fpga: region: move device tree support to of-fpga-region.c

Create of-fpga-region.c and move the following functions without
modification from fpga-region.c.

* of_fpga_region_find
* of_fpga_region_get_mgr
* of_fpga_region_get_bridges
* child_regions_with_firmware
* of_fpga_region_parse_ov
* of_fpga_region_notify_pre_apply
* of_fpga_region_notify_post_remove
* of_fpga_region_notify
* of_fpga_region_probe
* of_fpga_region_remove

Create two new functions with some code from fpga_region_init/exit.

* of_fpga_region_init
* of_fpga_region_exit

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

4 files changed, 509 insertions, 455 deletions

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index ad5448f718b3..12bd1c760c32 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -13,10 +13,18 @@ if FPGA
 
 config FPGA_REGION
 	tristate "FPGA Region"
-	depends on OF && FPGA_BRIDGE
+	depends on FPGA_BRIDGE
+	help
+	  FPGA Region common code.  A FPGA Region controls a FPGA Manager
+	  and the FPGA Bridges associated with either a reconfigurable
+	  region of an FPGA or a whole FPGA.
+
+config OF_FPGA_REGION
+	tristate "FPGA Region Device Tree Overlay Support"
+	depends on OF && FPGA_REGION
 	help
-	  FPGA Regions allow loading FPGA images under control of
-	  the Device Tree.
+	  Support for loading FPGA images by applying a Device Tree
+	  overlay.
 
 config FPGA_MGR_ICE40_SPI
 	tristate "Lattice iCE40 SPI"
@@ -74,7 +82,6 @@ config FPGA_MGR_ZYNQ_FPGA
 
 config FPGA_BRIDGE
 	tristate "FPGA Bridge Framework"
-	depends on OF
 	help
 	  Say Y here if you want to support bridges connected between host
 	  processors and FPGAs or between FPGAs.
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index f98dcf1d89e1..3cb276a0f88d 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -26,3 +26,4 @@ obj-$(CONFIG_XILINX_PR_DECOUPLER)	+= xilinx-pr-decoupler.o
 
 # High Level Interfaces
 obj-$(CONFIG_FPGA_REGION)		+= fpga-region.o
+obj-$(CONFIG_OF_FPGA_REGION)		+= of-fpga-region.o
diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index 5c0869576cd1..afc61885a601 100644
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -2,6 +2,7 @@
  * FPGA Region - Device Tree support for FPGA programming under Linux
  *
  *  Copyright (C) 2013-2016 Altera Corporation
+ *  Copyright (C) 2017 Intel Corporation
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -23,7 +24,6 @@
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/module.h>
-#include <linux/of_platform.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 
@@ -44,30 +44,6 @@ struct fpga_region *fpga_region_class_find(
 }
 EXPORT_SYMBOL_GPL(fpga_region_class_find);
 
-static const struct of_device_id fpga_region_of_match[] = {
-	{ .compatible = "fpga-region", },
-	{},
-};
-MODULE_DEVICE_TABLE(of, fpga_region_of_match);
-
-static int fpga_region_of_node_match(struct device *dev, const void *data)
-{
-	return dev->of_node == data;
-}
-
-/**
- * of_fpga_region_find - find FPGA region
- * @np: device node of FPGA Region
- *
- * Caller will need to put_device(&region->dev) when done.
- *
- * Returns FPGA Region struct or NULL
- */
-static struct fpga_region *of_fpga_region_find(struct device_node *np)
-{
-	return fpga_region_class_find(NULL, np, fpga_region_of_node_match);
-}
-
 /**
  * fpga_region_get - get an exclusive reference to a fpga region
  * @region: FPGA Region struct
@@ -116,102 +92,6 @@ static void fpga_region_put(struct fpga_region *region)
 }
 
 /**
- * of_fpga_region_get_mgr - get reference for FPGA manager
- * @np: device node of FPGA region
- *
- * Get FPGA Manager from "fpga-mgr" property or from ancestor region.
- *
- * Caller should call fpga_mgr_put() when done with manager.
- *
- * Return: fpga manager struct or IS_ERR() condition containing error code.
- */
-static struct fpga_manager *of_fpga_region_get_mgr(struct device_node *np)
-{
-	struct device_node  *mgr_node;
-	struct fpga_manager *mgr;
-
-	of_node_get(np);
-	while (np) {
-		if (of_device_is_compatible(np, "fpga-region")) {
-			mgr_node = of_parse_phandle(np, "fpga-mgr", 0);
-			if (mgr_node) {
-				mgr = of_fpga_mgr_get(mgr_node);
-				of_node_put(np);
-				return mgr;
-			}
-		}
-		np = of_get_next_parent(np);
-	}
-	of_node_put(np);
-
-	return ERR_PTR(-EINVAL);
-}
-
-/**
- * of_fpga_region_get_bridges - create a list of bridges
- * @region: FPGA region
- *
- * Create a list of bridges including the parent bridge and the bridges
- * specified by "fpga-bridges" property.  Note that the
- * fpga_bridges_enable/disable/put functions are all fine with an empty list
- * if that happens.
- *
- * Caller should call fpga_bridges_put(&region->bridge_list) when
- * done with the bridges.
- *
- * Return 0 for success (even if there are no bridges specified)
- * or -EBUSY if any of the bridges are in use.
- */
-static int of_fpga_region_get_bridges(struct fpga_region *region)
-{
-	struct device *dev = &region->dev;
-	struct device_node *region_np = dev->of_node;
-	struct fpga_image_info *info = region->info;
-	struct device_node *br, *np, *parent_br = NULL;
-	int i, ret;
-
-	/* If parent is a bridge, add to list */
-	ret = of_fpga_bridge_get_to_list(region_np->parent, info,
-					 &region->bridge_list);
-
-	/* -EBUSY means parent is a bridge that is under use. Give up. */
-	if (ret == -EBUSY)
-		return ret;
-
-	/* Zero return code means parent was a bridge and was added to list. */
-	if (!ret)
-		parent_br = region_np->parent;
-
-	/* If overlay has a list of bridges, use it. */
-	if (of_parse_phandle(info->overlay, "fpga-bridges", 0))
-		np = info->overlay;
-	else
-		np = region_np;
-
-	for (i = 0; ; i++) {
-		br = of_parse_phandle(np, "fpga-bridges", i);
-		if (!br)
-			break;
-
-		/* If parent bridge is in list, skip it. */
-		if (br == parent_br)
-			continue;
-
-		/* If node is a bridge, get it and add to list */
-		ret = of_fpga_bridge_get_to_list(br, info,
-						 &region->bridge_list);
-
-		/* If any of the bridges are in use, give up */
-		if (ret == -EBUSY) {
-			fpga_bridges_put(&region->bridge_list);
-			return -EBUSY;
-		}
-	}
-
-	return 0;
-}
-
-/**
  * fpga_region_program_fpga - program FPGA
  * @region: FPGA region
  * Program an FPGA using fpga image info (region->info).
@@ -282,259 +162,6 @@ err_put_region:
 }
 EXPORT_SYMBOL_GPL(fpga_region_program_fpga);
 
-/**
- * child_regions_with_firmware
- * @overlay: device node of the overlay
- *
- * If the overlay adds child FPGA regions, they are not allowed to have
- * firmware-name property.
- *
- * Return 0 for OK or -EINVAL if child FPGA region adds firmware-name.
- */
-static int child_regions_with_firmware(struct device_node *overlay)
-{
-	struct device_node *child_region;
-	const char *child_firmware_name;
-	int ret = 0;
-
-	of_node_get(overlay);
-
-	child_region = of_find_matching_node(overlay, fpga_region_of_match);
-	while (child_region) {
-		if (!of_property_read_string(child_region, "firmware-name",
-					     &child_firmware_name)) {
-			ret = -EINVAL;
-			break;
-		}
-		child_region = of_find_matching_node(child_region,
-						     fpga_region_of_match);
-	}
-
-	of_node_put(child_region);
-
-	if (ret)
-		pr_err("firmware-name not allowed in child FPGA region: %pOF",
-		       child_region);
-
-	return ret;
-}
-
-/**
- * of_fpga_region_parse_ov - parse and check overlay applied to region
- *
- * @region: FPGA region
- * @overlay: overlay applied to the FPGA region
- *
- * Given an overlay applied to a FPGA region, parse the FPGA image specific
- * info in the overlay and do some checking.
- *
- * Returns:
- *   NULL if overlay doesn't direct us to program the FPGA.
- *   fpga_image_info struct if there is an image to program.
- *   error code for invalid overlay.
- */
-static struct fpga_image_info *of_fpga_region_parse_ov(
-						struct fpga_region *region,
-						struct device_node *overlay)
-{
-	struct device *dev = &region->dev;
-	struct fpga_image_info *info;
-	const char *firmware_name;
-	int ret;
-
-	if (region->info) {
-		dev_err(dev, "Region already has overlay applied.\n");
-		return ERR_PTR(-EINVAL);
-	}
-
-	/*
-	 * Reject overlay if child FPGA Regions added in the overlay have
-	 * firmware-name property (would mean that an FPGA region that has
-	 * not been added to the live tree yet is doing FPGA programming).
-	 */
-	ret = child_regions_with_firmware(overlay);
-	if (ret)
-		return ERR_PTR(ret);
-
-	info = fpga_image_info_alloc(dev);
-	if (!info)
-		return ERR_PTR(-ENOMEM);
-
-	info->overlay = overlay;
-
-	/* Read FPGA region properties from the overlay */
-	if (of_property_read_bool(overlay, "partial-fpga-config"))
-		info->flags |= FPGA_MGR_PARTIAL_RECONFIG;
-
-	if (of_property_read_bool(overlay, "external-fpga-config"))
-		info->flags |= FPGA_MGR_EXTERNAL_CONFIG;
-
-	if (of_property_read_bool(overlay, "encrypted-fpga-config"))
-		info->flags |= FPGA_MGR_ENCRYPTED_BITSTREAM;
-
-	if (!of_property_read_string(overlay, "firmware-name",
-				     &firmware_name)) {
-		info->firmware_name = devm_kstrdup(dev, firmware_name,
-						   GFP_KERNEL);
-		if (!info->firmware_name)
-			return ERR_PTR(-ENOMEM);
-	}
-
-	of_property_read_u32(overlay, "region-unfreeze-timeout-us",
-			     &info->enable_timeout_us);
-
-	of_property_read_u32(overlay, "region-freeze-timeout-us",
-			     &info->disable_timeout_us);
-
-	of_property_read_u32(overlay, "config-complete-timeout-us",
-			     &info->config_complete_timeout_us);
-
-	/* If overlay is not programming the FPGA, don't need FPGA image info */
-	if (!info->firmware_name) {
-		ret = 0;
-		goto ret_no_info;
-	}
-
-	/*
-	 * If overlay informs us FPGA was externally programmed, specifying
-	 * firmware here would be ambiguous.
-	 */
-	if (info->flags & FPGA_MGR_EXTERNAL_CONFIG) {
-		dev_err(dev, "error: specified firmware and external-fpga-config");
-		ret = -EINVAL;
-		goto ret_no_info;
-	}
-
-	return info;
-ret_no_info:
-	fpga_image_info_free(info);
-	return ERR_PTR(ret);
-}
-
-/**
- * of_fpga_region_notify_pre_apply - pre-apply overlay notification
- *
- * @region: FPGA region that the overlay was applied to
- * @nd: overlay notification data
- *
- * Called when an overlay targeted to a FPGA Region is about to be applied.
- * Parses the overlay for properties that influence how the FPGA will be
- * programmed and does some checking. If the checks pass, programs the FPGA.
- * If the checks fail, overlay is rejected and does not get added to the
- * live tree.
- *
- * Returns 0 for success or negative error code for failure.
- */
-static int of_fpga_region_notify_pre_apply(struct fpga_region *region,
-					   struct of_overlay_notify_data *nd)
-{
-	struct device *dev = &region->dev;
-	struct fpga_image_info *info;
-	int ret;
-
-	if (region->info) {
-		dev_err(dev, "Region already has overlay applied.\n");
-		return -EINVAL;
-	}
-
-	info = of_fpga_region_parse_ov(region, nd->overlay);
-	if (IS_ERR(info))
-		return PTR_ERR(info);
-
-	if (!info)
-		return 0;
-
-	region->info = info;
-	ret = fpga_region_program_fpga(region);
-	if (ret) {
-		/* error; reject overlay */
-		fpga_image_info_free(info);
-		region->info = NULL;
-	}
-
-	return ret;
-}
-
-/**
- * of_fpga_region_notify_post_remove - post-remove overlay notification
- *
- * @region: FPGA region that was targeted by the overlay that was removed
- * @nd: overlay notification data
- *
- * Called after an overlay has been removed if the overlay's target was a
- * FPGA region.
- */
-static void of_fpga_region_notify_post_remove(struct fpga_region *region,
-					      struct of_overlay_notify_data *nd)
-{
-	fpga_bridges_disable(&region->bridge_list);
-	fpga_bridges_put(&region->bridge_list);
-	fpga_image_info_free(region->info);
-	region->info = NULL;
-}
-
-/**
- * of_fpga_region_notify - reconfig notifier for dynamic DT changes
- * @nb:		notifier block
- * @action:	notifier action
- * @arg:	reconfig data
- *
- * This notifier handles programming a FPGA when a "firmware-name" property is
- * added to a fpga-region.
- *
- * Returns NOTIFY_OK or error if FPGA programming fails.
- */
-static int of_fpga_region_notify(struct notifier_block *nb,
-				 unsigned long action, void *arg)
-{
-	struct of_overlay_notify_data *nd = arg;
-	struct fpga_region *region;
-	int ret;
-
-	switch (action) {
-	case OF_OVERLAY_PRE_APPLY:
-		pr_debug("%s OF_OVERLAY_PRE_APPLY\n", __func__);
-		break;
-	case OF_OVERLAY_POST_APPLY:
-		pr_debug("%s OF_OVERLAY_POST_APPLY\n", __func__);
-		return NOTIFY_OK;       /* not for us */
-	case OF_OVERLAY_PRE_REMOVE:
-		pr_debug("%s OF_OVERLAY_PRE_REMOVE\n", __func__);
-		return NOTIFY_OK;       /* not for us */
-	case OF_OVERLAY_POST_REMOVE:
-		pr_debug("%s OF_OVERLAY_POST_REMOVE\n", __func__);
-		break;
-	default:			/* should not happen */
-		return NOTIFY_OK;
-	}
-
-	region = of_fpga_region_find(nd->target);
-	if (!region)
-		return NOTIFY_OK;
-
-	ret = 0;
-	switch (action) {
-	case OF_OVERLAY_PRE_APPLY:
-		ret = of_fpga_region_notify_pre_apply(region, nd);
-		break;
-
-	case OF_OVERLAY_POST_REMOVE:
-		of_fpga_region_notify_post_remove(region, nd);
-		break;
-	}
-
-	put_device(&region->dev);
-
-	if (ret)
-		return notifier_from_errno(ret);
-
-	return NOTIFY_OK;
-}
-
-static struct notifier_block fpga_region_of_nb = {
-	.notifier_call = of_fpga_region_notify,
-};
-
 int fpga_region_register(struct device *dev, struct fpga_region *region)
 {
 	int id, ret = 0;
@@ -576,64 +203,6 @@ int fpga_region_unregister(struct fpga_region *region)
 }
 EXPORT_SYMBOL_GPL(fpga_region_unregister);
 
-static int of_fpga_region_probe(struct platform_device *pdev)
-{
-	struct device *dev = &pdev->dev;
-	struct device_node *np = dev->of_node;
-	struct fpga_region *region;
-	struct fpga_manager *mgr;
-	int ret;
-
-	/* Find the FPGA mgr specified by region or parent region. */
-	mgr = of_fpga_region_get_mgr(np);
-	if (IS_ERR(mgr))
-		return -EPROBE_DEFER;
-
-	region = devm_kzalloc(dev, sizeof(*region), GFP_KERNEL);
-	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);
-	if (ret)
-		goto eprobe_mgr_put;
-
-	of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
-
-	dev_info(dev, "FPGA Region probed\n");
-
-	return 0;
-
-eprobe_mgr_put:
-	fpga_mgr_put(mgr);
-	return ret;
-}
-
-static int of_fpga_region_remove(struct platform_device *pdev)
-{
-	struct fpga_region *region = platform_get_drvdata(pdev);
-
-	fpga_region_unregister(region);
-	fpga_mgr_put(region->mgr);
-
-	return 0;
-}
-
-static struct platform_driver of_fpga_region_driver = {
-	.probe = of_fpga_region_probe,
-	.remove = of_fpga_region_remove,
-	.driver = {
-		.name	= "fpga-region",
-		.of_match_table = of_match_ptr(fpga_region_of_match),
-	},
-};
-
 static void fpga_region_dev_release(struct device *dev)
 {
 	struct fpga_region *region = to_fpga_region(dev);
@@ -647,36 +216,17 @@ static void fpga_region_dev_release(struct device *dev)
  */
 static int __init fpga_region_init(void)
 {
-	int ret;
-
 	fpga_region_class = class_create(THIS_MODULE, "fpga_region");
 	if (IS_ERR(fpga_region_class))
 		return PTR_ERR(fpga_region_class);
 
 	fpga_region_class->dev_release = fpga_region_dev_release;
 
-	ret = of_overlay_notifier_register(&fpga_region_of_nb);
-	if (ret)
-		goto err_class;
-
-	ret = platform_driver_register(&of_fpga_region_driver);
-	if (ret)
-		goto err_plat;
-
 	return 0;
-
-err_plat:
-	of_overlay_notifier_unregister(&fpga_region_of_nb);
-err_class:
-	class_destroy(fpga_region_class);
-	ida_destroy(&fpga_region_ida);
-	return ret;
 }
 
 static void __exit fpga_region_exit(void)
 {
-	platform_driver_unregister(&of_fpga_region_driver);
-	of_overlay_notifier_unregister(&fpga_region_of_nb);
 	class_destroy(fpga_region_class);
 	ida_destroy(&fpga_region_ida);
 }
diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
new file mode 100644
index 000000000000..1533506ef0e4
--- /dev/null
+++ b/drivers/fpga/of-fpga-region.c
@@ -0,0 +1,496 @@
+/*
+ * FPGA Region - Device Tree support for FPGA programming under Linux
+ *
+ *  Copyright (C) 2013-2016 Altera Corporation
+ *  Copyright (C) 2017 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/fpga/fpga-bridge.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/fpga/fpga-region.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+static const struct of_device_id fpga_region_of_match[] = {
+	{ .compatible = "fpga-region", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, fpga_region_of_match);
+
+static int fpga_region_of_node_match(struct device *dev, const void *data)
+{
+	return dev->of_node == data;
+}
+
+/**
+ * of_fpga_region_find - find FPGA region
+ * @np: device node of FPGA Region
+ *
+ * Caller will need to put_device(&region->dev) when done.
+ *
+ * Returns FPGA Region struct or NULL
+ */
+static struct fpga_region *of_fpga_region_find(struct device_node *np)
+{
+	return fpga_region_class_find(NULL, np, fpga_region_of_node_match);
+}
+
+/**
+ * of_fpga_region_get_mgr - get reference for FPGA manager
+ * @np: device node of FPGA region
+ *
+ * Get FPGA Manager from "fpga-mgr" property or from ancestor region.
+ *
+ * Caller should call fpga_mgr_put() when done with manager.
+ *
+ * Return: fpga manager struct or IS_ERR() condition containing error code.
+ */
+static struct fpga_manager *of_fpga_region_get_mgr(struct device_node *np)
+{
+	struct device_node  *mgr_node;
+	struct fpga_manager *mgr;
+
+	of_node_get(np);
+	while (np) {
+		if (of_device_is_compatible(np, "fpga-region")) {
+			mgr_node = of_parse_phandle(np, "fpga-mgr", 0);
+			if (mgr_node) {
+				mgr = of_fpga_mgr_get(mgr_node);
+				of_node_put(np);
+				return mgr;
+			}
+		}
+		np = of_get_next_parent(np);
+	}
+	of_node_put(np);
+
+	return ERR_PTR(-EINVAL);
+}
+
+/**
+ * of_fpga_region_get_bridges - create a list of bridges
+ * @region: FPGA region
+ *
+ * Create a list of bridges including the parent bridge and the bridges
+ * specified by "fpga-bridges" property.  Note that the
+ * fpga_bridges_enable/disable/put functions are all fine with an empty list
+ * if that happens.
+ *
+ * Caller should call fpga_bridges_put(&region->bridge_list) when
+ * done with the bridges.
+ *
+ * Return 0 for success (even if there are no bridges specified)
+ * or -EBUSY if any of the bridges are in use.
+ */
+static int of_fpga_region_get_bridges(struct fpga_region *region)
+{
+	struct device *dev = &region->dev;
+	struct device_node *region_np = dev->of_node;
+	struct fpga_image_info *info = region->info;
+	struct device_node *br, *np, *parent_br = NULL;
+	int i, ret;
+
+	/* If parent is a bridge, add to list */
+	ret = of_fpga_bridge_get_to_list(region_np->parent, info,
+					 &region->bridge_list);
+
+	/* -EBUSY means parent is a bridge that is under use. Give up. */
+	if (ret == -EBUSY)
+		return ret;
+
+	/* Zero return code means parent was a bridge and was added to list. */
+	if (!ret)
+		parent_br = region_np->parent;
+
+	/* If overlay has a list of bridges, use it. */
+	if (of_parse_phandle(info->overlay, "fpga-bridges", 0))
+		np = info->overlay;
+	else
+		np = region_np;
+
+	for (i = 0; ; i++) {
+		br = of_parse_phandle(np, "fpga-bridges", i);
+		if (!br)
+			break;
+
+		/* If parent bridge is in list, skip it. */
+		if (br == parent_br)
+			continue;
+
+		/* If node is a bridge, get it and add to list */
+		ret = of_fpga_bridge_get_to_list(br, info,
+						 &region->bridge_list);
+
+		/* If any of the bridges are in use, give up */
+		if (ret == -EBUSY) {
+			fpga_bridges_put(&region->bridge_list);
+			return -EBUSY;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * child_regions_with_firmware
+ * @overlay: device node of the overlay
+ *
+ * If the overlay adds child FPGA regions, they are not allowed to have
+ * firmware-name property.
+ *
+ * Return 0 for OK or -EINVAL if child FPGA region adds firmware-name.
+ */
+static int child_regions_with_firmware(struct device_node *overlay)
+{
+	struct device_node *child_region;
+	const char *child_firmware_name;
+	int ret = 0;
+
+	of_node_get(overlay);
+
+	child_region = of_find_matching_node(overlay, fpga_region_of_match);
+	while (child_region) {
+		if (!of_property_read_string(child_region, "firmware-name",
+					     &child_firmware_name)) {
+			ret = -EINVAL;
+			break;
+		}
+		child_region = of_find_matching_node(child_region,
+						     fpga_region_of_match);
+	}
+
+	of_node_put(child_region);
+
+	if (ret)
+		pr_err("firmware-name not allowed in child FPGA region: %pOF",
+		       child_region);
+
+	return ret;
+}
+
+/**
+ * of_fpga_region_parse_ov - parse and check overlay applied to region
+ *
+ * @region: FPGA region
+ * @overlay: overlay applied to the FPGA region
+ *
+ * Given an overlay applied to a FPGA region, parse the FPGA image specific
+ * info in the overlay and do some checking.
+ *
+ * Returns:
+ *   NULL if overlay doesn't direct us to program the FPGA.
+ *   fpga_image_info struct if there is an image to program.
+ *   error code for invalid overlay.
+ */
+static struct fpga_image_info *of_fpga_region_parse_ov(
+						struct fpga_region *region,
+						struct device_node *overlay)
+{
+	struct device *dev = &region->dev;
+	struct fpga_image_info *info;
+	const char *firmware_name;
+	int ret;
+
+	if (region->info) {
+		dev_err(dev, "Region already has overlay applied.\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	/*
+	 * Reject overlay if child FPGA Regions added in the overlay have
+	 * firmware-name property (would mean that an FPGA region that has
+	 * not been added to the live tree yet is doing FPGA programming).
+	 */
+	ret = child_regions_with_firmware(overlay);
+	if (ret)
+		return ERR_PTR(ret);
+
+	info = fpga_image_info_alloc(dev);
+	if (!info)
+		return ERR_PTR(-ENOMEM);
+
+	info->overlay = overlay;
+
+	/* Read FPGA region properties from the overlay */
+	if (of_property_read_bool(overlay, "partial-fpga-config"))
+		info->flags |= FPGA_MGR_PARTIAL_RECONFIG;
+
+	if (of_property_read_bool(overlay, "external-fpga-config"))
+		info->flags |= FPGA_MGR_EXTERNAL_CONFIG;
+
+	if (of_property_read_bool(overlay, "encrypted-fpga-config"))
+		info->flags |= FPGA_MGR_ENCRYPTED_BITSTREAM;
+
+	if (!of_property_read_string(overlay, "firmware-name",
+				     &firmware_name)) {
+		info->firmware_name = devm_kstrdup(dev, firmware_name,
+						   GFP_KERNEL);
+		if (!info->firmware_name)
+			return ERR_PTR(-ENOMEM);
+	}
+
+	of_property_read_u32(overlay, "region-unfreeze-timeout-us",
+			     &info->enable_timeout_us);
+
+	of_property_read_u32(overlay, "region-freeze-timeout-us",
+			     &info->disable_timeout_us);
+
+	of_property_read_u32(overlay, "config-complete-timeout-us",
+			     &info->config_complete_timeout_us);
+
+	/* If overlay is not programming the FPGA, don't need FPGA image info */
+	if (!info->firmware_name) {
+		ret = 0;
+		goto ret_no_info;
+	}
+
+	/*
+	 * If overlay informs us FPGA was externally programmed, specifying
+	 * firmware here would be ambiguous.
+	 */
+	if (info->flags & FPGA_MGR_EXTERNAL_CONFIG) {
+		dev_err(dev, "error: specified firmware and external-fpga-config");
+		ret = -EINVAL;
+		goto ret_no_info;
+	}
+
+	return info;
+ret_no_info:
+	fpga_image_info_free(info);
+	return ERR_PTR(ret);
+}
+
+/**
+ * of_fpga_region_notify_pre_apply - pre-apply overlay notification
+ *
+ * @region: FPGA region that the overlay was applied to
+ * @nd: overlay notification data
+ *
+ * Called when an overlay targeted to a FPGA Region is about to be applied.
+ * Parses the overlay for properties that influence how the FPGA will be
+ * programmed and does some checking. If the checks pass, programs the FPGA.
+ * If the checks fail, overlay is rejected and does not get added to the
+ * live tree.
+ *
+ * Returns 0 for success or negative error code for failure.
+ */
+static int of_fpga_region_notify_pre_apply(struct fpga_region *region,
+					   struct of_overlay_notify_data *nd)
+{
+	struct device *dev = &region->dev;
+	struct fpga_image_info *info;
+	int ret;
+
+	if (region->info) {
+		dev_err(dev, "Region already has overlay applied.\n");
+		return -EINVAL;
+	}
+
+	info = of_fpga_region_parse_ov(region, nd->overlay);
+	if (IS_ERR(info))
+		return PTR_ERR(info);
+
+	if (!info)
+		return 0;
+
+	region->info = info;
+	ret = fpga_region_program_fpga(region);
+	if (ret) {
+		/* error; reject overlay */
+		fpga_image_info_free(info);
+		region->info = NULL;
+	}
+
+	return ret;
+}
+
+/**
+ * of_fpga_region_notify_post_remove - post-remove overlay notification
+ *
+ * @region: FPGA region that was targeted by the overlay that was removed
+ * @nd: overlay notification data
+ *
+ * Called after an overlay has been removed if the overlay's target was a
+ * FPGA region.
+ */
+static void of_fpga_region_notify_post_remove(struct fpga_region *region,
+					      struct of_overlay_notify_data *nd)
+{
+	fpga_bridges_disable(&region->bridge_list);
+	fpga_bridges_put(&region->bridge_list);
+	fpga_image_info_free(region->info);
+	region->info = NULL;
+}
+
+/**
+ * of_fpga_region_notify - reconfig notifier for dynamic DT changes
+ * @nb:		notifier block
+ * @action:	notifier action
+ * @arg:	reconfig data
+ *
+ * This notifier handles programming a FPGA when a "firmware-name" property is
+ * added to a fpga-region.
+ *
+ * Returns NOTIFY_OK or error if FPGA programming fails.
+ */
+static int of_fpga_region_notify(struct notifier_block *nb,
+				 unsigned long action, void *arg)
+{
+	struct of_overlay_notify_data *nd = arg;
+	struct fpga_region *region;
+	int ret;
+
+	switch (action) {
+	case OF_OVERLAY_PRE_APPLY:
+		pr_debug("%s OF_OVERLAY_PRE_APPLY\n", __func__);
+		break;
+	case OF_OVERLAY_POST_APPLY:
+		pr_debug("%s OF_OVERLAY_POST_APPLY\n", __func__);
+		return NOTIFY_OK;       /* not for us */
+	case OF_OVERLAY_PRE_REMOVE:
+		pr_debug("%s OF_OVERLAY_PRE_REMOVE\n", __func__);
+		return NOTIFY_OK;       /* not for us */
+	case OF_OVERLAY_POST_REMOVE:
+		pr_debug("%s OF_OVERLAY_POST_REMOVE\n", __func__);
+		break;
+	default:			/* should not happen */
+		return NOTIFY_OK;
+	}
+
+	region = of_fpga_region_find(nd->target);
+	if (!region)
+		return NOTIFY_OK;
+
+	ret = 0;
+	switch (action) {
+	case OF_OVERLAY_PRE_APPLY:
+		ret = of_fpga_region_notify_pre_apply(region, nd);
+		break;
+
+	case OF_OVERLAY_POST_REMOVE:
+		of_fpga_region_notify_post_remove(region, nd);
+		break;
+	}
+
+	put_device(&region->dev);
+
+	if (ret)
+		return notifier_from_errno(ret);
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block fpga_region_of_nb = {
+	.notifier_call = of_fpga_region_notify,
+};
+
+static int of_fpga_region_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct fpga_region *region;
+	struct fpga_manager *mgr;
+	int ret;
+
+	/* Find the FPGA mgr specified by region or parent region. */
+	mgr = of_fpga_region_get_mgr(np);
+	if (IS_ERR(mgr))
+		return -EPROBE_DEFER;
+
+	region = devm_kzalloc(dev, sizeof(*region), GFP_KERNEL);
+	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);
+	if (ret)
+		goto eprobe_mgr_put;
+
+	of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
+
+	dev_info(dev, "FPGA Region probed\n");
+
+	return 0;
+
+eprobe_mgr_put:
+	fpga_mgr_put(mgr);
+	return ret;
+}
+
+static int of_fpga_region_remove(struct platform_device *pdev)
+{
+	struct fpga_region *region = platform_get_drvdata(pdev);
+
+	fpga_region_unregister(region);
+	fpga_mgr_put(region->mgr);
+
+	return 0;
+}
+
+static struct platform_driver of_fpga_region_driver = {
+	.probe = of_fpga_region_probe,
+	.remove = of_fpga_region_remove,
+	.driver = {
+		.name	= "of-fpga-region",
+		.of_match_table = of_match_ptr(fpga_region_of_match),
+	},
+};
+
+/**
+ * fpga_region_init - init function for fpga_region class
+ * Creates the fpga_region class and registers a reconfig notifier.
+ */
+static int __init of_fpga_region_init(void)
+{
+	int ret;
+
+	ret = of_overlay_notifier_register(&fpga_region_of_nb);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&of_fpga_region_driver);
+	if (ret)
+		goto err_plat;
+
+	return 0;
+
+err_plat:
+	of_overlay_notifier_unregister(&fpga_region_of_nb);
+	return ret;
+}
+
+static void __exit of_fpga_region_exit(void)
+{
+	platform_driver_unregister(&of_fpga_region_driver);
+	of_overlay_notifier_unregister(&fpga_region_of_nb);
+}
+
+subsys_initcall(of_fpga_region_init);
+module_exit(of_fpga_region_exit);
+
+MODULE_DESCRIPTION("FPGA Region");
+MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
+MODULE_LICENSE("GPL v2");