1 files changed, 173 insertions, 2 deletions

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 177f8d767df4..e425a868cd3a 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -30,6 +30,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/types.h>
+#include <linux/device.h>
 #include <linux/list.h>
 #include <linux/acpi.h>
 #include <acpi/acpi_bus.h>
@@ -65,6 +66,7 @@ struct wmi_block {
         acpi_handle handle;
         wmi_notify_handler handler;
         void *handler_data;
+        struct device *dev;
 };
 
 static struct wmi_block wmi_blocks;
@@ -195,6 +197,34 @@ static bool wmi_parse_guid(const u8 *src, u8 *dest)
         return true;
 }
 
+/*
+ * Convert a raw GUID to the ACII string representation
+ */
+static int wmi_gtoa(const char *in, char *out)
+{
+        int i;
+
+        for (i = 3; i >= 0; i--)
+                out += sprintf(out, "%02X", in[i] & 0xFF);
+
+        out += sprintf(out, "-");
+        out += sprintf(out, "%02X", in[5] & 0xFF);
+        out += sprintf(out, "%02X", in[4] & 0xFF);
+        out += sprintf(out, "-");
+        out += sprintf(out, "%02X", in[7] & 0xFF);
+        out += sprintf(out, "%02X", in[6] & 0xFF);
+        out += sprintf(out, "-");
+        out += sprintf(out, "%02X", in[8] & 0xFF);
+        out += sprintf(out, "%02X", in[9] & 0xFF);
+        out += sprintf(out, "-");
+
+        for (i = 10; i <= 15; i++)
+                out += sprintf(out, "%02X", in[i] & 0xFF);
+
+        out = '\0';
+        return 0;
+}
+
 static bool find_guid(const char *guid_string, struct wmi_block **out)
 {
         char tmp[16], guid_input[16];
@@ -555,6 +585,138 @@ bool wmi_has_guid(const char *guid_string)
 EXPORT_SYMBOL_GPL(wmi_has_guid);
 
 /*
+ * sysfs interface
+ */
+static ssize_t show_modalias(struct device *dev, struct device_attribute *attr,
+                             char *buf)
+{
+        char guid_string[37];
+        struct wmi_block *wblock;
+
+        wblock = dev_get_drvdata(dev);
+        if (!wblock)
+                return -ENOMEM;
+
+        wmi_gtoa(wblock->gblock.guid, guid_string);
+
+        return sprintf(buf, "wmi:%s\n", guid_string);
+}
+static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
+
+static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+        char guid_string[37];
+
+        struct wmi_block *wblock;
+
+        if (add_uevent_var(env, "MODALIAS="))
+                return -ENOMEM;
+
+        wblock = dev_get_drvdata(dev);
+        if (!wblock)
+                return -ENOMEM;
+
+        wmi_gtoa(wblock->gblock.guid, guid_string);
+
+        strcpy(&env->buf[env->buflen - 1], "wmi:");
+        memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
+        env->buflen += 40;
+
+        return 0;
+}
+
+static void wmi_dev_free(struct device *dev)
+{
+        kfree(dev);
+}
+
+static struct class wmi_class = {
+        .name = "wmi",
+        .dev_release = wmi_dev_free,
+        .dev_uevent = wmi_dev_uevent,
+};
+
+static int wmi_create_devs(void)
+{
+        int result;
+        char guid_string[37];
+        struct guid_block *gblock;
+        struct wmi_block *wblock;
+        struct list_head *p;
+        struct device *guid_dev;
+
+        /* Create devices for all the GUIDs */
+        list_for_each(p, &wmi_blocks.list) {
+                wblock = list_entry(p, struct wmi_block, list);
+
+                guid_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
+                if (!guid_dev)
+                        return -ENOMEM;
+
+                wblock->dev = guid_dev;
+
+                guid_dev->class = &wmi_class;
+                dev_set_drvdata(guid_dev, wblock);
+
+                gblock = &wblock->gblock;
+
+                wmi_gtoa(gblock->guid, guid_string);
+                dev_set_name(guid_dev, guid_string);
+
+                result = device_register(guid_dev);
+                if (result)
+                        return result;
+
+                result = device_create_file(guid_dev, &dev_attr_modalias);
+                if (result)
+                        return result;
+        }
+
+        return 0;
+}
+
+static void wmi_remove_devs(void)
+{
+        struct guid_block *gblock;
+        struct wmi_block *wblock;
+        struct list_head *p;
+        struct device *guid_dev;
+
+        /* Delete devices for all the GUIDs */
+        list_for_each(p, &wmi_blocks.list) {
+                wblock = list_entry(p, struct wmi_block, list);
+
+                guid_dev = wblock->dev;
+                gblock = &wblock->gblock;
+
+                device_remove_file(guid_dev, &dev_attr_modalias);
+
+                device_unregister(guid_dev);
+        }
+}
+
+static void wmi_class_exit(void)
+{
+        wmi_remove_devs();
+        class_unregister(&wmi_class);
+}
+
+static int wmi_class_init(void)
+{
+        int ret;
+
+        ret = class_register(&wmi_class);
+        if (ret)
+                return ret;
+
+        ret = wmi_create_devs();
+        if (ret)
+                wmi_class_exit();
+
+        return ret;
+}
+
+/*
  * Parse the _WDG method for the GUID data blocks
  */
 static __init acpi_status parse_wdg(acpi_handle handle)
@@ -709,10 +871,17 @@ static int __init acpi_wmi_init(void)
 
         if (result < 0) {
                 printk(KERN_INFO PREFIX "Error loading mapper\n");
-        } else {
-                printk(KERN_INFO PREFIX "Mapper loaded\n");
+                return -ENODEV;
+        }
+
+        result = wmi_class_init();
+        if (result) {
+                acpi_bus_unregister_driver(&acpi_wmi_driver);
+                return result;
         }
 
+        printk(KERN_INFO PREFIX "Mapper loaded\n");
+
         return result;
 }
 
@@ -721,6 +890,8 @@ static void __exit acpi_wmi_exit(void)
         struct list_head *p, *tmp;
         struct wmi_block *wblock;
 
+        wmi_class_exit();
+
         acpi_bus_unregister_driver(&acpi_wmi_driver);
 
         list_for_each_safe(p, tmp, &wmi_blocks.list) {