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, delay: 0, cd_irq: 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(ws: host->ws);
78 if (of_alias_get_id(np: host->parent->of_node, stem: "mmc") < 0)
79 ida_simple_remove(&mmc_host_ida, host->index);
80 kfree(objp: 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(class: &mmc_host_class);
101}
102
103void mmc_unregister_host_class(void)
104{
105 class_unregister(class: &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(timer: &host->retune_timer,
117 expires: 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 and after first doing re-tuning.
123 */
124void mmc_retune_pause(struct mmc_host *host)
125{
126 if (!host->retune_paused) {
127 host->retune_paused = 1;
128 mmc_retune_needed(host);
129 mmc_retune_hold(host);
130 }
131}
132EXPORT_SYMBOL(mmc_retune_pause);
133
134void mmc_retune_unpause(struct mmc_host *host)
135{
136 if (host->retune_paused) {
137 host->retune_paused = 0;
138 mmc_retune_release(host);
139 }
140}
141EXPORT_SYMBOL(mmc_retune_unpause);
142
143/**
144 * mmc_retune_disable() - exit a transfer mode that requires retuning
145 * @host: host which should not retune anymore
146 *
147 * It is not meant for temporarily preventing retuning!
148 */
149void mmc_retune_disable(struct mmc_host *host)
150{
151 mmc_retune_unpause(host);
152 host->can_retune = 0;
153 del_timer_sync(timer: &host->retune_timer);
154 mmc_retune_clear(host);
155}
156
157void mmc_retune_timer_stop(struct mmc_host *host)
158{
159 del_timer_sync(timer: &host->retune_timer);
160}
161EXPORT_SYMBOL(mmc_retune_timer_stop);
162
163void mmc_retune_hold(struct mmc_host *host)
164{
165 if (!host->hold_retune)
166 host->retune_now = 1;
167 host->hold_retune += 1;
168}
169
170void mmc_retune_release(struct mmc_host *host)
171{
172 if (host->hold_retune)
173 host->hold_retune -= 1;
174 else
175 WARN_ON(1);
176}
177EXPORT_SYMBOL(mmc_retune_release);
178
179int mmc_retune(struct mmc_host *host)
180{
181 bool return_to_hs400 = false;
182 int err;
183
184 if (host->retune_now)
185 host->retune_now = 0;
186 else
187 return 0;
188
189 if (!host->need_retune || host->doing_retune || !host->card)
190 return 0;
191
192 host->need_retune = 0;
193
194 host->doing_retune = 1;
195
196 if (host->ios.timing == MMC_TIMING_MMC_HS400) {
197 err = mmc_hs400_to_hs200(card: host->card);
198 if (err)
199 goto out;
200
201 return_to_hs400 = true;
202 }
203
204 err = mmc_execute_tuning(card: host->card);
205 if (err)
206 goto out;
207
208 if (return_to_hs400)
209 err = mmc_hs200_to_hs400(card: host->card);
210out:
211 host->doing_retune = 0;
212
213 return err;
214}
215
216static void mmc_retune_timer(struct timer_list *t)
217{
218 struct mmc_host *host = from_timer(host, t, retune_timer);
219
220 mmc_retune_needed(host);
221}
222
223static void mmc_of_parse_timing_phase(struct device *dev, const char *prop,
224 struct mmc_clk_phase *phase)
225{
226 int degrees[2] = {0};
227 int rc;
228
229 rc = device_property_read_u32_array(dev, propname: prop, val: degrees, nval: 2);
230 phase->valid = !rc;
231 if (phase->valid) {
232 phase->in_deg = degrees[0];
233 phase->out_deg = degrees[1];
234 }
235}
236
237void
238mmc_of_parse_clk_phase(struct mmc_host *host, struct mmc_clk_phase_map *map)
239{
240 struct device *dev = host->parent;
241
242 mmc_of_parse_timing_phase(dev, prop: "clk-phase-legacy",
243 phase: &map->phase[MMC_TIMING_LEGACY]);
244 mmc_of_parse_timing_phase(dev, prop: "clk-phase-mmc-hs",
245 phase: &map->phase[MMC_TIMING_MMC_HS]);
246 mmc_of_parse_timing_phase(dev, prop: "clk-phase-sd-hs",
247 phase: &map->phase[MMC_TIMING_SD_HS]);
248 mmc_of_parse_timing_phase(dev, prop: "clk-phase-uhs-sdr12",
249 phase: &map->phase[MMC_TIMING_UHS_SDR12]);
250 mmc_of_parse_timing_phase(dev, prop: "clk-phase-uhs-sdr25",
251 phase: &map->phase[MMC_TIMING_UHS_SDR25]);
252 mmc_of_parse_timing_phase(dev, prop: "clk-phase-uhs-sdr50",
253 phase: &map->phase[MMC_TIMING_UHS_SDR50]);
254 mmc_of_parse_timing_phase(dev, prop: "clk-phase-uhs-sdr104",
255 phase: &map->phase[MMC_TIMING_UHS_SDR104]);
256 mmc_of_parse_timing_phase(dev, prop: "clk-phase-uhs-ddr50",
257 phase: &map->phase[MMC_TIMING_UHS_DDR50]);
258 mmc_of_parse_timing_phase(dev, prop: "clk-phase-mmc-ddr52",
259 phase: &map->phase[MMC_TIMING_MMC_DDR52]);
260 mmc_of_parse_timing_phase(dev, prop: "clk-phase-mmc-hs200",
261 phase: &map->phase[MMC_TIMING_MMC_HS200]);
262 mmc_of_parse_timing_phase(dev, prop: "clk-phase-mmc-hs400",
263 phase: &map->phase[MMC_TIMING_MMC_HS400]);
264}
265EXPORT_SYMBOL(mmc_of_parse_clk_phase);
266
267/**
268 * mmc_of_parse() - parse host's device properties
269 * @host: host whose properties should be parsed.
270 *
271 * To keep the rest of the MMC subsystem unaware of whether DT has been
272 * used to instantiate and configure this host instance or not, we
273 * parse the properties and set respective generic mmc-host flags and
274 * parameters.
275 */
276int mmc_of_parse(struct mmc_host *host)
277{
278 struct device *dev = host->parent;
279 u32 bus_width, drv_type, cd_debounce_delay_ms;
280 int ret;
281
282 if (!dev || !dev_fwnode(dev))
283 return 0;
284
285 /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
286 if (device_property_read_u32(dev, propname: "bus-width", val: &bus_width) < 0) {
287 dev_dbg(host->parent,
288 "\"bus-width\" property is missing, assuming 1 bit.\n");
289 bus_width = 1;
290 }
291
292 switch (bus_width) {
293 case 8:
294 host->caps |= MMC_CAP_8_BIT_DATA;
295 fallthrough; /* Hosts capable of 8-bit can also do 4 bits */
296 case 4:
297 host->caps |= MMC_CAP_4_BIT_DATA;
298 break;
299 case 1:
300 break;
301 default:
302 dev_err(host->parent,
303 "Invalid \"bus-width\" value %u!\n", bus_width);
304 return -EINVAL;
305 }
306
307 /* f_max is obtained from the optional "max-frequency" property */
308 device_property_read_u32(dev, propname: "max-frequency", val: &host->f_max);
309
310 /*
311 * Configure CD and WP pins. They are both by default active low to
312 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
313 * mmc-gpio helpers are used to attach, configure and use them. If
314 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
315 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
316 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
317 * is set. If the "non-removable" property is found, the
318 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
319 * configuration is performed.
320 */
321
322 /* Parse Card Detection */
323
324 if (device_property_read_bool(dev, propname: "non-removable")) {
325 host->caps |= MMC_CAP_NONREMOVABLE;
326 } else {
327 if (device_property_read_bool(dev, propname: "cd-inverted"))
328 host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
329
330 if (device_property_read_u32(dev, propname: "cd-debounce-delay-ms",
331 val: &cd_debounce_delay_ms))
332 cd_debounce_delay_ms = 200;
333
334 if (device_property_read_bool(dev, propname: "broken-cd"))
335 host->caps |= MMC_CAP_NEEDS_POLL;
336
337 ret = mmc_gpiod_request_cd(host, con_id: "cd", idx: 0, override_active_level: false,
338 debounce: cd_debounce_delay_ms * 1000);
339 if (!ret)
340 dev_info(host->parent, "Got CD GPIO\n");
341 else if (ret != -ENOENT && ret != -ENOSYS)
342 return ret;
343 }
344
345 /* Parse Write Protection */
346
347 if (device_property_read_bool(dev, propname: "wp-inverted"))
348 host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
349
350 ret = mmc_gpiod_request_ro(host, con_id: "wp", idx: 0, debounce: 0);
351 if (!ret)
352 dev_info(host->parent, "Got WP GPIO\n");
353 else if (ret != -ENOENT && ret != -ENOSYS)
354 return ret;
355
356 if (device_property_read_bool(dev, propname: "disable-wp"))
357 host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
358
359 if (device_property_read_bool(dev, propname: "cap-sd-highspeed"))
360 host->caps |= MMC_CAP_SD_HIGHSPEED;
361 if (device_property_read_bool(dev, propname: "cap-mmc-highspeed"))
362 host->caps |= MMC_CAP_MMC_HIGHSPEED;
363 if (device_property_read_bool(dev, propname: "sd-uhs-sdr12"))
364 host->caps |= MMC_CAP_UHS_SDR12;
365 if (device_property_read_bool(dev, propname: "sd-uhs-sdr25"))
366 host->caps |= MMC_CAP_UHS_SDR25;
367 if (device_property_read_bool(dev, propname: "sd-uhs-sdr50"))
368 host->caps |= MMC_CAP_UHS_SDR50;
369 if (device_property_read_bool(dev, propname: "sd-uhs-sdr104"))
370 host->caps |= MMC_CAP_UHS_SDR104;
371 if (device_property_read_bool(dev, propname: "sd-uhs-ddr50"))
372 host->caps |= MMC_CAP_UHS_DDR50;
373 if (device_property_read_bool(dev, propname: "cap-power-off-card"))
374 host->caps |= MMC_CAP_POWER_OFF_CARD;
375 if (device_property_read_bool(dev, propname: "cap-mmc-hw-reset"))
376 host->caps |= MMC_CAP_HW_RESET;
377 if (device_property_read_bool(dev, propname: "cap-sdio-irq"))
378 host->caps |= MMC_CAP_SDIO_IRQ;
379 if (device_property_read_bool(dev, propname: "full-pwr-cycle"))
380 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
381 if (device_property_read_bool(dev, propname: "full-pwr-cycle-in-suspend"))
382 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND;
383 if (device_property_read_bool(dev, propname: "keep-power-in-suspend"))
384 host->pm_caps |= MMC_PM_KEEP_POWER;
385 if (device_property_read_bool(dev, propname: "wakeup-source") ||
386 device_property_read_bool(dev, propname: "enable-sdio-wakeup")) /* legacy */
387 host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
388 if (device_property_read_bool(dev, propname: "mmc-ddr-3_3v"))
389 host->caps |= MMC_CAP_3_3V_DDR;
390 if (device_property_read_bool(dev, propname: "mmc-ddr-1_8v"))
391 host->caps |= MMC_CAP_1_8V_DDR;
392 if (device_property_read_bool(dev, propname: "mmc-ddr-1_2v"))
393 host->caps |= MMC_CAP_1_2V_DDR;
394 if (device_property_read_bool(dev, propname: "mmc-hs200-1_8v"))
395 host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
396 if (device_property_read_bool(dev, propname: "mmc-hs200-1_2v"))
397 host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
398 if (device_property_read_bool(dev, propname: "mmc-hs400-1_8v"))
399 host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
400 if (device_property_read_bool(dev, propname: "mmc-hs400-1_2v"))
401 host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
402 if (device_property_read_bool(dev, propname: "mmc-hs400-enhanced-strobe"))
403 host->caps2 |= MMC_CAP2_HS400_ES;
404 if (device_property_read_bool(dev, propname: "no-sdio"))
405 host->caps2 |= MMC_CAP2_NO_SDIO;
406 if (device_property_read_bool(dev, propname: "no-sd"))
407 host->caps2 |= MMC_CAP2_NO_SD;
408 if (device_property_read_bool(dev, propname: "no-mmc"))
409 host->caps2 |= MMC_CAP2_NO_MMC;
410 if (device_property_read_bool(dev, propname: "no-mmc-hs400"))
411 host->caps2 &= ~(MMC_CAP2_HS400_1_8V | MMC_CAP2_HS400_1_2V |
412 MMC_CAP2_HS400_ES);
413
414 /* Must be after "non-removable" check */
415 if (device_property_read_u32(dev, propname: "fixed-emmc-driver-type", val: &drv_type) == 0) {
416 if (host->caps & MMC_CAP_NONREMOVABLE)
417 host->fixed_drv_type = drv_type;
418 else
419 dev_err(host->parent,
420 "can't use fixed driver type, media is removable\n");
421 }
422
423 host->dsr_req = !device_property_read_u32(dev, propname: "dsr", val: &host->dsr);
424 if (host->dsr_req && (host->dsr & ~0xffff)) {
425 dev_err(host->parent,
426 "device tree specified broken value for DSR: 0x%x, ignoring\n",
427 host->dsr);
428 host->dsr_req = 0;
429 }
430
431 device_property_read_u32(dev, propname: "post-power-on-delay-ms",
432 val: &host->ios.power_delay_ms);
433
434 return mmc_pwrseq_alloc(host);
435}
436
437EXPORT_SYMBOL(mmc_of_parse);
438
439/**
440 * mmc_of_parse_voltage - return mask of supported voltages
441 * @host: host whose properties should be parsed.
442 * @mask: mask of voltages available for MMC/SD/SDIO
443 *
444 * Parse the "voltage-ranges" property, returning zero if it is not
445 * found, negative errno if the voltage-range specification is invalid,
446 * or one if the voltage-range is specified and successfully parsed.
447 */
448int mmc_of_parse_voltage(struct mmc_host *host, u32 *mask)
449{
450 const char *prop = "voltage-ranges";
451 struct device *dev = host->parent;
452 u32 *voltage_ranges;
453 int num_ranges, i;
454 int ret;
455
456 if (!device_property_present(dev, propname: prop)) {
457 dev_dbg(dev, "%s unspecified\n", prop);
458 return 0;
459 }
460
461 ret = device_property_count_u32(dev, propname: prop);
462 if (ret < 0)
463 return ret;
464
465 num_ranges = ret / 2;
466 if (!num_ranges) {
467 dev_err(dev, "%s empty\n", prop);
468 return -EINVAL;
469 }
470
471 voltage_ranges = kcalloc(n: 2 * num_ranges, size: sizeof(*voltage_ranges), GFP_KERNEL);
472 if (!voltage_ranges)
473 return -ENOMEM;
474
475 ret = device_property_read_u32_array(dev, propname: prop, val: voltage_ranges, nval: 2 * num_ranges);
476 if (ret) {
477 kfree(objp: voltage_ranges);
478 return ret;
479 }
480
481 for (i = 0; i < num_ranges; i++) {
482 const int j = i * 2;
483 u32 ocr_mask;
484
485 ocr_mask = mmc_vddrange_to_ocrmask(vdd_min: voltage_ranges[j + 0],
486 vdd_max: voltage_ranges[j + 1]);
487 if (!ocr_mask) {
488 dev_err(dev, "range #%d in %s is invalid\n", i, prop);
489 kfree(objp: voltage_ranges);
490 return -EINVAL;
491 }
492 *mask |= ocr_mask;
493 }
494
495 kfree(objp: voltage_ranges);
496
497 return 1;
498}
499EXPORT_SYMBOL(mmc_of_parse_voltage);
500
501/**
502 * mmc_first_nonreserved_index() - get the first index that is not reserved
503 */
504static int mmc_first_nonreserved_index(void)
505{
506 int max;
507
508 max = of_alias_get_highest_id(stem: "mmc");
509 if (max < 0)
510 return 0;
511
512 return max + 1;
513}
514
515/**
516 * mmc_alloc_host - initialise the per-host structure.
517 * @extra: sizeof private data structure
518 * @dev: pointer to host device model structure
519 *
520 * Initialise the per-host structure.
521 */
522struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
523{
524 int index;
525 struct mmc_host *host;
526 int alias_id, min_idx, max_idx;
527
528 host = kzalloc(size: sizeof(struct mmc_host) + extra, GFP_KERNEL);
529 if (!host)
530 return NULL;
531
532 /* scanning will be enabled when we're ready */
533 host->rescan_disable = 1;
534
535 alias_id = of_alias_get_id(np: dev->of_node, stem: "mmc");
536 if (alias_id >= 0) {
537 index = alias_id;
538 } else {
539 min_idx = mmc_first_nonreserved_index();
540 max_idx = 0;
541
542 index = ida_simple_get(&mmc_host_ida, min_idx, max_idx, GFP_KERNEL);
543 if (index < 0) {
544 kfree(objp: host);
545 return NULL;
546 }
547 }
548
549 host->index = index;
550
551 dev_set_name(dev: &host->class_dev, name: "mmc%d", host->index);
552 host->ws = wakeup_source_register(NULL, name: dev_name(dev: &host->class_dev));
553
554 host->parent = dev;
555 host->class_dev.parent = dev;
556 host->class_dev.class = &mmc_host_class;
557 device_initialize(dev: &host->class_dev);
558 device_enable_async_suspend(dev: &host->class_dev);
559
560 if (mmc_gpio_alloc(host)) {
561 put_device(dev: &host->class_dev);
562 return NULL;
563 }
564
565 spin_lock_init(&host->lock);
566 init_waitqueue_head(&host->wq);
567 INIT_DELAYED_WORK(&host->detect, mmc_rescan);
568 INIT_WORK(&host->sdio_irq_work, sdio_irq_work);
569 timer_setup(&host->retune_timer, mmc_retune_timer, 0);
570
571 /*
572 * By default, hosts do not support SGIO or large requests.
573 * They have to set these according to their abilities.
574 */
575 host->max_segs = 1;
576 host->max_seg_size = PAGE_SIZE;
577
578 host->max_req_size = PAGE_SIZE;
579 host->max_blk_size = 512;
580 host->max_blk_count = PAGE_SIZE / 512;
581
582 host->fixed_drv_type = -EINVAL;
583 host->ios.power_delay_ms = 10;
584 host->ios.power_mode = MMC_POWER_UNDEFINED;
585
586 return host;
587}
588
589EXPORT_SYMBOL(mmc_alloc_host);
590
591static void devm_mmc_host_release(struct device *dev, void *res)
592{
593 mmc_free_host(*(struct mmc_host **)res);
594}
595
596struct mmc_host *devm_mmc_alloc_host(struct device *dev, int extra)
597{
598 struct mmc_host **dr, *host;
599
600 dr = devres_alloc(devm_mmc_host_release, sizeof(*dr), GFP_KERNEL);
601 if (!dr)
602 return NULL;
603
604 host = mmc_alloc_host(extra, dev);
605 if (!host) {
606 devres_free(res: dr);
607 return NULL;
608 }
609
610 *dr = host;
611 devres_add(dev, res: dr);
612
613 return host;
614}
615EXPORT_SYMBOL(devm_mmc_alloc_host);
616
617static int mmc_validate_host_caps(struct mmc_host *host)
618{
619 struct device *dev = host->parent;
620 u32 caps = host->caps, caps2 = host->caps2;
621
622 if (caps & MMC_CAP_SDIO_IRQ && !host->ops->enable_sdio_irq) {
623 dev_warn(dev, "missing ->enable_sdio_irq() ops\n");
624 return -EINVAL;
625 }
626
627 if (caps2 & (MMC_CAP2_HS400_ES | MMC_CAP2_HS400) &&
628 !(caps & MMC_CAP_8_BIT_DATA) && !(caps2 & MMC_CAP2_NO_MMC)) {
629 dev_warn(dev, "drop HS400 support since no 8-bit bus\n");
630 host->caps2 = caps2 & ~MMC_CAP2_HS400_ES & ~MMC_CAP2_HS400;
631 }
632
633 return 0;
634}
635
636/**
637 * mmc_add_host - initialise host hardware
638 * @host: mmc host
639 *
640 * Register the host with the driver model. The host must be
641 * prepared to start servicing requests before this function
642 * completes.
643 */
644int mmc_add_host(struct mmc_host *host)
645{
646 int err;
647
648 err = mmc_validate_host_caps(host);
649 if (err)
650 return err;
651
652 err = device_add(dev: &host->class_dev);
653 if (err)
654 return err;
655
656 led_trigger_register_simple(name: dev_name(dev: &host->class_dev), trigger: &host->led);
657
658 mmc_add_host_debugfs(host);
659
660 mmc_start_host(host);
661 return 0;
662}
663
664EXPORT_SYMBOL(mmc_add_host);
665
666/**
667 * mmc_remove_host - remove host hardware
668 * @host: mmc host
669 *
670 * Unregister and remove all cards associated with this host,
671 * and power down the MMC bus. No new requests will be issued
672 * after this function has returned.
673 */
674void mmc_remove_host(struct mmc_host *host)
675{
676 mmc_stop_host(host);
677
678 mmc_remove_host_debugfs(host);
679
680 device_del(dev: &host->class_dev);
681
682 led_trigger_unregister_simple(trigger: host->led);
683}
684
685EXPORT_SYMBOL(mmc_remove_host);
686
687/**
688 * mmc_free_host - free the host structure
689 * @host: mmc host
690 *
691 * Free the host once all references to it have been dropped.
692 */
693void mmc_free_host(struct mmc_host *host)
694{
695 mmc_pwrseq_free(host);
696 put_device(dev: &host->class_dev);
697}
698
699EXPORT_SYMBOL(mmc_free_host);
700

source code of linux/drivers/mmc/core/host.c