/* * TI OMAP1 Real Time Clock interface for Linux * * Copyright (C) 2003 MontaVista Software, Inc. * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com> * * Copyright (C) 2006 David Brownell (new RTC framework) * * 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/kernel.h> #include <linux/init.h> #include <linux/module.h> #include <linux/ioport.h> #include <linux/delay.h> #include <linux/rtc.h> #include <linux/bcd.h> #include <linux/platform_device.h> #include <asm/io.h> #include <asm/mach/time.h> /* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock * with century-range alarm matching, driven by the 32kHz clock. * * The main user-visible ways it differs from PC RTCs are by omitting * "don't care" alarm fields and sub-second periodic IRQs, and having * an autoadjust mechanism to calibrate to the true oscillator rate. * * Board-specific wiring options include using split power mode with * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset), * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from * low power modes). See the BOARD-SPECIFIC CUSTOMIZATION comment. */ #define OMAP_RTC_BASE 0xfffb4800 /* RTC registers */ #define OMAP_RTC_SECONDS_REG 0x00 #define OMAP_RTC_MINUTES_REG 0x04 #define OMAP_RTC_HOURS_REG 0x08 #define OMAP_RTC_DAYS_REG 0x0C #define OMAP_RTC_MONTHS_REG 0x10 #define OMAP_RTC_YEARS_REG 0x14 #define OMAP_RTC_WEEKS_REG 0x18 #define OMAP_RTC_ALARM_SECONDS_REG 0x20 #define OMAP_RTC_ALARM_MINUTES_REG 0x24 #define OMAP_RTC_ALARM_HOURS_REG 0x28 #define OMAP_RTC_ALARM_DAYS_REG 0x2c #define OMAP_RTC_ALARM_MONTHS_REG 0x30 #define OMAP_RTC_ALARM_YEARS_REG 0x34 #define OMAP_RTC_CTRL_REG 0x40 #define OMAP_RTC_STATUS_REG 0x44 #define OMAP_RTC_INTERRUPTS_REG 0x48 #define OMAP_RTC_COMP_LSB_REG 0x4c #define OMAP_RTC_COMP_MSB_REG 0x50 #define OMAP_RTC_OSC_REG 0x54 /* OMAP_RTC_CTRL_REG bit fields: */ #define OMAP_RTC_CTRL_SPLIT (1<<7) #define OMAP_RTC_CTRL_DISABLE (1<<6) #define OMAP_RTC_CTRL_SET_32_COUNTER (1<<5) #define OMAP_RTC_CTRL_TEST (1<<4) #define OMAP_RTC_CTRL_MODE_12_24 (1<<3) #define OMAP_RTC_CTRL_AUTO_COMP (1<<2) #define OMAP_RTC_CTRL_ROUND_30S (1<<1) #define OMAP_RTC_CTRL_STOP (1<<0) /* OMAP_RTC_STATUS_REG bit fields: */ #define OMAP_RTC_STATUS_POWER_UP (1<<7) #define OMAP_RTC_STATUS_ALARM (1<<6) #define OMAP_RTC_STATUS_1D_EVENT (1<<5) #define OMAP_RTC_STATUS_1H_EVENT (1<<4) #define OMAP_RTC_STATUS_1M_EVENT (1<<3) #define OMAP_RTC_STATUS_1S_EVENT (1<<2) #define OMAP_RTC_STATUS_RUN (1<<1) #define OMAP_RTC_STATUS_BUSY (1<<0) /* OMAP_RTC_INTERRUPTS_REG bit fields: */ #define OMAP_RTC_INTERRUPTS_IT_ALARM (1<<3) #define OMAP_RTC_INTERRUPTS_IT_TIMER (1<<2) #define rtc_read(addr) omap_readb(OMAP_RTC_BASE + (addr)) #define rtc_write(val, addr) omap_writeb(val, OMAP_RTC_BASE + (addr)) /* platform_bus isn't hotpluggable, so for static linkage it'd be safe * to get rid of probe() and remove() code ... too bad the driver struct * remembers probe(), that's about 25% of the runtime footprint!! */ #ifndef MODULE #undef __devexit #undef __devexit_p #define __devexit __exit #define __devexit_p __exit_p #endif /* we rely on the rtc framework to handle locking (rtc->ops_lock), * so the only other requirement is that register accesses which * require BUSY to be clear are made with IRQs locally disabled */ static void rtc_wait_not_busy(void) { int count = 0; u8 status; /* BUSY may stay active for 1/32768 second (~30 usec) */ for (count = 0; count < 50; count++) { status = rtc_read(OMAP_RTC_STATUS_REG); if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0) break; udelay(1); } /* now we have ~15 usec to read/write various registers */ } static irqreturn_t rtc_irq(int irq, void *class_dev) { unsigned long events = 0; u8 irq_data; irq_data = rtc_read(OMAP_RTC_STATUS_REG); /* alarm irq? */ if (irq_data & OMAP_RTC_STATUS_ALARM) { rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG); events |= RTC_IRQF | RTC_AF; } /* 1/sec periodic/update irq? */ if (irq_data & OMAP_RTC_STATUS_1S_EVENT) events |= RTC_IRQF | RTC_UF; rtc_update_irq(class_dev, 1, events); return IRQ_HANDLED; } #ifdef CONFIG_RTC_INTF_DEV static int omap_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { u8 reg; switch (cmd) { case RTC_AIE_OFF: case RTC_AIE_ON: case RTC_UIE_OFF: case RTC_UIE_ON: break; default: return -ENOIOCTLCMD; } local_irq_disable(); rtc_wait_not_busy(); reg = rtc_read(OMAP_RTC_INTERRUPTS_REG); switch (cmd) { /* AIE = Alarm Interrupt Enable */ case RTC_AIE_OFF: reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM; break; case RTC_AIE_ON: reg |= OMAP_RTC_INTERRUPTS_IT_ALARM; break; /* UIE = Update Interrupt Enable (1/second) */ case RTC_UIE_OFF: reg &= ~OMAP_RTC_INTERRUPTS_IT_TIMER; break; case RTC_UIE_ON: reg |= OMAP_RTC_INTERRUPTS_IT_TIMER; break; } rtc_wait_not_busy(); rtc_write(reg, OMAP_RTC_INTERRUPTS_REG); local_irq_enable(); return 0; } #else #define omap_rtc_ioctl NULL #endif /* this hardware doesn't support "don't care" alarm fields */ static int tm2bcd(struct rtc_time *tm) { if (rtc_valid_tm(tm) != 0) return -EINVAL; tm->tm_sec = BIN2BCD(tm->tm_sec); tm->tm_min = BIN2BCD(tm->tm_min); tm->tm_hour = BIN2BCD(tm->tm_hour); tm->tm_mday = BIN2BCD(tm->tm_mday); tm->tm_mon = BIN2BCD(tm->tm_mon + 1); /* epoch == 1900 */ if (tm->tm_year < 100 || tm->tm_year > 199) return -EINVAL; tm->tm_year = BIN2BCD(tm->tm_year - 100); return 0; } static void bcd2tm(struct rtc_time *tm) { tm->tm_sec = BCD2BIN(tm->tm_sec); tm->tm_min = BCD2BIN(tm->tm_min); tm->tm_hour = BCD2BIN(tm->tm_hour); tm->tm_mday = BCD2BIN(tm->tm_mday); tm->tm_mon = BCD2BIN(tm->tm_mon) - 1; /* epoch == 1900 */ tm->tm_year = BCD2BIN(tm->tm_year) + 100; } static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm) { /* we don't report wday/yday/isdst ... */ local_irq_disable(); rtc_wait_not_busy(); tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG); tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG); tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG); tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG); tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG); tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG); local_irq_enable(); bcd2tm(tm); return 0; } static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm) { if (tm2bcd(tm) < 0) return -EINVAL; local_irq_disable(); rtc_wait_not_busy(); rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG); rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG); rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG); rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG); rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG); rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG); local_irq_enable(); return 0; } static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) { local_irq_disable(); rtc_wait_not_busy(); alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG); alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG); alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG); alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG); alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG); alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG); local_irq_enable(); bcd2tm(&alm->time); alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG) & OMAP_RTC_INTERRUPTS_IT_ALARM); return 0; } static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) { u8 reg; /* Much userspace code uses RTC_ALM_SET, thus "don't care" for * day/month/year specifies alarms up to 24 hours in the future. * So we need to handle that ... but let's ignore the "don't care" * values for hours/minutes/seconds. */ if (alm->time.tm_mday <= 0 && alm->time.tm_mon < 0 && alm->time.tm_year < 0) { struct rtc_time tm; unsigned long now, then; omap_rtc_read_time(dev, &tm); rtc_tm_to_time(&tm, &now); alm->time.tm_mday = tm.tm_mday; alm->time.tm_mon = tm.tm_mon; alm->time.tm_year = tm.tm_year; rtc_tm_to_time(&alm->time, &then); /* sometimes the alarm wraps into tomorrow */ if (then < now) { rtc_time_to_tm(now + 24 * 60 * 60, &tm); alm->time.tm_mday = tm.tm_mday; alm->time.tm_mon = tm.tm_mon; alm->time.tm_year = tm.tm_year; } } if (tm2bcd(&alm->time) < 0) return -EINVAL; local_irq_disable(); rtc_wait_not_busy(); rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG); rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG); rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG); rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG); rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG); rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG); reg = rtc_read(OMAP_RTC_INTERRUPTS_REG); if (alm->enabled) reg |= OMAP_RTC_INTERRUPTS_IT_ALARM; else reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM; rtc_write(reg, OMAP_RTC_INTERRUPTS_REG); local_irq_enable(); return 0; } static struct rtc_class_ops omap_rtc_ops = { .ioctl = omap_rtc_ioctl, .read_time = omap_rtc_read_time, .set_time = omap_rtc_set_time, .read_alarm = omap_rtc_read_alarm, .set_alarm = omap_rtc_set_alarm, }; static int omap_rtc_alarm; static int omap_rtc_timer; static int __devinit omap_rtc_probe(struct platform_device *pdev) { struct resource *res, *mem; struct rtc_device *rtc; u8 reg, new_ctrl; omap_rtc_timer = platform_get_irq(pdev, 0); if (omap_rtc_timer <= 0) { pr_debug("%s: no update irq?\n", pdev->name); return -ENOENT; } omap_rtc_alarm = platform_get_irq(pdev, 1); if (omap_rtc_alarm <= 0) { pr_debug("%s: no alarm irq?\n", pdev->name); return -ENOENT; } /* NOTE: using static mapping for RTC registers */ res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (res && res->start != OMAP_RTC_BASE) { pr_debug("%s: RTC registers at %08x, expected %08x\n", pdev->name, (unsigned) res->start, OMAP_RTC_BASE); return -ENOENT; } if (res) mem = request_mem_region(res->start, res->end - res->start + 1, pdev->name); else mem = NULL; if (!mem) { pr_debug("%s: RTC registers at %08x are not free\n", pdev->name, OMAP_RTC_BASE); return -EBUSY; } rtc = rtc_device_register(pdev->name, &pdev->dev, &omap_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) { pr_debug("%s: can't register RTC device, err %ld\n", pdev->name, PTR_ERR(rtc)); goto fail; } platform_set_drvdata(pdev, rtc); class_set_devdata(&rtc->class_dev, mem); /* clear pending irqs, and set 1/second periodic, * which we'll use instead of update irqs */ rtc_write(0, OMAP_RTC_INTERRUPTS_REG); /* clear old status */ reg = rtc_read(OMAP_RTC_STATUS_REG); if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) { pr_info("%s: RTC power up reset detected\n", pdev->name); rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG); } if (reg & (u8) OMAP_RTC_STATUS_ALARM) rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG); /* handle periodic and alarm irqs */ if (request_irq(omap_rtc_timer, rtc_irq, IRQF_DISABLED, rtc->class_dev.class_id, &rtc->class_dev)) { pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n", pdev->name, omap_rtc_timer); goto fail0; } if (request_irq(omap_rtc_alarm, rtc_irq, IRQF_DISABLED, rtc->class_dev.class_id, &rtc->class_dev)) { pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n", pdev->name, omap_rtc_alarm); goto fail1; } /* On boards with split power, RTC_ON_NOFF won't reset the RTC */ reg = rtc_read(OMAP_RTC_CTRL_REG); if (reg & (u8) OMAP_RTC_CTRL_STOP) pr_info("%s: already running\n", pdev->name); /* force to 24 hour mode */ new_ctrl = reg & ~(OMAP_RTC_CTRL_SPLIT|OMAP_RTC_CTRL_AUTO_COMP); new_ctrl |= OMAP_RTC_CTRL_STOP; /* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE: * * - Boards wired so that RTC_WAKE_INT does something, and muxed * right (W13_1610_RTC_WAKE_INT is the default after chip reset), * should initialize the device wakeup flag appropriately. * * - Boards wired so RTC_ON_nOFF is used as the reset signal, * rather than nPWRON_RESET, should forcibly enable split * power mode. (Some chip errata report that RTC_CTRL_SPLIT * is write-only, and always reads as zero...) */ device_init_wakeup(&pdev->dev, 0); if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT) pr_info("%s: split power mode\n", pdev->name); if (reg != new_ctrl) rtc_write(new_ctrl, OMAP_RTC_CTRL_REG); return 0; fail1: free_irq(omap_rtc_timer, NULL); fail0: rtc_device_unregister(rtc); fail: release_resource(mem); return -EIO; } static int __devexit omap_rtc_remove(struct platform_device *pdev) { struct rtc_device *rtc = platform_get_drvdata(pdev);; device_init_wakeup(&pdev->dev, 0); /* leave rtc running, but disable irqs */ rtc_write(0, OMAP_RTC_INTERRUPTS_REG); free_irq(omap_rtc_timer, rtc); free_irq(omap_rtc_alarm, rtc); release_resource(class_get_devdata(&rtc->class_dev)); rtc_device_unregister(rtc); return 0; } #ifdef CONFIG_PM static struct timespec rtc_delta; static u8 irqstat; static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state) { struct rtc_time rtc_tm; struct timespec time; time.tv_nsec = 0; omap_rtc_read_time(NULL, &rtc_tm); rtc_tm_to_time(&rtc_tm, &time.tv_sec); save_time_delta(&rtc_delta, &time); irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG); /* FIXME the RTC alarm is not currently acting as a wakeup event * source, and in fact this enable() call is just saving a flag * that's never used... */ if (device_may_wakeup(&pdev->dev)) enable_irq_wake(omap_rtc_alarm); else rtc_write(0, OMAP_RTC_INTERRUPTS_REG); return 0; } static int omap_rtc_resume(struct platform_device *pdev) { struct rtc_time rtc_tm; struct timespec time; time.tv_nsec = 0; omap_rtc_read_time(NULL, &rtc_tm); rtc_tm_to_time(&rtc_tm, &time.tv_sec); restore_time_delta(&rtc_delta, &time); if (device_may_wakeup(&pdev->dev)) disable_irq_wake(omap_rtc_alarm); else rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG); return 0; } #else #define omap_rtc_suspend NULL #define omap_rtc_resume NULL #endif static void omap_rtc_shutdown(struct platform_device *pdev) { rtc_write(0, OMAP_RTC_INTERRUPTS_REG); } MODULE_ALIAS("omap_rtc"); static struct platform_driver omap_rtc_driver = { .probe = omap_rtc_probe, .remove = __devexit_p(omap_rtc_remove), .suspend = omap_rtc_suspend, .resume = omap_rtc_resume, .shutdown = omap_rtc_shutdown, .driver = { .name = "omap_rtc", .owner = THIS_MODULE, }, }; static int __init rtc_init(void) { return platform_driver_register(&omap_rtc_driver); } module_init(rtc_init); static void __exit rtc_exit(void) { platform_driver_unregister(&omap_rtc_driver); } module_exit(rtc_exit); MODULE_AUTHOR("George G. Davis (and others)"); MODULE_LICENSE("GPL");