/* ------------------------------------------------------------------------- *//* i2c-elv.c i2c-hw access for philips style parallel port adapters	     *//* ------------------------------------------------------------------------- *//*   Copyright (C) 1995-2000 Simon G. Vogl    This program is free software; you can redistribute it and/or modify    it under the terms of the GNU General Public License as published by    the Free Software Foundation; either version 2 of the License, or    (at your option) any later version.    This program is distributed in the hope that it will be useful,    but WITHOUT ANY WARRANTY; without even the implied warranty of    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    GNU General Public License for more details.    You should have received a copy of the GNU General Public License    along with this program; if not, write to the Free Software    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.		     *//* ------------------------------------------------------------------------- *//* With some changes from Ky鰏ti M鋖kki <kmalkki@cc.hut.fi> and even   Frodo Looijaard <frodol@dds.nl> *//* $Id: i2c-elv.c,v 1.2 2004/02/06 13:19:45 laputa Exp $ */#include <linux/kernel.h>#include <linux/module.h>#include <linux/delay.h>#include <linux/slab.h>#include <linux/version.h>#include <linux/init.h>#include <asm/uaccess.h>#include <linux/ioport.h>#include <asm/io.h>#include <linux/errno.h>#include <linux/i2c.h>#include <linux/i2c-algo-bit.h>#define DEFAULT_BASE 0x378static int base=0;static unsigned char PortData = 0;/* ----- global defines -----------------------------------------------	*/#define DEB(x)		/* should be reasonable open, close &c. 	*/#define DEB2(x) 	/* low level debugging - very slow 		*/#define DEBE(x)	x	/* error messages 				*/#define DEBINIT(x) x	/* detection status messages			*//* --- Convenience defines for the parallel port:			*/#define BASE	(unsigned int)(data)#define DATA	BASE			/* Centronics data port		*/#define STAT	(BASE+1)		/* Centronics status port	*/#define CTRL	(BASE+2)		/* Centronics control port	*//* ----- local functions ----------------------------------------------	*/static void bit_elv_setscl(void *data, int state){	if (state) {		PortData &= 0xfe;	} else {		PortData |=1;	}	outb(PortData, DATA);}static void bit_elv_setsda(void *data, int state){	if (state) {		PortData &=0xfd;	} else {		PortData |=2;	}	outb(PortData, DATA);} static int bit_elv_getscl(void *data){	return ( 0 == ( (inb_p(STAT)) & 0x08 ) );}static int bit_elv_getsda(void *data){	return ( 0 == ( (inb_p(STAT)) & 0x40 ) );}static int bit_elv_init(void){	if (check_region(base,(base == 0x3bc)? 3 : 8) < 0 ) {		return -ENODEV;		} else {						/* test for ELV adap. 	*/		if (inb(base+1) & 0x80) {	/* BUSY should be high	*/			DEBINIT(printk("i2c-elv.o: Busy was low.\n"));			return -ENODEV;		} else {			outb(0x0c,base+2);	/* SLCT auf low		*/			udelay(400);			if ( !(inb(base+1) && 0x10) ) {				outb(0x04,base+2);				DEBINIT(printk("i2c-elv.o: Select was high.\n"));				return -ENODEV;			}		}		request_region(base,(base == 0x3bc)? 3 : 8,			"i2c (ELV adapter)");		PortData = 0;		bit_elv_setsda((void*)base,1);		bit_elv_setscl((void*)base,1);	}	return 0;}static void __exit bit_elv_exit(void){	release_region( base , (base == 0x3bc)? 3 : 8 );}static int bit_elv_reg(struct i2c_client *client){	return 0;}static int bit_elv_unreg(struct i2c_client *client){	return 0;}static void bit_elv_inc_use(struct i2c_adapter *adap){	MOD_INC_USE_COUNT;}static void bit_elv_dec_use(struct i2c_adapter *adap){	MOD_DEC_USE_COUNT;}/* ------------------------------------------------------------------------ * Encapsulate the above functions in the correct operations structure. * This is only done when more than one hardware adapter is supported. */static struct i2c_algo_bit_data bit_elv_data = {	NULL,	bit_elv_setsda,	bit_elv_setscl,	bit_elv_getsda,	bit_elv_getscl,	80, 80, 100,		/*	waits, timeout */};static struct i2c_adapter bit_elv_ops = {	"ELV Parallel port adaptor",	I2C_HW_B_ELV,	NULL,	&bit_elv_data,	bit_elv_inc_use,	bit_elv_dec_use,	bit_elv_reg,	bit_elv_unreg,	};static int __init i2c_bitelv_init(void){	printk("i2c-elv.o: i2c ELV parallel port adapter module\n");	if (base==0) {		/* probe some values */		base=DEFAULT_BASE;		bit_elv_data.data=(void*)DEFAULT_BASE;		if (bit_elv_init()==0) {			if(i2c_bit_add_bus(&bit_elv_ops) < 0)				return -ENODEV;		} else {			return -ENODEV;		}	} else {		bit_elv_ops.data=(void*)base;		if (bit_elv_init()==0) {			if(i2c_bit_add_bus(&bit_elv_ops) < 0)				return -ENODEV;		} else {			return -ENODEV;		}	}	printk("i2c-elv.o: found device at %#x.\n",base);	return 0;}static void __exit i2c_bitelv_exit(void){	i2c_bit_del_bus(&bit_elv_ops);	bit_elv_exit();}EXPORT_NO_SYMBOLS;MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");MODULE_DESCRIPTION("I2C-Bus adapter routines for ELV parallel port adapter");MODULE_LICENSE("GPL");MODULE_PARM(base, "i");module_init(i2c_bitelv_init);module_exit(i2c_bitelv_exit);