linux/drivers/rtc/rtc-cmos.c
David Brownell 35d3fdd5f3 rtc-cmos: improve HPET IRQ glue
Resolve http://bugzilla.kernel.org/show_bug.cgi?id=11051 and other bugs
related to the way the HPET glue code in rtc-cmos was incomplete and
inconsistent:

 * Switch the approach so that the basic driver code flow isn't
   changed by having HPET ... instead, just have HPET shadow the
   RTC_CONTROL irq enables and RTC_FREQ_SELECT data.  It's only
   coping with IRQ thievery, after all.

 * Do that consistently (!!) to avoid problems when the HPET code
   is out of sync with the real RTC intent.  Examples include:

   - cmos_procfs(), which now reports correct data

   - cmos_irq_set_state() ... also removing the previous PIE_{ON,OFF}
     ioctl support so only one code path manages "periodic" IRQs

   - cmos_do_shutdown() ... currently a "just in case" change.

   - cmos_suspend() and cmos_resume() ... also handling a bug that
     was specific to HPET's IRQ thievery, where the alarm wasn't
     disabled after waking the system

 * Always call that HPET code under the RTC spinlock (it doesn't do
   its own locking)

Also clean up the HPET glue:

 * Add some comments explaining what's going on.

 * Switch to having just one #ifdef for the HPET glue, and inline
   functions (not #defines) to avoid some compiler warnings.

 * Have the probe message also report when HPET IRQs are involved

This still leaves various holes in the HPET glue, like the emulated update
IRQs being out of sync with the RTC, alarms never using day or month
matches, and many extra IRQs (at 64 Hz).

[akpm@linux-foundation.org: fix build]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Tomas Janousek <tomi@nomi.cz>
Cc: Bernhard Walle <bwalle@suse.de>
Cc: Carlos R. Mafra <crmafra@ift.unesp.br>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:34 -07:00

1051 lines
26 KiB
C

/*
* 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
/*----------------------------------------------------------------*/
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 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;
unsigned char rtc_control, rtc_intr;
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 */
rtc_control = CMOS_READ(RTC_CONTROL);
rtc_control &= ~RTC_AIE;
CMOS_WRITE(rtc_control, RTC_CONTROL);
hpet_mask_rtc_irq_bit(RTC_AIE);
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(rtc_intr))
rtc_update_irq(cmos->rtc, 1, rtc_intr);
/* 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) {
rtc_control |= RTC_AIE;
CMOS_WRITE(rtc_control, RTC_CONTROL);
hpet_set_rtc_irq_bit(RTC_AIE);
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(rtc_intr))
rtc_update_irq(cmos->rtc, 1, rtc_intr);
}
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 char rtc_control, rtc_intr;
unsigned long flags;
if (!is_valid_irq(cmos->irq))
return -ENXIO;
spin_lock_irqsave(&rtc_lock, flags);
rtc_control = CMOS_READ(RTC_CONTROL);
if (enabled) {
rtc_control |= RTC_PIE;
hpet_set_rtc_irq_bit(RTC_PIE);
} else {
rtc_control &= ~RTC_PIE;
hpet_mask_rtc_irq_bit(RTC_PIE);
}
CMOS_WRITE(rtc_control, RTC_CONTROL);
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(rtc_intr))
rtc_update_irq(cmos->rtc, 1, rtc_intr);
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 char rtc_control, rtc_intr;
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);
rtc_control = CMOS_READ(RTC_CONTROL);
switch (cmd) {
case RTC_AIE_OFF: /* alarm off */
rtc_control &= ~RTC_AIE;
hpet_mask_rtc_irq_bit(RTC_AIE);
break;
case RTC_AIE_ON: /* alarm on */
rtc_control |= RTC_AIE;
hpet_set_rtc_irq_bit(RTC_AIE);
break;
case RTC_UIE_OFF: /* update off */
rtc_control &= ~RTC_UIE;
hpet_mask_rtc_irq_bit(RTC_UIE);
break;
case RTC_UIE_ON: /* update on */
rtc_control |= RTC_UIE;
hpet_set_rtc_irq_bit(RTC_UIE);
break;
}
CMOS_WRITE(rtc_control, RTC_CONTROL);
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(rtc_intr))
rtc_update_irq(cmos->rtc, 1, rtc_intr);
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 ((off + count) > attr->size)
count = attr->size - off;
spin_lock_irq(&rtc_lock);
for (retval = 0, off += NVRAM_OFFSET; count--; retval++, off++)
*buf++ = CMOS_READ(off);
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 ((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.
*/
spin_lock_irq(&rtc_lock);
for (retval = 0, off += NVRAM_OFFSET; count--; retval++, off++) {
/* don't trash RTC registers */
if (off == cmos->day_alrm
|| off == cmos->mon_alrm
|| off == cmos->century)
buf++;
else
CMOS_WRITE(*buf++, off);
}
spin_unlock_irq(&rtc_lock);
return retval;
}
static struct bin_attribute nvram = {
.attr = {
.name = "nvram",
.mode = S_IRUGO | S_IWUSR,
.owner = THIS_MODULE,
},
.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 = CMOS_READ(RTC_CONTROL);
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, and for now we ignore the way newer
* chips can address 256 bytes (using two more i/o ports).
*/
#if defined(CONFIG_ATARI)
address_space = 64;
#elif defined(__i386__) || defined(__x86_64__) || defined(__arm__)
address_space = 128;
#else
#warning Assuming 128 bytes of RTC+NVRAM address space, not 64 bytes.
address_space = 128;
#endif
/* 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.
*
* NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
* allegedly some older rtcs need that to handle irqs properly
*/
rtc_control = CMOS_READ(RTC_CONTROL);
rtc_control &= ~(RTC_PIE | RTC_AIE | RTC_UIE);
CMOS_WRITE(rtc_control, RTC_CONTROL);
hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE);
CMOS_READ(RTC_INTR_FLAGS);
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 (!(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%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" : "",
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)
{
unsigned char rtc_control;
spin_lock_irq(&rtc_lock);
rtc_control = CMOS_READ(RTC_CONTROL);
rtc_control &= ~RTC_IRQMASK;
CMOS_WRITE(rtc_control, RTC_CONTROL);
hpet_mask_rtc_irq_bit(RTC_IRQMASK);
CMOS_READ(RTC_INTR_FLAGS);
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);
int do_wake = device_may_wakeup(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 irqstat;
unsigned char mask;
if (do_wake)
mask = RTC_IRQMASK & ~RTC_AIE;
else
mask = RTC_IRQMASK;
tmp &= ~mask;
CMOS_WRITE(tmp, RTC_CONTROL);
hpet_mask_rtc_irq_bit(mask);
irqstat = CMOS_READ(RTC_INTR_FLAGS);
irqstat &= (tmp & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(irqstat))
rtc_update_irq(cmos->rtc, 1, irqstat);
}
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;
}
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_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
#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_PNP
#include <linux/pnp.h>
static int __devinit
cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
{
/* REVISIT paranoia argues for a shutdown notifier, since PNP
* drivers can't provide shutdown() methods to disable IRQs.
* Or better yet, fix PNP to allow those methods...
*/
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 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),
/* 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)
{
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)
{
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,
}
};
static int __init cmos_init(void)
{
#ifdef CONFIG_PNP
if (pnp_platform_devices)
return pnp_register_driver(&cmos_pnp_driver);
else
return platform_driver_probe(&cmos_platform_driver,
cmos_platform_probe);
#else
return platform_driver_probe(&cmos_platform_driver,
cmos_platform_probe);
#endif /* CONFIG_PNP */
}
module_init(cmos_init);
static void __exit cmos_exit(void)
{
#ifdef CONFIG_PNP
if (pnp_platform_devices)
pnp_unregister_driver(&cmos_pnp_driver);
else
platform_driver_unregister(&cmos_platform_driver);
#else
platform_driver_unregister(&cmos_platform_driver);
#endif /* CONFIG_PNP */
}
module_exit(cmos_exit);
MODULE_AUTHOR("David Brownell");
MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
MODULE_LICENSE("GPL");