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linux/drivers/acpi/sleep/proc.c
Linus Torvalds c67c36e4b8 Fix /proc/acpi/alarm BCD alarm encodings 
This fixes some totally illogical and wrong code that converts things to
and from BCD mode essentially randomly, does math on values in BCD mode
etc etc.  Introduce a few helper functions to make it a bit more obvious
what is going on, and make sure that we always do all the arithmetic
(and anythign else, for that matter) in binary, not BCD.

Tested by Mark Lord, who found the problem originally, and also pushed
the patch back and reminded me about it.

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-25 15:08:03 -07:00

532 lines
12 KiB
C
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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/sleep
* /proc/acpi/alarm
* /proc/acpi/wakeup
*/
ACPI_MODULE_NAME("sleep")
#ifdef CONFIG_ACPI_PROCFS
static int acpi_system_sleep_seq_show(struct seq_file *seq, void *offset)
{
int i;
ACPI_FUNCTION_TRACE("acpi_system_sleep_seq_show");
for (i = 0; i <= ACPI_STATE_S5; i++) {
if (sleep_states[i]) {
seq_printf(seq, "S%d ", i);
}
}
seq_puts(seq, "\n");
return 0;
}
static int acpi_system_sleep_open_fs(struct inode *inode, struct file *file)
{
return single_open(file, acpi_system_sleep_seq_show, PDE(inode)->data);
}
static ssize_t
acpi_system_write_sleep(struct file *file,
const char __user * buffer, size_t count, loff_t * ppos)
{
char str[12];
u32 state = 0;
int error = 0;
if (count > sizeof(str) - 1)
goto Done;
memset(str, 0, sizeof(str));
if (copy_from_user(str, buffer, count))
return -EFAULT;
/* Check for S4 bios request */
if (!strcmp(str, "4b")) {
error = acpi_suspend(4);
goto Done;
}
state = simple_strtoul(str, NULL, 0);
#ifdef CONFIG_HIBERNATION
if (state == 4) {
error = hibernate();
goto Done;
}
#endif
error = acpi_suspend(state);
Done:
return error ? error : count;
}
#endif /* CONFIG_ACPI_PROCFS */
#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 int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
{
u32 sec, min, hr;
u32 day, mo, yr, cent = 0;
unsigned char rtc_control = 0;
unsigned long flags;
ACPI_FUNCTION_TRACE("acpi_system_alarm_seq_show");
spin_lock_irqsave(&rtc_lock, flags);
sec = CMOS_READ(RTC_SECONDS_ALARM);
min = CMOS_READ(RTC_MINUTES_ALARM);
hr = CMOS_READ(RTC_HOURS_ALARM);
rtc_control = CMOS_READ(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;
else
day = CMOS_READ(RTC_DAY_OF_MONTH);
if (acpi_gbl_FADT.month_alarm)
mo = CMOS_READ(acpi_gbl_FADT.month_alarm);
else
mo = CMOS_READ(RTC_MONTH);
if (acpi_gbl_FADT.century)
cent = CMOS_READ(acpi_gbl_FADT.century);
yr = CMOS_READ(RTC_YEAR);
spin_unlock_irqrestore(&rtc_lock, flags);
if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
BCD_TO_BIN(sec);
BCD_TO_BIN(min);
BCD_TO_BIN(hr);
BCD_TO_BIN(day);
BCD_TO_BIN(mo);
BCD_TO_BIN(yr);
BCD_TO_BIN(cent);
}
/* 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;
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.
*/
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;
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)
BCD_TO_BIN(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)
BIN_TO_BCD(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;
ACPI_FUNCTION_TRACE("acpi_system_write_alarm");
if (count > sizeof(alarm_string) - 1)
return_VALUE(-EINVAL);
if (copy_from_user(alarm_string, buffer, count))
return_VALUE(-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;
if (sec > 59) {
min += 1;
sec -= 60;
}
if (min > 59) {
hr += 1;
min -= 60;
}
if (hr > 23) {
day += 1;
hr -= 24;
}
if (day > 31) {
mo += 1;
day -= 31;
}
if (mo > 12) {
yr += 1;
mo -= 12;
}
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;
}
if (min > 59) {
hr++;
min -= 60;
}
if (hr > 23) {
day++;
hr -= 24;
}
if (day > 31) {
mo++;
day -= 31;
}
if (mo > 12) {
yr++;
mo -= 12;
}
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)
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_VALUE(result ? result : count);
}
#endif /* HAVE_ACPI_LEGACY_ALARM */
extern struct list_head acpi_wakeup_device_list;
extern spinlock_t acpi_device_lock;
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");
spin_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;
spin_unlock(&acpi_device_lock);
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 ? '*' : ' ',
dev->wakeup.state.enabled ? "enabled" : "disabled");
if (ldev)
seq_printf(seq, "%s:%s",
ldev->bus ? ldev->bus->name : "no-bus",
ldev->bus_id);
seq_printf(seq, "\n");
put_device(ldev);
spin_lock(&acpi_device_lock);
}
spin_unlock(&acpi_device_lock);
return 0;
}
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] = "";
int len = count;
struct acpi_device *found_dev = NULL;
if (len > 4)
len = 4;
if (copy_from_user(strbuf, buffer, len))
return -EFAULT;
strbuf[len] = '\0';
sscanf(strbuf, "%s", str);
spin_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)) {
dev->wakeup.state.enabled =
dev->wakeup.state.enabled ? 0 : 1;
found_dev = dev;
break;
}
}
if (found_dev) {
list_for_each_safe(node, next, &acpi_wakeup_device_list) {
struct acpi_device *dev = container_of(node,
struct
acpi_device,
wakeup_list);
if ((dev != found_dev) &&
(dev->wakeup.gpe_number ==
found_dev->wakeup.gpe_number)
&& (dev->wakeup.gpe_device ==
found_dev->wakeup.gpe_device)) {
printk(KERN_WARNING
"ACPI: '%s' and '%s' have the same GPE, "
"can't disable/enable one seperately\n",
dev->pnp.bus_id, found_dev->pnp.bus_id);
dev->wakeup.state.enabled =
found_dev->wakeup.state.enabled;
}
}
}
spin_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 = {
.open = acpi_system_wakeup_device_open_fs,
.read = seq_read,
.write = acpi_system_write_wakeup_device,
.llseek = seq_lseek,
.release = single_release,
};
#ifdef CONFIG_ACPI_PROCFS
static const struct file_operations acpi_system_sleep_fops = {
.open = acpi_system_sleep_open_fs,
.read = seq_read,
.write = acpi_system_write_sleep,
.llseek = seq_lseek,
.release = single_release,
};
#endif /* CONFIG_ACPI_PROCFS */
#ifdef HAVE_ACPI_LEGACY_ALARM
static const struct file_operations acpi_system_alarm_fops = {
.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 */
static int __init acpi_sleep_proc_init(void)
{
struct proc_dir_entry *entry = NULL;
if (acpi_disabled)
return 0;
#ifdef CONFIG_ACPI_PROCFS
/* 'sleep' [R/W] */
entry =
create_proc_entry("sleep", S_IFREG | S_IRUGO | S_IWUSR,
acpi_root_dir);
if (entry)
entry->proc_fops = &acpi_system_sleep_fops;
#endif /* CONFIG_ACPI_PROCFS */
#ifdef HAVE_ACPI_LEGACY_ALARM
/* 'alarm' [R/W] */
entry =
create_proc_entry("alarm", S_IFREG | S_IRUGO | S_IWUSR,
acpi_root_dir);
if (entry)
entry->proc_fops = &acpi_system_alarm_fops;
acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
#endif /* HAVE_ACPI_LEGACY_ALARM */
/* 'wakeup device' [R/W] */
entry =
create_proc_entry("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
acpi_root_dir);
if (entry)
entry->proc_fops = &acpi_system_wakeup_device_fops;
return 0;
}
late_initcall(acpi_sleep_proc_init);
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