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/* linux/drivers/i2c/scx200_i2c.c

   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>

   National Semiconductor SCx200 I2C bus on GPIO pins

   Based on i2c-velleman.c 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.

*/

#include <linux/config.h>

#include <linux/module.h>

#include <linux/errno.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/i2c.h>

#include <linux/i2c-algo-bit.h>

#include <asm/io.h>

#include <linux/scx200_gpio.h>

#define NAME "scx200_i2c"

MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");

MODULE_DESCRIPTION("NatSemi SCx200 I2C Driver");

MODULE_LICENSE("GPL");

MODULE_PARM(scl, "i");

MODULE_PARM_DESC(scl, "GPIO line for SCL");

MODULE_PARM(sda, "i");

MODULE_PARM_DESC(sda, "GPIO line for SDA");

static int scl = CONFIG_SCx200_I2C_SCL;

static int sda = CONFIG_SCx200_I2C_SDA;

static void scx200_i2c_setscl(void *data, int state)

{

        scx200_gpio_set(scl, state);

}

static void scx200_i2c_setsda(void *data, int state)

{

        scx200_gpio_set(sda, state);

}

static int scx200_i2c_getscl(void *data)

{

        return scx200_gpio_get(scl);

}

static int scx200_i2c_getsda(void *data)

{

        return scx200_gpio_get(sda);

}

static int scx200_i2c_reg(struct i2c_client *client)

{

        return 0;

}

static int scx200_i2c_unreg(struct i2c_client *client)

{

        return 0;

}

static void scx200_i2c_inc_use(struct i2c_adapter *adap)

{

        MOD_INC_USE_COUNT;

}

static void scx200_i2c_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 scx200_i2c_data = {

        NULL,

        scx200_i2c_setsda,

        scx200_i2c_setscl,

        scx200_i2c_getsda,

        scx200_i2c_getscl,

        10, 10, 100,            /* waits, timeout */

};

static struct i2c_adapter scx200_i2c_ops = {

        .name              = "NatSemi SCx200 I2C",

        .id                = I2C_HW_B_VELLE,

        .algo_data         = &scx200_i2c_data,

        .inc_use           = scx200_i2c_inc_use,

        .dec_use           = scx200_i2c_dec_use,

        .client_register   = scx200_i2c_reg,

        .client_unregister = scx200_i2c_unreg,

};

int scx200_i2c_init(void)

{

        printk(KERN_DEBUG NAME ": NatSemi SCx200 I2C Driver\n");

        if (!scx200_gpio_present()) {

                printk(KERN_ERR NAME ": no SCx200 gpio pins available\n");

                return -ENODEV;

        }

        printk(KERN_DEBUG NAME ": SCL=GPIO%02u, SDA=GPIO%02u\n",

               scl, sda);

        if (scl == -1 || sda == -1 || scl == sda) {

                printk(KERN_ERR NAME ": scl and sda must be specified\n");

                return -EINVAL;

        }

        /* Configure GPIOs as open collector outputs */

        scx200_gpio_configure(scl, ~2, 5);

        scx200_gpio_configure(sda, ~2, 5);

        if (i2c_bit_add_bus(&scx200_i2c_ops) < 0) {

                printk(KERN_ERR NAME ": adapter %s registration failed\n",

                       scx200_i2c_ops.name);

                return -ENODEV;

        }

        return 0;

}

void scx200_i2c_cleanup(void)

{

        i2c_bit_del_bus(&scx200_i2c_ops);

}

module_init(scx200_i2c_init);

module_exit(scx200_i2c_cleanup);

/*

    Local variables:

        compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules"

        c-basic-offset: 8

    End:

*/