[mirror_ubuntu-hirsute-kernel.git] / drivers / input / serio / libps2.c

/*
 * PS/2 driver library
 *
 * Copyright (c) 1999-2002 Vojtech Pavlik
 * Copyright (c) 2004 Dmitry Torokhov
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/delay.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/i8042.h>
#include <linux/libps2.h>

#define DRIVER_DESC	"PS/2 driver library"

MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
MODULE_DESCRIPTION("PS/2 driver library");
MODULE_LICENSE("GPL");

/*
 * ps2_sendbyte() sends a byte to the device and waits for acknowledge.
 * It doesn't handle retransmission, though it could - because if there
 * is a need for retransmissions device has to be replaced anyway.
 *
 * ps2_sendbyte() can only be called from a process context.
 */

int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout)
{
	serio_pause_rx(ps2dev->serio);
	ps2dev->nak = 1;
	ps2dev->flags |= PS2_FLAG_ACK;
	serio_continue_rx(ps2dev->serio);

	if (serio_write(ps2dev->serio, byte) == 0)
		wait_event_timeout(ps2dev->wait,
				   !(ps2dev->flags & PS2_FLAG_ACK),
				   msecs_to_jiffies(timeout));

	serio_pause_rx(ps2dev->serio);
	ps2dev->flags &= ~PS2_FLAG_ACK;
	serio_continue_rx(ps2dev->serio);

	return -ps2dev->nak;
}
EXPORT_SYMBOL(ps2_sendbyte);

void ps2_begin_command(struct ps2dev *ps2dev)
{
	struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex;

	mutex_lock(m);
}
EXPORT_SYMBOL(ps2_begin_command);

void ps2_end_command(struct ps2dev *ps2dev)
{
	struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex;

	mutex_unlock(m);
}
EXPORT_SYMBOL(ps2_end_command);

/*
 * ps2_drain() waits for device to transmit requested number of bytes
 * and discards them.
 */

void ps2_drain(struct ps2dev *ps2dev, size_t maxbytes, unsigned int timeout)
{
	if (maxbytes > sizeof(ps2dev->cmdbuf)) {
		WARN_ON(1);
		maxbytes = sizeof(ps2dev->cmdbuf);
	}

	ps2_begin_command(ps2dev);

	serio_pause_rx(ps2dev->serio);
	ps2dev->flags = PS2_FLAG_CMD;
	ps2dev->cmdcnt = maxbytes;
	serio_continue_rx(ps2dev->serio);

	wait_event_timeout(ps2dev->wait,
			   !(ps2dev->flags & PS2_FLAG_CMD),
			   msecs_to_jiffies(timeout));

	ps2_end_command(ps2dev);
}
EXPORT_SYMBOL(ps2_drain);

/*
 * ps2_is_keyboard_id() checks received ID byte against the list of
 * known keyboard IDs.
 */

bool ps2_is_keyboard_id(u8 id_byte)
{
	static const u8 keyboard_ids[] = {
		0xab,	/* Regular keyboards		*/
		0xac,	/* NCD Sun keyboard		*/
		0x2b,	/* Trust keyboard, translated	*/
		0x5d,	/* Trust keyboard		*/
		0x60,	/* NMB SGI keyboard, translated */
		0x47,	/* NMB SGI keyboard		*/
	};

	return memchr(keyboard_ids, id_byte, sizeof(keyboard_ids)) != NULL;
}
EXPORT_SYMBOL(ps2_is_keyboard_id);

/*
 * ps2_adjust_timeout() is called after receiving 1st byte of command
 * response and tries to reduce remaining timeout to speed up command
 * completion.
 */

static int ps2_adjust_timeout(struct ps2dev *ps2dev,
			      unsigned int command, unsigned int timeout)
{
	switch (command) {
	case PS2_CMD_RESET_BAT:
		/*
		 * Device has sent the first response byte after
		 * reset command, reset is thus done, so we can
		 * shorten the timeout.
		 * The next byte will come soon (keyboard) or not
		 * at all (mouse).
		 */
		if (timeout > msecs_to_jiffies(100))
			timeout = msecs_to_jiffies(100);
		break;

	case PS2_CMD_GETID:
		/*
		 * Microsoft Natural Elite keyboard responds to
		 * the GET ID command as it were a mouse, with
		 * a single byte. Fail the command so atkbd will
		 * use alternative probe to detect it.
		 */
		if (ps2dev->cmdbuf[1] == 0xaa) {
			serio_pause_rx(ps2dev->serio);
			ps2dev->flags = 0;
			serio_continue_rx(ps2dev->serio);
			timeout = 0;
		}

		/*
		 * If device behind the port is not a keyboard there
		 * won't be 2nd byte of ID response.
		 */
		if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) {
			serio_pause_rx(ps2dev->serio);
			ps2dev->flags = ps2dev->cmdcnt = 0;
			serio_continue_rx(ps2dev->serio);
			timeout = 0;
		}
		break;

	default:
		break;
	}

	return timeout;
}

/*
 * ps2_command() sends a command and its parameters to the mouse,
 * then waits for the response and puts it in the param array.
 *
 * ps2_command() can only be called from a process context
 */

int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
{
	unsigned int timeout;
	unsigned int send = (command >> 12) & 0xf;
	unsigned int receive = (command >> 8) & 0xf;
	int rc = -1;
	int i;

	if (receive > sizeof(ps2dev->cmdbuf)) {
		WARN_ON(1);
		return -1;
	}

	if (send && !param) {
		WARN_ON(1);
		return -1;
	}

	serio_pause_rx(ps2dev->serio);
	ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;
	ps2dev->cmdcnt = receive;
	if (receive && param)
		for (i = 0; i < receive; i++)
			ps2dev->cmdbuf[(receive - 1) - i] = param[i];
	serio_continue_rx(ps2dev->serio);

	/*
	 * Some devices (Synaptics) peform the reset before
	 * ACKing the reset command, and so it can take a long
	 * time before the ACK arrives.
	 */
	if (ps2_sendbyte(ps2dev, command & 0xff,
			 command == PS2_CMD_RESET_BAT ? 1000 : 200)) {
		serio_pause_rx(ps2dev->serio);
		goto out_reset_flags;
	}

	for (i = 0; i < send; i++) {
		if (ps2_sendbyte(ps2dev, param[i], 200)) {
			serio_pause_rx(ps2dev->serio);
			goto out_reset_flags;
		}
	}

	/*
	 * The reset command takes a long time to execute.
	 */
	timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500);

	timeout = wait_event_timeout(ps2dev->wait,
				     !(ps2dev->flags & PS2_FLAG_CMD1), timeout);

	if (ps2dev->cmdcnt && !(ps2dev->flags & PS2_FLAG_CMD1)) {

		timeout = ps2_adjust_timeout(ps2dev, command, timeout);
		wait_event_timeout(ps2dev->wait,
				   !(ps2dev->flags & PS2_FLAG_CMD), timeout);
	}

	serio_pause_rx(ps2dev->serio);

	if (param)
		for (i = 0; i < receive; i++)
			param[i] = ps2dev->cmdbuf[(receive - 1) - i];

	if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1))
		goto out_reset_flags;

	rc = 0;

 out_reset_flags:
	ps2dev->flags = 0;
	serio_continue_rx(ps2dev->serio);

	return rc;
}
EXPORT_SYMBOL(__ps2_command);

int ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
{
	int rc;

	ps2_begin_command(ps2dev);
	rc = __ps2_command(ps2dev, param, command);
	ps2_end_command(ps2dev);

	return rc;
}
EXPORT_SYMBOL(ps2_command);

/*
 * ps2_init() initializes ps2dev structure
 */

void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
{
	mutex_init(&ps2dev->cmd_mutex);
	lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth);
	init_waitqueue_head(&ps2dev->wait);
	ps2dev->serio = serio;
}
EXPORT_SYMBOL(ps2_init);

/*
 * ps2_handle_ack() is supposed to be used in interrupt handler
 * to properly process ACK/NAK of a command from a PS/2 device.
 */

bool ps2_handle_ack(struct ps2dev *ps2dev, u8 data)
{
	switch (data) {
	case PS2_RET_ACK:
		ps2dev->nak = 0;
		break;

	case PS2_RET_NAK:
		ps2dev->flags |= PS2_FLAG_NAK;
		ps2dev->nak = PS2_RET_NAK;
		break;

	case PS2_RET_ERR:
		if (ps2dev->flags & PS2_FLAG_NAK) {
			ps2dev->flags &= ~PS2_FLAG_NAK;
			ps2dev->nak = PS2_RET_ERR;
			break;
		}

	/*
	 * Workaround for mice which don't ACK the Get ID command.
	 * These are valid mouse IDs that we recognize.
	 */
	case 0x00:
	case 0x03:
	case 0x04:
		if (ps2dev->flags & PS2_FLAG_WAITID) {
			ps2dev->nak = 0;
			break;
		}
		/* Fall through */
	default:
		return false;
	}

	if (!ps2dev->nak) {
		ps2dev->flags &= ~PS2_FLAG_NAK;
		if (ps2dev->cmdcnt)
			ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;
	}

	ps2dev->flags &= ~PS2_FLAG_ACK;
	wake_up(&ps2dev->wait);

	if (data != PS2_RET_ACK)
		ps2_handle_response(ps2dev, data);

	return true;
}
EXPORT_SYMBOL(ps2_handle_ack);

/*
 * ps2_handle_response() is supposed to be used in interrupt handler
 * to properly store device's response to a command and notify process
 * waiting for completion of the command.
 */

bool ps2_handle_response(struct ps2dev *ps2dev, u8 data)
{
	if (ps2dev->cmdcnt)
		ps2dev->cmdbuf[--ps2dev->cmdcnt] = data;

	if (ps2dev->flags & PS2_FLAG_CMD1) {
		ps2dev->flags &= ~PS2_FLAG_CMD1;
		if (ps2dev->cmdcnt)
			wake_up(&ps2dev->wait);
	}

	if (!ps2dev->cmdcnt) {
		ps2dev->flags &= ~PS2_FLAG_CMD;
		wake_up(&ps2dev->wait);
	}

	return true;
}
EXPORT_SYMBOL(ps2_handle_response);

void ps2_cmd_aborted(struct ps2dev *ps2dev)
{
	if (ps2dev->flags & PS2_FLAG_ACK)
		ps2dev->nak = 1;

	if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
		wake_up(&ps2dev->wait);

	/* reset all flags except last nack */
	ps2dev->flags &= PS2_FLAG_NAK;
}
EXPORT_SYMBOL(ps2_cmd_aborted);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* PS/2 driver library
	3	*
	4	* Copyright (c) 1999-2002 Vojtech Pavlik
	5	* Copyright (c) 2004 Dmitry Torokhov
	6	*/
	7
	8	/*
	9	* This program is free software; you can redistribute it and/or modify it
	10	* under the terms of the GNU General Public License version 2 as published by
	11	* the Free Software Foundation.
	12	*/
	13
	14	#include <linux/delay.h>
	15	#include <linux/module.h>
d43c36dc	16	#include <linux/sched.h>
1da177e4 LT	17	#include <linux/interrupt.h>
	18	#include <linux/input.h>
	19	#include <linux/serio.h>
181d683d	20	#include <linux/i8042.h>
1da177e4 LT	21	#include <linux/libps2.h>
	22
	23	#define DRIVER_DESC "PS/2 driver library"
	24
	25	MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
	26	MODULE_DESCRIPTION("PS/2 driver library");
	27	MODULE_LICENSE("GPL");
	28
1da177e4	29	/*
c611763d DT	30	* ps2_sendbyte() sends a byte to the device and waits for acknowledge.
	31	* It doesn't handle retransmission, though it could - because if there
	32	* is a need for retransmissions device has to be replaced anyway.
1da177e4	33	*
c611763d	34	* ps2_sendbyte() can only be called from a process context.
1da177e4 LT	35	*/
1da177e4 LT	36
b28bad65	37	int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout)
1da177e4 LT	38	{
	39	serio_pause_rx(ps2dev->serio);
	40	ps2dev->nak = 1;
	41	ps2dev->flags \|= PS2_FLAG_ACK;
	42	serio_continue_rx(ps2dev->serio);
	43
	44	if (serio_write(ps2dev->serio, byte) == 0)
	45	wait_event_timeout(ps2dev->wait,
	46	!(ps2dev->flags & PS2_FLAG_ACK),
	47	msecs_to_jiffies(timeout));
	48
	49	serio_pause_rx(ps2dev->serio);
	50	ps2dev->flags &= ~PS2_FLAG_ACK;
	51	serio_continue_rx(ps2dev->serio);
	52
	53	return -ps2dev->nak;
	54	}
5206c0d5	55	EXPORT_SYMBOL(ps2_sendbyte);
1da177e4	56
181d683d DT	57	void ps2_begin_command(struct ps2dev *ps2dev)
181d683d DT	58	{
40974618	59	struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex;
181d683d	60
40974618	61	mutex_lock(m);
181d683d DT	62	}
	63	EXPORT_SYMBOL(ps2_begin_command);
	64
	65	void ps2_end_command(struct ps2dev *ps2dev)
	66	{
40974618	67	struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex;
181d683d	68
40974618	69	mutex_unlock(m);
181d683d DT	70	}
	71	EXPORT_SYMBOL(ps2_end_command);
	72
c611763d DT	73	/*
	74	* ps2_drain() waits for device to transmit requested number of bytes
	75	* and discards them.
	76	*/
	77
b28bad65	78	void ps2_drain(struct ps2dev *ps2dev, size_t maxbytes, unsigned int timeout)
c611763d DT	79	{
	80	if (maxbytes > sizeof(ps2dev->cmdbuf)) {
	81	WARN_ON(1);
	82	maxbytes = sizeof(ps2dev->cmdbuf);
	83	}
	84
181d683d	85	ps2_begin_command(ps2dev);
c611763d DT	86
	87	serio_pause_rx(ps2dev->serio);
	88	ps2dev->flags = PS2_FLAG_CMD;
	89	ps2dev->cmdcnt = maxbytes;
	90	serio_continue_rx(ps2dev->serio);
	91
	92	wait_event_timeout(ps2dev->wait,
	93	!(ps2dev->flags & PS2_FLAG_CMD),
	94	msecs_to_jiffies(timeout));
181d683d DT	95
181d683d DT	96	ps2_end_command(ps2dev);
c611763d	97	}
5206c0d5	98	EXPORT_SYMBOL(ps2_drain);
c611763d	99
905ab9d1 DT	100	/*
	101	* ps2_is_keyboard_id() checks received ID byte against the list of
	102	* known keyboard IDs.
	103	*/
	104
b28bad65	105	bool ps2_is_keyboard_id(u8 id_byte)
905ab9d1	106	{
b28bad65	107	static const u8 keyboard_ids[] = {
905ab9d1 DT	108	0xab, /* Regular keyboards */
	109	0xac, /* NCD Sun keyboard */
	110	0x2b, /* Trust keyboard, translated */
	111	0x5d, /* Trust keyboard */
	112	0x60, /* NMB SGI keyboard, translated */
	113	0x47, /* NMB SGI keyboard */
	114	};
	115
	116	return memchr(keyboard_ids, id_byte, sizeof(keyboard_ids)) != NULL;
	117	}
5206c0d5	118	EXPORT_SYMBOL(ps2_is_keyboard_id);
905ab9d1 DT	119
	120	/*
	121	* ps2_adjust_timeout() is called after receiving 1st byte of command
	122	* response and tries to reduce remaining timeout to speed up command
	123	* completion.
	124	*/
	125
b28bad65 DT	126	static int ps2_adjust_timeout(struct ps2dev *ps2dev,
b28bad65 DT	127	unsigned int command, unsigned int timeout)
905ab9d1 DT	128	{
905ab9d1 DT	129	switch (command) {
d5e0d918 DT	130	case PS2_CMD_RESET_BAT:
	131	/*
	132	* Device has sent the first response byte after
	133	* reset command, reset is thus done, so we can
	134	* shorten the timeout.
	135	* The next byte will come soon (keyboard) or not
	136	* at all (mouse).
	137	*/
	138	if (timeout > msecs_to_jiffies(100))
	139	timeout = msecs_to_jiffies(100);
	140	break;
905ab9d1	141
d5e0d918 DT	142	case PS2_CMD_GETID:
	143	/*
	144	* Microsoft Natural Elite keyboard responds to
	145	* the GET ID command as it were a mouse, with
	146	* a single byte. Fail the command so atkbd will
	147	* use alternative probe to detect it.
	148	*/
	149	if (ps2dev->cmdbuf[1] == 0xaa) {
	150	serio_pause_rx(ps2dev->serio);
	151	ps2dev->flags = 0;
	152	serio_continue_rx(ps2dev->serio);
	153	timeout = 0;
	154	}
905ab9d1	155
d5e0d918 DT	156	/*
	157	* If device behind the port is not a keyboard there
	158	* won't be 2nd byte of ID response.
	159	*/
	160	if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) {
	161	serio_pause_rx(ps2dev->serio);
	162	ps2dev->flags = ps2dev->cmdcnt = 0;
	163	serio_continue_rx(ps2dev->serio);
	164	timeout = 0;
	165	}
	166	break;
	167
	168	default:
	169	break;
905ab9d1 DT	170	}
	171
	172	return timeout;
	173	}
	174
1da177e4 LT	175	/*
	176	* ps2_command() sends a command and its parameters to the mouse,
	177	* then waits for the response and puts it in the param array.
	178	*
	179	* ps2_command() can only be called from a process context
	180	*/
	181
b28bad65	182	int __ps2_command(struct ps2dev ps2dev, u8 param, unsigned int command)
1da177e4	183	{
b28bad65 DT	184	unsigned int timeout;
	185	unsigned int send = (command >> 12) & 0xf;
	186	unsigned int receive = (command >> 8) & 0xf;
1da177e4 LT	187	int rc = -1;
	188	int i;
	189
c611763d DT	190	if (receive > sizeof(ps2dev->cmdbuf)) {
	191	WARN_ON(1);
	192	return -1;
	193	}
	194
95349fe8 DT	195	if (send && !param) {
	196	WARN_ON(1);
	197	return -1;
	198	}
	199
1da177e4 LT	200	serio_pause_rx(ps2dev->serio);
	201	ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;
	202	ps2dev->cmdcnt = receive;
	203	if (receive && param)
	204	for (i = 0; i < receive; i++)
	205	ps2dev->cmdbuf[(receive - 1) - i] = param[i];
	206	serio_continue_rx(ps2dev->serio);
	207
	208	/*
	209	* Some devices (Synaptics) peform the reset before
	210	* ACKing the reset command, and so it can take a long
83ae417b	211	* time before the ACK arrives.
1da177e4	212	*/
c611763d	213	if (ps2_sendbyte(ps2dev, command & 0xff,
218c1f76 DV	214	command == PS2_CMD_RESET_BAT ? 1000 : 200)) {
	215	serio_pause_rx(ps2dev->serio);
	216	goto out_reset_flags;
	217	}
1da177e4	218
218c1f76 DV	219	for (i = 0; i < send; i++) {
	220	if (ps2_sendbyte(ps2dev, param[i], 200)) {
	221	serio_pause_rx(ps2dev->serio);
	222	goto out_reset_flags;
	223	}
	224	}
1da177e4 LT	225
	226	/*
	227	* The reset command takes a long time to execute.
	228	*/
	229	timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500);
	230
	231	timeout = wait_event_timeout(ps2dev->wait,
	232	!(ps2dev->flags & PS2_FLAG_CMD1), timeout);
	233
a3ce6ea4	234	if (ps2dev->cmdcnt && !(ps2dev->flags & PS2_FLAG_CMD1)) {
1da177e4	235
905ab9d1	236	timeout = ps2_adjust_timeout(ps2dev, command, timeout);
1da177e4 LT	237	wait_event_timeout(ps2dev->wait,
	238	!(ps2dev->flags & PS2_FLAG_CMD), timeout);
	239	}
	240
218c1f76 DV	241	serio_pause_rx(ps2dev->serio);
218c1f76 DV	242
1da177e4 LT	243	if (param)
	244	for (i = 0; i < receive; i++)
	245	param[i] = ps2dev->cmdbuf[(receive - 1) - i];
	246
	247	if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT \|\| ps2dev->cmdcnt != 1))
218c1f76	248	goto out_reset_flags;
1da177e4 LT	249
	250	rc = 0;
	251
218c1f76	252	out_reset_flags:
1da177e4 LT	253	ps2dev->flags = 0;
	254	serio_continue_rx(ps2dev->serio);
	255
fc69f4a6 TL	256	return rc;
	257	}
	258	EXPORT_SYMBOL(__ps2_command);
	259
b28bad65	260	int ps2_command(struct ps2dev ps2dev, u8 param, unsigned int command)
fc69f4a6 TL	261	{
	262	int rc;
	263
181d683d	264	ps2_begin_command(ps2dev);
fc69f4a6	265	rc = __ps2_command(ps2dev, param, command);
181d683d	266	ps2_end_command(ps2dev);
fc69f4a6	267
1da177e4 LT	268	return rc;
1da177e4 LT	269	}
5206c0d5	270	EXPORT_SYMBOL(ps2_command);
1da177e4	271
1da177e4 LT	272	/*
	273	* ps2_init() initializes ps2dev structure
	274	*/
	275
	276	void ps2_init(struct ps2dev ps2dev, struct serio serio)
	277	{
c4e32e9f	278	mutex_init(&ps2dev->cmd_mutex);
88aa0103	279	lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth);
1da177e4 LT	280	init_waitqueue_head(&ps2dev->wait);
	281	ps2dev->serio = serio;
	282	}
5206c0d5	283	EXPORT_SYMBOL(ps2_init);
1da177e4 LT	284
	285	/*
	286	* ps2_handle_ack() is supposed to be used in interrupt handler
	287	* to properly process ACK/NAK of a command from a PS/2 device.
	288	*/
	289
b28bad65	290	bool ps2_handle_ack(struct ps2dev *ps2dev, u8 data)
1da177e4 LT	291	{
1da177e4 LT	292	switch (data) {
d5e0d918 DT	293	case PS2_RET_ACK:
	294	ps2dev->nak = 0;
	295	break;
	296
	297	case PS2_RET_NAK:
	298	ps2dev->flags \|= PS2_FLAG_NAK;
	299	ps2dev->nak = PS2_RET_NAK;
	300	break;
	301
	302	case PS2_RET_ERR:
	303	if (ps2dev->flags & PS2_FLAG_NAK) {
	304	ps2dev->flags &= ~PS2_FLAG_NAK;
	305	ps2dev->nak = PS2_RET_ERR;
1da177e4	306	break;
d5e0d918	307	}
1da177e4	308
d5e0d918 DT	309	/*
	310	* Workaround for mice which don't ACK the Get ID command.
	311	* These are valid mouse IDs that we recognize.
	312	*/
	313	case 0x00:
	314	case 0x03:
	315	case 0x04:
	316	if (ps2dev->flags & PS2_FLAG_WAITID) {
	317	ps2dev->nak = 0;
1da177e4	318	break;
d5e0d918 DT	319	}
	320	/* Fall through */
	321	default:
b28bad65	322	return false;
1da177e4 LT	323	}
1da177e4 LT	324
a2d781fc DT	325	if (!ps2dev->nak) {
	326	ps2dev->flags &= ~PS2_FLAG_NAK;
	327	if (ps2dev->cmdcnt)
	328	ps2dev->flags \|= PS2_FLAG_CMD \| PS2_FLAG_CMD1;
	329	}
1da177e4 LT	330
	331	ps2dev->flags &= ~PS2_FLAG_ACK;
	332	wake_up(&ps2dev->wait);
	333
	334	if (data != PS2_RET_ACK)
	335	ps2_handle_response(ps2dev, data);
	336
b28bad65	337	return true;
1da177e4	338	}
5206c0d5	339	EXPORT_SYMBOL(ps2_handle_ack);
1da177e4 LT	340
	341	/*
	342	* ps2_handle_response() is supposed to be used in interrupt handler
	343	* to properly store device's response to a command and notify process
	344	* waiting for completion of the command.
	345	*/
	346
b28bad65	347	bool ps2_handle_response(struct ps2dev *ps2dev, u8 data)
1da177e4 LT	348	{
	349	if (ps2dev->cmdcnt)
	350	ps2dev->cmdbuf[--ps2dev->cmdcnt] = data;
	351
	352	if (ps2dev->flags & PS2_FLAG_CMD1) {
	353	ps2dev->flags &= ~PS2_FLAG_CMD1;
	354	if (ps2dev->cmdcnt)
	355	wake_up(&ps2dev->wait);
	356	}
	357
	358	if (!ps2dev->cmdcnt) {
	359	ps2dev->flags &= ~PS2_FLAG_CMD;
	360	wake_up(&ps2dev->wait);
	361	}
	362
b28bad65	363	return true;
1da177e4	364	}
5206c0d5	365	EXPORT_SYMBOL(ps2_handle_response);
1da177e4 LT	366
	367	void ps2_cmd_aborted(struct ps2dev *ps2dev)
	368	{
	369	if (ps2dev->flags & PS2_FLAG_ACK)
	370	ps2dev->nak = 1;
	371
	372	if (ps2dev->flags & (PS2_FLAG_ACK \| PS2_FLAG_CMD))
	373	wake_up(&ps2dev->wait);
	374
a2d781fc DT	375	/* reset all flags except last nack */
a2d781fc DT	376	ps2dev->flags &= PS2_FLAG_NAK;
1da177e4	377	}
5206c0d5	378	EXPORT_SYMBOL(ps2_cmd_aborted);