/* * RTC class driver for "CMOS RTC": PCs, ACPI, etc * * Copyright (C) 1996 Paul Gortmaker (drivers/char/rtc.c) * Copyright (C) 2006 David Brownell (convert to new 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. */ /* * The original "cmos clock" chip was an MC146818 chip, now obsolete. * That defined the register interface now provided by all PCs, some * non-PC systems, and incorporated into ACPI. Modern PC chipsets * integrate an MC146818 clone in their southbridge, and boards use * that instead of discrete clones like the DS12887 or M48T86. There * are also clones that connect using the LPC bus. * * That register API is also used directly by various other drivers * (notably for integrated NVRAM), infrastructure (x86 has code to * bypass the RTC framework, directly reading the RTC during boot * and updating minutes/seconds for systems using NTP synch) and * utilities (like userspace 'hwclock', if no /dev node exists). * * So **ALL** calls to CMOS_READ and CMOS_WRITE must be done with * interrupts disabled, holding the global rtc_lock, to exclude those * other drivers and utilities on correctly configured systems. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/spinlock.h> #include <linux/platform_device.h> #include <linux/mod_devicetable.h> #include <linux/log2.h> /* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */ #include <asm-generic/rtc.h> struct cmos_rtc { struct rtc_device *rtc; struct device *dev; int irq; struct resource *iomem; void (*wake_on)(struct device *); void (*wake_off)(struct device *); u8 enabled_wake; u8 suspend_ctrl; /* newer hardware extends the original register set */ u8 day_alrm; u8 mon_alrm; u8 century; }; /* both platform and pnp busses use negative numbers for invalid irqs */ #define is_valid_irq(n) ((n) > 0) static const char driver_name[] = "rtc_cmos"; /* The RTC_INTR register may have e.g. RTC_PF set even if RTC_PIE is clear; * always mask it against the irq enable bits in RTC_CONTROL. Bit values * are the same: PF==PIE, AF=AIE, UF=UIE; so RTC_IRQMASK works with both. */ #define RTC_IRQMASK (RTC_PF | RTC_AF | RTC_UF) static inline int is_intr(u8 rtc_intr) { if (!(rtc_intr & RTC_IRQF)) return 0; return rtc_intr & RTC_IRQMASK; } /*----------------------------------------------------------------*/ /* Much modern x86 hardware has HPETs (10+ MHz timers) which, because * many BIOS programmers don't set up "sane mode" IRQ routing, are mostly * used in a broken "legacy replacement" mode. The breakage includes * HPET #1 hijacking the IRQ for this RTC, and being unavailable for * other (better) use. * * When that broken mode is in use, platform glue provides a partial * emulation of hardware RTC IRQ facilities using HPET #1. We don't * want to use HPET for anything except those IRQs though... */ #ifdef CONFIG_HPET_EMULATE_RTC #include <asm/hpet.h> #else static inline int is_hpet_enabled(void) { return 0; } static inline int hpet_mask_rtc_irq_bit(unsigned long mask) { return 0; } static inline int hpet_set_rtc_irq_bit(unsigned long mask) { return 0; } static inline int hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec) { return 0; } static inline int hpet_set_periodic_freq(unsigned long freq) { return 0; } static inline int hpet_rtc_dropped_irq(void) { return 0; } static inline int hpet_rtc_timer_init(void) { return 0; } extern irq_handler_t hpet_rtc_interrupt; static inline int hpet_register_irq_handler(irq_handler_t handler) { return 0; } static inline int hpet_unregister_irq_handler(irq_handler_t handler) { return 0; } #endif /*----------------------------------------------------------------*/ #ifdef RTC_PORT /* Most newer x86 systems have two register banks, the first used * for RTC and NVRAM and the second only for NVRAM. Caller must * own rtc_lock ... and we won't worry about access during NMI. */ #define can_bank2 true static inline unsigned char cmos_read_bank2(unsigned char addr) { outb(addr, RTC_PORT(2)); return inb(RTC_PORT(3)); } static inline void cmos_write_bank2(unsigned char val, unsigned char addr) { outb(addr, RTC_PORT(2)); outb(val, RTC_PORT(2)); } #else #define can_bank2 false static inline unsigned char cmos_read_bank2(unsigned char addr) { return 0; } static inline void cmos_write_bank2(unsigned char val, unsigned char addr) { } #endif /*----------------------------------------------------------------*/ static int cmos_read_time(struct device *dev, struct rtc_time *t) { /* REVISIT: if the clock has a "century" register, use * that instead of the heuristic in get_rtc_time(). * That'll make Y3K compatility (year > 2070) easy! */ get_rtc_time(t); return 0; } static int cmos_set_time(struct device *dev, struct rtc_time *t) { /* REVISIT: set the "century" register if available * * NOTE: this ignores the issue whereby updating the seconds * takes effect exactly 500ms after we write the register. * (Also queueing and other delays before we get this far.) */ return set_rtc_time(t); } static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t) { struct cmos_rtc *cmos = dev_get_drvdata(dev); unsigned char rtc_control; if (!is_valid_irq(cmos->irq)) return -EIO; /* Basic alarms only support hour, minute, and seconds fields. * Some also support day and month, for alarms up to a year in * the future. */ t->time.tm_mday = -1; t->time.tm_mon = -1; spin_lock_irq(&rtc_lock); t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM); t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM); t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM); if (cmos->day_alrm) { /* ignore upper bits on readback per ACPI spec */ t->time.tm_mday = CMOS_READ(cmos->day_alrm) & 0x3f; if (!t->time.tm_mday) t->time.tm_mday = -1; if (cmos->mon_alrm) { t->time.tm_mon = CMOS_READ(cmos->mon_alrm); if (!t->time.tm_mon) t->time.tm_mon = -1; } } rtc_control = CMOS_READ(RTC_CONTROL); spin_unlock_irq(&rtc_lock); if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { if (((unsigned)t->time.tm_sec) < 0x60) t->time.tm_sec = bcd2bin(t->time.tm_sec); else t->time.tm_sec = -1; if (((unsigned)t->time.tm_min) < 0x60) t->time.tm_min = bcd2bin(t->time.tm_min); else t->time.tm_min = -1; if (((unsigned)t->time.tm_hour) < 0x24) t->time.tm_hour = bcd2bin(t->time.tm_hour); else t->time.tm_hour = -1; if (cmos->day_alrm) { if (((unsigned)t->time.tm_mday) <= 0x31) t->time.tm_mday = bcd2bin(t->time.tm_mday); else t->time.tm_mday = -1; if (cmos->mon_alrm) { if (((unsigned)t->time.tm_mon) <= 0x12) t->time.tm_mon = bcd2bin(t->time.tm_mon)-1; else t->time.tm_mon = -1; } } } t->time.tm_year = -1; t->enabled = !!(rtc_control & RTC_AIE); t->pending = 0; return 0; } static void cmos_checkintr(struct cmos_rtc *cmos, unsigned char rtc_control) { unsigned char rtc_intr; /* NOTE after changing RTC_xIE bits we always read INTR_FLAGS; * allegedly some older rtcs need that to handle irqs properly */ rtc_intr = CMOS_READ(RTC_INTR_FLAGS); if (is_hpet_enabled()) return; rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF; if (is_intr(rtc_intr)) rtc_update_irq(cmos->rtc, 1, rtc_intr); } static void cmos_irq_enable(struct cmos_rtc *cmos, unsigned char mask) { unsigned char rtc_control; /* flush any pending IRQ status, notably for update irqs, * before we enable new IRQs */ rtc_control = CMOS_READ(RTC_CONTROL); cmos_checkintr(cmos, rtc_control); rtc_control |= mask; CMOS_WRITE(rtc_control, RTC_CONTROL); hpet_set_rtc_irq_bit(mask); cmos_checkintr(cmos, rtc_control); } static void cmos_irq_disable(struct cmos_rtc *cmos, unsigned char mask) { unsigned char rtc_control; rtc_control = CMOS_READ(RTC_CONTROL); rtc_control &= ~mask; CMOS_WRITE(rtc_control, RTC_CONTROL); hpet_mask_rtc_irq_bit(mask); cmos_checkintr(cmos, rtc_control); } static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t) { struct cmos_rtc *cmos = dev_get_drvdata(dev); unsigned char mon, mday, hrs, min, sec, rtc_control; if (!is_valid_irq(cmos->irq)) return -EIO; mon = t->time.tm_mon + 1; mday = t->time.tm_mday; hrs = t->time.tm_hour; min = t->time.tm_min; sec = t->time.tm_sec; rtc_control = CMOS_READ(RTC_CONTROL); if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { /* Writing 0xff means "don't care" or "match all". */ mon = (mon <= 12) ? bin2bcd(mon) : 0xff; mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff; hrs = (hrs < 24) ? bin2bcd(hrs) : 0xff; min = (min < 60) ? bin2bcd(min) : 0xff; sec = (sec < 60) ? bin2bcd(sec) : 0xff; } spin_lock_irq(&rtc_lock); /* next rtc irq must not be from previous alarm setting */ cmos_irq_disable(cmos, RTC_AIE); /* update alarm */ CMOS_WRITE(hrs, RTC_HOURS_ALARM); CMOS_WRITE(min, RTC_MINUTES_ALARM); CMOS_WRITE(sec, RTC_SECONDS_ALARM); /* the system may support an "enhanced" alarm */ if (cmos->day_alrm) { CMOS_WRITE(mday, cmos->day_alrm); if (cmos->mon_alrm) CMOS_WRITE(mon, cmos->mon_alrm); } /* FIXME the HPET alarm glue currently ignores day_alrm * and mon_alrm ... */ hpet_set_alarm_time(t->time.tm_hour, t->time.tm_min, t->time.tm_sec); if (t->enabled) cmos_irq_enable(cmos, RTC_AIE); spin_unlock_irq(&rtc_lock); return 0; } static int cmos_irq_set_freq(struct device *dev, int freq) { struct cmos_rtc *cmos = dev_get_drvdata(dev); int f; unsigned long flags; if (!is_valid_irq(cmos->irq)) return -ENXIO; if (!is_power_of_2(freq)) return -EINVAL; /* 0 = no irqs; 1 = 2^15 Hz ... 15 = 2^0 Hz */ f = ffs(freq); if (f-- > 16) return -EINVAL; f = 16 - f; spin_lock_irqsave(&rtc_lock, flags); hpet_set_periodic_freq(freq); CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT); spin_unlock_irqrestore(&rtc_lock, flags); return 0; } static int cmos_irq_set_state(struct device *dev, int enabled) { struct cmos_rtc *cmos = dev_get_drvdata(dev); unsigned long flags; if (!is_valid_irq(cmos->irq)) return -ENXIO; spin_lock_irqsave(&rtc_lock, flags); if (enabled) cmos_irq_enable(cmos, RTC_PIE); else cmos_irq_disable(cmos, RTC_PIE); spin_unlock_irqrestore(&rtc_lock, flags); return 0; } static int cmos_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct cmos_rtc *cmos = dev_get_drvdata(dev); unsigned long flags; if (!is_valid_irq(cmos->irq)) return -EINVAL; spin_lock_irqsave(&rtc_lock, flags); if (enabled) cmos_irq_enable(cmos, RTC_AIE); else cmos_irq_disable(cmos, RTC_AIE); spin_unlock_irqrestore(&rtc_lock, flags); return 0; } static int cmos_update_irq_enable(struct device *dev, unsigned int enabled) { struct cmos_rtc *cmos = dev_get_drvdata(dev); unsigned long flags; if (!is_valid_irq(cmos->irq)) return -EINVAL; spin_lock_irqsave(&rtc_lock, flags); if (enabled) cmos_irq_enable(cmos, RTC_UIE); else cmos_irq_disable(cmos, RTC_UIE); spin_unlock_irqrestore(&rtc_lock, flags); return 0; } #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE) static int cmos_procfs(struct device *dev, struct seq_file *seq) { struct cmos_rtc *cmos = dev_get_drvdata(dev); unsigned char rtc_control, valid; spin_lock_irq(&rtc_lock); rtc_control = CMOS_READ(RTC_CONTROL); valid = CMOS_READ(RTC_VALID); spin_unlock_irq(&rtc_lock); /* NOTE: at least ICH6 reports battery status using a different * (non-RTC) bit; and SQWE is ignored on many current systems. */ return seq_printf(seq, "periodic_IRQ\t: %s\n" "update_IRQ\t: %s\n" "HPET_emulated\t: %s\n" // "square_wave\t: %s\n" "BCD\t\t: %s\n" "DST_enable\t: %s\n" "periodic_freq\t: %d\n" "batt_status\t: %s\n", (rtc_control & RTC_PIE) ? "yes" : "no", (rtc_control & RTC_UIE) ? "yes" : "no", is_hpet_enabled() ? "yes" : "no", // (rtc_control & RTC_SQWE) ? "yes" : "no", (rtc_control & RTC_DM_BINARY) ? "no" : "yes", (rtc_control & RTC_DST_EN) ? "yes" : "no", cmos->rtc->irq_freq, (valid & RTC_VRT) ? "okay" : "dead"); } #else #define cmos_procfs NULL #endif static const struct rtc_class_ops cmos_rtc_ops = { .read_time = cmos_read_time, .set_time = cmos_set_time, .read_alarm = cmos_read_alarm, .set_alarm = cmos_set_alarm, .proc = cmos_procfs, .irq_set_freq = cmos_irq_set_freq, .irq_set_state = cmos_irq_set_state, .alarm_irq_enable = cmos_alarm_irq_enable, .update_irq_enable = cmos_update_irq_enable, }; /*----------------------------------------------------------------*/ /* * All these chips have at least 64 bytes of address space, shared by * RTC registers and NVRAM. Most of those bytes of NVRAM are used * by boot firmware. Modern chips have 128 or 256 bytes. */ #define NVRAM_OFFSET (RTC_REG_D + 1) static ssize_t cmos_nvram_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { int retval; if (unlikely(off >= attr->size)) return 0; if (unlikely(off < 0)) return -EINVAL; if ((off + count) > attr->size) count = attr->size - off; off += NVRAM_OFFSET; spin_lock_irq(&rtc_lock); for (retval = 0; count; count--, off++, retval++) { if (off < 128) *buf++ = CMOS_READ(off); else if (can_bank2) *buf++ = cmos_read_bank2(off); else break; } spin_unlock_irq(&rtc_lock); return retval; } static ssize_t cmos_nvram_write(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { struct cmos_rtc *cmos; int retval; cmos = dev_get_drvdata(container_of(kobj, struct device, kobj)); if (unlikely(off >= attr->size)) return -EFBIG; if (unlikely(off < 0)) return -EINVAL; if ((off + count) > attr->size) count = attr->size - off; /* NOTE: on at least PCs and Ataris, the boot firmware uses a * checksum on part of the NVRAM data. That's currently ignored * here. If userspace is smart enough to know what fields of * NVRAM to update, updating checksums is also part of its job. */ off += NVRAM_OFFSET; spin_lock_irq(&rtc_lock); for (retval = 0; count; count--, off++, retval++) { /* don't trash RTC registers */ if (off == cmos->day_alrm || off == cmos->mon_alrm || off == cmos->century) buf++; else if (off < 128) CMOS_WRITE(*buf++, off); else if (can_bank2) cmos_write_bank2(*buf++, off); else break; } spin_unlock_irq(&rtc_lock); return retval; } static struct bin_attribute nvram = { .attr = { .name = "nvram", .mode = S_IRUGO | S_IWUSR, }, .read = cmos_nvram_read, .write = cmos_nvram_write, /* size gets set up later */ }; /*----------------------------------------------------------------*/ static struct cmos_rtc cmos_rtc; static irqreturn_t cmos_interrupt(int irq, void *p) { u8 irqstat; u8 rtc_control; spin_lock(&rtc_lock); /* When the HPET interrupt handler calls us, the interrupt * status is passed as arg1 instead of the irq number. But * always clear irq status, even when HPET is in the way. * * Note that HPET and RTC are almost certainly out of phase, * giving different IRQ status ... */ irqstat = CMOS_READ(RTC_INTR_FLAGS); rtc_control = CMOS_READ(RTC_CONTROL); if (is_hpet_enabled()) irqstat = (unsigned long)irq & 0xF0; irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF; /* All Linux RTC alarms should be treated as if they were oneshot. * Similar code may be needed in system wakeup paths, in case the * alarm woke the system. */ if (irqstat & RTC_AIE) { rtc_control &= ~RTC_AIE; CMOS_WRITE(rtc_control, RTC_CONTROL); hpet_mask_rtc_irq_bit(RTC_AIE); CMOS_READ(RTC_INTR_FLAGS); } spin_unlock(&rtc_lock); if (is_intr(irqstat)) { rtc_update_irq(p, 1, irqstat); return IRQ_HANDLED; } else return IRQ_NONE; } #ifdef CONFIG_PNP #define INITSECTION #else #define INITSECTION __init #endif static int INITSECTION cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) { struct cmos_rtc_board_info *info = dev->platform_data; int retval = 0; unsigned char rtc_control; unsigned address_space; /* there can be only one ... */ if (cmos_rtc.dev) return -EBUSY; if (!ports) return -ENODEV; /* Claim I/O ports ASAP, minimizing conflict with legacy driver. * * REVISIT non-x86 systems may instead use memory space resources * (needing ioremap etc), not i/o space resources like this ... */ ports = request_region(ports->start, ports->end + 1 - ports->start, driver_name); if (!ports) { dev_dbg(dev, "i/o registers already in use\n"); return -EBUSY; } cmos_rtc.irq = rtc_irq; cmos_rtc.iomem = ports; /* Heuristic to deduce NVRAM size ... do what the legacy NVRAM * driver did, but don't reject unknown configs. Old hardware * won't address 128 bytes. Newer chips have multiple banks, * though they may not be listed in one I/O resource. */ #if defined(CONFIG_ATARI) address_space = 64; #elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) \ || defined(__sparc__) || defined(__mips__) address_space = 128; #else #warning Assuming 128 bytes of RTC+NVRAM address space, not 64 bytes. address_space = 128; #endif if (can_bank2 && ports->end > (ports->start + 1)) address_space = 256; /* For ACPI systems extension info comes from the FADT. On others, * board specific setup provides it as appropriate. Systems where * the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and * some almost-clones) can provide hooks to make that behave. * * Note that ACPI doesn't preclude putting these registers into * "extended" areas of the chip, including some that we won't yet * expect CMOS_READ and friends to handle. */ if (info) { if (info->rtc_day_alarm && info->rtc_day_alarm < 128) cmos_rtc.day_alrm = info->rtc_day_alarm; if (info->rtc_mon_alarm && info->rtc_mon_alarm < 128) cmos_rtc.mon_alrm = info->rtc_mon_alarm; if (info->rtc_century && info->rtc_century < 128) cmos_rtc.century = info->rtc_century; if (info->wake_on && info->wake_off) { cmos_rtc.wake_on = info->wake_on; cmos_rtc.wake_off = info->wake_off; } } cmos_rtc.dev = dev; dev_set_drvdata(dev, &cmos_rtc); cmos_rtc.rtc = rtc_device_register(driver_name, dev, &cmos_rtc_ops, THIS_MODULE); if (IS_ERR(cmos_rtc.rtc)) { retval = PTR_ERR(cmos_rtc.rtc); goto cleanup0; } rename_region(ports, dev_name(&cmos_rtc.rtc->dev)); spin_lock_irq(&rtc_lock); /* force periodic irq to CMOS reset default of 1024Hz; * * REVISIT it's been reported that at least one x86_64 ALI mobo * doesn't use 32KHz here ... for portability we might need to * do something about other clock frequencies. */ cmos_rtc.rtc->irq_freq = 1024; hpet_set_periodic_freq(cmos_rtc.rtc->irq_freq); CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT); /* disable irqs */ cmos_irq_disable(&cmos_rtc, RTC_PIE | RTC_AIE | RTC_UIE); rtc_control = CMOS_READ(RTC_CONTROL); spin_unlock_irq(&rtc_lock); /* FIXME: * <asm-generic/rtc.h> doesn't know 12-hour mode either. */ if (is_valid_irq(rtc_irq) && !(rtc_control & RTC_24H)) { dev_warn(dev, "only 24-hr supported\n"); retval = -ENXIO; goto cleanup1; } if (is_valid_irq(rtc_irq)) { irq_handler_t rtc_cmos_int_handler; if (is_hpet_enabled()) { int err; rtc_cmos_int_handler = hpet_rtc_interrupt; err = hpet_register_irq_handler(cmos_interrupt); if (err != 0) { printk(KERN_WARNING "hpet_register_irq_handler " " failed in rtc_init()."); goto cleanup1; } } else rtc_cmos_int_handler = cmos_interrupt; retval = request_irq(rtc_irq, rtc_cmos_int_handler, IRQF_DISABLED, dev_name(&cmos_rtc.rtc->dev), cmos_rtc.rtc); if (retval < 0) { dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq); goto cleanup1; } } hpet_rtc_timer_init(); /* export at least the first block of NVRAM */ nvram.size = address_space - NVRAM_OFFSET; retval = sysfs_create_bin_file(&dev->kobj, &nvram); if (retval < 0) { dev_dbg(dev, "can't create nvram file? %d\n", retval); goto cleanup2; } pr_info("%s: %s%s, %zd bytes nvram%s\n", dev_name(&cmos_rtc.rtc->dev), !is_valid_irq(rtc_irq) ? "no alarms" : cmos_rtc.mon_alrm ? "alarms up to one year" : cmos_rtc.day_alrm ? "alarms up to one month" : "alarms up to one day", cmos_rtc.century ? ", y3k" : "", nvram.size, is_hpet_enabled() ? ", hpet irqs" : ""); return 0; cleanup2: if (is_valid_irq(rtc_irq)) free_irq(rtc_irq, cmos_rtc.rtc); cleanup1: cmos_rtc.dev = NULL; rtc_device_unregister(cmos_rtc.rtc); cleanup0: release_region(ports->start, ports->end + 1 - ports->start); return retval; } static void cmos_do_shutdown(void) { spin_lock_irq(&rtc_lock); cmos_irq_disable(&cmos_rtc, RTC_IRQMASK); spin_unlock_irq(&rtc_lock); } static void __exit cmos_do_remove(struct device *dev) { struct cmos_rtc *cmos = dev_get_drvdata(dev); struct resource *ports; cmos_do_shutdown(); sysfs_remove_bin_file(&dev->kobj, &nvram); if (is_valid_irq(cmos->irq)) { free_irq(cmos->irq, cmos->rtc); hpet_unregister_irq_handler(cmos_interrupt); } rtc_device_unregister(cmos->rtc); cmos->rtc = NULL; ports = cmos->iomem; release_region(ports->start, ports->end + 1 - ports->start); cmos->iomem = NULL; cmos->dev = NULL; dev_set_drvdata(dev, NULL); } #ifdef CONFIG_PM static int cmos_suspend(struct device *dev, pm_message_t mesg) { struct cmos_rtc *cmos = dev_get_drvdata(dev); unsigned char tmp; /* only the alarm might be a wakeup event source */ spin_lock_irq(&rtc_lock); cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL); if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) { unsigned char mask; if (device_may_wakeup(dev)) mask = RTC_IRQMASK & ~RTC_AIE; else mask = RTC_IRQMASK; tmp &= ~mask; CMOS_WRITE(tmp, RTC_CONTROL); /* shut down hpet emulation - we don't need it for alarm */ hpet_mask_rtc_irq_bit(RTC_PIE|RTC_AIE|RTC_UIE); cmos_checkintr(cmos, tmp); } spin_unlock_irq(&rtc_lock); if (tmp & RTC_AIE) { cmos->enabled_wake = 1; if (cmos->wake_on) cmos->wake_on(dev); else enable_irq_wake(cmos->irq); } pr_debug("%s: suspend%s, ctrl %02x\n", dev_name(&cmos_rtc.rtc->dev), (tmp & RTC_AIE) ? ", alarm may wake" : "", tmp); return 0; } /* We want RTC alarms to wake us from e.g. ACPI G2/S5 "soft off", even * after a detour through G3 "mechanical off", although the ACPI spec * says wakeup should only work from G1/S4 "hibernate". To most users, * distinctions between S4 and S5 are pointless. So when the hardware * allows, don't draw that distinction. */ static inline int cmos_poweroff(struct device *dev) { return cmos_suspend(dev, PMSG_HIBERNATE); } static int cmos_resume(struct device *dev) { struct cmos_rtc *cmos = dev_get_drvdata(dev); unsigned char tmp = cmos->suspend_ctrl; /* re-enable any irqs previously active */ if (tmp & RTC_IRQMASK) { unsigned char mask; if (cmos->enabled_wake) { if (cmos->wake_off) cmos->wake_off(dev); else disable_irq_wake(cmos->irq); cmos->enabled_wake = 0; } spin_lock_irq(&rtc_lock); do { CMOS_WRITE(tmp, RTC_CONTROL); hpet_set_rtc_irq_bit(tmp & RTC_IRQMASK); mask = CMOS_READ(RTC_INTR_FLAGS); mask &= (tmp & RTC_IRQMASK) | RTC_IRQF; if (!is_hpet_enabled() || !is_intr(mask)) break; /* force one-shot behavior if HPET blocked * the wake alarm's irq */ rtc_update_irq(cmos->rtc, 1, mask); tmp &= ~RTC_AIE; hpet_mask_rtc_irq_bit(RTC_AIE); } while (mask & RTC_AIE); spin_unlock_irq(&rtc_lock); } pr_debug("%s: resume, ctrl %02x\n", dev_name(&cmos_rtc.rtc->dev), tmp); return 0; } #else #define cmos_suspend NULL #define cmos_resume NULL static inline int cmos_poweroff(struct device *dev) { return -ENOSYS; } #endif /*----------------------------------------------------------------*/ /* On non-x86 systems, a "CMOS" RTC lives most naturally on platform_bus. * ACPI systems always list these as PNPACPI devices, and pre-ACPI PCs * probably list them in similar PNPBIOS tables; so PNP is more common. * * We don't use legacy "poke at the hardware" probing. Ancient PCs that * predate even PNPBIOS should set up platform_bus devices. */ #ifdef CONFIG_ACPI #include <linux/acpi.h> #ifdef CONFIG_PM static u32 rtc_handler(void *context) { acpi_clear_event(ACPI_EVENT_RTC); acpi_disable_event(ACPI_EVENT_RTC, 0); return ACPI_INTERRUPT_HANDLED; } static inline void rtc_wake_setup(void) { acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL); /* * After the RTC handler is installed, the Fixed_RTC event should * be disabled. Only when the RTC alarm is set will it be enabled. */ acpi_clear_event(ACPI_EVENT_RTC); acpi_disable_event(ACPI_EVENT_RTC, 0); } static void rtc_wake_on(struct device *dev) { acpi_clear_event(ACPI_EVENT_RTC); acpi_enable_event(ACPI_EVENT_RTC, 0); } static void rtc_wake_off(struct device *dev) { acpi_disable_event(ACPI_EVENT_RTC, 0); } #else #define rtc_wake_setup() do{}while(0) #define rtc_wake_on NULL #define rtc_wake_off NULL #endif /* Every ACPI platform has a mc146818 compatible "cmos rtc". Here we find * its device node and pass extra config data. This helps its driver use * capabilities that the now-obsolete mc146818 didn't have, and informs it * that this board's RTC is wakeup-capable (per ACPI spec). */ static struct cmos_rtc_board_info acpi_rtc_info; static void __devinit cmos_wake_setup(struct device *dev) { if (acpi_disabled) return; rtc_wake_setup(); acpi_rtc_info.wake_on = rtc_wake_on; acpi_rtc_info.wake_off = rtc_wake_off; /* workaround bug in some ACPI tables */ if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) { dev_dbg(dev, "bogus FADT month_alarm (%d)\n", acpi_gbl_FADT.month_alarm); acpi_gbl_FADT.month_alarm = 0; } acpi_rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm; acpi_rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm; acpi_rtc_info.rtc_century = acpi_gbl_FADT.century; /* NOTE: S4_RTC_WAKE is NOT currently useful to Linux */ if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE) dev_info(dev, "RTC can wake from S4\n"); dev->platform_data = &acpi_rtc_info; /* RTC always wakes from S1/S2/S3, and often S4/STD */ device_init_wakeup(dev, 1); } #else static void __devinit cmos_wake_setup(struct device *dev) { } #endif #ifdef CONFIG_PNP #include <linux/pnp.h> static int __devinit cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) { cmos_wake_setup(&pnp->dev); if (pnp_port_start(pnp,0) == 0x70 && !pnp_irq_valid(pnp,0)) /* Some machines contain a PNP entry for the RTC, but * don't define the IRQ. It should always be safe to * hardcode it in these cases */ return cmos_do_probe(&pnp->dev, pnp_get_resource(pnp, IORESOURCE_IO, 0), 8); else return cmos_do_probe(&pnp->dev, pnp_get_resource(pnp, IORESOURCE_IO, 0), pnp_irq(pnp, 0)); } static void __exit cmos_pnp_remove(struct pnp_dev *pnp) { cmos_do_remove(&pnp->dev); } #ifdef CONFIG_PM static int cmos_pnp_suspend(struct pnp_dev *pnp, pm_message_t mesg) { return cmos_suspend(&pnp->dev, mesg); } static int cmos_pnp_resume(struct pnp_dev *pnp) { return cmos_resume(&pnp->dev); } #else #define cmos_pnp_suspend NULL #define cmos_pnp_resume NULL #endif static void cmos_pnp_shutdown(struct pnp_dev *pnp) { if (system_state == SYSTEM_POWER_OFF && !cmos_poweroff(&pnp->dev)) return; cmos_do_shutdown(); } static const struct pnp_device_id rtc_ids[] = { { .id = "PNP0b00", }, { .id = "PNP0b01", }, { .id = "PNP0b02", }, { }, }; MODULE_DEVICE_TABLE(pnp, rtc_ids); static struct pnp_driver cmos_pnp_driver = { .name = (char *) driver_name, .id_table = rtc_ids, .probe = cmos_pnp_probe, .remove = __exit_p(cmos_pnp_remove), .shutdown = cmos_pnp_shutdown, /* flag ensures resume() gets called, and stops syslog spam */ .flags = PNP_DRIVER_RES_DO_NOT_CHANGE, .suspend = cmos_pnp_suspend, .resume = cmos_pnp_resume, }; #endif /* CONFIG_PNP */ /*----------------------------------------------------------------*/ /* Platform setup should have set up an RTC device, when PNP is * unavailable ... this could happen even on (older) PCs. */ static int __init cmos_platform_probe(struct platform_device *pdev) { cmos_wake_setup(&pdev->dev); return cmos_do_probe(&pdev->dev, platform_get_resource(pdev, IORESOURCE_IO, 0), platform_get_irq(pdev, 0)); } static int __exit cmos_platform_remove(struct platform_device *pdev) { cmos_do_remove(&pdev->dev); return 0; } static void cmos_platform_shutdown(struct platform_device *pdev) { if (system_state == SYSTEM_POWER_OFF && !cmos_poweroff(&pdev->dev)) return; cmos_do_shutdown(); } /* work with hotplug and coldplug */ MODULE_ALIAS("platform:rtc_cmos"); static struct platform_driver cmos_platform_driver = { .remove = __exit_p(cmos_platform_remove), .shutdown = cmos_platform_shutdown, .driver = { .name = (char *) driver_name, .suspend = cmos_suspend, .resume = cmos_resume, } }; #ifdef CONFIG_PNP static bool pnp_driver_registered; #endif static bool platform_driver_registered; static int __init cmos_init(void) { int retval = 0; #ifdef CONFIG_PNP retval = pnp_register_driver(&cmos_pnp_driver); if (retval == 0) pnp_driver_registered = true; #endif if (!cmos_rtc.dev) { retval = platform_driver_probe(&cmos_platform_driver, cmos_platform_probe); if (retval == 0) platform_driver_registered = true; } if (retval == 0) return 0; #ifdef CONFIG_PNP if (pnp_driver_registered) pnp_unregister_driver(&cmos_pnp_driver); #endif return retval; } module_init(cmos_init); static void __exit cmos_exit(void) { #ifdef CONFIG_PNP if (pnp_driver_registered) pnp_unregister_driver(&cmos_pnp_driver); #endif if (platform_driver_registered) platform_driver_unregister(&cmos_platform_driver); } module_exit(cmos_exit); MODULE_AUTHOR("David Brownell"); MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs"); MODULE_LICENSE("GPL");