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ACPI: use PNPID:instance_no as bus_id of ACPI device

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Previously we used the device name in the DSDT, but would
crash upon encountering a duplicate. Also, exposing the
DSDT device name to the user in a patch isn't a good idea,
because it is arbitrary.

After some discussion, we finally decided to use
"PNPID:instance_no" as the bus_id of ACPI devices.

Two attributes for each device are added at the same time,
the full pathname in ACPI namespace and hardware_id if it has.

NOTE:	acpi_bus_id_list is used to keep the information of PNPID
	and instance number of the given PNPID. Loop the
	acpi_bus_id_list to find the instance_no of the	same PNPID
	when register a device. If failed, i.e. we don't have a
	node with this PNPID, allocate one and link it to this list.

NOTE:	Now I don't take the memory free work in charge.
	If necessary, I can add a reference count in
	struct acpi_device_bus_id, and check the reference and
	when unregister a device, i.e. memory is freed when
	the reference count of a given PNPID is 0.

Signed-off-by: Li Shaohua <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Zhang Rui 2006-12-08 17:23:43 +08:00 committed by Len Brown
parent ae8433324b
commit e49bd2dd5a
1 changed files with 109 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

118
drivers/acpi/scan.c
View File

@ -21,9 +21,15 @@ extern struct acpi_device *acpi_root;
#define ACPI_BUS_DEVICE_NAME "System Bus"
static LIST_HEAD(acpi_device_list);
static LIST_HEAD(acpi_bus_id_list);
DEFINE_SPINLOCK(acpi_device_lock);
LIST_HEAD(acpi_wakeup_device_list);
struct acpi_device_bus_id{
char bus_id[9];
unsigned int instance_no;
struct list_head node;
};
static int acpi_eject_operation(acpi_handle handle, int lockable)
{
struct acpi_object_list arg_list;
@ -103,18 +109,61 @@ acpi_eject_store(struct device *d, struct device_attribute *attr,
static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
static void acpi_device_setup_files(struct acpi_device *dev)
static ssize_t
acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
struct acpi_device *acpi_dev = to_acpi_device(dev);
return sprintf(buf, "%s\n", acpi_dev->pnp.hardware_id);
}
static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
static ssize_t
acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
struct acpi_device *acpi_dev = to_acpi_device(dev);
struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
int result;
result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
if(result)
goto end;
result = sprintf(buf, "%s\n", (char*)path.pointer);
kfree(path.pointer);
end:
return result;
}
static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
static int acpi_device_setup_files(struct acpi_device *dev)
{
acpi_status status;
acpi_handle temp;
int result = 0;
/*
* If device has _EJ0, 'eject' file is created that is used to trigger
* hot-removal function from userland.
* Devices gotten from FADT don't have a "path" attribute
*/
if(dev->handle) {
result = device_create_file(&dev->dev, &dev_attr_path);
if(result)
goto end;
}
if(dev->flags.hardware_id) {
result = device_create_file(&dev->dev, &dev_attr_hid);
if(result)
goto end;
}
/*
* If device has _EJ0, 'eject' file is created that is used to trigger
* hot-removal function from userland.
*/
status = acpi_get_handle(dev->handle, "_EJ0", &temp);
if (ACPI_SUCCESS(status))
device_create_file(&dev->dev, &dev_attr_eject);
result = device_create_file(&dev->dev, &dev_attr_eject);
end:
return result;
}
static void acpi_device_remove_files(struct acpi_device *dev)
@ -129,6 +178,11 @@ static void acpi_device_remove_files(struct acpi_device *dev)
status = acpi_get_handle(dev->handle, "_EJ0", &temp);
if (ACPI_SUCCESS(status))
device_remove_file(&dev->dev, &dev_attr_eject);
if(dev->flags.hardware_id)
device_remove_file(&dev->dev, &dev_attr_hid);
if(dev->handle)
device_remove_file(&dev->dev, &dev_attr_path);
}
/* --------------------------------------------------------------------------
ACPI Bus operations
@ -260,9 +314,12 @@ static struct bus_type acpi_bus_type = {
.uevent = acpi_device_uevent,
};
static void acpi_device_register(struct acpi_device *device,
static int acpi_device_register(struct acpi_device *device,
struct acpi_device *parent)
{
int result;
struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
int found = 0;
/*
* Linkage
* -------
@ -273,7 +330,33 @@ static void acpi_device_register(struct acpi_device *device,
INIT_LIST_HEAD(&device->g_list);
INIT_LIST_HEAD(&device->wakeup_list);
new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
if (!new_bus_id) {
printk(KERN_ERR PREFIX "Memory allocation error\n");
return -ENOMEM;
}
spin_lock(&acpi_device_lock);
/*
* Find suitable bus_id and instance number in acpi_bus_id_list
* If failed, create one and link it into acpi_bus_id_list
*/
list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
if(!strcmp(acpi_device_bus_id->bus_id, device->flags.hardware_id? device->pnp.hardware_id : "PNPIDNON")) {
acpi_device_bus_id->instance_no ++;
found = 1;
kfree(new_bus_id);
break;
}
}
if(!found) {
acpi_device_bus_id = new_bus_id;
strcpy(acpi_device_bus_id->bus_id, device->flags.hardware_id ? device->pnp.hardware_id : "PNPIDNON");
acpi_device_bus_id->instance_no = 0;
list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
}
sprintf(device->dev.bus_id, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
if (device->parent) {
list_add_tail(&device->node, &device->parent->children);
list_add_tail(&device->g_list, &device->parent->g_list);
@ -287,12 +370,29 @@ static void acpi_device_register(struct acpi_device *device,
device->dev.parent = &parent->dev;
device->dev.bus = &acpi_bus_type;
device_initialize(&device->dev);
sprintf(device->dev.bus_id, "%s", device->pnp.bus_id);
device->dev.release = &acpi_device_release;
device_add(&device->dev);
result = device_add(&device->dev);
if(result) {
printk("Error adding device %s", device->dev.bus_id);
goto end;
}
result = acpi_device_setup_files(device);
if(result)
ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error creating sysfs interface for device %s\n", device->dev.bus_id));
acpi_device_setup_files(device);
device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
return 0;
end:
spin_lock(&acpi_device_lock);
if (device->parent) {
list_del(&device->node);
list_del(&device->g_list);
} else
list_del(&device->g_list);
list_del(&device->wakeup_list);
spin_unlock(&acpi_device_lock);
return result;
}
static void acpi_device_unregister(struct acpi_device *device, int type)
@ -1035,7 +1135,7 @@ acpi_add_single_object(struct acpi_device **child,
acpi_device_get_debug_info(device, handle, type);
acpi_device_register(device, parent);
result = acpi_device_register(device, parent);
end:
if (!result)