360 lines
10 KiB
C
360 lines
10 KiB
C
/*
|
|
* 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/gfp.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>
|
|
#include <linux/module.h>
|
|
|
|
#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 last_jiffies;
|
|
int irq;
|
|
unsigned int irqen;
|
|
int alrm_sec;
|
|
int alrm_min;
|
|
int alrm_hour;
|
|
int alrm_mday;
|
|
spinlock_t lock;
|
|
};
|
|
|
|
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->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->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 platform_device *pdev = dev_id;
|
|
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
|
|
void __iomem *ioaddr = pdata->ioaddr;
|
|
unsigned long events = 0;
|
|
|
|
spin_lock(&pdata->lock);
|
|
/* read and clear interrupt */
|
|
if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
|
|
events = RTC_IRQF;
|
|
if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
|
|
events |= RTC_UF;
|
|
else
|
|
events |= RTC_AF;
|
|
rtc_update_irq(pdata->rtc, 1, events);
|
|
}
|
|
spin_unlock(&pdata->lock);
|
|
return events ? IRQ_HANDLED : IRQ_NONE;
|
|
}
|
|
|
|
static int ds1553_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
|
|
{
|
|
struct platform_device *pdev = to_platform_device(dev);
|
|
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
|
|
|
|
if (pdata->irq <= 0)
|
|
return -EINVAL;
|
|
if (enabled)
|
|
pdata->irqen |= RTC_AF;
|
|
else
|
|
pdata->irqen &= ~RTC_AF;
|
|
ds1553_rtc_update_alarm(pdata);
|
|
return 0;
|
|
}
|
|
|
|
static const 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,
|
|
.alarm_irq_enable = ds1553_rtc_alarm_irq_enable,
|
|
};
|
|
|
|
static ssize_t ds1553_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;
|
|
ssize_t count;
|
|
|
|
for (count = 0; count < size; count++)
|
|
*buf++ = readb(ioaddr + pos++);
|
|
return count;
|
|
}
|
|
|
|
static ssize_t ds1553_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;
|
|
ssize_t count;
|
|
|
|
for (count = 0; count < size; count++)
|
|
writeb(*buf++, ioaddr + pos++);
|
|
return count;
|
|
}
|
|
|
|
static struct bin_attribute ds1553_nvram_attr = {
|
|
.attr = {
|
|
.name = "nvram",
|
|
.mode = S_IRUGO | S_IWUSR,
|
|
},
|
|
.size = RTC_OFFSET,
|
|
.read = ds1553_nvram_read,
|
|
.write = ds1553_nvram_write,
|
|
};
|
|
|
|
static int ds1553_rtc_probe(struct platform_device *pdev)
|
|
{
|
|
struct resource *res;
|
|
unsigned int cen, sec;
|
|
struct rtc_plat_data *pdata;
|
|
void __iomem *ioaddr;
|
|
int ret = 0;
|
|
|
|
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
|
|
if (!pdata)
|
|
return -ENOMEM;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
ioaddr = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(ioaddr))
|
|
return PTR_ERR(ioaddr);
|
|
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");
|
|
|
|
spin_lock_init(&pdata->lock);
|
|
pdata->last_jiffies = jiffies;
|
|
platform_set_drvdata(pdev, pdata);
|
|
|
|
pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
|
|
&ds1553_rtc_ops, THIS_MODULE);
|
|
if (IS_ERR(pdata->rtc))
|
|
return PTR_ERR(pdata->rtc);
|
|
|
|
if (pdata->irq > 0) {
|
|
writeb(0, ioaddr + RTC_INTERRUPTS);
|
|
if (devm_request_irq(&pdev->dev, pdata->irq,
|
|
ds1553_rtc_interrupt,
|
|
0, pdev->name, pdev) < 0) {
|
|
dev_warn(&pdev->dev, "interrupt not available.\n");
|
|
pdata->irq = 0;
|
|
}
|
|
}
|
|
|
|
ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
|
|
if (ret)
|
|
dev_err(&pdev->dev, "unable to create sysfs file: %s\n",
|
|
ds1553_nvram_attr.attr.name);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int 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);
|
|
if (pdata->irq > 0)
|
|
writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
|
|
return 0;
|
|
}
|
|
|
|
/* work with hotplug and coldplug */
|
|
MODULE_ALIAS("platform:rtc-ds1553");
|
|
|
|
static struct platform_driver ds1553_rtc_driver = {
|
|
.probe = ds1553_rtc_probe,
|
|
.remove = ds1553_rtc_remove,
|
|
.driver = {
|
|
.name = "rtc-ds1553",
|
|
},
|
|
};
|
|
|
|
module_platform_driver(ds1553_rtc_driver);
|
|
|
|
MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
|
|
MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
|
|
MODULE_LICENSE("GPL");
|