1 /*
2 * linux/drivers/mmc/core/core.c
3 *
4 * Copyright (C) 2003-2004 Russell King, All Rights Reserved.
5 * SD support Copyright (C) 2004 Ian Molton, All Rights Reserved.
6 * Copyright (C) 2005-2008 Pierre Ossman, All Rights Reserved.
7 * MMCv4 support Copyright (C) 2006 Philip Langdale, All Rights Reserved.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/completion.h>
17 #include <linux/device.h>
18 #include <linux/delay.h>
19 #include <linux/pagemap.h>
20 #include <linux/err.h>
21 #include <linux/leds.h>
22 #include <linux/scatterlist.h>
23 #include <linux/log2.h>
24 #include <linux/wakelock.h>
25
26 #include <linux/mmc/card.h>
27 #include <linux/mmc/host.h>
28 #include <linux/mmc/mmc.h>
29 #include <linux/mmc/sd.h>
30
31 #include "core.h"
32 #include "bus.h"
33 #include "host.h"
34 #include "sdio_bus.h"
35
36 #include "mmc_ops.h"
37 #include "sd_ops.h"
38 #include "sdio_ops.h"
39
40 static struct workqueue_struct *workqueue;
41 static struct wake_lock mmc_delayed_work_wake_lock;
42
43 /*
44 * Enabling software CRCs on the data blocks can be a significant (30%)
45 * performance cost, and for other reasons may not always be desired.
46 * So we allow it it to be disabled.
47 */
48 int use_spi_crc = 1;
49 module_param(use_spi_crc, bool, 0);
50
51 /*
52 * Internal function. Schedule delayed work in the MMC work queue.
53 */
mmc_schedule_delayed_work(struct delayed_work * work,unsigned long delay)54 static int mmc_schedule_delayed_work(struct delayed_work *work,
55 unsigned long delay)
56 {
57 wake_lock(&mmc_delayed_work_wake_lock);
58 return queue_delayed_work(workqueue, work, delay);
59 }
60
61 /*
62 * Internal function. Flush all scheduled work from the MMC work queue.
63 */
mmc_flush_scheduled_work(void)64 static void mmc_flush_scheduled_work(void)
65 {
66 flush_workqueue(workqueue);
67 }
68
69 /**
70 * mmc_request_done - finish processing an MMC request
71 * @host: MMC host which completed request
72 * @mrq: MMC request which request
73 *
74 * MMC drivers should call this function when they have completed
75 * their processing of a request.
76 */
mmc_request_done(struct mmc_host * host,struct mmc_request * mrq)77 void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
78 {
79 struct mmc_command *cmd = mrq->cmd;
80 int err = cmd->error;
81
82 if (err && cmd->retries && mmc_host_is_spi(host)) {
83 if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND)
84 cmd->retries = 0;
85 }
86
87 if (err && cmd->retries) {
88 pr_debug("%s: req failed (CMD%u): %d, retrying...\n",
89 mmc_hostname(host), cmd->opcode, err);
90
91 cmd->retries--;
92 cmd->error = 0;
93 host->ops->request(host, mrq);
94 } else {
95 led_trigger_event(host->led, LED_OFF);
96
97 pr_debug("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n",
98 mmc_hostname(host), cmd->opcode, err,
99 cmd->resp[0], cmd->resp[1],
100 cmd->resp[2], cmd->resp[3]);
101
102 if (mrq->data) {
103 pr_debug("%s: %d bytes transferred: %d\n",
104 mmc_hostname(host),
105 mrq->data->bytes_xfered, mrq->data->error);
106 }
107
108 if (mrq->stop) {
109 pr_debug("%s: (CMD%u): %d: %08x %08x %08x %08x\n",
110 mmc_hostname(host), mrq->stop->opcode,
111 mrq->stop->error,
112 mrq->stop->resp[0], mrq->stop->resp[1],
113 mrq->stop->resp[2], mrq->stop->resp[3]);
114 }
115
116 if (mrq->done)
117 mrq->done(mrq);
118 }
119 }
120
121 EXPORT_SYMBOL(mmc_request_done);
122
123 static void
mmc_start_request(struct mmc_host * host,struct mmc_request * mrq)124 mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
125 {
126 #ifdef CONFIG_MMC_DEBUG
127 unsigned int i, sz;
128 struct scatterlist *sg;
129 #endif
130
131 pr_debug("%s: starting CMD%u arg %08x flags %08x\n",
132 mmc_hostname(host), mrq->cmd->opcode,
133 mrq->cmd->arg, mrq->cmd->flags);
134
135 if (mrq->data) {
136 pr_debug("%s: blksz %d blocks %d flags %08x "
137 "tsac %d ms nsac %d\n",
138 mmc_hostname(host), mrq->data->blksz,
139 mrq->data->blocks, mrq->data->flags,
140 mrq->data->timeout_ns / 1000000,
141 mrq->data->timeout_clks);
142 }
143
144 if (mrq->stop) {
145 pr_debug("%s: CMD%u arg %08x flags %08x\n",
146 mmc_hostname(host), mrq->stop->opcode,
147 mrq->stop->arg, mrq->stop->flags);
148 }
149
150 WARN_ON(!host->claimed);
151
152 led_trigger_event(host->led, LED_FULL);
153
154 mrq->cmd->error = 0;
155 mrq->cmd->mrq = mrq;
156 if (mrq->data) {
157 BUG_ON(mrq->data->blksz > host->max_blk_size);
158 BUG_ON(mrq->data->blocks > host->max_blk_count);
159 BUG_ON(mrq->data->blocks * mrq->data->blksz >
160 host->max_req_size);
161
162 #ifdef CONFIG_MMC_DEBUG
163 sz = 0;
164 for_each_sg(mrq->data->sg, sg, mrq->data->sg_len, i)
165 sz += sg->length;
166 BUG_ON(sz != mrq->data->blocks * mrq->data->blksz);
167 #endif
168
169 mrq->cmd->data = mrq->data;
170 mrq->data->error = 0;
171 mrq->data->mrq = mrq;
172 if (mrq->stop) {
173 mrq->data->stop = mrq->stop;
174 mrq->stop->error = 0;
175 mrq->stop->mrq = mrq;
176 }
177 }
178 host->ops->request(host, mrq);
179 }
180
mmc_wait_done(struct mmc_request * mrq)181 static void mmc_wait_done(struct mmc_request *mrq)
182 {
183 complete(mrq->done_data);
184 }
185
186 /**
187 * mmc_wait_for_req - start a request and wait for completion
188 * @host: MMC host to start command
189 * @mrq: MMC request to start
190 *
191 * Start a new MMC custom command request for a host, and wait
192 * for the command to complete. Does not attempt to parse the
193 * response.
194 */
mmc_wait_for_req(struct mmc_host * host,struct mmc_request * mrq)195 void mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq)
196 {
197 DECLARE_COMPLETION_ONSTACK(complete);
198
199 mrq->done_data = &complete;
200 mrq->done = mmc_wait_done;
201
202 mmc_start_request(host, mrq);
203
204 wait_for_completion(&complete);
205 }
206
207 EXPORT_SYMBOL(mmc_wait_for_req);
208
209 /**
210 * mmc_wait_for_cmd - start a command and wait for completion
211 * @host: MMC host to start command
212 * @cmd: MMC command to start
213 * @retries: maximum number of retries
214 *
215 * Start a new MMC command for a host, and wait for the command
216 * to complete. Return any error that occurred while the command
217 * was executing. Do not attempt to parse the response.
218 */
mmc_wait_for_cmd(struct mmc_host * host,struct mmc_command * cmd,int retries)219 int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries)
220 {
221 struct mmc_request mrq;
222
223 WARN_ON(!host->claimed);
224
225 memset(&mrq, 0, sizeof(struct mmc_request));
226
227 memset(cmd->resp, 0, sizeof(cmd->resp));
228 cmd->retries = retries;
229
230 mrq.cmd = cmd;
231 cmd->data = NULL;
232
233 mmc_wait_for_req(host, &mrq);
234
235 return cmd->error;
236 }
237
238 EXPORT_SYMBOL(mmc_wait_for_cmd);
239
240 /**
241 * mmc_set_data_timeout - set the timeout for a data command
242 * @data: data phase for command
243 * @card: the MMC card associated with the data transfer
244 *
245 * Computes the data timeout parameters according to the
246 * correct algorithm given the card type.
247 */
mmc_set_data_timeout(struct mmc_data * data,const struct mmc_card * card)248 void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card)
249 {
250 unsigned int mult;
251
252 /*
253 * SDIO cards only define an upper 1 s limit on access.
254 */
255 if (mmc_card_sdio(card)) {
256 data->timeout_ns = 1000000000;
257 data->timeout_clks = 0;
258 return;
259 }
260
261 /*
262 * SD cards use a 100 multiplier rather than 10
263 */
264 mult = mmc_card_sd(card) ? 100 : 10;
265
266 /*
267 * Scale up the multiplier (and therefore the timeout) by
268 * the r2w factor for writes.
269 */
270 if (data->flags & MMC_DATA_WRITE)
271 mult <<= card->csd.r2w_factor;
272
273 data->timeout_ns = card->csd.tacc_ns * mult;
274 data->timeout_clks = card->csd.tacc_clks * mult;
275
276 /*
277 * SD cards also have an upper limit on the timeout.
278 */
279 if (mmc_card_sd(card)) {
280 unsigned int timeout_us, limit_us;
281
282 timeout_us = data->timeout_ns / 1000;
283 timeout_us += data->timeout_clks * 1000 /
284 (card->host->ios.clock / 1000);
285
286 if (data->flags & MMC_DATA_WRITE)
287 /*
288 * The limit is really 250 ms, but that is
289 * insufficient for some crappy cards.
290 */
291 limit_us = 300000;
292 else
293 limit_us = 100000;
294
295 /*
296 * SDHC cards always use these fixed values.
297 */
298 if (timeout_us > limit_us || mmc_card_blockaddr(card)) {
299 data->timeout_ns = limit_us * 1000;
300 data->timeout_clks = 0;
301 }
302 }
303 }
304 EXPORT_SYMBOL(mmc_set_data_timeout);
305
306 /**
307 * mmc_align_data_size - pads a transfer size to a more optimal value
308 * @card: the MMC card associated with the data transfer
309 * @sz: original transfer size
310 *
311 * Pads the original data size with a number of extra bytes in
312 * order to avoid controller bugs and/or performance hits
313 * (e.g. some controllers revert to PIO for certain sizes).
314 *
315 * Returns the improved size, which might be unmodified.
316 *
317 * Note that this function is only relevant when issuing a
318 * single scatter gather entry.
319 */
mmc_align_data_size(struct mmc_card * card,unsigned int sz)320 unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz)
321 {
322 /*
323 * FIXME: We don't have a system for the controller to tell
324 * the core about its problems yet, so for now we just 32-bit
325 * align the size.
326 */
327 sz = ((sz + 3) / 4) * 4;
328
329 return sz;
330 }
331 EXPORT_SYMBOL(mmc_align_data_size);
332
333 /**
334 * __mmc_claim_host - exclusively claim a host
335 * @host: mmc host to claim
336 * @abort: whether or not the operation should be aborted
337 *
338 * Claim a host for a set of operations. If @abort is non null and
339 * dereference a non-zero value then this will return prematurely with
340 * that non-zero value without acquiring the lock. Returns zero
341 * with the lock held otherwise.
342 */
__mmc_claim_host(struct mmc_host * host,atomic_t * abort)343 int __mmc_claim_host(struct mmc_host *host, atomic_t *abort)
344 {
345 DECLARE_WAITQUEUE(wait, current);
346 unsigned long flags;
347 int stop;
348
349 might_sleep();
350
351 add_wait_queue(&host->wq, &wait);
352 spin_lock_irqsave(&host->lock, flags);
353 while (1) {
354 set_current_state(TASK_UNINTERRUPTIBLE);
355 stop = abort ? atomic_read(abort) : 0;
356 if (stop || !host->claimed)
357 break;
358 spin_unlock_irqrestore(&host->lock, flags);
359 schedule();
360 spin_lock_irqsave(&host->lock, flags);
361 }
362 set_current_state(TASK_RUNNING);
363 if (!stop)
364 host->claimed = 1;
365 else
366 wake_up(&host->wq);
367 spin_unlock_irqrestore(&host->lock, flags);
368 remove_wait_queue(&host->wq, &wait);
369 return stop;
370 }
371
372 EXPORT_SYMBOL(__mmc_claim_host);
373
374 /**
375 * mmc_release_host - release a host
376 * @host: mmc host to release
377 *
378 * Release a MMC host, allowing others to claim the host
379 * for their operations.
380 */
mmc_release_host(struct mmc_host * host)381 void mmc_release_host(struct mmc_host *host)
382 {
383 unsigned long flags;
384
385 WARN_ON(!host->claimed);
386
387 spin_lock_irqsave(&host->lock, flags);
388 host->claimed = 0;
389 spin_unlock_irqrestore(&host->lock, flags);
390
391 wake_up(&host->wq);
392 }
393
394 EXPORT_SYMBOL(mmc_release_host);
395
396 /*
397 * Internal function that does the actual ios call to the host driver,
398 * optionally printing some debug output.
399 */
mmc_set_ios(struct mmc_host * host)400 static inline void mmc_set_ios(struct mmc_host *host)
401 {
402 struct mmc_ios *ios = &host->ios;
403
404 pr_debug("%s: clock %uHz busmode %u powermode %u cs %u Vdd %u "
405 "width %u timing %u\n",
406 mmc_hostname(host), ios->clock, ios->bus_mode,
407 ios->power_mode, ios->chip_select, ios->vdd,
408 ios->bus_width, ios->timing);
409
410 host->ops->set_ios(host, ios);
411 }
412
413 /*
414 * Control chip select pin on a host.
415 */
mmc_set_chip_select(struct mmc_host * host,int mode)416 void mmc_set_chip_select(struct mmc_host *host, int mode)
417 {
418 host->ios.chip_select = mode;
419 mmc_set_ios(host);
420 }
421
422 /*
423 * Sets the host clock to the highest possible frequency that
424 * is below "hz".
425 */
mmc_set_clock(struct mmc_host * host,unsigned int hz)426 void mmc_set_clock(struct mmc_host *host, unsigned int hz)
427 {
428 WARN_ON(hz < host->f_min);
429
430 if (hz > host->f_max)
431 hz = host->f_max;
432
433 host->ios.clock = hz;
434 mmc_set_ios(host);
435 }
436
437 /*
438 * Change the bus mode (open drain/push-pull) of a host.
439 */
mmc_set_bus_mode(struct mmc_host * host,unsigned int mode)440 void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode)
441 {
442 host->ios.bus_mode = mode;
443 mmc_set_ios(host);
444 }
445
446 /*
447 * Change data bus width of a host.
448 */
mmc_set_bus_width(struct mmc_host * host,unsigned int width)449 void mmc_set_bus_width(struct mmc_host *host, unsigned int width)
450 {
451 host->ios.bus_width = width;
452 mmc_set_ios(host);
453 }
454
455 /**
456 * mmc_vdd_to_ocrbitnum - Convert a voltage to the OCR bit number
457 * @vdd: voltage (mV)
458 * @low_bits: prefer low bits in boundary cases
459 *
460 * This function returns the OCR bit number according to the provided @vdd
461 * value. If conversion is not possible a negative errno value returned.
462 *
463 * Depending on the @low_bits flag the function prefers low or high OCR bits
464 * on boundary voltages. For example,
465 * with @low_bits = true, 3300 mV translates to ilog2(MMC_VDD_32_33);
466 * with @low_bits = false, 3300 mV translates to ilog2(MMC_VDD_33_34);
467 *
468 * Any value in the [1951:1999] range translates to the ilog2(MMC_VDD_20_21).
469 */
mmc_vdd_to_ocrbitnum(int vdd,bool low_bits)470 static int mmc_vdd_to_ocrbitnum(int vdd, bool low_bits)
471 {
472 const int max_bit = ilog2(MMC_VDD_35_36);
473 int bit;
474
475 if (vdd < 1650 || vdd > 3600)
476 return -EINVAL;
477
478 if (vdd >= 1650 && vdd <= 1950)
479 return ilog2(MMC_VDD_165_195);
480
481 if (low_bits)
482 vdd -= 1;
483
484 /* Base 2000 mV, step 100 mV, bit's base 8. */
485 bit = (vdd - 2000) / 100 + 8;
486 if (bit > max_bit)
487 return max_bit;
488 return bit;
489 }
490
491 /**
492 * mmc_vddrange_to_ocrmask - Convert a voltage range to the OCR mask
493 * @vdd_min: minimum voltage value (mV)
494 * @vdd_max: maximum voltage value (mV)
495 *
496 * This function returns the OCR mask bits according to the provided @vdd_min
497 * and @vdd_max values. If conversion is not possible the function returns 0.
498 *
499 * Notes wrt boundary cases:
500 * This function sets the OCR bits for all boundary voltages, for example
501 * [3300:3400] range is translated to MMC_VDD_32_33 | MMC_VDD_33_34 |
502 * MMC_VDD_34_35 mask.
503 */
mmc_vddrange_to_ocrmask(int vdd_min,int vdd_max)504 u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max)
505 {
506 u32 mask = 0;
507
508 if (vdd_max < vdd_min)
509 return 0;
510
511 /* Prefer high bits for the boundary vdd_max values. */
512 vdd_max = mmc_vdd_to_ocrbitnum(vdd_max, false);
513 if (vdd_max < 0)
514 return 0;
515
516 /* Prefer low bits for the boundary vdd_min values. */
517 vdd_min = mmc_vdd_to_ocrbitnum(vdd_min, true);
518 if (vdd_min < 0)
519 return 0;
520
521 /* Fill the mask, from max bit to min bit. */
522 while (vdd_max >= vdd_min)
523 mask |= 1 << vdd_max--;
524
525 return mask;
526 }
527 EXPORT_SYMBOL(mmc_vddrange_to_ocrmask);
528
529 /*
530 * Mask off any voltages we don't support and select
531 * the lowest voltage
532 */
mmc_select_voltage(struct mmc_host * host,u32 ocr)533 u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
534 {
535 int bit;
536
537 ocr &= host->ocr_avail;
538
539 bit = ffs(ocr);
540 if (bit) {
541 bit -= 1;
542
543 ocr &= 3 << bit;
544
545 host->ios.vdd = bit;
546 mmc_set_ios(host);
547 } else {
548 pr_warning("%s: host doesn't support card's voltages\n",
549 mmc_hostname(host));
550 ocr = 0;
551 }
552
553 return ocr;
554 }
555
556 /*
557 * Select timing parameters for host.
558 */
mmc_set_timing(struct mmc_host * host,unsigned int timing)559 void mmc_set_timing(struct mmc_host *host, unsigned int timing)
560 {
561 host->ios.timing = timing;
562 mmc_set_ios(host);
563 }
564
565 /*
566 * Apply power to the MMC stack. This is a two-stage process.
567 * First, we enable power to the card without the clock running.
568 * We then wait a bit for the power to stabilise. Finally,
569 * enable the bus drivers and clock to the card.
570 *
571 * We must _NOT_ enable the clock prior to power stablising.
572 *
573 * If a host does all the power sequencing itself, ignore the
574 * initial MMC_POWER_UP stage.
575 */
mmc_power_up(struct mmc_host * host)576 static void mmc_power_up(struct mmc_host *host)
577 {
578 int bit = fls(host->ocr_avail) - 1;
579
580 host->ios.vdd = bit;
581 if (mmc_host_is_spi(host)) {
582 host->ios.chip_select = MMC_CS_HIGH;
583 host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;
584 } else {
585 host->ios.chip_select = MMC_CS_DONTCARE;
586 host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
587 }
588 host->ios.power_mode = MMC_POWER_UP;
589 host->ios.bus_width = MMC_BUS_WIDTH_1;
590 host->ios.timing = MMC_TIMING_LEGACY;
591 mmc_set_ios(host);
592
593 /*
594 * This delay should be sufficient to allow the power supply
595 * to reach the minimum voltage.
596 */
597 mmc_delay(10);
598
599 host->ios.clock = host->f_min;
600 host->ios.power_mode = MMC_POWER_ON;
601 mmc_set_ios(host);
602
603 /*
604 * This delay must be at least 74 clock sizes, or 1 ms, or the
605 * time required to reach a stable voltage.
606 */
607 mmc_delay(10);
608 }
609
mmc_power_off(struct mmc_host * host)610 static void mmc_power_off(struct mmc_host *host)
611 {
612 host->ios.clock = 0;
613 host->ios.vdd = 0;
614 if (!mmc_host_is_spi(host)) {
615 host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
616 host->ios.chip_select = MMC_CS_DONTCARE;
617 }
618 host->ios.power_mode = MMC_POWER_OFF;
619 host->ios.bus_width = MMC_BUS_WIDTH_1;
620 host->ios.timing = MMC_TIMING_LEGACY;
621 mmc_set_ios(host);
622 }
623
624 /*
625 * Cleanup when the last reference to the bus operator is dropped.
626 */
__mmc_release_bus(struct mmc_host * host)627 static void __mmc_release_bus(struct mmc_host *host)
628 {
629 BUG_ON(!host);
630 BUG_ON(host->bus_refs);
631 BUG_ON(!host->bus_dead);
632
633 host->bus_ops = NULL;
634 }
635
636 /*
637 * Increase reference count of bus operator
638 */
mmc_bus_get(struct mmc_host * host)639 static inline void mmc_bus_get(struct mmc_host *host)
640 {
641 unsigned long flags;
642
643 spin_lock_irqsave(&host->lock, flags);
644 host->bus_refs++;
645 spin_unlock_irqrestore(&host->lock, flags);
646 }
647
648 /*
649 * Decrease reference count of bus operator and free it if
650 * it is the last reference.
651 */
mmc_bus_put(struct mmc_host * host)652 static inline void mmc_bus_put(struct mmc_host *host)
653 {
654 unsigned long flags;
655
656 spin_lock_irqsave(&host->lock, flags);
657 host->bus_refs--;
658 if ((host->bus_refs == 0) && host->bus_ops)
659 __mmc_release_bus(host);
660 spin_unlock_irqrestore(&host->lock, flags);
661 }
662
mmc_resume_bus(struct mmc_host * host)663 int mmc_resume_bus(struct mmc_host *host)
664 {
665 if (!mmc_bus_needs_resume(host))
666 return -EINVAL;
667
668 printk("%s: Starting deferred resume\n", mmc_hostname(host));
669 host->bus_resume_flags &= ~MMC_BUSRESUME_NEEDS_RESUME;
670 mmc_bus_get(host);
671 if (host->bus_ops && !host->bus_dead) {
672 mmc_power_up(host);
673 BUG_ON(!host->bus_ops->resume);
674 host->bus_ops->resume(host);
675 }
676
677 if (host->bus_ops->detect && !host->bus_dead)
678 host->bus_ops->detect(host);
679
680 mmc_bus_put(host);
681 printk("%s: Deferred resume completed\n", mmc_hostname(host));
682 return 0;
683 }
684
685 EXPORT_SYMBOL(mmc_resume_bus);
686
687 /*
688 * Assign a mmc bus handler to a host. Only one bus handler may control a
689 * host at any given time.
690 */
mmc_attach_bus(struct mmc_host * host,const struct mmc_bus_ops * ops)691 void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops)
692 {
693 unsigned long flags;
694
695 BUG_ON(!host);
696 BUG_ON(!ops);
697
698 WARN_ON(!host->claimed);
699
700 spin_lock_irqsave(&host->lock, flags);
701
702 BUG_ON(host->bus_ops);
703 BUG_ON(host->bus_refs);
704
705 host->bus_ops = ops;
706 host->bus_refs = 1;
707 host->bus_dead = 0;
708
709 spin_unlock_irqrestore(&host->lock, flags);
710 }
711
712 /*
713 * Remove the current bus handler from a host. Assumes that there are
714 * no interesting cards left, so the bus is powered down.
715 */
mmc_detach_bus(struct mmc_host * host)716 void mmc_detach_bus(struct mmc_host *host)
717 {
718 unsigned long flags;
719
720 BUG_ON(!host);
721
722 WARN_ON(!host->claimed);
723 WARN_ON(!host->bus_ops);
724
725 spin_lock_irqsave(&host->lock, flags);
726
727 host->bus_dead = 1;
728
729 spin_unlock_irqrestore(&host->lock, flags);
730
731 mmc_power_off(host);
732
733 mmc_bus_put(host);
734 }
735
736 /**
737 * mmc_detect_change - process change of state on a MMC socket
738 * @host: host which changed state.
739 * @delay: optional delay to wait before detection (jiffies)
740 *
741 * MMC drivers should call this when they detect a card has been
742 * inserted or removed. The MMC layer will confirm that any
743 * present card is still functional, and initialize any newly
744 * inserted.
745 */
mmc_detect_change(struct mmc_host * host,unsigned long delay)746 void mmc_detect_change(struct mmc_host *host, unsigned long delay)
747 {
748 #ifdef CONFIG_MMC_DEBUG
749 unsigned long flags;
750 spin_lock_irqsave(&host->lock, flags);
751 WARN_ON(host->removed);
752 spin_unlock_irqrestore(&host->lock, flags);
753 #endif
754
755 mmc_schedule_delayed_work(&host->detect, delay);
756 }
757
758 EXPORT_SYMBOL(mmc_detect_change);
759
760
mmc_rescan(struct work_struct * work)761 void mmc_rescan(struct work_struct *work)
762 {
763 struct mmc_host *host =
764 container_of(work, struct mmc_host, detect.work);
765 u32 ocr;
766 int err;
767 int extend_wakelock = 0;
768
769 mmc_bus_get(host);
770
771 /* if there is a card registered, check whether it is still present */
772 if ((host->bus_ops != NULL) &&
773 host->bus_ops->detect && !host->bus_dead) {
774 host->bus_ops->detect(host);
775 /* If the card was removed the bus will be marked
776 * as dead - extend the wakelock so userspace
777 * can respond */
778 if (host->bus_dead)
779 extend_wakelock = 1;
780 }
781
782 mmc_bus_put(host);
783
784
785 mmc_bus_get(host);
786
787 /* if there still is a card present, stop here */
788 if (host->bus_ops != NULL) {
789 mmc_bus_put(host);
790 goto out;
791 }
792
793 /* detect a newly inserted card */
794
795 /*
796 * Only we can add a new handler, so it's safe to
797 * release the lock here.
798 */
799 mmc_bus_put(host);
800
801 if (host->ops->get_cd && host->ops->get_cd(host) == 0)
802 goto out;
803
804 mmc_claim_host(host);
805 mmc_power_up(host);
806 mmc_go_idle(host);
807 mmc_send_if_cond(host, host->ocr_avail);
808
809 /*
810 * First we search for SDIO...
811 */
812 err = mmc_send_io_op_cond(host, 0, &ocr);
813 if (!err) {
814 if (mmc_attach_sdio(host, ocr))
815 mmc_power_off(host);
816 extend_wakelock = 1;
817 goto out;
818 }
819
820 /*
821 * ...then normal SD...
822 */
823 err = mmc_send_app_op_cond(host, 0, &ocr);
824 if (!err) {
825 if (mmc_attach_sd(host, ocr))
826 mmc_power_off(host);
827 extend_wakelock = 1;
828 goto out;
829 }
830
831 /*
832 * ...and finally MMC.
833 */
834 err = mmc_send_op_cond(host, 0, &ocr);
835 if (!err) {
836 if (mmc_attach_mmc(host, ocr))
837 mmc_power_off(host);
838 extend_wakelock = 1;
839 goto out;
840 }
841
842 mmc_release_host(host);
843 mmc_power_off(host);
844
845 out:
846 if (extend_wakelock)
847 wake_lock_timeout(&mmc_delayed_work_wake_lock, HZ / 2);
848 else
849 wake_unlock(&mmc_delayed_work_wake_lock);
850
851 if (host->caps & MMC_CAP_NEEDS_POLL)
852 mmc_schedule_delayed_work(&host->detect, HZ);
853 }
854
mmc_start_host(struct mmc_host * host)855 void mmc_start_host(struct mmc_host *host)
856 {
857 mmc_power_off(host);
858 mmc_detect_change(host, 0);
859 }
860
mmc_stop_host(struct mmc_host * host)861 void mmc_stop_host(struct mmc_host *host)
862 {
863 #ifdef CONFIG_MMC_DEBUG
864 unsigned long flags;
865 spin_lock_irqsave(&host->lock, flags);
866 host->removed = 1;
867 spin_unlock_irqrestore(&host->lock, flags);
868 #endif
869
870 cancel_delayed_work(&host->detect);
871 mmc_flush_scheduled_work();
872
873 mmc_bus_get(host);
874 if (host->bus_ops && !host->bus_dead) {
875 if (host->bus_ops->remove)
876 host->bus_ops->remove(host);
877
878 mmc_claim_host(host);
879 mmc_detach_bus(host);
880 mmc_release_host(host);
881 }
882 mmc_bus_put(host);
883
884 BUG_ON(host->card);
885
886 mmc_power_off(host);
887 }
888
889 #ifdef CONFIG_PM
890
891 /**
892 * mmc_suspend_host - suspend a host
893 * @host: mmc host
894 * @state: suspend mode (PM_SUSPEND_xxx)
895 */
mmc_suspend_host(struct mmc_host * host,pm_message_t state)896 int mmc_suspend_host(struct mmc_host *host, pm_message_t state)
897 {
898 if (mmc_bus_needs_resume(host))
899 return 0;
900
901 cancel_delayed_work(&host->detect);
902 mmc_flush_scheduled_work();
903
904 mmc_bus_get(host);
905 if (host->bus_ops && !host->bus_dead) {
906 if (host->bus_ops->suspend)
907 host->bus_ops->suspend(host);
908 if (!host->bus_ops->resume) {
909 if (host->bus_ops->remove)
910 host->bus_ops->remove(host);
911
912 mmc_claim_host(host);
913 mmc_detach_bus(host);
914 mmc_release_host(host);
915 }
916 }
917 mmc_bus_put(host);
918
919 mmc_power_off(host);
920
921 return 0;
922 }
923
924 EXPORT_SYMBOL(mmc_suspend_host);
925
926 /**
927 * mmc_resume_host - resume a previously suspended host
928 * @host: mmc host
929 */
mmc_resume_host(struct mmc_host * host)930 int mmc_resume_host(struct mmc_host *host)
931 {
932 mmc_bus_get(host);
933 if (host->bus_resume_flags & MMC_BUSRESUME_MANUAL_RESUME) {
934 host->bus_resume_flags |= MMC_BUSRESUME_NEEDS_RESUME;
935 mmc_bus_put(host);
936 return 0;
937 }
938
939 if (host->bus_ops && !host->bus_dead) {
940 mmc_power_up(host);
941 mmc_select_voltage(host, host->ocr);
942 BUG_ON(!host->bus_ops->resume);
943 host->bus_ops->resume(host);
944 }
945 mmc_bus_put(host);
946
947 /*
948 * We add a slight delay here so that resume can progress
949 * in parallel.
950 */
951 mmc_detect_change(host, 1);
952
953 return 0;
954 }
955
956 EXPORT_SYMBOL(mmc_resume_host);
957
958 #endif
959
960 #ifdef CONFIG_MMC_EMBEDDED_SDIO
mmc_set_embedded_sdio_data(struct mmc_host * host,struct sdio_cis * cis,struct sdio_cccr * cccr,struct sdio_embedded_func * funcs,int num_funcs)961 void mmc_set_embedded_sdio_data(struct mmc_host *host,
962 struct sdio_cis *cis,
963 struct sdio_cccr *cccr,
964 struct sdio_embedded_func *funcs,
965 int num_funcs)
966 {
967 host->embedded_sdio_data.cis = cis;
968 host->embedded_sdio_data.cccr = cccr;
969 host->embedded_sdio_data.funcs = funcs;
970 host->embedded_sdio_data.num_funcs = num_funcs;
971 }
972
973 EXPORT_SYMBOL(mmc_set_embedded_sdio_data);
974 #endif
975
mmc_init(void)976 static int __init mmc_init(void)
977 {
978 int ret;
979
980 wake_lock_init(&mmc_delayed_work_wake_lock, WAKE_LOCK_SUSPEND, "mmc_delayed_work");
981
982 workqueue = create_singlethread_workqueue("kmmcd");
983 if (!workqueue)
984 return -ENOMEM;
985
986 ret = mmc_register_bus();
987 if (ret)
988 goto destroy_workqueue;
989
990 ret = mmc_register_host_class();
991 if (ret)
992 goto unregister_bus;
993
994 ret = sdio_register_bus();
995 if (ret)
996 goto unregister_host_class;
997
998 return 0;
999
1000 unregister_host_class:
1001 mmc_unregister_host_class();
1002 unregister_bus:
1003 mmc_unregister_bus();
1004 destroy_workqueue:
1005 destroy_workqueue(workqueue);
1006
1007 return ret;
1008 }
1009
mmc_exit(void)1010 static void __exit mmc_exit(void)
1011 {
1012 sdio_unregister_bus();
1013 mmc_unregister_host_class();
1014 mmc_unregister_bus();
1015 destroy_workqueue(workqueue);
1016 wake_lock_destroy(&mmc_delayed_work_wake_lock);
1017 }
1018
1019 subsys_initcall(mmc_init);
1020 module_exit(mmc_exit);
1021
1022 MODULE_LICENSE("GPL");
1023