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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/drivers/mmc/core/host.c
4 *
5 * Copyright (C) 2003 Russell King, All Rights Reserved.
6 * Copyright (C) 2007-2008 Pierre Ossman
7 * Copyright (C) 2010 Linus Walleij
8 *
9 * MMC host class device management
10 */
11
12#include <linux/device.h>
13#include <linux/err.h>
14#include <linux/idr.h>
15#include <linux/of.h>
16#include <linux/of_gpio.h>
17#include <linux/pagemap.h>
18#include <linux/pm_wakeup.h>
19#include <linux/export.h>
20#include <linux/leds.h>
21#include <linux/slab.h>
22
23#include <linux/mmc/host.h>
24#include <linux/mmc/card.h>
25#include <linux/mmc/slot-gpio.h>
26
27#include "core.h"
28#include "crypto.h"
29#include "host.h"
30#include "slot-gpio.h"
31#include "pwrseq.h"
32#include "sdio_ops.h"
33
34#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
35
36static DEFINE_IDA(mmc_host_ida);
37
38#ifdef CONFIG_PM_SLEEP
39static int mmc_host_class_prepare(struct device *dev)
40{
41 struct mmc_host *host = cls_dev_to_mmc_host(dev);
42
43 /*
44 * It's safe to access the bus_ops pointer, as both userspace and the
45 * workqueue for detecting cards are frozen at this point.
46 */
47 if (!host->bus_ops)
48 return 0;
49
50 /* Validate conditions for system suspend. */
51 if (host->bus_ops->pre_suspend)
52 return host->bus_ops->pre_suspend(host);
53
54 return 0;
55}
56
57static void mmc_host_class_complete(struct device *dev)
58{
59 struct mmc_host *host = cls_dev_to_mmc_host(dev);
60
61 _mmc_detect_change(host, 0, false);
62}
63
64static const struct dev_pm_ops mmc_host_class_dev_pm_ops = {
65 .prepare = mmc_host_class_prepare,
66 .complete = mmc_host_class_complete,
67};
68
69#define MMC_HOST_CLASS_DEV_PM_OPS (&mmc_host_class_dev_pm_ops)
70#else
71#define MMC_HOST_CLASS_DEV_PM_OPS NULL
72#endif
73
74static void mmc_host_classdev_release(struct device *dev)
75{
76 struct mmc_host *host = cls_dev_to_mmc_host(dev);
77 wakeup_source_unregister(host->ws);
78 if (of_alias_get_id(host->parent->of_node, "mmc") < 0)
79 ida_simple_remove(&mmc_host_ida, host->index);
80 kfree(host);
81}
82
83static int mmc_host_classdev_shutdown(struct device *dev)
84{
85 struct mmc_host *host = cls_dev_to_mmc_host(dev);
86
87 __mmc_stop_host(host);
88 return 0;
89}
90
91static struct class mmc_host_class = {
92 .name = "mmc_host",
93 .dev_release = mmc_host_classdev_release,
94 .shutdown_pre = mmc_host_classdev_shutdown,
95 .pm = MMC_HOST_CLASS_DEV_PM_OPS,
96};
97
98int mmc_register_host_class(void)
99{
100 return class_register(&mmc_host_class);
101}
102
103void mmc_unregister_host_class(void)
104{
105 class_unregister(&mmc_host_class);
106}
107
108/**
109 * mmc_retune_enable() - enter a transfer mode that requires retuning
110 * @host: host which should retune now
111 */
112void mmc_retune_enable(struct mmc_host *host)
113{
114 host->can_retune = 1;
115 if (host->retune_period)
116 mod_timer(&host->retune_timer,
117 jiffies + host->retune_period * HZ);
118}
119
120/*
121 * Pause re-tuning for a small set of operations. The pause begins after the
122 * next command.
123 */
124void mmc_retune_pause(struct mmc_host *host)
125{
126 if (!host->retune_paused) {
127 host->retune_paused = 1;
128 mmc_retune_hold(host);
129 }
130}
131EXPORT_SYMBOL(mmc_retune_pause);
132
133void mmc_retune_unpause(struct mmc_host *host)
134{
135 if (host->retune_paused) {
136 host->retune_paused = 0;
137 mmc_retune_release(host);
138 }
139}
140EXPORT_SYMBOL(mmc_retune_unpause);
141
142/**
143 * mmc_retune_disable() - exit a transfer mode that requires retuning
144 * @host: host which should not retune anymore
145 *
146 * It is not meant for temporarily preventing retuning!
147 */
148void mmc_retune_disable(struct mmc_host *host)
149{
150 mmc_retune_unpause(host);
151 host->can_retune = 0;
152 del_timer_sync(&host->retune_timer);
153 mmc_retune_clear(host);
154}
155
156void mmc_retune_timer_stop(struct mmc_host *host)
157{
158 del_timer_sync(&host->retune_timer);
159}
160EXPORT_SYMBOL(mmc_retune_timer_stop);
161
162void mmc_retune_hold(struct mmc_host *host)
163{
164 if (!host->hold_retune)
165 host->retune_now = 1;
166 host->hold_retune += 1;
167}
168
169void mmc_retune_release(struct mmc_host *host)
170{
171 if (host->hold_retune)
172 host->hold_retune -= 1;
173 else
174 WARN_ON(1);
175}
176EXPORT_SYMBOL(mmc_retune_release);
177
178int mmc_retune(struct mmc_host *host)
179{
180 bool return_to_hs400 = false;
181 int err;
182
183 if (host->retune_now)
184 host->retune_now = 0;
185 else
186 return 0;
187
188 if (!host->need_retune || host->doing_retune || !host->card)
189 return 0;
190
191 host->need_retune = 0;
192
193 host->doing_retune = 1;
194
195 if (host->ios.timing == MMC_TIMING_MMC_HS400) {
196 err = mmc_hs400_to_hs200(host->card);
197 if (err)
198 goto out;
199
200 return_to_hs400 = true;
201 }
202
203 err = mmc_execute_tuning(host->card);
204 if (err)
205 goto out;
206
207 if (return_to_hs400)
208 err = mmc_hs200_to_hs400(host->card);
209out:
210 host->doing_retune = 0;
211
212 return err;
213}
214
215static void mmc_retune_timer(struct timer_list *t)
216{
217 struct mmc_host *host = from_timer(host, t, retune_timer);
218
219 mmc_retune_needed(host);
220}
221
222static void mmc_of_parse_timing_phase(struct device *dev, const char *prop,
223 struct mmc_clk_phase *phase)
224{
225 int degrees[2] = {0};
226 int rc;
227
228 rc = device_property_read_u32_array(dev, prop, degrees, 2);
229 phase->valid = !rc;
230 if (phase->valid) {
231 phase->in_deg = degrees[0];
232 phase->out_deg = degrees[1];
233 }
234}
235
236void
237mmc_of_parse_clk_phase(struct mmc_host *host, struct mmc_clk_phase_map *map)
238{
239 struct device *dev = host->parent;
240
241 mmc_of_parse_timing_phase(dev, "clk-phase-legacy",
242 &map->phase[MMC_TIMING_LEGACY]);
243 mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs",
244 &map->phase[MMC_TIMING_MMC_HS]);
245 mmc_of_parse_timing_phase(dev, "clk-phase-sd-hs",
246 &map->phase[MMC_TIMING_SD_HS]);
247 mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr12",
248 &map->phase[MMC_TIMING_UHS_SDR12]);
249 mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr25",
250 &map->phase[MMC_TIMING_UHS_SDR25]);
251 mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr50",
252 &map->phase[MMC_TIMING_UHS_SDR50]);
253 mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr104",
254 &map->phase[MMC_TIMING_UHS_SDR104]);
255 mmc_of_parse_timing_phase(dev, "clk-phase-uhs-ddr50",
256 &map->phase[MMC_TIMING_UHS_DDR50]);
257 mmc_of_parse_timing_phase(dev, "clk-phase-mmc-ddr52",
258 &map->phase[MMC_TIMING_MMC_DDR52]);
259 mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs200",
260 &map->phase[MMC_TIMING_MMC_HS200]);
261 mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs400",
262 &map->phase[MMC_TIMING_MMC_HS400]);
263}
264EXPORT_SYMBOL(mmc_of_parse_clk_phase);
265
266/**
267 * mmc_of_parse() - parse host's device properties
268 * @host: host whose properties should be parsed.
269 *
270 * To keep the rest of the MMC subsystem unaware of whether DT has been
271 * used to instantiate and configure this host instance or not, we
272 * parse the properties and set respective generic mmc-host flags and
273 * parameters.
274 */
275int mmc_of_parse(struct mmc_host *host)
276{
277 struct device *dev = host->parent;
278 u32 bus_width, drv_type, cd_debounce_delay_ms;
279 int ret;
280
281 if (!dev || !dev_fwnode(dev))
282 return 0;
283
284 /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
285 if (device_property_read_u32(dev, "bus-width", &bus_width) < 0) {
286 dev_dbg(host->parent,
287 "\"bus-width\" property is missing, assuming 1 bit.\n");
288 bus_width = 1;
289 }
290
291 switch (bus_width) {
292 case 8:
293 host->caps |= MMC_CAP_8_BIT_DATA;
294 fallthrough; /* Hosts capable of 8-bit can also do 4 bits */
295 case 4:
296 host->caps |= MMC_CAP_4_BIT_DATA;
297 break;
298 case 1:
299 break;
300 default:
301 dev_err(host->parent,
302 "Invalid \"bus-width\" value %u!\n", bus_width);
303 return -EINVAL;
304 }
305
306 /* f_max is obtained from the optional "max-frequency" property */
307 device_property_read_u32(dev, "max-frequency", &host->f_max);
308
309 /*
310 * Configure CD and WP pins. They are both by default active low to
311 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
312 * mmc-gpio helpers are used to attach, configure and use them. If
313 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
314 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
315 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
316 * is set. If the "non-removable" property is found, the
317 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
318 * configuration is performed.
319 */
320
321 /* Parse Card Detection */
322
323 if (device_property_read_bool(dev, "non-removable")) {
324 host->caps |= MMC_CAP_NONREMOVABLE;
325 } else {
326 if (device_property_read_bool(dev, "cd-inverted"))
327 host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
328
329 if (device_property_read_u32(dev, "cd-debounce-delay-ms",
330 &cd_debounce_delay_ms))
331 cd_debounce_delay_ms = 200;
332
333 if (device_property_read_bool(dev, "broken-cd"))
334 host->caps |= MMC_CAP_NEEDS_POLL;
335
336 ret = mmc_gpiod_request_cd(host, "cd", 0, false,
337 cd_debounce_delay_ms * 1000);
338 if (!ret)
339 dev_info(host->parent, "Got CD GPIO\n");
340 else if (ret != -ENOENT && ret != -ENOSYS)
341 return ret;
342 }
343
344 /* Parse Write Protection */
345
346 if (device_property_read_bool(dev, "wp-inverted"))
347 host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
348
349 ret = mmc_gpiod_request_ro(host, "wp", 0, 0);
350 if (!ret)
351 dev_info(host->parent, "Got WP GPIO\n");
352 else if (ret != -ENOENT && ret != -ENOSYS)
353 return ret;
354
355 if (device_property_read_bool(dev, "disable-wp"))
356 host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
357
358 if (device_property_read_bool(dev, "cap-sd-highspeed"))
359 host->caps |= MMC_CAP_SD_HIGHSPEED;
360 if (device_property_read_bool(dev, "cap-mmc-highspeed"))
361 host->caps |= MMC_CAP_MMC_HIGHSPEED;
362 if (device_property_read_bool(dev, "sd-uhs-sdr12"))
363 host->caps |= MMC_CAP_UHS_SDR12;
364 if (device_property_read_bool(dev, "sd-uhs-sdr25"))
365 host->caps |= MMC_CAP_UHS_SDR25;
366 if (device_property_read_bool(dev, "sd-uhs-sdr50"))
367 host->caps |= MMC_CAP_UHS_SDR50;
368 if (device_property_read_bool(dev, "sd-uhs-sdr104"))
369 host->caps |= MMC_CAP_UHS_SDR104;
370 if (device_property_read_bool(dev, "sd-uhs-ddr50"))
371 host->caps |= MMC_CAP_UHS_DDR50;
372 if (device_property_read_bool(dev, "cap-power-off-card"))
373 host->caps |= MMC_CAP_POWER_OFF_CARD;
374 if (device_property_read_bool(dev, "cap-mmc-hw-reset"))
375 host->caps |= MMC_CAP_HW_RESET;
376 if (device_property_read_bool(dev, "cap-sdio-irq"))
377 host->caps |= MMC_CAP_SDIO_IRQ;
378 if (device_property_read_bool(dev, "full-pwr-cycle"))
379 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
380 if (device_property_read_bool(dev, "full-pwr-cycle-in-suspend"))
381 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND;
382 if (device_property_read_bool(dev, "keep-power-in-suspend"))
383 host->pm_caps |= MMC_PM_KEEP_POWER;
384 if (device_property_read_bool(dev, "wakeup-source") ||
385 device_property_read_bool(dev, "enable-sdio-wakeup")) /* legacy */
386 host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
387 if (device_property_read_bool(dev, "mmc-ddr-3_3v"))
388 host->caps |= MMC_CAP_3_3V_DDR;
389 if (device_property_read_bool(dev, "mmc-ddr-1_8v"))
390 host->caps |= MMC_CAP_1_8V_DDR;
391 if (device_property_read_bool(dev, "mmc-ddr-1_2v"))
392 host->caps |= MMC_CAP_1_2V_DDR;
393 if (device_property_read_bool(dev, "mmc-hs200-1_8v"))
394 host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
395 if (device_property_read_bool(dev, "mmc-hs200-1_2v"))
396 host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
397 if (device_property_read_bool(dev, "mmc-hs400-1_8v"))
398 host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
399 if (device_property_read_bool(dev, "mmc-hs400-1_2v"))
400 host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
401 if (device_property_read_bool(dev, "mmc-hs400-enhanced-strobe"))
402 host->caps2 |= MMC_CAP2_HS400_ES;
403 if (device_property_read_bool(dev, "no-sdio"))
404 host->caps2 |= MMC_CAP2_NO_SDIO;
405 if (device_property_read_bool(dev, "no-sd"))
406 host->caps2 |= MMC_CAP2_NO_SD;
407 if (device_property_read_bool(dev, "no-mmc"))
408 host->caps2 |= MMC_CAP2_NO_MMC;
409 if (device_property_read_bool(dev, "no-mmc-hs400"))
410 host->caps2 &= ~(MMC_CAP2_HS400_1_8V | MMC_CAP2_HS400_1_2V |
411 MMC_CAP2_HS400_ES);
412
413 /* Must be after "non-removable" check */
414 if (device_property_read_u32(dev, "fixed-emmc-driver-type", &drv_type) == 0) {
415 if (host->caps & MMC_CAP_NONREMOVABLE)
416 host->fixed_drv_type = drv_type;
417 else
418 dev_err(host->parent,
419 "can't use fixed driver type, media is removable\n");
420 }
421
422 host->dsr_req = !device_property_read_u32(dev, "dsr", &host->dsr);
423 if (host->dsr_req && (host->dsr & ~0xffff)) {
424 dev_err(host->parent,
425 "device tree specified broken value for DSR: 0x%x, ignoring\n",
426 host->dsr);
427 host->dsr_req = 0;
428 }
429
430 device_property_read_u32(dev, "post-power-on-delay-ms",
431 &host->ios.power_delay_ms);
432
433 return mmc_pwrseq_alloc(host);
434}
435
436EXPORT_SYMBOL(mmc_of_parse);
437
438/**
439 * mmc_of_parse_voltage - return mask of supported voltages
440 * @host: host whose properties should be parsed.
441 * @mask: mask of voltages available for MMC/SD/SDIO
442 *
443 * Parse the "voltage-ranges" property, returning zero if it is not
444 * found, negative errno if the voltage-range specification is invalid,
445 * or one if the voltage-range is specified and successfully parsed.
446 */
447int mmc_of_parse_voltage(struct mmc_host *host, u32 *mask)
448{
449 const char *prop = "voltage-ranges";
450 struct device *dev = host->parent;
451 u32 *voltage_ranges;
452 int num_ranges, i;
453 int ret;
454
455 if (!device_property_present(dev, prop)) {
456 dev_dbg(dev, "%s unspecified\n", prop);
457 return 0;
458 }
459
460 ret = device_property_count_u32(dev, prop);
461 if (ret < 0)
462 return ret;
463
464 num_ranges = ret / 2;
465 if (!num_ranges) {
466 dev_err(dev, "%s empty\n", prop);
467 return -EINVAL;
468 }
469
470 voltage_ranges = kcalloc(2 * num_ranges, sizeof(*voltage_ranges), GFP_KERNEL);
471 if (!voltage_ranges)
472 return -ENOMEM;
473
474 ret = device_property_read_u32_array(dev, prop, voltage_ranges, 2 * num_ranges);
475 if (ret) {
476 kfree(voltage_ranges);
477 return ret;
478 }
479
480 for (i = 0; i < num_ranges; i++) {
481 const int j = i * 2;
482 u32 ocr_mask;
483
484 ocr_mask = mmc_vddrange_to_ocrmask(voltage_ranges[j + 0],
485 voltage_ranges[j + 1]);
486 if (!ocr_mask) {
487 dev_err(dev, "range #%d in %s is invalid\n", i, prop);
488 kfree(voltage_ranges);
489 return -EINVAL;
490 }
491 *mask |= ocr_mask;
492 }
493
494 kfree(voltage_ranges);
495
496 return 1;
497}
498EXPORT_SYMBOL(mmc_of_parse_voltage);
499
500/**
501 * mmc_first_nonreserved_index() - get the first index that is not reserved
502 */
503static int mmc_first_nonreserved_index(void)
504{
505 int max;
506
507 max = of_alias_get_highest_id("mmc");
508 if (max < 0)
509 return 0;
510
511 return max + 1;
512}
513
514/**
515 * mmc_alloc_host - initialise the per-host structure.
516 * @extra: sizeof private data structure
517 * @dev: pointer to host device model structure
518 *
519 * Initialise the per-host structure.
520 */
521struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
522{
523 int index;
524 struct mmc_host *host;
525 int alias_id, min_idx, max_idx;
526
527 host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
528 if (!host)
529 return NULL;
530
531 /* scanning will be enabled when we're ready */
532 host->rescan_disable = 1;
533
534 alias_id = of_alias_get_id(dev->of_node, "mmc");
535 if (alias_id >= 0) {
536 index = alias_id;
537 } else {
538 min_idx = mmc_first_nonreserved_index();
539 max_idx = 0;
540
541 index = ida_simple_get(&mmc_host_ida, min_idx, max_idx, GFP_KERNEL);
542 if (index < 0) {
543 kfree(host);
544 return NULL;
545 }
546 }
547
548 host->index = index;
549
550 dev_set_name(&host->class_dev, "mmc%d", host->index);
551 host->ws = wakeup_source_register(NULL, dev_name(&host->class_dev));
552
553 host->parent = dev;
554 host->class_dev.parent = dev;
555 host->class_dev.class = &mmc_host_class;
556 device_initialize(&host->class_dev);
557 device_enable_async_suspend(&host->class_dev);
558
559 if (mmc_gpio_alloc(host)) {
560 put_device(&host->class_dev);
561 return NULL;
562 }
563
564 spin_lock_init(&host->lock);
565 init_waitqueue_head(&host->wq);
566 INIT_DELAYED_WORK(&host->detect, mmc_rescan);
567 INIT_WORK(&host->sdio_irq_work, sdio_irq_work);
568 timer_setup(&host->retune_timer, mmc_retune_timer, 0);
569
570 /*
571 * By default, hosts do not support SGIO or large requests.
572 * They have to set these according to their abilities.
573 */
574 host->max_segs = 1;
575 host->max_seg_size = PAGE_SIZE;
576
577 host->max_req_size = PAGE_SIZE;
578 host->max_blk_size = 512;
579 host->max_blk_count = PAGE_SIZE / 512;
580
581 host->fixed_drv_type = -EINVAL;
582 host->ios.power_delay_ms = 10;
583 host->ios.power_mode = MMC_POWER_UNDEFINED;
584
585 return host;
586}
587
588EXPORT_SYMBOL(mmc_alloc_host);
589
590static void devm_mmc_host_release(struct device *dev, void *res)
591{
592 mmc_free_host(*(struct mmc_host **)res);
593}
594
595struct mmc_host *devm_mmc_alloc_host(struct device *dev, int extra)
596{
597 struct mmc_host **dr, *host;
598
599 dr = devres_alloc(devm_mmc_host_release, sizeof(*dr), GFP_KERNEL);
600 if (!dr)
601 return NULL;
602
603 host = mmc_alloc_host(extra, dev);
604 if (!host) {
605 devres_free(dr);
606 return NULL;
607 }
608
609 *dr = host;
610 devres_add(dev, dr);
611
612 return host;
613}
614EXPORT_SYMBOL(devm_mmc_alloc_host);
615
616static int mmc_validate_host_caps(struct mmc_host *host)
617{
618 struct device *dev = host->parent;
619 u32 caps = host->caps, caps2 = host->caps2;
620
621 if (caps & MMC_CAP_SDIO_IRQ && !host->ops->enable_sdio_irq) {
622 dev_warn(dev, "missing ->enable_sdio_irq() ops\n");
623 return -EINVAL;
624 }
625
626 if (caps2 & (MMC_CAP2_HS400_ES | MMC_CAP2_HS400) &&
627 !(caps & MMC_CAP_8_BIT_DATA) && !(caps2 & MMC_CAP2_NO_MMC)) {
628 dev_warn(dev, "drop HS400 support since no 8-bit bus\n");
629 host->caps2 = caps2 & ~MMC_CAP2_HS400_ES & ~MMC_CAP2_HS400;
630 }
631
632 return 0;
633}
634
635/**
636 * mmc_add_host - initialise host hardware
637 * @host: mmc host
638 *
639 * Register the host with the driver model. The host must be
640 * prepared to start servicing requests before this function
641 * completes.
642 */
643int mmc_add_host(struct mmc_host *host)
644{
645 int err;
646
647 err = mmc_validate_host_caps(host);
648 if (err)
649 return err;
650
651 err = device_add(&host->class_dev);
652 if (err)
653 return err;
654
655 led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
656
657 mmc_add_host_debugfs(host);
658
659 mmc_start_host(host);
660 return 0;
661}
662
663EXPORT_SYMBOL(mmc_add_host);
664
665/**
666 * mmc_remove_host - remove host hardware
667 * @host: mmc host
668 *
669 * Unregister and remove all cards associated with this host,
670 * and power down the MMC bus. No new requests will be issued
671 * after this function has returned.
672 */
673void mmc_remove_host(struct mmc_host *host)
674{
675 mmc_stop_host(host);
676
677 mmc_remove_host_debugfs(host);
678
679 device_del(&host->class_dev);
680
681 led_trigger_unregister_simple(host->led);
682}
683
684EXPORT_SYMBOL(mmc_remove_host);
685
686/**
687 * mmc_free_host - free the host structure
688 * @host: mmc host
689 *
690 * Free the host once all references to it have been dropped.
691 */
692void mmc_free_host(struct mmc_host *host)
693{
694 cancel_delayed_work_sync(&host->detect);
695 mmc_pwrseq_free(host);
696 put_device(&host->class_dev);
697}
698
699EXPORT_SYMBOL(mmc_free_host);
1/*
2 * linux/drivers/mmc/core/host.c
3 *
4 * Copyright (C) 2003 Russell King, All Rights Reserved.
5 * Copyright (C) 2007-2008 Pierre Ossman
6 * Copyright (C) 2010 Linus Walleij
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 * MMC host class device management
13 */
14
15#include <linux/device.h>
16#include <linux/err.h>
17#include <linux/idr.h>
18#include <linux/pagemap.h>
19#include <linux/leds.h>
20#include <linux/slab.h>
21#include <linux/suspend.h>
22
23#include <linux/mmc/host.h>
24#include <linux/mmc/card.h>
25
26#include "core.h"
27#include "host.h"
28
29#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
30
31static void mmc_host_classdev_release(struct device *dev)
32{
33 struct mmc_host *host = cls_dev_to_mmc_host(dev);
34 kfree(host);
35}
36
37static struct class mmc_host_class = {
38 .name = "mmc_host",
39 .dev_release = mmc_host_classdev_release,
40};
41
42int mmc_register_host_class(void)
43{
44 return class_register(&mmc_host_class);
45}
46
47void mmc_unregister_host_class(void)
48{
49 class_unregister(&mmc_host_class);
50}
51
52static DEFINE_IDR(mmc_host_idr);
53static DEFINE_SPINLOCK(mmc_host_lock);
54
55#ifdef CONFIG_MMC_CLKGATE
56
57/*
58 * Enabling clock gating will make the core call out to the host
59 * once up and once down when it performs a request or card operation
60 * intermingled in any fashion. The driver will see this through
61 * set_ios() operations with ios.clock field set to 0 to gate (disable)
62 * the block clock, and to the old frequency to enable it again.
63 */
64static void mmc_host_clk_gate_delayed(struct mmc_host *host)
65{
66 unsigned long tick_ns;
67 unsigned long freq = host->ios.clock;
68 unsigned long flags;
69
70 if (!freq) {
71 pr_debug("%s: frequency set to 0 in disable function, "
72 "this means the clock is already disabled.\n",
73 mmc_hostname(host));
74 return;
75 }
76 /*
77 * New requests may have appeared while we were scheduling,
78 * then there is no reason to delay the check before
79 * clk_disable().
80 */
81 spin_lock_irqsave(&host->clk_lock, flags);
82
83 /*
84 * Delay n bus cycles (at least 8 from MMC spec) before attempting
85 * to disable the MCI block clock. The reference count may have
86 * gone up again after this delay due to rescheduling!
87 */
88 if (!host->clk_requests) {
89 spin_unlock_irqrestore(&host->clk_lock, flags);
90 tick_ns = DIV_ROUND_UP(1000000000, freq);
91 ndelay(host->clk_delay * tick_ns);
92 } else {
93 /* New users appeared while waiting for this work */
94 spin_unlock_irqrestore(&host->clk_lock, flags);
95 return;
96 }
97 mutex_lock(&host->clk_gate_mutex);
98 spin_lock_irqsave(&host->clk_lock, flags);
99 if (!host->clk_requests) {
100 spin_unlock_irqrestore(&host->clk_lock, flags);
101 /* This will set host->ios.clock to 0 */
102 mmc_gate_clock(host);
103 spin_lock_irqsave(&host->clk_lock, flags);
104 pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
105 }
106 spin_unlock_irqrestore(&host->clk_lock, flags);
107 mutex_unlock(&host->clk_gate_mutex);
108}
109
110/*
111 * Internal work. Work to disable the clock at some later point.
112 */
113static void mmc_host_clk_gate_work(struct work_struct *work)
114{
115 struct mmc_host *host = container_of(work, struct mmc_host,
116 clk_gate_work);
117
118 mmc_host_clk_gate_delayed(host);
119}
120
121/**
122 * mmc_host_clk_hold - ungate hardware MCI clocks
123 * @host: host to ungate.
124 *
125 * Makes sure the host ios.clock is restored to a non-zero value
126 * past this call. Increase clock reference count and ungate clock
127 * if we're the first user.
128 */
129void mmc_host_clk_hold(struct mmc_host *host)
130{
131 unsigned long flags;
132
133 mutex_lock(&host->clk_gate_mutex);
134 spin_lock_irqsave(&host->clk_lock, flags);
135 if (host->clk_gated) {
136 spin_unlock_irqrestore(&host->clk_lock, flags);
137 mmc_ungate_clock(host);
138 spin_lock_irqsave(&host->clk_lock, flags);
139 pr_debug("%s: ungated MCI clock\n", mmc_hostname(host));
140 }
141 host->clk_requests++;
142 spin_unlock_irqrestore(&host->clk_lock, flags);
143 mutex_unlock(&host->clk_gate_mutex);
144}
145
146/**
147 * mmc_host_may_gate_card - check if this card may be gated
148 * @card: card to check.
149 */
150static bool mmc_host_may_gate_card(struct mmc_card *card)
151{
152 /* If there is no card we may gate it */
153 if (!card)
154 return true;
155 /*
156 * Don't gate SDIO cards! These need to be clocked at all times
157 * since they may be independent systems generating interrupts
158 * and other events. The clock requests counter from the core will
159 * go down to zero since the core does not need it, but we will not
160 * gate the clock, because there is somebody out there that may still
161 * be using it.
162 */
163 return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING);
164}
165
166/**
167 * mmc_host_clk_release - gate off hardware MCI clocks
168 * @host: host to gate.
169 *
170 * Calls the host driver with ios.clock set to zero as often as possible
171 * in order to gate off hardware MCI clocks. Decrease clock reference
172 * count and schedule disabling of clock.
173 */
174void mmc_host_clk_release(struct mmc_host *host)
175{
176 unsigned long flags;
177
178 spin_lock_irqsave(&host->clk_lock, flags);
179 host->clk_requests--;
180 if (mmc_host_may_gate_card(host->card) &&
181 !host->clk_requests)
182 queue_work(system_nrt_wq, &host->clk_gate_work);
183 spin_unlock_irqrestore(&host->clk_lock, flags);
184}
185
186/**
187 * mmc_host_clk_rate - get current clock frequency setting
188 * @host: host to get the clock frequency for.
189 *
190 * Returns current clock frequency regardless of gating.
191 */
192unsigned int mmc_host_clk_rate(struct mmc_host *host)
193{
194 unsigned long freq;
195 unsigned long flags;
196
197 spin_lock_irqsave(&host->clk_lock, flags);
198 if (host->clk_gated)
199 freq = host->clk_old;
200 else
201 freq = host->ios.clock;
202 spin_unlock_irqrestore(&host->clk_lock, flags);
203 return freq;
204}
205
206/**
207 * mmc_host_clk_init - set up clock gating code
208 * @host: host with potential clock to control
209 */
210static inline void mmc_host_clk_init(struct mmc_host *host)
211{
212 host->clk_requests = 0;
213 /* Hold MCI clock for 8 cycles by default */
214 host->clk_delay = 8;
215 host->clk_gated = false;
216 INIT_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
217 spin_lock_init(&host->clk_lock);
218 mutex_init(&host->clk_gate_mutex);
219}
220
221/**
222 * mmc_host_clk_exit - shut down clock gating code
223 * @host: host with potential clock to control
224 */
225static inline void mmc_host_clk_exit(struct mmc_host *host)
226{
227 /*
228 * Wait for any outstanding gate and then make sure we're
229 * ungated before exiting.
230 */
231 if (cancel_work_sync(&host->clk_gate_work))
232 mmc_host_clk_gate_delayed(host);
233 if (host->clk_gated)
234 mmc_host_clk_hold(host);
235 /* There should be only one user now */
236 WARN_ON(host->clk_requests > 1);
237}
238
239#else
240
241static inline void mmc_host_clk_init(struct mmc_host *host)
242{
243}
244
245static inline void mmc_host_clk_exit(struct mmc_host *host)
246{
247}
248
249#endif
250
251/**
252 * mmc_alloc_host - initialise the per-host structure.
253 * @extra: sizeof private data structure
254 * @dev: pointer to host device model structure
255 *
256 * Initialise the per-host structure.
257 */
258struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
259{
260 int err;
261 struct mmc_host *host;
262
263 if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
264 return NULL;
265
266 host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
267 if (!host)
268 return NULL;
269
270 spin_lock(&mmc_host_lock);
271 err = idr_get_new(&mmc_host_idr, host, &host->index);
272 spin_unlock(&mmc_host_lock);
273 if (err)
274 goto free;
275
276 dev_set_name(&host->class_dev, "mmc%d", host->index);
277
278 host->parent = dev;
279 host->class_dev.parent = dev;
280 host->class_dev.class = &mmc_host_class;
281 device_initialize(&host->class_dev);
282
283 mmc_host_clk_init(host);
284
285 spin_lock_init(&host->lock);
286 init_waitqueue_head(&host->wq);
287 INIT_DELAYED_WORK(&host->detect, mmc_rescan);
288 INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable);
289#ifdef CONFIG_PM
290 host->pm_notify.notifier_call = mmc_pm_notify;
291#endif
292
293 /*
294 * By default, hosts do not support SGIO or large requests.
295 * They have to set these according to their abilities.
296 */
297 host->max_segs = 1;
298 host->max_seg_size = PAGE_CACHE_SIZE;
299
300 host->max_req_size = PAGE_CACHE_SIZE;
301 host->max_blk_size = 512;
302 host->max_blk_count = PAGE_CACHE_SIZE / 512;
303
304 return host;
305
306free:
307 kfree(host);
308 return NULL;
309}
310
311EXPORT_SYMBOL(mmc_alloc_host);
312
313/**
314 * mmc_add_host - initialise host hardware
315 * @host: mmc host
316 *
317 * Register the host with the driver model. The host must be
318 * prepared to start servicing requests before this function
319 * completes.
320 */
321int mmc_add_host(struct mmc_host *host)
322{
323 int err;
324
325 WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
326 !host->ops->enable_sdio_irq);
327
328 err = device_add(&host->class_dev);
329 if (err)
330 return err;
331
332 led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
333
334#ifdef CONFIG_DEBUG_FS
335 mmc_add_host_debugfs(host);
336#endif
337
338 mmc_start_host(host);
339 register_pm_notifier(&host->pm_notify);
340
341 return 0;
342}
343
344EXPORT_SYMBOL(mmc_add_host);
345
346/**
347 * mmc_remove_host - remove host hardware
348 * @host: mmc host
349 *
350 * Unregister and remove all cards associated with this host,
351 * and power down the MMC bus. No new requests will be issued
352 * after this function has returned.
353 */
354void mmc_remove_host(struct mmc_host *host)
355{
356 unregister_pm_notifier(&host->pm_notify);
357 mmc_stop_host(host);
358
359#ifdef CONFIG_DEBUG_FS
360 mmc_remove_host_debugfs(host);
361#endif
362
363 device_del(&host->class_dev);
364
365 led_trigger_unregister_simple(host->led);
366
367 mmc_host_clk_exit(host);
368}
369
370EXPORT_SYMBOL(mmc_remove_host);
371
372/**
373 * mmc_free_host - free the host structure
374 * @host: mmc host
375 *
376 * Free the host once all references to it have been dropped.
377 */
378void mmc_free_host(struct mmc_host *host)
379{
380 spin_lock(&mmc_host_lock);
381 idr_remove(&mmc_host_idr, host->index);
382 spin_unlock(&mmc_host_lock);
383
384 put_device(&host->class_dev);
385}
386
387EXPORT_SYMBOL(mmc_free_host);