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b93931a6 PO |
1 | /* |
2 | * linux/drivers/mmc/core/host.c | |
3 | * | |
4 | * Copyright (C) 2003 Russell King, All Rights Reserved. | |
ff3112f5 | 5 | * Copyright (C) 2007-2008 Pierre Ossman |
04566831 | 6 | * Copyright (C) 2010 Linus Walleij |
b93931a6 PO |
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> | |
af8350c7 | 19 | #include <linux/leds.h> |
5a0e3ad6 | 20 | #include <linux/slab.h> |
4c2ef25f | 21 | #include <linux/suspend.h> |
b93931a6 PO |
22 | |
23 | #include <linux/mmc/host.h> | |
04566831 | 24 | #include <linux/mmc/card.h> |
b93931a6 PO |
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 | ||
31 | static 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 | ||
37 | static struct class mmc_host_class = { | |
38 | .name = "mmc_host", | |
39 | .dev_release = mmc_host_classdev_release, | |
40 | }; | |
41 | ||
42 | int mmc_register_host_class(void) | |
43 | { | |
44 | return class_register(&mmc_host_class); | |
45 | } | |
46 | ||
47 | void mmc_unregister_host_class(void) | |
48 | { | |
49 | class_unregister(&mmc_host_class); | |
50 | } | |
51 | ||
52 | static DEFINE_IDR(mmc_host_idr); | |
53 | static DEFINE_SPINLOCK(mmc_host_lock); | |
54 | ||
04566831 LW |
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 | */ | |
64 | static 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 | } | |
26fc8775 | 97 | mmc_claim_host(host); |
04566831 LW |
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); | |
26fc8775 | 107 | mmc_release_host(host); |
04566831 LW |
108 | } |
109 | ||
110 | /* | |
111 | * Internal work. Work to disable the clock at some later point. | |
112 | */ | |
113 | static 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_ungate - 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 | */ | |
129 | void mmc_host_clk_ungate(struct mmc_host *host) | |
130 | { | |
131 | unsigned long flags; | |
132 | ||
26fc8775 | 133 | mmc_claim_host(host); |
04566831 LW |
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); | |
26fc8775 | 143 | mmc_release_host(host); |
04566831 LW |
144 | } |
145 | ||
146 | /** | |
147 | * mmc_host_may_gate_card - check if this card may be gated | |
148 | * @card: card to check. | |
149 | */ | |
150 | static 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 | */ | |
db993500 | 163 | return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING); |
04566831 LW |
164 | } |
165 | ||
166 | /** | |
167 | * mmc_host_clk_gate - 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 | */ | |
174 | void mmc_host_clk_gate(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 | schedule_work(&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 | */ | |
192 | unsigned 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 | */ | |
210 | static 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); | |
04566831 LW |
218 | } |
219 | ||
220 | /** | |
221 | * mmc_host_clk_exit - shut down clock gating code | |
222 | * @host: host with potential clock to control | |
223 | */ | |
224 | static inline void mmc_host_clk_exit(struct mmc_host *host) | |
225 | { | |
226 | /* | |
227 | * Wait for any outstanding gate and then make sure we're | |
228 | * ungated before exiting. | |
229 | */ | |
230 | if (cancel_work_sync(&host->clk_gate_work)) | |
231 | mmc_host_clk_gate_delayed(host); | |
232 | if (host->clk_gated) | |
233 | mmc_host_clk_ungate(host); | |
c288b855 LW |
234 | /* There should be only one user now */ |
235 | WARN_ON(host->clk_requests > 1); | |
04566831 LW |
236 | } |
237 | ||
238 | #else | |
239 | ||
240 | static inline void mmc_host_clk_init(struct mmc_host *host) | |
241 | { | |
242 | } | |
243 | ||
244 | static inline void mmc_host_clk_exit(struct mmc_host *host) | |
245 | { | |
246 | } | |
247 | ||
248 | #endif | |
249 | ||
b93931a6 PO |
250 | /** |
251 | * mmc_alloc_host - initialise the per-host structure. | |
252 | * @extra: sizeof private data structure | |
253 | * @dev: pointer to host device model structure | |
254 | * | |
255 | * Initialise the per-host structure. | |
256 | */ | |
257 | struct mmc_host *mmc_alloc_host(int extra, struct device *dev) | |
258 | { | |
ff3112f5 | 259 | int err; |
b93931a6 PO |
260 | struct mmc_host *host; |
261 | ||
ff3112f5 PO |
262 | if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL)) |
263 | return NULL; | |
264 | ||
be760a9d | 265 | host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL); |
b93931a6 PO |
266 | if (!host) |
267 | return NULL; | |
268 | ||
ff3112f5 PO |
269 | spin_lock(&mmc_host_lock); |
270 | err = idr_get_new(&mmc_host_idr, host, &host->index); | |
271 | spin_unlock(&mmc_host_lock); | |
272 | if (err) | |
273 | goto free; | |
274 | ||
d1b26863 | 275 | dev_set_name(&host->class_dev, "mmc%d", host->index); |
ff3112f5 | 276 | |
b93931a6 PO |
277 | host->parent = dev; |
278 | host->class_dev.parent = dev; | |
279 | host->class_dev.class = &mmc_host_class; | |
280 | device_initialize(&host->class_dev); | |
281 | ||
04566831 LW |
282 | mmc_host_clk_init(host); |
283 | ||
b93931a6 PO |
284 | spin_lock_init(&host->lock); |
285 | init_waitqueue_head(&host->wq); | |
286 | INIT_DELAYED_WORK(&host->detect, mmc_rescan); | |
8ea926b2 | 287 | INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable); |
81ca03a0 | 288 | #ifdef CONFIG_PM |
4c2ef25f | 289 | host->pm_notify.notifier_call = mmc_pm_notify; |
81ca03a0 | 290 | #endif |
b93931a6 PO |
291 | |
292 | /* | |
293 | * By default, hosts do not support SGIO or large requests. | |
294 | * They have to set these according to their abilities. | |
295 | */ | |
a36274e0 | 296 | host->max_segs = 1; |
b93931a6 PO |
297 | host->max_seg_size = PAGE_CACHE_SIZE; |
298 | ||
299 | host->max_req_size = PAGE_CACHE_SIZE; | |
300 | host->max_blk_size = 512; | |
301 | host->max_blk_count = PAGE_CACHE_SIZE / 512; | |
302 | ||
303 | return host; | |
ff3112f5 PO |
304 | |
305 | free: | |
306 | kfree(host); | |
307 | return NULL; | |
b93931a6 PO |
308 | } |
309 | ||
310 | EXPORT_SYMBOL(mmc_alloc_host); | |
311 | ||
312 | /** | |
313 | * mmc_add_host - initialise host hardware | |
314 | * @host: mmc host | |
67a61c48 PO |
315 | * |
316 | * Register the host with the driver model. The host must be | |
317 | * prepared to start servicing requests before this function | |
318 | * completes. | |
b93931a6 PO |
319 | */ |
320 | int mmc_add_host(struct mmc_host *host) | |
321 | { | |
322 | int err; | |
323 | ||
17b759af NP |
324 | WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) && |
325 | !host->ops->enable_sdio_irq); | |
326 | ||
d1b26863 | 327 | led_trigger_register_simple(dev_name(&host->class_dev), &host->led); |
af8350c7 | 328 | |
b93931a6 PO |
329 | err = device_add(&host->class_dev); |
330 | if (err) | |
331 | return err; | |
332 | ||
6edd8ee6 HS |
333 | #ifdef CONFIG_DEBUG_FS |
334 | mmc_add_host_debugfs(host); | |
335 | #endif | |
336 | ||
b93931a6 | 337 | mmc_start_host(host); |
4c2ef25f | 338 | register_pm_notifier(&host->pm_notify); |
b93931a6 PO |
339 | |
340 | return 0; | |
341 | } | |
342 | ||
343 | EXPORT_SYMBOL(mmc_add_host); | |
344 | ||
345 | /** | |
346 | * mmc_remove_host - remove host hardware | |
347 | * @host: mmc host | |
348 | * | |
349 | * Unregister and remove all cards associated with this host, | |
67a61c48 PO |
350 | * and power down the MMC bus. No new requests will be issued |
351 | * after this function has returned. | |
b93931a6 PO |
352 | */ |
353 | void mmc_remove_host(struct mmc_host *host) | |
354 | { | |
4c2ef25f | 355 | unregister_pm_notifier(&host->pm_notify); |
b93931a6 PO |
356 | mmc_stop_host(host); |
357 | ||
6edd8ee6 HS |
358 | #ifdef CONFIG_DEBUG_FS |
359 | mmc_remove_host_debugfs(host); | |
360 | #endif | |
361 | ||
b93931a6 PO |
362 | device_del(&host->class_dev); |
363 | ||
77f1fd6e | 364 | led_trigger_unregister_simple(host->led); |
04566831 LW |
365 | |
366 | mmc_host_clk_exit(host); | |
b93931a6 PO |
367 | } |
368 | ||
369 | EXPORT_SYMBOL(mmc_remove_host); | |
370 | ||
371 | /** | |
372 | * mmc_free_host - free the host structure | |
373 | * @host: mmc host | |
374 | * | |
375 | * Free the host once all references to it have been dropped. | |
376 | */ | |
377 | void mmc_free_host(struct mmc_host *host) | |
378 | { | |
ff3112f5 PO |
379 | spin_lock(&mmc_host_lock); |
380 | idr_remove(&mmc_host_idr, host->index); | |
381 | spin_unlock(&mmc_host_lock); | |
382 | ||
b93931a6 PO |
383 | put_device(&host->class_dev); |
384 | } | |
385 | ||
386 | EXPORT_SYMBOL(mmc_free_host); |