linux-hardened/drivers/acpi/glue.c
David Brownell 19bfe37caa workaround rtc-related acpi table bugs
This works around a bug seen in some RTC-related ACPI table entries, and
tweaks related diagnostics to follow the ACPI convention.

The bug prevents misleading boot-time messages: platforms affected by this
bug wrongly report they can support alarms up to one year in the future,
when in fact the longest alarm is just 24 hours.  That will surprise anyone
trying to use those extended alarms.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:18 -07:00

347 lines
8 KiB
C

/*
* Link physical devices with ACPI devices support
*
* Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com>
* Copyright (c) 2005 Intel Corp.
*
* This file is released under the GPLv2.
*/
#include <linux/init.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/rwsem.h>
#include <linux/acpi.h>
#define ACPI_GLUE_DEBUG 0
#if ACPI_GLUE_DEBUG
#define DBG(x...) printk(PREFIX x)
#else
#define DBG(x...)
#endif
static LIST_HEAD(bus_type_list);
static DECLARE_RWSEM(bus_type_sem);
int register_acpi_bus_type(struct acpi_bus_type *type)
{
if (acpi_disabled)
return -ENODEV;
if (type && type->bus && type->find_device) {
down_write(&bus_type_sem);
list_add_tail(&type->list, &bus_type_list);
up_write(&bus_type_sem);
printk(KERN_INFO PREFIX "bus type %s registered\n",
type->bus->name);
return 0;
}
return -ENODEV;
}
EXPORT_SYMBOL(register_acpi_bus_type);
int unregister_acpi_bus_type(struct acpi_bus_type *type)
{
if (acpi_disabled)
return 0;
if (type) {
down_write(&bus_type_sem);
list_del_init(&type->list);
up_write(&bus_type_sem);
printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
type->bus->name);
return 0;
}
return -ENODEV;
}
EXPORT_SYMBOL(unregister_acpi_bus_type);
static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
{
struct acpi_bus_type *tmp, *ret = NULL;
down_read(&bus_type_sem);
list_for_each_entry(tmp, &bus_type_list, list) {
if (tmp->bus == type) {
ret = tmp;
break;
}
}
up_read(&bus_type_sem);
return ret;
}
static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
{
struct acpi_bus_type *tmp;
int ret = -ENODEV;
down_read(&bus_type_sem);
list_for_each_entry(tmp, &bus_type_list, list) {
if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
ret = 0;
break;
}
}
up_read(&bus_type_sem);
return ret;
}
/* Get device's handler per its address under its parent */
struct acpi_find_child {
acpi_handle handle;
acpi_integer address;
};
static acpi_status
do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
{
acpi_status status;
struct acpi_device_info *info;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
struct acpi_find_child *find = context;
status = acpi_get_object_info(handle, &buffer);
if (ACPI_SUCCESS(status)) {
info = buffer.pointer;
if (info->address == find->address)
find->handle = handle;
kfree(buffer.pointer);
}
return AE_OK;
}
acpi_handle acpi_get_child(acpi_handle parent, acpi_integer address)
{
struct acpi_find_child find = { NULL, address };
if (!parent)
return NULL;
acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
1, do_acpi_find_child, &find, NULL);
return find.handle;
}
EXPORT_SYMBOL(acpi_get_child);
/* Link ACPI devices with physical devices */
static void acpi_glue_data_handler(acpi_handle handle,
u32 function, void *context)
{
/* we provide an empty handler */
}
/* Note: a success call will increase reference count by one */
struct device *acpi_get_physical_device(acpi_handle handle)
{
acpi_status status;
struct device *dev;
status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
if (ACPI_SUCCESS(status))
return get_device(dev);
return NULL;
}
EXPORT_SYMBOL(acpi_get_physical_device);
static int acpi_bind_one(struct device *dev, acpi_handle handle)
{
acpi_status status;
if (dev->archdata.acpi_handle) {
printk(KERN_WARNING PREFIX
"Drivers changed 'acpi_handle' for %s\n", dev->bus_id);
return -EINVAL;
}
get_device(dev);
status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
if (ACPI_FAILURE(status)) {
put_device(dev);
return -EINVAL;
}
dev->archdata.acpi_handle = handle;
return 0;
}
static int acpi_unbind_one(struct device *dev)
{
if (!dev->archdata.acpi_handle)
return 0;
if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {
/* acpi_get_physical_device increase refcnt by one */
put_device(dev);
acpi_detach_data(dev->archdata.acpi_handle,
acpi_glue_data_handler);
dev->archdata.acpi_handle = NULL;
/* acpi_bind_one increase refcnt by one */
put_device(dev);
} else {
printk(KERN_ERR PREFIX
"Oops, 'acpi_handle' corrupt for %s\n", dev->bus_id);
}
return 0;
}
static int acpi_platform_notify(struct device *dev)
{
struct acpi_bus_type *type;
acpi_handle handle;
int ret = -EINVAL;
if (!dev->bus || !dev->parent) {
/* bridge devices genernally haven't bus or parent */
ret = acpi_find_bridge_device(dev, &handle);
goto end;
}
type = acpi_get_bus_type(dev->bus);
if (!type) {
DBG("No ACPI bus support for %s\n", dev->bus_id);
ret = -EINVAL;
goto end;
}
if ((ret = type->find_device(dev, &handle)) != 0)
DBG("Can't get handler for %s\n", dev->bus_id);
end:
if (!ret)
acpi_bind_one(dev, handle);
#if ACPI_GLUE_DEBUG
if (!ret) {
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_get_name(dev->archdata.acpi_handle,
ACPI_FULL_PATHNAME, &buffer);
DBG("Device %s -> %s\n", dev->bus_id, (char *)buffer.pointer);
kfree(buffer.pointer);
} else
DBG("Device %s -> No ACPI support\n", dev->bus_id);
#endif
return ret;
}
static int acpi_platform_notify_remove(struct device *dev)
{
acpi_unbind_one(dev);
return 0;
}
static int __init init_acpi_device_notify(void)
{
if (acpi_disabled)
return 0;
if (platform_notify || platform_notify_remove) {
printk(KERN_ERR PREFIX "Can't use platform_notify\n");
return 0;
}
platform_notify = acpi_platform_notify;
platform_notify_remove = acpi_platform_notify_remove;
return 0;
}
arch_initcall(init_acpi_device_notify);
#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
#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);
}
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);
}
#else
#define rtc_wake_setup() do{}while(0)
#define rtc_wake_on NULL
#define rtc_wake_off NULL
#endif
/* 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).
*/
#include <linux/mc146818rtc.h>
static struct cmos_rtc_board_info rtc_info;
/* PNP devices are registered in a subsys_initcall();
* ACPI specifies the PNP IDs to use.
*/
#include <linux/pnp.h>
static int __init pnp_match(struct device *dev, void *data)
{
static const char *ids[] = { "PNP0b00", "PNP0b01", "PNP0b02", };
struct pnp_dev *pnp = to_pnp_dev(dev);
int i;
for (i = 0; i < ARRAY_SIZE(ids); i++) {
if (compare_pnp_id(pnp->id, ids[i]) != 0)
return 1;
}
return 0;
}
static struct device *__init get_rtc_dev(void)
{
return bus_find_device(&pnp_bus_type, NULL, NULL, pnp_match);
}
static int __init acpi_rtc_init(void)
{
struct device *dev = get_rtc_dev();
if (dev) {
rtc_wake_setup();
rtc_info.wake_on = rtc_wake_on;
rtc_info.wake_off = rtc_wake_off;
/* workaround bug in some ACPI tables */
if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
DBG("bogus FADT month_alarm\n");
acpi_gbl_FADT.month_alarm = 0;
}
rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
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)
printk(PREFIX "RTC can wake from S4\n");
dev->platform_data = &rtc_info;
/* RTC always wakes from S1/S2/S3, and often S4/STD */
device_init_wakeup(dev, 1);
put_device(dev);
} else
DBG("RTC unavailable?\n");
return 0;
}
/* do this between RTC subsys_initcall() and rtc_cmos driver_initcall() */
fs_initcall(acpi_rtc_init);
#endif