[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/moduleparam.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/init.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");

EXPORT_SYMBOL(ps2_init);
EXPORT_SYMBOL(ps2_sendbyte);
EXPORT_SYMBOL(ps2_drain);
EXPORT_SYMBOL(ps2_command);
EXPORT_SYMBOL(ps2_schedule_command);
EXPORT_SYMBOL(ps2_handle_ack);
EXPORT_SYMBOL(ps2_handle_response);
EXPORT_SYMBOL(ps2_cmd_aborted);

/* Work structure to schedule execution of a command */
struct ps2work {
	struct work_struct work;
	struct ps2dev *ps2dev;
	int command;
	unsigned char param[0];
};


/*
 * 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, unsigned char byte, 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;
}

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

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

	down(&ps2dev->cmd_sem);

	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));
	up(&ps2dev->cmd_sem);
}

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

static inline int ps2_is_keyboard_id(char id_byte)
{
	static char 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;
}

/*
 * 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, int command, 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:
			/*
			 * 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, unsigned char *param, int command)
{
	int timeout;
	int send = (command >> 12) & 0xf;
	int receive = (command >> 8) & 0xf;
	int rc = -1;
	int i;

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

	down(&ps2dev->cmd_sem);

	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 arrrives.
	 */
	if (ps2_sendbyte(ps2dev, command & 0xff,
			 command == PS2_CMD_RESET_BAT ? 1000 : 200))
		goto out;

	for (i = 0; i < send; i++)
		if (ps2_sendbyte(ps2dev, param[i], 200))
			goto out;

	/*
	 * 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 && timeout > 0) {

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

	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;

	rc = 0;

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

	up(&ps2dev->cmd_sem);
	return rc;
}

/*
 * ps2_execute_scheduled_command() sends a command, previously scheduled by
 * ps2_schedule_command(), to a PS/2 device (keyboard, mouse, etc.)
 */

static void ps2_execute_scheduled_command(void *data)
{
	struct ps2work *ps2work = data;

	ps2_command(ps2work->ps2dev, ps2work->param, ps2work->command);
	kfree(ps2work);
}

/*
 * ps2_schedule_command() allows to schedule delayed execution of a PS/2
 * command and can be used to issue a command from an interrupt or softirq
 * context.
 */

int ps2_schedule_command(struct ps2dev *ps2dev, unsigned char *param, int command)
{
	struct ps2work *ps2work;
	int send = (command >> 12) & 0xf;
	int receive = (command >> 8) & 0xf;

	if (!(ps2work = kmalloc(sizeof(struct ps2work) + max(send, receive), GFP_ATOMIC)))
		return -1;

	memset(ps2work, 0, sizeof(struct ps2work));
	ps2work->ps2dev = ps2dev;
	ps2work->command = command;
	memcpy(ps2work->param, param, send);
	INIT_WORK(&ps2work->work, ps2_execute_scheduled_command, ps2work);

	if (!schedule_work(&ps2work->work)) {
		kfree(ps2work);
		return -1;
	}

	return 0;
}

/*
 * ps2_init() initializes ps2dev structure
 */

void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
{
	init_MUTEX(&ps2dev->cmd_sem);
	init_waitqueue_head(&ps2dev->wait);
	ps2dev->serio = serio;
}

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

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

		case PS2_RET_NAK:
			ps2dev->nak = 1;
			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 0;
	}


	if (!ps2dev->nak && 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 1;
}

/*
 * 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.
 */

int ps2_handle_response(struct ps2dev *ps2dev, unsigned char 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 1;
}

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);

	ps2dev->flags = 0;
}
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>
	16	#include <linux/moduleparam.h>
	17	#include <linux/slab.h>
	18	#include <linux/interrupt.h>
	19	#include <linux/input.h>
	20	#include <linux/serio.h>
	21	#include <linux/init.h>
	22	#include <linux/libps2.h>
	23
	24	#define DRIVER_DESC "PS/2 driver library"
	25
	26	MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
	27	MODULE_DESCRIPTION("PS/2 driver library");
	28	MODULE_LICENSE("GPL");
	29
	30	EXPORT_SYMBOL(ps2_init);
	31	EXPORT_SYMBOL(ps2_sendbyte);
c611763d	32	EXPORT_SYMBOL(ps2_drain);
1da177e4 LT	33	EXPORT_SYMBOL(ps2_command);
	34	EXPORT_SYMBOL(ps2_schedule_command);
	35	EXPORT_SYMBOL(ps2_handle_ack);
	36	EXPORT_SYMBOL(ps2_handle_response);
	37	EXPORT_SYMBOL(ps2_cmd_aborted);
	38
	39	/* Work structure to schedule execution of a command */
	40	struct ps2work {
	41	struct work_struct work;
	42	struct ps2dev *ps2dev;
	43	int command;
	44	unsigned char param[0];
	45	};
	46
	47
	48	/*
c611763d DT	49	* ps2_sendbyte() sends a byte to the device and waits for acknowledge.
	50	* It doesn't handle retransmission, though it could - because if there
	51	* is a need for retransmissions device has to be replaced anyway.
1da177e4	52	*
c611763d	53	* ps2_sendbyte() can only be called from a process context.
1da177e4 LT	54	*/
	55
	56	int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout)
	57	{
	58	serio_pause_rx(ps2dev->serio);
	59	ps2dev->nak = 1;
	60	ps2dev->flags \|= PS2_FLAG_ACK;
	61	serio_continue_rx(ps2dev->serio);
	62
	63	if (serio_write(ps2dev->serio, byte) == 0)
	64	wait_event_timeout(ps2dev->wait,
	65	!(ps2dev->flags & PS2_FLAG_ACK),
	66	msecs_to_jiffies(timeout));
	67
	68	serio_pause_rx(ps2dev->serio);
	69	ps2dev->flags &= ~PS2_FLAG_ACK;
	70	serio_continue_rx(ps2dev->serio);
	71
	72	return -ps2dev->nak;
	73	}
	74
c611763d DT	75	/*
	76	* ps2_drain() waits for device to transmit requested number of bytes
	77	* and discards them.
	78	*/
	79
	80	void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout)
	81	{
	82	if (maxbytes > sizeof(ps2dev->cmdbuf)) {
	83	WARN_ON(1);
	84	maxbytes = sizeof(ps2dev->cmdbuf);
	85	}
	86
	87	down(&ps2dev->cmd_sem);
	88
	89	serio_pause_rx(ps2dev->serio);
	90	ps2dev->flags = PS2_FLAG_CMD;
	91	ps2dev->cmdcnt = maxbytes;
	92	serio_continue_rx(ps2dev->serio);
	93
	94	wait_event_timeout(ps2dev->wait,
	95	!(ps2dev->flags & PS2_FLAG_CMD),
	96	msecs_to_jiffies(timeout));
	97	up(&ps2dev->cmd_sem);
	98	}
	99
905ab9d1 DT	100	/*
	101	* ps2_is_keyboard_id() checks received ID byte against the list of
	102	* known keyboard IDs.
	103	*/
	104
	105	static inline int ps2_is_keyboard_id(char id_byte)
	106	{
	107	static char keyboard_ids[] = {
	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	}
	118
	119	/*
	120	* ps2_adjust_timeout() is called after receiving 1st byte of command
	121	* response and tries to reduce remaining timeout to speed up command
	122	* completion.
	123	*/
	124
	125	static int ps2_adjust_timeout(struct ps2dev *ps2dev, int command, int timeout)
	126	{
	127	switch (command) {
	128	case PS2_CMD_RESET_BAT:
	129	/*
	130	* Device has sent the first response byte after
	131	* reset command, reset is thus done, so we can
	132	* shorten the timeout.
	133	* The next byte will come soon (keyboard) or not
	134	* at all (mouse).
	135	*/
	136	if (timeout > msecs_to_jiffies(100))
	137	timeout = msecs_to_jiffies(100);
	138	break;
	139
	140	case PS2_CMD_GETID:
	141	/*
	142	* If device behind the port is not a keyboard there
	143	* won't be 2nd byte of ID response.
	144	*/
	145	if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) {
	146	serio_pause_rx(ps2dev->serio);
	147	ps2dev->flags = ps2dev->cmdcnt = 0;
	148	serio_continue_rx(ps2dev->serio);
	149	timeout = 0;
	150	}
	151	break;
	152
	153	default:
	154	break;
	155	}
	156
	157	return timeout;
	158	}
	159
1da177e4 LT	160	/*
	161	* ps2_command() sends a command and its parameters to the mouse,
	162	* then waits for the response and puts it in the param array.
	163	*
	164	* ps2_command() can only be called from a process context
	165	*/
	166
	167	int ps2_command(struct ps2dev ps2dev, unsigned char param, int command)
	168	{
	169	int timeout;
	170	int send = (command >> 12) & 0xf;
	171	int receive = (command >> 8) & 0xf;
	172	int rc = -1;
	173	int i;
	174
c611763d DT	175	if (receive > sizeof(ps2dev->cmdbuf)) {
	176	WARN_ON(1);
	177	return -1;
	178	}
	179
1da177e4 LT	180	down(&ps2dev->cmd_sem);
	181
	182	serio_pause_rx(ps2dev->serio);
	183	ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;
	184	ps2dev->cmdcnt = receive;
	185	if (receive && param)
	186	for (i = 0; i < receive; i++)
	187	ps2dev->cmdbuf[(receive - 1) - i] = param[i];
	188	serio_continue_rx(ps2dev->serio);
	189
	190	/*
	191	* Some devices (Synaptics) peform the reset before
	192	* ACKing the reset command, and so it can take a long
	193	* time before the ACK arrrives.
	194	*/
c611763d DT	195	if (ps2_sendbyte(ps2dev, command & 0xff,
	196	command == PS2_CMD_RESET_BAT ? 1000 : 200))
	197	goto out;
1da177e4 LT	198
	199	for (i = 0; i < send; i++)
	200	if (ps2_sendbyte(ps2dev, param[i], 200))
	201	goto out;
	202
	203	/*
	204	* The reset command takes a long time to execute.
	205	*/
	206	timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500);
	207
	208	timeout = wait_event_timeout(ps2dev->wait,
	209	!(ps2dev->flags & PS2_FLAG_CMD1), timeout);
	210
	211	if (ps2dev->cmdcnt && timeout > 0) {
	212
905ab9d1	213	timeout = ps2_adjust_timeout(ps2dev, command, timeout);
1da177e4 LT	214	wait_event_timeout(ps2dev->wait,
	215	!(ps2dev->flags & PS2_FLAG_CMD), timeout);
	216	}
	217
	218	if (param)
	219	for (i = 0; i < receive; i++)
	220	param[i] = ps2dev->cmdbuf[(receive - 1) - i];
	221
	222	if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT \|\| ps2dev->cmdcnt != 1))
	223	goto out;
	224
	225	rc = 0;
	226
905ab9d1	227	out:
1da177e4 LT	228	serio_pause_rx(ps2dev->serio);
	229	ps2dev->flags = 0;
	230	serio_continue_rx(ps2dev->serio);
	231
	232	up(&ps2dev->cmd_sem);
	233	return rc;
	234	}
	235
	236	/*
	237	* ps2_execute_scheduled_command() sends a command, previously scheduled by
	238	* ps2_schedule_command(), to a PS/2 device (keyboard, mouse, etc.)
	239	*/
	240
	241	static void ps2_execute_scheduled_command(void *data)
	242	{
	243	struct ps2work *ps2work = data;
	244
	245	ps2_command(ps2work->ps2dev, ps2work->param, ps2work->command);
	246	kfree(ps2work);
	247	}
	248
	249	/*
	250	* ps2_schedule_command() allows to schedule delayed execution of a PS/2
	251	* command and can be used to issue a command from an interrupt or softirq
	252	* context.
	253	*/
	254
	255	int ps2_schedule_command(struct ps2dev ps2dev, unsigned char param, int command)
	256	{
	257	struct ps2work *ps2work;
	258	int send = (command >> 12) & 0xf;
	259	int receive = (command >> 8) & 0xf;
	260
	261	if (!(ps2work = kmalloc(sizeof(struct ps2work) + max(send, receive), GFP_ATOMIC)))
	262	return -1;
	263
	264	memset(ps2work, 0, sizeof(struct ps2work));
	265	ps2work->ps2dev = ps2dev;
	266	ps2work->command = command;
	267	memcpy(ps2work->param, param, send);
	268	INIT_WORK(&ps2work->work, ps2_execute_scheduled_command, ps2work);
	269
	270	if (!schedule_work(&ps2work->work)) {
	271	kfree(ps2work);
	272	return -1;
	273	}
	274
	275	return 0;
	276	}
	277
	278	/*
	279	* ps2_init() initializes ps2dev structure
	280	*/
	281
	282	void ps2_init(struct ps2dev ps2dev, struct serio serio)
	283	{
	284	init_MUTEX(&ps2dev->cmd_sem);
	285	init_waitqueue_head(&ps2dev->wait);
	286	ps2dev->serio = serio;
	287	}
	288
	289	/*
	290	* ps2_handle_ack() is supposed to be used in interrupt handler
	291	* to properly process ACK/NAK of a command from a PS/2 device.
292	*/
293
294	int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data)
295	{
296	switch (data) {
297	case PS2_RET_ACK:
298	ps2dev->nak = 0;
299	break;
300
301	case PS2_RET_NAK:
302	ps2dev->nak = 1;
303	break;
304
305	/*
306	* Workaround for mice which don't ACK the Get ID command.
307	* These are valid mouse IDs that we recognize.
308	*/
309	case 0x00:
310	case 0x03:
311	case 0x04:
312	if (ps2dev->flags & PS2_FLAG_WAITID) {
313	ps2dev->nak = 0;
314	break;
315	}
316	/* Fall through */
317	default:
318	return 0;
319	}
320
321
322	if (!ps2dev->nak && ps2dev->cmdcnt)
323	ps2dev->flags \|= PS2_FLAG_CMD \| PS2_FLAG_CMD1;
324
325	ps2dev->flags &= ~PS2_FLAG_ACK;
326	wake_up(&ps2dev->wait);
327
328	if (data != PS2_RET_ACK)
329	ps2_handle_response(ps2dev, data);
330
331	return 1;
332	}
333
334	/*
335	* ps2_handle_response() is supposed to be used in interrupt handler
336	* to properly store device's response to a command and notify process
337	* waiting for completion of the command.
338	*/
339
340	int ps2_handle_response(struct ps2dev *ps2dev, unsigned char data)
341	{
342	if (ps2dev->cmdcnt)
343	ps2dev->cmdbuf[--ps2dev->cmdcnt] = data;
344
345	if (ps2dev->flags & PS2_FLAG_CMD1) {
346	ps2dev->flags &= ~PS2_FLAG_CMD1;
347	if (ps2dev->cmdcnt)
348	wake_up(&ps2dev->wait);
349	}
350
351	if (!ps2dev->cmdcnt) {
352	ps2dev->flags &= ~PS2_FLAG_CMD;
353	wake_up(&ps2dev->wait);
354	}
355
356	return 1;
357	}
358
359	void ps2_cmd_aborted(struct ps2dev *ps2dev)
360	{
361	if (ps2dev->flags & PS2_FLAG_ACK)
362	ps2dev->nak = 1;
363
364	if (ps2dev->flags & (PS2_FLAG_ACK \| PS2_FLAG_CMD))
365	wake_up(&ps2dev->wait);
366
367	ps2dev->flags = 0;
368	}
369