611 lines
14 KiB
C
611 lines
14 KiB
C
/*
|
|
* 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_get_drvdata(dev);
|
|
int control, stat;
|
|
int ret;
|
|
u8 buf[4];
|
|
|
|
if (ds3232->irq <= 0)
|
|
return -EINVAL;
|
|
|
|
buf[0] = bin2bcd(alarm->time.tm_sec);
|
|
buf[1] = bin2bcd(alarm->time.tm_min);
|
|
buf[2] = bin2bcd(alarm->time.tm_hour);
|
|
buf[3] = bin2bcd(alarm->time.tm_mday);
|
|
|
|
/* clear alarm interrupt enable bit */
|
|
ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
|
|
if (ret)
|
|
goto out;
|
|
control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
|
|
ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* clear any pending alarm flag */
|
|
ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
|
|
if (ret)
|
|
goto out;
|
|
stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
|
|
ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = regmap_bulk_write(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (alarm->enabled) {
|
|
control |= DS3232_REG_CR_A1IE;
|
|
ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
|
|
}
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int ds3232_update_alarm(struct device *dev, unsigned int enabled)
|
|
{
|
|
struct ds3232 *ds3232 = dev_get_drvdata(dev);
|
|
int control;
|
|
int ret;
|
|
|
|
ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (enabled)
|
|
/* enable alarm1 interrupt */
|
|
control |= DS3232_REG_CR_A1IE;
|
|
else
|
|
/* disable alarm1 interrupt */
|
|
control &= ~(DS3232_REG_CR_A1IE);
|
|
ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
|
|
{
|
|
struct ds3232 *ds3232 = dev_get_drvdata(dev);
|
|
|
|
if (ds3232->irq <= 0)
|
|
return -EINVAL;
|
|
|
|
return ds3232_update_alarm(dev, enabled);
|
|
}
|
|
|
|
static irqreturn_t ds3232_irq(int irq, void *dev_id)
|
|
{
|
|
struct device *dev = dev_id;
|
|
struct ds3232 *ds3232 = dev_get_drvdata(dev);
|
|
struct mutex *lock = &ds3232->rtc->ops_lock;
|
|
int ret;
|
|
int stat, control;
|
|
|
|
mutex_lock(lock);
|
|
|
|
ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
|
|
if (ret)
|
|
goto unlock;
|
|
|
|
if (stat & DS3232_REG_SR_A1F) {
|
|
ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
|
|
if (ret) {
|
|
dev_warn(ds3232->dev,
|
|
"Read Control Register error %d\n", ret);
|
|
} else {
|
|
/* disable alarm1 interrupt */
|
|
control &= ~(DS3232_REG_CR_A1IE);
|
|
ret = regmap_write(ds3232->regmap, DS3232_REG_CR,
|
|
control);
|
|
if (ret) {
|
|
dev_warn(ds3232->dev,
|
|
"Write Control Register error %d\n",
|
|
ret);
|
|
goto unlock;
|
|
}
|
|
|
|
/* clear the alarm pend flag */
|
|
stat &= ~DS3232_REG_SR_A1F;
|
|
ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
|
|
if (ret) {
|
|
dev_warn(ds3232->dev,
|
|
"Write Status Register error %d\n",
|
|
ret);
|
|
goto unlock;
|
|
}
|
|
|
|
rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);
|
|
}
|
|
}
|
|
|
|
unlock:
|
|
mutex_unlock(lock);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static const struct rtc_class_ops ds3232_rtc_ops = {
|
|
.read_time = ds3232_read_time,
|
|
.set_time = ds3232_set_time,
|
|
.read_alarm = ds3232_read_alarm,
|
|
.set_alarm = ds3232_set_alarm,
|
|
.alarm_irq_enable = ds3232_alarm_irq_enable,
|
|
};
|
|
|
|
static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq,
|
|
const char *name)
|
|
{
|
|
struct ds3232 *ds3232;
|
|
int ret;
|
|
|
|
ds3232 = devm_kzalloc(dev, sizeof(*ds3232), GFP_KERNEL);
|
|
if (!ds3232)
|
|
return -ENOMEM;
|
|
|
|
ds3232->regmap = regmap;
|
|
ds3232->irq = irq;
|
|
ds3232->dev = dev;
|
|
dev_set_drvdata(dev, ds3232);
|
|
|
|
ret = ds3232_check_rtc_status(dev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
|
|
THIS_MODULE);
|
|
if (IS_ERR(ds3232->rtc))
|
|
return PTR_ERR(ds3232->rtc);
|
|
|
|
if (ds3232->irq > 0) {
|
|
ret = devm_request_threaded_irq(dev, ds3232->irq, NULL,
|
|
ds3232_irq,
|
|
IRQF_SHARED | IRQF_ONESHOT,
|
|
name, dev);
|
|
if (ret) {
|
|
ds3232->irq = 0;
|
|
dev_err(dev, "unable to request IRQ\n");
|
|
} else
|
|
device_init_wakeup(dev, 1);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int ds3232_suspend(struct device *dev)
|
|
{
|
|
struct ds3232 *ds3232 = dev_get_drvdata(dev);
|
|
|
|
if (device_may_wakeup(dev)) {
|
|
if (enable_irq_wake(ds3232->irq))
|
|
dev_warn_once(dev, "Cannot set wakeup source\n");
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ds3232_resume(struct device *dev)
|
|
{
|
|
struct ds3232 *ds3232 = dev_get_drvdata(dev);
|
|
|
|
if (device_may_wakeup(dev))
|
|
disable_irq_wake(ds3232->irq);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static const struct dev_pm_ops ds3232_pm_ops = {
|
|
SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
|
|
};
|
|
|
|
#if IS_ENABLED(CONFIG_I2C)
|
|
|
|
static int ds3232_i2c_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct regmap *regmap;
|
|
static const struct regmap_config config = {
|
|
.reg_bits = 8,
|
|
.val_bits = 8,
|
|
};
|
|
|
|
regmap = devm_regmap_init_i2c(client, &config);
|
|
if (IS_ERR(regmap)) {
|
|
dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
|
|
__func__, PTR_ERR(regmap));
|
|
return PTR_ERR(regmap);
|
|
}
|
|
|
|
return ds3232_probe(&client->dev, regmap, client->irq, client->name);
|
|
}
|
|
|
|
static const struct i2c_device_id ds3232_id[] = {
|
|
{ "ds3232", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, ds3232_id);
|
|
|
|
static struct i2c_driver ds3232_driver = {
|
|
.driver = {
|
|
.name = "rtc-ds3232",
|
|
.pm = &ds3232_pm_ops,
|
|
},
|
|
.probe = ds3232_i2c_probe,
|
|
.id_table = ds3232_id,
|
|
};
|
|
|
|
static int ds3232_register_driver(void)
|
|
{
|
|
return i2c_add_driver(&ds3232_driver);
|
|
}
|
|
|
|
static void ds3232_unregister_driver(void)
|
|
{
|
|
i2c_del_driver(&ds3232_driver);
|
|
}
|
|
|
|
#else
|
|
|
|
static int ds3232_register_driver(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void ds3232_unregister_driver(void)
|
|
{
|
|
}
|
|
|
|
#endif
|
|
|
|
#if IS_ENABLED(CONFIG_SPI_MASTER)
|
|
|
|
static int ds3234_probe(struct spi_device *spi)
|
|
{
|
|
int res;
|
|
unsigned int tmp;
|
|
static const struct regmap_config config = {
|
|
.reg_bits = 8,
|
|
.val_bits = 8,
|
|
.write_flag_mask = 0x80,
|
|
};
|
|
struct regmap *regmap;
|
|
|
|
regmap = devm_regmap_init_spi(spi, &config);
|
|
if (IS_ERR(regmap)) {
|
|
dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
|
|
__func__, PTR_ERR(regmap));
|
|
return PTR_ERR(regmap);
|
|
}
|
|
|
|
spi->mode = SPI_MODE_3;
|
|
spi->bits_per_word = 8;
|
|
spi_setup(spi);
|
|
|
|
res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp);
|
|
if (res)
|
|
return res;
|
|
|
|
/* Control settings
|
|
*
|
|
* CONTROL_REG
|
|
* BIT 7 6 5 4 3 2 1 0
|
|
* EOSC BBSQW CONV RS2 RS1 INTCN A2IE A1IE
|
|
*
|
|
* 0 0 0 1 1 1 0 0
|
|
*
|
|
* CONTROL_STAT_REG
|
|
* BIT 7 6 5 4 3 2 1 0
|
|
* OSF BB32kHz CRATE1 CRATE0 EN32kHz BSY A2F A1F
|
|
*
|
|
* 1 0 0 0 1 0 0 0
|
|
*/
|
|
res = regmap_read(regmap, DS3232_REG_CR, &tmp);
|
|
if (res)
|
|
return res;
|
|
res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c);
|
|
if (res)
|
|
return res;
|
|
|
|
res = regmap_read(regmap, DS3232_REG_SR, &tmp);
|
|
if (res)
|
|
return res;
|
|
res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88);
|
|
if (res)
|
|
return res;
|
|
|
|
/* Print our settings */
|
|
res = regmap_read(regmap, DS3232_REG_CR, &tmp);
|
|
if (res)
|
|
return res;
|
|
dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
|
|
|
|
res = regmap_read(regmap, DS3232_REG_SR, &tmp);
|
|
if (res)
|
|
return res;
|
|
dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
|
|
|
|
return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234");
|
|
}
|
|
|
|
static struct spi_driver ds3234_driver = {
|
|
.driver = {
|
|
.name = "ds3234",
|
|
},
|
|
.probe = ds3234_probe,
|
|
};
|
|
|
|
static int ds3234_register_driver(void)
|
|
{
|
|
return spi_register_driver(&ds3234_driver);
|
|
}
|
|
|
|
static void ds3234_unregister_driver(void)
|
|
{
|
|
spi_unregister_driver(&ds3234_driver);
|
|
}
|
|
|
|
#else
|
|
|
|
static int ds3234_register_driver(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void ds3234_unregister_driver(void)
|
|
{
|
|
}
|
|
|
|
#endif
|
|
|
|
static int __init ds323x_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = ds3232_register_driver();
|
|
if (ret) {
|
|
pr_err("Failed to register ds3232 driver: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = ds3234_register_driver();
|
|
if (ret) {
|
|
pr_err("Failed to register ds3234 driver: %d\n", ret);
|
|
ds3232_unregister_driver();
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
module_init(ds323x_init)
|
|
|
|
static void __exit ds323x_exit(void)
|
|
{
|
|
ds3234_unregister_driver();
|
|
ds3232_unregister_driver();
|
|
}
|
|
module_exit(ds323x_exit)
|
|
|
|
MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
|
|
MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
|
|
MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("spi:ds3234");
|