Commit 6a8a8108 authored by Ben Dooks's avatar Ben Dooks Committed by Russell King

[ARM PATCH] 2232/2: S3C2410 - RTC driver

Patch from Ben Dooks

S3C2410/S3C2440 RTC driver using arch/arm/common/rtctime.c as
a base. Supports alarm, and periodic IRQ from 1 to 64Hz

Signed-off-by: Ben Dooks
Signed-off-by: Russell King
parent fd8ae422
......@@ -790,6 +790,14 @@ config DS1302
will get access to the real time clock (or hardware clock) built
into your computer.
config S3C2410_RTC
bool "S3C2410 RTC Driver"
depends on ARCH_S3C2410
help
RTC (Realtime Clock) driver for the clock inbuilt into the
Samsung S3C2410. This can provide periodic interrupt rates
from 1Hz to 64Hz for user programs, and wakeup from Alarm.
config COBALT_LCD
bool "Support for Cobalt LCD"
depends on MIPS_COBALT
......
......@@ -64,6 +64,7 @@ obj-$(CONFIG_EFI_RTC) += efirtc.o
obj-$(CONFIG_SGI_DS1286) += ds1286.o
obj-$(CONFIG_SGI_IP27_RTC) += ip27-rtc.o
obj-$(CONFIG_DS1302) += ds1302.o
obj-$(CONFIG_S3C2410_RTC) += s3c2410-rtc.o
ifeq ($(CONFIG_GENERIC_NVRAM),y)
obj-$(CONFIG_NVRAM) += generic_nvram.o
else
......
/* 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
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/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 S3C2410_VA_RTC
#define S3C2410_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 spinlock_t s3c2410_rtc_pie_lock = SPIN_LOCK_UNLOCKED;
/* 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 void 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;
}
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 void 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 ? */
}
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_year & 0xff, tm->tm_mon & 0xff, tm->tm_mday & 0xff,
tm->tm_hour, tm->tm_min, tm->tm_sec);
if (alrm->enabled || 1) {
alrm_en = readb(S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
writeb(0x00, S3C2410_RTCALM);
if (tm->tm_sec < 60) {
alrm_en |= S3C2410_RTCALM_SECEN;
writeb(BIN2BCD(tm->tm_sec), S3C2410_ALMSEC);
}
if (tm->tm_min < 60) {
alrm_en |= S3C2410_RTCALM_MINEN;
writeb(BIN2BCD(tm->tm_min), S3C2410_ALMMIN);
}
if (tm->tm_hour < 24) {
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 device *dev, 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(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(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(dev, "removing S3C2410_RTCCON_CLKRST\n");
tmp = readb(S3C2410_RTCCON);
writeb(tmp & ~S3C2410_RTCCON_CLKRST, S3C2410_RTCCON);
}
}
}
static int s3c2410_rtc_remove(struct 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 device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct resource *res;
int ret;
pr_debug("%s: probe=%p, device=%p\n", __FUNCTION__, pdev, dev);
/* find the IRQs */
s3c2410_rtc_tickno = platform_get_irq(pdev, 1);
if (s3c2410_rtc_tickno <= 0) {
dev_err(dev, "no irq for rtc tick\n");
return -ENOENT;
}
s3c2410_rtc_alarmno = platform_get_irq(pdev, 0);
if (s3c2410_rtc_alarmno <= 0) {
dev_err(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(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(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(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(dev, 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(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 device *dev, u32 state, u32 level)
{
struct rtc_time tm;
struct timespec time;
time.tv_nsec = 0;
if (level == SUSPEND_POWER_DOWN) {
/* 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(dev, 0);
}
return 0;
}
static int s3c2410_rtc_resume(struct device *dev, u32 level)
{
struct rtc_time tm;
struct timespec time;
time.tv_nsec = 0;
s3c2410_rtc_enable(dev, 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 device_driver s3c2410_rtcdrv = {
.name = "s3c2410-rtc",
.bus = &platform_bus_type,
.probe = s3c2410_rtc_probe,
.remove = s3c2410_rtc_remove,
.suspend = s3c2410_rtc_suspend,
.resume = s3c2410_rtc_resume,
};
static char __initdata banner[] = "S3C2410 RTC, (c) 2004 Simtec Electronics\n";
static int __init s3c2410_rtc_init(void)
{
printk(banner);
return driver_register(&s3c2410_rtcdrv);
}
static void __exit s3c2410_rtc_exit(void)
{
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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