 {
1224 	int i;
1225 
1226 	if (!i8042_forcenorestore && pm_suspend_via_firmware())
1227 		i8042_controller_reset(true);
1228 
1229 	/* Set up serio interrupts for system wakeup. */
1230 	for (i = 0; i < I8042_NUM_PORTS; i++) {
1231 		struct serio *serio = i8042_ports[i].serio;
1232 
1233 		if (serio && device_may_wakeup(&serio->dev))
1234 			enable_irq_wake(i8042_ports[i].irq);
1235 	}
1236 
1237 	return 0;
1238 }
1239 
1240 static int i8042_pm_resume_noirq(struct device *dev)
1241 {
1242 	if (i8042_forcenorestore || !pm_resume_via_firmware())
1243 		i8042_handle_data(0);
1244 
1245 	return 0;
1246 }
1247 
1248 static int i8042_pm_resume(struct device *dev)
1249 {
1250 	bool want_reset;
1251 	int i;
1252 
1253 	for (i = 0; i < I8042_NUM_PORTS; i++) {
1254 		struct serio *serio = i8042_ports[i].serio;
1255 
1256 		if (serio && device_may_wakeup(&serio->dev))
1257 			disable_irq_wake(i8042_ports[i].irq);
1258 	}
1259 
1260 	/*
1261 	 * If platform firmware was not going to be involved in suspend, we did
1262 	 * not restore the controller state to whatever it had been at boot
1263 	 * time, so we do not need to do anything.
1264 	 */
1265 	if (i8042_forcenorestore || !pm_suspend_via_firmware())
1266 		return 0;
1267 
1268 	/*
1269 	 * We only need to reset the controller if we are resuming after handing
1270 	 * off control to the platform firmware, otherwise we can simply restore
1271 	 * the mode.
1272 	 */
1273 	want_reset = pm_resume_via_firmware();
1274 
1275 	return i8042_controller_resume(want_reset);
1276 }
1277 
1278 static int i8042_pm_thaw(struct device *dev)
1279 {
1280 	i8042_handle_data(0);
1281 
1282 	return 0;
1283 }
1284 
1285 static int i8042_pm_reset(struct device *dev)
1286 {
1287 	i8042_controller_reset(false);
1288 
1289 	return 0;
1290 }
1291 
1292 static int i8042_pm_restore(struct device *dev)
1293 {
1294 	return i8042_controller_resume(false);
1295 }
1296 
1297 static const struct dev_pm_ops i8042_pm_ops = {
1298 	.suspend	= i8042_pm_suspend,
1299 	.resume_noirq	= i8042_pm_resume_noirq,
1300 	.resume		= i8042_pm_resume,
1301 	.thaw		= i8042_pm_thaw,
1302 	.poweroff	= i8042_pm_reset,
1303 	.restore	= i8042_pm_restore,
1304 };
1305 
1306 #endif /* CONFIG_PM */
1307 
1308 /*
1309  * We need to reset the 8042 back to original mode on system shutdown,
1310  * because otherwise BIOSes will be confused.
1311  */
1312 
1313 static void i8042_shutdown(struct platform_device *dev)
1314 {
1315 	i8042_controller_reset(false);
1316 }
1317 
1318 static int i8042_create_kbd_port(void)
1319 {
1320 	struct serio *serio;
1321 	struct i8042_port *port = &i8042_ports[I8042_KBD_PORT_NO];
1322 
1323 	serio = kzalloc(sizeof(*serio), GFP_KERNEL);
1324 	if (!serio)
1325 		return -ENOMEM;
1326 
1327 	serio->id.type		= i8042_direct ? SERIO_8042 : SERIO_8042_XL;
1328 	serio->write		= i8042_dumbkbd ? NULL : i8042_kbd_write;
1329 	serio->start		= i8042_start;
1330 	serio->stop		= i8042_stop;
1331 	serio->close		= i8042_port_close;
1332 	serio->ps2_cmd_mutex	= &i8042_mutex;
1333 	serio->port_data	= port;
1334 	serio->dev.parent	= &i8042_platform_device->dev;
1335 	strscpy(serio->name, "i8042 KBD port", sizeof(serio->name));
1336 	strscpy(serio->phys, I8042_KBD_PHYS_DESC, sizeof(serio->phys));
1337 	strscpy(serio->firmware_id, i8042_kbd_firmware_id,
1338 		sizeof(serio->firmware_id));
1339 	set_primary_fwnode(&serio->dev, i8042_kbd_fwnode);
1340 
1341 	port->serio = serio;
1342 	port->irq = I8042_KBD_IRQ;
1343 
1344 	return 0;
1345 }
1346 
1347 static int i8042_create_aux_port(int idx)
1348 {
1349 	struct serio *serio;
1350 	int port_no = idx < 0 ? I8042_AUX_PORT_NO : I8042_MUX_PORT_NO + idx;
1351 	struct i8042_port *port = &i8042_ports[port_no];
1352 
1353 	serio = kzalloc(sizeof(*serio), GFP_KERNEL);
1354 	if (!serio)
1355 		return -ENOMEM;
1356 
1357 	serio->id.type		= SERIO_8042;
1358 	serio->write		= i8042_aux_write;
1359 	serio->start		= i8042_start;
1360 	serio->stop		= i8042_stop;
1361 	serio->ps2_cmd_mutex	= &i8042_mutex;
1362 	serio->port_data	= port;
1363 	serio->dev.parent	= &i8042_platform_device->dev;
1364 	if (idx < 0) {
1365 		strscpy(serio->name, "i8042 AUX port", sizeof(serio->name));
1366 		strscpy(serio->phys, I8042_AUX_PHYS_DESC, sizeof(serio->phys));
1367 		strscpy(serio->firmware_id, i8042_aux_firmware_id,
1368 			sizeof(serio->firmware_id));
1369 		serio->close = i8042_port_close;
1370 	} else {
1371 		snprintf(serio->name, sizeof(serio->name), "i8042 AUX%d port", idx);
1372 		snprintf(serio->phys, sizeof(serio->phys), I8042_MUX_PHYS_DESC, idx + 1);
1373 		strscpy(serio->firmware_id, i8042_aux_firmware_id,
1374 			sizeof(serio->firmware_id));
1375 	}
1376 
1377 	port->serio = serio;
1378 	port->mux = idx;
1379 	port->irq = I8042_AUX_IRQ;
1380 
1381 	return 0;
1382 }
1383 
1384 static void i8042_free_kbd_port(void)
1385 {
1386 	kfree(i8042_ports[I8042_KBD_PORT_NO].serio);
1387 	i8042_ports[I8042_KBD_PORT_NO].serio = NULL;
1388 }
1389 
1390 static void i8042_free_aux_ports(void)
1391 {
1392 	int i;
1393 
1394 	for (i = I8042_AUX_PORT_NO; i < I8042_NUM_PORTS; i++) {
1395 		kfree(i8042_ports[i].serio);
1396 		i8042_ports[i].serio = NULL;
1397 	}
1398 }
1399 
1400 static void i8042_register_ports(void)
1401 {
1402 	int i;
1403 
1404 	for (i = 0; i < I8042_NUM_PORTS; i++) {
1405 		struct serio *serio = i8042_ports[i].serio;
1406 
1407 		if (!serio)
1408 			continue;
1409 
1410 		printk(KERN_INFO "serio: %s at %#lx,%#lx irq %d\n",
1411 			serio->name,
1412 			(unsigned long) I8042_DATA_REG,
1413 			(unsigned long) I8042_COMMAND_REG,
1414 			i8042_ports[i].irq);
1415 		serio_register_port(serio);
1416 	}
1417 }
1418 
1419 static void i8042_unregister_ports(void)
1420 {
1421 	int i;
1422 
1423 	for (i = 0; i < I8042_NUM_PORTS; i++) {
1424 		if (i8042_ports[i].serio) {
1425 			serio_unregister_port(i8042_ports[i].serio);
1426 			i8042_ports[i].serio = NULL;
1427 		}
1428 	}
1429 }
1430 
1431 static void i8042_free_irqs(void)
1432 {
1433 	if (i8042_aux_irq_registered)
1434 		free_irq(I8042_AUX_IRQ, i8042_platform_device);
1435 	if (i8042_kbd_irq_registered)
1436 		free_irq(I8042_KBD_IRQ, i8042_platform_device);
1437 
1438 	i8042_aux_irq_registered = i8042_kbd_irq_registered = false;
1439 }
1440 
1441 static int i8042_setup_aux(void)
1442 {
1443 	int (*aux_enable)(void);
1444 	int error;
1445 	int i;
1446 
1447 	if (i8042_check_aux())
1448 		return -ENODEV;
1449 
1450 	if (i8042_nomux || i8042_check_mux()) {
1451 		error = i8042_create_aux_port(-1);
1452 		if (error)
1453 			goto err_free_ports;
1454 		aux_enable = i8042_enable_aux_port;
1455 	} else {
1456 		for (i = 0; i < I8042_NUM_MUX_PORTS; i++) {
1457 			error = i8042_create_aux_port(i);
1458 			if (error)
1459 				goto err_free_ports;
1460 		}
1461 		aux_enable = i8042_enable_mux_ports;
1462 	}
1463 
1464 	error = request_irq(I8042_AUX_IRQ, i8042_interrupt, IRQF_SHARED,
1465 			    "i8042", i8042_platform_device);
1466 	if (error)
1467 		goto err_free_ports;
1468 
1469 	error = aux_enable();
1470 	if (error)
1471 		goto err_free_irq;
1472 
1473 	i8042_aux_irq_registered = true;
1474 	return 0;
1475 
1476  err_free_irq:
1477 	free_irq(I8042_AUX_IRQ, i8042_platform_device);
1478  err_free_ports:
1479 	i8042_free_aux_ports();
1480 	return error;
1481 }
1482 
1483 static int i8042_setup_kbd(void)
1484 {
1485 	int error;
1486 
1487 	error = i8042_create_kbd_port();
1488 	if (error)
1489 		return error;
1490 
1491 	error = request_irq(I8042_KBD_IRQ, i8042_interrupt, IRQF_SHARED,
1492 			    "i8042", i8042_platform_device);
1493 	if (error)
1494 		goto err_free_port;
1495 
1496 	error = i8042_enable_kbd_port();
1497 	if (error)
1498 		goto err_free_irq;
1499 
1500 	i8042_kbd_irq_registered = true;
1501 	return 0;
1502 
1503  err_free_irq:
1504 	free_irq(I8042_KBD_IRQ, i8042_platform_device);
1505  err_free_port:
1506 	i8042_free_kbd_port();
1507 	return error;
1508 }
1509 
1510 static int i8042_kbd_bind_notifier(struct notifier_block *nb,
1511 				   unsigned long action, void *data)
1512 {
1513 	struct device *dev = data;
1514 	struct serio *serio = to_serio_port(dev);
1515 	struct i8042_port *port = serio->port_data;
1516 
1517 	if (serio != i8042_ports[I8042_KBD_PORT_NO].serio)
1518 		return 0;
1519 
1520 	switch (action) {
1521 	case BUS_NOTIFY_BOUND_DRIVER:
1522 		port->driver_bound = true;
1523 		break;
1524 
1525 	case BUS_NOTIFY_UNBIND_DRIVER:
1526 		port->driver_bound = false;
1527 		break;
1528 	}
1529 
1530 	return 0;
1531 }
1532 
1533 static int i8042_probe(struct platform_device *dev)
1534 {
1535 	int error;
1536 
1537 	if (i8042_reset == I8042_RESET_ALWAYS) {
1538 		error = i8042_controller_selftest();
1539 		if (error)
1540 			return error;
1541 	}
1542 
1543 	error = i8042_controller_init();
1544 	if (error)
1545 		return error;
1546 
1547 #ifdef CONFIG_X86
1548 	if (i8042_dritek)
1549 		i8042_dritek_enable();
1550 #endif
1551 
1552 	if (!i8042_noaux) {
1553 		error = i8042_setup_aux();
1554 		if (error && error != -ENODEV && error != -EBUSY)
1555 			goto out_fail;
1556 	}
1557 
1558 	if (!i8042_nokbd) {
1559 		error = i8042_setup_kbd();
1560 		if (error)
1561 			goto out_fail;
1562 	}
1563 /*
1564  * Ok, everything is ready, let's register all serio ports
1565  */
1566 	i8042_register_ports();
1567 
1568 	return 0;
1569 
1570  out_fail:
1571 	i8042_free_aux_ports();	/* in case KBD failed but AUX not */
1572 	i8042_free_irqs();
1573 	i8042_controller_reset(false);
1574 
1575 	return error;
1576 }
1577 
1578 static void i8042_remove(struct platform_device *dev)
1579 {
1580 	i8042_unregister_ports();
1581 	i8042_free_irqs();
1582 	i8042_controller_reset(false);
1583 }
1584 
1585 static struct platform_driver i8042_driver = {
1586 	.driver		= {
1587 		.name	= "i8042",
1588 #ifdef CONFIG_PM
1589 		.pm	= &i8042_pm_ops,
1590 #endif
1591 	},
1592 	.probe		= i8042_probe,
1593 	.remove		= i8042_remove,
1594 	.shutdown	= i8042_shutdown,
1595 };
1596 
1597 static struct notifier_block i8042_kbd_bind_notifier_block = {
1598 	.notifier_call = i8042_kbd_bind_notifier,
1599 };
1600 
1601 static int __init i8042_init(void)
1602 {
1603 	int err;
1604 
1605 	dbg_init();
1606 
1607 	err = i8042_platform_init();
1608 	if (err)
1609 		return (err == -ENODEV) ? 0 : err;
1610 
1611 	err = i8042_controller_check();
1612 	if (err)
1613 		goto err_platform_exit;
1614 
1615 	/* Set this before creating the dev to allow i8042_command to work right away */
1616 	i8042_present = true;
1617 
1618 	err = platform_driver_register(&i8042_driver);
1619 	if (err)
1620 		goto err_platform_exit;
1621 
1622 	i8042_platform_device = platform_device_alloc("i8042", -1);
1623 	if (!i8042_platform_device) {
1624 		err = -ENOMEM;
1625 		goto err_unregister_driver;
1626 	}
1627 
1628 	err = platform_device_add(i8042_platform_device);
1629 	if (err)
1630 		goto err_free_device;
1631 
1632 	bus_register_notifier(&serio_bus, &i8042_kbd_bind_notifier_block);
1633 	panic_blink = i8042_panic_blink;
1634 
1635 	return 0;
1636 
1637 err_free_device:
1638 	platform_device_put(i8042_platform_device);
1639 err_unregister_driver:
1640 	platform_driver_unregister(&i8042_driver);
1641  err_platform_exit:
1642 	i8042_platform_exit();
1643 	return err;
1644 }
1645 
1646 static void __exit i8042_exit(void)
1647 {
1648 	if (!i8042_present)
1649 		return;
1650 
1651 	platform_device_unregister(i8042_platform_device);
1652 	platform_driver_unregister(&i8042_driver);
1653 	i8042_platform_exit();
1654 
1655 	bus_unregister_notifier(&serio_bus, &i8042_kbd_bind_notifier_block);
1656 	panic_blink = NULL;
1657 }
1658 
1659 module_init(i8042_init);
1660 module_exit(i8042_exit);
1661