xref: /openbmc/linux/drivers/mmc/core/mmc_ops.c (revision 0da85d1e)
1 /*
2  *  linux/drivers/mmc/core/mmc_ops.h
3  *
4  *  Copyright 2006-2007 Pierre Ossman
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or (at
9  * your option) any later version.
10  */
11 
12 #include <linux/slab.h>
13 #include <linux/export.h>
14 #include <linux/types.h>
15 #include <linux/scatterlist.h>
16 
17 #include <linux/mmc/host.h>
18 #include <linux/mmc/card.h>
19 #include <linux/mmc/mmc.h>
20 
21 #include "core.h"
22 #include "mmc_ops.h"
23 
24 #define MMC_OPS_TIMEOUT_MS	(10 * 60 * 1000) /* 10 minute timeout */
25 
26 static const u8 tuning_blk_pattern_4bit[] = {
27 	0xff, 0x0f, 0xff, 0x00, 0xff, 0xcc, 0xc3, 0xcc,
28 	0xc3, 0x3c, 0xcc, 0xff, 0xfe, 0xff, 0xfe, 0xef,
29 	0xff, 0xdf, 0xff, 0xdd, 0xff, 0xfb, 0xff, 0xfb,
30 	0xbf, 0xff, 0x7f, 0xff, 0x77, 0xf7, 0xbd, 0xef,
31 	0xff, 0xf0, 0xff, 0xf0, 0x0f, 0xfc, 0xcc, 0x3c,
32 	0xcc, 0x33, 0xcc, 0xcf, 0xff, 0xef, 0xff, 0xee,
33 	0xff, 0xfd, 0xff, 0xfd, 0xdf, 0xff, 0xbf, 0xff,
34 	0xbb, 0xff, 0xf7, 0xff, 0xf7, 0x7f, 0x7b, 0xde,
35 };
36 
37 static const u8 tuning_blk_pattern_8bit[] = {
38 	0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00,
39 	0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc, 0xcc,
40 	0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff, 0xff,
41 	0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee, 0xff,
42 	0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd, 0xdd,
43 	0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff, 0xbb,
44 	0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff, 0xff,
45 	0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee, 0xff,
46 	0xff, 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00,
47 	0x00, 0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc,
48 	0xcc, 0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff,
49 	0xff, 0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee,
50 	0xff, 0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd,
51 	0xdd, 0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff,
52 	0xbb, 0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff,
53 	0xff, 0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee,
54 };
55 
56 static inline int __mmc_send_status(struct mmc_card *card, u32 *status,
57 				    bool ignore_crc)
58 {
59 	int err;
60 	struct mmc_command cmd = {0};
61 
62 	BUG_ON(!card);
63 	BUG_ON(!card->host);
64 
65 	cmd.opcode = MMC_SEND_STATUS;
66 	if (!mmc_host_is_spi(card->host))
67 		cmd.arg = card->rca << 16;
68 	cmd.flags = MMC_RSP_SPI_R2 | MMC_RSP_R1 | MMC_CMD_AC;
69 	if (ignore_crc)
70 		cmd.flags &= ~MMC_RSP_CRC;
71 
72 	err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);
73 	if (err)
74 		return err;
75 
76 	/* NOTE: callers are required to understand the difference
77 	 * between "native" and SPI format status words!
78 	 */
79 	if (status)
80 		*status = cmd.resp[0];
81 
82 	return 0;
83 }
84 
85 int mmc_send_status(struct mmc_card *card, u32 *status)
86 {
87 	return __mmc_send_status(card, status, false);
88 }
89 
90 static int _mmc_select_card(struct mmc_host *host, struct mmc_card *card)
91 {
92 	int err;
93 	struct mmc_command cmd = {0};
94 
95 	BUG_ON(!host);
96 
97 	cmd.opcode = MMC_SELECT_CARD;
98 
99 	if (card) {
100 		cmd.arg = card->rca << 16;
101 		cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
102 	} else {
103 		cmd.arg = 0;
104 		cmd.flags = MMC_RSP_NONE | MMC_CMD_AC;
105 	}
106 
107 	err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
108 	if (err)
109 		return err;
110 
111 	return 0;
112 }
113 
114 int mmc_select_card(struct mmc_card *card)
115 {
116 	BUG_ON(!card);
117 
118 	return _mmc_select_card(card->host, card);
119 }
120 
121 int mmc_deselect_cards(struct mmc_host *host)
122 {
123 	return _mmc_select_card(host, NULL);
124 }
125 
126 /*
127  * Write the value specified in the device tree or board code into the optional
128  * 16 bit Driver Stage Register. This can be used to tune raise/fall times and
129  * drive strength of the DAT and CMD outputs. The actual meaning of a given
130  * value is hardware dependant.
131  * The presence of the DSR register can be determined from the CSD register,
132  * bit 76.
133  */
134 int mmc_set_dsr(struct mmc_host *host)
135 {
136 	struct mmc_command cmd = {0};
137 
138 	cmd.opcode = MMC_SET_DSR;
139 
140 	cmd.arg = (host->dsr << 16) | 0xffff;
141 	cmd.flags = MMC_RSP_NONE | MMC_CMD_AC;
142 
143 	return mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
144 }
145 
146 int mmc_go_idle(struct mmc_host *host)
147 {
148 	int err;
149 	struct mmc_command cmd = {0};
150 
151 	/*
152 	 * Non-SPI hosts need to prevent chipselect going active during
153 	 * GO_IDLE; that would put chips into SPI mode.  Remind them of
154 	 * that in case of hardware that won't pull up DAT3/nCS otherwise.
155 	 *
156 	 * SPI hosts ignore ios.chip_select; it's managed according to
157 	 * rules that must accommodate non-MMC slaves which this layer
158 	 * won't even know about.
159 	 */
160 	if (!mmc_host_is_spi(host)) {
161 		mmc_set_chip_select(host, MMC_CS_HIGH);
162 		mmc_delay(1);
163 	}
164 
165 	cmd.opcode = MMC_GO_IDLE_STATE;
166 	cmd.arg = 0;
167 	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_NONE | MMC_CMD_BC;
168 
169 	err = mmc_wait_for_cmd(host, &cmd, 0);
170 
171 	mmc_delay(1);
172 
173 	if (!mmc_host_is_spi(host)) {
174 		mmc_set_chip_select(host, MMC_CS_DONTCARE);
175 		mmc_delay(1);
176 	}
177 
178 	host->use_spi_crc = 0;
179 
180 	return err;
181 }
182 
183 int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
184 {
185 	struct mmc_command cmd = {0};
186 	int i, err = 0;
187 
188 	BUG_ON(!host);
189 
190 	cmd.opcode = MMC_SEND_OP_COND;
191 	cmd.arg = mmc_host_is_spi(host) ? 0 : ocr;
192 	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R3 | MMC_CMD_BCR;
193 
194 	for (i = 100; i; i--) {
195 		err = mmc_wait_for_cmd(host, &cmd, 0);
196 		if (err)
197 			break;
198 
199 		/* if we're just probing, do a single pass */
200 		if (ocr == 0)
201 			break;
202 
203 		/* otherwise wait until reset completes */
204 		if (mmc_host_is_spi(host)) {
205 			if (!(cmd.resp[0] & R1_SPI_IDLE))
206 				break;
207 		} else {
208 			if (cmd.resp[0] & MMC_CARD_BUSY)
209 				break;
210 		}
211 
212 		err = -ETIMEDOUT;
213 
214 		mmc_delay(10);
215 	}
216 
217 	if (rocr && !mmc_host_is_spi(host))
218 		*rocr = cmd.resp[0];
219 
220 	return err;
221 }
222 
223 int mmc_all_send_cid(struct mmc_host *host, u32 *cid)
224 {
225 	int err;
226 	struct mmc_command cmd = {0};
227 
228 	BUG_ON(!host);
229 	BUG_ON(!cid);
230 
231 	cmd.opcode = MMC_ALL_SEND_CID;
232 	cmd.arg = 0;
233 	cmd.flags = MMC_RSP_R2 | MMC_CMD_BCR;
234 
235 	err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
236 	if (err)
237 		return err;
238 
239 	memcpy(cid, cmd.resp, sizeof(u32) * 4);
240 
241 	return 0;
242 }
243 
244 int mmc_set_relative_addr(struct mmc_card *card)
245 {
246 	int err;
247 	struct mmc_command cmd = {0};
248 
249 	BUG_ON(!card);
250 	BUG_ON(!card->host);
251 
252 	cmd.opcode = MMC_SET_RELATIVE_ADDR;
253 	cmd.arg = card->rca << 16;
254 	cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
255 
256 	err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);
257 	if (err)
258 		return err;
259 
260 	return 0;
261 }
262 
263 static int
264 mmc_send_cxd_native(struct mmc_host *host, u32 arg, u32 *cxd, int opcode)
265 {
266 	int err;
267 	struct mmc_command cmd = {0};
268 
269 	BUG_ON(!host);
270 	BUG_ON(!cxd);
271 
272 	cmd.opcode = opcode;
273 	cmd.arg = arg;
274 	cmd.flags = MMC_RSP_R2 | MMC_CMD_AC;
275 
276 	err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
277 	if (err)
278 		return err;
279 
280 	memcpy(cxd, cmd.resp, sizeof(u32) * 4);
281 
282 	return 0;
283 }
284 
285 /*
286  * NOTE: void *buf, caller for the buf is required to use DMA-capable
287  * buffer or on-stack buffer (with some overhead in callee).
288  */
289 static int
290 mmc_send_cxd_data(struct mmc_card *card, struct mmc_host *host,
291 		u32 opcode, void *buf, unsigned len)
292 {
293 	struct mmc_request mrq = {NULL};
294 	struct mmc_command cmd = {0};
295 	struct mmc_data data = {0};
296 	struct scatterlist sg;
297 
298 	mrq.cmd = &cmd;
299 	mrq.data = &data;
300 
301 	cmd.opcode = opcode;
302 	cmd.arg = 0;
303 
304 	/* NOTE HACK:  the MMC_RSP_SPI_R1 is always correct here, but we
305 	 * rely on callers to never use this with "native" calls for reading
306 	 * CSD or CID.  Native versions of those commands use the R2 type,
307 	 * not R1 plus a data block.
308 	 */
309 	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
310 
311 	data.blksz = len;
312 	data.blocks = 1;
313 	data.flags = MMC_DATA_READ;
314 	data.sg = &sg;
315 	data.sg_len = 1;
316 
317 	sg_init_one(&sg, buf, len);
318 
319 	if (opcode == MMC_SEND_CSD || opcode == MMC_SEND_CID) {
320 		/*
321 		 * The spec states that CSR and CID accesses have a timeout
322 		 * of 64 clock cycles.
323 		 */
324 		data.timeout_ns = 0;
325 		data.timeout_clks = 64;
326 	} else
327 		mmc_set_data_timeout(&data, card);
328 
329 	mmc_wait_for_req(host, &mrq);
330 
331 	if (cmd.error)
332 		return cmd.error;
333 	if (data.error)
334 		return data.error;
335 
336 	return 0;
337 }
338 
339 int mmc_send_csd(struct mmc_card *card, u32 *csd)
340 {
341 	int ret, i;
342 	u32 *csd_tmp;
343 
344 	if (!mmc_host_is_spi(card->host))
345 		return mmc_send_cxd_native(card->host, card->rca << 16,
346 				csd, MMC_SEND_CSD);
347 
348 	csd_tmp = kzalloc(16, GFP_KERNEL);
349 	if (!csd_tmp)
350 		return -ENOMEM;
351 
352 	ret = mmc_send_cxd_data(card, card->host, MMC_SEND_CSD, csd_tmp, 16);
353 	if (ret)
354 		goto err;
355 
356 	for (i = 0;i < 4;i++)
357 		csd[i] = be32_to_cpu(csd_tmp[i]);
358 
359 err:
360 	kfree(csd_tmp);
361 	return ret;
362 }
363 
364 int mmc_send_cid(struct mmc_host *host, u32 *cid)
365 {
366 	int ret, i;
367 	u32 *cid_tmp;
368 
369 	if (!mmc_host_is_spi(host)) {
370 		if (!host->card)
371 			return -EINVAL;
372 		return mmc_send_cxd_native(host, host->card->rca << 16,
373 				cid, MMC_SEND_CID);
374 	}
375 
376 	cid_tmp = kzalloc(16, GFP_KERNEL);
377 	if (!cid_tmp)
378 		return -ENOMEM;
379 
380 	ret = mmc_send_cxd_data(NULL, host, MMC_SEND_CID, cid_tmp, 16);
381 	if (ret)
382 		goto err;
383 
384 	for (i = 0;i < 4;i++)
385 		cid[i] = be32_to_cpu(cid_tmp[i]);
386 
387 err:
388 	kfree(cid_tmp);
389 	return ret;
390 }
391 
392 int mmc_get_ext_csd(struct mmc_card *card, u8 **new_ext_csd)
393 {
394 	int err;
395 	u8 *ext_csd;
396 
397 	if (!card || !new_ext_csd)
398 		return -EINVAL;
399 
400 	if (!mmc_can_ext_csd(card))
401 		return -EOPNOTSUPP;
402 
403 	/*
404 	 * As the ext_csd is so large and mostly unused, we don't store the
405 	 * raw block in mmc_card.
406 	 */
407 	ext_csd = kzalloc(512, GFP_KERNEL);
408 	if (!ext_csd)
409 		return -ENOMEM;
410 
411 	err = mmc_send_cxd_data(card, card->host, MMC_SEND_EXT_CSD, ext_csd,
412 				512);
413 	if (err)
414 		kfree(ext_csd);
415 	else
416 		*new_ext_csd = ext_csd;
417 
418 	return err;
419 }
420 EXPORT_SYMBOL_GPL(mmc_get_ext_csd);
421 
422 int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp)
423 {
424 	struct mmc_command cmd = {0};
425 	int err;
426 
427 	cmd.opcode = MMC_SPI_READ_OCR;
428 	cmd.arg = highcap ? (1 << 30) : 0;
429 	cmd.flags = MMC_RSP_SPI_R3;
430 
431 	err = mmc_wait_for_cmd(host, &cmd, 0);
432 
433 	*ocrp = cmd.resp[1];
434 	return err;
435 }
436 
437 int mmc_spi_set_crc(struct mmc_host *host, int use_crc)
438 {
439 	struct mmc_command cmd = {0};
440 	int err;
441 
442 	cmd.opcode = MMC_SPI_CRC_ON_OFF;
443 	cmd.flags = MMC_RSP_SPI_R1;
444 	cmd.arg = use_crc;
445 
446 	err = mmc_wait_for_cmd(host, &cmd, 0);
447 	if (!err)
448 		host->use_spi_crc = use_crc;
449 	return err;
450 }
451 
452 /**
453  *	__mmc_switch - modify EXT_CSD register
454  *	@card: the MMC card associated with the data transfer
455  *	@set: cmd set values
456  *	@index: EXT_CSD register index
457  *	@value: value to program into EXT_CSD register
458  *	@timeout_ms: timeout (ms) for operation performed by register write,
459  *                   timeout of zero implies maximum possible timeout
460  *	@use_busy_signal: use the busy signal as response type
461  *	@send_status: send status cmd to poll for busy
462  *	@ignore_crc: ignore CRC errors when sending status cmd to poll for busy
463  *
464  *	Modifies the EXT_CSD register for selected card.
465  */
466 int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
467 		unsigned int timeout_ms, bool use_busy_signal, bool send_status,
468 		bool ignore_crc)
469 {
470 	struct mmc_host *host = card->host;
471 	int err;
472 	struct mmc_command cmd = {0};
473 	unsigned long timeout;
474 	u32 status = 0;
475 	bool use_r1b_resp = use_busy_signal;
476 
477 	/*
478 	 * If the cmd timeout and the max_busy_timeout of the host are both
479 	 * specified, let's validate them. A failure means we need to prevent
480 	 * the host from doing hw busy detection, which is done by converting
481 	 * to a R1 response instead of a R1B.
482 	 */
483 	if (timeout_ms && host->max_busy_timeout &&
484 		(timeout_ms > host->max_busy_timeout))
485 		use_r1b_resp = false;
486 
487 	cmd.opcode = MMC_SWITCH;
488 	cmd.arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
489 		  (index << 16) |
490 		  (value << 8) |
491 		  set;
492 	cmd.flags = MMC_CMD_AC;
493 	if (use_r1b_resp) {
494 		cmd.flags |= MMC_RSP_SPI_R1B | MMC_RSP_R1B;
495 		/*
496 		 * A busy_timeout of zero means the host can decide to use
497 		 * whatever value it finds suitable.
498 		 */
499 		cmd.busy_timeout = timeout_ms;
500 	} else {
501 		cmd.flags |= MMC_RSP_SPI_R1 | MMC_RSP_R1;
502 	}
503 
504 	if (index == EXT_CSD_SANITIZE_START)
505 		cmd.sanitize_busy = true;
506 
507 	err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
508 	if (err)
509 		return err;
510 
511 	/* No need to check card status in case of unblocking command */
512 	if (!use_busy_signal)
513 		return 0;
514 
515 	/*
516 	 * CRC errors shall only be ignored in cases were CMD13 is used to poll
517 	 * to detect busy completion.
518 	 */
519 	if ((host->caps & MMC_CAP_WAIT_WHILE_BUSY) && use_r1b_resp)
520 		ignore_crc = false;
521 
522 	/* We have an unspecified cmd timeout, use the fallback value. */
523 	if (!timeout_ms)
524 		timeout_ms = MMC_OPS_TIMEOUT_MS;
525 
526 	/* Must check status to be sure of no errors. */
527 	timeout = jiffies + msecs_to_jiffies(timeout_ms);
528 	do {
529 		if (send_status) {
530 			err = __mmc_send_status(card, &status, ignore_crc);
531 			if (err)
532 				return err;
533 		}
534 		if ((host->caps & MMC_CAP_WAIT_WHILE_BUSY) && use_r1b_resp)
535 			break;
536 		if (mmc_host_is_spi(host))
537 			break;
538 
539 		/*
540 		 * We are not allowed to issue a status command and the host
541 		 * does'nt support MMC_CAP_WAIT_WHILE_BUSY, then we can only
542 		 * rely on waiting for the stated timeout to be sufficient.
543 		 */
544 		if (!send_status) {
545 			mmc_delay(timeout_ms);
546 			return 0;
547 		}
548 
549 		/* Timeout if the device never leaves the program state. */
550 		if (time_after(jiffies, timeout)) {
551 			pr_err("%s: Card stuck in programming state! %s\n",
552 				mmc_hostname(host), __func__);
553 			return -ETIMEDOUT;
554 		}
555 	} while (R1_CURRENT_STATE(status) == R1_STATE_PRG);
556 
557 	if (mmc_host_is_spi(host)) {
558 		if (status & R1_SPI_ILLEGAL_COMMAND)
559 			return -EBADMSG;
560 	} else {
561 		if (status & 0xFDFFA000)
562 			pr_warn("%s: unexpected status %#x after switch\n",
563 				mmc_hostname(host), status);
564 		if (status & R1_SWITCH_ERROR)
565 			return -EBADMSG;
566 	}
567 
568 	return 0;
569 }
570 EXPORT_SYMBOL_GPL(__mmc_switch);
571 
572 int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
573 		unsigned int timeout_ms)
574 {
575 	return __mmc_switch(card, set, index, value, timeout_ms, true, true,
576 				false);
577 }
578 EXPORT_SYMBOL_GPL(mmc_switch);
579 
580 int mmc_send_tuning(struct mmc_host *host)
581 {
582 	struct mmc_request mrq = {NULL};
583 	struct mmc_command cmd = {0};
584 	struct mmc_data data = {0};
585 	struct scatterlist sg;
586 	struct mmc_ios *ios = &host->ios;
587 	const u8 *tuning_block_pattern;
588 	int size, err = 0;
589 	u8 *data_buf;
590 	u32 opcode;
591 
592 	if (ios->bus_width == MMC_BUS_WIDTH_8) {
593 		tuning_block_pattern = tuning_blk_pattern_8bit;
594 		size = sizeof(tuning_blk_pattern_8bit);
595 		opcode = MMC_SEND_TUNING_BLOCK_HS200;
596 	} else if (ios->bus_width == MMC_BUS_WIDTH_4) {
597 		tuning_block_pattern = tuning_blk_pattern_4bit;
598 		size = sizeof(tuning_blk_pattern_4bit);
599 		opcode = MMC_SEND_TUNING_BLOCK;
600 	} else
601 		return -EINVAL;
602 
603 	data_buf = kzalloc(size, GFP_KERNEL);
604 	if (!data_buf)
605 		return -ENOMEM;
606 
607 	mrq.cmd = &cmd;
608 	mrq.data = &data;
609 
610 	cmd.opcode = opcode;
611 	cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
612 
613 	data.blksz = size;
614 	data.blocks = 1;
615 	data.flags = MMC_DATA_READ;
616 
617 	/*
618 	 * According to the tuning specs, Tuning process
619 	 * is normally shorter 40 executions of CMD19,
620 	 * and timeout value should be shorter than 150 ms
621 	 */
622 	data.timeout_ns = 150 * NSEC_PER_MSEC;
623 
624 	data.sg = &sg;
625 	data.sg_len = 1;
626 	sg_init_one(&sg, data_buf, size);
627 
628 	mmc_wait_for_req(host, &mrq);
629 
630 	if (cmd.error) {
631 		err = cmd.error;
632 		goto out;
633 	}
634 
635 	if (data.error) {
636 		err = data.error;
637 		goto out;
638 	}
639 
640 	if (memcmp(data_buf, tuning_block_pattern, size))
641 		err = -EIO;
642 
643 out:
644 	kfree(data_buf);
645 	return err;
646 }
647 EXPORT_SYMBOL_GPL(mmc_send_tuning);
648 
649 static int
650 mmc_send_bus_test(struct mmc_card *card, struct mmc_host *host, u8 opcode,
651 		  u8 len)
652 {
653 	struct mmc_request mrq = {NULL};
654 	struct mmc_command cmd = {0};
655 	struct mmc_data data = {0};
656 	struct scatterlist sg;
657 	u8 *data_buf;
658 	u8 *test_buf;
659 	int i, err;
660 	static u8 testdata_8bit[8] = { 0x55, 0xaa, 0, 0, 0, 0, 0, 0 };
661 	static u8 testdata_4bit[4] = { 0x5a, 0, 0, 0 };
662 
663 	/* dma onto stack is unsafe/nonportable, but callers to this
664 	 * routine normally provide temporary on-stack buffers ...
665 	 */
666 	data_buf = kmalloc(len, GFP_KERNEL);
667 	if (!data_buf)
668 		return -ENOMEM;
669 
670 	if (len == 8)
671 		test_buf = testdata_8bit;
672 	else if (len == 4)
673 		test_buf = testdata_4bit;
674 	else {
675 		pr_err("%s: Invalid bus_width %d\n",
676 		       mmc_hostname(host), len);
677 		kfree(data_buf);
678 		return -EINVAL;
679 	}
680 
681 	if (opcode == MMC_BUS_TEST_W)
682 		memcpy(data_buf, test_buf, len);
683 
684 	mrq.cmd = &cmd;
685 	mrq.data = &data;
686 	cmd.opcode = opcode;
687 	cmd.arg = 0;
688 
689 	/* NOTE HACK:  the MMC_RSP_SPI_R1 is always correct here, but we
690 	 * rely on callers to never use this with "native" calls for reading
691 	 * CSD or CID.  Native versions of those commands use the R2 type,
692 	 * not R1 plus a data block.
693 	 */
694 	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
695 
696 	data.blksz = len;
697 	data.blocks = 1;
698 	if (opcode == MMC_BUS_TEST_R)
699 		data.flags = MMC_DATA_READ;
700 	else
701 		data.flags = MMC_DATA_WRITE;
702 
703 	data.sg = &sg;
704 	data.sg_len = 1;
705 	mmc_set_data_timeout(&data, card);
706 	sg_init_one(&sg, data_buf, len);
707 	mmc_wait_for_req(host, &mrq);
708 	err = 0;
709 	if (opcode == MMC_BUS_TEST_R) {
710 		for (i = 0; i < len / 4; i++)
711 			if ((test_buf[i] ^ data_buf[i]) != 0xff) {
712 				err = -EIO;
713 				break;
714 			}
715 	}
716 	kfree(data_buf);
717 
718 	if (cmd.error)
719 		return cmd.error;
720 	if (data.error)
721 		return data.error;
722 
723 	return err;
724 }
725 
726 int mmc_bus_test(struct mmc_card *card, u8 bus_width)
727 {
728 	int err, width;
729 
730 	if (bus_width == MMC_BUS_WIDTH_8)
731 		width = 8;
732 	else if (bus_width == MMC_BUS_WIDTH_4)
733 		width = 4;
734 	else if (bus_width == MMC_BUS_WIDTH_1)
735 		return 0; /* no need for test */
736 	else
737 		return -EINVAL;
738 
739 	/*
740 	 * Ignore errors from BUS_TEST_W.  BUS_TEST_R will fail if there
741 	 * is a problem.  This improves chances that the test will work.
742 	 */
743 	mmc_send_bus_test(card, card->host, MMC_BUS_TEST_W, width);
744 	err = mmc_send_bus_test(card, card->host, MMC_BUS_TEST_R, width);
745 	return err;
746 }
747 
748 int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status)
749 {
750 	struct mmc_command cmd = {0};
751 	unsigned int opcode;
752 	int err;
753 
754 	if (!card->ext_csd.hpi) {
755 		pr_warn("%s: Card didn't support HPI command\n",
756 			mmc_hostname(card->host));
757 		return -EINVAL;
758 	}
759 
760 	opcode = card->ext_csd.hpi_cmd;
761 	if (opcode == MMC_STOP_TRANSMISSION)
762 		cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
763 	else if (opcode == MMC_SEND_STATUS)
764 		cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
765 
766 	cmd.opcode = opcode;
767 	cmd.arg = card->rca << 16 | 1;
768 
769 	err = mmc_wait_for_cmd(card->host, &cmd, 0);
770 	if (err) {
771 		pr_warn("%s: error %d interrupting operation. "
772 			"HPI command response %#x\n", mmc_hostname(card->host),
773 			err, cmd.resp[0]);
774 		return err;
775 	}
776 	if (status)
777 		*status = cmd.resp[0];
778 
779 	return 0;
780 }
781 
782 int mmc_can_ext_csd(struct mmc_card *card)
783 {
784 	return (card && card->csd.mmca_vsn > CSD_SPEC_VER_3);
785 }
786