linux-imx

/*

 * rtc-tps65910.c -- TPS65910 Real Time Clock interface

 *

 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.

 * Author: Venu Byravarasu <vbyravarasu@nvidia.com>

 *

 * Based on original TI driver rtc-twl.c

 *   Copyright (C) 2007 MontaVista Software, Inc

 *   Author: Alexandre Rusev <source@mvista.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/kernel.h>

#include <linux/errno.h>

#include <linux/init.h>

#include <linux/module.h>

#include <linux/types.h>

#include <linux/rtc.h>

#include <linux/bcd.h>

#include <linux/math64.h>

#include <linux/platform_device.h>

#include <linux/interrupt.h>

#include <linux/mfd/tps65910.h>

​

struct tps65910_rtc {

    struct rtc_device   *rtc;

    int irq;

};

​

/* Total number of RTC registers needed to set time*/

#define NUM_TIME_REGS   (TPS65910_YEARS - TPS65910_SECONDS + 1)

​

/* Total number of RTC registers needed to set compensation registers */

#define NUM_COMP_REGS   (TPS65910_RTC_COMP_MSB - TPS65910_RTC_COMP_LSB + 1)

​

/* Min and max values supported with 'offset' interface (swapped sign) */

#define MIN_OFFSET  (-277761)

#define MAX_OFFSET  (277778)

​

/* Number of ticks per hour */

#define TICKS_PER_HOUR  (32768 * 3600)

​

/* Multiplier for ppb conversions */

#define PPB_MULT    (1000000000LL)

​

static int tps65910_rtc_alarm_irq_enable(struct device *dev,

                     unsigned int enabled)

{

    struct tps65910 *tps = dev_get_drvdata(dev->parent);

    u8 val = 0;

​

    if (enabled)

        val = TPS65910_RTC_INTERRUPTS_IT_ALARM;

​

    return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val);

}

​

/*

 * Gets current tps65910 RTC time and date parameters.

 *

 * The RTC's time/alarm representation is not what gmtime(3) requires

 * Linux to use:

 *

 *  - Months are 1..12 vs Linux 0-11

 *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)

 */

static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm)

{

    unsigned char rtc_data[NUM_TIME_REGS];

    struct tps65910 *tps = dev_get_drvdata(dev->parent);

    int ret;

​

    /* Copy RTC counting registers to static registers or latches */

    ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,

        TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME);

    if (ret < 0) {

        dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret);

        return ret;

    }

​

    ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data,

        NUM_TIME_REGS);

    if (ret < 0) {

        dev_err(dev, "reading from RTC failed with err:%d\n", ret);

        return ret;

    }

​

    tm->tm_sec = bcd2bin(rtc_data[0]);