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");