1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  linux/drivers/spi/spi-loopback-test.c
4  *
5  *  (c) Martin Sperl <kernel@martin.sperl.org>
6  *
7  *  Loopback test driver to test several typical spi_message conditions
8  *  that a spi_master driver may encounter
9  *  this can also get used for regression testing
10  */
11 
12 #include <linux/delay.h>
13 #include <linux/kernel.h>
14 #include <linux/ktime.h>
15 #include <linux/list.h>
16 #include <linux/list_sort.h>
17 #include <linux/module.h>
18 #include <linux/of_device.h>
19 #include <linux/printk.h>
20 #include <linux/vmalloc.h>
21 #include <linux/spi/spi.h>
22 
23 #include "spi-test.h"
24 
25 /* flag to only simulate transfers */
26 static int simulate_only;
27 module_param(simulate_only, int, 0);
28 MODULE_PARM_DESC(simulate_only, "if not 0 do not execute the spi message");
29 
30 /* dump spi messages */
31 static int dump_messages;
32 module_param(dump_messages, int, 0);
33 MODULE_PARM_DESC(dump_messages,
34 		 "=1 dump the basic spi_message_structure, " \
35 		 "=2 dump the spi_message_structure including data, " \
36 		 "=3 dump the spi_message structure before and after execution");
37 /* the device is jumpered for loopback - enabling some rx_buf tests */
38 static int loopback;
39 module_param(loopback, int, 0);
40 MODULE_PARM_DESC(loopback,
41 		 "if set enable loopback mode, where the rx_buf "	\
42 		 "is checked to match tx_buf after the spi_message "	\
43 		 "is executed");
44 
45 static int loop_req;
46 module_param(loop_req, int, 0);
47 MODULE_PARM_DESC(loop_req,
48 		 "if set controller will be asked to enable test loop mode. " \
49 		 "If controller supported it, MISO and MOSI will be connected");
50 
51 static int no_cs;
52 module_param(no_cs, int, 0);
53 MODULE_PARM_DESC(no_cs,
54 		 "if set Chip Select (CS) will not be used");
55 
56 /* run only a specific test */
57 static int run_only_test = -1;
58 module_param(run_only_test, int, 0);
59 MODULE_PARM_DESC(run_only_test,
60 		 "only run the test with this number (0-based !)");
61 
62 /* use vmalloc'ed buffers */
63 static int use_vmalloc;
64 module_param(use_vmalloc, int, 0644);
65 MODULE_PARM_DESC(use_vmalloc,
66 		 "use vmalloc'ed buffers instead of kmalloc'ed");
67 
68 /* check rx ranges */
69 static int check_ranges = 1;
70 module_param(check_ranges, int, 0644);
71 MODULE_PARM_DESC(check_ranges,
72 		 "checks rx_buffer pattern are valid");
73 
74 /* the actual tests to execute */
75 static struct spi_test spi_tests[] = {
76 	{
77 		.description	= "tx/rx-transfer - start of page",
78 		.fill_option	= FILL_COUNT_8,
79 		.iterate_len    = { ITERATE_MAX_LEN },
80 		.iterate_tx_align = ITERATE_ALIGN,
81 		.iterate_rx_align = ITERATE_ALIGN,
82 		.transfer_count = 1,
83 		.transfers		= {
84 			{
85 				.tx_buf = TX(0),
86 				.rx_buf = RX(0),
87 			},
88 		},
89 	},
90 	{
91 		.description	= "tx/rx-transfer - crossing PAGE_SIZE",
92 		.fill_option	= FILL_COUNT_8,
93 		.iterate_len    = { ITERATE_MAX_LEN },
94 		.iterate_tx_align = ITERATE_ALIGN,
95 		.iterate_rx_align = ITERATE_ALIGN,
96 		.transfer_count = 1,
97 		.transfers		= {
98 			{
99 				.tx_buf = TX(PAGE_SIZE - 4),
100 				.rx_buf = RX(PAGE_SIZE - 4),
101 			},
102 		},
103 	},
104 	{
105 		.description	= "tx-transfer - only",
106 		.fill_option	= FILL_COUNT_8,
107 		.iterate_len    = { ITERATE_MAX_LEN },
108 		.iterate_tx_align = ITERATE_ALIGN,
109 		.transfer_count = 1,
110 		.transfers		= {
111 			{
112 				.tx_buf = TX(0),
113 			},
114 		},
115 	},
116 	{
117 		.description	= "rx-transfer - only",
118 		.fill_option	= FILL_COUNT_8,
119 		.iterate_len    = { ITERATE_MAX_LEN },
120 		.iterate_rx_align = ITERATE_ALIGN,
121 		.transfer_count = 1,
122 		.transfers		= {
123 			{
124 				.rx_buf = RX(0),
125 			},
126 		},
127 	},
128 	{
129 		.description	= "two tx-transfers - alter both",
130 		.fill_option	= FILL_COUNT_8,
131 		.iterate_len    = { ITERATE_LEN },
132 		.iterate_tx_align = ITERATE_ALIGN,
133 		.iterate_transfer_mask = BIT(0) | BIT(1),
134 		.transfer_count = 2,
135 		.transfers		= {
136 			{
137 				.tx_buf = TX(0),
138 			},
139 			{
140 				/* this is why we cant use ITERATE_MAX_LEN */
141 				.tx_buf = TX(SPI_TEST_MAX_SIZE_HALF),
142 			},
143 		},
144 	},
145 	{
146 		.description	= "two tx-transfers - alter first",
147 		.fill_option	= FILL_COUNT_8,
148 		.iterate_len    = { ITERATE_MAX_LEN },
149 		.iterate_tx_align = ITERATE_ALIGN,
150 		.iterate_transfer_mask = BIT(0),
151 		.transfer_count = 2,
152 		.transfers		= {
153 			{
154 				.tx_buf = TX(64),
155 			},
156 			{
157 				.len = 1,
158 				.tx_buf = TX(0),
159 			},
160 		},
161 	},
162 	{
163 		.description	= "two tx-transfers - alter second",
164 		.fill_option	= FILL_COUNT_8,
165 		.iterate_len    = { ITERATE_MAX_LEN },
166 		.iterate_tx_align = ITERATE_ALIGN,
167 		.iterate_transfer_mask = BIT(1),
168 		.transfer_count = 2,
169 		.transfers		= {
170 			{
171 				.len = 16,
172 				.tx_buf = TX(0),
173 			},
174 			{
175 				.tx_buf = TX(64),
176 			},
177 		},
178 	},
179 	{
180 		.description	= "two transfers tx then rx - alter both",
181 		.fill_option	= FILL_COUNT_8,
182 		.iterate_len    = { ITERATE_MAX_LEN },
183 		.iterate_tx_align = ITERATE_ALIGN,
184 		.iterate_transfer_mask = BIT(0) | BIT(1),
185 		.transfer_count = 2,
186 		.transfers		= {
187 			{
188 				.tx_buf = TX(0),
189 			},
190 			{
191 				.rx_buf = RX(0),
192 			},
193 		},
194 	},
195 	{
196 		.description	= "two transfers tx then rx - alter tx",
197 		.fill_option	= FILL_COUNT_8,
198 		.iterate_len    = { ITERATE_MAX_LEN },
199 		.iterate_tx_align = ITERATE_ALIGN,
200 		.iterate_transfer_mask = BIT(0),
201 		.transfer_count = 2,
202 		.transfers		= {
203 			{
204 				.tx_buf = TX(0),
205 			},
206 			{
207 				.len = 1,
208 				.rx_buf = RX(0),
209 			},
210 		},
211 	},
212 	{
213 		.description	= "two transfers tx then rx - alter rx",
214 		.fill_option	= FILL_COUNT_8,
215 		.iterate_len    = { ITERATE_MAX_LEN },
216 		.iterate_tx_align = ITERATE_ALIGN,
217 		.iterate_transfer_mask = BIT(1),
218 		.transfer_count = 2,
219 		.transfers		= {
220 			{
221 				.len = 1,
222 				.tx_buf = TX(0),
223 			},
224 			{
225 				.rx_buf = RX(0),
226 			},
227 		},
228 	},
229 	{
230 		.description	= "two tx+rx transfers - alter both",
231 		.fill_option	= FILL_COUNT_8,
232 		.iterate_len    = { ITERATE_LEN },
233 		.iterate_tx_align = ITERATE_ALIGN,
234 		.iterate_transfer_mask = BIT(0) | BIT(1),
235 		.transfer_count = 2,
236 		.transfers		= {
237 			{
238 				.tx_buf = TX(0),
239 				.rx_buf = RX(0),
240 			},
241 			{
242 				/* making sure we align without overwrite
243 				 * the reason we can not use ITERATE_MAX_LEN
244 				 */
245 				.tx_buf = TX(SPI_TEST_MAX_SIZE_HALF),
246 				.rx_buf = RX(SPI_TEST_MAX_SIZE_HALF),
247 			},
248 		},
249 	},
250 	{
251 		.description	= "two tx+rx transfers - alter first",
252 		.fill_option	= FILL_COUNT_8,
253 		.iterate_len    = { ITERATE_MAX_LEN },
254 		.iterate_tx_align = ITERATE_ALIGN,
255 		.iterate_transfer_mask = BIT(0),
256 		.transfer_count = 2,
257 		.transfers		= {
258 			{
259 				/* making sure we align without overwrite */
260 				.tx_buf = TX(1024),
261 				.rx_buf = RX(1024),
262 			},
263 			{
264 				.len = 1,
265 				/* making sure we align without overwrite */
266 				.tx_buf = TX(0),
267 				.rx_buf = RX(0),
268 			},
269 		},
270 	},
271 	{
272 		.description	= "two tx+rx transfers - alter second",
273 		.fill_option	= FILL_COUNT_8,
274 		.iterate_len    = { ITERATE_MAX_LEN },
275 		.iterate_tx_align = ITERATE_ALIGN,
276 		.iterate_transfer_mask = BIT(1),
277 		.transfer_count = 2,
278 		.transfers		= {
279 			{
280 				.len = 1,
281 				.tx_buf = TX(0),
282 				.rx_buf = RX(0),
283 			},
284 			{
285 				/* making sure we align without overwrite */
286 				.tx_buf = TX(1024),
287 				.rx_buf = RX(1024),
288 			},
289 		},
290 	},
291 	{
292 		.description	= "two tx+rx transfers - delay after transfer",
293 		.fill_option	= FILL_COUNT_8,
294 		.iterate_len    = { ITERATE_MAX_LEN },
295 		.iterate_transfer_mask = BIT(0) | BIT(1),
296 		.transfer_count = 2,
297 		.transfers		= {
298 			{
299 				.tx_buf = TX(0),
300 				.rx_buf = RX(0),
301 				.delay = {
302 					.value = 1000,
303 					.unit = SPI_DELAY_UNIT_USECS,
304 				},
305 			},
306 			{
307 				.tx_buf = TX(0),
308 				.rx_buf = RX(0),
309 				.delay = {
310 					.value = 1000,
311 					.unit = SPI_DELAY_UNIT_USECS,
312 				},
313 			},
314 		},
315 	},
316 
317 	{ /* end of tests sequence */ }
318 };
319 
320 static int spi_loopback_test_probe(struct spi_device *spi)
321 {
322 	int ret;
323 
324 	if (loop_req || no_cs) {
325 		spi->mode |= loop_req ? SPI_LOOP : 0;
326 		spi->mode |= no_cs ? SPI_NO_CS : 0;
327 		ret = spi_setup(spi);
328 		if (ret) {
329 			dev_err(&spi->dev, "SPI setup with SPI_LOOP or SPI_NO_CS failed (%d)\n",
330 				ret);
331 			return ret;
332 		}
333 	}
334 
335 	dev_info(&spi->dev, "Executing spi-loopback-tests\n");
336 
337 	ret = spi_test_run_tests(spi, spi_tests);
338 
339 	dev_info(&spi->dev, "Finished spi-loopback-tests with return: %i\n",
340 		 ret);
341 
342 	return ret;
343 }
344 
345 /* non const match table to permit to change via a module parameter */
346 static struct of_device_id spi_loopback_test_of_match[] = {
347 	{ .compatible	= "linux,spi-loopback-test", },
348 	{ }
349 };
350 
351 /* allow to override the compatible string via a module_parameter */
352 module_param_string(compatible, spi_loopback_test_of_match[0].compatible,
353 		    sizeof(spi_loopback_test_of_match[0].compatible),
354 		    0000);
355 
356 MODULE_DEVICE_TABLE(of, spi_loopback_test_of_match);
357 
358 static struct spi_driver spi_loopback_test_driver = {
359 	.driver = {
360 		.name = "spi-loopback-test",
361 		.owner = THIS_MODULE,
362 		.of_match_table = spi_loopback_test_of_match,
363 	},
364 	.probe = spi_loopback_test_probe,
365 };
366 
367 module_spi_driver(spi_loopback_test_driver);
368 
369 MODULE_AUTHOR("Martin Sperl <kernel@martin.sperl.org>");
370 MODULE_DESCRIPTION("test spi_driver to check core functionality");
371 MODULE_LICENSE("GPL");
372 
373 /*-------------------------------------------------------------------------*/
374 
375 /* spi_test implementation */
376 
377 #define RANGE_CHECK(ptr, plen, start, slen) \
378 	((ptr >= start) && (ptr + plen <= start + slen))
379 
380 /* we allocate one page more, to allow for offsets */
381 #define SPI_TEST_MAX_SIZE_PLUS (SPI_TEST_MAX_SIZE + PAGE_SIZE)
382 
383 static void spi_test_print_hex_dump(char *pre, const void *ptr, size_t len)
384 {
385 	/* limit the hex_dump */
386 	if (len < 1024) {
387 		print_hex_dump(KERN_INFO, pre,
388 			       DUMP_PREFIX_OFFSET, 16, 1,
389 			       ptr, len, 0);
390 		return;
391 	}
392 	/* print head */
393 	print_hex_dump(KERN_INFO, pre,
394 		       DUMP_PREFIX_OFFSET, 16, 1,
395 		       ptr, 512, 0);
396 	/* print tail */
397 	pr_info("%s truncated - continuing at offset %04zx\n",
398 		pre, len - 512);
399 	print_hex_dump(KERN_INFO, pre,
400 		       DUMP_PREFIX_OFFSET, 16, 1,
401 		       ptr + (len - 512), 512, 0);
402 }
403 
404 static void spi_test_dump_message(struct spi_device *spi,
405 				  struct spi_message *msg,
406 				  bool dump_data)
407 {
408 	struct spi_transfer *xfer;
409 	int i;
410 	u8 b;
411 
412 	dev_info(&spi->dev, "  spi_msg@%pK\n", msg);
413 	if (msg->status)
414 		dev_info(&spi->dev, "    status:        %i\n",
415 			 msg->status);
416 	dev_info(&spi->dev, "    frame_length:  %i\n",
417 		 msg->frame_length);
418 	dev_info(&spi->dev, "    actual_length: %i\n",
419 		 msg->actual_length);
420 
421 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
422 		dev_info(&spi->dev, "    spi_transfer@%pK\n", xfer);
423 		dev_info(&spi->dev, "      len:    %i\n", xfer->len);
424 		dev_info(&spi->dev, "      tx_buf: %pK\n", xfer->tx_buf);
425 		if (dump_data && xfer->tx_buf)
426 			spi_test_print_hex_dump("          TX: ",
427 						xfer->tx_buf,
428 						xfer->len);
429 
430 		dev_info(&spi->dev, "      rx_buf: %pK\n", xfer->rx_buf);
431 		if (dump_data && xfer->rx_buf)
432 			spi_test_print_hex_dump("          RX: ",
433 						xfer->rx_buf,
434 						xfer->len);
435 		/* check for unwritten test pattern on rx_buf */
436 		if (xfer->rx_buf) {
437 			for (i = 0 ; i < xfer->len ; i++) {
438 				b = ((u8 *)xfer->rx_buf)[xfer->len - 1 - i];
439 				if (b != SPI_TEST_PATTERN_UNWRITTEN)
440 					break;
441 			}
442 			if (i)
443 				dev_info(&spi->dev,
444 					 "      rx_buf filled with %02x starts at offset: %i\n",
445 					 SPI_TEST_PATTERN_UNWRITTEN,
446 					 xfer->len - i);
447 		}
448 	}
449 }
450 
451 struct rx_ranges {
452 	struct list_head list;
453 	u8 *start;
454 	u8 *end;
455 };
456 
457 static int rx_ranges_cmp(void *priv, struct list_head *a, struct list_head *b)
458 {
459 	struct rx_ranges *rx_a = list_entry(a, struct rx_ranges, list);
460 	struct rx_ranges *rx_b = list_entry(b, struct rx_ranges, list);
461 
462 	if (rx_a->start > rx_b->start)
463 		return 1;
464 	if (rx_a->start < rx_b->start)
465 		return -1;
466 	return 0;
467 }
468 
469 static int spi_check_rx_ranges(struct spi_device *spi,
470 			       struct spi_message *msg,
471 			       void *rx)
472 {
473 	struct spi_transfer *xfer;
474 	struct rx_ranges ranges[SPI_TEST_MAX_TRANSFERS], *r;
475 	int i = 0;
476 	LIST_HEAD(ranges_list);
477 	u8 *addr;
478 	int ret = 0;
479 
480 	/* loop over all transfers to fill in the rx_ranges */
481 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
482 		/* if there is no rx, then no check is needed */
483 		if (!xfer->rx_buf)
484 			continue;
485 		/* fill in the rx_range */
486 		if (RANGE_CHECK(xfer->rx_buf, xfer->len,
487 				rx, SPI_TEST_MAX_SIZE_PLUS)) {
488 			ranges[i].start = xfer->rx_buf;
489 			ranges[i].end = xfer->rx_buf + xfer->len;
490 			list_add(&ranges[i].list, &ranges_list);
491 			i++;
492 		}
493 	}
494 
495 	/* if no ranges, then we can return and avoid the checks...*/
496 	if (!i)
497 		return 0;
498 
499 	/* sort the list */
500 	list_sort(NULL, &ranges_list, rx_ranges_cmp);
501 
502 	/* and iterate over all the rx addresses */
503 	for (addr = rx; addr < (u8 *)rx + SPI_TEST_MAX_SIZE_PLUS; addr++) {
504 		/* if we are the DO not write pattern,
505 		 * then continue with the loop...
506 		 */
507 		if (*addr == SPI_TEST_PATTERN_DO_NOT_WRITE)
508 			continue;
509 
510 		/* check if we are inside a range */
511 		list_for_each_entry(r, &ranges_list, list) {
512 			/* if so then set to end... */
513 			if ((addr >= r->start) && (addr < r->end))
514 				addr = r->end;
515 		}
516 		/* second test after a (hopefull) translation */
517 		if (*addr == SPI_TEST_PATTERN_DO_NOT_WRITE)
518 			continue;
519 
520 		/* if still not found then something has modified too much */
521 		/* we could list the "closest" transfer here... */
522 		dev_err(&spi->dev,
523 			"loopback strangeness - rx changed outside of allowed range at: %pK\n",
524 			addr);
525 		/* do not return, only set ret,
526 		 * so that we list all addresses
527 		 */
528 		ret = -ERANGE;
529 	}
530 
531 	return ret;
532 }
533 
534 static int spi_test_check_elapsed_time(struct spi_device *spi,
535 				       struct spi_test *test)
536 {
537 	int i;
538 	unsigned long long estimated_time = 0;
539 	unsigned long long delay_usecs = 0;
540 
541 	for (i = 0; i < test->transfer_count; i++) {
542 		struct spi_transfer *xfer = test->transfers + i;
543 		unsigned long long nbits = (unsigned long long)BITS_PER_BYTE *
544 					   xfer->len;
545 
546 		delay_usecs += xfer->delay.value;
547 		if (!xfer->speed_hz)
548 			continue;
549 		estimated_time += div_u64(nbits * NSEC_PER_SEC, xfer->speed_hz);
550 	}
551 
552 	estimated_time += delay_usecs * NSEC_PER_USEC;
553 	if (test->elapsed_time < estimated_time) {
554 		dev_err(&spi->dev,
555 			"elapsed time %lld ns is shorter than minimum estimated time %lld ns\n",
556 			test->elapsed_time, estimated_time);
557 
558 		return -EINVAL;
559 	}
560 
561 	return 0;
562 }
563 
564 static int spi_test_check_loopback_result(struct spi_device *spi,
565 					  struct spi_message *msg,
566 					  void *tx, void *rx)
567 {
568 	struct spi_transfer *xfer;
569 	u8 rxb, txb;
570 	size_t i;
571 	int ret;
572 
573 	/* checks rx_buffer pattern are valid with loopback or without */
574 	if (check_ranges) {
575 		ret = spi_check_rx_ranges(spi, msg, rx);
576 		if (ret)
577 			return ret;
578 	}
579 
580 	/* if we run without loopback, then return now */
581 	if (!loopback)
582 		return 0;
583 
584 	/* if applicable to transfer check that rx_buf is equal to tx_buf */
585 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
586 		/* if there is no rx, then no check is needed */
587 		if (!xfer->len || !xfer->rx_buf)
588 			continue;
589 		/* so depending on tx_buf we need to handle things */
590 		if (xfer->tx_buf) {
591 			for (i = 0; i < xfer->len; i++) {
592 				txb = ((u8 *)xfer->tx_buf)[i];
593 				rxb = ((u8 *)xfer->rx_buf)[i];
594 				if (txb != rxb)
595 					goto mismatch_error;
596 			}
597 		} else {
598 			/* first byte received */
599 			txb = ((u8 *)xfer->rx_buf)[0];
600 			/* first byte may be 0 or xff */
601 			if (!((txb == 0) || (txb == 0xff))) {
602 				dev_err(&spi->dev,
603 					"loopback strangeness - we expect 0x00 or 0xff, but not 0x%02x\n",
604 					txb);
605 				return -EINVAL;
606 			}
607 			/* check that all bytes are identical */
608 			for (i = 1; i < xfer->len; i++) {
609 				rxb = ((u8 *)xfer->rx_buf)[i];
610 				if (rxb != txb)
611 					goto mismatch_error;
612 			}
613 		}
614 	}
615 
616 	return 0;
617 
618 mismatch_error:
619 	dev_err(&spi->dev,
620 		"loopback strangeness - transfer mismatch on byte %04zx - expected 0x%02x, but got 0x%02x\n",
621 		i, txb, rxb);
622 
623 	return -EINVAL;
624 }
625 
626 static int spi_test_translate(struct spi_device *spi,
627 			      void **ptr, size_t len,
628 			      void *tx, void *rx)
629 {
630 	size_t off;
631 
632 	/* return on null */
633 	if (!*ptr)
634 		return 0;
635 
636 	/* in the MAX_SIZE_HALF case modify the pointer */
637 	if (((size_t)*ptr) & SPI_TEST_MAX_SIZE_HALF)
638 		/* move the pointer to the correct range */
639 		*ptr += (SPI_TEST_MAX_SIZE_PLUS / 2) -
640 			SPI_TEST_MAX_SIZE_HALF;
641 
642 	/* RX range
643 	 * - we check against MAX_SIZE_PLUS to allow for automated alignment
644 	 */
645 	if (RANGE_CHECK(*ptr, len,  RX(0), SPI_TEST_MAX_SIZE_PLUS)) {
646 		off = *ptr - RX(0);
647 		*ptr = rx + off;
648 
649 		return 0;
650 	}
651 
652 	/* TX range */
653 	if (RANGE_CHECK(*ptr, len,  TX(0), SPI_TEST_MAX_SIZE_PLUS)) {
654 		off = *ptr - TX(0);
655 		*ptr = tx + off;
656 
657 		return 0;
658 	}
659 
660 	dev_err(&spi->dev,
661 		"PointerRange [%pK:%pK[ not in range [%pK:%pK[ or [%pK:%pK[\n",
662 		*ptr, *ptr + len,
663 		RX(0), RX(SPI_TEST_MAX_SIZE),
664 		TX(0), TX(SPI_TEST_MAX_SIZE));
665 
666 	return -EINVAL;
667 }
668 
669 static int spi_test_fill_pattern(struct spi_device *spi,
670 				 struct spi_test *test)
671 {
672 	struct spi_transfer *xfers = test->transfers;
673 	u8 *tx_buf;
674 	size_t count = 0;
675 	int i, j;
676 
677 #ifdef __BIG_ENDIAN
678 #define GET_VALUE_BYTE(value, index, bytes) \
679 	(value >> (8 * (bytes - 1 - count % bytes)))
680 #else
681 #define GET_VALUE_BYTE(value, index, bytes) \
682 	(value >> (8 * (count % bytes)))
683 #endif
684 
685 	/* fill all transfers with the pattern requested */
686 	for (i = 0; i < test->transfer_count; i++) {
687 		/* fill rx_buf with SPI_TEST_PATTERN_UNWRITTEN */
688 		if (xfers[i].rx_buf)
689 			memset(xfers[i].rx_buf, SPI_TEST_PATTERN_UNWRITTEN,
690 			       xfers[i].len);
691 		/* if tx_buf is NULL then skip */
692 		tx_buf = (u8 *)xfers[i].tx_buf;
693 		if (!tx_buf)
694 			continue;
695 		/* modify all the transfers */
696 		for (j = 0; j < xfers[i].len; j++, tx_buf++, count++) {
697 			/* fill tx */
698 			switch (test->fill_option) {
699 			case FILL_MEMSET_8:
700 				*tx_buf = test->fill_pattern;
701 				break;
702 			case FILL_MEMSET_16:
703 				*tx_buf = GET_VALUE_BYTE(test->fill_pattern,
704 							 count, 2);
705 				break;
706 			case FILL_MEMSET_24:
707 				*tx_buf = GET_VALUE_BYTE(test->fill_pattern,
708 							 count, 3);
709 				break;
710 			case FILL_MEMSET_32:
711 				*tx_buf = GET_VALUE_BYTE(test->fill_pattern,
712 							 count, 4);
713 				break;
714 			case FILL_COUNT_8:
715 				*tx_buf = count;
716 				break;
717 			case FILL_COUNT_16:
718 				*tx_buf = GET_VALUE_BYTE(count, count, 2);
719 				break;
720 			case FILL_COUNT_24:
721 				*tx_buf = GET_VALUE_BYTE(count, count, 3);
722 				break;
723 			case FILL_COUNT_32:
724 				*tx_buf = GET_VALUE_BYTE(count, count, 4);
725 				break;
726 			case FILL_TRANSFER_BYTE_8:
727 				*tx_buf = j;
728 				break;
729 			case FILL_TRANSFER_BYTE_16:
730 				*tx_buf = GET_VALUE_BYTE(j, j, 2);
731 				break;
732 			case FILL_TRANSFER_BYTE_24:
733 				*tx_buf = GET_VALUE_BYTE(j, j, 3);
734 				break;
735 			case FILL_TRANSFER_BYTE_32:
736 				*tx_buf = GET_VALUE_BYTE(j, j, 4);
737 				break;
738 			case FILL_TRANSFER_NUM:
739 				*tx_buf = i;
740 				break;
741 			default:
742 				dev_err(&spi->dev,
743 					"unsupported fill_option: %i\n",
744 					test->fill_option);
745 				return -EINVAL;
746 			}
747 		}
748 	}
749 
750 	return 0;
751 }
752 
753 static int _spi_test_run_iter(struct spi_device *spi,
754 			      struct spi_test *test,
755 			      void *tx, void *rx)
756 {
757 	struct spi_message *msg = &test->msg;
758 	struct spi_transfer *x;
759 	int i, ret;
760 
761 	/* initialize message - zero-filled via static initialization */
762 	spi_message_init_no_memset(msg);
763 
764 	/* fill rx with the DO_NOT_WRITE pattern */
765 	memset(rx, SPI_TEST_PATTERN_DO_NOT_WRITE, SPI_TEST_MAX_SIZE_PLUS);
766 
767 	/* add the individual transfers */
768 	for (i = 0; i < test->transfer_count; i++) {
769 		x = &test->transfers[i];
770 
771 		/* patch the values of tx_buf */
772 		ret = spi_test_translate(spi, (void **)&x->tx_buf, x->len,
773 					 (void *)tx, rx);
774 		if (ret)
775 			return ret;
776 
777 		/* patch the values of rx_buf */
778 		ret = spi_test_translate(spi, &x->rx_buf, x->len,
779 					 (void *)tx, rx);
780 		if (ret)
781 			return ret;
782 
783 		/* and add it to the list */
784 		spi_message_add_tail(x, msg);
785 	}
786 
787 	/* fill in the transfer buffers with pattern */
788 	ret = spi_test_fill_pattern(spi, test);
789 	if (ret)
790 		return ret;
791 
792 	/* and execute */
793 	if (test->execute_msg)
794 		ret = test->execute_msg(spi, test, tx, rx);
795 	else
796 		ret = spi_test_execute_msg(spi, test, tx, rx);
797 
798 	/* handle result */
799 	if (ret == test->expected_return)
800 		return 0;
801 
802 	dev_err(&spi->dev,
803 		"test failed - test returned %i, but we expect %i\n",
804 		ret, test->expected_return);
805 
806 	if (ret)
807 		return ret;
808 
809 	/* if it is 0, as we expected something else,
810 	 * then return something special
811 	 */
812 	return -EFAULT;
813 }
814 
815 static int spi_test_run_iter(struct spi_device *spi,
816 			     const struct spi_test *testtemplate,
817 			     void *tx, void *rx,
818 			     size_t len,
819 			     size_t tx_off,
820 			     size_t rx_off
821 	)
822 {
823 	struct spi_test test;
824 	int i, tx_count, rx_count;
825 
826 	/* copy the test template to test */
827 	memcpy(&test, testtemplate, sizeof(test));
828 
829 	/* if iterate_transfer_mask is not set,
830 	 * then set it to first transfer only
831 	 */
832 	if (!(test.iterate_transfer_mask & (BIT(test.transfer_count) - 1)))
833 		test.iterate_transfer_mask = 1;
834 
835 	/* count number of transfers with tx/rx_buf != NULL */
836 	rx_count = tx_count = 0;
837 	for (i = 0; i < test.transfer_count; i++) {
838 		if (test.transfers[i].tx_buf)
839 			tx_count++;
840 		if (test.transfers[i].rx_buf)
841 			rx_count++;
842 	}
843 
844 	/* in some iteration cases warn and exit early,
845 	 * as there is nothing to do, that has not been tested already...
846 	 */
847 	if (tx_off && (!tx_count)) {
848 		dev_warn_once(&spi->dev,
849 			      "%s: iterate_tx_off configured with tx_buf==NULL - ignoring\n",
850 			      test.description);
851 		return 0;
852 	}
853 	if (rx_off && (!rx_count)) {
854 		dev_warn_once(&spi->dev,
855 			      "%s: iterate_rx_off configured with rx_buf==NULL - ignoring\n",
856 			      test.description);
857 		return 0;
858 	}
859 
860 	/* write out info */
861 	if (!(len || tx_off || rx_off)) {
862 		dev_info(&spi->dev, "Running test %s\n", test.description);
863 	} else {
864 		dev_info(&spi->dev,
865 			 "  with iteration values: len = %zu, tx_off = %zu, rx_off = %zu\n",
866 			 len, tx_off, rx_off);
867 	}
868 
869 	/* update in the values from iteration values */
870 	for (i = 0; i < test.transfer_count; i++) {
871 		/* only when bit in transfer mask is set */
872 		if (!(test.iterate_transfer_mask & BIT(i)))
873 			continue;
874 		test.transfers[i].len = len;
875 		if (test.transfers[i].tx_buf)
876 			test.transfers[i].tx_buf += tx_off;
877 		if (test.transfers[i].tx_buf)
878 			test.transfers[i].rx_buf += rx_off;
879 	}
880 
881 	/* and execute */
882 	return _spi_test_run_iter(spi, &test, tx, rx);
883 }
884 
885 /**
886  * spi_test_execute_msg - default implementation to run a test
887  *
888  * @spi: @spi_device on which to run the @spi_message
889  * @test: the test to execute, which already contains @msg
890  * @tx:   the tx buffer allocated for the test sequence
891  * @rx:   the rx buffer allocated for the test sequence
892  *
893  * Returns: error code of spi_sync as well as basic error checking
894  */
895 int spi_test_execute_msg(struct spi_device *spi, struct spi_test *test,
896 			 void *tx, void *rx)
897 {
898 	struct spi_message *msg = &test->msg;
899 	int ret = 0;
900 	int i;
901 
902 	/* only if we do not simulate */
903 	if (!simulate_only) {
904 		ktime_t start;
905 
906 		/* dump the complete message before and after the transfer */
907 		if (dump_messages == 3)
908 			spi_test_dump_message(spi, msg, true);
909 
910 		start = ktime_get();
911 		/* run spi message */
912 		ret = spi_sync(spi, msg);
913 		test->elapsed_time = ktime_to_ns(ktime_sub(ktime_get(), start));
914 		if (ret == -ETIMEDOUT) {
915 			dev_info(&spi->dev,
916 				 "spi-message timed out - rerunning...\n");
917 			/* rerun after a few explicit schedules */
918 			for (i = 0; i < 16; i++)
919 				schedule();
920 			ret = spi_sync(spi, msg);
921 		}
922 		if (ret) {
923 			dev_err(&spi->dev,
924 				"Failed to execute spi_message: %i\n",
925 				ret);
926 			goto exit;
927 		}
928 
929 		/* do some extra error checks */
930 		if (msg->frame_length != msg->actual_length) {
931 			dev_err(&spi->dev,
932 				"actual length differs from expected\n");
933 			ret = -EIO;
934 			goto exit;
935 		}
936 
937 		/* run rx-buffer tests */
938 		ret = spi_test_check_loopback_result(spi, msg, tx, rx);
939 		if (ret)
940 			goto exit;
941 
942 		ret = spi_test_check_elapsed_time(spi, test);
943 	}
944 
945 	/* if requested or on error dump message (including data) */
946 exit:
947 	if (dump_messages || ret)
948 		spi_test_dump_message(spi, msg,
949 				      (dump_messages >= 2) || (ret));
950 
951 	return ret;
952 }
953 EXPORT_SYMBOL_GPL(spi_test_execute_msg);
954 
955 /**
956  * spi_test_run_test - run an individual spi_test
957  *                     including all the relevant iterations on:
958  *                     length and buffer alignment
959  *
960  * @spi:  the spi_device to send the messages to
961  * @test: the test which we need to execute
962  * @tx:   the tx buffer allocated for the test sequence
963  * @rx:   the rx buffer allocated for the test sequence
964  *
965  * Returns: status code of spi_sync or other failures
966  */
967 
968 int spi_test_run_test(struct spi_device *spi, const struct spi_test *test,
969 		      void *tx, void *rx)
970 {
971 	int idx_len;
972 	size_t len;
973 	size_t tx_align, rx_align;
974 	int ret;
975 
976 	/* test for transfer limits */
977 	if (test->transfer_count >= SPI_TEST_MAX_TRANSFERS) {
978 		dev_err(&spi->dev,
979 			"%s: Exceeded max number of transfers with %i\n",
980 			test->description, test->transfer_count);
981 		return -E2BIG;
982 	}
983 
984 	/* setting up some values in spi_message
985 	 * based on some settings in spi_master
986 	 * some of this can also get done in the run() method
987 	 */
988 
989 	/* iterate over all the iterable values using macros
990 	 * (to make it a bit more readable...
991 	 */
992 #define FOR_EACH_ALIGNMENT(var)						\
993 	for (var = 0;							\
994 	    var < (test->iterate_##var ?				\
995 			(spi->master->dma_alignment ?			\
996 			 spi->master->dma_alignment :			\
997 			 test->iterate_##var) :				\
998 			1);						\
999 	    var++)
1000 
1001 	for (idx_len = 0; idx_len < SPI_TEST_MAX_ITERATE &&
1002 	     (len = test->iterate_len[idx_len]) != -1; idx_len++) {
1003 		FOR_EACH_ALIGNMENT(tx_align) {
1004 			FOR_EACH_ALIGNMENT(rx_align) {
1005 				/* and run the iteration */
1006 				ret = spi_test_run_iter(spi, test,
1007 							tx, rx,
1008 							len,
1009 							tx_align,
1010 							rx_align);
1011 				if (ret)
1012 					return ret;
1013 			}
1014 		}
1015 	}
1016 
1017 	return 0;
1018 }
1019 EXPORT_SYMBOL_GPL(spi_test_run_test);
1020 
1021 /**
1022  * spi_test_run_tests - run an array of spi_messages tests
1023  * @spi: the spi device on which to run the tests
1024  * @tests: NULL-terminated array of @spi_test
1025  *
1026  * Returns: status errors as per @spi_test_run_test()
1027  */
1028 
1029 int spi_test_run_tests(struct spi_device *spi,
1030 		       struct spi_test *tests)
1031 {
1032 	char *rx = NULL, *tx = NULL;
1033 	int ret = 0, count = 0;
1034 	struct spi_test *test;
1035 
1036 	/* allocate rx/tx buffers of 128kB size without devm
1037 	 * in the hope that is on a page boundary
1038 	 */
1039 	if (use_vmalloc)
1040 		rx = vmalloc(SPI_TEST_MAX_SIZE_PLUS);
1041 	else
1042 		rx = kzalloc(SPI_TEST_MAX_SIZE_PLUS, GFP_KERNEL);
1043 	if (!rx)
1044 		return -ENOMEM;
1045 
1046 
1047 	if (use_vmalloc)
1048 		tx = vmalloc(SPI_TEST_MAX_SIZE_PLUS);
1049 	else
1050 		tx = kzalloc(SPI_TEST_MAX_SIZE_PLUS, GFP_KERNEL);
1051 	if (!tx) {
1052 		ret = -ENOMEM;
1053 		goto err_tx;
1054 	}
1055 
1056 	/* now run the individual tests in the table */
1057 	for (test = tests, count = 0; test->description[0];
1058 	     test++, count++) {
1059 		/* only run test if requested */
1060 		if ((run_only_test > -1) && (count != run_only_test))
1061 			continue;
1062 		/* run custom implementation */
1063 		if (test->run_test)
1064 			ret = test->run_test(spi, test, tx, rx);
1065 		else
1066 			ret = spi_test_run_test(spi, test, tx, rx);
1067 		if (ret)
1068 			goto out;
1069 		/* add some delays so that we can easily
1070 		 * detect the individual tests when using a logic analyzer
1071 		 * we also add scheduling to avoid potential spi_timeouts...
1072 		 */
1073 		mdelay(100);
1074 		schedule();
1075 	}
1076 
1077 out:
1078 	kvfree(tx);
1079 err_tx:
1080 	kvfree(rx);
1081 	return ret;
1082 }
1083 EXPORT_SYMBOL_GPL(spi_test_run_tests);
1084