linux/drivers/acpi/glue.c
Thomas Renninger 22c13f9d81 ACPI: video: Ignore devices that aren't present in hardware
This is a reimplemention of commit
0119509c4f
from Matthew Garrett <mjg59@srcf.ucam.org>

This patch got removed because of a regression: ThinkPads with a
Intel graphics card and an Integrated Graphics Device BIOS implementation
stopped working.
In fact, they only worked because the ACPI device of the discrete, the
wrong one, got used (via int10). So ACPI functions were poking on the wrong
hardware used which is a sever bug.
The next patch provides support for above ThinkPads to be able to
switch brightness via the legacy thinkpad_acpi driver and automatically
detect when to use it.

Original commit message from Matthew Garrett:
    Vendors often ship machines with a choice of integrated or discrete
    graphics, and use the same DSDT for both. As a result, the ACPI video
    module will locate devices that may not exist on this specific platform.
    Attempt to determine whether the device exists or not, and abort the
    device creation if it doesn't.

http://bugzilla.kernel.org/show_bug.cgi?id=9614

Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2008-11-07 23:49:23 -05:00

302 lines
7.3 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);
/* ToDo: When a PCI bridge is found, return the PCI device behind the bridge
* This should work in general, but did not on a Lenovo T61 for the
* graphics card. But this must be fixed when the PCI device is
* bound and the kernel device struct is attached to the acpi device
* Note: A success call will increase reference count by one
* Do call put_device(dev) on the returned device then
*/
struct device *acpi_get_physical_pci_device(acpi_handle handle)
{
struct device *dev;
long long device_id;
acpi_status status;
status =
acpi_evaluate_integer(handle, "_ADR", NULL, &device_id);
if (ACPI_FAILURE(status))
return NULL;
/* We need to attempt to determine whether the _ADR refers to a
PCI device or not. There's no terribly good way to do this,
so the best we can hope for is to assume that there'll never
be a device in the host bridge */
if (device_id >= 0x10000) {
/* It looks like a PCI device. Does it exist? */
dev = acpi_get_physical_device(handle);
} else {
/* It doesn't look like a PCI device. Does its parent
exist? */
acpi_handle phandle;
if (acpi_get_parent(handle, &phandle))
return NULL;
dev = acpi_get_physical_device(phandle);
}
if (!dev)
return NULL;
return dev;
}
EXPORT_SYMBOL(acpi_get_physical_pci_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) {
dev_warn(dev, "Drivers changed 'acpi_handle'\n");
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");
if (acpi_dev->wakeup.flags.valid) {
device_set_wakeup_capable(dev, true);
device_set_wakeup_enable(dev,
acpi_dev->wakeup.state.enabled);
}
}
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 {
dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
}
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);