1 // SPDX-License-Identifier: GPL-2.0
3 * FPGA Region - Device Tree support for FPGA programming under Linux
5 * Copyright (C) 2013-2016 Altera Corporation
6 * Copyright (C) 2017 Intel Corporation
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_platform.h>
16 #include <linux/slab.h>
17 #include <linux/spinlock.h>
19 static const struct of_device_id fpga_region_of_match
[] = {
20 { .compatible
= "fpga-region", },
23 MODULE_DEVICE_TABLE(of
, fpga_region_of_match
);
25 static int fpga_region_of_node_match(struct device
*dev
, const void *data
)
27 return dev
->of_node
== data
;
31 * of_fpga_region_find - find FPGA region
32 * @np: device node of FPGA Region
34 * Caller will need to put_device(®ion->dev) when done.
36 * Returns FPGA Region struct or NULL
38 static struct fpga_region
*of_fpga_region_find(struct device_node
*np
)
40 return fpga_region_class_find(NULL
, np
, fpga_region_of_node_match
);
44 * of_fpga_region_get_mgr - get reference for FPGA manager
45 * @np: device node of FPGA region
47 * Get FPGA Manager from "fpga-mgr" property or from ancestor region.
49 * Caller should call fpga_mgr_put() when done with manager.
51 * Return: fpga manager struct or IS_ERR() condition containing error code.
53 static struct fpga_manager
*of_fpga_region_get_mgr(struct device_node
*np
)
55 struct device_node
*mgr_node
;
56 struct fpga_manager
*mgr
;
60 if (of_device_is_compatible(np
, "fpga-region")) {
61 mgr_node
= of_parse_phandle(np
, "fpga-mgr", 0);
63 mgr
= of_fpga_mgr_get(mgr_node
);
64 of_node_put(mgr_node
);
69 np
= of_get_next_parent(np
);
73 return ERR_PTR(-EINVAL
);
77 * of_fpga_region_get_bridges - create a list of bridges
78 * @region: FPGA region
80 * Create a list of bridges including the parent bridge and the bridges
81 * specified by "fpga-bridges" property. Note that the
82 * fpga_bridges_enable/disable/put functions are all fine with an empty list
85 * Caller should call fpga_bridges_put(®ion->bridge_list) when
86 * done with the bridges.
88 * Return 0 for success (even if there are no bridges specified)
89 * or -EBUSY if any of the bridges are in use.
91 static int of_fpga_region_get_bridges(struct fpga_region
*region
)
93 struct device
*dev
= ®ion
->dev
;
94 struct device_node
*region_np
= dev
->of_node
;
95 struct fpga_image_info
*info
= region
->info
;
96 struct device_node
*br
, *np
, *parent_br
= NULL
;
99 /* If parent is a bridge, add to list */
100 ret
= of_fpga_bridge_get_to_list(region_np
->parent
, info
,
101 ®ion
->bridge_list
);
103 /* -EBUSY means parent is a bridge that is under use. Give up. */
107 /* Zero return code means parent was a bridge and was added to list. */
109 parent_br
= region_np
->parent
;
111 /* If overlay has a list of bridges, use it. */
112 br
= of_parse_phandle(info
->overlay
, "fpga-bridges", 0);
121 br
= of_parse_phandle(np
, "fpga-bridges", i
);
125 /* If parent bridge is in list, skip it. */
126 if (br
== parent_br
) {
131 /* If node is a bridge, get it and add to list */
132 ret
= of_fpga_bridge_get_to_list(br
, info
,
133 ®ion
->bridge_list
);
136 /* If any of the bridges are in use, give up */
138 fpga_bridges_put(®ion
->bridge_list
);
147 * child_regions_with_firmware
148 * @overlay: device node of the overlay
150 * If the overlay adds child FPGA regions, they are not allowed to have
151 * firmware-name property.
153 * Return 0 for OK or -EINVAL if child FPGA region adds firmware-name.
155 static int child_regions_with_firmware(struct device_node
*overlay
)
157 struct device_node
*child_region
;
158 const char *child_firmware_name
;
161 of_node_get(overlay
);
163 child_region
= of_find_matching_node(overlay
, fpga_region_of_match
);
164 while (child_region
) {
165 if (!of_property_read_string(child_region
, "firmware-name",
166 &child_firmware_name
)) {
170 child_region
= of_find_matching_node(child_region
,
171 fpga_region_of_match
);
174 of_node_put(child_region
);
177 pr_err("firmware-name not allowed in child FPGA region: %pOF",
184 * of_fpga_region_parse_ov - parse and check overlay applied to region
186 * @region: FPGA region
187 * @overlay: overlay applied to the FPGA region
189 * Given an overlay applied to a FPGA region, parse the FPGA image specific
190 * info in the overlay and do some checking.
193 * NULL if overlay doesn't direct us to program the FPGA.
194 * fpga_image_info struct if there is an image to program.
195 * error code for invalid overlay.
197 static struct fpga_image_info
*of_fpga_region_parse_ov(
198 struct fpga_region
*region
,
199 struct device_node
*overlay
)
201 struct device
*dev
= ®ion
->dev
;
202 struct fpga_image_info
*info
;
203 const char *firmware_name
;
207 dev_err(dev
, "Region already has overlay applied.\n");
208 return ERR_PTR(-EINVAL
);
212 * Reject overlay if child FPGA Regions added in the overlay have
213 * firmware-name property (would mean that an FPGA region that has
214 * not been added to the live tree yet is doing FPGA programming).
216 ret
= child_regions_with_firmware(overlay
);
220 info
= fpga_image_info_alloc(dev
);
222 return ERR_PTR(-ENOMEM
);
224 info
->overlay
= overlay
;
226 /* Read FPGA region properties from the overlay */
227 if (of_property_read_bool(overlay
, "partial-fpga-config"))
228 info
->flags
|= FPGA_MGR_PARTIAL_RECONFIG
;
230 if (of_property_read_bool(overlay
, "external-fpga-config"))
231 info
->flags
|= FPGA_MGR_EXTERNAL_CONFIG
;
233 if (of_property_read_bool(overlay
, "encrypted-fpga-config"))
234 info
->flags
|= FPGA_MGR_ENCRYPTED_BITSTREAM
;
236 if (!of_property_read_string(overlay
, "firmware-name",
238 info
->firmware_name
= devm_kstrdup(dev
, firmware_name
,
240 if (!info
->firmware_name
)
241 return ERR_PTR(-ENOMEM
);
244 of_property_read_u32(overlay
, "region-unfreeze-timeout-us",
245 &info
->enable_timeout_us
);
247 of_property_read_u32(overlay
, "region-freeze-timeout-us",
248 &info
->disable_timeout_us
);
250 of_property_read_u32(overlay
, "config-complete-timeout-us",
251 &info
->config_complete_timeout_us
);
253 /* If overlay is not programming the FPGA, don't need FPGA image info */
254 if (!info
->firmware_name
) {
260 * If overlay informs us FPGA was externally programmed, specifying
261 * firmware here would be ambiguous.
263 if (info
->flags
& FPGA_MGR_EXTERNAL_CONFIG
) {
264 dev_err(dev
, "error: specified firmware and external-fpga-config");
271 fpga_image_info_free(info
);
276 * of_fpga_region_notify_pre_apply - pre-apply overlay notification
278 * @region: FPGA region that the overlay was applied to
279 * @nd: overlay notification data
281 * Called when an overlay targeted to a FPGA Region is about to be applied.
282 * Parses the overlay for properties that influence how the FPGA will be
283 * programmed and does some checking. If the checks pass, programs the FPGA.
284 * If the checks fail, overlay is rejected and does not get added to the
287 * Returns 0 for success or negative error code for failure.
289 static int of_fpga_region_notify_pre_apply(struct fpga_region
*region
,
290 struct of_overlay_notify_data
*nd
)
292 struct device
*dev
= ®ion
->dev
;
293 struct fpga_image_info
*info
;
296 info
= of_fpga_region_parse_ov(region
, nd
->overlay
);
298 return PTR_ERR(info
);
300 /* If overlay doesn't program the FPGA, accept it anyway. */
305 dev_err(dev
, "Region already has overlay applied.\n");
310 ret
= fpga_region_program_fpga(region
);
312 /* error; reject overlay */
313 fpga_image_info_free(info
);
321 * of_fpga_region_notify_post_remove - post-remove overlay notification
323 * @region: FPGA region that was targeted by the overlay that was removed
324 * @nd: overlay notification data
326 * Called after an overlay has been removed if the overlay's target was a
329 static void of_fpga_region_notify_post_remove(struct fpga_region
*region
,
330 struct of_overlay_notify_data
*nd
)
332 fpga_bridges_disable(®ion
->bridge_list
);
333 fpga_bridges_put(®ion
->bridge_list
);
334 fpga_image_info_free(region
->info
);
339 * of_fpga_region_notify - reconfig notifier for dynamic DT changes
340 * @nb: notifier block
341 * @action: notifier action
342 * @arg: reconfig data
344 * This notifier handles programming a FPGA when a "firmware-name" property is
345 * added to a fpga-region.
347 * Returns NOTIFY_OK or error if FPGA programming fails.
349 static int of_fpga_region_notify(struct notifier_block
*nb
,
350 unsigned long action
, void *arg
)
352 struct of_overlay_notify_data
*nd
= arg
;
353 struct fpga_region
*region
;
357 case OF_OVERLAY_PRE_APPLY
:
358 pr_debug("%s OF_OVERLAY_PRE_APPLY\n", __func__
);
360 case OF_OVERLAY_POST_APPLY
:
361 pr_debug("%s OF_OVERLAY_POST_APPLY\n", __func__
);
362 return NOTIFY_OK
; /* not for us */
363 case OF_OVERLAY_PRE_REMOVE
:
364 pr_debug("%s OF_OVERLAY_PRE_REMOVE\n", __func__
);
365 return NOTIFY_OK
; /* not for us */
366 case OF_OVERLAY_POST_REMOVE
:
367 pr_debug("%s OF_OVERLAY_POST_REMOVE\n", __func__
);
369 default: /* should not happen */
373 region
= of_fpga_region_find(nd
->target
);
379 case OF_OVERLAY_PRE_APPLY
:
380 ret
= of_fpga_region_notify_pre_apply(region
, nd
);
383 case OF_OVERLAY_POST_REMOVE
:
384 of_fpga_region_notify_post_remove(region
, nd
);
388 put_device(®ion
->dev
);
391 return notifier_from_errno(ret
);
396 static struct notifier_block fpga_region_of_nb
= {
397 .notifier_call
= of_fpga_region_notify
,
400 static int of_fpga_region_probe(struct platform_device
*pdev
)
402 struct device
*dev
= &pdev
->dev
;
403 struct device_node
*np
= dev
->of_node
;
404 struct fpga_region
*region
;
405 struct fpga_manager
*mgr
;
408 /* Find the FPGA mgr specified by region or parent region. */
409 mgr
= of_fpga_region_get_mgr(np
);
411 return -EPROBE_DEFER
;
413 region
= devm_fpga_region_create(dev
, mgr
, of_fpga_region_get_bridges
);
419 ret
= fpga_region_register(region
);
423 of_platform_populate(np
, fpga_region_of_match
, NULL
, ®ion
->dev
);
424 platform_set_drvdata(pdev
, region
);
426 dev_info(dev
, "FPGA Region probed\n");
435 static int of_fpga_region_remove(struct platform_device
*pdev
)
437 struct fpga_region
*region
= platform_get_drvdata(pdev
);
438 struct fpga_manager
*mgr
= region
->mgr
;
440 fpga_region_unregister(region
);
446 static struct platform_driver of_fpga_region_driver
= {
447 .probe
= of_fpga_region_probe
,
448 .remove
= of_fpga_region_remove
,
450 .name
= "of-fpga-region",
451 .of_match_table
= of_match_ptr(fpga_region_of_match
),
456 * fpga_region_init - init function for fpga_region class
457 * Creates the fpga_region class and registers a reconfig notifier.
459 static int __init
of_fpga_region_init(void)
463 ret
= of_overlay_notifier_register(&fpga_region_of_nb
);
467 ret
= platform_driver_register(&of_fpga_region_driver
);
474 of_overlay_notifier_unregister(&fpga_region_of_nb
);
478 static void __exit
of_fpga_region_exit(void)
480 platform_driver_unregister(&of_fpga_region_driver
);
481 of_overlay_notifier_unregister(&fpga_region_of_nb
);
484 subsys_initcall(of_fpga_region_init
);
485 module_exit(of_fpga_region_exit
);
487 MODULE_DESCRIPTION("FPGA Region");
488 MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
489 MODULE_LICENSE("GPL v2");