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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/of.h>
19#include <linux/of_gpio.h>
20#include <linux/pagemap.h>
21#include <linux/export.h>
22#include <linux/leds.h>
23#include <linux/slab.h>
24#include <linux/suspend.h>
25
26#include <linux/mmc/host.h>
27#include <linux/mmc/card.h>
28#include <linux/mmc/slot-gpio.h>
29
30#include "core.h"
31#include "host.h"
32
33#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
34
35static void mmc_host_classdev_release(struct device *dev)
36{
37 struct mmc_host *host = cls_dev_to_mmc_host(dev);
38 mutex_destroy(&host->slot.lock);
39 kfree(host);
40}
41
42static struct class mmc_host_class = {
43 .name = "mmc_host",
44 .dev_release = mmc_host_classdev_release,
45};
46
47int mmc_register_host_class(void)
48{
49 return class_register(&mmc_host_class);
50}
51
52void mmc_unregister_host_class(void)
53{
54 class_unregister(&mmc_host_class);
55}
56
57static DEFINE_IDR(mmc_host_idr);
58static DEFINE_SPINLOCK(mmc_host_lock);
59
60#ifdef CONFIG_MMC_CLKGATE
61static ssize_t clkgate_delay_show(struct device *dev,
62 struct device_attribute *attr, char *buf)
63{
64 struct mmc_host *host = cls_dev_to_mmc_host(dev);
65 return snprintf(buf, PAGE_SIZE, "%lu\n", host->clkgate_delay);
66}
67
68static ssize_t clkgate_delay_store(struct device *dev,
69 struct device_attribute *attr, const char *buf, size_t count)
70{
71 struct mmc_host *host = cls_dev_to_mmc_host(dev);
72 unsigned long flags, value;
73
74 if (kstrtoul(buf, 0, &value))
75 return -EINVAL;
76
77 spin_lock_irqsave(&host->clk_lock, flags);
78 host->clkgate_delay = value;
79 spin_unlock_irqrestore(&host->clk_lock, flags);
80 return count;
81}
82
83/*
84 * Enabling clock gating will make the core call out to the host
85 * once up and once down when it performs a request or card operation
86 * intermingled in any fashion. The driver will see this through
87 * set_ios() operations with ios.clock field set to 0 to gate (disable)
88 * the block clock, and to the old frequency to enable it again.
89 */
90static void mmc_host_clk_gate_delayed(struct mmc_host *host)
91{
92 unsigned long tick_ns;
93 unsigned long freq = host->ios.clock;
94 unsigned long flags;
95
96 if (!freq) {
97 pr_debug("%s: frequency set to 0 in disable function, "
98 "this means the clock is already disabled.\n",
99 mmc_hostname(host));
100 return;
101 }
102 /*
103 * New requests may have appeared while we were scheduling,
104 * then there is no reason to delay the check before
105 * clk_disable().
106 */
107 spin_lock_irqsave(&host->clk_lock, flags);
108
109 /*
110 * Delay n bus cycles (at least 8 from MMC spec) before attempting
111 * to disable the MCI block clock. The reference count may have
112 * gone up again after this delay due to rescheduling!
113 */
114 if (!host->clk_requests) {
115 spin_unlock_irqrestore(&host->clk_lock, flags);
116 tick_ns = DIV_ROUND_UP(1000000000, freq);
117 ndelay(host->clk_delay * tick_ns);
118 } else {
119 /* New users appeared while waiting for this work */
120 spin_unlock_irqrestore(&host->clk_lock, flags);
121 return;
122 }
123 mutex_lock(&host->clk_gate_mutex);
124 spin_lock_irqsave(&host->clk_lock, flags);
125 if (!host->clk_requests) {
126 spin_unlock_irqrestore(&host->clk_lock, flags);
127 /* This will set host->ios.clock to 0 */
128 mmc_gate_clock(host);
129 spin_lock_irqsave(&host->clk_lock, flags);
130 pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
131 }
132 spin_unlock_irqrestore(&host->clk_lock, flags);
133 mutex_unlock(&host->clk_gate_mutex);
134}
135
136/*
137 * Internal work. Work to disable the clock at some later point.
138 */
139static void mmc_host_clk_gate_work(struct work_struct *work)
140{
141 struct mmc_host *host = container_of(work, struct mmc_host,
142 clk_gate_work.work);
143
144 mmc_host_clk_gate_delayed(host);
145}
146
147/**
148 * mmc_host_clk_hold - ungate hardware MCI clocks
149 * @host: host to ungate.
150 *
151 * Makes sure the host ios.clock is restored to a non-zero value
152 * past this call. Increase clock reference count and ungate clock
153 * if we're the first user.
154 */
155void mmc_host_clk_hold(struct mmc_host *host)
156{
157 unsigned long flags;
158
159 /* cancel any clock gating work scheduled by mmc_host_clk_release() */
160 cancel_delayed_work_sync(&host->clk_gate_work);
161 mutex_lock(&host->clk_gate_mutex);
162 spin_lock_irqsave(&host->clk_lock, flags);
163 if (host->clk_gated) {
164 spin_unlock_irqrestore(&host->clk_lock, flags);
165 mmc_ungate_clock(host);
166 spin_lock_irqsave(&host->clk_lock, flags);
167 pr_debug("%s: ungated MCI clock\n", mmc_hostname(host));
168 }
169 host->clk_requests++;
170 spin_unlock_irqrestore(&host->clk_lock, flags);
171 mutex_unlock(&host->clk_gate_mutex);
172}
173
174/**
175 * mmc_host_may_gate_card - check if this card may be gated
176 * @card: card to check.
177 */
178static bool mmc_host_may_gate_card(struct mmc_card *card)
179{
180 /* If there is no card we may gate it */
181 if (!card)
182 return true;
183 /*
184 * Don't gate SDIO cards! These need to be clocked at all times
185 * since they may be independent systems generating interrupts
186 * and other events. The clock requests counter from the core will
187 * go down to zero since the core does not need it, but we will not
188 * gate the clock, because there is somebody out there that may still
189 * be using it.
190 */
191 return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING);
192}
193
194/**
195 * mmc_host_clk_release - gate off hardware MCI clocks
196 * @host: host to gate.
197 *
198 * Calls the host driver with ios.clock set to zero as often as possible
199 * in order to gate off hardware MCI clocks. Decrease clock reference
200 * count and schedule disabling of clock.
201 */
202void mmc_host_clk_release(struct mmc_host *host)
203{
204 unsigned long flags;
205
206 spin_lock_irqsave(&host->clk_lock, flags);
207 host->clk_requests--;
208 if (mmc_host_may_gate_card(host->card) &&
209 !host->clk_requests)
210 schedule_delayed_work(&host->clk_gate_work,
211 msecs_to_jiffies(host->clkgate_delay));
212 spin_unlock_irqrestore(&host->clk_lock, flags);
213}
214
215/**
216 * mmc_host_clk_rate - get current clock frequency setting
217 * @host: host to get the clock frequency for.
218 *
219 * Returns current clock frequency regardless of gating.
220 */
221unsigned int mmc_host_clk_rate(struct mmc_host *host)
222{
223 unsigned long freq;
224 unsigned long flags;
225
226 spin_lock_irqsave(&host->clk_lock, flags);
227 if (host->clk_gated)
228 freq = host->clk_old;
229 else
230 freq = host->ios.clock;
231 spin_unlock_irqrestore(&host->clk_lock, flags);
232 return freq;
233}
234
235/**
236 * mmc_host_clk_init - set up clock gating code
237 * @host: host with potential clock to control
238 */
239static inline void mmc_host_clk_init(struct mmc_host *host)
240{
241 host->clk_requests = 0;
242 /* Hold MCI clock for 8 cycles by default */
243 host->clk_delay = 8;
244 /*
245 * Default clock gating delay is 0ms to avoid wasting power.
246 * This value can be tuned by writing into sysfs entry.
247 */
248 host->clkgate_delay = 0;
249 host->clk_gated = false;
250 INIT_DELAYED_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
251 spin_lock_init(&host->clk_lock);
252 mutex_init(&host->clk_gate_mutex);
253}
254
255/**
256 * mmc_host_clk_exit - shut down clock gating code
257 * @host: host with potential clock to control
258 */
259static inline void mmc_host_clk_exit(struct mmc_host *host)
260{
261 /*
262 * Wait for any outstanding gate and then make sure we're
263 * ungated before exiting.
264 */
265 if (cancel_delayed_work_sync(&host->clk_gate_work))
266 mmc_host_clk_gate_delayed(host);
267 if (host->clk_gated)
268 mmc_host_clk_hold(host);
269 /* There should be only one user now */
270 WARN_ON(host->clk_requests > 1);
271}
272
273static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
274{
275 host->clkgate_delay_attr.show = clkgate_delay_show;
276 host->clkgate_delay_attr.store = clkgate_delay_store;
277 sysfs_attr_init(&host->clkgate_delay_attr.attr);
278 host->clkgate_delay_attr.attr.name = "clkgate_delay";
279 host->clkgate_delay_attr.attr.mode = S_IRUGO | S_IWUSR;
280 if (device_create_file(&host->class_dev, &host->clkgate_delay_attr))
281 pr_err("%s: Failed to create clkgate_delay sysfs entry\n",
282 mmc_hostname(host));
283}
284#else
285
286static inline void mmc_host_clk_init(struct mmc_host *host)
287{
288}
289
290static inline void mmc_host_clk_exit(struct mmc_host *host)
291{
292}
293
294static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
295{
296}
297
298#endif
299
300/**
301 * mmc_of_parse() - parse host's device-tree node
302 * @host: host whose node should be parsed.
303 *
304 * To keep the rest of the MMC subsystem unaware of whether DT has been
305 * used to to instantiate and configure this host instance or not, we
306 * parse the properties and set respective generic mmc-host flags and
307 * parameters.
308 */
309int mmc_of_parse(struct mmc_host *host)
310{
311 struct device_node *np;
312 u32 bus_width;
313 bool explicit_inv_wp, gpio_inv_wp = false;
314 enum of_gpio_flags flags;
315 int len, ret, gpio;
316
317 if (!host->parent || !host->parent->of_node)
318 return 0;
319
320 np = host->parent->of_node;
321
322 /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
323 if (of_property_read_u32(np, "bus-width", &bus_width) < 0) {
324 dev_dbg(host->parent,
325 "\"bus-width\" property is missing, assuming 1 bit.\n");
326 bus_width = 1;
327 }
328
329 switch (bus_width) {
330 case 8:
331 host->caps |= MMC_CAP_8_BIT_DATA;
332 /* Hosts capable of 8-bit transfers can also do 4 bits */
333 case 4:
334 host->caps |= MMC_CAP_4_BIT_DATA;
335 break;
336 case 1:
337 break;
338 default:
339 dev_err(host->parent,
340 "Invalid \"bus-width\" value %u!\n", bus_width);
341 return -EINVAL;
342 }
343
344 /* f_max is obtained from the optional "max-frequency" property */
345 of_property_read_u32(np, "max-frequency", &host->f_max);
346
347 /*
348 * Configure CD and WP pins. They are both by default active low to
349 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
350 * mmc-gpio helpers are used to attach, configure and use them. If
351 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
352 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
353 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
354 * is set. If the "non-removable" property is found, the
355 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
356 * configuration is performed.
357 */
358
359 /* Parse Card Detection */
360 if (of_find_property(np, "non-removable", &len)) {
361 host->caps |= MMC_CAP_NONREMOVABLE;
362 } else {
363 bool explicit_inv_cd, gpio_inv_cd = false;
364
365 explicit_inv_cd = of_property_read_bool(np, "cd-inverted");
366
367 if (of_find_property(np, "broken-cd", &len))
368 host->caps |= MMC_CAP_NEEDS_POLL;
369
370 gpio = of_get_named_gpio_flags(np, "cd-gpios", 0, &flags);
371 if (gpio == -EPROBE_DEFER)
372 return gpio;
373 if (gpio_is_valid(gpio)) {
374 if (!(flags & OF_GPIO_ACTIVE_LOW))
375 gpio_inv_cd = true;
376
377 ret = mmc_gpio_request_cd(host, gpio, 0);
378 if (ret < 0) {
379 dev_err(host->parent,
380 "Failed to request CD GPIO #%d: %d!\n",
381 gpio, ret);
382 return ret;
383 } else {
384 dev_info(host->parent, "Got CD GPIO #%d.\n",
385 gpio);
386 }
387 }
388
389 if (explicit_inv_cd ^ gpio_inv_cd)
390 host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
391 }
392
393 /* Parse Write Protection */
394 explicit_inv_wp = of_property_read_bool(np, "wp-inverted");
395
396 gpio = of_get_named_gpio_flags(np, "wp-gpios", 0, &flags);
397 if (gpio == -EPROBE_DEFER) {
398 ret = -EPROBE_DEFER;
399 goto out;
400 }
401 if (gpio_is_valid(gpio)) {
402 if (!(flags & OF_GPIO_ACTIVE_LOW))
403 gpio_inv_wp = true;
404
405 ret = mmc_gpio_request_ro(host, gpio);
406 if (ret < 0) {
407 dev_err(host->parent,
408 "Failed to request WP GPIO: %d!\n", ret);
409 goto out;
410 } else {
411 dev_info(host->parent, "Got WP GPIO #%d.\n",
412 gpio);
413 }
414 }
415 if (explicit_inv_wp ^ gpio_inv_wp)
416 host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
417
418 if (of_find_property(np, "cap-sd-highspeed", &len))
419 host->caps |= MMC_CAP_SD_HIGHSPEED;
420 if (of_find_property(np, "cap-mmc-highspeed", &len))
421 host->caps |= MMC_CAP_MMC_HIGHSPEED;
422 if (of_find_property(np, "sd-uhs-sdr12", &len))
423 host->caps |= MMC_CAP_UHS_SDR12;
424 if (of_find_property(np, "sd-uhs-sdr25", &len))
425 host->caps |= MMC_CAP_UHS_SDR25;
426 if (of_find_property(np, "sd-uhs-sdr50", &len))
427 host->caps |= MMC_CAP_UHS_SDR50;
428 if (of_find_property(np, "sd-uhs-sdr104", &len))
429 host->caps |= MMC_CAP_UHS_SDR104;
430 if (of_find_property(np, "sd-uhs-ddr50", &len))
431 host->caps |= MMC_CAP_UHS_DDR50;
432 if (of_find_property(np, "cap-power-off-card", &len))
433 host->caps |= MMC_CAP_POWER_OFF_CARD;
434 if (of_find_property(np, "cap-sdio-irq", &len))
435 host->caps |= MMC_CAP_SDIO_IRQ;
436 if (of_find_property(np, "full-pwr-cycle", &len))
437 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
438 if (of_find_property(np, "keep-power-in-suspend", &len))
439 host->pm_caps |= MMC_PM_KEEP_POWER;
440 if (of_find_property(np, "enable-sdio-wakeup", &len))
441 host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
442 if (of_find_property(np, "mmc-ddr-1_8v", &len))
443 host->caps |= MMC_CAP_1_8V_DDR;
444 if (of_find_property(np, "mmc-ddr-1_2v", &len))
445 host->caps |= MMC_CAP_1_2V_DDR;
446 if (of_find_property(np, "mmc-hs200-1_8v", &len))
447 host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
448 if (of_find_property(np, "mmc-hs200-1_2v", &len))
449 host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
450
451 return 0;
452
453out:
454 mmc_gpio_free_cd(host);
455 return ret;
456}
457
458EXPORT_SYMBOL(mmc_of_parse);
459
460/**
461 * mmc_alloc_host - initialise the per-host structure.
462 * @extra: sizeof private data structure
463 * @dev: pointer to host device model structure
464 *
465 * Initialise the per-host structure.
466 */
467struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
468{
469 int err;
470 struct mmc_host *host;
471
472 host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
473 if (!host)
474 return NULL;
475
476 /* scanning will be enabled when we're ready */
477 host->rescan_disable = 1;
478 idr_preload(GFP_KERNEL);
479 spin_lock(&mmc_host_lock);
480 err = idr_alloc(&mmc_host_idr, host, 0, 0, GFP_NOWAIT);
481 if (err >= 0)
482 host->index = err;
483 spin_unlock(&mmc_host_lock);
484 idr_preload_end();
485 if (err < 0)
486 goto free;
487
488 dev_set_name(&host->class_dev, "mmc%d", host->index);
489
490 host->parent = dev;
491 host->class_dev.parent = dev;
492 host->class_dev.class = &mmc_host_class;
493 device_initialize(&host->class_dev);
494
495 mmc_host_clk_init(host);
496
497 mutex_init(&host->slot.lock);
498 host->slot.cd_irq = -EINVAL;
499
500 spin_lock_init(&host->lock);
501 init_waitqueue_head(&host->wq);
502 INIT_DELAYED_WORK(&host->detect, mmc_rescan);
503#ifdef CONFIG_PM
504 host->pm_notify.notifier_call = mmc_pm_notify;
505#endif
506
507 /*
508 * By default, hosts do not support SGIO or large requests.
509 * They have to set these according to their abilities.
510 */
511 host->max_segs = 1;
512 host->max_seg_size = PAGE_CACHE_SIZE;
513
514 host->max_req_size = PAGE_CACHE_SIZE;
515 host->max_blk_size = 512;
516 host->max_blk_count = PAGE_CACHE_SIZE / 512;
517
518 return host;
519
520free:
521 kfree(host);
522 return NULL;
523}
524
525EXPORT_SYMBOL(mmc_alloc_host);
526
527/**
528 * mmc_add_host - initialise host hardware
529 * @host: mmc host
530 *
531 * Register the host with the driver model. The host must be
532 * prepared to start servicing requests before this function
533 * completes.
534 */
535int mmc_add_host(struct mmc_host *host)
536{
537 int err;
538
539 WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
540 !host->ops->enable_sdio_irq);
541
542 err = device_add(&host->class_dev);
543 if (err)
544 return err;
545
546 led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
547
548#ifdef CONFIG_DEBUG_FS
549 mmc_add_host_debugfs(host);
550#endif
551 mmc_host_clk_sysfs_init(host);
552
553 mmc_start_host(host);
554 register_pm_notifier(&host->pm_notify);
555
556 return 0;
557}
558
559EXPORT_SYMBOL(mmc_add_host);
560
561/**
562 * mmc_remove_host - remove host hardware
563 * @host: mmc host
564 *
565 * Unregister and remove all cards associated with this host,
566 * and power down the MMC bus. No new requests will be issued
567 * after this function has returned.
568 */
569void mmc_remove_host(struct mmc_host *host)
570{
571 unregister_pm_notifier(&host->pm_notify);
572 mmc_stop_host(host);
573
574#ifdef CONFIG_DEBUG_FS
575 mmc_remove_host_debugfs(host);
576#endif
577
578 device_del(&host->class_dev);
579
580 led_trigger_unregister_simple(host->led);
581
582 mmc_host_clk_exit(host);
583}
584
585EXPORT_SYMBOL(mmc_remove_host);
586
587/**
588 * mmc_free_host - free the host structure
589 * @host: mmc host
590 *
591 * Free the host once all references to it have been dropped.
592 */
593void mmc_free_host(struct mmc_host *host)
594{
595 spin_lock(&mmc_host_lock);
596 idr_remove(&mmc_host_idr, host->index);
597 spin_unlock(&mmc_host_lock);
598
599 put_device(&host->class_dev);
600}
601
602EXPORT_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);