host.c

  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/pagemap.h>
 17#include <linux/export.h>
 18#include <linux/leds.h>
 19#include <linux/slab.h>
 20
 21#include <linux/mmc/host.h>
 22#include <linux/mmc/card.h>
 23#include <linux/mmc/slot-gpio.h>
 24
 25#include "core.h"
 26#include "crypto.h"
 27#include "host.h"
 28#include "slot-gpio.h"
 29#include "pwrseq.h"
 30#include "sdio_ops.h"
 31
 32#define cls_dev_to_mmc_host(d)	container_of(d, struct mmc_host, class_dev)
 33
 34static DEFINE_IDA(mmc_host_ida);
 35
 36#ifdef CONFIG_PM_SLEEP
 37static int mmc_host_class_prepare(struct device *dev)
 38{
 39	struct mmc_host *host = cls_dev_to_mmc_host(dev);
 40
 41	/*
 42	 * It's safe to access the bus_ops pointer, as both userspace and the
 43	 * workqueue for detecting cards are frozen at this point.
 44	 */
 45	if (!host->bus_ops)
 46		return 0;
 47
 48	/* Validate conditions for system suspend. */
 49	if (host->bus_ops->pre_suspend)
 50		return host->bus_ops->pre_suspend(host);
 51
 52	return 0;
 53}
 54
 55static void mmc_host_class_complete(struct device *dev)
 56{
 57	struct mmc_host *host = cls_dev_to_mmc_host(dev);
 58
 59	_mmc_detect_change(host, 0, false);
 60}
 61
 62static const struct dev_pm_ops mmc_host_class_dev_pm_ops = {
 63	.prepare = mmc_host_class_prepare,
 64	.complete = mmc_host_class_complete,
 65};
 66
 67#define MMC_HOST_CLASS_DEV_PM_OPS (&mmc_host_class_dev_pm_ops)
 68#else
 69#define MMC_HOST_CLASS_DEV_PM_OPS NULL
 70#endif
 71
 72static void mmc_host_classdev_release(struct device *dev)
 73{
 74	struct mmc_host *host = cls_dev_to_mmc_host(dev);
 75	wakeup_source_unregister(host->ws);
 76	if (of_alias_get_id(host->parent->of_node, "mmc") < 0)
 77		ida_free(&mmc_host_ida, host->index);
 78	kfree(host);
 79}
 80
 81static int mmc_host_classdev_shutdown(struct device *dev)
 82{
 83	struct mmc_host *host = cls_dev_to_mmc_host(dev);
 84
 85	__mmc_stop_host(host);
 86	return 0;
 87}
 88
 89static const struct class mmc_host_class = {
 90	.name		= "mmc_host",
 91	.dev_release	= mmc_host_classdev_release,
 92	.shutdown_pre	= mmc_host_classdev_shutdown,
 93	.pm		= MMC_HOST_CLASS_DEV_PM_OPS,
 94};
 95
 96int mmc_register_host_class(void)
 97{
 98	return class_register(&mmc_host_class);
 99}
100
101void mmc_unregister_host_class(void)
102{
103	class_unregister(&mmc_host_class);
104}
105
106/**
107 * mmc_retune_enable() - enter a transfer mode that requires retuning
108 * @host: host which should retune now
109 */
110void mmc_retune_enable(struct mmc_host *host)
111{
112	host->can_retune = 1;
113	if (host->retune_period)
114		mod_timer(&host->retune_timer,
115			  jiffies + host->retune_period * HZ);
116}
117
118/*
119 * Pause re-tuning for a small set of operations.  The pause begins after the
120 * next command.
121 */
122void mmc_retune_pause(struct mmc_host *host)
123{
124	if (!host->retune_paused) {
125		host->retune_paused = 1;
126		mmc_retune_hold(host);
127	}
128}
129EXPORT_SYMBOL(mmc_retune_pause);
130
131void mmc_retune_unpause(struct mmc_host *host)
132{
133	if (host->retune_paused) {
134		host->retune_paused = 0;
135		mmc_retune_release(host);
136	}
137}
138EXPORT_SYMBOL(mmc_retune_unpause);
139
140/**
141 * mmc_retune_disable() - exit a transfer mode that requires retuning
142 * @host: host which should not retune anymore
143 *
144 * It is not meant for temporarily preventing retuning!
145 */
146void mmc_retune_disable(struct mmc_host *host)
147{
148	mmc_retune_unpause(host);
149	host->can_retune = 0;
150	timer_delete_sync(&host->retune_timer);
151	mmc_retune_clear(host);
152}
153
154void mmc_retune_timer_stop(struct mmc_host *host)
155{
156	timer_delete_sync(&host->retune_timer);
157}
158EXPORT_SYMBOL(mmc_retune_timer_stop);
159
160void mmc_retune_hold(struct mmc_host *host)
161{
162	if (!host->hold_retune)
163		host->retune_now = 1;
164	host->hold_retune += 1;
165}
166
167void mmc_retune_release(struct mmc_host *host)
168{
169	if (host->hold_retune)
170		host->hold_retune -= 1;
171	else
172		WARN_ON(1);
173}
174EXPORT_SYMBOL(mmc_retune_release);
175
176int mmc_retune(struct mmc_host *host)
177{
178	bool return_to_hs400 = false;
179	int err;
180
181	if (host->retune_now)
182		host->retune_now = 0;
183	else
184		return 0;
185
186	if (!host->need_retune || host->doing_retune || !host->card)
187		return 0;
188
189	host->need_retune = 0;
190
191	host->doing_retune = 1;
192
193	if (host->ios.timing == MMC_TIMING_MMC_HS400) {
194		err = mmc_hs400_to_hs200(host->card);
195		if (err)
196			goto out;
197
198		return_to_hs400 = true;
199	}
200
201	err = mmc_execute_tuning(host->card);
202	if (err)
203		goto out;
204
205	if (return_to_hs400)
206		err = mmc_hs200_to_hs400(host->card);
207out:
208	host->doing_retune = 0;
209
210	return err;
211}
212
213static void mmc_retune_timer(struct timer_list *t)
214{
215	struct mmc_host *host = timer_container_of(host, t, retune_timer);
216
217	mmc_retune_needed(host);
218}
219
220static void mmc_of_parse_timing_phase(struct device *dev, const char *prop,
221				      struct mmc_clk_phase *phase)
222{
223	int degrees[2] = {0};
224	int rc;
225
226	rc = device_property_read_u32_array(dev, prop, degrees, 2);
227	phase->valid = !rc;
228	if (phase->valid) {
229		phase->in_deg = degrees[0];
230		phase->out_deg = degrees[1];
231	}
232}
233
234void
235mmc_of_parse_clk_phase(struct device *dev, struct mmc_clk_phase_map *map)
236{
237	mmc_of_parse_timing_phase(dev, "clk-phase-legacy",
238				  &map->phase[MMC_TIMING_LEGACY]);
239	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs",
240				  &map->phase[MMC_TIMING_MMC_HS]);
241	mmc_of_parse_timing_phase(dev, "clk-phase-sd-hs",
242				  &map->phase[MMC_TIMING_SD_HS]);
243	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr12",
244				  &map->phase[MMC_TIMING_UHS_SDR12]);
245	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr25",
246				  &map->phase[MMC_TIMING_UHS_SDR25]);
247	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr50",
248				  &map->phase[MMC_TIMING_UHS_SDR50]);
249	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr104",
250				  &map->phase[MMC_TIMING_UHS_SDR104]);
251	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-ddr50",
252				  &map->phase[MMC_TIMING_UHS_DDR50]);
253	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-ddr52",
254				  &map->phase[MMC_TIMING_MMC_DDR52]);
255	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs200",
256				  &map->phase[MMC_TIMING_MMC_HS200]);
257	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs400",
258				  &map->phase[MMC_TIMING_MMC_HS400]);
259}
260EXPORT_SYMBOL(mmc_of_parse_clk_phase);
261
262/**
263 * mmc_of_parse() - parse host's device properties
264 * @host: host whose properties should be parsed.
265 *
266 * To keep the rest of the MMC subsystem unaware of whether DT has been
267 * used to instantiate and configure this host instance or not, we
268 * parse the properties and set respective generic mmc-host flags and
269 * parameters.
270 */
271int mmc_of_parse(struct mmc_host *host)
272{
273	struct device *dev = host->parent;
274	u32 bus_width, drv_type, cd_debounce_delay_ms;
275	int ret;
276
277	if (!dev || !dev_fwnode(dev))
278		return 0;
279
280	/* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
281	if (device_property_read_u32(dev, "bus-width", &bus_width) < 0) {
282		dev_dbg(host->parent,
283			"\"bus-width\" property is missing, assuming 1 bit.\n");
284		bus_width = 1;
285	}
286
287	switch (bus_width) {
288	case 8:
289		host->caps |= MMC_CAP_8_BIT_DATA;
290		fallthrough;	/* Hosts capable of 8-bit can also do 4 bits */
291	case 4:
292		host->caps |= MMC_CAP_4_BIT_DATA;
293		break;
294	case 1:
295		break;
296	default:
297		dev_err(host->parent,
298			"Invalid \"bus-width\" value %u!\n", bus_width);
299		return -EINVAL;
300	}
301
302	/* f_max is obtained from the optional "max-frequency" property */
303	device_property_read_u32(dev, "max-frequency", &host->f_max);
304
305	device_property_read_u32(dev, "max-sd-hs-hz", &host->max_sd_hs_hz);
306
307	/*
308	 * Configure CD and WP pins. They are both by default active low to
309	 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
310	 * mmc-gpio helpers are used to attach, configure and use them. If
311	 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
312	 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
313	 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
314	 * is set. If the "non-removable" property is found, the
315	 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
316	 * configuration is performed.
317	 */
318
319	/* Parse Card Detection */
320
321	if (device_property_read_bool(dev, "non-removable")) {
322		host->caps |= MMC_CAP_NONREMOVABLE;
323	} else {
324		if (device_property_read_bool(dev, "cd-inverted"))
325			host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
326
327		if (device_property_read_u32(dev, "cd-debounce-delay-ms",
328					     &cd_debounce_delay_ms))
329			cd_debounce_delay_ms = 200;
330
331		if (device_property_read_bool(dev, "broken-cd"))
332			host->caps |= MMC_CAP_NEEDS_POLL;
333
334		ret = mmc_gpiod_request_cd(host, "cd", 0, false,
335					   cd_debounce_delay_ms * 1000);
336		if (!ret)
337			dev_info(host->parent, "Got CD GPIO\n");
338		else if (ret != -ENOENT && ret != -ENOSYS)
339			return ret;
340	}
341
342	/* Parse Write Protection */
343
344	if (device_property_read_bool(dev, "wp-inverted"))
345		host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
346
347	ret = mmc_gpiod_request_ro(host, "wp", 0, 0);
348	if (!ret)
349		dev_info(host->parent, "Got WP GPIO\n");
350	else if (ret != -ENOENT && ret != -ENOSYS)
351		return ret;
352
353	if (device_property_read_bool(dev, "disable-wp"))
354		host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
355
356	if (device_property_read_bool(dev, "cap-sd-highspeed"))
357		host->caps |= MMC_CAP_SD_HIGHSPEED;
358	if (device_property_read_bool(dev, "cap-mmc-highspeed"))
359		host->caps |= MMC_CAP_MMC_HIGHSPEED;
360	if (device_property_read_bool(dev, "sd-uhs-sdr12"))
361		host->caps |= MMC_CAP_UHS_SDR12;
362	if (device_property_read_bool(dev, "sd-uhs-sdr25"))
363		host->caps |= MMC_CAP_UHS_SDR25;
364	if (device_property_read_bool(dev, "sd-uhs-sdr50"))
365		host->caps |= MMC_CAP_UHS_SDR50;
366	if (device_property_read_bool(dev, "sd-uhs-sdr104"))
367		host->caps |= MMC_CAP_UHS_SDR104;
368	if (device_property_read_bool(dev, "sd-uhs-ddr50"))
369		host->caps |= MMC_CAP_UHS_DDR50;
370	if (device_property_read_bool(dev, "cap-power-off-card"))
371		host->caps |= MMC_CAP_POWER_OFF_CARD;
372	if (device_property_read_bool(dev, "cap-mmc-hw-reset"))
373		host->caps |= MMC_CAP_HW_RESET;
374	if (device_property_read_bool(dev, "cap-sdio-irq"))
375		host->caps |= MMC_CAP_SDIO_IRQ;
376	if (device_property_read_bool(dev, "full-pwr-cycle"))
377		host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
378	if (device_property_read_bool(dev, "full-pwr-cycle-in-suspend"))
379		host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND;
380	if (device_property_read_bool(dev, "keep-power-in-suspend"))
381		host->pm_caps |= MMC_PM_KEEP_POWER;
382	if (device_property_read_bool(dev, "wakeup-source") ||
383	    device_property_read_bool(dev, "enable-sdio-wakeup")) /* legacy */
384		host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
385	if (device_property_read_bool(dev, "mmc-ddr-3_3v"))
386		host->caps |= MMC_CAP_3_3V_DDR;
387	if (device_property_read_bool(dev, "mmc-ddr-1_8v"))
388		host->caps |= MMC_CAP_1_8V_DDR;
389	if (device_property_read_bool(dev, "mmc-ddr-1_2v"))
390		host->caps |= MMC_CAP_1_2V_DDR;
391	if (device_property_read_bool(dev, "mmc-hs200-1_8v"))
392		host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
393	if (device_property_read_bool(dev, "mmc-hs200-1_2v"))
394		host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
395	if (device_property_read_bool(dev, "mmc-hs400-1_8v"))
396		host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
397	if (device_property_read_bool(dev, "mmc-hs400-1_2v"))
398		host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
399	if (device_property_read_bool(dev, "mmc-hs400-enhanced-strobe"))
400		host->caps2 |= MMC_CAP2_HS400_ES;
401	if (device_property_read_bool(dev, "no-sdio"))
402		host->caps2 |= MMC_CAP2_NO_SDIO;
403	if (device_property_read_bool(dev, "no-sd"))
404		host->caps2 |= MMC_CAP2_NO_SD;
405	if (device_property_read_bool(dev, "no-mmc"))
406		host->caps2 |= MMC_CAP2_NO_MMC;
407	if (device_property_read_bool(dev, "no-mmc-hs400"))
408		host->caps2 &= ~(MMC_CAP2_HS400_1_8V | MMC_CAP2_HS400_1_2V |
409				 MMC_CAP2_HS400_ES);
410
411	/* Must be after "non-removable" check */
412	if (device_property_read_u32(dev, "fixed-emmc-driver-type", &drv_type) == 0) {
413		if (host->caps & MMC_CAP_NONREMOVABLE)
414			host->fixed_drv_type = drv_type;
415		else
416			dev_err(host->parent,
417				"can't use fixed driver type, media is removable\n");
418	}
419
420	host->dsr_req = !device_property_read_u32(dev, "dsr", &host->dsr);
421	if (host->dsr_req && (host->dsr & ~0xffff)) {
422		dev_err(host->parent,
423			"device tree specified broken value for DSR: 0x%x, ignoring\n",
424			host->dsr);
425		host->dsr_req = 0;
426	}
427
428	device_property_read_u32(dev, "post-power-on-delay-ms",
429				 &host->ios.power_delay_ms);
430
431	return mmc_pwrseq_alloc(host);
432}
433
434EXPORT_SYMBOL(mmc_of_parse);
435
436/**
437 * mmc_of_parse_voltage - return mask of supported voltages
438 * @host: host whose properties should be parsed.
439 * @mask: mask of voltages available for MMC/SD/SDIO
440 *
441 * Parse the "voltage-ranges" property, returning zero if it is not
442 * found, negative errno if the voltage-range specification is invalid,
443 * or one if the voltage-range is specified and successfully parsed.
444 */
445int mmc_of_parse_voltage(struct mmc_host *host, u32 *mask)
446{
447	const char *prop = "voltage-ranges";
448	struct device *dev = host->parent;
449	u32 *voltage_ranges;
450	int num_ranges, i;
451	int ret;
452
453	if (!device_property_present(dev, prop)) {
454		dev_dbg(dev, "%s unspecified\n", prop);
455		return 0;
456	}
457
458	ret = device_property_count_u32(dev, prop);
459	if (ret < 0)
460		return ret;
461
462	num_ranges = ret / 2;
463	if (!num_ranges) {
464		dev_err(dev, "%s empty\n", prop);
465		return -EINVAL;
466	}
467
468	voltage_ranges = kcalloc(2 * num_ranges, sizeof(*voltage_ranges), GFP_KERNEL);
469	if (!voltage_ranges)
470		return -ENOMEM;
471
472	ret = device_property_read_u32_array(dev, prop, voltage_ranges, 2 * num_ranges);
473	if (ret) {
474		kfree(voltage_ranges);
475		return ret;
476	}
477
478	for (i = 0; i < num_ranges; i++) {
479		const int j = i * 2;
480		u32 ocr_mask;
481
482		ocr_mask = mmc_vddrange_to_ocrmask(voltage_ranges[j + 0],
483						   voltage_ranges[j + 1]);
484		if (!ocr_mask) {
485			dev_err(dev, "range #%d in %s is invalid\n", i, prop);
486			kfree(voltage_ranges);
487			return -EINVAL;
488		}
489		*mask |= ocr_mask;
490	}
491
492	kfree(voltage_ranges);
493
494	return 1;
495}
496EXPORT_SYMBOL(mmc_of_parse_voltage);
497
498/**
499 * mmc_first_nonreserved_index() - get the first index that is not reserved
500 */
501static int mmc_first_nonreserved_index(void)
502{
503	int max;
504
505	max = of_alias_get_highest_id("mmc");
506	if (max < 0)
507		return 0;
508
509	return max + 1;
510}
511
512/**
513 *	mmc_alloc_host - initialise the per-host structure.
514 *	@extra: sizeof private data structure
515 *	@dev: pointer to host device model structure
516 *
517 *	Initialise the per-host structure.
518 */
519struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
520{
521	int index;
522	struct mmc_host *host;
523	int alias_id, min_idx, max_idx;
524
525	host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
526	if (!host)
527		return NULL;
528
529	/* scanning will be enabled when we're ready */
530	host->rescan_disable = 1;
531
532	alias_id = of_alias_get_id(dev->of_node, "mmc");
533	if (alias_id >= 0) {
534		index = alias_id;
535	} else {
536		min_idx = mmc_first_nonreserved_index();
537		max_idx = 0;
538
539		index = ida_alloc_range(&mmc_host_ida, min_idx, max_idx - 1,
540					GFP_KERNEL);
541		if (index < 0) {
542			kfree(host);
543			return NULL;
544		}
545	}
546
547	host->index = index;
548
549	dev_set_name(&host->class_dev, "mmc%d", host->index);
550	host->ws = wakeup_source_register(NULL, dev_name(&host->class_dev));
551
552	host->parent = dev;
553	host->class_dev.parent = dev;
554	host->class_dev.class = &mmc_host_class;
555	device_initialize(&host->class_dev);
556	device_enable_async_suspend(&host->class_dev);
557
558	if (mmc_gpio_alloc(host)) {
559		put_device(&host->class_dev);
560		return NULL;
561	}
562
563	spin_lock_init(&host->lock);
564	init_waitqueue_head(&host->wq);
565	INIT_DELAYED_WORK(&host->detect, mmc_rescan);
566	INIT_WORK(&host->sdio_irq_work, sdio_irq_work);
567	timer_setup(&host->retune_timer, mmc_retune_timer, 0);
568
569	INIT_WORK(&host->supply.uv_work, mmc_undervoltage_workfn);
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(dr);
607		return NULL;
608	}
609
610	*dr = host;
611	devres_add(dev, 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(&host->class_dev);
653	if (err)
654		return err;
655
656	led_trigger_register_simple(dev_name(&host->class_dev), &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(&host->class_dev);
681
682	led_trigger_unregister_simple(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	cancel_delayed_work_sync(&host->detect);
696	mmc_pwrseq_free(host);
697	put_device(&host->class_dev);
698}
699
700EXPORT_SYMBOL(mmc_free_host);