[PATCH] AT91RM9200 RTC

The new Atmel AT91SAM9261 and AT91SAM9260 processors do not have the
internal RTC peripheral.  This RTC driver is therefore
AT91RM9200-specific.

This patch renames rtc-at91.c to rtc-at91rm9200.c, and changes the name
of the configuration option.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 429 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
new file mode 100644
index 000000000000..5c8addcaf1fb
--- /dev/null
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -0,0 +1,429 @@
+/*
+ *	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 platform_device *pdev = 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 const 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,
+				IRQF_DISABLED | IRQF_SHARED,
+				"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);
+	device_init_wakeup(&pdev->dev, 1);
+
+	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);
+	device_init_wakeup(&pdev->dev, 0);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+
+/* AT91RM9200 RTC Power management control */
+
+static struct timespec at91_rtc_delta;
+static u32 at91_rtc_imr;
+
+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);
+
+	/* this IRQ is shared with DBGU and other hardware which isn't
+	 * necessarily doing PM like we are...
+	 */
+	at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
+			& (AT91_RTC_ALARM|AT91_RTC_SECEV);
+	if (at91_rtc_imr) {
+		if (device_may_wakeup(&pdev->dev))
+			enable_irq_wake(AT91_ID_SYS);
+		else
+			at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
+	}
+
+	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);
+
+	if (at91_rtc_imr) {
+		if (device_may_wakeup(&pdev->dev))
+			disable_irq_wake(AT91_ID_SYS);
+		else
+			at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
+	}
+
+	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");