/* * An I2C driver for the PCF85063 RTC * Copyright 2014 Rose Technology * * Author: Søren Andersen <san@rosetechnology.dk> * Maintainers: http://www.nslu2-linux.org/ * * based on the other drivers in this same directory. * * 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. */ #include <linux/i2c.h> #include <linux/bcd.h> #include <linux/rtc.h> #include <linux/module.h> #define DRV_VERSION "0.0.1" #define PCF85063_REG_CTRL1 0x00 /* status */ #define PCF85063_REG_CTRL2 0x01 #define PCF85063_REG_SC 0x04 /* datetime */ #define PCF85063_REG_MN 0x05 #define PCF85063_REG_HR 0x06 #define PCF85063_REG_DM 0x07 #define PCF85063_REG_DW 0x08 #define PCF85063_REG_MO 0x09 #define PCF85063_REG_YR 0x0A #define PCF85063_MO_C 0x80 /* century */ static struct i2c_driver pcf85063_driver; struct pcf85063 { struct rtc_device *rtc; int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */ int voltage_low; /* indicates if a low_voltage was detected */ }; /* * In the routines that deal directly with the pcf85063 hardware, we use * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. */ static int pcf85063_get_datetime(struct i2c_client *client, struct rtc_time *tm) { struct pcf85063 *pcf85063 = i2c_get_clientdata(client); unsigned char buf[13] = { PCF85063_REG_CTRL1 }; struct i2c_msg msgs[] = { {/* setup read ptr */ .addr = client->addr, .len = 1, .buf = buf }, {/* read status + date */ .addr = client->addr, .flags = I2C_M_RD, .len = 13, .buf = buf }, }; /* read registers */ if ((i2c_transfer(client->adapter, msgs, 2)) != 2) { dev_err(&client->dev, "%s: read error\n", __func__); return -EIO; } tm->tm_sec = bcd2bin(buf[PCF85063_REG_SC] & 0x7F); tm->tm_min = bcd2bin(buf[PCF85063_REG_MN] & 0x7F); tm->tm_hour = bcd2bin(buf[PCF85063_REG_HR] & 0x3F); /* rtc hr 0-23 */ tm->tm_mday = bcd2bin(buf[PCF85063_REG_DM] & 0x3F); tm->tm_wday = buf[PCF85063_REG_DW] & 0x07; tm->tm_mon = bcd2bin(buf[PCF85063_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ tm->tm_year = bcd2bin(buf[PCF85063_REG_YR]); if (tm->tm_year < 70) tm->tm_year += 100; /* assume we are in 1970...2069 */ /* detect the polarity heuristically. see note above. */ pcf85063->c_polarity = (buf[PCF85063_REG_MO] & PCF85063_MO_C) ? (tm->tm_year >= 100) : (tm->tm_year < 100); /* the clock can give out invalid datetime, but we cannot return * -EINVAL otherwise hwclock will refuse to set the time on bootup. */ if (rtc_valid_tm(tm) < 0) dev_err(&client->dev, "retrieved date/time is not valid.\n"); return 0; } static int pcf85063_set_datetime(struct i2c_client *client, struct rtc_time *tm) { int i = 0, err = 0; unsigned char buf[11]; /* Control & status */ buf[PCF85063_REG_CTRL1] = 0; buf[PCF85063_REG_CTRL2] = 5; /* hours, minutes and seconds */ buf[PCF85063_REG_SC] = bin2bcd(tm->tm_sec) & 0x7F; buf[PCF85063_REG_MN] = bin2bcd(tm->tm_min); buf[PCF85063_REG_HR] = bin2bcd(tm->tm_hour); /* Day of month, 1 - 31 */ buf[PCF85063_REG_DM] = bin2bcd(tm->tm_mday); /* Day, 0 - 6 */ buf[PCF85063_REG_DW] = tm->tm_wday & 0x07; /* month, 1 - 12 */ buf[PCF85063_REG_MO] = bin2bcd(tm->tm_mon + 1); /* year and century */ buf[PCF85063_REG_YR] = bin2bcd(tm->tm_year % 100); /* write register's data */ for (i = 0; i < sizeof(buf); i++) { unsigned char data[2] = { i, buf[i] }; err = i2c_master_send(client, data, sizeof(data)); if (err != sizeof(data)) { dev_err(&client->dev, "%s: err=%d addr=%02x, data=%02x\n", __func__, err, data[0], data[1]); return -EIO; } } return 0; } static int pcf85063_rtc_read_time(struct device *dev, struct rtc_time *tm) { return pcf85063_get_datetime(to_i2c_client(dev), tm); } static int pcf85063_rtc_set_time(struct device *dev, struct rtc_time *tm) { return pcf85063_set_datetime(to_i2c_client(dev), tm); } static const struct rtc_class_ops pcf85063_rtc_ops = { .read_time = pcf85063_rtc_read_time, .set_time = pcf85063_rtc_set_time }; static int pcf85063_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct pcf85063 *pcf85063; dev_dbg(&client->dev, "%s\n", __func__); if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) return -ENODEV; pcf85063 = devm_kzalloc(&client->dev, sizeof(struct pcf85063), GFP_KERNEL); if (!pcf85063) return -ENOMEM; dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); i2c_set_clientdata(client, pcf85063); pcf85063->rtc = devm_rtc_device_register(&client->dev, pcf85063_driver.driver.name, &pcf85063_rtc_ops, THIS_MODULE); return PTR_ERR_OR_ZERO(pcf85063->rtc); } static const struct i2c_device_id pcf85063_id[] = { { "pcf85063", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, pcf85063_id); #ifdef CONFIG_OF static const struct of_device_id pcf85063_of_match[] = { { .compatible = "nxp,pcf85063" }, {} }; MODULE_DEVICE_TABLE(of, pcf85063_of_match); #endif static struct i2c_driver pcf85063_driver = { .driver = { .name = "rtc-pcf85063", .owner = THIS_MODULE, .of_match_table = of_match_ptr(pcf85063_of_match), }, .probe = pcf85063_probe, .id_table = pcf85063_id, }; module_i2c_driver(pcf85063_driver); MODULE_AUTHOR("Søren Andersen <san@rosetechnology.dk>"); MODULE_DESCRIPTION("PCF85063 RTC driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_VERSION);