Subversion Repositories shark

/* ------------------------------------------------------------------------- */
/* i2c-velleman.c i2c-hw access for Velleman K9000 adapters                  */
/* ------------------------------------------------------------------------- */
/*   Copyright (C) 1995-96, 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.                */
/* ------------------------------------------------------------------------- */

/* $Id: i2c-velleman.c,v 1.1 2004-01-28 15:12:07 giacomo Exp $ */

#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include <asm/io.h>

/* ----- 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                               */

                                        /* Pin Port  Inverted   name    */
#define I2C_SDA         0x02            /*  ctrl bit 1  (inv)   */
#define I2C_SCL         0x08            /*  ctrl bit 3  (inv)   */

#define I2C_SDAIN       0x10            /* stat bit 4           */
#define I2C_SCLIN       0x08            /* ctrl bit 3 (inv)(reads own output)*/

#define I2C_DMASK       0xfd
#define I2C_CMASK       0xf7


/* --- 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      */

#define DEFAULT_BASE 0x378
static int base=0;

/* ----- local functions --------------------------------------------------- */

static void bit_velle_setscl(void *data, int state)
{
        if (state) {
                outb(inb(CTRL) & I2C_CMASK,   CTRL);
        } else {
                outb(inb(CTRL) | I2C_SCL, CTRL);
        }
       
}

static void bit_velle_setsda(void *data, int state)
{
        if (state) {
                outb(inb(CTRL) & I2C_DMASK , CTRL);
        } else {
                outb(inb(CTRL) | I2C_SDA, CTRL);
        }
       
}

static int bit_velle_getscl(void *data)
{
        return ( 0 == ( (inb(CTRL)) & I2C_SCLIN ) );
}

static int bit_velle_getsda(void *data)
{
        return ( 0 != ( (inb(STAT)) & I2C_SDAIN ) );
}

static int bit_velle_init(void)
{
        if (!request_region(base, (base == 0x3bc) ? 3 : 8,
                        "i2c (Vellemann adapter)"))
                return -ENODEV;

        bit_velle_setsda((void*)base,1);
        bit_velle_setscl((void*)base,1);
        return 0;
}

/* ------------------------------------------------------------------------
 * 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_velle_data = {
        .setsda         = bit_velle_setsda,
        .setscl         = bit_velle_setscl,
        .getsda         = bit_velle_getsda,
        .getscl         = bit_velle_getscl,
        .udelay         = 10,
        .mdelay         = 10,
        .timeout        = HZ
};

static struct i2c_adapter bit_velle_ops = {
        .owner          = THIS_MODULE,
        .algo_data      = &bit_velle_data,
        .name           = "Velleman K8000",
};

static int __init i2c_bitvelle_init(void)
{
        printk(KERN_INFO "i2c-velleman: i2c Velleman K8000 driver\n");
        if (base==0) {
                /* probe some values */
                base=DEFAULT_BASE;
                bit_velle_data.data=(void*)DEFAULT_BASE;
                if (bit_velle_init()==0) {
                        if(i2c_bit_add_bus(&bit_velle_ops) < 0)
                                return -ENODEV;
                } else {
                        return -ENODEV;
                }
        } else {
                bit_velle_data.data=(void*)base;
                if (bit_velle_init()==0) {
                        if(i2c_bit_add_bus(&bit_velle_ops) < 0)
                                return -ENODEV;
                } else {
                        return -ENODEV;
                }
        }
        printk(KERN_DEBUG "i2c-velleman: found device at %#x.\n",base);
        return 0;
}

static void __exit i2c_bitvelle_exit(void)
{      
        i2c_bit_del_bus(&bit_velle_ops);
        release_region(base, (base == 0x3bc) ? 3 : 8);
}

MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
MODULE_DESCRIPTION("I2C-Bus adapter routines for Velleman K8000 adapter");
MODULE_LICENSE("GPL");

MODULE_PARM(base, "i");

module_init(i2c_bitvelle_init);
module_exit(i2c_bitvelle_exit);