rtc-at91rm9200.rar_For Real

/* * Real Time Clock interface for Linux on Atmel AT91RM9200 * * * 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 <mach/at91_rtc.h> #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 will 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", __func__, 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", __func__, 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; alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM) ? 1 : 0; pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 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_IDR, AT91_RTC_ALARM); 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); if (alrm->enabled) { at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM); at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM); } pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec); return 0; } static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { pr_debug("%s(): cmd=%08x\n", __func__, enabled); if (enabled) { at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM); at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM); } else at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM); return 0; } /* * 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, "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"); 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, 1, events); pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__, events >> 8, events & 0x000000FF); return IRQ_HANDLED; } return IRQ_NONE; /* not handled */ } static const struct rtc_class_ops at91_rtc_ops = { .read_time = at91_rtc_readtime, .set_time = at91_rtc_settime, .read_alarm = at91_rtc_readalarm, .set_alarm = at91_rtc_setalarm, .proc = at91_rtc_proc, .alarm_irq_enable = at91_rtc_alarm_irq_enable, }; /* * 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_SHARED, "at91_rtc", pdev); if (ret) { printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n", AT91_ID_SYS); return ret; } /* cpu init code should really have flagged this device as * being wake-capable; if it didn't, do that here. */ if (!device_can_wakeup(&pdev->dev)) device_init_wakeup(&pdev->dev, 1); 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