xref: /openbmc/linux/drivers/mmc/core/mmc.c (revision 6abaa0c9)
1 /*
2  *  linux/drivers/mmc/mmc.c
3  *
4  *  Copyright (C) 2003-2004 Russell King, All Rights Reserved.
5  *  Copyright (C) 2005-2007 Pierre Ossman, All Rights Reserved.
6  *  MMCv4 support Copyright (C) 2006 Philip Langdale, All Rights Reserved.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/err.h>
14 
15 #include <linux/mmc/host.h>
16 #include <linux/mmc/card.h>
17 #include <linux/mmc/mmc.h>
18 
19 #include "core.h"
20 #include "sysfs.h"
21 #include "mmc_ops.h"
22 
23 static const unsigned int tran_exp[] = {
24 	10000,		100000,		1000000,	10000000,
25 	0,		0,		0,		0
26 };
27 
28 static const unsigned char tran_mant[] = {
29 	0,	10,	12,	13,	15,	20,	25,	30,
30 	35,	40,	45,	50,	55,	60,	70,	80,
31 };
32 
33 static const unsigned int tacc_exp[] = {
34 	1,	10,	100,	1000,	10000,	100000,	1000000, 10000000,
35 };
36 
37 static const unsigned int tacc_mant[] = {
38 	0,	10,	12,	13,	15,	20,	25,	30,
39 	35,	40,	45,	50,	55,	60,	70,	80,
40 };
41 
42 #define UNSTUFF_BITS(resp,start,size)					\
43 	({								\
44 		const int __size = size;				\
45 		const u32 __mask = (__size < 32 ? 1 << __size : 0) - 1;	\
46 		const int __off = 3 - ((start) / 32);			\
47 		const int __shft = (start) & 31;			\
48 		u32 __res;						\
49 									\
50 		__res = resp[__off] >> __shft;				\
51 		if (__size + __shft > 32)				\
52 			__res |= resp[__off-1] << ((32 - __shft) % 32);	\
53 		__res & __mask;						\
54 	})
55 
56 /*
57  * Given the decoded CSD structure, decode the raw CID to our CID structure.
58  */
59 static void mmc_decode_cid(struct mmc_card *card)
60 {
61 	u32 *resp = card->raw_cid;
62 
63 	/*
64 	 * The selection of the format here is based upon published
65 	 * specs from sandisk and from what people have reported.
66 	 */
67 	switch (card->csd.mmca_vsn) {
68 	case 0: /* MMC v1.0 - v1.2 */
69 	case 1: /* MMC v1.4 */
70 		card->cid.manfid	= UNSTUFF_BITS(resp, 104, 24);
71 		card->cid.prod_name[0]	= UNSTUFF_BITS(resp, 96, 8);
72 		card->cid.prod_name[1]	= UNSTUFF_BITS(resp, 88, 8);
73 		card->cid.prod_name[2]	= UNSTUFF_BITS(resp, 80, 8);
74 		card->cid.prod_name[3]	= UNSTUFF_BITS(resp, 72, 8);
75 		card->cid.prod_name[4]	= UNSTUFF_BITS(resp, 64, 8);
76 		card->cid.prod_name[5]	= UNSTUFF_BITS(resp, 56, 8);
77 		card->cid.prod_name[6]	= UNSTUFF_BITS(resp, 48, 8);
78 		card->cid.hwrev		= UNSTUFF_BITS(resp, 44, 4);
79 		card->cid.fwrev		= UNSTUFF_BITS(resp, 40, 4);
80 		card->cid.serial	= UNSTUFF_BITS(resp, 16, 24);
81 		card->cid.month		= UNSTUFF_BITS(resp, 12, 4);
82 		card->cid.year		= UNSTUFF_BITS(resp, 8, 4) + 1997;
83 		break;
84 
85 	case 2: /* MMC v2.0 - v2.2 */
86 	case 3: /* MMC v3.1 - v3.3 */
87 	case 4: /* MMC v4 */
88 		card->cid.manfid	= UNSTUFF_BITS(resp, 120, 8);
89 		card->cid.oemid		= UNSTUFF_BITS(resp, 104, 16);
90 		card->cid.prod_name[0]	= UNSTUFF_BITS(resp, 96, 8);
91 		card->cid.prod_name[1]	= UNSTUFF_BITS(resp, 88, 8);
92 		card->cid.prod_name[2]	= UNSTUFF_BITS(resp, 80, 8);
93 		card->cid.prod_name[3]	= UNSTUFF_BITS(resp, 72, 8);
94 		card->cid.prod_name[4]	= UNSTUFF_BITS(resp, 64, 8);
95 		card->cid.prod_name[5]	= UNSTUFF_BITS(resp, 56, 8);
96 		card->cid.serial	= UNSTUFF_BITS(resp, 16, 32);
97 		card->cid.month		= UNSTUFF_BITS(resp, 12, 4);
98 		card->cid.year		= UNSTUFF_BITS(resp, 8, 4) + 1997;
99 		break;
100 
101 	default:
102 		printk("%s: card has unknown MMCA version %d\n",
103 			mmc_hostname(card->host), card->csd.mmca_vsn);
104 		mmc_card_set_bad(card);
105 		break;
106 	}
107 }
108 
109 /*
110  * Given a 128-bit response, decode to our card CSD structure.
111  */
112 static void mmc_decode_csd(struct mmc_card *card)
113 {
114 	struct mmc_csd *csd = &card->csd;
115 	unsigned int e, m, csd_struct;
116 	u32 *resp = card->raw_csd;
117 
118 	/*
119 	 * We only understand CSD structure v1.1 and v1.2.
120 	 * v1.2 has extra information in bits 15, 11 and 10.
121 	 */
122 	csd_struct = UNSTUFF_BITS(resp, 126, 2);
123 	if (csd_struct != 1 && csd_struct != 2) {
124 		printk("%s: unrecognised CSD structure version %d\n",
125 			mmc_hostname(card->host), csd_struct);
126 		mmc_card_set_bad(card);
127 		return;
128 	}
129 
130 	csd->mmca_vsn	 = UNSTUFF_BITS(resp, 122, 4);
131 	m = UNSTUFF_BITS(resp, 115, 4);
132 	e = UNSTUFF_BITS(resp, 112, 3);
133 	csd->tacc_ns	 = (tacc_exp[e] * tacc_mant[m] + 9) / 10;
134 	csd->tacc_clks	 = UNSTUFF_BITS(resp, 104, 8) * 100;
135 
136 	m = UNSTUFF_BITS(resp, 99, 4);
137 	e = UNSTUFF_BITS(resp, 96, 3);
138 	csd->max_dtr	  = tran_exp[e] * tran_mant[m];
139 	csd->cmdclass	  = UNSTUFF_BITS(resp, 84, 12);
140 
141 	e = UNSTUFF_BITS(resp, 47, 3);
142 	m = UNSTUFF_BITS(resp, 62, 12);
143 	csd->capacity	  = (1 + m) << (e + 2);
144 
145 	csd->read_blkbits = UNSTUFF_BITS(resp, 80, 4);
146 	csd->read_partial = UNSTUFF_BITS(resp, 79, 1);
147 	csd->write_misalign = UNSTUFF_BITS(resp, 78, 1);
148 	csd->read_misalign = UNSTUFF_BITS(resp, 77, 1);
149 	csd->r2w_factor = UNSTUFF_BITS(resp, 26, 3);
150 	csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4);
151 	csd->write_partial = UNSTUFF_BITS(resp, 21, 1);
152 }
153 
154 /*
155  * Read and decode extended CSD.
156  */
157 static int mmc_read_ext_csd(struct mmc_card *card)
158 {
159 	int err;
160 	u8 *ext_csd;
161 
162 	BUG_ON(!card);
163 
164 	err = MMC_ERR_FAILED;
165 
166 	if (card->csd.mmca_vsn < CSD_SPEC_VER_4)
167 		return MMC_ERR_NONE;
168 
169 	/*
170 	 * As the ext_csd is so large and mostly unused, we don't store the
171 	 * raw block in mmc_card.
172 	 */
173 	ext_csd = kmalloc(512, GFP_KERNEL);
174 	if (!ext_csd) {
175 		printk(KERN_ERR "%s: could not allocate a buffer to "
176 			"receive the ext_csd. mmc v4 cards will be "
177 			"treated as v3.\n", mmc_hostname(card->host));
178 		return MMC_ERR_FAILED;
179 	}
180 
181 	err = mmc_send_ext_csd(card, ext_csd);
182 	if (err != MMC_ERR_NONE) {
183 		/*
184 		 * High capacity cards should have this "magic" size
185 		 * stored in their CSD.
186 		 */
187 		if (card->csd.capacity == (4096 * 512)) {
188 			printk(KERN_ERR "%s: unable to read EXT_CSD "
189 				"on a possible high capacity card. "
190 				"Card will be ignored.\n",
191 				mmc_hostname(card->host));
192 		} else {
193 			printk(KERN_WARNING "%s: unable to read "
194 				"EXT_CSD, performance might "
195 				"suffer.\n",
196 				mmc_hostname(card->host));
197 			err = MMC_ERR_NONE;
198 		}
199 		goto out;
200 	}
201 
202 	card->ext_csd.sectors =
203 		ext_csd[EXT_CSD_SEC_CNT + 0] << 0 |
204 		ext_csd[EXT_CSD_SEC_CNT + 1] << 8 |
205 		ext_csd[EXT_CSD_SEC_CNT + 2] << 16 |
206 		ext_csd[EXT_CSD_SEC_CNT + 3] << 24;
207 	if (card->ext_csd.sectors)
208 		mmc_card_set_blockaddr(card);
209 
210 	switch (ext_csd[EXT_CSD_CARD_TYPE]) {
211 	case EXT_CSD_CARD_TYPE_52 | EXT_CSD_CARD_TYPE_26:
212 		card->ext_csd.hs_max_dtr = 52000000;
213 		break;
214 	case EXT_CSD_CARD_TYPE_26:
215 		card->ext_csd.hs_max_dtr = 26000000;
216 		break;
217 	default:
218 		/* MMC v4 spec says this cannot happen */
219 		printk(KERN_WARNING "%s: card is mmc v4 but doesn't "
220 			"support any high-speed modes.\n",
221 			mmc_hostname(card->host));
222 		goto out;
223 	}
224 
225 out:
226 	kfree(ext_csd);
227 
228 	return err;
229 }
230 
231 /*
232  * Handle the detection and initialisation of a card.
233  *
234  * In the case of a resume, "curcard" will contain the card
235  * we're trying to reinitialise.
236  */
237 static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
238 	struct mmc_card *oldcard)
239 {
240 	struct mmc_card *card;
241 	int err;
242 	u32 cid[4];
243 	unsigned int max_dtr;
244 
245 	BUG_ON(!host);
246 	BUG_ON(!host->claimed);
247 
248 	/*
249 	 * Since we're changing the OCR value, we seem to
250 	 * need to tell some cards to go back to the idle
251 	 * state.  We wait 1ms to give cards time to
252 	 * respond.
253 	 */
254 	mmc_go_idle(host);
255 
256 	/* The extra bit indicates that we support high capacity */
257 	err = mmc_send_op_cond(host, ocr | (1 << 30), NULL);
258 	if (err != MMC_ERR_NONE)
259 		goto err;
260 
261 	/*
262 	 * Fetch CID from card.
263 	 */
264 	err = mmc_all_send_cid(host, cid);
265 	if (err != MMC_ERR_NONE)
266 		goto err;
267 
268 	if (oldcard) {
269 		if (memcmp(cid, oldcard->raw_cid, sizeof(cid)) != 0)
270 			goto err;
271 
272 		card = oldcard;
273 	} else {
274 		/*
275 		 * Allocate card structure.
276 		 */
277 		card = mmc_alloc_card(host);
278 		if (IS_ERR(card))
279 			goto err;
280 
281 		card->type = MMC_TYPE_MMC;
282 		card->rca = 1;
283 		memcpy(card->raw_cid, cid, sizeof(card->raw_cid));
284 	}
285 
286 	/*
287 	 * Set card RCA.
288 	 */
289 	err = mmc_set_relative_addr(card);
290 	if (err != MMC_ERR_NONE)
291 		goto free_card;
292 
293 	mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
294 
295 	if (!oldcard) {
296 		/*
297 		 * Fetch CSD from card.
298 		 */
299 		err = mmc_send_csd(card, card->raw_csd);
300 		if (err != MMC_ERR_NONE)
301 			goto free_card;
302 
303 		mmc_decode_csd(card);
304 		mmc_decode_cid(card);
305 	}
306 
307 	/*
308 	 * Select card, as all following commands rely on that.
309 	 */
310 	err = mmc_select_card(card);
311 	if (err != MMC_ERR_NONE)
312 		goto free_card;
313 
314 	if (!oldcard) {
315 		/*
316 		 * Fetch and process extened CSD.
317 		 */
318 		err = mmc_read_ext_csd(card);
319 		if (err != MMC_ERR_NONE)
320 			goto free_card;
321 	}
322 
323 	/*
324 	 * Activate high speed (if supported)
325 	 */
326 	if ((card->ext_csd.hs_max_dtr != 0) &&
327 		(host->caps & MMC_CAP_MMC_HIGHSPEED)) {
328 		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
329 			EXT_CSD_HS_TIMING, 1);
330 		if (err != MMC_ERR_NONE)
331 			goto free_card;
332 
333 		mmc_card_set_highspeed(card);
334 
335 		mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
336 	}
337 
338 	/*
339 	 * Compute bus speed.
340 	 */
341 	max_dtr = (unsigned int)-1;
342 
343 	if (mmc_card_highspeed(card)) {
344 		if (max_dtr > card->ext_csd.hs_max_dtr)
345 			max_dtr = card->ext_csd.hs_max_dtr;
346 	} else if (max_dtr > card->csd.max_dtr) {
347 		max_dtr = card->csd.max_dtr;
348 	}
349 
350 	mmc_set_clock(host, max_dtr);
351 
352 	/*
353 	 * Activate wide bus (if supported).
354 	 */
355 	if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) &&
356 		(host->caps & MMC_CAP_4_BIT_DATA)) {
357 		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
358 			EXT_CSD_BUS_WIDTH, EXT_CSD_BUS_WIDTH_4);
359 		if (err != MMC_ERR_NONE)
360 			goto free_card;
361 
362 		mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
363 	}
364 
365 	if (!oldcard)
366 		host->card = card;
367 
368 	return MMC_ERR_NONE;
369 
370 free_card:
371 	if (!oldcard)
372 		mmc_remove_card(card);
373 err:
374 
375 	return MMC_ERR_FAILED;
376 }
377 
378 /*
379  * Host is being removed. Free up the current card.
380  */
381 static void mmc_remove(struct mmc_host *host)
382 {
383 	BUG_ON(!host);
384 	BUG_ON(!host->card);
385 
386 	mmc_remove_card(host->card);
387 	host->card = NULL;
388 }
389 
390 /*
391  * Card detection callback from host.
392  */
393 static void mmc_detect(struct mmc_host *host)
394 {
395 	int err;
396 
397 	BUG_ON(!host);
398 	BUG_ON(!host->card);
399 
400 	mmc_claim_host(host);
401 
402 	/*
403 	 * Just check if our card has been removed.
404 	 */
405 	err = mmc_send_status(host->card, NULL);
406 
407 	mmc_release_host(host);
408 
409 	if (err != MMC_ERR_NONE) {
410 		mmc_remove_card(host->card);
411 		host->card = NULL;
412 
413 		mmc_claim_host(host);
414 		mmc_detach_bus(host);
415 		mmc_release_host(host);
416 	}
417 }
418 
419 #ifdef CONFIG_MMC_UNSAFE_RESUME
420 
421 /*
422  * Suspend callback from host.
423  */
424 static void mmc_suspend(struct mmc_host *host)
425 {
426 	BUG_ON(!host);
427 	BUG_ON(!host->card);
428 
429 	mmc_claim_host(host);
430 	mmc_deselect_cards(host);
431 	host->card->state &= ~MMC_STATE_HIGHSPEED;
432 	mmc_release_host(host);
433 }
434 
435 /*
436  * Resume callback from host.
437  *
438  * This function tries to determine if the same card is still present
439  * and, if so, restore all state to it.
440  */
441 static void mmc_resume(struct mmc_host *host)
442 {
443 	int err;
444 
445 	BUG_ON(!host);
446 	BUG_ON(!host->card);
447 
448 	mmc_claim_host(host);
449 
450 	err = mmc_sd_init_card(host, host->ocr, host->card);
451 	if (err != MMC_ERR_NONE) {
452 		mmc_remove_card(host->card);
453 		host->card = NULL;
454 
455 		mmc_detach_bus(host);
456 	}
457 
458 	mmc_release_host(host);
459 }
460 
461 #else
462 
463 #define mmc_suspend NULL
464 #define mmc_resume NULL
465 
466 #endif
467 
468 static const struct mmc_bus_ops mmc_ops = {
469 	.remove = mmc_remove,
470 	.detect = mmc_detect,
471 	.suspend = mmc_suspend,
472 	.resume = mmc_resume,
473 };
474 
475 /*
476  * Starting point for MMC card init.
477  */
478 int mmc_attach_mmc(struct mmc_host *host, u32 ocr)
479 {
480 	int err;
481 
482 	BUG_ON(!host);
483 	BUG_ON(!host->claimed);
484 
485 	mmc_attach_bus(host, &mmc_ops);
486 
487 	/*
488 	 * Sanity check the voltages that the card claims to
489 	 * support.
490 	 */
491 	if (ocr & 0x7F) {
492 		printk(KERN_WARNING "%s: card claims to support voltages "
493 		       "below the defined range. These will be ignored.\n",
494 		       mmc_hostname(host));
495 		ocr &= ~0x7F;
496 	}
497 
498 	host->ocr = mmc_select_voltage(host, ocr);
499 
500 	/*
501 	 * Can we support the voltage of the card?
502 	 */
503 	if (!host->ocr)
504 		goto err;
505 
506 	/*
507 	 * Detect and init the card.
508 	 */
509 	err = mmc_sd_init_card(host, host->ocr, NULL);
510 	if (err != MMC_ERR_NONE)
511 		goto err;
512 
513 	mmc_release_host(host);
514 
515 	err = mmc_register_card(host->card);
516 	if (err)
517 		goto reclaim_host;
518 
519 	return 0;
520 
521 reclaim_host:
522 	mmc_claim_host(host);
523 	mmc_remove_card(host->card);
524 	host->card = NULL;
525 err:
526 	mmc_detach_bus(host);
527 	mmc_release_host(host);
528 
529 	return 0;
530 }
531 
532