summary refs log tree commit diff
path: root/drivers/platform/x86/dell-wmi-descriptor.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/platform/x86/dell-wmi-descriptor.c')
-rw-r--r--drivers/platform/x86/dell-wmi-descriptor.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/platform/x86/dell-wmi-descriptor.c b/drivers/platform/x86/dell-wmi-descriptor.c
index 28ef5f37cfbf..4dfef1f53481 100644
--- a/drivers/platform/x86/dell-wmi-descriptor.c
+++ b/drivers/platform/x86/dell-wmi-descriptor.c
@@ -21,14 +21,26 @@
 #include <linux/wmi.h>
 #include "dell-wmi-descriptor.h"
 
+#define DELL_WMI_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492"
+
 struct descriptor_priv {
 	struct list_head list;
 	u32 interface_version;
 	u32 size;
 };
+static int descriptor_valid = -EPROBE_DEFER;
 static LIST_HEAD(wmi_list);
 static DEFINE_MUTEX(list_mutex);
 
+int dell_wmi_get_descriptor_valid(void)
+{
+	if (!wmi_has_guid(DELL_WMI_DESCRIPTOR_GUID))
+		return -ENODEV;
+
+	return descriptor_valid;
+}
+EXPORT_SYMBOL_GPL(dell_wmi_get_descriptor_valid);
+
 bool dell_wmi_get_interface_version(u32 *version)
 {
 	struct descriptor_priv *priv;
@@ -91,6 +103,7 @@ static int dell_wmi_descriptor_probe(struct wmi_device *wdev)
 	if (obj->type != ACPI_TYPE_BUFFER) {
 		dev_err(&wdev->dev, "Dell descriptor has wrong type\n");
 		ret = -EINVAL;
+		descriptor_valid = ret;
 		goto out;
 	}
 
@@ -102,6 +115,7 @@ static int dell_wmi_descriptor_probe(struct wmi_device *wdev)
 			"Dell descriptor buffer has unexpected length (%d)\n",
 			obj->buffer.length);
 		ret = -EINVAL;
+		descriptor_valid = ret;
 		goto out;
 	}
 
@@ -111,8 +125,10 @@ static int dell_wmi_descriptor_probe(struct wmi_device *wdev)
 		dev_err(&wdev->dev, "Dell descriptor buffer has invalid signature (%8ph)\n",
 			buffer);
 		ret = -EINVAL;
+		descriptor_valid = ret;
 		goto out;
 	}
+	descriptor_valid = 0;
 
 	if (buffer[2] != 0 && buffer[2] != 1)
 		dev_warn(&wdev->dev, "Dell descriptor buffer has unknown version (%lu)\n",