root/i2c/trunk/kernel/i2c-velleman.c @ 3330

/* ------------------------------------------------------------------------- */
/* i2c-velleman.c i2c-hw access for Velleman K9000 adapters                  */
/* ------------------------------------------------------------------------- */
/*   Copyright (C) 1995-96 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.                */
/* ------------------------------------------------------------------------- 
static char rcsid[] = "$Id$";
  ------------------------------------------------------------------------- */

#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/module.h>
#if LINUX_VERSION_CODE >= 0x020135
#include <linux/init.h>
#else
#define __init 
#endif
#include <linux/string.h>  /* for 2.0 kernels to get NULL   */
#include <asm/errno.h>     /* for 2.0 kernels to get ENODEV */
#include <asm/io.h>

#include "i2c.h"
#include "i2c-algo-bit.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 (check_region(base,(base == 0x3bc)? 3 : 8) < 0 ) {
                DEBE(printk("i2c_init: Port %#x already in use.\n", base));
                return -ENODEV;
        } else {
                request_region(base, (base == 0x3bc)? 3 : 8, 
                        "i2c (Vellemann adapter)");
                bit_velle_setsda((void*)base,1);
                bit_velle_setscl((void*)base,1);
        }
        return 0;
}

static void bit_velle_exit(void)
{       
        release_region( base , (base == 0x3bc)? 3 : 8 );
}


static int bit_velle_reg(struct i2c_client *client)
{
        return 0;
}

static int bit_velle_unreg(struct i2c_client *client)
{
        return 0;
}

static void bit_velle_inc_use(struct i2c_adapter *adap)
{
#ifdef MODULE
        MOD_INC_USE_COUNT;
#endif
}

static void bit_velle_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_velle_data = {
        NULL,
        bit_velle_setsda,
        bit_velle_setscl,
        bit_velle_getsda,
        bit_velle_getscl,
        10, 10, 100,            /*      waits, timeout */
};

static struct i2c_adapter bit_velle_ops = {
        "Philips Parallel port adapter",
        I2C_HW_B_LP,
        NULL,
        &bit_velle_data,
        bit_velle_inc_use,
        bit_velle_dec_use,
        bit_velle_reg,
        bit_velle_unreg,
};

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


#ifdef MODULE
MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
MODULE_DESCRIPTION("I2C-Bus adapter routines for Velleman K9000 adapter");

MODULE_PARM(base, "i");

int init_module(void) 
{
        return i2c_bitvelle_init();
}

void cleanup_module(void) 
{
        i2c_bit_del_bus(&bit_velle_ops);
        bit_velle_exit();
}

#endif