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[PATCH] rtc: ds1743 support
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The real time clocks ds1742 and ds1743 differs only in the size of the
nvram.  This patch changes the existing ds1742 driver to support also
ds1743.  The main change is that the nvram size is determined from the
resource attached to the device.

The patch have benefitted from suggestions from Atsushi Nemeto, who is the
author of the ds1742 driver.

Signed-off-by: Torsten Rasmussen Rasmussen <tr@newtec.dk>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Torsten Ertbjerg Rasmussen authored and Linus Torvalds committed Dec 7, 2006
1 parent 3908fd2 commit f9231a0
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Showing 2 changed files with 41 additions and 30 deletions.
4 changes: 2 additions & 2 deletions drivers/rtc/Kconfig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -154,11 +154,11 @@ config RTC_DRV_DS1672
will be called rtc-ds1672.

config RTC_DRV_DS1742
tristate "Dallas DS1742"
tristate "Dallas DS1742/1743"
depends on RTC_CLASS
help
If you say yes here you get support for the
Dallas DS1742 timekeeping chip.
Dallas DS1742/1743 timekeeping chip.

This driver can also be built as a module. If so, the module
will be called rtc-ds1742.
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67 changes: 39 additions & 28 deletions drivers/rtc/rtc-ds1742.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,10 @@
* 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>
Expand All @@ -17,20 +21,19 @@
#include <linux/platform_device.h>
#include <linux/io.h>

#define DRV_VERSION "0.2"
#define DRV_VERSION "0.3"

#define RTC_REG_SIZE 0x800
#define RTC_OFFSET 0x7f8
#define RTC_SIZE 8

#define RTC_CONTROL (RTC_OFFSET + 0)
#define RTC_CENTURY (RTC_OFFSET + 0)
#define RTC_SECONDS (RTC_OFFSET + 1)
#define RTC_MINUTES (RTC_OFFSET + 2)
#define RTC_HOURS (RTC_OFFSET + 3)
#define RTC_DAY (RTC_OFFSET + 4)
#define RTC_DATE (RTC_OFFSET + 5)
#define RTC_MONTH (RTC_OFFSET + 6)
#define RTC_YEAR (RTC_OFFSET + 7)
#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
Expand All @@ -48,7 +51,10 @@

struct rtc_plat_data {
struct rtc_device *rtc;
void __iomem *ioaddr;
void __iomem *ioaddr_nvram;
void __iomem *ioaddr_rtc;
size_t size_nvram;
size_t size;
unsigned long baseaddr;
unsigned long last_jiffies;
};
Expand All @@ -57,7 +63,7 @@ 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;
void __iomem *ioaddr = pdata->ioaddr_rtc;
u8 century;

century = BIN2BCD((tm->tm_year + 1900) / 100);
Expand All @@ -82,7 +88,7 @@ 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;
void __iomem *ioaddr = pdata->ioaddr_rtc;
unsigned int year, month, day, hour, minute, second, week;
unsigned int century;

Expand Down Expand Up @@ -127,10 +133,10 @@ static ssize_t ds1742_nvram_read(struct kobject *kobj, char *buf,
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;
void __iomem *ioaddr = pdata->ioaddr_nvram;
ssize_t count;

for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
*buf++ = readb(ioaddr + pos++);
return count;
}
Expand All @@ -141,10 +147,10 @@ static ssize_t ds1742_nvram_write(struct kobject *kobj, char *buf,
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;
void __iomem *ioaddr = pdata->ioaddr_nvram;
ssize_t count;

for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
writeb(*buf++, ioaddr + pos++);
return count;
}
Expand All @@ -155,7 +161,6 @@ static struct bin_attribute ds1742_nvram_attr = {
.mode = S_IRUGO | S_IWUGO,
.owner = THIS_MODULE,
},
.size = RTC_OFFSET,
.read = ds1742_nvram_read,
.write = ds1742_nvram_write,
};
Expand All @@ -175,19 +180,23 @@ static int __init ds1742_rtc_probe(struct platform_device *pdev)
pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) {
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, RTC_REG_SIZE);
ioaddr = ioremap(pdata->baseaddr, pdata->size);
if (!ioaddr) {
ret = -ENOMEM;
goto out;
}
pdata->ioaddr = ioaddr;
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;
Expand All @@ -208,17 +217,19 @@ static int __init ds1742_rtc_probe(struct platform_device *pdev)
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 (ioaddr)
iounmap(ioaddr);
if (pdata->ioaddr_nvram)
iounmap(pdata->ioaddr_nvram);
if (pdata->baseaddr)
release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
release_mem_region(pdata->baseaddr, pdata->size);
kfree(pdata);
return ret;
}
Expand All @@ -229,8 +240,8 @@ static int __devexit ds1742_rtc_remove(struct platform_device *pdev)

sysfs_remove_bin_file(&pdev->dev.kobj, &ds1742_nvram_attr);
rtc_device_unregister(pdata->rtc);
iounmap(pdata->ioaddr);
release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
iounmap(pdata->ioaddr_nvram);
release_mem_region(pdata->baseaddr, pdata->size);
kfree(pdata);
return 0;
}
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