--- /dev/null
+/*
+ * 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");
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