blob: 3222fdbad75ab080e0ba5cd191650bf1a4a5d67a [file] [log] [blame]
Alan Tull0fa20cd2016-11-01 14:14:29 -05001/*
2 * FPGA Region - Device Tree support for FPGA programming under Linux
3 *
4 * Copyright (C) 2013-2016 Altera Corporation
5 *
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.
9 *
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
13 * more details.
14 *
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/>.
17 */
18
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>
28
29/**
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
35 */
36struct fpga_region {
37 struct device dev;
38 struct mutex mutex; /* for exclusive reference to region */
39 struct list_head bridge_list;
40 struct fpga_image_info *info;
41};
42
43#define to_fpga_region(d) container_of(d, struct fpga_region, dev)
44
45static DEFINE_IDA(fpga_region_ida);
46static struct class *fpga_region_class;
47
48static const struct of_device_id fpga_region_of_match[] = {
49 { .compatible = "fpga-region", },
50 {},
51};
52MODULE_DEVICE_TABLE(of, fpga_region_of_match);
53
54static int fpga_region_of_node_match(struct device *dev, const void *data)
55{
56 return dev->of_node == data;
57}
58
59/**
60 * fpga_region_find - find FPGA region
61 * @np: device node of FPGA Region
62 * Caller will need to put_device(&region->dev) when done.
63 * Returns FPGA Region struct or NULL
64 */
65static struct fpga_region *fpga_region_find(struct device_node *np)
66{
67 struct device *dev;
68
69 dev = class_find_device(fpga_region_class, NULL, np,
70 fpga_region_of_node_match);
71 if (!dev)
72 return NULL;
73
74 return to_fpga_region(dev);
75}
76
77/**
78 * fpga_region_get - get an exclusive reference to a fpga region
79 * @region: FPGA Region struct
80 *
81 * Caller should call fpga_region_put() when done with region.
82 *
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.
86 */
87static struct fpga_region *fpga_region_get(struct fpga_region *region)
88{
89 struct device *dev = &region->dev;
90
91 if (!mutex_trylock(&region->mutex)) {
92 dev_dbg(dev, "%s: FPGA Region already in use\n", __func__);
93 return ERR_PTR(-EBUSY);
94 }
95
96 get_device(dev);
97 of_node_get(dev->of_node);
98 if (!try_module_get(dev->parent->driver->owner)) {
99 of_node_put(dev->of_node);
100 put_device(dev);
101 mutex_unlock(&region->mutex);
102 return ERR_PTR(-ENODEV);
103 }
104
105 dev_dbg(&region->dev, "get\n");
106
107 return region;
108}
109
110/**
111 * fpga_region_put - release a reference to a region
112 *
113 * @region: FPGA region
114 */
115static void fpga_region_put(struct fpga_region *region)
116{
117 struct device *dev = &region->dev;
118
119 dev_dbg(&region->dev, "put\n");
120
121 module_put(dev->parent->driver->owner);
122 of_node_put(dev->of_node);
123 put_device(dev);
124 mutex_unlock(&region->mutex);
125}
126
127/**
128 * fpga_region_get_manager - get exclusive reference for FPGA manager
129 * @region: FPGA region
130 *
131 * Get FPGA Manager from "fpga-mgr" property or from ancestor region.
132 *
133 * Caller should call fpga_mgr_put() when done with manager.
134 *
135 * Return: fpga manager struct or IS_ERR() condition containing error code.
136 */
137static struct fpga_manager *fpga_region_get_manager(struct fpga_region *region)
138{
139 struct device *dev = &region->dev;
140 struct device_node *np = dev->of_node;
141 struct device_node *mgr_node;
142 struct fpga_manager *mgr;
143
144 of_node_get(np);
145 while (np) {
146 if (of_device_is_compatible(np, "fpga-region")) {
147 mgr_node = of_parse_phandle(np, "fpga-mgr", 0);
148 if (mgr_node) {
149 mgr = of_fpga_mgr_get(mgr_node);
150 of_node_put(np);
151 return mgr;
152 }
153 }
154 np = of_get_next_parent(np);
155 }
156 of_node_put(np);
157
158 return ERR_PTR(-EINVAL);
159}
160
161/**
162 * fpga_region_get_bridges - create a list of bridges
163 * @region: FPGA region
164 * @overlay: device node of the overlay
165 *
166 * Create a list of bridges including the parent bridge and the bridges
167 * specified by "fpga-bridges" property. Note that the
168 * fpga_bridges_enable/disable/put functions are all fine with an empty list
169 * if that happens.
170 *
171 * Caller should call fpga_bridges_put(&region->bridge_list) when
172 * done with the bridges.
173 *
174 * Return 0 for success (even if there are no bridges specified)
175 * or -EBUSY if any of the bridges are in use.
176 */
177static int fpga_region_get_bridges(struct fpga_region *region,
178 struct device_node *overlay)
179{
180 struct device *dev = &region->dev;
181 struct device_node *region_np = dev->of_node;
182 struct device_node *br, *np, *parent_br = NULL;
183 int i, ret;
184
185 /* If parent is a bridge, add to list */
186 ret = fpga_bridge_get_to_list(region_np->parent, region->info,
187 &region->bridge_list);
188 if (ret == -EBUSY)
189 return ret;
190
191 if (!ret)
192 parent_br = region_np->parent;
193
194 /* If overlay has a list of bridges, use it. */
195 if (of_parse_phandle(overlay, "fpga-bridges", 0))
196 np = overlay;
197 else
198 np = region_np;
199
200 for (i = 0; ; i++) {
201 br = of_parse_phandle(np, "fpga-bridges", i);
202 if (!br)
203 break;
204
205 /* If parent bridge is in list, skip it. */
206 if (br == parent_br)
207 continue;
208
209 /* If node is a bridge, get it and add to list */
210 ret = fpga_bridge_get_to_list(br, region->info,
211 &region->bridge_list);
212
213 /* If any of the bridges are in use, give up */
214 if (ret == -EBUSY) {
215 fpga_bridges_put(&region->bridge_list);
216 return -EBUSY;
217 }
218 }
219
220 return 0;
221}
222
223/**
224 * fpga_region_program_fpga - program FPGA
225 * @region: FPGA region
226 * @firmware_name: name of FPGA image firmware file
227 * @overlay: device node of the overlay
228 * Program an FPGA using information in the device tree.
229 * Function assumes that there is a firmware-name property.
230 * Return 0 for success or negative error code.
231 */
232static int fpga_region_program_fpga(struct fpga_region *region,
233 const char *firmware_name,
234 struct device_node *overlay)
235{
236 struct fpga_manager *mgr;
237 int ret;
238
239 region = fpga_region_get(region);
240 if (IS_ERR(region)) {
241 pr_err("failed to get fpga region\n");
242 return PTR_ERR(region);
243 }
244
245 mgr = fpga_region_get_manager(region);
246 if (IS_ERR(mgr)) {
247 pr_err("failed to get fpga region manager\n");
248 return PTR_ERR(mgr);
249 }
250
251 ret = fpga_region_get_bridges(region, overlay);
252 if (ret) {
253 pr_err("failed to get fpga region bridges\n");
254 goto err_put_mgr;
255 }
256
257 ret = fpga_bridges_disable(&region->bridge_list);
258 if (ret) {
259 pr_err("failed to disable region bridges\n");
260 goto err_put_br;
261 }
262
263 ret = fpga_mgr_firmware_load(mgr, region->info, firmware_name);
264 if (ret) {
265 pr_err("failed to load fpga image\n");
266 goto err_put_br;
267 }
268
269 ret = fpga_bridges_enable(&region->bridge_list);
270 if (ret) {
271 pr_err("failed to enable region bridges\n");
272 goto err_put_br;
273 }
274
275 fpga_mgr_put(mgr);
276 fpga_region_put(region);
277
278 return 0;
279
280err_put_br:
281 fpga_bridges_put(&region->bridge_list);
282err_put_mgr:
283 fpga_mgr_put(mgr);
284 fpga_region_put(region);
285
286 return ret;
287}
288
289/**
290 * child_regions_with_firmware
291 * @overlay: device node of the overlay
292 *
293 * If the overlay adds child FPGA regions, they are not allowed to have
294 * firmware-name property.
295 *
296 * Return 0 for OK or -EINVAL if child FPGA region adds firmware-name.
297 */
298static int child_regions_with_firmware(struct device_node *overlay)
299{
300 struct device_node *child_region;
301 const char *child_firmware_name;
302 int ret = 0;
303
304 of_node_get(overlay);
305
306 child_region = of_find_matching_node(overlay, fpga_region_of_match);
307 while (child_region) {
308 if (!of_property_read_string(child_region, "firmware-name",
309 &child_firmware_name)) {
310 ret = -EINVAL;
311 break;
312 }
313 child_region = of_find_matching_node(child_region,
314 fpga_region_of_match);
315 }
316
317 of_node_put(child_region);
318
319 if (ret)
320 pr_err("firmware-name not allowed in child FPGA region: %s",
321 child_region->full_name);
322
323 return ret;
324}
325
326/**
327 * fpga_region_notify_pre_apply - pre-apply overlay notification
328 *
329 * @region: FPGA region that the overlay was applied to
330 * @nd: overlay notification data
331 *
332 * Called after when an overlay targeted to a FPGA Region is about to be
333 * applied. Function will check the properties that will be added to the FPGA
334 * region. If the checks pass, it will program the FPGA.
335 *
336 * The checks are:
337 * The overlay must add either firmware-name or external-fpga-config property
338 * to the FPGA Region.
339 *
340 * firmware-name : program the FPGA
341 * external-fpga-config : FPGA is already programmed
342 *
343 * The overlay can add other FPGA regions, but child FPGA regions cannot have a
344 * firmware-name property since those regions don't exist yet.
345 *
346 * If the overlay that breaks the rules, notifier returns an error and the
347 * overlay is rejected before it goes into the main tree.
348 *
349 * Returns 0 for success or negative error code for failure.
350 */
351static int fpga_region_notify_pre_apply(struct fpga_region *region,
352 struct of_overlay_notify_data *nd)
353{
354 const char *firmware_name = NULL;
355 struct fpga_image_info *info;
356 int ret;
357
358 info = devm_kzalloc(&region->dev, sizeof(*info), GFP_KERNEL);
359 if (!info)
360 return -ENOMEM;
361
362 region->info = info;
363
364 /* Reject overlay if child FPGA Regions have firmware-name property */
365 ret = child_regions_with_firmware(nd->overlay);
366 if (ret)
367 return ret;
368
369 /* Read FPGA region properties from the overlay */
370 if (of_property_read_bool(nd->overlay, "partial-fpga-config"))
371 info->flags |= FPGA_MGR_PARTIAL_RECONFIG;
372
373 if (of_property_read_bool(nd->overlay, "external-fpga-config"))
374 info->flags |= FPGA_MGR_EXTERNAL_CONFIG;
375
376 of_property_read_string(nd->overlay, "firmware-name", &firmware_name);
377
378 of_property_read_u32(nd->overlay, "region-unfreeze-timeout-us",
379 &info->enable_timeout_us);
380
381 of_property_read_u32(nd->overlay, "region-freeze-timeout-us",
382 &info->disable_timeout_us);
383
384 /* If FPGA was externally programmed, don't specify firmware */
385 if ((info->flags & FPGA_MGR_EXTERNAL_CONFIG) && firmware_name) {
386 pr_err("error: specified firmware and external-fpga-config");
387 return -EINVAL;
388 }
389
390 /* FPGA is already configured externally. We're done. */
391 if (info->flags & FPGA_MGR_EXTERNAL_CONFIG)
392 return 0;
393
394 /* If we got this far, we should be programming the FPGA */
395 if (!firmware_name) {
396 pr_err("should specify firmware-name or external-fpga-config\n");
397 return -EINVAL;
398 }
399
400 return fpga_region_program_fpga(region, firmware_name, nd->overlay);
401}
402
403/**
404 * fpga_region_notify_post_remove - post-remove overlay notification
405 *
406 * @region: FPGA region that was targeted by the overlay that was removed
407 * @nd: overlay notification data
408 *
409 * Called after an overlay has been removed if the overlay's target was a
410 * FPGA region.
411 */
412static void fpga_region_notify_post_remove(struct fpga_region *region,
413 struct of_overlay_notify_data *nd)
414{
415 fpga_bridges_disable(&region->bridge_list);
416 fpga_bridges_put(&region->bridge_list);
417 devm_kfree(&region->dev, region->info);
418 region->info = NULL;
419}
420
421/**
422 * of_fpga_region_notify - reconfig notifier for dynamic DT changes
423 * @nb: notifier block
424 * @action: notifier action
425 * @arg: reconfig data
426 *
427 * This notifier handles programming a FPGA when a "firmware-name" property is
428 * added to a fpga-region.
429 *
430 * Returns NOTIFY_OK or error if FPGA programming fails.
431 */
432static int of_fpga_region_notify(struct notifier_block *nb,
433 unsigned long action, void *arg)
434{
435 struct of_overlay_notify_data *nd = arg;
436 struct fpga_region *region;
437 int ret;
438
439 switch (action) {
440 case OF_OVERLAY_PRE_APPLY:
441 pr_debug("%s OF_OVERLAY_PRE_APPLY\n", __func__);
442 break;
443 case OF_OVERLAY_POST_APPLY:
444 pr_debug("%s OF_OVERLAY_POST_APPLY\n", __func__);
445 return NOTIFY_OK; /* not for us */
446 case OF_OVERLAY_PRE_REMOVE:
447 pr_debug("%s OF_OVERLAY_PRE_REMOVE\n", __func__);
448 return NOTIFY_OK; /* not for us */
449 case OF_OVERLAY_POST_REMOVE:
450 pr_debug("%s OF_OVERLAY_POST_REMOVE\n", __func__);
451 break;
452 default: /* should not happen */
453 return NOTIFY_OK;
454 }
455
456 region = fpga_region_find(nd->target);
457 if (!region)
458 return NOTIFY_OK;
459
460 ret = 0;
461 switch (action) {
462 case OF_OVERLAY_PRE_APPLY:
463 ret = fpga_region_notify_pre_apply(region, nd);
464 break;
465
466 case OF_OVERLAY_POST_REMOVE:
467 fpga_region_notify_post_remove(region, nd);
468 break;
469 }
470
471 put_device(&region->dev);
472
473 if (ret)
474 return notifier_from_errno(ret);
475
476 return NOTIFY_OK;
477}
478
479static struct notifier_block fpga_region_of_nb = {
480 .notifier_call = of_fpga_region_notify,
481};
482
483static int fpga_region_probe(struct platform_device *pdev)
484{
485 struct device *dev = &pdev->dev;
486 struct device_node *np = dev->of_node;
487 struct fpga_region *region;
488 int id, ret = 0;
489
490 region = kzalloc(sizeof(*region), GFP_KERNEL);
491 if (!region)
492 return -ENOMEM;
493
494 id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL);
495 if (id < 0) {
496 ret = id;
497 goto err_kfree;
498 }
499
500 mutex_init(&region->mutex);
501 INIT_LIST_HEAD(&region->bridge_list);
502
503 device_initialize(&region->dev);
504 region->dev.class = fpga_region_class;
505 region->dev.parent = dev;
506 region->dev.of_node = np;
507 region->dev.id = id;
508 dev_set_drvdata(dev, region);
509
510 ret = dev_set_name(&region->dev, "region%d", id);
511 if (ret)
512 goto err_remove;
513
514 ret = device_add(&region->dev);
515 if (ret)
516 goto err_remove;
517
518 of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
519
520 dev_info(dev, "FPGA Region probed\n");
521
522 return 0;
523
524err_remove:
525 ida_simple_remove(&fpga_region_ida, id);
526err_kfree:
527 kfree(region);
528
529 return ret;
530}
531
532static int fpga_region_remove(struct platform_device *pdev)
533{
534 struct fpga_region *region = platform_get_drvdata(pdev);
535
536 device_unregister(&region->dev);
537
538 return 0;
539}
540
541static struct platform_driver fpga_region_driver = {
542 .probe = fpga_region_probe,
543 .remove = fpga_region_remove,
544 .driver = {
545 .name = "fpga-region",
546 .of_match_table = of_match_ptr(fpga_region_of_match),
547 },
548};
549
550static void fpga_region_dev_release(struct device *dev)
551{
552 struct fpga_region *region = to_fpga_region(dev);
553
554 ida_simple_remove(&fpga_region_ida, region->dev.id);
555 kfree(region);
556}
557
558/**
559 * fpga_region_init - init function for fpga_region class
560 * Creates the fpga_region class and registers a reconfig notifier.
561 */
562static int __init fpga_region_init(void)
563{
564 int ret;
565
566 fpga_region_class = class_create(THIS_MODULE, "fpga_region");
567 if (IS_ERR(fpga_region_class))
568 return PTR_ERR(fpga_region_class);
569
570 fpga_region_class->dev_release = fpga_region_dev_release;
571
572 ret = of_overlay_notifier_register(&fpga_region_of_nb);
573 if (ret)
574 goto err_class;
575
576 ret = platform_driver_register(&fpga_region_driver);
577 if (ret)
578 goto err_plat;
579
580 return 0;
581
582err_plat:
583 of_overlay_notifier_unregister(&fpga_region_of_nb);
584err_class:
585 class_destroy(fpga_region_class);
586 ida_destroy(&fpga_region_ida);
587 return ret;
588}
589
590static void __exit fpga_region_exit(void)
591{
592 platform_driver_unregister(&fpga_region_driver);
593 of_overlay_notifier_unregister(&fpga_region_of_nb);
594 class_destroy(fpga_region_class);
595 ida_destroy(&fpga_region_ida);
596}
597
598subsys_initcall(fpga_region_init);
599module_exit(fpga_region_exit);
600
601MODULE_DESCRIPTION("FPGA Region");
602MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
603MODULE_LICENSE("GPL v2");