diff options
Diffstat (limited to 'drivers/rtc/rtc-pcf85363.c')
| -rw-r--r-- | drivers/rtc/rtc-pcf85363.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c new file mode 100644 index 000000000000..ea04e9f0930b --- /dev/null +++ b/drivers/rtc/rtc-pcf85363.c @@ -0,0 +1,220 @@ +/* + * 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, ®map_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"); |