linux/drivers/rtc/rtc-pcf85363.c

221 lines
5.3 KiB
C

/*
* drivers/rtc/rtc-pcf85363.c
*
* Driver for NXP PCF85363 real-time clock.
*
* Copyright (C) 2017 Eric Nelson
*
* 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.
*
* Based loosely on rtc-8583 by Russell King, Wolfram Sang and Juergen Beisert
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/bcd.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
/*
* Date/Time registers
*/
#define DT_100THS 0x00
#define DT_SECS 0x01
#define DT_MINUTES 0x02
#define DT_HOURS 0x03
#define DT_DAYS 0x04
#define DT_WEEKDAYS 0x05
#define DT_MONTHS 0x06
#define DT_YEARS 0x07
/*
* Alarm registers
*/
#define DT_SECOND_ALM1 0x08
#define DT_MINUTE_ALM1 0x09
#define DT_HOUR_ALM1 0x0a
#define DT_DAY_ALM1 0x0b
#define DT_MONTH_ALM1 0x0c
#define DT_MINUTE_ALM2 0x0d
#define DT_HOUR_ALM2 0x0e
#define DT_WEEKDAY_ALM2 0x0f
#define DT_ALARM_EN 0x10
/*
* Time stamp registers
*/
#define DT_TIMESTAMP1 0x11
#define DT_TIMESTAMP2 0x17
#define DT_TIMESTAMP3 0x1d
#define DT_TS_MODE 0x23
/*
* control registers
*/
#define CTRL_OFFSET 0x24
#define CTRL_OSCILLATOR 0x25
#define CTRL_BATTERY 0x26
#define CTRL_PIN_IO 0x27
#define CTRL_FUNCTION 0x28
#define CTRL_INTA_EN 0x29
#define CTRL_INTB_EN 0x2a
#define CTRL_FLAGS 0x2b
#define CTRL_RAMBYTE 0x2c
#define CTRL_WDOG 0x2d
#define CTRL_STOP_EN 0x2e
#define CTRL_RESETS 0x2f
#define CTRL_RAM 0x40
#define NVRAM_SIZE 0x40
static struct i2c_driver pcf85363_driver;
struct pcf85363 {
struct device *dev;
struct rtc_device *rtc;
struct nvmem_config nvmem_cfg;
struct regmap *regmap;
};
static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
unsigned char buf[DT_YEARS + 1];
int ret, len = sizeof(buf);
/* read the RTC date and time registers all at once */
ret = regmap_bulk_read(pcf85363->regmap, DT_100THS, buf, len);
if (ret) {
dev_err(dev, "%s: error %d\n", __func__, ret);
return ret;
}
tm->tm_year = bcd2bin(buf[DT_YEARS]);
/* adjust for 1900 base of rtc_time */
tm->tm_year += 100;
tm->tm_wday = buf[DT_WEEKDAYS] & 7;
buf[DT_SECS] &= 0x7F;
tm->tm_sec = bcd2bin(buf[DT_SECS]);
buf[DT_MINUTES] &= 0x7F;
tm->tm_min = bcd2bin(buf[DT_MINUTES]);
tm->tm_hour = bcd2bin(buf[DT_HOURS]);
tm->tm_mday = bcd2bin(buf[DT_DAYS]);
tm->tm_mon = bcd2bin(buf[DT_MONTHS]) - 1;
return 0;
}
static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
unsigned char buf[DT_YEARS + 1];
int len = sizeof(buf);
buf[DT_100THS] = 0;
buf[DT_SECS] = bin2bcd(tm->tm_sec);
buf[DT_MINUTES] = bin2bcd(tm->tm_min);
buf[DT_HOURS] = bin2bcd(tm->tm_hour);
buf[DT_DAYS] = bin2bcd(tm->tm_mday);
buf[DT_WEEKDAYS] = tm->tm_wday;
buf[DT_MONTHS] = bin2bcd(tm->tm_mon + 1);
buf[DT_YEARS] = bin2bcd(tm->tm_year % 100);
return regmap_bulk_write(pcf85363->regmap, DT_100THS,
buf, len);
}
static const struct rtc_class_ops rtc_ops = {
.read_time = pcf85363_rtc_read_time,
.set_time = pcf85363_rtc_set_time,
};
static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val,
size_t bytes)
{
struct pcf85363 *pcf85363 = priv;
return regmap_bulk_read(pcf85363->regmap, CTRL_RAM + offset,
val, bytes);
}
static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val,
size_t bytes)
{
struct pcf85363 *pcf85363 = priv;
return regmap_bulk_write(pcf85363->regmap, CTRL_RAM + offset,
val, bytes);
}
static const struct regmap_config regmap_config = {
.reg_bits = 8,
.val_bits = 8,
};
static int pcf85363_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pcf85363 *pcf85363;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
pcf85363 = devm_kzalloc(&client->dev, sizeof(struct pcf85363),
GFP_KERNEL);
if (!pcf85363)
return -ENOMEM;
pcf85363->regmap = devm_regmap_init_i2c(client, &regmap_config);
if (IS_ERR(pcf85363->regmap)) {
dev_err(&client->dev, "regmap allocation failed\n");
return PTR_ERR(pcf85363->regmap);
}
pcf85363->dev = &client->dev;
i2c_set_clientdata(client, pcf85363);
pcf85363->rtc = devm_rtc_allocate_device(pcf85363->dev);
if (IS_ERR(pcf85363->rtc))
return PTR_ERR(pcf85363->rtc);
pcf85363->nvmem_cfg.name = "pcf85363-";
pcf85363->nvmem_cfg.word_size = 1;
pcf85363->nvmem_cfg.stride = 1;
pcf85363->nvmem_cfg.size = NVRAM_SIZE;
pcf85363->nvmem_cfg.reg_read = pcf85363_nvram_read;
pcf85363->nvmem_cfg.reg_write = pcf85363_nvram_write;
pcf85363->nvmem_cfg.priv = pcf85363;
pcf85363->rtc->nvmem_config = &pcf85363->nvmem_cfg;
pcf85363->rtc->ops = &rtc_ops;
return rtc_register_device(pcf85363->rtc);
}
static const struct of_device_id dev_ids[] = {
{ .compatible = "nxp,pcf85363" },
{}
};
MODULE_DEVICE_TABLE(of, dev_ids);
static struct i2c_driver pcf85363_driver = {
.driver = {
.name = "pcf85363",
.of_match_table = of_match_ptr(dev_ids),
},
.probe = pcf85363_probe,
};
module_i2c_driver(pcf85363_driver);
MODULE_AUTHOR("Eric Nelson");
MODULE_DESCRIPTION("pcf85363 I2C RTC driver");
MODULE_LICENSE("GPL");