saa7164-i2c.c

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/*
 *  Driver for the NXP SAA7164 PCIe bridge
 *
 *  Copyright (c) 2010 Steven Toth <[email protected]>
 *
 *  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/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/io.h>

#include "saa7164.h"

static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
{
    struct saa7164_i2c *bus = i2c_adap->algo_data;
    struct saa7164_dev *dev = bus->dev;
    int i, retval = 0;

    dprintk(DBGLVL_I2C, "%s(num = %d)\n", __func__, num);

    for (i = 0 ; i < num; i++) {
        dprintk(DBGLVL_I2C, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
            __func__, num, msgs[i].addr, msgs[i].len);
        if (msgs[i].flags & I2C_M_RD) {
            /* Unsupported - Yet*/
            printk(KERN_ERR "%s() Unsupported - Yet\n", __func__);
            continue;
        } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
               msgs[i].addr == msgs[i + 1].addr) {
            /* write then read from same address */

            retval = saa7164_api_i2c_read(bus, msgs[i].addr,
                msgs[i].len, msgs[i].buf,
                msgs[i+1].len, msgs[i+1].buf
                );

            i++;

            if (retval < 0)
                goto err;
        } else {
            /* write */
            retval = saa7164_api_i2c_write(bus, msgs[i].addr,
                msgs[i].len, msgs[i].buf);
        }
        if (retval < 0)
            goto err;
    }
    return num;

err:
    return retval;
}

static u32 saa7164_functionality(struct i2c_adapter *adap)
{
    return I2C_FUNC_I2C;
}

static struct i2c_algorithm saa7164_i2c_algo_template = {
    .master_xfer    = i2c_xfer,
    .functionality  = saa7164_functionality,
};

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

static struct i2c_adapter saa7164_i2c_adap_template = {
    .name              = "saa7164",
    .owner             = THIS_MODULE,
    .algo              = &saa7164_i2c_algo_template,
};

static struct i2c_client saa7164_i2c_client_template = {
    .name   = "saa7164 internal",
};

int saa7164_i2c_register(struct saa7164_i2c *bus)
{
    struct saa7164_dev *dev = bus->dev;

    dprintk(DBGLVL_I2C, "%s(bus = %d)\n", __func__, bus->nr);

    bus->i2c_adap = saa7164_i2c_adap_template;
    bus->i2c_client = saa7164_i2c_client_template;

    bus->i2c_adap.dev.parent = &dev->pci->dev;

    strlcpy(bus->i2c_adap.name, bus->dev->name,
        sizeof(bus->i2c_adap.name));

    bus->i2c_adap.algo_data = bus;
    i2c_set_adapdata(&bus->i2c_adap, bus);
    i2c_add_adapter(&bus->i2c_adap);

    bus->i2c_client.adapter = &bus->i2c_adap;

    if (0 != bus->i2c_rc)
        printk(KERN_ERR "%s: i2c bus %d register FAILED\n",
            dev->name, bus->nr);

    return bus->i2c_rc;
}

int saa7164_i2c_unregister(struct saa7164_i2c *bus)
{
    i2c_del_adapter(&bus->i2c_adap);
    return 0;
}