fpga: add devm_fpga_region_create

Add devm_fpga_region_create() which is the
managed version of fpga_region_create().

Change current region drivers to use
devm_fpga_region_create().

Signed-off-by: Alan Tull <atull@kernel.org>
Suggested-by: Federico Vaga <federico.vaga@cern.ch>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 63 insertions, 20 deletions

diff --git a/drivers/fpga/dfl-fme-region.c b/drivers/fpga/dfl-fme-region.c
index 51a5ac2293a7..ec134ec93f08 100644
--- a/drivers/fpga/dfl-fme-region.c
+++ b/drivers/fpga/dfl-fme-region.c
@@ -39,7 +39,7 @@ static int fme_region_probe(struct platform_device *pdev)
         if (IS_ERR(mgr))
                 return -EPROBE_DEFER;
 
-        region = fpga_region_create(dev, mgr, fme_region_get_bridges);
+        region = devm_fpga_region_create(dev, mgr, fme_region_get_bridges);
         if (!region) {
                 ret = -ENOMEM;
                 goto eprobe_mgr_put;
@@ -51,14 +51,12 @@ static int fme_region_probe(struct platform_device *pdev)
 
         ret = fpga_region_register(region);
         if (ret)
-                goto region_free;
+                goto eprobe_mgr_put;
 
         dev_dbg(dev, "DFL FME FPGA Region probed\n");
 
         return 0;
 
-region_free:
-        fpga_region_free(region);
 eprobe_mgr_put:
         fpga_mgr_put(mgr);
         return ret;
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
index a9b521bccb06..2c09e502e721 100644
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -899,7 +899,7 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)
         if (!cdev)
                 return ERR_PTR(-ENOMEM);
 
-        cdev->region = fpga_region_create(info->dev, NULL, NULL);
+        cdev->region = devm_fpga_region_create(info->dev, NULL, NULL);
         if (!cdev->region) {
                 ret = -ENOMEM;
                 goto free_cdev_exit;
@@ -911,7 +911,7 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)
 
         ret = fpga_region_register(cdev->region);
         if (ret)
-                goto free_region_exit;
+                goto free_cdev_exit;
 
         /* create and init build info for enumeration */
         binfo = devm_kzalloc(info->dev, sizeof(*binfo), GFP_KERNEL);
@@ -942,8 +942,6 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)
 
 unregister_region_exit:
         fpga_region_unregister(cdev->region);
-free_region_exit:
-        fpga_region_free(cdev->region);
 free_cdev_exit:
         devm_kfree(info->dev, cdev);
         return ERR_PTR(ret);
diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index 0d65220d5ec5..bde5a9d460c5 100644
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -185,6 +185,10 @@ ATTRIBUTE_GROUPS(fpga_region);
  * @mgr: manager that programs this region
  * @get_bridges: optional function to get bridges to a list
  *
+ * The caller of this function is responsible for freeing the resulting region
+ * struct with fpga_region_free().  Using devm_fpga_region_create() instead is
+ * recommended.
+ *
  * Return: struct fpga_region or NULL
  */
 struct fpga_region
@@ -230,8 +234,8 @@ err_free:
 EXPORT_SYMBOL_GPL(fpga_region_create);
 
 /**
- * fpga_region_free - free a struct fpga_region
- * @region: FPGA region created by fpga_region_create
+ * fpga_region_free - free a FPGA region created by fpga_region_create()
+ * @region: FPGA region
  */
 void fpga_region_free(struct fpga_region *region)
 {
@@ -240,21 +244,69 @@ void fpga_region_free(struct fpga_region *region)
 }
 EXPORT_SYMBOL_GPL(fpga_region_free);
 
+static void devm_fpga_region_release(struct device *dev, void *res)
+{
+        struct fpga_region *region = *(struct fpga_region **)res;
+
+        fpga_region_free(region);
+}
+
+/**
+ * devm_fpga_region_create - create and initialize a managed FPGA region struct
+ * @dev: device parent
+ * @mgr: manager that programs this region
+ * @get_bridges: optional function to get bridges to a list
+ *
+ * This function is intended for use in a FPGA region driver's probe function.
+ * After the region driver creates the region struct with
+ * devm_fpga_region_create(), it should register it with fpga_region_register().
+ * The region driver's remove function should call fpga_region_unregister().
+ * The region struct allocated with this function will be freed automatically on
+ * driver detach.  This includes the case of a probe function returning error
+ * before calling fpga_region_register(), the struct will still get cleaned up.
+ *
+ * Return: struct fpga_region or NULL
+ */
+struct fpga_region
+*devm_fpga_region_create(struct device *dev,
+                         struct fpga_manager *mgr,
+                         int (*get_bridges)(struct fpga_region *))
+{
+        struct fpga_region **ptr, *region;
+
+        ptr = devres_alloc(devm_fpga_region_release, sizeof(*ptr), GFP_KERNEL);
+        if (!ptr)
+                return NULL;
+
+        region = fpga_region_create(dev, mgr, get_bridges);
+        if (!region) {
+                devres_free(ptr);
+        } else {
+                *ptr = region;
+                devres_add(dev, ptr);
+        }
+
+        return region;
+}
+EXPORT_SYMBOL_GPL(devm_fpga_region_create);
+
 /**
  * fpga_region_register - register a FPGA region
- * @region: FPGA region created by fpga_region_create
+ * @region: FPGA region
+ *
  * Return: 0 or -errno
  */
 int fpga_region_register(struct fpga_region *region)
 {
         return device_add(&region->dev);
-
 }
 EXPORT_SYMBOL_GPL(fpga_region_register);
 
 /**
- * fpga_region_unregister - unregister and free a FPGA region
+ * fpga_region_unregister - unregister a FPGA region
  * @region: FPGA region
+ *
+ * This function is intended for use in a FPGA region driver's remove function.
  */
 void fpga_region_unregister(struct fpga_region *region)
 {
@@ -264,9 +316,6 @@ EXPORT_SYMBOL_GPL(fpga_region_unregister);
 
 static void fpga_region_dev_release(struct device *dev)
 {
-        struct fpga_region *region = to_fpga_region(dev);
-
-        fpga_region_free(region);
 }
 
 /**
diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
index 052a1342ab7e..122286fd255a 100644
--- a/drivers/fpga/of-fpga-region.c
+++ b/drivers/fpga/of-fpga-region.c
@@ -410,7 +410,7 @@ static int of_fpga_region_probe(struct platform_device *pdev)
         if (IS_ERR(mgr))
                 return -EPROBE_DEFER;
 
-        region = fpga_region_create(dev, mgr, of_fpga_region_get_bridges);
+        region = devm_fpga_region_create(dev, mgr, of_fpga_region_get_bridges);
         if (!region) {
                 ret = -ENOMEM;
                 goto eprobe_mgr_put;
@@ -418,7 +418,7 @@ static int of_fpga_region_probe(struct platform_device *pdev)
 
         ret = fpga_region_register(region);
         if (ret)
-                goto eprobe_free;
+                goto eprobe_mgr_put;
 
         of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
         dev_set_drvdata(dev, region);
@@ -427,8 +427,6 @@ 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;