Commit 9bf5b4f5 authored by Atsushi Nemoto's avatar Atsushi Nemoto Committed by Linus Torvalds
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[PATCH] RTC: add rtc-ds1553 driver



Add an RTC driver for the Dallas DS1553 RTC chip.

[akpm@osdl.org: cleanups, compile fix]
Signed-off-by: default avatarAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent e7a8bb12
......@@ -111,6 +111,16 @@ config RTC_DRV_DS1307
This driver can also be built as a module. If so, the module
will be called rtc-ds1307.
config RTC_DRV_DS1553
tristate "Dallas DS1553"
depends on RTC_CLASS
help
If you say yes here you get support for the
Dallas DS1553 timekeeping chip.
This driver can also be built as a module. If so, the module
will be called rtc-ds1553.
config RTC_DRV_DS1672
tristate "Dallas/Maxim DS1672"
depends on RTC_CLASS && I2C
......
......@@ -19,6 +19,7 @@ obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o
obj-$(CONFIG_RTC_DRV_PCF8583) += rtc-pcf8583.o
obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o
obj-$(CONFIG_RTC_DRV_M48T86) += rtc-m48t86.o
obj-$(CONFIG_RTC_DRV_DS1553) += rtc-ds1553.o
obj-$(CONFIG_RTC_DRV_EP93XX) += rtc-ep93xx.o
obj-$(CONFIG_RTC_DRV_SA1100) += rtc-sa1100.o
obj-$(CONFIG_RTC_DRV_VR41XX) += rtc-vr41xx.o
......
/*
* An rtc driver for the Dallas DS1553
*
* 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.
*/
#include <linux/bcd.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#define DRV_VERSION "0.1"
#define RTC_REG_SIZE 0x2000
#define RTC_OFFSET 0x1ff0
#define RTC_FLAGS (RTC_OFFSET + 0)
#define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
#define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
#define RTC_HOURS_ALARM (RTC_OFFSET + 4)
#define RTC_DATE_ALARM (RTC_OFFSET + 5)
#define RTC_INTERRUPTS (RTC_OFFSET + 6)
#define RTC_WATCHDOG (RTC_OFFSET + 7)
#define RTC_CONTROL (RTC_OFFSET + 8)
#define RTC_CENTURY (RTC_OFFSET + 8)
#define RTC_SECONDS (RTC_OFFSET + 9)
#define RTC_MINUTES (RTC_OFFSET + 10)
#define RTC_HOURS (RTC_OFFSET + 11)
#define RTC_DAY (RTC_OFFSET + 12)
#define RTC_DATE (RTC_OFFSET + 13)
#define RTC_MONTH (RTC_OFFSET + 14)
#define RTC_YEAR (RTC_OFFSET + 15)
#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 Flags register */
#define RTC_FLAGS_AF 0x40
#define RTC_FLAGS_BLF 0x10
/* Bits in the Interrupts register */
#define RTC_INTS_AE 0x80
struct rtc_plat_data {
struct rtc_device *rtc;
void __iomem *ioaddr;
unsigned long baseaddr;
unsigned long last_jiffies;
int irq;
unsigned int irqen;
int alrm_sec;
int alrm_min;
int alrm_hour;
int alrm_mday;
};
static int ds1553_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;
u8 century;
century = BIN2BCD((tm->tm_year + 1900) / 100);
writeb(RTC_WRITE, pdata->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 ds1553_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;
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 void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata)
{
void __iomem *ioaddr = pdata->ioaddr;
unsigned long flags;
spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
0x80 : BIN2BCD(pdata->alrm_mday),
ioaddr + RTC_DATE_ALARM);
writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
0x80 : BIN2BCD(pdata->alrm_hour),
ioaddr + RTC_HOURS_ALARM);
writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
0x80 : BIN2BCD(pdata->alrm_min),
ioaddr + RTC_MINUTES_ALARM);
writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
0x80 : BIN2BCD(pdata->alrm_sec),
ioaddr + RTC_SECONDS_ALARM);
writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS);
readb(ioaddr + RTC_FLAGS); /* clear interrupts */
spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
}
static int ds1553_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
if (pdata->irq < 0)
return -EINVAL;
pdata->alrm_mday = alrm->time.tm_mday;
pdata->alrm_hour = alrm->time.tm_hour;
pdata->alrm_min = alrm->time.tm_min;
pdata->alrm_sec = alrm->time.tm_sec;
if (alrm->enabled)
pdata->irqen |= RTC_AF;
ds1553_rtc_update_alarm(pdata);
return 0;
}
static int ds1553_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
if (pdata->irq < 0)
return -EINVAL;
alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
return 0;
}
static irqreturn_t ds1553_rtc_interrupt(int irq, void *dev_id,
struct pt_regs *regs)
{
struct platform_device *pdev = dev_id;
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
void __iomem *ioaddr = pdata->ioaddr;
unsigned long events = RTC_IRQF;
/* read and clear interrupt */
if (!(readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF))
return IRQ_NONE;
if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
events |= RTC_UF;
else
events |= RTC_AF;
rtc_update_irq(&pdata->rtc->class_dev, 1, events);
return IRQ_HANDLED;
}
static void ds1553_rtc_release(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
if (pdata->irq >= 0) {
pdata->irqen = 0;
ds1553_rtc_update_alarm(pdata);
}
}
static int ds1553_rtc_ioctl(struct device *dev, unsigned int cmd,
unsigned long arg)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
if (pdata->irq < 0)
return -ENOIOCTLCMD;
switch (cmd) {
case RTC_AIE_OFF:
pdata->irqen &= ~RTC_AF;
ds1553_rtc_update_alarm(pdata);
break;
case RTC_AIE_ON:
pdata->irqen |= RTC_AF;
ds1553_rtc_update_alarm(pdata);
break;
case RTC_UIE_OFF:
pdata->irqen &= ~RTC_UF;
ds1553_rtc_update_alarm(pdata);
break;
case RTC_UIE_ON:
pdata->irqen |= RTC_UF;
ds1553_rtc_update_alarm(pdata);
break;
default:
return -ENOIOCTLCMD;
}
return 0;
}
static struct rtc_class_ops ds1553_rtc_ops = {
.read_time = ds1553_rtc_read_time,
.set_time = ds1553_rtc_set_time,
.read_alarm = ds1553_rtc_read_alarm,
.set_alarm = ds1553_rtc_set_alarm,
.release = ds1553_rtc_release,
.ioctl = ds1553_rtc_ioctl,
};
static ssize_t ds1553_nvram_read(struct kobject *kobj, 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;
ssize_t count;
for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
*buf++ = readb(ioaddr + pos++);
return count;
}
static ssize_t ds1553_nvram_write(struct kobject *kobj, 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;
ssize_t count;
for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
writeb(*buf++, ioaddr + pos++);
return count;
}
static struct bin_attribute ds1553_nvram_attr = {
.attr = {
.name = "nvram",
.mode = S_IRUGO | S_IWUGO,
.owner = THIS_MODULE,
},
.size = RTC_OFFSET,
.read = ds1553_nvram_read,
.write = ds1553_nvram_write,
};
static int __init ds1553_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->irq = -1;
if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) {
ret = -EBUSY;
goto out;
}
pdata->baseaddr = res->start;
ioaddr = ioremap(pdata->baseaddr, RTC_REG_SIZE);
if (!ioaddr) {
ret = -ENOMEM;
goto out;
}
pdata->ioaddr = ioaddr;
pdata->irq = platform_get_irq(pdev, 0);
/* turn RTC on if it was not on */
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_FLAGS) & RTC_FLAGS_BLF)
dev_warn(&pdev->dev, "voltage-low detected.\n");
if (pdata->irq >= 0) {
writeb(0, ioaddr + RTC_INTERRUPTS);
if (request_irq(pdata->irq, ds1553_rtc_interrupt, SA_SHIRQ,
pdev->name, pdev) < 0) {
dev_warn(&pdev->dev, "interrupt not available.\n");
pdata->irq = -1;
}
}
rtc = rtc_device_register(pdev->name, &pdev->dev,
&ds1553_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);
sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
return 0;
out:
if (pdata->irq >= 0)
free_irq(pdata->irq, pdev);
if (ioaddr)
iounmap(ioaddr);
if (pdata->baseaddr)
release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
kfree(pdata);
return ret;
}
static int __devexit ds1553_rtc_remove(struct platform_device *pdev)
{
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
sysfs_remove_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
rtc_device_unregister(pdata->rtc);
if (pdata->irq >= 0) {
writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
free_irq(pdata->irq, pdev);
}
iounmap(pdata->ioaddr);
release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
kfree(pdata);
return 0;
}
static struct platform_driver ds1553_rtc_driver = {
.probe = ds1553_rtc_probe,
.remove = __devexit_p(ds1553_rtc_remove),
.driver = {
.name = "ds1553",
.owner = THIS_MODULE,
},
};
static __init int ds1553_init(void)
{
return platform_driver_register(&ds1553_rtc_driver);
}
static __exit void ds1553_exit(void)
{
return platform_driver_unregister(&ds1553_rtc_driver);
}
module_init(ds1553_init);
module_exit(ds1553_exit);
MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
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