// SPDX-License-Identifier: GPL-2.0-or-later
/*
* RTC client/driver for the Maxim/Dallas DS3232/DS3234 Real-Time Clock
*
* Copyright (C) 2009-2011 Freescale Semiconductor.
* Author: Jack Lan <[email protected]>
* Copyright (C) 2008 MIMOMax Wireless Ltd.
*/
#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>
#include <linux/hwmon.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
#define DS3232_REG_TEMPERATURE 0x11
#define DS3232_REG_SRAM_START 0x14
#define DS3232_REG_SRAM_END 0xFF
#define DS3232_REG_SRAM_SIZE 236
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 0;
}
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->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;
}
/*
* Temperature sensor support for ds3232/ds3234 devices.
* A user-initiated temperature conversion is not started by this function,
* so the temperature is updated once every 64 seconds.
*/
static int ds3232_hwmon_read_temp(struct device *dev, long int *mC)
{
struct ds3232 *ds3232 = dev_get_drvdata(dev);
u8 temp_buf[2];
s16 temp;
int ret;
ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_TEMPERATURE, temp_buf,
sizeof(temp_buf));
if (ret < 0)
return ret;
/*
* Temperature is represented as a 10-bit code with a resolution of
* 0.25 degree celsius and encoded in two's complement format.
*/
temp = (temp_buf[0] << 8) | temp_buf[1];
temp >>= 6;
*mC = temp * 250;
return 0;
}
static umode_t ds3232_hwmon_is_visible(const void *data,
enum hwmon_sensor_types type,
u32 attr, int channel)
{
if (type != hwmon_temp)
return 0;
switch (attr) {
case hwmon_temp_input:
return 0444;
default:
return 0;
}
}
static int ds3232_hwmon_read(struct device *dev,
enum hwmon_sensor_types type,
u32 attr, int channel, long *temp)
{
int err;
switch (attr) {
case hwmon_temp_input:
err = ds3232_hwmon_read_temp(dev, temp);
break;
default:
err = -EOPNOTSUPP;
break;
}
return err;
}
static u32 ds3232_hwmon_chip_config[] = {
HWMON_C_REGISTER_TZ,
0
};
static const struct hwmon_channel_info ds3232_hwmon_chip = {
.type = hwmon_chip,
.config = ds3232_hwmon_chip_config,
};
static u32 ds3232_hwmon_temp_config[] = {
HWMON_T_INPUT,
0
};
static const struct hwmon_channel_info ds3232_hwmon_temp = {
.type = hwmon_temp,
.config = ds3232_hwmon_temp_config,
};
static const struct hwmon_channel_info * const ds3232_hwmon_info[] = {
&ds3232_hwmon_chip,
&ds3232_hwmon_temp,
NULL
};
static const struct hwmon_ops ds3232_hwmon_hwmon_ops = {
.is_visible = ds3232_hwmon_is_visible,
.read = ds3232_hwmon_read,
};
static const struct hwmon_chip_info ds3232_hwmon_chip_info = {
.ops = &ds3232_hwmon_hwmon_ops,
.info = ds3232_hwmon_info,
};
static void ds3232_hwmon_register(struct device *dev, const char *name)
{
struct ds3232 *ds3232 = dev_get_drvdata(dev);
struct device *hwmon_dev;
if (!IS_ENABLED(CONFIG_RTC_DRV_DS3232_HWMON))
return;
hwmon_dev = devm_hwmon_device_register_with_info(dev, name, ds3232,
&ds3232_hwmon_chip_info,
NULL);
if (IS_ERR(hwmon_dev)) {
dev_err(dev, "unable to register hwmon device %ld\n",
PTR_ERR(hwmon_dev));
}
}
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);
int ret;
int stat, control;
rtc_lock(ds3232->rtc);
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:
rtc_unlock(ds3232->rtc);
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_nvmem_read(void *priv, unsigned int offset, void *val,
size_t bytes)
{
struct regmap *ds3232_regmap = (struct regmap *)priv;
return regmap_bulk_read(ds3232_regmap, DS3232_REG_SRAM_START + offset,
val, bytes);
}
static int ds3232_nvmem_write(void *priv, unsigned int offset, void *val,
size_t bytes)
{
struct regmap *ds3232_regmap = (struct regmap *)priv;
return regmap_bulk_write(ds3232_regmap, DS3232_REG_SRAM_START + offset,
val, bytes);
}
static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq,
const char *name)
{
struct ds3232 *ds3232;
int ret;
struct nvmem_config nvmem_cfg = {
.name = "ds3232_sram",
.stride = 1,
.size = DS3232_REG_SRAM_SIZE,
.word_size = 1,
.reg_read = ds3232_nvmem_read,
.reg_write = ds3232_nvmem_write,
.priv = regmap,
.type = NVMEM_TYPE_BATTERY_BACKED
};
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;
if (ds3232->irq > 0)
device_init_wakeup(dev, 1);
ds3232_hwmon_register(dev, name);
ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
THIS_MODULE);
if (IS_ERR(ds3232->rtc))
return PTR_ERR(ds3232->rtc);
ret = devm_rtc_nvmem_register(ds3232->rtc, &nvmem_cfg);
if(ret)
return ret;
if (ds3232->irq > 0) {
ret = devm_request_threaded_irq(dev, ds3232->irq, NULL,
ds3232_irq,
IRQF_SHARED | IRQF_ONESHOT,
name, dev);
if (ret) {
device_set_wakeup_capable(dev, 0);
ds3232->irq = 0;
dev_err(dev, "unable to request IRQ\n");
}
}
return 0;
}
#if IS_ENABLED(CONFIG_I2C)
#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)
};
static int ds3232_i2c_probe(struct i2c_client *client)
{
struct regmap *regmap;
static const struct regmap_config config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = DS3232_REG_SRAM_END,
};
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" },
{ }
};
MODULE_DEVICE_TABLE(i2c, ds3232_id);
static const __maybe_unused struct of_device_id ds3232_of_match[] = {
{ .compatible = "dallas,ds3232" },
{ }
};
MODULE_DEVICE_TABLE(of, ds3232_of_match);
static struct i2c_driver ds3232_driver = {
.driver = {
.name = "rtc-ds3232",
.of_match_table = of_match_ptr(ds3232_of_match),
.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,
.max_register = DS3232_REG_SRAM_END,
.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 <[email protected]>");
MODULE_AUTHOR("Dennis Aberilla <[email protected]>");
MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:ds3234");
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