Loading...
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);
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/export.h>
20#include <linux/leds.h>
21#include <linux/slab.h>
22#include <linux/suspend.h>
23
24#include <linux/mmc/host.h>
25#include <linux/mmc/card.h>
26
27#include "core.h"
28#include "host.h"
29
30#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
31
32static void mmc_host_classdev_release(struct device *dev)
33{
34 struct mmc_host *host = cls_dev_to_mmc_host(dev);
35 kfree(host);
36}
37
38static struct class mmc_host_class = {
39 .name = "mmc_host",
40 .dev_release = mmc_host_classdev_release,
41};
42
43int mmc_register_host_class(void)
44{
45 return class_register(&mmc_host_class);
46}
47
48void mmc_unregister_host_class(void)
49{
50 class_unregister(&mmc_host_class);
51}
52
53static DEFINE_IDR(mmc_host_idr);
54static DEFINE_SPINLOCK(mmc_host_lock);
55
56#ifdef CONFIG_MMC_CLKGATE
57static ssize_t clkgate_delay_show(struct device *dev,
58 struct device_attribute *attr, char *buf)
59{
60 struct mmc_host *host = cls_dev_to_mmc_host(dev);
61 return snprintf(buf, PAGE_SIZE, "%lu\n", host->clkgate_delay);
62}
63
64static ssize_t clkgate_delay_store(struct device *dev,
65 struct device_attribute *attr, const char *buf, size_t count)
66{
67 struct mmc_host *host = cls_dev_to_mmc_host(dev);
68 unsigned long flags, value;
69
70 if (kstrtoul(buf, 0, &value))
71 return -EINVAL;
72
73 spin_lock_irqsave(&host->clk_lock, flags);
74 host->clkgate_delay = value;
75 spin_unlock_irqrestore(&host->clk_lock, flags);
76 return count;
77}
78
79/*
80 * Enabling clock gating will make the core call out to the host
81 * once up and once down when it performs a request or card operation
82 * intermingled in any fashion. The driver will see this through
83 * set_ios() operations with ios.clock field set to 0 to gate (disable)
84 * the block clock, and to the old frequency to enable it again.
85 */
86static void mmc_host_clk_gate_delayed(struct mmc_host *host)
87{
88 unsigned long tick_ns;
89 unsigned long freq = host->ios.clock;
90 unsigned long flags;
91
92 if (!freq) {
93 pr_debug("%s: frequency set to 0 in disable function, "
94 "this means the clock is already disabled.\n",
95 mmc_hostname(host));
96 return;
97 }
98 /*
99 * New requests may have appeared while we were scheduling,
100 * then there is no reason to delay the check before
101 * clk_disable().
102 */
103 spin_lock_irqsave(&host->clk_lock, flags);
104
105 /*
106 * Delay n bus cycles (at least 8 from MMC spec) before attempting
107 * to disable the MCI block clock. The reference count may have
108 * gone up again after this delay due to rescheduling!
109 */
110 if (!host->clk_requests) {
111 spin_unlock_irqrestore(&host->clk_lock, flags);
112 tick_ns = DIV_ROUND_UP(1000000000, freq);
113 ndelay(host->clk_delay * tick_ns);
114 } else {
115 /* New users appeared while waiting for this work */
116 spin_unlock_irqrestore(&host->clk_lock, flags);
117 return;
118 }
119 mutex_lock(&host->clk_gate_mutex);
120 spin_lock_irqsave(&host->clk_lock, flags);
121 if (!host->clk_requests) {
122 spin_unlock_irqrestore(&host->clk_lock, flags);
123 /* This will set host->ios.clock to 0 */
124 mmc_gate_clock(host);
125 spin_lock_irqsave(&host->clk_lock, flags);
126 pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
127 }
128 spin_unlock_irqrestore(&host->clk_lock, flags);
129 mutex_unlock(&host->clk_gate_mutex);
130}
131
132/*
133 * Internal work. Work to disable the clock at some later point.
134 */
135static void mmc_host_clk_gate_work(struct work_struct *work)
136{
137 struct mmc_host *host = container_of(work, struct mmc_host,
138 clk_gate_work.work);
139
140 mmc_host_clk_gate_delayed(host);
141}
142
143/**
144 * mmc_host_clk_hold - ungate hardware MCI clocks
145 * @host: host to ungate.
146 *
147 * Makes sure the host ios.clock is restored to a non-zero value
148 * past this call. Increase clock reference count and ungate clock
149 * if we're the first user.
150 */
151void mmc_host_clk_hold(struct mmc_host *host)
152{
153 unsigned long flags;
154
155 /* cancel any clock gating work scheduled by mmc_host_clk_release() */
156 cancel_delayed_work_sync(&host->clk_gate_work);
157 mutex_lock(&host->clk_gate_mutex);
158 spin_lock_irqsave(&host->clk_lock, flags);
159 if (host->clk_gated) {
160 spin_unlock_irqrestore(&host->clk_lock, flags);
161 mmc_ungate_clock(host);
162 spin_lock_irqsave(&host->clk_lock, flags);
163 pr_debug("%s: ungated MCI clock\n", mmc_hostname(host));
164 }
165 host->clk_requests++;
166 spin_unlock_irqrestore(&host->clk_lock, flags);
167 mutex_unlock(&host->clk_gate_mutex);
168}
169
170/**
171 * mmc_host_may_gate_card - check if this card may be gated
172 * @card: card to check.
173 */
174static bool mmc_host_may_gate_card(struct mmc_card *card)
175{
176 /* If there is no card we may gate it */
177 if (!card)
178 return true;
179 /*
180 * Don't gate SDIO cards! These need to be clocked at all times
181 * since they may be independent systems generating interrupts
182 * and other events. The clock requests counter from the core will
183 * go down to zero since the core does not need it, but we will not
184 * gate the clock, because there is somebody out there that may still
185 * be using it.
186 */
187 return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING);
188}
189
190/**
191 * mmc_host_clk_release - gate off hardware MCI clocks
192 * @host: host to gate.
193 *
194 * Calls the host driver with ios.clock set to zero as often as possible
195 * in order to gate off hardware MCI clocks. Decrease clock reference
196 * count and schedule disabling of clock.
197 */
198void mmc_host_clk_release(struct mmc_host *host)
199{
200 unsigned long flags;
201
202 spin_lock_irqsave(&host->clk_lock, flags);
203 host->clk_requests--;
204 if (mmc_host_may_gate_card(host->card) &&
205 !host->clk_requests)
206 queue_delayed_work(system_nrt_wq, &host->clk_gate_work,
207 msecs_to_jiffies(host->clkgate_delay));
208 spin_unlock_irqrestore(&host->clk_lock, flags);
209}
210
211/**
212 * mmc_host_clk_rate - get current clock frequency setting
213 * @host: host to get the clock frequency for.
214 *
215 * Returns current clock frequency regardless of gating.
216 */
217unsigned int mmc_host_clk_rate(struct mmc_host *host)
218{
219 unsigned long freq;
220 unsigned long flags;
221
222 spin_lock_irqsave(&host->clk_lock, flags);
223 if (host->clk_gated)
224 freq = host->clk_old;
225 else
226 freq = host->ios.clock;
227 spin_unlock_irqrestore(&host->clk_lock, flags);
228 return freq;
229}
230
231/**
232 * mmc_host_clk_init - set up clock gating code
233 * @host: host with potential clock to control
234 */
235static inline void mmc_host_clk_init(struct mmc_host *host)
236{
237 host->clk_requests = 0;
238 /* Hold MCI clock for 8 cycles by default */
239 host->clk_delay = 8;
240 /*
241 * Default clock gating delay is 0ms to avoid wasting power.
242 * This value can be tuned by writing into sysfs entry.
243 */
244 host->clkgate_delay = 0;
245 host->clk_gated = false;
246 INIT_DELAYED_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
247 spin_lock_init(&host->clk_lock);
248 mutex_init(&host->clk_gate_mutex);
249}
250
251/**
252 * mmc_host_clk_exit - shut down clock gating code
253 * @host: host with potential clock to control
254 */
255static inline void mmc_host_clk_exit(struct mmc_host *host)
256{
257 /*
258 * Wait for any outstanding gate and then make sure we're
259 * ungated before exiting.
260 */
261 if (cancel_delayed_work_sync(&host->clk_gate_work))
262 mmc_host_clk_gate_delayed(host);
263 if (host->clk_gated)
264 mmc_host_clk_hold(host);
265 /* There should be only one user now */
266 WARN_ON(host->clk_requests > 1);
267}
268
269static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
270{
271 host->clkgate_delay_attr.show = clkgate_delay_show;
272 host->clkgate_delay_attr.store = clkgate_delay_store;
273 sysfs_attr_init(&host->clkgate_delay_attr.attr);
274 host->clkgate_delay_attr.attr.name = "clkgate_delay";
275 host->clkgate_delay_attr.attr.mode = S_IRUGO | S_IWUSR;
276 if (device_create_file(&host->class_dev, &host->clkgate_delay_attr))
277 pr_err("%s: Failed to create clkgate_delay sysfs entry\n",
278 mmc_hostname(host));
279}
280#else
281
282static inline void mmc_host_clk_init(struct mmc_host *host)
283{
284}
285
286static inline void mmc_host_clk_exit(struct mmc_host *host)
287{
288}
289
290static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
291{
292}
293
294#endif
295
296/**
297 * mmc_alloc_host - initialise the per-host structure.
298 * @extra: sizeof private data structure
299 * @dev: pointer to host device model structure
300 *
301 * Initialise the per-host structure.
302 */
303struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
304{
305 int err;
306 struct mmc_host *host;
307
308 if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
309 return NULL;
310
311 host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
312 if (!host)
313 return NULL;
314
315 spin_lock(&mmc_host_lock);
316 err = idr_get_new(&mmc_host_idr, host, &host->index);
317 spin_unlock(&mmc_host_lock);
318 if (err)
319 goto free;
320
321 dev_set_name(&host->class_dev, "mmc%d", host->index);
322
323 host->parent = dev;
324 host->class_dev.parent = dev;
325 host->class_dev.class = &mmc_host_class;
326 device_initialize(&host->class_dev);
327
328 mmc_host_clk_init(host);
329
330 spin_lock_init(&host->lock);
331 init_waitqueue_head(&host->wq);
332 INIT_DELAYED_WORK(&host->detect, mmc_rescan);
333#ifdef CONFIG_PM
334 host->pm_notify.notifier_call = mmc_pm_notify;
335#endif
336
337 /*
338 * By default, hosts do not support SGIO or large requests.
339 * They have to set these according to their abilities.
340 */
341 host->max_segs = 1;
342 host->max_seg_size = PAGE_CACHE_SIZE;
343
344 host->max_req_size = PAGE_CACHE_SIZE;
345 host->max_blk_size = 512;
346 host->max_blk_count = PAGE_CACHE_SIZE / 512;
347
348 return host;
349
350free:
351 kfree(host);
352 return NULL;
353}
354
355EXPORT_SYMBOL(mmc_alloc_host);
356
357/**
358 * mmc_add_host - initialise host hardware
359 * @host: mmc host
360 *
361 * Register the host with the driver model. The host must be
362 * prepared to start servicing requests before this function
363 * completes.
364 */
365int mmc_add_host(struct mmc_host *host)
366{
367 int err;
368
369 WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
370 !host->ops->enable_sdio_irq);
371
372 err = device_add(&host->class_dev);
373 if (err)
374 return err;
375
376 led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
377
378#ifdef CONFIG_DEBUG_FS
379 mmc_add_host_debugfs(host);
380#endif
381 mmc_host_clk_sysfs_init(host);
382
383 mmc_start_host(host);
384 register_pm_notifier(&host->pm_notify);
385
386 return 0;
387}
388
389EXPORT_SYMBOL(mmc_add_host);
390
391/**
392 * mmc_remove_host - remove host hardware
393 * @host: mmc host
394 *
395 * Unregister and remove all cards associated with this host,
396 * and power down the MMC bus. No new requests will be issued
397 * after this function has returned.
398 */
399void mmc_remove_host(struct mmc_host *host)
400{
401 unregister_pm_notifier(&host->pm_notify);
402 mmc_stop_host(host);
403
404#ifdef CONFIG_DEBUG_FS
405 mmc_remove_host_debugfs(host);
406#endif
407
408 device_del(&host->class_dev);
409
410 led_trigger_unregister_simple(host->led);
411
412 mmc_host_clk_exit(host);
413}
414
415EXPORT_SYMBOL(mmc_remove_host);
416
417/**
418 * mmc_free_host - free the host structure
419 * @host: mmc host
420 *
421 * Free the host once all references to it have been dropped.
422 */
423void mmc_free_host(struct mmc_host *host)
424{
425 spin_lock(&mmc_host_lock);
426 idr_remove(&mmc_host_idr, host->index);
427 spin_unlock(&mmc_host_lock);
428
429 put_device(&host->class_dev);
430}
431
432EXPORT_SYMBOL(mmc_free_host);