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21aeda95 AT |
1 | /* |
2 | * FPGA Bridge Framework Driver | |
3 | * | |
4 | * Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved. | |
5 | * | |
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. | |
9 | * | |
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 | |
13 | * more details. | |
14 | * | |
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/>. | |
17 | */ | |
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> | |
25 | ||
26 | static DEFINE_IDA(fpga_bridge_ida); | |
27 | static struct class *fpga_bridge_class; | |
28 | ||
29 | /* Lock for adding/removing bridges to linked lists*/ | |
47910a49 | 30 | static spinlock_t bridge_list_lock; |
21aeda95 AT |
31 | |
32 | static int fpga_bridge_of_node_match(struct device *dev, const void *data) | |
33 | { | |
34 | return dev->of_node == data; | |
35 | } | |
36 | ||
37 | /** | |
38 | * fpga_bridge_enable - Enable transactions on the bridge | |
39 | * | |
40 | * @bridge: FPGA bridge | |
41 | * | |
42 | * Return: 0 for success, error code otherwise. | |
43 | */ | |
44 | int fpga_bridge_enable(struct fpga_bridge *bridge) | |
45 | { | |
46 | dev_dbg(&bridge->dev, "enable\n"); | |
47 | ||
48 | if (bridge->br_ops && bridge->br_ops->enable_set) | |
49 | return bridge->br_ops->enable_set(bridge, 1); | |
50 | ||
51 | return 0; | |
52 | } | |
53 | EXPORT_SYMBOL_GPL(fpga_bridge_enable); | |
54 | ||
55 | /** | |
56 | * fpga_bridge_disable - Disable transactions on the bridge | |
57 | * | |
58 | * @bridge: FPGA bridge | |
59 | * | |
60 | * Return: 0 for success, error code otherwise. | |
61 | */ | |
62 | int fpga_bridge_disable(struct fpga_bridge *bridge) | |
63 | { | |
64 | dev_dbg(&bridge->dev, "disable\n"); | |
65 | ||
66 | if (bridge->br_ops && bridge->br_ops->enable_set) | |
67 | return bridge->br_ops->enable_set(bridge, 0); | |
68 | ||
69 | return 0; | |
70 | } | |
71 | EXPORT_SYMBOL_GPL(fpga_bridge_disable); | |
72 | ||
73 | /** | |
74 | * of_fpga_bridge_get - get an exclusive reference to a fpga bridge | |
75 | * | |
76 | * @np: node pointer of a FPGA bridge | |
77 | * @info: fpga image specific information | |
78 | * | |
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. | |
82 | */ | |
83 | struct fpga_bridge *of_fpga_bridge_get(struct device_node *np, | |
84 | struct fpga_image_info *info) | |
85 | ||
86 | { | |
87 | struct device *dev; | |
88 | struct fpga_bridge *bridge; | |
89 | int ret = -ENODEV; | |
90 | ||
91 | dev = class_find_device(fpga_bridge_class, NULL, np, | |
92 | fpga_bridge_of_node_match); | |
93 | if (!dev) | |
94 | goto err_dev; | |
95 | ||
96 | bridge = to_fpga_bridge(dev); | |
97 | if (!bridge) | |
98 | goto err_dev; | |
99 | ||
100 | bridge->info = info; | |
101 | ||
102 | if (!mutex_trylock(&bridge->mutex)) { | |
103 | ret = -EBUSY; | |
104 | goto err_dev; | |
105 | } | |
106 | ||
107 | if (!try_module_get(dev->parent->driver->owner)) | |
108 | goto err_ll_mod; | |
109 | ||
110 | dev_dbg(&bridge->dev, "get\n"); | |
111 | ||
112 | return bridge; | |
113 | ||
114 | err_ll_mod: | |
115 | mutex_unlock(&bridge->mutex); | |
116 | err_dev: | |
117 | put_device(dev); | |
118 | return ERR_PTR(ret); | |
119 | } | |
120 | EXPORT_SYMBOL_GPL(of_fpga_bridge_get); | |
121 | ||
122 | /** | |
123 | * fpga_bridge_put - release a reference to a bridge | |
124 | * | |
125 | * @bridge: FPGA bridge | |
126 | */ | |
127 | void fpga_bridge_put(struct fpga_bridge *bridge) | |
128 | { | |
129 | dev_dbg(&bridge->dev, "put\n"); | |
130 | ||
131 | bridge->info = NULL; | |
132 | module_put(bridge->dev.parent->driver->owner); | |
133 | mutex_unlock(&bridge->mutex); | |
134 | put_device(&bridge->dev); | |
135 | } | |
136 | EXPORT_SYMBOL_GPL(fpga_bridge_put); | |
137 | ||
138 | /** | |
139 | * fpga_bridges_enable - enable bridges in a list | |
140 | * @bridge_list: list of FPGA bridges | |
141 | * | |
142 | * Enable each bridge in the list. If list is empty, do nothing. | |
143 | * | |
144 | * Return 0 for success or empty bridge list; return error code otherwise. | |
145 | */ | |
146 | int fpga_bridges_enable(struct list_head *bridge_list) | |
147 | { | |
148 | struct fpga_bridge *bridge; | |
149 | struct list_head *node; | |
150 | int ret; | |
151 | ||
152 | list_for_each(node, bridge_list) { | |
153 | bridge = list_entry(node, struct fpga_bridge, node); | |
154 | ret = fpga_bridge_enable(bridge); | |
155 | if (ret) | |
156 | return ret; | |
157 | } | |
158 | ||
159 | return 0; | |
160 | } | |
161 | EXPORT_SYMBOL_GPL(fpga_bridges_enable); | |
162 | ||
163 | /** | |
164 | * fpga_bridges_disable - disable bridges in a list | |
165 | * | |
166 | * @bridge_list: list of FPGA bridges | |
167 | * | |
168 | * Disable each bridge in the list. If list is empty, do nothing. | |
169 | * | |
170 | * Return 0 for success or empty bridge list; return error code otherwise. | |
171 | */ | |
172 | int fpga_bridges_disable(struct list_head *bridge_list) | |
173 | { | |
174 | struct fpga_bridge *bridge; | |
175 | struct list_head *node; | |
176 | int ret; | |
177 | ||
178 | list_for_each(node, bridge_list) { | |
179 | bridge = list_entry(node, struct fpga_bridge, node); | |
180 | ret = fpga_bridge_disable(bridge); | |
181 | if (ret) | |
182 | return ret; | |
183 | } | |
184 | ||
185 | return 0; | |
186 | } | |
187 | EXPORT_SYMBOL_GPL(fpga_bridges_disable); | |
188 | ||
189 | /** | |
190 | * fpga_bridges_put - put bridges | |
191 | * | |
192 | * @bridge_list: list of FPGA bridges | |
193 | * | |
194 | * For each bridge in the list, put the bridge and remove it from the list. | |
195 | * If list is empty, do nothing. | |
196 | */ | |
197 | void fpga_bridges_put(struct list_head *bridge_list) | |
198 | { | |
199 | struct fpga_bridge *bridge; | |
200 | struct list_head *node, *next; | |
201 | unsigned long flags; | |
202 | ||
203 | list_for_each_safe(node, next, bridge_list) { | |
204 | bridge = list_entry(node, struct fpga_bridge, node); | |
205 | ||
206 | fpga_bridge_put(bridge); | |
207 | ||
208 | spin_lock_irqsave(&bridge_list_lock, flags); | |
209 | list_del(&bridge->node); | |
210 | spin_unlock_irqrestore(&bridge_list_lock, flags); | |
211 | } | |
212 | } | |
213 | EXPORT_SYMBOL_GPL(fpga_bridges_put); | |
214 | ||
215 | /** | |
216 | * fpga_bridges_get_to_list - get a bridge, add it to a list | |
217 | * | |
218 | * @np: node pointer of a FPGA bridge | |
219 | * @info: fpga image specific information | |
220 | * @bridge_list: list of FPGA bridges | |
221 | * | |
222 | * Get an exclusive reference to the bridge and and it to the list. | |
223 | * | |
224 | * Return 0 for success, error code from of_fpga_bridge_get() othewise. | |
225 | */ | |
226 | int fpga_bridge_get_to_list(struct device_node *np, | |
227 | struct fpga_image_info *info, | |
228 | struct list_head *bridge_list) | |
229 | { | |
230 | struct fpga_bridge *bridge; | |
231 | unsigned long flags; | |
232 | ||
233 | bridge = of_fpga_bridge_get(np, info); | |
234 | if (IS_ERR(bridge)) | |
235 | return PTR_ERR(bridge); | |
236 | ||
237 | spin_lock_irqsave(&bridge_list_lock, flags); | |
238 | list_add(&bridge->node, bridge_list); | |
239 | spin_unlock_irqrestore(&bridge_list_lock, flags); | |
240 | ||
241 | return 0; | |
242 | } | |
243 | EXPORT_SYMBOL_GPL(fpga_bridge_get_to_list); | |
244 | ||
245 | static ssize_t name_show(struct device *dev, | |
246 | struct device_attribute *attr, char *buf) | |
247 | { | |
248 | struct fpga_bridge *bridge = to_fpga_bridge(dev); | |
249 | ||
250 | return sprintf(buf, "%s\n", bridge->name); | |
251 | } | |
252 | ||
253 | static ssize_t state_show(struct device *dev, | |
254 | struct device_attribute *attr, char *buf) | |
255 | { | |
256 | struct fpga_bridge *bridge = to_fpga_bridge(dev); | |
257 | int enable = 1; | |
258 | ||
259 | if (bridge->br_ops && bridge->br_ops->enable_show) | |
260 | enable = bridge->br_ops->enable_show(bridge); | |
261 | ||
262 | return sprintf(buf, "%s\n", enable ? "enabled" : "disabled"); | |
263 | } | |
264 | ||
265 | static DEVICE_ATTR_RO(name); | |
266 | static DEVICE_ATTR_RO(state); | |
267 | ||
268 | static struct attribute *fpga_bridge_attrs[] = { | |
269 | &dev_attr_name.attr, | |
270 | &dev_attr_state.attr, | |
271 | NULL, | |
272 | }; | |
273 | ATTRIBUTE_GROUPS(fpga_bridge); | |
274 | ||
275 | /** | |
276 | * fpga_bridge_register - register a fpga bridge driver | |
277 | * @dev: FPGA bridge device from pdev | |
278 | * @name: FPGA bridge name | |
279 | * @br_ops: pointer to structure of fpga bridge ops | |
280 | * @priv: FPGA bridge private data | |
281 | * | |
282 | * Return: 0 for success, error code otherwise. | |
283 | */ | |
284 | int fpga_bridge_register(struct device *dev, const char *name, | |
285 | const struct fpga_bridge_ops *br_ops, void *priv) | |
286 | { | |
287 | struct fpga_bridge *bridge; | |
288 | int id, ret = 0; | |
289 | ||
290 | if (!name || !strlen(name)) { | |
291 | dev_err(dev, "Attempt to register with no name!\n"); | |
292 | return -EINVAL; | |
293 | } | |
294 | ||
295 | bridge = kzalloc(sizeof(*bridge), GFP_KERNEL); | |
296 | if (!bridge) | |
297 | return -ENOMEM; | |
298 | ||
299 | id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL); | |
300 | if (id < 0) { | |
301 | ret = id; | |
302 | goto error_kfree; | |
303 | } | |
304 | ||
305 | mutex_init(&bridge->mutex); | |
306 | INIT_LIST_HEAD(&bridge->node); | |
307 | ||
308 | bridge->name = name; | |
309 | bridge->br_ops = br_ops; | |
310 | bridge->priv = priv; | |
311 | ||
312 | device_initialize(&bridge->dev); | |
313 | bridge->dev.class = fpga_bridge_class; | |
314 | bridge->dev.parent = dev; | |
315 | bridge->dev.of_node = dev->of_node; | |
316 | bridge->dev.id = id; | |
317 | dev_set_drvdata(dev, bridge); | |
318 | ||
319 | ret = dev_set_name(&bridge->dev, "br%d", id); | |
320 | if (ret) | |
321 | goto error_device; | |
322 | ||
323 | ret = device_add(&bridge->dev); | |
324 | if (ret) | |
325 | goto error_device; | |
326 | ||
327 | of_platform_populate(dev->of_node, NULL, NULL, dev); | |
328 | ||
329 | dev_info(bridge->dev.parent, "fpga bridge [%s] registered\n", | |
330 | bridge->name); | |
331 | ||
332 | return 0; | |
333 | ||
334 | error_device: | |
335 | ida_simple_remove(&fpga_bridge_ida, id); | |
336 | error_kfree: | |
337 | kfree(bridge); | |
338 | ||
339 | return ret; | |
340 | } | |
341 | EXPORT_SYMBOL_GPL(fpga_bridge_register); | |
342 | ||
343 | /** | |
344 | * fpga_bridge_unregister - unregister a fpga bridge driver | |
345 | * @dev: FPGA bridge device from pdev | |
346 | */ | |
347 | void fpga_bridge_unregister(struct device *dev) | |
348 | { | |
349 | struct fpga_bridge *bridge = dev_get_drvdata(dev); | |
350 | ||
351 | /* | |
352 | * If the low level driver provides a method for putting bridge into | |
353 | * a desired state upon unregister, do it. | |
354 | */ | |
355 | if (bridge->br_ops && bridge->br_ops->fpga_bridge_remove) | |
356 | bridge->br_ops->fpga_bridge_remove(bridge); | |
357 | ||
358 | device_unregister(&bridge->dev); | |
359 | } | |
360 | EXPORT_SYMBOL_GPL(fpga_bridge_unregister); | |
361 | ||
362 | static void fpga_bridge_dev_release(struct device *dev) | |
363 | { | |
364 | struct fpga_bridge *bridge = to_fpga_bridge(dev); | |
365 | ||
366 | ida_simple_remove(&fpga_bridge_ida, bridge->dev.id); | |
367 | kfree(bridge); | |
368 | } | |
369 | ||
370 | static int __init fpga_bridge_dev_init(void) | |
371 | { | |
372 | spin_lock_init(&bridge_list_lock); | |
373 | ||
374 | fpga_bridge_class = class_create(THIS_MODULE, "fpga_bridge"); | |
375 | if (IS_ERR(fpga_bridge_class)) | |
376 | return PTR_ERR(fpga_bridge_class); | |
377 | ||
378 | fpga_bridge_class->dev_groups = fpga_bridge_groups; | |
379 | fpga_bridge_class->dev_release = fpga_bridge_dev_release; | |
380 | ||
381 | return 0; | |
382 | } | |
383 | ||
384 | static void __exit fpga_bridge_dev_exit(void) | |
385 | { | |
386 | class_destroy(fpga_bridge_class); | |
387 | ida_destroy(&fpga_bridge_ida); | |
388 | } | |
389 | ||
390 | MODULE_DESCRIPTION("FPGA Bridge Driver"); | |
391 | MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>"); | |
392 | MODULE_LICENSE("GPL v2"); | |
393 | ||
394 | subsys_initcall(fpga_bridge_dev_init); | |
395 | module_exit(fpga_bridge_dev_exit); |