ACPI / scan: ACPI device object sysfs attribute for _STA evaluation
This patch adds a "status" attribute for an ACPI device. This status
attribute shows the value of the _STA object. The _STA object returns
current status of an ACPI device: enabled, disabled, functioning,
present.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[rjw: Subject and changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 32b3401..c0f57ff 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -602,6 +602,20 @@
}
static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
+static ssize_t status_show(struct device *dev, struct device_attribute *attr,
+ char *buf) {
+ struct acpi_device *acpi_dev = to_acpi_device(dev);
+ acpi_status status;
+ unsigned long long sta;
+
+ status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ return sprintf(buf, "%llu\n", sta);
+}
+static DEVICE_ATTR_RO(status);
+
static int acpi_device_setup_files(struct acpi_device *dev)
{
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
@@ -657,6 +671,12 @@
dev->pnp.sun = (unsigned long)-1;
}
+ if (acpi_has_method(dev->handle, "_STA")) {
+ result = device_create_file(&dev->dev, &dev_attr_status);
+ if (result)
+ goto end;
+ }
+
/*
* If device has _EJ0, 'eject' file is created that is used to trigger
* hot-removal function from userland.
@@ -712,6 +732,8 @@
device_remove_file(&dev->dev, &dev_attr_adr);
device_remove_file(&dev->dev, &dev_attr_modalias);
device_remove_file(&dev->dev, &dev_attr_hid);
+ if (acpi_has_method(dev->handle, "_STA"))
+ device_remove_file(&dev->dev, &dev_attr_status);
if (dev->handle)
device_remove_file(&dev->dev, &dev_attr_path);
}