1 files changed, 81 insertions, 16 deletions

diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index 6db1661a5625..516dd22bbb26 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -727,20 +727,79 @@ static int acpi_callsetfunc(acpi_handle handle, char *name, int value,
         return -1;
 }
 
-static int sony_find_snc_handle(int handle)
+struct sony_nc_handles {
+        u16 cap[0x10];
+        struct device_attribute devattr;
+};
+
+struct sony_nc_handles *handles;
+
+static ssize_t sony_nc_handles_show(struct device *dev,
+                struct device_attribute *attr, char *buffer)
+{
+        ssize_t len = 0;
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(handles->cap); i++) {
+                len += snprintf(buffer + len, PAGE_SIZE - len, "0x%.4x ",
+                                handles->cap[i]);
+        }
+        len += snprintf(buffer + len, PAGE_SIZE - len, "\n");
+
+        return len;
+}
+
+static int sony_nc_handles_setup(struct platform_device *pd)
 {
         int i;
         int result;
 
-        for (i = 0x20; i < 0x30; i++) {
-                acpi_callsetfunc(sony_nc_acpi_handle, "SN00", i, &result);
-                if (result == handle) {
-                        dprintk("found handle 0x%.4x (offset: 0x%.2x)\n",
-                                        handle, i - 0x20);
-                        return i-0x20;
+        handles = kzalloc(sizeof(*handles), GFP_KERNEL);
+
+        sysfs_attr_init(&handles->devattr.attr);
+        handles->devattr.attr.name = "handles";
+        handles->devattr.attr.mode = S_IRUGO;
+        handles->devattr.show = sony_nc_handles_show;
+
+        for (i = 0; i < ARRAY_SIZE(handles->cap); i++) {
+                if (!acpi_callsetfunc(sony_nc_acpi_handle,
+                                        "SN00", i + 0x20, &result)) {
+                        dprintk("caching handle 0x%.4x (offset: 0x%.2x)\n",
+                                        result, i);
+                        handles->cap[i] = result;
                 }
         }
 
+        /* allow reading capabilities via sysfs */
+        if (device_create_file(&pd->dev, &handles->devattr)) {
+                kfree(handles);
+                handles = NULL;
+                return -1;
+        }
+
+        return 0;
+}
+
+static int sony_nc_handles_cleanup(struct platform_device *pd)
+{
+        if (handles) {
+                device_remove_file(&pd->dev, &handles->devattr);
+                kfree(handles);
+                handles = NULL;
+        }
+        return 0;
+}
+
+static int sony_find_snc_handle(int handle)
+{
+        int i;
+        for (i = 0; i < 0x10; i++) {
+                if (handles->cap[i] == handle) {
+                        dprintk("found handle 0x%.4x (offset: 0x%.2x)\n",
+                                        handle, i);
+                        return i;
+                }
+        }
         dprintk("handle 0x%.4x not found\n", handle);
         return -1;
 }
@@ -1274,6 +1333,10 @@ static int sony_nc_add(struct acpi_device *device)
                 goto outwalk;
         }
 
+        result = sony_pf_add();
+        if (result)
+                goto outpresent;
+
         if (debug) {
                 status = acpi_walk_namespace(ACPI_TYPE_METHOD,
                                 sony_nc_acpi_handle, 1, sony_walk_callback,
@@ -1281,7 +1344,7 @@ static int sony_nc_add(struct acpi_device *device)
                 if (ACPI_FAILURE(status)) {
                         pr_warn(DRV_PFX "unable to walk acpi resources\n");
                         result = -ENODEV;
-                        goto outwalk;
+                        goto outpresent;
                 }
         }
 
@@ -1294,6 +1357,8 @@ static int sony_nc_add(struct acpi_device *device)
         if (ACPI_SUCCESS(acpi_get_handle(sony_nc_acpi_handle, "SN00",
                                          &handle))) {
                 dprintk("Doing SNC setup\n");
+                if (sony_nc_handles_setup(sony_pf_device))
+                        goto outpresent;
                 sony_nc_function_setup(device);
                 sony_nc_rfkill_setup(device);
         }
@@ -1302,7 +1367,7 @@ static int sony_nc_add(struct acpi_device *device)
         result = sony_laptop_setup_input(device);
         if (result) {
                 pr_err(DRV_PFX "Unable to create input devices.\n");
-                goto outwalk;
+                goto outsnc;
         }
 
         if (acpi_video_backlight_support()) {
@@ -1330,10 +1395,6 @@ static int sony_nc_add(struct acpi_device *device)
 
         }
 
-        result = sony_pf_add();
-        if (result)
-                goto outbacklight;
-
         /* create sony_pf sysfs attributes related to the SNC device */
         for (item = sony_nc_values; item->name; ++item) {
 
@@ -1379,14 +1440,17 @@ static int sony_nc_add(struct acpi_device *device)
         for (item = sony_nc_values; item->name; ++item) {
                 device_remove_file(&sony_pf_device->dev, &item->devattr);
         }
-        sony_pf_remove();
-
-      outbacklight:
         if (sony_backlight_device)
                 backlight_device_unregister(sony_backlight_device);
 
         sony_laptop_remove_input();
 
+      outsnc:
+        sony_nc_handles_cleanup(sony_pf_device);
+
+      outpresent:
+        sony_pf_remove();
+
       outwalk:
         sony_nc_rfkill_cleanup();
         return result;
@@ -1405,6 +1469,7 @@ static int sony_nc_remove(struct acpi_device *device, int type)
                 device_remove_file(&sony_pf_device->dev, &item->devattr);
         }
 
+        sony_nc_handles_cleanup(sony_pf_device);
         sony_pf_remove();
         sony_laptop_remove_input();
         sony_nc_rfkill_cleanup();