diff options
Diffstat (limited to 'drivers/rtc/rtc-pcf8563.c')
| -rw-r--r-- | drivers/rtc/rtc-pcf8563.c | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c new file mode 100644 index 0000000..d857d45 --- /dev/null +++ b/drivers/rtc/rtc-pcf8563.c @@ -0,0 +1,353 @@ +/* + * An I2C driver for the Philips PCF8563 RTC + * Copyright 2005-06 Tower Technologies + * + * Author: Alessandro Zummo <a.zummo@towertech.it> + * 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 <linux/i2c.h> +#include <linux/bcd.h> +#include <linux/rtc.h> + +#define DRV_VERSION "0.4.2" + +/* Addresses to scan: none + * This chip cannot be reliably autodetected. An empty eeprom + * located at 0x51 will pass the validation routine due to + * the way the registers are implemented. + */ +static unsigned short normal_i2c[] = { I2C_CLIENT_END }; + +/* Module parameters */ +I2C_CLIENT_INSMOD; + +#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 int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind); +static int pcf8563_detach(struct i2c_client *client); + +/* + * 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) +{ + unsigned char buf[13] = { PCF8563_REG_ST1 }; + + struct i2c_msg msgs[] = { + { client->addr, 0, 1, buf }, /* setup read ptr */ + { client->addr, I2C_M_RD, 13, buf }, /* read status + date */ + }; + + /* read registers */ + if ((i2c_transfer(client->adapter, msgs, 2)) != 2) { + dev_err(&client->dev, "%s: read error\n", __FUNCTION__); + return -EIO; + } + + if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) + 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", + __FUNCTION__, + 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]) + + (buf[PCF8563_REG_MO] & PCF8563_MO_C ? 100 : 0); + + dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " + "mday=%d, mon=%d, year=%d, wday=%d\n", + __FUNCTION__, + 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) +{ + 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", + __FUNCTION__, + 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 (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", + __FUNCTION__, err, data[0], data[1]); + return -EIO; + } + }; + + return 0; +} + +struct pcf8563_limit +{ + unsigned char reg; + unsigned char mask; + unsigned char min; + unsigned char max; +}; + +static int pcf8563_validate_client(struct i2c_client *client) +{ + int i; + + static const struct pcf8563_limit pattern[] = { + /* register, mask, min, max */ + { PCF8563_REG_SC, 0x7F, 0, 59 }, + { PCF8563_REG_MN, 0x7F, 0, 59 }, + { PCF8563_REG_HR, 0x3F, 0, 23 }, + { PCF8563_REG_DM, 0x3F, 0, 31 }, + { PCF8563_REG_MO, 0x1F, 0, 12 }, + }; + + /* check limits (only registers with bcd values) */ + for (i = 0; i < ARRAY_SIZE(pattern); i++) { + int xfer; + unsigned char value; + unsigned char buf = pattern[i].reg; + + struct i2c_msg msgs[] = { + { client->addr, 0, 1, &buf }, + { client->addr, I2C_M_RD, 1, &buf }, + }; + + xfer = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + + if (xfer != ARRAY_SIZE(msgs)) { + dev_err(&client->adapter->dev, + "%s: could not read register 0x%02X\n", + __FUNCTION__, pattern[i].reg); + + return -EIO; + } + + value = BCD2BIN(buf & pattern[i].mask); + + if (value > pattern[i].max || + value < pattern[i].min) { + dev_dbg(&client->adapter->dev, + "%s: pattern=%d, reg=%x, mask=0x%02x, min=%d, " + "max=%d, value=%d, raw=0x%02X\n", + __FUNCTION__, i, pattern[i].reg, pattern[i].mask, + pattern[i].min, pattern[i].max, + value, buf); + + return -ENODEV; + } + } + + return 0; +} + +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 int pcf8563_rtc_proc(struct device *dev, struct seq_file *seq) +{ + seq_printf(seq, "24hr\t\t: yes\n"); + return 0; +} + +static struct rtc_class_ops pcf8563_rtc_ops = { + .proc = pcf8563_rtc_proc, + .read_time = pcf8563_rtc_read_time, + .set_time = pcf8563_rtc_set_time, +}; + +static int pcf8563_attach(struct i2c_adapter *adapter) +{ + return i2c_probe(adapter, &addr_data, pcf8563_probe); +} + +static struct i2c_driver pcf8563_driver = { + .driver = { + .name = "pcf8563", + }, + .id = I2C_DRIVERID_PCF8563, + .attach_adapter = &pcf8563_attach, + .detach_client = &pcf8563_detach, +}; + +static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind) +{ + struct i2c_client *client; + struct rtc_device *rtc; + + int err = 0; + + dev_dbg(&adapter->dev, "%s\n", __FUNCTION__); + + if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) { + err = -ENODEV; + goto exit; + } + + if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) { + err = -ENOMEM; + goto exit; + } + + client->addr = address; + client->driver = &pcf8563_driver; + client->adapter = adapter; + + strlcpy(client->name, pcf8563_driver.driver.name, I2C_NAME_SIZE); + + /* Verify the chip is really an PCF8563 */ + if (kind < 0) { + if (pcf8563_validate_client(client) < 0) { + err = -ENODEV; + goto exit_kfree; + } + } + + /* Inform the i2c layer */ + if ((err = i2c_attach_client(client))) + goto exit_kfree; + + dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); + + rtc = rtc_device_register(pcf8563_driver.driver.name, &client->dev, + &pcf8563_rtc_ops, THIS_MODULE); + + if (IS_ERR(rtc)) { + err = PTR_ERR(rtc); + dev_err(&client->dev, + "unable to register the class device\n"); + goto exit_detach; + } + + i2c_set_clientdata(client, rtc); + + return 0; + +exit_detach: + i2c_detach_client(client); + +exit_kfree: + kfree(client); + +exit: + return err; +} + +static int pcf8563_detach(struct i2c_client *client) +{ + int err; + struct rtc_device *rtc = i2c_get_clientdata(client); + + dev_dbg(&client->dev, "%s\n", __FUNCTION__); + + if (rtc) + rtc_device_unregister(rtc); + + if ((err = i2c_detach_client(client))) + return err; + + kfree(client); + + return 0; +} + +static int __init pcf8563_init(void) +{ + return i2c_add_driver(&pcf8563_driver); +} + +static void __exit pcf8563_exit(void) +{ + i2c_del_driver(&pcf8563_driver); +} + +MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); +MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(DRV_VERSION); + +module_init(pcf8563_init); +module_exit(pcf8563_exit); |
