/* * An i2c driver for the Xicor/Intersil X1205 RTC * Copyright 2004 Karen Spearel * Copyright 2005 Alessandro Zummo * * please send all reports to: * Karen Spearel <kas111 at gmail dot com> * Alessandro Zummo <a.zummo@towertech.it> * * based on a lot of other RTC drivers. * * 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/delay.h> #define DRV_VERSION "1.0.7" /* Addresses to scan: none. This chip is located at * 0x6f and uses a two bytes register addressing. * Two bytes need to be written to read a single register, * while most other chips just require one and take the second * one as the data to be written. To prevent corrupting * unknown chips, the user must explicitely set the probe parameter. */ static unsigned short normal_i2c[] = { I2C_CLIENT_END }; /* Insmod parameters */ I2C_CLIENT_INSMOD; /* offsets into CCR area */ #define CCR_SEC 0 #define CCR_MIN 1 #define CCR_HOUR 2 #define CCR_MDAY 3 #define CCR_MONTH 4 #define CCR_YEAR 5 #define CCR_WDAY 6 #define CCR_Y2K 7 #define X1205_REG_SR 0x3F /* status register */ #define X1205_REG_Y2K 0x37 #define X1205_REG_DW 0x36 #define X1205_REG_YR 0x35 #define X1205_REG_MO 0x34 #define X1205_REG_DT 0x33 #define X1205_REG_HR 0x32 #define X1205_REG_MN 0x31 #define X1205_REG_SC 0x30 #define X1205_REG_DTR 0x13 #define X1205_REG_ATR 0x12 #define X1205_REG_INT 0x11 #define X1205_REG_0 0x10 #define X1205_REG_Y2K1 0x0F #define X1205_REG_DWA1 0x0E #define X1205_REG_YRA1 0x0D #define X1205_REG_MOA1 0x0C #define X1205_REG_DTA1 0x0B #define X1205_REG_HRA1 0x0A #define X1205_REG_MNA1 0x09 #define X1205_REG_SCA1 0x08 #define X1205_REG_Y2K0 0x07 #define X1205_REG_DWA0 0x06 #define X1205_REG_YRA0 0x05 #define X1205_REG_MOA0 0x04 #define X1205_REG_DTA0 0x03 #define X1205_REG_HRA0 0x02 #define X1205_REG_MNA0 0x01 #define X1205_REG_SCA0 0x00 #define X1205_CCR_BASE 0x30 /* Base address of CCR */ #define X1205_ALM0_BASE 0x00 /* Base address of ALARM0 */ #define X1205_SR_RTCF 0x01 /* Clock failure */ #define X1205_SR_WEL 0x02 /* Write Enable Latch */ #define X1205_SR_RWEL 0x04 /* Register Write Enable */ #define X1205_DTR_DTR0 0x01 #define X1205_DTR_DTR1 0x02 #define X1205_DTR_DTR2 0x04 #define X1205_HR_MIL 0x80 /* Set in ccr.hour for 24 hr mode */ /* Prototypes */ static int x1205_attach(struct i2c_adapter *adapter); static int x1205_detach(struct i2c_client *client); static int x1205_probe(struct i2c_adapter *adapter, int address, int kind); static struct i2c_driver x1205_driver = { .driver = { .name = "x1205", }, .id = I2C_DRIVERID_X1205, .attach_adapter = &x1205_attach, .detach_client = &x1205_detach, }; /* * In the routines that deal directly with the x1205 hardware, we use * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch * Epoch is initialized as 2000. Time is set to UTC. */ static int x1205_get_datetime(struct i2c_client *client, struct rtc_time *tm, unsigned char reg_base) { unsigned char dt_addr[2] = { 0, reg_base }; unsigned char buf[8]; struct i2c_msg msgs[] = { { client->addr, 0, 2, dt_addr }, /* setup read ptr */ { client->addr, I2C_M_RD, 8, buf }, /* read date */ }; /* read date registers */ if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { dev_err(&client->dev, "%s: read error\n", __FUNCTION__); return -EIO; } dev_dbg(&client->dev, "%s: raw read data - sec=%02x, min=%02x, hr=%02x, " "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n", __FUNCTION__, buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); tm->tm_sec = BCD2BIN(buf[CCR_SEC]); tm->tm_min = BCD2BIN(buf[CCR_MIN]); tm->tm_hour = BCD2BIN(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */ tm->tm_mday = BCD2BIN(buf[CCR_MDAY]); tm->tm_mon = BCD2BIN(buf[CCR_MONTH]) - 1; /* mon is 0-11 */ tm->tm_year = BCD2BIN(buf[CCR_YEAR]) + (BCD2BIN(buf[CCR_Y2K]) * 100) - 1900; tm->tm_wday = buf[CCR_WDAY]; 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); return 0; } static int x1205_get_status(struct i2c_client *client, unsigned char *sr) { static unsigned char sr_addr[2] = { 0, X1205_REG_SR }; struct i2c_msg msgs[] = { { client->addr, 0, 2, sr_addr }, /* setup read ptr */ { client->addr, I2C_M_RD, 1, sr }, /* read status */ }; /* read status register */ if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { dev_err(&client->dev, "%s: read error\n", __FUNCTION__); return -EIO; } return 0; } static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm, int datetoo, u8 reg_base) { int i, xfer; unsigned char buf[8]; static const unsigned char wel[3] = { 0, X1205_REG_SR, X1205_SR_WEL }; static const unsigned char rwel[3] = { 0, X1205_REG_SR, X1205_SR_WEL | X1205_SR_RWEL }; static const unsigned char diswe[3] = { 0, X1205_REG_SR, 0 }; dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d\n", __FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour); buf[CCR_SEC] = BIN2BCD(tm->tm_sec); buf[CCR_MIN] = BIN2BCD(tm->tm_min); /* set hour and 24hr bit */ buf[CCR_HOUR] = BIN2BCD(tm->tm_hour) | X1205_HR_MIL; /* should we also set the date? */ if (datetoo) { dev_dbg(&client->dev, "%s: mday=%d, mon=%d, year=%d, wday=%d\n", __FUNCTION__, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); buf[CCR_MDAY] = BIN2BCD(tm->tm_mday); /* month, 1 - 12 */ buf[CCR_MONTH] = BIN2BCD(tm->tm_mon + 1); /* year, since the rtc epoch*/ buf[CCR_YEAR] = BIN2BCD(tm->tm_year % 100); buf[CCR_WDAY] = tm->tm_wday & 0x07; buf[CCR_Y2K] = BIN2BCD(tm->tm_year / 100); } /* this sequence is required to unlock the chip */ if ((xfer = i2c_master_send(client, wel, 3)) != 3) { dev_err(&client->dev, "%s: wel - %d\n", __FUNCTION__, xfer); return -EIO; } if ((xfer = i2c_master_send(client, rwel, 3)) != 3) { dev_err(&client->dev, "%s: rwel - %d\n", __FUNCTION__, xfer); return -EIO; } /* write register's data */ for (i = 0; i < (datetoo ? 8 : 3); i++) { unsigned char rdata[3] = { 0, reg_base + i, buf[i] }; xfer = i2c_master_send(client, rdata, 3); if (xfer != 3) { dev_err(&client->dev, "%s: xfer=%d addr=%02x, data=%02x\n", __FUNCTION__, xfer, rdata[1], rdata[2]); return -EIO; } }; /* disable further writes */ if ((xfer = i2c_master_send(client, diswe, 3)) != 3) { dev_err(&client->dev, "%s: diswe - %d\n", __FUNCTION__, xfer); return -EIO; } return 0; } static int x1205_fix_osc(struct i2c_client *client) { int err; struct rtc_time tm; tm.tm_hour = tm.tm_min = tm.tm_sec = 0; if ((err = x1205_set_datetime(client, &tm, 0, X1205_CCR_BASE)) < 0) dev_err(&client->dev, "unable to restart the oscillator\n"); return err; } static int x1205_get_dtrim(struct i2c_client *client, int *trim) { unsigned char dtr; static unsigned char dtr_addr[2] = { 0, X1205_REG_DTR }; struct i2c_msg msgs[] = { { client->addr, 0, 2, dtr_addr }, /* setup read ptr */ { client->addr, I2C_M_RD, 1, &dtr }, /* read dtr */ }; /* read dtr register */ if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { dev_err(&client->dev, "%s: read error\n", __FUNCTION__); return -EIO; } dev_dbg(&client->dev, "%s: raw dtr=%x\n", __FUNCTION__, dtr); *trim = 0; if (dtr & X1205_DTR_DTR0) *trim += 20; if (dtr & X1205_DTR_DTR1) *trim += 10; if (dtr & X1205_DTR_DTR2) *trim = -*trim; return 0; } static int x1205_get_atrim(struct i2c_client *client, int *trim) { s8 atr; static unsigned char atr_addr[2] = { 0, X1205_REG_ATR }; struct i2c_msg msgs[] = { { client->addr, 0, 2, atr_addr }, /* setup read ptr */ { client->addr, I2C_M_RD, 1, &atr }, /* read atr */ }; /* read atr register */ if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { dev_err(&client->dev, "%s: read error\n", __FUNCTION__); return -EIO; } dev_dbg(&client->dev, "%s: raw atr=%x\n", __FUNCTION__, atr); /* atr is a two's complement value on 6 bits, * perform sign extension. The formula is * Catr = (atr * 0.25pF) + 11.00pF. */ if (atr & 0x20) atr |= 0xC0; dev_dbg(&client->dev, "%s: raw atr=%x (%d)\n", __FUNCTION__, atr, atr); *trim = (atr * 250) + 11000; dev_dbg(&client->dev, "%s: real=%d\n", __FUNCTION__, *trim); return 0; } struct x1205_limit { unsigned char reg, mask, min, max; }; static int x1205_validate_client(struct i2c_client *client) { int i, xfer; /* Probe array. We will read the register at the specified * address and check if the given bits are zero. */ static const unsigned char probe_zero_pattern[] = { /* register, mask */ X1205_REG_SR, 0x18, X1205_REG_DTR, 0xF8, X1205_REG_ATR, 0xC0, X1205_REG_INT, 0x18, X1205_REG_0, 0xFF, }; static const struct x1205_limit probe_limits_pattern[] = { /* register, mask, min, max */ { X1205_REG_Y2K, 0xFF, 19, 20 }, { X1205_REG_DW, 0xFF, 0, 6 }, { X1205_REG_YR, 0xFF, 0, 99 }, { X1205_REG_MO, 0xFF, 0, 12 }, { X1205_REG_DT, 0xFF, 0, 31 }, { X1205_REG_HR, 0x7F, 0, 23 }, { X1205_REG_MN, 0xFF, 0, 59 }, { X1205_REG_SC, 0xFF, 0, 59 }, { X1205_REG_Y2K1, 0xFF, 19, 20 }, { X1205_REG_Y2K0, 0xFF, 19, 20 }, }; /* check that registers have bits a 0 where expected */ for (i = 0; i < ARRAY_SIZE(probe_zero_pattern); i += 2) { unsigned char buf; unsigned char addr[2] = { 0, probe_zero_pattern[i] }; struct i2c_msg msgs[2] = { { client->addr, 0, 2, addr }, { client->addr, I2C_M_RD, 1, &buf }, }; if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) { dev_err(&client->adapter->dev, "%s: could not read register %x\n", __FUNCTION__, probe_zero_pattern[i]); return -EIO; } if ((buf & probe_zero_pattern[i+1]) != 0) { dev_err(&client->adapter->dev, "%s: register=%02x, zero pattern=%d, value=%x\n", __FUNCTION__, probe_zero_pattern[i], i, buf); return -ENODEV; } } /* check limits (only registers with bcd values) */ for (i = 0; i < ARRAY_SIZE(probe_limits_pattern); i++) { unsigned char reg, value; unsigned char addr[2] = { 0, probe_limits_pattern[i].reg }; struct i2c_msg msgs[2] = { { client->addr, 0, 2, addr }, { client->addr, I2C_M_RD, 1, ® }, }; if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) { dev_err(&client->adapter->dev, "%s: could not read register %x\n", __FUNCTION__, probe_limits_pattern[i].reg); return -EIO; } value = BCD2BIN(reg & probe_limits_pattern[i].mask); if (value > probe_limits_pattern[i].max || value < probe_limits_pattern[i].min) { dev_dbg(&client->adapter->dev, "%s: register=%x, lim pattern=%d, value=%d\n", __FUNCTION__, probe_limits_pattern[i].reg, i, value); return -ENODEV; } } return 0; } static int x1205_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { return x1205_get_datetime(to_i2c_client(dev), &alrm->time, X1205_ALM0_BASE); } static int x1205_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { return x1205_set_datetime(to_i2c_client(dev), &alrm->time, 1, X1205_ALM0_BASE); } static int x1205_rtc_read_time(struct device *dev, struct rtc_time *tm) { return x1205_get_datetime(to_i2c_client(dev), tm, X1205_CCR_BASE); } static int x1205_rtc_set_time(struct device *dev, struct rtc_time *tm) { return x1205_set_datetime(to_i2c_client(dev), tm, 1, X1205_CCR_BASE); } static int x1205_rtc_proc(struct device *dev, struct seq_file *seq) { int err, dtrim, atrim; if ((err = x1205_get_dtrim(to_i2c_client(dev), &dtrim)) == 0) seq_printf(seq, "digital_trim\t: %d ppm\n", dtrim); if ((err = x1205_get_atrim(to_i2c_client(dev), &atrim)) == 0) seq_printf(seq, "analog_trim\t: %d.%02d pF\n", atrim / 1000, atrim % 1000); return 0; } static struct rtc_class_ops x1205_rtc_ops = { .proc = x1205_rtc_proc, .read_time = x1205_rtc_read_time, .set_time = x1205_rtc_set_time, .read_alarm = x1205_rtc_read_alarm, .set_alarm = x1205_rtc_set_alarm, }; static ssize_t x1205_sysfs_show_atrim(struct device *dev, struct device_attribute *attr, char *buf) { int err, atrim; err = x1205_get_atrim(to_i2c_client(dev), &atrim); if (err) return err; return sprintf(buf, "%d.%02d pF\n", atrim / 1000, atrim % 1000); } static DEVICE_ATTR(atrim, S_IRUGO, x1205_sysfs_show_atrim, NULL); static ssize_t x1205_sysfs_show_dtrim(struct device *dev, struct device_attribute *attr, char *buf) { int err, dtrim; err = x1205_get_dtrim(to_i2c_client(dev), &dtrim); if (err) return err; return sprintf(buf, "%d ppm\n", dtrim); } static DEVICE_ATTR(dtrim, S_IRUGO, x1205_sysfs_show_dtrim, NULL); static int x1205_attach(struct i2c_adapter *adapter) { return i2c_probe(adapter, &addr_data, x1205_probe); } static int x1205_probe(struct i2c_adapter *adapter, int address, int kind) { int err = 0; unsigned char sr; struct i2c_client *client; struct rtc_device *rtc; 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; } /* I2C client */ client->addr = address; client->driver = &x1205_driver; client->adapter = adapter; strlcpy(client->name, x1205_driver.driver.name, I2C_NAME_SIZE); /* Verify the chip is really an X1205 */ if (kind < 0) { if (x1205_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(x1205_driver.driver.name, &client->dev, &x1205_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) { err = PTR_ERR(rtc); goto exit_detach; } i2c_set_clientdata(client, rtc); /* Check for power failures and eventualy enable the osc */ if ((err = x1205_get_status(client, &sr)) == 0) { if (sr & X1205_SR_RTCF) { dev_err(&client->dev, "power failure detected, " "please set the clock\n"); udelay(50); x1205_fix_osc(client); } } else dev_err(&client->dev, "couldn't read status\n"); device_create_file(&client->dev, &dev_attr_atrim); device_create_file(&client->dev, &dev_attr_dtrim); return 0; exit_detach: i2c_detach_client(client); exit_kfree: kfree(client); exit: return err; } static int x1205_detach(struct i2c_client *client) { int err; struct rtc_device *rtc = i2c_get_clientdata(client); if (rtc) rtc_device_unregister(rtc); if ((err = i2c_detach_client(client))) return err; kfree(client); return 0; } static int __init x1205_init(void) { return i2c_add_driver(&x1205_driver); } static void __exit x1205_exit(void) { i2c_del_driver(&x1205_driver); } MODULE_AUTHOR( "Karen Spearel <kas111 at gmail dot com>, " "Alessandro Zummo <a.zummo@towertech.it>"); MODULE_DESCRIPTION("Xicor/Intersil X1205 RTC driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_VERSION); module_init(x1205_init); module_exit(x1205_exit);