1 /* 2 * FPGA Bridge Framework Driver 3 * 4 * Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved. 5 * Copyright (C) 2017 Intel Corporation 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms and conditions of the GNU General Public License, 9 * version 2, as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License along with 17 * this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 #include <linux/fpga/fpga-bridge.h> 20 #include <linux/idr.h> 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/of_platform.h> 24 #include <linux/slab.h> 25 #include <linux/spinlock.h> 26 27 static DEFINE_IDA(fpga_bridge_ida); 28 static struct class *fpga_bridge_class; 29 30 /* Lock for adding/removing bridges to linked lists*/ 31 static spinlock_t bridge_list_lock; 32 33 static int fpga_bridge_of_node_match(struct device *dev, const void *data) 34 { 35 return dev->of_node == data; 36 } 37 38 /** 39 * fpga_bridge_enable - Enable transactions on the bridge 40 * 41 * @bridge: FPGA bridge 42 * 43 * Return: 0 for success, error code otherwise. 44 */ 45 int fpga_bridge_enable(struct fpga_bridge *bridge) 46 { 47 dev_dbg(&bridge->dev, "enable\n"); 48 49 if (bridge->br_ops && bridge->br_ops->enable_set) 50 return bridge->br_ops->enable_set(bridge, 1); 51 52 return 0; 53 } 54 EXPORT_SYMBOL_GPL(fpga_bridge_enable); 55 56 /** 57 * fpga_bridge_disable - Disable transactions on the bridge 58 * 59 * @bridge: FPGA bridge 60 * 61 * Return: 0 for success, error code otherwise. 62 */ 63 int fpga_bridge_disable(struct fpga_bridge *bridge) 64 { 65 dev_dbg(&bridge->dev, "disable\n"); 66 67 if (bridge->br_ops && bridge->br_ops->enable_set) 68 return bridge->br_ops->enable_set(bridge, 0); 69 70 return 0; 71 } 72 EXPORT_SYMBOL_GPL(fpga_bridge_disable); 73 74 static struct fpga_bridge *__fpga_bridge_get(struct device *dev, 75 struct fpga_image_info *info) 76 { 77 struct fpga_bridge *bridge; 78 int ret = -ENODEV; 79 80 bridge = to_fpga_bridge(dev); 81 82 bridge->info = info; 83 84 if (!mutex_trylock(&bridge->mutex)) { 85 ret = -EBUSY; 86 goto err_dev; 87 } 88 89 if (!try_module_get(dev->parent->driver->owner)) 90 goto err_ll_mod; 91 92 dev_dbg(&bridge->dev, "get\n"); 93 94 return bridge; 95 96 err_ll_mod: 97 mutex_unlock(&bridge->mutex); 98 err_dev: 99 put_device(dev); 100 return ERR_PTR(ret); 101 } 102 103 /** 104 * of_fpga_bridge_get - get an exclusive reference to a fpga bridge 105 * 106 * @np: node pointer of a FPGA bridge 107 * @info: fpga image specific information 108 * 109 * Return fpga_bridge struct if successful. 110 * Return -EBUSY if someone already has a reference to the bridge. 111 * Return -ENODEV if @np is not a FPGA Bridge. 112 */ 113 struct fpga_bridge *of_fpga_bridge_get(struct device_node *np, 114 struct fpga_image_info *info) 115 { 116 struct device *dev; 117 118 dev = class_find_device(fpga_bridge_class, NULL, np, 119 fpga_bridge_of_node_match); 120 if (!dev) 121 return ERR_PTR(-ENODEV); 122 123 return __fpga_bridge_get(dev, info); 124 } 125 EXPORT_SYMBOL_GPL(of_fpga_bridge_get); 126 127 static int fpga_bridge_dev_match(struct device *dev, const void *data) 128 { 129 return dev->parent == data; 130 } 131 132 /** 133 * fpga_bridge_get - get an exclusive reference to a fpga bridge 134 * @dev: parent device that fpga bridge was registered with 135 * 136 * Given a device, get an exclusive reference to a fpga bridge. 137 * 138 * Return: fpga manager struct or IS_ERR() condition containing error code. 139 */ 140 struct fpga_bridge *fpga_bridge_get(struct device *dev, 141 struct fpga_image_info *info) 142 { 143 struct device *bridge_dev; 144 145 bridge_dev = class_find_device(fpga_bridge_class, NULL, dev, 146 fpga_bridge_dev_match); 147 if (!bridge_dev) 148 return ERR_PTR(-ENODEV); 149 150 return __fpga_bridge_get(bridge_dev, info); 151 } 152 EXPORT_SYMBOL_GPL(fpga_bridge_get); 153 154 /** 155 * fpga_bridge_put - release a reference to a bridge 156 * 157 * @bridge: FPGA bridge 158 */ 159 void fpga_bridge_put(struct fpga_bridge *bridge) 160 { 161 dev_dbg(&bridge->dev, "put\n"); 162 163 bridge->info = NULL; 164 module_put(bridge->dev.parent->driver->owner); 165 mutex_unlock(&bridge->mutex); 166 put_device(&bridge->dev); 167 } 168 EXPORT_SYMBOL_GPL(fpga_bridge_put); 169 170 /** 171 * fpga_bridges_enable - enable bridges in a list 172 * @bridge_list: list of FPGA bridges 173 * 174 * Enable each bridge in the list. If list is empty, do nothing. 175 * 176 * Return 0 for success or empty bridge list; return error code otherwise. 177 */ 178 int fpga_bridges_enable(struct list_head *bridge_list) 179 { 180 struct fpga_bridge *bridge; 181 int ret; 182 183 list_for_each_entry(bridge, bridge_list, node) { 184 ret = fpga_bridge_enable(bridge); 185 if (ret) 186 return ret; 187 } 188 189 return 0; 190 } 191 EXPORT_SYMBOL_GPL(fpga_bridges_enable); 192 193 /** 194 * fpga_bridges_disable - disable bridges in a list 195 * 196 * @bridge_list: list of FPGA bridges 197 * 198 * Disable each bridge in the list. If list is empty, do nothing. 199 * 200 * Return 0 for success or empty bridge list; return error code otherwise. 201 */ 202 int fpga_bridges_disable(struct list_head *bridge_list) 203 { 204 struct fpga_bridge *bridge; 205 int ret; 206 207 list_for_each_entry(bridge, bridge_list, node) { 208 ret = fpga_bridge_disable(bridge); 209 if (ret) 210 return ret; 211 } 212 213 return 0; 214 } 215 EXPORT_SYMBOL_GPL(fpga_bridges_disable); 216 217 /** 218 * fpga_bridges_put - put bridges 219 * 220 * @bridge_list: list of FPGA bridges 221 * 222 * For each bridge in the list, put the bridge and remove it from the list. 223 * If list is empty, do nothing. 224 */ 225 void fpga_bridges_put(struct list_head *bridge_list) 226 { 227 struct fpga_bridge *bridge, *next; 228 unsigned long flags; 229 230 list_for_each_entry_safe(bridge, next, bridge_list, node) { 231 fpga_bridge_put(bridge); 232 233 spin_lock_irqsave(&bridge_list_lock, flags); 234 list_del(&bridge->node); 235 spin_unlock_irqrestore(&bridge_list_lock, flags); 236 } 237 } 238 EXPORT_SYMBOL_GPL(fpga_bridges_put); 239 240 /** 241 * of_fpga_bridge_get_to_list - get a bridge, add it to a list 242 * 243 * @np: node pointer of a FPGA bridge 244 * @info: fpga image specific information 245 * @bridge_list: list of FPGA bridges 246 * 247 * Get an exclusive reference to the bridge and and it to the list. 248 * 249 * Return 0 for success, error code from of_fpga_bridge_get() othewise. 250 */ 251 int of_fpga_bridge_get_to_list(struct device_node *np, 252 struct fpga_image_info *info, 253 struct list_head *bridge_list) 254 { 255 struct fpga_bridge *bridge; 256 unsigned long flags; 257 258 bridge = of_fpga_bridge_get(np, info); 259 if (IS_ERR(bridge)) 260 return PTR_ERR(bridge); 261 262 spin_lock_irqsave(&bridge_list_lock, flags); 263 list_add(&bridge->node, bridge_list); 264 spin_unlock_irqrestore(&bridge_list_lock, flags); 265 266 return 0; 267 } 268 EXPORT_SYMBOL_GPL(of_fpga_bridge_get_to_list); 269 270 /** 271 * fpga_bridge_get_to_list - given device, get a bridge, add it to a list 272 * 273 * @dev: FPGA bridge device 274 * @info: fpga image specific information 275 * @bridge_list: list of FPGA bridges 276 * 277 * Get an exclusive reference to the bridge and and it to the list. 278 * 279 * Return 0 for success, error code from fpga_bridge_get() othewise. 280 */ 281 int fpga_bridge_get_to_list(struct device *dev, 282 struct fpga_image_info *info, 283 struct list_head *bridge_list) 284 { 285 struct fpga_bridge *bridge; 286 unsigned long flags; 287 288 bridge = fpga_bridge_get(dev, info); 289 if (IS_ERR(bridge)) 290 return PTR_ERR(bridge); 291 292 spin_lock_irqsave(&bridge_list_lock, flags); 293 list_add(&bridge->node, bridge_list); 294 spin_unlock_irqrestore(&bridge_list_lock, flags); 295 296 return 0; 297 } 298 EXPORT_SYMBOL_GPL(fpga_bridge_get_to_list); 299 300 static ssize_t name_show(struct device *dev, 301 struct device_attribute *attr, char *buf) 302 { 303 struct fpga_bridge *bridge = to_fpga_bridge(dev); 304 305 return sprintf(buf, "%s\n", bridge->name); 306 } 307 308 static ssize_t state_show(struct device *dev, 309 struct device_attribute *attr, char *buf) 310 { 311 struct fpga_bridge *bridge = to_fpga_bridge(dev); 312 int enable = 1; 313 314 if (bridge->br_ops && bridge->br_ops->enable_show) 315 enable = bridge->br_ops->enable_show(bridge); 316 317 return sprintf(buf, "%s\n", enable ? "enabled" : "disabled"); 318 } 319 320 static DEVICE_ATTR_RO(name); 321 static DEVICE_ATTR_RO(state); 322 323 static struct attribute *fpga_bridge_attrs[] = { 324 &dev_attr_name.attr, 325 &dev_attr_state.attr, 326 NULL, 327 }; 328 ATTRIBUTE_GROUPS(fpga_bridge); 329 330 /** 331 * fpga_bridge_register - register a fpga bridge driver 332 * @dev: FPGA bridge device from pdev 333 * @name: FPGA bridge name 334 * @br_ops: pointer to structure of fpga bridge ops 335 * @priv: FPGA bridge private data 336 * 337 * Return: 0 for success, error code otherwise. 338 */ 339 int fpga_bridge_register(struct device *dev, const char *name, 340 const struct fpga_bridge_ops *br_ops, void *priv) 341 { 342 struct fpga_bridge *bridge; 343 int id, ret = 0; 344 345 if (!name || !strlen(name)) { 346 dev_err(dev, "Attempt to register with no name!\n"); 347 return -EINVAL; 348 } 349 350 bridge = kzalloc(sizeof(*bridge), GFP_KERNEL); 351 if (!bridge) 352 return -ENOMEM; 353 354 id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL); 355 if (id < 0) { 356 ret = id; 357 goto error_kfree; 358 } 359 360 mutex_init(&bridge->mutex); 361 INIT_LIST_HEAD(&bridge->node); 362 363 bridge->name = name; 364 bridge->br_ops = br_ops; 365 bridge->priv = priv; 366 367 device_initialize(&bridge->dev); 368 bridge->dev.groups = br_ops->groups; 369 bridge->dev.class = fpga_bridge_class; 370 bridge->dev.parent = dev; 371 bridge->dev.of_node = dev->of_node; 372 bridge->dev.id = id; 373 dev_set_drvdata(dev, bridge); 374 375 ret = dev_set_name(&bridge->dev, "br%d", id); 376 if (ret) 377 goto error_device; 378 379 ret = device_add(&bridge->dev); 380 if (ret) 381 goto error_device; 382 383 of_platform_populate(dev->of_node, NULL, NULL, dev); 384 385 dev_info(bridge->dev.parent, "fpga bridge [%s] registered\n", 386 bridge->name); 387 388 return 0; 389 390 error_device: 391 ida_simple_remove(&fpga_bridge_ida, id); 392 error_kfree: 393 kfree(bridge); 394 395 return ret; 396 } 397 EXPORT_SYMBOL_GPL(fpga_bridge_register); 398 399 /** 400 * fpga_bridge_unregister - unregister a fpga bridge driver 401 * @dev: FPGA bridge device from pdev 402 */ 403 void fpga_bridge_unregister(struct device *dev) 404 { 405 struct fpga_bridge *bridge = dev_get_drvdata(dev); 406 407 /* 408 * If the low level driver provides a method for putting bridge into 409 * a desired state upon unregister, do it. 410 */ 411 if (bridge->br_ops && bridge->br_ops->fpga_bridge_remove) 412 bridge->br_ops->fpga_bridge_remove(bridge); 413 414 device_unregister(&bridge->dev); 415 } 416 EXPORT_SYMBOL_GPL(fpga_bridge_unregister); 417 418 static void fpga_bridge_dev_release(struct device *dev) 419 { 420 struct fpga_bridge *bridge = to_fpga_bridge(dev); 421 422 ida_simple_remove(&fpga_bridge_ida, bridge->dev.id); 423 kfree(bridge); 424 } 425 426 static int __init fpga_bridge_dev_init(void) 427 { 428 spin_lock_init(&bridge_list_lock); 429 430 fpga_bridge_class = class_create(THIS_MODULE, "fpga_bridge"); 431 if (IS_ERR(fpga_bridge_class)) 432 return PTR_ERR(fpga_bridge_class); 433 434 fpga_bridge_class->dev_groups = fpga_bridge_groups; 435 fpga_bridge_class->dev_release = fpga_bridge_dev_release; 436 437 return 0; 438 } 439 440 static void __exit fpga_bridge_dev_exit(void) 441 { 442 class_destroy(fpga_bridge_class); 443 ida_destroy(&fpga_bridge_ida); 444 } 445 446 MODULE_DESCRIPTION("FPGA Bridge Driver"); 447 MODULE_AUTHOR("Alan Tull <atull@kernel.org>"); 448 MODULE_LICENSE("GPL v2"); 449 450 subsys_initcall(fpga_bridge_dev_init); 451 module_exit(fpga_bridge_dev_exit); 452