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/*
* 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);
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