MMC: S3C24XX MMC/SD driver.

This is the latest S3C MMC/SD driver by Thomas Kleffel
with cleanups as suggested by AKPM done by Ben Dooks.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Kleffel <tk@maintech.de>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/host/s3cmci.c b/drivers/mmc/host/s3cmci.c
new file mode 100644
index 0000000..c6a4d3c
--- /dev/null
+++ b/drivers/mmc/host/s3cmci.c
@@ -0,0 +1,1343 @@
+/*
+ *  linux/drivers/mmc/s3cmci.h - Samsung S3C MCI driver
+ *
+ *  Copyright (C) 2004-2006 maintech GmbH, Thomas Kleffel <tk@maintech.de>
+ *
+ * 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/dma-mapping.h>
+#include <linux/clk.h>
+#include <linux/mmc/host.h>
+#include <linux/platform_device.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+
+#include <asm/dma.h>
+
+#include <asm/arch/regs-sdi.h>
+#include <asm/arch/regs-gpio.h>
+
+#include "s3cmci.h"
+
+#define DRIVER_NAME "s3c-mci"
+
+enum dbg_channels {
+	dbg_err   = (1 << 0),
+	dbg_debug = (1 << 1),
+	dbg_info  = (1 << 2),
+	dbg_irq   = (1 << 3),
+	dbg_sg    = (1 << 4),
+	dbg_dma   = (1 << 5),
+	dbg_pio   = (1 << 6),
+	dbg_fail  = (1 << 7),
+	dbg_conf  = (1 << 8),
+};
+
+static const int dbgmap_err   = dbg_err | dbg_fail;
+static const int dbgmap_info  = dbg_info | dbg_conf;
+static const int dbgmap_debug = dbg_debug;
+
+#define dbg(host, channels, args...)		  \
+	do {					  \
+	if (dbgmap_err & channels) 		  \
+		dev_err(&host->pdev->dev, args);  \
+	else if (dbgmap_info & channels)	  \
+		dev_info(&host->pdev->dev, args); \
+	else if (dbgmap_debug & channels)	  \
+		dev_dbg(&host->pdev->dev, args);  \
+	} while (0)
+
+#define RESSIZE(ressource) (((ressource)->end - (ressource)->start)+1)
+
+static struct s3c2410_dma_client s3cmci_dma_client = {
+	.name		= "s3c-mci",
+};
+
+static void finalize_request(struct s3cmci_host *host);
+static void s3cmci_send_request(struct mmc_host *mmc);
+static void s3cmci_reset(struct s3cmci_host *host);
+
+#ifdef CONFIG_MMC_DEBUG
+
+static void dbg_dumpregs(struct s3cmci_host *host, char *prefix)
+{
+	u32 con, pre, cmdarg, cmdcon, cmdsta, r0, r1, r2, r3, timer, bsize;
+	u32 datcon, datcnt, datsta, fsta, imask;
+
+	con 	= readl(host->base + S3C2410_SDICON);
+	pre 	= readl(host->base + S3C2410_SDIPRE);
+	cmdarg 	= readl(host->base + S3C2410_SDICMDARG);
+	cmdcon 	= readl(host->base + S3C2410_SDICMDCON);
+	cmdsta 	= readl(host->base + S3C2410_SDICMDSTAT);
+	r0 	= readl(host->base + S3C2410_SDIRSP0);
+	r1 	= readl(host->base + S3C2410_SDIRSP1);
+	r2 	= readl(host->base + S3C2410_SDIRSP2);
+	r3 	= readl(host->base + S3C2410_SDIRSP3);
+	timer 	= readl(host->base + S3C2410_SDITIMER);
+	bsize 	= readl(host->base + S3C2410_SDIBSIZE);
+	datcon 	= readl(host->base + S3C2410_SDIDCON);
+	datcnt 	= readl(host->base + S3C2410_SDIDCNT);
+	datsta 	= readl(host->base + S3C2410_SDIDSTA);
+	fsta 	= readl(host->base + S3C2410_SDIFSTA);
+	imask   = readl(host->base + host->sdiimsk);
+
+	dbg(host, dbg_debug, "%s  CON:[%08x]  PRE:[%08x]  TMR:[%08x]\n",
+				prefix, con, pre, timer);
+
+	dbg(host, dbg_debug, "%s CCON:[%08x] CARG:[%08x] CSTA:[%08x]\n",
+				prefix, cmdcon, cmdarg, cmdsta);
+
+	dbg(host, dbg_debug, "%s DCON:[%08x] FSTA:[%08x]"
+			       " DSTA:[%08x] DCNT:[%08x]\n",
+				prefix, datcon, fsta, datsta, datcnt);
+
+	dbg(host, dbg_debug, "%s   R0:[%08x]   R1:[%08x]"
+			       "   R2:[%08x]   R3:[%08x]\n",
+				prefix, r0, r1, r2, r3);
+}
+
+static void prepare_dbgmsg(struct s3cmci_host *host, struct mmc_command *cmd,
+			   int stop)
+{
+	snprintf(host->dbgmsg_cmd, 300,
+		 "#%u%s op:%i arg:0x%08x flags:0x08%x retries:%u",
+		 host->ccnt, (stop ? " (STOP)" : ""),
+		 cmd->opcode, cmd->arg, cmd->flags, cmd->retries);
+
+	if (cmd->data) {
+		snprintf(host->dbgmsg_dat, 300,
+			 "#%u bsize:%u blocks:%u bytes:%u",
+			 host->dcnt, cmd->data->blksz,
+			 cmd->data->blocks,
+			 cmd->data->blocks * cmd->data->blksz);
+	} else {
+		host->dbgmsg_dat[0] = '\0';
+	}
+}
+
+static void dbg_dumpcmd(struct s3cmci_host *host, struct mmc_command *cmd,
+			int fail)
+{
+	unsigned int dbglvl = fail ? dbg_fail : dbg_debug;
+
+	if (!cmd)
+		return;
+
+	if (cmd->error == 0) {
+		dbg(host, dbglvl, "CMD[OK] %s R0:0x%08x\n",
+			host->dbgmsg_cmd, cmd->resp[0]);
+	} else {
+		dbg(host, dbglvl, "CMD[ERR %i] %s Status:%s\n",
+			cmd->error, host->dbgmsg_cmd, host->status);
+	}
+
+	if (!cmd->data)
+		return;
+
+	if (cmd->data->error == 0) {
+		dbg(host, dbglvl, "DAT[OK] %s\n", host->dbgmsg_dat);
+	} else {
+		dbg(host, dbglvl, "DAT[ERR %i] %s DCNT:0x%08x\n",
+			cmd->data->error, host->dbgmsg_dat,
+			readl(host->base + S3C2410_SDIDCNT));
+	}
+}
+#else
+static void dbg_dumpcmd(struct s3cmci_host *host,
+			struct mmc_command *cmd, int fail) { }
+
+static void prepare_dbgmsg(struct s3cmci_host *host, struct mmc_command *cmd,
+			   int stop) { }
+
+static void dbg_dumpregs(struct s3cmci_host *host, char *prefix) { }
+
+#endif /* CONFIG_MMC_DEBUG */
+
+static inline u32 enable_imask(struct s3cmci_host *host, u32 imask)
+{
+	u32 newmask;
+
+	newmask = readl(host->base + host->sdiimsk);
+	newmask |= imask;
+
+	writel(newmask, host->base + host->sdiimsk);
+
+	return newmask;
+}
+
+static inline u32 disable_imask(struct s3cmci_host *host, u32 imask)
+{
+	u32 newmask;
+
+	newmask = readl(host->base + host->sdiimsk);
+	newmask &= ~imask;
+
+	writel(newmask, host->base + host->sdiimsk);
+
+	return newmask;
+}
+
+static inline void clear_imask(struct s3cmci_host *host)
+{
+	writel(0, host->base + host->sdiimsk);
+}
+
+static inline int get_data_buffer(struct s3cmci_host *host,
+				  u32 *words, u32 **pointer)
+{
+	struct scatterlist *sg;
+
+	if (host->pio_active == XFER_NONE)
+		return -EINVAL;
+
+	if ((!host->mrq) || (!host->mrq->data))
+		return -EINVAL;
+
+	if (host->pio_sgptr >= host->mrq->data->sg_len) {
+		dbg(host, dbg_debug, "no more buffers (%i/%i)\n",
+		      host->pio_sgptr, host->mrq->data->sg_len);
+		return -EBUSY;
+	}
+	sg = &host->mrq->data->sg[host->pio_sgptr];
+
+	*words = sg->length >> 2;
+	*pointer = sg_virt(sg);
+
+	host->pio_sgptr++;
+
+	dbg(host, dbg_sg, "new buffer (%i/%i)\n",
+	    host->pio_sgptr, host->mrq->data->sg_len);
+
+	return 0;
+}
+
+static inline u32 fifo_count(struct s3cmci_host *host)
+{
+	u32 fifostat = readl(host->base + S3C2410_SDIFSTA);
+
+	fifostat &= S3C2410_SDIFSTA_COUNTMASK;
+	return fifostat >> 2;
+}
+
+static inline u32 fifo_free(struct s3cmci_host *host)
+{
+	u32 fifostat = readl(host->base + S3C2410_SDIFSTA);
+
+	fifostat &= S3C2410_SDIFSTA_COUNTMASK;
+	return (63 - fifostat) >> 2;
+}
+
+static void do_pio_read(struct s3cmci_host *host)
+{
+	int res;
+	u32 fifo;
+	void __iomem *from_ptr;
+
+	/* write real prescaler to host, it might be set slow to fix */
+	writel(host->prescaler, host->base + S3C2410_SDIPRE);
+
+	from_ptr = host->base + host->sdidata;
+
+	while ((fifo = fifo_count(host))) {
+		if (!host->pio_words) {
+			res = get_data_buffer(host, &host->pio_words,
+					      &host->pio_ptr);
+			if (res) {
+				host->pio_active = XFER_NONE;
+				host->complete_what = COMPLETION_FINALIZE;
+
+				dbg(host, dbg_pio, "pio_read(): "
+				    "complete (no more data).\n");
+				return;
+			}
+
+			dbg(host, dbg_pio,
+			    "pio_read(): new target: [%i]@[%p]\n",
+			    host->pio_words, host->pio_ptr);
+		}
+
+		dbg(host, dbg_pio,
+		    "pio_read(): fifo:[%02i] buffer:[%03i] dcnt:[%08X]\n",
+		    fifo, host->pio_words,
+		    readl(host->base + S3C2410_SDIDCNT));
+
+		if (fifo > host->pio_words)
+			fifo = host->pio_words;
+
+		host->pio_words -= fifo;
+		host->pio_count += fifo;
+
+		while (fifo--)
+			*(host->pio_ptr++) = readl(from_ptr);
+	}
+
+	if (!host->pio_words) {
+		res = get_data_buffer(host, &host->pio_words, &host->pio_ptr);
+		if (res) {
+			dbg(host, dbg_pio,
+			    "pio_read(): complete (no more buffers).\n");
+			host->pio_active = XFER_NONE;
+			host->complete_what = COMPLETION_FINALIZE;
+
+			return;
+		}
+	}
+
+	enable_imask(host,
+		     S3C2410_SDIIMSK_RXFIFOHALF | S3C2410_SDIIMSK_RXFIFOLAST);
+}
+
+static void do_pio_write(struct s3cmci_host *host)
+{
+	void __iomem *to_ptr;
+	int res;
+	u32 fifo;
+
+	to_ptr = host->base + host->sdidata;
+
+	while ((fifo = fifo_free(host))) {
+		if (!host->pio_words) {
+			res = get_data_buffer(host, &host->pio_words,
+							&host->pio_ptr);
+			if (res) {
+				dbg(host, dbg_pio,
+				    "pio_write(): complete (no more data).\n");
+				host->pio_active = XFER_NONE;
+
+				return;
+			}
+
+			dbg(host, dbg_pio,
+			    "pio_write(): new source: [%i]@[%p]\n",
+			    host->pio_words, host->pio_ptr);
+
+		}
+
+		if (fifo > host->pio_words)
+			fifo = host->pio_words;
+
+		host->pio_words -= fifo;
+		host->pio_count += fifo;
+
+		while (fifo--)
+			writel(*(host->pio_ptr++), to_ptr);
+	}
+
+	enable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
+}
+
+static void pio_tasklet(unsigned long data)
+{
+	struct s3cmci_host *host = (struct s3cmci_host *) data;
+
+
+	if (host->pio_active == XFER_WRITE)
+		do_pio_write(host);
+
+	if (host->pio_active == XFER_READ)
+		do_pio_read(host);
+
+	if (host->complete_what == COMPLETION_FINALIZE) {
+		clear_imask(host);
+		if (host->pio_active != XFER_NONE) {
+			dbg(host, dbg_err, "unfinished %s "
+			    "- pio_count:[%u] pio_words:[%u]\n",
+			    (host->pio_active == XFER_READ) ? "read" : "write",
+			    host->pio_count, host->pio_words);
+
+			host->mrq->data->error = -EINVAL;
+		}
+
+		disable_irq(host->irq);
+		finalize_request(host);
+	}
+}
+
+/*
+ * ISR for SDI Interface IRQ
+ * Communication between driver and ISR works as follows:
+ *   host->mrq 			points to current request
+ *   host->complete_what	Indicates when the request is considered done
+ *     COMPLETION_CMDSENT	  when the command was sent
+ *     COMPLETION_RSPFIN          when a response was received
+ *     COMPLETION_XFERFINISH	  when the data transfer is finished
+ *     COMPLETION_XFERFINISH_RSPFIN both of the above.
+ *   host->complete_request	is the completion-object the driver waits for
+ *
+ * 1) Driver sets up host->mrq and host->complete_what
+ * 2) Driver prepares the transfer
+ * 3) Driver enables interrupts
+ * 4) Driver starts transfer
+ * 5) Driver waits for host->complete_rquest
+ * 6) ISR checks for request status (errors and success)
+ * 6) ISR sets host->mrq->cmd->error and host->mrq->data->error
+ * 7) ISR completes host->complete_request
+ * 8) ISR disables interrupts
+ * 9) Driver wakes up and takes care of the request
+ *
+ * Note: "->error"-fields are expected to be set to 0 before the request
+ *       was issued by mmc.c - therefore they are only set, when an error
+ *       contition comes up
+ */
+
+static irqreturn_t s3cmci_irq(int irq, void *dev_id)
+{
+	struct s3cmci_host *host = dev_id;
+	struct mmc_command *cmd;
+	u32 mci_csta, mci_dsta, mci_fsta, mci_dcnt, mci_imsk;
+	u32 mci_cclear, mci_dclear;
+	unsigned long iflags;
+
+	spin_lock_irqsave(&host->complete_lock, iflags);
+
+	mci_csta = readl(host->base + S3C2410_SDICMDSTAT);
+	mci_dsta = readl(host->base + S3C2410_SDIDSTA);
+	mci_dcnt = readl(host->base + S3C2410_SDIDCNT);
+	mci_fsta = readl(host->base + S3C2410_SDIFSTA);
+	mci_imsk = readl(host->base + host->sdiimsk);
+	mci_cclear = 0;
+	mci_dclear = 0;
+
+	if ((host->complete_what == COMPLETION_NONE) ||
+	    (host->complete_what == COMPLETION_FINALIZE)) {
+		host->status = "nothing to complete";
+		clear_imask(host);
+		goto irq_out;
+	}
+
+	if (!host->mrq) {
+		host->status = "no active mrq";
+		clear_imask(host);
+		goto irq_out;
+	}
+
+	cmd = host->cmd_is_stop ? host->mrq->stop : host->mrq->cmd;
+
+	if (!cmd) {
+		host->status = "no active cmd";
+		clear_imask(host);
+		goto irq_out;
+	}
+
+	if (!host->dodma) {
+		if ((host->pio_active == XFER_WRITE) &&
+		    (mci_fsta & S3C2410_SDIFSTA_TFDET)) {
+
+			disable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
+			tasklet_schedule(&host->pio_tasklet);
+			host->status = "pio tx";
+		}
+
+		if ((host->pio_active == XFER_READ) &&
+		    (mci_fsta & S3C2410_SDIFSTA_RFDET)) {
+
+			disable_imask(host,
+				      S3C2410_SDIIMSK_RXFIFOHALF |
+				      S3C2410_SDIIMSK_RXFIFOLAST);
+
+			tasklet_schedule(&host->pio_tasklet);
+			host->status = "pio rx";
+		}
+	}
+
+	if (mci_csta & S3C2410_SDICMDSTAT_CMDTIMEOUT) {
+		cmd->error = -ETIMEDOUT;
+		host->status = "error: command timeout";
+		goto fail_transfer;
+	}
+
+	if (mci_csta & S3C2410_SDICMDSTAT_CMDSENT) {
+		if (host->complete_what == COMPLETION_CMDSENT) {
+			host->status = "ok: command sent";
+			goto close_transfer;
+		}
+
+		mci_cclear |= S3C2410_SDICMDSTAT_CMDSENT;
+	}
+
+	if (mci_csta & S3C2410_SDICMDSTAT_CRCFAIL) {
+		if (cmd->flags & MMC_RSP_CRC) {
+			cmd->error = -EILSEQ;
+			host->status = "error: bad command crc";
+			goto fail_transfer;
+		}
+
+		mci_cclear |= S3C2410_SDICMDSTAT_CRCFAIL;
+	}
+
+	if (mci_csta & S3C2410_SDICMDSTAT_RSPFIN) {
+		if (host->complete_what == COMPLETION_RSPFIN) {
+			host->status = "ok: command response received";
+			goto close_transfer;
+		}
+
+		if (host->complete_what == COMPLETION_XFERFINISH_RSPFIN)
+			host->complete_what = COMPLETION_XFERFINISH;
+
+		mci_cclear |= S3C2410_SDICMDSTAT_RSPFIN;
+	}
+
+	/* errors handled after this point are only relevant
+	   when a data transfer is in progress */
+
+	if (!cmd->data)
+		goto clear_status_bits;
+
+	/* Check for FIFO failure */
+	if (host->is2440) {
+		if (mci_fsta & S3C2440_SDIFSTA_FIFOFAIL) {
+			host->mrq->data->error = -EILSEQ;
+			host->status = "error: 2440 fifo failure";
+			goto fail_transfer;
+		}
+	} else {
+		if (mci_dsta & S3C2410_SDIDSTA_FIFOFAIL) {
+			cmd->data->error = -EILSEQ;
+			host->status = "error:  fifo failure";
+			goto fail_transfer;
+		}
+	}
+
+	if (mci_dsta & S3C2410_SDIDSTA_RXCRCFAIL) {
+		cmd->data->error = -EILSEQ;
+		host->status = "error: bad data crc (outgoing)";
+		goto fail_transfer;
+	}
+
+	if (mci_dsta & S3C2410_SDIDSTA_CRCFAIL) {
+		cmd->data->error = -EILSEQ;
+		host->status = "error: bad data crc (incoming)";
+		goto fail_transfer;
+	}
+
+	if (mci_dsta & S3C2410_SDIDSTA_DATATIMEOUT) {
+		cmd->data->error = -ETIMEDOUT;
+		host->status = "error: data timeout";
+		goto fail_transfer;
+	}
+
+	if (mci_dsta & S3C2410_SDIDSTA_XFERFINISH) {
+		if (host->complete_what == COMPLETION_XFERFINISH) {
+			host->status = "ok: data transfer completed";
+			goto close_transfer;
+		}
+
+		if (host->complete_what == COMPLETION_XFERFINISH_RSPFIN)
+			host->complete_what = COMPLETION_RSPFIN;
+
+		mci_dclear |= S3C2410_SDIDSTA_XFERFINISH;
+	}
+
+clear_status_bits:
+	writel(mci_cclear, host->base + S3C2410_SDICMDSTAT);
+	writel(mci_dclear, host->base + S3C2410_SDIDSTA);
+
+	goto irq_out;
+
+fail_transfer:
+	host->pio_active = XFER_NONE;
+
+close_transfer:
+	host->complete_what = COMPLETION_FINALIZE;
+
+	clear_imask(host);
+	tasklet_schedule(&host->pio_tasklet);
+
+	goto irq_out;
+
+irq_out:
+	dbg(host, dbg_irq,
+	    "csta:0x%08x dsta:0x%08x fsta:0x%08x dcnt:0x%08x status:%s.\n",
+	    mci_csta, mci_dsta, mci_fsta, mci_dcnt, host->status);
+
+	spin_unlock_irqrestore(&host->complete_lock, iflags);
+	return IRQ_HANDLED;
+
+}
+
+/*
+ * ISR for the CardDetect Pin
+*/
+
+static irqreturn_t s3cmci_irq_cd(int irq, void *dev_id)
+{
+	struct s3cmci_host *host = (struct s3cmci_host *)dev_id;
+
+	dbg(host, dbg_irq, "card detect\n");
+
+	mmc_detect_change(host->mmc, 500);
+
+	return IRQ_HANDLED;
+}
+
+void s3cmci_dma_done_callback(struct s3c2410_dma_chan *dma_ch, void *buf_id,
+			      int size, enum s3c2410_dma_buffresult result)
+{
+	struct s3cmci_host *host = buf_id;
+	unsigned long iflags;
+	u32 mci_csta, mci_dsta, mci_fsta, mci_dcnt;
+
+	mci_csta = readl(host->base + S3C2410_SDICMDSTAT);
+	mci_dsta = readl(host->base + S3C2410_SDIDSTA);
+	mci_fsta = readl(host->base + S3C2410_SDIFSTA);
+	mci_dcnt = readl(host->base + S3C2410_SDIDCNT);
+
+	BUG_ON(!host->mrq);
+	BUG_ON(!host->mrq->data);
+	BUG_ON(!host->dmatogo);
+
+	spin_lock_irqsave(&host->complete_lock, iflags);
+
+	if (result != S3C2410_RES_OK) {
+		dbg(host, dbg_fail, "DMA FAILED: csta=0x%08x dsta=0x%08x "
+			"fsta=0x%08x dcnt:0x%08x result:0x%08x toGo:%u\n",
+			mci_csta, mci_dsta, mci_fsta,
+			mci_dcnt, result, host->dmatogo);
+
+		goto fail_request;
+	}
+
+	host->dmatogo--;
+	if (host->dmatogo) {
+		dbg(host, dbg_dma, "DMA DONE  Size:%i DSTA:[%08x] "
+			"DCNT:[%08x] toGo:%u\n",
+			size, mci_dsta, mci_dcnt, host->dmatogo);
+
+		goto out;
+	}
+
+	dbg(host, dbg_dma, "DMA FINISHED Size:%i DSTA:%08x DCNT:%08x\n",
+		size, mci_dsta, mci_dcnt);
+
+	host->complete_what = COMPLETION_FINALIZE;
+
+out:
+	tasklet_schedule(&host->pio_tasklet);
+	spin_unlock_irqrestore(&host->complete_lock, iflags);
+	return;
+
+
+fail_request:
+	host->mrq->data->error = -EINVAL;
+	host->complete_what = COMPLETION_FINALIZE;
+	writel(0, host->base + host->sdiimsk);
+	goto out;
+
+}
+
+static void finalize_request(struct s3cmci_host *host)
+{
+	struct mmc_request *mrq = host->mrq;
+	struct mmc_command *cmd = host->cmd_is_stop ? mrq->stop : mrq->cmd;
+	int debug_as_failure = 0;
+
+	if (host->complete_what != COMPLETION_FINALIZE)
+		return;
+
+	if (!mrq)
+		return;
+
+	if (cmd->data && (cmd->error == 0) &&
+	    (cmd->data->error == 0)) {
+		if (host->dodma && (!host->dma_complete)) {
+			dbg(host, dbg_dma, "DMA Missing!\n");
+			return;
+		}
+	}
+
+	/* Read response from controller. */
+	cmd->resp[0] = readl(host->base + S3C2410_SDIRSP0);
+	cmd->resp[1] = readl(host->base + S3C2410_SDIRSP1);
+	cmd->resp[2] = readl(host->base + S3C2410_SDIRSP2);
+	cmd->resp[3] = readl(host->base + S3C2410_SDIRSP3);
+
+	writel(host->prescaler, host->base + S3C2410_SDIPRE);
+
+	if (cmd->error)
+		debug_as_failure = 1;
+
+	if (cmd->data && cmd->data->error)
+		debug_as_failure = 1;
+
+	dbg_dumpcmd(host, cmd, debug_as_failure);
+
+	/* Cleanup controller */
+	writel(0, host->base + S3C2410_SDICMDARG);
+	writel(0, host->base + S3C2410_SDIDCON);
+	writel(0, host->base + S3C2410_SDICMDCON);
+	writel(0, host->base + host->sdiimsk);
+
+	if (cmd->data && cmd->error)
+		cmd->data->error = cmd->error;
+
+	if (cmd->data && cmd->data->stop && (!host->cmd_is_stop)) {
+		host->cmd_is_stop = 1;
+		s3cmci_send_request(host->mmc);
+		return;
+	}
+
+	/* If we have no data transfer we are finished here */
+	if (!mrq->data)
+		goto request_done;
+
+	/* Calulate the amout of bytes transfer if there was no error */
+	if (mrq->data->error == 0) {
+		mrq->data->bytes_xfered =
+			(mrq->data->blocks * mrq->data->blksz);
+	} else {
+		mrq->data->bytes_xfered = 0;
+	}
+
+	/* If we had an error while transfering data we flush the
+	 * DMA channel and the fifo to clear out any garbage. */
+	if (mrq->data->error != 0) {
+		if (host->dodma)
+			s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH);
+
+		if (host->is2440) {
+			/* Clear failure register and reset fifo. */
+			writel(S3C2440_SDIFSTA_FIFORESET |
+			       S3C2440_SDIFSTA_FIFOFAIL,
+			       host->base + S3C2410_SDIFSTA);
+		} else {
+			u32 mci_con;
+
+			/* reset fifo */
+			mci_con = readl(host->base + S3C2410_SDICON);
+			mci_con |= S3C2410_SDICON_FIFORESET;
+
+			writel(mci_con, host->base + S3C2410_SDICON);
+		}
+	}
+
+request_done:
+	host->complete_what = COMPLETION_NONE;
+	host->mrq = NULL;
+	mmc_request_done(host->mmc, mrq);
+}
+
+
+void s3cmci_dma_setup(struct s3cmci_host *host, enum s3c2410_dmasrc source)
+{
+	static enum s3c2410_dmasrc last_source = -1;
+	static int setup_ok;
+
+	if (last_source == source)
+		return;
+
+	last_source = source;
+
+	s3c2410_dma_devconfig(host->dma, source, 3,
+			      host->mem->start + host->sdidata);
+
+	if (!setup_ok) {
+		s3c2410_dma_config(host->dma, 4,
+			(S3C2410_DCON_HWTRIG | S3C2410_DCON_CH0_SDI));
+		s3c2410_dma_set_buffdone_fn(host->dma,
+					    s3cmci_dma_done_callback);
+		s3c2410_dma_setflags(host->dma, S3C2410_DMAF_AUTOSTART);
+		setup_ok = 1;
+	}
+}
+
+static void s3cmci_send_command(struct s3cmci_host *host,
+					struct mmc_command *cmd)
+{
+	u32 ccon, imsk;
+
+	imsk  = S3C2410_SDIIMSK_CRCSTATUS | S3C2410_SDIIMSK_CMDTIMEOUT |
+		S3C2410_SDIIMSK_RESPONSEND | S3C2410_SDIIMSK_CMDSENT |
+		S3C2410_SDIIMSK_RESPONSECRC;
+
+	enable_imask(host, imsk);
+
+	if (cmd->data)
+		host->complete_what = COMPLETION_XFERFINISH_RSPFIN;
+	else if (cmd->flags & MMC_RSP_PRESENT)
+		host->complete_what = COMPLETION_RSPFIN;
+	else
+		host->complete_what = COMPLETION_CMDSENT;
+
+	writel(cmd->arg, host->base + S3C2410_SDICMDARG);
+
+	ccon  = cmd->opcode & S3C2410_SDICMDCON_INDEX;
+	ccon |= S3C2410_SDICMDCON_SENDERHOST | S3C2410_SDICMDCON_CMDSTART;
+
+	if (cmd->flags & MMC_RSP_PRESENT)
+		ccon |= S3C2410_SDICMDCON_WAITRSP;
+
+	if (cmd->flags & MMC_RSP_136)
+		ccon |= S3C2410_SDICMDCON_LONGRSP;
+
+	writel(ccon, host->base + S3C2410_SDICMDCON);
+}
+
+static int s3cmci_setup_data(struct s3cmci_host *host, struct mmc_data *data)
+{
+	u32 dcon, imsk, stoptries = 3;
+
+	/* write DCON register */
+
+	if (!data) {
+		writel(0, host->base + S3C2410_SDIDCON);
+		return 0;
+	}
+
+	while (readl(host->base + S3C2410_SDIDSTA) &
+	       (S3C2410_SDIDSTA_TXDATAON | S3C2410_SDIDSTA_RXDATAON)) {
+
+		dbg(host, dbg_err,
+		    "mci_setup_data() transfer stillin progress.\n");
+
+		writel(0, host->base + S3C2410_SDIDCON);
+		s3cmci_reset(host);
+
+		if ((stoptries--) == 0) {
+			dbg_dumpregs(host, "DRF");
+			return -EINVAL;
+		}
+	}
+
+	dcon  = data->blocks & S3C2410_SDIDCON_BLKNUM_MASK;
+
+	if (host->dodma)
+		dcon |= S3C2410_SDIDCON_DMAEN;
+
+	if (host->bus_width == MMC_BUS_WIDTH_4)
+		dcon |= S3C2410_SDIDCON_WIDEBUS;
+
+	if (!(data->flags & MMC_DATA_STREAM))
+		dcon |= S3C2410_SDIDCON_BLOCKMODE;
+
+	if (data->flags & MMC_DATA_WRITE) {
+		dcon |= S3C2410_SDIDCON_TXAFTERRESP;
+		dcon |= S3C2410_SDIDCON_XFER_TXSTART;
+	}
+
+	if (data->flags & MMC_DATA_READ) {
+		dcon |= S3C2410_SDIDCON_RXAFTERCMD;
+		dcon |= S3C2410_SDIDCON_XFER_RXSTART;
+	}
+
+	if (host->is2440) {
+		dcon |= S3C2440_SDIDCON_DS_WORD;
+		dcon |= S3C2440_SDIDCON_DATSTART;
+	}
+
+	writel(dcon, host->base + S3C2410_SDIDCON);
+
+	/* write BSIZE register */
+
+	writel(data->blksz, host->base + S3C2410_SDIBSIZE);
+
+	/* add to IMASK register */
+	imsk = S3C2410_SDIIMSK_FIFOFAIL | S3C2410_SDIIMSK_DATACRC |
+	       S3C2410_SDIIMSK_DATATIMEOUT | S3C2410_SDIIMSK_DATAFINISH;
+
+	enable_imask(host, imsk);
+
+	/* write TIMER register */
+
+	if (host->is2440) {
+		writel(0x007FFFFF, host->base + S3C2410_SDITIMER);
+	} else {
+		writel(0x0000FFFF, host->base + S3C2410_SDITIMER);
+
+		/* FIX: set slow clock to prevent timeouts on read */
+		if (data->flags & MMC_DATA_READ)
+			writel(0xFF, host->base + S3C2410_SDIPRE);
+	}
+
+	return 0;
+}
+
+#define BOTH_DIR (MMC_DATA_WRITE | MMC_DATA_READ)
+
+static int s3cmci_prepare_pio(struct s3cmci_host *host, struct mmc_data *data)
+{
+	int rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0;
+
+	BUG_ON((data->flags & BOTH_DIR) == BOTH_DIR);
+
+	host->pio_sgptr = 0;
+	host->pio_words = 0;
+	host->pio_count = 0;
+	host->pio_active = rw ? XFER_WRITE : XFER_READ;
+
+	if (rw) {
+		do_pio_write(host);
+		enable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
+	} else {
+		enable_imask(host, S3C2410_SDIIMSK_RXFIFOHALF
+			     | S3C2410_SDIIMSK_RXFIFOLAST);
+	}
+
+	return 0;
+}
+
+static int s3cmci_prepare_dma(struct s3cmci_host *host, struct mmc_data *data)
+{
+	int dma_len, i;
+	int rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0;
+
+	BUG_ON((data->flags & BOTH_DIR) == BOTH_DIR);
+
+	s3cmci_dma_setup(host, rw ? S3C2410_DMASRC_MEM : S3C2410_DMASRC_HW);
+	s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH);
+
+	dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+			     (rw) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+
+	if (dma_len == 0)
+		return -ENOMEM;
+
+	host->dma_complete = 0;
+	host->dmatogo = dma_len;
+
+	for (i = 0; i < dma_len; i++) {
+		int res;
+
+		dbg(host, dbg_dma, "enqueue %i:%u@%u\n", i,
+			sg_dma_address(&data->sg[i]),
+			sg_dma_len(&data->sg[i]));
+
+		res = s3c2410_dma_enqueue(host->dma, (void *) host,
+					  sg_dma_address(&data->sg[i]),
+					  sg_dma_len(&data->sg[i]));
+
+		if (res) {
+			s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH);
+			return -EBUSY;
+		}
+	}
+
+	s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_START);
+
+	return 0;
+}
+
+static void s3cmci_send_request(struct mmc_host *mmc)
+{
+	struct s3cmci_host *host = mmc_priv(mmc);
+	struct mmc_request *mrq = host->mrq;
+	struct mmc_command *cmd = host->cmd_is_stop ? mrq->stop : mrq->cmd;
+
+	host->ccnt++;
+	prepare_dbgmsg(host, cmd, host->cmd_is_stop);
+
+	/* Clear command, data and fifo status registers
+	   Fifo clear only necessary on 2440, but doesn't hurt on 2410
+	*/
+	writel(0xFFFFFFFF, host->base + S3C2410_SDICMDSTAT);
+	writel(0xFFFFFFFF, host->base + S3C2410_SDIDSTA);
+	writel(0xFFFFFFFF, host->base + S3C2410_SDIFSTA);
+
+	if (cmd->data) {
+		int res = s3cmci_setup_data(host, cmd->data);
+
+		host->dcnt++;
+
+		if (res) {
+			cmd->error = -EINVAL;
+			cmd->data->error = -EINVAL;
+
+			mmc_request_done(mmc, mrq);
+			return;
+		}
+
+		if (host->dodma)
+			res = s3cmci_prepare_dma(host, cmd->data);
+		else
+			res = s3cmci_prepare_pio(host, cmd->data);
+
+		if (res) {
+			cmd->error = res;
+			cmd->data->error = res;
+
+			mmc_request_done(mmc, mrq);
+			return;
+		}
+	}
+
+	/* Send command */
+	s3cmci_send_command(host, cmd);
+
+	/* Enable Interrupt */
+	enable_irq(host->irq);
+}
+
+static void s3cmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+	struct s3cmci_host *host = mmc_priv(mmc);
+
+	host->status = "mmc request";
+	host->cmd_is_stop = 0;
+	host->mrq = mrq;
+
+	s3cmci_send_request(mmc);
+}
+
+static void s3cmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct s3cmci_host *host = mmc_priv(mmc);
+	u32 mci_psc, mci_con;
+
+	/* Set the power state */
+
+	mci_con = readl(host->base + S3C2410_SDICON);
+
+	switch (ios->power_mode) {
+	case MMC_POWER_ON:
+	case MMC_POWER_UP:
+		s3c2410_gpio_cfgpin(S3C2410_GPE5, S3C2410_GPE5_SDCLK);
+		s3c2410_gpio_cfgpin(S3C2410_GPE6, S3C2410_GPE6_SDCMD);
+		s3c2410_gpio_cfgpin(S3C2410_GPE7, S3C2410_GPE7_SDDAT0);
+		s3c2410_gpio_cfgpin(S3C2410_GPE8, S3C2410_GPE8_SDDAT1);
+		s3c2410_gpio_cfgpin(S3C2410_GPE9, S3C2410_GPE9_SDDAT2);
+		s3c2410_gpio_cfgpin(S3C2410_GPE10, S3C2410_GPE10_SDDAT3);
+
+		if (!host->is2440)
+			mci_con |= S3C2410_SDICON_FIFORESET;
+
+		break;
+
+	case MMC_POWER_OFF:
+	default:
+		s3c2410_gpio_setpin(S3C2410_GPE5, 0);
+		s3c2410_gpio_cfgpin(S3C2410_GPE5, S3C2410_GPE5_OUTP);
+
+		if (host->is2440)
+			mci_con |= S3C2440_SDICON_SDRESET;
+
+		break;
+	}
+
+	/* Set clock */
+	for (mci_psc = 0; mci_psc < 255; mci_psc++) {
+		host->real_rate = host->clk_rate / (host->clk_div*(mci_psc+1));
+
+		if (host->real_rate <= ios->clock)
+			break;
+	}
+
+	if (mci_psc > 255)
+		mci_psc = 255;
+
+	host->prescaler = mci_psc;
+	writel(host->prescaler, host->base + S3C2410_SDIPRE);
+
+	/* If requested clock is 0, real_rate will be 0, too */
+	if (ios->clock == 0)
+		host->real_rate = 0;
+
+	/* Set CLOCK_ENABLE */
+	if (ios->clock)
+		mci_con |= S3C2410_SDICON_CLOCKTYPE;
+	else
+		mci_con &= ~S3C2410_SDICON_CLOCKTYPE;
+
+	writel(mci_con, host->base + S3C2410_SDICON);
+
+	if ((ios->power_mode == MMC_POWER_ON) ||
+	    (ios->power_mode == MMC_POWER_UP)) {
+		dbg(host, dbg_conf, "running at %lukHz (requested: %ukHz).\n",
+			host->real_rate/1000, ios->clock/1000);
+	} else {
+		dbg(host, dbg_conf, "powered down.\n");
+	}
+
+	host->bus_width = ios->bus_width;
+}
+
+static void s3cmci_reset(struct s3cmci_host *host)
+{
+	u32 con = readl(host->base + S3C2410_SDICON);
+
+	con |= S3C2440_SDICON_SDRESET;
+	writel(con, host->base + S3C2410_SDICON);
+}
+
+static struct mmc_host_ops s3cmci_ops = {
+	.request	= s3cmci_request,
+	.set_ios	= s3cmci_set_ios,
+};
+
+static int __devinit s3cmci_probe(struct platform_device *pdev, int is2440)
+{
+	struct s3cmci_host *host;
+	struct mmc_host	*mmc;
+	int ret;
+
+	mmc = mmc_alloc_host(sizeof(struct s3cmci_host), &pdev->dev);
+	if (!mmc) {
+		ret = -ENOMEM;
+		goto probe_out;
+	}
+
+	host = mmc_priv(mmc);
+	host->mmc 	= mmc;
+	host->pdev	= pdev;
+	host->is2440	= is2440;
+
+	spin_lock_init(&host->complete_lock);
+	tasklet_init(&host->pio_tasklet, pio_tasklet, (unsigned long) host);
+
+	if (is2440) {
+		host->sdiimsk	= S3C2440_SDIIMSK;
+		host->sdidata	= S3C2440_SDIDATA;
+		host->clk_div	= 1;
+	} else {
+		host->sdiimsk	= S3C2410_SDIIMSK;
+		host->sdidata	= S3C2410_SDIDATA;
+		host->clk_div	= 2;
+	}
+
+	host->dodma		= 0;
+	host->complete_what 	= COMPLETION_NONE;
+	host->pio_active 	= XFER_NONE;
+
+	host->dma		= S3CMCI_DMA;
+	host->irq_cd		= IRQ_EINT2;
+
+	host->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!host->mem) {
+		dev_err(&pdev->dev,
+			"failed to get io memory region resouce.\n");
+
+		ret = -ENOENT;
+		goto probe_free_host;
+	}
+
+	host->mem = request_mem_region(host->mem->start,
+				       RESSIZE(host->mem), pdev->name);
+
+	if (!host->mem) {
+		dev_err(&pdev->dev, "failed to request io memory region.\n");
+		ret = -ENOENT;
+		goto probe_free_host;
+	}
+
+	host->base = ioremap(host->mem->start, RESSIZE(host->mem));
+	if (host->base == 0) {
+		dev_err(&pdev->dev, "failed to ioremap() io memory region.\n");
+		ret = -EINVAL;
+		goto probe_free_mem_region;
+	}
+
+	host->irq = platform_get_irq(pdev, 0);
+	if (host->irq == 0) {
+		dev_err(&pdev->dev, "failed to get interrupt resouce.\n");
+		ret = -EINVAL;
+		goto probe_iounmap;
+	}
+
+	if (request_irq(host->irq, s3cmci_irq, 0, DRIVER_NAME, host)) {
+		dev_err(&pdev->dev, "failed to request mci interrupt.\n");
+		ret = -ENOENT;
+		goto probe_iounmap;
+	}
+
+	/* We get spurious interrupts even when we have set the IMSK
+	 * register to ignore everything, so use disable_irq() to make
+	 * ensure we don't lock the system with un-serviceable requests. */
+
+	disable_irq(host->irq);
+
+	s3c2410_gpio_cfgpin(S3C2410_GPF2, S3C2410_GPF2_EINT2);
+	set_irq_type(host->irq_cd, IRQT_BOTHEDGE);
+
+	if (request_irq(host->irq_cd, s3cmci_irq_cd, 0, DRIVER_NAME, host)) {
+		dev_err(&pdev->dev,
+			"failed to request card detect interrupt.\n");
+		ret = -ENOENT;
+		goto probe_free_irq;
+	}
+
+	if (s3c2410_dma_request(S3CMCI_DMA, &s3cmci_dma_client, NULL)) {
+		dev_err(&pdev->dev, "unable to get DMA channel.\n");
+		ret = -EBUSY;
+		goto probe_free_irq_cd;
+	}
+
+	host->clk = clk_get(&pdev->dev, "sdi");
+	if (IS_ERR(host->clk)) {
+		dev_err(&pdev->dev, "failed to find clock source.\n");
+		ret = PTR_ERR(host->clk);
+		host->clk = NULL;
+		goto probe_free_host;
+	}
+
+	ret = clk_enable(host->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable clock source.\n");
+		goto clk_free;
+	}
+
+	host->clk_rate = clk_get_rate(host->clk);
+
+	mmc->ops 	= &s3cmci_ops;
+	mmc->ocr_avail	= MMC_VDD_32_33;
+	mmc->caps	= MMC_CAP_4_BIT_DATA;
+	mmc->f_min 	= host->clk_rate / (host->clk_div * 256);
+	mmc->f_max 	= host->clk_rate / host->clk_div;
+
+	mmc->max_blk_count	= 4095;
+	mmc->max_blk_size	= 4095;
+	mmc->max_req_size	= 4095 * 512;
+	mmc->max_seg_size	= mmc->max_req_size;
+
+	mmc->max_phys_segs	= 128;
+	mmc->max_hw_segs	= 128;
+
+	dbg(host, dbg_debug,
+	    "probe: mode:%s mapped mci_base:%p irq:%u irq_cd:%u dma:%u.\n",
+	    (host->is2440?"2440":""),
+	    host->base, host->irq, host->irq_cd, host->dma);
+
+	ret = mmc_add_host(mmc);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to add mmc host.\n");
+		goto free_dmabuf;
+	}
+
+	platform_set_drvdata(pdev, mmc);
+	dev_info(&pdev->dev, "initialisation done.\n");
+
+	return 0;
+
+ free_dmabuf:
+	clk_disable(host->clk);
+
+ clk_free:
+	clk_put(host->clk);
+
+ probe_free_irq_cd:
+	free_irq(host->irq_cd, host);
+
+ probe_free_irq:
+	free_irq(host->irq, host);
+
+ probe_iounmap:
+	iounmap(host->base);
+
+ probe_free_mem_region:
+	release_mem_region(host->mem->start, RESSIZE(host->mem));
+
+ probe_free_host:
+	mmc_free_host(mmc);
+ probe_out:
+	return ret;
+}
+
+static int __devexit s3cmci_remove(struct platform_device *pdev)
+{
+	struct mmc_host		*mmc  = platform_get_drvdata(pdev);
+	struct s3cmci_host	*host = mmc_priv(mmc);
+
+	mmc_remove_host(mmc);
+
+	clk_disable(host->clk);
+	clk_put(host->clk);
+
+	tasklet_disable(&host->pio_tasklet);
+
+	free_irq(host->irq_cd, host);
+	free_irq(host->irq, host);
+
+	iounmap(host->base);
+	release_mem_region(host->mem->start, RESSIZE(host->mem));
+
+	mmc_free_host(mmc);
+	return 0;
+}
+
+static int __devinit s3cmci_probe_2410(struct platform_device *dev)
+{
+	return s3cmci_probe(dev, 0);
+}
+
+static int __devinit s3cmci_probe_2412(struct platform_device *dev)
+{
+	return s3cmci_probe(dev, 1);
+}
+
+static int __devinit s3cmci_probe_2440(struct platform_device *dev)
+{
+	return s3cmci_probe(dev, 1);
+}
+
+#ifdef CONFIG_PM
+
+static int s3cmci_suspend(struct platform_device *dev, pm_message_t state)
+{
+	struct mmc_host *mmc = platform_get_drvdata(dev);
+
+	return  mmc_suspend_host(mmc, state);
+}
+
+static int s3cmci_resume(struct platform_device *dev)
+{
+	struct mmc_host *mmc = platform_get_drvdata(dev);
+
+	return mmc_resume_host(mmc);
+}
+
+#else /* CONFIG_PM */
+#define s3cmci_suspend NULL
+#define s3cmci_resume NULL
+#endif /* CONFIG_PM */
+
+
+static struct platform_driver s3cmci_driver_2410 = {
+	.driver.name	= "s3c2410-sdi",
+	.driver.owner	= THIS_MODULE,
+	.probe		= s3cmci_probe_2410,
+	.remove		= __devexit_p(s3cmci_remove),
+	.suspend	= s3cmci_suspend,
+	.resume		= s3cmci_resume,
+};
+
+static struct platform_driver s3cmci_driver_2412 = {
+	.driver.name	= "s3c2412-sdi",
+	.driver.owner	= THIS_MODULE,
+	.probe		= s3cmci_probe_2412,
+	.remove		= __devexit_p(s3cmci_remove),
+	.suspend	= s3cmci_suspend,
+	.resume		= s3cmci_resume,
+};
+
+static struct platform_driver s3cmci_driver_2440 = {
+	.driver.name	= "s3c2440-sdi",
+	.driver.owner	= THIS_MODULE,
+	.probe		= s3cmci_probe_2440,
+	.remove		= __devexit_p(s3cmci_remove),
+	.suspend	= s3cmci_suspend,
+	.resume		= s3cmci_resume,
+};
+
+
+static int __init s3cmci_init(void)
+{
+	platform_driver_register(&s3cmci_driver_2410);
+	platform_driver_register(&s3cmci_driver_2412);
+	platform_driver_register(&s3cmci_driver_2440);
+	return 0;
+}
+
+static void __exit s3cmci_exit(void)
+{
+	platform_driver_unregister(&s3cmci_driver_2410);
+	platform_driver_unregister(&s3cmci_driver_2412);
+	platform_driver_unregister(&s3cmci_driver_2440);
+}
+
+module_init(s3cmci_init);
+module_exit(s3cmci_exit);
+
+MODULE_DESCRIPTION("Samsung S3C MMC/SD Card Interface driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Thomas Kleffel <tk@maintech.de>");