Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/drivers/mmc/mmc.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
File MIME type: text/plain
File size: 20425 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* |
2 | * linux/drivers/mmc/mmc.c |
3 | * |
4 | * Copyright (C) 2003-2004 Russell King, All Rights Reserved. |
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 version 2 as |
8 | * published by the Free Software Foundation. |
9 | */ |
10 | #include <linux/config.h> |
11 | #include <linux/module.h> |
12 | #include <linux/init.h> |
13 | #include <linux/interrupt.h> |
14 | #include <linux/completion.h> |
15 | #include <linux/device.h> |
16 | #include <linux/delay.h> |
17 | #include <linux/pagemap.h> |
18 | #include <linux/err.h> |
19 | |
20 | #include <linux/mmc/card.h> |
21 | #include <linux/mmc/host.h> |
22 | #include <linux/mmc/protocol.h> |
23 | |
24 | #include "mmc.h" |
25 | |
26 | #ifdef CONFIG_MMC_DEBUG |
27 | #define DBG(x...) printk(KERN_DEBUG x) |
28 | #else |
29 | #define DBG(x...) do { } while (0) |
30 | #endif |
31 | |
32 | #define CMD_RETRIES 3 |
33 | |
34 | /* |
35 | * OCR Bit positions to 10s of Vdd mV. |
36 | */ |
37 | static const unsigned short mmc_ocr_bit_to_vdd[] = { |
38 | 150, 155, 160, 165, 170, 180, 190, 200, |
39 | 210, 220, 230, 240, 250, 260, 270, 280, |
40 | 290, 300, 310, 320, 330, 340, 350, 360 |
41 | }; |
42 | |
43 | static const unsigned int tran_exp[] = { |
44 | 10000, 100000, 1000000, 10000000, |
45 | 0, 0, 0, 0 |
46 | }; |
47 | |
48 | static const unsigned char tran_mant[] = { |
49 | 0, 10, 12, 13, 15, 20, 25, 30, |
50 | 35, 40, 45, 50, 55, 60, 70, 80, |
51 | }; |
52 | |
53 | static const unsigned int tacc_exp[] = { |
54 | 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, |
55 | }; |
56 | |
57 | static const unsigned int tacc_mant[] = { |
58 | 0, 10, 12, 13, 15, 20, 25, 30, |
59 | 35, 40, 45, 50, 55, 60, 70, 80, |
60 | }; |
61 | |
62 | |
63 | /** |
64 | * mmc_request_done - finish processing an MMC command |
65 | * @host: MMC host which completed command |
66 | * @mrq: MMC request which completed |
67 | * |
68 | * MMC drivers should call this function when they have completed |
69 | * their processing of a command. This should be called before the |
70 | * data part of the command has completed. |
71 | */ |
72 | void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq) |
73 | { |
74 | struct mmc_command *cmd = mrq->cmd; |
75 | int err = mrq->cmd->error; |
76 | DBG("MMC: req done (%02x): %d: %08x %08x %08x %08x\n", cmd->opcode, |
77 | err, cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3]); |
78 | |
79 | if (err && cmd->retries) { |
80 | cmd->retries--; |
81 | cmd->error = 0; |
82 | host->ops->request(host, mrq); |
83 | } else if (mrq->done) { |
84 | mrq->done(mrq); |
85 | } |
86 | } |
87 | |
88 | EXPORT_SYMBOL(mmc_request_done); |
89 | |
90 | /** |
91 | * mmc_start_request - start a command on a host |
92 | * @host: MMC host to start command on |
93 | * @mrq: MMC request to start |
94 | * |
95 | * Queue a command on the specified host. We expect the |
96 | * caller to be holding the host lock with interrupts disabled. |
97 | */ |
98 | void |
99 | mmc_start_request(struct mmc_host *host, struct mmc_request *mrq) |
100 | { |
101 | DBG("MMC: starting cmd %02x arg %08x flags %08x\n", |
102 | mrq->cmd->opcode, mrq->cmd->arg, mrq->cmd->flags); |
103 | |
104 | WARN_ON(host->card_busy == NULL); |
105 | |
106 | mrq->cmd->error = 0; |
107 | mrq->cmd->mrq = mrq; |
108 | if (mrq->data) { |
109 | mrq->cmd->data = mrq->data; |
110 | mrq->data->error = 0; |
111 | mrq->data->mrq = mrq; |
112 | if (mrq->stop) { |
113 | mrq->data->stop = mrq->stop; |
114 | mrq->stop->error = 0; |
115 | mrq->stop->mrq = mrq; |
116 | } |
117 | } |
118 | host->ops->request(host, mrq); |
119 | } |
120 | |
121 | EXPORT_SYMBOL(mmc_start_request); |
122 | |
123 | static void mmc_wait_done(struct mmc_request *mrq) |
124 | { |
125 | complete(mrq->done_data); |
126 | } |
127 | |
128 | int mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq) |
129 | { |
130 | DECLARE_COMPLETION(complete); |
131 | |
132 | mrq->done_data = &complete; |
133 | mrq->done = mmc_wait_done; |
134 | |
135 | mmc_start_request(host, mrq); |
136 | |
137 | wait_for_completion(&complete); |
138 | |
139 | return 0; |
140 | } |
141 | |
142 | EXPORT_SYMBOL(mmc_wait_for_req); |
143 | |
144 | /** |
145 | * mmc_wait_for_cmd - start a command and wait for completion |
146 | * @host: MMC host to start command |
147 | * @cmd: MMC command to start |
148 | * @retries: maximum number of retries |
149 | * |
150 | * Start a new MMC command for a host, and wait for the command |
151 | * to complete. Return any error that occurred while the command |
152 | * was executing. Do not attempt to parse the response. |
153 | */ |
154 | int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries) |
155 | { |
156 | struct mmc_request mrq; |
157 | |
158 | BUG_ON(host->card_busy == NULL); |
159 | |
160 | memset(&mrq, 0, sizeof(struct mmc_request)); |
161 | |
162 | memset(cmd->resp, 0, sizeof(cmd->resp)); |
163 | cmd->retries = retries; |
164 | |
165 | mrq.cmd = cmd; |
166 | cmd->data = NULL; |
167 | |
168 | mmc_wait_for_req(host, &mrq); |
169 | |
170 | return cmd->error; |
171 | } |
172 | |
173 | EXPORT_SYMBOL(mmc_wait_for_cmd); |
174 | |
175 | |
176 | |
177 | /** |
178 | * __mmc_claim_host - exclusively claim a host |
179 | * @host: mmc host to claim |
180 | * @card: mmc card to claim host for |
181 | * |
182 | * Claim a host for a set of operations. If a valid card |
183 | * is passed and this wasn't the last card selected, select |
184 | * the card before returning. |
185 | * |
186 | * Note: you should use mmc_card_claim_host or mmc_claim_host. |
187 | */ |
188 | int __mmc_claim_host(struct mmc_host *host, struct mmc_card *card) |
189 | { |
190 | DECLARE_WAITQUEUE(wait, current); |
191 | unsigned long flags; |
192 | int err = 0; |
193 | |
194 | add_wait_queue(&host->wq, &wait); |
195 | spin_lock_irqsave(&host->lock, flags); |
196 | while (1) { |
197 | set_current_state(TASK_UNINTERRUPTIBLE); |
198 | if (host->card_busy == NULL) |
199 | break; |
200 | spin_unlock_irqrestore(&host->lock, flags); |
201 | schedule(); |
202 | spin_lock_irqsave(&host->lock, flags); |
203 | } |
204 | set_current_state(TASK_RUNNING); |
205 | host->card_busy = card; |
206 | spin_unlock_irqrestore(&host->lock, flags); |
207 | remove_wait_queue(&host->wq, &wait); |
208 | |
209 | if (card != (void *)-1 && host->card_selected != card) { |
210 | struct mmc_command cmd; |
211 | |
212 | host->card_selected = card; |
213 | |
214 | cmd.opcode = MMC_SELECT_CARD; |
215 | cmd.arg = card->rca << 16; |
216 | cmd.flags = MMC_RSP_R1; |
217 | |
218 | err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES); |
219 | } |
220 | |
221 | return err; |
222 | } |
223 | |
224 | EXPORT_SYMBOL(__mmc_claim_host); |
225 | |
226 | /** |
227 | * mmc_release_host - release a host |
228 | * @host: mmc host to release |
229 | * |
230 | * Release a MMC host, allowing others to claim the host |
231 | * for their operations. |
232 | */ |
233 | void mmc_release_host(struct mmc_host *host) |
234 | { |
235 | unsigned long flags; |
236 | |
237 | BUG_ON(host->card_busy == NULL); |
238 | |
239 | spin_lock_irqsave(&host->lock, flags); |
240 | host->card_busy = NULL; |
241 | spin_unlock_irqrestore(&host->lock, flags); |
242 | |
243 | wake_up(&host->wq); |
244 | } |
245 | |
246 | EXPORT_SYMBOL(mmc_release_host); |
247 | |
248 | /* |
249 | * Ensure that no card is selected. |
250 | */ |
251 | static void mmc_deselect_cards(struct mmc_host *host) |
252 | { |
253 | struct mmc_command cmd; |
254 | |
255 | if (host->card_selected) { |
256 | host->card_selected = NULL; |
257 | |
258 | cmd.opcode = MMC_SELECT_CARD; |
259 | cmd.arg = 0; |
260 | cmd.flags = MMC_RSP_NONE; |
261 | |
262 | mmc_wait_for_cmd(host, &cmd, 0); |
263 | } |
264 | } |
265 | |
266 | |
267 | static inline void mmc_delay(unsigned int ms) |
268 | { |
269 | if (ms < HZ / 1000) { |
270 | yield(); |
271 | mdelay(ms); |
272 | } else { |
273 | msleep_interruptible (ms); |
274 | } |
275 | } |
276 | |
277 | /* |
278 | * Mask off any voltages we don't support and select |
279 | * the lowest voltage |
280 | */ |
281 | static u32 mmc_select_voltage(struct mmc_host *host, u32 ocr) |
282 | { |
283 | int bit; |
284 | |
285 | ocr &= host->ocr_avail; |
286 | |
287 | bit = ffs(ocr); |
288 | if (bit) { |
289 | bit -= 1; |
290 | |
291 | ocr = 3 << bit; |
292 | |
293 | host->ios.vdd = bit; |
294 | host->ops->set_ios(host, &host->ios); |
295 | } else { |
296 | ocr = 0; |
297 | } |
298 | |
299 | return ocr; |
300 | } |
301 | |
302 | #define UNSTUFF_BITS(resp,start,size) \ |
303 | ({ \ |
304 | const int __size = size; \ |
305 | const u32 __mask = (__size < 32 ? 1 << __size : 0) - 1; \ |
306 | const int __off = 3 - ((start) / 32); \ |
307 | const int __shft = (start) & 31; \ |
308 | u32 __res; \ |
309 | \ |
310 | __res = resp[__off] >> __shft; \ |
311 | if (__size + __shft > 32) \ |
312 | __res |= resp[__off-1] << ((32 - __shft) % 32); \ |
313 | __res & __mask; \ |
314 | }) |
315 | |
316 | /* |
317 | * Given the decoded CSD structure, decode the raw CID to our CID structure. |
318 | */ |
319 | static void mmc_decode_cid(struct mmc_card *card) |
320 | { |
321 | u32 *resp = card->raw_cid; |
322 | |
323 | memset(&card->cid, 0, sizeof(struct mmc_cid)); |
324 | |
325 | /* |
326 | * The selection of the format here is guesswork based upon |
327 | * information people have sent to date. |
328 | */ |
329 | switch (card->csd.mmca_vsn) { |
330 | case 0: /* MMC v1.? */ |
331 | case 1: /* MMC v1.4 */ |
332 | card->cid.manfid = UNSTUFF_BITS(resp, 104, 24); |
333 | card->cid.prod_name[0] = UNSTUFF_BITS(resp, 96, 8); |
334 | card->cid.prod_name[1] = UNSTUFF_BITS(resp, 88, 8); |
335 | card->cid.prod_name[2] = UNSTUFF_BITS(resp, 80, 8); |
336 | card->cid.prod_name[3] = UNSTUFF_BITS(resp, 72, 8); |
337 | card->cid.prod_name[4] = UNSTUFF_BITS(resp, 64, 8); |
338 | card->cid.prod_name[5] = UNSTUFF_BITS(resp, 56, 8); |
339 | card->cid.prod_name[6] = UNSTUFF_BITS(resp, 48, 8); |
340 | card->cid.hwrev = UNSTUFF_BITS(resp, 44, 4); |
341 | card->cid.fwrev = UNSTUFF_BITS(resp, 40, 4); |
342 | card->cid.serial = UNSTUFF_BITS(resp, 16, 24); |
343 | card->cid.month = UNSTUFF_BITS(resp, 12, 4); |
344 | card->cid.year = UNSTUFF_BITS(resp, 8, 4) + 1997; |
345 | break; |
346 | |
347 | case 2: /* MMC v2.x ? */ |
348 | case 3: /* MMC v3.x ? */ |
349 | card->cid.manfid = UNSTUFF_BITS(resp, 120, 8); |
350 | card->cid.oemid = UNSTUFF_BITS(resp, 104, 16); |
351 | card->cid.prod_name[0] = UNSTUFF_BITS(resp, 96, 8); |
352 | card->cid.prod_name[1] = UNSTUFF_BITS(resp, 88, 8); |
353 | card->cid.prod_name[2] = UNSTUFF_BITS(resp, 80, 8); |
354 | card->cid.prod_name[3] = UNSTUFF_BITS(resp, 72, 8); |
355 | card->cid.prod_name[4] = UNSTUFF_BITS(resp, 64, 8); |
356 | card->cid.prod_name[5] = UNSTUFF_BITS(resp, 56, 8); |
357 | card->cid.serial = UNSTUFF_BITS(resp, 16, 32); |
358 | card->cid.month = UNSTUFF_BITS(resp, 12, 4); |
359 | card->cid.year = UNSTUFF_BITS(resp, 8, 4) + 1997; |
360 | break; |
361 | |
362 | default: |
363 | printk("%s: card has unknown MMCA version %d\n", |
364 | card->host->host_name, card->csd.mmca_vsn); |
365 | mmc_card_set_bad(card); |
366 | break; |
367 | } |
368 | } |
369 | |
370 | /* |
371 | * Given a 128-bit response, decode to our card CSD structure. |
372 | */ |
373 | static void mmc_decode_csd(struct mmc_card *card) |
374 | { |
375 | struct mmc_csd *csd = &card->csd; |
376 | unsigned int e, m, csd_struct; |
377 | u32 *resp = card->raw_csd; |
378 | |
379 | /* |
380 | * We only understand CSD structure v1.1 and v2. |
381 | * v2 has extra information in bits 15, 11 and 10. |
382 | */ |
383 | csd_struct = UNSTUFF_BITS(resp, 126, 2); |
384 | if (csd_struct != 1 && csd_struct != 2) { |
385 | printk("%s: unrecognised CSD structure version %d\n", |
386 | card->host->host_name, csd_struct); |
387 | mmc_card_set_bad(card); |
388 | return; |
389 | } |
390 | |
391 | csd->mmca_vsn = UNSTUFF_BITS(resp, 122, 4); |
392 | m = UNSTUFF_BITS(resp, 115, 4); |
393 | e = UNSTUFF_BITS(resp, 112, 3); |
394 | csd->tacc_ns = (tacc_exp[e] * tacc_mant[m] + 9) / 10; |
395 | csd->tacc_clks = UNSTUFF_BITS(resp, 104, 8) * 100; |
396 | |
397 | m = UNSTUFF_BITS(resp, 99, 4); |
398 | e = UNSTUFF_BITS(resp, 96, 3); |
399 | csd->max_dtr = tran_exp[e] * tran_mant[m]; |
400 | csd->cmdclass = UNSTUFF_BITS(resp, 84, 12); |
401 | |
402 | e = UNSTUFF_BITS(resp, 47, 3); |
403 | m = UNSTUFF_BITS(resp, 62, 12); |
404 | csd->capacity = (1 + m) << (e + 2); |
405 | |
406 | csd->read_blkbits = UNSTUFF_BITS(resp, 80, 4); |
407 | } |
408 | |
409 | /* |
410 | * Locate a MMC card on this MMC host given a raw CID. |
411 | */ |
412 | static struct mmc_card *mmc_find_card(struct mmc_host *host, u32 *raw_cid) |
413 | { |
414 | struct mmc_card *card; |
415 | |
416 | list_for_each_entry(card, &host->cards, node) { |
417 | if (memcmp(card->raw_cid, raw_cid, sizeof(card->raw_cid)) == 0) |
418 | return card; |
419 | } |
420 | return NULL; |
421 | } |
422 | |
423 | /* |
424 | * Allocate a new MMC card, and assign a unique RCA. |
425 | */ |
426 | static struct mmc_card * |
427 | mmc_alloc_card(struct mmc_host *host, u32 *raw_cid, unsigned int *frca) |
428 | { |
429 | struct mmc_card *card, *c; |
430 | unsigned int rca = *frca; |
431 | |
432 | card = kmalloc(sizeof(struct mmc_card), GFP_KERNEL); |
433 | if (!card) |
434 | return ERR_PTR(-ENOMEM); |
435 | |
436 | mmc_init_card(card, host); |
437 | memcpy(card->raw_cid, raw_cid, sizeof(card->raw_cid)); |
438 | |
439 | again: |
440 | list_for_each_entry(c, &host->cards, node) |
441 | if (c->rca == rca) { |
442 | rca++; |
443 | goto again; |
444 | } |
445 | |
446 | card->rca = rca; |
447 | |
448 | *frca = rca; |
449 | |
450 | return card; |
451 | } |
452 | |
453 | /* |
454 | * Tell attached cards to go to IDLE state |
455 | */ |
456 | static void mmc_idle_cards(struct mmc_host *host) |
457 | { |
458 | struct mmc_command cmd; |
459 | |
460 | cmd.opcode = MMC_GO_IDLE_STATE; |
461 | cmd.arg = 0; |
462 | cmd.flags = MMC_RSP_NONE; |
463 | |
464 | mmc_wait_for_cmd(host, &cmd, 0); |
465 | |
466 | mmc_delay(1); |
467 | } |
468 | |
469 | /* |
470 | * Apply power to the MMC stack. |
471 | */ |
472 | static void mmc_power_up(struct mmc_host *host) |
473 | { |
474 | int bit = fls(host->ocr_avail) - 1; |
475 | |
476 | host->ios.vdd = bit; |
477 | host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN; |
478 | host->ios.power_mode = MMC_POWER_UP; |
479 | host->ops->set_ios(host, &host->ios); |
480 | |
481 | mmc_delay(1); |
482 | |
483 | host->ios.clock = host->f_min; |
484 | host->ios.power_mode = MMC_POWER_ON; |
485 | host->ops->set_ios(host, &host->ios); |
486 | |
487 | mmc_delay(2); |
488 | } |
489 | |
490 | static void mmc_power_off(struct mmc_host *host) |
491 | { |
492 | host->ios.clock = 0; |
493 | host->ios.vdd = 0; |
494 | host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN; |
495 | host->ios.power_mode = MMC_POWER_OFF; |
496 | host->ops->set_ios(host, &host->ios); |
497 | } |
498 | |
499 | static int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr) |
500 | { |
501 | struct mmc_command cmd; |
502 | int i, err = 0; |
503 | |
504 | cmd.opcode = MMC_SEND_OP_COND; |
505 | cmd.arg = ocr; |
506 | cmd.flags = MMC_RSP_R3; |
507 | |
508 | for (i = 100; i; i--) { |
509 | err = mmc_wait_for_cmd(host, &cmd, 0); |
510 | if (err != MMC_ERR_NONE) |
511 | break; |
512 | |
513 | if (cmd.resp[0] & MMC_CARD_BUSY || ocr == 0) |
514 | break; |
515 | |
516 | err = MMC_ERR_TIMEOUT; |
517 | |
518 | mmc_delay(10); |
519 | } |
520 | |
521 | if (rocr) |
522 | *rocr = cmd.resp[0]; |
523 | |
524 | return err; |
525 | } |
526 | |
527 | /* |
528 | * Discover cards by requesting their CID. If this command |
529 | * times out, it is not an error; there are no further cards |
530 | * to be discovered. Add new cards to the list. |
531 | * |
532 | * Create a mmc_card entry for each discovered card, assigning |
533 | * it an RCA, and save the raw CID for decoding later. |
534 | */ |
535 | static void mmc_discover_cards(struct mmc_host *host) |
536 | { |
537 | struct mmc_card *card; |
538 | unsigned int first_rca = 1, err; |
539 | |
540 | while (1) { |
541 | struct mmc_command cmd; |
542 | |
543 | cmd.opcode = MMC_ALL_SEND_CID; |
544 | cmd.arg = 0; |
545 | cmd.flags = MMC_RSP_R2; |
546 | |
547 | err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES); |
548 | if (err == MMC_ERR_TIMEOUT) { |
549 | err = MMC_ERR_NONE; |
550 | break; |
551 | } |
552 | if (err != MMC_ERR_NONE) { |
553 | printk(KERN_ERR "%s: error requesting CID: %d\n", |
554 | host->host_name, err); |
555 | break; |
556 | } |
557 | |
558 | card = mmc_find_card(host, cmd.resp); |
559 | if (!card) { |
560 | card = mmc_alloc_card(host, cmd.resp, &first_rca); |
561 | if (IS_ERR(card)) { |
562 | err = PTR_ERR(card); |
563 | break; |
564 | } |
565 | list_add(&card->node, &host->cards); |
566 | } |
567 | |
568 | card->state &= ~MMC_STATE_DEAD; |
569 | |
570 | cmd.opcode = MMC_SET_RELATIVE_ADDR; |
571 | cmd.arg = card->rca << 16; |
572 | cmd.flags = MMC_RSP_R1; |
573 | |
574 | err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES); |
575 | if (err != MMC_ERR_NONE) |
576 | mmc_card_set_dead(card); |
577 | } |
578 | } |
579 | |
580 | static void mmc_read_csds(struct mmc_host *host) |
581 | { |
582 | struct mmc_card *card; |
583 | |
584 | list_for_each_entry(card, &host->cards, node) { |
585 | struct mmc_command cmd; |
586 | int err; |
587 | |
588 | if (card->state & (MMC_STATE_DEAD|MMC_STATE_PRESENT)) |
589 | continue; |
590 | |
591 | cmd.opcode = MMC_SEND_CSD; |
592 | cmd.arg = card->rca << 16; |
593 | cmd.flags = MMC_RSP_R2; |
594 | |
595 | err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES); |
596 | if (err != MMC_ERR_NONE) { |
597 | mmc_card_set_dead(card); |
598 | continue; |
599 | } |
600 | |
601 | memcpy(card->raw_csd, cmd.resp, sizeof(card->raw_csd)); |
602 | |
603 | mmc_decode_csd(card); |
604 | mmc_decode_cid(card); |
605 | } |
606 | } |
607 | |
608 | static unsigned int mmc_calculate_clock(struct mmc_host *host) |
609 | { |
610 | struct mmc_card *card; |
611 | unsigned int max_dtr = host->f_max; |
612 | |
613 | list_for_each_entry(card, &host->cards, node) |
614 | if (!mmc_card_dead(card) && max_dtr > card->csd.max_dtr) |
615 | max_dtr = card->csd.max_dtr; |
616 | |
617 | DBG("MMC: selected %d.%03dMHz transfer rate\n", |
618 | max_dtr / 1000000, (max_dtr / 1000) % 1000); |
619 | |
620 | return max_dtr; |
621 | } |
622 | |
623 | /* |
624 | * Check whether cards we already know about are still present. |
625 | * We do this by requesting status, and checking whether a card |
626 | * responds. |
627 | * |
628 | * A request for status does not cause a state change in data |
629 | * transfer mode. |
630 | */ |
631 | static void mmc_check_cards(struct mmc_host *host) |
632 | { |
633 | struct list_head *l, *n; |
634 | |
635 | mmc_deselect_cards(host); |
636 | |
637 | list_for_each_safe(l, n, &host->cards) { |
638 | struct mmc_card *card = mmc_list_to_card(l); |
639 | struct mmc_command cmd; |
640 | int err; |
641 | |
642 | cmd.opcode = MMC_SEND_STATUS; |
643 | cmd.arg = card->rca << 16; |
644 | cmd.flags = MMC_RSP_R1; |
645 | |
646 | err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES); |
647 | if (err == MMC_ERR_NONE) |
648 | continue; |
649 | |
650 | mmc_card_set_dead(card); |
651 | } |
652 | } |
653 | |
654 | static void mmc_setup(struct mmc_host *host) |
655 | { |
656 | if (host->ios.power_mode != MMC_POWER_ON) { |
657 | int err; |
658 | u32 ocr; |
659 | |
660 | mmc_power_up(host); |
661 | mmc_idle_cards(host); |
662 | |
663 | err = mmc_send_op_cond(host, 0, &ocr); |
664 | if (err != MMC_ERR_NONE) |
665 | return; |
666 | |
667 | host->ocr = mmc_select_voltage(host, ocr); |
668 | |
669 | /* |
670 | * Since we're changing the OCR value, we seem to |
671 | * need to tell some cards to go back to the idle |
672 | * state. We wait 1ms to give cards time to |
673 | * respond. |
674 | */ |
675 | if (host->ocr) |
676 | mmc_idle_cards(host); |
677 | } else { |
678 | host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN; |
679 | host->ios.clock = host->f_min; |
680 | host->ops->set_ios(host, &host->ios); |
681 | |
682 | /* |
683 | * We should remember the OCR mask from the existing |
684 | * cards, and detect the new cards OCR mask, combine |
685 | * the two and re-select the VDD. However, if we do |
686 | * change VDD, we should do an idle, and then do a |
687 | * full re-initialisation. We would need to notify |
688 | * drivers so that they can re-setup the cards as |
689 | * well, while keeping their queues at bay. |
690 | * |
691 | * For the moment, we take the easy way out - if the |
692 | * new cards don't like our currently selected VDD, |
693 | * they drop off the bus. |
694 | */ |
695 | } |
696 | |
697 | if (host->ocr == 0) |
698 | return; |
699 | |
700 | /* |
701 | * Send the selected OCR multiple times... until the cards |
702 | * all get the idea that they should be ready for CMD2. |
703 | * (My SanDisk card seems to need this.) |
704 | */ |
705 | mmc_send_op_cond(host, host->ocr, NULL); |
706 | |
707 | mmc_discover_cards(host); |
708 | |
709 | /* |
710 | * Ok, now switch to push-pull mode. |
711 | */ |
712 | host->ios.bus_mode = MMC_BUSMODE_PUSHPULL; |
713 | host->ops->set_ios(host, &host->ios); |
714 | |
715 | mmc_read_csds(host); |
716 | } |
717 | |
718 | |
719 | /** |
720 | * mmc_detect_change - process change of state on a MMC socket |
721 | * @host: host which changed state. |
722 | * |
723 | * All we know is that card(s) have been inserted or removed |
724 | * from the socket(s). We don't know which socket or cards. |
725 | */ |
726 | void mmc_detect_change(struct mmc_host *host) |
727 | { |
728 | schedule_work(&host->detect); |
729 | } |
730 | |
731 | EXPORT_SYMBOL(mmc_detect_change); |
732 | |
733 | |
734 | static void mmc_rescan(void *data) |
735 | { |
736 | struct mmc_host *host = data; |
737 | struct list_head *l, *n; |
738 | |
739 | mmc_claim_host(host); |
740 | |
741 | if (host->ios.power_mode == MMC_POWER_ON) |
742 | mmc_check_cards(host); |
743 | |
744 | mmc_setup(host); |
745 | |
746 | if (!list_empty(&host->cards)) { |
747 | /* |
748 | * (Re-)calculate the fastest clock rate which the |
749 | * attached cards and the host support. |
750 | */ |
751 | host->ios.clock = mmc_calculate_clock(host); |
752 | host->ops->set_ios(host, &host->ios); |
753 | } |
754 | |
755 | mmc_release_host(host); |
756 | |
757 | list_for_each_safe(l, n, &host->cards) { |
758 | struct mmc_card *card = mmc_list_to_card(l); |
759 | |
760 | /* |
761 | * If this is a new and good card, register it. |
762 | */ |
763 | if (!mmc_card_present(card) && !mmc_card_dead(card)) { |
764 | if (mmc_register_card(card)) |
765 | mmc_card_set_dead(card); |
766 | else |
767 | mmc_card_set_present(card); |
768 | } |
769 | |
770 | /* |
771 | * If this card is dead, destroy it. |
772 | */ |
773 | if (mmc_card_dead(card)) { |
774 | list_del(&card->node); |
775 | mmc_remove_card(card); |
776 | } |
777 | } |
778 | |
779 | /* |
780 | * If we discover that there are no cards on the |
781 | * bus, turn off the clock and power down. |
782 | */ |
783 | if (list_empty(&host->cards)) |
784 | mmc_power_off(host); |
785 | } |
786 | |
787 | |
788 | /** |
789 | * mmc_alloc_host - initialise the per-host structure. |
790 | * @extra: sizeof private data structure |
791 | * @dev: pointer to host device model structure |
792 | * |
793 | * Initialise the per-host structure. |
794 | */ |
795 | struct mmc_host *mmc_alloc_host(int extra, struct device *dev) |
796 | { |
797 | struct mmc_host *host; |
798 | |
799 | host = kmalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL); |
800 | if (host) { |
801 | memset(host, 0, sizeof(struct mmc_host) + extra); |
802 | |
803 | spin_lock_init(&host->lock); |
804 | init_waitqueue_head(&host->wq); |
805 | INIT_LIST_HEAD(&host->cards); |
806 | INIT_WORK(&host->detect, mmc_rescan, host); |
807 | |
808 | host->dev = dev; |
809 | |
810 | /* |
811 | * By default, hosts do not support SGIO or large requests. |
812 | * They have to set these according to their abilities. |
813 | */ |
814 | host->max_hw_segs = 1; |
815 | host->max_phys_segs = 1; |
816 | host->max_sectors = 1 << (PAGE_CACHE_SHIFT - 9); |
817 | host->max_seg_size = PAGE_CACHE_SIZE; |
818 | } |
819 | |
820 | return host; |
821 | } |
822 | |
823 | EXPORT_SYMBOL(mmc_alloc_host); |
824 | |
825 | /** |
826 | * mmc_add_host - initialise host hardware |
827 | * @host: mmc host |
828 | */ |
829 | int mmc_add_host(struct mmc_host *host) |
830 | { |
831 | static unsigned int host_num; |
832 | |
833 | snprintf(host->host_name, sizeof(host->host_name), |
834 | "mmc%d", host_num++); |
835 | |
836 | mmc_power_off(host); |
837 | mmc_detect_change(host); |
838 | |
839 | return 0; |
840 | } |
841 | |
842 | EXPORT_SYMBOL(mmc_add_host); |
843 | |
844 | /** |
845 | * mmc_remove_host - remove host hardware |
846 | * @host: mmc host |
847 | * |
848 | * Unregister and remove all cards associated with this host, |
849 | * and power down the MMC bus. |
850 | */ |
851 | void mmc_remove_host(struct mmc_host *host) |
852 | { |
853 | struct list_head *l, *n; |
854 | |
855 | list_for_each_safe(l, n, &host->cards) { |
856 | struct mmc_card *card = mmc_list_to_card(l); |
857 | |
858 | mmc_remove_card(card); |
859 | } |
860 | |
861 | mmc_power_off(host); |
862 | } |
863 | |
864 | EXPORT_SYMBOL(mmc_remove_host); |
865 | |
866 | /** |
867 | * mmc_free_host - free the host structure |
868 | * @host: mmc host |
869 | * |
870 | * Free the host once all references to it have been dropped. |
871 | */ |
872 | void mmc_free_host(struct mmc_host *host) |
873 | { |
874 | flush_scheduled_work(); |
875 | kfree(host); |
876 | } |
877 | |
878 | EXPORT_SYMBOL(mmc_free_host); |
879 | |
880 | #ifdef CONFIG_PM |
881 | |
882 | /** |
883 | * mmc_suspend_host - suspend a host |
884 | * @host: mmc host |
885 | * @state: suspend mode (PM_SUSPEND_xxx) |
886 | */ |
887 | int mmc_suspend_host(struct mmc_host *host, pm_message_t state) |
888 | { |
889 | mmc_claim_host(host); |
890 | mmc_deselect_cards(host); |
891 | mmc_power_off(host); |
892 | mmc_release_host(host); |
893 | |
894 | return 0; |
895 | } |
896 | |
897 | EXPORT_SYMBOL(mmc_suspend_host); |
898 | |
899 | /** |
900 | * mmc_resume_host - resume a previously suspended host |
901 | * @host: mmc host |
902 | */ |
903 | int mmc_resume_host(struct mmc_host *host) |
904 | { |
905 | mmc_detect_change(host); |
906 | |
907 | return 0; |
908 | } |
909 | |
910 | EXPORT_SYMBOL(mmc_resume_host); |
911 | |
912 | #endif |
913 | |
914 | MODULE_LICENSE("GPL"); |