diff options
Diffstat (limited to 'drivers/rtc/rtc-at91.c')
| -rw-r--r-- | drivers/rtc/rtc-at91.c | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-at91.c b/drivers/rtc/rtc-at91.c new file mode 100644 index 00000000000..b676f443c17 --- /dev/null +++ b/drivers/rtc/rtc-at91.c @@ -0,0 +1,407 @@ +/* + * 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 = 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"); |