linux-imx

/*

 * RTC driver for Rockchip RK808

 *

 * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd

 *

 * Author: Chris Zhong <zyw@rock-chips.com>

 * Author: Zhang Qing <zhangqing@rock-chips.com>

 *

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

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

 * more details.

 */

​

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/rtc.h>

#include <linux/bcd.h>

#include <linux/mfd/rk808.h>

#include <linux/platform_device.h>

#include <linux/i2c.h>

​

/* RTC_CTRL_REG bitfields */

#define BIT_RTC_CTRL_REG_STOP_RTC_M     BIT(0)

​

/* RK808 has a shadowed register for saving a "frozen" RTC time.

 * When user setting "GET_TIME" to 1, the time will save in this shadowed

 * register. If set "READSEL" to 1, user read rtc time register, actually

 * get the time of that moment. If we need the real time, clr this bit.

 */

#define BIT_RTC_CTRL_REG_RTC_GET_TIME       BIT(6)

#define BIT_RTC_CTRL_REG_RTC_READSEL_M      BIT(7)

#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M   BIT(3)

#define RTC_STATUS_MASK     0xFE

​

#define SECONDS_REG_MSK     0x7F

#define MINUTES_REG_MAK     0x7F

#define HOURS_REG_MSK       0x3F

#define DAYS_REG_MSK        0x3F

#define MONTHS_REG_MSK      0x1F

#define YEARS_REG_MSK       0xFF

#define WEEKS_REG_MSK       0x7

​

/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */

​

#define NUM_TIME_REGS   (RK808_WEEKS_REG - RK808_SECONDS_REG + 1)

#define NUM_ALARM_REGS  (RK808_ALARM_YEARS_REG - RK808_ALARM_SECONDS_REG + 1)

​

struct rk808_rtc {

    struct rk808 *rk808;

    struct rtc_device *rtc;

    int irq;

};

​

/*

 * The Rockchip calendar used by the RK808 counts November with 31 days. We use

 * these translation functions to convert its dates to/from the Gregorian

 * calendar used by the rest of the world. We arbitrarily define Jan 1st, 2016

 * as the day when both calendars were in sync, and treat all other dates