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/*

 *  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) 2005-2007 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"

extern int mmc_attach_mmc(struct mmc_host *host, u32 ocr);

extern int mmc_attach_sd(struct mmc_host *host, u32 ocr);

extern int mmc_attach_sdio(struct mmc_host *host, u32 ocr);

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;

#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 (i = 0;i < mrq->data->sg_len;i++)

                        sz += mrq->data->sg[i].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 = 1000* 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)

                        limit_us = 250000;

                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_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.

 */

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);

                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);

                        return;

                }

                /*

                 * ...then normal SD...

                 */

                err = mmc_send_app_op_cond(host, 0, &ocr);

                if (!err) {

                        if (mmc_attach_sd(host, ocr))

                                mmc_power_off(host);

                        return;

                }

                /*

                 * ...and finally MMC.

                 */

                err = mmc_send_op_cond(host, 0, &ocr);

                if (!err) {

                        if (mmc_attach_mmc(host, ocr))

                                mmc_power_off(host);

                        return;

                }

                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);

        }

}

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();