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rtc-cmos.c
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rtc-cmos.c
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/*
* 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>
/* 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);
/* REVISIT this assumes PC style usage: 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;
if (!is_valid_irq(cmos->irq))
return -EIO;
/* REVISIT this assumes PC style usage: always BCD */
/* Writing 0xff means "don't care" or "match all". */
mon = t->time.tm_mon + 1;
mon = (mon <= 12) ? bin2bcd(mon) : 0xff;
mday = t->time.tm_mday;
mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
hrs = t->time.tm_hour;
hrs = (hrs < 24) ? bin2bcd(hrs) : 0xff;
min = t->time.tm_min;
min = (min < 60) ? bin2bcd(min) : 0xff;
sec = t->time.tm_sec;
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;
/* 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;
}
#if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
static int
cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
unsigned long flags;
switch (cmd) {
case RTC_AIE_OFF:
case RTC_AIE_ON:
case RTC_UIE_OFF:
case RTC_UIE_ON:
if (!is_valid_irq(cmos->irq))
return -EINVAL;
break;
/* PIE ON/OFF is handled by cmos_irq_set_state() */
default:
return -ENOIOCTLCMD;
}
spin_lock_irqsave(&rtc_lock, flags);
switch (cmd) {
case RTC_AIE_OFF: /* alarm off */
cmos_irq_disable(cmos, RTC_AIE);
break;
case RTC_AIE_ON: /* alarm on */
cmos_irq_enable(cmos, RTC_AIE);
break;
case RTC_UIE_OFF: /* update off */
cmos_irq_disable(cmos, RTC_UIE);
break;
case RTC_UIE_ON: /* update on */
cmos_irq_enable(cmos, RTC_UIE);
break;
}
spin_unlock_irqrestore(&rtc_lock, flags);
return 0;
}
#else
#define cmos_rtc_ioctl NULL
#endif
#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 = {
.ioctl = cmos_rtc_ioctl,
.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,
};
/*----------------------------------------------------------------*/
/*
* 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 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 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__)
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.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;
}
cmos_rtc.dev = dev;
dev_set_drvdata(dev, &cmos_rtc);
rename_region(ports, cmos_rtc.rtc->dev.bus_id);
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 teach the alarm code how to handle binary mode;
* <asm-generic/rtc.h> doesn't know 12-hour mode either.
*/
if (is_valid_irq(rtc_irq) &&
(!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY)))) {
dev_dbg(dev, "only 24-hr BCD mode 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, cmos_rtc.rtc->dev.bus_id,
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: alarms up to one %s%s, %zd bytes nvram%s\n",
cmos_rtc.rtc->dev.bus_id,
is_valid_irq(rtc_irq)
? (cmos_rtc.mon_alrm
? "year"
: (cmos_rtc.day_alrm
? "month" : "day"))
: "no",
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);
hpet_mask_rtc_irq_bit(mask);
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",
cmos_rtc.rtc->dev.bus_id,
(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",
cmos_rtc.rtc->dev.bus_id,
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)