[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 const 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->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->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 pointer if successful.
 * * -EBUSY if someone already has a reference to the bridge.
 * * -ENODEV if @np is not an FPGA Bridge or can't take parent driver refcount.
 */
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 or an 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 or an 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->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->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 const struct class fpga_bridge_class = {
	.name = "fpga_bridge",
	.dev_groups = fpga_bridge_groups,
	.dev_release = fpga_bridge_dev_release,
};

static int __init fpga_bridge_dev_init(void)
{
	return class_register(&fpga_bridge_class);
}

static void __exit fpga_bridge_dev_exit(void)
{
	class_unregister(&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);
7bb2d219	17	static const struct class fpga_bridge_class;
21aeda95 AT	18
21aeda95 AT	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
b1a91ca2	33	if (bridge->br_ops->enable_set)
21aeda95 AT	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
b1a91ca2	51	if (bridge->br_ops->enable_set)
21aeda95 AT	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	*
8e665c9c MP	90	* @np: node pointer of an FPGA bridge.
8e665c9c MP	91	* @info: fpga image specific information.
9c1c4b27	92	*
8e665c9c MP	93	* Return:
	94	* * fpga_bridge struct pointer if successful.
	95	* * -EBUSY if someone already has a reference to the bridge.
	96	* * -ENODEV if @np is not an FPGA Bridge or can't take parent driver refcount.
9c1c4b27 AT	97	*/
	98	struct fpga_bridge of_fpga_bridge_get(struct device_node np,
	99	struct fpga_image_info *info)
	100	{
	101	struct device *dev;
	102
7bb2d219	103	dev = class_find_device_by_of_node(&fpga_bridge_class, np);
9c1c4b27 AT	104	if (!dev)
	105	return ERR_PTR(-ENODEV);
	106
	107	return __fpga_bridge_get(dev, info);
	108	}
21aeda95 AT	109	EXPORT_SYMBOL_GPL(of_fpga_bridge_get);
21aeda95 AT	110
9c1c4b27 AT	111	static int fpga_bridge_dev_match(struct device dev, const void data)
	112	{
	113	return dev->parent == data;
	114	}
	115
	116	/**
e7555cf6	117	* fpga_bridge_get - get an exclusive reference to an fpga bridge
9c1c4b27	118	* @dev: parent device that fpga bridge was registered with
7ef1a2c1	119	* @info: fpga image specific information
9c1c4b27	120	*
e7555cf6	121	* Given a device, get an exclusive reference to an fpga bridge.
9c1c4b27	122	*
b4d9a0e5	123	* Return: fpga bridge struct or IS_ERR() condition containing error code.
9c1c4b27 AT	124	*/
	125	struct fpga_bridge fpga_bridge_get(struct device dev,
	126	struct fpga_image_info *info)
	127	{
	128	struct device *bridge_dev;
	129
7bb2d219	130	bridge_dev = class_find_device(&fpga_bridge_class, NULL, dev,
9c1c4b27 AT	131	fpga_bridge_dev_match);
	132	if (!bridge_dev)
	133	return ERR_PTR(-ENODEV);
	134
	135	return __fpga_bridge_get(bridge_dev, info);
	136	}
	137	EXPORT_SYMBOL_GPL(fpga_bridge_get);
	138
21aeda95 AT	139	/**
	140	* fpga_bridge_put - release a reference to a bridge
	141	*
	142	* @bridge: FPGA bridge
	143	*/
	144	void fpga_bridge_put(struct fpga_bridge *bridge)
	145	{
	146	dev_dbg(&bridge->dev, "put\n");
	147
	148	bridge->info = NULL;
	149	module_put(bridge->dev.parent->driver->owner);
	150	mutex_unlock(&bridge->mutex);
	151	put_device(&bridge->dev);
	152	}
	153	EXPORT_SYMBOL_GPL(fpga_bridge_put);
	154
	155	/**
	156	* fpga_bridges_enable - enable bridges in a list
	157	* @bridge_list: list of FPGA bridges
	158	*
8e665c9c	159	* Enable each bridge in the list. If list is empty, do nothing.
21aeda95	160	*
8e665c9c	161	* Return: 0 for success or empty bridge list or an error code otherwise.
21aeda95 AT	162	*/
	163	int fpga_bridges_enable(struct list_head *bridge_list)
	164	{
	165	struct fpga_bridge *bridge;
21aeda95 AT	166	int ret;
21aeda95 AT	167
c37235cc	168	list_for_each_entry(bridge, bridge_list, node) {
21aeda95 AT	169	ret = fpga_bridge_enable(bridge);
	170	if (ret)
	171	return ret;
	172	}
	173
	174	return 0;
	175	}
	176	EXPORT_SYMBOL_GPL(fpga_bridges_enable);
	177
	178	/**
	179	* fpga_bridges_disable - disable bridges in a list
	180	*
	181	* @bridge_list: list of FPGA bridges
	182	*
8e665c9c	183	* Disable each bridge in the list. If list is empty, do nothing.
21aeda95	184	*
8e665c9c	185	* Return: 0 for success or empty bridge list or an error code otherwise.
21aeda95 AT	186	*/
	187	int fpga_bridges_disable(struct list_head *bridge_list)
	188	{
	189	struct fpga_bridge *bridge;
21aeda95 AT	190	int ret;
21aeda95 AT	191
c37235cc	192	list_for_each_entry(bridge, bridge_list, node) {
21aeda95 AT	193	ret = fpga_bridge_disable(bridge);
	194	if (ret)
	195	return ret;
	196	}
	197
	198	return 0;
	199	}
	200	EXPORT_SYMBOL_GPL(fpga_bridges_disable);
	201
	202	/**
	203	* fpga_bridges_put - put bridges
	204	*
	205	* @bridge_list: list of FPGA bridges
	206	*
	207	* For each bridge in the list, put the bridge and remove it from the list.
	208	* If list is empty, do nothing.
	209	*/
	210	void fpga_bridges_put(struct list_head *bridge_list)
	211	{
c37235cc	212	struct fpga_bridge bridge, next;
21aeda95 AT	213	unsigned long flags;
21aeda95 AT	214
c37235cc	215	list_for_each_entry_safe(bridge, next, bridge_list, node) {
21aeda95 AT	216	fpga_bridge_put(bridge);
	217
	218	spin_lock_irqsave(&bridge_list_lock, flags);
	219	list_del(&bridge->node);
	220	spin_unlock_irqrestore(&bridge_list_lock, flags);
	221	}
	222	}
	223	EXPORT_SYMBOL_GPL(fpga_bridges_put);
	224
	225	/**
9c1c4b27	226	* of_fpga_bridge_get_to_list - get a bridge, add it to a list
21aeda95	227	*
e7555cf6	228	* @np: node pointer of an FPGA bridge
21aeda95 AT	229	* @info: fpga image specific information
	230	* @bridge_list: list of FPGA bridges
	231	*
0a05cdf1	232	* Get an exclusive reference to the bridge and it to the list.
21aeda95	233	*
8e665c9c	234	* Return: 0 for success, error code from of_fpga_bridge_get() otherwise.
21aeda95	235	*/
9c1c4b27 AT	236	int of_fpga_bridge_get_to_list(struct device_node *np,
	237	struct fpga_image_info *info,
	238	struct list_head *bridge_list)
	239	{
	240	struct fpga_bridge *bridge;
	241	unsigned long flags;
	242
	243	bridge = of_fpga_bridge_get(np, info);
	244	if (IS_ERR(bridge))
	245	return PTR_ERR(bridge);
	246
	247	spin_lock_irqsave(&bridge_list_lock, flags);
	248	list_add(&bridge->node, bridge_list);
	249	spin_unlock_irqrestore(&bridge_list_lock, flags);
	250
	251	return 0;
	252	}
	253	EXPORT_SYMBOL_GPL(of_fpga_bridge_get_to_list);
	254
	255	/**
	256	* fpga_bridge_get_to_list - given device, get a bridge, add it to a list
	257	*
	258	* @dev: FPGA bridge device
	259	* @info: fpga image specific information
	260	* @bridge_list: list of FPGA bridges
	261	*
0a05cdf1	262	* Get an exclusive reference to the bridge and it to the list.
9c1c4b27	263	*
8e665c9c	264	* Return: 0 for success, error code from fpga_bridge_get() otherwise.
9c1c4b27 AT	265	*/
9c1c4b27 AT	266	int fpga_bridge_get_to_list(struct device *dev,
21aeda95 AT	267	struct fpga_image_info *info,
	268	struct list_head *bridge_list)
	269	{
	270	struct fpga_bridge *bridge;
	271	unsigned long flags;
	272
9c1c4b27	273	bridge = fpga_bridge_get(dev, info);
21aeda95 AT	274	if (IS_ERR(bridge))
	275	return PTR_ERR(bridge);
	276
	277	spin_lock_irqsave(&bridge_list_lock, flags);
	278	list_add(&bridge->node, bridge_list);
	279	spin_unlock_irqrestore(&bridge_list_lock, flags);
	280
	281	return 0;
	282	}
	283	EXPORT_SYMBOL_GPL(fpga_bridge_get_to_list);
	284
	285	static ssize_t name_show(struct device *dev,
	286	struct device_attribute attr, char buf)
	287	{
	288	struct fpga_bridge *bridge = to_fpga_bridge(dev);
	289
	290	return sprintf(buf, "%s\n", bridge->name);
	291	}
	292
	293	static ssize_t state_show(struct device *dev,
	294	struct device_attribute attr, char buf)
	295	{
	296	struct fpga_bridge *bridge = to_fpga_bridge(dev);
48ca6e5f	297	int state = 1;
21aeda95	298
b1a91ca2	299	if (bridge->br_ops->enable_show) {
48ca6e5f MP	300	state = bridge->br_ops->enable_show(bridge);
	301	if (state < 0)
	302	return state;
	303	}
21aeda95	304
48ca6e5f	305	return sysfs_emit(buf, "%s\n", state ? "enabled" : "disabled");
21aeda95 AT	306	}
	307
	308	static DEVICE_ATTR_RO(name);
	309	static DEVICE_ATTR_RO(state);
	310
	311	static struct attribute *fpga_bridge_attrs[] = {
	312	&dev_attr_name.attr,
	313	&dev_attr_state.attr,
	314	NULL,
	315	};
	316	ATTRIBUTE_GROUPS(fpga_bridge);
	317
	318	/**
0d70af3c	319	* fpga_bridge_register - create and register an FPGA Bridge device
ceb8ab3c	320	* @parent: FPGA bridge device from pdev
21aeda95 AT	321	* @name: FPGA bridge name
	322	* @br_ops: pointer to structure of fpga bridge ops
	323	* @priv: FPGA bridge private data
	324	*
0d70af3c	325	* Return: struct fpga_bridge pointer or ERR_PTR()
21aeda95	326	*/
0d70af3c RW	327	struct fpga_bridge *
	328	fpga_bridge_register(struct device parent, const char name,
	329	const struct fpga_bridge_ops *br_ops,
	330	void *priv)
21aeda95 AT	331	{
21aeda95 AT	332	struct fpga_bridge *bridge;
d3fbd739	333	int id, ret;
21aeda95	334
0d70af3c RW	335	if (!br_ops) {
	336	dev_err(parent, "Attempt to register without fpga_bridge_ops\n");
	337	return ERR_PTR(-EINVAL);
	338	}
	339
21aeda95	340	if (!name \|\| !strlen(name)) {
ceb8ab3c	341	dev_err(parent, "Attempt to register with no name!\n");
0d70af3c	342	return ERR_PTR(-EINVAL);
21aeda95 AT	343	}
	344
	345	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
	346	if (!bridge)
0d70af3c	347	return ERR_PTR(-ENOMEM);
21aeda95	348
a5e3d775	349	id = ida_alloc(&fpga_bridge_ida, GFP_KERNEL);
0d70af3c RW	350	if (id < 0) {
0d70af3c RW	351	ret = id;
21aeda95	352	goto error_kfree;
0d70af3c	353	}
21aeda95 AT	354
	355	mutex_init(&bridge->mutex);
	356	INIT_LIST_HEAD(&bridge->node);
	357
	358	bridge->name = name;
	359	bridge->br_ops = br_ops;
	360	bridge->priv = priv;
	361
845089bb	362	bridge->dev.groups = br_ops->groups;
7bb2d219	363	bridge->dev.class = &fpga_bridge_class;
ceb8ab3c RW	364	bridge->dev.parent = parent;
ceb8ab3c RW	365	bridge->dev.of_node = parent->of_node;
21aeda95	366	bridge->dev.id = id;
21aeda95 AT	367
	368	ret = dev_set_name(&bridge->dev, "br%d", id);
	369	if (ret)
	370	goto error_device;
	371
0d70af3c RW	372	ret = device_register(&bridge->dev);
	373	if (ret) {
	374	put_device(&bridge->dev);
	375	return ERR_PTR(ret);
	376	}
	377
dc70eb86 AL	378	of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
dc70eb86 AL	379
371cd1b1	380	return bridge;
21aeda95 AT	381
21aeda95 AT	382	error_device:
a5e3d775	383	ida_free(&fpga_bridge_ida, id);
21aeda95 AT	384	error_kfree:
	385	kfree(bridge);
	386
0d70af3c	387	return ERR_PTR(ret);
21aeda95 AT	388	}
	389	EXPORT_SYMBOL_GPL(fpga_bridge_register);
	390
	391	/**
e7555cf6	392	* fpga_bridge_unregister - unregister an FPGA bridge
213befe0 AT	393	*
	394	* @bridge: FPGA bridge struct
	395	*
e7555cf6	396	* This function is intended for use in an FPGA bridge driver's remove function.
21aeda95	397	*/
371cd1b1	398	void fpga_bridge_unregister(struct fpga_bridge *bridge)
21aeda95	399	{
21aeda95 AT	400	/*
	401	* If the low level driver provides a method for putting bridge into
	402	* a desired state upon unregister, do it.
	403	*/
b1a91ca2	404	if (bridge->br_ops->fpga_bridge_remove)
21aeda95 AT	405	bridge->br_ops->fpga_bridge_remove(bridge);
	406
	407	device_unregister(&bridge->dev);
	408	}
	409	EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
	410
	411	static void fpga_bridge_dev_release(struct device *dev)
	412	{
0d70af3c RW	413	struct fpga_bridge *bridge = to_fpga_bridge(dev);
0d70af3c RW	414
a5e3d775	415	ida_free(&fpga_bridge_ida, bridge->dev.id);
0d70af3c	416	kfree(bridge);
21aeda95 AT	417	}
21aeda95 AT	418
7bb2d219 IO	419	static const struct class fpga_bridge_class = {
	420	.name = "fpga_bridge",
	421	.dev_groups = fpga_bridge_groups,
	422	.dev_release = fpga_bridge_dev_release,
	423	};
	424
21aeda95 AT	425	static int __init fpga_bridge_dev_init(void)
21aeda95 AT	426	{
7bb2d219	427	return class_register(&fpga_bridge_class);
21aeda95 AT	428	}
	429
	430	static void __exit fpga_bridge_dev_exit(void)
	431	{
7bb2d219	432	class_unregister(&fpga_bridge_class);
21aeda95 AT	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);