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linux/drivers/char/s3c2410-rtc.c

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/* drivers/char/s3c2410_rtc.c
*
* Copyright (c) 2004 Simtec Electronics <linux@simtec.co.uk>
* http://www.simtec.co.uk/products/SWLINUX/
*
* 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 Internal RTC Driver
*
* Changelog:
* 08-Nov-2004 BJD Initial creation
* 12-Nov-2004 BJD Added periodic IRQ and PM code
* 22-Nov-2004 BJD Sign-test on alarm code to check for <0
* 10-Mar-2005 LCVR Changed S3C2410_VA_RTC to S3C24XX_VA_RTC
*/
#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 <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/hardware/clock.h>
#include <asm/arch/regs-rtc.h>
/* need this for the RTC_AF definitions */
#include <linux/mc146818rtc.h>
#undef S3C24XX_VA_RTC
#define S3C24XX_VA_RTC s3c2410_rtc_base
static struct resource *s3c2410_rtc_mem;
static void __iomem *s3c2410_rtc_base;
static int s3c2410_rtc_alarmno = NO_IRQ;
static int s3c2410_rtc_tickno = NO_IRQ;
static int s3c2410_rtc_freq = 1;
static DEFINE_SPINLOCK(s3c2410_rtc_pie_lock);
/* IRQ Handlers */
static irqreturn_t s3c2410_rtc_alarmirq(int irq, void *id, struct pt_regs *r)
{
rtc_update(1, RTC_AF | RTC_IRQF);
return IRQ_HANDLED;
}
static irqreturn_t s3c2410_rtc_tickirq(int irq, void *id, struct pt_regs *r)
{
rtc_update(1, RTC_PF | RTC_IRQF);
return IRQ_HANDLED;
}
/* Update control registers */
static void s3c2410_rtc_setaie(int to)
{
unsigned int tmp;
pr_debug("%s: aie=%d\n", __FUNCTION__, to);
tmp = readb(S3C2410_RTCALM);
if (to)
tmp |= S3C2410_RTCALM_ALMEN;
else
tmp &= ~S3C2410_RTCALM_ALMEN;
writeb(tmp, S3C2410_RTCALM);
}
static void s3c2410_rtc_setpie(int to)
{
unsigned int tmp;
pr_debug("%s: pie=%d\n", __FUNCTION__, to);
spin_lock_irq(&s3c2410_rtc_pie_lock);
tmp = readb(S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
if (to)
tmp |= S3C2410_TICNT_ENABLE;
writeb(tmp, S3C2410_TICNT);
spin_unlock_irq(&s3c2410_rtc_pie_lock);
}
static void s3c2410_rtc_setfreq(int freq)
{
unsigned int tmp;
spin_lock_irq(&s3c2410_rtc_pie_lock);
tmp = readb(S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
s3c2410_rtc_freq = freq;
tmp |= (128 / freq)-1;
writeb(tmp, S3C2410_TICNT);
spin_unlock_irq(&s3c2410_rtc_pie_lock);
}
/* Time read/write */
static int s3c2410_rtc_gettime(struct rtc_time *rtc_tm)
{
unsigned int have_retried = 0;
retry_get_time:
rtc_tm->tm_min = readb(S3C2410_RTCMIN);
rtc_tm->tm_hour = readb(S3C2410_RTCHOUR);
rtc_tm->tm_mday = readb(S3C2410_RTCDATE);
rtc_tm->tm_mon = readb(S3C2410_RTCMON);
rtc_tm->tm_year = readb(S3C2410_RTCYEAR);
rtc_tm->tm_sec = readb(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 s3c2410_rtc_settime(struct rtc_time *tm)
{
/* the rtc gets round the y2k problem by just not supporting it */
if (tm->tm_year < 100)
return -EINVAL;
writeb(BIN2BCD(tm->tm_sec), S3C2410_RTCSEC);
writeb(BIN2BCD(tm->tm_min), S3C2410_RTCMIN);
writeb(BIN2BCD(tm->tm_hour), S3C2410_RTCHOUR);
writeb(BIN2BCD(tm->tm_mday), S3C2410_RTCDATE);
writeb(BIN2BCD(tm->tm_mon + 1), S3C2410_RTCMON);
writeb(BIN2BCD(tm->tm_year - 100), S3C2410_RTCYEAR);
return 0;
}
static int s3c2410_rtc_getalarm(struct rtc_wkalrm *alrm)
{
struct rtc_time *alm_tm = &alrm->time;
unsigned int alm_en;
alm_tm->tm_sec = readb(S3C2410_ALMSEC);
alm_tm->tm_min = readb(S3C2410_ALMMIN);
alm_tm->tm_hour = readb(S3C2410_ALMHOUR);
alm_tm->tm_mon = readb(S3C2410_ALMMON);
alm_tm->tm_mday = readb(S3C2410_ALMDATE);
alm_tm->tm_year = readb(S3C2410_ALMYEAR);
alm_en = readb(S3C2410_RTCALM);
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;
}
/* todo - set alrm->enabled ? */
return 0;
}
static int s3c2410_rtc_setalarm(struct rtc_wkalrm *alrm)
{
struct rtc_time *tm = &alrm->time;
unsigned int alrm_en;
pr_debug("s3c2410_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);
if (alrm->enabled || 1) {
alrm_en = readb(S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
writeb(0x00, S3C2410_RTCALM);
if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
alrm_en |= S3C2410_RTCALM_SECEN;
writeb(BIN2BCD(tm->tm_sec), S3C2410_ALMSEC);
}
if (tm->tm_min < 60 && tm->tm_min >= 0) {
alrm_en |= S3C2410_RTCALM_MINEN;
writeb(BIN2BCD(tm->tm_min), S3C2410_ALMMIN);
}
if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
alrm_en |= S3C2410_RTCALM_HOUREN;
writeb(BIN2BCD(tm->tm_hour), S3C2410_ALMHOUR);
}
pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
writeb(alrm_en, S3C2410_RTCALM);
enable_irq_wake(s3c2410_rtc_alarmno);
} else {
alrm_en = readb(S3C2410_RTCALM);
alrm_en &= ~S3C2410_RTCALM_ALMEN;
writeb(alrm_en, S3C2410_RTCALM);
disable_irq_wake(s3c2410_rtc_alarmno);
}
return 0;
}
static int s3c2410_rtc_ioctl(unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case RTC_AIE_OFF:
case RTC_AIE_ON:
s3c2410_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
return 0;
case RTC_PIE_OFF:
case RTC_PIE_ON:
s3c2410_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
return 0;
case RTC_IRQP_READ:
return put_user(s3c2410_rtc_freq, (unsigned long __user *)arg);
case RTC_IRQP_SET:
if (arg < 1 || arg > 64)
return -EINVAL;
if (!capable(CAP_SYS_RESOURCE))
return -EACCES;
/* check for power of 2 */
if ((arg & (arg-1)) != 0)
return -EINVAL;
pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
s3c2410_rtc_setfreq(arg);
return 0;
case RTC_UIE_ON:
case RTC_UIE_OFF:
return -EINVAL;
}
return -EINVAL;
}
static int s3c2410_rtc_proc(char *buf)
{
unsigned int rtcalm = readb(S3C2410_RTCALM);
unsigned int ticnt = readb (S3C2410_TICNT);
char *p = buf;
p += sprintf(p, "alarm_IRQ\t: %s\n",
(rtcalm & S3C2410_RTCALM_ALMEN) ? "yes" : "no" );
p += sprintf(p, "periodic_IRQ\t: %s\n",
(ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
p += sprintf(p, "periodic_freq\t: %d\n", s3c2410_rtc_freq);
return p - buf;
}
static int s3c2410_rtc_open(void)
{
int ret;
ret = request_irq(s3c2410_rtc_alarmno, s3c2410_rtc_alarmirq,
SA_INTERRUPT, "s3c2410-rtc alarm", NULL);
if (ret)
printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_alarmno);
ret = request_irq(s3c2410_rtc_tickno, s3c2410_rtc_tickirq,
SA_INTERRUPT, "s3c2410-rtc tick", NULL);
if (ret) {
printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_tickno);
goto tick_err;
}
return ret;
tick_err:
free_irq(s3c2410_rtc_alarmno, NULL);
return ret;
}
static void s3c2410_rtc_release(void)
{
/* do not clear AIE here, it may be needed for wake */
s3c2410_rtc_setpie(0);
free_irq(s3c2410_rtc_alarmno, NULL);
free_irq(s3c2410_rtc_tickno, NULL);
}
static struct rtc_ops s3c2410_rtcops = {
.owner = THIS_MODULE,
.open = s3c2410_rtc_open,
.release = s3c2410_rtc_release,
.ioctl = s3c2410_rtc_ioctl,
.read_time = s3c2410_rtc_gettime,
.set_time = s3c2410_rtc_settime,
.read_alarm = s3c2410_rtc_getalarm,
.set_alarm = s3c2410_rtc_setalarm,
.proc = s3c2410_rtc_proc,
};
static void s3c2410_rtc_enable(struct platform_device *pdev, int en)
{
unsigned int tmp;
if (s3c2410_rtc_base == NULL)
return;
if (!en) {
tmp = readb(S3C2410_RTCCON);
writeb(tmp & ~S3C2410_RTCCON_RTCEN, S3C2410_RTCCON);
tmp = readb(S3C2410_TICNT);
writeb(tmp & ~S3C2410_TICNT_ENABLE, S3C2410_TICNT);
} else {
/* re-enable the device, and check it is ok */
if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
tmp = readb(S3C2410_RTCCON);
writeb(tmp | S3C2410_RTCCON_RTCEN , S3C2410_RTCCON);
}
if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
dev_info(&pdev->dev, "removing S3C2410_RTCCON_CNTSEL\n");
tmp = readb(S3C2410_RTCCON);
writeb(tmp& ~S3C2410_RTCCON_CNTSEL , S3C2410_RTCCON);
}
if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
dev_info(&pdev->dev, "removing S3C2410_RTCCON_CLKRST\n");
tmp = readb(S3C2410_RTCCON);
writeb(tmp & ~S3C2410_RTCCON_CLKRST, S3C2410_RTCCON);
}
}
}
static int s3c2410_rtc_remove(struct platform_device *dev)
{
unregister_rtc(&s3c2410_rtcops);
s3c2410_rtc_setpie(0);
s3c2410_rtc_setaie(0);
if (s3c2410_rtc_mem != NULL) {
pr_debug("s3c2410_rtc: releasing s3c2410_rtc_mem\n");
iounmap(s3c2410_rtc_base);
release_resource(s3c2410_rtc_mem);
kfree(s3c2410_rtc_mem);
}
return 0;
}
static int s3c2410_rtc_probe(struct platform_device *pdev)
{
struct resource *res;
int ret;
pr_debug("%s: probe=%p\n", __FUNCTION__, pdev);
/* find the IRQs */
s3c2410_rtc_tickno = platform_get_irq(pdev, 1);
if (s3c2410_rtc_tickno <= 0) {
dev_err(&pdev->dev, "no irq for rtc tick\n");
return -ENOENT;
}
s3c2410_rtc_alarmno = platform_get_irq(pdev, 0);
if (s3c2410_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",
s3c2410_rtc_tickno, s3c2410_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;
}
s3c2410_rtc_mem = request_mem_region(res->start, res->end-res->start+1,
pdev->name);
if (s3c2410_rtc_mem == NULL) {
dev_err(&pdev->dev, "failed to reserve memory region\n");
ret = -ENOENT;
goto exit_err;
}
s3c2410_rtc_base = ioremap(res->start, res->end - res->start + 1);
if (s3c2410_rtc_base == NULL) {
dev_err(&pdev->dev, "failed ioremap()\n");
ret = -EINVAL;
goto exit_err;
}
s3c2410_rtc_mem = res;
pr_debug("s3c2410_rtc_base=%p\n", s3c2410_rtc_base);
pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
/* check to see if everything is setup correctly */
s3c2410_rtc_enable(pdev, 1);
pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
s3c2410_rtc_setfreq(s3c2410_rtc_freq);
/* register RTC and exit */
register_rtc(&s3c2410_rtcops);
return 0;
exit_err:
dev_err(&pdev->dev, "error %d during initialisation\n", ret);
return ret;
}
#ifdef CONFIG_PM
/* S3C2410 RTC Power management control */
static struct timespec s3c2410_rtc_delta;
static int ticnt_save;
static int s3c2410_rtc_suspend(struct platform_device *pdev, pm_message_t state)
{
struct rtc_time tm;
struct timespec time;
time.tv_nsec = 0;
/* save TICNT for anyone using periodic interrupts */
ticnt_save = readb(S3C2410_TICNT);
/* calculate time delta for suspend */
s3c2410_rtc_gettime(&tm);
rtc_tm_to_time(&tm, &time.tv_sec);
save_time_delta(&s3c2410_rtc_delta, &time);
s3c2410_rtc_enable(pdev, 0);
return 0;
}
static int s3c2410_rtc_resume(struct platform_device *pdev)
{
struct rtc_time tm;
struct timespec time;
time.tv_nsec = 0;
s3c2410_rtc_enable(pdev, 1);
s3c2410_rtc_gettime(&tm);
rtc_tm_to_time(&tm, &time.tv_sec);
restore_time_delta(&s3c2410_rtc_delta, &time);
writeb(ticnt_save, S3C2410_TICNT);
return 0;
}
#else
#define s3c2410_rtc_suspend NULL
#define s3c2410_rtc_resume NULL
#endif
static struct platform_driver s3c2410_rtcdrv = {
.probe = s3c2410_rtc_probe,
.remove = s3c2410_rtc_remove,
.suspend = s3c2410_rtc_suspend,
.resume = s3c2410_rtc_resume,
.driver = {
.name = "s3c2410-rtc",
.owner = THIS_MODULE,
},
};
static char __initdata banner[] = "S3C2410 RTC, (c) 2004 Simtec Electronics\n";
static int __init s3c2410_rtc_init(void)
{
printk(banner);
return platform_driver_register(&s3c2410_rtcdrv);
}
static void __exit s3c2410_rtc_exit(void)
{
platform_driver_unregister(&s3c2410_rtcdrv);
}
module_init(s3c2410_rtc_init);
module_exit(s3c2410_rtc_exit);
MODULE_DESCRIPTION("S3C24XX RTC Driver");
MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
MODULE_LICENSE("GPL");
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