Revision 0e81a8ae37687845f7cdfa2adce14ea6a5f1dd34 authored by Linus Torvalds on 01 April 2008, 19:44:26 UTC, committed by Linus Torvalds on 01 April 2008, 19:44:26 UTC
1 parent 00460dd
rtc-s3c.c
/* drivers/rtc/rtc-s3c.c
*
* Copyright (c) 2004,2006 Simtec Electronics
* Ben Dooks, <ben@simtec.co.uk>
* http://armlinux.simtec.co.uk/
*
* 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.
*
* S3C2410/S3C2440/S3C24XX Internal RTC Driver
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/clk.h>
#include <linux/log2.h>
#include <asm/hardware.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/rtc.h>
#include <asm/mach/time.h>
#include <asm/plat-s3c/regs-rtc.h>
/* I have yet to find an S3C implementation with more than one
* of these rtc blocks in */
static struct resource *s3c_rtc_mem;
static void __iomem *s3c_rtc_base;
static int s3c_rtc_alarmno = NO_IRQ;
static int s3c_rtc_tickno = NO_IRQ;
static int s3c_rtc_freq = 1;
static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
static unsigned int tick_count;
/* IRQ Handlers */
static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
{
struct rtc_device *rdev = id;
rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
return IRQ_HANDLED;
}
static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
{
struct rtc_device *rdev = id;
rtc_update_irq(rdev, tick_count++, RTC_PF | RTC_IRQF);
return IRQ_HANDLED;
}
/* Update control registers */
static void s3c_rtc_setaie(int to)
{
unsigned int tmp;
pr_debug("%s: aie=%d\n", __FUNCTION__, to);
tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
if (to)
tmp |= S3C2410_RTCALM_ALMEN;
writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
}
static void s3c_rtc_setpie(int to)
{
unsigned int tmp;
pr_debug("%s: pie=%d\n", __FUNCTION__, to);
spin_lock_irq(&s3c_rtc_pie_lock);
tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
if (to)
tmp |= S3C2410_TICNT_ENABLE;
writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
spin_unlock_irq(&s3c_rtc_pie_lock);
}
static void s3c_rtc_setfreq(int freq)
{
unsigned int tmp;
spin_lock_irq(&s3c_rtc_pie_lock);
tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
s3c_rtc_freq = freq;
tmp |= (128 / freq)-1;
writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
spin_unlock_irq(&s3c_rtc_pie_lock);
}
/* Time read/write */
static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
{
unsigned int have_retried = 0;
void __iomem *base = s3c_rtc_base;
retry_get_time:
rtc_tm->tm_min = readb(base + S3C2410_RTCMIN);
rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
rtc_tm->tm_mon = readb(base + S3C2410_RTCMON);
rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
rtc_tm->tm_sec = readb(base + S3C2410_RTCSEC);
/* the only way to work out wether the system was mid-update
* when we read it is to check the second counter, and if it
* is zero, then we re-try the entire read
*/
if (rtc_tm->tm_sec == 0 && !have_retried) {
have_retried = 1;
goto retry_get_time;
}
pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
BCD_TO_BIN(rtc_tm->tm_sec);
BCD_TO_BIN(rtc_tm->tm_min);
BCD_TO_BIN(rtc_tm->tm_hour);
BCD_TO_BIN(rtc_tm->tm_mday);
BCD_TO_BIN(rtc_tm->tm_mon);
BCD_TO_BIN(rtc_tm->tm_year);
rtc_tm->tm_year += 100;
rtc_tm->tm_mon -= 1;
return 0;
}
static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
{
void __iomem *base = s3c_rtc_base;
int year = tm->tm_year - 100;
pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
tm->tm_year, tm->tm_mon, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
/* we get around y2k by simply not supporting it */
if (year < 0 || year >= 100) {
dev_err(dev, "rtc only supports 100 years\n");
return -EINVAL;
}
writeb(BIN2BCD(tm->tm_sec), base + S3C2410_RTCSEC);
writeb(BIN2BCD(tm->tm_min), base + S3C2410_RTCMIN);
writeb(BIN2BCD(tm->tm_hour), base + S3C2410_RTCHOUR);
writeb(BIN2BCD(tm->tm_mday), base + S3C2410_RTCDATE);
writeb(BIN2BCD(tm->tm_mon + 1), base + S3C2410_RTCMON);
writeb(BIN2BCD(year), base + S3C2410_RTCYEAR);
return 0;
}
static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct rtc_time *alm_tm = &alrm->time;
void __iomem *base = s3c_rtc_base;
unsigned int alm_en;
alm_tm->tm_sec = readb(base + S3C2410_ALMSEC);
alm_tm->tm_min = readb(base + S3C2410_ALMMIN);
alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
alm_tm->tm_mon = readb(base + S3C2410_ALMMON);
alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
alm_en = readb(base + S3C2410_RTCALM);
alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
alm_en,
alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
/* decode the alarm enable field */
if (alm_en & S3C2410_RTCALM_SECEN)
BCD_TO_BIN(alm_tm->tm_sec);
else
alm_tm->tm_sec = 0xff;
if (alm_en & S3C2410_RTCALM_MINEN)
BCD_TO_BIN(alm_tm->tm_min);
else
alm_tm->tm_min = 0xff;
if (alm_en & S3C2410_RTCALM_HOUREN)
BCD_TO_BIN(alm_tm->tm_hour);
else
alm_tm->tm_hour = 0xff;
if (alm_en & S3C2410_RTCALM_DAYEN)
BCD_TO_BIN(alm_tm->tm_mday);
else
alm_tm->tm_mday = 0xff;
if (alm_en & S3C2410_RTCALM_MONEN) {
BCD_TO_BIN(alm_tm->tm_mon);
alm_tm->tm_mon -= 1;
} else {
alm_tm->tm_mon = 0xff;
}
if (alm_en & S3C2410_RTCALM_YEAREN)
BCD_TO_BIN(alm_tm->tm_year);
else
alm_tm->tm_year = 0xffff;
return 0;
}
static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct rtc_time *tm = &alrm->time;
void __iomem *base = s3c_rtc_base;
unsigned int alrm_en;
pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
alrm->enabled,
tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
writeb(0x00, base + S3C2410_RTCALM);
if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
alrm_en |= S3C2410_RTCALM_SECEN;
writeb(BIN2BCD(tm->tm_sec), base + S3C2410_ALMSEC);
}
if (tm->tm_min < 60 && tm->tm_min >= 0) {
alrm_en |= S3C2410_RTCALM_MINEN;
writeb(BIN2BCD(tm->tm_min), base + S3C2410_ALMMIN);
}
if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
alrm_en |= S3C2410_RTCALM_HOUREN;
writeb(BIN2BCD(tm->tm_hour), base + S3C2410_ALMHOUR);
}
pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
writeb(alrm_en, base + S3C2410_RTCALM);
if (0) {
alrm_en = readb(base + S3C2410_RTCALM);
alrm_en &= ~S3C2410_RTCALM_ALMEN;
writeb(alrm_en, base + S3C2410_RTCALM);
disable_irq_wake(s3c_rtc_alarmno);
}
if (alrm->enabled)
enable_irq_wake(s3c_rtc_alarmno);
else
disable_irq_wake(s3c_rtc_alarmno);
return 0;
}
static int s3c_rtc_ioctl(struct device *dev,
unsigned int cmd, unsigned long arg)
{
unsigned int ret = -ENOIOCTLCMD;
switch (cmd) {
case RTC_AIE_OFF:
case RTC_AIE_ON:
s3c_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
ret = 0;
break;
case RTC_PIE_OFF:
case RTC_PIE_ON:
tick_count = 0;
s3c_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
ret = 0;
break;
case RTC_IRQP_READ:
ret = put_user(s3c_rtc_freq, (unsigned long __user *)arg);
break;
case RTC_IRQP_SET:
if (!is_power_of_2(arg)) {
ret = -EINVAL;
goto exit;
}
pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
s3c_rtc_setfreq(arg);
ret = 0;
break;
case RTC_UIE_ON:
case RTC_UIE_OFF:
ret = -EINVAL;
}
exit:
return ret;
}
static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
{
unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
seq_printf(seq, "periodic_IRQ\t: %s\n",
(ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
seq_printf(seq, "periodic_freq\t: %d\n", s3c_rtc_freq);
return 0;
}
static int s3c_rtc_open(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
int ret;
ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
IRQF_DISABLED, "s3c2410-rtc alarm", rtc_dev);
if (ret) {
dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
return ret;
}
ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
IRQF_DISABLED, "s3c2410-rtc tick", rtc_dev);
if (ret) {
dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
goto tick_err;
}
return ret;
tick_err:
free_irq(s3c_rtc_alarmno, rtc_dev);
return ret;
}
static void s3c_rtc_release(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
/* do not clear AIE here, it may be needed for wake */
s3c_rtc_setpie(0);
free_irq(s3c_rtc_alarmno, rtc_dev);
free_irq(s3c_rtc_tickno, rtc_dev);
}
static const struct rtc_class_ops s3c_rtcops = {
.open = s3c_rtc_open,
.release = s3c_rtc_release,
.ioctl = s3c_rtc_ioctl,
.read_time = s3c_rtc_gettime,
.set_time = s3c_rtc_settime,
.read_alarm = s3c_rtc_getalarm,
.set_alarm = s3c_rtc_setalarm,
.proc = s3c_rtc_proc,
};
static void s3c_rtc_enable(struct platform_device *pdev, int en)
{
void __iomem *base = s3c_rtc_base;
unsigned int tmp;
if (s3c_rtc_base == NULL)
return;
if (!en) {
tmp = readb(base + S3C2410_RTCCON);
writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
tmp = readb(base + S3C2410_TICNT);
writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
} else {
/* re-enable the device, and check it is ok */
if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
tmp = readb(base + S3C2410_RTCCON);
writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
}
if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
tmp = readb(base + S3C2410_RTCCON);
writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
}
if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
tmp = readb(base + S3C2410_RTCCON);
writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
}
}
}
static int s3c_rtc_remove(struct platform_device *dev)
{
struct rtc_device *rtc = platform_get_drvdata(dev);
platform_set_drvdata(dev, NULL);
rtc_device_unregister(rtc);
s3c_rtc_setpie(0);
s3c_rtc_setaie(0);
iounmap(s3c_rtc_base);
release_resource(s3c_rtc_mem);
kfree(s3c_rtc_mem);
return 0;
}
static int s3c_rtc_probe(struct platform_device *pdev)
{
struct rtc_device *rtc;
struct resource *res;
int ret;
pr_debug("%s: probe=%p\n", __FUNCTION__, pdev);
/* find the IRQs */
s3c_rtc_tickno = platform_get_irq(pdev, 1);
if (s3c_rtc_tickno < 0) {
dev_err(&pdev->dev, "no irq for rtc tick\n");
return -ENOENT;
}
s3c_rtc_alarmno = platform_get_irq(pdev, 0);
if (s3c_rtc_alarmno < 0) {
dev_err(&pdev->dev, "no irq for alarm\n");
return -ENOENT;
}
pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
s3c_rtc_tickno, s3c_rtc_alarmno);
/* get the memory region */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res == NULL) {
dev_err(&pdev->dev, "failed to get memory region resource\n");
return -ENOENT;
}
s3c_rtc_mem = request_mem_region(res->start,
res->end-res->start+1,
pdev->name);
if (s3c_rtc_mem == NULL) {
dev_err(&pdev->dev, "failed to reserve memory region\n");
ret = -ENOENT;
goto err_nores;
}
s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
if (s3c_rtc_base == NULL) {
dev_err(&pdev->dev, "failed ioremap()\n");
ret = -EINVAL;
goto err_nomap;
}
/* check to see if everything is setup correctly */
s3c_rtc_enable(pdev, 1);
pr_debug("s3c2410_rtc: RTCCON=%02x\n",
readb(s3c_rtc_base + S3C2410_RTCCON));
s3c_rtc_setfreq(s3c_rtc_freq);
/* register RTC and exit */
rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
THIS_MODULE);
if (IS_ERR(rtc)) {
dev_err(&pdev->dev, "cannot attach rtc\n");
ret = PTR_ERR(rtc);
goto err_nortc;
}
rtc->max_user_freq = 128;
platform_set_drvdata(pdev, rtc);
return 0;
err_nortc:
s3c_rtc_enable(pdev, 0);
iounmap(s3c_rtc_base);
err_nomap:
release_resource(s3c_rtc_mem);
err_nores:
return ret;
}
#ifdef CONFIG_PM
/* RTC Power management control */
static int ticnt_save;
static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
{
/* save TICNT for anyone using periodic interrupts */
ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
s3c_rtc_enable(pdev, 0);
return 0;
}
static int s3c_rtc_resume(struct platform_device *pdev)
{
s3c_rtc_enable(pdev, 1);
writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
return 0;
}
#else
#define s3c_rtc_suspend NULL
#define s3c_rtc_resume NULL
#endif
static struct platform_driver s3c2410_rtcdrv = {
.probe = s3c_rtc_probe,
.remove = s3c_rtc_remove,
.suspend = s3c_rtc_suspend,
.resume = s3c_rtc_resume,
.driver = {
.name = "s3c2410-rtc",
.owner = THIS_MODULE,
},
};
static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
static int __init s3c_rtc_init(void)
{
printk(banner);
return platform_driver_register(&s3c2410_rtcdrv);
}
static void __exit s3c_rtc_exit(void)
{
platform_driver_unregister(&s3c2410_rtcdrv);
}
module_init(s3c_rtc_init);
module_exit(s3c_rtc_exit);
MODULE_DESCRIPTION("Samsung S3C RTC Driver");
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_LICENSE("GPL");
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