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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 
36 static DEFINE_IDA(mmc_host_ida);
37 
38 #ifdef CONFIG_PM_SLEEP
mmc_host_class_prepare(struct device * dev)39 static 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 
mmc_host_class_complete(struct device * dev)57 static 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 
64 static 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 
mmc_host_classdev_release(struct device * dev)74 static 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 
mmc_host_classdev_shutdown(struct device * dev)83 static 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 
91 static 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 
mmc_register_host_class(void)98 int mmc_register_host_class(void)
99 {
100 	return class_register(&mmc_host_class);
101 }
102 
mmc_unregister_host_class(void)103 void 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  */
mmc_retune_enable(struct mmc_host * host)112 void 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 and after first doing re-tuning.
123  */
mmc_retune_pause(struct mmc_host * host)124 void 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 }
132 EXPORT_SYMBOL(mmc_retune_pause);
133 
mmc_retune_unpause(struct mmc_host * host)134 void 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 }
141 EXPORT_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  */
mmc_retune_disable(struct mmc_host * host)149 void mmc_retune_disable(struct mmc_host *host)
150 {
151 	mmc_retune_unpause(host);
152 	host->can_retune = 0;
153 	del_timer_sync(&host->retune_timer);
154 	mmc_retune_clear(host);
155 }
156 
mmc_retune_timer_stop(struct mmc_host * host)157 void mmc_retune_timer_stop(struct mmc_host *host)
158 {
159 	del_timer_sync(&host->retune_timer);
160 }
161 EXPORT_SYMBOL(mmc_retune_timer_stop);
162 
mmc_retune_hold(struct mmc_host * host)163 void 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 EXPORT_SYMBOL(mmc_retune_hold);
170 
mmc_retune_release(struct mmc_host * host)171 void mmc_retune_release(struct mmc_host *host)
172 {
173 	if (host->hold_retune)
174 		host->hold_retune -= 1;
175 	else
176 		WARN_ON(1);
177 }
178 EXPORT_SYMBOL(mmc_retune_release);
179 
mmc_retune(struct mmc_host * host)180 int mmc_retune(struct mmc_host *host)
181 {
182 	bool return_to_hs400 = false;
183 	int err;
184 
185 	if (host->retune_now)
186 		host->retune_now = 0;
187 	else
188 		return 0;
189 
190 	if (!host->need_retune || host->doing_retune || !host->card)
191 		return 0;
192 
193 	host->need_retune = 0;
194 
195 	host->doing_retune = 1;
196 
197 	if (host->ios.timing == MMC_TIMING_MMC_HS400) {
198 		err = mmc_hs400_to_hs200(host->card);
199 		if (err)
200 			goto out;
201 
202 		return_to_hs400 = true;
203 	}
204 
205 	err = mmc_execute_tuning(host->card);
206 	if (err)
207 		goto out;
208 
209 	if (return_to_hs400)
210 		err = mmc_hs200_to_hs400(host->card);
211 out:
212 	host->doing_retune = 0;
213 
214 	return err;
215 }
216 
mmc_retune_timer(struct timer_list * t)217 static void mmc_retune_timer(struct timer_list *t)
218 {
219 	struct mmc_host *host = from_timer(host, t, retune_timer);
220 
221 	mmc_retune_needed(host);
222 }
223 
mmc_of_parse_timing_phase(struct device * dev,const char * prop,struct mmc_clk_phase * phase)224 static void mmc_of_parse_timing_phase(struct device *dev, const char *prop,
225 				      struct mmc_clk_phase *phase)
226 {
227 	int degrees[2] = {0};
228 	int rc;
229 
230 	rc = device_property_read_u32_array(dev, prop, degrees, 2);
231 	phase->valid = !rc;
232 	if (phase->valid) {
233 		phase->in_deg = degrees[0];
234 		phase->out_deg = degrees[1];
235 	}
236 }
237 
238 void
mmc_of_parse_clk_phase(struct mmc_host * host,struct mmc_clk_phase_map * map)239 mmc_of_parse_clk_phase(struct mmc_host *host, struct mmc_clk_phase_map *map)
240 {
241 	struct device *dev = host->parent;
242 
243 	mmc_of_parse_timing_phase(dev, "clk-phase-legacy",
244 				  &map->phase[MMC_TIMING_LEGACY]);
245 	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs",
246 				  &map->phase[MMC_TIMING_MMC_HS]);
247 	mmc_of_parse_timing_phase(dev, "clk-phase-sd-hs",
248 				  &map->phase[MMC_TIMING_SD_HS]);
249 	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr12",
250 				  &map->phase[MMC_TIMING_UHS_SDR12]);
251 	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr25",
252 				  &map->phase[MMC_TIMING_UHS_SDR25]);
253 	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr50",
254 				  &map->phase[MMC_TIMING_UHS_SDR50]);
255 	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr104",
256 				  &map->phase[MMC_TIMING_UHS_SDR104]);
257 	mmc_of_parse_timing_phase(dev, "clk-phase-uhs-ddr50",
258 				  &map->phase[MMC_TIMING_UHS_DDR50]);
259 	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-ddr52",
260 				  &map->phase[MMC_TIMING_MMC_DDR52]);
261 	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs200",
262 				  &map->phase[MMC_TIMING_MMC_HS200]);
263 	mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs400",
264 				  &map->phase[MMC_TIMING_MMC_HS400]);
265 }
266 EXPORT_SYMBOL(mmc_of_parse_clk_phase);
267 
268 /**
269  * mmc_of_parse() - parse host's device properties
270  * @host: host whose properties should be parsed.
271  *
272  * To keep the rest of the MMC subsystem unaware of whether DT has been
273  * used to to instantiate and configure this host instance or not, we
274  * parse the properties and set respective generic mmc-host flags and
275  * parameters.
276  */
mmc_of_parse(struct mmc_host * host)277 int mmc_of_parse(struct mmc_host *host)
278 {
279 	struct device *dev = host->parent;
280 	u32 bus_width, drv_type, cd_debounce_delay_ms;
281 	int ret;
282 
283 	if (!dev || !dev_fwnode(dev))
284 		return 0;
285 
286 	/* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
287 	if (device_property_read_u32(dev, "bus-width", &bus_width) < 0) {
288 		dev_dbg(host->parent,
289 			"\"bus-width\" property is missing, assuming 1 bit.\n");
290 		bus_width = 1;
291 	}
292 
293 	switch (bus_width) {
294 	case 8:
295 		host->caps |= MMC_CAP_8_BIT_DATA;
296 		fallthrough;	/* Hosts capable of 8-bit can also do 4 bits */
297 	case 4:
298 		host->caps |= MMC_CAP_4_BIT_DATA;
299 		break;
300 	case 1:
301 		break;
302 	default:
303 		dev_err(host->parent,
304 			"Invalid \"bus-width\" value %u!\n", bus_width);
305 		return -EINVAL;
306 	}
307 
308 	/* f_max is obtained from the optional "max-frequency" property */
309 	device_property_read_u32(dev, "max-frequency", &host->f_max);
310 
311 	/*
312 	 * Configure CD and WP pins. They are both by default active low to
313 	 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
314 	 * mmc-gpio helpers are used to attach, configure and use them. If
315 	 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
316 	 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
317 	 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
318 	 * is set. If the "non-removable" property is found, the
319 	 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
320 	 * configuration is performed.
321 	 */
322 
323 	/* Parse Card Detection */
324 
325 	if (device_property_read_bool(dev, "non-removable")) {
326 		host->caps |= MMC_CAP_NONREMOVABLE;
327 	} else {
328 		if (device_property_read_bool(dev, "cd-inverted"))
329 			host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
330 
331 		if (device_property_read_u32(dev, "cd-debounce-delay-ms",
332 					     &cd_debounce_delay_ms))
333 			cd_debounce_delay_ms = 200;
334 
335 		if (device_property_read_bool(dev, "broken-cd"))
336 			host->caps |= MMC_CAP_NEEDS_POLL;
337 
338 		ret = mmc_gpiod_request_cd(host, "cd", 0, false,
339 					   cd_debounce_delay_ms * 1000);
340 		if (!ret)
341 			dev_info(host->parent, "Got CD GPIO\n");
342 		else if (ret != -ENOENT && ret != -ENOSYS)
343 			return ret;
344 	}
345 
346 	/* Parse Write Protection */
347 
348 	if (device_property_read_bool(dev, "wp-inverted"))
349 		host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
350 
351 	ret = mmc_gpiod_request_ro(host, "wp", 0, 0);
352 	if (!ret)
353 		dev_info(host->parent, "Got WP GPIO\n");
354 	else if (ret != -ENOENT && ret != -ENOSYS)
355 		return ret;
356 
357 	if (device_property_read_bool(dev, "disable-wp"))
358 		host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
359 
360 	if (device_property_read_bool(dev, "cap-sd-highspeed"))
361 		host->caps |= MMC_CAP_SD_HIGHSPEED;
362 	if (device_property_read_bool(dev, "cap-mmc-highspeed"))
363 		host->caps |= MMC_CAP_MMC_HIGHSPEED;
364 	if (device_property_read_bool(dev, "sd-uhs-sdr12"))
365 		host->caps |= MMC_CAP_UHS_SDR12;
366 	if (device_property_read_bool(dev, "sd-uhs-sdr25"))
367 		host->caps |= MMC_CAP_UHS_SDR25;
368 	if (device_property_read_bool(dev, "sd-uhs-sdr50"))
369 		host->caps |= MMC_CAP_UHS_SDR50;
370 	if (device_property_read_bool(dev, "sd-uhs-sdr104"))
371 		host->caps |= MMC_CAP_UHS_SDR104;
372 	if (device_property_read_bool(dev, "sd-uhs-ddr50"))
373 		host->caps |= MMC_CAP_UHS_DDR50;
374 	if (device_property_read_bool(dev, "cap-power-off-card"))
375 		host->caps |= MMC_CAP_POWER_OFF_CARD;
376 	if (device_property_read_bool(dev, "cap-mmc-hw-reset"))
377 		host->caps |= MMC_CAP_HW_RESET;
378 	if (device_property_read_bool(dev, "cap-sdio-irq"))
379 		host->caps |= MMC_CAP_SDIO_IRQ;
380 	if (device_property_read_bool(dev, "full-pwr-cycle"))
381 		host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
382 	if (device_property_read_bool(dev, "full-pwr-cycle-in-suspend"))
383 		host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND;
384 	if (device_property_read_bool(dev, "keep-power-in-suspend"))
385 		host->pm_caps |= MMC_PM_KEEP_POWER;
386 	if (device_property_read_bool(dev, "wakeup-source") ||
387 	    device_property_read_bool(dev, "enable-sdio-wakeup")) /* legacy */
388 		host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
389 	if (device_property_read_bool(dev, "mmc-ddr-3_3v"))
390 		host->caps |= MMC_CAP_3_3V_DDR;
391 	if (device_property_read_bool(dev, "mmc-ddr-1_8v"))
392 		host->caps |= MMC_CAP_1_8V_DDR;
393 	if (device_property_read_bool(dev, "mmc-ddr-1_2v"))
394 		host->caps |= MMC_CAP_1_2V_DDR;
395 	if (device_property_read_bool(dev, "mmc-hs200-1_8v"))
396 		host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
397 	if (device_property_read_bool(dev, "mmc-hs200-1_2v"))
398 		host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
399 	if (device_property_read_bool(dev, "mmc-hs400-1_8v"))
400 		host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
401 	if (device_property_read_bool(dev, "mmc-hs400-1_2v"))
402 		host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
403 	if (device_property_read_bool(dev, "mmc-hs400-enhanced-strobe"))
404 		host->caps2 |= MMC_CAP2_HS400_ES;
405 	if (device_property_read_bool(dev, "no-sdio"))
406 		host->caps2 |= MMC_CAP2_NO_SDIO;
407 	if (device_property_read_bool(dev, "no-sd"))
408 		host->caps2 |= MMC_CAP2_NO_SD;
409 	if (device_property_read_bool(dev, "no-mmc"))
410 		host->caps2 |= MMC_CAP2_NO_MMC;
411 	if (device_property_read_bool(dev, "no-mmc-hs400"))
412 		host->caps2 &= ~(MMC_CAP2_HS400_1_8V | MMC_CAP2_HS400_1_2V |
413 				 MMC_CAP2_HS400_ES);
414 
415 	/* Must be after "non-removable" check */
416 	if (device_property_read_u32(dev, "fixed-emmc-driver-type", &drv_type) == 0) {
417 		if (host->caps & MMC_CAP_NONREMOVABLE)
418 			host->fixed_drv_type = drv_type;
419 		else
420 			dev_err(host->parent,
421 				"can't use fixed driver type, media is removable\n");
422 	}
423 
424 	host->dsr_req = !device_property_read_u32(dev, "dsr", &host->dsr);
425 	if (host->dsr_req && (host->dsr & ~0xffff)) {
426 		dev_err(host->parent,
427 			"device tree specified broken value for DSR: 0x%x, ignoring\n",
428 			host->dsr);
429 		host->dsr_req = 0;
430 	}
431 
432 	device_property_read_u32(dev, "post-power-on-delay-ms",
433 				 &host->ios.power_delay_ms);
434 
435 	return mmc_pwrseq_alloc(host);
436 }
437 
438 EXPORT_SYMBOL(mmc_of_parse);
439 
440 /**
441  * mmc_of_parse_voltage - return mask of supported voltages
442  * @host: host whose properties should be parsed.
443  * @mask: mask of voltages available for MMC/SD/SDIO
444  *
445  * Parse the "voltage-ranges" property, returning zero if it is not
446  * found, negative errno if the voltage-range specification is invalid,
447  * or one if the voltage-range is specified and successfully parsed.
448  */
mmc_of_parse_voltage(struct mmc_host * host,u32 * mask)449 int mmc_of_parse_voltage(struct mmc_host *host, u32 *mask)
450 {
451 	const char *prop = "voltage-ranges";
452 	struct device *dev = host->parent;
453 	u32 *voltage_ranges;
454 	int num_ranges, i;
455 	int ret;
456 
457 	if (!device_property_present(dev, prop)) {
458 		dev_dbg(dev, "%s unspecified\n", prop);
459 		return 0;
460 	}
461 
462 	ret = device_property_count_u32(dev, prop);
463 	if (ret < 0)
464 		return ret;
465 
466 	num_ranges = ret / 2;
467 	if (!num_ranges) {
468 		dev_err(dev, "%s empty\n", prop);
469 		return -EINVAL;
470 	}
471 
472 	voltage_ranges = kcalloc(2 * num_ranges, sizeof(*voltage_ranges), GFP_KERNEL);
473 	if (!voltage_ranges)
474 		return -ENOMEM;
475 
476 	ret = device_property_read_u32_array(dev, prop, voltage_ranges, 2 * num_ranges);
477 	if (ret) {
478 		kfree(voltage_ranges);
479 		return ret;
480 	}
481 
482 	for (i = 0; i < num_ranges; i++) {
483 		const int j = i * 2;
484 		u32 ocr_mask;
485 
486 		ocr_mask = mmc_vddrange_to_ocrmask(voltage_ranges[j + 0],
487 						   voltage_ranges[j + 1]);
488 		if (!ocr_mask) {
489 			dev_err(dev, "range #%d in %s is invalid\n", i, prop);
490 			kfree(voltage_ranges);
491 			return -EINVAL;
492 		}
493 		*mask |= ocr_mask;
494 	}
495 
496 	kfree(voltage_ranges);
497 
498 	return 1;
499 }
500 EXPORT_SYMBOL(mmc_of_parse_voltage);
501 
502 /**
503  * mmc_first_nonreserved_index() - get the first index that is not reserved
504  */
mmc_first_nonreserved_index(void)505 static int mmc_first_nonreserved_index(void)
506 {
507 	int max;
508 
509 	max = of_alias_get_highest_id("mmc");
510 	if (max < 0)
511 		return 0;
512 
513 	return max + 1;
514 }
515 
516 /**
517  *	mmc_alloc_host - initialise the per-host structure.
518  *	@extra: sizeof private data structure
519  *	@dev: pointer to host device model structure
520  *
521  *	Initialise the per-host structure.
522  */
mmc_alloc_host(int extra,struct device * dev)523 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
524 {
525 	int index;
526 	struct mmc_host *host;
527 	int alias_id, min_idx, max_idx;
528 
529 	host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
530 	if (!host)
531 		return NULL;
532 
533 	/* scanning will be enabled when we're ready */
534 	host->rescan_disable = 1;
535 
536 	alias_id = of_alias_get_id(dev->of_node, "mmc");
537 	if (alias_id >= 0) {
538 		index = alias_id;
539 	} else {
540 		min_idx = mmc_first_nonreserved_index();
541 		max_idx = 0;
542 
543 		index = ida_simple_get(&mmc_host_ida, min_idx, max_idx, GFP_KERNEL);
544 		if (index < 0) {
545 			kfree(host);
546 			return NULL;
547 		}
548 	}
549 
550 	host->index = index;
551 
552 	dev_set_name(&host->class_dev, "mmc%d", host->index);
553 	host->ws = wakeup_source_register(NULL, dev_name(&host->class_dev));
554 
555 	host->parent = dev;
556 	host->class_dev.parent = dev;
557 	host->class_dev.class = &mmc_host_class;
558 	device_initialize(&host->class_dev);
559 	device_enable_async_suspend(&host->class_dev);
560 
561 	if (mmc_gpio_alloc(host)) {
562 		put_device(&host->class_dev);
563 		return NULL;
564 	}
565 
566 	spin_lock_init(&host->lock);
567 	init_waitqueue_head(&host->wq);
568 	INIT_DELAYED_WORK(&host->detect, mmc_rescan);
569 	INIT_WORK(&host->sdio_irq_work, sdio_irq_work);
570 	timer_setup(&host->retune_timer, mmc_retune_timer, 0);
571 
572 	/*
573 	 * By default, hosts do not support SGIO or large requests.
574 	 * They have to set these according to their abilities.
575 	 */
576 	host->max_segs = 1;
577 	host->max_seg_size = PAGE_SIZE;
578 
579 	host->max_req_size = PAGE_SIZE;
580 	host->max_blk_size = 512;
581 	host->max_blk_count = PAGE_SIZE / 512;
582 
583 	host->fixed_drv_type = -EINVAL;
584 	host->ios.power_delay_ms = 10;
585 	host->ios.power_mode = MMC_POWER_UNDEFINED;
586 
587 	return host;
588 }
589 
590 EXPORT_SYMBOL(mmc_alloc_host);
591 
mmc_validate_host_caps(struct mmc_host * host)592 static int mmc_validate_host_caps(struct mmc_host *host)
593 {
594 	struct device *dev = host->parent;
595 	u32 caps = host->caps, caps2 = host->caps2;
596 
597 	if (caps & MMC_CAP_SDIO_IRQ && !host->ops->enable_sdio_irq) {
598 		dev_warn(dev, "missing ->enable_sdio_irq() ops\n");
599 		return -EINVAL;
600 	}
601 
602 	if (caps2 & (MMC_CAP2_HS400_ES | MMC_CAP2_HS400) &&
603 	    !(caps & MMC_CAP_8_BIT_DATA) && !(caps2 & MMC_CAP2_NO_MMC)) {
604 		dev_warn(dev, "drop HS400 support since no 8-bit bus\n");
605 		host->caps2 = caps2 & ~MMC_CAP2_HS400_ES & ~MMC_CAP2_HS400;
606 	}
607 
608 	return 0;
609 }
610 
611 /**
612  *	mmc_add_host - initialise host hardware
613  *	@host: mmc host
614  *
615  *	Register the host with the driver model. The host must be
616  *	prepared to start servicing requests before this function
617  *	completes.
618  */
mmc_add_host(struct mmc_host * host)619 int mmc_add_host(struct mmc_host *host)
620 {
621 	int err;
622 
623 	err = mmc_validate_host_caps(host);
624 	if (err)
625 		return err;
626 
627 	err = device_add(&host->class_dev);
628 	if (err)
629 		return err;
630 
631 	led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
632 
633 #ifdef CONFIG_DEBUG_FS
634 	mmc_add_host_debugfs(host);
635 #endif
636 
637 	mmc_start_host(host);
638 	return 0;
639 }
640 
641 EXPORT_SYMBOL(mmc_add_host);
642 
643 /**
644  *	mmc_remove_host - remove host hardware
645  *	@host: mmc host
646  *
647  *	Unregister and remove all cards associated with this host,
648  *	and power down the MMC bus. No new requests will be issued
649  *	after this function has returned.
650  */
mmc_remove_host(struct mmc_host * host)651 void mmc_remove_host(struct mmc_host *host)
652 {
653 	mmc_stop_host(host);
654 
655 #ifdef CONFIG_DEBUG_FS
656 	mmc_remove_host_debugfs(host);
657 #endif
658 
659 	device_del(&host->class_dev);
660 
661 	led_trigger_unregister_simple(host->led);
662 }
663 
664 EXPORT_SYMBOL(mmc_remove_host);
665 
666 /**
667  *	mmc_free_host - free the host structure
668  *	@host: mmc host
669  *
670  *	Free the host once all references to it have been dropped.
671  */
mmc_free_host(struct mmc_host * host)672 void mmc_free_host(struct mmc_host *host)
673 {
674 	cancel_delayed_work_sync(&host->detect);
675 	mmc_pwrseq_free(host);
676 	put_device(&host->class_dev);
677 }
678 
679 EXPORT_SYMBOL(mmc_free_host);
680