drivers/mmc/core/sdio.c - kernel/msm-4.9 - Gitiles

 /*
  *  linux/drivers/mmc/sdio.c
  *
  *  Copyright 2006-2007 Pierre Ossman
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or (at
  * your option) any later version.
  */

 #include <linux/err.h>
 #include <linux/pm_runtime.h>

 #include <linux/mmc/host.h>
 #include <linux/mmc/card.h>
 #include <linux/mmc/sdio.h>
 #include <linux/mmc/sdio_func.h>
 #include <linux/mmc/sdio_ids.h>

 #include "core.h"
 #include "bus.h"
 #include "sd.h"
 #include "sdio_bus.h"
 #include "mmc_ops.h"
 #include "sd_ops.h"
 #include "sdio_ops.h"
 #include "sdio_cis.h"

 static int sdio_read_fbr(struct sdio_func *func)
 {
 	int ret;
 	unsigned char data;

 	if (mmc_card_nonstd_func_interface(func->card)) {
 		func->class = SDIO_CLASS_NONE;
 		return 0;
 	}

 	ret = mmc_io_rw_direct(func->card, 0, 0,
 		SDIO_FBR_BASE(func->num) + SDIO_FBR_STD_IF, 0, &data);
 	if (ret)
 		goto out;

 	data &= 0x0f;

 	if (data == 0x0f) {
 		ret = mmc_io_rw_direct(func->card, 0, 0,
 			SDIO_FBR_BASE(func->num) + SDIO_FBR_STD_IF_EXT, 0, &data);
 		if (ret)
 			goto out;
 	}

 	func->class = data;

 out:
 	return ret;
 }

 static int sdio_init_func(struct mmc_card *card, unsigned int fn)
 {
 	int ret;
 	struct sdio_func *func;

 	BUG_ON(fn > SDIO_MAX_FUNCS);

 	func = sdio_alloc_func(card);
 	if (IS_ERR(func))
 		return PTR_ERR(func);

 	func->num = fn;

 	if (!(card->quirks & MMC_QUIRK_NONSTD_SDIO)) {
 		ret = sdio_read_fbr(func);
 		if (ret)
 			goto fail;

 		ret = sdio_read_func_cis(func);
 		if (ret)
 			goto fail;
 	} else {
 		func->vendor = func->card->cis.vendor;
 		func->device = func->card->cis.device;
 		func->max_blksize = func->card->cis.blksize;
 	}

 	card->sdio_func[fn - 1] = func;

 	return 0;

 fail:
 	/*
 	 * It is okay to remove the function here even though we hold
 	 * the host lock as we haven't registered the device yet.
 	 */
 	sdio_remove_func(func);
 	return ret;
 }

 static int sdio_read_cccr(struct mmc_card *card)
 {
 	int ret;
 	int cccr_vsn;
 	unsigned char data;

 	memset(&card->cccr, 0, sizeof(struct sdio_cccr));

 	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_CCCR, 0, &data);
 	if (ret)
 		goto out;

 	cccr_vsn = data & 0x0f;

 	if (cccr_vsn > SDIO_CCCR_REV_1_20) {
 		printk(KERN_ERR "%s: unrecognised CCCR structure version %d\n",
 			mmc_hostname(card->host), cccr_vsn);
 		return -EINVAL;
 	}

 	card->cccr.sdio_vsn = (data & 0xf0) >> 4;

 	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_CAPS, 0, &data);
 	if (ret)
 		goto out;

 	if (data & SDIO_CCCR_CAP_SMB)
 		card->cccr.multi_block = 1;
 	if (data & SDIO_CCCR_CAP_LSC)
 		card->cccr.low_speed = 1;
 	if (data & SDIO_CCCR_CAP_4BLS)
 		card->cccr.wide_bus = 1;

 	if (cccr_vsn >= SDIO_CCCR_REV_1_10) {
 		ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_POWER, 0, &data);
 		if (ret)
 			goto out;

 		if (data & SDIO_POWER_SMPC)
 			card->cccr.high_power = 1;
 	}

 	if (cccr_vsn >= SDIO_CCCR_REV_1_20) {
 		ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &data);
 		if (ret)
 			goto out;

 		if (data & SDIO_SPEED_SHS)
 			card->cccr.high_speed = 1;
 	}

 out:
 	return ret;
 }

 static int sdio_enable_wide(struct mmc_card *card)
 {
 	int ret;
 	u8 ctrl;

 	if (!(card->host->caps & MMC_CAP_4_BIT_DATA))
 		return 0;

 	if (card->cccr.low_speed && !card->cccr.wide_bus)
 		return 0;

 	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
 	if (ret)
 		return ret;

 	ctrl |= SDIO_BUS_WIDTH_4BIT;

 	ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
 	if (ret)
 		return ret;

 	return 1;
 }

 /*
  * If desired, disconnect the pull-up resistor on CD/DAT[3] (pin 1)
  * of the card. This may be required on certain setups of boards,
  * controllers and embedded sdio device which do not need the card's
  * pull-up. As a result, card detection is disabled and power is saved.
  */
 static int sdio_disable_cd(struct mmc_card *card)
 {
 	int ret;
 	u8 ctrl;

 	if (!mmc_card_disable_cd(card))
 		return 0;

 	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
 	if (ret)
 		return ret;

 	ctrl |= SDIO_BUS_CD_DISABLE;

 	return mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
 }

 /*
  * Devices that remain active during a system suspend are
  * put back into 1-bit mode.
  */
 static int sdio_disable_wide(struct mmc_card *card)
 {
 	int ret;
 	u8 ctrl;

 	if (!(card->host->caps & MMC_CAP_4_BIT_DATA))
 		return 0;

 	if (card->cccr.low_speed && !card->cccr.wide_bus)
 		return 0;

 	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
 	if (ret)
 		return ret;

 	if (!(ctrl & SDIO_BUS_WIDTH_4BIT))
 		return 0;

 	ctrl &= ~SDIO_BUS_WIDTH_4BIT;
 	ctrl |= SDIO_BUS_ASYNC_INT;

 	ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
 	if (ret)
 		return ret;

 	mmc_set_bus_width(card->host, MMC_BUS_WIDTH_1);

 	return 0;
 }


 static int sdio_enable_4bit_bus(struct mmc_card *card)
 {
 	int err;

 	if (card->type == MMC_TYPE_SDIO)
 		return sdio_enable_wide(card);

 	if ((card->host->caps & MMC_CAP_4_BIT_DATA) &&
 		(card->scr.bus_widths & SD_SCR_BUS_WIDTH_4)) {
 		err = mmc_app_set_bus_width(card, MMC_BUS_WIDTH_4);
 		if (err)
 			return err;
 	} else
 		return 0;

 	err = sdio_enable_wide(card);
 	if (err <= 0)
 		mmc_app_set_bus_width(card, MMC_BUS_WIDTH_1);

 	return err;
 }


 /*
  * Test if the card supports high-speed mode and, if so, switch to it.
  */
 static int mmc_sdio_switch_hs(struct mmc_card *card, int enable)
 {
 	int ret;
 	u8 speed;

 	if (!(card->host->caps & MMC_CAP_SD_HIGHSPEED))
 		return 0;

 	if (!card->cccr.high_speed)
 		return 0;

 	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
 	if (ret)
 		return ret;

 	if (enable)
 		speed |= SDIO_SPEED_EHS;
 	else
 		speed &= ~SDIO_SPEED_EHS;

 	ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_SPEED, speed, NULL);
 	if (ret)
 		return ret;

 	return 1;
 }

 /*
  * Enable SDIO/combo card's high-speed mode. Return 0/1 if [not]supported.
  */
 static int sdio_enable_hs(struct mmc_card *card)
 {
 	int ret;

 	ret = mmc_sdio_switch_hs(card, true);
 	if (ret <= 0 || card->type == MMC_TYPE_SDIO)
 		return ret;

 	ret = mmc_sd_switch_hs(card);
 	if (ret <= 0)
 		mmc_sdio_switch_hs(card, false);

 	return ret;
 }

 static unsigned mmc_sdio_get_max_clock(struct mmc_card *card)
 {
 	unsigned max_dtr;

 	if (mmc_card_highspeed(card)) {
 		/*
 		 * The SDIO specification doesn't mention how
 		 * the CIS transfer speed register relates to
 		 * high-speed, but it seems that 50 MHz is
 		 * mandatory.
 		 */
 		max_dtr = 50000000;
 	} else {
 		max_dtr = card->cis.max_dtr;
 	}

 	if (card->type == MMC_TYPE_SD_COMBO)
 		max_dtr = min(max_dtr, mmc_sd_get_max_clock(card));

 	return max_dtr;
 }

 /*
  * Handle the detection and initialisation of a card.
  *
  * In the case of a resume, "oldcard" will contain the card
  * we're trying to reinitialise.
  */
 static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 			      struct mmc_card *oldcard, int powered_resume)
 {
 	struct mmc_card *card;
 	int err;

 	BUG_ON(!host);
 	WARN_ON(!host->claimed);

 	/*
 	 * Inform the card of the voltage
 	 */
 	if (!powered_resume) {
 		err = mmc_send_io_op_cond(host, host->ocr, &ocr);
 		if (err)
 			goto err;
 	}

 	/*
 	 * For SPI, enable CRC as appropriate.
 	 */
 	if (mmc_host_is_spi(host)) {
 		err = mmc_spi_set_crc(host, use_spi_crc);
 		if (err)
 			goto err;
 	}

 	/*
 	 * Allocate card structure.
 	 */
 	card = mmc_alloc_card(host, NULL);
 	if (IS_ERR(card)) {
 		err = PTR_ERR(card);
 		goto err;
 	}

 	if ((ocr & R4_MEMORY_PRESENT) &&
 	    mmc_sd_get_cid(host, host->ocr & ocr, card->raw_cid, NULL) == 0) {
 		card->type = MMC_TYPE_SD_COMBO;

 		if (oldcard && (oldcard->type != MMC_TYPE_SD_COMBO ||
 		    memcmp(card->raw_cid, oldcard->raw_cid, sizeof(card->raw_cid)) != 0)) {
 			mmc_remove_card(card);
 			return -ENOENT;
 		}
 	} else {
 		card->type = MMC_TYPE_SDIO;

 		if (oldcard && oldcard->type != MMC_TYPE_SDIO) {
 			mmc_remove_card(card);
 			return -ENOENT;
 		}
 	}

 	/*
 	 * Call the optional HC's init_card function to handle quirks.
 	 */
 	if (host->ops->init_card)
 		host->ops->init_card(host, card);

 	/*
 	 * For native busses:  set card RCA and quit open drain mode.
 	 */
 	if (!powered_resume && !mmc_host_is_spi(host)) {
 		err = mmc_send_relative_addr(host, &card->rca);
 		if (err)
 			goto remove;

 		/*
 		 * Update oldcard with the new RCA received from the SDIO
 		 * device -- we're doing this so that it's updated in the
 		 * "card" struct when oldcard overwrites that later.
 		 */
 		if (oldcard)
 			oldcard->rca = card->rca;
 	}

 	/*
 	 * Read CSD, before selecting the card
 	 */
 	if (!oldcard && card->type == MMC_TYPE_SD_COMBO) {
 		err = mmc_sd_get_csd(host, card);
 		if (err)
 			return err;

 		mmc_decode_cid(card);
 	}

 	/*
 	 * Select card, as all following commands rely on that.
 	 */
 	if (!powered_resume && !mmc_host_is_spi(host)) {
 		err = mmc_select_card(card);
 		if (err)
 			goto remove;
 	}

 	if (card->quirks & MMC_QUIRK_NONSTD_SDIO) {
 		/*
 		 * This is non-standard SDIO device, meaning it doesn't
 		 * have any CIA (Common I/O area) registers present.
 		 * It's host's responsibility to fill cccr and cis
 		 * structures in init_card().
 		 */
 		mmc_set_clock(host, card->cis.max_dtr);

 		if (card->cccr.high_speed) {
 			mmc_card_set_highspeed(card);
 			mmc_set_timing(card->host, MMC_TIMING_SD_HS);
 		}

 		goto finish;
 	}

 	/*
 	 * Read the common registers.
 	 */
 	err = sdio_read_cccr(card);
 	if (err)
 		goto remove;

 	/*
 	 * Read the common CIS tuples.
 	 */
 	err = sdio_read_common_cis(card);
 	if (err)
 		goto remove;

 	if (oldcard) {
 		int same = (card->cis.vendor == oldcard->cis.vendor &&
 			    card->cis.device == oldcard->cis.device);
 		mmc_remove_card(card);
 		if (!same)
 			return -ENOENT;

 		card = oldcard;
 	}
 	mmc_fixup_device(card, NULL);

 	if (card->type == MMC_TYPE_SD_COMBO) {
 		err = mmc_sd_setup_card(host, card, oldcard != NULL);
 		/* handle as SDIO-only card if memory init failed */
 		if (err) {
 			mmc_go_idle(host);
 			if (mmc_host_is_spi(host))
 				/* should not fail, as it worked previously */
 				mmc_spi_set_crc(host, use_spi_crc);
 			card->type = MMC_TYPE_SDIO;
 		} else
 			card->dev.type = &sd_type;
 	}

 	/*
 	 * If needed, disconnect card detection pull-up resistor.
 	 */
 	err = sdio_disable_cd(card);
 	if (err)
 		goto remove;

 	/*
 	 * Switch to high-speed (if supported).
 	 */
 	err = sdio_enable_hs(card);
 	if (err > 0)
 		mmc_sd_go_highspeed(card);
 	else if (err)
 		goto remove;

 	/*
 	 * Change to the card's maximum speed.
 	 */
 	mmc_set_clock(host, mmc_sdio_get_max_clock(card));

 	/*
 	 * Switch to wider bus (if supported).
 	 */
 	err = sdio_enable_4bit_bus(card);
 	if (err > 0)
 		mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
 	else if (err)
 		goto remove;

 finish:
 	if (!oldcard)
 		host->card = card;
 	return 0;

 remove:
 	if (!oldcard)
 		mmc_remove_card(card);

 err:
 	return err;
 }

 /*
  * Host is being removed. Free up the current card.
  */
 static void mmc_sdio_remove(struct mmc_host *host)
 {
 	int i;

 	BUG_ON(!host);
 	BUG_ON(!host->card);

 	for (i = 0;i < host->card->sdio_funcs;i++) {
 		if (host->card->sdio_func[i]) {
 			sdio_remove_func(host->card->sdio_func[i]);
 			host->card->sdio_func[i] = NULL;
 		}
 	}

 	mmc_remove_card(host->card);
 	host->card = NULL;
 }

 /*
  * Card detection callback from host.
  */
 static void mmc_sdio_detect(struct mmc_host *host)
 {
 	int err;

 	BUG_ON(!host);
 	BUG_ON(!host->card);

 	/* Make sure card is powered before detecting it */
 	if (host->caps & MMC_CAP_POWER_OFF_CARD) {
 		err = pm_runtime_get_sync(&host->card->dev);
 		if (err < 0)
 			goto out;
 	}

 	mmc_claim_host(host);

 	/*
 	 * Just check if our card has been removed.
 	 */
 	err = mmc_select_card(host->card);

 	mmc_release_host(host);

 	/*
 	 * Tell PM core it's OK to power off the card now.
 	 *
 	 * The _sync variant is used in order to ensure that the card
 	 * is left powered off in case an error occurred, and the card
 	 * is going to be removed.
 	 *
 	 * Since there is no specific reason to believe a new user
 	 * is about to show up at this point, the _sync variant is
 	 * desirable anyway.
 	 */
 	if (host->caps & MMC_CAP_POWER_OFF_CARD)
 		pm_runtime_put_sync(&host->card->dev);

 out:
 	if (err) {
 		mmc_sdio_remove(host);

 		mmc_claim_host(host);
 		mmc_detach_bus(host);
 		mmc_power_off(host);
 		mmc_release_host(host);
 	}
 }

 /*
  * SDIO suspend.  We need to suspend all functions separately.
  * Therefore all registered functions must have drivers with suspend
  * and resume methods.  Failing that we simply remove the whole card.
  */
 static int mmc_sdio_suspend(struct mmc_host *host)
 {
 	int i, err = 0;

 	for (i = 0; i < host->card->sdio_funcs; i++) {
 		struct sdio_func *func = host->card->sdio_func[i];
 		if (func && sdio_func_present(func) && func->dev.driver) {
 			const struct dev_pm_ops *pmops = func->dev.driver->pm;
 			if (!pmops || !pmops->suspend || !pmops->resume) {
 				/* force removal of entire card in that case */
 				err = -ENOSYS;
 			} else
 				err = pmops->suspend(&func->dev);
 			if (err)
 				break;
 		}
 	}
 	while (err && --i >= 0) {
 		struct sdio_func *func = host->card->sdio_func[i];
 		if (func && sdio_func_present(func) && func->dev.driver) {
 			const struct dev_pm_ops *pmops = func->dev.driver->pm;
 			pmops->resume(&func->dev);
 		}
 	}

 	if (!err && mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host)) {
 		mmc_claim_host(host);
 		sdio_disable_wide(host->card);
 		mmc_release_host(host);
 	}

 	return err;
 }

 static int mmc_sdio_resume(struct mmc_host *host)
 {
 	int i, err = 0;

 	BUG_ON(!host);
 	BUG_ON(!host->card);

 	/* Basic card reinitialization. */
 	mmc_claim_host(host);

 	/* No need to reinitialize powered-resumed nonremovable cards */
 	if (mmc_card_is_removable(host) || !mmc_card_keep_power(host))
 		err = mmc_sdio_init_card(host, host->ocr, host->card,
 					mmc_card_keep_power(host));
 	else if (mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host)) {
 		/* We may have switched to 1-bit mode during suspend */
 		err = sdio_enable_4bit_bus(host->card);
 		if (err > 0) {
 			mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
 			err = 0;
 		}
 	}

 	if (!err && host->sdio_irqs)
 		mmc_signal_sdio_irq(host);
 	mmc_release_host(host);

 	/*
 	 * If the card looked to be the same as before suspending, then
 	 * we proceed to resume all card functions.  If one of them returns
 	 * an error then we simply return that error to the core and the
 	 * card will be redetected as new.  It is the responsibility of
 	 * the function driver to perform further tests with the extra
 	 * knowledge it has of the card to confirm the card is indeed the
 	 * same as before suspending (same MAC address for network cards,
 	 * etc.) and return an error otherwise.
 	 */
 	for (i = 0; !err && i < host->card->sdio_funcs; i++) {
 		struct sdio_func *func = host->card->sdio_func[i];
 		if (func && sdio_func_present(func) && func->dev.driver) {
 			const struct dev_pm_ops *pmops = func->dev.driver->pm;
 			err = pmops->resume(&func->dev);
 		}
 	}

 	return err;
 }

 static int mmc_sdio_power_restore(struct mmc_host *host)
 {
 	int ret;
 	u32 ocr;

 	BUG_ON(!host);
 	BUG_ON(!host->card);

 	mmc_claim_host(host);

 	/*
 	 * Reset the card by performing the same steps that are taken by
 	 * mmc_rescan_try_freq() and mmc_attach_sdio() during a "normal" probe.
 	 *
 	 * sdio_reset() is technically not needed. Having just powered up the
 	 * hardware, it should already be in reset state. However, some
 	 * platforms (such as SD8686 on OLPC) do not instantly cut power,
 	 * meaning that a reset is required when restoring power soon after
 	 * powering off. It is harmless in other cases.
 	 *
 	 * The CMD5 reset (mmc_send_io_op_cond()), according to the SDIO spec,
 	 * is not necessary for non-removable cards. However, it is required
 	 * for OLPC SD8686 (which expects a [CMD5,5,3,7] init sequence), and
 	 * harmless in other situations.
 	 *
 	 * With these steps taken, mmc_select_voltage() is also required to
 	 * restore the correct voltage setting of the card.
 	 */
 	sdio_reset(host);
 	mmc_go_idle(host);
 	mmc_send_if_cond(host, host->ocr_avail);

 	ret = mmc_send_io_op_cond(host, 0, &ocr);
 	if (ret)
 		goto out;

 	if (host->ocr_avail_sdio)
 		host->ocr_avail = host->ocr_avail_sdio;

 	host->ocr = mmc_select_voltage(host, ocr & ~0x7F);
 	if (!host->ocr) {
 		ret = -EINVAL;
 		goto out;
 	}

 	ret = mmc_sdio_init_card(host, host->ocr, host->card,
 				mmc_card_keep_power(host));
 	if (!ret && host->sdio_irqs)
 		mmc_signal_sdio_irq(host);

 out:
 	mmc_release_host(host);

 	return ret;
 }

 static const struct mmc_bus_ops mmc_sdio_ops = {
 	.remove = mmc_sdio_remove,
 	.detect = mmc_sdio_detect,
 	.suspend = mmc_sdio_suspend,
 	.resume = mmc_sdio_resume,
 	.power_restore = mmc_sdio_power_restore,
 };


 /*
  * Starting point for SDIO card init.
  */
 int mmc_attach_sdio(struct mmc_host *host)
 {
 	int err, i, funcs;
 	u32 ocr;
 	struct mmc_card *card;

 	BUG_ON(!host);
 	WARN_ON(!host->claimed);

 	err = mmc_send_io_op_cond(host, 0, &ocr);
 	if (err)
 		return err;

 	mmc_attach_bus(host, &mmc_sdio_ops);
 	if (host->ocr_avail_sdio)
 		host->ocr_avail = host->ocr_avail_sdio;

 	/*
 	 * Sanity check the voltages that the card claims to
 	 * support.
 	 */
 	if (ocr & 0x7F) {
 		printk(KERN_WARNING "%s: card claims to support voltages "
 		       "below the defined range. These will be ignored.\n",
 		       mmc_hostname(host));
 		ocr &= ~0x7F;
 	}

 	host->ocr = mmc_select_voltage(host, ocr);

 	/*
 	 * Can we support the voltage(s) of the card(s)?
 	 */
 	if (!host->ocr) {
 		err = -EINVAL;
 		goto err;
 	}

 	/*
 	 * Detect and init the card.
 	 */
 	err = mmc_sdio_init_card(host, host->ocr, NULL, 0);
 	if (err)
 		goto err;
 	card = host->card;

 	/*
 	 * Enable runtime PM only if supported by host+card+board
 	 */
 	if (host->caps & MMC_CAP_POWER_OFF_CARD) {
 		/*
 		 * Let runtime PM core know our card is active
 		 */
 		err = pm_runtime_set_active(&card->dev);
 		if (err)
 			goto remove;

 		/*
 		 * Enable runtime PM for this card
 		 */
 		pm_runtime_enable(&card->dev);
 	}

 	/*
 	 * The number of functions on the card is encoded inside
 	 * the ocr.
 	 */
 	funcs = (ocr & 0x70000000) >> 28;
 	card->sdio_funcs = 0;

 	/*
 	 * Initialize (but don't add) all present functions.
 	 */
 	for (i = 0; i < funcs; i++, card->sdio_funcs++) {
 		err = sdio_init_func(host->card, i + 1);
 		if (err)
 			goto remove;

 		/*
 		 * Enable Runtime PM for this func (if supported)
 		 */
 		if (host->caps & MMC_CAP_POWER_OFF_CARD)
 			pm_runtime_enable(&card->sdio_func[i]->dev);
 	}

 	/*
 	 * First add the card to the driver model...
 	 */
 	mmc_release_host(host);
 	err = mmc_add_card(host->card);
 	if (err)
 		goto remove_added;

 	/*
 	 * ...then the SDIO functions.
 	 */
 	for (i = 0;i < funcs;i++) {
 		err = sdio_add_func(host->card->sdio_func[i]);
 		if (err)
 			goto remove_added;
 	}

 	mmc_claim_host(host);
 	return 0;


 remove_added:
 	/* Remove without lock if the device has been added. */
 	mmc_sdio_remove(host);
 	mmc_claim_host(host);
 remove:
 	/* And with lock if it hasn't been added. */
 	mmc_release_host(host);
 	if (host->card)
 		mmc_sdio_remove(host);
 	mmc_claim_host(host);
 err:
 	mmc_detach_bus(host);

 	printk(KERN_ERR "%s: error %d whilst initialising SDIO card\n",
 		mmc_hostname(host), err);

 	return err;
 }
	/*
	* linux/drivers/mmc/sdio.c
	*
	* Copyright 2006-2007 Pierre Ossman
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or (at
	* your option) any later version.
	*/

	#include <linux/err.h>
	#include <linux/pm_runtime.h>

	#include <linux/mmc/host.h>
	#include <linux/mmc/card.h>
	#include <linux/mmc/sdio.h>
	#include <linux/mmc/sdio_func.h>
	#include <linux/mmc/sdio_ids.h>

	#include "core.h"
	#include "bus.h"
	#include "sd.h"
	#include "sdio_bus.h"
	#include "mmc_ops.h"
	#include "sd_ops.h"
	#include "sdio_ops.h"
	#include "sdio_cis.h"

	static int sdio_read_fbr(struct sdio_func *func)
	{
	int ret;
	unsigned char data;

	if (mmc_card_nonstd_func_interface(func->card)) {
	func->class = SDIO_CLASS_NONE;
	return 0;
	}

	ret = mmc_io_rw_direct(func->card, 0, 0,
	SDIO_FBR_BASE(func->num) + SDIO_FBR_STD_IF, 0, &data);
	if (ret)
	goto out;

	data &= 0x0f;

	if (data == 0x0f) {
	ret = mmc_io_rw_direct(func->card, 0, 0,
	SDIO_FBR_BASE(func->num) + SDIO_FBR_STD_IF_EXT, 0, &data);
	if (ret)
	goto out;
	}

	func->class = data;

	out:
	return ret;
	}

	static int sdio_init_func(struct mmc_card *card, unsigned int fn)
	{
	int ret;
	struct sdio_func *func;

	BUG_ON(fn > SDIO_MAX_FUNCS);

	func = sdio_alloc_func(card);
	if (IS_ERR(func))
	return PTR_ERR(func);

	func->num = fn;

	if (!(card->quirks & MMC_QUIRK_NONSTD_SDIO)) {
	ret = sdio_read_fbr(func);
	if (ret)
	goto fail;

	ret = sdio_read_func_cis(func);
	if (ret)
	goto fail;
	} else {
	func->vendor = func->card->cis.vendor;
	func->device = func->card->cis.device;
	func->max_blksize = func->card->cis.blksize;
	}

	card->sdio_func[fn - 1] = func;

	return 0;

	fail:
	/*
	* It is okay to remove the function here even though we hold
	* the host lock as we haven't registered the device yet.
	*/
	sdio_remove_func(func);
	return ret;
	}

	static int sdio_read_cccr(struct mmc_card *card)
	{
	int ret;
	int cccr_vsn;
	unsigned char data;

	memset(&card->cccr, 0, sizeof(struct sdio_cccr));

	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_CCCR, 0, &data);
	if (ret)
	goto out;

	cccr_vsn = data & 0x0f;

	if (cccr_vsn > SDIO_CCCR_REV_1_20) {
	printk(KERN_ERR "%s: unrecognised CCCR structure version %d\n",
	mmc_hostname(card->host), cccr_vsn);
	return -EINVAL;
	}

	card->cccr.sdio_vsn = (data & 0xf0) >> 4;

	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_CAPS, 0, &data);
	if (ret)
	goto out;

	if (data & SDIO_CCCR_CAP_SMB)
	card->cccr.multi_block = 1;
	if (data & SDIO_CCCR_CAP_LSC)
	card->cccr.low_speed = 1;
	if (data & SDIO_CCCR_CAP_4BLS)
	card->cccr.wide_bus = 1;

	if (cccr_vsn >= SDIO_CCCR_REV_1_10) {
	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_POWER, 0, &data);
	if (ret)
	goto out;

	if (data & SDIO_POWER_SMPC)
	card->cccr.high_power = 1;
	}

	if (cccr_vsn >= SDIO_CCCR_REV_1_20) {
	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &data);
	if (ret)
	goto out;

	if (data & SDIO_SPEED_SHS)
	card->cccr.high_speed = 1;
	}

	out:
	return ret;
	}

	static int sdio_enable_wide(struct mmc_card *card)
	{
	int ret;
	u8 ctrl;

	if (!(card->host->caps & MMC_CAP_4_BIT_DATA))
	return 0;

	if (card->cccr.low_speed && !card->cccr.wide_bus)
	return 0;

	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
	if (ret)
	return ret;

	ctrl \|= SDIO_BUS_WIDTH_4BIT;

	ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
	if (ret)
	return ret;

	return 1;
	}

	/*
	* If desired, disconnect the pull-up resistor on CD/DAT[3] (pin 1)
	* of the card. This may be required on certain setups of boards,
	* controllers and embedded sdio device which do not need the card's
	* pull-up. As a result, card detection is disabled and power is saved.
	*/
	static int sdio_disable_cd(struct mmc_card *card)
	{
	int ret;
	u8 ctrl;

	if (!mmc_card_disable_cd(card))
	return 0;

	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
	if (ret)
	return ret;

	ctrl \|= SDIO_BUS_CD_DISABLE;

	return mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
	}

	/*
	* Devices that remain active during a system suspend are
	* put back into 1-bit mode.
	*/
	static int sdio_disable_wide(struct mmc_card *card)
	{
	int ret;
	u8 ctrl;

	if (!(card->host->caps & MMC_CAP_4_BIT_DATA))
	return 0;

	if (card->cccr.low_speed && !card->cccr.wide_bus)
	return 0;

	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
	if (ret)
	return ret;

	if (!(ctrl & SDIO_BUS_WIDTH_4BIT))
	return 0;

	ctrl &= ~SDIO_BUS_WIDTH_4BIT;
	ctrl \|= SDIO_BUS_ASYNC_INT;

	ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
	if (ret)
	return ret;

	mmc_set_bus_width(card->host, MMC_BUS_WIDTH_1);

	return 0;
	}


	static int sdio_enable_4bit_bus(struct mmc_card *card)
	{
	int err;

	if (card->type == MMC_TYPE_SDIO)
	return sdio_enable_wide(card);

	if ((card->host->caps & MMC_CAP_4_BIT_DATA) &&
	(card->scr.bus_widths & SD_SCR_BUS_WIDTH_4)) {
	err = mmc_app_set_bus_width(card, MMC_BUS_WIDTH_4);
	if (err)
	return err;
	} else
	return 0;

	err = sdio_enable_wide(card);
	if (err <= 0)
	mmc_app_set_bus_width(card, MMC_BUS_WIDTH_1);

	return err;
	}


	/*
	* Test if the card supports high-speed mode and, if so, switch to it.
	*/
	static int mmc_sdio_switch_hs(struct mmc_card *card, int enable)
	{
	int ret;
	u8 speed;

	if (!(card->host->caps & MMC_CAP_SD_HIGHSPEED))
	return 0;

	if (!card->cccr.high_speed)
	return 0;

	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
	if (ret)
	return ret;

	if (enable)
	speed \|= SDIO_SPEED_EHS;
	else
	speed &= ~SDIO_SPEED_EHS;

	ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_SPEED, speed, NULL);
	if (ret)
	return ret;

	return 1;
	}

	/*
	* Enable SDIO/combo card's high-speed mode. Return 0/1 if [not]supported.
	*/
	static int sdio_enable_hs(struct mmc_card *card)
	{
	int ret;

	ret = mmc_sdio_switch_hs(card, true);
	if (ret <= 0 \|\| card->type == MMC_TYPE_SDIO)
	return ret;

	ret = mmc_sd_switch_hs(card);
	if (ret <= 0)
	mmc_sdio_switch_hs(card, false);

	return ret;
	}

	static unsigned mmc_sdio_get_max_clock(struct mmc_card *card)
	{
	unsigned max_dtr;

	if (mmc_card_highspeed(card)) {
	/*
	* The SDIO specification doesn't mention how
	* the CIS transfer speed register relates to
	* high-speed, but it seems that 50 MHz is
	* mandatory.
	*/
	max_dtr = 50000000;
	} else {
	max_dtr = card->cis.max_dtr;
	}

	if (card->type == MMC_TYPE_SD_COMBO)
	max_dtr = min(max_dtr, mmc_sd_get_max_clock(card));

	return max_dtr;
	}

	/*
	* Handle the detection and initialisation of a card.
	*
	* In the case of a resume, "oldcard" will contain the card
	* we're trying to reinitialise.
	*/
	static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
	struct mmc_card *oldcard, int powered_resume)
	{
	struct mmc_card *card;
	int err;

	BUG_ON(!host);
	WARN_ON(!host->claimed);

	/*
	* Inform the card of the voltage
	*/
	if (!powered_resume) {
	err = mmc_send_io_op_cond(host, host->ocr, &ocr);
	if (err)
	goto err;
	}

	/*
	* For SPI, enable CRC as appropriate.
	*/
	if (mmc_host_is_spi(host)) {
	err = mmc_spi_set_crc(host, use_spi_crc);
	if (err)
	goto err;
	}

	/*
	* Allocate card structure.
	*/
	card = mmc_alloc_card(host, NULL);
	if (IS_ERR(card)) {
	err = PTR_ERR(card);
	goto err;
	}

	if ((ocr & R4_MEMORY_PRESENT) &&
	mmc_sd_get_cid(host, host->ocr & ocr, card->raw_cid, NULL) == 0) {
	card->type = MMC_TYPE_SD_COMBO;

	if (oldcard && (oldcard->type != MMC_TYPE_SD_COMBO \|\|
	memcmp(card->raw_cid, oldcard->raw_cid, sizeof(card->raw_cid)) != 0)) {
	mmc_remove_card(card);
	return -ENOENT;
	}
	} else {
	card->type = MMC_TYPE_SDIO;

	if (oldcard && oldcard->type != MMC_TYPE_SDIO) {
	mmc_remove_card(card);
	return -ENOENT;
	}
	}

	/*
	* Call the optional HC's init_card function to handle quirks.
	*/
	if (host->ops->init_card)
	host->ops->init_card(host, card);

	/*
	* For native busses: set card RCA and quit open drain mode.
	*/
	if (!powered_resume && !mmc_host_is_spi(host)) {
	err = mmc_send_relative_addr(host, &card->rca);
	if (err)
	goto remove;

	/*
	* Update oldcard with the new RCA received from the SDIO
	* device -- we're doing this so that it's updated in the
	* "card" struct when oldcard overwrites that later.
	*/
	if (oldcard)
	oldcard->rca = card->rca;
	}

	/*
	* Read CSD, before selecting the card
	*/
	if (!oldcard && card->type == MMC_TYPE_SD_COMBO) {
	err = mmc_sd_get_csd(host, card);
	if (err)
	return err;

	mmc_decode_cid(card);
	}

	/*
	* Select card, as all following commands rely on that.
	*/
	if (!powered_resume && !mmc_host_is_spi(host)) {
	err = mmc_select_card(card);
	if (err)
	goto remove;
	}

	if (card->quirks & MMC_QUIRK_NONSTD_SDIO) {
	/*
	* This is non-standard SDIO device, meaning it doesn't
	* have any CIA (Common I/O area) registers present.
	* It's host's responsibility to fill cccr and cis
	* structures in init_card().
	*/
	mmc_set_clock(host, card->cis.max_dtr);

	if (card->cccr.high_speed) {
	mmc_card_set_highspeed(card);
	mmc_set_timing(card->host, MMC_TIMING_SD_HS);
	}

	goto finish;
	}

	/*
	* Read the common registers.
	*/
	err = sdio_read_cccr(card);
	if (err)
	goto remove;

	/*
	* Read the common CIS tuples.
	*/
	err = sdio_read_common_cis(card);
	if (err)
	goto remove;

	if (oldcard) {
	int same = (card->cis.vendor == oldcard->cis.vendor &&
	card->cis.device == oldcard->cis.device);
	mmc_remove_card(card);
	if (!same)
	return -ENOENT;

	card = oldcard;
	}
	mmc_fixup_device(card, NULL);

	if (card->type == MMC_TYPE_SD_COMBO) {
	err = mmc_sd_setup_card(host, card, oldcard != NULL);
	/* handle as SDIO-only card if memory init failed */
	if (err) {
	mmc_go_idle(host);
	if (mmc_host_is_spi(host))
	/* should not fail, as it worked previously */
	mmc_spi_set_crc(host, use_spi_crc);
	card->type = MMC_TYPE_SDIO;
	} else
	card->dev.type = &sd_type;
	}

	/*
	* If needed, disconnect card detection pull-up resistor.
	*/
	err = sdio_disable_cd(card);
	if (err)
	goto remove;

	/*
	* Switch to high-speed (if supported).
	*/
	err = sdio_enable_hs(card);
	if (err > 0)
	mmc_sd_go_highspeed(card);
	else if (err)
	goto remove;

	/*
	* Change to the card's maximum speed.
	*/
	mmc_set_clock(host, mmc_sdio_get_max_clock(card));

	/*
	* Switch to wider bus (if supported).
	*/
	err = sdio_enable_4bit_bus(card);
	if (err > 0)
	mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
	else if (err)
	goto remove;

	finish:
	if (!oldcard)
	host->card = card;
	return 0;

	remove:
	if (!oldcard)
	mmc_remove_card(card);

	err:
	return err;
	}

	/*
	* Host is being removed. Free up the current card.
	*/
	static void mmc_sdio_remove(struct mmc_host *host)
	{
	int i;

	BUG_ON(!host);
	BUG_ON(!host->card);

	for (i = 0;i < host->card->sdio_funcs;i++) {
	if (host->card->sdio_func[i]) {
	sdio_remove_func(host->card->sdio_func[i]);
	host->card->sdio_func[i] = NULL;
	}
	}

	mmc_remove_card(host->card);
	host->card = NULL;
	}

	/*
	* Card detection callback from host.
	*/
	static void mmc_sdio_detect(struct mmc_host *host)
	{
	int err;

	BUG_ON(!host);
	BUG_ON(!host->card);

	/* Make sure card is powered before detecting it */
	if (host->caps & MMC_CAP_POWER_OFF_CARD) {
	err = pm_runtime_get_sync(&host->card->dev);
	if (err < 0)
	goto out;
	}

	mmc_claim_host(host);

	/*
	* Just check if our card has been removed.
	*/
	err = mmc_select_card(host->card);

	mmc_release_host(host);

	/*
	* Tell PM core it's OK to power off the card now.
	*
	* The _sync variant is used in order to ensure that the card
	* is left powered off in case an error occurred, and the card
	* is going to be removed.
	*
	* Since there is no specific reason to believe a new user
	* is about to show up at this point, the _sync variant is
	* desirable anyway.
	*/
	if (host->caps & MMC_CAP_POWER_OFF_CARD)
	pm_runtime_put_sync(&host->card->dev);

	out:
	if (err) {
	mmc_sdio_remove(host);

	mmc_claim_host(host);
	mmc_detach_bus(host);
	mmc_power_off(host);
	mmc_release_host(host);
	}
	}

	/*
	* SDIO suspend. We need to suspend all functions separately.
	* Therefore all registered functions must have drivers with suspend
	* and resume methods. Failing that we simply remove the whole card.
	*/
	static int mmc_sdio_suspend(struct mmc_host *host)
	{
	int i, err = 0;

	for (i = 0; i < host->card->sdio_funcs; i++) {
	struct sdio_func *func = host->card->sdio_func[i];
	if (func && sdio_func_present(func) && func->dev.driver) {
	const struct dev_pm_ops *pmops = func->dev.driver->pm;
	if (!pmops \|\| !pmops->suspend \|\| !pmops->resume) {
	/* force removal of entire card in that case */
	err = -ENOSYS;
	} else
	err = pmops->suspend(&func->dev);
	if (err)
	break;
	}
	}
	while (err && --i >= 0) {
	struct sdio_func *func = host->card->sdio_func[i];
	if (func && sdio_func_present(func) && func->dev.driver) {
	const struct dev_pm_ops *pmops = func->dev.driver->pm;
	pmops->resume(&func->dev);
	}
	}

	if (!err && mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host)) {
	mmc_claim_host(host);
	sdio_disable_wide(host->card);
	mmc_release_host(host);
	}

	return err;
	}

	static int mmc_sdio_resume(struct mmc_host *host)
	{
	int i, err = 0;

	BUG_ON(!host);
	BUG_ON(!host->card);

	/* Basic card reinitialization. */
	mmc_claim_host(host);

	/* No need to reinitialize powered-resumed nonremovable cards */
	if (mmc_card_is_removable(host) \|\| !mmc_card_keep_power(host))
	err = mmc_sdio_init_card(host, host->ocr, host->card,
	mmc_card_keep_power(host));
	else if (mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host)) {
	/* We may have switched to 1-bit mode during suspend */
	err = sdio_enable_4bit_bus(host->card);
	if (err > 0) {
	mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
	err = 0;
	}
	}

	if (!err && host->sdio_irqs)
	mmc_signal_sdio_irq(host);
	mmc_release_host(host);

	/*
	* If the card looked to be the same as before suspending, then
	* we proceed to resume all card functions. If one of them returns
	* an error then we simply return that error to the core and the
	* card will be redetected as new. It is the responsibility of
	* the function driver to perform further tests with the extra
	* knowledge it has of the card to confirm the card is indeed the
	* same as before suspending (same MAC address for network cards,
	* etc.) and return an error otherwise.
	*/
	for (i = 0; !err && i < host->card->sdio_funcs; i++) {
	struct sdio_func *func = host->card->sdio_func[i];
	if (func && sdio_func_present(func) && func->dev.driver) {
	const struct dev_pm_ops *pmops = func->dev.driver->pm;
	err = pmops->resume(&func->dev);
	}
	}

	return err;
	}

	static int mmc_sdio_power_restore(struct mmc_host *host)
	{
	int ret;
	u32 ocr;

	BUG_ON(!host);
	BUG_ON(!host->card);

	mmc_claim_host(host);

	/*
	* Reset the card by performing the same steps that are taken by
	* mmc_rescan_try_freq() and mmc_attach_sdio() during a "normal" probe.
	*
	* sdio_reset() is technically not needed. Having just powered up the
	* hardware, it should already be in reset state. However, some
	* platforms (such as SD8686 on OLPC) do not instantly cut power,
	* meaning that a reset is required when restoring power soon after
	* powering off. It is harmless in other cases.
	*
	* The CMD5 reset (mmc_send_io_op_cond()), according to the SDIO spec,
	* is not necessary for non-removable cards. However, it is required
	* for OLPC SD8686 (which expects a [CMD5,5,3,7] init sequence), and
	* harmless in other situations.
	*
	* With these steps taken, mmc_select_voltage() is also required to
	* restore the correct voltage setting of the card.
	*/
	sdio_reset(host);
	mmc_go_idle(host);
	mmc_send_if_cond(host, host->ocr_avail);

	ret = mmc_send_io_op_cond(host, 0, &ocr);
	if (ret)
	goto out;

	if (host->ocr_avail_sdio)
	host->ocr_avail = host->ocr_avail_sdio;

	host->ocr = mmc_select_voltage(host, ocr & ~0x7F);
	if (!host->ocr) {
	ret = -EINVAL;
	goto out;
	}

	ret = mmc_sdio_init_card(host, host->ocr, host->card,
	mmc_card_keep_power(host));
	if (!ret && host->sdio_irqs)
	mmc_signal_sdio_irq(host);

	out:
	mmc_release_host(host);

	return ret;
	}

	static const struct mmc_bus_ops mmc_sdio_ops = {
	.remove = mmc_sdio_remove,
	.detect = mmc_sdio_detect,
	.suspend = mmc_sdio_suspend,
	.resume = mmc_sdio_resume,
	.power_restore = mmc_sdio_power_restore,
	};


	/*
	* Starting point for SDIO card init.
	*/
	int mmc_attach_sdio(struct mmc_host *host)
	{
	int err, i, funcs;
	u32 ocr;
	struct mmc_card *card;

	BUG_ON(!host);
	WARN_ON(!host->claimed);

	err = mmc_send_io_op_cond(host, 0, &ocr);
	if (err)
	return err;

	mmc_attach_bus(host, &mmc_sdio_ops);
	if (host->ocr_avail_sdio)
	host->ocr_avail = host->ocr_avail_sdio;

	/*
	* Sanity check the voltages that the card claims to
	* support.
	*/
	if (ocr & 0x7F) {
	printk(KERN_WARNING "%s: card claims to support voltages "
	"below the defined range. These will be ignored.\n",
	mmc_hostname(host));
	ocr &= ~0x7F;
	}

	host->ocr = mmc_select_voltage(host, ocr);

	/*
	* Can we support the voltage(s) of the card(s)?
	*/
	if (!host->ocr) {
	err = -EINVAL;
	goto err;
	}

	/*
	* Detect and init the card.
	*/
	err = mmc_sdio_init_card(host, host->ocr, NULL, 0);
	if (err)
	goto err;
	card = host->card;

	/*
	* Enable runtime PM only if supported by host+card+board
	*/
	if (host->caps & MMC_CAP_POWER_OFF_CARD) {
	/*
	* Let runtime PM core know our card is active
	*/
	err = pm_runtime_set_active(&card->dev);
	if (err)
	goto remove;

	/*
	* Enable runtime PM for this card
	*/
	pm_runtime_enable(&card->dev);
	}

	/*
	* The number of functions on the card is encoded inside
	* the ocr.
	*/
	funcs = (ocr & 0x70000000) >> 28;
	card->sdio_funcs = 0;

	/*
	* Initialize (but don't add) all present functions.
	*/
	for (i = 0; i < funcs; i++, card->sdio_funcs++) {
	err = sdio_init_func(host->card, i + 1);
	if (err)
	goto remove;

	/*
	* Enable Runtime PM for this func (if supported)
	*/
	if (host->caps & MMC_CAP_POWER_OFF_CARD)
	pm_runtime_enable(&card->sdio_func[i]->dev);
	}

	/*
	* First add the card to the driver model...
	*/
	mmc_release_host(host);
	err = mmc_add_card(host->card);
	if (err)
	goto remove_added;

	/*
	* ...then the SDIO functions.
	*/
	for (i = 0;i < funcs;i++) {
	err = sdio_add_func(host->card->sdio_func[i]);
	if (err)
	goto remove_added;
	}

	mmc_claim_host(host);
	return 0;


	remove_added:
	/* Remove without lock if the device has been added. */
	mmc_sdio_remove(host);
	mmc_claim_host(host);
	remove:
	/* And with lock if it hasn't been added. */
	mmc_release_host(host);
	if (host->card)
	mmc_sdio_remove(host);
	mmc_claim_host(host);
	err:
	mmc_detach_bus(host);

	printk(KERN_ERR "%s: error %d whilst initialising SDIO card\n",
	mmc_hostname(host), err);

	return err;
	}