1 /* 2 * FPGA Region - Device Tree support for FPGA programming under Linux 3 * 4 * Copyright (C) 2013-2016 Altera Corporation 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 20 #include <linux/fpga/fpga-bridge.h> 21 #include <linux/fpga/fpga-mgr.h> 22 #include <linux/fpga/fpga-region.h> 23 #include <linux/idr.h> 24 #include <linux/kernel.h> 25 #include <linux/list.h> 26 #include <linux/module.h> 27 #include <linux/of_platform.h> 28 #include <linux/slab.h> 29 #include <linux/spinlock.h> 30 31 static const struct of_device_id fpga_region_of_match[] = { 32 { .compatible = "fpga-region", }, 33 {}, 34 }; 35 MODULE_DEVICE_TABLE(of, fpga_region_of_match); 36 37 static int fpga_region_of_node_match(struct device *dev, const void *data) 38 { 39 return dev->of_node == data; 40 } 41 42 /** 43 * of_fpga_region_find - find FPGA region 44 * @np: device node of FPGA Region 45 * 46 * Caller will need to put_device(®ion->dev) when done. 47 * 48 * Returns FPGA Region struct or NULL 49 */ 50 static struct fpga_region *of_fpga_region_find(struct device_node *np) 51 { 52 return fpga_region_class_find(NULL, np, fpga_region_of_node_match); 53 } 54 55 /** 56 * of_fpga_region_get_mgr - get reference for FPGA manager 57 * @np: device node of FPGA region 58 * 59 * Get FPGA Manager from "fpga-mgr" property or from ancestor region. 60 * 61 * Caller should call fpga_mgr_put() when done with manager. 62 * 63 * Return: fpga manager struct or IS_ERR() condition containing error code. 64 */ 65 static struct fpga_manager *of_fpga_region_get_mgr(struct device_node *np) 66 { 67 struct device_node *mgr_node; 68 struct fpga_manager *mgr; 69 70 of_node_get(np); 71 while (np) { 72 if (of_device_is_compatible(np, "fpga-region")) { 73 mgr_node = of_parse_phandle(np, "fpga-mgr", 0); 74 if (mgr_node) { 75 mgr = of_fpga_mgr_get(mgr_node); 76 of_node_put(np); 77 return mgr; 78 } 79 } 80 np = of_get_next_parent(np); 81 } 82 of_node_put(np); 83 84 return ERR_PTR(-EINVAL); 85 } 86 87 /** 88 * of_fpga_region_get_bridges - create a list of bridges 89 * @region: FPGA region 90 * 91 * Create a list of bridges including the parent bridge and the bridges 92 * specified by "fpga-bridges" property. Note that the 93 * fpga_bridges_enable/disable/put functions are all fine with an empty list 94 * if that happens. 95 * 96 * Caller should call fpga_bridges_put(®ion->bridge_list) when 97 * done with the bridges. 98 * 99 * Return 0 for success (even if there are no bridges specified) 100 * or -EBUSY if any of the bridges are in use. 101 */ 102 static int of_fpga_region_get_bridges(struct fpga_region *region) 103 { 104 struct device *dev = ®ion->dev; 105 struct device_node *region_np = dev->of_node; 106 struct fpga_image_info *info = region->info; 107 struct device_node *br, *np, *parent_br = NULL; 108 int i, ret; 109 110 /* If parent is a bridge, add to list */ 111 ret = of_fpga_bridge_get_to_list(region_np->parent, info, 112 ®ion->bridge_list); 113 114 /* -EBUSY means parent is a bridge that is under use. Give up. */ 115 if (ret == -EBUSY) 116 return ret; 117 118 /* Zero return code means parent was a bridge and was added to list. */ 119 if (!ret) 120 parent_br = region_np->parent; 121 122 /* If overlay has a list of bridges, use it. */ 123 if (of_parse_phandle(info->overlay, "fpga-bridges", 0)) 124 np = info->overlay; 125 else 126 np = region_np; 127 128 for (i = 0; ; i++) { 129 br = of_parse_phandle(np, "fpga-bridges", i); 130 if (!br) 131 break; 132 133 /* If parent bridge is in list, skip it. */ 134 if (br == parent_br) 135 continue; 136 137 /* If node is a bridge, get it and add to list */ 138 ret = of_fpga_bridge_get_to_list(br, info, 139 ®ion->bridge_list); 140 141 /* If any of the bridges are in use, give up */ 142 if (ret == -EBUSY) { 143 fpga_bridges_put(®ion->bridge_list); 144 return -EBUSY; 145 } 146 } 147 148 return 0; 149 } 150 151 /** 152 * child_regions_with_firmware 153 * @overlay: device node of the overlay 154 * 155 * If the overlay adds child FPGA regions, they are not allowed to have 156 * firmware-name property. 157 * 158 * Return 0 for OK or -EINVAL if child FPGA region adds firmware-name. 159 */ 160 static int child_regions_with_firmware(struct device_node *overlay) 161 { 162 struct device_node *child_region; 163 const char *child_firmware_name; 164 int ret = 0; 165 166 of_node_get(overlay); 167 168 child_region = of_find_matching_node(overlay, fpga_region_of_match); 169 while (child_region) { 170 if (!of_property_read_string(child_region, "firmware-name", 171 &child_firmware_name)) { 172 ret = -EINVAL; 173 break; 174 } 175 child_region = of_find_matching_node(child_region, 176 fpga_region_of_match); 177 } 178 179 of_node_put(child_region); 180 181 if (ret) 182 pr_err("firmware-name not allowed in child FPGA region: %pOF", 183 child_region); 184 185 return ret; 186 } 187 188 /** 189 * of_fpga_region_parse_ov - parse and check overlay applied to region 190 * 191 * @region: FPGA region 192 * @overlay: overlay applied to the FPGA region 193 * 194 * Given an overlay applied to a FPGA region, parse the FPGA image specific 195 * info in the overlay and do some checking. 196 * 197 * Returns: 198 * NULL if overlay doesn't direct us to program the FPGA. 199 * fpga_image_info struct if there is an image to program. 200 * error code for invalid overlay. 201 */ 202 static struct fpga_image_info *of_fpga_region_parse_ov( 203 struct fpga_region *region, 204 struct device_node *overlay) 205 { 206 struct device *dev = ®ion->dev; 207 struct fpga_image_info *info; 208 const char *firmware_name; 209 int ret; 210 211 if (region->info) { 212 dev_err(dev, "Region already has overlay applied.\n"); 213 return ERR_PTR(-EINVAL); 214 } 215 216 /* 217 * Reject overlay if child FPGA Regions added in the overlay have 218 * firmware-name property (would mean that an FPGA region that has 219 * not been added to the live tree yet is doing FPGA programming). 220 */ 221 ret = child_regions_with_firmware(overlay); 222 if (ret) 223 return ERR_PTR(ret); 224 225 info = fpga_image_info_alloc(dev); 226 if (!info) 227 return ERR_PTR(-ENOMEM); 228 229 info->overlay = overlay; 230 231 /* Read FPGA region properties from the overlay */ 232 if (of_property_read_bool(overlay, "partial-fpga-config")) 233 info->flags |= FPGA_MGR_PARTIAL_RECONFIG; 234 235 if (of_property_read_bool(overlay, "external-fpga-config")) 236 info->flags |= FPGA_MGR_EXTERNAL_CONFIG; 237 238 if (of_property_read_bool(overlay, "encrypted-fpga-config")) 239 info->flags |= FPGA_MGR_ENCRYPTED_BITSTREAM; 240 241 if (!of_property_read_string(overlay, "firmware-name", 242 &firmware_name)) { 243 info->firmware_name = devm_kstrdup(dev, firmware_name, 244 GFP_KERNEL); 245 if (!info->firmware_name) 246 return ERR_PTR(-ENOMEM); 247 } 248 249 of_property_read_u32(overlay, "region-unfreeze-timeout-us", 250 &info->enable_timeout_us); 251 252 of_property_read_u32(overlay, "region-freeze-timeout-us", 253 &info->disable_timeout_us); 254 255 of_property_read_u32(overlay, "config-complete-timeout-us", 256 &info->config_complete_timeout_us); 257 258 /* If overlay is not programming the FPGA, don't need FPGA image info */ 259 if (!info->firmware_name) { 260 ret = 0; 261 goto ret_no_info; 262 } 263 264 /* 265 * If overlay informs us FPGA was externally programmed, specifying 266 * firmware here would be ambiguous. 267 */ 268 if (info->flags & FPGA_MGR_EXTERNAL_CONFIG) { 269 dev_err(dev, "error: specified firmware and external-fpga-config"); 270 ret = -EINVAL; 271 goto ret_no_info; 272 } 273 274 return info; 275 ret_no_info: 276 fpga_image_info_free(info); 277 return ERR_PTR(ret); 278 } 279 280 /** 281 * of_fpga_region_notify_pre_apply - pre-apply overlay notification 282 * 283 * @region: FPGA region that the overlay was applied to 284 * @nd: overlay notification data 285 * 286 * Called when an overlay targeted to a FPGA Region is about to be applied. 287 * Parses the overlay for properties that influence how the FPGA will be 288 * programmed and does some checking. If the checks pass, programs the FPGA. 289 * If the checks fail, overlay is rejected and does not get added to the 290 * live tree. 291 * 292 * Returns 0 for success or negative error code for failure. 293 */ 294 static int of_fpga_region_notify_pre_apply(struct fpga_region *region, 295 struct of_overlay_notify_data *nd) 296 { 297 struct device *dev = ®ion->dev; 298 struct fpga_image_info *info; 299 int ret; 300 301 if (region->info) { 302 dev_err(dev, "Region already has overlay applied.\n"); 303 return -EINVAL; 304 } 305 306 info = of_fpga_region_parse_ov(region, nd->overlay); 307 if (IS_ERR(info)) 308 return PTR_ERR(info); 309 310 if (!info) 311 return 0; 312 313 region->info = info; 314 ret = fpga_region_program_fpga(region); 315 if (ret) { 316 /* error; reject overlay */ 317 fpga_image_info_free(info); 318 region->info = NULL; 319 } 320 321 return ret; 322 } 323 324 /** 325 * of_fpga_region_notify_post_remove - post-remove overlay notification 326 * 327 * @region: FPGA region that was targeted by the overlay that was removed 328 * @nd: overlay notification data 329 * 330 * Called after an overlay has been removed if the overlay's target was a 331 * FPGA region. 332 */ 333 static void of_fpga_region_notify_post_remove(struct fpga_region *region, 334 struct of_overlay_notify_data *nd) 335 { 336 fpga_bridges_disable(®ion->bridge_list); 337 fpga_bridges_put(®ion->bridge_list); 338 fpga_image_info_free(region->info); 339 region->info = NULL; 340 } 341 342 /** 343 * of_fpga_region_notify - reconfig notifier for dynamic DT changes 344 * @nb: notifier block 345 * @action: notifier action 346 * @arg: reconfig data 347 * 348 * This notifier handles programming a FPGA when a "firmware-name" property is 349 * added to a fpga-region. 350 * 351 * Returns NOTIFY_OK or error if FPGA programming fails. 352 */ 353 static int of_fpga_region_notify(struct notifier_block *nb, 354 unsigned long action, void *arg) 355 { 356 struct of_overlay_notify_data *nd = arg; 357 struct fpga_region *region; 358 int ret; 359 360 switch (action) { 361 case OF_OVERLAY_PRE_APPLY: 362 pr_debug("%s OF_OVERLAY_PRE_APPLY\n", __func__); 363 break; 364 case OF_OVERLAY_POST_APPLY: 365 pr_debug("%s OF_OVERLAY_POST_APPLY\n", __func__); 366 return NOTIFY_OK; /* not for us */ 367 case OF_OVERLAY_PRE_REMOVE: 368 pr_debug("%s OF_OVERLAY_PRE_REMOVE\n", __func__); 369 return NOTIFY_OK; /* not for us */ 370 case OF_OVERLAY_POST_REMOVE: 371 pr_debug("%s OF_OVERLAY_POST_REMOVE\n", __func__); 372 break; 373 default: /* should not happen */ 374 return NOTIFY_OK; 375 } 376 377 region = of_fpga_region_find(nd->target); 378 if (!region) 379 return NOTIFY_OK; 380 381 ret = 0; 382 switch (action) { 383 case OF_OVERLAY_PRE_APPLY: 384 ret = of_fpga_region_notify_pre_apply(region, nd); 385 break; 386 387 case OF_OVERLAY_POST_REMOVE: 388 of_fpga_region_notify_post_remove(region, nd); 389 break; 390 } 391 392 put_device(®ion->dev); 393 394 if (ret) 395 return notifier_from_errno(ret); 396 397 return NOTIFY_OK; 398 } 399 400 static struct notifier_block fpga_region_of_nb = { 401 .notifier_call = of_fpga_region_notify, 402 }; 403 404 static int of_fpga_region_probe(struct platform_device *pdev) 405 { 406 struct device *dev = &pdev->dev; 407 struct device_node *np = dev->of_node; 408 struct fpga_region *region; 409 struct fpga_manager *mgr; 410 int ret; 411 412 /* Find the FPGA mgr specified by region or parent region. */ 413 mgr = of_fpga_region_get_mgr(np); 414 if (IS_ERR(mgr)) 415 return -EPROBE_DEFER; 416 417 region = devm_kzalloc(dev, sizeof(*region), GFP_KERNEL); 418 if (!region) { 419 ret = -ENOMEM; 420 goto eprobe_mgr_put; 421 } 422 423 region->mgr = mgr; 424 425 /* Specify how to get bridges for this type of region. */ 426 region->get_bridges = of_fpga_region_get_bridges; 427 428 ret = fpga_region_register(dev, region); 429 if (ret) 430 goto eprobe_mgr_put; 431 432 of_platform_populate(np, fpga_region_of_match, NULL, ®ion->dev); 433 434 dev_info(dev, "FPGA Region probed\n"); 435 436 return 0; 437 438 eprobe_mgr_put: 439 fpga_mgr_put(mgr); 440 return ret; 441 } 442 443 static int of_fpga_region_remove(struct platform_device *pdev) 444 { 445 struct fpga_region *region = platform_get_drvdata(pdev); 446 447 fpga_region_unregister(region); 448 fpga_mgr_put(region->mgr); 449 450 return 0; 451 } 452 453 static struct platform_driver of_fpga_region_driver = { 454 .probe = of_fpga_region_probe, 455 .remove = of_fpga_region_remove, 456 .driver = { 457 .name = "of-fpga-region", 458 .of_match_table = of_match_ptr(fpga_region_of_match), 459 }, 460 }; 461 462 /** 463 * fpga_region_init - init function for fpga_region class 464 * Creates the fpga_region class and registers a reconfig notifier. 465 */ 466 static int __init of_fpga_region_init(void) 467 { 468 int ret; 469 470 ret = of_overlay_notifier_register(&fpga_region_of_nb); 471 if (ret) 472 return ret; 473 474 ret = platform_driver_register(&of_fpga_region_driver); 475 if (ret) 476 goto err_plat; 477 478 return 0; 479 480 err_plat: 481 of_overlay_notifier_unregister(&fpga_region_of_nb); 482 return ret; 483 } 484 485 static void __exit of_fpga_region_exit(void) 486 { 487 platform_driver_unregister(&of_fpga_region_driver); 488 of_overlay_notifier_unregister(&fpga_region_of_nb); 489 } 490 491 subsys_initcall(of_fpga_region_init); 492 module_exit(of_fpga_region_exit); 493 494 MODULE_DESCRIPTION("FPGA Region"); 495 MODULE_AUTHOR("Alan Tull <atull@kernel.org>"); 496 MODULE_LICENSE("GPL v2"); 497