1 files changed, 45 insertions, 19 deletions

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 32affd3fa8bd..272800692088 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -45,6 +45,33 @@ struct i2c_acpi_lookup {
 	u32 min_speed;
 };
 
+/**
+ * i2c_acpi_get_i2c_resource - Gets I2cSerialBus resource if type matches
+ * @ares:	ACPI resource
+ * @i2c:	Pointer to I2cSerialBus resource will be returned here
+ *
+ * Checks if the given ACPI resource is of type I2cSerialBus.
+ * In this case, returns a pointer to it to the caller.
+ *
+ * Returns true if resource type is of I2cSerialBus, otherwise false.
+ */
+bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
+			       struct acpi_resource_i2c_serialbus **i2c)
+{
+	struct acpi_resource_i2c_serialbus *sb;
+
+	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+		return false;
+
+	sb = &ares->data.i2c_serial_bus;
+	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
+		return false;
+
+	*i2c = sb;
+	return true;
+}
+EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource);
+
 static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
 {
 	struct i2c_acpi_lookup *lookup = data;
@@ -52,11 +79,7 @@ static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
 	struct acpi_resource_i2c_serialbus *sb;
 	acpi_status status;
 
-	if (info->addr || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
-		return 1;
-
-	sb = &ares->data.i2c_serial_bus;
-	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
+	if (info->addr || !i2c_acpi_get_i2c_resource(ares, &sb))
 		return 1;
 
 	if (lookup->index != -1 && lookup->n++ != lookup->index)
@@ -65,7 +88,7 @@ static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
 	status = acpi_get_handle(lookup->device_handle,
 				 sb->resource_source.string_ptr,
 				 &lookup->adapter_handle);
-	if (!ACPI_SUCCESS(status))
+	if (ACPI_FAILURE(status))
 		return 1;
 
 	info->addr = sb->slave_address;
@@ -386,20 +409,22 @@ struct notifier_block i2c_acpi_notifier = {
  *
  * Also see i2c_new_device, which this function calls to create the i2c-client.
  *
- * Returns a pointer to the new i2c-client, or NULL if the adapter is not found.
+ * Returns a pointer to the new i2c-client, or error pointer in case of failure.
+ * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
  */
 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
 				       struct i2c_board_info *info)
 {
 	struct i2c_acpi_lookup lookup;
 	struct i2c_adapter *adapter;
+	struct i2c_client *client;
 	struct acpi_device *adev;
 	LIST_HEAD(resource_list);
 	int ret;
 
 	adev = ACPI_COMPANION(dev);
 	if (!adev)
-		return NULL;
+		return ERR_PTR(-EINVAL);
 
 	memset(&lookup, 0, sizeof(lookup));
 	lookup.info = info;
@@ -408,16 +433,23 @@ struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
 
 	ret = acpi_dev_get_resources(adev, &resource_list,
 				     i2c_acpi_fill_info, &lookup);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
 	acpi_dev_free_resource_list(&resource_list);
 
-	if (ret < 0 || !info->addr)
-		return NULL;
+	if (!info->addr)
+		return ERR_PTR(-EADDRNOTAVAIL);
 
 	adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
 	if (!adapter)
-		return NULL;
+		return ERR_PTR(-EPROBE_DEFER);
+
+	client = i2c_new_device(adapter, info);
+	if (!client)
+		return ERR_PTR(-ENODEV);
 
-	return i2c_new_device(adapter, info);
+	return client;
 }
 EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
 
@@ -525,13 +557,7 @@ i2c_acpi_space_handler(u32 function, acpi_physical_address command,
 		goto err;
 	}
 
-	if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) {
-		ret = AE_BAD_PARAMETER;
-		goto err;
-	}
-
-	sb = &ares->data.i2c_serial_bus;
-	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) {
+	if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
 		ret = AE_BAD_PARAMETER;
 		goto err;
 	}