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Alan Tull473f01f2018-05-16 18:49:58 -05001// SPDX-License-Identifier: GPL-2.0
Alan Tull21aeda92016-11-01 14:14:28 -05002/*
3 * FPGA Bridge Framework Driver
4 *
5 * Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
Alan Tull9c1c4b22017-11-15 14:20:11 -06006 * Copyright (C) 2017 Intel Corporation
Alan Tull21aeda92016-11-01 14:14:28 -05007 */
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
16static DEFINE_IDA(fpga_bridge_ida);
17static struct class *fpga_bridge_class;
18
19/* Lock for adding/removing bridges to linked lists*/
Dinh Nguyen47910a42017-02-27 09:18:59 -060020static spinlock_t bridge_list_lock;
Alan Tull21aeda92016-11-01 14:14:28 -050021
22static int fpga_bridge_of_node_match(struct device *dev, const void *data)
23{
24 return dev->of_node == data;
25}
26
27/**
28 * fpga_bridge_enable - Enable transactions on the bridge
29 *
30 * @bridge: FPGA bridge
31 *
32 * Return: 0 for success, error code otherwise.
33 */
34int fpga_bridge_enable(struct fpga_bridge *bridge)
35{
36 dev_dbg(&bridge->dev, "enable\n");
37
38 if (bridge->br_ops && bridge->br_ops->enable_set)
39 return bridge->br_ops->enable_set(bridge, 1);
40
41 return 0;
42}
43EXPORT_SYMBOL_GPL(fpga_bridge_enable);
44
45/**
46 * fpga_bridge_disable - Disable transactions on the bridge
47 *
48 * @bridge: FPGA bridge
49 *
50 * Return: 0 for success, error code otherwise.
51 */
52int fpga_bridge_disable(struct fpga_bridge *bridge)
53{
54 dev_dbg(&bridge->dev, "disable\n");
55
56 if (bridge->br_ops && bridge->br_ops->enable_set)
57 return bridge->br_ops->enable_set(bridge, 0);
58
59 return 0;
60}
61EXPORT_SYMBOL_GPL(fpga_bridge_disable);
62
Alan Tull9c1c4b22017-11-15 14:20:11 -060063static struct fpga_bridge *__fpga_bridge_get(struct device *dev,
64 struct fpga_image_info *info)
Alan Tull21aeda92016-11-01 14:14:28 -050065{
Alan Tull21aeda92016-11-01 14:14:28 -050066 struct fpga_bridge *bridge;
67 int ret = -ENODEV;
68
Alan Tull21aeda92016-11-01 14:14:28 -050069 bridge = to_fpga_bridge(dev);
Alan Tull21aeda92016-11-01 14:14:28 -050070
71 bridge->info = info;
72
73 if (!mutex_trylock(&bridge->mutex)) {
74 ret = -EBUSY;
75 goto err_dev;
76 }
77
78 if (!try_module_get(dev->parent->driver->owner))
79 goto err_ll_mod;
80
81 dev_dbg(&bridge->dev, "get\n");
82
83 return bridge;
84
85err_ll_mod:
86 mutex_unlock(&bridge->mutex);
87err_dev:
88 put_device(dev);
89 return ERR_PTR(ret);
90}
Alan Tull9c1c4b22017-11-15 14:20:11 -060091
92/**
93 * of_fpga_bridge_get - get an exclusive reference to a fpga bridge
94 *
95 * @np: node pointer of a FPGA bridge
96 * @info: fpga image specific information
97 *
98 * Return fpga_bridge struct if successful.
99 * Return -EBUSY if someone already has a reference to the bridge.
100 * Return -ENODEV if @np is not a FPGA Bridge.
101 */
102struct fpga_bridge *of_fpga_bridge_get(struct device_node *np,
103 struct fpga_image_info *info)
104{
105 struct device *dev;
106
107 dev = class_find_device(fpga_bridge_class, NULL, np,
108 fpga_bridge_of_node_match);
109 if (!dev)
110 return ERR_PTR(-ENODEV);
111
112 return __fpga_bridge_get(dev, info);
113}
Alan Tull21aeda92016-11-01 14:14:28 -0500114EXPORT_SYMBOL_GPL(of_fpga_bridge_get);
115
Alan Tull9c1c4b22017-11-15 14:20:11 -0600116static int fpga_bridge_dev_match(struct device *dev, const void *data)
117{
118 return dev->parent == data;
119}
120
121/**
122 * fpga_bridge_get - get an exclusive reference to a fpga bridge
123 * @dev: parent device that fpga bridge was registered with
Alan Tull060ac5c2018-05-16 18:50:00 -0500124 * @info: fpga manager info
Alan Tull9c1c4b22017-11-15 14:20:11 -0600125 *
126 * Given a device, get an exclusive reference to a fpga bridge.
127 *
128 * Return: fpga manager struct or IS_ERR() condition containing error code.
129 */
130struct fpga_bridge *fpga_bridge_get(struct device *dev,
131 struct fpga_image_info *info)
132{
133 struct device *bridge_dev;
134
135 bridge_dev = class_find_device(fpga_bridge_class, NULL, dev,
136 fpga_bridge_dev_match);
137 if (!bridge_dev)
138 return ERR_PTR(-ENODEV);
139
140 return __fpga_bridge_get(bridge_dev, info);
141}
142EXPORT_SYMBOL_GPL(fpga_bridge_get);
143
Alan Tull21aeda92016-11-01 14:14:28 -0500144/**
145 * fpga_bridge_put - release a reference to a bridge
146 *
147 * @bridge: FPGA bridge
148 */
149void fpga_bridge_put(struct fpga_bridge *bridge)
150{
151 dev_dbg(&bridge->dev, "put\n");
152
153 bridge->info = NULL;
154 module_put(bridge->dev.parent->driver->owner);
155 mutex_unlock(&bridge->mutex);
156 put_device(&bridge->dev);
157}
158EXPORT_SYMBOL_GPL(fpga_bridge_put);
159
160/**
161 * fpga_bridges_enable - enable bridges in a list
162 * @bridge_list: list of FPGA bridges
163 *
164 * Enable each bridge in the list. If list is empty, do nothing.
165 *
166 * Return 0 for success or empty bridge list; return error code otherwise.
167 */
168int fpga_bridges_enable(struct list_head *bridge_list)
169{
170 struct fpga_bridge *bridge;
Alan Tull21aeda92016-11-01 14:14:28 -0500171 int ret;
172
Moritz Fischerc37235c2017-03-10 12:47:11 -0800173 list_for_each_entry(bridge, bridge_list, node) {
Alan Tull21aeda92016-11-01 14:14:28 -0500174 ret = fpga_bridge_enable(bridge);
175 if (ret)
176 return ret;
177 }
178
179 return 0;
180}
181EXPORT_SYMBOL_GPL(fpga_bridges_enable);
182
183/**
184 * fpga_bridges_disable - disable bridges in a list
185 *
186 * @bridge_list: list of FPGA bridges
187 *
188 * Disable each bridge in the list. If list is empty, do nothing.
189 *
190 * Return 0 for success or empty bridge list; return error code otherwise.
191 */
192int fpga_bridges_disable(struct list_head *bridge_list)
193{
194 struct fpga_bridge *bridge;
Alan Tull21aeda92016-11-01 14:14:28 -0500195 int ret;
196
Moritz Fischerc37235c2017-03-10 12:47:11 -0800197 list_for_each_entry(bridge, bridge_list, node) {
Alan Tull21aeda92016-11-01 14:14:28 -0500198 ret = fpga_bridge_disable(bridge);
199 if (ret)
200 return ret;
201 }
202
203 return 0;
204}
205EXPORT_SYMBOL_GPL(fpga_bridges_disable);
206
207/**
208 * fpga_bridges_put - put bridges
209 *
210 * @bridge_list: list of FPGA bridges
211 *
212 * For each bridge in the list, put the bridge and remove it from the list.
213 * If list is empty, do nothing.
214 */
215void fpga_bridges_put(struct list_head *bridge_list)
216{
Moritz Fischerc37235c2017-03-10 12:47:11 -0800217 struct fpga_bridge *bridge, *next;
Alan Tull21aeda92016-11-01 14:14:28 -0500218 unsigned long flags;
219
Moritz Fischerc37235c2017-03-10 12:47:11 -0800220 list_for_each_entry_safe(bridge, next, bridge_list, node) {
Alan Tull21aeda92016-11-01 14:14:28 -0500221 fpga_bridge_put(bridge);
222
223 spin_lock_irqsave(&bridge_list_lock, flags);
224 list_del(&bridge->node);
225 spin_unlock_irqrestore(&bridge_list_lock, flags);
226 }
227}
228EXPORT_SYMBOL_GPL(fpga_bridges_put);
229
230/**
Alan Tull9c1c4b22017-11-15 14:20:11 -0600231 * of_fpga_bridge_get_to_list - get a bridge, add it to a list
Alan Tull21aeda92016-11-01 14:14:28 -0500232 *
233 * @np: node pointer of a FPGA bridge
234 * @info: fpga image specific information
235 * @bridge_list: list of FPGA bridges
236 *
237 * Get an exclusive reference to the bridge and and it to the list.
238 *
239 * Return 0 for success, error code from of_fpga_bridge_get() othewise.
240 */
Alan Tull9c1c4b22017-11-15 14:20:11 -0600241int of_fpga_bridge_get_to_list(struct device_node *np,
242 struct fpga_image_info *info,
243 struct list_head *bridge_list)
244{
245 struct fpga_bridge *bridge;
246 unsigned long flags;
247
248 bridge = of_fpga_bridge_get(np, info);
249 if (IS_ERR(bridge))
250 return PTR_ERR(bridge);
251
252 spin_lock_irqsave(&bridge_list_lock, flags);
253 list_add(&bridge->node, bridge_list);
254 spin_unlock_irqrestore(&bridge_list_lock, flags);
255
256 return 0;
257}
258EXPORT_SYMBOL_GPL(of_fpga_bridge_get_to_list);
259
260/**
261 * fpga_bridge_get_to_list - given device, get a bridge, add it to a list
262 *
263 * @dev: FPGA bridge device
264 * @info: fpga image specific information
265 * @bridge_list: list of FPGA bridges
266 *
267 * Get an exclusive reference to the bridge and and it to the list.
268 *
269 * Return 0 for success, error code from fpga_bridge_get() othewise.
270 */
271int fpga_bridge_get_to_list(struct device *dev,
Alan Tull21aeda92016-11-01 14:14:28 -0500272 struct fpga_image_info *info,
273 struct list_head *bridge_list)
274{
275 struct fpga_bridge *bridge;
276 unsigned long flags;
277
Alan Tull9c1c4b22017-11-15 14:20:11 -0600278 bridge = fpga_bridge_get(dev, info);
Alan Tull21aeda92016-11-01 14:14:28 -0500279 if (IS_ERR(bridge))
280 return PTR_ERR(bridge);
281
282 spin_lock_irqsave(&bridge_list_lock, flags);
283 list_add(&bridge->node, bridge_list);
284 spin_unlock_irqrestore(&bridge_list_lock, flags);
285
286 return 0;
287}
288EXPORT_SYMBOL_GPL(fpga_bridge_get_to_list);
289
290static ssize_t name_show(struct device *dev,
291 struct device_attribute *attr, char *buf)
292{
293 struct fpga_bridge *bridge = to_fpga_bridge(dev);
294
295 return sprintf(buf, "%s\n", bridge->name);
296}
297
298static ssize_t state_show(struct device *dev,
299 struct device_attribute *attr, char *buf)
300{
301 struct fpga_bridge *bridge = to_fpga_bridge(dev);
302 int enable = 1;
303
304 if (bridge->br_ops && bridge->br_ops->enable_show)
305 enable = bridge->br_ops->enable_show(bridge);
306
307 return sprintf(buf, "%s\n", enable ? "enabled" : "disabled");
308}
309
310static DEVICE_ATTR_RO(name);
311static DEVICE_ATTR_RO(state);
312
313static struct attribute *fpga_bridge_attrs[] = {
314 &dev_attr_name.attr,
315 &dev_attr_state.attr,
316 NULL,
317};
318ATTRIBUTE_GROUPS(fpga_bridge);
319
320/**
Alan Tull371cd1b2018-05-16 18:49:56 -0500321 * fpga_bridge_create - create and initialize a struct fpga_bridge
Alan Tull21aeda92016-11-01 14:14:28 -0500322 * @dev: FPGA bridge device from pdev
323 * @name: FPGA bridge name
324 * @br_ops: pointer to structure of fpga bridge ops
325 * @priv: FPGA bridge private data
326 *
Alan Tull371cd1b2018-05-16 18:49:56 -0500327 * Return: struct fpga_bridge or NULL
Alan Tull21aeda92016-11-01 14:14:28 -0500328 */
Alan Tull371cd1b2018-05-16 18:49:56 -0500329struct fpga_bridge *fpga_bridge_create(struct device *dev, const char *name,
330 const struct fpga_bridge_ops *br_ops,
331 void *priv)
Alan Tull21aeda92016-11-01 14:14:28 -0500332{
333 struct fpga_bridge *bridge;
334 int id, ret = 0;
335
336 if (!name || !strlen(name)) {
337 dev_err(dev, "Attempt to register with no name!\n");
Alan Tull371cd1b2018-05-16 18:49:56 -0500338 return NULL;
Alan Tull21aeda92016-11-01 14:14:28 -0500339 }
340
341 bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
342 if (!bridge)
Alan Tull371cd1b2018-05-16 18:49:56 -0500343 return NULL;
Alan Tull21aeda92016-11-01 14:14:28 -0500344
345 id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL);
346 if (id < 0) {
347 ret = id;
348 goto error_kfree;
349 }
350
351 mutex_init(&bridge->mutex);
352 INIT_LIST_HEAD(&bridge->node);
353
354 bridge->name = name;
355 bridge->br_ops = br_ops;
356 bridge->priv = priv;
357
358 device_initialize(&bridge->dev);
Alan Tull845089b2017-11-15 14:20:28 -0600359 bridge->dev.groups = br_ops->groups;
Alan Tull21aeda92016-11-01 14:14:28 -0500360 bridge->dev.class = fpga_bridge_class;
361 bridge->dev.parent = dev;
362 bridge->dev.of_node = dev->of_node;
363 bridge->dev.id = id;
Alan Tull21aeda92016-11-01 14:14:28 -0500364
365 ret = dev_set_name(&bridge->dev, "br%d", id);
366 if (ret)
367 goto error_device;
368
Alan Tull371cd1b2018-05-16 18:49:56 -0500369 return bridge;
Alan Tull21aeda92016-11-01 14:14:28 -0500370
371error_device:
372 ida_simple_remove(&fpga_bridge_ida, id);
373error_kfree:
374 kfree(bridge);
375
Alan Tull371cd1b2018-05-16 18:49:56 -0500376 return NULL;
377}
378EXPORT_SYMBOL_GPL(fpga_bridge_create);
379
380/**
381 * fpga_bridge_free - free a fpga bridge and its id
382 * @bridge: FPGA bridge struct created by fpga_bridge_create
383 */
384void fpga_bridge_free(struct fpga_bridge *bridge)
385{
386 ida_simple_remove(&fpga_bridge_ida, bridge->dev.id);
387 kfree(bridge);
388}
389EXPORT_SYMBOL_GPL(fpga_bridge_free);
390
391/**
392 * fpga_bridge_register - register a fpga bridge
393 * @bridge: FPGA bridge struct created by fpga_bridge_create
394 *
395 * Return: 0 for success, error code otherwise.
396 */
397int fpga_bridge_register(struct fpga_bridge *bridge)
398{
399 struct device *dev = &bridge->dev;
400 int ret;
401
402 ret = device_add(dev);
403 if (ret)
404 return ret;
405
406 of_platform_populate(dev->of_node, NULL, NULL, dev);
407
408 dev_info(dev->parent, "fpga bridge [%s] registered\n", bridge->name);
409
410 return 0;
Alan Tull21aeda92016-11-01 14:14:28 -0500411}
412EXPORT_SYMBOL_GPL(fpga_bridge_register);
413
414/**
Alan Tullfdff4052018-05-16 18:50:06 -0500415 * fpga_bridge_unregister - unregister and free a fpga bridge
Alan Tull371cd1b2018-05-16 18:49:56 -0500416 * @bridge: FPGA bridge struct created by fpga_bridge_create
Alan Tull21aeda92016-11-01 14:14:28 -0500417 */
Alan Tull371cd1b2018-05-16 18:49:56 -0500418void fpga_bridge_unregister(struct fpga_bridge *bridge)
Alan Tull21aeda92016-11-01 14:14:28 -0500419{
Alan Tull21aeda92016-11-01 14:14:28 -0500420 /*
421 * If the low level driver provides a method for putting bridge into
422 * a desired state upon unregister, do it.
423 */
424 if (bridge->br_ops && bridge->br_ops->fpga_bridge_remove)
425 bridge->br_ops->fpga_bridge_remove(bridge);
426
427 device_unregister(&bridge->dev);
428}
429EXPORT_SYMBOL_GPL(fpga_bridge_unregister);
430
431static void fpga_bridge_dev_release(struct device *dev)
432{
433 struct fpga_bridge *bridge = to_fpga_bridge(dev);
434
Alan Tull371cd1b2018-05-16 18:49:56 -0500435 fpga_bridge_free(bridge);
Alan Tull21aeda92016-11-01 14:14:28 -0500436}
437
438static int __init fpga_bridge_dev_init(void)
439{
440 spin_lock_init(&bridge_list_lock);
441
442 fpga_bridge_class = class_create(THIS_MODULE, "fpga_bridge");
443 if (IS_ERR(fpga_bridge_class))
444 return PTR_ERR(fpga_bridge_class);
445
446 fpga_bridge_class->dev_groups = fpga_bridge_groups;
447 fpga_bridge_class->dev_release = fpga_bridge_dev_release;
448
449 return 0;
450}
451
452static void __exit fpga_bridge_dev_exit(void)
453{
454 class_destroy(fpga_bridge_class);
455 ida_destroy(&fpga_bridge_ida);
456}
457
458MODULE_DESCRIPTION("FPGA Bridge Driver");
Alan Tull9c1c4b22017-11-15 14:20:11 -0600459MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
Alan Tull21aeda92016-11-01 14:14:28 -0500460MODULE_LICENSE("GPL v2");
461
462subsys_initcall(fpga_bridge_dev_init);
463module_exit(fpga_bridge_dev_exit);