/*
* 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 const 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 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;
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);
