fpga: region: change api, add fpga_region_create/free

Add fpga_region_create/free API functions.

Change fpga_region_register to take FPGA region struct as the only
parameter.  Change fpga_region_unregister to return void.

  struct fpga_region *fpga_region_create(struct device *dev,
                        struct fpga_manager *mgr,
                        int (*get_bridges)(struct fpga_region *));
  void fpga_region_free(struct fpga_region *region);
  int fpga_region_register(struct fpga_region *region);
  void fpga_region_unregister(struct fpga_region *region);

Remove groups storage from struct fpga_region, it's not
needed.  Callers can just "region->dev.groups = groups;"
after calling fpga_region_create.

Update the drivers that call fpga_region_register with the new API.

Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/fpga/fpga-region.txt

@@ -42,8 +42,7 @@ The FPGA region API
 To register or unregister a region:
 -----------------------------------
 
-	int fpga_region_register(struct device *dev,
-				 struct fpga_region *region);
+	int fpga_region_register(struct fpga_region *region);
 	int fpga_region_unregister(struct fpga_region *region);
 
 An example of usage can be seen in the probe function of [3]

drivers/fpga/fpga-region.c

@@ -167,18 +167,36 @@ int fpga_region_program_fpga(struct fpga_region *region)
 }
 EXPORT_SYMBOL_GPL(fpga_region_program_fpga);
 
-int fpga_region_register(struct device *dev, struct fpga_region *region)
+/**
+ * fpga_region_create - alloc and init a struct fpga_region
+ * @dev: device parent
+ * @mgr: manager that programs this region
+ * @get_bridges: optional function to get bridges to a list
+ *
+ * Return: struct fpga_region or NULL
+ */
+struct fpga_region
+*fpga_region_create(struct device *dev,
+		    struct fpga_manager *mgr,
+		    int (*get_bridges)(struct fpga_region *))
 {
+	struct fpga_region *region;
 	int id, ret = 0;
 
+	region = kzalloc(sizeof(*region), GFP_KERNEL);
+	if (!region)
+		return NULL;
+
 	id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL);
 	if (id < 0)
-		return id;
+		goto err_free;
 
+	region->mgr = mgr;
+	region->get_bridges = get_bridges;
 	mutex_init(&region->mutex);
 	INIT_LIST_HEAD(&region->bridge_list);
+
 	device_initialize(&region->dev);
-	region->dev.groups = region->groups;
 	region->dev.class = fpga_region_class;
 	region->dev.parent = dev;
 	region->dev.of_node = dev->of_node;
@@ -188,23 +206,47 @@ int fpga_region_register(struct device *dev, struct fpga_region *region)
 	if (ret)
 		goto err_remove;
 
-	ret = device_add(&region->dev);
-	if (ret)
-		goto err_remove;
-
-	return 0;
+	return region;
 
 err_remove:
 	ida_simple_remove(&fpga_region_ida, id);
-	return ret;
+err_free:
+	kfree(region);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(fpga_region_create);
+
+/**
+ * fpga_region_free - free a struct fpga_region
+ * @region: FPGA region created by fpga_region_create
+ */
+void fpga_region_free(struct fpga_region *region)
+{
+	ida_simple_remove(&fpga_region_ida, region->dev.id);
+	kfree(region);
+}
+EXPORT_SYMBOL_GPL(fpga_region_free);
+
+/*
+ * fpga_region_register - register a FPGA region
+ * @region: FPGA region created by fpga_region_create
+ * Return: 0 or -errno
+ */
+int fpga_region_register(struct fpga_region *region)
+{
+	return device_add(&region->dev);
+
 }
 EXPORT_SYMBOL_GPL(fpga_region_register);
 
-int fpga_region_unregister(struct fpga_region *region)
+/*
+ * fpga_region_unregister - unregister a FPGA region
+ * @region: FPGA region
+ */
+void fpga_region_unregister(struct fpga_region *region)
 {
 	device_unregister(&region->dev);
-
-	return 0;
 }
 EXPORT_SYMBOL_GPL(fpga_region_unregister);
 
@@ -212,7 +254,7 @@ static void fpga_region_dev_release(struct device *dev)
 {
 	struct fpga_region *region = to_fpga_region(dev);
 
-	ida_simple_remove(&fpga_region_ida, region->dev.id);
+	fpga_region_free(region);
 }
 
 /**

drivers/fpga/of-fpga-region.c

@@ -422,20 +422,15 @@ static int of_fpga_region_probe(struct platform_device *pdev)
 	if (IS_ERR(mgr))
 		return -EPROBE_DEFER;
 
-	region = devm_kzalloc(dev, sizeof(*region), GFP_KERNEL);
+	region = fpga_region_create(dev, mgr, of_fpga_region_get_bridges);
 	if (!region) {
 		ret = -ENOMEM;
 		goto eprobe_mgr_put;
 	}
 
-	region->mgr = mgr;
-
-	/* Specify how to get bridges for this type of region. */
-	region->get_bridges = of_fpga_region_get_bridges;
-
-	ret = fpga_region_register(dev, region);
+	ret = fpga_region_register(region);
 	if (ret)
-		goto eprobe_mgr_put;
+		goto eprobe_free;
 
 	of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
 	dev_set_drvdata(dev, region);
@@ -444,6 +439,8 @@ static int of_fpga_region_probe(struct platform_device *pdev)
 
 	return 0;
 
+eprobe_free:
+	fpga_region_free(region);
 eprobe_mgr_put:
 	fpga_mgr_put(mgr);
 	return ret;

include/linux/fpga/fpga-region.h

@@ -14,7 +14,6 @@
  * @info: FPGA image info
  * @priv: private data
  * @get_bridges: optional function to get bridges to a list
- * @groups: optional attribute groups.
  */
 struct fpga_region {
 	struct device dev;
@@ -24,7 +23,6 @@ struct fpga_region {
 	struct fpga_image_info *info;
 	void *priv;
 	int (*get_bridges)(struct fpga_region *region);
-	const struct attribute_group **groups;
 };
 
 #define to_fpga_region(d) container_of(d, struct fpga_region, dev)
@@ -34,7 +32,12 @@ struct fpga_region *fpga_region_class_find(
 	int (*match)(struct device *, const void *));
 
 int fpga_region_program_fpga(struct fpga_region *region);
-int fpga_region_register(struct device *dev, struct fpga_region *region);
-int fpga_region_unregister(struct fpga_region *region);
+
+struct fpga_region
+*fpga_region_create(struct device *dev, struct fpga_manager *mgr,
+		    int (*get_bridges)(struct fpga_region *));
+void fpga_region_free(struct fpga_region *region);
+int fpga_region_register(struct fpga_region *region);
+void fpga_region_unregister(struct fpga_region *region);
 
 #endif /* _FPGA_REGION_H */