linux/drivers/rtc/rtc-ds1553.c

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/*
* 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 "0.2"
#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;
resource_size_t 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;
}
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:55:46 +02:00
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 = 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, 1, events);
return IRQ_HANDLED;
}
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; /* fall back into rtc-dev's emulation */
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 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,
.ioctl = ds1553_rtc_ioctl,
};
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 07:57:22 +02:00
static ssize_t ds1553_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;
ssize_t count;
for (count = 0; size > 0 && pos < RTC_OFFSET; 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 07:57:22 +02:00
static ssize_t ds1553_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;
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_IWUSR,
},
.size = RTC_OFFSET,
.read = ds1553_nvram_read,
.write = ds1553_nvram_write,
};
static int __devinit 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;
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,
IRQF_DISABLED | IRQF_SHARED,
pdev->name, pdev) < 0) {
dev_warn(&pdev->dev, "interrupt not available.\n");
pdata->irq = 0;
}
}
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);
ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
if (ret)
goto out;
return 0;
out:
if (pdata->rtc)
rtc_device_unregister(pdata->rtc);
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;
}
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:rtc-ds1553");
static struct platform_driver ds1553_rtc_driver = {
.probe = ds1553_rtc_probe,
.remove = __devexit_p(ds1553_rtc_remove),
.driver = {
.name = "rtc-ds1553",
.owner = THIS_MODULE,
},
};
static __init int ds1553_init(void)
{
return platform_driver_register(&ds1553_rtc_driver);
}
static __exit void ds1553_exit(void)
{
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);