/* * 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_INT_ALME (1<<6) /* alarm enable */ #define ISL1208_REG_INT_IM (1<<7) /* interrupt/alarm mode */ #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_toggle_alarm(struct i2c_client *client, int enable) { int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT); if (icr < 0) { dev_err(&client->dev, "%s: reading INT failed\n", __func__); return icr; } if (enable) icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM; else icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM); icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr); if (icr < 0) { dev_err(&client->dev, "%s: writing INT failed\n", __func__); return icr; } return 0; } 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 icr, yr, 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); /* The alarm doesn't store the year so get it from the rtc section */ yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR); if (yr < 0) { dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__); return yr; } tm->tm_year = bcd2bin(yr) + 100; icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT); if (icr < 0) { dev_err(&client->dev, "%s: reading INT failed\n", __func__); return icr; } alarm->enabled = !!(icr & ISL1208_REG_INT_ALME); return 0; } static int isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm) { struct rtc_time *alarm_tm = &alarm->time; u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, }; const int offs = ISL1208_REG_SCA; unsigned long rtc_secs, alarm_secs; struct rtc_time rtc_tm; int err, enable; err = isl1208_i2c_read_time(client, &rtc_tm); if (err) return err; err = rtc_tm_to_time(&rtc_tm, &rtc_secs); if (err) return err; err = rtc_tm_to_time(alarm_tm, &alarm_secs); if (err) return err; /* If the alarm time is before the current time disable the alarm */ if (!alarm->enabled || alarm_secs <= rtc_secs) enable = 0x00; else enable = 0x80; /* Program the alarm and enable it for each setting */ regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable; regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable; regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) | ISL1208_REG_HR_MIL | enable; regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable; regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable; regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable; /* write ALARM registers */ err = isl1208_i2c_set_regs(client, offs, regs, ISL1208_ALARM_SECTION_LEN); if (err < 0) { dev_err(&client->dev, "%s: writing ALARM section failed\n", __func__); return err; } err = isl1208_rtc_toggle_alarm(client, enable); if (err) return err; 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 int isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm); } static irqreturn_t isl1208_rtc_interrupt(int irq, void *data) { unsigned long timeout = jiffies + msecs_to_jiffies(1000); struct i2c_client *client = data; int handled = 0, sr, err; /* * I2C reads get NAK'ed if we read straight away after an interrupt? * Using a mdelay/msleep didn't seem to help either, so we work around * this by continually trying to read the register for a short time. */ while (1) { sr = isl1208_i2c_get_sr(client); if (sr >= 0) break; if (time_after(jiffies, timeout)) { dev_err(&client->dev, "%s: reading SR failed\n", __func__); return sr; } } if (sr & ISL1208_REG_SR_ALM) { dev_dbg(&client->dev, "alarm!\n"); /* Clear the alarm */ sr &= ~ISL1208_REG_SR_ALM; sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr); if (sr < 0) dev_err(&client->dev, "%s: writing SR failed\n", __func__); else handled = 1; /* Disable the alarm */ err = isl1208_rtc_toggle_alarm(client, 0); if (err) return err; } return handled ? IRQ_HANDLED : IRQ_NONE; } 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 struct attribute *isl1208_rtc_attrs[] = { &dev_attr_atrim.attr, &dev_attr_dtrim.attr, &dev_attr_usr.attr, NULL }; static const struct attribute_group isl1208_rtc_sysfs_files = { .attrs = isl1208_rtc_attrs, }; 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"); if (client->irq > 0) { rc = request_threaded_irq(client->irq, NULL, isl1208_rtc_interrupt, IRQF_SHARED, isl1208_driver.driver.name, client); if (!rc) { device_init_wakeup(&client->dev, 1); enable_irq_wake(client->irq); } else { dev_err(&client->dev, "Unable to request irq %d, no alarm support\n", client->irq); client->irq = 0; } } rtc = rtc_device_register(isl1208_driver.driver.name, &client->dev, &isl1208_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) { rc = PTR_ERR(rtc); goto exit_free_irq; } 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 = sysfs_create_group(&client->dev.kobj, &isl1208_rtc_sysfs_files); if (rc) goto exit_unregister; return 0; exit_unregister: rtc_device_unregister(rtc); exit_free_irq: if (client->irq) free_irq(client->irq, client); return rc; } static int isl1208_remove(struct i2c_client *client) { struct rtc_device *rtc = i2c_get_clientdata(client); sysfs_remove_group(&client->dev.kobj, &isl1208_rtc_sysfs_files); rtc_device_unregister(rtc); if (client->irq) free_irq(client->irq, client); 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, }; module_i2c_driver(isl1208_driver); MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>"); MODULE_DESCRIPTION("Intersil ISL1208 RTC driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_VERSION);