/* * An I2C driver for the Philips PCF8563 RTC * Copyright 2005-06 Tower Technologies * * Author: Alessandro Zummo * Maintainers: http://www.nslu2-linux.org/ * * based on the other drivers in this same directory. * * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf * * 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 #include #include #include #include #include #define DRV_VERSION "0.4.3" #define PCF8563_REG_ST1 0x00 /* status */ #define PCF8563_REG_ST2 0x01 #define PCF8563_REG_SC 0x02 /* datetime */ #define PCF8563_REG_MN 0x03 #define PCF8563_REG_HR 0x04 #define PCF8563_REG_DM 0x05 #define PCF8563_REG_DW 0x06 #define PCF8563_REG_MO 0x07 #define PCF8563_REG_YR 0x08 #define PCF8563_REG_AMN 0x09 /* alarm */ #define PCF8563_REG_AHR 0x0A #define PCF8563_REG_ADM 0x0B #define PCF8563_REG_ADW 0x0C #define PCF8563_REG_CLKO 0x0D /* clock out */ #define PCF8563_REG_TMRC 0x0E /* timer control */ #define PCF8563_REG_TMR 0x0F /* timer */ #define PCF8563_SC_LV 0x80 /* low voltage */ #define PCF8563_MO_C 0x80 /* century */ static struct i2c_driver pcf8563_driver; struct pcf8563 { struct rtc_device *rtc; /* * The meaning of MO_C bit varies by the chip type. * From PCF8563 datasheet: this bit is toggled when the years * register overflows from 99 to 00 * 0 indicates the century is 20xx * 1 indicates the century is 19xx * From RTC8564 datasheet: this bit indicates change of * century. When the year digit data overflows from 99 to 00, * this bit is set. By presetting it to 0 while still in the * 20th century, it will be set in year 2000, ... * There seems no reliable way to know how the system use this * bit. So let's do it heuristically, assuming we are live in * 1970...2069. */ int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */ int voltage_low; /* incicates if a low_voltage was detected */ }; /* * In the routines that deal directly with the pcf8563 hardware, we use * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. */ static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) { struct pcf8563 *pcf8563 = i2c_get_clientdata(client); unsigned char buf[13] = { PCF8563_REG_ST1 }; 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; } if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) { pcf8563->voltage_low = 1; dev_info(&client->dev, "low voltage detected, date/time is not reliable.\n"); } dev_dbg(&client->dev, "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, " "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", __func__, buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7], buf[8]); tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F); tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F); tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */ tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F); tm->tm_wday = buf[PCF8563_REG_DW] & 0x07; tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]); if (tm->tm_year < 70) tm->tm_year += 100; /* assume we are in 1970...2069 */ /* detect the polarity heuristically. see note above. */ pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ? (tm->tm_year >= 100) : (tm->tm_year < 100); dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); /* 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 pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm) { struct pcf8563 *pcf8563 = i2c_get_clientdata(client); int i, err; unsigned char buf[9]; dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); /* hours, minutes and seconds */ buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec); buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min); buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour); buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday); /* month, 1 - 12 */ buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1); /* year and century */ buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100); if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100)) buf[PCF8563_REG_MO] |= PCF8563_MO_C; buf[PCF8563_REG_DW] = tm->tm_wday & 0x07; /* write register's data */ for (i = 0; i < 7; i++) { unsigned char data[2] = { PCF8563_REG_SC + i, buf[PCF8563_REG_SC + 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; } #ifdef CONFIG_RTC_INTF_DEV static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev)); struct rtc_time tm; switch (cmd) { case RTC_VL_READ: if (pcf8563->voltage_low) dev_info(dev, "low voltage detected, date/time is not reliable.\n"); if (copy_to_user((void __user *)arg, &pcf8563->voltage_low, sizeof(int))) return -EFAULT; return 0; case RTC_VL_CLR: /* * Clear the VL bit in the seconds register in case * the time has not been set already (which would * have cleared it). This does not really matter * because of the cached voltage_low value but do it * anyway for consistency. */ if (pcf8563_get_datetime(to_i2c_client(dev), &tm)) pcf8563_set_datetime(to_i2c_client(dev), &tm); /* Clear the cached value. */ pcf8563->voltage_low = 0; return 0; default: return -ENOIOCTLCMD; } } #else #define pcf8563_rtc_ioctl NULL #endif static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm) { return pcf8563_get_datetime(to_i2c_client(dev), tm); } static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm) { return pcf8563_set_datetime(to_i2c_client(dev), tm); } static const struct rtc_class_ops pcf8563_rtc_ops = { .ioctl = pcf8563_rtc_ioctl, .read_time = pcf8563_rtc_read_time, .set_time = pcf8563_rtc_set_time, }; static int pcf8563_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct pcf8563 *pcf8563; dev_dbg(&client->dev, "%s\n", __func__); if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) return -ENODEV; pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563), GFP_KERNEL); if (!pcf8563) return -ENOMEM; dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); i2c_set_clientdata(client, pcf8563); pcf8563->rtc = devm_rtc_device_register(&client->dev, pcf8563_driver.driver.name, &pcf8563_rtc_ops, THIS_MODULE); if (IS_ERR(pcf8563->rtc)) return PTR_ERR(pcf8563->rtc); return 0; } static const struct i2c_device_id pcf8563_id[] = { { "pcf8563", 0 }, { "rtc8564", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, pcf8563_id); #ifdef CONFIG_OF static const struct of_device_id pcf8563_of_match[] = { { .compatible = "nxp,pcf8563" }, {} }; MODULE_DEVICE_TABLE(of, pcf8563_of_match); #endif static struct i2c_driver pcf8563_driver = { .driver = { .name = "rtc-pcf8563", .owner = THIS_MODULE, .of_match_table = of_match_ptr(pcf8563_of_match), }, .probe = pcf8563_probe, .id_table = pcf8563_id, }; module_i2c_driver(pcf8563_driver); MODULE_AUTHOR("Alessandro Zummo "); MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_VERSION);