/*
* 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 DEFINE_MUTEX(m41t80_rtc_mutex);
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[] = {
{
.compatible = "st,m41t62",
.data = (void *)(M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT)
},
{
.compatible = "st,m41t65",
.data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_WD)
},
{
.compatible = "st,m41t80",
.data = (void *)(M41T80_FEATURE_SQ)
},
{
.compatible = "st,m41t81",
.data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_SQ)
},
{
.compatible = "st,m41t81s",
.data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
},
{
.compatible = "st,m41t82",
.data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
},
{
.compatible = "st,m41t83",
.data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
},
{
.compatible = "st,m41t84",
.data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
},
{
.compatible = "st,m41t85",
.data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
},
{
.compatible = "st,m41t87",
.data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ)
},
{
.compatible = "microcrystal,rv4162",
.data = (void *)(M41T80_FEATURE_SQ | M41T80_FEATURE_WD | M41T80_FEATURE_SQ_ALT)
},
/* DT compatibility only, do not use compatibles below: */
{
.compatible = "st,rv4162",
.data = (void *)(M41T80_FEATURE_SQ | M41T80_FEATURE_WD | M41T80_FEATURE_SQ_ALT)
},
{
.compatible = "rv4162",
.