linux-imx

/*

 * rtc-fm3130.c - RTC driver for Ramtron FM3130 I2C chip.

 *

 *  Copyright (C) 2008 Sergey Lapin

 *  Based on ds1307 driver by James Chapman and David Brownell

 *

 * 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/module.h>

#include <linux/i2c.h>

#include <linux/rtc.h>

#include <linux/bcd.h>

#include <linux/slab.h>

​

#define FM3130_RTC_CONTROL  (0x0)

#define FM3130_CAL_CONTROL  (0x1)

#define FM3130_RTC_SECONDS  (0x2)

#define FM3130_RTC_MINUTES  (0x3)

#define FM3130_RTC_HOURS    (0x4)

#define FM3130_RTC_DAY      (0x5)

#define FM3130_RTC_DATE     (0x6)

#define FM3130_RTC_MONTHS   (0x7)

#define FM3130_RTC_YEARS    (0x8)

​

#define FM3130_ALARM_SECONDS    (0x9)

#define FM3130_ALARM_MINUTES    (0xa)

#define FM3130_ALARM_HOURS  (0xb)

#define FM3130_ALARM_DATE   (0xc)

#define FM3130_ALARM_MONTHS (0xd)

#define FM3130_ALARM_WP_CONTROL (0xe)

​

#define FM3130_CAL_CONTROL_BIT_nOSCEN (1 << 7) /* Osciallator enabled */

#define FM3130_RTC_CONTROL_BIT_LB (1 << 7) /* Low battery */

#define FM3130_RTC_CONTROL_BIT_AF (1 << 6) /* Alarm flag */

#define FM3130_RTC_CONTROL_BIT_CF (1 << 5) /* Century overflow */

#define FM3130_RTC_CONTROL_BIT_POR (1 << 4) /* Power on reset */

#define FM3130_RTC_CONTROL_BIT_AEN (1 << 3) /* Alarm enable */

#define FM3130_RTC_CONTROL_BIT_CAL (1 << 2) /* Calibration mode */

#define FM3130_RTC_CONTROL_BIT_WRITE (1 << 1) /* W=1 -> write mode W=0 normal */

#define FM3130_RTC_CONTROL_BIT_READ (1 << 0) /* R=1 -> read mode R=0 normal */

​

#define FM3130_CLOCK_REGS 7

#define FM3130_ALARM_REGS 5

​

struct fm3130 {

    u8          reg_addr_time;

    u8          reg_addr_alarm;

    u8          regs[15];

    struct i2c_msg      msg[4];

    struct i2c_client   *client;

    struct rtc_device   *rtc;

    int         alarm_valid;

    int         data_valid;

};

static const struct i2c_device_id fm3130_id[] = {

    { "fm3130", 0 },

    { }

};

MODULE_DEVICE_TABLE(i2c, fm3130_id);

​

#define FM3130_MODE_NORMAL      0

#define FM3130_MODE_WRITE       1

#define FM3130_MODE_READ        2

​

static void fm3130_rtc_mode(struct device *dev, int mode)

{

    struct fm3130 *fm3130 = dev_get_drvdata(dev);

​

    fm3130->regs[FM3130_RTC_CONTROL] =

        i2c_smbus_read_byte_data(fm3130->client, FM3130_RTC_CONTROL);

    switch (mode) {

    case FM3130_MODE_NORMAL:

        fm3130->regs[FM3130_RTC_CONTROL] &=

            ~(FM3130_RTC_CONTROL_BIT_WRITE |

            FM3130_RTC_CONTROL_BIT_READ);

        break;

    case FM3130_MODE_WRITE:

        fm3130->regs[FM3130_RTC_CONTROL] |= FM3130_RTC_CONTROL_BIT_WRITE;

        break;

    case FM3130_MODE_READ:

        fm3130->regs[FM3130_RTC_CONTROL] |= FM3130_RTC_CONTROL_BIT_READ;

        break;

    default:

        dev_dbg(dev, "invalid mode %d\n", mode);

        break;

    }

​

    i2c_smbus_write_byte_data(fm3130->client,

         FM3130_RTC_CONTROL, fm3130->regs[FM3130_RTC_CONTROL]);