2 * FPGA Region - Device Tree support for FPGA programming under Linux
4 * Copyright (C) 2013-2016 Altera Corporation
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.
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
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/>.
19 #include <linux/fpga/fpga-bridge.h>
20 #include <linux/fpga/fpga-mgr.h>
21 #include <linux/idr.h>
22 #include <linux/kernel.h>
23 #include <linux/list.h>
24 #include <linux/module.h>
25 #include <linux/of_platform.h>
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
30 * struct fpga_region - FPGA Region structure
31 * @dev: FPGA Region device
32 * @mutex: enforces exclusive reference to region
33 * @bridge_list: list of FPGA bridges specified in region
34 * @info: fpga image specific information
38 struct mutex mutex; /* for exclusive reference to region */
39 struct list_head bridge_list;
40 struct fpga_image_info *info;
43 #define to_fpga_region(d) container_of(d, struct fpga_region, dev)
45 static DEFINE_IDA(fpga_region_ida);
46 static struct class *fpga_region_class;
48 static const struct of_device_id fpga_region_of_match[] = {
49 { .compatible = "fpga-region", },
52 MODULE_DEVICE_TABLE(of, fpga_region_of_match);
54 static int fpga_region_of_node_match(struct device *dev, const void *data)
56 return dev->of_node == data;
60 * fpga_region_find - find FPGA region
61 * @np: device node of FPGA Region
62 * Caller will need to put_device(®ion->dev) when done.
63 * Returns FPGA Region struct or NULL
65 static struct fpga_region *fpga_region_find(struct device_node *np)
69 dev = class_find_device(fpga_region_class, NULL, np,
70 fpga_region_of_node_match);
74 return to_fpga_region(dev);
78 * fpga_region_get - get an exclusive reference to a fpga region
79 * @region: FPGA Region struct
81 * Caller should call fpga_region_put() when done with region.
83 * Return fpga_region struct if successful.
84 * Return -EBUSY if someone already has a reference to the region.
85 * Return -ENODEV if @np is not a FPGA Region.
87 static struct fpga_region *fpga_region_get(struct fpga_region *region)
89 struct device *dev = ®ion->dev;
91 if (!mutex_trylock(®ion->mutex)) {
92 dev_dbg(dev, "%s: FPGA Region already in use\n", __func__);
93 return ERR_PTR(-EBUSY);
97 of_node_get(dev->of_node);
98 if (!try_module_get(dev->parent->driver->owner)) {
99 of_node_put(dev->of_node);
101 mutex_unlock(®ion->mutex);
102 return ERR_PTR(-ENODEV);
105 dev_dbg(®ion->dev, "get\n");
111 * fpga_region_put - release a reference to a region
113 * @region: FPGA region
115 static void fpga_region_put(struct fpga_region *region)
117 struct device *dev = ®ion->dev;
119 dev_dbg(®ion->dev, "put\n");
121 module_put(dev->parent->driver->owner);
122 of_node_put(dev->of_node);
124 mutex_unlock(®ion->mutex);
128 * fpga_region_get_manager - get exclusive reference for FPGA manager
129 * @region: FPGA region
131 * Get FPGA Manager from "fpga-mgr" property or from ancestor region.
133 * Caller should call fpga_mgr_put() when done with manager.
135 * Return: fpga manager struct or IS_ERR() condition containing error code.
137 static struct fpga_manager *fpga_region_get_manager(struct fpga_region *region)
139 struct device *dev = ®ion->dev;
140 struct device_node *np = dev->of_node;
141 struct device_node *mgr_node;
142 struct fpga_manager *mgr;
146 if (of_device_is_compatible(np, "fpga-region")) {
147 mgr_node = of_parse_phandle(np, "fpga-mgr", 0);
149 mgr = of_fpga_mgr_get(mgr_node);
150 of_node_put(mgr_node);
155 np = of_get_next_parent(np);
159 return ERR_PTR(-EINVAL);
163 * fpga_region_get_bridges - create a list of bridges
164 * @region: FPGA region
165 * @overlay: device node of the overlay
167 * Create a list of bridges including the parent bridge and the bridges
168 * specified by "fpga-bridges" property. Note that the
169 * fpga_bridges_enable/disable/put functions are all fine with an empty list
172 * Caller should call fpga_bridges_put(®ion->bridge_list) when
173 * done with the bridges.
175 * Return 0 for success (even if there are no bridges specified)
176 * or -EBUSY if any of the bridges are in use.
178 static int fpga_region_get_bridges(struct fpga_region *region,
179 struct device_node *overlay)
181 struct device *dev = ®ion->dev;
182 struct device_node *region_np = dev->of_node;
183 struct device_node *br, *np, *parent_br = NULL;
186 /* If parent is a bridge, add to list */
187 ret = fpga_bridge_get_to_list(region_np->parent, region->info,
188 ®ion->bridge_list);
193 parent_br = region_np->parent;
195 /* If overlay has a list of bridges, use it. */
196 br = of_parse_phandle(overlay, "fpga-bridges", 0);
205 br = of_parse_phandle(np, "fpga-bridges", i);
209 /* If parent bridge is in list, skip it. */
210 if (br == parent_br) {
215 /* If node is a bridge, get it and add to list */
216 ret = fpga_bridge_get_to_list(br, region->info,
217 ®ion->bridge_list);
220 /* If any of the bridges are in use, give up */
222 fpga_bridges_put(®ion->bridge_list);
231 * fpga_region_program_fpga - program FPGA
232 * @region: FPGA region
233 * @firmware_name: name of FPGA image firmware file
234 * @overlay: device node of the overlay
235 * Program an FPGA using information in the device tree.
236 * Function assumes that there is a firmware-name property.
237 * Return 0 for success or negative error code.
239 static int fpga_region_program_fpga(struct fpga_region *region,
240 const char *firmware_name,
241 struct device_node *overlay)
243 struct fpga_manager *mgr;
246 region = fpga_region_get(region);
247 if (IS_ERR(region)) {
248 pr_err("failed to get fpga region\n");
249 return PTR_ERR(region);
252 mgr = fpga_region_get_manager(region);
254 pr_err("failed to get fpga region manager\n");
259 ret = fpga_region_get_bridges(region, overlay);
261 pr_err("failed to get fpga region bridges\n");
265 ret = fpga_bridges_disable(®ion->bridge_list);
267 pr_err("failed to disable region bridges\n");
271 ret = fpga_mgr_firmware_load(mgr, region->info, firmware_name);
273 pr_err("failed to load fpga image\n");
277 ret = fpga_bridges_enable(®ion->bridge_list);
279 pr_err("failed to enable region bridges\n");
284 fpga_region_put(region);
289 fpga_bridges_put(®ion->bridge_list);
293 fpga_region_put(region);
299 * child_regions_with_firmware
300 * @overlay: device node of the overlay
302 * If the overlay adds child FPGA regions, they are not allowed to have
303 * firmware-name property.
305 * Return 0 for OK or -EINVAL if child FPGA region adds firmware-name.
307 static int child_regions_with_firmware(struct device_node *overlay)
309 struct device_node *child_region;
310 const char *child_firmware_name;
313 of_node_get(overlay);
315 child_region = of_find_matching_node(overlay, fpga_region_of_match);
316 while (child_region) {
317 if (!of_property_read_string(child_region, "firmware-name",
318 &child_firmware_name)) {
322 child_region = of_find_matching_node(child_region,
323 fpga_region_of_match);
326 of_node_put(child_region);
329 pr_err("firmware-name not allowed in child FPGA region: %pOF",
336 * fpga_region_notify_pre_apply - pre-apply overlay notification
338 * @region: FPGA region that the overlay was applied to
339 * @nd: overlay notification data
341 * Called after when an overlay targeted to a FPGA Region is about to be
342 * applied. Function will check the properties that will be added to the FPGA
343 * region. If the checks pass, it will program the FPGA.
346 * The overlay must add either firmware-name or external-fpga-config property
347 * to the FPGA Region.
349 * firmware-name : program the FPGA
350 * external-fpga-config : FPGA is already programmed
351 * encrypted-fpga-config : FPGA bitstream is encrypted
353 * The overlay can add other FPGA regions, but child FPGA regions cannot have a
354 * firmware-name property since those regions don't exist yet.
356 * If the overlay that breaks the rules, notifier returns an error and the
357 * overlay is rejected before it goes into the main tree.
359 * Returns 0 for success or negative error code for failure.
361 static int fpga_region_notify_pre_apply(struct fpga_region *region,
362 struct of_overlay_notify_data *nd)
364 const char *firmware_name = NULL;
365 struct fpga_image_info *info;
368 info = devm_kzalloc(®ion->dev, sizeof(*info), GFP_KERNEL);
374 /* Reject overlay if child FPGA Regions have firmware-name property */
375 ret = child_regions_with_firmware(nd->overlay);
379 /* Read FPGA region properties from the overlay */
380 if (of_property_read_bool(nd->overlay, "partial-fpga-config"))
381 info->flags |= FPGA_MGR_PARTIAL_RECONFIG;
383 if (of_property_read_bool(nd->overlay, "external-fpga-config"))
384 info->flags |= FPGA_MGR_EXTERNAL_CONFIG;
386 if (of_property_read_bool(nd->overlay, "encrypted-fpga-config"))
387 info->flags |= FPGA_MGR_ENCRYPTED_BITSTREAM;
389 of_property_read_string(nd->overlay, "firmware-name", &firmware_name);
391 of_property_read_u32(nd->overlay, "region-unfreeze-timeout-us",
392 &info->enable_timeout_us);
394 of_property_read_u32(nd->overlay, "region-freeze-timeout-us",
395 &info->disable_timeout_us);
397 of_property_read_u32(nd->overlay, "config-complete-timeout-us",
398 &info->config_complete_timeout_us);
400 /* If FPGA was externally programmed, don't specify firmware */
401 if ((info->flags & FPGA_MGR_EXTERNAL_CONFIG) && firmware_name) {
402 pr_err("error: specified firmware and external-fpga-config");
406 /* FPGA is already configured externally. We're done. */
407 if (info->flags & FPGA_MGR_EXTERNAL_CONFIG)
410 /* If we got this far, we should be programming the FPGA */
411 if (!firmware_name) {
412 pr_err("should specify firmware-name or external-fpga-config\n");
416 return fpga_region_program_fpga(region, firmware_name, nd->overlay);
420 * fpga_region_notify_post_remove - post-remove overlay notification
422 * @region: FPGA region that was targeted by the overlay that was removed
423 * @nd: overlay notification data
425 * Called after an overlay has been removed if the overlay's target was a
428 static void fpga_region_notify_post_remove(struct fpga_region *region,
429 struct of_overlay_notify_data *nd)
431 fpga_bridges_disable(®ion->bridge_list);
432 fpga_bridges_put(®ion->bridge_list);
433 devm_kfree(®ion->dev, region->info);
438 * of_fpga_region_notify - reconfig notifier for dynamic DT changes
439 * @nb: notifier block
440 * @action: notifier action
441 * @arg: reconfig data
443 * This notifier handles programming a FPGA when a "firmware-name" property is
444 * added to a fpga-region.
446 * Returns NOTIFY_OK or error if FPGA programming fails.
448 static int of_fpga_region_notify(struct notifier_block *nb,
449 unsigned long action, void *arg)
451 struct of_overlay_notify_data *nd = arg;
452 struct fpga_region *region;
456 case OF_OVERLAY_PRE_APPLY:
457 pr_debug("%s OF_OVERLAY_PRE_APPLY\n", __func__);
459 case OF_OVERLAY_POST_APPLY:
460 pr_debug("%s OF_OVERLAY_POST_APPLY\n", __func__);
461 return NOTIFY_OK; /* not for us */
462 case OF_OVERLAY_PRE_REMOVE:
463 pr_debug("%s OF_OVERLAY_PRE_REMOVE\n", __func__);
464 return NOTIFY_OK; /* not for us */
465 case OF_OVERLAY_POST_REMOVE:
466 pr_debug("%s OF_OVERLAY_POST_REMOVE\n", __func__);
468 default: /* should not happen */
472 region = fpga_region_find(nd->target);
478 case OF_OVERLAY_PRE_APPLY:
479 ret = fpga_region_notify_pre_apply(region, nd);
482 case OF_OVERLAY_POST_REMOVE:
483 fpga_region_notify_post_remove(region, nd);
487 put_device(®ion->dev);
490 return notifier_from_errno(ret);
495 static struct notifier_block fpga_region_of_nb = {
496 .notifier_call = of_fpga_region_notify,
499 static int fpga_region_probe(struct platform_device *pdev)
501 struct device *dev = &pdev->dev;
502 struct device_node *np = dev->of_node;
503 struct fpga_region *region;
506 region = kzalloc(sizeof(*region), GFP_KERNEL);
510 id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL);
516 mutex_init(®ion->mutex);
517 INIT_LIST_HEAD(®ion->bridge_list);
519 device_initialize(®ion->dev);
520 region->dev.class = fpga_region_class;
521 region->dev.parent = dev;
522 region->dev.of_node = np;
524 dev_set_drvdata(dev, region);
526 ret = dev_set_name(®ion->dev, "region%d", id);
530 ret = device_add(®ion->dev);
534 of_platform_populate(np, fpga_region_of_match, NULL, ®ion->dev);
536 dev_info(dev, "FPGA Region probed\n");
541 ida_simple_remove(&fpga_region_ida, id);
548 static int fpga_region_remove(struct platform_device *pdev)
550 struct fpga_region *region = platform_get_drvdata(pdev);
552 device_unregister(®ion->dev);
557 static struct platform_driver fpga_region_driver = {
558 .probe = fpga_region_probe,
559 .remove = fpga_region_remove,
561 .name = "fpga-region",
562 .of_match_table = of_match_ptr(fpga_region_of_match),
566 static void fpga_region_dev_release(struct device *dev)
568 struct fpga_region *region = to_fpga_region(dev);
570 ida_simple_remove(&fpga_region_ida, region->dev.id);
575 * fpga_region_init - init function for fpga_region class
576 * Creates the fpga_region class and registers a reconfig notifier.
578 static int __init fpga_region_init(void)
582 fpga_region_class = class_create(THIS_MODULE, "fpga_region");
583 if (IS_ERR(fpga_region_class))
584 return PTR_ERR(fpga_region_class);
586 fpga_region_class->dev_release = fpga_region_dev_release;
588 ret = of_overlay_notifier_register(&fpga_region_of_nb);
592 ret = platform_driver_register(&fpga_region_driver);
599 of_overlay_notifier_unregister(&fpga_region_of_nb);
601 class_destroy(fpga_region_class);
602 ida_destroy(&fpga_region_ida);
606 static void __exit fpga_region_exit(void)
608 platform_driver_unregister(&fpga_region_driver);
609 of_overlay_notifier_unregister(&fpga_region_of_nb);
610 class_destroy(fpga_region_class);
611 ida_destroy(&fpga_region_ida);
614 subsys_initcall(fpga_region_init);
615 module_exit(fpga_region_exit);
617 MODULE_DESCRIPTION("FPGA Region");
618 MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
619 MODULE_LICENSE("GPL v2");