Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 914 insertions, 0 deletions

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
new file mode 100644
index 000000000000..e40026328251
--- /dev/null
+++ b/drivers/mmc/mmc.c
@@ -0,0 +1,914 @@
+/*
+ *  linux/drivers/mmc/mmc.c
+ *
+ *  Copyright (C) 2003-2004 Russell King, 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/config.h>
+#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/mmc/card.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/protocol.h>
+
+#include "mmc.h"
+
+#ifdef CONFIG_MMC_DEBUG
+#define DBG(x...)	printk(KERN_DEBUG x)
+#else
+#define DBG(x...)	do { } while (0)
+#endif
+
+#define CMD_RETRIES	3
+
+/*
+ * OCR Bit positions to 10s of Vdd mV.
+ */
+static const unsigned short mmc_ocr_bit_to_vdd[] = {
+	150,	155,	160,	165,	170,	180,	190,	200,
+	210,	220,	230,	240,	250,	260,	270,	280,
+	290,	300,	310,	320,	330,	340,	350,	360
+};
+
+static const unsigned int tran_exp[] = {
+	10000,		100000,		1000000,	10000000,
+	0,		0,		0,		0
+};
+
+static const unsigned char tran_mant[] = {
+	0,	10,	12,	13,	15,	20,	25,	30,
+	35,	40,	45,	50,	55,	60,	70,	80,
+};
+
+static const unsigned int tacc_exp[] = {
+	1,	10,	100,	1000,	10000,	100000,	1000000, 10000000,
+};
+
+static const unsigned int tacc_mant[] = {
+	0,	10,	12,	13,	15,	20,	25,	30,
+	35,	40,	45,	50,	55,	60,	70,	80,
+};
+
+
+/**
+ *	mmc_request_done - finish processing an MMC command
+ *	@host: MMC host which completed command
+ *	@mrq: MMC request which completed
+ *
+ *	MMC drivers should call this function when they have completed
+ *	their processing of a command.  This should be called before the
+ *	data part of the command has completed.
+ */
+void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
+{
+	struct mmc_command *cmd = mrq->cmd;
+	int err = mrq->cmd->error;
+	DBG("MMC: req done (%02x): %d: %08x %08x %08x %08x\n", cmd->opcode,
+	    err, cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3]);
+
+	if (err && cmd->retries) {
+		cmd->retries--;
+		cmd->error = 0;
+		host->ops->request(host, mrq);
+	} else if (mrq->done) {
+		mrq->done(mrq);
+	}
+}
+
+EXPORT_SYMBOL(mmc_request_done);
+
+/**
+ *	mmc_start_request - start a command on a host
+ *	@host: MMC host to start command on
+ *	@mrq: MMC request to start
+ *
+ *	Queue a command on the specified host.  We expect the
+ *	caller to be holding the host lock with interrupts disabled.
+ */
+void
+mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
+{
+	DBG("MMC: starting cmd %02x arg %08x flags %08x\n",
+	    mrq->cmd->opcode, mrq->cmd->arg, mrq->cmd->flags);
+
+	WARN_ON(host->card_busy == NULL);
+
+	mrq->cmd->error = 0;
+	mrq->cmd->mrq = mrq;
+	if (mrq->data) {
+		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);
+}
+
+EXPORT_SYMBOL(mmc_start_request);
+
+static void mmc_wait_done(struct mmc_request *mrq)
+{
+	complete(mrq->done_data);
+}
+
+int mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq)
+{
+	DECLARE_COMPLETION(complete);
+
+	mrq->done_data = &complete;
+	mrq->done = mmc_wait_done;
+
+	mmc_start_request(host, mrq);
+
+	wait_for_completion(&complete);
+
+	return 0;
+}
+
+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;
+
+	BUG_ON(host->card_busy == NULL);
+
+	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_claim_host - exclusively claim a host
+ *	@host: mmc host to claim
+ *	@card: mmc card to claim host for
+ *
+ *	Claim a host for a set of operations.  If a valid card
+ *	is passed and this wasn't the last card selected, select
+ *	the card before returning.
+ *
+ *	Note: you should use mmc_card_claim_host or mmc_claim_host.
+ */
+int __mmc_claim_host(struct mmc_host *host, struct mmc_card *card)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	unsigned long flags;
+	int err = 0;
+
+	add_wait_queue(&host->wq, &wait);
+	spin_lock_irqsave(&host->lock, flags);
+	while (1) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		if (host->card_busy == NULL)
+			break;
+		spin_unlock_irqrestore(&host->lock, flags);
+		schedule();
+		spin_lock_irqsave(&host->lock, flags);
+	}
+	set_current_state(TASK_RUNNING);
+	host->card_busy = card;
+	spin_unlock_irqrestore(&host->lock, flags);
+	remove_wait_queue(&host->wq, &wait);
+
+	if (card != (void *)-1 && host->card_selected != card) {
+		struct mmc_command cmd;
+
+		host->card_selected = card;
+
+		cmd.opcode = MMC_SELECT_CARD;
+		cmd.arg = card->rca << 16;
+		cmd.flags = MMC_RSP_R1;
+
+		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
+	}
+
+	return err;
+}
+
+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;
+
+	BUG_ON(host->card_busy == NULL);
+
+	spin_lock_irqsave(&host->lock, flags);
+	host->card_busy = NULL;
+	spin_unlock_irqrestore(&host->lock, flags);
+
+	wake_up(&host->wq);
+}
+
+EXPORT_SYMBOL(mmc_release_host);
+
+/*
+ * Ensure that no card is selected.
+ */
+static void mmc_deselect_cards(struct mmc_host *host)
+{
+	struct mmc_command cmd;
+
+	if (host->card_selected) {
+		host->card_selected = NULL;
+
+		cmd.opcode = MMC_SELECT_CARD;
+		cmd.arg = 0;
+		cmd.flags = MMC_RSP_NONE;
+
+		mmc_wait_for_cmd(host, &cmd, 0);
+	}
+}
+
+
+static inline void mmc_delay(unsigned int ms)
+{
+	if (ms < HZ / 1000) {
+		yield();
+		mdelay(ms);
+	} else {
+		msleep_interruptible (ms);
+	}
+}
+
+/*
+ * Mask off any voltages we don't support and select
+ * the lowest voltage
+ */
+static 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;
+		host->ops->set_ios(host, &host->ios);
+	} else {
+		ocr = 0;
+	}
+
+	return ocr;
+}
+
+#define UNSTUFF_BITS(resp,start,size)					\
+	({								\
+		const int __size = size;				\
+		const u32 __mask = (__size < 32 ? 1 << __size : 0) - 1;	\
+		const int __off = 3 - ((start) / 32);			\
+		const int __shft = (start) & 31;			\
+		u32 __res;						\
+									\
+		__res = resp[__off] >> __shft;				\
+		if (__size + __shft > 32)				\
+			__res |= resp[__off-1] << ((32 - __shft) % 32);	\
+		__res & __mask;						\
+	})
+
+/*
+ * Given the decoded CSD structure, decode the raw CID to our CID structure.
+ */
+static void mmc_decode_cid(struct mmc_card *card)
+{
+	u32 *resp = card->raw_cid;
+
+	memset(&card->cid, 0, sizeof(struct mmc_cid));
+
+	/*
+	 * The selection of the format here is guesswork based upon
+	 * information people have sent to date.
+	 */
+	switch (card->csd.mmca_vsn) {
+	case 0: /* MMC v1.? */
+	case 1: /* MMC v1.4 */
+		card->cid.manfid	= UNSTUFF_BITS(resp, 104, 24);
+		card->cid.prod_name[0]	= UNSTUFF_BITS(resp, 96, 8);
+		card->cid.prod_name[1]	= UNSTUFF_BITS(resp, 88, 8);
+		card->cid.prod_name[2]	= UNSTUFF_BITS(resp, 80, 8);
+		card->cid.prod_name[3]	= UNSTUFF_BITS(resp, 72, 8);
+		card->cid.prod_name[4]	= UNSTUFF_BITS(resp, 64, 8);
+		card->cid.prod_name[5]	= UNSTUFF_BITS(resp, 56, 8);
+		card->cid.prod_name[6]	= UNSTUFF_BITS(resp, 48, 8);
+		card->cid.hwrev		= UNSTUFF_BITS(resp, 44, 4);
+		card->cid.fwrev		= UNSTUFF_BITS(resp, 40, 4);
+		card->cid.serial	= UNSTUFF_BITS(resp, 16, 24);
+		card->cid.month		= UNSTUFF_BITS(resp, 12, 4);
+		card->cid.year		= UNSTUFF_BITS(resp, 8, 4) + 1997;
+		break;
+
+	case 2: /* MMC v2.x ? */
+	case 3: /* MMC v3.x ? */
+		card->cid.manfid	= UNSTUFF_BITS(resp, 120, 8);
+		card->cid.oemid		= UNSTUFF_BITS(resp, 104, 16);
+		card->cid.prod_name[0]	= UNSTUFF_BITS(resp, 96, 8);
+		card->cid.prod_name[1]	= UNSTUFF_BITS(resp, 88, 8);
+		card->cid.prod_name[2]	= UNSTUFF_BITS(resp, 80, 8);
+		card->cid.prod_name[3]	= UNSTUFF_BITS(resp, 72, 8);
+		card->cid.prod_name[4]	= UNSTUFF_BITS(resp, 64, 8);
+		card->cid.prod_name[5]	= UNSTUFF_BITS(resp, 56, 8);
+		card->cid.serial	= UNSTUFF_BITS(resp, 16, 32);
+		card->cid.month		= UNSTUFF_BITS(resp, 12, 4);
+		card->cid.year		= UNSTUFF_BITS(resp, 8, 4) + 1997;
+		break;
+
+	default:
+		printk("%s: card has unknown MMCA version %d\n",
+			card->host->host_name, card->csd.mmca_vsn);
+		mmc_card_set_bad(card);
+		break;
+	}
+}
+
+/*
+ * Given a 128-bit response, decode to our card CSD structure.
+ */
+static void mmc_decode_csd(struct mmc_card *card)
+{
+	struct mmc_csd *csd = &card->csd;
+	unsigned int e, m, csd_struct;
+	u32 *resp = card->raw_csd;
+
+	/*
+	 * We only understand CSD structure v1.1 and v2.
+	 * v2 has extra information in bits 15, 11 and 10.
+	 */
+	csd_struct = UNSTUFF_BITS(resp, 126, 2);
+	if (csd_struct != 1 && csd_struct != 2) {
+		printk("%s: unrecognised CSD structure version %d\n",
+			card->host->host_name, csd_struct);
+		mmc_card_set_bad(card);
+		return;
+	}
+
+	csd->mmca_vsn	 = UNSTUFF_BITS(resp, 122, 4);
+	m = UNSTUFF_BITS(resp, 115, 4);
+	e = UNSTUFF_BITS(resp, 112, 3);
+	csd->tacc_ns	 = (tacc_exp[e] * tacc_mant[m] + 9) / 10;
+	csd->tacc_clks	 = UNSTUFF_BITS(resp, 104, 8) * 100;
+
+	m = UNSTUFF_BITS(resp, 99, 4);
+	e = UNSTUFF_BITS(resp, 96, 3);
+	csd->max_dtr	  = tran_exp[e] * tran_mant[m];
+	csd->cmdclass	  = UNSTUFF_BITS(resp, 84, 12);
+
+	e = UNSTUFF_BITS(resp, 47, 3);
+	m = UNSTUFF_BITS(resp, 62, 12);
+	csd->capacity	  = (1 + m) << (e + 2);
+
+	csd->read_blkbits = UNSTUFF_BITS(resp, 80, 4);
+}
+
+/*
+ * Locate a MMC card on this MMC host given a raw CID.
+ */
+static struct mmc_card *mmc_find_card(struct mmc_host *host, u32 *raw_cid)
+{
+	struct mmc_card *card;
+
+	list_for_each_entry(card, &host->cards, node) {
+		if (memcmp(card->raw_cid, raw_cid, sizeof(card->raw_cid)) == 0)
+			return card;
+	}
+	return NULL;
+}
+
+/*
+ * Allocate a new MMC card, and assign a unique RCA.
+ */
+static struct mmc_card *
+mmc_alloc_card(struct mmc_host *host, u32 *raw_cid, unsigned int *frca)
+{
+	struct mmc_card *card, *c;
+	unsigned int rca = *frca;
+
+	card = kmalloc(sizeof(struct mmc_card), GFP_KERNEL);
+	if (!card)
+		return ERR_PTR(-ENOMEM);
+
+	mmc_init_card(card, host);
+	memcpy(card->raw_cid, raw_cid, sizeof(card->raw_cid));
+
+ again:
+	list_for_each_entry(c, &host->cards, node)
+		if (c->rca == rca) {
+			rca++;
+			goto again;
+		}
+
+	card->rca = rca;
+
+	*frca = rca;
+
+	return card;
+}
+
+/*
+ * Tell attached cards to go to IDLE state
+ */
+static void mmc_idle_cards(struct mmc_host *host)
+{
+	struct mmc_command cmd;
+
+	cmd.opcode = MMC_GO_IDLE_STATE;
+	cmd.arg = 0;
+	cmd.flags = MMC_RSP_NONE;
+
+	mmc_wait_for_cmd(host, &cmd, 0);
+
+	mmc_delay(1);
+}
+
+/*
+ * Apply power to the MMC stack.
+ */
+static void mmc_power_up(struct mmc_host *host)
+{
+	int bit = fls(host->ocr_avail) - 1;
+
+	host->ios.vdd = bit;
+	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
+	host->ios.power_mode = MMC_POWER_UP;
+	host->ops->set_ios(host, &host->ios);
+
+	mmc_delay(1);
+
+	host->ios.clock = host->f_min;
+	host->ios.power_mode = MMC_POWER_ON;
+	host->ops->set_ios(host, &host->ios);
+
+	mmc_delay(2);
+}
+
+static void mmc_power_off(struct mmc_host *host)
+{
+	host->ios.clock = 0;
+	host->ios.vdd = 0;
+	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
+	host->ios.power_mode = MMC_POWER_OFF;
+	host->ops->set_ios(host, &host->ios);
+}
+
+static int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
+{
+	struct mmc_command cmd;
+	int i, err = 0;
+
+	cmd.opcode = MMC_SEND_OP_COND;
+	cmd.arg = ocr;
+	cmd.flags = MMC_RSP_R3;
+
+	for (i = 100; i; i--) {
+		err = mmc_wait_for_cmd(host, &cmd, 0);
+		if (err != MMC_ERR_NONE)
+			break;
+
+		if (cmd.resp[0] & MMC_CARD_BUSY || ocr == 0)
+			break;
+
+		err = MMC_ERR_TIMEOUT;
+
+		mmc_delay(10);
+	}
+
+	if (rocr)
+		*rocr = cmd.resp[0];
+
+	return err;
+}
+
+/*
+ * Discover cards by requesting their CID.  If this command
+ * times out, it is not an error; there are no further cards
+ * to be discovered.  Add new cards to the list.
+ *
+ * Create a mmc_card entry for each discovered card, assigning
+ * it an RCA, and save the raw CID for decoding later.
+ */
+static void mmc_discover_cards(struct mmc_host *host)
+{
+	struct mmc_card *card;
+	unsigned int first_rca = 1, err;
+
+	while (1) {
+		struct mmc_command cmd;
+
+		cmd.opcode = MMC_ALL_SEND_CID;
+		cmd.arg = 0;
+		cmd.flags = MMC_RSP_R2;
+
+		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
+		if (err == MMC_ERR_TIMEOUT) {
+			err = MMC_ERR_NONE;
+			break;
+		}
+		if (err != MMC_ERR_NONE) {
+			printk(KERN_ERR "%s: error requesting CID: %d\n",
+				host->host_name, err);
+			break;
+		}
+
+		card = mmc_find_card(host, cmd.resp);
+		if (!card) {
+			card = mmc_alloc_card(host, cmd.resp, &first_rca);
+			if (IS_ERR(card)) {
+				err = PTR_ERR(card);
+				break;
+			}
+			list_add(&card->node, &host->cards);
+		}
+
+		card->state &= ~MMC_STATE_DEAD;
+
+		cmd.opcode = MMC_SET_RELATIVE_ADDR;
+		cmd.arg = card->rca << 16;
+		cmd.flags = MMC_RSP_R1;
+
+		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
+		if (err != MMC_ERR_NONE)
+			mmc_card_set_dead(card);
+	}
+}
+
+static void mmc_read_csds(struct mmc_host *host)
+{
+	struct mmc_card *card;
+
+	list_for_each_entry(card, &host->cards, node) {
+		struct mmc_command cmd;
+		int err;
+
+		if (card->state & (MMC_STATE_DEAD|MMC_STATE_PRESENT))
+			continue;
+
+		cmd.opcode = MMC_SEND_CSD;
+		cmd.arg = card->rca << 16;
+		cmd.flags = MMC_RSP_R2;
+
+		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
+		if (err != MMC_ERR_NONE) {
+			mmc_card_set_dead(card);
+			continue;
+		}
+
+		memcpy(card->raw_csd, cmd.resp, sizeof(card->raw_csd));
+
+		mmc_decode_csd(card);
+		mmc_decode_cid(card);
+	}
+}
+
+static unsigned int mmc_calculate_clock(struct mmc_host *host)
+{
+	struct mmc_card *card;
+	unsigned int max_dtr = host->f_max;
+
+	list_for_each_entry(card, &host->cards, node)
+		if (!mmc_card_dead(card) && max_dtr > card->csd.max_dtr)
+			max_dtr = card->csd.max_dtr;
+
+	DBG("MMC: selected %d.%03dMHz transfer rate\n",
+	    max_dtr / 1000000, (max_dtr / 1000) % 1000);
+
+	return max_dtr;
+}
+
+/*
+ * Check whether cards we already know about are still present.
+ * We do this by requesting status, and checking whether a card
+ * responds.
+ *
+ * A request for status does not cause a state change in data
+ * transfer mode.
+ */
+static void mmc_check_cards(struct mmc_host *host)
+{
+	struct list_head *l, *n;
+
+	mmc_deselect_cards(host);
+
+	list_for_each_safe(l, n, &host->cards) {
+		struct mmc_card *card = mmc_list_to_card(l);
+		struct mmc_command cmd;
+		int err;
+
+		cmd.opcode = MMC_SEND_STATUS;
+		cmd.arg = card->rca << 16;
+		cmd.flags = MMC_RSP_R1;
+
+		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
+		if (err == MMC_ERR_NONE)
+			continue;
+
+		mmc_card_set_dead(card);
+	}
+}
+
+static void mmc_setup(struct mmc_host *host)
+{
+	if (host->ios.power_mode != MMC_POWER_ON) {
+		int err;
+		u32 ocr;
+
+		mmc_power_up(host);
+		mmc_idle_cards(host);
+
+		err = mmc_send_op_cond(host, 0, &ocr);
+		if (err != MMC_ERR_NONE)
+			return;
+
+		host->ocr = mmc_select_voltage(host, ocr);
+
+		/*
+		 * Since we're changing the OCR value, we seem to
+		 * need to tell some cards to go back to the idle
+		 * state.  We wait 1ms to give cards time to
+		 * respond.
+		 */
+		if (host->ocr)
+			mmc_idle_cards(host);
+	} else {
+		host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
+		host->ios.clock = host->f_min;
+		host->ops->set_ios(host, &host->ios);
+
+		/*
+		 * We should remember the OCR mask from the existing
+		 * cards, and detect the new cards OCR mask, combine
+		 * the two and re-select the VDD.  However, if we do
+		 * change VDD, we should do an idle, and then do a
+		 * full re-initialisation.  We would need to notify
+		 * drivers so that they can re-setup the cards as
+		 * well, while keeping their queues at bay.
+		 *
+		 * For the moment, we take the easy way out - if the
+		 * new cards don't like our currently selected VDD,
+		 * they drop off the bus.
+		 */
+	}
+
+	if (host->ocr == 0)
+		return;
+
+	/*
+	 * Send the selected OCR multiple times... until the cards
+	 * all get the idea that they should be ready for CMD2.
+	 * (My SanDisk card seems to need this.)
+	 */
+	mmc_send_op_cond(host, host->ocr, NULL);
+
+	mmc_discover_cards(host);
+
+	/*
+	 * Ok, now switch to push-pull mode.
+	 */
+	host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;
+	host->ops->set_ios(host, &host->ios);
+
+	mmc_read_csds(host);
+}
+
+
+/**
+ *	mmc_detect_change - process change of state on a MMC socket
+ *	@host: host which changed state.
+ *
+ *	All we know is that card(s) have been inserted or removed
+ *	from the socket(s).  We don't know which socket or cards.
+ */
+void mmc_detect_change(struct mmc_host *host)
+{
+	schedule_work(&host->detect);
+}
+
+EXPORT_SYMBOL(mmc_detect_change);
+
+
+static void mmc_rescan(void *data)
+{
+	struct mmc_host *host = data;
+	struct list_head *l, *n;
+
+	mmc_claim_host(host);
+
+	if (host->ios.power_mode == MMC_POWER_ON)
+		mmc_check_cards(host);
+
+	mmc_setup(host);
+
+	if (!list_empty(&host->cards)) {
+		/*
+		 * (Re-)calculate the fastest clock rate which the
+		 * attached cards and the host support.
+		 */
+		host->ios.clock = mmc_calculate_clock(host);
+		host->ops->set_ios(host, &host->ios);
+	}
+
+	mmc_release_host(host);
+
+	list_for_each_safe(l, n, &host->cards) {
+		struct mmc_card *card = mmc_list_to_card(l);
+
+		/*
+		 * If this is a new and good card, register it.
+		 */
+		if (!mmc_card_present(card) && !mmc_card_dead(card)) {
+			if (mmc_register_card(card))
+				mmc_card_set_dead(card);
+			else
+				mmc_card_set_present(card);
+		}
+
+		/*
+		 * If this card is dead, destroy it.
+		 */
+		if (mmc_card_dead(card)) {
+			list_del(&card->node);
+			mmc_remove_card(card);
+		}
+	}
+
+	/*
+	 * If we discover that there are no cards on the
+	 * bus, turn off the clock and power down.
+	 */
+	if (list_empty(&host->cards))
+		mmc_power_off(host);
+}
+
+
+/**
+ *	mmc_alloc_host - initialise the per-host structure.
+ *	@extra: sizeof private data structure
+ *	@dev: pointer to host device model structure
+ *
+ *	Initialise the per-host structure.
+ */
+struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
+{
+	struct mmc_host *host;
+
+	host = kmalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
+	if (host) {
+		memset(host, 0, sizeof(struct mmc_host) + extra);
+
+		spin_lock_init(&host->lock);
+		init_waitqueue_head(&host->wq);
+		INIT_LIST_HEAD(&host->cards);
+		INIT_WORK(&host->detect, mmc_rescan, host);
+
+		host->dev = dev;
+
+		/*
+		 * By default, hosts do not support SGIO or large requests.
+		 * They have to set these according to their abilities.
+		 */
+		host->max_hw_segs = 1;
+		host->max_phys_segs = 1;
+		host->max_sectors = 1 << (PAGE_CACHE_SHIFT - 9);
+		host->max_seg_size = PAGE_CACHE_SIZE;
+	}
+
+	return host;
+}
+
+EXPORT_SYMBOL(mmc_alloc_host);
+
+/**
+ *	mmc_add_host - initialise host hardware
+ *	@host: mmc host
+ */
+int mmc_add_host(struct mmc_host *host)
+{
+	static unsigned int host_num;
+
+	snprintf(host->host_name, sizeof(host->host_name),
+		 "mmc%d", host_num++);
+
+	mmc_power_off(host);
+	mmc_detect_change(host);
+
+	return 0;
+}
+
+EXPORT_SYMBOL(mmc_add_host);
+
+/**
+ *	mmc_remove_host - remove host hardware
+ *	@host: mmc host
+ *
+ *	Unregister and remove all cards associated with this host,
+ *	and power down the MMC bus.
+ */
+void mmc_remove_host(struct mmc_host *host)
+{
+	struct list_head *l, *n;
+
+	list_for_each_safe(l, n, &host->cards) {
+		struct mmc_card *card = mmc_list_to_card(l);
+
+		mmc_remove_card(card);
+	}
+
+	mmc_power_off(host);
+}
+
+EXPORT_SYMBOL(mmc_remove_host);
+
+/**
+ *	mmc_free_host - free the host structure
+ *	@host: mmc host
+ *
+ *	Free the host once all references to it have been dropped.
+ */
+void mmc_free_host(struct mmc_host *host)
+{
+	flush_scheduled_work();
+	kfree(host);
+}
+
+EXPORT_SYMBOL(mmc_free_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, u32 state)
+{
+	mmc_claim_host(host);
+	mmc_deselect_cards(host);
+	mmc_power_off(host);
+	mmc_release_host(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_detect_change(host);
+
+	return 0;
+}
+
+EXPORT_SYMBOL(mmc_resume_host);
+
+#endif
+
+MODULE_LICENSE("GPL");