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path: root/drivers/char/s3c2410-rtc.c
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Diffstat (limited to 'drivers/char/s3c2410-rtc.c')
-rw-r--r--drivers/char/s3c2410-rtc.c588
1 files changed, 588 insertions, 0 deletions
diff --git a/drivers/char/s3c2410-rtc.c b/drivers/char/s3c2410-rtc.c
new file mode 100644
index 000000000000..ec666395a26c
--- /dev/null
+++ b/drivers/char/s3c2410-rtc.c
@@ -0,0 +1,588 @@
+/* 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/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 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_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 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");