drivers/fpga/fpga-bridge.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * FPGA Bridge Framework Driver
  *
  *  Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
  *  Copyright (C) 2017 Intel Corporation
  */
 #include <linux/fpga/fpga-bridge.h>
 #include <linux/idr.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>

 static DEFINE_IDA(fpga_bridge_ida);
 static struct class *fpga_bridge_class;

 /* Lock for adding/removing bridges to linked lists*/
 static DEFINE_SPINLOCK(bridge_list_lock);

 /**
  * fpga_bridge_enable - Enable transactions on the bridge
  *
  * @bridge: FPGA bridge
  *
  * Return: 0 for success, error code otherwise.
  */
 int fpga_bridge_enable(struct fpga_bridge *bridge)
 {
 	dev_dbg(&bridge->dev, "enable\n");

 	if (bridge->br_ops && bridge->br_ops->enable_set)
 		return bridge->br_ops->enable_set(bridge, 1);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(fpga_bridge_enable);

 /**
  * fpga_bridge_disable - Disable transactions on the bridge
  *
  * @bridge: FPGA bridge
  *
  * Return: 0 for success, error code otherwise.
  */
 int fpga_bridge_disable(struct fpga_bridge *bridge)
 {
 	dev_dbg(&bridge->dev, "disable\n");

 	if (bridge->br_ops && bridge->br_ops->enable_set)
 		return bridge->br_ops->enable_set(bridge, 0);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(fpga_bridge_disable);

 static struct fpga_bridge *__fpga_bridge_get(struct device *dev,
 					     struct fpga_image_info *info)
 {
 	struct fpga_bridge *bridge;
 	int ret = -ENODEV;

 	bridge = to_fpga_bridge(dev);

 	bridge->info = info;

 	if (!mutex_trylock(&bridge->mutex)) {
 		ret = -EBUSY;
 		goto err_dev;
 	}

 	if (!try_module_get(dev->parent->driver->owner))
 		goto err_ll_mod;

 	dev_dbg(&bridge->dev, "get\n");

 	return bridge;

 err_ll_mod:
 	mutex_unlock(&bridge->mutex);
 err_dev:
 	put_device(dev);
 	return ERR_PTR(ret);
 }

 /**
  * of_fpga_bridge_get - get an exclusive reference to an fpga bridge
  *
  * @np: node pointer of an FPGA bridge
  * @info: fpga image specific information
  *
  * Return fpga_bridge struct if successful.
  * Return -EBUSY if someone already has a reference to the bridge.
  * Return -ENODEV if @np is not an FPGA Bridge.
  */
 struct fpga_bridge *of_fpga_bridge_get(struct device_node *np,
 				       struct fpga_image_info *info)
 {
 	struct device *dev;

 	dev = class_find_device_by_of_node(fpga_bridge_class, np);
 	if (!dev)
 		return ERR_PTR(-ENODEV);

 	return __fpga_bridge_get(dev, info);
 }
 EXPORT_SYMBOL_GPL(of_fpga_bridge_get);

 static int fpga_bridge_dev_match(struct device *dev, const void *data)
 {
 	return dev->parent == data;
 }

 /**
  * fpga_bridge_get - get an exclusive reference to an fpga bridge
  * @dev:	parent device that fpga bridge was registered with
  * @info:	fpga image specific information
  *
  * Given a device, get an exclusive reference to an fpga bridge.
  *
  * Return: fpga bridge struct or IS_ERR() condition containing error code.
  */
 struct fpga_bridge *fpga_bridge_get(struct device *dev,
 				    struct fpga_image_info *info)
 {
 	struct device *bridge_dev;

 	bridge_dev = class_find_device(fpga_bridge_class, NULL, dev,
 				       fpga_bridge_dev_match);
 	if (!bridge_dev)
 		return ERR_PTR(-ENODEV);

 	return __fpga_bridge_get(bridge_dev, info);
 }
 EXPORT_SYMBOL_GPL(fpga_bridge_get);

 /**
  * fpga_bridge_put - release a reference to a bridge
  *
  * @bridge: FPGA bridge
  */
 void fpga_bridge_put(struct fpga_bridge *bridge)
 {
 	dev_dbg(&bridge->dev, "put\n");

 	bridge->info = NULL;
 	module_put(bridge->dev.parent->driver->owner);
 	mutex_unlock(&bridge->mutex);
 	put_device(&bridge->dev);
 }
 EXPORT_SYMBOL_GPL(fpga_bridge_put);

 /**
  * fpga_bridges_enable - enable bridges in a list
  * @bridge_list: list of FPGA bridges
  *
  * Enable each bridge in the list.  If list is empty, do nothing.
  *
  * Return 0 for success or empty bridge list; return error code otherwise.
  */
 int fpga_bridges_enable(struct list_head *bridge_list)
 {
 	struct fpga_bridge *bridge;
 	int ret;

 	list_for_each_entry(bridge, bridge_list, node) {
 		ret = fpga_bridge_enable(bridge);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(fpga_bridges_enable);

 /**
  * fpga_bridges_disable - disable bridges in a list
  *
  * @bridge_list: list of FPGA bridges
  *
  * Disable each bridge in the list.  If list is empty, do nothing.
  *
  * Return 0 for success or empty bridge list; return error code otherwise.
  */
 int fpga_bridges_disable(struct list_head *bridge_list)
 {
 	struct fpga_bridge *bridge;
 	int ret;

 	list_for_each_entry(bridge, bridge_list, node) {
 		ret = fpga_bridge_disable(bridge);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(fpga_bridges_disable);

 /**
  * fpga_bridges_put - put bridges
  *
  * @bridge_list: list of FPGA bridges
  *
  * For each bridge in the list, put the bridge and remove it from the list.
  * If list is empty, do nothing.
  */
 void fpga_bridges_put(struct list_head *bridge_list)
 {
 	struct fpga_bridge *bridge, *next;
 	unsigned long flags;

 	list_for_each_entry_safe(bridge, next, bridge_list, node) {
 		fpga_bridge_put(bridge);

 		spin_lock_irqsave(&bridge_list_lock, flags);
 		list_del(&bridge->node);
 		spin_unlock_irqrestore(&bridge_list_lock, flags);
 	}
 }
 EXPORT_SYMBOL_GPL(fpga_bridges_put);

 /**
  * of_fpga_bridge_get_to_list - get a bridge, add it to a list
  *
  * @np: node pointer of an FPGA bridge
  * @info: fpga image specific information
  * @bridge_list: list of FPGA bridges
  *
  * Get an exclusive reference to the bridge and it to the list.
  *
  * Return 0 for success, error code from of_fpga_bridge_get() otherwise.
  */
 int of_fpga_bridge_get_to_list(struct device_node *np,
 			       struct fpga_image_info *info,
 			       struct list_head *bridge_list)
 {
 	struct fpga_bridge *bridge;
 	unsigned long flags;

 	bridge = of_fpga_bridge_get(np, info);
 	if (IS_ERR(bridge))
 		return PTR_ERR(bridge);

 	spin_lock_irqsave(&bridge_list_lock, flags);
 	list_add(&bridge->node, bridge_list);
 	spin_unlock_irqrestore(&bridge_list_lock, flags);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(of_fpga_bridge_get_to_list);

 /**
  * fpga_bridge_get_to_list - given device, get a bridge, add it to a list
  *
  * @dev: FPGA bridge device
  * @info: fpga image specific information
  * @bridge_list: list of FPGA bridges
  *
  * Get an exclusive reference to the bridge and it to the list.
  *
  * Return 0 for success, error code from fpga_bridge_get() otherwise.
  */
 int fpga_bridge_get_to_list(struct device *dev,
 			    struct fpga_image_info *info,
 			    struct list_head *bridge_list)
 {
 	struct fpga_bridge *bridge;
 	unsigned long flags;

 	bridge = fpga_bridge_get(dev, info);
 	if (IS_ERR(bridge))
 		return PTR_ERR(bridge);

 	spin_lock_irqsave(&bridge_list_lock, flags);
 	list_add(&bridge->node, bridge_list);
 	spin_unlock_irqrestore(&bridge_list_lock, flags);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(fpga_bridge_get_to_list);

 static ssize_t name_show(struct device *dev,
 			 struct device_attribute *attr, char *buf)
 {
 	struct fpga_bridge *bridge = to_fpga_bridge(dev);

 	return sprintf(buf, "%s\n", bridge->name);
 }

 static ssize_t state_show(struct device *dev,
 			  struct device_attribute *attr, char *buf)
 {
 	struct fpga_bridge *bridge = to_fpga_bridge(dev);
 	int state = 1;

 	if (bridge->br_ops && bridge->br_ops->enable_show) {
 		state = bridge->br_ops->enable_show(bridge);
 		if (state < 0)
 			return state;
 	}

 	return sysfs_emit(buf, "%s\n", state ? "enabled" : "disabled");
 }

 static DEVICE_ATTR_RO(name);
 static DEVICE_ATTR_RO(state);

 static struct attribute *fpga_bridge_attrs[] = {
 	&dev_attr_name.attr,
 	&dev_attr_state.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(fpga_bridge);

 /**
  * fpga_bridge_register - create and register an FPGA Bridge device
  * @parent:	FPGA bridge device from pdev
  * @name:	FPGA bridge name
  * @br_ops:	pointer to structure of fpga bridge ops
  * @priv:	FPGA bridge private data
  *
  * Return: struct fpga_bridge pointer or ERR_PTR()
  */
 struct fpga_bridge *
 fpga_bridge_register(struct device *parent, const char *name,
 		     const struct fpga_bridge_ops *br_ops,
 		     void *priv)
 {
 	struct fpga_bridge *bridge;
 	int id, ret;

 	if (!br_ops) {
 		dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
 		return ERR_PTR(-EINVAL);
 	}

 	if (!name || !strlen(name)) {
 		dev_err(parent, "Attempt to register with no name!\n");
 		return ERR_PTR(-EINVAL);
 	}

 	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
 	if (!bridge)
 		return ERR_PTR(-ENOMEM);

 	id = ida_alloc(&fpga_bridge_ida, GFP_KERNEL);
 	if (id < 0) {
 		ret = id;
 		goto error_kfree;
 	}

 	mutex_init(&bridge->mutex);
 	INIT_LIST_HEAD(&bridge->node);

 	bridge->name = name;
 	bridge->br_ops = br_ops;
 	bridge->priv = priv;

 	bridge->dev.groups = br_ops->groups;
 	bridge->dev.class = fpga_bridge_class;
 	bridge->dev.parent = parent;
 	bridge->dev.of_node = parent->of_node;
 	bridge->dev.id = id;

 	ret = dev_set_name(&bridge->dev, "br%d", id);
 	if (ret)
 		goto error_device;

 	ret = device_register(&bridge->dev);
 	if (ret) {
 		put_device(&bridge->dev);
 		return ERR_PTR(ret);
 	}

 	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);

 	return bridge;

 error_device:
 	ida_free(&fpga_bridge_ida, id);
 error_kfree:
 	kfree(bridge);

 	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(fpga_bridge_register);

 /**
  * fpga_bridge_unregister - unregister an FPGA bridge
  *
  * @bridge: FPGA bridge struct
  *
  * This function is intended for use in an FPGA bridge driver's remove function.
  */
 void fpga_bridge_unregister(struct fpga_bridge *bridge)
 {
 	/*
 	 * If the low level driver provides a method for putting bridge into
 	 * a desired state upon unregister, do it.
 	 */
 	if (bridge->br_ops && bridge->br_ops->fpga_bridge_remove)
 		bridge->br_ops->fpga_bridge_remove(bridge);

 	device_unregister(&bridge->dev);
 }
 EXPORT_SYMBOL_GPL(fpga_bridge_unregister);

 static void fpga_bridge_dev_release(struct device *dev)
 {
 	struct fpga_bridge *bridge = to_fpga_bridge(dev);

 	ida_free(&fpga_bridge_ida, bridge->dev.id);
 	kfree(bridge);
 }

 static int __init fpga_bridge_dev_init(void)
 {
 	fpga_bridge_class = class_create("fpga_bridge");
 	if (IS_ERR(fpga_bridge_class))
 		return PTR_ERR(fpga_bridge_class);

 	fpga_bridge_class->dev_groups = fpga_bridge_groups;
 	fpga_bridge_class->dev_release = fpga_bridge_dev_release;

 	return 0;
 }

 static void __exit fpga_bridge_dev_exit(void)
 {
 	class_destroy(fpga_bridge_class);
 	ida_destroy(&fpga_bridge_ida);
 }

 MODULE_DESCRIPTION("FPGA Bridge Driver");
 MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
 MODULE_LICENSE("GPL v2");

 subsys_initcall(fpga_bridge_dev_init);
 module_exit(fpga_bridge_dev_exit);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* FPGA Bridge Framework Driver
	*
	* Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
	* Copyright (C) 2017 Intel Corporation
	*/
	#include <linux/fpga/fpga-bridge.h>
	#include <linux/idr.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of_platform.h>
	#include <linux/slab.h>
	#include <linux/spinlock.h>

	static DEFINE_IDA(fpga_bridge_ida);
	static struct class *fpga_bridge_class;

	/* Lock for adding/removing bridges to linked lists*/
	static DEFINE_SPINLOCK(bridge_list_lock);

	/**
	* fpga_bridge_enable - Enable transactions on the bridge
	*
	* @bridge: FPGA bridge
	*
	* Return: 0 for success, error code otherwise.
	*/
	int fpga_bridge_enable(struct fpga_bridge *bridge)
	{
	dev_dbg(&bridge->dev, "enable\n");

	if (bridge->br_ops && bridge->br_ops->enable_set)
	return bridge->br_ops->enable_set(bridge, 1);

	return 0;
	}
	EXPORT_SYMBOL_GPL(fpga_bridge_enable);

	/**
	* fpga_bridge_disable - Disable transactions on the bridge
	*
	* @bridge: FPGA bridge
	*
	* Return: 0 for success, error code otherwise.
	*/
	int fpga_bridge_disable(struct fpga_bridge *bridge)
	{
	dev_dbg(&bridge->dev, "disable\n");

	if (bridge->br_ops && bridge->br_ops->enable_set)
	return bridge->br_ops->enable_set(bridge, 0);

	return 0;
	}
	EXPORT_SYMBOL_GPL(fpga_bridge_disable);

	static struct fpga_bridge __fpga_bridge_get(struct device dev,
	struct fpga_image_info *info)
	{
	struct fpga_bridge *bridge;
	int ret = -ENODEV;

	bridge = to_fpga_bridge(dev);

	bridge->info = info;

	if (!mutex_trylock(&bridge->mutex)) {
	ret = -EBUSY;
	goto err_dev;
	}

	if (!try_module_get(dev->parent->driver->owner))
	goto err_ll_mod;

	dev_dbg(&bridge->dev, "get\n");

	return bridge;

	err_ll_mod:
	mutex_unlock(&bridge->mutex);
	err_dev:
	put_device(dev);
	return ERR_PTR(ret);
	}

	/**
	* of_fpga_bridge_get - get an exclusive reference to an fpga bridge
	*
	* @np: node pointer of an FPGA bridge
	* @info: fpga image specific information
	*
	* Return fpga_bridge struct if successful.
	* Return -EBUSY if someone already has a reference to the bridge.
	* Return -ENODEV if @np is not an FPGA Bridge.
	*/
	struct fpga_bridge of_fpga_bridge_get(struct device_node np,
	struct fpga_image_info *info)
	{
	struct device *dev;

	dev = class_find_device_by_of_node(fpga_bridge_class, np);
	if (!dev)
	return ERR_PTR(-ENODEV);

	return __fpga_bridge_get(dev, info);
	}
	EXPORT_SYMBOL_GPL(of_fpga_bridge_get);

	static int fpga_bridge_dev_match(struct device dev, const void data)
	{
	return dev->parent == data;
	}

	/**
	* fpga_bridge_get - get an exclusive reference to an fpga bridge
	* @dev: parent device that fpga bridge was registered with
	* @info: fpga image specific information
	*
	* Given a device, get an exclusive reference to an fpga bridge.
	*
	* Return: fpga bridge struct or IS_ERR() condition containing error code.
	*/
	struct fpga_bridge fpga_bridge_get(struct device dev,
	struct fpga_image_info *info)
	{
	struct device *bridge_dev;

	bridge_dev = class_find_device(fpga_bridge_class, NULL, dev,
	fpga_bridge_dev_match);
	if (!bridge_dev)
	return ERR_PTR(-ENODEV);

	return __fpga_bridge_get(bridge_dev, info);
	}
	EXPORT_SYMBOL_GPL(fpga_bridge_get);

	/**
	* fpga_bridge_put - release a reference to a bridge
	*
	* @bridge: FPGA bridge
	*/
	void fpga_bridge_put(struct fpga_bridge *bridge)
	{
	dev_dbg(&bridge->dev, "put\n");

	bridge->info = NULL;
	module_put(bridge->dev.parent->driver->owner);
	mutex_unlock(&bridge->mutex);
	put_device(&bridge->dev);
	}
	EXPORT_SYMBOL_GPL(fpga_bridge_put);

	/**
	* fpga_bridges_enable - enable bridges in a list
	* @bridge_list: list of FPGA bridges
	*
	* Enable each bridge in the list. If list is empty, do nothing.
	*
	* Return 0 for success or empty bridge list; return error code otherwise.
	*/
	int fpga_bridges_enable(struct list_head *bridge_list)
	{
	struct fpga_bridge *bridge;
	int ret;

	list_for_each_entry(bridge, bridge_list, node) {
	ret = fpga_bridge_enable(bridge);
	if (ret)
	return ret;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(fpga_bridges_enable);

	/**
	* fpga_bridges_disable - disable bridges in a list
	*
	* @bridge_list: list of FPGA bridges
	*
	* Disable each bridge in the list. If list is empty, do nothing.
	*
	* Return 0 for success or empty bridge list; return error code otherwise.
	*/
	int fpga_bridges_disable(struct list_head *bridge_list)
	{
	struct fpga_bridge *bridge;
	int ret;

	list_for_each_entry(bridge, bridge_list, node) {
	ret = fpga_bridge_disable(bridge);
	if (ret)
	return ret;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(fpga_bridges_disable);

	/**
	* fpga_bridges_put - put bridges
	*
	* @bridge_list: list of FPGA bridges
	*
	* For each bridge in the list, put the bridge and remove it from the list.
	* If list is empty, do nothing.
	*/
	void fpga_bridges_put(struct list_head *bridge_list)
	{
	struct fpga_bridge bridge, next;
	unsigned long flags;

	list_for_each_entry_safe(bridge, next, bridge_list, node) {
	fpga_bridge_put(bridge);

	spin_lock_irqsave(&bridge_list_lock, flags);
	list_del(&bridge->node);
	spin_unlock_irqrestore(&bridge_list_lock, flags);
	}
	}
	EXPORT_SYMBOL_GPL(fpga_bridges_put);

	/**
	* of_fpga_bridge_get_to_list - get a bridge, add it to a list
	*
	* @np: node pointer of an FPGA bridge
	* @info: fpga image specific information
	* @bridge_list: list of FPGA bridges
	*
	* Get an exclusive reference to the bridge and it to the list.
	*
	* Return 0 for success, error code from of_fpga_bridge_get() otherwise.
	*/
	int of_fpga_bridge_get_to_list(struct device_node *np,
	struct fpga_image_info *info,
	struct list_head *bridge_list)
	{
	struct fpga_bridge *bridge;
	unsigned long flags;

	bridge = of_fpga_bridge_get(np, info);
	if (IS_ERR(bridge))
	return PTR_ERR(bridge);

	spin_lock_irqsave(&bridge_list_lock, flags);
	list_add(&bridge->node, bridge_list);
	spin_unlock_irqrestore(&bridge_list_lock, flags);

	return 0;
	}
	EXPORT_SYMBOL_GPL(of_fpga_bridge_get_to_list);

	/**
	* fpga_bridge_get_to_list - given device, get a bridge, add it to a list
	*
	* @dev: FPGA bridge device
	* @info: fpga image specific information
	* @bridge_list: list of FPGA bridges
	*
	* Get an exclusive reference to the bridge and it to the list.
	*
	* Return 0 for success, error code from fpga_bridge_get() otherwise.
	*/
	int fpga_bridge_get_to_list(struct device *dev,
	struct fpga_image_info *info,
	struct list_head *bridge_list)
	{
	struct fpga_bridge *bridge;
	unsigned long flags;

	bridge = fpga_bridge_get(dev, info);
	if (IS_ERR(bridge))
	return PTR_ERR(bridge);

	spin_lock_irqsave(&bridge_list_lock, flags);
	list_add(&bridge->node, bridge_list);
	spin_unlock_irqrestore(&bridge_list_lock, flags);

	return 0;
	}
	EXPORT_SYMBOL_GPL(fpga_bridge_get_to_list);

	static ssize_t name_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct fpga_bridge *bridge = to_fpga_bridge(dev);

	return sprintf(buf, "%s\n", bridge->name);
	}

	static ssize_t state_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct fpga_bridge *bridge = to_fpga_bridge(dev);
	int state = 1;

	if (bridge->br_ops && bridge->br_ops->enable_show) {
	state = bridge->br_ops->enable_show(bridge);
	if (state < 0)
	return state;
	}

	return sysfs_emit(buf, "%s\n", state ? "enabled" : "disabled");
	}

	static DEVICE_ATTR_RO(name);
	static DEVICE_ATTR_RO(state);

	static struct attribute *fpga_bridge_attrs[] = {
	&dev_attr_name.attr,
	&dev_attr_state.attr,
	NULL,
	};
	ATTRIBUTE_GROUPS(fpga_bridge);

	/**
	* fpga_bridge_register - create and register an FPGA Bridge device
	* @parent: FPGA bridge device from pdev
	* @name: FPGA bridge name
	* @br_ops: pointer to structure of fpga bridge ops
	* @priv: FPGA bridge private data
	*
	* Return: struct fpga_bridge pointer or ERR_PTR()
	*/
	struct fpga_bridge *
	fpga_bridge_register(struct device parent, const char name,
	const struct fpga_bridge_ops *br_ops,
	void *priv)
	{
	struct fpga_bridge *bridge;
	int id, ret;

	if (!br_ops) {
	dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
	return ERR_PTR(-EINVAL);
	}

	if (!name \|\| !strlen(name)) {
	dev_err(parent, "Attempt to register with no name!\n");
	return ERR_PTR(-EINVAL);
	}

	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
	if (!bridge)
	return ERR_PTR(-ENOMEM);

	id = ida_alloc(&fpga_bridge_ida, GFP_KERNEL);
	if (id < 0) {
	ret = id;
	goto error_kfree;
	}

	mutex_init(&bridge->mutex);
	INIT_LIST_HEAD(&bridge->node);

	bridge->name = name;
	bridge->br_ops = br_ops;
	bridge->priv = priv;

	bridge->dev.groups = br_ops->groups;
	bridge->dev.class = fpga_bridge_class;
	bridge->dev.parent = parent;
	bridge->dev.of_node = parent->of_node;
	bridge->dev.id = id;

	ret = dev_set_name(&bridge->dev, "br%d", id);
	if (ret)
	goto error_device;

	ret = device_register(&bridge->dev);
	if (ret) {
	put_device(&bridge->dev);
	return ERR_PTR(ret);
	}

	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);

	return bridge;

	error_device:
	ida_free(&fpga_bridge_ida, id);
	error_kfree:
	kfree(bridge);

	return ERR_PTR(ret);
	}
	EXPORT_SYMBOL_GPL(fpga_bridge_register);

	/**
	* fpga_bridge_unregister - unregister an FPGA bridge
	*
	* @bridge: FPGA bridge struct
	*
	* This function is intended for use in an FPGA bridge driver's remove function.
	*/
	void fpga_bridge_unregister(struct fpga_bridge *bridge)
	{
	/*
	* If the low level driver provides a method for putting bridge into
	* a desired state upon unregister, do it.
	*/
	if (bridge->br_ops && bridge->br_ops->fpga_bridge_remove)
	bridge->br_ops->fpga_bridge_remove(bridge);

	device_unregister(&bridge->dev);
	}
	EXPORT_SYMBOL_GPL(fpga_bridge_unregister);

	static void fpga_bridge_dev_release(struct device *dev)
	{
	struct fpga_bridge *bridge = to_fpga_bridge(dev);

	ida_free(&fpga_bridge_ida, bridge->dev.id);
	kfree(bridge);
	}

	static int __init fpga_bridge_dev_init(void)
	{
	fpga_bridge_class = class_create("fpga_bridge");
	if (IS_ERR(fpga_bridge_class))
	return PTR_ERR(fpga_bridge_class);

	fpga_bridge_class->dev_groups = fpga_bridge_groups;
	fpga_bridge_class->dev_release = fpga_bridge_dev_release;

	return 0;
	}

	static void __exit fpga_bridge_dev_exit(void)
	{
	class_destroy(fpga_bridge_class);
	ida_destroy(&fpga_bridge_ida);
	}

	MODULE_DESCRIPTION("FPGA Bridge Driver");
	MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
	MODULE_LICENSE("GPL v2");

	subsys_initcall(fpga_bridge_dev_init);
	module_exit(fpga_bridge_dev_exit);