linux-imx

/*

 * An rtc/i2c driver for the Dallas DS1672

 * Copyright 2005-06 Tower Technologies

 *

 * Author: Alessandro Zummo <a.zummo@towertech.it>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

​

#include <linux/i2c.h>

#include <linux/rtc.h>

#include <linux/module.h>

​

/* Registers */

​

#define DS1672_REG_CNT_BASE 0

#define DS1672_REG_CONTROL  4

#define DS1672_REG_TRICKLE  5

​

#define DS1672_REG_CONTROL_EOSC 0x80

​

static struct i2c_driver ds1672_driver;

​

/*

 * In the routines that deal directly with the ds1672 hardware, we use

 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch

 * Epoch is initialized as 2000. Time is set to UTC.

 */

static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm)

{

    unsigned long time;

    unsigned char addr = DS1672_REG_CNT_BASE;

    unsigned char buf[4];

​

    struct i2c_msg msgs[] = {

        {/* setup read ptr */

            .addr = client->addr,

            .len = 1,

            .buf = &addr

        },

        {/* read date */

            .addr = client->addr,

            .flags = I2C_M_RD,

            .len = 4,

            .buf = buf

        },

    };

​

    /* read date registers */

    if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {

        dev_err(&client->dev, "%s: read error\n", __func__);

        return -EIO;

    }

​

    dev_dbg(&client->dev,

        "%s: raw read data - counters=%02x,%02x,%02x,%02x\n",

        __func__, buf[0], buf[1], buf[2], buf[3]);

​

    time = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |

           (buf[1] << 8) | buf[0];

​

    rtc_time_to_tm(time, tm);

​

    dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "

        "mday=%d, mon=%d, year=%d, wday=%d\n",

        __func__, tm->tm_sec, tm->tm_min, tm->tm_hour,

        tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

​

    return 0;

}

​

static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs)

{

    int xfer;

    unsigned char buf[6];

​

    buf[0] = DS1672_REG_CNT_BASE;

    buf[1] = secs & 0x000000FF;

    buf[2] = (secs & 0x0000FF00) >> 8;

    buf[3] = (secs & 0x00FF0000) >> 16;

    buf[4] = (secs & 0xFF000000) >> 24;

    buf[5] = 0;     /* set control reg to enable counting */

​

    xfer = i2c_master_send(client, buf, 6);

    if (xfer != 6) {

        dev_err(&client->dev, "%s: send: %d\n", __func__, xfer);

        return -EIO;

    }

​

    return 0;