1 /*
2  *  linux/drivers/spi/spi-loopback-test.c
3  *
4  *  (c) Martin Sperl <kernel@martin.sperl.org>
5  *
6  *  Loopback test driver to test several typical spi_message conditions
7  *  that a spi_master driver may encounter
8  *  this can also get used for regression testing
9  *
10  *  This program is free software; you can redistribute it and/or modify
11  *  it under the terms of the GNU General Public License as published by
12  *  the Free Software Foundation; either version 2 of the License, or
13  *  (at your option) any later version.
14  *
15  *  This program is distributed in the hope that it will be useful,
16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *  GNU General Public License for more details.
19  */
20 
21 #include <linux/delay.h>
22 #include <linux/kernel.h>
23 #include <linux/list.h>
24 #include <linux/list_sort.h>
25 #include <linux/module.h>
26 #include <linux/of_device.h>
27 #include <linux/printk.h>
28 #include <linux/spi/spi.h>
29 
30 #include "spi-test.h"
31 
32 /* flag to only simulate transfers */
33 int simulate_only;
34 module_param(simulate_only, int, 0);
35 MODULE_PARM_DESC(simulate_only, "if not 0 do not execute the spi message");
36 
37 /* dump spi messages */
38 int dump_messages;
39 module_param(dump_messages, int, 0);
40 MODULE_PARM_DESC(dump_messages,
41 		 "=1 dump the basic spi_message_structure, " \
42 		 "=2 dump the spi_message_structure including data, " \
43 		 "=3 dump the spi_message structure before and after execution");
44 /* the device is jumpered for loopback - enabling some rx_buf tests */
45 int loopback;
46 module_param(loopback, int, 0);
47 MODULE_PARM_DESC(loopback,
48 		 "if set enable loopback mode, where the rx_buf "	\
49 		 "is checked to match tx_buf after the spi_message "	\
50 		 "is executed");
51 
52 /* run only a specific test */
53 int run_only_test = -1;
54 module_param(run_only_test, int, 0);
55 MODULE_PARM_DESC(run_only_test,
56 		 "only run the test with this number (0-based !)");
57 
58 /* the actual tests to execute */
59 static struct spi_test spi_tests[] = {
60 	{
61 		.description	= "tx/rx-transfer - start of page",
62 		.fill_option	= FILL_COUNT_8,
63 		.iterate_len    = { ITERATE_MAX_LEN },
64 		.iterate_tx_align = ITERATE_ALIGN,
65 		.iterate_rx_align = ITERATE_ALIGN,
66 		.transfers		= {
67 			{
68 				.len = 1,
69 				.tx_buf = TX(0),
70 				.rx_buf = RX(0),
71 			},
72 		},
73 	},
74 	{
75 		.description	= "tx/rx-transfer - crossing PAGE_SIZE",
76 		.fill_option	= FILL_COUNT_8,
77 		.iterate_len    = { ITERATE_MAX_LEN },
78 		.iterate_tx_align = ITERATE_ALIGN,
79 		.iterate_rx_align = ITERATE_ALIGN,
80 		.transfers		= {
81 			{
82 				.len = 1,
83 				.tx_buf = TX(PAGE_SIZE - 4),
84 				.rx_buf = RX(PAGE_SIZE - 4),
85 			},
86 		},
87 	},
88 	{
89 		.description	= "tx-transfer - only",
90 		.fill_option	= FILL_COUNT_8,
91 		.iterate_len    = { ITERATE_MAX_LEN },
92 		.iterate_tx_align = ITERATE_ALIGN,
93 		.transfers		= {
94 			{
95 				.len = 1,
96 				.tx_buf = TX(0),
97 			},
98 		},
99 	},
100 	{
101 		.description	= "rx-transfer - only",
102 		.fill_option	= FILL_COUNT_8,
103 		.iterate_len    = { ITERATE_MAX_LEN },
104 		.iterate_rx_align = ITERATE_ALIGN,
105 		.transfers		= {
106 			{
107 				.len = 1,
108 				.rx_buf = RX(0),
109 			},
110 		},
111 	},
112 	{
113 		.description	= "two tx-transfers - alter both",
114 		.fill_option	= FILL_COUNT_8,
115 		.iterate_len    = { ITERATE_LEN },
116 		.iterate_tx_align = ITERATE_ALIGN,
117 		.iterate_transfer_mask = BIT(0) | BIT(1),
118 		.transfers		= {
119 			{
120 				.len = 1,
121 				.tx_buf = TX(0),
122 			},
123 			{
124 				.len = 1,
125 				/* this is why we cant use ITERATE_MAX_LEN */
126 				.tx_buf = TX(SPI_TEST_MAX_SIZE_HALF),
127 			},
128 		},
129 	},
130 	{
131 		.description	= "two tx-transfers - alter first",
132 		.fill_option	= FILL_COUNT_8,
133 		.iterate_len    = { ITERATE_MAX_LEN },
134 		.iterate_tx_align = ITERATE_ALIGN,
135 		.iterate_transfer_mask = BIT(1),
136 		.transfers		= {
137 			{
138 				.len = 1,
139 				.tx_buf = TX(64),
140 			},
141 			{
142 				.len = 1,
143 				.tx_buf = TX(0),
144 			},
145 		},
146 	},
147 	{
148 		.description	= "two tx-transfers - alter second",
149 		.fill_option	= FILL_COUNT_8,
150 		.iterate_len    = { ITERATE_MAX_LEN },
151 		.iterate_tx_align = ITERATE_ALIGN,
152 		.iterate_transfer_mask = BIT(0),
153 		.transfers		= {
154 			{
155 				.len = 16,
156 				.tx_buf = TX(0),
157 			},
158 			{
159 				.len = 1,
160 				.tx_buf = TX(64),
161 			},
162 		},
163 	},
164 	{
165 		.description	= "two transfers tx then rx - alter both",
166 		.fill_option	= FILL_COUNT_8,
167 		.iterate_len    = { ITERATE_MAX_LEN },
168 		.iterate_tx_align = ITERATE_ALIGN,
169 		.iterate_transfer_mask = BIT(0) | BIT(1),
170 		.transfers		= {
171 			{
172 				.len = 1,
173 				.tx_buf = TX(0),
174 			},
175 			{
176 				.len = 1,
177 				.rx_buf = RX(0),
178 			},
179 		},
180 	},
181 	{
182 		.description	= "two transfers tx then rx - alter tx",
183 		.fill_option	= FILL_COUNT_8,
184 		.iterate_len    = { ITERATE_MAX_LEN },
185 		.iterate_tx_align = ITERATE_ALIGN,
186 		.iterate_transfer_mask = BIT(0),
187 		.transfers		= {
188 			{
189 				.len = 1,
190 				.tx_buf = TX(0),
191 			},
192 			{
193 				.len = 1,
194 				.rx_buf = RX(0),
195 			},
196 		},
197 	},
198 	{
199 		.description	= "two transfers tx then rx - alter rx",
200 		.fill_option	= FILL_COUNT_8,
201 		.iterate_len    = { ITERATE_MAX_LEN },
202 		.iterate_tx_align = ITERATE_ALIGN,
203 		.iterate_transfer_mask = BIT(1),
204 		.transfers		= {
205 			{
206 				.len = 1,
207 				.tx_buf = TX(0),
208 			},
209 			{
210 				.len = 1,
211 				.rx_buf = RX(0),
212 			},
213 		},
214 	},
215 	{
216 		.description	= "two tx+rx transfers - alter both",
217 		.fill_option	= FILL_COUNT_8,
218 		.iterate_len    = { ITERATE_LEN },
219 		.iterate_tx_align = ITERATE_ALIGN,
220 		.iterate_transfer_mask = BIT(0) | BIT(1),
221 		.transfers		= {
222 			{
223 				.len = 1,
224 				.tx_buf = TX(0),
225 				.rx_buf = RX(0),
226 			},
227 			{
228 				.len = 1,
229 				/* making sure we align without overwrite
230 				 * the reason we can not use ITERATE_MAX_LEN
231 				 */
232 				.tx_buf = TX(SPI_TEST_MAX_SIZE_HALF),
233 				.rx_buf = RX(SPI_TEST_MAX_SIZE_HALF),
234 			},
235 		},
236 	},
237 	{
238 		.description	= "two tx+rx transfers - alter first",
239 		.fill_option	= FILL_COUNT_8,
240 		.iterate_len    = { ITERATE_MAX_LEN },
241 		.iterate_tx_align = ITERATE_ALIGN,
242 		.iterate_transfer_mask = BIT(0),
243 		.transfers		= {
244 			{
245 				.len = 1,
246 				/* making sure we align without overwrite */
247 				.tx_buf = TX(1024),
248 				.rx_buf = RX(1024),
249 			},
250 			{
251 				.len = 1,
252 				/* making sure we align without overwrite */
253 				.tx_buf = TX(0),
254 				.rx_buf = RX(0),
255 			},
256 		},
257 	},
258 	{
259 		.description	= "two tx+rx transfers - alter second",
260 		.fill_option	= FILL_COUNT_8,
261 		.iterate_len    = { ITERATE_MAX_LEN },
262 		.iterate_tx_align = ITERATE_ALIGN,
263 		.iterate_transfer_mask = BIT(1),
264 		.transfers		= {
265 			{
266 				.len = 1,
267 				.tx_buf = TX(0),
268 				.rx_buf = RX(0),
269 			},
270 			{
271 				.len = 1,
272 				/* making sure we align without overwrite */
273 				.tx_buf = TX(1024),
274 				.rx_buf = RX(1024),
275 			},
276 		},
277 	},
278 
279 	{ /* end of tests sequence */ }
280 };
281 
282 static int spi_loopback_test_probe(struct spi_device *spi)
283 {
284 	int ret;
285 
286 	dev_info(&spi->dev, "Executing spi-loopback-tests\n");
287 
288 	ret = spi_test_run_tests(spi, spi_tests);
289 
290 	dev_info(&spi->dev, "Finished spi-loopback-tests with return: %i\n",
291 		 ret);
292 
293 	return ret;
294 }
295 
296 /* non const match table to permit to change via a module parameter */
297 static struct of_device_id spi_loopback_test_of_match[] = {
298 	{ .compatible	= "linux,spi-loopback-test", },
299 	{ }
300 };
301 
302 /* allow to override the compatible string via a module_parameter */
303 module_param_string(compatible, spi_loopback_test_of_match[0].compatible,
304 		    sizeof(spi_loopback_test_of_match[0].compatible),
305 		    0000);
306 
307 MODULE_DEVICE_TABLE(of, spi_loopback_test_of_match);
308 
309 static struct spi_driver spi_loopback_test_driver = {
310 	.driver = {
311 		.name = "spi-loopback-test",
312 		.owner = THIS_MODULE,
313 		.of_match_table = spi_loopback_test_of_match,
314 	},
315 	.probe = spi_loopback_test_probe,
316 };
317 
318 module_spi_driver(spi_loopback_test_driver);
319 
320 MODULE_AUTHOR("Martin Sperl <kernel@martin.sperl.org>");
321 MODULE_DESCRIPTION("test spi_driver to check core functionality");
322 MODULE_LICENSE("GPL");
323 
324 /*-------------------------------------------------------------------------*/
325 
326 /* spi_test implementation */
327 
328 #define RANGE_CHECK(ptr, plen, start, slen) \
329 	((ptr >= start) && (ptr + plen <= start + slen))
330 
331 /* we allocate one page more, to allow for offsets */
332 #define SPI_TEST_MAX_SIZE_PLUS (SPI_TEST_MAX_SIZE + PAGE_SIZE)
333 
334 static void spi_test_print_hex_dump(char *pre, const void *ptr, size_t len)
335 {
336 	/* limit the hex_dump */
337 	if (len < 1024) {
338 		print_hex_dump(KERN_INFO, pre,
339 			       DUMP_PREFIX_OFFSET, 16, 1,
340 			       ptr, len, 0);
341 		return;
342 	}
343 	/* print head */
344 	print_hex_dump(KERN_INFO, pre,
345 		       DUMP_PREFIX_OFFSET, 16, 1,
346 		       ptr, 512, 0);
347 	/* print tail */
348 	pr_info("%s truncated - continuing at offset %04zx\n",
349 		pre, len - 512);
350 	print_hex_dump(KERN_INFO, pre,
351 		       DUMP_PREFIX_OFFSET, 16, 1,
352 		       ptr + (len - 512), 512, 0);
353 }
354 
355 static void spi_test_dump_message(struct spi_device *spi,
356 				  struct spi_message *msg,
357 				  bool dump_data)
358 {
359 	struct spi_transfer *xfer;
360 	int i;
361 	u8 b;
362 
363 	dev_info(&spi->dev, "  spi_msg@%pK\n", msg);
364 	if (msg->status)
365 		dev_info(&spi->dev, "    status:        %i\n",
366 			 msg->status);
367 	dev_info(&spi->dev, "    frame_length:  %i\n",
368 		 msg->frame_length);
369 	dev_info(&spi->dev, "    actual_length: %i\n",
370 		 msg->actual_length);
371 
372 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
373 		dev_info(&spi->dev, "    spi_transfer@%pK\n", xfer);
374 		dev_info(&spi->dev, "      len:    %i\n", xfer->len);
375 		dev_info(&spi->dev, "      tx_buf: %pK\n", xfer->tx_buf);
376 		if (dump_data && xfer->tx_buf)
377 			spi_test_print_hex_dump("          TX: ",
378 						xfer->tx_buf,
379 						xfer->len);
380 
381 		dev_info(&spi->dev, "      rx_buf: %pK\n", xfer->rx_buf);
382 		if (dump_data && xfer->rx_buf)
383 			spi_test_print_hex_dump("          RX: ",
384 						xfer->rx_buf,
385 						xfer->len);
386 		/* check for unwritten test pattern on rx_buf */
387 		if (xfer->rx_buf) {
388 			for (i = 0 ; i < xfer->len ; i++) {
389 				b = ((u8 *)xfer->rx_buf)[xfer->len - 1 - i];
390 				if (b != SPI_TEST_PATTERN_UNWRITTEN)
391 					break;
392 			}
393 			if (i)
394 				dev_info(&spi->dev,
395 					 "      rx_buf filled with %02x starts at offset: %i\n",
396 					 SPI_TEST_PATTERN_UNWRITTEN,
397 					 xfer->len - i);
398 		}
399 	}
400 }
401 
402 struct rx_ranges {
403 	struct list_head list;
404 	u8 *start;
405 	u8 *end;
406 };
407 
408 static int rx_ranges_cmp(void *priv, struct list_head *a, struct list_head *b)
409 {
410 	struct rx_ranges *rx_a = list_entry(a, struct rx_ranges, list);
411 	struct rx_ranges *rx_b = list_entry(b, struct rx_ranges, list);
412 
413 	if (rx_a->start > rx_b->start)
414 		return 1;
415 	if (rx_a->start < rx_b->start)
416 		return -1;
417 	return 0;
418 }
419 
420 static int spi_check_rx_ranges(struct spi_device *spi,
421 			       struct spi_message *msg,
422 			       void *rx)
423 {
424 	struct spi_transfer *xfer;
425 	struct rx_ranges ranges[SPI_TEST_MAX_TRANSFERS], *r;
426 	int i = 0;
427 	LIST_HEAD(ranges_list);
428 	u8 *addr;
429 	int ret = 0;
430 
431 	/* loop over all transfers to fill in the rx_ranges */
432 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
433 		/* if there is no rx, then no check is needed */
434 		if (!xfer->rx_buf)
435 			continue;
436 		/* fill in the rx_range */
437 		if (RANGE_CHECK(xfer->rx_buf, xfer->len,
438 				rx, SPI_TEST_MAX_SIZE_PLUS)) {
439 			ranges[i].start = xfer->rx_buf;
440 			ranges[i].end = xfer->rx_buf + xfer->len;
441 			list_add(&ranges[i].list, &ranges_list);
442 			i++;
443 		}
444 	}
445 
446 	/* if no ranges, then we can return and avoid the checks...*/
447 	if (!i)
448 		return 0;
449 
450 	/* sort the list */
451 	list_sort(NULL, &ranges_list, rx_ranges_cmp);
452 
453 	/* and iterate over all the rx addresses */
454 	for (addr = rx; addr < (u8 *)rx + SPI_TEST_MAX_SIZE_PLUS; addr++) {
455 		/* if we are the DO not write pattern,
456 		 * then continue with the loop...
457 		 */
458 		if (*addr == SPI_TEST_PATTERN_DO_NOT_WRITE)
459 			continue;
460 
461 		/* check if we are inside a range */
462 		list_for_each_entry(r, &ranges_list, list) {
463 			/* if so then set to end... */
464 			if ((addr >= r->start) && (addr < r->end))
465 				addr = r->end;
466 		}
467 		/* second test after a (hopefull) translation */
468 		if (*addr == SPI_TEST_PATTERN_DO_NOT_WRITE)
469 			continue;
470 
471 		/* if still not found then something has modified too much */
472 		/* we could list the "closest" transfer here... */
473 		dev_err(&spi->dev,
474 			"loopback strangeness - rx changed outside of allowed range at: %pK\n",
475 			addr);
476 		/* do not return, only set ret,
477 		 * so that we list all addresses
478 		 */
479 		ret = -ERANGE;
480 	}
481 
482 	return ret;
483 }
484 
485 static int spi_test_check_loopback_result(struct spi_device *spi,
486 					  struct spi_message *msg,
487 					  void *tx, void *rx)
488 {
489 	struct spi_transfer *xfer;
490 	u8 rxb, txb;
491 	size_t i;
492 	int ret;
493 
494 	/* checks rx_buffer pattern are valid with loopback or without */
495 	ret = spi_check_rx_ranges(spi, msg, rx);
496 	if (ret)
497 		return ret;
498 
499 	/* if we run without loopback, then return now */
500 	if (!loopback)
501 		return 0;
502 
503 	/* if applicable to transfer check that rx_buf is equal to tx_buf */
504 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
505 		/* if there is no rx, then no check is needed */
506 		if (!xfer->rx_buf)
507 			continue;
508 		/* so depending on tx_buf we need to handle things */
509 		if (xfer->tx_buf) {
510 			for (i = 1; i < xfer->len; i++) {
511 				txb = ((u8 *)xfer->tx_buf)[i];
512 				rxb = ((u8 *)xfer->rx_buf)[i];
513 				if (txb != rxb)
514 					goto mismatch_error;
515 			}
516 		} else {
517 			/* first byte received */
518 			txb = ((u8 *)xfer->rx_buf)[0];
519 			/* first byte may be 0 or xff */
520 			if (!((txb == 0) || (txb == 0xff))) {
521 				dev_err(&spi->dev,
522 					"loopback strangeness - we expect 0x00 or 0xff, but not 0x%02x\n",
523 					txb);
524 				return -EINVAL;
525 			}
526 			/* check that all bytes are identical */
527 			for (i = 1; i < xfer->len; i++) {
528 				rxb = ((u8 *)xfer->rx_buf)[i];
529 				if (rxb != txb)
530 					goto mismatch_error;
531 			}
532 		}
533 	}
534 
535 	return 0;
536 
537 mismatch_error:
538 	dev_err(&spi->dev,
539 		"loopback strangeness - transfer mismatch on byte %04zx - expected 0x%02x, but got 0x%02x\n",
540 		i, txb, rxb);
541 
542 	return -EINVAL;
543 }
544 
545 static int spi_test_translate(struct spi_device *spi,
546 			      void **ptr, size_t len,
547 			      void *tx, void *rx)
548 {
549 	size_t off;
550 
551 	/* return on null */
552 	if (!*ptr)
553 		return 0;
554 
555 	/* in the MAX_SIZE_HALF case modify the pointer */
556 	if (((size_t)*ptr) & SPI_TEST_MAX_SIZE_HALF)
557 		/* move the pointer to the correct range */
558 		*ptr += (SPI_TEST_MAX_SIZE_PLUS / 2) -
559 			SPI_TEST_MAX_SIZE_HALF;
560 
561 	/* RX range
562 	 * - we check against MAX_SIZE_PLUS to allow for automated alignment
563 	 */
564 	if (RANGE_CHECK(*ptr, len,  RX(0), SPI_TEST_MAX_SIZE_PLUS)) {
565 		off = *ptr - RX(0);
566 		*ptr = rx + off;
567 
568 		return 0;
569 	}
570 
571 	/* TX range */
572 	if (RANGE_CHECK(*ptr, len,  TX(0), SPI_TEST_MAX_SIZE_PLUS)) {
573 		off = *ptr - TX(0);
574 		*ptr = tx + off;
575 
576 		return 0;
577 	}
578 
579 	dev_err(&spi->dev,
580 		"PointerRange [%pK:%pK[ not in range [%pK:%pK[ or [%pK:%pK[\n",
581 		*ptr, *ptr + len,
582 		RX(0), RX(SPI_TEST_MAX_SIZE),
583 		TX(0), TX(SPI_TEST_MAX_SIZE));
584 
585 	return -EINVAL;
586 }
587 
588 static int spi_test_fill_pattern(struct spi_device *spi,
589 				 struct spi_test *test)
590 {
591 	struct spi_transfer *xfers = test->transfers;
592 	u8 *tx_buf;
593 	size_t count = 0;
594 	int i, j;
595 
596 #ifdef __BIG_ENDIAN
597 #define GET_VALUE_BYTE(value, index, bytes) \
598 	(value >> (8 * (bytes - 1 - count % bytes)))
599 #else
600 #define GET_VALUE_BYTE(value, index, bytes) \
601 	(value >> (8 * (count % bytes)))
602 #endif
603 
604 	/* fill all transfers with the pattern requested */
605 	for (i = 0; i < test->transfer_count; i++) {
606 		/* fill rx_buf with SPI_TEST_PATTERN_UNWRITTEN */
607 		if (xfers[i].rx_buf)
608 			memset(xfers[i].rx_buf, SPI_TEST_PATTERN_UNWRITTEN,
609 			       xfers[i].len);
610 		/* if tx_buf is NULL then skip */
611 		tx_buf = (u8 *)xfers[i].tx_buf;
612 		if (!tx_buf)
613 			continue;
614 		/* modify all the transfers */
615 		for (j = 0; j < xfers[i].len; j++, tx_buf++, count++) {
616 			/* fill tx */
617 			switch (test->fill_option) {
618 			case FILL_MEMSET_8:
619 				*tx_buf = test->fill_pattern;
620 				break;
621 			case FILL_MEMSET_16:
622 				*tx_buf = GET_VALUE_BYTE(test->fill_pattern,
623 							 count, 2);
624 				break;
625 			case FILL_MEMSET_24:
626 				*tx_buf = GET_VALUE_BYTE(test->fill_pattern,
627 							 count, 3);
628 				break;
629 			case FILL_MEMSET_32:
630 				*tx_buf = GET_VALUE_BYTE(test->fill_pattern,
631 							 count, 4);
632 				break;
633 			case FILL_COUNT_8:
634 				*tx_buf = count;
635 				break;
636 			case FILL_COUNT_16:
637 				*tx_buf = GET_VALUE_BYTE(count, count, 2);
638 				break;
639 			case FILL_COUNT_24:
640 				*tx_buf = GET_VALUE_BYTE(count, count, 3);
641 				break;
642 			case FILL_COUNT_32:
643 				*tx_buf = GET_VALUE_BYTE(count, count, 4);
644 				break;
645 			case FILL_TRANSFER_BYTE_8:
646 				*tx_buf = j;
647 				break;
648 			case FILL_TRANSFER_BYTE_16:
649 				*tx_buf = GET_VALUE_BYTE(j, j, 2);
650 				break;
651 			case FILL_TRANSFER_BYTE_24:
652 				*tx_buf = GET_VALUE_BYTE(j, j, 3);
653 				break;
654 			case FILL_TRANSFER_BYTE_32:
655 				*tx_buf = GET_VALUE_BYTE(j, j, 4);
656 				break;
657 			case FILL_TRANSFER_NUM:
658 				*tx_buf = i;
659 				break;
660 			default:
661 				dev_err(&spi->dev,
662 					"unsupported fill_option: %i\n",
663 					test->fill_option);
664 				return -EINVAL;
665 			}
666 		}
667 	}
668 
669 	return 0;
670 }
671 
672 static int _spi_test_run_iter(struct spi_device *spi,
673 			      struct spi_test *test,
674 			      void *tx, void *rx)
675 {
676 	struct spi_message *msg = &test->msg;
677 	struct spi_transfer *x;
678 	int i, ret;
679 
680 	/* initialize message - zero-filled via static initialization */
681 	spi_message_init_no_memset(msg);
682 
683 	/* fill rx with the DO_NOT_WRITE pattern */
684 	memset(rx, SPI_TEST_PATTERN_DO_NOT_WRITE, SPI_TEST_MAX_SIZE_PLUS);
685 
686 	/* add the individual transfers */
687 	for (i = 0; i < test->transfer_count; i++) {
688 		x = &test->transfers[i];
689 
690 		/* patch the values of tx_buf */
691 		ret = spi_test_translate(spi, (void **)&x->tx_buf, x->len,
692 					 (void *)tx, rx);
693 		if (ret)
694 			return ret;
695 
696 		/* patch the values of rx_buf */
697 		ret = spi_test_translate(spi, &x->rx_buf, x->len,
698 					 (void *)tx, rx);
699 		if (ret)
700 			return ret;
701 
702 		/* and add it to the list */
703 		spi_message_add_tail(x, msg);
704 	}
705 
706 	/* fill in the transfer buffers with pattern */
707 	ret = spi_test_fill_pattern(spi, test);
708 	if (ret)
709 		return ret;
710 
711 	/* and execute */
712 	if (test->execute_msg)
713 		ret = test->execute_msg(spi, test, tx, rx);
714 	else
715 		ret = spi_test_execute_msg(spi, test, tx, rx);
716 
717 	/* handle result */
718 	if (ret == test->expected_return)
719 		return 0;
720 
721 	dev_err(&spi->dev,
722 		"test failed - test returned %i, but we expect %i\n",
723 		ret, test->expected_return);
724 
725 	if (ret)
726 		return ret;
727 
728 	/* if it is 0, as we expected something else,
729 	 * then return something special
730 	 */
731 	return -EFAULT;
732 }
733 
734 static int spi_test_run_iter(struct spi_device *spi,
735 			     const struct spi_test *testtemplate,
736 			     void *tx, void *rx,
737 			     size_t len,
738 			     size_t tx_off,
739 			     size_t rx_off
740 	)
741 {
742 	struct spi_test test;
743 	int i, tx_count, rx_count;
744 
745 	/* copy the test template to test */
746 	memcpy(&test, testtemplate, sizeof(test));
747 
748 	/* set up test->transfers to the correct count */
749 	if (!test.transfer_count) {
750 		for (i = 0;
751 		    (i < SPI_TEST_MAX_TRANSFERS) && test.transfers[i].len;
752 		    i++) {
753 			test.transfer_count++;
754 		}
755 	}
756 
757 	/* if iterate_transfer_mask is not set,
758 	 * then set it to first transfer only
759 	 */
760 	if (!(test.iterate_transfer_mask & (BIT(test.transfer_count) - 1)))
761 		test.iterate_transfer_mask = 1;
762 
763 	/* count number of transfers with tx/rx_buf != NULL */
764 	rx_count = tx_count = 0;
765 	for (i = 0; i < test.transfer_count; i++) {
766 		if (test.transfers[i].tx_buf)
767 			tx_count++;
768 		if (test.transfers[i].rx_buf)
769 			rx_count++;
770 	}
771 
772 	/* in some iteration cases warn and exit early,
773 	 * as there is nothing to do, that has not been tested already...
774 	 */
775 	if (tx_off && (!tx_count)) {
776 		dev_warn_once(&spi->dev,
777 			      "%s: iterate_tx_off configured with tx_buf==NULL - ignoring\n",
778 			      test.description);
779 		return 0;
780 	}
781 	if (rx_off && (!rx_count)) {
782 		dev_warn_once(&spi->dev,
783 			      "%s: iterate_rx_off configured with rx_buf==NULL - ignoring\n",
784 			      test.description);
785 		return 0;
786 	}
787 
788 	/* write out info */
789 	if (!(len || tx_off || rx_off)) {
790 		dev_info(&spi->dev, "Running test %s\n", test.description);
791 	} else {
792 		dev_info(&spi->dev,
793 			 "  with iteration values: len = %zu, tx_off = %zu, rx_off = %zu\n",
794 			 len, tx_off, rx_off);
795 	}
796 
797 	/* update in the values from iteration values */
798 	for (i = 0; i < test.transfer_count; i++) {
799 		/* only when bit in transfer mask is set */
800 		if (!(test.iterate_transfer_mask & BIT(i)))
801 			continue;
802 		if (len)
803 			test.transfers[i].len = len;
804 		if (test.transfers[i].tx_buf)
805 			test.transfers[i].tx_buf += tx_off;
806 		if (test.transfers[i].tx_buf)
807 			test.transfers[i].rx_buf += rx_off;
808 	}
809 
810 	/* and execute */
811 	return _spi_test_run_iter(spi, &test, tx, rx);
812 }
813 
814 /**
815  * spi_test_execute_msg - default implementation to run a test
816  *
817  * spi: @spi_device on which to run the @spi_message
818  * test: the test to execute, which already contains @msg
819  * tx:   the tx buffer allocated for the test sequence
820  * rx:   the rx buffer allocated for the test sequence
821  *
822  * Returns: error code of spi_sync as well as basic error checking
823  */
824 int spi_test_execute_msg(struct spi_device *spi, struct spi_test *test,
825 			 void *tx, void *rx)
826 {
827 	struct spi_message *msg = &test->msg;
828 	int ret = 0;
829 	int i;
830 
831 	/* only if we do not simulate */
832 	if (!simulate_only) {
833 		/* dump the complete message before and after the transfer */
834 		if (dump_messages == 3)
835 			spi_test_dump_message(spi, msg, true);
836 
837 		/* run spi message */
838 		ret = spi_sync(spi, msg);
839 		if (ret == -ETIMEDOUT) {
840 			dev_info(&spi->dev,
841 				 "spi-message timed out - reruning...\n");
842 			/* rerun after a few explicit schedules */
843 			for (i = 0; i < 16; i++)
844 				schedule();
845 			ret = spi_sync(spi, msg);
846 		}
847 		if (ret) {
848 			dev_err(&spi->dev,
849 				"Failed to execute spi_message: %i\n",
850 				ret);
851 			goto exit;
852 		}
853 
854 		/* do some extra error checks */
855 		if (msg->frame_length != msg->actual_length) {
856 			dev_err(&spi->dev,
857 				"actual length differs from expected\n");
858 			ret = -EIO;
859 			goto exit;
860 		}
861 
862 		/* run rx-buffer tests */
863 		ret = spi_test_check_loopback_result(spi, msg, tx, rx);
864 	}
865 
866 	/* if requested or on error dump message (including data) */
867 exit:
868 	if (dump_messages || ret)
869 		spi_test_dump_message(spi, msg,
870 				      (dump_messages >= 2) || (ret));
871 
872 	return ret;
873 }
874 EXPORT_SYMBOL_GPL(spi_test_execute_msg);
875 
876 /**
877  * spi_test_run_test - run an individual spi_test
878  *                     including all the relevant iterations on:
879  *                     length and buffer alignment
880  *
881  * spi:  the spi_device to send the messages to
882  * test: the test which we need to execute
883  * tx:   the tx buffer allocated for the test sequence
884  * rx:   the rx buffer allocated for the test sequence
885  *
886  * Returns: status code of spi_sync or other failures
887  */
888 
889 int spi_test_run_test(struct spi_device *spi, const struct spi_test *test,
890 		      void *tx, void *rx)
891 {
892 	int idx_len;
893 	size_t len;
894 	size_t tx_align, rx_align;
895 	int ret;
896 
897 	/* test for transfer limits */
898 	if (test->transfer_count >= SPI_TEST_MAX_TRANSFERS) {
899 		dev_err(&spi->dev,
900 			"%s: Exceeded max number of transfers with %i\n",
901 			test->description, test->transfer_count);
902 		return -E2BIG;
903 	}
904 
905 	/* setting up some values in spi_message
906 	 * based on some settings in spi_master
907 	 * some of this can also get done in the run() method
908 	 */
909 
910 	/* iterate over all the iterable values using macros
911 	 * (to make it a bit more readable...
912 	 */
913 #define FOR_EACH_ITERATE(var, defaultvalue)				\
914 	for (idx_##var = -1, var = defaultvalue;			\
915 	     ((idx_##var < 0) ||					\
916 		     (							\
917 			     (idx_##var < SPI_TEST_MAX_ITERATE) &&	\
918 			     (var = test->iterate_##var[idx_##var])	\
919 		     )							\
920 	     );								\
921 	     idx_##var++)
922 #define FOR_EACH_ALIGNMENT(var)						\
923 	for (var = 0;							\
924 	    var < (test->iterate_##var ?				\
925 			(spi->master->dma_alignment ?			\
926 			 spi->master->dma_alignment :			\
927 			 test->iterate_##var) :				\
928 			1);						\
929 	    var++)
930 
931 	FOR_EACH_ITERATE(len, 0) {
932 		FOR_EACH_ALIGNMENT(tx_align) {
933 			FOR_EACH_ALIGNMENT(rx_align) {
934 				/* and run the iteration */
935 				ret = spi_test_run_iter(spi, test,
936 							tx, rx,
937 							len,
938 							tx_align,
939 							rx_align);
940 				if (ret)
941 					return ret;
942 			}
943 		}
944 	}
945 
946 	return 0;
947 }
948 EXPORT_SYMBOL_GPL(spi_test_run_test);
949 
950 /**
951  * spi_test_run_tests - run an array of spi_messages tests
952  * @spi: the spi device on which to run the tests
953  * @tests: NULL-terminated array of @spi_test
954  *
955  * Returns: status errors as per @spi_test_run_test()
956  */
957 
958 int spi_test_run_tests(struct spi_device *spi,
959 		       struct spi_test *tests)
960 {
961 	char *rx = NULL, *tx = NULL;
962 	int ret = 0, count = 0;
963 	struct spi_test *test;
964 
965 	/* allocate rx/tx buffers of 128kB size without devm
966 	 * in the hope that is on a page boundary
967 	 */
968 	rx = kzalloc(SPI_TEST_MAX_SIZE_PLUS, GFP_KERNEL);
969 	if (!rx) {
970 		ret = -ENOMEM;
971 		goto out;
972 	}
973 
974 	tx = kzalloc(SPI_TEST_MAX_SIZE_PLUS, GFP_KERNEL);
975 	if (!tx) {
976 		ret = -ENOMEM;
977 		goto out;
978 	}
979 
980 	/* now run the individual tests in the table */
981 	for (test = tests, count = 0; test->description[0];
982 	     test++, count++) {
983 		/* only run test if requested */
984 		if ((run_only_test > -1) && (count != run_only_test))
985 			continue;
986 		/* run custom implementation */
987 		if (test->run_test)
988 			ret = test->run_test(spi, test, tx, rx);
989 		else
990 			ret = spi_test_run_test(spi, test, tx, rx);
991 		if (ret)
992 			goto out;
993 		/* add some delays so that we can easily
994 		 * detect the individual tests when using a logic analyzer
995 		 * we also add scheduling to avoid potential spi_timeouts...
996 		 */
997 		mdelay(100);
998 		schedule();
999 	}
1000 
1001 out:
1002 	kfree(rx);
1003 	kfree(tx);
1004 	return ret;
1005 }
1006 EXPORT_SYMBOL_GPL(spi_test_run_tests);
1007