2 * FPGA Bridge Framework Driver
4 * Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License along with
16 * this program. If not, see <http://www.gnu.org/licenses/>.
18 #include <linux/fpga/fpga-bridge.h>
19 #include <linux/idr.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/of_platform.h>
23 #include <linux/slab.h>
24 #include <linux/spinlock.h>
26 static DEFINE_IDA(fpga_bridge_ida
);
27 static struct class *fpga_bridge_class
;
29 /* Lock for adding/removing bridges to linked lists*/
30 static spinlock_t bridge_list_lock
;
32 static int fpga_bridge_of_node_match(struct device
*dev
, const void *data
)
34 return dev
->of_node
== data
;
38 * fpga_bridge_enable - Enable transactions on the bridge
40 * @bridge: FPGA bridge
42 * Return: 0 for success, error code otherwise.
44 int fpga_bridge_enable(struct fpga_bridge
*bridge
)
46 dev_dbg(&bridge
->dev
, "enable\n");
48 if (bridge
->br_ops
&& bridge
->br_ops
->enable_set
)
49 return bridge
->br_ops
->enable_set(bridge
, 1);
53 EXPORT_SYMBOL_GPL(fpga_bridge_enable
);
56 * fpga_bridge_disable - Disable transactions on the bridge
58 * @bridge: FPGA bridge
60 * Return: 0 for success, error code otherwise.
62 int fpga_bridge_disable(struct fpga_bridge
*bridge
)
64 dev_dbg(&bridge
->dev
, "disable\n");
66 if (bridge
->br_ops
&& bridge
->br_ops
->enable_set
)
67 return bridge
->br_ops
->enable_set(bridge
, 0);
71 EXPORT_SYMBOL_GPL(fpga_bridge_disable
);
74 * of_fpga_bridge_get - get an exclusive reference to a fpga bridge
76 * @np: node pointer of a FPGA bridge
77 * @info: fpga image specific information
79 * Return fpga_bridge struct if successful.
80 * Return -EBUSY if someone already has a reference to the bridge.
81 * Return -ENODEV if @np is not a FPGA Bridge.
83 struct fpga_bridge
*of_fpga_bridge_get(struct device_node
*np
,
84 struct fpga_image_info
*info
)
88 struct fpga_bridge
*bridge
;
91 dev
= class_find_device(fpga_bridge_class
, NULL
, np
,
92 fpga_bridge_of_node_match
);
96 bridge
= to_fpga_bridge(dev
);
102 if (!mutex_trylock(&bridge
->mutex
)) {
107 if (!try_module_get(dev
->parent
->driver
->owner
))
110 dev_dbg(&bridge
->dev
, "get\n");
115 mutex_unlock(&bridge
->mutex
);
120 EXPORT_SYMBOL_GPL(of_fpga_bridge_get
);
123 * fpga_bridge_put - release a reference to a bridge
125 * @bridge: FPGA bridge
127 void fpga_bridge_put(struct fpga_bridge
*bridge
)
129 dev_dbg(&bridge
->dev
, "put\n");
132 module_put(bridge
->dev
.parent
->driver
->owner
);
133 mutex_unlock(&bridge
->mutex
);
134 put_device(&bridge
->dev
);
136 EXPORT_SYMBOL_GPL(fpga_bridge_put
);
139 * fpga_bridges_enable - enable bridges in a list
140 * @bridge_list: list of FPGA bridges
142 * Enable each bridge in the list. If list is empty, do nothing.
144 * Return 0 for success or empty bridge list; return error code otherwise.
146 int fpga_bridges_enable(struct list_head
*bridge_list
)
148 struct fpga_bridge
*bridge
;
151 list_for_each_entry(bridge
, bridge_list
, node
) {
152 ret
= fpga_bridge_enable(bridge
);
159 EXPORT_SYMBOL_GPL(fpga_bridges_enable
);
162 * fpga_bridges_disable - disable bridges in a list
164 * @bridge_list: list of FPGA bridges
166 * Disable each bridge in the list. If list is empty, do nothing.
168 * Return 0 for success or empty bridge list; return error code otherwise.
170 int fpga_bridges_disable(struct list_head
*bridge_list
)
172 struct fpga_bridge
*bridge
;
175 list_for_each_entry(bridge
, bridge_list
, node
) {
176 ret
= fpga_bridge_disable(bridge
);
183 EXPORT_SYMBOL_GPL(fpga_bridges_disable
);
186 * fpga_bridges_put - put bridges
188 * @bridge_list: list of FPGA bridges
190 * For each bridge in the list, put the bridge and remove it from the list.
191 * If list is empty, do nothing.
193 void fpga_bridges_put(struct list_head
*bridge_list
)
195 struct fpga_bridge
*bridge
, *next
;
198 list_for_each_entry_safe(bridge
, next
, bridge_list
, node
) {
199 fpga_bridge_put(bridge
);
201 spin_lock_irqsave(&bridge_list_lock
, flags
);
202 list_del(&bridge
->node
);
203 spin_unlock_irqrestore(&bridge_list_lock
, flags
);
206 EXPORT_SYMBOL_GPL(fpga_bridges_put
);
209 * fpga_bridges_get_to_list - get a bridge, add it to a list
211 * @np: node pointer of a FPGA bridge
212 * @info: fpga image specific information
213 * @bridge_list: list of FPGA bridges
215 * Get an exclusive reference to the bridge and and it to the list.
217 * Return 0 for success, error code from of_fpga_bridge_get() othewise.
219 int fpga_bridge_get_to_list(struct device_node
*np
,
220 struct fpga_image_info
*info
,
221 struct list_head
*bridge_list
)
223 struct fpga_bridge
*bridge
;
226 bridge
= of_fpga_bridge_get(np
, info
);
228 return PTR_ERR(bridge
);
230 spin_lock_irqsave(&bridge_list_lock
, flags
);
231 list_add(&bridge
->node
, bridge_list
);
232 spin_unlock_irqrestore(&bridge_list_lock
, flags
);
236 EXPORT_SYMBOL_GPL(fpga_bridge_get_to_list
);
238 static ssize_t
name_show(struct device
*dev
,
239 struct device_attribute
*attr
, char *buf
)
241 struct fpga_bridge
*bridge
= to_fpga_bridge(dev
);
243 return sprintf(buf
, "%s\n", bridge
->name
);
246 static ssize_t
state_show(struct device
*dev
,
247 struct device_attribute
*attr
, char *buf
)
249 struct fpga_bridge
*bridge
= to_fpga_bridge(dev
);
252 if (bridge
->br_ops
&& bridge
->br_ops
->enable_show
)
253 enable
= bridge
->br_ops
->enable_show(bridge
);
255 return sprintf(buf
, "%s\n", enable
? "enabled" : "disabled");
258 static DEVICE_ATTR_RO(name
);
259 static DEVICE_ATTR_RO(state
);
261 static struct attribute
*fpga_bridge_attrs
[] = {
263 &dev_attr_state
.attr
,
266 ATTRIBUTE_GROUPS(fpga_bridge
);
269 * fpga_bridge_register - register a fpga bridge driver
270 * @dev: FPGA bridge device from pdev
271 * @name: FPGA bridge name
272 * @br_ops: pointer to structure of fpga bridge ops
273 * @priv: FPGA bridge private data
275 * Return: 0 for success, error code otherwise.
277 int fpga_bridge_register(struct device
*dev
, const char *name
,
278 const struct fpga_bridge_ops
*br_ops
, void *priv
)
280 struct fpga_bridge
*bridge
;
283 if (!name
|| !strlen(name
)) {
284 dev_err(dev
, "Attempt to register with no name!\n");
288 bridge
= kzalloc(sizeof(*bridge
), GFP_KERNEL
);
292 id
= ida_simple_get(&fpga_bridge_ida
, 0, 0, GFP_KERNEL
);
298 mutex_init(&bridge
->mutex
);
299 INIT_LIST_HEAD(&bridge
->node
);
302 bridge
->br_ops
= br_ops
;
305 device_initialize(&bridge
->dev
);
306 bridge
->dev
.class = fpga_bridge_class
;
307 bridge
->dev
.parent
= dev
;
308 bridge
->dev
.of_node
= dev
->of_node
;
310 dev_set_drvdata(dev
, bridge
);
312 ret
= dev_set_name(&bridge
->dev
, "br%d", id
);
316 ret
= device_add(&bridge
->dev
);
320 of_platform_populate(dev
->of_node
, NULL
, NULL
, dev
);
322 dev_info(bridge
->dev
.parent
, "fpga bridge [%s] registered\n",
328 ida_simple_remove(&fpga_bridge_ida
, id
);
334 EXPORT_SYMBOL_GPL(fpga_bridge_register
);
337 * fpga_bridge_unregister - unregister a fpga bridge driver
338 * @dev: FPGA bridge device from pdev
340 void fpga_bridge_unregister(struct device
*dev
)
342 struct fpga_bridge
*bridge
= dev_get_drvdata(dev
);
345 * If the low level driver provides a method for putting bridge into
346 * a desired state upon unregister, do it.
348 if (bridge
->br_ops
&& bridge
->br_ops
->fpga_bridge_remove
)
349 bridge
->br_ops
->fpga_bridge_remove(bridge
);
351 device_unregister(&bridge
->dev
);
353 EXPORT_SYMBOL_GPL(fpga_bridge_unregister
);
355 static void fpga_bridge_dev_release(struct device
*dev
)
357 struct fpga_bridge
*bridge
= to_fpga_bridge(dev
);
359 ida_simple_remove(&fpga_bridge_ida
, bridge
->dev
.id
);
363 static int __init
fpga_bridge_dev_init(void)
365 spin_lock_init(&bridge_list_lock
);
367 fpga_bridge_class
= class_create(THIS_MODULE
, "fpga_bridge");
368 if (IS_ERR(fpga_bridge_class
))
369 return PTR_ERR(fpga_bridge_class
);
371 fpga_bridge_class
->dev_groups
= fpga_bridge_groups
;
372 fpga_bridge_class
->dev_release
= fpga_bridge_dev_release
;
377 static void __exit
fpga_bridge_dev_exit(void)
379 class_destroy(fpga_bridge_class
);
380 ida_destroy(&fpga_bridge_ida
);
383 MODULE_DESCRIPTION("FPGA Bridge Driver");
384 MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
385 MODULE_LICENSE("GPL v2");
387 subsys_initcall(fpga_bridge_dev_init
);
388 module_exit(fpga_bridge_dev_exit
);