205 lines
5.4 KiB
C
205 lines
5.4 KiB
C
/*
|
|
* An I2C driver for the PCF85063 RTC
|
|
* Copyright 2014 Rose Technology
|
|
*
|
|
* Author: Søren Andersen <san@rosetechnology.dk>
|
|
* Maintainers: http://www.nslu2-linux.org/
|
|
*
|
|
* based on the other drivers in this same directory.
|
|
*
|
|
* 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/module.h>
|
|
|
|
#define DRV_VERSION "0.0.1"
|
|
|
|
#define PCF85063_REG_CTRL1 0x00 /* status */
|
|
#define PCF85063_REG_CTRL2 0x01
|
|
|
|
#define PCF85063_REG_SC 0x04 /* datetime */
|
|
#define PCF85063_REG_MN 0x05
|
|
#define PCF85063_REG_HR 0x06
|
|
#define PCF85063_REG_DM 0x07
|
|
#define PCF85063_REG_DW 0x08
|
|
#define PCF85063_REG_MO 0x09
|
|
#define PCF85063_REG_YR 0x0A
|
|
|
|
#define PCF85063_MO_C 0x80 /* century */
|
|
|
|
static struct i2c_driver pcf85063_driver;
|
|
|
|
struct pcf85063 {
|
|
struct rtc_device *rtc;
|
|
int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
|
|
int voltage_low; /* indicates if a low_voltage was detected */
|
|
};
|
|
|
|
/*
|
|
* In the routines that deal directly with the pcf85063 hardware, we use
|
|
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
|
|
*/
|
|
static int pcf85063_get_datetime(struct i2c_client *client, struct rtc_time *tm)
|
|
{
|
|
struct pcf85063 *pcf85063 = i2c_get_clientdata(client);
|
|
unsigned char buf[13] = { PCF85063_REG_CTRL1 };
|
|
struct i2c_msg msgs[] = {
|
|
{/* setup read ptr */
|
|
.addr = client->addr,
|
|
.len = 1,
|
|
.buf = buf
|
|
},
|
|
{/* read status + date */
|
|
.addr = client->addr,
|
|
.flags = I2C_M_RD,
|
|
.len = 13,
|
|
.buf = buf
|
|
},
|
|
};
|
|
|
|
/* read registers */
|
|
if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
|
|
dev_err(&client->dev, "%s: read error\n", __func__);
|
|
return -EIO;
|
|
}
|
|
|
|
tm->tm_sec = bcd2bin(buf[PCF85063_REG_SC] & 0x7F);
|
|
tm->tm_min = bcd2bin(buf[PCF85063_REG_MN] & 0x7F);
|
|
tm->tm_hour = bcd2bin(buf[PCF85063_REG_HR] & 0x3F); /* rtc hr 0-23 */
|
|
tm->tm_mday = bcd2bin(buf[PCF85063_REG_DM] & 0x3F);
|
|
tm->tm_wday = buf[PCF85063_REG_DW] & 0x07;
|
|
tm->tm_mon = bcd2bin(buf[PCF85063_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
|
|
tm->tm_year = bcd2bin(buf[PCF85063_REG_YR]);
|
|
if (tm->tm_year < 70)
|
|
tm->tm_year += 100; /* assume we are in 1970...2069 */
|
|
/* detect the polarity heuristically. see note above. */
|
|
pcf85063->c_polarity = (buf[PCF85063_REG_MO] & PCF85063_MO_C) ?
|
|
(tm->tm_year >= 100) : (tm->tm_year < 100);
|
|
|
|
/* the clock can give out invalid datetime, but we cannot return
|
|
* -EINVAL otherwise hwclock will refuse to set the time on bootup.
|
|
*/
|
|
if (rtc_valid_tm(tm) < 0)
|
|
dev_err(&client->dev, "retrieved date/time is not valid.\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pcf85063_set_datetime(struct i2c_client *client, struct rtc_time *tm)
|
|
{
|
|
int i = 0, err = 0;
|
|
unsigned char buf[11];
|
|
|
|
/* Control & status */
|
|
buf[PCF85063_REG_CTRL1] = 0;
|
|
buf[PCF85063_REG_CTRL2] = 5;
|
|
|
|
/* hours, minutes and seconds */
|
|
buf[PCF85063_REG_SC] = bin2bcd(tm->tm_sec) & 0x7F;
|
|
|
|
buf[PCF85063_REG_MN] = bin2bcd(tm->tm_min);
|
|
buf[PCF85063_REG_HR] = bin2bcd(tm->tm_hour);
|
|
|
|
/* Day of month, 1 - 31 */
|
|
buf[PCF85063_REG_DM] = bin2bcd(tm->tm_mday);
|
|
|
|
/* Day, 0 - 6 */
|
|
buf[PCF85063_REG_DW] = tm->tm_wday & 0x07;
|
|
|
|
/* month, 1 - 12 */
|
|
buf[PCF85063_REG_MO] = bin2bcd(tm->tm_mon + 1);
|
|
|
|
/* year and century */
|
|
buf[PCF85063_REG_YR] = bin2bcd(tm->tm_year % 100);
|
|
|
|
/* write register's data */
|
|
for (i = 0; i < sizeof(buf); i++) {
|
|
unsigned char data[2] = { i, buf[i] };
|
|
|
|
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;
|
|
}
|
|
|
|
static int pcf85063_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
return pcf85063_get_datetime(to_i2c_client(dev), tm);
|
|
}
|
|
|
|
static int pcf85063_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
return pcf85063_set_datetime(to_i2c_client(dev), tm);
|
|
}
|
|
|
|
static const struct rtc_class_ops pcf85063_rtc_ops = {
|
|
.read_time = pcf85063_rtc_read_time,
|
|
.set_time = pcf85063_rtc_set_time
|
|
};
|
|
|
|
static int pcf85063_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct pcf85063 *pcf85063;
|
|
|
|
dev_dbg(&client->dev, "%s\n", __func__);
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
|
|
return -ENODEV;
|
|
|
|
pcf85063 = devm_kzalloc(&client->dev, sizeof(struct pcf85063),
|
|
GFP_KERNEL);
|
|
if (!pcf85063)
|
|
return -ENOMEM;
|
|
|
|
dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
|
|
|
|
i2c_set_clientdata(client, pcf85063);
|
|
|
|
pcf85063->rtc = devm_rtc_device_register(&client->dev,
|
|
pcf85063_driver.driver.name,
|
|
&pcf85063_rtc_ops, THIS_MODULE);
|
|
|
|
return PTR_ERR_OR_ZERO(pcf85063->rtc);
|
|
}
|
|
|
|
static const struct i2c_device_id pcf85063_id[] = {
|
|
{ "pcf85063", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, pcf85063_id);
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id pcf85063_of_match[] = {
|
|
{ .compatible = "nxp,pcf85063" },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(of, pcf85063_of_match);
|
|
#endif
|
|
|
|
static struct i2c_driver pcf85063_driver = {
|
|
.driver = {
|
|
.name = "rtc-pcf85063",
|
|
.owner = THIS_MODULE,
|
|
.of_match_table = of_match_ptr(pcf85063_of_match),
|
|
},
|
|
.probe = pcf85063_probe,
|
|
.id_table = pcf85063_id,
|
|
};
|
|
|
|
module_i2c_driver(pcf85063_driver);
|
|
|
|
MODULE_AUTHOR("Søren Andersen <san@rosetechnology.dk>");
|
|
MODULE_DESCRIPTION("PCF85063 RTC driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION(DRV_VERSION);
|