linux-imx

/*

 * I2C client/driver for the ST M41T80 family of i2c rtc chips.

 *

 * Author: Alexander Bigga <ab@mycable.de>

 *

 * Based on m41t00.c by Mark A. Greer <mgreer@mvista.com>

 *

 * 2006 (c) mycable GmbH

 *

 * 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.

 *

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/bcd.h>

#include <linux/clk-provider.h>

#include <linux/i2c.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/of_device.h>

#include <linux/rtc.h>

#include <linux/slab.h>

#include <linux/mutex.h>

#include <linux/string.h>

#ifdef CONFIG_RTC_DRV_M41T80_WDT

#include <linux/fs.h>

#include <linux/ioctl.h>

#include <linux/miscdevice.h>

#include <linux/reboot.h>

#include <linux/watchdog.h>

#endif

​

#define M41T80_REG_SSEC     0x00

#define M41T80_REG_SEC      0x01

#define M41T80_REG_MIN      0x02

#define M41T80_REG_HOUR     0x03

#define M41T80_REG_WDAY     0x04

#define M41T80_REG_DAY      0x05

#define M41T80_REG_MON      0x06

#define M41T80_REG_YEAR     0x07

#define M41T80_REG_ALARM_MON    0x0a

#define M41T80_REG_ALARM_DAY    0x0b

#define M41T80_REG_ALARM_HOUR   0x0c

#define M41T80_REG_ALARM_MIN    0x0d

#define M41T80_REG_ALARM_SEC    0x0e

#define M41T80_REG_FLAGS    0x0f

#define M41T80_REG_SQW      0x13

​

#define M41T80_DATETIME_REG_SIZE    (M41T80_REG_YEAR + 1)

#define M41T80_ALARM_REG_SIZE   \

    (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON)

​

#define M41T80_SQW_MAX_FREQ 32768

​

#define M41T80_SEC_ST       BIT(7)  /* ST: Stop Bit */

#define M41T80_ALMON_AFE    BIT(7)  /* AFE: AF Enable Bit */

#define M41T80_ALMON_SQWE   BIT(6)  /* SQWE: SQW Enable Bit */

#define M41T80_ALHOUR_HT    BIT(6)  /* HT: Halt Update Bit */

#define M41T80_FLAGS_OF     BIT(2)  /* OF: Oscillator Failure Bit */

#define M41T80_FLAGS_AF     BIT(6)  /* AF: Alarm Flag Bit */

#define M41T80_FLAGS_BATT_LOW   BIT(4)  /* BL: Battery Low Bit */

#define M41T80_WATCHDOG_RB2 BIT(7)  /* RB: Watchdog resolution */

#define M41T80_WATCHDOG_RB1 BIT(1)  /* RB: Watchdog resolution */

#define M41T80_WATCHDOG_RB0 BIT(0)  /* RB: Watchdog resolution */

​

#define M41T80_FEATURE_HT   BIT(0)  /* Halt feature */

#define M41T80_FEATURE_BL   BIT(1)  /* Battery low indicator */

#define M41T80_FEATURE_SQ   BIT(2)  /* Squarewave feature */

#define M41T80_FEATURE_WD   BIT(3)  /* Extra watchdog resolution */

#define M41T80_FEATURE_SQ_ALT   BIT(4)  /* RSx bits are in reg 4 */

​

static const struct i2c_device_id m41t80_id[] = {

    { "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT },

    { "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD },

    { "m41t80", M41T80_FEATURE_SQ },

    { "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ},

    { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },

    { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },

    { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },

    { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },

    { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },

    { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },

    { "rv4162", M41T80_FEATURE_SQ | M41T80_FEATURE_WD | M41T80_FEATURE_SQ_ALT },

    { }

};

MODULE_DEVICE_TABLE(i2c, m41t80_id);

​

static const struct of_device_id m41t80_of_match[] = {