linux/drivers/acpi/glue.c
David Brownell 1071695f17 ACPI: crosslink ACPI and "real" device nodes
Add cross-links between ACPI device and "real" devices in sysfs,
exposing otherwise-hidden interrelationships between the various
device nodes for ACPI stuff.  As a representative example, one
hardware device is exposed as two logical devices (PNP and ACPI):

  .../pnp0/00:06/
  .../LNXSYSTM:00/device:00/PNP0A03:00/device:15/PNP0B00:00/

The PNP device gets a "firmware_node" link pointing to the ACPI device,
and is what a Linux device driver binds to.  The ACPI device has instead
a "physical_node" link pointing back to the PNP device.  Other firmware
frameworks, like OpenFirmware, could do the same thing to couple their
firmware tables to the rest of the system.

(Based on a patch from Zhang Rui.  This version is modified to not
depend on the patch makig ACPI initialize driver model wakeup flags.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2008-02-23 01:32:56 -05:00

363 lines
8.4 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...) do { } while(0)
#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;
}
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;
}
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)
{
struct acpi_device *acpi_dev;
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;
status = acpi_bus_get_device(handle, &acpi_dev);
if (!ACPI_FAILURE(status)) {
int ret;
ret = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
"firmware_node");
ret = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
"physical_node");
}
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)) {
struct acpi_device *acpi_dev;
/* acpi_get_physical_device increase refcnt by one */
put_device(dev);
if (!acpi_bus_get_device(dev->archdata.acpi_handle,
&acpi_dev)) {
sysfs_remove_link(&dev->kobj, "firmware_node");
sysfs_remove_link(&acpi_dev->dev.kobj, "physical_node");
}
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