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>
32 #include "slot-gpio.h"
35 #define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
37 static DEFINE_IDR(mmc_host_idr);
38 static DEFINE_SPINLOCK(mmc_host_lock);
40 static void mmc_host_classdev_release(struct device *dev)
42 struct mmc_host *host = cls_dev_to_mmc_host(dev);
43 spin_lock(&mmc_host_lock);
44 idr_remove(&mmc_host_idr, host->index);
45 spin_unlock(&mmc_host_lock);
49 static struct class mmc_host_class = {
51 .dev_release = mmc_host_classdev_release,
54 int mmc_register_host_class(void)
56 return class_register(&mmc_host_class);
59 void mmc_unregister_host_class(void)
61 class_unregister(&mmc_host_class);
64 #ifdef CONFIG_MMC_CLKGATE
65 static ssize_t clkgate_delay_show(struct device *dev,
66 struct device_attribute *attr, char *buf)
68 struct mmc_host *host = cls_dev_to_mmc_host(dev);
69 return snprintf(buf, PAGE_SIZE, "%lu\n", host->clkgate_delay);
72 static ssize_t clkgate_delay_store(struct device *dev,
73 struct device_attribute *attr, const char *buf, size_t count)
75 struct mmc_host *host = cls_dev_to_mmc_host(dev);
76 unsigned long flags, value;
78 if (kstrtoul(buf, 0, &value))
81 spin_lock_irqsave(&host->clk_lock, flags);
82 host->clkgate_delay = value;
83 spin_unlock_irqrestore(&host->clk_lock, flags);
88 * Enabling clock gating will make the core call out to the host
89 * once up and once down when it performs a request or card operation
90 * intermingled in any fashion. The driver will see this through
91 * set_ios() operations with ios.clock field set to 0 to gate (disable)
92 * the block clock, and to the old frequency to enable it again.
94 static void mmc_host_clk_gate_delayed(struct mmc_host *host)
96 unsigned long tick_ns;
97 unsigned long freq = host->ios.clock;
101 pr_debug("%s: frequency set to 0 in disable function, "
102 "this means the clock is already disabled.\n",
107 * New requests may have appeared while we were scheduling,
108 * then there is no reason to delay the check before
111 spin_lock_irqsave(&host->clk_lock, flags);
114 * Delay n bus cycles (at least 8 from MMC spec) before attempting
115 * to disable the MCI block clock. The reference count may have
116 * gone up again after this delay due to rescheduling!
118 if (!host->clk_requests) {
119 spin_unlock_irqrestore(&host->clk_lock, flags);
120 tick_ns = DIV_ROUND_UP(1000000000, freq);
121 ndelay(host->clk_delay * tick_ns);
123 /* New users appeared while waiting for this work */
124 spin_unlock_irqrestore(&host->clk_lock, flags);
127 mutex_lock(&host->clk_gate_mutex);
128 spin_lock_irqsave(&host->clk_lock, flags);
129 if (!host->clk_requests) {
130 spin_unlock_irqrestore(&host->clk_lock, flags);
131 /* This will set host->ios.clock to 0 */
132 mmc_gate_clock(host);
133 spin_lock_irqsave(&host->clk_lock, flags);
134 pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
136 spin_unlock_irqrestore(&host->clk_lock, flags);
137 mutex_unlock(&host->clk_gate_mutex);
141 * Internal work. Work to disable the clock at some later point.
143 static void mmc_host_clk_gate_work(struct work_struct *work)
145 struct mmc_host *host = container_of(work, struct mmc_host,
148 mmc_host_clk_gate_delayed(host);
152 * mmc_host_clk_hold - ungate hardware MCI clocks
153 * @host: host to ungate.
155 * Makes sure the host ios.clock is restored to a non-zero value
156 * past this call. Increase clock reference count and ungate clock
157 * if we're the first user.
159 void mmc_host_clk_hold(struct mmc_host *host)
163 /* cancel any clock gating work scheduled by mmc_host_clk_release() */
164 cancel_delayed_work_sync(&host->clk_gate_work);
165 mutex_lock(&host->clk_gate_mutex);
166 spin_lock_irqsave(&host->clk_lock, flags);
167 if (host->clk_gated) {
168 spin_unlock_irqrestore(&host->clk_lock, flags);
169 mmc_ungate_clock(host);
170 spin_lock_irqsave(&host->clk_lock, flags);
171 pr_debug("%s: ungated MCI clock\n", mmc_hostname(host));
173 host->clk_requests++;
174 spin_unlock_irqrestore(&host->clk_lock, flags);
175 mutex_unlock(&host->clk_gate_mutex);
179 * mmc_host_may_gate_card - check if this card may be gated
180 * @card: card to check.
182 static bool mmc_host_may_gate_card(struct mmc_card *card)
184 /* If there is no card we may gate it */
188 * Don't gate SDIO cards! These need to be clocked at all times
189 * since they may be independent systems generating interrupts
190 * and other events. The clock requests counter from the core will
191 * go down to zero since the core does not need it, but we will not
192 * gate the clock, because there is somebody out there that may still
195 return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING);
199 * mmc_host_clk_release - gate off hardware MCI clocks
200 * @host: host to gate.
202 * Calls the host driver with ios.clock set to zero as often as possible
203 * in order to gate off hardware MCI clocks. Decrease clock reference
204 * count and schedule disabling of clock.
206 void mmc_host_clk_release(struct mmc_host *host)
210 spin_lock_irqsave(&host->clk_lock, flags);
211 host->clk_requests--;
212 if (mmc_host_may_gate_card(host->card) &&
214 schedule_delayed_work(&host->clk_gate_work,
215 msecs_to_jiffies(host->clkgate_delay));
216 spin_unlock_irqrestore(&host->clk_lock, flags);
220 * mmc_host_clk_rate - get current clock frequency setting
221 * @host: host to get the clock frequency for.
223 * Returns current clock frequency regardless of gating.
225 unsigned int mmc_host_clk_rate(struct mmc_host *host)
230 spin_lock_irqsave(&host->clk_lock, flags);
232 freq = host->clk_old;
234 freq = host->ios.clock;
235 spin_unlock_irqrestore(&host->clk_lock, flags);
240 * mmc_host_clk_init - set up clock gating code
241 * @host: host with potential clock to control
243 static inline void mmc_host_clk_init(struct mmc_host *host)
245 host->clk_requests = 0;
246 /* Hold MCI clock for 8 cycles by default */
249 * Default clock gating delay is 0ms to avoid wasting power.
250 * This value can be tuned by writing into sysfs entry.
252 host->clkgate_delay = 0;
253 host->clk_gated = false;
254 INIT_DELAYED_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
255 spin_lock_init(&host->clk_lock);
256 mutex_init(&host->clk_gate_mutex);
260 * mmc_host_clk_exit - shut down clock gating code
261 * @host: host with potential clock to control
263 static inline void mmc_host_clk_exit(struct mmc_host *host)
266 * Wait for any outstanding gate and then make sure we're
267 * ungated before exiting.
269 if (cancel_delayed_work_sync(&host->clk_gate_work))
270 mmc_host_clk_gate_delayed(host);
272 mmc_host_clk_hold(host);
273 /* There should be only one user now */
274 WARN_ON(host->clk_requests > 1);
277 static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
279 host->clkgate_delay_attr.show = clkgate_delay_show;
280 host->clkgate_delay_attr.store = clkgate_delay_store;
281 sysfs_attr_init(&host->clkgate_delay_attr.attr);
282 host->clkgate_delay_attr.attr.name = "clkgate_delay";
283 host->clkgate_delay_attr.attr.mode = S_IRUGO | S_IWUSR;
284 if (device_create_file(&host->class_dev, &host->clkgate_delay_attr))
285 pr_err("%s: Failed to create clkgate_delay sysfs entry\n",
290 static inline void mmc_host_clk_init(struct mmc_host *host)
294 static inline void mmc_host_clk_exit(struct mmc_host *host)
298 static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
305 * mmc_of_parse() - parse host's device-tree node
306 * @host: host whose node should be parsed.
308 * To keep the rest of the MMC subsystem unaware of whether DT has been
309 * used to to instantiate and configure this host instance or not, we
310 * parse the properties and set respective generic mmc-host flags and
313 int mmc_of_parse(struct mmc_host *host)
315 struct device_node *np;
318 bool cd_cap_invert, cd_gpio_invert = false;
319 bool ro_cap_invert, ro_gpio_invert = false;
321 if (!host->parent || !host->parent->of_node)
324 np = host->parent->of_node;
326 /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
327 if (of_property_read_u32(np, "bus-width", &bus_width) < 0) {
328 dev_dbg(host->parent,
329 "\"bus-width\" property is missing, assuming 1 bit.\n");
335 host->caps |= MMC_CAP_8_BIT_DATA;
336 /* Hosts capable of 8-bit transfers can also do 4 bits */
338 host->caps |= MMC_CAP_4_BIT_DATA;
343 dev_err(host->parent,
344 "Invalid \"bus-width\" value %u!\n", bus_width);
348 /* f_max is obtained from the optional "max-frequency" property */
349 of_property_read_u32(np, "max-frequency", &host->f_max);
352 * Configure CD and WP pins. They are both by default active low to
353 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
354 * mmc-gpio helpers are used to attach, configure and use them. If
355 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
356 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
357 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
358 * is set. If the "non-removable" property is found, the
359 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
360 * configuration is performed.
363 /* Parse Card Detection */
364 if (of_find_property(np, "non-removable", &len)) {
365 host->caps |= MMC_CAP_NONREMOVABLE;
367 cd_cap_invert = of_property_read_bool(np, "cd-inverted");
369 if (of_find_property(np, "broken-cd", &len))
370 host->caps |= MMC_CAP_NEEDS_POLL;
372 ret = mmc_gpiod_request_cd(host, "cd", 0, true,
375 dev_info(host->parent, "Got CD GPIO\n");
376 else if (ret != -ENOENT)
380 * There are two ways to flag that the CD line is inverted:
381 * through the cd-inverted flag and by the GPIO line itself
382 * being inverted from the GPIO subsystem. This is a leftover
383 * from the times when the GPIO subsystem did not make it
384 * possible to flag a line as inverted.
386 * If the capability on the host AND the GPIO line are
387 * both inverted, the end result is that the CD line is
390 if (cd_cap_invert ^ cd_gpio_invert)
391 host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
394 /* Parse Write Protection */
395 ro_cap_invert = of_property_read_bool(np, "wp-inverted");
397 ret = mmc_gpiod_request_ro(host, "wp", 0, false, 0, &ro_gpio_invert);
399 dev_info(host->parent, "Got WP GPIO\n");
400 else if (ret != -ENOENT)
403 /* See the comment on CD inversion above */
404 if (ro_cap_invert ^ ro_gpio_invert)
405 host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
407 if (of_find_property(np, "cap-sd-highspeed", &len))
408 host->caps |= MMC_CAP_SD_HIGHSPEED;
409 if (of_find_property(np, "cap-mmc-highspeed", &len))
410 host->caps |= MMC_CAP_MMC_HIGHSPEED;
411 if (of_find_property(np, "sd-uhs-sdr12", &len))
412 host->caps |= MMC_CAP_UHS_SDR12;
413 if (of_find_property(np, "sd-uhs-sdr25", &len))
414 host->caps |= MMC_CAP_UHS_SDR25;
415 if (of_find_property(np, "sd-uhs-sdr50", &len))
416 host->caps |= MMC_CAP_UHS_SDR50;
417 if (of_find_property(np, "sd-uhs-sdr104", &len))
418 host->caps |= MMC_CAP_UHS_SDR104;
419 if (of_find_property(np, "sd-uhs-ddr50", &len))
420 host->caps |= MMC_CAP_UHS_DDR50;
421 if (of_find_property(np, "cap-power-off-card", &len))
422 host->caps |= MMC_CAP_POWER_OFF_CARD;
423 if (of_find_property(np, "cap-sdio-irq", &len))
424 host->caps |= MMC_CAP_SDIO_IRQ;
425 if (of_find_property(np, "full-pwr-cycle", &len))
426 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
427 if (of_find_property(np, "keep-power-in-suspend", &len))
428 host->pm_caps |= MMC_PM_KEEP_POWER;
429 if (of_find_property(np, "enable-sdio-wakeup", &len))
430 host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
431 if (of_find_property(np, "mmc-ddr-1_8v", &len))
432 host->caps |= MMC_CAP_1_8V_DDR;
433 if (of_find_property(np, "mmc-ddr-1_2v", &len))
434 host->caps |= MMC_CAP_1_2V_DDR;
435 if (of_find_property(np, "mmc-hs200-1_8v", &len))
436 host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
437 if (of_find_property(np, "mmc-hs200-1_2v", &len))
438 host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
439 if (of_find_property(np, "mmc-hs400-1_8v", &len))
440 host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
441 if (of_find_property(np, "mmc-hs400-1_2v", &len))
442 host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
444 host->dsr_req = !of_property_read_u32(np, "dsr", &host->dsr);
445 if (host->dsr_req && (host->dsr & ~0xffff)) {
446 dev_err(host->parent,
447 "device tree specified broken value for DSR: 0x%x, ignoring\n",
452 return mmc_pwrseq_alloc(host);
455 EXPORT_SYMBOL(mmc_of_parse);
458 * mmc_alloc_host - initialise the per-host structure.
459 * @extra: sizeof private data structure
460 * @dev: pointer to host device model structure
462 * Initialise the per-host structure.
464 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
467 struct mmc_host *host;
469 host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
473 /* scanning will be enabled when we're ready */
474 host->rescan_disable = 1;
475 idr_preload(GFP_KERNEL);
476 spin_lock(&mmc_host_lock);
477 err = idr_alloc(&mmc_host_idr, host, 0, 0, GFP_NOWAIT);
480 spin_unlock(&mmc_host_lock);
487 dev_set_name(&host->class_dev, "mmc%d", host->index);
490 host->class_dev.parent = dev;
491 host->class_dev.class = &mmc_host_class;
492 device_initialize(&host->class_dev);
494 if (mmc_gpio_alloc(host)) {
495 put_device(&host->class_dev);
499 mmc_host_clk_init(host);
501 spin_lock_init(&host->lock);
502 init_waitqueue_head(&host->wq);
503 INIT_DELAYED_WORK(&host->detect, mmc_rescan);
505 host->pm_notify.notifier_call = mmc_pm_notify;
509 * By default, hosts do not support SGIO or large requests.
510 * They have to set these according to their abilities.
513 host->max_seg_size = PAGE_CACHE_SIZE;
515 host->max_req_size = PAGE_CACHE_SIZE;
516 host->max_blk_size = 512;
517 host->max_blk_count = PAGE_CACHE_SIZE / 512;
522 EXPORT_SYMBOL(mmc_alloc_host);
525 * mmc_add_host - initialise host hardware
528 * Register the host with the driver model. The host must be
529 * prepared to start servicing requests before this function
532 int mmc_add_host(struct mmc_host *host)
536 WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
537 !host->ops->enable_sdio_irq);
539 err = device_add(&host->class_dev);
543 led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
545 #ifdef CONFIG_DEBUG_FS
546 mmc_add_host_debugfs(host);
548 mmc_host_clk_sysfs_init(host);
550 mmc_start_host(host);
551 register_pm_notifier(&host->pm_notify);
556 EXPORT_SYMBOL(mmc_add_host);
559 * mmc_remove_host - remove host hardware
562 * Unregister and remove all cards associated with this host,
563 * and power down the MMC bus. No new requests will be issued
564 * after this function has returned.
566 void mmc_remove_host(struct mmc_host *host)
568 unregister_pm_notifier(&host->pm_notify);
571 #ifdef CONFIG_DEBUG_FS
572 mmc_remove_host_debugfs(host);
575 device_del(&host->class_dev);
577 led_trigger_unregister_simple(host->led);
579 mmc_host_clk_exit(host);
582 EXPORT_SYMBOL(mmc_remove_host);
585 * mmc_free_host - free the host structure
588 * Free the host once all references to it have been dropped.
590 void mmc_free_host(struct mmc_host *host)
592 mmc_pwrseq_free(host);
593 put_device(&host->class_dev);
596 EXPORT_SYMBOL(mmc_free_host);