forked from Minki/linux
rtc: basic implementation of Epson RX-8581 I2C Real Time Clock
Provide the basic "get" and "set" functionality for the Epson RX-8581 I2C RTC. It currently does not support the RTC's Alarm or Fixed-cycle timer. [akpm@linux-foundation.org: need log2.h for ilog2(), remove unneeded initialisation] Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com> Signed-off-by: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Martyn Welch
Linus Torvalds
parent
077eaf5b40
commit
a7fa9851b6
@ -277,6 +277,14 @@ config RTC_DRV_FM3130
|
||||
This driver can also be built as a module. If so the module
|
||||
will be called rtc-fm3130.
|
||||
|
||||
config RTC_DRV_RX8581
|
||||
tristate "Epson RX-8581"
|
||||
help
|
||||
If you say yes here you will get support for the Epson RX-8581.
|
||||
|
||||
This driver can also be built as a module. If so the module
|
||||
will be called rtc-rx8581.
|
||||
|
||||
endif # I2C
|
||||
|
||||
comment "SPI RTC drivers"
|
||||
|
||||
@ -57,6 +57,7 @@ obj-$(CONFIG_RTC_DRV_R9701) += rtc-r9701.o
|
||||
obj-$(CONFIG_RTC_DRV_RS5C313) += rtc-rs5c313.o
|
||||
obj-$(CONFIG_RTC_DRV_RS5C348) += rtc-rs5c348.o
|
||||
obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o
|
||||
obj-$(CONFIG_RTC_DRV_RX8581) += rtc-rx8581.o
|
||||
obj-$(CONFIG_RTC_DRV_S35390A) += rtc-s35390a.o
|
||||
obj-$(CONFIG_RTC_DRV_S3C) += rtc-s3c.o
|
||||
obj-$(CONFIG_RTC_DRV_SA1100) += rtc-sa1100.o
|
||||
|
||||
281
drivers/rtc/rtc-rx8581.c
Normal file
281
drivers/rtc/rtc-rx8581.c
Normal file
@ -0,0 +1,281 @@
|
||||
/*
|
||||
* An I2C driver for the Epson RX8581 RTC
|
||||
*
|
||||
* Author: Martyn Welch <martyn.welch@gefanuc.com>
|
||||
* Copyright 2008 GE Fanuc Intelligent Platforms Embedded Systems, Inc.
|
||||
*
|
||||
* 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.
|
||||
*
|
||||
* Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC)
|
||||
* Copyright 2005-06 Tower Technologies
|
||||
*/
|
||||
|
||||
#include <linux/module.h>
|
||||
#include <linux/i2c.h>
|
||||
#include <linux/bcd.h>
|
||||
#include <linux/rtc.h>
|
||||
#include <linux/log2.h>
|
||||
|
||||
#define DRV_VERSION "0.1"
|
||||
|
||||
#define RX8581_REG_SC 0x00 /* Second in BCD */
|
||||
#define RX8581_REG_MN 0x01 /* Minute in BCD */
|
||||
#define RX8581_REG_HR 0x02 /* Hour in BCD */
|
||||
#define RX8581_REG_DW 0x03 /* Day of Week */
|
||||
#define RX8581_REG_DM 0x04 /* Day of Month in BCD */
|
||||
#define RX8581_REG_MO 0x05 /* Month in BCD */
|
||||
#define RX8581_REG_YR 0x06 /* Year in BCD */
|
||||
#define RX8581_REG_RAM 0x07 /* RAM */
|
||||
#define RX8581_REG_AMN 0x08 /* Alarm Min in BCD*/
|
||||
#define RX8581_REG_AHR 0x09 /* Alarm Hour in BCD */
|
||||
#define RX8581_REG_ADM 0x0A
|
||||
#define RX8581_REG_ADW 0x0A
|
||||
#define RX8581_REG_TMR0 0x0B
|
||||
#define RX8581_REG_TMR1 0x0C
|
||||
#define RX8581_REG_EXT 0x0D /* Extension Register */
|
||||
#define RX8581_REG_FLAG 0x0E /* Flag Register */
|
||||
#define RX8581_REG_CTRL 0x0F /* Control Register */
|
||||
|
||||
|
||||
/* Flag Register bit definitions */
|
||||
#define RX8581_FLAG_UF 0x20 /* Update */
|
||||
#define RX8581_FLAG_TF 0x10 /* Timer */
|
||||
#define RX8581_FLAG_AF 0x08 /* Alarm */
|
||||
#define RX8581_FLAG_VLF 0x02 /* Voltage Low */
|
||||
|
||||
/* Control Register bit definitions */
|
||||
#define RX8581_CTRL_UIE 0x20 /* Update Interrupt Enable */
|
||||
#define RX8581_CTRL_TIE 0x10 /* Timer Interrupt Enable */
|
||||
#define RX8581_CTRL_AIE 0x08 /* Alarm Interrupt Enable */
|
||||
#define RX8581_CTRL_STOP 0x02 /* STOP bit */
|
||||
#define RX8581_CTRL_RESET 0x01 /* RESET bit */
|
||||
|
||||
static struct i2c_driver rx8581_driver;
|
||||
|
||||
/*
|
||||
* In the routines that deal directly with the rx8581 hardware, we use
|
||||
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
|
||||
*/
|
||||
static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm)
|
||||
{
|
||||
unsigned char date[7];
|
||||
int data, err;
|
||||
|
||||
/* First we ensure that the "update flag" is not set, we read the
|
||||
* time and date then re-read the "update flag". If the update flag
|
||||
* has been set, we know that the time has changed during the read so
|
||||
* we repeat the whole process again.
|
||||
*/
|
||||
data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
|
||||
if (data < 0) {
|
||||
dev_err(&client->dev, "Unable to read device flags\n");
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
do {
|
||||
/* If update flag set, clear it */
|
||||
if (data & RX8581_FLAG_UF) {
|
||||
err = i2c_smbus_write_byte_data(client,
|
||||
RX8581_REG_FLAG, (data & ~RX8581_FLAG_UF));
|
||||
if (err != 0) {
|
||||
dev_err(&client->dev, "Unable to write device "
|
||||
"flags\n");
|
||||
return -EIO;
|
||||
}
|
||||
}
|
||||
|
||||
/* Now read time and date */
|
||||
err = i2c_smbus_read_i2c_block_data(client, RX8581_REG_SC,
|
||||
7, date);
|
||||
if (err < 0) {
|
||||
dev_err(&client->dev, "Unable to read date\n");
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
/* Check flag register */
|
||||
data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
|
||||
if (data < 0) {
|
||||
dev_err(&client->dev, "Unable to read device flags\n");
|
||||
return -EIO;
|
||||
}
|
||||
} while (data & RX8581_FLAG_UF);
|
||||
|
||||
if (data & RX8581_FLAG_VLF)
|
||||
dev_info(&client->dev,
|
||||
"low voltage detected, date/time is not reliable.\n");
|
||||
|
||||
dev_dbg(&client->dev,
|
||||
"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
|
||||
"wday=%02x, mday=%02x, mon=%02x, year=%02x\n",
|
||||
__func__,
|
||||
date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
|
||||
|
||||
tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F);
|
||||
tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F);
|
||||
tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */
|
||||
tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F);
|
||||
tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F);
|
||||
tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
|
||||
tm->tm_year = bcd2bin(date[RX8581_REG_YR]);
|
||||
if (tm->tm_year < 70)
|
||||
tm->tm_year += 100; /* assume we are in 1970...2069 */
|
||||
|
||||
|
||||
dev_dbg(&client->dev, "%s: tm is 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);
|
||||
|
||||
err = rtc_valid_tm(tm);
|
||||
if (err < 0)
|
||||
dev_err(&client->dev, "retrieved date/time is not valid.\n");
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm)
|
||||
{
|
||||
int data, err;
|
||||
unsigned char buf[7];
|
||||
|
||||
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);
|
||||
|
||||
/* hours, minutes and seconds */
|
||||
buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec);
|
||||
buf[RX8581_REG_MN] = bin2bcd(tm->tm_min);
|
||||
buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour);
|
||||
|
||||
buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday);
|
||||
|
||||
/* month, 1 - 12 */
|
||||
buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1);
|
||||
|
||||
/* year and century */
|
||||
buf[RX8581_REG_YR] = bin2bcd(tm->tm_year % 100);
|
||||
buf[RX8581_REG_DW] = (0x1 << tm->tm_wday);
|
||||
|
||||
/* Stop the clock */
|
||||
data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
|
||||
if (data < 0) {
|
||||
dev_err(&client->dev, "Unable to read control register\n");
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG,
|
||||
(data | RX8581_CTRL_STOP));
|
||||
if (err < 0) {
|
||||
dev_err(&client->dev, "Unable to write control register\n");
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
/* write register's data */
|
||||
err = i2c_smbus_write_i2c_block_data(client, RX8581_REG_SC, 7, buf);
|
||||
if (err < 0) {
|
||||
dev_err(&client->dev, "Unable to write to date registers\n");
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
/* Restart the clock */
|
||||
data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
|
||||
if (data < 0) {
|
||||
dev_err(&client->dev, "Unable to read control register\n");
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG,
|
||||
(data | ~(RX8581_CTRL_STOP)));
|
||||
if (err != 0) {
|
||||
dev_err(&client->dev, "Unable to write control register\n");
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
||||
{
|
||||
return rx8581_get_datetime(to_i2c_client(dev), tm);
|
||||
}
|
||||
|
||||
static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
||||
{
|
||||
return rx8581_set_datetime(to_i2c_client(dev), tm);
|
||||
}
|
||||
|
||||
static const struct rtc_class_ops rx8581_rtc_ops = {
|
||||
.read_time = rx8581_rtc_read_time,
|
||||
.set_time = rx8581_rtc_set_time,
|
||||
};
|
||||
|
||||
static int __devinit rx8581_probe(struct i2c_client *client,
|
||||
const struct i2c_device_id *id)
|
||||
{
|
||||
struct rtc_device *rtc;
|
||||
|
||||
dev_dbg(&client->dev, "%s\n", __func__);
|
||||
|
||||
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
|
||||
return -ENODEV;
|
||||
|
||||
dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
|
||||
|
||||
rtc = rtc_device_register(rx8581_driver.driver.name,
|
||||
&client->dev, &rx8581_rtc_ops, THIS_MODULE);
|
||||
|
||||
if (IS_ERR(rtc))
|
||||
return PTR_ERR(rtc);
|
||||
|
||||
i2c_set_clientdata(client, rtc);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int __devexit rx8581_remove(struct i2c_client *client)
|
||||
{
|
||||
struct rtc_device *rtc = i2c_get_clientdata(client);
|
||||
|
||||
rtc_device_unregister(rtc);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const struct i2c_device_id rx8581_id[] = {
|
||||
{ "rx8581", 0 },
|
||||
{ }
|
||||
};
|
||||
MODULE_DEVICE_TABLE(i2c, rx8581_id);
|
||||
|
||||
static struct i2c_driver rx8581_driver = {
|
||||
.driver = {
|
||||
.name = "rtc-rx8581",
|
||||
.owner = THIS_MODULE,
|
||||
},
|
||||
.probe = rx8581_probe,
|
||||
.remove = __devexit_p(rx8581_remove),
|
||||
.id_table = rx8581_id,
|
||||
};
|
||||
|
||||
static int __init rx8581_init(void)
|
||||
{
|
||||
return i2c_add_driver(&rx8581_driver);
|
||||
}
|
||||
|
||||
static void __exit rx8581_exit(void)
|
||||
{
|
||||
i2c_del_driver(&rx8581_driver);
|
||||
}
|
||||
|
||||
MODULE_AUTHOR("Martyn Welch <martyn.welch@gefanuc.com>");
|
||||
MODULE_DESCRIPTION("Epson RX-8581 RTC driver");
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_VERSION(DRV_VERSION);
|
||||
|
||||
module_init(rx8581_init);
|
||||
module_exit(rx8581_exit);
|
||||
Loading…
Reference in New Issue
Block a user