/* * 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/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"); /* * 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;}EXPORT_SYMBOL(ps2_sendbyte); void ps2_begin_command(struct ps2dev *ps2dev){	mutex_lock(&ps2dev->cmd_mutex); 	if (i8042_check_port_owner(ps2dev->serio))		i8042_lock_chip();}EXPORT_SYMBOL(ps2_begin_command); void ps2_end_command(struct ps2dev *ps2dev){	if (i8042_check_port_owner(ps2dev->serio))		i8042_unlock_chip(); 	mutex_unlock(&ps2dev->cmd_mutex);}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, int maxbytes, 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. */ int ps2_is_keyboard_id(char id_byte){	static const 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;}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, 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:			/*			 * 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, 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;	} 	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))		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 && !(ps2dev->flags & PS2_FLAG_CMD1)) { 		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); 	return rc;}EXPORT_SYMBOL(__ps2_command); int ps2_command(struct ps2dev *ps2dev, unsigned char *param, 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. */ 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->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 0;	}  	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 1;}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. */ 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;}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);