/* * x1205.c - An i2c driver for the Xicor X1205 RTC * Copyright 2004 Karen Spearel * Copyright 2005 Alessandro Zummo * * please send all reports to: * kas11 at tampabay dot rr dot com * a dot zummo at towertech dot it * * 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 as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ #include #include #include #include #include #include #include #include #include #define DRV_VERSION "0.9.9" /* 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; I2C_CLIENT_MODULE_PARM(hctosys, "Set the system time from the hardware clock upon initialization"); /* 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 int x1205_command(struct i2c_client *client, unsigned int cmd, void *arg); static struct i2c_driver x1205_driver = { .driver = { .name = "x1205", }, .attach_adapter = &x1205_attach, .detach_client = &x1205_detach, }; struct x1205_data { struct i2c_client client; struct list_head list; unsigned int epoch; }; static const unsigned char days_in_mo[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; static LIST_HEAD(x1205_clients); /* Workaround until the I2C subsytem will allow to send * commands to a specific client. This function will send the command * to the first client. */ int x1205_do_command(unsigned int cmd, void *arg) { struct list_head *walk; struct list_head *tmp; struct x1205_data *data; list_for_each_safe(walk, tmp, &x1205_clients) { data = list_entry(walk, struct x1205_data, list); return x1205_command(&data->client, cmd, arg); } return -ENODEV; } #define is_leap(year) \ ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0)) /* make sure the rtc_time values are in bounds */ static int x1205_validate_tm(struct rtc_time *tm) { int year = tm->tm_year + 1900; if ((tm->tm_year < 70) || (tm->tm_year > 255)) return -EINVAL; if ((tm->tm_mon > 11) || (tm->tm_mday == 0)) return -EINVAL; if (tm->tm_mday > days_in_mo[tm->tm_mon] + ((tm->tm_mon == 1) && is_leap(year))) return -EINVAL; if ((tm->tm_hour >= 24) || (tm->tm_min >= 60) || (tm->tm_sec >= 60)) return -EINVAL; return 0; } /* * 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, u8 reg_base) { unsigned char dt_addr[2] = { 0, reg_base }; static unsigned char sr_addr[2] = { 0, X1205_REG_SR }; unsigned char buf[8], sr; struct i2c_msg msgs[] = { { client->addr, 0, 2, sr_addr }, /* setup read ptr */ { client->addr, I2C_M_RD, 1, &sr }, /* read status */ { client->addr, 0, 2, dt_addr }, /* setup read ptr */ { client->addr, I2C_M_RD, 8, buf }, /* read date */ }; struct x1205_data *data = i2c_get_clientdata(client); /* read status register */ if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { dev_err(&client->dev, "%s: read error\n", __FUNCTION__); return -EIO; } /* check for battery failure */ if (sr & X1205_SR_RTCF) { dev_warn(&client->dev, "Clock had a power failure, you must set the date.\n"); return -EINVAL; } /* read date registers */ if ((i2c_transfer(client->adapter, &msgs[2], 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]); data->epoch = BCD2BIN(buf[CCR_Y2K]) * 100; tm->tm_year = BCD2BIN(buf[CCR_YEAR]) + data->epoch - 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_set_datetime(struct i2c_client *client, struct rtc_time *tm, int datetoo, u8 reg_base) { int i, err, 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 }; struct x1205_data *data = i2c_get_clientdata(client); /* check if all values in the tm struct are correct */ if ((err = x1205_validate_tm(tm)) < 0) return err; 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); 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) { buf[CCR_MDAY] = BIN2BCD(tm->tm_mday); /* month, 0 - 11 */ buf[CCR_MONTH] = BIN2BCD(tm->tm_mon); /* year, since 1900 */ buf[CCR_YEAR] = BIN2BCD(tm->tm_year + 1900 - data->epoch); buf[CCR_WDAY] = tm->tm_wday & 0x07; buf[CCR_Y2K] = BIN2BCD(data->epoch / 100); } /* this sequence is required to unlock the chip */ xfer = i2c_master_send(client, wel, 3); if (xfer != 3) { dev_err(&client->dev, "%s: wel - %d\n", __FUNCTION__, xfer); return -EIO; } xfer = i2c_master_send(client, rwel, 3); if (xfer != 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 */ xfer = i2c_master_send(client, diswe, 3); if (xfer != 3) { dev_err(&client->dev, "%s: diswe - %d\n", __FUNCTION__, xfer); return -EIO; } return 0; } 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; } static int x1205_hctosys(struct i2c_client *client) { int err; struct rtc_time tm; struct timespec tv; err = x1205_command(client, X1205_CMD_GETDATETIME, &tm); if (err) { dev_err(&client->dev, "Unable to set the system clock\n"); return err; } /* IMPORTANT: the RTC only stores whole seconds. It is arbitrary * whether it stores the most close value or the value with partial * seconds truncated. However, it is important that we use it to store * the truncated value. This is because otherwise it is necessary, * in an rtc sync function, to read both xtime.tv_sec and * xtime.tv_nsec. On some processors (i.e. ARM), an atomic read * of >32bits is not possible. So storing the most close value would * slow down the sync API. So here we have the truncated value and * the best guess is to add 0.5s. */ tv.tv_nsec = NSEC_PER_SEC >> 1; /* WARNING: this is not the C library 'mktime' call, it is a built in * inline function from include/linux/time.h. It expects (requires) * the month to be in the range 1-12 */ tv.tv_sec = mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec); do_settimeofday(&tv); dev_info(&client->dev, "setting the system clock to %d-%d-%d %d:%d:%d\n", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec); return 0; } struct x1205_limit { unsigned char reg; unsigned char mask; unsigned char min; unsigned char 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 }, }; xfer = i2c_transfer(client->adapter, msgs, 2); if (xfer != 2) { dev_err(&client->adapter->dev, "%s: could not read register %x\n", __FUNCTION__, addr[1]); 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__, addr[1], 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, ® }, }; xfer = i2c_transfer(client->adapter, msgs, 2); if (xfer != 2) { dev_err(&client->adapter->dev, "%s: could not read register %x\n", __FUNCTION__, addr[1]); 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__, addr[1], i, value); return -ENODEV; } } return 0; } static int x1205_attach(struct i2c_adapter *adapter) { dev_dbg(&adapter->dev, "%s\n", __FUNCTION__); return i2c_probe(adapter, &addr_data, x1205_probe); } int x1205_direct_attach(int adapter_id, struct i2c_client_address_data *address_data) { int err; struct i2c_adapter *adapter = i2c_get_adapter(adapter_id); if (adapter) { err = i2c_probe(adapter, address_data, x1205_probe); i2c_put_adapter(adapter); return err; } return -ENODEV; } static int x1205_probe(struct i2c_adapter *adapter, int address, int kind) { struct i2c_client *client; struct x1205_data *data; int err = 0; dev_dbg(&adapter->dev, "%s\n", __FUNCTION__); if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) { err = -ENODEV; goto exit; } if (!(data = kzalloc(sizeof(struct x1205_data), GFP_KERNEL))) { err = -ENOMEM; goto exit; } /* Initialize our structures */ data->epoch = 2000; client = &data->client; client->addr = address; client->driver = &x1205_driver; client->adapter = adapter; strlcpy(client->name, "x1205", I2C_NAME_SIZE); i2c_set_clientdata(client, data); /* 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; list_add(&data->list, &x1205_clients); dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); /* If requested, set the system time */ if (hctosys) x1205_hctosys(client); return 0; exit_kfree: kfree(data); exit: return err; } static int x1205_detach(struct i2c_client *client) { int err; struct x1205_data *data = i2c_get_clientdata(client); dev_dbg(&client->dev, "%s\n", __FUNCTION__); if ((err = i2c_detach_client(client))) return err; list_del(&data->list); kfree(data); return 0; } static int x1205_command(struct i2c_client *client, unsigned int cmd, void *param) { if (param == NULL) return -EINVAL; if (!capable(CAP_SYS_TIME)) return -EACCES; dev_dbg(&client->dev, "%s: cmd=%d\n", __FUNCTION__, cmd); switch (cmd) { case X1205_CMD_GETDATETIME: return x1205_get_datetime(client, param, X1205_CCR_BASE); case X1205_CMD_SETTIME: return x1205_set_datetime(client, param, 0, X1205_CCR_BASE); case X1205_CMD_SETDATETIME: return x1205_set_datetime(client, param, 1, X1205_CCR_BASE); case X1205_CMD_GETALARM: return x1205_get_datetime(client, param, X1205_ALM0_BASE); case X1205_CMD_SETALARM: return x1205_set_datetime(client, param, 1, X1205_ALM0_BASE); case X1205_CMD_GETDTRIM: return x1205_get_dtrim(client, param); case X1205_CMD_GETATRIM: return x1205_get_atrim(client, param); default: return -EINVAL; } } 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 , " "Alessandro Zummo "); MODULE_DESCRIPTION("Xicor X1205 RTC driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_VERSION); EXPORT_SYMBOL_GPL(x1205_do_command); EXPORT_SYMBOL_GPL(x1205_direct_attach); module_init(x1205_init); module_exit(x1205_exit);