[PATCH] AT91RM9200 RTC driver (788b1fc6) · Commits · 戴 / test

drivers/rtc/Kconfig

+6 −0

Original line number	Diff line number	Diff line
		@@ -202,6 +202,12 @@ config RTC_DRV_PL031
		To compile this driver as a module, choose M here: the
		module will be called rtc-pl031.

		config RTC_DRV_AT91
		tristate "AT91RM9200"
		depends on RTC_CLASS && ARCH_AT91RM9200
		help
		Driver for the Atmel AT91RM9200's internal RTC (Realtime Clock).

		config RTC_DRV_TEST
		tristate "Test driver/device"
		depends on RTC_CLASS

drivers/rtc/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -25,3 +25,4 @@ obj-$(CONFIG_RTC_DRV_VR41XX) += rtc-vr41xx.o
		obj-$(CONFIG_RTC_DRV_PL031) += rtc-pl031.o
		obj-$(CONFIG_RTC_DRV_MAX6902) += rtc-max6902.o
		obj-$(CONFIG_RTC_DRV_V3020) += rtc-v3020.o
		obj-$(CONFIG_RTC_DRV_AT91) += rtc-at91.o

drivers/rtc/rtc-at91.c

0 → 100644

+388 −0

Original line number	Diff line number	Diff line
		/*
		* 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");

Admin message