xref: /openbmc/linux/drivers/mmc/core/host.c (revision 0edbfea5)
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 #define cls_dev_to_mmc_host(d)	container_of(d, struct mmc_host, class_dev)
35 
36 static DEFINE_IDA(mmc_host_ida);
37 static DEFINE_SPINLOCK(mmc_host_lock);
38 
39 static void mmc_host_classdev_release(struct device *dev)
40 {
41 	struct mmc_host *host = cls_dev_to_mmc_host(dev);
42 	spin_lock(&mmc_host_lock);
43 	ida_remove(&mmc_host_ida, host->index);
44 	spin_unlock(&mmc_host_lock);
45 	kfree(host);
46 }
47 
48 static struct class mmc_host_class = {
49 	.name		= "mmc_host",
50 	.dev_release	= mmc_host_classdev_release,
51 };
52 
53 int mmc_register_host_class(void)
54 {
55 	return class_register(&mmc_host_class);
56 }
57 
58 void mmc_unregister_host_class(void)
59 {
60 	class_unregister(&mmc_host_class);
61 }
62 
63 void mmc_retune_enable(struct mmc_host *host)
64 {
65 	host->can_retune = 1;
66 	if (host->retune_period)
67 		mod_timer(&host->retune_timer,
68 			  jiffies + host->retune_period * HZ);
69 }
70 
71 /*
72  * Pause re-tuning for a small set of operations.  The pause begins after the
73  * next command and after first doing re-tuning.
74  */
75 void mmc_retune_pause(struct mmc_host *host)
76 {
77 	if (!host->retune_paused) {
78 		host->retune_paused = 1;
79 		mmc_retune_needed(host);
80 		mmc_retune_hold(host);
81 	}
82 }
83 EXPORT_SYMBOL(mmc_retune_pause);
84 
85 void mmc_retune_unpause(struct mmc_host *host)
86 {
87 	if (host->retune_paused) {
88 		host->retune_paused = 0;
89 		mmc_retune_release(host);
90 	}
91 }
92 EXPORT_SYMBOL(mmc_retune_unpause);
93 
94 void mmc_retune_disable(struct mmc_host *host)
95 {
96 	mmc_retune_unpause(host);
97 	host->can_retune = 0;
98 	del_timer_sync(&host->retune_timer);
99 	host->retune_now = 0;
100 	host->need_retune = 0;
101 }
102 
103 void mmc_retune_timer_stop(struct mmc_host *host)
104 {
105 	del_timer_sync(&host->retune_timer);
106 }
107 EXPORT_SYMBOL(mmc_retune_timer_stop);
108 
109 void mmc_retune_hold(struct mmc_host *host)
110 {
111 	if (!host->hold_retune)
112 		host->retune_now = 1;
113 	host->hold_retune += 1;
114 }
115 
116 void mmc_retune_release(struct mmc_host *host)
117 {
118 	if (host->hold_retune)
119 		host->hold_retune -= 1;
120 	else
121 		WARN_ON(1);
122 }
123 
124 int mmc_retune(struct mmc_host *host)
125 {
126 	bool return_to_hs400 = false;
127 	int err;
128 
129 	if (host->retune_now)
130 		host->retune_now = 0;
131 	else
132 		return 0;
133 
134 	if (!host->need_retune || host->doing_retune || !host->card)
135 		return 0;
136 
137 	host->need_retune = 0;
138 
139 	host->doing_retune = 1;
140 
141 	if (host->ios.timing == MMC_TIMING_MMC_HS400) {
142 		err = mmc_hs400_to_hs200(host->card);
143 		if (err)
144 			goto out;
145 
146 		return_to_hs400 = true;
147 
148 		if (host->ops->prepare_hs400_tuning)
149 			host->ops->prepare_hs400_tuning(host, &host->ios);
150 	}
151 
152 	err = mmc_execute_tuning(host->card);
153 	if (err)
154 		goto out;
155 
156 	if (return_to_hs400)
157 		err = mmc_hs200_to_hs400(host->card);
158 out:
159 	host->doing_retune = 0;
160 
161 	return err;
162 }
163 
164 static void mmc_retune_timer(unsigned long data)
165 {
166 	struct mmc_host *host = (struct mmc_host *)data;
167 
168 	mmc_retune_needed(host);
169 }
170 
171 /**
172  *	mmc_of_parse() - parse host's device-tree node
173  *	@host: host whose node should be parsed.
174  *
175  * To keep the rest of the MMC subsystem unaware of whether DT has been
176  * used to to instantiate and configure this host instance or not, we
177  * parse the properties and set respective generic mmc-host flags and
178  * parameters.
179  */
180 int mmc_of_parse(struct mmc_host *host)
181 {
182 	struct device_node *np;
183 	u32 bus_width;
184 	int ret;
185 	bool cd_cap_invert, cd_gpio_invert = false;
186 	bool ro_cap_invert, ro_gpio_invert = false;
187 
188 	if (!host->parent || !host->parent->of_node)
189 		return 0;
190 
191 	np = host->parent->of_node;
192 
193 	/* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
194 	if (of_property_read_u32(np, "bus-width", &bus_width) < 0) {
195 		dev_dbg(host->parent,
196 			"\"bus-width\" property is missing, assuming 1 bit.\n");
197 		bus_width = 1;
198 	}
199 
200 	switch (bus_width) {
201 	case 8:
202 		host->caps |= MMC_CAP_8_BIT_DATA;
203 		/* Hosts capable of 8-bit transfers can also do 4 bits */
204 	case 4:
205 		host->caps |= MMC_CAP_4_BIT_DATA;
206 		break;
207 	case 1:
208 		break;
209 	default:
210 		dev_err(host->parent,
211 			"Invalid \"bus-width\" value %u!\n", bus_width);
212 		return -EINVAL;
213 	}
214 
215 	/* f_max is obtained from the optional "max-frequency" property */
216 	of_property_read_u32(np, "max-frequency", &host->f_max);
217 
218 	/*
219 	 * Configure CD and WP pins. They are both by default active low to
220 	 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
221 	 * mmc-gpio helpers are used to attach, configure and use them. If
222 	 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
223 	 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
224 	 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
225 	 * is set. If the "non-removable" property is found, the
226 	 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
227 	 * configuration is performed.
228 	 */
229 
230 	/* Parse Card Detection */
231 	if (of_property_read_bool(np, "non-removable")) {
232 		host->caps |= MMC_CAP_NONREMOVABLE;
233 	} else {
234 		cd_cap_invert = of_property_read_bool(np, "cd-inverted");
235 
236 		if (of_property_read_bool(np, "broken-cd"))
237 			host->caps |= MMC_CAP_NEEDS_POLL;
238 
239 		ret = mmc_gpiod_request_cd(host, "cd", 0, true,
240 					   0, &cd_gpio_invert);
241 		if (!ret)
242 			dev_info(host->parent, "Got CD GPIO\n");
243 		else if (ret != -ENOENT && ret != -ENOSYS)
244 			return ret;
245 
246 		/*
247 		 * There are two ways to flag that the CD line is inverted:
248 		 * through the cd-inverted flag and by the GPIO line itself
249 		 * being inverted from the GPIO subsystem. This is a leftover
250 		 * from the times when the GPIO subsystem did not make it
251 		 * possible to flag a line as inverted.
252 		 *
253 		 * If the capability on the host AND the GPIO line are
254 		 * both inverted, the end result is that the CD line is
255 		 * not inverted.
256 		 */
257 		if (cd_cap_invert ^ cd_gpio_invert)
258 			host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
259 	}
260 
261 	/* Parse Write Protection */
262 	ro_cap_invert = of_property_read_bool(np, "wp-inverted");
263 
264 	ret = mmc_gpiod_request_ro(host, "wp", 0, false, 0, &ro_gpio_invert);
265 	if (!ret)
266 		dev_info(host->parent, "Got WP GPIO\n");
267 	else if (ret != -ENOENT && ret != -ENOSYS)
268 		return ret;
269 
270 	if (of_property_read_bool(np, "disable-wp"))
271 		host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
272 
273 	/* See the comment on CD inversion above */
274 	if (ro_cap_invert ^ ro_gpio_invert)
275 		host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
276 
277 	if (of_property_read_bool(np, "cap-sd-highspeed"))
278 		host->caps |= MMC_CAP_SD_HIGHSPEED;
279 	if (of_property_read_bool(np, "cap-mmc-highspeed"))
280 		host->caps |= MMC_CAP_MMC_HIGHSPEED;
281 	if (of_property_read_bool(np, "sd-uhs-sdr12"))
282 		host->caps |= MMC_CAP_UHS_SDR12;
283 	if (of_property_read_bool(np, "sd-uhs-sdr25"))
284 		host->caps |= MMC_CAP_UHS_SDR25;
285 	if (of_property_read_bool(np, "sd-uhs-sdr50"))
286 		host->caps |= MMC_CAP_UHS_SDR50;
287 	if (of_property_read_bool(np, "sd-uhs-sdr104"))
288 		host->caps |= MMC_CAP_UHS_SDR104;
289 	if (of_property_read_bool(np, "sd-uhs-ddr50"))
290 		host->caps |= MMC_CAP_UHS_DDR50;
291 	if (of_property_read_bool(np, "cap-power-off-card"))
292 		host->caps |= MMC_CAP_POWER_OFF_CARD;
293 	if (of_property_read_bool(np, "cap-mmc-hw-reset"))
294 		host->caps |= MMC_CAP_HW_RESET;
295 	if (of_property_read_bool(np, "cap-sdio-irq"))
296 		host->caps |= MMC_CAP_SDIO_IRQ;
297 	if (of_property_read_bool(np, "full-pwr-cycle"))
298 		host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
299 	if (of_property_read_bool(np, "keep-power-in-suspend"))
300 		host->pm_caps |= MMC_PM_KEEP_POWER;
301 	if (of_property_read_bool(np, "wakeup-source") ||
302 	    of_property_read_bool(np, "enable-sdio-wakeup")) /* legacy */
303 		host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
304 	if (of_property_read_bool(np, "mmc-ddr-1_8v"))
305 		host->caps |= MMC_CAP_1_8V_DDR;
306 	if (of_property_read_bool(np, "mmc-ddr-1_2v"))
307 		host->caps |= MMC_CAP_1_2V_DDR;
308 	if (of_property_read_bool(np, "mmc-hs200-1_8v"))
309 		host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
310 	if (of_property_read_bool(np, "mmc-hs200-1_2v"))
311 		host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
312 	if (of_property_read_bool(np, "mmc-hs400-1_8v"))
313 		host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
314 	if (of_property_read_bool(np, "mmc-hs400-1_2v"))
315 		host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
316 
317 	host->dsr_req = !of_property_read_u32(np, "dsr", &host->dsr);
318 	if (host->dsr_req && (host->dsr & ~0xffff)) {
319 		dev_err(host->parent,
320 			"device tree specified broken value for DSR: 0x%x, ignoring\n",
321 			host->dsr);
322 		host->dsr_req = 0;
323 	}
324 
325 	return mmc_pwrseq_alloc(host);
326 }
327 
328 EXPORT_SYMBOL(mmc_of_parse);
329 
330 /**
331  *	mmc_alloc_host - initialise the per-host structure.
332  *	@extra: sizeof private data structure
333  *	@dev: pointer to host device model structure
334  *
335  *	Initialise the per-host structure.
336  */
337 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
338 {
339 	int err;
340 	struct mmc_host *host;
341 
342 	host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
343 	if (!host)
344 		return NULL;
345 
346 	/* scanning will be enabled when we're ready */
347 	host->rescan_disable = 1;
348 
349 again:
350 	if (!ida_pre_get(&mmc_host_ida, GFP_KERNEL)) {
351 		kfree(host);
352 		return NULL;
353 	}
354 
355 	spin_lock(&mmc_host_lock);
356 	err = ida_get_new(&mmc_host_ida, &host->index);
357 	spin_unlock(&mmc_host_lock);
358 
359 	if (err == -EAGAIN) {
360 		goto again;
361 	} else if (err) {
362 		kfree(host);
363 		return NULL;
364 	}
365 
366 	dev_set_name(&host->class_dev, "mmc%d", host->index);
367 
368 	host->parent = dev;
369 	host->class_dev.parent = dev;
370 	host->class_dev.class = &mmc_host_class;
371 	device_initialize(&host->class_dev);
372 	device_enable_async_suspend(&host->class_dev);
373 
374 	if (mmc_gpio_alloc(host)) {
375 		put_device(&host->class_dev);
376 		return NULL;
377 	}
378 
379 	spin_lock_init(&host->lock);
380 	init_waitqueue_head(&host->wq);
381 	INIT_DELAYED_WORK(&host->detect, mmc_rescan);
382 	setup_timer(&host->retune_timer, mmc_retune_timer, (unsigned long)host);
383 
384 	/*
385 	 * By default, hosts do not support SGIO or large requests.
386 	 * They have to set these according to their abilities.
387 	 */
388 	host->max_segs = 1;
389 	host->max_seg_size = PAGE_SIZE;
390 
391 	host->max_req_size = PAGE_SIZE;
392 	host->max_blk_size = 512;
393 	host->max_blk_count = PAGE_SIZE / 512;
394 
395 	return host;
396 }
397 
398 EXPORT_SYMBOL(mmc_alloc_host);
399 
400 /**
401  *	mmc_add_host - initialise host hardware
402  *	@host: mmc host
403  *
404  *	Register the host with the driver model. The host must be
405  *	prepared to start servicing requests before this function
406  *	completes.
407  */
408 int mmc_add_host(struct mmc_host *host)
409 {
410 	int err;
411 
412 	WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
413 		!host->ops->enable_sdio_irq);
414 
415 	err = device_add(&host->class_dev);
416 	if (err)
417 		return err;
418 
419 	led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
420 
421 #ifdef CONFIG_DEBUG_FS
422 	mmc_add_host_debugfs(host);
423 #endif
424 
425 	mmc_start_host(host);
426 	mmc_register_pm_notifier(host);
427 
428 	return 0;
429 }
430 
431 EXPORT_SYMBOL(mmc_add_host);
432 
433 /**
434  *	mmc_remove_host - remove host hardware
435  *	@host: mmc host
436  *
437  *	Unregister and remove all cards associated with this host,
438  *	and power down the MMC bus. No new requests will be issued
439  *	after this function has returned.
440  */
441 void mmc_remove_host(struct mmc_host *host)
442 {
443 	mmc_unregister_pm_notifier(host);
444 	mmc_stop_host(host);
445 
446 #ifdef CONFIG_DEBUG_FS
447 	mmc_remove_host_debugfs(host);
448 #endif
449 
450 	device_del(&host->class_dev);
451 
452 	led_trigger_unregister_simple(host->led);
453 }
454 
455 EXPORT_SYMBOL(mmc_remove_host);
456 
457 /**
458  *	mmc_free_host - free the host structure
459  *	@host: mmc host
460  *
461  *	Free the host once all references to it have been dropped.
462  */
463 void mmc_free_host(struct mmc_host *host)
464 {
465 	mmc_pwrseq_free(host);
466 	put_device(&host->class_dev);
467 }
468 
469 EXPORT_SYMBOL(mmc_free_host);
470