260 строки
7.4 KiB
C
260 строки
7.4 KiB
C
/*
|
|
* An rtc driver for the Dallas DS1742
|
|
*
|
|
* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
|
|
*
|
|
* 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.
|
|
*
|
|
* Copyright (C) 2006 Torsten Ertbjerg Rasmussen <tr@newtec.dk>
|
|
* - nvram size determined from resource
|
|
* - this ds1742 driver now supports ds1743.
|
|
*/
|
|
|
|
#include <linux/bcd.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/io.h>
|
|
|
|
#define DRV_VERSION "0.4"
|
|
|
|
#define RTC_SIZE 8
|
|
|
|
#define RTC_CONTROL 0
|
|
#define RTC_CENTURY 0
|
|
#define RTC_SECONDS 1
|
|
#define RTC_MINUTES 2
|
|
#define RTC_HOURS 3
|
|
#define RTC_DAY 4
|
|
#define RTC_DATE 5
|
|
#define RTC_MONTH 6
|
|
#define RTC_YEAR 7
|
|
|
|
#define RTC_CENTURY_MASK 0x3f
|
|
#define RTC_SECONDS_MASK 0x7f
|
|
#define RTC_DAY_MASK 0x07
|
|
|
|
/* Bits in the Control/Century register */
|
|
#define RTC_WRITE 0x80
|
|
#define RTC_READ 0x40
|
|
|
|
/* Bits in the Seconds register */
|
|
#define RTC_STOP 0x80
|
|
|
|
/* Bits in the Day register */
|
|
#define RTC_BATT_FLAG 0x80
|
|
|
|
struct rtc_plat_data {
|
|
struct rtc_device *rtc;
|
|
void __iomem *ioaddr_nvram;
|
|
void __iomem *ioaddr_rtc;
|
|
size_t size_nvram;
|
|
size_t size;
|
|
unsigned long last_jiffies;
|
|
struct bin_attribute nvram_attr;
|
|
};
|
|
|
|
static int ds1742_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct platform_device *pdev = to_platform_device(dev);
|
|
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
|
|
void __iomem *ioaddr = pdata->ioaddr_rtc;
|
|
u8 century;
|
|
|
|
century = bin2bcd((tm->tm_year + 1900) / 100);
|
|
|
|
writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
|
|
|
|
writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
|
|
writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
|
|
writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
|
|
writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
|
|
writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
|
|
writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
|
|
writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
|
|
|
|
/* RTC_CENTURY and RTC_CONTROL share same register */
|
|
writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
|
|
writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
|
|
return 0;
|
|
}
|
|
|
|
static int ds1742_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct platform_device *pdev = to_platform_device(dev);
|
|
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
|
|
void __iomem *ioaddr = pdata->ioaddr_rtc;
|
|
unsigned int year, month, day, hour, minute, second, week;
|
|
unsigned int century;
|
|
|
|
/* give enough time to update RTC in case of continuous read */
|
|
if (pdata->last_jiffies == jiffies)
|
|
msleep(1);
|
|
pdata->last_jiffies = jiffies;
|
|
writeb(RTC_READ, ioaddr + RTC_CONTROL);
|
|
second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
|
|
minute = readb(ioaddr + RTC_MINUTES);
|
|
hour = readb(ioaddr + RTC_HOURS);
|
|
day = readb(ioaddr + RTC_DATE);
|
|
week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
|
|
month = readb(ioaddr + RTC_MONTH);
|
|
year = readb(ioaddr + RTC_YEAR);
|
|
century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
|
|
writeb(0, ioaddr + RTC_CONTROL);
|
|
tm->tm_sec = bcd2bin(second);
|
|
tm->tm_min = bcd2bin(minute);
|
|
tm->tm_hour = bcd2bin(hour);
|
|
tm->tm_mday = bcd2bin(day);
|
|
tm->tm_wday = bcd2bin(week);
|
|
tm->tm_mon = bcd2bin(month) - 1;
|
|
/* year is 1900 + tm->tm_year */
|
|
tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
|
|
|
|
if (rtc_valid_tm(tm) < 0) {
|
|
dev_err(dev, "retrieved date/time is not valid.\n");
|
|
rtc_time_to_tm(0, tm);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const struct rtc_class_ops ds1742_rtc_ops = {
|
|
.read_time = ds1742_rtc_read_time,
|
|
.set_time = ds1742_rtc_set_time,
|
|
};
|
|
|
|
static ssize_t ds1742_nvram_read(struct file *filp, struct kobject *kobj,
|
|
struct bin_attribute *bin_attr,
|
|
char *buf, loff_t pos, size_t size)
|
|
{
|
|
struct device *dev = container_of(kobj, struct device, kobj);
|
|
struct platform_device *pdev = to_platform_device(dev);
|
|
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
|
|
void __iomem *ioaddr = pdata->ioaddr_nvram;
|
|
ssize_t count;
|
|
|
|
for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
|
|
*buf++ = readb(ioaddr + pos++);
|
|
return count;
|
|
}
|
|
|
|
static ssize_t ds1742_nvram_write(struct file *filp, struct kobject *kobj,
|
|
struct bin_attribute *bin_attr,
|
|
char *buf, loff_t pos, size_t size)
|
|
{
|
|
struct device *dev = container_of(kobj, struct device, kobj);
|
|
struct platform_device *pdev = to_platform_device(dev);
|
|
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
|
|
void __iomem *ioaddr = pdata->ioaddr_nvram;
|
|
ssize_t count;
|
|
|
|
for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
|
|
writeb(*buf++, ioaddr + pos++);
|
|
return count;
|
|
}
|
|
|
|
static int __devinit ds1742_rtc_probe(struct platform_device *pdev)
|
|
{
|
|
struct rtc_device *rtc;
|
|
struct resource *res;
|
|
unsigned int cen, sec;
|
|
struct rtc_plat_data *pdata;
|
|
void __iomem *ioaddr;
|
|
int ret = 0;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (!res)
|
|
return -ENODEV;
|
|
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
|
|
if (!pdata)
|
|
return -ENOMEM;
|
|
pdata->size = res->end - res->start + 1;
|
|
if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
|
|
pdev->name))
|
|
return -EBUSY;
|
|
ioaddr = devm_ioremap(&pdev->dev, res->start, pdata->size);
|
|
if (!ioaddr)
|
|
return -ENOMEM;
|
|
|
|
pdata->ioaddr_nvram = ioaddr;
|
|
pdata->size_nvram = pdata->size - RTC_SIZE;
|
|
pdata->ioaddr_rtc = ioaddr + pdata->size_nvram;
|
|
|
|
sysfs_bin_attr_init(&pdata->nvram_attr);
|
|
pdata->nvram_attr.attr.name = "nvram";
|
|
pdata->nvram_attr.attr.mode = S_IRUGO | S_IWUSR;
|
|
pdata->nvram_attr.read = ds1742_nvram_read;
|
|
pdata->nvram_attr.write = ds1742_nvram_write;
|
|
pdata->nvram_attr.size = pdata->size_nvram;
|
|
|
|
/* turn RTC on if it was not on */
|
|
ioaddr = pdata->ioaddr_rtc;
|
|
sec = readb(ioaddr + RTC_SECONDS);
|
|
if (sec & RTC_STOP) {
|
|
sec &= RTC_SECONDS_MASK;
|
|
cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
|
|
writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
|
|
writeb(sec, ioaddr + RTC_SECONDS);
|
|
writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
|
|
}
|
|
if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG))
|
|
dev_warn(&pdev->dev, "voltage-low detected.\n");
|
|
|
|
pdata->last_jiffies = jiffies;
|
|
platform_set_drvdata(pdev, pdata);
|
|
rtc = rtc_device_register(pdev->name, &pdev->dev,
|
|
&ds1742_rtc_ops, THIS_MODULE);
|
|
if (IS_ERR(rtc))
|
|
return PTR_ERR(rtc);
|
|
pdata->rtc = rtc;
|
|
|
|
ret = sysfs_create_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "creating nvram file in sysfs failed\n");
|
|
rtc_device_unregister(rtc);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int __devexit ds1742_rtc_remove(struct platform_device *pdev)
|
|
{
|
|
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
|
|
|
|
sysfs_remove_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
|
|
rtc_device_unregister(pdata->rtc);
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver ds1742_rtc_driver = {
|
|
.probe = ds1742_rtc_probe,
|
|
.remove = __devexit_p(ds1742_rtc_remove),
|
|
.driver = {
|
|
.name = "rtc-ds1742",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
static __init int ds1742_init(void)
|
|
{
|
|
return platform_driver_register(&ds1742_rtc_driver);
|
|
}
|
|
|
|
static __exit void ds1742_exit(void)
|
|
{
|
|
platform_driver_unregister(&ds1742_rtc_driver);
|
|
}
|
|
|
|
module_init(ds1742_init);
|
|
module_exit(ds1742_exit);
|
|
|
|
MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
|
|
MODULE_DESCRIPTION("Dallas DS1742 RTC driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION(DRV_VERSION);
|
|
MODULE_ALIAS("platform:rtc-ds1742");
|