1 /*
2  *  linux/drivers/spi/spi-loopback-test.c
3  *
4  *  (c) Martin Sperl <[email protected]>
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/ktime.h>
24 #include <linux/list.h>
25 #include <linux/list_sort.h>
26 #include <linux/module.h>
27 #include <linux/of_device.h>
28 #include <linux/printk.h>
29 #include <linux/spi/spi.h>
30 
31 #include "spi-test.h"
32 
33 /* flag to only simulate transfers */
34 int simulate_only;
35 module_param(simulate_only, int, 0);
36 MODULE_PARM_DESC(simulate_only, "if not 0 do not execute the spi message");
37 
38 /* dump spi messages */
39 int dump_messages;
40 module_param(dump_messages, int, 0);
41 MODULE_PARM_DESC(dump_messages,
42 		 "=1 dump the basic spi_message_structure, " \
43 		 "=2 dump the spi_message_structure including data, " \
44 		 "=3 dump the spi_message structure before and after execution");
45 /* the device is jumpered for loopback - enabling some rx_buf tests */
46 int loopback;
47 module_param(loopback, int, 0);
48 MODULE_PARM_DESC(loopback,
49 		 "if set enable loopback mode, where the rx_buf "	\
50 		 "is checked to match tx_buf after the spi_message "	\
51 		 "is executed");
52 
53 /* run only a specific test */
54 int run_only_test = -1;
55 module_param(run_only_test, int, 0);
56 MODULE_PARM_DESC(run_only_test,
57 		 "only run the test with this number (0-based !)");
58 
59 /* the actual tests to execute */
60 static struct spi_test spi_tests[] = {
61 	{
62 		.description	= "tx/rx-transfer - start of page",
63 		.fill_option	= FILL_COUNT_8,
64 		.iterate_len    = { ITERATE_MAX_LEN },
65 		.iterate_tx_align = ITERATE_ALIGN,
66 		.iterate_rx_align = ITERATE_ALIGN,
67 		.transfer_count = 1,
68 		.transfers		= {
69 			{
70 				.tx_buf = TX(0),
71 				.rx_buf = RX(0),
72 			},
73 		},
74 	},
75 	{
76 		.description	= "tx/rx-transfer - crossing PAGE_SIZE",
77 		.fill_option	= FILL_COUNT_8,
78 		.iterate_len    = { ITERATE_MAX_LEN },
79 		.iterate_tx_align = ITERATE_ALIGN,
80 		.iterate_rx_align = ITERATE_ALIGN,
81 		.transfer_count = 1,
82 		.transfers		= {
83 			{
84 				.tx_buf = TX(PAGE_SIZE - 4),
85 				.rx_buf = RX(PAGE_SIZE - 4),
86 			},
87 		},
88 	},
89 	{
90 		.description	= "tx-transfer - only",
91 		.fill_option	= FILL_COUNT_8,
92 		.iterate_len    = { ITERATE_MAX_LEN },
93 		.iterate_tx_align = ITERATE_ALIGN,
94 		.transfer_count = 1,
95 		.transfers		= {
96 			{
97 				.tx_buf = TX(0),
98 			},
99 		},
100 	},
101 	{
102 		.description	= "rx-transfer - only",
103 		.fill_option	= FILL_COUNT_8,
104 		.iterate_len    = { ITERATE_MAX_LEN },
105 		.iterate_rx_align = ITERATE_ALIGN,
106 		.transfer_count = 1,
107 		.transfers		= {
108 			{
109 				.rx_buf = RX(0),
110 			},
111 		},
112 	},
113 	{
114 		.description	= "two tx-transfers - alter both",
115 		.fill_option	= FILL_COUNT_8,
116 		.iterate_len    = { ITERATE_LEN },
117 		.iterate_tx_align = ITERATE_ALIGN,
118 		.iterate_transfer_mask = BIT(0) | BIT(1),
119 		.transfer_count = 2,
120 		.transfers		= {
121 			{
122 				.tx_buf = TX(0),
123 			},
124 			{
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(0),
136 		.transfer_count = 2,
137 		.transfers		= {
138 			{
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(1),
153 		.transfer_count = 2,
154 		.transfers		= {
155 			{
156 				.len = 16,
157 				.tx_buf = TX(0),
158 			},
159 			{
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 		.transfer_count = 2,
171 		.transfers		= {
172 			{
173 				.tx_buf = TX(0),
174 			},
175 			{
176 				.rx_buf = RX(0),
177 			},
178 		},
179 	},
180 	{
181 		.description	= "two transfers tx then rx - alter tx",
182 		.fill_option	= FILL_COUNT_8,
183 		.iterate_len    = { ITERATE_MAX_LEN },
184 		.iterate_tx_align = ITERATE_ALIGN,
185 		.iterate_transfer_mask = BIT(0),
186 		.transfer_count = 2,
187 		.transfers		= {
188 			{
189 				.tx_buf = TX(0),
190 			},
191 			{
192 				.len = 1,
193 				.rx_buf = RX(0),
194 			},
195 		},
196 	},
197 	{
198 		.description	= "two transfers tx then rx - alter rx",
199 		.fill_option	= FILL_COUNT_8,
200 		.iterate_len    = { ITERATE_MAX_LEN },
201 		.iterate_tx_align = ITERATE_ALIGN,
202 		.iterate_transfer_mask = BIT(1),
203 		.transfer_count = 2,
204 		.transfers		= {
205 			{
206 				.len = 1,
207 				.tx_buf = TX(0),
208 			},
209 			{
210 				.rx_buf = RX(0),
211 			},
212 		},
213 	},
214 	{
215 		.description	= "two tx+rx transfers - alter both",
216 		.fill_option	= FILL_COUNT_8,
217 		.iterate_len    = { ITERATE_LEN },
218 		.iterate_tx_align = ITERATE_ALIGN,
219 		.iterate_transfer_mask = BIT(0) | BIT(1),
220 		.transfer_count = 2,
221 		.transfers		= {
222 			{
223 				.tx_buf = TX(0),
224 				.rx_buf = RX(0),
225 			},
226 			{
227 				/* making sure we align without overwrite
228 				 * the reason we can not use ITERATE_MAX_LEN
229 				 */
230 				.tx_buf = TX(SPI_TEST_MAX_SIZE_HALF),
231 				.rx_buf = RX(SPI_TEST_MAX_SIZE_HALF),
232 			},
233 		},
234 	},
235 	{
236 		.description	= "two tx+rx transfers - alter first",
237 		.fill_option	= FILL_COUNT_8,
238 		.iterate_len    = { ITERATE_MAX_LEN },
239 		.iterate_tx_align = ITERATE_ALIGN,
240 		.iterate_transfer_mask = BIT(0),
241 		.transfer_count = 2,
242 		.transfers		= {
243 			{
244 				/* making sure we align without overwrite */
245 				.tx_buf = TX(1024),
246 				.rx_buf = RX(1024),
247 			},
248 			{
249 				.len = 1,
250 				/* making sure we align without overwrite */
251 				.tx_buf = TX(0),
252 				.rx_buf = RX(0),
253 			},
254 		},
255 	},
256 	{
257 		.description	= "two tx+rx transfers - alter second",
258 		.fill_option	= FILL_COUNT_8,
259 		.iterate_len    = { ITERATE_MAX_LEN },
260 		.iterate_tx_align = ITERATE_ALIGN,
261 		.iterate_transfer_mask = BIT(1),
262 		.transfer_count = 2,
263 		.transfers		= {
264 			{
265 				.len = 1,
266 				.tx_buf = TX(0),
267 				.rx_buf = RX(0),
268 			},
269 			{
270 				/* making sure we align without overwrite */
271 				.tx_buf = TX(1024),
272 				.rx_buf = RX(1024),
273 			},
274 		},
275 	},
276 	{
277 		.description	= "two tx+rx transfers - delay after transfer",
278 		.fill_option	= FILL_COUNT_8,
279 		.iterate_len    = { ITERATE_MAX_LEN },
280 		.iterate_transfer_mask = BIT(0) | BIT(1),
281 		.transfer_count = 2,
282 		.transfers		= {
283 			{
284 				.tx_buf = TX(0),
285 				.rx_buf = RX(0),
286 				.delay_usecs = 1000,
287 			},
288 			{
289 				.tx_buf = TX(0),
290 				.rx_buf = RX(0),
291 				.delay_usecs = 1000,
292 			},
293 		},
294 	},
295 
296 	{ /* end of tests sequence */ }
297 };
298 
299 static int spi_loopback_test_probe(struct spi_device *spi)
300 {
301 	int ret;
302 
303 	dev_info(&spi->dev, "Executing spi-loopback-tests\n");
304 
305 	ret = spi_test_run_tests(spi, spi_tests);
306 
307 	dev_info(&spi->dev, "Finished spi-loopback-tests with return: %i\n",
308 		 ret);
309 
310 	return ret;
311 }
312 
313 /* non const match table to permit to change via a module parameter */
314 static struct of_device_id spi_loopback_test_of_match[] = {
315 	{ .compatible	= "linux,spi-loopback-test", },
316 	{ }
317 };
318 
319 /* allow to override the compatible string via a module_parameter */
320 module_param_string(compatible, spi_loopback_test_of_match[0].compatible,
321 		    sizeof(spi_loopback_test_of_match[0].compatible),
322 		    0000);
323 
324 MODULE_DEVICE_TABLE(of, spi_loopback_test_of_match);
325 
326 static struct spi_driver spi_loopback_test_driver = {
327 	.driver = {
328 		.name = "spi-loopback-test",
329 		.owner = THIS_MODULE,
330 		.of_match_table = spi_loopback_test_of_match,
331 	},
332 	.probe = spi_loopback_test_probe,
333 };
334 
335 module_spi_driver(spi_loopback_test_driver);
336 
337 MODULE_AUTHOR("Martin Sperl <[email protected]>");
338 MODULE_DESCRIPTION("test spi_driver to check core functionality");
339 MODULE_LICENSE("GPL");
340 
341 /*-------------------------------------------------------------------------*/
342 
343 /* spi_test implementation */
344 
345 #define RANGE_CHECK(ptr, plen, start, slen) \
346 	((ptr >= start) && (ptr + plen <= start + slen))
347 
348 /* we allocate one page more, to allow for offsets */
349 #define SPI_TEST_MAX_SIZE_PLUS (SPI_TEST_MAX_SIZE + PAGE_SIZE)
350 
351 static void spi_test_print_hex_dump(char *pre, const void *ptr, size_t len)
352 {
353 	/* limit the hex_dump */
354 	if (len < 1024) {
355 		print_hex_dump(KERN_INFO, pre,
356 			       DUMP_PREFIX_OFFSET, 16, 1,
357 			       ptr, len, 0);
358 		return;
359 	}
360 	/* print head */
361 	print_hex_dump(KERN_INFO, pre,
362 		       DUMP_PREFIX_OFFSET, 16, 1,
363 		       ptr, 512, 0);
364 	/* print tail */
365 	pr_info("%s truncated - continuing at offset %04zx\n",
366 		pre, len - 512);
367 	print_hex_dump(KERN_INFO, pre,
368 		       DUMP_PREFIX_OFFSET, 16, 1,
369 		       ptr + (len - 512), 512, 0);
370 }
371 
372 static void spi_test_dump_message(struct spi_device *spi,
373 				  struct spi_message *msg,
374 				  bool dump_data)
375 {
376 	struct spi_transfer *xfer;
377 	int i;
378 	u8 b;
379 
380 	dev_info(&spi->dev, "  spi_msg@%pK\n", msg);
381 	if (msg->status)
382 		dev_info(&spi->dev, "    status:        %i\n",
383 			 msg->status);
384 	dev_info(&spi->dev, "    frame_length:  %i\n",
385 		 msg->frame_length);
386 	dev_info(&spi->dev, "    actual_length: %i\n",
387 		 msg->actual_length);
388 
389 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
390 		dev_info(&spi->dev, "    spi_transfer@%pK\n", xfer);
391 		dev_info(&spi->dev, "      len:    %i\n", xfer->len);
392 		dev_info(&spi->dev, "      tx_buf: %pK\n", xfer->tx_buf);
393 		if (dump_data && xfer->tx_buf)
394 			spi_test_print_hex_dump("          TX: ",
395 						xfer->tx_buf,
396 						xfer->len);
397 
398 		dev_info(&spi->dev, "      rx_buf: %pK\n", xfer->rx_buf);
399 		if (dump_data && xfer->rx_buf)
400 			spi_test_print_hex_dump("          RX: ",
401 						xfer->rx_buf,
402 						xfer->len);
403 		/* check for unwritten test pattern on rx_buf */
404 		if (xfer->rx_buf) {
405 			for (i = 0 ; i < xfer->len ; i++) {
406 				b = ((u8 *)xfer->rx_buf)[xfer->len - 1 - i];
407 				if (b != SPI_TEST_PATTERN_UNWRITTEN)
408 					break;
409 			}
410 			if (i)
411 				dev_info(&spi->dev,
412 					 "      rx_buf filled with %02x starts at offset: %i\n",
413 					 SPI_TEST_PATTERN_UNWRITTEN,
414 					 xfer->len - i);
415 		}
416 	}
417 }
418 
419 struct rx_ranges {
420 	struct list_head list;
421 	u8 *start;
422 	u8 *end;
423 };
424 
425 static int rx_ranges_cmp(void *priv, struct list_head *a, struct list_head *b)
426 {
427 	struct rx_ranges *rx_a = list_entry(a, struct rx_ranges, list);
428 	struct rx_ranges *rx_b = list_entry(b, struct rx_ranges, list);
429 
430 	if (rx_a->start > rx_b->start)
431 		return 1;
432 	if (rx_a->start < rx_b->start)
433 		return -1;
434 	return 0;
435 }
436 
437 static int spi_check_rx_ranges(struct spi_device *spi,
438 			       struct spi_message *msg,
439 			       void *rx)
440 {
441 	struct spi_transfer *xfer;
442 	struct rx_ranges ranges[SPI_TEST_MAX_TRANSFERS], *r;
443 	int i = 0;
444 	LIST_HEAD(ranges_list);
445 	u8 *addr;
446 	int ret = 0;
447 
448 	/* loop over all transfers to fill in the rx_ranges */
449 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
450 		/* if there is no rx, then no check is needed */
451 		if (!xfer->rx_buf)
452 			continue;
453 		/* fill in the rx_range */
454 		if (RANGE_CHECK(xfer->rx_buf, xfer->len,
455 				rx, SPI_TEST_MAX_SIZE_PLUS)) {
456 			ranges[i].start = xfer->rx_buf;
457 			ranges[i].end = xfer->rx_buf + xfer->len;
458 			list_add(&ranges[i].list, &ranges_list);
459 			i++;
460 		}
461 	}
462 
463 	/* if no ranges, then we can return and avoid the checks...*/
464 	if (!i)
465 		return 0;
466 
467 	/* sort the list */
468 	list_sort(NULL, &ranges_list, rx_ranges_cmp);
469 
470 	/* and iterate over all the rx addresses */
471 	for (addr = rx; addr < (u8 *)rx + SPI_TEST_MAX_SIZE_PLUS; addr++) {
472 		/* if we are the DO not write pattern,
473 		 * then continue with the loop...
474 		 */
475 		if (*addr == SPI_TEST_PATTERN_DO_NOT_WRITE)
476 			continue;
477 
478 		/* check if we are inside a range */
479 		list_for_each_entry(r, &ranges_list, list) {
480 			/* if so then set to end... */
481 			if ((addr >= r->start) && (addr < r->end))
482 				addr = r->end;
483 		}
484 		/* second test after a (hopefull) translation */
485 		if (*addr == SPI_TEST_PATTERN_DO_NOT_WRITE)
486 			continue;
487 
488 		/* if still not found then something has modified too much */
489 		/* we could list the "closest" transfer here... */
490 		dev_err(&spi->dev,
491 			"loopback strangeness - rx changed outside of allowed range at: %pK\n",
492 			addr);
493 		/* do not return, only set ret,
494 		 * so that we list all addresses
495 		 */
496 		ret = -ERANGE;
497 	}
498 
499 	return ret;
500 }
501 
502 static int spi_test_check_elapsed_time(struct spi_device *spi,
503 				       struct spi_test *test)
504 {
505 	int i;
506 	unsigned long long estimated_time = 0;
507 	unsigned long long delay_usecs = 0;
508 
509 	for (i = 0; i < test->transfer_count; i++) {
510 		struct spi_transfer *xfer = test->transfers + i;
511 		unsigned long long nbits = (unsigned long long)BITS_PER_BYTE *
512 					   xfer->len;
513 
514 		delay_usecs += xfer->delay_usecs;
515 		if (!xfer->speed_hz)
516 			continue;
517 		estimated_time += div_u64(nbits * NSEC_PER_SEC, xfer->speed_hz);
518 	}
519 
520 	estimated_time += delay_usecs * NSEC_PER_USEC;
521 	if (test->elapsed_time < estimated_time) {
522 		dev_err(&spi->dev,
523 			"elapsed time %lld ns is shorter than minimam estimated time %lld ns\n",
524 			test->elapsed_time, estimated_time);
525 
526 		return -EINVAL;
527 	}
528 
529 	return 0;
530 }
531 
532 static int spi_test_check_loopback_result(struct spi_device *spi,
533 					  struct spi_message *msg,
534 					  void *tx, void *rx)
535 {
536 	struct spi_transfer *xfer;
537 	u8 rxb, txb;
538 	size_t i;
539 	int ret;
540 
541 	/* checks rx_buffer pattern are valid with loopback or without */
542 	ret = spi_check_rx_ranges(spi, msg, rx);
543 	if (ret)
544 		return ret;
545 
546 	/* if we run without loopback, then return now */
547 	if (!loopback)
548 		return 0;
549 
550 	/* if applicable to transfer check that rx_buf is equal to tx_buf */
551 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
552 		/* if there is no rx, then no check is needed */
553 		if (!xfer->len || !xfer->rx_buf)
554 			continue;
555 		/* so depending on tx_buf we need to handle things */
556 		if (xfer->tx_buf) {
557 			for (i = 0; i < xfer->len; i++) {
558 				txb = ((u8 *)xfer->tx_buf)[i];
559 				rxb = ((u8 *)xfer->rx_buf)[i];
560 				if (txb != rxb)
561 					goto mismatch_error;
562 			}
563 		} else {
564 			/* first byte received */
565 			txb = ((u8 *)xfer->rx_buf)[0];
566 			/* first byte may be 0 or xff */
567 			if (!((txb == 0) || (txb == 0xff))) {
568 				dev_err(&spi->dev,
569 					"loopback strangeness - we expect 0x00 or 0xff, but not 0x%02x\n",
570 					txb);
571 				return -EINVAL;
572 			}
573 			/* check that all bytes are identical */
574 			for (i = 1; i < xfer->len; i++) {
575 				rxb = ((u8 *)xfer->rx_buf)[i];
576 				if (rxb != txb)
577 					goto mismatch_error;
578 			}
579 		}
580 	}
581 
582 	return 0;
583 
584 mismatch_error:
585 	dev_err(&spi->dev,
586 		"loopback strangeness - transfer mismatch on byte %04zx - expected 0x%02x, but got 0x%02x\n",
587 		i, txb, rxb);
588 
589 	return -EINVAL;
590 }
591 
592 static int spi_test_translate(struct spi_device *spi,
593 			      void **ptr, size_t len,
594 			      void *tx, void *rx)
595 {
596 	size_t off;
597 
598 	/* return on null */
599 	if (!*ptr)
600 		return 0;
601 
602 	/* in the MAX_SIZE_HALF case modify the pointer */
603 	if (((size_t)*ptr) & SPI_TEST_MAX_SIZE_HALF)
604 		/* move the pointer to the correct range */
605 		*ptr += (SPI_TEST_MAX_SIZE_PLUS / 2) -
606 			SPI_TEST_MAX_SIZE_HALF;
607 
608 	/* RX range
609 	 * - we check against MAX_SIZE_PLUS to allow for automated alignment
610 	 */
611 	if (RANGE_CHECK(*ptr, len,  RX(0), SPI_TEST_MAX_SIZE_PLUS)) {
612 		off = *ptr - RX(0);
613 		*ptr = rx + off;
614 
615 		return 0;
616 	}
617 
618 	/* TX range */
619 	if (RANGE_CHECK(*ptr, len,  TX(0), SPI_TEST_MAX_SIZE_PLUS)) {
620 		off = *ptr - TX(0);
621 		*ptr = tx + off;
622 
623 		return 0;
624 	}
625 
626 	dev_err(&spi->dev,
627 		"PointerRange [%pK:%pK[ not in range [%pK:%pK[ or [%pK:%pK[\n",
628 		*ptr, *ptr + len,
629 		RX(0), RX(SPI_TEST_MAX_SIZE),
630 		TX(0), TX(SPI_TEST_MAX_SIZE));
631 
632 	return -EINVAL;
633 }
634 
635 static int spi_test_fill_pattern(struct spi_device *spi,
636 				 struct spi_test *test)
637 {
638 	struct spi_transfer *xfers = test->transfers;
639 	u8 *tx_buf;
640 	size_t count = 0;
641 	int i, j;
642 
643 #ifdef __BIG_ENDIAN
644 #define GET_VALUE_BYTE(value, index, bytes) \
645 	(value >> (8 * (bytes - 1 - count % bytes)))
646 #else
647 #define GET_VALUE_BYTE(value, index, bytes) \
648 	(value >> (8 * (count % bytes)))
649 #endif
650 
651 	/* fill all transfers with the pattern requested */
652 	for (i = 0; i < test->transfer_count; i++) {
653 		/* fill rx_buf with SPI_TEST_PATTERN_UNWRITTEN */
654 		if (xfers[i].rx_buf)
655 			memset(xfers[i].rx_buf, SPI_TEST_PATTERN_UNWRITTEN,
656 			       xfers[i].len);
657 		/* if tx_buf is NULL then skip */
658 		tx_buf = (u8 *)xfers[i].tx_buf;
659 		if (!tx_buf)
660 			continue;
661 		/* modify all the transfers */
662 		for (j = 0; j < xfers[i].len; j++, tx_buf++, count++) {
663 			/* fill tx */
664 			switch (test->fill_option) {
665 			case FILL_MEMSET_8:
666 				*tx_buf = test->fill_pattern;
667 				break;
668 			case FILL_MEMSET_16:
669 				*tx_buf = GET_VALUE_BYTE(test->fill_pattern,
670 							 count, 2);
671 				break;
672 			case FILL_MEMSET_24:
673 				*tx_buf = GET_VALUE_BYTE(test->fill_pattern,
674 							 count, 3);
675 				break;
676 			case FILL_MEMSET_32:
677 				*tx_buf = GET_VALUE_BYTE(test->fill_pattern,
678 							 count, 4);
679 				break;
680 			case FILL_COUNT_8:
681 				*tx_buf = count;
682 				break;
683 			case FILL_COUNT_16:
684 				*tx_buf = GET_VALUE_BYTE(count, count, 2);
685 				break;
686 			case FILL_COUNT_24:
687 				*tx_buf = GET_VALUE_BYTE(count, count, 3);
688 				break;
689 			case FILL_COUNT_32:
690 				*tx_buf = GET_VALUE_BYTE(count, count, 4);
691 				break;
692 			case FILL_TRANSFER_BYTE_8:
693 				*tx_buf = j;
694 				break;
695 			case FILL_TRANSFER_BYTE_16:
696 				*tx_buf = GET_VALUE_BYTE(j, j, 2);
697 				break;
698 			case FILL_TRANSFER_BYTE_24:
699 				*tx_buf = GET_VALUE_BYTE(j, j, 3);
700 				break;
701 			case FILL_TRANSFER_BYTE_32:
702 				*tx_buf = GET_VALUE_BYTE(j, j, 4);
703 				break;
704 			case FILL_TRANSFER_NUM:
705 				*tx_buf = i;
706 				break;
707 			default:
708 				dev_err(&spi->dev,
709 					"unsupported fill_option: %i\n",
710 					test->fill_option);
711 				return -EINVAL;
712 			}
713 		}
714 	}
715 
716 	return 0;
717 }
718 
719 static int _spi_test_run_iter(struct spi_device *spi,
720 			      struct spi_test *test,
721 			      void *tx, void *rx)
722 {
723 	struct spi_message *msg = &test->msg;
724 	struct spi_transfer *x;
725 	int i, ret;
726 
727 	/* initialize message - zero-filled via static initialization */
728 	spi_message_init_no_memset(msg);
729 
730 	/* fill rx with the DO_NOT_WRITE pattern */
731 	memset(rx, SPI_TEST_PATTERN_DO_NOT_WRITE, SPI_TEST_MAX_SIZE_PLUS);
732 
733 	/* add the individual transfers */
734 	for (i = 0; i < test->transfer_count; i++) {
735 		x = &test->transfers[i];
736 
737 		/* patch the values of tx_buf */
738 		ret = spi_test_translate(spi, (void **)&x->tx_buf, x->len,
739 					 (void *)tx, rx);
740 		if (ret)
741 			return ret;
742 
743 		/* patch the values of rx_buf */
744 		ret = spi_test_translate(spi, &x->rx_buf, x->len,
745 					 (void *)tx, rx);
746 		if (ret)
747 			return ret;
748 
749 		/* and add it to the list */
750 		spi_message_add_tail(x, msg);
751 	}
752 
753 	/* fill in the transfer buffers with pattern */
754 	ret = spi_test_fill_pattern(spi, test);
755 	if (ret)
756 		return ret;
757 
758 	/* and execute */
759 	if (test->execute_msg)
760 		ret = test->execute_msg(spi, test, tx, rx);
761 	else
762 		ret = spi_test_execute_msg(spi, test, tx, rx);
763 
764 	/* handle result */
765 	if (ret == test->expected_return)
766 		return 0;
767 
768 	dev_err(&spi->dev,
769 		"test failed - test returned %i, but we expect %i\n",
770 		ret, test->expected_return);
771 
772 	if (ret)
773 		return ret;
774 
775 	/* if it is 0, as we expected something else,
776 	 * then return something special
777 	 */
778 	return -EFAULT;
779 }
780 
781 static int spi_test_run_iter(struct spi_device *spi,
782 			     const struct spi_test *testtemplate,
783 			     void *tx, void *rx,
784 			     size_t len,
785 			     size_t tx_off,
786 			     size_t rx_off
787 	)
788 {
789 	struct spi_test test;
790 	int i, tx_count, rx_count;
791 
792 	/* copy the test template to test */
793 	memcpy(&test, testtemplate, sizeof(test));
794 
795 	/* if iterate_transfer_mask is not set,
796 	 * then set it to first transfer only
797 	 */
798 	if (!(test.iterate_transfer_mask & (BIT(test.transfer_count) - 1)))
799 		test.iterate_transfer_mask = 1;
800 
801 	/* count number of transfers with tx/rx_buf != NULL */
802 	rx_count = tx_count = 0;
803 	for (i = 0; i < test.transfer_count; i++) {
804 		if (test.transfers[i].tx_buf)
805 			tx_count++;
806 		if (test.transfers[i].rx_buf)
807 			rx_count++;
808 	}
809 
810 	/* in some iteration cases warn and exit early,
811 	 * as there is nothing to do, that has not been tested already...
812 	 */
813 	if (tx_off && (!tx_count)) {
814 		dev_warn_once(&spi->dev,
815 			      "%s: iterate_tx_off configured with tx_buf==NULL - ignoring\n",
816 			      test.description);
817 		return 0;
818 	}
819 	if (rx_off && (!rx_count)) {
820 		dev_warn_once(&spi->dev,
821 			      "%s: iterate_rx_off configured with rx_buf==NULL - ignoring\n",
822 			      test.description);
823 		return 0;
824 	}
825 
826 	/* write out info */
827 	if (!(len || tx_off || rx_off)) {
828 		dev_info(&spi->dev, "Running test %s\n", test.description);
829 	} else {
830 		dev_info(&spi->dev,
831 			 "  with iteration values: len = %zu, tx_off = %zu, rx_off = %zu\n",
832 			 len, tx_off, rx_off);
833 	}
834 
835 	/* update in the values from iteration values */
836 	for (i = 0; i < test.transfer_count; i++) {
837 		/* only when bit in transfer mask is set */
838 		if (!(test.iterate_transfer_mask & BIT(i)))
839 			continue;
840 		test.transfers[i].len = len;
841 		if (test.transfers[i].tx_buf)
842 			test.transfers[i].tx_buf += tx_off;
843 		if (test.transfers[i].tx_buf)
844 			test.transfers[i].rx_buf += rx_off;
845 	}
846 
847 	/* and execute */
848 	return _spi_test_run_iter(spi, &test, tx, rx);
849 }
850 
851 /**
852  * spi_test_execute_msg - default implementation to run a test
853  *
854  * spi: @spi_device on which to run the @spi_message
855  * test: the test to execute, which already contains @msg
856  * tx:   the tx buffer allocated for the test sequence
857  * rx:   the rx buffer allocated for the test sequence
858  *
859  * Returns: error code of spi_sync as well as basic error checking
860  */
861 int spi_test_execute_msg(struct spi_device *spi, struct spi_test *test,
862 			 void *tx, void *rx)
863 {
864 	struct spi_message *msg = &test->msg;
865 	int ret = 0;
866 	int i;
867 
868 	/* only if we do not simulate */
869 	if (!simulate_only) {
870 		ktime_t start;
871 
872 		/* dump the complete message before and after the transfer */
873 		if (dump_messages == 3)
874 			spi_test_dump_message(spi, msg, true);
875 
876 		start = ktime_get();
877 		/* run spi message */
878 		ret = spi_sync(spi, msg);
879 		test->elapsed_time = ktime_to_ns(ktime_sub(ktime_get(), start));
880 		if (ret == -ETIMEDOUT) {
881 			dev_info(&spi->dev,
882 				 "spi-message timed out - reruning...\n");
883 			/* rerun after a few explicit schedules */
884 			for (i = 0; i < 16; i++)
885 				schedule();
886 			ret = spi_sync(spi, msg);
887 		}
888 		if (ret) {
889 			dev_err(&spi->dev,
890 				"Failed to execute spi_message: %i\n",
891 				ret);
892 			goto exit;
893 		}
894 
895 		/* do some extra error checks */
896 		if (msg->frame_length != msg->actual_length) {
897 			dev_err(&spi->dev,
898 				"actual length differs from expected\n");
899 			ret = -EIO;
900 			goto exit;
901 		}
902 
903 		/* run rx-buffer tests */
904 		ret = spi_test_check_loopback_result(spi, msg, tx, rx);
905 		if (ret)
906 			goto exit;
907 
908 		ret = spi_test_check_elapsed_time(spi, test);
909 	}
910 
911 	/* if requested or on error dump message (including data) */
912 exit:
913 	if (dump_messages || ret)
914 		spi_test_dump_message(spi, msg,
915 				      (dump_messages >= 2) || (ret));
916 
917 	return ret;
918 }
919 EXPORT_SYMBOL_GPL(spi_test_execute_msg);
920 
921 /**
922  * spi_test_run_test - run an individual spi_test
923  *                     including all the relevant iterations on:
924  *                     length and buffer alignment
925  *
926  * spi:  the spi_device to send the messages to
927  * test: the test which we need to execute
928  * tx:   the tx buffer allocated for the test sequence
929  * rx:   the rx buffer allocated for the test sequence
930  *
931  * Returns: status code of spi_sync or other failures
932  */
933 
934 int spi_test_run_test(struct spi_device *spi, const struct spi_test *test,
935 		      void *tx, void *rx)
936 {
937 	int idx_len;
938 	size_t len;
939 	size_t tx_align, rx_align;
940 	int ret;
941 
942 	/* test for transfer limits */
943 	if (test->transfer_count >= SPI_TEST_MAX_TRANSFERS) {
944 		dev_err(&spi->dev,
945 			"%s: Exceeded max number of transfers with %i\n",
946 			test->description, test->transfer_count);
947 		return -E2BIG;
948 	}
949 
950 	/* setting up some values in spi_message
951 	 * based on some settings in spi_master
952 	 * some of this can also get done in the run() method
953 	 */
954 
955 	/* iterate over all the iterable values using macros
956 	 * (to make it a bit more readable...
957 	 */
958 #define FOR_EACH_ALIGNMENT(var)						\
959 	for (var = 0;							\
960 	    var < (test->iterate_##var ?				\
961 			(spi->master->dma_alignment ?			\
962 			 spi->master->dma_alignment :			\
963 			 test->iterate_##var) :				\
964 			1);						\
965 	    var++)
966 
967 	for (idx_len = 0; idx_len < SPI_TEST_MAX_ITERATE &&
968 	     (len = test->iterate_len[idx_len]) != -1; idx_len++) {
969 		FOR_EACH_ALIGNMENT(tx_align) {
970 			FOR_EACH_ALIGNMENT(rx_align) {
971 				/* and run the iteration */
972 				ret = spi_test_run_iter(spi, test,
973 							tx, rx,
974 							len,
975 							tx_align,
976 							rx_align);
977 				if (ret)
978 					return ret;
979 			}
980 		}
981 	}
982 
983 	return 0;
984 }
985 EXPORT_SYMBOL_GPL(spi_test_run_test);
986 
987 /**
988  * spi_test_run_tests - run an array of spi_messages tests
989  * @spi: the spi device on which to run the tests
990  * @tests: NULL-terminated array of @spi_test
991  *
992  * Returns: status errors as per @spi_test_run_test()
993  */
994 
995 int spi_test_run_tests(struct spi_device *spi,
996 		       struct spi_test *tests)
997 {
998 	char *rx = NULL, *tx = NULL;
999 	int ret = 0, count = 0;
1000 	struct spi_test *test;
1001 
1002 	/* allocate rx/tx buffers of 128kB size without devm
1003 	 * in the hope that is on a page boundary
1004 	 */
1005 	rx = kzalloc(SPI_TEST_MAX_SIZE_PLUS, GFP_KERNEL);
1006 	if (!rx) {
1007 		ret = -ENOMEM;
1008 		goto out;
1009 	}
1010 
1011 	tx = kzalloc(SPI_TEST_MAX_SIZE_PLUS, GFP_KERNEL);
1012 	if (!tx) {
1013 		ret = -ENOMEM;
1014 		goto out;
1015 	}
1016 
1017 	/* now run the individual tests in the table */
1018 	for (test = tests, count = 0; test->description[0];
1019 	     test++, count++) {
1020 		/* only run test if requested */
1021 		if ((run_only_test > -1) && (count != run_only_test))
1022 			continue;
1023 		/* run custom implementation */
1024 		if (test->run_test)
1025 			ret = test->run_test(spi, test, tx, rx);
1026 		else
1027 			ret = spi_test_run_test(spi, test, tx, rx);
1028 		if (ret)
1029 			goto out;
1030 		/* add some delays so that we can easily
1031 		 * detect the individual tests when using a logic analyzer
1032 		 * we also add scheduling to avoid potential spi_timeouts...
1033 		 */
1034 		mdelay(100);
1035 		schedule();
1036 	}
1037 
1038 out:
1039 	kfree(rx);
1040 	kfree(tx);
1041 	return ret;
1042 }
1043 EXPORT_SYMBOL_GPL(spi_test_run_tests);
1044