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path: root/drivers/rtc/rtc-cmos.c
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-rw-r--r--drivers/rtc/rtc-cmos.c1194
1 files changed, 1194 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
new file mode 100644
index 00000000..911e75cd
--- /dev/null
+++ b/drivers/rtc/rtc-cmos.c
@@ -0,0 +1,1194 @@
+/*
+ * 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>
+#include <linux/pm.h>
+#include <linux/of.h>
+#include <linux/of_platform.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_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;
+}
+
+#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,
+ .alarm_irq_enable = cmos_alarm_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__) \
+ || defined(__powerpc__)
+ 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)
+{
+ 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);
+}
+
+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;
+}
+
+static SIMPLE_DEV_PM_OPS(cmos_pm_ops, cmos_suspend, cmos_resume);
+
+#else
+
+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>
+
+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);
+}
+
+/* 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);
+}
+
+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 */
+
+#ifdef CONFIG_OF
+static const struct of_device_id of_cmos_match[] = {
+ {
+ .compatible = "motorola,mc146818",
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, of_cmos_match);
+
+static __init void cmos_of_init(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct rtc_time time;
+ int ret;
+ const __be32 *val;
+
+ if (!node)
+ return;
+
+ val = of_get_property(node, "ctrl-reg", NULL);
+ if (val)
+ CMOS_WRITE(be32_to_cpup(val), RTC_CONTROL);
+
+ val = of_get_property(node, "freq-reg", NULL);
+ if (val)
+ CMOS_WRITE(be32_to_cpup(val), RTC_FREQ_SELECT);
+
+ get_rtc_time(&time);
+ ret = rtc_valid_tm(&time);
+ if (ret) {
+ struct rtc_time def_time = {
+ .tm_year = 1,
+ .tm_mday = 1,
+ };
+ set_rtc_time(&def_time);
+ }
+}
+#else
+static inline void cmos_of_init(struct platform_device *pdev) {}
+#define of_cmos_match NULL
+#endif
+/*----------------------------------------------------------------*/
+
+/* 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_of_init(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,
+#ifdef CONFIG_PM
+ .pm = &cmos_pm_ops,
+#endif
+ .of_match_table = of_cmos_match,
+ }
+};
+
+#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");
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-10 18:23:31 +0000