linux-imx

/*

 *  Real Time Clock driver for Wolfson Microelectronics WM8350

 *

 *  Copyright (C) 2007, 2008 Wolfson Microelectronics PLC.

 *

 *  Author: Liam Girdwood

 *          linux@wolfsonmicro.com

 *

 *  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.

 *

 */

​

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/time.h>

#include <linux/rtc.h>

#include <linux/bcd.h>

#include <linux/interrupt.h>

#include <linux/ioctl.h>

#include <linux/completion.h>

#include <linux/mfd/wm8350/rtc.h>

#include <linux/mfd/wm8350/core.h>

#include <linux/delay.h>

#include <linux/platform_device.h>

​

#define WM8350_SET_ALM_RETRIES  5

#define WM8350_SET_TIME_RETRIES 5

#define WM8350_GET_TIME_RETRIES 5

​

/*

 * Read current time and date in RTC

 */

static int wm8350_rtc_readtime(struct device *dev, struct rtc_time *tm)

{

    struct wm8350 *wm8350 = dev_get_drvdata(dev);

    u16 time1[4], time2[4];

    int retries = WM8350_GET_TIME_RETRIES, ret;

​

    /*

     * Read the time twice and compare.

     * If time1 == time2, then time is valid else retry.

     */

    do {

        ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,

                    4, time1);

        if (ret < 0)

            return ret;

        ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,

                    4, time2);

        if (ret < 0)

            return ret;

​

        if (memcmp(time1, time2, sizeof(time1)) == 0) {

            tm->tm_sec = time1[0] & WM8350_RTC_SECS_MASK;

​

            tm->tm_min = (time1[0] & WM8350_RTC_MINS_MASK)

                >> WM8350_RTC_MINS_SHIFT;

​

            tm->tm_hour = time1[1] & WM8350_RTC_HRS_MASK;

​

            tm->tm_wday = ((time1[1] >> WM8350_RTC_DAY_SHIFT)

                       & 0x7) - 1;

​

            tm->tm_mon = ((time1[2] & WM8350_RTC_MTH_MASK)

                      >> WM8350_RTC_MTH_SHIFT) - 1;

​

            tm->tm_mday = (time1[2] & WM8350_RTC_DATE_MASK);

​

            tm->tm_year = ((time1[3] & WM8350_RTC_YHUNDREDS_MASK)

                       >> WM8350_RTC_YHUNDREDS_SHIFT) * 100;

            tm->tm_year += time1[3] & WM8350_RTC_YUNITS_MASK;

​

            tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon,

                            tm->tm_year);

            tm->tm_year -= 1900;

​

            dev_dbg(dev, "Read (%d left): %04x %04x %04x %04x\n",

                retries,

                time1[0], time1[1], time1[2], time1[3]);

​

            return 0;

        }

    } while (retries--);

​

    dev_err(dev, "timed out reading RTC time\n");

    return -EIO;

}

​

/*