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