[linux-block.git] / drivers / fpga / fpga-bridge.c

// 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);
Commit	Line	Data
473f01f7	1	// SPDX-License-Identifier: GPL-2.0
21aeda95 AT	2	/*
	3	* FPGA Bridge Framework Driver
	4	*
	5	* Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
9c1c4b27	6	* Copyright (C) 2017 Intel Corporation
21aeda95 AT	7	*/
	8	#include <linux/fpga/fpga-bridge.h>
	9	#include <linux/idr.h>
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/of_platform.h>
	13	#include <linux/slab.h>
	14	#include <linux/spinlock.h>
	15
	16	static DEFINE_IDA(fpga_bridge_ida);
	17	static struct class *fpga_bridge_class;
	18
	19	/* Lock for adding/removing bridges to linked lists*/
f5187329	20	static DEFINE_SPINLOCK(bridge_list_lock);
21aeda95	21
21aeda95 AT	22	/**
	23	* fpga_bridge_enable - Enable transactions on the bridge
	24	*
	25	* @bridge: FPGA bridge
	26	*
	27	* Return: 0 for success, error code otherwise.
	28	*/
	29	int fpga_bridge_enable(struct fpga_bridge *bridge)
	30	{
	31	dev_dbg(&bridge->dev, "enable\n");
	32
	33	if (bridge->br_ops && bridge->br_ops->enable_set)
	34	return bridge->br_ops->enable_set(bridge, 1);
	35
	36	return 0;
	37	}
	38	EXPORT_SYMBOL_GPL(fpga_bridge_enable);
	39
	40	/**
	41	* fpga_bridge_disable - Disable transactions on the bridge
	42	*
	43	* @bridge: FPGA bridge
	44	*
	45	* Return: 0 for success, error code otherwise.
	46	*/
	47	int fpga_bridge_disable(struct fpga_bridge *bridge)
	48	{
	49	dev_dbg(&bridge->dev, "disable\n");
	50
	51	if (bridge->br_ops && bridge->br_ops->enable_set)
	52	return bridge->br_ops->enable_set(bridge, 0);
	53
	54	return 0;
	55	}
	56	EXPORT_SYMBOL_GPL(fpga_bridge_disable);
	57
9c1c4b27 AT	58	static struct fpga_bridge __fpga_bridge_get(struct device dev,
9c1c4b27 AT	59	struct fpga_image_info *info)
21aeda95	60	{
21aeda95 AT	61	struct fpga_bridge *bridge;
	62	int ret = -ENODEV;
	63
21aeda95	64	bridge = to_fpga_bridge(dev);
21aeda95 AT	65
	66	bridge->info = info;
	67
	68	if (!mutex_trylock(&bridge->mutex)) {
	69	ret = -EBUSY;
	70	goto err_dev;
	71	}
	72
	73	if (!try_module_get(dev->parent->driver->owner))
	74	goto err_ll_mod;
	75
	76	dev_dbg(&bridge->dev, "get\n");
	77
	78	return bridge;
	79
	80	err_ll_mod:
	81	mutex_unlock(&bridge->mutex);
	82	err_dev:
	83	put_device(dev);
	84	return ERR_PTR(ret);
	85	}
9c1c4b27 AT	86
9c1c4b27 AT	87	/**
e7555cf6	88	* of_fpga_bridge_get - get an exclusive reference to an fpga bridge
9c1c4b27	89	*
e7555cf6	90	* @np: node pointer of an FPGA bridge
9c1c4b27 AT	91	* @info: fpga image specific information
	92	*
	93	* Return fpga_bridge struct if successful.
	94	* Return -EBUSY if someone already has a reference to the bridge.
e7555cf6	95	* Return -ENODEV if @np is not an FPGA Bridge.
9c1c4b27 AT	96	*/
	97	struct fpga_bridge of_fpga_bridge_get(struct device_node np,
	98	struct fpga_image_info *info)
	99	{
	100	struct device *dev;
	101
cfba5de9	102	dev = class_find_device_by_of_node(fpga_bridge_class, np);
9c1c4b27 AT	103	if (!dev)
	104	return ERR_PTR(-ENODEV);
	105
	106	return __fpga_bridge_get(dev, info);
	107	}
21aeda95 AT	108	EXPORT_SYMBOL_GPL(of_fpga_bridge_get);
21aeda95 AT	109
9c1c4b27 AT	110	static int fpga_bridge_dev_match(struct device dev, const void data)
	111	{
	112	return dev->parent == data;
	113	}
	114
	115	/**
e7555cf6	116	* fpga_bridge_get - get an exclusive reference to an fpga bridge
9c1c4b27	117	* @dev: parent device that fpga bridge was registered with
7ef1a2c1	118	* @info: fpga image specific information
9c1c4b27	119	*
e7555cf6	120	* Given a device, get an exclusive reference to an fpga bridge.
9c1c4b27	121	*
b4d9a0e5	122	* Return: fpga bridge struct or IS_ERR() condition containing error code.
9c1c4b27 AT	123	*/
	124	struct fpga_bridge fpga_bridge_get(struct device dev,
	125	struct fpga_image_info *info)
	126	{
	127	struct device *bridge_dev;
	128
	129	bridge_dev = class_find_device(fpga_bridge_class, NULL, dev,
	130	fpga_bridge_dev_match);
	131	if (!bridge_dev)
	132	return ERR_PTR(-ENODEV);
	133
	134	return __fpga_bridge_get(bridge_dev, info);
	135	}
	136	EXPORT_SYMBOL_GPL(fpga_bridge_get);
	137
21aeda95 AT	138	/**
	139	* fpga_bridge_put - release a reference to a bridge
	140	*
	141	* @bridge: FPGA bridge
	142	*/
	143	void fpga_bridge_put(struct fpga_bridge *bridge)
	144	{
	145	dev_dbg(&bridge->dev, "put\n");
	146
	147	bridge->info = NULL;
	148	module_put(bridge->dev.parent->driver->owner);
	149	mutex_unlock(&bridge->mutex);
	150	put_device(&bridge->dev);
	151	}
	152	EXPORT_SYMBOL_GPL(fpga_bridge_put);
	153
	154	/**
	155	* fpga_bridges_enable - enable bridges in a list
	156	* @bridge_list: list of FPGA bridges
	157	*
	158	* Enable each bridge in the list. If list is empty, do nothing.
	159	*
	160	* Return 0 for success or empty bridge list; return error code otherwise.
	161	*/
	162	int fpga_bridges_enable(struct list_head *bridge_list)
	163	{
	164	struct fpga_bridge *bridge;
21aeda95 AT	165	int ret;
21aeda95 AT	166
c37235cc	167	list_for_each_entry(bridge, bridge_list, node) {
21aeda95 AT	168	ret = fpga_bridge_enable(bridge);
	169	if (ret)
	170	return ret;
	171	}
	172
	173	return 0;
	174	}
	175	EXPORT_SYMBOL_GPL(fpga_bridges_enable);
	176
	177	/**
	178	* fpga_bridges_disable - disable bridges in a list
	179	*
	180	* @bridge_list: list of FPGA bridges
	181	*
	182	* Disable each bridge in the list. If list is empty, do nothing.
	183	*
	184	* Return 0 for success or empty bridge list; return error code otherwise.
	185	*/
	186	int fpga_bridges_disable(struct list_head *bridge_list)
	187	{
	188	struct fpga_bridge *bridge;
21aeda95 AT	189	int ret;
21aeda95 AT	190
c37235cc	191	list_for_each_entry(bridge, bridge_list, node) {
21aeda95 AT	192	ret = fpga_bridge_disable(bridge);
	193	if (ret)
	194	return ret;
	195	}
	196
	197	return 0;
	198	}
	199	EXPORT_SYMBOL_GPL(fpga_bridges_disable);
	200
	201	/**
	202	* fpga_bridges_put - put bridges
	203	*
	204	* @bridge_list: list of FPGA bridges
	205	*
	206	* For each bridge in the list, put the bridge and remove it from the list.
	207	* If list is empty, do nothing.
	208	*/
	209	void fpga_bridges_put(struct list_head *bridge_list)
	210	{
c37235cc	211	struct fpga_bridge bridge, next;
21aeda95 AT	212	unsigned long flags;
21aeda95 AT	213
c37235cc	214	list_for_each_entry_safe(bridge, next, bridge_list, node) {
21aeda95 AT	215	fpga_bridge_put(bridge);
	216
	217	spin_lock_irqsave(&bridge_list_lock, flags);
	218	list_del(&bridge->node);
	219	spin_unlock_irqrestore(&bridge_list_lock, flags);
	220	}
	221	}
	222	EXPORT_SYMBOL_GPL(fpga_bridges_put);
	223
	224	/**
9c1c4b27	225	* of_fpga_bridge_get_to_list - get a bridge, add it to a list
21aeda95	226	*
e7555cf6	227	* @np: node pointer of an FPGA bridge
21aeda95 AT	228	* @info: fpga image specific information
	229	* @bridge_list: list of FPGA bridges
	230	*
0a05cdf1	231	* Get an exclusive reference to the bridge and it to the list.
21aeda95	232	*
580e3137	233	* Return 0 for success, error code from of_fpga_bridge_get() otherwise.
21aeda95	234	*/
9c1c4b27 AT	235	int of_fpga_bridge_get_to_list(struct device_node *np,
	236	struct fpga_image_info *info,
	237	struct list_head *bridge_list)
	238	{
	239	struct fpga_bridge *bridge;
	240	unsigned long flags;
	241
	242	bridge = of_fpga_bridge_get(np, info);
	243	if (IS_ERR(bridge))
	244	return PTR_ERR(bridge);
	245
	246	spin_lock_irqsave(&bridge_list_lock, flags);
	247	list_add(&bridge->node, bridge_list);
	248	spin_unlock_irqrestore(&bridge_list_lock, flags);
	249
	250	return 0;
	251	}
	252	EXPORT_SYMBOL_GPL(of_fpga_bridge_get_to_list);
	253
	254	/**
	255	* fpga_bridge_get_to_list - given device, get a bridge, add it to a list
	256	*
	257	* @dev: FPGA bridge device
	258	* @info: fpga image specific information
	259	* @bridge_list: list of FPGA bridges
	260	*
0a05cdf1	261	* Get an exclusive reference to the bridge and it to the list.
9c1c4b27	262	*
580e3137	263	* Return 0 for success, error code from fpga_bridge_get() otherwise.
9c1c4b27 AT	264	*/
9c1c4b27 AT	265	int fpga_bridge_get_to_list(struct device *dev,
21aeda95 AT	266	struct fpga_image_info *info,
	267	struct list_head *bridge_list)
	268	{
	269	struct fpga_bridge *bridge;
	270	unsigned long flags;
	271
9c1c4b27	272	bridge = fpga_bridge_get(dev, info);
21aeda95 AT	273	if (IS_ERR(bridge))
	274	return PTR_ERR(bridge);
	275
	276	spin_lock_irqsave(&bridge_list_lock, flags);
	277	list_add(&bridge->node, bridge_list);
	278	spin_unlock_irqrestore(&bridge_list_lock, flags);
	279
	280	return 0;
	281	}
	282	EXPORT_SYMBOL_GPL(fpga_bridge_get_to_list);
	283
	284	static ssize_t name_show(struct device *dev,
	285	struct device_attribute attr, char buf)
	286	{
	287	struct fpga_bridge *bridge = to_fpga_bridge(dev);
	288
	289	return sprintf(buf, "%s\n", bridge->name);
	290	}
	291
	292	static ssize_t state_show(struct device *dev,
	293	struct device_attribute attr, char buf)
	294	{
	295	struct fpga_bridge *bridge = to_fpga_bridge(dev);
48ca6e5f	296	int state = 1;
21aeda95	297
48ca6e5f MP	298	if (bridge->br_ops && bridge->br_ops->enable_show) {
	299	state = bridge->br_ops->enable_show(bridge);
	300	if (state < 0)
	301	return state;
	302	}
21aeda95	303
48ca6e5f	304	return sysfs_emit(buf, "%s\n", state ? "enabled" : "disabled");
21aeda95 AT	305	}
	306
	307	static DEVICE_ATTR_RO(name);
	308	static DEVICE_ATTR_RO(state);
	309
	310	static struct attribute *fpga_bridge_attrs[] = {
	311	&dev_attr_name.attr,
	312	&dev_attr_state.attr,
	313	NULL,
	314	};
	315	ATTRIBUTE_GROUPS(fpga_bridge);
	316
	317	/**
0d70af3c	318	* fpga_bridge_register - create and register an FPGA Bridge device
ceb8ab3c	319	* @parent: FPGA bridge device from pdev
21aeda95 AT	320	* @name: FPGA bridge name
	321	* @br_ops: pointer to structure of fpga bridge ops
	322	* @priv: FPGA bridge private data
	323	*
0d70af3c	324	* Return: struct fpga_bridge pointer or ERR_PTR()
21aeda95	325	*/
0d70af3c RW	326	struct fpga_bridge *
	327	fpga_bridge_register(struct device parent, const char name,
	328	const struct fpga_bridge_ops *br_ops,
	329	void *priv)
21aeda95 AT	330	{
21aeda95 AT	331	struct fpga_bridge *bridge;
d3fbd739	332	int id, ret;
21aeda95	333
0d70af3c RW	334	if (!br_ops) {
	335	dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
	336	return ERR_PTR(-EINVAL);
	337	}
	338
21aeda95	339	if (!name \|\| !strlen(name)) {
ceb8ab3c	340	dev_err(parent, "Attempt to register with no name!\n");
0d70af3c	341	return ERR_PTR(-EINVAL);
21aeda95 AT	342	}
	343
	344	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
	345	if (!bridge)
0d70af3c	346	return ERR_PTR(-ENOMEM);
21aeda95	347
a5e3d775	348	id = ida_alloc(&fpga_bridge_ida, GFP_KERNEL);
0d70af3c RW	349	if (id < 0) {
0d70af3c RW	350	ret = id;
21aeda95	351	goto error_kfree;
0d70af3c	352	}
21aeda95 AT	353
	354	mutex_init(&bridge->mutex);
	355	INIT_LIST_HEAD(&bridge->node);
	356
	357	bridge->name = name;
	358	bridge->br_ops = br_ops;
	359	bridge->priv = priv;
	360
845089bb	361	bridge->dev.groups = br_ops->groups;
21aeda95	362	bridge->dev.class = fpga_bridge_class;
ceb8ab3c RW	363	bridge->dev.parent = parent;
ceb8ab3c RW	364	bridge->dev.of_node = parent->of_node;
21aeda95	365	bridge->dev.id = id;
21aeda95 AT	366
	367	ret = dev_set_name(&bridge->dev, "br%d", id);
	368	if (ret)
	369	goto error_device;
	370
0d70af3c RW	371	ret = device_register(&bridge->dev);
	372	if (ret) {
	373	put_device(&bridge->dev);
	374	return ERR_PTR(ret);
	375	}
	376
dc70eb86 AL	377	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
dc70eb86 AL	378
371cd1b1	379	return bridge;
21aeda95 AT	380
21aeda95 AT	381	error_device:
a5e3d775	382	ida_free(&fpga_bridge_ida, id);
21aeda95 AT	383	error_kfree:
	384	kfree(bridge);
	385
0d70af3c	386	return ERR_PTR(ret);
21aeda95 AT	387	}
	388	EXPORT_SYMBOL_GPL(fpga_bridge_register);
	389
	390	/**
e7555cf6	391	* fpga_bridge_unregister - unregister an FPGA bridge
213befe0 AT	392	*
	393	* @bridge: FPGA bridge struct
	394	*
e7555cf6	395	* This function is intended for use in an FPGA bridge driver's remove function.
21aeda95	396	*/
371cd1b1	397	void fpga_bridge_unregister(struct fpga_bridge *bridge)
21aeda95	398	{
21aeda95 AT	399	/*
	400	* If the low level driver provides a method for putting bridge into
	401	* a desired state upon unregister, do it.
	402	*/
	403	if (bridge->br_ops && bridge->br_ops->fpga_bridge_remove)
	404	bridge->br_ops->fpga_bridge_remove(bridge);
	405
	406	device_unregister(&bridge->dev);
	407	}
	408	EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
	409
	410	static void fpga_bridge_dev_release(struct device *dev)
	411	{
0d70af3c RW	412	struct fpga_bridge *bridge = to_fpga_bridge(dev);
0d70af3c RW	413
a5e3d775	414	ida_free(&fpga_bridge_ida, bridge->dev.id);
0d70af3c	415	kfree(bridge);
21aeda95 AT	416	}
	417
	418	static int __init fpga_bridge_dev_init(void)
	419	{
1aaba11d	420	fpga_bridge_class = class_create("fpga_bridge");
21aeda95 AT	421	if (IS_ERR(fpga_bridge_class))
	422	return PTR_ERR(fpga_bridge_class);
	423
	424	fpga_bridge_class->dev_groups = fpga_bridge_groups;
	425	fpga_bridge_class->dev_release = fpga_bridge_dev_release;
	426
	427	return 0;
	428	}
	429
	430	static void __exit fpga_bridge_dev_exit(void)
	431	{
	432	class_destroy(fpga_bridge_class);
	433	ida_destroy(&fpga_bridge_ida);
	434	}
	435
	436	MODULE_DESCRIPTION("FPGA Bridge Driver");
9c1c4b27	437	MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
21aeda95 AT	438	MODULE_LICENSE("GPL v2");
	439
	440	subsys_initcall(fpga_bridge_dev_init);
	441	module_exit(fpga_bridge_dev_exit);