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/*
* RTC client/driver for the Maxim/Dallas DS3232/DS3234 Real-Time Clock
*
* Copyright (C) 2009-2011 Freescale Semiconductor.
* Author: Jack Lan <jack.lan@freescale.com>
* Copyright (C) 2008 MIMOMax Wireless Ltd.
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/spi/spi.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/slab.h>
#include <linux/regmap.h>
#define DS3232_REG_SECONDS 0x00
#define DS3232_REG_MINUTES 0x01
#define DS3232_REG_HOURS 0x02
#define DS3232_REG_AMPM 0x02
#define DS3232_REG_DAY 0x03
#define DS3232_REG_DATE 0x04
#define DS3232_REG_MONTH 0x05
#define DS3232_REG_CENTURY 0x05
#define DS3232_REG_YEAR 0x06
#define DS3232_REG_ALARM1 0x07 /* Alarm 1 BASE */
#define DS3232_REG_ALARM2 0x0B /* Alarm 2 BASE */
#define DS3232_REG_CR 0x0E /* Control register */
# define DS3232_REG_CR_nEOSC 0x80
# define DS3232_REG_CR_INTCN 0x04
# define DS3232_REG_CR_A2IE 0x02
# define DS3232_REG_CR_A1IE 0x01
#define DS3232_REG_SR 0x0F /* control/status register */
# define DS3232_REG_SR_OSF 0x80
# define DS3232_REG_SR_BSY 0x04
# define DS3232_REG_SR_A2F 0x02
# define DS3232_REG_SR_A1F 0x01
struct ds3232 {
struct device *dev;
struct regmap *regmap;
int irq;
struct rtc_device *rtc;
bool suspended;
};
static int ds3232_check_rtc_status(struct device *dev)
{
struct ds3232 *ds3232 = dev_get_drvdata(dev);
int ret = 0;
int control, stat;
ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
if (ret)
return ret;
if (stat & DS3232_REG_SR_OSF)
dev_warn(dev,
"oscillator discontinuity flagged, "
"time unreliable\n");
stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
if (ret)
return ret;
/* If the alarm is pending, clear it before requesting
* the interrupt, so an interrupt event isn't reported
* before everything is initialized.
*/
ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
if (ret)
return ret;
control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
control |= DS3232_REG_CR_INTCN;
return regmap_write(ds3232->regmap, DS3232_REG_CR, control);
}
static int ds3232_read_time(struct device *dev, struct rtc_time *time)
{
struct ds3232 *ds3232 = dev_get_drvdata(dev);
int ret;
u8 buf[7];
unsigned int year, month, day, hour, minute, second;
unsigned int week, twelve_hr, am_pm;
unsigned int century, add_century = 0;
ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
if (ret)
return ret;
second = buf[0];
minute = buf[1];
hour = buf[2];
week = buf[3];
day = buf[4];
month = buf[5];
year = buf[6];
/* Extract additional information for AM/PM and century */
twelve_hr = hour & 0x40;
am_pm = hour & 0x20;
century = month & 0x80;
/* Write to rtc_time structure */
time->tm_sec = bcd2bin(second);
time->tm_min = bcd2bin(minute);
if (twelve_hr) {
/* Convert to 24 hr */
if (am_pm)
time->tm_hour = bcd2bin(hour & 0x1F) + 12;
else
time->tm_hour = bcd2bin(hour & 0x1F);
} else {
time->tm_hour = bcd2bin(hour);
}
/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
time->tm_wday = bcd2bin(week) - 1;
time->tm_mday = bcd2bin(day);
/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
time->tm_mon = bcd2bin(month & 0x7F) - 1;
if (century)
add_century = 100;
time->tm_year = bcd2bin(year) + add_century;
return rtc_valid_tm(time);
}
static int ds3232_set_time(struct device *dev, struct rtc_time *time)
{
struct ds3232 *ds3232 = dev_get_drvdata(dev);
u8 buf[7];
/* Extract time from rtc_time and load into ds3232*/
buf[0] = bin2bcd(time->tm_sec);
buf[1] = bin2bcd(time->tm_min);
buf[2] = bin2bcd(time->tm_hour);
/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
buf[3] = bin2bcd(time->tm_wday + 1);
buf[4] = bin2bcd(time->tm_mday); /* Date */
/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
buf[5] = bin2bcd(time->tm_mon + 1);
if (time->tm_year >= 100) {
buf[5] |= 0x80;
buf[6] = bin2bcd(time->tm_year - 100);
} else {
buf[6] = bin2bcd(time->tm_year);
}
return regmap_bulk_write(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
}
/*
* DS3232 has two alarm, we only use alarm1
* According to linux specification, only support one-shot alarm
* no periodic alarm mode
*/
static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct ds3232 *ds3232 = dev_get_drvdata(dev);
int control, stat;
int ret;
u8 buf[4];
ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
if (ret)
goto out;
ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
if (ret)
goto out;
ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
if (ret)
goto out;
alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
alarm->time.tm_min = bcd2bin(buf[1] & 0x7F);
alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F);
alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F);
alarm->time.tm_mon = -1;
alarm->time.tm_year = -1;
alarm->time.tm_wday = -1;
alarm->time.tm_yday = -1;
alarm->time.tm_isdst = -1;
alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
alarm->pending = !!(stat & DS3232_REG_SR_A1F);
ret = 0;
out:
return ret;
}
/*
* linux rtc-module does not support wday alarm
* and only 24h time mode supported indeed
*/
static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct ds3232 *ds3232 = dev_g
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