xref: /openbmc/linux/drivers/fpga/fpga-mgr.c (revision bcda5fd3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * FPGA Manager Core
4  *
5  *  Copyright (C) 2013-2015 Altera Corporation
6  *  Copyright (C) 2017 Intel Corporation
7  *
8  * With code from the mailing list:
9  * Copyright (C) 2013 Xilinx, Inc.
10  */
11 #include <linux/firmware.h>
12 #include <linux/fpga/fpga-mgr.h>
13 #include <linux/idr.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/mutex.h>
17 #include <linux/slab.h>
18 #include <linux/scatterlist.h>
19 #include <linux/highmem.h>
20 
21 static DEFINE_IDA(fpga_mgr_ida);
22 static struct class *fpga_mgr_class;
23 
24 struct fpga_mgr_devres {
25 	struct fpga_manager *mgr;
26 };
27 
28 /**
29  * fpga_image_info_alloc - Allocate an FPGA image info struct
30  * @dev: owning device
31  *
32  * Return: struct fpga_image_info or NULL
33  */
34 struct fpga_image_info *fpga_image_info_alloc(struct device *dev)
35 {
36 	struct fpga_image_info *info;
37 
38 	get_device(dev);
39 
40 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
41 	if (!info) {
42 		put_device(dev);
43 		return NULL;
44 	}
45 
46 	info->dev = dev;
47 
48 	return info;
49 }
50 EXPORT_SYMBOL_GPL(fpga_image_info_alloc);
51 
52 /**
53  * fpga_image_info_free - Free an FPGA image info struct
54  * @info: FPGA image info struct to free
55  */
56 void fpga_image_info_free(struct fpga_image_info *info)
57 {
58 	struct device *dev;
59 
60 	if (!info)
61 		return;
62 
63 	dev = info->dev;
64 	if (info->firmware_name)
65 		devm_kfree(dev, info->firmware_name);
66 
67 	devm_kfree(dev, info);
68 	put_device(dev);
69 }
70 EXPORT_SYMBOL_GPL(fpga_image_info_free);
71 
72 /*
73  * Call the low level driver's write_init function.  This will do the
74  * device-specific things to get the FPGA into the state where it is ready to
75  * receive an FPGA image. The low level driver only gets to see the first
76  * initial_header_size bytes in the buffer.
77  */
78 static int fpga_mgr_write_init_buf(struct fpga_manager *mgr,
79 				   struct fpga_image_info *info,
80 				   const char *buf, size_t count)
81 {
82 	int ret;
83 
84 	mgr->state = FPGA_MGR_STATE_WRITE_INIT;
85 	if (!mgr->mops->initial_header_size)
86 		ret = mgr->mops->write_init(mgr, info, NULL, 0);
87 	else
88 		ret = mgr->mops->write_init(
89 		    mgr, info, buf, min(mgr->mops->initial_header_size, count));
90 
91 	if (ret) {
92 		dev_err(&mgr->dev, "Error preparing FPGA for writing\n");
93 		mgr->state = FPGA_MGR_STATE_WRITE_INIT_ERR;
94 		return ret;
95 	}
96 
97 	return 0;
98 }
99 
100 static int fpga_mgr_write_init_sg(struct fpga_manager *mgr,
101 				  struct fpga_image_info *info,
102 				  struct sg_table *sgt)
103 {
104 	struct sg_mapping_iter miter;
105 	size_t len;
106 	char *buf;
107 	int ret;
108 
109 	if (!mgr->mops->initial_header_size)
110 		return fpga_mgr_write_init_buf(mgr, info, NULL, 0);
111 
112 	/*
113 	 * First try to use miter to map the first fragment to access the
114 	 * header, this is the typical path.
115 	 */
116 	sg_miter_start(&miter, sgt->sgl, sgt->nents, SG_MITER_FROM_SG);
117 	if (sg_miter_next(&miter) &&
118 	    miter.length >= mgr->mops->initial_header_size) {
119 		ret = fpga_mgr_write_init_buf(mgr, info, miter.addr,
120 					      miter.length);
121 		sg_miter_stop(&miter);
122 		return ret;
123 	}
124 	sg_miter_stop(&miter);
125 
126 	/* Otherwise copy the fragments into temporary memory. */
127 	buf = kmalloc(mgr->mops->initial_header_size, GFP_KERNEL);
128 	if (!buf)
129 		return -ENOMEM;
130 
131 	len = sg_copy_to_buffer(sgt->sgl, sgt->nents, buf,
132 				mgr->mops->initial_header_size);
133 	ret = fpga_mgr_write_init_buf(mgr, info, buf, len);
134 
135 	kfree(buf);
136 
137 	return ret;
138 }
139 
140 /*
141  * After all the FPGA image has been written, do the device specific steps to
142  * finish and set the FPGA into operating mode.
143  */
144 static int fpga_mgr_write_complete(struct fpga_manager *mgr,
145 				   struct fpga_image_info *info)
146 {
147 	int ret;
148 
149 	mgr->state = FPGA_MGR_STATE_WRITE_COMPLETE;
150 	ret = mgr->mops->write_complete(mgr, info);
151 	if (ret) {
152 		dev_err(&mgr->dev, "Error after writing image data to FPGA\n");
153 		mgr->state = FPGA_MGR_STATE_WRITE_COMPLETE_ERR;
154 		return ret;
155 	}
156 	mgr->state = FPGA_MGR_STATE_OPERATING;
157 
158 	return 0;
159 }
160 
161 /**
162  * fpga_mgr_buf_load_sg - load fpga from image in buffer from a scatter list
163  * @mgr:	fpga manager
164  * @info:	fpga image specific information
165  * @sgt:	scatterlist table
166  *
167  * Step the low level fpga manager through the device-specific steps of getting
168  * an FPGA ready to be configured, writing the image to it, then doing whatever
169  * post-configuration steps necessary.  This code assumes the caller got the
170  * mgr pointer from of_fpga_mgr_get() or fpga_mgr_get() and checked that it is
171  * not an error code.
172  *
173  * This is the preferred entry point for FPGA programming, it does not require
174  * any contiguous kernel memory.
175  *
176  * Return: 0 on success, negative error code otherwise.
177  */
178 static int fpga_mgr_buf_load_sg(struct fpga_manager *mgr,
179 				struct fpga_image_info *info,
180 				struct sg_table *sgt)
181 {
182 	int ret;
183 
184 	ret = fpga_mgr_write_init_sg(mgr, info, sgt);
185 	if (ret)
186 		return ret;
187 
188 	/* Write the FPGA image to the FPGA. */
189 	mgr->state = FPGA_MGR_STATE_WRITE;
190 	if (mgr->mops->write_sg) {
191 		ret = mgr->mops->write_sg(mgr, sgt);
192 	} else {
193 		struct sg_mapping_iter miter;
194 
195 		sg_miter_start(&miter, sgt->sgl, sgt->nents, SG_MITER_FROM_SG);
196 		while (sg_miter_next(&miter)) {
197 			ret = mgr->mops->write(mgr, miter.addr, miter.length);
198 			if (ret)
199 				break;
200 		}
201 		sg_miter_stop(&miter);
202 	}
203 
204 	if (ret) {
205 		dev_err(&mgr->dev, "Error while writing image data to FPGA\n");
206 		mgr->state = FPGA_MGR_STATE_WRITE_ERR;
207 		return ret;
208 	}
209 
210 	return fpga_mgr_write_complete(mgr, info);
211 }
212 
213 static int fpga_mgr_buf_load_mapped(struct fpga_manager *mgr,
214 				    struct fpga_image_info *info,
215 				    const char *buf, size_t count)
216 {
217 	int ret;
218 
219 	ret = fpga_mgr_write_init_buf(mgr, info, buf, count);
220 	if (ret)
221 		return ret;
222 
223 	/*
224 	 * Write the FPGA image to the FPGA.
225 	 */
226 	mgr->state = FPGA_MGR_STATE_WRITE;
227 	ret = mgr->mops->write(mgr, buf, count);
228 	if (ret) {
229 		dev_err(&mgr->dev, "Error while writing image data to FPGA\n");
230 		mgr->state = FPGA_MGR_STATE_WRITE_ERR;
231 		return ret;
232 	}
233 
234 	return fpga_mgr_write_complete(mgr, info);
235 }
236 
237 /**
238  * fpga_mgr_buf_load - load fpga from image in buffer
239  * @mgr:	fpga manager
240  * @info:	fpga image info
241  * @buf:	buffer contain fpga image
242  * @count:	byte count of buf
243  *
244  * Step the low level fpga manager through the device-specific steps of getting
245  * an FPGA ready to be configured, writing the image to it, then doing whatever
246  * post-configuration steps necessary.  This code assumes the caller got the
247  * mgr pointer from of_fpga_mgr_get() and checked that it is not an error code.
248  *
249  * Return: 0 on success, negative error code otherwise.
250  */
251 static int fpga_mgr_buf_load(struct fpga_manager *mgr,
252 			     struct fpga_image_info *info,
253 			     const char *buf, size_t count)
254 {
255 	struct page **pages;
256 	struct sg_table sgt;
257 	const void *p;
258 	int nr_pages;
259 	int index;
260 	int rc;
261 
262 	/*
263 	 * This is just a fast path if the caller has already created a
264 	 * contiguous kernel buffer and the driver doesn't require SG, non-SG
265 	 * drivers will still work on the slow path.
266 	 */
267 	if (mgr->mops->write)
268 		return fpga_mgr_buf_load_mapped(mgr, info, buf, count);
269 
270 	/*
271 	 * Convert the linear kernel pointer into a sg_table of pages for use
272 	 * by the driver.
273 	 */
274 	nr_pages = DIV_ROUND_UP((unsigned long)buf + count, PAGE_SIZE) -
275 		   (unsigned long)buf / PAGE_SIZE;
276 	pages = kmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);
277 	if (!pages)
278 		return -ENOMEM;
279 
280 	p = buf - offset_in_page(buf);
281 	for (index = 0; index < nr_pages; index++) {
282 		if (is_vmalloc_addr(p))
283 			pages[index] = vmalloc_to_page(p);
284 		else
285 			pages[index] = kmap_to_page((void *)p);
286 		if (!pages[index]) {
287 			kfree(pages);
288 			return -EFAULT;
289 		}
290 		p += PAGE_SIZE;
291 	}
292 
293 	/*
294 	 * The temporary pages list is used to code share the merging algorithm
295 	 * in sg_alloc_table_from_pages
296 	 */
297 	rc = sg_alloc_table_from_pages(&sgt, pages, index, offset_in_page(buf),
298 				       count, GFP_KERNEL);
299 	kfree(pages);
300 	if (rc)
301 		return rc;
302 
303 	rc = fpga_mgr_buf_load_sg(mgr, info, &sgt);
304 	sg_free_table(&sgt);
305 
306 	return rc;
307 }
308 
309 /**
310  * fpga_mgr_firmware_load - request firmware and load to fpga
311  * @mgr:	fpga manager
312  * @info:	fpga image specific information
313  * @image_name:	name of image file on the firmware search path
314  *
315  * Request an FPGA image using the firmware class, then write out to the FPGA.
316  * Update the state before each step to provide info on what step failed if
317  * there is a failure.  This code assumes the caller got the mgr pointer
318  * from of_fpga_mgr_get() or fpga_mgr_get() and checked that it is not an error
319  * code.
320  *
321  * Return: 0 on success, negative error code otherwise.
322  */
323 static int fpga_mgr_firmware_load(struct fpga_manager *mgr,
324 				  struct fpga_image_info *info,
325 				  const char *image_name)
326 {
327 	struct device *dev = &mgr->dev;
328 	const struct firmware *fw;
329 	int ret;
330 
331 	dev_info(dev, "writing %s to %s\n", image_name, mgr->name);
332 
333 	mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ;
334 
335 	ret = request_firmware(&fw, image_name, dev);
336 	if (ret) {
337 		mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ_ERR;
338 		dev_err(dev, "Error requesting firmware %s\n", image_name);
339 		return ret;
340 	}
341 
342 	ret = fpga_mgr_buf_load(mgr, info, fw->data, fw->size);
343 
344 	release_firmware(fw);
345 
346 	return ret;
347 }
348 
349 /**
350  * fpga_mgr_load - load FPGA from scatter/gather table, buffer, or firmware
351  * @mgr:	fpga manager
352  * @info:	fpga image information.
353  *
354  * Load the FPGA from an image which is indicated in @info.  If successful, the
355  * FPGA ends up in operating mode.
356  *
357  * Return: 0 on success, negative error code otherwise.
358  */
359 int fpga_mgr_load(struct fpga_manager *mgr, struct fpga_image_info *info)
360 {
361 	if (info->sgt)
362 		return fpga_mgr_buf_load_sg(mgr, info, info->sgt);
363 	if (info->buf && info->count)
364 		return fpga_mgr_buf_load(mgr, info, info->buf, info->count);
365 	if (info->firmware_name)
366 		return fpga_mgr_firmware_load(mgr, info, info->firmware_name);
367 	return -EINVAL;
368 }
369 EXPORT_SYMBOL_GPL(fpga_mgr_load);
370 
371 static const char * const state_str[] = {
372 	[FPGA_MGR_STATE_UNKNOWN] =		"unknown",
373 	[FPGA_MGR_STATE_POWER_OFF] =		"power off",
374 	[FPGA_MGR_STATE_POWER_UP] =		"power up",
375 	[FPGA_MGR_STATE_RESET] =		"reset",
376 
377 	/* requesting FPGA image from firmware */
378 	[FPGA_MGR_STATE_FIRMWARE_REQ] =		"firmware request",
379 	[FPGA_MGR_STATE_FIRMWARE_REQ_ERR] =	"firmware request error",
380 
381 	/* Preparing FPGA to receive image */
382 	[FPGA_MGR_STATE_WRITE_INIT] =		"write init",
383 	[FPGA_MGR_STATE_WRITE_INIT_ERR] =	"write init error",
384 
385 	/* Writing image to FPGA */
386 	[FPGA_MGR_STATE_WRITE] =		"write",
387 	[FPGA_MGR_STATE_WRITE_ERR] =		"write error",
388 
389 	/* Finishing configuration after image has been written */
390 	[FPGA_MGR_STATE_WRITE_COMPLETE] =	"write complete",
391 	[FPGA_MGR_STATE_WRITE_COMPLETE_ERR] =	"write complete error",
392 
393 	/* FPGA reports to be in normal operating mode */
394 	[FPGA_MGR_STATE_OPERATING] =		"operating",
395 };
396 
397 static ssize_t name_show(struct device *dev,
398 			 struct device_attribute *attr, char *buf)
399 {
400 	struct fpga_manager *mgr = to_fpga_manager(dev);
401 
402 	return sprintf(buf, "%s\n", mgr->name);
403 }
404 
405 static ssize_t state_show(struct device *dev,
406 			  struct device_attribute *attr, char *buf)
407 {
408 	struct fpga_manager *mgr = to_fpga_manager(dev);
409 
410 	return sprintf(buf, "%s\n", state_str[mgr->state]);
411 }
412 
413 static ssize_t status_show(struct device *dev,
414 			   struct device_attribute *attr, char *buf)
415 {
416 	struct fpga_manager *mgr = to_fpga_manager(dev);
417 	u64 status;
418 	int len = 0;
419 
420 	if (!mgr->mops->status)
421 		return -ENOENT;
422 
423 	status = mgr->mops->status(mgr);
424 
425 	if (status & FPGA_MGR_STATUS_OPERATION_ERR)
426 		len += sprintf(buf + len, "reconfig operation error\n");
427 	if (status & FPGA_MGR_STATUS_CRC_ERR)
428 		len += sprintf(buf + len, "reconfig CRC error\n");
429 	if (status & FPGA_MGR_STATUS_INCOMPATIBLE_IMAGE_ERR)
430 		len += sprintf(buf + len, "reconfig incompatible image\n");
431 	if (status & FPGA_MGR_STATUS_IP_PROTOCOL_ERR)
432 		len += sprintf(buf + len, "reconfig IP protocol error\n");
433 	if (status & FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR)
434 		len += sprintf(buf + len, "reconfig fifo overflow error\n");
435 
436 	return len;
437 }
438 
439 static DEVICE_ATTR_RO(name);
440 static DEVICE_ATTR_RO(state);
441 static DEVICE_ATTR_RO(status);
442 
443 static struct attribute *fpga_mgr_attrs[] = {
444 	&dev_attr_name.attr,
445 	&dev_attr_state.attr,
446 	&dev_attr_status.attr,
447 	NULL,
448 };
449 ATTRIBUTE_GROUPS(fpga_mgr);
450 
451 static struct fpga_manager *__fpga_mgr_get(struct device *dev)
452 {
453 	struct fpga_manager *mgr;
454 
455 	mgr = to_fpga_manager(dev);
456 
457 	if (!try_module_get(dev->parent->driver->owner))
458 		goto err_dev;
459 
460 	return mgr;
461 
462 err_dev:
463 	put_device(dev);
464 	return ERR_PTR(-ENODEV);
465 }
466 
467 static int fpga_mgr_dev_match(struct device *dev, const void *data)
468 {
469 	return dev->parent == data;
470 }
471 
472 /**
473  * fpga_mgr_get - Given a device, get a reference to an fpga mgr.
474  * @dev:	parent device that fpga mgr was registered with
475  *
476  * Return: fpga manager struct or IS_ERR() condition containing error code.
477  */
478 struct fpga_manager *fpga_mgr_get(struct device *dev)
479 {
480 	struct device *mgr_dev = class_find_device(fpga_mgr_class, NULL, dev,
481 						   fpga_mgr_dev_match);
482 	if (!mgr_dev)
483 		return ERR_PTR(-ENODEV);
484 
485 	return __fpga_mgr_get(mgr_dev);
486 }
487 EXPORT_SYMBOL_GPL(fpga_mgr_get);
488 
489 /**
490  * of_fpga_mgr_get - Given a device node, get a reference to an fpga mgr.
491  *
492  * @node:	device node
493  *
494  * Return: fpga manager struct or IS_ERR() condition containing error code.
495  */
496 struct fpga_manager *of_fpga_mgr_get(struct device_node *node)
497 {
498 	struct device *dev;
499 
500 	dev = class_find_device_by_of_node(fpga_mgr_class, node);
501 	if (!dev)
502 		return ERR_PTR(-ENODEV);
503 
504 	return __fpga_mgr_get(dev);
505 }
506 EXPORT_SYMBOL_GPL(of_fpga_mgr_get);
507 
508 /**
509  * fpga_mgr_put - release a reference to an fpga manager
510  * @mgr:	fpga manager structure
511  */
512 void fpga_mgr_put(struct fpga_manager *mgr)
513 {
514 	module_put(mgr->dev.parent->driver->owner);
515 	put_device(&mgr->dev);
516 }
517 EXPORT_SYMBOL_GPL(fpga_mgr_put);
518 
519 /**
520  * fpga_mgr_lock - Lock FPGA manager for exclusive use
521  * @mgr:	fpga manager
522  *
523  * Given a pointer to FPGA Manager (from fpga_mgr_get() or
524  * of_fpga_mgr_put()) attempt to get the mutex. The user should call
525  * fpga_mgr_lock() and verify that it returns 0 before attempting to
526  * program the FPGA.  Likewise, the user should call fpga_mgr_unlock
527  * when done programming the FPGA.
528  *
529  * Return: 0 for success or -EBUSY
530  */
531 int fpga_mgr_lock(struct fpga_manager *mgr)
532 {
533 	if (!mutex_trylock(&mgr->ref_mutex)) {
534 		dev_err(&mgr->dev, "FPGA manager is in use.\n");
535 		return -EBUSY;
536 	}
537 
538 	return 0;
539 }
540 EXPORT_SYMBOL_GPL(fpga_mgr_lock);
541 
542 /**
543  * fpga_mgr_unlock - Unlock FPGA manager after done programming
544  * @mgr:	fpga manager
545  */
546 void fpga_mgr_unlock(struct fpga_manager *mgr)
547 {
548 	mutex_unlock(&mgr->ref_mutex);
549 }
550 EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
551 
552 /**
553  * fpga_mgr_create - create and initialize an FPGA manager struct
554  * @parent:	fpga manager device from pdev
555  * @name:	fpga manager name
556  * @mops:	pointer to structure of fpga manager ops
557  * @priv:	fpga manager private data
558  *
559  * The caller of this function is responsible for freeing the struct with
560  * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
561  *
562  * Return: pointer to struct fpga_manager or NULL
563  */
564 struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
565 				     const struct fpga_manager_ops *mops,
566 				     void *priv)
567 {
568 	struct fpga_manager *mgr;
569 	int id, ret;
570 
571 	if (!mops || !mops->write_complete || !mops->state ||
572 	    !mops->write_init || (!mops->write && !mops->write_sg) ||
573 	    (mops->write && mops->write_sg)) {
574 		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
575 		return NULL;
576 	}
577 
578 	if (!name || !strlen(name)) {
579 		dev_err(parent, "Attempt to register with no name!\n");
580 		return NULL;
581 	}
582 
583 	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
584 	if (!mgr)
585 		return NULL;
586 
587 	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
588 	if (id < 0)
589 		goto error_kfree;
590 
591 	mutex_init(&mgr->ref_mutex);
592 
593 	mgr->name = name;
594 	mgr->mops = mops;
595 	mgr->priv = priv;
596 
597 	device_initialize(&mgr->dev);
598 	mgr->dev.class = fpga_mgr_class;
599 	mgr->dev.groups = mops->groups;
600 	mgr->dev.parent = parent;
601 	mgr->dev.of_node = parent->of_node;
602 	mgr->dev.id = id;
603 
604 	ret = dev_set_name(&mgr->dev, "fpga%d", id);
605 	if (ret)
606 		goto error_device;
607 
608 	return mgr;
609 
610 error_device:
611 	ida_simple_remove(&fpga_mgr_ida, id);
612 error_kfree:
613 	kfree(mgr);
614 
615 	return NULL;
616 }
617 EXPORT_SYMBOL_GPL(fpga_mgr_create);
618 
619 /**
620  * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
621  * @mgr:	fpga manager struct
622  */
623 void fpga_mgr_free(struct fpga_manager *mgr)
624 {
625 	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
626 	kfree(mgr);
627 }
628 EXPORT_SYMBOL_GPL(fpga_mgr_free);
629 
630 static void devm_fpga_mgr_release(struct device *dev, void *res)
631 {
632 	struct fpga_mgr_devres *dr = res;
633 
634 	fpga_mgr_free(dr->mgr);
635 }
636 
637 /**
638  * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
639  * @parent:	fpga manager device from pdev
640  * @name:	fpga manager name
641  * @mops:	pointer to structure of fpga manager ops
642  * @priv:	fpga manager private data
643  *
644  * This function is intended for use in an FPGA manager driver's probe function.
645  * After the manager driver creates the manager struct with
646  * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
647  * manager driver's remove function should call fpga_mgr_unregister().  The
648  * manager struct allocated with this function will be freed automatically on
649  * driver detach.  This includes the case of a probe function returning error
650  * before calling fpga_mgr_register(), the struct will still get cleaned up.
651  *
652  * Return: pointer to struct fpga_manager or NULL
653  */
654 struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
655 					  const struct fpga_manager_ops *mops,
656 					  void *priv)
657 {
658 	struct fpga_mgr_devres *dr;
659 
660 	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
661 	if (!dr)
662 		return NULL;
663 
664 	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
665 	if (!dr->mgr) {
666 		devres_free(dr);
667 		return NULL;
668 	}
669 
670 	devres_add(parent, dr);
671 
672 	return dr->mgr;
673 }
674 EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
675 
676 /**
677  * fpga_mgr_register - register an FPGA manager
678  * @mgr: fpga manager struct
679  *
680  * Return: 0 on success, negative error code otherwise.
681  */
682 int fpga_mgr_register(struct fpga_manager *mgr)
683 {
684 	int ret;
685 
686 	/*
687 	 * Initialize framework state by requesting low level driver read state
688 	 * from device.  FPGA may be in reset mode or may have been programmed
689 	 * by bootloader or EEPROM.
690 	 */
691 	mgr->state = mgr->mops->state(mgr);
692 
693 	ret = device_add(&mgr->dev);
694 	if (ret)
695 		goto error_device;
696 
697 	dev_info(&mgr->dev, "%s registered\n", mgr->name);
698 
699 	return 0;
700 
701 error_device:
702 	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
703 
704 	return ret;
705 }
706 EXPORT_SYMBOL_GPL(fpga_mgr_register);
707 
708 /**
709  * fpga_mgr_unregister - unregister an FPGA manager
710  * @mgr: fpga manager struct
711  *
712  * This function is intended for use in an FPGA manager driver's remove function.
713  */
714 void fpga_mgr_unregister(struct fpga_manager *mgr)
715 {
716 	dev_info(&mgr->dev, "%s %s\n", __func__, mgr->name);
717 
718 	/*
719 	 * If the low level driver provides a method for putting fpga into
720 	 * a desired state upon unregister, do it.
721 	 */
722 	if (mgr->mops->fpga_remove)
723 		mgr->mops->fpga_remove(mgr);
724 
725 	device_unregister(&mgr->dev);
726 }
727 EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
728 
729 static int fpga_mgr_devres_match(struct device *dev, void *res,
730 				 void *match_data)
731 {
732 	struct fpga_mgr_devres *dr = res;
733 
734 	return match_data == dr->mgr;
735 }
736 
737 static void devm_fpga_mgr_unregister(struct device *dev, void *res)
738 {
739 	struct fpga_mgr_devres *dr = res;
740 
741 	fpga_mgr_unregister(dr->mgr);
742 }
743 
744 /**
745  * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
746  * @dev: managing device for this FPGA manager
747  * @mgr: fpga manager struct
748  *
749  * This is the devres variant of fpga_mgr_register() for which the unregister
750  * function will be called automatically when the managing device is detached.
751  */
752 int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
753 {
754 	struct fpga_mgr_devres *dr;
755 	int ret;
756 
757 	/*
758 	 * Make sure that the struct fpga_manager * that is passed in is
759 	 * managed itself.
760 	 */
761 	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
762 				 fpga_mgr_devres_match, mgr)))
763 		return -EINVAL;
764 
765 	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
766 	if (!dr)
767 		return -ENOMEM;
768 
769 	ret = fpga_mgr_register(mgr);
770 	if (ret) {
771 		devres_free(dr);
772 		return ret;
773 	}
774 
775 	dr->mgr = mgr;
776 	devres_add(dev, dr);
777 
778 	return 0;
779 }
780 EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
781 
782 static void fpga_mgr_dev_release(struct device *dev)
783 {
784 }
785 
786 static int __init fpga_mgr_class_init(void)
787 {
788 	pr_info("FPGA manager framework\n");
789 
790 	fpga_mgr_class = class_create(THIS_MODULE, "fpga_manager");
791 	if (IS_ERR(fpga_mgr_class))
792 		return PTR_ERR(fpga_mgr_class);
793 
794 	fpga_mgr_class->dev_groups = fpga_mgr_groups;
795 	fpga_mgr_class->dev_release = fpga_mgr_dev_release;
796 
797 	return 0;
798 }
799 
800 static void __exit fpga_mgr_class_exit(void)
801 {
802 	class_destroy(fpga_mgr_class);
803 	ida_destroy(&fpga_mgr_ida);
804 }
805 
806 MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
807 MODULE_DESCRIPTION("FPGA manager framework");
808 MODULE_LICENSE("GPL v2");
809 
810 subsys_initcall(fpga_mgr_class_init);
811 module_exit(fpga_mgr_class_exit);
812