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1// SPDX-License-Identifier: GPL-2.02/*3 * FPGA Region - Device Tree support for FPGA programming under Linux4 *5 * Copyright (C) 2013-2016 Altera Corporation6 * Copyright (C) 2017 Intel Corporation7 */8#include <linux/fpga/fpga-bridge.h>9#include <linux/fpga/fpga-mgr.h>10#include <linux/fpga/fpga-region.h>11#include <linux/idr.h>12#include <linux/kernel.h>13#include <linux/list.h>14#include <linux/module.h>15#include <linux/of.h>16#include <linux/of_platform.h>17#include <linux/platform_device.h>18#include <linux/slab.h>19#include <linux/spinlock.h>20 21static const struct of_device_id fpga_region_of_match[] = {22 { .compatible = "fpga-region", },23 {},24};25MODULE_DEVICE_TABLE(of, fpga_region_of_match);26 27/**28 * of_fpga_region_find - find FPGA region29 * @np: device node of FPGA Region30 *31 * Caller will need to put_device(®ion->dev) when done.32 *33 * Return: FPGA Region struct or NULL34 */35static struct fpga_region *of_fpga_region_find(struct device_node *np)36{37 return fpga_region_class_find(NULL, np, device_match_of_node);38}39 40/**41 * of_fpga_region_get_mgr - get reference for FPGA manager42 * @np: device node of FPGA region43 *44 * Get FPGA Manager from "fpga-mgr" property or from ancestor region.45 *46 * Caller should call fpga_mgr_put() when done with manager.47 *48 * Return: fpga manager struct or IS_ERR() condition containing error code.49 */50static struct fpga_manager *of_fpga_region_get_mgr(struct device_node *np)51{52 struct device_node *mgr_node;53 struct fpga_manager *mgr;54 55 of_node_get(np);56 while (np) {57 if (of_device_is_compatible(np, "fpga-region")) {58 mgr_node = of_parse_phandle(np, "fpga-mgr", 0);59 if (mgr_node) {60 mgr = of_fpga_mgr_get(mgr_node);61 of_node_put(mgr_node);62 of_node_put(np);63 return mgr;64 }65 }66 np = of_get_next_parent(np);67 }68 of_node_put(np);69 70 return ERR_PTR(-EINVAL);71}72 73/**74 * of_fpga_region_get_bridges - create a list of bridges75 * @region: FPGA region76 *77 * Create a list of bridges including the parent bridge and the bridges78 * specified by "fpga-bridges" property. Note that the79 * fpga_bridges_enable/disable/put functions are all fine with an empty list80 * if that happens.81 *82 * Caller should call fpga_bridges_put(®ion->bridge_list) when83 * done with the bridges.84 *85 * Return: 0 for success (even if there are no bridges specified)86 * or -EBUSY if any of the bridges are in use.87 */88static int of_fpga_region_get_bridges(struct fpga_region *region)89{90 struct device *dev = ®ion->dev;91 struct device_node *region_np = dev->of_node;92 struct fpga_image_info *info = region->info;93 struct device_node *br, *np, *parent_br = NULL;94 int i, ret;95 96 /* If parent is a bridge, add to list */97 ret = of_fpga_bridge_get_to_list(region_np->parent, info,98 ®ion->bridge_list);99 100 /* -EBUSY means parent is a bridge that is under use. Give up. */101 if (ret == -EBUSY)102 return ret;103 104 /* Zero return code means parent was a bridge and was added to list. */105 if (!ret)106 parent_br = region_np->parent;107 108 /* If overlay has a list of bridges, use it. */109 br = of_parse_phandle(info->overlay, "fpga-bridges", 0);110 if (br) {111 of_node_put(br);112 np = info->overlay;113 } else {114 np = region_np;115 }116 117 for (i = 0; ; i++) {118 br = of_parse_phandle(np, "fpga-bridges", i);119 if (!br)120 break;121 122 /* If parent bridge is in list, skip it. */123 if (br == parent_br) {124 of_node_put(br);125 continue;126 }127 128 /* If node is a bridge, get it and add to list */129 ret = of_fpga_bridge_get_to_list(br, info,130 ®ion->bridge_list);131 of_node_put(br);132 133 /* If any of the bridges are in use, give up */134 if (ret == -EBUSY) {135 fpga_bridges_put(®ion->bridge_list);136 return -EBUSY;137 }138 }139 140 return 0;141}142 143/**144 * child_regions_with_firmware - Used to check the child region info.145 * @overlay: device node of the overlay146 *147 * If the overlay adds child FPGA regions, they are not allowed to have148 * firmware-name property.149 *150 * Return: 0 for OK or -EINVAL if child FPGA region adds firmware-name.151 */152static int child_regions_with_firmware(struct device_node *overlay)153{154 struct device_node *child_region;155 const char *child_firmware_name;156 int ret = 0;157 158 of_node_get(overlay);159 160 child_region = of_find_matching_node(overlay, fpga_region_of_match);161 while (child_region) {162 if (!of_property_read_string(child_region, "firmware-name",163 &child_firmware_name)) {164 ret = -EINVAL;165 break;166 }167 child_region = of_find_matching_node(child_region,168 fpga_region_of_match);169 }170 171 of_node_put(child_region);172 173 if (ret)174 pr_err("firmware-name not allowed in child FPGA region: %pOF",175 child_region);176 177 return ret;178}179 180/**181 * of_fpga_region_parse_ov - parse and check overlay applied to region182 *183 * @region: FPGA region184 * @overlay: overlay applied to the FPGA region185 *186 * Given an overlay applied to an FPGA region, parse the FPGA image specific187 * info in the overlay and do some checking.188 *189 * Return:190 * NULL if overlay doesn't direct us to program the FPGA.191 * fpga_image_info struct if there is an image to program.192 * error code for invalid overlay.193 */194static struct fpga_image_info *195of_fpga_region_parse_ov(struct fpga_region *region,196 struct device_node *overlay)197{198 struct device *dev = ®ion->dev;199 struct fpga_image_info *info;200 const char *firmware_name;201 int ret;202 203 if (region->info) {204 dev_err(dev, "Region already has overlay applied.\n");205 return ERR_PTR(-EINVAL);206 }207 208 /*209 * Reject overlay if child FPGA Regions added in the overlay have210 * firmware-name property (would mean that an FPGA region that has211 * not been added to the live tree yet is doing FPGA programming).212 */213 ret = child_regions_with_firmware(overlay);214 if (ret)215 return ERR_PTR(ret);216 217 info = fpga_image_info_alloc(dev);218 if (!info)219 return ERR_PTR(-ENOMEM);220 221 info->overlay = overlay;222 223 /* Read FPGA region properties from the overlay */224 if (of_property_read_bool(overlay, "partial-fpga-config"))225 info->flags |= FPGA_MGR_PARTIAL_RECONFIG;226 227 if (of_property_read_bool(overlay, "external-fpga-config"))228 info->flags |= FPGA_MGR_EXTERNAL_CONFIG;229 230 if (of_property_read_bool(overlay, "encrypted-fpga-config"))231 info->flags |= FPGA_MGR_ENCRYPTED_BITSTREAM;232 233 if (!of_property_read_string(overlay, "firmware-name",234 &firmware_name)) {235 info->firmware_name = devm_kstrdup(dev, firmware_name,236 GFP_KERNEL);237 if (!info->firmware_name)238 return ERR_PTR(-ENOMEM);239 }240 241 of_property_read_u32(overlay, "region-unfreeze-timeout-us",242 &info->enable_timeout_us);243 244 of_property_read_u32(overlay, "region-freeze-timeout-us",245 &info->disable_timeout_us);246 247 of_property_read_u32(overlay, "config-complete-timeout-us",248 &info->config_complete_timeout_us);249 250 /* If overlay is not programming the FPGA, don't need FPGA image info */251 if (!info->firmware_name) {252 ret = 0;253 goto ret_no_info;254 }255 256 /*257 * If overlay informs us FPGA was externally programmed, specifying258 * firmware here would be ambiguous.259 */260 if (info->flags & FPGA_MGR_EXTERNAL_CONFIG) {261 dev_err(dev, "error: specified firmware and external-fpga-config");262 ret = -EINVAL;263 goto ret_no_info;264 }265 266 return info;267ret_no_info:268 fpga_image_info_free(info);269 return ERR_PTR(ret);270}271 272/**273 * of_fpga_region_notify_pre_apply - pre-apply overlay notification274 *275 * @region: FPGA region that the overlay was applied to276 * @nd: overlay notification data277 *278 * Called when an overlay targeted to an FPGA Region is about to be applied.279 * Parses the overlay for properties that influence how the FPGA will be280 * programmed and does some checking. If the checks pass, programs the FPGA.281 * If the checks fail, overlay is rejected and does not get added to the282 * live tree.283 *284 * Return: 0 for success or negative error code for failure.285 */286static int of_fpga_region_notify_pre_apply(struct fpga_region *region,287 struct of_overlay_notify_data *nd)288{289 struct device *dev = ®ion->dev;290 struct fpga_image_info *info;291 int ret;292 293 info = of_fpga_region_parse_ov(region, nd->overlay);294 if (IS_ERR(info))295 return PTR_ERR(info);296 297 /* If overlay doesn't program the FPGA, accept it anyway. */298 if (!info)299 return 0;300 301 if (region->info) {302 dev_err(dev, "Region already has overlay applied.\n");303 return -EINVAL;304 }305 306 region->info = info;307 ret = fpga_region_program_fpga(region);308 if (ret) {309 /* error; reject overlay */310 fpga_image_info_free(info);311 region->info = NULL;312 }313 314 return ret;315}316 317/**318 * of_fpga_region_notify_post_remove - post-remove overlay notification319 *320 * @region: FPGA region that was targeted by the overlay that was removed321 * @nd: overlay notification data322 *323 * Called after an overlay has been removed if the overlay's target was a324 * FPGA region.325 */326static void of_fpga_region_notify_post_remove(struct fpga_region *region,327 struct of_overlay_notify_data *nd)328{329 fpga_bridges_disable(®ion->bridge_list);330 fpga_bridges_put(®ion->bridge_list);331 fpga_image_info_free(region->info);332 region->info = NULL;333}334 335/**336 * of_fpga_region_notify - reconfig notifier for dynamic DT changes337 * @nb: notifier block338 * @action: notifier action339 * @arg: reconfig data340 *341 * This notifier handles programming an FPGA when a "firmware-name" property is342 * added to an fpga-region.343 *344 * Return: NOTIFY_OK or error if FPGA programming fails.345 */346static int of_fpga_region_notify(struct notifier_block *nb,347 unsigned long action, void *arg)348{349 struct of_overlay_notify_data *nd = arg;350 struct fpga_region *region;351 int ret;352 353 switch (action) {354 case OF_OVERLAY_PRE_APPLY:355 pr_debug("%s OF_OVERLAY_PRE_APPLY\n", __func__);356 break;357 case OF_OVERLAY_POST_APPLY:358 pr_debug("%s OF_OVERLAY_POST_APPLY\n", __func__);359 return NOTIFY_OK; /* not for us */360 case OF_OVERLAY_PRE_REMOVE:361 pr_debug("%s OF_OVERLAY_PRE_REMOVE\n", __func__);362 return NOTIFY_OK; /* not for us */363 case OF_OVERLAY_POST_REMOVE:364 pr_debug("%s OF_OVERLAY_POST_REMOVE\n", __func__);365 break;366 default: /* should not happen */367 return NOTIFY_OK;368 }369 370 region = of_fpga_region_find(nd->target);371 if (!region)372 return NOTIFY_OK;373 374 ret = 0;375 switch (action) {376 case OF_OVERLAY_PRE_APPLY:377 ret = of_fpga_region_notify_pre_apply(region, nd);378 break;379 380 case OF_OVERLAY_POST_REMOVE:381 of_fpga_region_notify_post_remove(region, nd);382 break;383 }384 385 put_device(®ion->dev);386 387 if (ret)388 return notifier_from_errno(ret);389 390 return NOTIFY_OK;391}392 393static struct notifier_block fpga_region_of_nb = {394 .notifier_call = of_fpga_region_notify,395};396 397static int of_fpga_region_probe(struct platform_device *pdev)398{399 struct device *dev = &pdev->dev;400 struct device_node *np = dev->of_node;401 struct fpga_region *region;402 struct fpga_manager *mgr;403 int ret;404 405 /* Find the FPGA mgr specified by region or parent region. */406 mgr = of_fpga_region_get_mgr(np);407 if (IS_ERR(mgr))408 return -EPROBE_DEFER;409 410 region = fpga_region_register(dev, mgr, of_fpga_region_get_bridges);411 if (IS_ERR(region)) {412 ret = PTR_ERR(region);413 goto eprobe_mgr_put;414 }415 416 of_platform_populate(np, fpga_region_of_match, NULL, ®ion->dev);417 platform_set_drvdata(pdev, region);418 419 dev_info(dev, "FPGA Region probed\n");420 421 return 0;422 423eprobe_mgr_put:424 fpga_mgr_put(mgr);425 return ret;426}427 428static void of_fpga_region_remove(struct platform_device *pdev)429{430 struct fpga_region *region = platform_get_drvdata(pdev);431 struct fpga_manager *mgr = region->mgr;432 433 fpga_region_unregister(region);434 fpga_mgr_put(mgr);435}436 437static struct platform_driver of_fpga_region_driver = {438 .probe = of_fpga_region_probe,439 .remove_new = of_fpga_region_remove,440 .driver = {441 .name = "of-fpga-region",442 .of_match_table = of_match_ptr(fpga_region_of_match),443 },444};445 446/**447 * of_fpga_region_init - init function for fpga_region class448 * Creates the fpga_region class and registers a reconfig notifier.449 *450 * Return: 0 on success, negative error code otherwise.451 */452static int __init of_fpga_region_init(void)453{454 int ret;455 456 ret = of_overlay_notifier_register(&fpga_region_of_nb);457 if (ret)458 return ret;459 460 ret = platform_driver_register(&of_fpga_region_driver);461 if (ret)462 goto err_plat;463 464 return 0;465 466err_plat:467 of_overlay_notifier_unregister(&fpga_region_of_nb);468 return ret;469}470 471static void __exit of_fpga_region_exit(void)472{473 platform_driver_unregister(&of_fpga_region_driver);474 of_overlay_notifier_unregister(&fpga_region_of_nb);475}476 477subsys_initcall(of_fpga_region_init);478module_exit(of_fpga_region_exit);479 480MODULE_DESCRIPTION("FPGA Region");481MODULE_AUTHOR("Alan Tull <atull@kernel.org>");482MODULE_LICENSE("GPL v2");483