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linux/drivers/rtc/rtc-s3c.c

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/* drivers/rtc/rtc-s3c.c
*
* Copyright (c) 2010 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* 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 <linux/slab.h>
#include <mach/hardware.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <plat/regs-rtc.h>
enum s3c_cpu_type {
TYPE_S3C2410,
TYPE_S3C64XX,
};
/* I have yet to find an S3C implementation with more than one
* of these rtc blocks in */
static struct resource *s3c_rtc_mem;
static struct clk *rtc_clk;
static void __iomem *s3c_rtc_base;
static int s3c_rtc_alarmno = NO_IRQ;
static int s3c_rtc_tickno = NO_IRQ;
static bool wake_en;
static enum s3c_cpu_type s3c_rtc_cpu_type;
static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
/* IRQ Handlers */
static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
{
struct rtc_device *rdev = id;
clk_enable(rtc_clk);
rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
if (s3c_rtc_cpu_type == TYPE_S3C64XX)
writeb(S3C2410_INTP_ALM, s3c_rtc_base + S3C2410_INTP);
clk_disable(rtc_clk);
return IRQ_HANDLED;
}
static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
{
struct rtc_device *rdev = id;
clk_enable(rtc_clk);
rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
if (s3c_rtc_cpu_type == TYPE_S3C64XX)
writeb(S3C2410_INTP_TIC, s3c_rtc_base + S3C2410_INTP);
clk_disable(rtc_clk);
return IRQ_HANDLED;
}
/* Update control registers */
static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
{
unsigned int tmp;
pr_debug("%s: aie=%d\n", __func__, enabled);
clk_enable(rtc_clk);
tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
if (enabled)
tmp |= S3C2410_RTCALM_ALMEN;
writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
clk_disable(rtc_clk);
return 0;
}
static int s3c_rtc_setfreq(struct device *dev, int freq)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
unsigned int tmp = 0;
if (!is_power_of_2(freq))
return -EINVAL;
clk_enable(rtc_clk);
spin_lock_irq(&s3c_rtc_pie_lock);
if (s3c_rtc_cpu_type == TYPE_S3C2410) {
tmp = readb(s3c_rtc_base + S3C2410_TICNT);
tmp &= S3C2410_TICNT_ENABLE;
}
tmp |= (rtc_dev->max_user_freq / freq)-1;
writel(tmp, s3c_rtc_base + S3C2410_TICNT);
spin_unlock_irq(&s3c_rtc_pie_lock);
clk_disable(rtc_clk);
return 0;
}
/* 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;
clk_enable(rtc_clk);
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;
}
rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
rtc_tm->tm_year += 100;
pr_debug("read time %04d.%02d.%02d %02d:%02d:%02d\n",
1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
rtc_tm->tm_mon -= 1;
clk_disable(rtc_clk);
return rtc_valid_tm(rtc_tm);
}
static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
{
void __iomem *base = s3c_rtc_base;
int year = tm->tm_year - 100;
clk_enable(rtc_clk);
pr_debug("set time %04d.%02d.%02d %02d:%02d:%02d\n",
1900 + 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);
clk_disable(rtc_clk);
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;
clk_enable(rtc_clk);
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 %d, %04d.%02d.%02d %02d:%02d:%02d\n",
alm_en,
1900 + 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)
alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
else
alm_tm->tm_sec = -1;
if (alm_en & S3C2410_RTCALM_MINEN)
alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
else
alm_tm->tm_min = -1;
if (alm_en & S3C2410_RTCALM_HOUREN)
alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
else
alm_tm->tm_hour = -1;
if (alm_en & S3C2410_RTCALM_DAYEN)
alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
else
alm_tm->tm_mday = -1;
if (alm_en & S3C2410_RTCALM_MONEN) {
alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
alm_tm->tm_mon -= 1;
} else {
alm_tm->tm_mon = -1;
}
if (alm_en & S3C2410_RTCALM_YEAREN)
alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
else
alm_tm->tm_year = -1;
clk_disable(rtc_clk);
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;
clk_enable(rtc_clk);
pr_debug("s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
alrm->enabled,
1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
tm->tm_hour, tm->tm_min, 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);
s3c_rtc_setaie(dev, alrm->enabled);
clk_disable(rtc_clk);
return 0;
}
static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
{
unsigned int ticnt;
clk_enable(rtc_clk);
if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
ticnt = readw(s3c_rtc_base + S3C2410_RTCCON);
ticnt &= S3C64XX_RTCCON_TICEN;
} else {
ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
ticnt &= S3C2410_TICNT_ENABLE;
}
seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt ? "yes" : "no");
clk_disable(rtc_clk);
return 0;
}
static const struct rtc_class_ops s3c_rtcops = {
.read_time = s3c_rtc_gettime,
.set_time = s3c_rtc_settime,
.read_alarm = s3c_rtc_getalarm,
.set_alarm = s3c_rtc_setalarm,
.proc = s3c_rtc_proc,
.alarm_irq_enable = s3c_rtc_setaie,
};
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;
clk_enable(rtc_clk);
if (!en) {
tmp = readw(base + S3C2410_RTCCON);
if (s3c_rtc_cpu_type == TYPE_S3C64XX)
tmp &= ~S3C64XX_RTCCON_TICEN;
tmp &= ~S3C2410_RTCCON_RTCEN;
writew(tmp, base + S3C2410_RTCCON);
if (s3c_rtc_cpu_type == TYPE_S3C2410) {
tmp = readb(base + S3C2410_TICNT);
tmp &= ~S3C2410_TICNT_ENABLE;
writeb(tmp, base + S3C2410_TICNT);
}
} else {
/* re-enable the device, and check it is ok */
if ((readw(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0) {
dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
tmp = readw(base + S3C2410_RTCCON);
writew(tmp | S3C2410_RTCCON_RTCEN,
base + S3C2410_RTCCON);
}
if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)) {
dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
tmp = readw(base + S3C2410_RTCCON);
writew(tmp & ~S3C2410_RTCCON_CNTSEL,
base + S3C2410_RTCCON);
}
if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)) {
dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
tmp = readw(base + S3C2410_RTCCON);
writew(tmp & ~S3C2410_RTCCON_CLKRST,
base + S3C2410_RTCCON);
}
}
clk_disable(rtc_clk);
}
static int __devexit s3c_rtc_remove(struct platform_device *dev)
{
struct rtc_device *rtc = platform_get_drvdata(dev);
free_irq(s3c_rtc_alarmno, rtc);
free_irq(s3c_rtc_tickno, rtc);
platform_set_drvdata(dev, NULL);
rtc_device_unregister(rtc);
s3c_rtc_setaie(&dev->dev, 0);
clk_put(rtc_clk);
rtc_clk = NULL;
iounmap(s3c_rtc_base);
release_resource(s3c_rtc_mem);
kfree(s3c_rtc_mem);
return 0;
}
static int __devinit s3c_rtc_probe(struct platform_device *pdev)
{
struct rtc_device *rtc;
struct rtc_time rtc_tm;
struct resource *res;
int ret;
pr_debug("%s: probe=%p\n", __func__, 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, resource_size(res),
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, resource_size(res));
if (s3c_rtc_base == NULL) {
dev_err(&pdev->dev, "failed ioremap()\n");
ret = -EINVAL;
goto err_nomap;
}
rtc_clk = clk_get(&pdev->dev, "rtc");
if (IS_ERR(rtc_clk)) {
dev_err(&pdev->dev, "failed to find rtc clock source\n");
ret = PTR_ERR(rtc_clk);
rtc_clk = NULL;
goto err_clk;
}
clk_enable(rtc_clk);
/* check to see if everything is setup correctly */
s3c_rtc_enable(pdev, 1);
pr_debug("s3c2410_rtc: RTCCON=%02x\n",
readw(s3c_rtc_base + S3C2410_RTCCON));
device_init_wakeup(&pdev->dev, 1);
/* 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;
}
s3c_rtc_cpu_type = platform_get_device_id(pdev)->driver_data;
/* Check RTC Time */
s3c_rtc_gettime(NULL, &rtc_tm);
if (rtc_valid_tm(&rtc_tm)) {
rtc_tm.tm_year = 100;
rtc_tm.tm_mon = 0;
rtc_tm.tm_mday = 1;
rtc_tm.tm_hour = 0;
rtc_tm.tm_min = 0;
rtc_tm.tm_sec = 0;
s3c_rtc_settime(NULL, &rtc_tm);
dev_warn(&pdev->dev, "warning: invalid RTC value so initializing it\n");
}
if (s3c_rtc_cpu_type == TYPE_S3C64XX)
rtc->max_user_freq = 32768;
else
rtc->max_user_freq = 128;
platform_set_drvdata(pdev, rtc);
s3c_rtc_setfreq(&pdev->dev, 1);
ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
IRQF_DISABLED, "s3c2410-rtc alarm", rtc);
if (ret) {
dev_err(&pdev->dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
goto err_alarm_irq;
}
ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
IRQF_DISABLED, "s3c2410-rtc tick", rtc);
if (ret) {
dev_err(&pdev->dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
free_irq(s3c_rtc_alarmno, rtc);
goto err_tick_irq;
}
clk_disable(rtc_clk);
return 0;
err_tick_irq:
free_irq(s3c_rtc_alarmno, rtc);
err_alarm_irq:
platform_set_drvdata(pdev, NULL);
rtc_device_unregister(rtc);
err_nortc:
s3c_rtc_enable(pdev, 0);
clk_disable(rtc_clk);
clk_put(rtc_clk);
err_clk:
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, ticnt_en_save;
static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
{
clk_enable(rtc_clk);
/* save TICNT for anyone using periodic interrupts */
ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
ticnt_en_save = readw(s3c_rtc_base + S3C2410_RTCCON);
ticnt_en_save &= S3C64XX_RTCCON_TICEN;
}
s3c_rtc_enable(pdev, 0);
if (device_may_wakeup(&pdev->dev) && !wake_en) {
if (enable_irq_wake(s3c_rtc_alarmno) == 0)
wake_en = true;
else
dev_err(&pdev->dev, "enable_irq_wake failed\n");
}
clk_disable(rtc_clk);
return 0;
}
static int s3c_rtc_resume(struct platform_device *pdev)
{
unsigned int tmp;
clk_enable(rtc_clk);
s3c_rtc_enable(pdev, 1);
writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
if (s3c_rtc_cpu_type == TYPE_S3C64XX && ticnt_en_save) {
tmp = readw(s3c_rtc_base + S3C2410_RTCCON);
writew(tmp | ticnt_en_save, s3c_rtc_base + S3C2410_RTCCON);
}
if (device_may_wakeup(&pdev->dev) && wake_en) {
disable_irq_wake(s3c_rtc_alarmno);
wake_en = false;
}
clk_disable(rtc_clk);
return 0;
}
#else
#define s3c_rtc_suspend NULL
#define s3c_rtc_resume NULL
#endif
static struct platform_device_id s3c_rtc_driver_ids[] = {
{
.name = "s3c2410-rtc",
.driver_data = TYPE_S3C2410,
}, {
.name = "s3c64xx-rtc",
.driver_data = TYPE_S3C64XX,
},
{ }
};
MODULE_DEVICE_TABLE(platform, s3c_rtc_driver_ids);
static struct platform_driver s3c_rtc_driver = {
.probe = s3c_rtc_probe,
.remove = __devexit_p(s3c_rtc_remove),
.suspend = s3c_rtc_suspend,
.resume = s3c_rtc_resume,
.id_table = s3c_rtc_driver_ids,
.driver = {
.name = "s3c-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(&s3c_rtc_driver);
}
static void __exit s3c_rtc_exit(void)
{
platform_driver_unregister(&s3c_rtc_driver);
}
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");
MODULE_ALIAS("platform:s3c2410-rtc");
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