/* * linux/drivers/mmc/core/core.c * * Copyright (C) 2003-2004 Russell King, All Rights Reserved. * SD support Copyright (C) 2004 Ian Molton, All Rights Reserved. * Copyright (C) 2005-2008 Pierre Ossman, All Rights Reserved. * MMCv4 support Copyright (C) 2006 Philip Langdale, All Rights Reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/module.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/completion.h> #include <linux/device.h> #include <linux/delay.h> #include <linux/pagemap.h> #include <linux/err.h> #include <linux/leds.h> #include <linux/scatterlist.h> #include <linux/mmc/card.h> #include <linux/mmc/host.h> #include <linux/mmc/mmc.h> #include <linux/mmc/sd.h> #include "core.h" #include "bus.h" #include "host.h" #include "sdio_bus.h" #include "mmc_ops.h" #include "sd_ops.h" #include "sdio_ops.h" static struct workqueue_struct *workqueue; /* * Enabling software CRCs on the data blocks can be a significant (30%) * performance cost, and for other reasons may not always be desired. * So we allow it it to be disabled. */ int use_spi_crc = 1; module_param(use_spi_crc, bool, 0); /* * Internal function. Schedule delayed work in the MMC work queue. */ static int mmc_schedule_delayed_work(struct delayed_work *work, unsigned long delay) { return queue_delayed_work(workqueue, work, delay); } /* * Internal function. Flush all scheduled work from the MMC work queue. */ static void mmc_flush_scheduled_work(void) { flush_workqueue(workqueue); } /** * mmc_request_done - finish processing an MMC request * @host: MMC host which completed request * @mrq: MMC request which request * * MMC drivers should call this function when they have completed * their processing of a request. */ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq) { struct mmc_command *cmd = mrq->cmd; int err = cmd->error; if (err && cmd->retries && mmc_host_is_spi(host)) { if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND) cmd->retries = 0; } if (err && cmd->retries) { pr_debug("%s: req failed (CMD%u): %d, retrying...\n", mmc_hostname(host), cmd->opcode, err); cmd->retries--; cmd->error = 0; host->ops->request(host, mrq); } else { led_trigger_event(host->led, LED_OFF); pr_debug("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n", mmc_hostname(host), cmd->opcode, err, cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3]); if (mrq->data) { pr_debug("%s: %d bytes transferred: %d\n", mmc_hostname(host), mrq->data->bytes_xfered, mrq->data->error); } if (mrq->stop) { pr_debug("%s: (CMD%u): %d: %08x %08x %08x %08x\n", mmc_hostname(host), mrq->stop->opcode, mrq->stop->error, mrq->stop->resp[0], mrq->stop->resp[1], mrq->stop->resp[2], mrq->stop->resp[3]); } if (mrq->done) mrq->done(mrq); } } EXPORT_SYMBOL(mmc_request_done); static void mmc_start_request(struct mmc_host *host, struct mmc_request *mrq) { #ifdef CONFIG_MMC_DEBUG unsigned int i, sz; struct scatterlist *sg; #endif pr_debug("%s: starting CMD%u arg %08x flags %08x\n", mmc_hostname(host), mrq->cmd->opcode, mrq->cmd->arg, mrq->cmd->flags); if (mrq->data) { pr_debug("%s: blksz %d blocks %d flags %08x " "tsac %d ms nsac %d\n", mmc_hostname(host), mrq->data->blksz, mrq->data->blocks, mrq->data->flags, mrq->data->timeout_ns / 1000000, mrq->data->timeout_clks); } if (mrq->stop) { pr_debug("%s: CMD%u arg %08x flags %08x\n", mmc_hostname(host), mrq->stop->opcode, mrq->stop->arg, mrq->stop->flags); } WARN_ON(!host->claimed); led_trigger_event(host->led, LED_FULL); mrq->cmd->error = 0; mrq->cmd->mrq = mrq; if (mrq->data) { BUG_ON(mrq->data->blksz > host->max_blk_size); BUG_ON(mrq->data->blocks > host->max_blk_count); BUG_ON(mrq->data->blocks * mrq->data->blksz > host->max_req_size); #ifdef CONFIG_MMC_DEBUG sz = 0; for_each_sg(mrq->data->sg, sg, mrq->data->sg_len, i) sz += sg->length; BUG_ON(sz != mrq->data->blocks * mrq->data->blksz); #endif mrq->cmd->data = mrq->data; mrq->data->error = 0; mrq->data->mrq = mrq; if (mrq->stop) { mrq->data->stop = mrq->stop; mrq->stop->error = 0; mrq->stop->mrq = mrq; } } host->ops->request(host, mrq); } static void mmc_wait_done(struct mmc_request *mrq) { complete(mrq->done_data); } /** * mmc_wait_for_req - start a request and wait for completion * @host: MMC host to start command * @mrq: MMC request to start * * Start a new MMC custom command request for a host, and wait * for the command to complete. Does not attempt to parse the * response. */ void mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq) { DECLARE_COMPLETION_ONSTACK(complete); mrq->done_data = &complete; mrq->done = mmc_wait_done; mmc_start_request(host, mrq); wait_for_completion(&complete); } EXPORT_SYMBOL(mmc_wait_for_req); /** * mmc_wait_for_cmd - start a command and wait for completion * @host: MMC host to start command * @cmd: MMC command to start * @retries: maximum number of retries * * Start a new MMC command for a host, and wait for the command * to complete. Return any error that occurred while the command * was executing. Do not attempt to parse the response. */ int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries) { struct mmc_request mrq; WARN_ON(!host->claimed); memset(&mrq, 0, sizeof(struct mmc_request)); memset(cmd->resp, 0, sizeof(cmd->resp)); cmd->retries = retries; mrq.cmd = cmd; cmd->data = NULL; mmc_wait_for_req(host, &mrq); return cmd->error; } EXPORT_SYMBOL(mmc_wait_for_cmd); /** * mmc_set_data_timeout - set the timeout for a data command * @data: data phase for command * @card: the MMC card associated with the data transfer * * Computes the data timeout parameters according to the * correct algorithm given the card type. */ void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card) { unsigned int mult; /* * SDIO cards only define an upper 1 s limit on access. */ if (mmc_card_sdio(card)) { data->timeout_ns = 1000000000; data->timeout_clks = 0; return; } /* * SD cards use a 100 multiplier rather than 10 */ mult = mmc_card_sd(card) ? 100 : 10; /* * Scale up the multiplier (and therefore the timeout) by * the r2w factor for writes. */ if (data->flags & MMC_DATA_WRITE) mult <<= card->csd.r2w_factor; data->timeout_ns = card->csd.tacc_ns * mult; data->timeout_clks = card->csd.tacc_clks * mult; /* * SD cards also have an upper limit on the timeout. */ if (mmc_card_sd(card)) { unsigned int timeout_us, limit_us; timeout_us = data->timeout_ns / 1000; timeout_us += data->timeout_clks * 1000 / (card->host->ios.clock / 1000); if (data->flags & MMC_DATA_WRITE) /* * The limit is really 250 ms, but that is * insufficient for some crappy cards. */ limit_us = 300000; else limit_us = 100000; /* * SDHC cards always use these fixed values. */ if (timeout_us > limit_us || mmc_card_blockaddr(card)) { data->timeout_ns = limit_us * 1000; data->timeout_clks = 0; } } } EXPORT_SYMBOL(mmc_set_data_timeout); /** * mmc_align_data_size - pads a transfer size to a more optimal value * @card: the MMC card associated with the data transfer * @sz: original transfer size * * Pads the original data size with a number of extra bytes in * order to avoid controller bugs and/or performance hits * (e.g. some controllers revert to PIO for certain sizes). * * Returns the improved size, which might be unmodified. * * Note that this function is only relevant when issuing a * single scatter gather entry. */ unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz) { /* * FIXME: We don't have a system for the controller to tell * the core about its problems yet, so for now we just 32-bit * align the size. */ sz = ((sz + 3) / 4) * 4; return sz; } EXPORT_SYMBOL(mmc_align_data_size); /** * __mmc_claim_host - exclusively claim a host * @host: mmc host to claim * @abort: whether or not the operation should be aborted * * Claim a host for a set of operations. If @abort is non null and * dereference a non-zero value then this will return prematurely with * that non-zero value without acquiring the lock. Returns zero * with the lock held otherwise. */ int __mmc_claim_host(struct mmc_host *host, atomic_t *abort) { DECLARE_WAITQUEUE(wait, current); unsigned long flags; int stop; might_sleep(); add_wait_queue(&host->wq, &wait); spin_lock_irqsave(&host->lock, flags); while (1) { set_current_state(TASK_UNINTERRUPTIBLE); stop = abort ? atomic_read(abort) : 0; if (stop || !host->claimed) break; spin_unlock_irqrestore(&host->lock, flags); schedule(); spin_lock_irqsave(&host->lock, flags); } set_current_state(TASK_RUNNING); if (!stop) host->claimed = 1; else wake_up(&host->wq); spin_unlock_irqrestore(&host->lock, flags); remove_wait_queue(&host->wq, &wait); return stop; } EXPORT_SYMBOL(__mmc_claim_host); /** * mmc_release_host - release a host * @host: mmc host to release * * Release a MMC host, allowing others to claim the host * for their operations. */ void mmc_release_host(struct mmc_host *host) { unsigned long flags; WARN_ON(!host->claimed); spin_lock_irqsave(&host->lock, flags); host->claimed = 0; spin_unlock_irqrestore(&host->lock, flags); wake_up(&host->wq); } EXPORT_SYMBOL(mmc_release_host); /* * Internal function that does the actual ios call to the host driver, * optionally printing some debug output. */ static inline void mmc_set_ios(struct mmc_host *host) { struct mmc_ios *ios = &host->ios; pr_debug("%s: clock %uHz busmode %u powermode %u cs %u Vdd %u " "width %u timing %u\n", mmc_hostname(host), ios->clock, ios->bus_mode, ios->power_mode, ios->chip_select, ios->vdd, ios->bus_width, ios->timing); host->ops->set_ios(host, ios); } /* * Control chip select pin on a host. */ void mmc_set_chip_select(struct mmc_host *host, int mode) { host->ios.chip_select = mode; mmc_set_ios(host); } /* * Sets the host clock to the highest possible frequency that * is below "hz". */ void mmc_set_clock(struct mmc_host *host, unsigned int hz) { WARN_ON(hz < host->f_min); if (hz > host->f_max) hz = host->f_max; host->ios.clock = hz; mmc_set_ios(host); } /* * Change the bus mode (open drain/push-pull) of a host. */ void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode) { host->ios.bus_mode = mode; mmc_set_ios(host); } /* * Change data bus width of a host. */ void mmc_set_bus_width(struct mmc_host *host, unsigned int width) { host->ios.bus_width = width; mmc_set_ios(host); } /* * Mask off any voltages we don't support and select * the lowest voltage */ u32 mmc_select_voltage(struct mmc_host *host, u32 ocr) { int bit; ocr &= host->ocr_avail; bit = ffs(ocr); if (bit) { bit -= 1; ocr &= 3 << bit; host->ios.vdd = bit; mmc_set_ios(host); } else { ocr = 0; } return ocr; } /* * Select timing parameters for host. */ void mmc_set_timing(struct mmc_host *host, unsigned int timing) { host->ios.timing = timing; mmc_set_ios(host); } /* * Apply power to the MMC stack. This is a two-stage process. * First, we enable power to the card without the clock running. * We then wait a bit for the power to stabilise. Finally, * enable the bus drivers and clock to the card. * * We must _NOT_ enable the clock prior to power stablising. * * If a host does all the power sequencing itself, ignore the * initial MMC_POWER_UP stage. */ static void mmc_power_up(struct mmc_host *host) { int bit = fls(host->ocr_avail) - 1; host->ios.vdd = bit; if (mmc_host_is_spi(host)) { host->ios.chip_select = MMC_CS_HIGH; host->ios.bus_mode = MMC_BUSMODE_PUSHPULL; } else { host->ios.chip_select = MMC_CS_DONTCARE; host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN; } host->ios.power_mode = MMC_POWER_UP; host->ios.bus_width = MMC_BUS_WIDTH_1; host->ios.timing = MMC_TIMING_LEGACY; mmc_set_ios(host); /* * This delay should be sufficient to allow the power supply * to reach the minimum voltage. */ mmc_delay(2); host->ios.clock = host->f_min; host->ios.power_mode = MMC_POWER_ON; mmc_set_ios(host); /* * This delay must be at least 74 clock sizes, or 1 ms, or the * time required to reach a stable voltage. */ mmc_delay(2); } static void mmc_power_off(struct mmc_host *host) { host->ios.clock = 0; host->ios.vdd = 0; if (!mmc_host_is_spi(host)) { host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN; host->ios.chip_select = MMC_CS_DONTCARE; } host->ios.power_mode = MMC_POWER_OFF; host->ios.bus_width = MMC_BUS_WIDTH_1; host->ios.timing = MMC_TIMING_LEGACY; mmc_set_ios(host); } /* * Cleanup when the last reference to the bus operator is dropped. */ static void __mmc_release_bus(struct mmc_host *host) { BUG_ON(!host); BUG_ON(host->bus_refs); BUG_ON(!host->bus_dead); host->bus_ops = NULL; } /* * Increase reference count of bus operator */ static inline void mmc_bus_get(struct mmc_host *host) { unsigned long flags; spin_lock_irqsave(&host->lock, flags); host->bus_refs++; spin_unlock_irqrestore(&host->lock, flags); } /* * Decrease reference count of bus operator and free it if * it is the last reference. */ static inline void mmc_bus_put(struct mmc_host *host) { unsigned long flags; spin_lock_irqsave(&host->lock, flags); host->bus_refs--; if ((host->bus_refs == 0) && host->bus_ops) __mmc_release_bus(host); spin_unlock_irqrestore(&host->lock, flags); } /* * Assign a mmc bus handler to a host. Only one bus handler may control a * host at any given time. */ void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops) { unsigned long flags; BUG_ON(!host); BUG_ON(!ops); WARN_ON(!host->claimed); spin_lock_irqsave(&host->lock, flags); BUG_ON(host->bus_ops); BUG_ON(host->bus_refs); host->bus_ops = ops; host->bus_refs = 1; host->bus_dead = 0; spin_unlock_irqrestore(&host->lock, flags); } /* * Remove the current bus handler from a host. Assumes that there are * no interesting cards left, so the bus is powered down. */ void mmc_detach_bus(struct mmc_host *host) { unsigned long flags; BUG_ON(!host); WARN_ON(!host->claimed); WARN_ON(!host->bus_ops); spin_lock_irqsave(&host->lock, flags); host->bus_dead = 1; spin_unlock_irqrestore(&host->lock, flags); mmc_power_off(host); mmc_bus_put(host); } /** * mmc_detect_change - process change of state on a MMC socket * @host: host which changed state. * @delay: optional delay to wait before detection (jiffies) * * MMC drivers should call this when they detect a card has been * inserted or removed. The MMC layer will confirm that any * present card is still functional, and initialize any newly * inserted. */ void mmc_detect_change(struct mmc_host *host, unsigned long delay) { #ifdef CONFIG_MMC_DEBUG unsigned long flags; spin_lock_irqsave(&host->lock, flags); WARN_ON(host->removed); spin_unlock_irqrestore(&host->lock, flags); #endif mmc_schedule_delayed_work(&host->detect, delay); } EXPORT_SYMBOL(mmc_detect_change); void mmc_rescan(struct work_struct *work) { struct mmc_host *host = container_of(work, struct mmc_host, detect.work); u32 ocr; int err; mmc_bus_get(host); if (host->bus_ops == NULL) { /* * Only we can add a new handler, so it's safe to * release the lock here. */ mmc_bus_put(host); if (host->ops->get_cd && host->ops->get_cd(host) == 0) goto out; mmc_claim_host(host); mmc_power_up(host); mmc_go_idle(host); mmc_send_if_cond(host, host->ocr_avail); /* * First we search for SDIO... */ err = mmc_send_io_op_cond(host, 0, &ocr); if (!err) { if (mmc_attach_sdio(host, ocr)) mmc_power_off(host); goto out; } /* * ...then normal SD... */ err = mmc_send_app_op_cond(host, 0, &ocr); if (!err) { if (mmc_attach_sd(host, ocr)) mmc_power_off(host); goto out; } /* * ...and finally MMC. */ err = mmc_send_op_cond(host, 0, &ocr); if (!err) { if (mmc_attach_mmc(host, ocr)) mmc_power_off(host); goto out; } mmc_release_host(host); mmc_power_off(host); } else { if (host->bus_ops->detect && !host->bus_dead) host->bus_ops->detect(host); mmc_bus_put(host); } out: if (host->caps & MMC_CAP_NEEDS_POLL) mmc_schedule_delayed_work(&host->detect, HZ); } void mmc_start_host(struct mmc_host *host) { mmc_power_off(host); mmc_detect_change(host, 0); } void mmc_stop_host(struct mmc_host *host) { #ifdef CONFIG_MMC_DEBUG unsigned long flags; spin_lock_irqsave(&host->lock, flags); host->removed = 1; spin_unlock_irqrestore(&host->lock, flags); #endif mmc_flush_scheduled_work(); mmc_bus_get(host); if (host->bus_ops && !host->bus_dead) { if (host->bus_ops->remove) host->bus_ops->remove(host); mmc_claim_host(host); mmc_detach_bus(host); mmc_release_host(host); } mmc_bus_put(host); BUG_ON(host->card); mmc_power_off(host); } #ifdef CONFIG_PM /** * mmc_suspend_host - suspend a host * @host: mmc host * @state: suspend mode (PM_SUSPEND_xxx) */ int mmc_suspend_host(struct mmc_host *host, pm_message_t state) { mmc_flush_scheduled_work(); mmc_bus_get(host); if (host->bus_ops && !host->bus_dead) { if (host->bus_ops->suspend) host->bus_ops->suspend(host); if (!host->bus_ops->resume) { if (host->bus_ops->remove) host->bus_ops->remove(host); mmc_claim_host(host); mmc_detach_bus(host); mmc_release_host(host); } } mmc_bus_put(host); mmc_power_off(host); return 0; } EXPORT_SYMBOL(mmc_suspend_host); /** * mmc_resume_host - resume a previously suspended host * @host: mmc host */ int mmc_resume_host(struct mmc_host *host) { mmc_bus_get(host); if (host->bus_ops && !host->bus_dead) { mmc_power_up(host); BUG_ON(!host->bus_ops->resume); host->bus_ops->resume(host); } mmc_bus_put(host); /* * We add a slight delay here so that resume can progress * in parallel. */ mmc_detect_change(host, 1); return 0; } EXPORT_SYMBOL(mmc_resume_host); #endif static int __init mmc_init(void) { int ret; workqueue = create_singlethread_workqueue("kmmcd"); if (!workqueue) return -ENOMEM; ret = mmc_register_bus(); if (ret) goto destroy_workqueue; ret = mmc_register_host_class(); if (ret) goto unregister_bus; ret = sdio_register_bus(); if (ret) goto unregister_host_class; return 0; unregister_host_class: mmc_unregister_host_class(); unregister_bus: mmc_unregister_bus(); destroy_workqueue: destroy_workqueue(workqueue); return ret; } static void __exit mmc_exit(void) { sdio_unregister_bus(); mmc_unregister_host_class(); mmc_unregister_bus(); destroy_workqueue(workqueue); } subsys_initcall(mmc_init); module_exit(mmc_exit); MODULE_LICENSE("GPL");