diff --git a/Documentation/ABI/testing/sysfs-devices-resource_in_use b/Documentation/ABI/testing/sysfs-devices-resource_in_use new file mode 100644 index 0000000000000000000000000000000000000000..b4a3bc5922a3094295158fe282e64c7158496f4e --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-resource_in_use @@ -0,0 +1,12 @@ +What: /sys/devices/.../resource_in_use +Date: January 2013 +Contact: Rafael J. Wysocki +Description: + The /sys/devices/.../resource_in_use attribute is only present + for device objects representing ACPI power resources. + + If present, it contains a number (0 or 1) representing the + current status of the given power resource (0 means that the + resource is not in use and therefore it has been turned off). + + This attribute is read-only. diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c index 3f16dd4db23e82275cf9129255e931d3081736f4..946720a4db57d7c4b745f6a5a148ba9da29d77c4 100644 --- a/drivers/acpi/power.c +++ b/drivers/acpi/power.c @@ -87,6 +87,12 @@ static DEFINE_MUTEX(power_resource_list_lock); Power Resource Management -------------------------------------------------------------------------- */ +static inline +struct acpi_power_resource *to_power_resource(struct acpi_device *device) +{ + return container_of(device, struct acpi_power_resource, device); +} + static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle) { struct acpi_device *device; @@ -94,7 +100,7 @@ static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle) if (acpi_bus_get_device(handle, &device)) return NULL; - return container_of(device, struct acpi_power_resource, device); + return to_power_resource(device); } static int acpi_power_resources_list_add(acpi_handle handle, @@ -678,6 +684,21 @@ static void acpi_release_power_resource(struct device *dev) kfree(resource); } +static ssize_t acpi_power_in_use_show(struct device *dev, + struct device_attribute *attr, + char *buf) { + struct acpi_power_resource *resource; + + resource = to_power_resource(to_acpi_device(dev)); + return sprintf(buf, "%u\n", !!resource->ref_count); +} +static DEVICE_ATTR(resource_in_use, 0444, acpi_power_in_use_show, NULL); + +static void acpi_power_sysfs_remove(struct acpi_device *device) +{ + device_remove_file(&device->dev, &dev_attr_resource_in_use); +} + int acpi_add_power_resource(acpi_handle handle) { struct acpi_power_resource *resource; @@ -725,6 +746,9 @@ int acpi_add_power_resource(acpi_handle handle) if (result) goto err; + if (!device_create_file(&device->dev, &dev_attr_resource_in_use)) + device->remove = acpi_power_sysfs_remove; + mutex_lock(&power_resource_list_lock); list_add(&resource->list_node, &acpi_power_resource_list); mutex_unlock(&power_resource_list_lock); diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 9761d589f3f5ee8de3cadf6562630add238ecaff..9801837876b7bcd2be21ee66ec859b81040c7e81 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -791,6 +791,9 @@ static void acpi_device_unregister(struct acpi_device *device) acpi_power_add_remove_device(device, false); acpi_device_remove_files(device); + if (device->remove) + device->remove(device); + device_del(&device->dev); /* * Drop the reference counts of all power resources the device depends diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index fca1b9cb27d977347c351a9e706683d1bb39cf2c..aef56a9f4e7033fe0a6afa878771cf3f679d5d7e 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -280,6 +280,7 @@ struct acpi_device { struct mutex physical_node_lock; DECLARE_BITMAP(physical_node_id_bitmap, ACPI_MAX_PHYSICAL_NODE); struct list_head power_dependent; + void (*remove)(struct acpi_device *); }; static inline void *acpi_driver_data(struct acpi_device *d)