linux-imx

/* drivers/rtc/rtc-max6902.c

 *

 * Copyright (C) 2006 8D Technologies inc.

 * Copyright (C) 2004 Compulab Ltd.

 *

 * 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.

 *

 * Driver for MAX6902 spi RTC

 *

 */

​

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/platform_device.h>

#include <linux/init.h>

#include <linux/rtc.h>

#include <linux/spi/spi.h>

#include <linux/bcd.h>

​

#define MAX6902_REG_SECONDS     0x01

#define MAX6902_REG_MINUTES     0x03

#define MAX6902_REG_HOURS       0x05

#define MAX6902_REG_DATE        0x07

#define MAX6902_REG_MONTH       0x09

#define MAX6902_REG_DAY         0x0B

#define MAX6902_REG_YEAR        0x0D

#define MAX6902_REG_CONTROL     0x0F

#define MAX6902_REG_CENTURY     0x13

​

static int max6902_set_reg(struct device *dev, unsigned char address,

                unsigned char data)

{

    struct spi_device *spi = to_spi_device(dev);

    unsigned char buf[2];

​

    /* MSB must be '0' to write */

    buf[0] = address & 0x7f;

    buf[1] = data;

​

    return spi_write_then_read(spi, buf, 2, NULL, 0);

}

​

static int max6902_get_reg(struct device *dev, unsigned char address,

                unsigned char *data)

{

    struct spi_device *spi = to_spi_device(dev);

​

    /* Set MSB to indicate read */

    *data = address | 0x80;

​

    return spi_write_then_read(spi, data, 1, data, 1);

}

​

static int max6902_read_time(struct device *dev, struct rtc_time *dt)

{

    int err, century;

    struct spi_device *spi = to_spi_device(dev);

    unsigned char buf[8];

​

    buf[0] = 0xbf;  /* Burst read */

​