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
25 #include <linux/mmc/host.h>
26 #include <linux/mmc/card.h>
27 #include <linux/mmc/slot-gpio.h>
28
29 #include "core.h"
30 #include "host.h"
31 #include "slot-gpio.h"
32 #include "pwrseq.h"
33
34 static DEFINE_IDA(mmc_host_ida);
35 static DEFINE_SPINLOCK(mmc_host_lock);
36
mmc_host_classdev_release(struct device * dev)37 static void mmc_host_classdev_release(struct device *dev)
38 {
39 struct mmc_host *host = cls_dev_to_mmc_host(dev);
40 spin_lock(&mmc_host_lock);
41 ida_remove(&mmc_host_ida, host->index);
42 spin_unlock(&mmc_host_lock);
43 kfree(host);
44 }
45
46 static struct class mmc_host_class = {
47 .name = "mmc_host",
48 .dev_release = mmc_host_classdev_release,
49 };
50
mmc_register_host_class(void)51 int mmc_register_host_class(void)
52 {
53 return class_register(&mmc_host_class);
54 }
55
mmc_unregister_host_class(void)56 void mmc_unregister_host_class(void)
57 {
58 class_unregister(&mmc_host_class);
59 }
60
mmc_retune_enable(struct mmc_host * host)61 void mmc_retune_enable(struct mmc_host *host)
62 {
63 host->can_retune = 1;
64 if (host->retune_period)
65 mod_timer(&host->retune_timer,
66 jiffies + host->retune_period * HZ);
67 }
68
69 /*
70 * Pause re-tuning for a small set of operations. The pause begins after the
71 * next command and after first doing re-tuning.
72 */
mmc_retune_pause(struct mmc_host * host)73 void mmc_retune_pause(struct mmc_host *host)
74 {
75 if (!host->retune_paused) {
76 host->retune_paused = 1;
77 mmc_retune_needed(host);
78 mmc_retune_hold(host);
79 }
80 }
81 EXPORT_SYMBOL(mmc_retune_pause);
82
mmc_retune_unpause(struct mmc_host * host)83 void mmc_retune_unpause(struct mmc_host *host)
84 {
85 if (host->retune_paused) {
86 host->retune_paused = 0;
87 mmc_retune_release(host);
88 }
89 }
90 EXPORT_SYMBOL(mmc_retune_unpause);
91
mmc_retune_disable(struct mmc_host * host)92 void mmc_retune_disable(struct mmc_host *host)
93 {
94 mmc_retune_unpause(host);
95 host->can_retune = 0;
96 del_timer_sync(&host->retune_timer);
97 host->retune_now = 0;
98 host->need_retune = 0;
99 }
100
mmc_retune_timer_stop(struct mmc_host * host)101 void mmc_retune_timer_stop(struct mmc_host *host)
102 {
103 del_timer_sync(&host->retune_timer);
104 }
105 EXPORT_SYMBOL(mmc_retune_timer_stop);
106
mmc_retune_hold(struct mmc_host * host)107 void mmc_retune_hold(struct mmc_host *host)
108 {
109 if (!host->hold_retune)
110 host->retune_now = 1;
111 host->hold_retune += 1;
112 }
113
mmc_retune_release(struct mmc_host * host)114 void mmc_retune_release(struct mmc_host *host)
115 {
116 if (host->hold_retune)
117 host->hold_retune -= 1;
118 else
119 WARN_ON(1);
120 }
121
mmc_retune(struct mmc_host * host)122 int mmc_retune(struct mmc_host *host)
123 {
124 bool return_to_hs400 = false;
125 int err;
126
127 if (host->retune_now)
128 host->retune_now = 0;
129 else
130 return 0;
131
132 if (!host->need_retune || host->doing_retune || !host->card)
133 return 0;
134
135 host->need_retune = 0;
136
137 host->doing_retune = 1;
138
139 if (host->ios.timing == MMC_TIMING_MMC_HS400) {
140 err = mmc_hs400_to_hs200(host->card);
141 if (err)
142 goto out;
143
144 return_to_hs400 = true;
145
146 if (host->ops->prepare_hs400_tuning)
147 host->ops->prepare_hs400_tuning(host, &host->ios);
148 }
149
150 err = mmc_execute_tuning(host->card);
151 if (err)
152 goto out;
153
154 if (return_to_hs400)
155 err = mmc_hs200_to_hs400(host->card);
156 out:
157 host->doing_retune = 0;
158
159 return err;
160 }
161
mmc_retune_timer(unsigned long data)162 static void mmc_retune_timer(unsigned long data)
163 {
164 struct mmc_host *host = (struct mmc_host *)data;
165
166 mmc_retune_needed(host);
167 }
168
169 /**
170 * mmc_of_parse() - parse host's device-tree node
171 * @host: host whose node should be parsed.
172 *
173 * To keep the rest of the MMC subsystem unaware of whether DT has been
174 * used to to instantiate and configure this host instance or not, we
175 * parse the properties and set respective generic mmc-host flags and
176 * parameters.
177 */
mmc_of_parse(struct mmc_host * host)178 int mmc_of_parse(struct mmc_host *host)
179 {
180 struct device *dev = host->parent;
181 u32 bus_width;
182 int ret;
183 bool cd_cap_invert, cd_gpio_invert = false;
184 bool ro_cap_invert, ro_gpio_invert = false;
185
186 if (!dev || !dev_fwnode(dev))
187 return 0;
188
189 /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
190 if (device_property_read_u32(dev, "bus-width", &bus_width) < 0) {
191 dev_dbg(host->parent,
192 "\"bus-width\" property is missing, assuming 1 bit.\n");
193 bus_width = 1;
194 }
195
196 switch (bus_width) {
197 case 8:
198 host->caps |= MMC_CAP_8_BIT_DATA;
199 /* Hosts capable of 8-bit transfers can also do 4 bits */
200 case 4:
201 host->caps |= MMC_CAP_4_BIT_DATA;
202 break;
203 case 1:
204 break;
205 default:
206 dev_err(host->parent,
207 "Invalid \"bus-width\" value %u!\n", bus_width);
208 return -EINVAL;
209 }
210
211 /* f_max is obtained from the optional "max-frequency" property */
212 device_property_read_u32(dev, "max-frequency", &host->f_max);
213
214 /*
215 * Configure CD and WP pins. They are both by default active low to
216 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
217 * mmc-gpio helpers are used to attach, configure and use them. If
218 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
219 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
220 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
221 * is set. If the "non-removable" property is found, the
222 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
223 * configuration is performed.
224 */
225
226 /* Parse Card Detection */
227 if (device_property_read_bool(dev, "non-removable")) {
228 host->caps |= MMC_CAP_NONREMOVABLE;
229 } else {
230 cd_cap_invert = device_property_read_bool(dev, "cd-inverted");
231
232 if (device_property_read_bool(dev, "broken-cd"))
233 host->caps |= MMC_CAP_NEEDS_POLL;
234
235 ret = mmc_gpiod_request_cd(host, "cd", 0, true,
236 0, &cd_gpio_invert);
237 if (!ret)
238 dev_info(host->parent, "Got CD GPIO\n");
239 else if (ret != -ENOENT && ret != -ENOSYS)
240 return ret;
241
242 /*
243 * There are two ways to flag that the CD line is inverted:
244 * through the cd-inverted flag and by the GPIO line itself
245 * being inverted from the GPIO subsystem. This is a leftover
246 * from the times when the GPIO subsystem did not make it
247 * possible to flag a line as inverted.
248 *
249 * If the capability on the host AND the GPIO line are
250 * both inverted, the end result is that the CD line is
251 * not inverted.
252 */
253 if (cd_cap_invert ^ cd_gpio_invert)
254 host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
255 }
256
257 /* Parse Write Protection */
258 ro_cap_invert = device_property_read_bool(dev, "wp-inverted");
259
260 ret = mmc_gpiod_request_ro(host, "wp", 0, false, 0, &ro_gpio_invert);
261 if (!ret)
262 dev_info(host->parent, "Got WP GPIO\n");
263 else if (ret != -ENOENT && ret != -ENOSYS)
264 return ret;
265
266 if (device_property_read_bool(dev, "disable-wp"))
267 host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
268
269 /* See the comment on CD inversion above */
270 if (ro_cap_invert ^ ro_gpio_invert)
271 host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
272
273 if (device_property_read_bool(dev, "cap-sd-highspeed"))
274 host->caps |= MMC_CAP_SD_HIGHSPEED;
275 if (device_property_read_bool(dev, "cap-mmc-highspeed"))
276 host->caps |= MMC_CAP_MMC_HIGHSPEED;
277 if (device_property_read_bool(dev, "sd-uhs-sdr12"))
278 host->caps |= MMC_CAP_UHS_SDR12;
279 if (device_property_read_bool(dev, "sd-uhs-sdr25"))
280 host->caps |= MMC_CAP_UHS_SDR25;
281 if (device_property_read_bool(dev, "sd-uhs-sdr50"))
282 host->caps |= MMC_CAP_UHS_SDR50;
283 if (device_property_read_bool(dev, "sd-uhs-sdr104"))
284 host->caps |= MMC_CAP_UHS_SDR104;
285 if (device_property_read_bool(dev, "sd-uhs-ddr50"))
286 host->caps |= MMC_CAP_UHS_DDR50;
287 if (device_property_read_bool(dev, "cap-power-off-card"))
288 host->caps |= MMC_CAP_POWER_OFF_CARD;
289 if (device_property_read_bool(dev, "cap-mmc-hw-reset"))
290 host->caps |= MMC_CAP_HW_RESET;
291 if (device_property_read_bool(dev, "cap-sdio-irq"))
292 host->caps |= MMC_CAP_SDIO_IRQ;
293 if (device_property_read_bool(dev, "full-pwr-cycle"))
294 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
295 if (device_property_read_bool(dev, "keep-power-in-suspend"))
296 host->pm_caps |= MMC_PM_KEEP_POWER;
297 if (device_property_read_bool(dev, "wakeup-source") ||
298 device_property_read_bool(dev, "enable-sdio-wakeup")) /* legacy */
299 host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
300 if (device_property_read_bool(dev, "mmc-ddr-1_8v"))
301 host->caps |= MMC_CAP_1_8V_DDR;
302 if (device_property_read_bool(dev, "mmc-ddr-1_2v"))
303 host->caps |= MMC_CAP_1_2V_DDR;
304 if (device_property_read_bool(dev, "mmc-hs200-1_8v"))
305 host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
306 if (device_property_read_bool(dev, "mmc-hs200-1_2v"))
307 host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
308 if (device_property_read_bool(dev, "mmc-hs400-1_8v"))
309 host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
310 if (device_property_read_bool(dev, "mmc-hs400-1_2v"))
311 host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
312 if (device_property_read_bool(dev, "mmc-hs400-enhanced-strobe"))
313 host->caps2 |= MMC_CAP2_HS400_ES;
314 if (device_property_read_bool(dev, "no-sdio"))
315 host->caps2 |= MMC_CAP2_NO_SDIO;
316 if (device_property_read_bool(dev, "no-sd"))
317 host->caps2 |= MMC_CAP2_NO_SD;
318 if (device_property_read_bool(dev, "no-mmc"))
319 host->caps2 |= MMC_CAP2_NO_MMC;
320
321 host->dsr_req = !device_property_read_u32(dev, "dsr", &host->dsr);
322 if (host->dsr_req && (host->dsr & ~0xffff)) {
323 dev_err(host->parent,
324 "device tree specified broken value for DSR: 0x%x, ignoring\n",
325 host->dsr);
326 host->dsr_req = 0;
327 }
328
329 return mmc_pwrseq_alloc(host);
330 }
331
332 EXPORT_SYMBOL(mmc_of_parse);
333
334 /**
335 * mmc_alloc_host - initialise the per-host structure.
336 * @extra: sizeof private data structure
337 * @dev: pointer to host device model structure
338 *
339 * Initialise the per-host structure.
340 */
mmc_alloc_host(int extra,struct device * dev)341 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
342 {
343 int err;
344 struct mmc_host *host;
345
346 host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
347 if (!host)
348 return NULL;
349
350 /* scanning will be enabled when we're ready */
351 host->rescan_disable = 1;
352
353 again:
354 if (!ida_pre_get(&mmc_host_ida, GFP_KERNEL)) {
355 kfree(host);
356 return NULL;
357 }
358
359 spin_lock(&mmc_host_lock);
360 err = ida_get_new(&mmc_host_ida, &host->index);
361 spin_unlock(&mmc_host_lock);
362
363 if (err == -EAGAIN) {
364 goto again;
365 } else if (err) {
366 kfree(host);
367 return NULL;
368 }
369
370 dev_set_name(&host->class_dev, "mmc%d", host->index);
371
372 host->parent = dev;
373 host->class_dev.parent = dev;
374 host->class_dev.class = &mmc_host_class;
375 device_initialize(&host->class_dev);
376 device_enable_async_suspend(&host->class_dev);
377
378 if (mmc_gpio_alloc(host)) {
379 put_device(&host->class_dev);
380 return NULL;
381 }
382
383 spin_lock_init(&host->lock);
384 init_waitqueue_head(&host->wq);
385 INIT_DELAYED_WORK(&host->detect, mmc_rescan);
386 setup_timer(&host->retune_timer, mmc_retune_timer, (unsigned long)host);
387
388 /*
389 * By default, hosts do not support SGIO or large requests.
390 * They have to set these according to their abilities.
391 */
392 host->max_segs = 1;
393 host->max_seg_size = PAGE_SIZE;
394
395 host->max_req_size = PAGE_SIZE;
396 host->max_blk_size = 512;
397 host->max_blk_count = PAGE_SIZE / 512;
398
399 return host;
400 }
401
402 EXPORT_SYMBOL(mmc_alloc_host);
403
404 /**
405 * mmc_add_host - initialise host hardware
406 * @host: mmc host
407 *
408 * Register the host with the driver model. The host must be
409 * prepared to start servicing requests before this function
410 * completes.
411 */
mmc_add_host(struct mmc_host * host)412 int mmc_add_host(struct mmc_host *host)
413 {
414 int err;
415
416 WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
417 !host->ops->enable_sdio_irq);
418
419 err = device_add(&host->class_dev);
420 if (err)
421 return err;
422
423 led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
424
425 #ifdef CONFIG_DEBUG_FS
426 mmc_add_host_debugfs(host);
427 #endif
428
429 #ifdef CONFIG_BLOCK
430 mmc_latency_hist_sysfs_init(host);
431 #endif
432
433 mmc_start_host(host);
434 if (!(host->pm_flags & MMC_PM_IGNORE_PM_NOTIFY))
435 mmc_register_pm_notifier(host);
436
437 return 0;
438 }
439
440 EXPORT_SYMBOL(mmc_add_host);
441
442 /**
443 * mmc_remove_host - remove host hardware
444 * @host: mmc host
445 *
446 * Unregister and remove all cards associated with this host,
447 * and power down the MMC bus. No new requests will be issued
448 * after this function has returned.
449 */
mmc_remove_host(struct mmc_host * host)450 void mmc_remove_host(struct mmc_host *host)
451 {
452 if (!(host->pm_flags & MMC_PM_IGNORE_PM_NOTIFY))
453 mmc_unregister_pm_notifier(host);
454 mmc_stop_host(host);
455
456 #ifdef CONFIG_DEBUG_FS
457 mmc_remove_host_debugfs(host);
458 #endif
459
460 #ifdef CONFIG_BLOCK
461 mmc_latency_hist_sysfs_exit(host);
462 #endif
463
464 device_del(&host->class_dev);
465
466 led_trigger_unregister_simple(host->led);
467 }
468
469 EXPORT_SYMBOL(mmc_remove_host);
470
471 /**
472 * mmc_free_host - free the host structure
473 * @host: mmc host
474 *
475 * Free the host once all references to it have been dropped.
476 */
mmc_free_host(struct mmc_host * host)477 void mmc_free_host(struct mmc_host *host)
478 {
479 mmc_pwrseq_free(host);
480 put_device(&host->class_dev);
481 }
482
483 EXPORT_SYMBOL(mmc_free_host);
484