/* * 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_VERSION "0.3" /* 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 static struct i2c_driver isl1208_driver; /* 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, 0, sizeof(reg_addr), reg_addr} , {client->addr, I2C_M_RD, len, buf} }; int ret; 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, 0, len + 1, i2c_buf} }; int ret; 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) { int sr = i2c_smbus_read_byte_data(client, ISL1208_REG_SR); if (sr < 0) return -EIO; return sr; } 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 atr; /* 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, }; /* The clock has an 8 bit wide bcd-coded register (they never learn) * for the year. tm_year is an offset from 1900 and we are interested * in the 2000-2099 range, so any value less than 100 is invalid. */ if (tm->tm_year < 100) return -EINVAL; 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 const 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 = 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 = 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 = 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_sysfs_register(struct device *dev) { int err; err = device_create_file(dev, &dev_attr_atrim); if (err) return err; err = device_create_file(dev, &dev_attr_dtrim); if (err) { device_remove_file(dev, &dev_attr_atrim); return err; } err = device_create_file(dev, &dev_attr_usr); if (err) { device_remove_file(dev, &dev_attr_atrim); device_remove_file(dev, &dev_attr_dtrim); } return 0; } static int isl1208_sysfs_unregister(struct device *dev) { device_remove_file(dev, &dev_attr_dtrim); device_remove_file(dev, &dev_attr_atrim); device_remove_file(dev, &dev_attr_usr); return 0; } static int isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id) { int rc = 0; struct rtc_device *rtc; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) return -ENODEV; if (isl1208_i2c_validate_client(client) < 0) return -ENODEV; dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); rtc = rtc_device_register(isl1208_driver.driver.name, &client->dev, &isl1208_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) return PTR_ERR(rtc); i2c_set_clientdata(client, rtc); rc = isl1208_i2c_get_sr(client); if (rc < 0) { dev_err(&client->dev, "reading status failed\n"); goto exit_unregister; } if (rc & ISL1208_REG_SR_RTCF) dev_warn(&client->dev, "rtc power failure detected, " "please set clock.\n"); rc = isl1208_sysfs_register(&client->dev); if (rc) goto exit_unregister; return 0; exit_unregister: rtc_device_unregister(rtc); return rc; } static int isl1208_remove(struct i2c_client *client) { struct rtc_device *rtc = i2c_get_clientdata(client); isl1208_sysfs_unregister(&client->dev); rtc_device_unregister(rtc); return 0; } static const struct i2c_device_id isl1208_id[] = { { "isl1208", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, isl1208_id); static struct i2c_driver isl1208_driver = { .driver = { .name = "rtc-isl1208", }, .probe = isl1208_probe, .remove = isl1208_remove, .id_table = isl1208_id, }; 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);