DaVinci SD/MMC patch for git (take 2)

This is a forward port of the SD/MMC driver from the latest LSP,
melded into linux-2.6.23-git. I've tried to keep the style updates
that were merged recently. I've fixed the exit code (in
davinci_mmcsd_exit) to release clocks, and some failure paths in
davinci_mmcsd_init.

The driver as is performs ~6MB/s reads and ~1MB/s writes with a
block size of 512k (i.e. still needs help!). This patch just makes
the driver usable again.
Signed-off-by: Bernard Blackham <bernard@largestprime.net>
Signed-off-by: Kevin Hilman <khilman@mvista.com>

drivers/mmc/host/davinci_mmc.c

@@ -24,13 +24,13 @@
  Modifications:
  ver. 1.0: Oct 2005, Purushotam Kumar   Initial version
  ver 1.1:  Nov  2005, Purushotam Kumar  Solved bugs
- ver 1.2:  Jan  2066, Purushotam Kumar   Added card remove insert support
+ ver 1.2:  Jan  2006, Purushotam Kumar   Added card remove insert support
  -
  *
-
  */
 
 #include <linux/module.h>
+#include <linux/version.h>
 #include <linux/tty.h>
 #include <linux/ioport.h>
 #include <linux/init.h>
@@ -41,35 +41,25 @@
 #include <linux/mmc/host.h>
 #include <linux/mmc/card.h>
 #include <linux/mmc/mmc.h>
-
 #include <asm/io.h>
 #include <asm/irq.h>
 #include <asm/hardware.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
 #include <asm/arch/irqs.h>
 #include <asm/arch/hardware.h>
 
 #include "davinci_mmc.h"
 #include <asm/arch/edma.h>
 
-/* FIXME: old defines  from old mmc.h */
-/* #define MMC_RSP_NONE	(0 << 0) */
-/* #define MMC_RSP_SHORT	(1 << 0) */
-/* #define MMC_RSP_LONG	(2 << 0) */
-/* #define MMC_RSP_MASK	(3 << 0) */
-/* #define MMC_RSP_CRC	(1 << 3)		/\* expect valid crc *\/ */
-/* #define MMC_RSP_BUSY	(1 << 4)		/\* card may send busy *\/ */
-#define MMC_RSP_SHORT	MMC_RSP_PRESENT
-#define MMC_RSP_LONG    MMC_RSP_136
-#define MMC_RSP_MASK    (MMC_RSP_PRESENT | MMC_RSP_136)
-
 extern void davinci_clean_channel(int ch_no);
 
 /* MMCSD Init clock in Hz in opendain mode */
-#define MMCSD_INIT_CLOCK		200000
-#define DRIVER_NAME			"mmc0"
-#define MMCINT_INTERRUPT		IRQ_MMCINT
-#define MMCSD_REGS_BASE_ADDR		DAVINCI_MMC_SD_BASE
-#define TCINTEN				(0x1<<20)
+#define MMCSD_INIT_CLOCK 		200000
+#define DRIVER_NAME 			"mmc0"
+#define MMCINT_INTERRUPT    		IRQ_MMCINT
+#define MMCSD_REGS_BASE_ADDR  		DAVINCI_MMC_SD_BASE
+#define TCINTEN 			(0x1<<20)
 
 /* This macro could not be defined to 0 (ZERO) or -ve value.
  * This value is multiplied to "HZ"
@@ -83,6 +73,8 @@ mmcsd_config_def mmcsd_cfg = {
 /* read write thresholds (in bytes) can be any power of 2 from 2 to 64 */
 	32,
 /* To use the DMA or not-- 1- Use DMA, 0-Interrupt mode */
+	1,
+/* flag Indicates 1bit/4bit mode */
 	1
 };
 
@@ -107,54 +99,71 @@ static struct mmc_request *que_mmc_request = NULL;
 /* tells whether card is initizlzed or not */
 static unsigned int is_card_initialized = 0;
 static unsigned int new_card_state = 0;	/* tells current state of card */
+static unsigned int is_card_removed = 0;
 
 static DEFINE_SPINLOCK(mmc_lock);
 
+#define RSP_TYPE(x)	((x) & ~(MMC_RSP_BUSY|MMC_RSP_OPCODE))
+#define MMCST1_BUSY	(1 << 0)
+
+static inline void wait_on_data(void)
+{
+	int cnt = 900000;
+	while (((mmcsd_regs->mmc_st1) & MMCST1_BUSY) && cnt) {
+		cnt--;
+		udelay(1);
+	}
+	if (!cnt) {
+		dev_warn(&mmc_dev, "ERROR: TOUT waiting for BUSY\n");
+	}
+}
+
 static void mmc_davinci_start_command(struct mmc_davinci_host *host,
 		struct mmc_command *cmd)
 {
 	u32 cmd_reg = 0;
 	u32 resp_type = 0;
 	u32 cmd_type = 0;
-	int byte_cnt = 0, i = 0;
 	unsigned long flags;
 
+#ifdef CONFIG_MMC_DEBUG
 	dev_dbg(&mmc_dev, "\nMMCSD : CMD%d, argument 0x%08x",
 		cmd->opcode, cmd->arg);
-	if (cmd->flags & MMC_RSP_SHORT)
-		dev_dbg(&mmc_dev, ", 32-bit response");
-	if (cmd->flags & MMC_RSP_LONG)
-		dev_dbg(&mmc_dev, ", 128-bit response");
-	if (cmd->flags & MMC_RSP_CRC)
-		dev_dbg(&mmc_dev, ", CRC");
-	if (cmd->flags & MMC_RSP_BUSY)
-		dev_dbg(&mmc_dev, ", busy notification");
-	else
-		dev_dbg(&mmc_dev, ", No busy notification");
+	switch (RSP_TYPE(mmc_resp_type(cmd))) {
+	case RSP_TYPE(MMC_RSP_R1):
+		dev_dbg(&mmc_dev, ", R1/R1b response");
+		break;
+	case RSP_TYPE(MMC_RSP_R2):
+		dev_dbg(&mmc_dev, ", R2 response");
+		break;
+	case RSP_TYPE(MMC_RSP_R3):
+		dev_dbg(&mmc_dev, ", R3 response");
+		break;
+	default:
+		break;
+	}
 	dev_dbg(&mmc_dev, "\n");
+#endif
 	host->cmd = cmd;
 
 	/* Protocol layer does not provide response type,
 	 * but our hardware needs to know exact type, not just size!
 	 */
-	switch (cmd->flags & MMC_RSP_MASK) {
+	switch (RSP_TYPE(mmc_resp_type(cmd))) {
 	case MMC_RSP_NONE:
 		/* resp 0 */
 		break;
-	case MMC_RSP_SHORT:
-		/* resp 1, resp 1b */
-		/* OR resp 3!! (assume this if bus is set opendrain) */
-		if (host->bus_mode == MMC_BUSMODE_OPENDRAIN) {
-			resp_type = 3;
-			if (cmd->opcode == 3)
-				resp_type = 1;
-		} else
-			resp_type = 1;
+	case RSP_TYPE(MMC_RSP_R1):
+		resp_type = 1;
 		break;
-	case MMC_RSP_LONG:
-		/* resp 2 */
+	case RSP_TYPE(MMC_RSP_R2):
 		resp_type = 2;
 		break;
+	case RSP_TYPE(MMC_RSP_R3):
+		resp_type = 3;
+		break;
+	default:
+		break;
 	}
 
 	/* Protocol layer does not provide command type, but our hardware
@@ -171,11 +180,11 @@ static void mmc_davinci_start_command(struct mmc_davinci_host *host,
 	 * rest are ac, except if opendrain
 	 */
 
-	if (host->data_dir)
+	if (mmc_cmd_type(cmd) == MMC_CMD_ADTC)
 		cmd_type = DAVINCI_MMC_CMDTYPE_ADTC;
-	else if (resp_type == 0 && cmd->opcode != 15)
+	else if (mmc_cmd_type(cmd) == MMC_CMD_BC)
 		cmd_type = DAVINCI_MMC_CMDTYPE_BC;
-	else if (host->bus_mode == MMC_BUSMODE_OPENDRAIN)
+	else if (mmc_cmd_type(cmd) == MMC_CMD_BCR)
 		cmd_type = DAVINCI_MMC_CMDTYPE_BCR;
 	else
 		cmd_type = DAVINCI_MMC_CMDTYPE_AC;
@@ -198,10 +207,9 @@ static void mmc_davinci_start_command(struct mmc_davinci_host *host,
 		cmd_reg = cmd_reg | (1 << 14);
 
 	/* Set for generating DMA Xfer event */
-	if ((host->use_dma == 1) && (host->data != NULL)
-			&& ((cmd->opcode == 18) || (cmd->opcode == 25)
-				|| (cmd->opcode == 24)
-				|| (cmd->opcode == 17)))
+	if ((host->do_dma == 1) && (host->data != NULL)
+	    && ((cmd->opcode == 18) || (cmd->opcode == 25)
+		|| (cmd->opcode == 24) || (cmd->opcode == 17)))
 		cmd_reg = cmd_reg | (1 << 16);
 
 	/* Setting whether command involves data transfer or not */
@@ -227,7 +235,7 @@ static void mmc_davinci_start_command(struct mmc_davinci_host *host,
 
 	/* Enable interrupt */
 	if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) {
-		if (host->use_dma != 1)
+		if (host->do_dma != 1)
 			mmcsd_regs->mmc_im = MMCSD_EVENT_EOFCMD
 					| MMCSD_EVENT_WRITE
 					| MMCSD_EVENT_ERROR_CMDCRC
@@ -243,7 +251,7 @@ static void mmc_davinci_start_command(struct mmc_davinci_host *host,
 					| MMCSD_EVENT_ERROR_DATATIMEOUT
 					| MMCSD_EVENT_BLOCK_XFERRED;
 	} else if (host->data_dir == DAVINCI_MMC_DATADIR_READ) {
-		if (host->use_dma != 1)
+		if (host->do_dma != 1)
 			mmcsd_regs->mmc_im = MMCSD_EVENT_EOFCMD
 					| MMCSD_EVENT_READ
 					| MMCSD_EVENT_ERROR_CMDCRC
@@ -271,25 +279,22 @@ static void mmc_davinci_start_command(struct mmc_davinci_host *host,
 	 */
 	if ((host->data_dir == DAVINCI_MMC_DATADIR_WRITE)
 			&& (cmd_type == DAVINCI_MMC_CMDTYPE_ADTC)
-			&& (host->use_dma != 1)) {
-		byte_cnt = mmcsd_cfg.rw_threshold;
-		host->bytes_left -= mmcsd_cfg.rw_threshold;
-		for (i = 0; i < (byte_cnt / 4); i++) {
-			mmcsd_regs->mmc_dxr = *host->buffer;
-			host->buffer++;
-		}
-	}
+			&& (host->do_dma != 1))
+		/* Fill the FIFO for Tx */
+		davinci_fifo_data_trans(host);
 
 	if (cmd->opcode == 7) {
 		spin_lock_irqsave(&mmc_lock, flags);
+		is_card_removed = 0;
 		new_card_state = 1;
 		is_card_initialized = 1;
 		host->old_card_state = new_card_state;
 		is_init_progress = 0;
 		spin_unlock_irqrestore(&mmc_lock, flags);
 	}
-	if (cmd->opcode == 1) {
+	if (cmd->opcode == 1 || cmd->opcode == 41) {
 		spin_lock_irqsave(&mmc_lock, flags);
+		is_card_initialized = 0;
 		is_init_progress = 1;
 		spin_unlock_irqrestore(&mmc_lock, flags);
 	}
@@ -302,47 +307,178 @@ static void mmc_davinci_start_command(struct mmc_davinci_host *host,
 
 static void mmc_davinci_dma_cb(int lch, u16 ch_status, void *data)
 {
-	int sync_dev = 0;
-	struct mmc_davinci_host *host = (struct mmc_davinci_host *)data;
+	if (DMA_COMPLETE != ch_status) {
+		struct mmc_davinci_host *host = (struct mmc_davinci_host *)data;
+		dev_warn(&mmc_dev, "[DMA FAILED]");
+		davinci_abort_dma(host);
+	}
+}
 
-	if (DMA_COMPLETE == ch_status) {
+static void davinci_fifo_data_trans(struct mmc_davinci_host *host)
+{
+	int n, i;
 
-		if (host->cmd == NULL && host->data == NULL) {
-			if (host->data_dir == DAVINCI_MMC_DATADIR_READ) {
-				sync_dev = DAVINCI_DMA_MMCTXEVT;
-			} else {
-				sync_dev = DAVINCI_DMA_MMCRXEVT;
-			}
-			dev_dbg(&mmc_dev,
-				"Interrupt from DMA when no request has been made\n");
-			davinci_stop_dma(sync_dev);
-			return;
-		}
+	if (host->buffer_bytes_left == 0) {
+		host->sg_idx++;
+		BUG_ON(host->sg_idx == host->sg_len);
+		mmc_davinci_sg_to_buf(host);
+	}
 
-		if (host->data_dir == DAVINCI_MMC_DATADIR_READ) {
-			sync_dev = DAVINCI_DMA_MMCTXEVT;	/* Write */
-		} else {
-			sync_dev = DAVINCI_DMA_MMCRXEVT;	/* Read */
+	n = mmcsd_cfg.rw_threshold;
+	if (n > host->buffer_bytes_left)
+		n = host->buffer_bytes_left;
+	host->buffer_bytes_left -= n;
+	host->bytes_left -= n;
+
+	if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) {
+		for (i = 0; i < (n / 4); i++) {
+			mmcsd_regs->mmc_dxr = *host->buffer;
+			host->buffer++;
 		}
-		davinci_stop_dma(sync_dev);
 	} else {
-		/* Handing of Event missed interreupt from DMA */
-		dev_dbg(&mmc_dev,
-			"Event miss interrupt has been generated by DMA\n");
-		if (host->data_dir == DAVINCI_MMC_DATADIR_READ) {
-			sync_dev = DAVINCI_DMA_MMCTXEVT;	/* Write */
-		} else {
-			sync_dev = DAVINCI_DMA_MMCRXEVT;	/* Read */
+		for (i = 0; i < (n / 4); i++) {
+			*host->buffer = mmcsd_regs->mmc_drr;
+			host->buffer++;
 		}
-		davinci_clean_channel(sync_dev);
 	}
 }
 
+static void davinci_reinit_chan(void)
+{
+	int sync_dev;
+
+	sync_dev = DAVINCI_DMA_MMCTXEVT;
+	davinci_stop_dma(sync_dev);
+	davinci_clean_channel(sync_dev);
+
+	sync_dev = DAVINCI_DMA_MMCRXEVT;
+	davinci_stop_dma(sync_dev);
+	davinci_clean_channel(sync_dev);
+}
+
+static void davinci_abort_dma(struct mmc_davinci_host *host)
+{
+	int sync_dev = 0;
+
+	if (host->data_dir == DAVINCI_MMC_DATADIR_READ)
+		sync_dev = DAVINCI_DMA_MMCTXEVT;
+	else
+		sync_dev = DAVINCI_DMA_MMCRXEVT;
+
+	davinci_stop_dma(sync_dev);
+	davinci_clean_channel(sync_dev);
+
+}
+
 static int mmc_davinci_start_dma_transfer(struct mmc_davinci_host *host,
 		struct mmc_request *req)
 {
-	const char *dev_name;
-	int sync_dev, r, edma_ch = 0, tcc = 0;
+	int use_dma = 1, i;
+	struct mmc_data *data = host->data;
+	int block_size = data->blksz;
+
+	host->sg_len = dma_map_sg(mmc_dev(host->mmc), data->sg, host->sg_len,
+				((data->flags & MMC_DATA_WRITE)
+				? DMA_TO_DEVICE
+				: DMA_FROM_DEVICE));
+
+	/* Decide if we can use DMA */
+	for (i = 0; i < host->sg_len; i++) {
+		if ((data->sg[i].length % block_size) != 0) {
+			use_dma = 0;
+			break;
+		}
+	}
+
+	if (!use_dma) {
+		dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->sg_len,
+				  (data->flags & MMC_DATA_WRITE)
+				? DMA_TO_DEVICE
+				: DMA_FROM_DEVICE);
+		return -1;
+	}
+
+	host->do_dma = 1;
+
+	host->dma_state = 0;
+
+	mmc_davinci_send_dma_request(host, req);
+
+	return 0;
+
+}
+
+static int davinci_release_dma_channels(struct mmc_davinci_host *host)
+{
+	davinci_free_dma(DAVINCI_DMA_MMCTXEVT);
+	davinci_free_dma(DAVINCI_DMA_MMCRXEVT);
+
+	if (host->edma_ch_details.cnt_chanel) {
+		davinci_free_dma(host->edma_ch_details.chanel_num[0]);
+		host->edma_ch_details.cnt_chanel = 0;
+	}
+
+	return 0;
+}
+
+static int davinci_acquire_dma_channels(struct mmc_davinci_host *host)
+{
+	int edma_chan_num, tcc = 0, r, sync_dev;
+	enum dma_event_q queue_no = EVENTQ_0;
+
+	/* Acquire master DMA write channel */
+	if ((r = davinci_request_dma(DAVINCI_DMA_MMCTXEVT, "MMC_WRITE",
+			mmc_davinci_dma_cb, host, &edma_chan_num, &tcc,
+			queue_no)) != 0) {
+		dev_warn(&mmc_dev,
+				"MMC: davinci_request_dma() failed with %d\n",
+				r);
+		return r;
+	}
+
+	/* Acquire master DMA read channel */
+	if ((r = davinci_request_dma(DAVINCI_DMA_MMCRXEVT, "MMC_READ",
+			mmc_davinci_dma_cb, host, &edma_chan_num, &tcc,
+			queue_no)) != 0) {
+		dev_warn(&mmc_dev,
+				"MMC: davinci_request_dma() failed with %d\n",
+				r);
+		goto free_master_write;
+	}
+
+	host->edma_ch_details.cnt_chanel = 0;
+
+	/* currently data Writes are done using single block mode,
+	 * so no DMA slave write channel is required for now */
+
+	/* Create a DMA slave read channel
+	 * (assuming max segments handled is 2) */
+	sync_dev = DAVINCI_DMA_MMCRXEVT;
+	if ((r = davinci_request_dma(DAVINCI_EDMA_PARAM_ANY, "LINK",
+			NULL, NULL, &edma_chan_num, &sync_dev,
+			queue_no)) != 0) {
+		dev_warn(&mmc_dev,
+			"MMC: davinci_request_dma() failed with %d\n", r);
+		goto free_master_read;
+	}
+
+	host->edma_ch_details.cnt_chanel++;
+	host->edma_ch_details.chanel_num[0] = edma_chan_num;
+
+	return 0;
+
+free_master_read:
+	davinci_free_dma(DAVINCI_DMA_MMCRXEVT);
+free_master_write:
+	davinci_free_dma(DAVINCI_DMA_MMCTXEVT);
+
+	return r;
+}
+
+static int mmc_davinci_send_dma_request(struct mmc_davinci_host *host,
+					struct mmc_request *req)
+{
+	int sync_dev;
 	unsigned char i, j;
 	unsigned short acnt, bcnt, ccnt;
 	unsigned int src_port, dst_port, temp_ccnt;
@@ -353,69 +489,50 @@ static int mmc_davinci_start_dma_transfer(struct mmc_davinci_host *host,
 	unsigned short bcntrld;
 	enum sync_dimension sync_mode;
 	edmacc_paramentry_regs temp;
-	enum dma_event_q queue_no = EVENTQ_0;
 	int edma_chan_num;
-	unsigned int num_eight_words = (req->data->blocks * 512) / 32;
 	static unsigned int option_read = 0;
 	static unsigned int option_write = 0;
-	static unsigned char dma_read_req = 1;
-	static unsigned char dma_write_req = 1;
+	struct mmc_data *data = host->data;
+	struct scatterlist *sg = &data->sg[0];
+	unsigned int count;
+	int num_frames, frame;
 
 #define MAX_C_CNT		64000
 
-	if ((req->data->flags & MMC_DATA_WRITE)) {
-		sync_dev = DAVINCI_DMA_MMCTXEVT;	/* Write */
-		dev_name = "MMC_WRITE";
+	frame = data->blksz;
+	count = sg_dma_len(sg);
 
-		if (dma_write_req) {
-			r = davinci_request_dma(sync_dev, dev_name,
-						mmc_davinci_dma_cb, host,
-						&edma_ch, &tcc, queue_no);
-			if (r != 0) {
-				dev_dbg(&mmc_dev,
-					"MMC: davinci_request_dma() failed with %d\n",
-r);
-				return r;
-			}
-			dma_write_req = 0;
-		}
-	} else {
-		sync_dev = DAVINCI_DMA_MMCRXEVT;	/* Read */
-		dev_name = "MMC_READ";
-		if (dma_read_req) {
-			r = davinci_request_dma(sync_dev, dev_name,
-						mmc_davinci_dma_cb, host,
-						&edma_ch, &tcc, queue_no);
-			if (r != 0) {
-				dev_dbg(&mmc_dev,
-					"MMC: davinci_request_dma() failed with %d\n",
-					r);
-				return r;
-			}
-			dma_read_req = 0;
-		}
+	if ((data->blocks == 1) && (count > data->blksz)) {
+		count = frame;
 	}
 
-	if ((req->data->flags & MMC_DATA_WRITE)) {
-		/* AB Sync Transfer */
-		/* Acnt =32, Bcnt= , Cnt=1 */
-
-		sync_dev = DAVINCI_DMA_MMCTXEVT;	/* Write */
+	if (count % 32 == 0) {
 		acnt = 4;
 		bcnt = 8;
-		if (num_eight_words > MAX_C_CNT) {
-			temp_ccnt = MAX_C_CNT;
-			ccnt = temp_ccnt;
-		} else {
-			ccnt = num_eight_words;
-			temp_ccnt = ccnt;
-		}
+		num_frames = count / 32;
+	} else {
+		acnt = count;
+		bcnt = 1;
+		num_frames = 1;
+	}
+
+	if (num_frames > MAX_C_CNT) {
+		temp_ccnt = MAX_C_CNT;
+		ccnt = temp_ccnt;
+	} else {
+		ccnt = num_frames;
+		temp_ccnt = ccnt;
+	}
+
+	if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) {
+		/*AB Sync Transfer */
+		sync_dev = DAVINCI_DMA_MMCTXEVT;
 
-		src_port = (unsigned int)virt_to_phys(req->data->mrq->buffer);
+		src_port = (unsigned int)sg_dma_address(sg);
 		mode_src = INCR;
 		fifo_width_src = W8BIT;	/* It's not cared as modeDsr is INCR */
-		src_bidx = 4;
-		src_cidx = 32;
+		src_bidx = acnt;
+		src_cidx = acnt * bcnt;
 		dst_port = MMCSD_REGS_BASE_ADDR + 0x2C;
 		mode_dst = INCR;
 		fifo_width_dst = W8BIT;	/* It's not cared as modeDsr is INCR */
@@ -425,27 +542,18 @@ r);
 		sync_mode = ABSYNC;
 
 	} else {
-		sync_dev = DAVINCI_DMA_MMCRXEVT;	/* Read */
-		acnt = 4;
-		bcnt = 8;
-		if (num_eight_words > MAX_C_CNT) {
-			temp_ccnt = MAX_C_CNT;
-			ccnt = temp_ccnt;
-		} else {
-			ccnt = num_eight_words;
-			temp_ccnt = ccnt;
-		}
+		sync_dev = DAVINCI_DMA_MMCRXEVT;
 
 		src_port = MMCSD_REGS_BASE_ADDR + 0x28;
 		mode_src = INCR;
 		fifo_width_src = W8BIT;
 		src_bidx = 0;
 		src_cidx = 0;
-		dst_port = (unsigned int)virt_to_phys(req->data->mrq->buffer);
+		dst_port = (unsigned int)sg_dma_address(sg);
 		mode_dst = INCR;
 		fifo_width_dst = W8BIT;	/* It's not cared as modeDsr is INCR */
-		dst_bidx = 4;
-		dst_cidx = 32;
+		dst_bidx = acnt;
+		dst_cidx = acnt * bcnt;
 		bcntrld = 8;
 		sync_mode = ABSYNC;
 	}
@@ -459,7 +567,6 @@ r);
 	davinci_set_dma_transfer_params(sync_dev, acnt, bcnt, ccnt, bcntrld,
 					sync_mode);
 
-	host->edma_ch_details.cnt_chanel = 0;
 	davinci_get_dma_params(sync_dev, &temp);
 	if (sync_dev == DAVINCI_DMA_MMCTXEVT) {
 		if (option_write == 0) {
@@ -478,12 +585,14 @@ r);
 		}
 	}
 
-	if (num_eight_words > MAX_C_CNT) {	/* Linking will be performed */
+	if (host->sg_len > 1) {
 		davinci_get_dma_params(sync_dev, &temp);
 		temp.opt &= ~TCINTEN;
 		davinci_set_dma_params(sync_dev, &temp);
 
-		for (i = 0; i < EDMA_MAX_LOGICAL_CHA_ALLOWED; i++) {
+		for (i = 0; i < host->sg_len - 1; i++) {
+			sg = &data->sg[i + 1];
+
 			if (i != 0) {
 				j = i - 1;
 				davinci_get_dma_params(
@@ -495,30 +604,24 @@ r);
 					&temp);
 			}
 
-			host->edma_ch_details.cnt_chanel++;
-			davinci_request_dma(DAVINCI_EDMA_PARAM_ANY, "LINK",
-					NULL, NULL, &edma_chan_num,
-					&sync_dev, queue_no);
-			host->edma_ch_details.chanel_num[i] = edma_chan_num;
-			ccnt = temp.ccnt & 0x0000FFFF;
-			if (sync_dev == DAVINCI_DMA_MMCTXEVT) {
-				temp.src = temp.src + (acnt * bcnt * ccnt);
-			} else {
-				temp.dst = temp.dst + (acnt * bcnt * ccnt);
-			}
+			edma_chan_num = host->edma_ch_details.chanel_num[0];
+
+			frame = data->blksz;
+			count = sg_dma_len(sg);
+
+			if ((data->blocks == 1) && (count > data->blksz))
+				count = frame;
+
+			ccnt = count / 32;
+
+			if (sync_dev == DAVINCI_DMA_MMCTXEVT)
+				temp.src = (unsigned int)sg_dma_address(sg);
+			else
+				temp.dst = (unsigned int)sg_dma_address(sg);
 			temp.opt |= TCINTEN;
 
-			if ((num_eight_words - temp_ccnt) > MAX_C_CNT) {
-				temp.ccnt = (temp.ccnt & 0xFFFF0000)
-					| MAX_C_CNT;
-				ccnt = temp.ccnt & 0x0000FFFF;
-				temp_ccnt = temp_ccnt + ccnt;
-			} else {
-				temp.ccnt = (temp.ccnt & 0xFFFF0000)
-					| (num_eight_words -temp_ccnt);
-				ccnt = temp.ccnt & 0x0000FFFF;
-				temp_ccnt = temp_ccnt + ccnt;
-			}
+			temp.ccnt = (temp.ccnt & 0xFFFF0000) | (ccnt);
+
 			davinci_set_dma_params(edma_chan_num, &temp);
 			if (i != 0) {
 				j = i - 1;
@@ -526,8 +629,6 @@ r);
 						chanel_num[j],
 						edma_chan_num);
 			}
-			if (temp_ccnt == num_eight_words)
-				break;
 		}
 		davinci_dma_link_lch(sync_dev,
 				host->edma_ch_details.chanel_num[0]);
@@ -540,8 +641,7 @@ r);
 static void
 mmc_davinci_prepare_data(struct mmc_davinci_host *host, struct mmc_request *req)
 {
-	int timeout;
-
+	int timeout, sg_len;
 	host->data = req->data;
 	if (req->data == NULL) {
 		host->data_dir = DAVINCI_MMC_DATADIR_NONE;
@@ -549,6 +649,9 @@ mmc_davinci_prepare_data(struct mmc_davinci_host *host, struct mmc_request *req)
 		mmcsd_regs->mmc_nblk = 0;
 		return;
 	}
+	/* Init idx */
+	host->sg_idx = 0;
+
 	dev_dbg(&mmc_dev,
 		"MMCSD : Data xfer (%s %s), "
 		"DTO %d cycles + %d ns, %d blocks of %d bytes\r\n",
@@ -589,15 +692,33 @@ mmc_davinci_prepare_data(struct mmc_davinci_host *host, struct mmc_request *req)
 		break;
 	}
 
-	if ((host->use_dma == 1)
-			&& (mmc_davinci_start_dma_transfer(host, req) == 0)) {
+	sg_len = (req->data->blocks == 1) ? 1 : req->data->sg_len;
+	host->sg_len = sg_len;
+
+	host->bytes_left = req->data->blocks * req->data->blksz;
+
+	if ((host->use_dma == 1) && (host->bytes_left % 32 == 0)
+	    && (mmc_davinci_start_dma_transfer(host, req) == 0)) {
 		host->buffer = NULL;
 		host->bytes_left = 0;
 	} else {
 		/* Revert to CPU Copy */
-		host->buffer = (u32 *) (req->data->mrq->buffer);
-		host->bytes_left = req->data->blocks * req->data->blksz;
-		host->use_dma = 0;
+
+		host->do_dma = 0;
+		mmc_davinci_sg_to_buf(host);
+	}
+}
+
+/* PIO only */
+static void mmc_davinci_sg_to_buf(struct mmc_davinci_host *host)
+{
+	struct scatterlist *sg;
+
+	sg = host->data->sg + host->sg_idx;
+	host->buffer_bytes_left = sg->length;
+	host->buffer = page_address(sg->page) + sg->offset;
+	if (host->buffer_bytes_left > host->bytes_left) {
+		host->buffer_bytes_left = host->bytes_left;
 	}
 }
 
@@ -606,14 +727,27 @@ static void mmc_davinci_request(struct mmc_host *mmc, struct mmc_request *req)
 	struct mmc_davinci_host *host = mmc_priv(mmc);
 	unsigned long flags;
 
+	if (is_card_removed) {
+		if (req->cmd) {
+			req->cmd->error |= MMC_ERR_TIMEOUT;
+			mmc_request_done(mmc, req);
+		}
+		dev_dbg(&mmc_dev,
+			"From code segment excuted when card removed\n");
+		return;
+	}
+
+	wait_on_data();
+
 	if (!is_card_detect_progress) {
 		spin_lock_irqsave(&mmc_lock, flags);
 		is_card_busy = 1;
 		spin_unlock_irqrestore(&mmc_lock, flags);
+		host->do_dma = 0;
 		mmc_davinci_prepare_data(host, req);
 		mmc_davinci_start_command(host, req->cmd);
 	} else {
-		/* Queu up the request as card dectection is being excuted */
+		/* Queue up the request as card dectection is being excuted */
 		que_mmc_host = mmc;
 		que_mmc_request = req;
 		spin_lock_irqsave(&mmc_lock, flags);
@@ -652,6 +786,13 @@ static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 	dev_dbg(&mmc_dev, "clock %dHz busmode %d powermode %d Vdd %d.%02d\r\n",
 		ios->clock, ios->bus_mode, ios->power_mode,
 		ios->vdd / 100, ios->vdd % 100);
+	if (ios->bus_width == MMC_BUS_WIDTH_4) {
+		dev_dbg(&mmc_dev, "\nEnabling 4 bit mode\n");
+		mmcsd_regs->mmc_ctl = mmcsd_regs->mmc_ctl | (1 << 2);
+	} else {
+		dev_dbg(&mmc_dev, "Disabling 4 bit mode\n");
+		mmcsd_regs->mmc_ctl = mmcsd_regs->mmc_ctl & ~(1 << 2);
+	}
 
 	if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN) {
 		open_drain_freq = ((unsigned int)cpu_arm_clk
@@ -660,8 +801,12 @@ static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 				| open_drain_freq;
 	} else {
 		mmc_push_pull_freq = calculate_freq_for_card(ios->clock);
+		mmcsd_regs->mmc_clk &= ~(0x100);
+		udelay(10);
 		mmcsd_regs->mmc_clk = (mmcsd_regs->mmc_clk & ~(0xFF))
 				| mmc_push_pull_freq;
+		mmcsd_regs->mmc_clk |= 0x100;
+		udelay(10);
 	}
 	host->bus_mode = ios->bus_mode;
 	if (ios->power_mode == MMC_POWER_UP) {
@@ -685,6 +830,15 @@ mmc_davinci_xfer_done(struct mmc_davinci_host *host, struct mmc_data *data)
 	if (data->error == MMC_ERR_NONE)
 		data->bytes_xfered += data->blocks * data->blksz;
 
+	if (host->do_dma) {
+		davinci_abort_dma(host);
+
+		dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->sg_len,
+			     (data->
+			      flags & MMC_DATA_WRITE) ? DMA_TO_DEVICE :
+			     DMA_FROM_DEVICE);
+	}
+
 	if (data->error == MMC_ERR_TIMEOUT) {
 		spin_lock_irqsave(&mmc_lock, flags);
 		is_card_busy = 0;
@@ -708,25 +862,24 @@ static void mmc_davinci_cmd_done(struct mmc_davinci_host *host,
 				 struct mmc_command *cmd)
 {
 	unsigned long flags;
-
 	host->cmd = NULL;
-	switch (cmd->flags & MMC_RSP_MASK) {
-	case MMC_RSP_NONE:
-		/* resp 0 */
-		break;
 
-	case MMC_RSP_SHORT:
-		/* response types 1, 1b, 3, 4, 5, 6 */
-		cmd->resp[0] = mmcsd_regs->mmc_rsp67;
-		break;
+	if (!cmd) {
+		dev_warn(&mmc_dev, "%s(): No cmd ptr\n", __FUNCTION__);
+		return;
+	}
 
-	case MMC_RSP_LONG:
-		/* response type 2 */
-		cmd->resp[3] = mmcsd_regs->mmc_rsp01;
-		cmd->resp[2] = mmcsd_regs->mmc_rsp23;
-		cmd->resp[1] = mmcsd_regs->mmc_rsp45;
-		cmd->resp[0] = mmcsd_regs->mmc_rsp67;
-		break;
+	if (cmd->flags & MMC_RSP_PRESENT) {
+		if (cmd->flags & MMC_RSP_136) {
+			/* response type 2 */
+			cmd->resp[3] = mmcsd_regs->mmc_rsp01;
+			cmd->resp[2] = mmcsd_regs->mmc_rsp23;
+			cmd->resp[1] = mmcsd_regs->mmc_rsp45;
+			cmd->resp[0] = mmcsd_regs->mmc_rsp67;
+		} else {
+			/* response types 1, 1b, 3, 4, 5, 6 */
+			cmd->resp[0] = mmcsd_regs->mmc_rsp67;
+		}
 	}
 
 	if (host->data == NULL || cmd->error != MMC_ERR_NONE) {
@@ -746,7 +899,6 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
 	u16 status;
 	int end_command;
 	int end_transfer;
-	int byte_cnt = 0, i = 0;
 	unsigned long flags;
 
 	if (host->is_core_command) {
@@ -783,44 +935,35 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
 			if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) {
 				if (status & MMCSD_EVENT_WRITE) {
 					/* Buffer almost empty */
-					if (host->bytes_left > 0) {
-						byte_cnt =
-							mmcsd_cfg.rw_threshold;
-						host->bytes_left -=
-							mmcsd_cfg.rw_threshold;
-						for (i = 0; i < (byte_cnt / 4);
-								i++) {
-							mmcsd_regs->mmc_dxr =
-								*host->buffer;
-							host->buffer++;
-						}
-					}
+					if (host->bytes_left > 0)
+						davinci_fifo_data_trans(host);
 				}
 			}
 
 			if (host->data_dir == DAVINCI_MMC_DATADIR_READ) {
 				if (status & MMCSD_EVENT_READ) {
 					/* Buffer almost empty */
-					if (host->bytes_left > 0) {
-						byte_cnt =
-							mmcsd_cfg.rw_threshold;
-						host->bytes_left -=
-							mmcsd_cfg.rw_threshold;
-						for (i = 0; i < (byte_cnt / 4);
-								i++) {
-							*host->buffer =
-								mmcsd_regs->
-									mmc_drr;
-							host->buffer++;
-						}
-					}
+					if (host->bytes_left > 0)
+						davinci_fifo_data_trans(host);
 				}
 			}
 
 			if (status & MMCSD_EVENT_BLOCK_XFERRED) {
 				/* Block sent/received */
 				if (host->data != NULL) {
-					end_transfer = 1;
+					if (host->do_dma == 1) {
+						end_transfer = 1;
+					} else {
+						/* if datasize<32 no RX ints are generated */
+						if (host->bytes_left > 0) {
+							davinci_fifo_data_trans
+							    (host);
+						}
+						end_transfer = 1;
+					}
+				} else {
+					dev_warn(&mmc_dev,
+						 "TC:host->data is NULL\n");
 				}
 			}
 
@@ -829,6 +972,7 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
 				if ((host->data) && (new_card_state != 0)) {
 					host->data->error |= MMC_ERR_TIMEOUT;
 					spin_lock_irqsave(&mmc_lock, flags);
+					is_card_removed = 1;
 					new_card_state = 0;
 					is_card_initialized = 0;
 					spin_unlock_irqrestore(&mmc_lock,
@@ -836,15 +980,23 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
 					dev_dbg(&mmc_dev,
 						"MMCSD: Data timeout, CMD%d and status is %x\r\n",
 						host->cmd->opcode, status);
+
+					if (host->cmd) {
+						host->cmd->error |=
+						    MMC_ERR_TIMEOUT;
+					}
 					end_transfer = 1;
-					host->cmd->error |= MMC_ERR_TIMEOUT;
 				}
-				dev_dbg(&mmc_dev,
-					"MMCSD: Data timeout, CMD%d and status is %x\r\n",
-					host->cmd->opcode, status);
 			}
 
 			if (status & MMCSD_EVENT_ERROR_DATACRC) {
+				/* DAT line portion is diabled and in reset state */
+				mmcsd_regs->mmc_ctl =
+				    mmcsd_regs->mmc_ctl | (1 << 1);
+				udelay(10);
+				mmcsd_regs->mmc_ctl =
+				    mmcsd_regs->mmc_ctl & ~(1 << 1);
+
 				/* Data CRC error */
 				if (host->data) {
 					host->data->error |= MMC_ERR_BADCRC;
@@ -859,6 +1011,10 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
 			}
 
 			if (status & MMCSD_EVENT_ERROR_CMDTIMEOUT) {
+				if (host->do_dma)
+					/* abort DMA transfer */
+					davinci_abort_dma(host);
+
 				/* Command timeout */
 				if (host->cmd) {
 					/* Timeouts are normal in case of
@@ -888,7 +1044,11 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
 				/* Command CRC error */
 				dev_dbg(&mmc_dev, "Command CRC error\r\n");
 				if (host->cmd) {
-					host->cmd->error |= MMC_ERR_BADCRC;
+					/* Ignore CMD CRC errors during high speed operation */
+					if (host->mmc->ios.clock <= 25000000) {
+						host->cmd->error |=
+						    MMC_ERR_BADCRC;
+					}
 					end_command = 1;
 				}
 			}
@@ -926,6 +1086,7 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
 
 			} else {
 				spin_lock_irqsave(&mmc_lock, flags);
+				is_card_removed = 1;
 				new_card_state = 0;
 				is_card_initialized = 0;
 				spin_unlock_irqrestore(&mmc_lock, flags);
@@ -945,15 +1106,17 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
 
 		}
 
-		if (host->cmd_code == 1) {
+		if (host->cmd_code == 1 || host->cmd_code == 55) {
 			if (status & MMCSD_EVENT_EOFCMD) {
 				spin_lock_irqsave(&mmc_lock, flags);
+				is_card_removed = 0;
 				new_card_state = 1;
 				is_card_initialized = 0;
 				spin_unlock_irqrestore(&mmc_lock, flags);
 			} else {
 
 				spin_lock_irqsave(&mmc_lock, flags);
+				is_card_removed = 1;
 				new_card_state = 0;
 				is_card_initialized = 0;
 				spin_unlock_irqrestore(&mmc_lock, flags);
@@ -970,19 +1133,31 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
 				is_req_queued_up = 0;
 				spin_unlock_irqrestore(&mmc_lock, flags);
 			}
-
 		}
 
 		if (host->cmd_code == 0) {
 			if (status & MMCSD_EVENT_EOFCMD) {
+				static int flag_sd_mmc;
 				host->is_core_command = 0;
-				host->cmd_code = 1;
-				dev_dbg(&mmc_dev,
-					"MMC-Probing mmc with cmd1\n");
-				/* Issue cmd1 */
-				mmcsd_regs->mmc_arghl = 0x80300000;
-				mmcsd_regs->mmc_cmd = 0x00000601;
 
+				if (flag_sd_mmc) {
+					flag_sd_mmc = 0;
+					host->cmd_code = 1;
+					/* Issue cmd1 */
+					mmcsd_regs->mmc_arghl = 0x80300000;
+					mmcsd_regs->mmc_cmd = 0x00000601;
+				} else {
+					flag_sd_mmc = 1;
+					host->cmd_code = 55;
+					/* Issue cmd55 */
+					mmcsd_regs->mmc_arghl = 0x0;
+					mmcsd_regs->mmc_cmd =
+					    ((0x0 | (1 << 9) | 55));
+				}
+
+				dev_dbg(&mmc_dev,
+					"MMC-Probing mmc with cmd%d\n",
+					host->cmd_code);
 			} else {
 				spin_lock_irqsave(&mmc_lock, flags);
 				new_card_state = 0;
@@ -999,12 +1174,22 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
 static struct mmc_host_ops mmc_davinci_ops = {
 	.request = mmc_davinci_request,
 	.set_ios = mmc_davinci_set_ios,
+	.get_ro = mmc_davinci_get_ro
 };
 
-void mmc_check_card(unsigned long data)
+static int mmc_davinci_get_ro(struct mmc_host *mmc)
+{
+	return 0;
+}
+
+static void mmc_check_card(unsigned long data)
 {
 	struct mmc_davinci_host *host = (struct mmc_davinci_host *)data;
 	unsigned long flags;
+	struct mmc_card *card = NULL;
+
+	if (host->mmc && host->mmc->card)
+		card = host->mmc->card;
 
 	if ((!is_card_detect_progress) || (!is_init_progress)) {
 		if (is_card_initialized) {
@@ -1014,7 +1199,8 @@ void mmc_check_card(unsigned long data)
 			is_card_detect_progress = 1;
 			spin_unlock_irqrestore(&mmc_lock, flags);
 			/* Issue cmd13 */
-			mmcsd_regs->mmc_arghl = 0x10000;
+			mmcsd_regs->mmc_arghl = (card && mmc_card_sd(card))
+				? (card->rca << 16) : 0x10000;
 			mmcsd_regs->mmc_cmd = 0x0000028D;
 		} else {
 			host->is_core_command = 0;
@@ -1041,6 +1227,8 @@ static void davinci_mmc_check_status(unsigned long data)
 
 	if (!is_card_busy) {
 		if (host->old_card_state ^ new_card_state) {
+			davinci_reinit_chan();
+			init_mmcsd_host();
 			mmc_detect_change(host->mmc, 0);
 			spin_lock_irqsave(&mmc_lock, flags);
 			host->old_card_state = new_card_state;
@@ -1057,6 +1245,7 @@ static void init_mmcsd_host(void)
 	mmcsd_regs->mmc_ctl = mmcsd_regs->mmc_ctl | 0x1;
 	/* DAT line portion is diabled and in reset state */
 	mmcsd_regs->mmc_ctl = mmcsd_regs->mmc_ctl | (1 << 1);
+	udelay(10);
 
 	mmcsd_regs->mmc_clk = 0x0;
 	mmcsd_regs->mmc_clk = mmcsd_regs->mmc_clk | (1 << 8);
@@ -1066,13 +1255,14 @@ static void init_mmcsd_host(void)
 
 	mmcsd_regs->mmc_ctl = mmcsd_regs->mmc_ctl & ~(0x1);
 	mmcsd_regs->mmc_ctl = mmcsd_regs->mmc_ctl & ~(1 << 1);
+	udelay(10);
 }
 
 static int davinci_mmcsd_probe(struct platform_device *pdev)
 {
 	struct mmc_davinci_host *host;
 	struct mmc_host *mmc;
-	int ret;
+	int ret = 0;
 
 	mmc = mmc_alloc_host(sizeof(struct mmc_davinci_host), &pdev->dev);
 	if (!mmc) {
@@ -1085,14 +1275,44 @@ static int davinci_mmcsd_probe(struct platform_device *pdev)
 
 	init_mmcsd_host();
 
+	if (mmcsd_cfg.use_4bit_mode) {
+		dev_warn(&mmc_dev, "Supporting 4-bit mode\n");
+		mmc->caps |= MMC_CAP_4_BIT_DATA;
+	} else
+		dev_warn(&mmc_dev, "Not Supporting 4-bit mode\n");
+
 	mmc->ops = &mmc_davinci_ops;
 	mmc->f_min = 312500;
-	mmc->f_max = 20000000;
+#ifdef CONFIG_MMC_HIGHSPEED
+	mmc->f_max = 50000000;
+#else
+	mmc->f_max = 25000000;
+#endif
 	mmc->ocr_avail = MMC_VDD_32_33;
 
+	mmc->max_phys_segs = 2;
+	mmc->max_hw_segs   = 2;
+	mmc->max_blk_size  = 4095;  /* BLEN is 11 bits */
+	mmc->max_blk_count = 65535; /* NBLK is 16 bits */
+	mmc->max_req_size  = mmc->max_blk_size * mmc->max_blk_count;
+	mmc->max_seg_size  = mmc->max_req_size;
+
+	dev_dbg(&mmc_dev, "max_phys_segs=%d\n", mmc->max_phys_segs);
+	dev_dbg(&mmc_dev, "max_hw_segs=%d\n", mmc->max_hw_segs);
+	dev_dbg(&mmc_dev, "max_blk_size=%d\n", mmc->max_blk_size);
+	dev_dbg(&mmc_dev, "max_req_size=%d\n", mmc->max_req_size);
+	dev_dbg(&mmc_dev, "max_seg_size=%d\n", mmc->max_seg_size);
+
 	host = mmc_priv(mmc);
 	host->mmc = mmc;	/* Important */
 
+	if (mmcsd_cfg.use_dma) {
+		dev_dbg(&mmc_dev, "Using DMA mode\n");
+		if (davinci_acquire_dma_channels(host) != 0)
+			goto out;
+	} else
+		dev_dbg(&mmc_dev, "Not Using DMA mode\n");
+
 	host->use_dma = mmcsd_cfg.use_dma;
 	host->irq = MMCINT_INTERRUPT;
 	host->sd_support = 1;
@@ -1122,13 +1342,20 @@ out:
 static int davinci_mmcsd_remove(struct platform_device *pdev)
 {
 	struct mmc_davinci_host *host = platform_get_drvdata(pdev);
+	unsigned long flags;
 
 	platform_set_drvdata(pdev, NULL);
-	mmc_remove_host(host->mmc);
-	free_irq(host->irq, host);
-	del_timer(&host->timer);
-	davinci_free_dma(DAVINCI_DMA_MMCTXEVT);
-	davinci_free_dma(DAVINCI_DMA_MMCRXEVT);
+	if (host) {
+		mmc_remove_host(host->mmc);
+		free_irq(host->irq, host);
+
+		spin_lock_irqsave(&mmc_lock, flags);
+		del_timer(&host->timer);
+		spin_unlock_irqrestore(&mmc_lock, flags);
+
+		davinci_release_dma_channels(host);
+	}
+
 	return 0;
 
 }
@@ -1222,14 +1449,26 @@ free1:
 		platform_device_unregister(&mmc_davinci_device);
 	}
 
+	if (clkp) {
+		mmc_clkp = NULL;
+		clk_put(clkp);
+	}
+
 	return -ENODEV;
 }
 
 static void __exit davinci_mmcsd_exit(void)
 {
+	struct clk *clkp;
+
 	platform_driver_unregister(&davinci_mmcsd_driver);
 	platform_device_unregister(&mmc_davinci_device);
-	clk_disable(mmc_clkp);
+
+	clkp = mmc_clkp;
+	mmc_clkp = NULL;
+
+	clk_disable(clkp);
+	clk_put(clkp);
 }
 
 module_init(davinci_mmcsd_init);

drivers/mmc/host/davinci_mmc.h

@@ -132,6 +132,7 @@ struct mmc_davinci_host {
 	int power_pin;
 
 	int use_dma;
+	int do_dma;
 	struct completion dma_completion;
 
 	struct timer_list timer;
@@ -143,10 +144,16 @@ struct mmc_davinci_host {
 
 	edma_ch_mmcsd edma_ch_details;
 
+	unsigned int sg_len;
+	int sg_idx;
+	unsigned int buffer_bytes_left;
+	unsigned int dma_len;
+	int dma_state;
 };
 typedef struct {
 	unsigned short rw_threshold;
 	unsigned short use_dma;
+	unsigned short use_4bit_mode;
 } mmcsd_config_def;
 
 typedef enum {
@@ -168,4 +175,20 @@ typedef enum {
 #define MMCSD_EVENT_ERROR \
  (MMCSD_EVENT_TIMEOUT_ERROR | MMCSD_EVENT_CRC_ERROR)
 
+static void init_mmcsd_host(void);
+
+static void davinci_fifo_data_trans(struct mmc_davinci_host *host);
+
+static void mmc_davinci_sg_to_buf(struct mmc_davinci_host *host);
+
+static int mmc_davinci_send_dma_request(struct mmc_davinci_host *host,
+					struct mmc_request *req);
+
+static void mmc_davinci_xfer_done(struct mmc_davinci_host *host,
+				  struct mmc_data *data);
+
+static int mmc_davinci_get_ro(struct mmc_host *mmc);
+
+static void davinci_abort_dma(struct mmc_davinci_host *host);
+
 #endif /* DAVINCI_MMC_H_ */