290 lines
6.9 KiB
C
290 lines
6.9 KiB
C
/*
|
|
* An I2C driver for the Intersil ISL 12022
|
|
*
|
|
* Author: Roman Fietze <roman.fietze@telemotive.de>
|
|
*
|
|
* Based on the Philips PCF8563 RTC
|
|
* by Alessandro Zummo <a.zummo@towertech.it>.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License version
|
|
* 2 as published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/i2c.h>
|
|
#include <linux/bcd.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <linux/err.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_device.h>
|
|
|
|
/* ISL register offsets */
|
|
#define ISL12022_REG_SC 0x00
|
|
#define ISL12022_REG_MN 0x01
|
|
#define ISL12022_REG_HR 0x02
|
|
#define ISL12022_REG_DT 0x03
|
|
#define ISL12022_REG_MO 0x04
|
|
#define ISL12022_REG_YR 0x05
|
|
#define ISL12022_REG_DW 0x06
|
|
|
|
#define ISL12022_REG_SR 0x07
|
|
#define ISL12022_REG_INT 0x08
|
|
|
|
/* ISL register bits */
|
|
#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
|
|
|
|
#define ISL12022_SR_LBAT85 (1 << 2)
|
|
#define ISL12022_SR_LBAT75 (1 << 1)
|
|
|
|
#define ISL12022_INT_WRTC (1 << 6)
|
|
|
|
|
|
static struct i2c_driver isl12022_driver;
|
|
|
|
struct isl12022 {
|
|
struct rtc_device *rtc;
|
|
|
|
bool write_enabled; /* true if write enable is set */
|
|
};
|
|
|
|
|
|
static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
|
|
uint8_t *data, size_t n)
|
|
{
|
|
struct i2c_msg msgs[] = {
|
|
{
|
|
.addr = client->addr,
|
|
.flags = 0,
|
|
.len = 1,
|
|
.buf = data
|
|
}, /* setup read ptr */
|
|
{
|
|
.addr = client->addr,
|
|
.flags = I2C_M_RD,
|
|
.len = n,
|
|
.buf = data
|
|
}
|
|
};
|
|
|
|
int ret;
|
|
|
|
data[0] = reg;
|
|
ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
|
|
if (ret != ARRAY_SIZE(msgs)) {
|
|
dev_err(&client->dev, "%s: read error, ret=%d\n",
|
|
__func__, ret);
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int isl12022_write_reg(struct i2c_client *client,
|
|
uint8_t reg, uint8_t val)
|
|
{
|
|
uint8_t data[2] = { reg, val };
|
|
int err;
|
|
|
|
err = i2c_master_send(client, data, sizeof(data));
|
|
if (err != sizeof(data)) {
|
|
dev_err(&client->dev,
|
|
"%s: err=%d addr=%02x, data=%02x\n",
|
|
__func__, err, data[0], data[1]);
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* In the routines that deal directly with the isl12022 hardware, we use
|
|
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
|
|
*/
|
|
static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
uint8_t buf[ISL12022_REG_INT + 1];
|
|
int ret;
|
|
|
|
ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
|
|
dev_warn(&client->dev,
|
|
"voltage dropped below %u%%, "
|
|
"date and time is not reliable.\n",
|
|
buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
|
|
}
|
|
|
|
dev_dbg(&client->dev,
|
|
"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
|
|
"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
|
|
"sr=%02x, int=%02x",
|
|
__func__,
|
|
buf[ISL12022_REG_SC],
|
|
buf[ISL12022_REG_MN],
|
|
buf[ISL12022_REG_HR],
|
|
buf[ISL12022_REG_DT],
|
|
buf[ISL12022_REG_MO],
|
|
buf[ISL12022_REG_YR],
|
|
buf[ISL12022_REG_DW],
|
|
buf[ISL12022_REG_SR],
|
|
buf[ISL12022_REG_INT]);
|
|
|
|
tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
|
|
tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
|
|
tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
|
|
tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
|
|
tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
|
|
tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
|
|
tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
|
|
|
|
dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
|
|
"mday=%d, mon=%d, year=%d, wday=%d\n",
|
|
__func__,
|
|
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 isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
struct isl12022 *isl12022 = i2c_get_clientdata(client);
|
|
size_t i;
|
|
int ret;
|
|
uint8_t buf[ISL12022_REG_DW + 1];
|
|
|
|
dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
|
|
"mday=%d, mon=%d, year=%d, wday=%d\n",
|
|
__func__,
|
|
tm->tm_sec, tm->tm_min, tm->tm_hour,
|
|
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
|
|
|
|
if (!isl12022->write_enabled) {
|
|
|
|
ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Check if WRTC (write rtc enable) is set factory default is
|
|
* 0 (not set) */
|
|
if (!(buf[0] & ISL12022_INT_WRTC)) {
|
|
dev_info(&client->dev,
|
|
"init write enable and 24 hour format\n");
|
|
|
|
/* Set the write enable bit. */
|
|
ret = isl12022_write_reg(client,
|
|
ISL12022_REG_INT,
|
|
buf[0] | ISL12022_INT_WRTC);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Write to any RTC register to start RTC, we use the
|
|
* HR register, setting the MIL bit to use the 24 hour
|
|
* format. */
|
|
ret = isl12022_read_regs(client, ISL12022_REG_HR,
|
|
buf, 1);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = isl12022_write_reg(client,
|
|
ISL12022_REG_HR,
|
|
buf[0] | ISL12022_HR_MIL);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
isl12022->write_enabled = true;
|
|
}
|
|
|
|
/* hours, minutes and seconds */
|
|
buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
|
|
buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
|
|
buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
|
|
|
|
buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
|
|
|
|
/* month, 1 - 12 */
|
|
buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
|
|
|
|
/* year and century */
|
|
buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
|
|
|
|
buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
|
|
|
|
/* write register's data */
|
|
for (i = 0; i < ARRAY_SIZE(buf); i++) {
|
|
ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
|
|
buf[ISL12022_REG_SC + i]);
|
|
if (ret)
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct rtc_class_ops isl12022_rtc_ops = {
|
|
.read_time = isl12022_rtc_read_time,
|
|
.set_time = isl12022_rtc_set_time,
|
|
};
|
|
|
|
static int isl12022_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct isl12022 *isl12022;
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
|
|
return -ENODEV;
|
|
|
|
isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
|
|
GFP_KERNEL);
|
|
if (!isl12022)
|
|
return -ENOMEM;
|
|
|
|
i2c_set_clientdata(client, isl12022);
|
|
|
|
isl12022->rtc = devm_rtc_device_register(&client->dev,
|
|
isl12022_driver.driver.name,
|
|
&isl12022_rtc_ops, THIS_MODULE);
|
|
return PTR_ERR_OR_ZERO(isl12022->rtc);
|
|
}
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id isl12022_dt_match[] = {
|
|
{ .compatible = "isl,isl12022" }, /* for backward compat., don't use */
|
|
{ .compatible = "isil,isl12022" },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(of, isl12022_dt_match);
|
|
#endif
|
|
|
|
static const struct i2c_device_id isl12022_id[] = {
|
|
{ "isl12022", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, isl12022_id);
|
|
|
|
static struct i2c_driver isl12022_driver = {
|
|
.driver = {
|
|
.name = "rtc-isl12022",
|
|
#ifdef CONFIG_OF
|
|
.of_match_table = of_match_ptr(isl12022_dt_match),
|
|
#endif
|
|
},
|
|
.probe = isl12022_probe,
|
|
.id_table = isl12022_id,
|
|
};
|
|
|
|
module_i2c_driver(isl12022_driver);
|
|
|
|
MODULE_AUTHOR("roman.fietze@telemotive.de");
|
|
MODULE_DESCRIPTION("ISL 12022 RTC driver");
|
|
MODULE_LICENSE("GPL");
|