aboutsummaryrefslogtreecommitdiff
path: root/drivers/fpga/fpga-mgr.c
blob: 188ffefa3cc3e25c3befebde04aec83e6c80b0fc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
/*
 * FPGA Manager Core
 *
 *  Copyright (C) 2013-2015 Altera Corporation
 *
 * With code from the mailing list:
 * Copyright (C) 2013 Xilinx, Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <linux/firmware.h>
#include <linux/fpga/fpga-mgr.h>
#include <linux/idr.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/scatterlist.h>
#include <linux/highmem.h>

static DEFINE_IDA(fpga_mgr_ida);
static struct class *fpga_mgr_class;

/*
 * Call the low level driver's write_init function.  This will do the
 * device-specific things to get the FPGA into the state where it is ready to
 * receive an FPGA image. The low level driver only gets to see the first
 * initial_header_size bytes in the buffer.
 */
static int fpga_mgr_write_init_buf(struct fpga_manager *mgr,
				   struct fpga_image_info *info,
				   const char *buf, size_t count)
{
	int ret;

	mgr->state = FPGA_MGR_STATE_WRITE_INIT;
	if (!mgr->mops->initial_header_size)
		ret = mgr->mops->write_init(mgr, info, NULL, 0);
	else
		ret = mgr->mops->write_init(
		    mgr, info, buf, min(mgr->mops->initial_header_size, count));

	if (ret) {
		dev_err(&mgr->dev, "Error preparing FPGA for writing\n");
		mgr->state = FPGA_MGR_STATE_WRITE_INIT_ERR;
		return ret;
	}

	return 0;
}

static int fpga_mgr_write_init_sg(struct fpga_manager *mgr,
				  struct fpga_image_info *info,
				  struct sg_table *sgt)
{
	struct sg_mapping_iter miter;
	size_t len;
	char *buf;
	int ret;

	if (!mgr->mops->initial_header_size)
		return fpga_mgr_write_init_buf(mgr, info, NULL, 0);

	/*
	 * First try to use miter to map the first fragment to access the
	 * header, this is the typical path.
	 */
	sg_miter_start(&miter, sgt->sgl, sgt->nents, SG_MITER_FROM_SG);
	if (sg_miter_next(&miter) &&
	    miter.length >= mgr->mops->initial_header_size) {
		ret = fpga_mgr_write_init_buf(mgr, info, miter.addr,
					      miter.length);
		sg_miter_stop(&miter);
		return ret;
	}
	sg_miter_stop(&miter);

	/* Otherwise copy the fragments into temporary memory. */
	buf = kmalloc(mgr->mops->initial_header_size, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	len = sg_copy_to_buffer(sgt->sgl, sgt->nents, buf,
				mgr->mops->initial_header_size);
	ret = fpga_mgr_write_init_buf(mgr, info, buf, len);

	kfree(buf);

	return ret;
}

/*
 * After all the FPGA image has been written, do the device specific steps to
 * finish and set the FPGA into operating mode.
 */
static int fpga_mgr_write_complete(struct fpga_manager *mgr,
				   struct fpga_image_info *info)
{
	int ret;

	mgr->state = FPGA_MGR_STATE_WRITE_COMPLETE;
	ret = mgr->mops->write_complete(mgr, info);
	if (ret) {
		dev_err(&mgr->dev, "Error after writing image data to FPGA\n");
		mgr->state = FPGA_MGR_STATE_WRITE_COMPLETE_ERR;
		return ret;
	}
	mgr->state = FPGA_MGR_STATE_OPERATING;

	return 0;
}

/**
 * fpga_mgr_buf_load_sg - load fpga from image in buffer from a scatter list
 * @mgr:	fpga manager
 * @info:	fpga image specific information
 * @sgt:	scatterlist table
 *
 * Step the low level fpga manager through the device-specific steps of getting
 * an FPGA ready to be configured, writing the image to it, then doing whatever
 * post-configuration steps necessary.  This code assumes the caller got the
 * mgr pointer from of_fpga_mgr_get() or fpga_mgr_get() and checked that it is
 * not an error code.
 *
 * This is the preferred entry point for FPGA programming, it does not require
 * any contiguous kernel memory.
 *
 * Return: 0 on success, negative error code otherwise.
 */
int fpga_mgr_buf_load_sg(struct fpga_manager *mgr, struct fpga_image_info *info,
			 struct sg_table *sgt)
{
	int ret;

	ret = fpga_mgr_write_init_sg(mgr, info, sgt);
	if (ret)
		return ret;

	/* Write the FPGA image to the FPGA. */
	mgr->state = FPGA_MGR_STATE_WRITE;
	if (mgr->mops->write_sg) {
		ret = mgr->mops->write_sg(mgr, sgt);
	} else {
		struct sg_mapping_iter miter;

		sg_miter_start(&miter, sgt->sgl, sgt->nents, SG_MITER_FROM_SG);
		while (sg_miter_next(&miter)) {
			ret = mgr->mops->write(mgr, miter.addr, miter.length);
			if (ret)
				break;
		}
		sg_miter_stop(&miter);
	}

	if (ret) {
		dev_err(&mgr->dev, "Error while writing image data to FPGA\n");
		mgr->state = FPGA_MGR_STATE_WRITE_ERR;
		return ret;
	}

	return fpga_mgr_write_complete(mgr, info);
}
EXPORT_SYMBOL_GPL(fpga_mgr_buf_load_sg);

static int fpga_mgr_buf_load_mapped(struct fpga_manager *mgr,
				    struct fpga_image_info *info,
				    const char *buf, size_t count)
{
	int ret;

	ret = fpga_mgr_write_init_buf(mgr, info, buf, count);
	if (ret)
		return ret;

	/*
	 * Write the FPGA image to the FPGA.
	 */
	mgr->state = FPGA_MGR_STATE_WRITE;
	ret = mgr->mops->write(mgr, buf, count);
	if (ret) {
		dev_err(&mgr->dev, "Error while writing image data to FPGA\n");
		mgr->state = FPGA_MGR_STATE_WRITE_ERR;
		return ret;
	}

	return fpga_mgr_write_complete(mgr, info);
}

/**
 * fpga_mgr_buf_load - load fpga from image in buffer
 * @mgr:	fpga manager
 * @flags:	flags setting fpga confuration modes
 * @buf:	buffer contain fpga image
 * @count:	byte count of buf
 *
 * Step the low level fpga manager through the device-specific steps of getting
 * an FPGA ready to be configured, writing the image to it, then doing whatever
 * post-configuration steps necessary.  This code assumes the caller got the
 * mgr pointer from of_fpga_mgr_get() and checked that it is not an error code.
 *
 * Return: 0 on success, negative error code otherwise.
 */
int fpga_mgr_buf_load(struct fpga_manager *mgr, struct fpga_image_info *info,
		      const char *buf, size_t count)
{
	struct page **pages;
	struct sg_table sgt;
	const void *p;
	int nr_pages;
	int index;
	int rc;

	/*
	 * This is just a fast path if the caller has already created a
	 * contiguous kernel buffer and the driver doesn't require SG, non-SG
	 * drivers will still work on the slow path.
	 */
	if (mgr->mops->write)
		return fpga_mgr_buf_load_mapped(mgr, info, buf, count);

	/*
	 * Convert the linear kernel pointer into a sg_table of pages for use
	 * by the driver.
	 */
	nr_pages = DIV_ROUND_UP((unsigned long)buf + count, PAGE_SIZE) -
		   (unsigned long)buf / PAGE_SIZE;
	pages = kmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);
	if (!pages)
		return -ENOMEM;

	p = buf - offset_in_page(buf);
	for (index = 0; index < nr_pages; index++) {
		if (is_vmalloc_addr(p))
			pages[index] = vmalloc_to_page(p);
		else
			pages[index] = kmap_to_page((void *)p);
		if (!pages[index]) {
			kfree(pages);
			return -EFAULT;
		}
		p += PAGE_SIZE;
	}

	/*
	 * The temporary pages list is used to code share the merging algorithm
	 * in sg_alloc_table_from_pages
	 */
	rc = sg_alloc_table_from_pages(&sgt, pages, index, offset_in_page(buf),
				       count, GFP_KERNEL);
	kfree(pages);
	if (rc)
		return rc;

	rc = fpga_mgr_buf_load_sg(mgr, info, &sgt);
	sg_free_table(&sgt);

	return rc;
}
EXPORT_SYMBOL_GPL(fpga_mgr_buf_load);

/**
 * fpga_mgr_firmware_load - request firmware and load to fpga
 * @mgr:	fpga manager
 * @info:	fpga image specific information
 * @image_name:	name of image file on the firmware search path
 *
 * Request an FPGA image using the firmware class, then write out to the FPGA.
 * Update the state before each step to provide info on what step failed if
 * there is a failure.  This code assumes the caller got the mgr pointer
 * from of_fpga_mgr_get() or fpga_mgr_get() and checked that it is not an error
 * code.
 *
 * Return: 0 on success, negative error code otherwise.
 */
int fpga_mgr_firmware_load(struct fpga_manager *mgr,
			   struct fpga_image_info *info,
			   const char *image_name)
{
	struct device *dev = &mgr->dev;
	const struct firmware *fw;
	int ret;

	dev_info(dev, "writing %s to %s\n", image_name, mgr->name);

	mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ;

	ret = request_firmware(&fw, image_name, dev);
	if (ret) {
		mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ_ERR;
		dev_err(dev, "Error requesting firmware %s\n", image_name);
		return ret;
	}

	ret = fpga_mgr_buf_load(mgr, info, fw->data, fw->size);

	release_firmware(fw);

	return ret;
}
EXPORT_SYMBOL_GPL(fpga_mgr_firmware_load);

static const char * const state_str[] = {
	[FPGA_MGR_STATE_UNKNOWN] =		"unknown",
	[FPGA_MGR_STATE_POWER_OFF] =		"power off",
	[FPGA_MGR_STATE_POWER_UP] =		"power up",
	[FPGA_MGR_STATE_RESET] =		"reset",

	/* requesting FPGA image from firmware */
	[FPGA_MGR_STATE_FIRMWARE_REQ] =		"firmware request",
	[FPGA_MGR_STATE_FIRMWARE_REQ_ERR] =	"firmware request error",

	/* Preparing FPGA to receive image */
	[FPGA_MGR_STATE_WRITE_INIT] =		"write init",
	[FPGA_MGR_STATE_WRITE_INIT_ERR] =	"write init error",

	/* Writing image to FPGA */
	[FPGA_MGR_STATE_WRITE] =		"write",
	[FPGA_MGR_STATE_WRITE_ERR] =		"write error",

	/* Finishing configuration after image has been written */
	[FPGA_MGR_STATE_WRITE_COMPLETE] =	"write complete",
	[FPGA_MGR_STATE_WRITE_COMPLETE_ERR] =	"write complete error",

	/* FPGA reports to be in normal operating mode */
	[FPGA_MGR_STATE_OPERATING] =		"operating",
};

static ssize_t name_show(struct device *dev,
			 struct device_attribute *attr, char *buf)
{
	struct fpga_manager *mgr = to_fpga_manager(dev);

	return sprintf(buf, "%s\n", mgr->name);
}

static ssize_t state_show(struct device *dev,
			  struct device_attribute *attr, char *buf)
{
	struct fpga_manager *mgr = to_fpga_manager(dev);

	return sprintf(buf, "%s\n", state_str[mgr->state]);
}

static DEVICE_ATTR_RO(name);
static DEVICE_ATTR_RO(state);

static struct attribute *fpga_mgr_attrs[] = {
	&dev_attr_name.attr,
	&dev_attr_state.attr,
	NULL,
};
ATTRIBUTE_GROUPS(fpga_mgr);

static struct fpga_manager *__fpga_mgr_get(struct device *dev)
{
	struct fpga_manager *mgr;
	int ret = -ENODEV;

	mgr = to_fpga_manager(dev);
	if (!mgr)
		goto err_dev;

	/* Get exclusive use of fpga manager */
	if (!mutex_trylock(&mgr->ref_mutex)) {
		ret = -EBUSY;
		goto err_dev;
	}

	if (!try_module_get(dev->parent->driver->owner))
		goto err_ll_mod;

	return mgr;

err_ll_mod:
	mutex_unlock(&mgr->ref_mutex);
err_dev:
	put_device(dev);
	return ERR_PTR(ret);
}

static int fpga_mgr_dev_match(struct device *dev, const void *data)
{
	return dev->parent == data;
}

/**
 * fpga_mgr_get - get an exclusive reference to a fpga mgr
 * @dev:	parent device that fpga mgr was registered with
 *
 * Given a device, get an exclusive reference to a fpga mgr.
 *
 * Return: fpga manager struct or IS_ERR() condition containing error code.
 */
struct fpga_manager *fpga_mgr_get(struct device *dev)
{
	struct device *mgr_dev = class_find_device(fpga_mgr_class, NULL, dev,
						   fpga_mgr_dev_match);
	if (!mgr_dev)
		return ERR_PTR(-ENODEV);

	return __fpga_mgr_get(mgr_dev);
}
EXPORT_SYMBOL_GPL(fpga_mgr_get);

static int fpga_mgr_of_node_match(struct device *dev, const void *data)
{
	return dev->of_node == data;
}

/**
 * of_fpga_mgr_get - get an exclusive reference to a fpga mgr
 * @node:	device node
 *
 * Given a device node, get an exclusive reference to a fpga mgr.
 *
 * Return: fpga manager struct or IS_ERR() condition containing error code.
 */
struct fpga_manager *of_fpga_mgr_get(struct device_node *node)
{
	struct device *dev;

	dev = class_find_device(fpga_mgr_class, NULL, node,
				fpga_mgr_of_node_match);
	if (!dev)
		return ERR_PTR(-ENODEV);

	return __fpga_mgr_get(dev);
}
EXPORT_SYMBOL_GPL(of_fpga_mgr_get);

/**
 * fpga_mgr_put - release a reference to a fpga manager
 * @mgr:	fpga manager structure
 */
void fpga_mgr_put(struct fpga_manager *mgr)
{
	module_put(mgr->dev.parent->driver->owner);
	mutex_unlock(&mgr->ref_mutex);
	put_device(&mgr->dev);
}
EXPORT_SYMBOL_GPL(fpga_mgr_put);

/**
 * fpga_mgr_register - register a low level fpga manager driver
 * @dev:	fpga manager device from pdev
 * @name:	fpga manager name
 * @mops:	pointer to structure of fpga manager ops
 * @priv:	fpga manager private data
 *
 * Return: 0 on success, negative error code otherwise.
 */
int fpga_mgr_register(struct device *dev, const char *name,
		      const struct fpga_manager_ops *mops,
		      void *priv)
{
	struct fpga_manager *mgr;
	int id, ret;

	if (!mops || !mops->write_complete || !mops->state ||
	    !mops->write_init || (!mops->write && !mops->write_sg) ||
	    (mops->write && mops->write_sg)) {
		dev_err(dev, "Attempt to register without fpga_manager_ops\n");
		return -EINVAL;
	}

	if (!name || !strlen(name)) {
		dev_err(dev, "Attempt to register with no name!\n");
		return -EINVAL;
	}

	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
	if (!mgr)
		return -ENOMEM;

	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
	if (id < 0) {
		ret = id;
		goto error_kfree;
	}

	mutex_init(&mgr->ref_mutex);

	mgr->name = name;
	mgr->mops = mops;
	mgr->priv = priv;

	/*
	 * Initialize framework state by requesting low level driver read state
	 * from device.  FPGA may be in reset mode or may have been programmed
	 * by bootloader or EEPROM.
	 */
	mgr->state = mgr->mops->state(mgr);

	device_initialize(&mgr->dev);
	mgr->dev.class = fpga_mgr_class;
	mgr->dev.parent = dev;
	mgr->dev.of_node = dev->of_node;
	mgr->dev.id = id;
	dev_set_drvdata(dev, mgr);

	ret = dev_set_name(&mgr->dev, "fpga%d", id);
	if (ret)
		goto error_device;

	ret = device_add(&mgr->dev);
	if (ret)
		goto error_device;

	dev_info(&mgr->dev, "%s registered\n", mgr->name);

	return 0;

error_device:
	ida_simple_remove(&fpga_mgr_ida, id);
error_kfree:
	kfree(mgr);

	return ret;
}
EXPORT_SYMBOL_GPL(fpga_mgr_register);

/**
 * fpga_mgr_unregister - unregister a low level fpga manager driver
 * @dev:	fpga manager device from pdev
 */
void fpga_mgr_unregister(struct device *dev)
{
	struct fpga_manager *mgr = dev_get_drvdata(dev);

	dev_info(&mgr->dev, "%s %s\n", __func__, mgr->name);

	/*
	 * If the low level driver provides a method for putting fpga into
	 * a desired state upon unregister, do it.
	 */
	if (mgr->mops->fpga_remove)
		mgr->mops->fpga_remove(mgr);

	device_unregister(&mgr->dev);
}
EXPORT_SYMBOL_GPL(fpga_mgr_unregister);

static void fpga_mgr_dev_release(struct device *dev)
{
	struct fpga_manager *mgr = to_fpga_manager(dev);

	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
	kfree(mgr);
}

static int __init fpga_mgr_class_init(void)
{
	pr_info("FPGA manager framework\n");

	fpga_mgr_class = class_create(THIS_MODULE, "fpga_manager");
	if (IS_ERR(fpga_mgr_class))
		return PTR_ERR(fpga_mgr_class);

	fpga_mgr_class->dev_groups = fpga_mgr_groups;
	fpga_mgr_class->dev_release = fpga_mgr_dev_release;

	return 0;
}

static void __exit fpga_mgr_class_exit(void)
{
	class_destroy(fpga_mgr_class);
	ida_destroy(&fpga_mgr_ida);
}

MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
MODULE_DESCRIPTION("FPGA manager framework");
MODULE_LICENSE("GPL v2");

subsys_initcall(fpga_mgr_class_init);
module_exit(fpga_mgr_class_exit);