diff options
Diffstat (limited to 'drivers/rtc/rtc-isl1208.c')
| -rw-r--r-- | drivers/rtc/rtc-isl1208.c | 591 |
1 files changed, 591 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-isl1208.c b/drivers/rtc/rtc-isl1208.c new file mode 100644 index 00000000000..f324d0a635d --- /dev/null +++ b/drivers/rtc/rtc-isl1208.c @@ -0,0 +1,591 @@ +/* + * Intersil ISL1208 rtc class driver + * + * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org> + * + * 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 <linux/module.h> +#include <linux/i2c.h> +#include <linux/bcd.h> +#include <linux/rtc.h> + +#define DRV_NAME "isl1208" +#define DRV_VERSION "0.2" + +/* Register map */ +/* rtc section */ +#define ISL1208_REG_SC 0x00 +#define ISL1208_REG_MN 0x01 +#define ISL1208_REG_HR 0x02 +#define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */ +#define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */ +#define ISL1208_REG_DT 0x03 +#define ISL1208_REG_MO 0x04 +#define ISL1208_REG_YR 0x05 +#define ISL1208_REG_DW 0x06 +#define ISL1208_RTC_SECTION_LEN 7 + +/* control/status section */ +#define ISL1208_REG_SR 0x07 +#define ISL1208_REG_SR_ARST (1<<7) /* auto reset */ +#define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */ +#define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */ +#define ISL1208_REG_SR_ALM (1<<2) /* alarm */ +#define ISL1208_REG_SR_BAT (1<<1) /* battery */ +#define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */ +#define ISL1208_REG_INT 0x08 +#define ISL1208_REG_09 0x09 /* reserved */ +#define ISL1208_REG_ATR 0x0a +#define ISL1208_REG_DTR 0x0b + +/* alarm section */ +#define ISL1208_REG_SCA 0x0c +#define ISL1208_REG_MNA 0x0d +#define ISL1208_REG_HRA 0x0e +#define ISL1208_REG_DTA 0x0f +#define ISL1208_REG_MOA 0x10 +#define ISL1208_REG_DWA 0x11 +#define ISL1208_ALARM_SECTION_LEN 6 + +/* user section */ +#define ISL1208_REG_USR1 0x12 +#define ISL1208_REG_USR2 0x13 +#define ISL1208_USR_SECTION_LEN 2 + +/* i2c configuration */ +#define ISL1208_I2C_ADDR 0xde + +static unsigned short normal_i2c[] = { + ISL1208_I2C_ADDR>>1, I2C_CLIENT_END +}; +I2C_CLIENT_INSMOD; /* defines addr_data */ + +static int isl1208_attach_adapter(struct i2c_adapter *adapter); +static int isl1208_detach_client(struct i2c_client *client); + +static struct i2c_driver isl1208_driver = { + .driver = { + .name = DRV_NAME, + }, + .id = I2C_DRIVERID_ISL1208, + .attach_adapter = &isl1208_attach_adapter, + .detach_client = &isl1208_detach_client, +}; + +/* block read */ +static int +isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[], + unsigned len) +{ + u8 reg_addr[1] = { reg }; + struct i2c_msg msgs[2] = { + { client->addr, client->flags, sizeof(reg_addr), reg_addr }, + { client->addr, client->flags | I2C_M_RD, len, buf } + }; + int ret; + + BUG_ON(len == 0); + BUG_ON(reg > ISL1208_REG_USR2); + BUG_ON(reg + len > ISL1208_REG_USR2 + 1); + + ret = i2c_transfer(client->adapter, msgs, 2); + if (ret > 0) + ret = 0; + return ret; +} + +/* block write */ +static int +isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[], + unsigned len) +{ + u8 i2c_buf[ISL1208_REG_USR2 + 2]; + struct i2c_msg msgs[1] = { + { client->addr, client->flags, len + 1, i2c_buf } + }; + int ret; + + BUG_ON(len == 0); + BUG_ON(reg > ISL1208_REG_USR2); + BUG_ON(reg + len > ISL1208_REG_USR2 + 1); + + i2c_buf[0] = reg; + memcpy(&i2c_buf[1], &buf[0], len); + + ret = i2c_transfer(client->adapter, msgs, 1); + if (ret > 0) + ret = 0; + return ret; +} + +/* simple check to see wether we have a isl1208 */ +static int isl1208_i2c_validate_client(struct i2c_client *client) +{ + u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, }; + u8 zero_mask[ISL1208_RTC_SECTION_LEN] = { + 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8 + }; + int i; + int ret; + + ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN); + if (ret < 0) + return ret; + + for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) { + if (regs[i] & zero_mask[i]) /* check if bits are cleared */ + return -ENODEV; + } + + return 0; +} + +static int isl1208_i2c_get_sr(struct i2c_client *client) +{ + return i2c_smbus_read_byte_data(client, ISL1208_REG_SR) == -1 ? -EIO:0; +} + +static int isl1208_i2c_get_atr(struct i2c_client *client) +{ + int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR); + + if (atr < 0) + return -EIO; + + /* The 6bit value in the ATR register controls the load + * capacitance C_load * in steps of 0.25pF + * + * bit (1<<5) of the ATR register is inverted + * + * C_load(ATR=0x20) = 4.50pF + * C_load(ATR=0x00) = 12.50pF + * C_load(ATR=0x1f) = 20.25pF + * + */ + + atr &= 0x3f; /* mask out lsb */ + atr ^= 1<<5; /* invert 6th bit */ + atr += 2*9; /* add offset of 4.5pF; unit[atr] = 0.25pF */ + + return atr; +} + +static int isl1208_i2c_get_dtr(struct i2c_client *client) +{ + int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR); + + if (dtr < 0) + return -EIO; + + /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */ + dtr = ((dtr & 0x3) * 20) * (dtr & (1<<2) ? -1 : 1); + + return dtr; +} + +static int isl1208_i2c_get_usr(struct i2c_client *client) +{ + u8 buf[ISL1208_USR_SECTION_LEN] = { 0, }; + int ret; + + ret = isl1208_i2c_read_regs (client, ISL1208_REG_USR1, buf, + ISL1208_USR_SECTION_LEN); + if (ret < 0) + return ret; + + return (buf[1] << 8) | buf[0]; +} + +static int isl1208_i2c_set_usr(struct i2c_client *client, u16 usr) +{ + u8 buf[ISL1208_USR_SECTION_LEN]; + + buf[0] = usr & 0xff; + buf[1] = (usr >> 8) & 0xff; + + return isl1208_i2c_set_regs (client, ISL1208_REG_USR1, buf, + ISL1208_USR_SECTION_LEN); +} + +static int isl1208_rtc_proc(struct device *dev, struct seq_file *seq) +{ + struct i2c_client *const client = to_i2c_client(dev); + int sr, dtr, atr, usr; + + sr = isl1208_i2c_get_sr(client); + if (sr < 0) { + dev_err(&client->dev, "%s: reading SR failed\n", __func__); + return sr; + } + + seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n", + (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "", + (sr & ISL1208_REG_SR_BAT) ? " BAT" : "", + (sr & ISL1208_REG_SR_ALM) ? " ALM" : "", + (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "", + (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "", + (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", + sr); + + seq_printf(seq, "batt_status\t: %s\n", + (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay"); + + dtr = isl1208_i2c_get_dtr(client); + if (dtr >= 0 -1) + seq_printf(seq, "digital_trim\t: %d ppm\n", dtr); + + atr = isl1208_i2c_get_atr(client); + if (atr >= 0) + seq_printf(seq, "analog_trim\t: %d.%.2d pF\n", + atr>>2, (atr&0x3)*25); + + usr = isl1208_i2c_get_usr(client); + if (usr >= 0) + seq_printf(seq, "user_data\t: 0x%.4x\n", usr); + + return 0; +} + + +static int isl1208_i2c_read_time(struct i2c_client *client, + struct rtc_time *tm) +{ + int sr; + u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, }; + + sr = isl1208_i2c_get_sr(client); + if (sr < 0) { + dev_err(&client->dev, "%s: reading SR failed\n", __func__); + return -EIO; + } + + sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN); + if (sr < 0) { + dev_err(&client->dev, "%s: reading RTC section failed\n", + __func__); + return sr; + } + + tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SC]); + tm->tm_min = BCD2BIN(regs[ISL1208_REG_MN]); + { /* HR field has a more complex interpretation */ + const u8 _hr = regs[ISL1208_REG_HR]; + if (_hr & ISL1208_REG_HR_MIL) /* 24h format */ + tm->tm_hour = BCD2BIN(_hr & 0x3f); + else { // 12h format + tm->tm_hour = BCD2BIN(_hr & 0x1f); + if (_hr & ISL1208_REG_HR_PM) /* PM flag set */ + tm->tm_hour += 12; + } + } + + tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DT]); + tm->tm_mon = BCD2BIN(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */ + tm->tm_year = BCD2BIN(regs[ISL1208_REG_YR]) + 100; + tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DW]); + + return 0; +} + +static int isl1208_i2c_read_alarm(struct i2c_client *client, + struct rtc_wkalrm *alarm) +{ + struct rtc_time *const tm = &alarm->time; + u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, }; + int sr; + + sr = isl1208_i2c_get_sr(client); + if (sr < 0) { + dev_err(&client->dev, "%s: reading SR failed\n", __func__); + return sr; + } + + sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs, + ISL1208_ALARM_SECTION_LEN); + if (sr < 0) { + dev_err(&client->dev, "%s: reading alarm section failed\n", + __func__); + return sr; + } + + /* MSB of each alarm register is an enable bit */ + tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SCA-ISL1208_REG_SCA] & 0x7f); + tm->tm_min = BCD2BIN(regs[ISL1208_REG_MNA-ISL1208_REG_SCA] & 0x7f); + tm->tm_hour = BCD2BIN(regs[ISL1208_REG_HRA-ISL1208_REG_SCA] & 0x3f); + tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DTA-ISL1208_REG_SCA] & 0x3f); + tm->tm_mon = BCD2BIN(regs[ISL1208_REG_MOA-ISL1208_REG_SCA] & 0x1f)-1; + tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DWA-ISL1208_REG_SCA] & 0x03); + + return 0; +} + +static int isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + return isl1208_i2c_read_time(to_i2c_client(dev), tm); +} + +static int isl1208_i2c_set_time(struct i2c_client *client, + struct rtc_time const *tm) +{ + int sr; + u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, }; + + regs[ISL1208_REG_SC] = BIN2BCD(tm->tm_sec); + regs[ISL1208_REG_MN] = BIN2BCD(tm->tm_min); + regs[ISL1208_REG_HR] = BIN2BCD(tm->tm_hour) | ISL1208_REG_HR_MIL; + + regs[ISL1208_REG_DT] = BIN2BCD(tm->tm_mday); + regs[ISL1208_REG_MO] = BIN2BCD(tm->tm_mon + 1); + regs[ISL1208_REG_YR] = BIN2BCD(tm->tm_year - 100); + + regs[ISL1208_REG_DW] = BIN2BCD(tm->tm_wday & 7); + + sr = isl1208_i2c_get_sr(client); + if (sr < 0) { + dev_err(&client->dev, "%s: reading SR failed\n", __func__); + return sr; + } + + /* set WRTC */ + sr = i2c_smbus_write_byte_data (client, ISL1208_REG_SR, + sr | ISL1208_REG_SR_WRTC); + if (sr < 0) { + dev_err(&client->dev, "%s: writing SR failed\n", __func__); + return sr; + } + + /* write RTC registers */ + sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN); + if (sr < 0) { + dev_err(&client->dev, "%s: writing RTC section failed\n", + __func__); + return sr; + } + + /* clear WRTC again */ + sr = i2c_smbus_write_byte_data (client, ISL1208_REG_SR, + sr & ~ISL1208_REG_SR_WRTC); + if (sr < 0) { + dev_err(&client->dev, "%s: writing SR failed\n", __func__); + return sr; + } + + return 0; +} + + +static int isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + return isl1208_i2c_set_time(to_i2c_client(dev), tm); +} + +static int isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm); +} + +static struct rtc_class_ops isl1208_rtc_ops = { + .proc = isl1208_rtc_proc, + .read_time = isl1208_rtc_read_time, + .set_time = isl1208_rtc_set_time, + .read_alarm = isl1208_rtc_read_alarm, + //.set_alarm = isl1208_rtc_set_alarm, +}; + +/* sysfs interface */ + +static ssize_t isl1208_sysfs_show_atrim(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int atr; + + atr = isl1208_i2c_get_atr(to_i2c_client(dev)); + if (atr < 0) + return atr; + + return sprintf(buf, "%d.%.2d pF\n", atr>>2, (atr&0x3)*25); +} +static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL); + +static ssize_t isl1208_sysfs_show_dtrim(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int dtr; + + dtr = isl1208_i2c_get_dtr(to_i2c_client(dev)); + if (dtr < 0) + return dtr; + + return sprintf(buf, "%d ppm\n", dtr); +} +static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL); + +static ssize_t isl1208_sysfs_show_usr(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int usr; + + usr = isl1208_i2c_get_usr(to_i2c_client(dev)); + if (usr < 0) + return usr; + + return sprintf(buf, "0x%.4x\n", usr); +} + +static ssize_t isl1208_sysfs_store_usr(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int usr = -1; + + if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) { + if (sscanf(buf, "%x", &usr) != 1) + return -EINVAL; + } else { + if (sscanf(buf, "%d", &usr) != 1) + return -EINVAL; + } + + if (usr < 0 || usr > 0xffff) + return -EINVAL; + + return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count; +} +static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr, + isl1208_sysfs_store_usr); + +static int +isl1208_probe(struct i2c_adapter *adapter, int addr, int kind) +{ + int rc = 0; + struct i2c_client *new_client = NULL; + struct rtc_device *rtc = NULL; + + if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) { + rc = -ENODEV; + goto failout; + } + + new_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); + if (new_client == NULL) { + rc = -ENOMEM; + goto failout; + } + + new_client->addr = addr; + new_client->adapter = adapter; + new_client->driver = &isl1208_driver; + new_client->flags = 0; + strcpy(new_client->name, DRV_NAME); + + if (kind < 0) { + rc = isl1208_i2c_validate_client(new_client); + if (rc < 0) + goto failout; + } + + rc = i2c_attach_client(new_client); + if (rc < 0) + goto failout; + + dev_info(&new_client->dev, + "chip found, driver version " DRV_VERSION "\n"); + + rtc = rtc_device_register(isl1208_driver.driver.name, + &new_client->dev, + &isl1208_rtc_ops, THIS_MODULE); + + if (IS_ERR(rtc)) { + rc = PTR_ERR(rtc); + goto failout_detach; + } + + i2c_set_clientdata(new_client, rtc); + + rc = isl1208_i2c_get_sr(new_client); + if (rc < 0) { + dev_err(&new_client->dev, "reading status failed\n"); + goto failout_unregister; + } + + if (rc & ISL1208_REG_SR_RTCF) + dev_warn(&new_client->dev, "rtc power failure detected, " + "please set clock.\n"); + + rc = device_create_file(&new_client->dev, &dev_attr_atrim); + if (rc < 0) + goto failout_unregister; + rc = device_create_file(&new_client->dev, &dev_attr_dtrim); + if (rc < 0) + goto failout_atrim; + rc = device_create_file(&new_client->dev, &dev_attr_usr); + if (rc < 0) + goto failout_dtrim; + + return 0; + + failout_dtrim: + device_remove_file(&new_client->dev, &dev_attr_dtrim); + failout_atrim: + device_remove_file(&new_client->dev, &dev_attr_atrim); + failout_unregister: + rtc_device_unregister(rtc); + failout_detach: + i2c_detach_client(new_client); + failout: + kfree(new_client); + return rc; +} + +static int +isl1208_attach_adapter (struct i2c_adapter *adapter) +{ + return i2c_probe(adapter, &addr_data, isl1208_probe); +} + +static int +isl1208_detach_client(struct i2c_client *client) +{ + int rc; + struct rtc_device *const rtc = i2c_get_clientdata(client); + + if (rtc) + rtc_device_unregister(rtc); /* do we need to kfree? */ + + rc = i2c_detach_client(client); + if (rc) + return rc; + + kfree(client); + + return 0; +} + +/* module management */ + +static int __init isl1208_init(void) +{ + return i2c_add_driver(&isl1208_driver); +} + +static void __exit isl1208_exit(void) +{ + i2c_del_driver(&isl1208_driver); +} + +MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>"); +MODULE_DESCRIPTION("Intersil ISL1208 RTC driver"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(DRV_VERSION); + +module_init(isl1208_init); +module_exit(isl1208_exit); |