xref: /openbmc/linux/drivers/input/serio/i8042.c (revision 82ced6fd)
1 /*
2  *  i8042 keyboard and mouse controller driver for Linux
3  *
4  *  Copyright (c) 1999-2004 Vojtech Pavlik
5  */
6 
7 /*
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License version 2 as published by
10  * the Free Software Foundation.
11  */
12 
13 #include <linux/delay.h>
14 #include <linux/module.h>
15 #include <linux/interrupt.h>
16 #include <linux/ioport.h>
17 #include <linux/init.h>
18 #include <linux/serio.h>
19 #include <linux/err.h>
20 #include <linux/rcupdate.h>
21 #include <linux/platform_device.h>
22 #include <linux/i8042.h>
23 
24 #include <asm/io.h>
25 
26 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
27 MODULE_DESCRIPTION("i8042 keyboard and mouse controller driver");
28 MODULE_LICENSE("GPL");
29 
30 static unsigned int i8042_nokbd;
31 module_param_named(nokbd, i8042_nokbd, bool, 0);
32 MODULE_PARM_DESC(nokbd, "Do not probe or use KBD port.");
33 
34 static unsigned int i8042_noaux;
35 module_param_named(noaux, i8042_noaux, bool, 0);
36 MODULE_PARM_DESC(noaux, "Do not probe or use AUX (mouse) port.");
37 
38 static unsigned int i8042_nomux;
39 module_param_named(nomux, i8042_nomux, bool, 0);
40 MODULE_PARM_DESC(nomux, "Do not check whether an active multiplexing conrtoller is present.");
41 
42 static unsigned int i8042_unlock;
43 module_param_named(unlock, i8042_unlock, bool, 0);
44 MODULE_PARM_DESC(unlock, "Ignore keyboard lock.");
45 
46 static unsigned int i8042_reset;
47 module_param_named(reset, i8042_reset, bool, 0);
48 MODULE_PARM_DESC(reset, "Reset controller during init and cleanup.");
49 
50 static unsigned int i8042_direct;
51 module_param_named(direct, i8042_direct, bool, 0);
52 MODULE_PARM_DESC(direct, "Put keyboard port into non-translated mode.");
53 
54 static unsigned int i8042_dumbkbd;
55 module_param_named(dumbkbd, i8042_dumbkbd, bool, 0);
56 MODULE_PARM_DESC(dumbkbd, "Pretend that controller can only read data from keyboard");
57 
58 static unsigned int i8042_noloop;
59 module_param_named(noloop, i8042_noloop, bool, 0);
60 MODULE_PARM_DESC(noloop, "Disable the AUX Loopback command while probing for the AUX port");
61 
62 static unsigned int i8042_blink_frequency = 500;
63 module_param_named(panicblink, i8042_blink_frequency, uint, 0600);
64 MODULE_PARM_DESC(panicblink, "Frequency with which keyboard LEDs should blink when kernel panics");
65 
66 #ifdef CONFIG_X86
67 static unsigned int i8042_dritek;
68 module_param_named(dritek, i8042_dritek, bool, 0);
69 MODULE_PARM_DESC(dritek, "Force enable the Dritek keyboard extension");
70 #endif
71 
72 #ifdef CONFIG_PNP
73 static int i8042_nopnp;
74 module_param_named(nopnp, i8042_nopnp, bool, 0);
75 MODULE_PARM_DESC(nopnp, "Do not use PNP to detect controller settings");
76 #endif
77 
78 #define DEBUG
79 #ifdef DEBUG
80 static int i8042_debug;
81 module_param_named(debug, i8042_debug, bool, 0600);
82 MODULE_PARM_DESC(debug, "Turn i8042 debugging mode on and off");
83 #endif
84 
85 #include "i8042.h"
86 
87 static DEFINE_SPINLOCK(i8042_lock);
88 
89 struct i8042_port {
90 	struct serio *serio;
91 	int irq;
92 	unsigned char exists;
93 	signed char mux;
94 };
95 
96 #define I8042_KBD_PORT_NO	0
97 #define I8042_AUX_PORT_NO	1
98 #define I8042_MUX_PORT_NO	2
99 #define I8042_NUM_PORTS		(I8042_NUM_MUX_PORTS + 2)
100 
101 static struct i8042_port i8042_ports[I8042_NUM_PORTS];
102 
103 static unsigned char i8042_initial_ctr;
104 static unsigned char i8042_ctr;
105 static unsigned char i8042_mux_present;
106 static unsigned char i8042_kbd_irq_registered;
107 static unsigned char i8042_aux_irq_registered;
108 static unsigned char i8042_suppress_kbd_ack;
109 static struct platform_device *i8042_platform_device;
110 
111 static irqreturn_t i8042_interrupt(int irq, void *dev_id);
112 
113 /*
114  * The i8042_wait_read() and i8042_wait_write functions wait for the i8042 to
115  * be ready for reading values from it / writing values to it.
116  * Called always with i8042_lock held.
117  */
118 
119 static int i8042_wait_read(void)
120 {
121 	int i = 0;
122 
123 	while ((~i8042_read_status() & I8042_STR_OBF) && (i < I8042_CTL_TIMEOUT)) {
124 		udelay(50);
125 		i++;
126 	}
127 	return -(i == I8042_CTL_TIMEOUT);
128 }
129 
130 static int i8042_wait_write(void)
131 {
132 	int i = 0;
133 
134 	while ((i8042_read_status() & I8042_STR_IBF) && (i < I8042_CTL_TIMEOUT)) {
135 		udelay(50);
136 		i++;
137 	}
138 	return -(i == I8042_CTL_TIMEOUT);
139 }
140 
141 /*
142  * i8042_flush() flushes all data that may be in the keyboard and mouse buffers
143  * of the i8042 down the toilet.
144  */
145 
146 static int i8042_flush(void)
147 {
148 	unsigned long flags;
149 	unsigned char data, str;
150 	int i = 0;
151 
152 	spin_lock_irqsave(&i8042_lock, flags);
153 
154 	while (((str = i8042_read_status()) & I8042_STR_OBF) && (i < I8042_BUFFER_SIZE)) {
155 		udelay(50);
156 		data = i8042_read_data();
157 		i++;
158 		dbg("%02x <- i8042 (flush, %s)", data,
159 			str & I8042_STR_AUXDATA ? "aux" : "kbd");
160 	}
161 
162 	spin_unlock_irqrestore(&i8042_lock, flags);
163 
164 	return i;
165 }
166 
167 /*
168  * i8042_command() executes a command on the i8042. It also sends the input
169  * parameter(s) of the commands to it, and receives the output value(s). The
170  * parameters are to be stored in the param array, and the output is placed
171  * into the same array. The number of the parameters and output values is
172  * encoded in bits 8-11 of the command number.
173  */
174 
175 static int __i8042_command(unsigned char *param, int command)
176 {
177 	int i, error;
178 
179 	if (i8042_noloop && command == I8042_CMD_AUX_LOOP)
180 		return -1;
181 
182 	error = i8042_wait_write();
183 	if (error)
184 		return error;
185 
186 	dbg("%02x -> i8042 (command)", command & 0xff);
187 	i8042_write_command(command & 0xff);
188 
189 	for (i = 0; i < ((command >> 12) & 0xf); i++) {
190 		error = i8042_wait_write();
191 		if (error)
192 			return error;
193 		dbg("%02x -> i8042 (parameter)", param[i]);
194 		i8042_write_data(param[i]);
195 	}
196 
197 	for (i = 0; i < ((command >> 8) & 0xf); i++) {
198 		error = i8042_wait_read();
199 		if (error) {
200 			dbg("     -- i8042 (timeout)");
201 			return error;
202 		}
203 
204 		if (command == I8042_CMD_AUX_LOOP &&
205 		    !(i8042_read_status() & I8042_STR_AUXDATA)) {
206 			dbg("     -- i8042 (auxerr)");
207 			return -1;
208 		}
209 
210 		param[i] = i8042_read_data();
211 		dbg("%02x <- i8042 (return)", param[i]);
212 	}
213 
214 	return 0;
215 }
216 
217 int i8042_command(unsigned char *param, int command)
218 {
219 	unsigned long flags;
220 	int retval;
221 
222 	spin_lock_irqsave(&i8042_lock, flags);
223 	retval = __i8042_command(param, command);
224 	spin_unlock_irqrestore(&i8042_lock, flags);
225 
226 	return retval;
227 }
228 EXPORT_SYMBOL(i8042_command);
229 
230 /*
231  * i8042_kbd_write() sends a byte out through the keyboard interface.
232  */
233 
234 static int i8042_kbd_write(struct serio *port, unsigned char c)
235 {
236 	unsigned long flags;
237 	int retval = 0;
238 
239 	spin_lock_irqsave(&i8042_lock, flags);
240 
241 	if (!(retval = i8042_wait_write())) {
242 		dbg("%02x -> i8042 (kbd-data)", c);
243 		i8042_write_data(c);
244 	}
245 
246 	spin_unlock_irqrestore(&i8042_lock, flags);
247 
248 	return retval;
249 }
250 
251 /*
252  * i8042_aux_write() sends a byte out through the aux interface.
253  */
254 
255 static int i8042_aux_write(struct serio *serio, unsigned char c)
256 {
257 	struct i8042_port *port = serio->port_data;
258 
259 	return i8042_command(&c, port->mux == -1 ?
260 					I8042_CMD_AUX_SEND :
261 					I8042_CMD_MUX_SEND + port->mux);
262 }
263 
264 /*
265  * i8042_start() is called by serio core when port is about to finish
266  * registering. It will mark port as existing so i8042_interrupt can
267  * start sending data through it.
268  */
269 static int i8042_start(struct serio *serio)
270 {
271 	struct i8042_port *port = serio->port_data;
272 
273 	port->exists = 1;
274 	mb();
275 	return 0;
276 }
277 
278 /*
279  * i8042_stop() marks serio port as non-existing so i8042_interrupt
280  * will not try to send data to the port that is about to go away.
281  * The function is called by serio core as part of unregister procedure.
282  */
283 static void i8042_stop(struct serio *serio)
284 {
285 	struct i8042_port *port = serio->port_data;
286 
287 	port->exists = 0;
288 
289 	/*
290 	 * We synchronize with both AUX and KBD IRQs because there is
291 	 * a (very unlikely) chance that AUX IRQ is raised for KBD port
292 	 * and vice versa.
293 	 */
294 	synchronize_irq(I8042_AUX_IRQ);
295 	synchronize_irq(I8042_KBD_IRQ);
296 	port->serio = NULL;
297 }
298 
299 /*
300  * i8042_interrupt() is the most important function in this driver -
301  * it handles the interrupts from the i8042, and sends incoming bytes
302  * to the upper layers.
303  */
304 
305 static irqreturn_t i8042_interrupt(int irq, void *dev_id)
306 {
307 	struct i8042_port *port;
308 	unsigned long flags;
309 	unsigned char str, data;
310 	unsigned int dfl;
311 	unsigned int port_no;
312 	int ret = 1;
313 
314 	spin_lock_irqsave(&i8042_lock, flags);
315 	str = i8042_read_status();
316 	if (unlikely(~str & I8042_STR_OBF)) {
317 		spin_unlock_irqrestore(&i8042_lock, flags);
318 		if (irq) dbg("Interrupt %d, without any data", irq);
319 		ret = 0;
320 		goto out;
321 	}
322 	data = i8042_read_data();
323 	spin_unlock_irqrestore(&i8042_lock, flags);
324 
325 	if (i8042_mux_present && (str & I8042_STR_AUXDATA)) {
326 		static unsigned long last_transmit;
327 		static unsigned char last_str;
328 
329 		dfl = 0;
330 		if (str & I8042_STR_MUXERR) {
331 			dbg("MUX error, status is %02x, data is %02x", str, data);
332 /*
333  * When MUXERR condition is signalled the data register can only contain
334  * 0xfd, 0xfe or 0xff if implementation follows the spec. Unfortunately
335  * it is not always the case. Some KBCs also report 0xfc when there is
336  * nothing connected to the port while others sometimes get confused which
337  * port the data came from and signal error leaving the data intact. They
338  * _do not_ revert to legacy mode (actually I've never seen KBC reverting
339  * to legacy mode yet, when we see one we'll add proper handling).
340  * Anyway, we process 0xfc, 0xfd, 0xfe and 0xff as timeouts, and for the
341  * rest assume that the data came from the same serio last byte
342  * was transmitted (if transmission happened not too long ago).
343  */
344 
345 			switch (data) {
346 				default:
347 					if (time_before(jiffies, last_transmit + HZ/10)) {
348 						str = last_str;
349 						break;
350 					}
351 					/* fall through - report timeout */
352 				case 0xfc:
353 				case 0xfd:
354 				case 0xfe: dfl = SERIO_TIMEOUT; data = 0xfe; break;
355 				case 0xff: dfl = SERIO_PARITY;  data = 0xfe; break;
356 			}
357 		}
358 
359 		port_no = I8042_MUX_PORT_NO + ((str >> 6) & 3);
360 		last_str = str;
361 		last_transmit = jiffies;
362 	} else {
363 
364 		dfl = ((str & I8042_STR_PARITY) ? SERIO_PARITY : 0) |
365 		      ((str & I8042_STR_TIMEOUT) ? SERIO_TIMEOUT : 0);
366 
367 		port_no = (str & I8042_STR_AUXDATA) ?
368 				I8042_AUX_PORT_NO : I8042_KBD_PORT_NO;
369 	}
370 
371 	port = &i8042_ports[port_no];
372 
373 	dbg("%02x <- i8042 (interrupt, %d, %d%s%s)",
374 	    data, port_no, irq,
375 	    dfl & SERIO_PARITY ? ", bad parity" : "",
376 	    dfl & SERIO_TIMEOUT ? ", timeout" : "");
377 
378 	if (unlikely(i8042_suppress_kbd_ack))
379 		if (port_no == I8042_KBD_PORT_NO &&
380 		    (data == 0xfa || data == 0xfe)) {
381 			i8042_suppress_kbd_ack--;
382 			goto out;
383 		}
384 
385 	if (likely(port->exists))
386 		serio_interrupt(port->serio, data, dfl);
387 
388  out:
389 	return IRQ_RETVAL(ret);
390 }
391 
392 /*
393  * i8042_enable_kbd_port enables keybaord port on chip
394  */
395 
396 static int i8042_enable_kbd_port(void)
397 {
398 	i8042_ctr &= ~I8042_CTR_KBDDIS;
399 	i8042_ctr |= I8042_CTR_KBDINT;
400 
401 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
402 		i8042_ctr &= ~I8042_CTR_KBDINT;
403 		i8042_ctr |= I8042_CTR_KBDDIS;
404 		printk(KERN_ERR "i8042.c: Failed to enable KBD port.\n");
405 		return -EIO;
406 	}
407 
408 	return 0;
409 }
410 
411 /*
412  * i8042_enable_aux_port enables AUX (mouse) port on chip
413  */
414 
415 static int i8042_enable_aux_port(void)
416 {
417 	i8042_ctr &= ~I8042_CTR_AUXDIS;
418 	i8042_ctr |= I8042_CTR_AUXINT;
419 
420 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
421 		i8042_ctr &= ~I8042_CTR_AUXINT;
422 		i8042_ctr |= I8042_CTR_AUXDIS;
423 		printk(KERN_ERR "i8042.c: Failed to enable AUX port.\n");
424 		return -EIO;
425 	}
426 
427 	return 0;
428 }
429 
430 /*
431  * i8042_enable_mux_ports enables 4 individual AUX ports after
432  * the controller has been switched into Multiplexed mode
433  */
434 
435 static int i8042_enable_mux_ports(void)
436 {
437 	unsigned char param;
438 	int i;
439 
440 	for (i = 0; i < I8042_NUM_MUX_PORTS; i++) {
441 		i8042_command(&param, I8042_CMD_MUX_PFX + i);
442 		i8042_command(&param, I8042_CMD_AUX_ENABLE);
443 	}
444 
445 	return i8042_enable_aux_port();
446 }
447 
448 /*
449  * i8042_set_mux_mode checks whether the controller has an active
450  * multiplexor and puts the chip into Multiplexed (1) or Legacy (0) mode.
451  */
452 
453 static int i8042_set_mux_mode(unsigned int mode, unsigned char *mux_version)
454 {
455 
456 	unsigned char param;
457 /*
458  * Get rid of bytes in the queue.
459  */
460 
461 	i8042_flush();
462 
463 /*
464  * Internal loopback test - send three bytes, they should come back from the
465  * mouse interface, the last should be version.
466  */
467 
468 	param = 0xf0;
469 	if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param != 0xf0)
470 		return -1;
471 	param = mode ? 0x56 : 0xf6;
472 	if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param != (mode ? 0x56 : 0xf6))
473 		return -1;
474 	param = mode ? 0xa4 : 0xa5;
475 	if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param == (mode ? 0xa4 : 0xa5))
476 		return -1;
477 
478 	if (mux_version)
479 		*mux_version = param;
480 
481 	return 0;
482 }
483 
484 /*
485  * i8042_check_mux() checks whether the controller supports the PS/2 Active
486  * Multiplexing specification by Synaptics, Phoenix, Insyde and
487  * LCS/Telegraphics.
488  */
489 
490 static int __devinit i8042_check_mux(void)
491 {
492 	unsigned char mux_version;
493 
494 	if (i8042_set_mux_mode(1, &mux_version))
495 		return -1;
496 
497 /*
498  * Workaround for interference with USB Legacy emulation
499  * that causes a v10.12 MUX to be found.
500  */
501 	if (mux_version == 0xAC)
502 		return -1;
503 
504 	printk(KERN_INFO "i8042.c: Detected active multiplexing controller, rev %d.%d.\n",
505 		(mux_version >> 4) & 0xf, mux_version & 0xf);
506 
507 /*
508  * Disable all muxed ports by disabling AUX.
509  */
510 	i8042_ctr |= I8042_CTR_AUXDIS;
511 	i8042_ctr &= ~I8042_CTR_AUXINT;
512 
513 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
514 		printk(KERN_ERR "i8042.c: Failed to disable AUX port, can't use MUX.\n");
515 		return -EIO;
516 	}
517 
518 	i8042_mux_present = 1;
519 
520 	return 0;
521 }
522 
523 /*
524  * The following is used to test AUX IRQ delivery.
525  */
526 static struct completion i8042_aux_irq_delivered __devinitdata;
527 static int i8042_irq_being_tested __devinitdata;
528 
529 static irqreturn_t __devinit i8042_aux_test_irq(int irq, void *dev_id)
530 {
531 	unsigned long flags;
532 	unsigned char str, data;
533 	int ret = 0;
534 
535 	spin_lock_irqsave(&i8042_lock, flags);
536 	str = i8042_read_status();
537 	if (str & I8042_STR_OBF) {
538 		data = i8042_read_data();
539 		if (i8042_irq_being_tested &&
540 		    data == 0xa5 && (str & I8042_STR_AUXDATA))
541 			complete(&i8042_aux_irq_delivered);
542 		ret = 1;
543 	}
544 	spin_unlock_irqrestore(&i8042_lock, flags);
545 
546 	return IRQ_RETVAL(ret);
547 }
548 
549 /*
550  * i8042_toggle_aux - enables or disables AUX port on i8042 via command and
551  * verifies success by readinng CTR. Used when testing for presence of AUX
552  * port.
553  */
554 static int __devinit i8042_toggle_aux(int on)
555 {
556 	unsigned char param;
557 	int i;
558 
559 	if (i8042_command(&param,
560 			on ? I8042_CMD_AUX_ENABLE : I8042_CMD_AUX_DISABLE))
561 		return -1;
562 
563 	/* some chips need some time to set the I8042_CTR_AUXDIS bit */
564 	for (i = 0; i < 100; i++) {
565 		udelay(50);
566 
567 		if (i8042_command(&param, I8042_CMD_CTL_RCTR))
568 			return -1;
569 
570 		if (!(param & I8042_CTR_AUXDIS) == on)
571 			return 0;
572 	}
573 
574 	return -1;
575 }
576 
577 /*
578  * i8042_check_aux() applies as much paranoia as it can at detecting
579  * the presence of an AUX interface.
580  */
581 
582 static int __devinit i8042_check_aux(void)
583 {
584 	int retval = -1;
585 	int irq_registered = 0;
586 	int aux_loop_broken = 0;
587 	unsigned long flags;
588 	unsigned char param;
589 
590 /*
591  * Get rid of bytes in the queue.
592  */
593 
594 	i8042_flush();
595 
596 /*
597  * Internal loopback test - filters out AT-type i8042's. Unfortunately
598  * SiS screwed up and their 5597 doesn't support the LOOP command even
599  * though it has an AUX port.
600  */
601 
602 	param = 0x5a;
603 	retval = i8042_command(&param, I8042_CMD_AUX_LOOP);
604 	if (retval || param != 0x5a) {
605 
606 /*
607  * External connection test - filters out AT-soldered PS/2 i8042's
608  * 0x00 - no error, 0x01-0x03 - clock/data stuck, 0xff - general error
609  * 0xfa - no error on some notebooks which ignore the spec
610  * Because it's common for chipsets to return error on perfectly functioning
611  * AUX ports, we test for this only when the LOOP command failed.
612  */
613 
614 		if (i8042_command(&param, I8042_CMD_AUX_TEST) ||
615 		    (param && param != 0xfa && param != 0xff))
616 			return -1;
617 
618 /*
619  * If AUX_LOOP completed without error but returned unexpected data
620  * mark it as broken
621  */
622 		if (!retval)
623 			aux_loop_broken = 1;
624 	}
625 
626 /*
627  * Bit assignment test - filters out PS/2 i8042's in AT mode
628  */
629 
630 	if (i8042_toggle_aux(0)) {
631 		printk(KERN_WARNING "Failed to disable AUX port, but continuing anyway... Is this a SiS?\n");
632 		printk(KERN_WARNING "If AUX port is really absent please use the 'i8042.noaux' option.\n");
633 	}
634 
635 	if (i8042_toggle_aux(1))
636 		return -1;
637 
638 /*
639  * Test AUX IRQ delivery to make sure BIOS did not grab the IRQ and
640  * used it for a PCI card or somethig else.
641  */
642 
643 	if (i8042_noloop || aux_loop_broken) {
644 /*
645  * Without LOOP command we can't test AUX IRQ delivery. Assume the port
646  * is working and hope we are right.
647  */
648 		retval = 0;
649 		goto out;
650 	}
651 
652 	if (request_irq(I8042_AUX_IRQ, i8042_aux_test_irq, IRQF_SHARED,
653 			"i8042", i8042_platform_device))
654 		goto out;
655 
656 	irq_registered = 1;
657 
658 	if (i8042_enable_aux_port())
659 		goto out;
660 
661 	spin_lock_irqsave(&i8042_lock, flags);
662 
663 	init_completion(&i8042_aux_irq_delivered);
664 	i8042_irq_being_tested = 1;
665 
666 	param = 0xa5;
667 	retval = __i8042_command(&param, I8042_CMD_AUX_LOOP & 0xf0ff);
668 
669 	spin_unlock_irqrestore(&i8042_lock, flags);
670 
671 	if (retval)
672 		goto out;
673 
674 	if (wait_for_completion_timeout(&i8042_aux_irq_delivered,
675 					msecs_to_jiffies(250)) == 0) {
676 /*
677  * AUX IRQ was never delivered so we need to flush the controller to
678  * get rid of the byte we put there; otherwise keyboard may not work.
679  */
680 		i8042_flush();
681 		retval = -1;
682 	}
683 
684  out:
685 
686 /*
687  * Disable the interface.
688  */
689 
690 	i8042_ctr |= I8042_CTR_AUXDIS;
691 	i8042_ctr &= ~I8042_CTR_AUXINT;
692 
693 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR))
694 		retval = -1;
695 
696 	if (irq_registered)
697 		free_irq(I8042_AUX_IRQ, i8042_platform_device);
698 
699 	return retval;
700 }
701 
702 static int i8042_controller_check(void)
703 {
704 	if (i8042_flush() == I8042_BUFFER_SIZE) {
705 		printk(KERN_ERR "i8042.c: No controller found.\n");
706 		return -ENODEV;
707 	}
708 
709 	return 0;
710 }
711 
712 static int i8042_controller_selftest(void)
713 {
714 	unsigned char param;
715 	int i = 0;
716 
717 	if (!i8042_reset)
718 		return 0;
719 
720 	/*
721 	 * We try this 5 times; on some really fragile systems this does not
722 	 * take the first time...
723 	 */
724 	do {
725 
726 		if (i8042_command(&param, I8042_CMD_CTL_TEST)) {
727 			printk(KERN_ERR "i8042.c: i8042 controller self test timeout.\n");
728 			return -ENODEV;
729 		}
730 
731 		if (param == I8042_RET_CTL_TEST)
732 			return 0;
733 
734 		printk(KERN_ERR "i8042.c: i8042 controller selftest failed. (%#x != %#x)\n",
735 			param, I8042_RET_CTL_TEST);
736 		msleep(50);
737 	} while (i++ < 5);
738 
739 #ifdef CONFIG_X86
740 	/*
741 	 * On x86, we don't fail entire i8042 initialization if controller
742 	 * reset fails in hopes that keyboard port will still be functional
743 	 * and user will still get a working keyboard. This is especially
744 	 * important on netbooks. On other arches we trust hardware more.
745 	 */
746 	printk(KERN_INFO
747 		"i8042: giving up on controller selftest, continuing anyway...\n");
748 	return 0;
749 #else
750 	return -EIO;
751 #endif
752 }
753 
754 /*
755  * i8042_controller init initializes the i8042 controller, and,
756  * most importantly, sets it into non-xlated mode if that's
757  * desired.
758  */
759 
760 static int i8042_controller_init(void)
761 {
762 	unsigned long flags;
763 
764 /*
765  * Save the CTR for restoral on unload / reboot.
766  */
767 
768 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_RCTR)) {
769 		printk(KERN_ERR "i8042.c: Can't read CTR while initializing i8042.\n");
770 		return -EIO;
771 	}
772 
773 	i8042_initial_ctr = i8042_ctr;
774 
775 /*
776  * Disable the keyboard interface and interrupt.
777  */
778 
779 	i8042_ctr |= I8042_CTR_KBDDIS;
780 	i8042_ctr &= ~I8042_CTR_KBDINT;
781 
782 /*
783  * Handle keylock.
784  */
785 
786 	spin_lock_irqsave(&i8042_lock, flags);
787 	if (~i8042_read_status() & I8042_STR_KEYLOCK) {
788 		if (i8042_unlock)
789 			i8042_ctr |= I8042_CTR_IGNKEYLOCK;
790 		else
791 			printk(KERN_WARNING "i8042.c: Warning: Keylock active.\n");
792 	}
793 	spin_unlock_irqrestore(&i8042_lock, flags);
794 
795 /*
796  * If the chip is configured into nontranslated mode by the BIOS, don't
797  * bother enabling translating and be happy.
798  */
799 
800 	if (~i8042_ctr & I8042_CTR_XLATE)
801 		i8042_direct = 1;
802 
803 /*
804  * Set nontranslated mode for the kbd interface if requested by an option.
805  * After this the kbd interface becomes a simple serial in/out, like the aux
806  * interface is. We don't do this by default, since it can confuse notebook
807  * BIOSes.
808  */
809 
810 	if (i8042_direct)
811 		i8042_ctr &= ~I8042_CTR_XLATE;
812 
813 /*
814  * Write CTR back.
815  */
816 
817 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
818 		printk(KERN_ERR "i8042.c: Can't write CTR while initializing i8042.\n");
819 		return -EIO;
820 	}
821 
822 	return 0;
823 }
824 
825 
826 /*
827  * Reset the controller and reset CRT to the original value set by BIOS.
828  */
829 
830 static void i8042_controller_reset(void)
831 {
832 	i8042_flush();
833 
834 /*
835  * Disable both KBD and AUX interfaces so they don't get in the way
836  */
837 
838 	i8042_ctr |= I8042_CTR_KBDDIS | I8042_CTR_AUXDIS;
839 	i8042_ctr &= ~(I8042_CTR_KBDINT | I8042_CTR_AUXINT);
840 
841 /*
842  * Disable MUX mode if present.
843  */
844 
845 	if (i8042_mux_present)
846 		i8042_set_mux_mode(0, NULL);
847 
848 /*
849  * Reset the controller if requested.
850  */
851 
852 	i8042_controller_selftest();
853 
854 /*
855  * Restore the original control register setting.
856  */
857 
858 	if (i8042_command(&i8042_initial_ctr, I8042_CMD_CTL_WCTR))
859 		printk(KERN_WARNING "i8042.c: Can't restore CTR.\n");
860 }
861 
862 
863 /*
864  * i8042_panic_blink() will flash the keyboard LEDs and is called when
865  * kernel panics. Flashing LEDs is useful for users running X who may
866  * not see the console and will help distingushing panics from "real"
867  * lockups.
868  *
869  * Note that DELAY has a limit of 10ms so we will not get stuck here
870  * waiting for KBC to free up even if KBD interrupt is off
871  */
872 
873 #define DELAY do { mdelay(1); if (++delay > 10) return delay; } while(0)
874 
875 static long i8042_panic_blink(long count)
876 {
877 	long delay = 0;
878 	static long last_blink;
879 	static char led;
880 
881 	/*
882 	 * We expect frequency to be about 1/2s. KDB uses about 1s.
883 	 * Make sure they are different.
884 	 */
885 	if (!i8042_blink_frequency)
886 		return 0;
887 	if (count - last_blink < i8042_blink_frequency)
888 		return 0;
889 
890 	led ^= 0x01 | 0x04;
891 	while (i8042_read_status() & I8042_STR_IBF)
892 		DELAY;
893 	dbg("%02x -> i8042 (panic blink)", 0xed);
894 	i8042_suppress_kbd_ack = 2;
895 	i8042_write_data(0xed); /* set leds */
896 	DELAY;
897 	while (i8042_read_status() & I8042_STR_IBF)
898 		DELAY;
899 	DELAY;
900 	dbg("%02x -> i8042 (panic blink)", led);
901 	i8042_write_data(led);
902 	DELAY;
903 	last_blink = count;
904 	return delay;
905 }
906 
907 #undef DELAY
908 
909 #ifdef CONFIG_X86
910 static void i8042_dritek_enable(void)
911 {
912 	char param = 0x90;
913 	int error;
914 
915 	error = i8042_command(&param, 0x1059);
916 	if (error)
917 		printk(KERN_WARNING
918 			"Failed to enable DRITEK extension: %d\n",
919 			error);
920 }
921 #endif
922 
923 #ifdef CONFIG_PM
924 /*
925  * Here we try to restore the original BIOS settings. We only want to
926  * do that once, when we really suspend, not when we taking memory
927  * snapshot for swsusp (in this case we'll perform required cleanup
928  * as part of shutdown process).
929  */
930 
931 static int i8042_suspend(struct platform_device *dev, pm_message_t state)
932 {
933 	if (dev->dev.power.power_state.event != state.event) {
934 		if (state.event == PM_EVENT_SUSPEND)
935 			i8042_controller_reset();
936 
937 		dev->dev.power.power_state = state;
938 	}
939 
940 	return 0;
941 }
942 
943 
944 /*
945  * Here we try to reset everything back to a state in which suspended
946  */
947 
948 static int i8042_resume(struct platform_device *dev)
949 {
950 	int error;
951 
952 /*
953  * Do not bother with restoring state if we haven't suspened yet
954  */
955 	if (dev->dev.power.power_state.event == PM_EVENT_ON)
956 		return 0;
957 
958 	error = i8042_controller_check();
959 	if (error)
960 		return error;
961 
962 	error = i8042_controller_selftest();
963 	if (error)
964 		return error;
965 
966 /*
967  * Restore original CTR value and disable all ports
968  */
969 
970 	i8042_ctr = i8042_initial_ctr;
971 	if (i8042_direct)
972 		i8042_ctr &= ~I8042_CTR_XLATE;
973 	i8042_ctr |= I8042_CTR_AUXDIS | I8042_CTR_KBDDIS;
974 	i8042_ctr &= ~(I8042_CTR_AUXINT | I8042_CTR_KBDINT);
975 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
976 		printk(KERN_WARNING "i8042: Can't write CTR to resume, retrying...\n");
977 		msleep(50);
978 		if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
979 			printk(KERN_ERR "i8042: CTR write retry failed\n");
980 			return -EIO;
981 		}
982 	}
983 
984 
985 #ifdef CONFIG_X86
986 	if (i8042_dritek)
987 		i8042_dritek_enable();
988 #endif
989 
990 	if (i8042_mux_present) {
991 		if (i8042_set_mux_mode(1, NULL) || i8042_enable_mux_ports())
992 			printk(KERN_WARNING
993 				"i8042: failed to resume active multiplexor, "
994 				"mouse won't work.\n");
995 	} else if (i8042_ports[I8042_AUX_PORT_NO].serio)
996 		i8042_enable_aux_port();
997 
998 	if (i8042_ports[I8042_KBD_PORT_NO].serio)
999 		i8042_enable_kbd_port();
1000 
1001 	i8042_interrupt(0, NULL);
1002 
1003 	dev->dev.power.power_state = PMSG_ON;
1004 
1005 	return 0;
1006 }
1007 #endif /* CONFIG_PM */
1008 
1009 /*
1010  * We need to reset the 8042 back to original mode on system shutdown,
1011  * because otherwise BIOSes will be confused.
1012  */
1013 
1014 static void i8042_shutdown(struct platform_device *dev)
1015 {
1016 	i8042_controller_reset();
1017 }
1018 
1019 static int __devinit i8042_create_kbd_port(void)
1020 {
1021 	struct serio *serio;
1022 	struct i8042_port *port = &i8042_ports[I8042_KBD_PORT_NO];
1023 
1024 	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
1025 	if (!serio)
1026 		return -ENOMEM;
1027 
1028 	serio->id.type		= i8042_direct ? SERIO_8042 : SERIO_8042_XL;
1029 	serio->write		= i8042_dumbkbd ? NULL : i8042_kbd_write;
1030 	serio->start		= i8042_start;
1031 	serio->stop		= i8042_stop;
1032 	serio->port_data	= port;
1033 	serio->dev.parent	= &i8042_platform_device->dev;
1034 	strlcpy(serio->name, "i8042 KBD port", sizeof(serio->name));
1035 	strlcpy(serio->phys, I8042_KBD_PHYS_DESC, sizeof(serio->phys));
1036 
1037 	port->serio = serio;
1038 	port->irq = I8042_KBD_IRQ;
1039 
1040 	return 0;
1041 }
1042 
1043 static int __devinit i8042_create_aux_port(int idx)
1044 {
1045 	struct serio *serio;
1046 	int port_no = idx < 0 ? I8042_AUX_PORT_NO : I8042_MUX_PORT_NO + idx;
1047 	struct i8042_port *port = &i8042_ports[port_no];
1048 
1049 	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
1050 	if (!serio)
1051 		return -ENOMEM;
1052 
1053 	serio->id.type		= SERIO_8042;
1054 	serio->write		= i8042_aux_write;
1055 	serio->start		= i8042_start;
1056 	serio->stop		= i8042_stop;
1057 	serio->port_data	= port;
1058 	serio->dev.parent	= &i8042_platform_device->dev;
1059 	if (idx < 0) {
1060 		strlcpy(serio->name, "i8042 AUX port", sizeof(serio->name));
1061 		strlcpy(serio->phys, I8042_AUX_PHYS_DESC, sizeof(serio->phys));
1062 	} else {
1063 		snprintf(serio->name, sizeof(serio->name), "i8042 AUX%d port", idx);
1064 		snprintf(serio->phys, sizeof(serio->phys), I8042_MUX_PHYS_DESC, idx + 1);
1065 	}
1066 
1067 	port->serio = serio;
1068 	port->mux = idx;
1069 	port->irq = I8042_AUX_IRQ;
1070 
1071 	return 0;
1072 }
1073 
1074 static void __devinit i8042_free_kbd_port(void)
1075 {
1076 	kfree(i8042_ports[I8042_KBD_PORT_NO].serio);
1077 	i8042_ports[I8042_KBD_PORT_NO].serio = NULL;
1078 }
1079 
1080 static void __devinit i8042_free_aux_ports(void)
1081 {
1082 	int i;
1083 
1084 	for (i = I8042_AUX_PORT_NO; i < I8042_NUM_PORTS; i++) {
1085 		kfree(i8042_ports[i].serio);
1086 		i8042_ports[i].serio = NULL;
1087 	}
1088 }
1089 
1090 static void __devinit i8042_register_ports(void)
1091 {
1092 	int i;
1093 
1094 	for (i = 0; i < I8042_NUM_PORTS; i++) {
1095 		if (i8042_ports[i].serio) {
1096 			printk(KERN_INFO "serio: %s at %#lx,%#lx irq %d\n",
1097 				i8042_ports[i].serio->name,
1098 				(unsigned long) I8042_DATA_REG,
1099 				(unsigned long) I8042_COMMAND_REG,
1100 				i8042_ports[i].irq);
1101 			serio_register_port(i8042_ports[i].serio);
1102 		}
1103 	}
1104 }
1105 
1106 static void __devexit i8042_unregister_ports(void)
1107 {
1108 	int i;
1109 
1110 	for (i = 0; i < I8042_NUM_PORTS; i++) {
1111 		if (i8042_ports[i].serio) {
1112 			serio_unregister_port(i8042_ports[i].serio);
1113 			i8042_ports[i].serio = NULL;
1114 		}
1115 	}
1116 }
1117 
1118 static void i8042_free_irqs(void)
1119 {
1120 	if (i8042_aux_irq_registered)
1121 		free_irq(I8042_AUX_IRQ, i8042_platform_device);
1122 	if (i8042_kbd_irq_registered)
1123 		free_irq(I8042_KBD_IRQ, i8042_platform_device);
1124 
1125 	i8042_aux_irq_registered = i8042_kbd_irq_registered = 0;
1126 }
1127 
1128 static int __devinit i8042_setup_aux(void)
1129 {
1130 	int (*aux_enable)(void);
1131 	int error;
1132 	int i;
1133 
1134 	if (i8042_check_aux())
1135 		return -ENODEV;
1136 
1137 	if (i8042_nomux || i8042_check_mux()) {
1138 		error = i8042_create_aux_port(-1);
1139 		if (error)
1140 			goto err_free_ports;
1141 		aux_enable = i8042_enable_aux_port;
1142 	} else {
1143 		for (i = 0; i < I8042_NUM_MUX_PORTS; i++) {
1144 			error = i8042_create_aux_port(i);
1145 			if (error)
1146 				goto err_free_ports;
1147 		}
1148 		aux_enable = i8042_enable_mux_ports;
1149 	}
1150 
1151 	error = request_irq(I8042_AUX_IRQ, i8042_interrupt, IRQF_SHARED,
1152 			    "i8042", i8042_platform_device);
1153 	if (error)
1154 		goto err_free_ports;
1155 
1156 	if (aux_enable())
1157 		goto err_free_irq;
1158 
1159 	i8042_aux_irq_registered = 1;
1160 	return 0;
1161 
1162  err_free_irq:
1163 	free_irq(I8042_AUX_IRQ, i8042_platform_device);
1164  err_free_ports:
1165 	i8042_free_aux_ports();
1166 	return error;
1167 }
1168 
1169 static int __devinit i8042_setup_kbd(void)
1170 {
1171 	int error;
1172 
1173 	error = i8042_create_kbd_port();
1174 	if (error)
1175 		return error;
1176 
1177 	error = request_irq(I8042_KBD_IRQ, i8042_interrupt, IRQF_SHARED,
1178 			    "i8042", i8042_platform_device);
1179 	if (error)
1180 		goto err_free_port;
1181 
1182 	error = i8042_enable_kbd_port();
1183 	if (error)
1184 		goto err_free_irq;
1185 
1186 	i8042_kbd_irq_registered = 1;
1187 	return 0;
1188 
1189  err_free_irq:
1190 	free_irq(I8042_KBD_IRQ, i8042_platform_device);
1191  err_free_port:
1192 	i8042_free_kbd_port();
1193 	return error;
1194 }
1195 
1196 static int __devinit i8042_probe(struct platform_device *dev)
1197 {
1198 	int error;
1199 
1200 	error = i8042_controller_selftest();
1201 	if (error)
1202 		return error;
1203 
1204 	error = i8042_controller_init();
1205 	if (error)
1206 		return error;
1207 
1208 #ifdef CONFIG_X86
1209 	if (i8042_dritek)
1210 		i8042_dritek_enable();
1211 #endif
1212 
1213 	if (!i8042_noaux) {
1214 		error = i8042_setup_aux();
1215 		if (error && error != -ENODEV && error != -EBUSY)
1216 			goto out_fail;
1217 	}
1218 
1219 	if (!i8042_nokbd) {
1220 		error = i8042_setup_kbd();
1221 		if (error)
1222 			goto out_fail;
1223 	}
1224 /*
1225  * Ok, everything is ready, let's register all serio ports
1226  */
1227 	i8042_register_ports();
1228 
1229 	return 0;
1230 
1231  out_fail:
1232 	i8042_free_aux_ports();	/* in case KBD failed but AUX not */
1233 	i8042_free_irqs();
1234 	i8042_controller_reset();
1235 
1236 	return error;
1237 }
1238 
1239 static int __devexit i8042_remove(struct platform_device *dev)
1240 {
1241 	i8042_unregister_ports();
1242 	i8042_free_irqs();
1243 	i8042_controller_reset();
1244 
1245 	return 0;
1246 }
1247 
1248 static struct platform_driver i8042_driver = {
1249 	.driver		= {
1250 		.name	= "i8042",
1251 		.owner	= THIS_MODULE,
1252 	},
1253 	.probe		= i8042_probe,
1254 	.remove		= __devexit_p(i8042_remove),
1255 	.shutdown	= i8042_shutdown,
1256 #ifdef CONFIG_PM
1257 	.suspend	= i8042_suspend,
1258 	.resume		= i8042_resume,
1259 #endif
1260 };
1261 
1262 static int __init i8042_init(void)
1263 {
1264 	int err;
1265 
1266 	dbg_init();
1267 
1268 	err = i8042_platform_init();
1269 	if (err)
1270 		return err;
1271 
1272 	err = i8042_controller_check();
1273 	if (err)
1274 		goto err_platform_exit;
1275 
1276 	err = platform_driver_register(&i8042_driver);
1277 	if (err)
1278 		goto err_platform_exit;
1279 
1280 	i8042_platform_device = platform_device_alloc("i8042", -1);
1281 	if (!i8042_platform_device) {
1282 		err = -ENOMEM;
1283 		goto err_unregister_driver;
1284 	}
1285 
1286 	err = platform_device_add(i8042_platform_device);
1287 	if (err)
1288 		goto err_free_device;
1289 
1290 	panic_blink = i8042_panic_blink;
1291 
1292 	return 0;
1293 
1294  err_free_device:
1295 	platform_device_put(i8042_platform_device);
1296  err_unregister_driver:
1297 	platform_driver_unregister(&i8042_driver);
1298  err_platform_exit:
1299 	i8042_platform_exit();
1300 
1301 	return err;
1302 }
1303 
1304 static void __exit i8042_exit(void)
1305 {
1306 	platform_device_unregister(i8042_platform_device);
1307 	platform_driver_unregister(&i8042_driver);
1308 	i8042_platform_exit();
1309 
1310 	panic_blink = NULL;
1311 }
1312 
1313 module_init(i8042_init);
1314 module_exit(i8042_exit);
1315