Subversion Repositories or1k

/* ------------------------------------------------------------------------- */

/* 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 Kyösti Mälkki <kmalkki@cc.hut.fi> and even

   Frodo Looijaard <frodol@dds.nl> */

/* $Id: i2c-elv.c,v 1.1.1.1 2004-04-15 01:38:31 phoenix Exp $ */

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/delay.h>

#include <linux/slab.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 0x378

static 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(KERN_DEBUG "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(KERN_DEBUG "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)

{

#ifdef MODULE

        MOD_INC_USE_COUNT;

#endif

}

static void bit_elv_dec_use(struct i2c_adapter *adap)

{

#ifdef MODULE

        MOD_DEC_USE_COUNT;

#endif

}

/* ------------------------------------------------------------------------

 * 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,

};

int __init i2c_bitelv_init(void)

{

        printk(KERN_INFO "i2c-elv.o: i2c ELV parallel port adapter module version %s (%s)\n", I2C_VERSION, I2C_DATE);

        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(KERN_DEBUG "i2c-elv.o: found device at %#x.\n",base);

        return 0;

}

EXPORT_NO_SYMBOLS;

#ifdef MODULE

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");

int init_module(void)

{

        return i2c_bitelv_init();

}

void cleanup_module(void)

{

        i2c_bit_del_bus(&bit_elv_ops);

        bit_elv_exit();

}

#endif