/* * 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;}