2 * linux/drivers/mmc/core/host.c
4 * Copyright (C) 2003 Russell King, All Rights Reserved.
5 * Copyright (C) 2007-2008 Pierre Ossman
6 * Copyright (C) 2010 Linus Walleij
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.
12 * MMC host class device management
15 #include <linux/device.h>
16 #include <linux/err.h>
17 #include <linux/idr.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>
26 #include <linux/mmc/host.h>
27 #include <linux/mmc/card.h>
28 #include <linux/mmc/slot-gpio.h>
33 #define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
35 static void mmc_host_classdev_release(struct device *dev)
37 struct mmc_host *host = cls_dev_to_mmc_host(dev);
39 mutex_destroy(&host->slot.lock);
43 static struct class mmc_host_class = {
45 .dev_release = mmc_host_classdev_release,
48 int mmc_register_host_class(void)
50 return class_register(&mmc_host_class);
53 void mmc_unregister_host_class(void)
55 class_unregister(&mmc_host_class);
58 static DEFINE_IDR(mmc_host_idr);
59 static DEFINE_SPINLOCK(mmc_host_lock);
61 #ifdef CONFIG_MMC_CLKGATE
62 static ssize_t clkgate_delay_show(struct device *dev,
63 struct device_attribute *attr, char *buf)
65 struct mmc_host *host = cls_dev_to_mmc_host(dev);
67 return snprintf(buf, PAGE_SIZE, "%lu\n", host->clkgate_delay);
70 static ssize_t clkgate_delay_store(struct device *dev,
71 struct device_attribute *attr,
72 const char *buf, size_t count)
74 struct mmc_host *host = cls_dev_to_mmc_host(dev);
75 unsigned long flags, value;
77 if (kstrtoul(buf, 0, &value))
80 spin_lock_irqsave(&host->clk_lock, flags);
81 host->clkgate_delay = value;
82 spin_unlock_irqrestore(&host->clk_lock, flags);
87 * Enabling clock gating will make the core call out to the host
88 * once up and once down when it performs a request or card operation
89 * intermingled in any fashion. The driver will see this through
90 * set_ios() operations with ios.clock field set to 0 to gate (disable)
91 * the block clock, and to the old frequency to enable it again.
93 static void mmc_host_clk_gate_delayed(struct mmc_host *host)
95 unsigned long tick_ns;
96 unsigned long freq = host->ios.clock;
100 pr_debug("%s: frequency set to 0 in disable function, "
101 "this means the clock is already disabled.\n",
106 * New requests may have appeared while we were scheduling,
107 * then there is no reason to delay the check before
110 spin_lock_irqsave(&host->clk_lock, flags);
113 * Delay n bus cycles (at least 8 from MMC spec) before attempting
114 * to disable the MCI block clock. The reference count may have
115 * gone up again after this delay due to rescheduling!
117 if (!host->clk_requests) {
118 spin_unlock_irqrestore(&host->clk_lock, flags);
119 tick_ns = DIV_ROUND_UP(1000000000, freq);
120 ndelay(host->clk_delay * tick_ns);
122 /* New users appeared while waiting for this work */
123 spin_unlock_irqrestore(&host->clk_lock, flags);
126 mutex_lock(&host->clk_gate_mutex);
127 spin_lock_irqsave(&host->clk_lock, flags);
128 if (!host->clk_requests) {
129 spin_unlock_irqrestore(&host->clk_lock, flags);
130 /* This will set host->ios.clock to 0 */
131 mmc_gate_clock(host);
132 spin_lock_irqsave(&host->clk_lock, flags);
133 pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
135 spin_unlock_irqrestore(&host->clk_lock, flags);
136 mutex_unlock(&host->clk_gate_mutex);
140 * Internal work. Work to disable the clock at some later point.
142 static void mmc_host_clk_gate_work(struct work_struct *work)
144 struct mmc_host *host = container_of(work, struct mmc_host,
147 mmc_host_clk_gate_delayed(host);
151 * mmc_host_clk_hold - ungate hardware MCI clocks
152 * @host: host to ungate.
154 * Makes sure the host ios.clock is restored to a non-zero value
155 * past this call. Increase clock reference count and ungate clock
156 * if we're the first user.
158 void mmc_host_clk_hold(struct mmc_host *host)
162 /* cancel any clock gating work scheduled by mmc_host_clk_release() */
163 cancel_delayed_work_sync(&host->clk_gate_work);
164 mutex_lock(&host->clk_gate_mutex);
165 spin_lock_irqsave(&host->clk_lock, flags);
166 if (host->clk_gated) {
167 spin_unlock_irqrestore(&host->clk_lock, flags);
168 mmc_ungate_clock(host);
169 spin_lock_irqsave(&host->clk_lock, flags);
170 pr_debug("%s: ungated MCI clock\n", mmc_hostname(host));
172 host->clk_requests++;
173 spin_unlock_irqrestore(&host->clk_lock, flags);
174 mutex_unlock(&host->clk_gate_mutex);
178 * mmc_host_may_gate_card - check if this card may be gated
179 * @card: card to check.
181 static bool mmc_host_may_gate_card(struct mmc_card *card)
183 /* If there is no card we may gate it */
187 * Don't gate SDIO cards! These need to be clocked at all times
188 * since they may be independent systems generating interrupts
189 * and other events. The clock requests counter from the core will
190 * go down to zero since the core does not need it, but we will not
191 * gate the clock, because there is somebody out there that may still
194 return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING);
198 * mmc_host_clk_release - gate off hardware MCI clocks
199 * @host: host to gate.
201 * Calls the host driver with ios.clock set to zero as often as possible
202 * in order to gate off hardware MCI clocks. Decrease clock reference
203 * count and schedule disabling of clock.
205 void mmc_host_clk_release(struct mmc_host *host)
209 spin_lock_irqsave(&host->clk_lock, flags);
210 host->clk_requests--;
211 if (mmc_host_may_gate_card(host->card) &&
213 schedule_delayed_work(&host->clk_gate_work,
214 msecs_to_jiffies(host->clkgate_delay));
215 spin_unlock_irqrestore(&host->clk_lock, flags);
219 * mmc_host_clk_rate - get current clock frequency setting
220 * @host: host to get the clock frequency for.
222 * Returns current clock frequency regardless of gating.
224 unsigned int mmc_host_clk_rate(struct mmc_host *host)
229 spin_lock_irqsave(&host->clk_lock, flags);
231 freq = host->clk_old;
233 freq = host->ios.clock;
234 spin_unlock_irqrestore(&host->clk_lock, flags);
239 * mmc_host_clk_init - set up clock gating code
240 * @host: host with potential clock to control
242 static inline void mmc_host_clk_init(struct mmc_host *host)
244 host->clk_requests = 0;
245 /* Hold MCI clock for 8 cycles by default */
248 * Default clock gating delay is 0ms to avoid wasting power.
249 * This value can be tuned by writing into sysfs entry.
251 host->clkgate_delay = 0;
252 host->clk_gated = false;
253 INIT_DELAYED_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
254 spin_lock_init(&host->clk_lock);
255 mutex_init(&host->clk_gate_mutex);
259 * mmc_host_clk_exit - shut down clock gating code
260 * @host: host with potential clock to control
262 static inline void mmc_host_clk_exit(struct mmc_host *host)
265 * Wait for any outstanding gate and then make sure we're
266 * ungated before exiting.
268 if (cancel_delayed_work_sync(&host->clk_gate_work))
269 mmc_host_clk_gate_delayed(host);
271 mmc_host_clk_hold(host);
272 /* There should be only one user now */
273 WARN_ON(host->clk_requests > 1);
276 static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
278 host->clkgate_delay_attr.show = clkgate_delay_show;
279 host->clkgate_delay_attr.store = clkgate_delay_store;
280 sysfs_attr_init(&host->clkgate_delay_attr.attr);
281 host->clkgate_delay_attr.attr.name = "clkgate_delay";
282 host->clkgate_delay_attr.attr.mode = S_IRUGO | S_IWUSR;
283 if (device_create_file(&host->class_dev, &host->clkgate_delay_attr))
284 pr_err("%s: Failed to create clkgate_delay sysfs entry\n",
289 static inline void mmc_host_clk_init(struct mmc_host *host)
293 static inline void mmc_host_clk_exit(struct mmc_host *host)
297 static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
304 * mmc_of_parse() - parse host's device-tree node
305 * @host: host whose node should be parsed.
307 * To keep the rest of the MMC subsystem unaware of whether DT has been
308 * used to to instantiate and configure this host instance or not, we
309 * parse the properties and set respective generic mmc-host flags and
312 int mmc_of_parse(struct mmc_host *host)
314 struct device_node *np;
316 bool explicit_inv_wp, gpio_inv_wp = false;
317 enum of_gpio_flags flags;
320 if (!host->parent || !host->parent->of_node)
323 np = host->parent->of_node;
325 /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
326 if (of_property_read_u32(np, "bus-width", &bus_width) < 0) {
327 dev_dbg(host->parent,
328 "\"bus-width\" property is missing, assuming 1 bit.\n");
334 host->caps |= MMC_CAP_8_BIT_DATA;
335 /* Hosts capable of 8-bit transfers can also do 4 bits */
337 host->caps |= MMC_CAP_4_BIT_DATA;
342 dev_err(host->parent,
343 "Invalid \"bus-width\" value %ud!\n", bus_width);
347 /* f_max is obtained from the optional "max-frequency" property */
348 of_property_read_u32(np, "max-frequency", &host->f_max);
351 * Configure CD and WP pins. They are both by default active low to
352 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
353 * mmc-gpio helpers are used to attach, configure and use them. If
354 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
355 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
356 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
357 * is set. If the "non-removable" property is found, the
358 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
359 * configuration is performed.
362 /* Parse Card Detection */
363 if (of_find_property(np, "non-removable", &len)) {
364 host->caps |= MMC_CAP_NONREMOVABLE;
366 bool explicit_inv_cd, gpio_inv_cd = false;
368 explicit_inv_cd = of_property_read_bool(np, "cd-inverted");
370 if (of_find_property(np, "broken-cd", &len))
371 host->caps |= MMC_CAP_NEEDS_POLL;
373 gpio = of_get_named_gpio_flags(np, "cd-gpios", 0, &flags);
374 if (gpio == -EPROBE_DEFER)
376 if (gpio_is_valid(gpio)) {
377 if (!(flags & OF_GPIO_ACTIVE_LOW))
380 ret = mmc_gpio_request_cd(host, gpio, 0);
382 dev_err(host->parent,
383 "Failed to request CD GPIO #%d: %d!\n",
387 dev_info(host->parent, "Got CD GPIO #%d.\n",
392 if (explicit_inv_cd ^ gpio_inv_cd)
393 host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
396 /* Parse Write Protection */
397 explicit_inv_wp = of_property_read_bool(np, "wp-inverted");
399 gpio = of_get_named_gpio_flags(np, "wp-gpios", 0, &flags);
400 if (gpio == -EPROBE_DEFER) {
404 if (gpio_is_valid(gpio)) {
405 if (!(flags & OF_GPIO_ACTIVE_LOW))
408 ret = mmc_gpio_request_ro(host, gpio);
410 dev_err(host->parent,
411 "Failed to request WP GPIO: %d!\n", ret);
414 dev_info(host->parent, "Got WP GPIO #%d.\n",
418 if (explicit_inv_wp ^ gpio_inv_wp)
419 host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
421 if (of_find_property(np, "cap-sd-highspeed", &len))
422 host->caps |= MMC_CAP_SD_HIGHSPEED;
423 if (of_find_property(np, "cap-mmc-highspeed", &len))
424 host->caps |= MMC_CAP_MMC_HIGHSPEED;
425 if (of_find_property(np, "cap-power-off-card", &len))
426 host->caps |= MMC_CAP_POWER_OFF_CARD;
427 if (of_find_property(np, "cap-sdio-irq", &len))
428 host->caps |= MMC_CAP_SDIO_IRQ;
429 if (of_find_property(np, "full-pwr-cycle", &len))
430 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
431 if (of_find_property(np, "keep-power-in-suspend", &len))
432 host->pm_caps |= MMC_PM_KEEP_POWER;
433 if (of_find_property(np, "enable-sdio-wakeup", &len))
434 host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
439 mmc_gpio_free_cd(host);
442 EXPORT_SYMBOL(mmc_of_parse);
445 * mmc_alloc_host - initialise the per-host structure.
446 * @extra: sizeof private data structure
447 * @dev: pointer to host device model structure
449 * Initialise the per-host structure.
451 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
454 struct mmc_host *host;
456 host = kzalloc(sizeof(*host) + extra, GFP_KERNEL);
460 /* scanning will be enabled when we're ready */
461 host->rescan_disable = 1;
462 idr_preload(GFP_KERNEL);
463 spin_lock(&mmc_host_lock);
464 err = idr_alloc(&mmc_host_idr, host, 0, 0, GFP_NOWAIT);
467 spin_unlock(&mmc_host_lock);
472 dev_set_name(&host->class_dev, "mmc%d", host->index);
475 host->class_dev.parent = dev;
476 host->class_dev.class = &mmc_host_class;
477 device_initialize(&host->class_dev);
479 mmc_host_clk_init(host);
481 mutex_init(&host->slot.lock);
482 host->slot.cd_irq = -EINVAL;
484 spin_lock_init(&host->lock);
485 init_waitqueue_head(&host->wq);
486 wake_lock_init(&host->detect_wake_lock, WAKE_LOCK_SUSPEND,
487 kasprintf(GFP_KERNEL, "%s_detect", mmc_hostname(host)));
488 INIT_DELAYED_WORK(&host->detect, mmc_rescan);
490 host->pm_notify.notifier_call = mmc_pm_notify;
494 * By default, hosts do not support SGIO or large requests.
495 * They have to set these according to their abilities.
498 host->max_seg_size = PAGE_CACHE_SIZE;
500 host->max_req_size = PAGE_CACHE_SIZE;
501 host->max_blk_size = 512;
502 host->max_blk_count = PAGE_CACHE_SIZE / 512;
510 EXPORT_SYMBOL(mmc_alloc_host);
513 * mmc_add_host - initialise host hardware
516 * Register the host with the driver model. The host must be
517 * prepared to start servicing requests before this function
520 static struct mmc_host *primary_sdio_host;
521 int mmc_add_host(struct mmc_host *host)
525 WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
526 !host->ops->enable_sdio_irq);
528 err = device_add(&host->class_dev);
532 led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
534 #ifdef CONFIG_DEBUG_FS
535 mmc_add_host_debugfs(host);
537 mmc_host_clk_sysfs_init(host);
539 mmc_start_host(host);
540 if (!(host->pm_flags & MMC_PM_IGNORE_PM_NOTIFY))
541 register_pm_notifier(&host->pm_notify);
543 if (host->restrict_caps & RESTRICT_CARD_TYPE_SDIO)
544 primary_sdio_host = host;
548 EXPORT_SYMBOL(mmc_add_host);
552 * mmc_remove_host - remove host hardware
555 * Unregister and remove all cards associated with this host,
556 * and power down the MMC bus. No new requests will be issued
557 * after this function has returned.
559 void mmc_remove_host(struct mmc_host *host)
561 if (!(host->pm_flags & MMC_PM_IGNORE_PM_NOTIFY))
562 unregister_pm_notifier(&host->pm_notify);
566 #ifdef CONFIG_DEBUG_FS
567 mmc_remove_host_debugfs(host);
570 device_del(&host->class_dev);
572 led_trigger_unregister_simple(host->led);
574 mmc_host_clk_exit(host);
576 EXPORT_SYMBOL(mmc_remove_host);
579 * mmc_free_host - free the host structure
582 * Free the host once all references to it have been dropped.
584 void mmc_free_host(struct mmc_host *host)
586 spin_lock(&mmc_host_lock);
587 idr_remove(&mmc_host_idr, host->index);
588 spin_unlock(&mmc_host_lock);
589 wake_lock_destroy(&host->detect_wake_lock);
591 put_device(&host->class_dev);
593 EXPORT_SYMBOL(mmc_free_host);
596 * mmc_host_rescan - triger software rescan flow
599 * rescan slot attach in the assigned host.
600 * If @host is NULL, default rescan primary_sdio_host
601 * saved by mmc_add_host().
602 * OR, rescan host from argument.
605 int mmc_host_rescan(struct mmc_host *host, int val, int is_cap_sdio_irq)
607 if (NULL != primary_sdio_host) {
609 host = primary_sdio_host;
611 pr_info("%s: mmc_host_rescan pass in host from argument!\n",
614 pr_err("sdio: host isn't initialization successfully.\n");
618 pr_info("%s:mmc host rescan start!\n", mmc_hostname(host));
620 /* 0: oob 1:cap-sdio-irq */
621 if (is_cap_sdio_irq == 1) {
622 host->caps |= MMC_CAP_SDIO_IRQ;
623 } else if (is_cap_sdio_irq == 0) {
624 host->caps &= ~MMC_CAP_SDIO_IRQ;
626 dev_err(&host->class_dev, "sdio: host doesn't identify oob or sdio_irq mode!\n");
630 if (!(host->caps & MMC_CAP_NONREMOVABLE) && host->ops->set_sdio_status)
631 host->ops->set_sdio_status(host, val);
635 EXPORT_SYMBOL(mmc_host_rescan);