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path: root/drivers/rtc/rtc-at91.c
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Diffstat (limited to 'drivers/rtc/rtc-at91.c')
-rw-r--r--drivers/rtc/rtc-at91.c388
1 files changed, 388 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-at91.c b/drivers/rtc/rtc-at91.c
new file mode 100644
index 000000000000..b03aba5f39eb
--- /dev/null
+++ b/drivers/rtc/rtc-at91.c
@@ -0,0 +1,388 @@
+/*
+ * Real Time Clock interface for Linux on Atmel AT91RM9200
+ *
+ * Copyright (C) 2002 Rick Bronson
+ *
+ * Converted to RTC class model by Andrew Victor
+ *
+ * Ported to Linux 2.6 by Steven Scholz
+ * Based on s3c2410-rtc.c Simtec Electronics
+ *
+ * Based on sa1100-rtc.c by Nils Faerber
+ * Based on rtc.c by Paul Gortmaker
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/time.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/interrupt.h>
+#include <linux/ioctl.h>
+#include <linux/completion.h>
+
+#include <asm/uaccess.h>
+#include <asm/rtc.h>
+
+#include <asm/mach/time.h>
+
+
+#define AT91_RTC_FREQ 1
+#define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */
+
+static DECLARE_COMPLETION(at91_rtc_updated);
+static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
+
+
+/*
+ * Decode time/date into rtc_time structure
+ */
+static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg, struct rtc_time *tm)
+{
+ unsigned int time, date;
+
+ /* must read twice in case it changes */
+ do {
+ time = at91_sys_read(timereg);
+ date = at91_sys_read(calreg);
+ } while ((time != at91_sys_read(timereg)) || (date != at91_sys_read(calreg)));
+
+ tm->tm_sec = BCD2BIN((time & AT91_RTC_SEC) >> 0);
+ tm->tm_min = BCD2BIN((time & AT91_RTC_MIN) >> 8);
+ tm->tm_hour = BCD2BIN((time & AT91_RTC_HOUR) >> 16);
+
+ /*
+ * The Calendar Alarm register does not have a field for
+ * the year - so these will return an invalid value. When an
+ * alarm is set, at91_alarm_year wille store the current year.
+ */
+ tm->tm_year = BCD2BIN(date & AT91_RTC_CENT) * 100; /* century */
+ tm->tm_year += BCD2BIN((date & AT91_RTC_YEAR) >> 8); /* year */
+
+ tm->tm_wday = BCD2BIN((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
+ tm->tm_mon = BCD2BIN((date & AT91_RTC_MONTH) >> 16) - 1;
+ tm->tm_mday = BCD2BIN((date & AT91_RTC_DATE) >> 24);
+}
+
+/*
+ * Read current time and date in RTC
+ */
+static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
+{
+ at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
+ tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
+ tm->tm_year = tm->tm_year - 1900;
+
+ pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+ 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+ return 0;
+}
+
+/*
+ * Set current time and date in RTC
+ */
+static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+ unsigned long cr;
+
+ pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+ 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+ /* Stop Time/Calendar from counting */
+ cr = at91_sys_read(AT91_RTC_CR);
+ at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
+
+ at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
+ wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
+ at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
+
+ at91_sys_write(AT91_RTC_TIMR,
+ BIN2BCD(tm->tm_sec) << 0
+ | BIN2BCD(tm->tm_min) << 8
+ | BIN2BCD(tm->tm_hour) << 16);
+
+ at91_sys_write(AT91_RTC_CALR,
+ BIN2BCD((tm->tm_year + 1900) / 100) /* century */
+ | BIN2BCD(tm->tm_year % 100) << 8 /* year */
+ | BIN2BCD(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */
+ | BIN2BCD(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */
+ | BIN2BCD(tm->tm_mday) << 24);
+
+ /* Restart Time/Calendar */
+ cr = at91_sys_read(AT91_RTC_CR);
+ at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
+
+ return 0;
+}
+
+/*
+ * Read alarm time and date in RTC
+ */
+static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct rtc_time *tm = &alrm->time;
+
+ at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
+ tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
+ tm->tm_year = at91_alarm_year - 1900;
+
+ pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+ 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+ return 0;
+}
+
+/*
+ * Set alarm time and date in RTC
+ */
+static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct rtc_time tm;
+
+ at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
+
+ at91_alarm_year = tm.tm_year;
+
+ tm.tm_hour = alrm->time.tm_hour;
+ tm.tm_min = alrm->time.tm_min;
+ tm.tm_sec = alrm->time.tm_sec;
+
+ at91_sys_write(AT91_RTC_TIMALR,
+ BIN2BCD(tm.tm_sec) << 0
+ | BIN2BCD(tm.tm_min) << 8
+ | BIN2BCD(tm.tm_hour) << 16
+ | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
+ at91_sys_write(AT91_RTC_CALALR,
+ BIN2BCD(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
+ | BIN2BCD(tm.tm_mday) << 24
+ | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
+
+ pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+ at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
+
+ return 0;
+}
+
+/*
+ * Handle commands from user-space
+ */
+static int at91_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+ int ret = 0;
+
+ pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __FUNCTION__, cmd, arg);
+
+ switch (cmd) {
+ case RTC_AIE_OFF: /* alarm off */
+ at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
+ break;
+ case RTC_AIE_ON: /* alarm on */
+ at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
+ break;
+ case RTC_UIE_OFF: /* update off */
+ case RTC_PIE_OFF: /* periodic off */
+ at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
+ break;
+ case RTC_UIE_ON: /* update on */
+ case RTC_PIE_ON: /* periodic on */
+ at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
+ break;
+ case RTC_IRQP_READ: /* read periodic alarm frequency */
+ ret = put_user(AT91_RTC_FREQ, (unsigned long *) arg);
+ break;
+ case RTC_IRQP_SET: /* set periodic alarm frequency */
+ if (arg != AT91_RTC_FREQ)
+ ret = -EINVAL;
+ break;
+ default:
+ ret = -ENOIOCTLCMD;
+ break;
+ }
+
+ return ret;
+}
+
+/*
+ * Provide additional RTC information in /proc/driver/rtc
+ */
+static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+ unsigned long imr = at91_sys_read(AT91_RTC_IMR);
+
+ seq_printf(seq, "alarm_IRQ\t: %s\n", (imr & AT91_RTC_ALARM) ? "yes" : "no");
+ seq_printf(seq, "update_IRQ\t: %s\n", (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
+ seq_printf(seq, "periodic_IRQ\t: %s\n", (imr & AT91_RTC_SECEV) ? "yes" : "no");
+ seq_printf(seq, "periodic_freq\t: %ld\n", (unsigned long) AT91_RTC_FREQ);
+
+ return 0;
+}
+
+/*
+ * IRQ handler for the RTC
+ */
+static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ struct platform_device *pdev = (struct platform_device *)dev_id;
+ struct rtc_device *rtc = platform_get_drvdata(pdev);
+ unsigned int rtsr;
+ unsigned long events = 0;
+
+ rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
+ if (rtsr) { /* this interrupt is shared! Is it ours? */
+ if (rtsr & AT91_RTC_ALARM)
+ events |= (RTC_AF | RTC_IRQF);
+ if (rtsr & AT91_RTC_SECEV)
+ events |= (RTC_UF | RTC_IRQF);
+ if (rtsr & AT91_RTC_ACKUPD)
+ complete(&at91_rtc_updated);
+
+ at91_sys_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
+
+ rtc_update_irq(&rtc->class_dev, 1, events);
+
+ pr_debug("%s(): num=%ld, events=0x%02lx\n", __FUNCTION__,
+ events >> 8, events & 0x000000FF);
+
+ return IRQ_HANDLED;
+ }
+ return IRQ_NONE; /* not handled */
+}
+
+static struct rtc_class_ops at91_rtc_ops = {
+ .ioctl = at91_rtc_ioctl,
+ .read_time = at91_rtc_readtime,
+ .set_time = at91_rtc_settime,
+ .read_alarm = at91_rtc_readalarm,
+ .set_alarm = at91_rtc_setalarm,
+ .proc = at91_rtc_proc,
+};
+
+/*
+ * Initialize and install RTC driver
+ */
+static int __init at91_rtc_probe(struct platform_device *pdev)
+{
+ struct rtc_device *rtc;
+ int ret;
+
+ at91_sys_write(AT91_RTC_CR, 0);
+ at91_sys_write(AT91_RTC_MR, 0); /* 24 hour mode */
+
+ /* Disable all interrupts */
+ at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | AT91_RTC_SECEV | AT91_RTC_TIMEV | AT91_RTC_CALEV);
+
+ ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt, SA_SHIRQ, "at91_rtc", pdev);
+ if (ret) {
+ printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n", AT91_ID_SYS);
+ return ret;
+ }
+
+ rtc = rtc_device_register(pdev->name, &pdev->dev, &at91_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc)) {
+ free_irq(AT91_ID_SYS, pdev);
+ return PTR_ERR(rtc);
+ }
+ platform_set_drvdata(pdev, rtc);
+
+ printk(KERN_INFO "AT91 Real Time Clock driver.\n");
+ return 0;
+}
+
+/*
+ * Disable and remove the RTC driver
+ */
+static int __devexit at91_rtc_remove(struct platform_device *pdev)
+{
+ struct rtc_device *rtc = platform_get_drvdata(pdev);
+
+ /* Disable all interrupts */
+ at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | AT91_RTC_SECEV | AT91_RTC_TIMEV | AT91_RTC_CALEV);
+ free_irq(AT91_ID_SYS, pdev);
+
+ rtc_device_unregister(rtc);
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+
+/* AT91RM9200 RTC Power management control */
+
+static struct timespec at91_rtc_delta;
+
+static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct rtc_time tm;
+ struct timespec time;
+
+ time.tv_nsec = 0;
+
+ /* calculate time delta for suspend */
+ at91_rtc_readtime(&pdev->dev, &tm);
+ rtc_tm_to_time(&tm, &time.tv_sec);
+ save_time_delta(&at91_rtc_delta, &time);
+
+ pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+ 1900 + tm.tm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
+
+ return 0;
+}
+
+static int at91_rtc_resume(struct platform_device *pdev)
+{
+ struct rtc_time tm;
+ struct timespec time;
+
+ time.tv_nsec = 0;
+
+ at91_rtc_readtime(&pdev->dev, &tm);
+ rtc_tm_to_time(&tm, &time.tv_sec);
+ restore_time_delta(&at91_rtc_delta, &time);
+
+ pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+ 1900 + tm.tm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
+
+ return 0;
+}
+#else
+#define at91_rtc_suspend NULL
+#define at91_rtc_resume NULL
+#endif
+
+static struct platform_driver at91_rtc_driver = {
+ .probe = at91_rtc_probe,
+ .remove = at91_rtc_remove,
+ .suspend = at91_rtc_suspend,
+ .resume = at91_rtc_resume,
+ .driver = {
+ .name = "at91_rtc",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init at91_rtc_init(void)
+{
+ return platform_driver_register(&at91_rtc_driver);
+}
+
+static void __exit at91_rtc_exit(void)
+{
+ platform_driver_unregister(&at91_rtc_driver);
+}
+
+
+module_init(at91_rtc_init);
+module_exit(at91_rtc_exit);
+
+MODULE_AUTHOR("Rick Bronson");
+MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
+MODULE_LICENSE("GPL");