linux/drivers/rtc/rtc-ds1742.c

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/*
* 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/delay.h>
#include <linux/jiffies.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#define DRV_VERSION "0.3"
#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;
resource_size_t baseaddr;
unsigned long last_jiffies;
};
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,
};
sysfs: add parameter "struct bin_attribute *" in .read/.write methods for sysfs binary attributes Well, first of all, I don't want to change so many files either. What I do: Adding a new parameter "struct bin_attribute *" in the .read/.write methods for the sysfs binary attributes. In fact, only the four lines change in fs/sysfs/bin.c and include/linux/sysfs.h do the real work. But I have to update all the files that use binary attributes to make them compatible with the new .read and .write methods. I'm not sure if I missed any. :( Why I do this: For a sysfs attribute, we can get a pointer pointing to the struct attribute in the .show/.store method, while we can't do this for the binary attributes. I don't know why this is different, but this does make it not so handy to use the binary attributes as the regular ones. So I think this patch is reasonable. :) Who benefits from it: The patch that exposes ACPI tables in sysfs requires such an improvement. All the table binary attributes share the same .read method. Parameter "struct bin_attribute *" is used to get the table signature and instance number which are used to distinguish different ACPI table binary attributes. Without this parameter, we need to offer different .read methods for different ACPI table binary attributes. This is impossible as there are various ACPI tables on different platforms, and we don't know what they are until they are loaded. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-06-09 05:57:22 +00:00
static ssize_t ds1742_nvram_read(struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t pos, size_t size)
{
struct platform_device *pdev =
to_platform_device(container_of(kobj, struct device, kobj));
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;
}
sysfs: add parameter "struct bin_attribute *" in .read/.write methods for sysfs binary attributes Well, first of all, I don't want to change so many files either. What I do: Adding a new parameter "struct bin_attribute *" in the .read/.write methods for the sysfs binary attributes. In fact, only the four lines change in fs/sysfs/bin.c and include/linux/sysfs.h do the real work. But I have to update all the files that use binary attributes to make them compatible with the new .read and .write methods. I'm not sure if I missed any. :( Why I do this: For a sysfs attribute, we can get a pointer pointing to the struct attribute in the .show/.store method, while we can't do this for the binary attributes. I don't know why this is different, but this does make it not so handy to use the binary attributes as the regular ones. So I think this patch is reasonable. :) Who benefits from it: The patch that exposes ACPI tables in sysfs requires such an improvement. All the table binary attributes share the same .read method. Parameter "struct bin_attribute *" is used to get the table signature and instance number which are used to distinguish different ACPI table binary attributes. Without this parameter, we need to offer different .read methods for different ACPI table binary attributes. This is impossible as there are various ACPI tables on different platforms, and we don't know what they are until they are loaded. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-06-09 05:57:22 +00:00
static ssize_t ds1742_nvram_write(struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t pos, size_t size)
{
struct platform_device *pdev =
to_platform_device(container_of(kobj, struct device, kobj));
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 struct bin_attribute ds1742_nvram_attr = {
.attr = {
.name = "nvram",
.mode = S_IRUGO | S_IWUSR,
},
.read = ds1742_nvram_read,
.write = ds1742_nvram_write,
/* REVISIT: size in sysfs won't match actual size... if it's
* not a constant, each RTC should have its own attribute.
*/
};
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 = NULL;
void __iomem *ioaddr = NULL;
int ret = 0;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
pdata->size = res->end - res->start + 1;
if (!request_mem_region(res->start, pdata->size, pdev->name)) {
ret = -EBUSY;
goto out;
}
pdata->baseaddr = res->start;
ioaddr = ioremap(pdata->baseaddr, pdata->size);
if (!ioaddr) {
ret = -ENOMEM;
goto out;
}
pdata->ioaddr_nvram = ioaddr;
pdata->size_nvram = pdata->size - RTC_SIZE;
pdata->ioaddr_rtc = ioaddr + 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");
rtc = rtc_device_register(pdev->name, &pdev->dev,
&ds1742_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc)) {
ret = PTR_ERR(rtc);
goto out;
}
pdata->rtc = rtc;
pdata->last_jiffies = jiffies;
platform_set_drvdata(pdev, pdata);
ds1742_nvram_attr.size = max(ds1742_nvram_attr.size,
pdata->size_nvram);
ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1742_nvram_attr);
if (ret)
goto out;
return 0;
out:
if (pdata->rtc)
rtc_device_unregister(pdata->rtc);
if (pdata->ioaddr_nvram)
iounmap(pdata->ioaddr_nvram);
if (pdata->baseaddr)
release_mem_region(pdata->baseaddr, pdata->size);
kfree(pdata);
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, &ds1742_nvram_attr);
rtc_device_unregister(pdata->rtc);
iounmap(pdata->ioaddr_nvram);
release_mem_region(pdata->baseaddr, pdata->size);
kfree(pdata);
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");