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();