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linux/drivers/acpi/proc.c
Rafael J. Wysocki f2b56bc808 ACPI / PM: Use device wakeup flags for handling ACPI wakeup devices 
There are ACPI devices (buttons and the laptop lid) that can wake up
the system from sleep states and have no "physical" companion
devices.  The ACPI subsystem uses two flags, wakeup.state.enabled and
wakeup.flags.always_enabled, for handling those devices, but they
are not accessible through the standard device wakeup infrastructure.
User space can only control them via the /proc/acpi/wakeup interface
that is not really convenient (e.g. the way in which devices are
enabled to wake up the system is not portable between different
systems, because it requires one to know the devices' "names" used in
the system's ACPI tables).

To address this problem, use standard device wakeup flags instead of
the special ACPI flags for handling those devices.  In particular,
use device_set_wakeup_capable() to mark the ACPI wakeup devices
during initialization and use device_set_wakeup_enable() to allow
or disallow them to wake up the system from sleep states.  Rework
the /proc/acpi/wakeup interface to take these changes into account.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
2011-01-07 01:17:41 -05:00

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#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/suspend.h>
#include <linux/bcd.h>
#include <asm/uaccess.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#ifdef CONFIG_X86
#include <linux/mc146818rtc.h>
#endif
#include "sleep.h"
#define _COMPONENT ACPI_SYSTEM_COMPONENT
/*
* this file provides support for:
* /proc/acpi/alarm
* /proc/acpi/wakeup
*/
ACPI_MODULE_NAME("sleep")
#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || !defined(CONFIG_X86)
/* use /sys/class/rtc/rtcX/wakealarm instead; it's not ACPI-specific */
#else
#define HAVE_ACPI_LEGACY_ALARM
#endif
#ifdef HAVE_ACPI_LEGACY_ALARM
static u32 cmos_bcd_read(int offset, int rtc_control);
static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
{
u32 sec, min, hr;
u32 day, mo, yr, cent = 0;
u32 today = 0;
unsigned char rtc_control = 0;
unsigned long flags;
spin_lock_irqsave(&rtc_lock, flags);
rtc_control = CMOS_READ(RTC_CONTROL);
sec = cmos_bcd_read(RTC_SECONDS_ALARM, rtc_control);
min = cmos_bcd_read(RTC_MINUTES_ALARM, rtc_control);
hr = cmos_bcd_read(RTC_HOURS_ALARM, rtc_control);
/* If we ever get an FACP with proper values... */
if (acpi_gbl_FADT.day_alarm) {
/* ACPI spec: only low 6 its should be cared */
day = CMOS_READ(acpi_gbl_FADT.day_alarm) & 0x3F;
if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
day = bcd2bin(day);
} else
day = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
if (acpi_gbl_FADT.month_alarm)
mo = cmos_bcd_read(acpi_gbl_FADT.month_alarm, rtc_control);
else {
mo = cmos_bcd_read(RTC_MONTH, rtc_control);
today = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
}
if (acpi_gbl_FADT.century)
cent = cmos_bcd_read(acpi_gbl_FADT.century, rtc_control);
yr = cmos_bcd_read(RTC_YEAR, rtc_control);
spin_unlock_irqrestore(&rtc_lock, flags);
/* we're trusting the FADT (see above) */
if (!acpi_gbl_FADT.century)
/* If we're not trusting the FADT, we should at least make it
* right for _this_ century... ehm, what is _this_ century?
*
* TBD:
* ASAP: find piece of code in the kernel, e.g. star tracker driver,
* which we can trust to determine the century correctly. Atom
* watch driver would be nice, too...
*
* if that has not happened, change for first release in 2050:
* if (yr<50)
* yr += 2100;
* else
* yr += 2000; // current line of code
*
* if that has not happened either, please do on 2099/12/31:23:59:59
* s/2000/2100
*
*/
yr += 2000;
else
yr += cent * 100;
/*
* Show correct dates for alarms up to a month into the future.
* This solves issues for nearly all situations with the common
* 30-day alarm clocks in PC hardware.
*/
if (day < today) {
if (mo < 12) {
mo += 1;
} else {
mo = 1;
yr += 1;
}
}
seq_printf(seq, "%4.4u-", yr);
(mo > 12) ? seq_puts(seq, "**-") : seq_printf(seq, "%2.2u-", mo);
(day > 31) ? seq_puts(seq, "** ") : seq_printf(seq, "%2.2u ", day);
(hr > 23) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", hr);
(min > 59) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", min);
(sec > 59) ? seq_puts(seq, "**\n") : seq_printf(seq, "%2.2u\n", sec);
return 0;
}
static int acpi_system_alarm_open_fs(struct inode *inode, struct file *file)
{
return single_open(file, acpi_system_alarm_seq_show, PDE(inode)->data);
}
static int get_date_field(char **p, u32 * value)
{
char *next = NULL;
char *string_end = NULL;
int result = -EINVAL;
/*
* Try to find delimeter, only to insert null. The end of the
* string won't have one, but is still valid.
*/
if (*p == NULL)
return result;
next = strpbrk(*p, "- :");
if (next)
*next++ = '\0';
*value = simple_strtoul(*p, &string_end, 10);
/* Signal success if we got a good digit */
if (string_end != *p)
result = 0;
if (next)
*p = next;
else
*p = NULL;
return result;
}
/* Read a possibly BCD register, always return binary */
static u32 cmos_bcd_read(int offset, int rtc_control)
{
u32 val = CMOS_READ(offset);
if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
val = bcd2bin(val);
return val;
}
/* Write binary value into possibly BCD register */
static void cmos_bcd_write(u32 val, int offset, int rtc_control)
{
if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
val = bin2bcd(val);
CMOS_WRITE(val, offset);
}
static ssize_t
acpi_system_write_alarm(struct file *file,
const char __user * buffer, size_t count, loff_t * ppos)
{
int result = 0;
char alarm_string[30] = { '\0' };
char *p = alarm_string;
u32 sec, min, hr, day, mo, yr;
int adjust = 0;
unsigned char rtc_control = 0;
if (count > sizeof(alarm_string) - 1)
return -EINVAL;
if (copy_from_user(alarm_string, buffer, count))
return -EFAULT;
alarm_string[count] = '\0';
/* check for time adjustment */
if (alarm_string[0] == '+') {
p++;
adjust = 1;
}
if ((result = get_date_field(&p, &yr)))
goto end;
if ((result = get_date_field(&p, &mo)))
goto end;
if ((result = get_date_field(&p, &day)))
goto end;
if ((result = get_date_field(&p, &hr)))
goto end;
if ((result = get_date_field(&p, &min)))
goto end;
if ((result = get_date_field(&p, &sec)))
goto end;
spin_lock_irq(&rtc_lock);
rtc_control = CMOS_READ(RTC_CONTROL);
if (adjust) {
yr += cmos_bcd_read(RTC_YEAR, rtc_control);
mo += cmos_bcd_read(RTC_MONTH, rtc_control);
day += cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
hr += cmos_bcd_read(RTC_HOURS, rtc_control);
min += cmos_bcd_read(RTC_MINUTES, rtc_control);
sec += cmos_bcd_read(RTC_SECONDS, rtc_control);
}
spin_unlock_irq(&rtc_lock);
if (sec > 59) {
min += sec/60;
sec = sec%60;
}
if (min > 59) {
hr += min/60;
min = min%60;
}
if (hr > 23) {
day += hr/24;
hr = hr%24;
}
if (day > 31) {
mo += day/32;
day = day%32;
}
if (mo > 12) {
yr += mo/13;
mo = mo%13;
}
spin_lock_irq(&rtc_lock);
/*
* Disable alarm interrupt before setting alarm timer or else
* when ACPI_EVENT_RTC is enabled, a spurious ACPI interrupt occurs
*/
rtc_control &= ~RTC_AIE;
CMOS_WRITE(rtc_control, RTC_CONTROL);
CMOS_READ(RTC_INTR_FLAGS);
/* write the fields the rtc knows about */
cmos_bcd_write(hr, RTC_HOURS_ALARM, rtc_control);
cmos_bcd_write(min, RTC_MINUTES_ALARM, rtc_control);
cmos_bcd_write(sec, RTC_SECONDS_ALARM, rtc_control);
/*
* If the system supports an enhanced alarm it will have non-zero
* offsets into the CMOS RAM here -- which for some reason are pointing
* to the RTC area of memory.
*/
if (acpi_gbl_FADT.day_alarm)
cmos_bcd_write(day, acpi_gbl_FADT.day_alarm, rtc_control);
if (acpi_gbl_FADT.month_alarm)
cmos_bcd_write(mo, acpi_gbl_FADT.month_alarm, rtc_control);
if (acpi_gbl_FADT.century) {
if (adjust)
yr += cmos_bcd_read(acpi_gbl_FADT.century, rtc_control) * 100;
cmos_bcd_write(yr / 100, acpi_gbl_FADT.century, rtc_control);
}
/* enable the rtc alarm interrupt */
rtc_control |= RTC_AIE;
CMOS_WRITE(rtc_control, RTC_CONTROL);
CMOS_READ(RTC_INTR_FLAGS);
spin_unlock_irq(&rtc_lock);
acpi_clear_event(ACPI_EVENT_RTC);
acpi_enable_event(ACPI_EVENT_RTC, 0);
*ppos += count;
result = 0;
end:
return result ? result : count;
}
#endif /* HAVE_ACPI_LEGACY_ALARM */
static int
acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset)
{
struct list_head *node, *next;
seq_printf(seq, "Device\tS-state\t Status Sysfs node\n");
mutex_lock(&acpi_device_lock);
list_for_each_safe(node, next, &acpi_wakeup_device_list) {
struct acpi_device *dev =
container_of(node, struct acpi_device, wakeup_list);
struct device *ldev;
if (!dev->wakeup.flags.valid)
continue;
ldev = acpi_get_physical_device(dev->handle);
seq_printf(seq, "%s\t S%d\t%c%-8s ",
dev->pnp.bus_id,
(u32) dev->wakeup.sleep_state,
dev->wakeup.flags.run_wake ? '*' : ' ',
(device_may_wakeup(&dev->dev)
|| (ldev && device_may_wakeup(ldev))) ?
"enabled" : "disabled");
if (ldev)
seq_printf(seq, "%s:%s",
ldev->bus ? ldev->bus->name : "no-bus",
dev_name(ldev));
seq_printf(seq, "\n");
put_device(ldev);
}
mutex_unlock(&acpi_device_lock);
return 0;
}
static void physical_device_enable_wakeup(struct acpi_device *adev)
{
struct device *dev = acpi_get_physical_device(adev->handle);
if (dev && device_can_wakeup(dev)) {
bool enable = !device_may_wakeup(dev);
device_set_wakeup_enable(dev, enable);
}
}
static ssize_t
acpi_system_write_wakeup_device(struct file *file,
const char __user * buffer,
size_t count, loff_t * ppos)
{
struct list_head *node, *next;
char strbuf[5];
char str[5] = "";
unsigned int len = count;
if (len > 4)
len = 4;
if (len < 0)
return -EFAULT;
if (copy_from_user(strbuf, buffer, len))
return -EFAULT;
strbuf[len] = '\0';
sscanf(strbuf, "%s", str);
mutex_lock(&acpi_device_lock);
list_for_each_safe(node, next, &acpi_wakeup_device_list) {
struct acpi_device *dev =
container_of(node, struct acpi_device, wakeup_list);
if (!dev->wakeup.flags.valid)
continue;
if (!strncmp(dev->pnp.bus_id, str, 4)) {
if (device_can_wakeup(&dev->dev)) {
bool enable = !device_may_wakeup(&dev->dev);
device_set_wakeup_enable(&dev->dev, enable);
} else {
physical_device_enable_wakeup(dev);
}
break;
}
}
mutex_unlock(&acpi_device_lock);
return count;
}
static int
acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file)
{
return single_open(file, acpi_system_wakeup_device_seq_show,
PDE(inode)->data);
}
static const struct file_operations acpi_system_wakeup_device_fops = {
.owner = THIS_MODULE,
.open = acpi_system_wakeup_device_open_fs,
.read = seq_read,
.write = acpi_system_write_wakeup_device,
.llseek = seq_lseek,
.release = single_release,
};
#ifdef HAVE_ACPI_LEGACY_ALARM
static const struct file_operations acpi_system_alarm_fops = {
.owner = THIS_MODULE,
.open = acpi_system_alarm_open_fs,
.read = seq_read,
.write = acpi_system_write_alarm,
.llseek = seq_lseek,
.release = single_release,
};
static u32 rtc_handler(void *context)
{
acpi_clear_event(ACPI_EVENT_RTC);
acpi_disable_event(ACPI_EVENT_RTC, 0);
return ACPI_INTERRUPT_HANDLED;
}
#endif /* HAVE_ACPI_LEGACY_ALARM */
int __init acpi_sleep_proc_init(void)
{
#ifdef HAVE_ACPI_LEGACY_ALARM
/* 'alarm' [R/W] */
proc_create("alarm", S_IFREG | S_IRUGO | S_IWUSR,
acpi_root_dir, &acpi_system_alarm_fops);
acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
/*
* Disable the RTC event after installing RTC handler.
* Only when RTC alarm is set will it be enabled.
*/
acpi_clear_event(ACPI_EVENT_RTC);
acpi_disable_event(ACPI_EVENT_RTC, 0);
#endif /* HAVE_ACPI_LEGACY_ALARM */
/* 'wakeup device' [R/W] */
proc_create("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
acpi_root_dir, &acpi_system_wakeup_device_fops);
return 0;
}
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