mmc: dw_mmc: Add Synopsys DesignWare mmc host driver.

This adds the mmc host driver for the Synopsys DesignWare mmc
host controller, found in a number of embedded SoC designs.

Signed-off-by: Will Newton <will.newton@imgtec.com>
Reviewed-by: Matt Fleming <matt@console-pimps.org>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

4 files changed, 1981 insertions, 0 deletions

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 9f47d38dcc7..5ec02a536c5 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -479,6 +479,22 @@ config SDH_BFIN_MISSING_CMD_PULLUP_WORKAROUND
 	help
 	  If you say yes here SD-Cards may work on the EZkit.
 
+config MMC_DW
+	tristate "Synopsys DesignWare Memory Card Interface"
+	depends on ARM
+	help
+	  This selects support for the Synopsys DesignWare Mobile Storage IP
+	  block, this provides host support for SD and MMC interfaces, in both
+	  PIO and external DMA modes.
+
+config MMC_DW_IDMAC
+	bool "Internal DMAC interface"
+	depends on MMC_DW
+	help
+	  This selects support for the internal DMAC block within the Synopsys
+	  Designware Mobile Storage IP block. This disables the external DMA
+	  interface.
+
 config MMC_SH_MMCIF
 	tristate "SuperH Internal MMCIF support"
 	depends on MMC_BLOCK && (SUPERH || ARCH_SHMOBILE)
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 6d1ff9e2736..e834fb223e9 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_MMC_TMIO)		+= tmio_mmc.o
 obj-$(CONFIG_MMC_CB710)	+= cb710-mmc.o
 obj-$(CONFIG_MMC_VIA_SDMMC)	+= via-sdmmc.o
 obj-$(CONFIG_SDH_BFIN)		+= bfin_sdh.o
+obj-$(CONFIG_MMC_DW)		+= dw_mmc.o
 obj-$(CONFIG_MMC_SH_MMCIF)	+= sh_mmcif.o
 obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
 obj-$(CONFIG_MMC_USHC)		+= ushc.o
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
new file mode 100644
index 00000000000..2fcc82577c1
--- /dev/null
+++ b/drivers/mmc/host/dw_mmc.c
@@ -0,0 +1,1796 @@
+/*
+ * Synopsys DesignWare Multimedia Card Interface driver
+ *  (Based on NXP driver for lpc 31xx)
+ *
+ * Copyright (C) 2009 NXP Semiconductors
+ * Copyright (C) 2009, 2010 Imagination Technologies Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/clk.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/dw_mmc.h>
+#include <linux/bitops.h>
+
+#include "dw_mmc.h"
+
+/* Common flag combinations */
+#define DW_MCI_DATA_ERROR_FLAGS	(SDMMC_INT_DTO | SDMMC_INT_DCRC | \
+				 SDMMC_INT_HTO | SDMMC_INT_SBE  | \
+				 SDMMC_INT_EBE)
+#define DW_MCI_CMD_ERROR_FLAGS	(SDMMC_INT_RTO | SDMMC_INT_RCRC | \
+				 SDMMC_INT_RESP_ERR)
+#define DW_MCI_ERROR_FLAGS	(DW_MCI_DATA_ERROR_FLAGS | \
+				 DW_MCI_CMD_ERROR_FLAGS  | SDMMC_INT_HLE)
+#define DW_MCI_SEND_STATUS	1
+#define DW_MCI_RECV_STATUS	2
+#define DW_MCI_DMA_THRESHOLD	16
+
+#ifdef CONFIG_MMC_DW_IDMAC
+struct idmac_desc {
+	u32		des0;	/* Control Descriptor */
+#define IDMAC_DES0_DIC	BIT(1)
+#define IDMAC_DES0_LD	BIT(2)
+#define IDMAC_DES0_FD	BIT(3)
+#define IDMAC_DES0_CH	BIT(4)
+#define IDMAC_DES0_ER	BIT(5)
+#define IDMAC_DES0_CES	BIT(30)
+#define IDMAC_DES0_OWN	BIT(31)
+
+	u32		des1;	/* Buffer sizes */
+#define IDMAC_SET_BUFFER1_SIZE(d, s) \
+	((d)->des1 = ((d)->des1 & 0x03ffc000) | ((s) & 0x3fff))
+
+	u32		des2;	/* buffer 1 physical address */
+
+	u32		des3;	/* buffer 2 physical address */
+};
+#endif /* CONFIG_MMC_DW_IDMAC */
+
+/**
+ * struct dw_mci_slot - MMC slot state
+ * @mmc: The mmc_host representing this slot.
+ * @host: The MMC controller this slot is using.
+ * @ctype: Card type for this slot.
+ * @mrq: mmc_request currently being processed or waiting to be
+ *	processed, or NULL when the slot is idle.
+ * @queue_node: List node for placing this node in the @queue list of
+ *	&struct dw_mci.
+ * @clock: Clock rate configured by set_ios(). Protected by host->lock.
+ * @flags: Random state bits associated with the slot.
+ * @id: Number of this slot.
+ * @last_detect_state: Most recently observed card detect state.
+ */
+struct dw_mci_slot {
+	struct mmc_host		*mmc;
+	struct dw_mci		*host;
+
+	u32			ctype;
+
+	struct mmc_request	*mrq;
+	struct list_head	queue_node;
+
+	unsigned int		clock;
+	unsigned long		flags;
+#define DW_MMC_CARD_PRESENT	0
+#define DW_MMC_CARD_NEED_INIT	1
+	int			id;
+	int			last_detect_state;
+};
+
+#if defined(CONFIG_DEBUG_FS)
+static int dw_mci_req_show(struct seq_file *s, void *v)
+{
+	struct dw_mci_slot *slot = s->private;
+	struct mmc_request *mrq;
+	struct mmc_command *cmd;
+	struct mmc_command *stop;
+	struct mmc_data	*data;
+
+	/* Make sure we get a consistent snapshot */
+	spin_lock_bh(&slot->host->lock);
+	mrq = slot->mrq;
+
+	if (mrq) {
+		cmd = mrq->cmd;
+		data = mrq->data;
+		stop = mrq->stop;
+
+		if (cmd)
+			seq_printf(s,
+				   "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
+				   cmd->opcode, cmd->arg, cmd->flags,
+				   cmd->resp[0], cmd->resp[1], cmd->resp[2],
+				   cmd->resp[2], cmd->error);
+		if (data)
+			seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
+				   data->bytes_xfered, data->blocks,
+				   data->blksz, data->flags, data->error);
+		if (stop)
+			seq_printf(s,
+				   "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
+				   stop->opcode, stop->arg, stop->flags,
+				   stop->resp[0], stop->resp[1], stop->resp[2],
+				   stop->resp[2], stop->error);
+	}
+
+	spin_unlock_bh(&slot->host->lock);
+
+	return 0;
+}
+
+static int dw_mci_req_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, dw_mci_req_show, inode->i_private);
+}
+
+static const struct file_operations dw_mci_req_fops = {
+	.owner		= THIS_MODULE,
+	.open		= dw_mci_req_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int dw_mci_regs_show(struct seq_file *s, void *v)
+{
+	seq_printf(s, "STATUS:\t0x%08x\n", SDMMC_STATUS);
+	seq_printf(s, "RINTSTS:\t0x%08x\n", SDMMC_RINTSTS);
+	seq_printf(s, "CMD:\t0x%08x\n", SDMMC_CMD);
+	seq_printf(s, "CTRL:\t0x%08x\n", SDMMC_CTRL);
+	seq_printf(s, "INTMASK:\t0x%08x\n", SDMMC_INTMASK);
+	seq_printf(s, "CLKENA:\t0x%08x\n", SDMMC_CLKENA);
+
+	return 0;
+}
+
+static int dw_mci_regs_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, dw_mci_regs_show, inode->i_private);
+}
+
+static const struct file_operations dw_mci_regs_fops = {
+	.owner		= THIS_MODULE,
+	.open		= dw_mci_regs_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static void dw_mci_init_debugfs(struct dw_mci_slot *slot)
+{
+	struct mmc_host	*mmc = slot->mmc;
+	struct dw_mci *host = slot->host;
+	struct dentry *root;
+	struct dentry *node;
+
+	root = mmc->debugfs_root;
+	if (!root)
+		return;
+
+	node = debugfs_create_file("regs", S_IRUSR, root, host,
+				   &dw_mci_regs_fops);
+	if (!node)
+		goto err;
+
+	node = debugfs_create_file("req", S_IRUSR, root, slot,
+				   &dw_mci_req_fops);
+	if (!node)
+		goto err;
+
+	node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state);
+	if (!node)
+		goto err;
+
+	node = debugfs_create_x32("pending_events", S_IRUSR, root,
+				  (u32 *)&host->pending_events);
+	if (!node)
+		goto err;
+
+	node = debugfs_create_x32("completed_events", S_IRUSR, root,
+				  (u32 *)&host->completed_events);
+	if (!node)
+		goto err;
+
+	return;
+
+err:
+	dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
+}
+#endif /* defined(CONFIG_DEBUG_FS) */
+
+static void dw_mci_set_timeout(struct dw_mci *host)
+{
+	/* timeout (maximum) */
+	mci_writel(host, TMOUT, 0xffffffff);
+}
+
+static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd)
+{
+	struct mmc_data	*data;
+	u32 cmdr;
+	cmd->error = -EINPROGRESS;
+
+	cmdr = cmd->opcode;
+
+	if (cmdr == MMC_STOP_TRANSMISSION)
+		cmdr |= SDMMC_CMD_STOP;
+	else
+		cmdr |= SDMMC_CMD_PRV_DAT_WAIT;
+
+	if (cmd->flags & MMC_RSP_PRESENT) {
+		/* We expect a response, so set this bit */
+		cmdr |= SDMMC_CMD_RESP_EXP;
+		if (cmd->flags & MMC_RSP_136)
+			cmdr |= SDMMC_CMD_RESP_LONG;
+	}
+
+	if (cmd->flags & MMC_RSP_CRC)
+		cmdr |= SDMMC_CMD_RESP_CRC;
+
+	data = cmd->data;
+	if (data) {
+		cmdr |= SDMMC_CMD_DAT_EXP;
+		if (data->flags & MMC_DATA_STREAM)
+			cmdr |= SDMMC_CMD_STRM_MODE;
+		if (data->flags & MMC_DATA_WRITE)
+			cmdr |= SDMMC_CMD_DAT_WR;
+	}
+
+	return cmdr;
+}
+
+static void dw_mci_start_command(struct dw_mci *host,
+				 struct mmc_command *cmd, u32 cmd_flags)
+{
+	host->cmd = cmd;
+	dev_vdbg(&host->pdev->dev,
+		 "start command: ARGR=0x%08x CMDR=0x%08x\n",
+		 cmd->arg, cmd_flags);
+
+	mci_writel(host, CMDARG, cmd->arg);
+	wmb();
+
+	mci_writel(host, CMD, cmd_flags | SDMMC_CMD_START);
+}
+
+static void send_stop_cmd(struct dw_mci *host, struct mmc_data *data)
+{
+	dw_mci_start_command(host, data->stop, host->stop_cmdr);
+}
+
+/* DMA interface functions */
+static void dw_mci_stop_dma(struct dw_mci *host)
+{
+	if (host->use_dma) {
+		host->dma_ops->stop(host);
+		host->dma_ops->cleanup(host);
+	} else {
+		/* Data transfer was stopped by the interrupt handler */
+		set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
+	}
+}
+
+#ifdef CONFIG_MMC_DW_IDMAC
+static void dw_mci_dma_cleanup(struct dw_mci *host)
+{
+	struct mmc_data *data = host->data;
+
+	if (data)
+		dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len,
+			     ((data->flags & MMC_DATA_WRITE)
+			      ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
+}
+
+static void dw_mci_idmac_stop_dma(struct dw_mci *host)
+{
+	u32 temp;
+
+	/* Disable and reset the IDMAC interface */
+	temp = mci_readl(host, CTRL);
+	temp &= ~SDMMC_CTRL_USE_IDMAC;
+	temp |= SDMMC_CTRL_DMA_RESET;
+	mci_writel(host, CTRL, temp);
+
+	/* Stop the IDMAC running */
+	temp = mci_readl(host, BMOD);
+	temp &= ~SDMMC_IDMAC_ENABLE;
+	mci_writel(host, BMOD, temp);
+}
+
+static void dw_mci_idmac_complete_dma(struct dw_mci *host)
+{
+	struct mmc_data *data = host->data;
+
+	dev_vdbg(&host->pdev->dev, "DMA complete\n");
+
+	host->dma_ops->cleanup(host);
+
+	/*
+	 * If the card was removed, data will be NULL. No point in trying to
+	 * send the stop command or waiting for NBUSY in this case.
+	 */
+	if (data) {
+		set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
+		tasklet_schedule(&host->tasklet);
+	}
+}
+
+static void dw_mci_translate_sglist(struct dw_mci *host, struct mmc_data *data,
+				    unsigned int sg_len)
+{
+	int i;
+	struct idmac_desc *desc = host->sg_cpu;
+
+	for (i = 0; i < sg_len; i++, desc++) {
+		unsigned int length = sg_dma_len(&data->sg[i]);
+		u32 mem_addr = sg_dma_address(&data->sg[i]);
+
+		/* Set the OWN bit and disable interrupts for this descriptor */
+		desc->des0 = IDMAC_DES0_OWN | IDMAC_DES0_DIC | IDMAC_DES0_CH;
+
+		/* Buffer length */
+		IDMAC_SET_BUFFER1_SIZE(desc, length);
+
+		/* Physical address to DMA to/from */
+		desc->des2 = mem_addr;
+	}
+
+	/* Set first descriptor */
+	desc = host->sg_cpu;
+	desc->des0 |= IDMAC_DES0_FD;
+
+	/* Set last descriptor */
+	desc = host->sg_cpu + (i - 1) * sizeof(struct idmac_desc);
+	desc->des0 &= ~(IDMAC_DES0_CH | IDMAC_DES0_DIC);
+	desc->des0 |= IDMAC_DES0_LD;
+
+	wmb();
+}
+
+static void dw_mci_idmac_start_dma(struct dw_mci *host, unsigned int sg_len)
+{
+	u32 temp;
+
+	dw_mci_translate_sglist(host, host->data, sg_len);
+
+	/* Select IDMAC interface */
+	temp = mci_readl(host, CTRL);
+	temp |= SDMMC_CTRL_USE_IDMAC;
+	mci_writel(host, CTRL, temp);
+
+	wmb();
+
+	/* Enable the IDMAC */
+	temp = mci_readl(host, BMOD);
+	temp |= SDMMC_IDMAC_ENABLE;
+	mci_writel(host, BMOD, temp);
+
+	/* Start it running */
+	mci_writel(host, PLDMND, 1);
+}
+
+static int dw_mci_idmac_init(struct dw_mci *host)
+{
+	struct idmac_desc *p;
+	int i;
+
+	/* Number of descriptors in the ring buffer */
+	host->ring_size = PAGE_SIZE / sizeof(struct idmac_desc);
+
+	/* Forward link the descriptor list */
+	for (i = 0, p = host->sg_cpu; i < host->ring_size - 1; i++, p++)
+		p->des3 = host->sg_dma + (sizeof(struct idmac_desc) * (i + 1));
+
+	/* Set the last descriptor as the end-of-ring descriptor */
+	p->des3 = host->sg_dma;
+	p->des0 = IDMAC_DES0_ER;
+
+	/* Mask out interrupts - get Tx & Rx complete only */
+	mci_writel(host, IDINTEN, SDMMC_IDMAC_INT_NI | SDMMC_IDMAC_INT_RI |
+		   SDMMC_IDMAC_INT_TI);
+
+	/* Set the descriptor base address */
+	mci_writel(host, DBADDR, host->sg_dma);
+	return 0;
+}
+
+static struct dw_mci_dma_ops dw_mci_idmac_ops = {
+	.init = dw_mci_idmac_init,
+	.start = dw_mci_idmac_start_dma,
+	.stop = dw_mci_idmac_stop_dma,
+	.complete = dw_mci_idmac_complete_dma,
+	.cleanup = dw_mci_dma_cleanup,
+};
+#endif /* CONFIG_MMC_DW_IDMAC */
+
+static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
+{
+	struct scatterlist *sg;
+	unsigned int i, direction, sg_len;
+	u32 temp;
+
+	/* If we don't have a channel, we can't do DMA */
+	if (!host->use_dma)
+		return -ENODEV;
+
+	/*
+	 * We don't do DMA on "complex" transfers, i.e. with
+	 * non-word-aligned buffers or lengths. Also, we don't bother
+	 * with all the DMA setup overhead for short transfers.
+	 */
+	if (data->blocks * data->blksz < DW_MCI_DMA_THRESHOLD)
+		return -EINVAL;
+	if (data->blksz & 3)
+		return -EINVAL;
+
+	for_each_sg(data->sg, sg, data->sg_len, i) {
+		if (sg->offset & 3 || sg->length & 3)
+			return -EINVAL;
+	}
+
+	if (data->flags & MMC_DATA_READ)
+		direction = DMA_FROM_DEVICE;
+	else
+		direction = DMA_TO_DEVICE;
+
+	sg_len = dma_map_sg(&host->pdev->dev, data->sg, data->sg_len,
+			    direction);
+
+	dev_vdbg(&host->pdev->dev,
+		 "sd sg_cpu: %#lx sg_dma: %#lx sg_len: %d\n",
+		 (unsigned long)host->sg_cpu, (unsigned long)host->sg_dma,
+		 sg_len);
+
+	/* Enable the DMA interface */
+	temp = mci_readl(host, CTRL);
+	temp |= SDMMC_CTRL_DMA_ENABLE;
+	mci_writel(host, CTRL, temp);
+
+	/* Disable RX/TX IRQs, let DMA handle it */
+	temp = mci_readl(host, INTMASK);
+	temp  &= ~(SDMMC_INT_RXDR | SDMMC_INT_TXDR);
+	mci_writel(host, INTMASK, temp);
+
+	host->dma_ops->start(host, sg_len);
+
+	return 0;
+}
+
+static void dw_mci_submit_data(struct dw_mci *host, struct mmc_data *data)
+{
+	u32 temp;
+
+	data->error = -EINPROGRESS;
+
+	WARN_ON(host->data);
+	host->sg = NULL;
+	host->data = data;
+
+	if (dw_mci_submit_data_dma(host, data)) {
+		host->sg = data->sg;
+		host->pio_offset = 0;
+		if (data->flags & MMC_DATA_READ)
+			host->dir_status = DW_MCI_RECV_STATUS;
+		else
+			host->dir_status = DW_MCI_SEND_STATUS;
+
+		temp = mci_readl(host, INTMASK);
+		temp |= SDMMC_INT_TXDR | SDMMC_INT_RXDR;
+		mci_writel(host, INTMASK, temp);
+
+		temp = mci_readl(host, CTRL);
+		temp &= ~SDMMC_CTRL_DMA_ENABLE;
+		mci_writel(host, CTRL, temp);
+	}
+}
+
+static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
+{
+	struct dw_mci *host = slot->host;
+	unsigned long timeout = jiffies + msecs_to_jiffies(500);
+	unsigned int cmd_status = 0;
+
+	mci_writel(host, CMDARG, arg);
+	wmb();
+	mci_writel(host, CMD, SDMMC_CMD_START | cmd);
+
+	while (time_before(jiffies, timeout)) {
+		cmd_status = mci_readl(host, CMD);
+		if (!(cmd_status & SDMMC_CMD_START))
+			return;
+	}
+	dev_err(&slot->mmc->class_dev,
+		"Timeout sending command (cmd %#x arg %#x status %#x)\n",
+		cmd, arg, cmd_status);
+}
+
+static void dw_mci_setup_bus(struct dw_mci_slot *slot)
+{
+	struct dw_mci *host = slot->host;
+	u32 div;
+
+	if (slot->clock != host->current_speed) {
+		if (host->bus_hz % slot->clock)
+			/*
+			 * move the + 1 after the divide to prevent
+			 * over-clocking the card.
+			 */
+			div = ((host->bus_hz / slot->clock) >> 1) + 1;
+		else
+			div = (host->bus_hz  / slot->clock) >> 1;
+
+		dev_info(&slot->mmc->class_dev,
+			 "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ"
+			 " div = %d)\n", slot->id, host->bus_hz, slot->clock,
+			 div ? ((host->bus_hz / div) >> 1) : host->bus_hz, div);
+
+		/* disable clock */
+		mci_writel(host, CLKENA, 0);
+		mci_writel(host, CLKSRC, 0);
+
+		/* inform CIU */
+		mci_send_cmd(slot,
+			     SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
+
+		/* set clock to desired speed */
+		mci_writel(host, CLKDIV, div);
+
+		/* inform CIU */
+		mci_send_cmd(slot,
+			     SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
+
+		/* enable clock */
+		mci_writel(host, CLKENA, SDMMC_CLKEN_ENABLE);
+
+		/* inform CIU */
+		mci_send_cmd(slot,
+			     SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
+
+		host->current_speed = slot->clock;
+	}
+
+	/* Set the current slot bus width */
+	mci_writel(host, CTYPE, slot->ctype);
+}
+
+static void dw_mci_start_request(struct dw_mci *host,
+				 struct dw_mci_slot *slot)
+{
+	struct mmc_request *mrq;
+	struct mmc_command *cmd;
+	struct mmc_data	*data;
+	u32 cmdflags;
+
+	mrq = slot->mrq;
+	if (host->pdata->select_slot)
+		host->pdata->select_slot(slot->id);
+
+	/* Slot specific timing and width adjustment */
+	dw_mci_setup_bus(slot);
+
+	host->cur_slot = slot;
+	host->mrq = mrq;
+
+	host->pending_events = 0;
+	host->completed_events = 0;
+	host->data_status = 0;
+
+	data = mrq->data;
+	if (data) {
+		dw_mci_set_timeout(host);
+		mci_writel(host, BYTCNT, data->blksz*data->blocks);
+		mci_writel(host, BLKSIZ, data->blksz);
+	}
+
+	cmd = mrq->cmd;
+	cmdflags = dw_mci_prepare_command(slot->mmc, cmd);
+
+	/* this is the first command, send the initialization clock */
+	if (test_and_clear_bit(DW_MMC_CARD_NEED_INIT, &slot->flags))
+		cmdflags |= SDMMC_CMD_INIT;
+
+	if (data) {
+		dw_mci_submit_data(host, data);
+		wmb();
+	}
+
+	dw_mci_start_command(host, cmd, cmdflags);
+
+	if (mrq->stop)
+		host->stop_cmdr = dw_mci_prepare_command(slot->mmc, mrq->stop);
+}
+
+static void dw_mci_queue_request(struct dw_mci *host, struct dw_mci_slot *slot,
+				 struct mmc_request *mrq)
+{
+	dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n",
+		 host->state);
+
+	spin_lock_bh(&host->lock);
+	slot->mrq = mrq;
+
+	if (host->state == STATE_IDLE) {
+		host->state = STATE_SENDING_CMD;
+		dw_mci_start_request(host, slot);
+	} else {
+		list_add_tail(&slot->queue_node, &host->queue);
+	}
+
+	spin_unlock_bh(&host->lock);
+}
+
+static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+	struct dw_mci_slot *slot = mmc_priv(mmc);
+	struct dw_mci *host = slot->host;
+
+	WARN_ON(slot->mrq);
+
+	if (!test_bit(DW_MMC_CARD_PRESENT, &slot->flags)) {
+		mrq->cmd->error = -ENOMEDIUM;
+		mmc_request_done(mmc, mrq);
+		return;
+	}
+
+	/* We don't support multiple blocks of weird lengths. */
+	dw_mci_queue_request(host, slot, mrq);
+}
+
+static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct dw_mci_slot *slot = mmc_priv(mmc);
+
+	/* set default 1 bit mode */
+	slot->ctype = SDMMC_CTYPE_1BIT;
+
+	switch (ios->bus_width) {
+	case MMC_BUS_WIDTH_1:
+		slot->ctype = SDMMC_CTYPE_1BIT;
+		break;
+	case MMC_BUS_WIDTH_4:
+		slot->ctype = SDMMC_CTYPE_4BIT;
+		break;
+	}
+
+	if (ios->clock) {
+		/*
+		 * Use mirror of ios->clock to prevent race with mmc
+		 * core ios update when finding the minimum.
+		 */
+		slot->clock = ios->clock;
+	}
+
+	switch (ios->power_mode) {
+	case MMC_POWER_UP:
+		set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
+		break;
+	default:
+		break;
+	}
+}
+
+static int dw_mci_get_ro(struct mmc_host *mmc)
+{
+	int read_only;
+	struct dw_mci_slot *slot = mmc_priv(mmc);
+	struct dw_mci_board *brd = slot->host->pdata;
+
+	/* Use platform get_ro function, else try on board write protect */
+	if (brd->get_ro)
+		read_only = brd->get_ro(slot->id);
+	else
+		read_only =
+			mci_readl(slot->host, WRTPRT) & (1 << slot->id) ? 1 : 0;
+
+	dev_dbg(&mmc->class_dev, "card is %s\n",
+		read_only ? "read-only" : "read-write");
+
+	return read_only;
+}
+
+static int dw_mci_get_cd(struct mmc_host *mmc)
+{
+	int present;
+	struct dw_mci_slot *slot = mmc_priv(mmc);
+	struct dw_mci_board *brd = slot->host->pdata;
+
+	/* Use platform get_cd function, else try onboard card detect */
+	if (brd->get_cd)
+		present = !brd->get_cd(slot->id);
+	else
+		present = (mci_readl(slot->host, CDETECT) & (1 << slot->id))
+			== 0 ? 1 : 0;
+
+	if (present)
+		dev_dbg(&mmc->class_dev, "card is present\n");
+	else
+		dev_dbg(&mmc->class_dev, "card is not present\n");
+
+	return present;
+}
+
+static const struct mmc_host_ops dw_mci_ops = {
+	.request	= dw_mci_request,
+	.set_ios	= dw_mci_set_ios,
+	.get_ro		= dw_mci_get_ro,
+	.get_cd		= dw_mci_get_cd,
+};
+
+static void dw_mci_request_end(struct dw_mci *host, struct mmc_request *mrq)
+	__releases(&host->lock)
+	__acquires(&host->lock)
+{
+	struct dw_mci_slot *slot;
+	struct mmc_host	*prev_mmc = host->cur_slot->mmc;
+
+	WARN_ON(host->cmd || host->data);
+
+	host->cur_slot->mrq = NULL;
+	host->mrq = NULL;
+	if (!list_empty(&host->queue)) {
+		slot = list_entry(host->queue.next,
+				  struct dw_mci_slot, queue_node);
+		list_del(&slot->queue_node);
+		dev_vdbg(&host->pdev->dev, "list not empty: %s is next\n",
+			 mmc_hostname(slot->mmc));
+		host->state = STATE_SENDING_CMD;
+		dw_mci_start_request(host, slot);
+	} else {
+		dev_vdbg(&host->pdev->dev, "list empty\n");
+		host->state = STATE_IDLE;
+	}
+
+	spin_unlock(&host->lock);
+	mmc_request_done(prev_mmc, mrq);
+	spin_lock(&host->lock);
+}
+
+static void dw_mci_command_complete(struct dw_mci *host, struct mmc_command *cmd)
+{
+	u32 status = host->cmd_status;
+
+	host->cmd_status = 0;
+
+	/* Read the response from the card (up to 16 bytes) */
+	if (cmd->flags & MMC_RSP_PRESENT) {
+		if (cmd->flags & MMC_RSP_136) {
+			cmd->resp[3] = mci_readl(host, RESP0);
+			cmd->resp[2] = mci_readl(host, RESP1);
+			cmd->resp[1] = mci_readl(host, RESP2);
+			cmd->resp[0] = mci_readl(host, RESP3);
+		} else {
+			cmd->resp[0] = mci_readl(host, RESP0);
+			cmd->resp[1] = 0;
+			cmd->resp[2] = 0;
+			cmd->resp[3] = 0;
+		}
+	}
+
+	if (status & SDMMC_INT_RTO)
+		cmd->error = -ETIMEDOUT;
+	else if ((cmd->flags & MMC_RSP_CRC) && (status & SDMMC_INT_RCRC))
+		cmd->error = -EILSEQ;
+	else if (status & SDMMC_INT_RESP_ERR)
+		cmd->error = -EIO;
+	else
+		cmd->error = 0;
+
+	if (cmd->error) {
+		/* newer ip versions need a delay between retries */
+		if (host->quirks & DW_MCI_QUIRK_RETRY_DELAY)
+			mdelay(20);
+
+		if (cmd->data) {
+			host->data = NULL;
+			dw_mci_stop_dma(host);
+		}
+	}
+}
+
+static void dw_mci_tasklet_func(unsigned long priv)
+{
+	struct dw_mci *host = (struct dw_mci *)priv;
+	struct mmc_data	*data;
+	struct mmc_command *cmd;
+	enum dw_mci_state state;
+	enum dw_mci_state prev_state;
+	u32 status;
+
+	spin_lock(&host->lock);
+
+	state = host->state;
+	data = host->data;
+
+	do {
+		prev_state = state;
+
+		switch (state) {
+		case STATE_IDLE:
+			break;
+
+		case STATE_SENDING_CMD:
+			if (!test_and_clear_bit(EVENT_CMD_COMPLETE,
+						&host->pending_events))
+				break;
+
+			cmd = host->cmd;
+			host->cmd = NULL;
+			set_bit(EVENT_CMD_COMPLETE, &host->completed_events);
+			dw_mci_command_complete(host, host->mrq->cmd);
+			if (!host->mrq->data || cmd->error) {
+				dw_mci_request_end(host, host->mrq);
+				goto unlock;
+			}
+
+			prev_state = state = STATE_SENDING_DATA;
+			/* fall through */
+
+		case STATE_SENDING_DATA:
+			if (test_and_clear_bit(EVENT_DATA_ERROR,
+					       &host->pending_events)) {
+				dw_mci_stop_dma(host);
+				if (data->stop)
+					send_stop_cmd(host, data);
+				state = STATE_DATA_ERROR;
+				break;
+			}
+
+			if (!test_and_clear_bit(EVENT_XFER_COMPLETE,
+						&host->pending_events))
+				break;
+
+			set_bit(EVENT_XFER_COMPLETE, &host->completed_events);
+			prev_state = state = STATE_DATA_BUSY;
+			/* fall through */
+
+		case STATE_DATA_BUSY:
+			if (!test_and_clear_bit(EVENT_DATA_COMPLETE,
+						&host->pending_events))
+				break;
+
+			host->data = NULL;
+			set_bit(EVENT_DATA_COMPLETE, &host->completed_events);
+			status = host->data_status;
+
+			if (status & DW_MCI_DATA_ERROR_FLAGS) {
+				if (status & SDMMC_INT_DTO) {
+					dev_err(&host->pdev->dev,
+						"data timeout error\n");
+					data->error = -ETIMEDOUT;
+				} else if (status & SDMMC_INT_DCRC) {
+					dev_err(&host->pdev->dev,
+						"data CRC error\n");
+					data->error = -EILSEQ;
+				} else {
+					dev_err(&host->pdev->dev,
+						"data FIFO error "
+						"(status=%08x)\n",
+						status);
+					data->error = -EIO;
+				}
+			} else {
+				data->bytes_xfered = data->blocks * data->blksz;
+				data->error = 0;
+			}
+
+			if (!data->stop) {
+				dw_mci_request_end(host, host->mrq);
+				goto unlock;
+			}
+
+			prev_state = state = STATE_SENDING_STOP;
+			if (!data->error)
+				send_stop_cmd(host, data);
+			/* fall through */
+
+		case STATE_SENDING_STOP:
+			if (!test_and_clear_bit(EVENT_CMD_COMPLETE,
+						&host->pending_events))
+				break;
+
+			host->cmd = NULL;
+			dw_mci_command_complete(host, host->mrq->stop);
+			dw_mci_request_end(host, host->mrq);
+			goto unlock;
+
+		case STATE_DATA_ERROR:
+			if (!test_and_clear_bit(EVENT_XFER_COMPLETE,
+						&host->pending_events))
+				break;
+
+			state = STATE_DATA_BUSY;
+			break;
+		}
+	} while (state != prev_state);
+
+	host->state = state;
+unlock:
+	spin_unlock(&host->lock);
+
+}
+
+static void dw_mci_push_data16(struct dw_mci *host, void *buf, int cnt)
+{
+	u16 *pdata = (u16 *)buf;
+
+	WARN_ON(cnt % 2 != 0);
+
+	cnt = cnt >> 1;
+	while (cnt > 0) {
+		mci_writew(host, DATA, *pdata++);
+		cnt--;
+	}
+}
+
+static void dw_mci_pull_data16(struct dw_mci *host, void *buf, int cnt)
+{
+	u16 *pdata = (u16 *)buf;
+
+	WARN_ON(cnt % 2 != 0);
+
+	cnt = cnt >> 1;
+	while (cnt > 0) {
+		*pdata++ = mci_readw(host, DATA);
+		cnt--;
+	}
+}
+
+static void dw_mci_push_data32(struct dw_mci *host, void *buf, int cnt)
+{
+	u32 *pdata = (u32 *)buf;
+
+	WARN_ON(cnt % 4 != 0);
+	WARN_ON((unsigned long)pdata & 0x3);
+
+	cnt = cnt >> 2;
+	while (cnt > 0) {
+		mci_writel(host, DATA, *pdata++);
+		cnt--;
+	}
+}
+
+static void dw_mci_pull_data32(struct dw_mci *host, void *buf, int cnt)
+{
+	u32 *pdata = (u32 *)buf;
+
+	WARN_ON(cnt % 4 != 0);
+	WARN_ON((unsigned long)pdata & 0x3);
+
+	cnt = cnt >> 2;
+	while (cnt > 0) {
+		*pdata++ = mci_readl(host, DATA);
+		cnt--;
+	}
+}
+
+static void dw_mci_push_data64(struct dw_mci *host, void *buf, int cnt)
+{
+	u64 *pdata = (u64 *)buf;
+
+	WARN_ON(cnt % 8 != 0);
+
+	cnt = cnt >> 3;
+	while (cnt > 0) {
+		mci_writeq(host, DATA, *pdata++);
+		cnt--;
+	}
+}
+
+static void dw_mci_pull_data64(struct dw_mci *host, void *buf, int cnt)
+{
+	u64 *pdata = (u64 *)buf;
+
+	WARN_ON(cnt % 8 != 0);
+
+	cnt = cnt >> 3;
+	while (cnt > 0) {
+		*pdata++ = mci_readq(host, DATA);
+		cnt--;
+	}
+}
+
+static void dw_mci_read_data_pio(struct dw_mci *host)
+{
+	struct scatterlist *sg = host->sg;
+	void *buf = sg_virt(sg);
+	unsigned int offset = host->pio_offset;
+	struct mmc_data	*data = host->data;
+	int shift = host->data_shift;
+	u32 status;
+	unsigned int nbytes = 0, len, old_len, count = 0;
+
+	do {
+		len = SDMMC_GET_FCNT(mci_readl(host, STATUS)) << shift;
+		if (count == 0)
+			old_len = len;
+
+		if (offset + len <= sg->length) {
+			host->pull_data(host, (void *)(buf + offset), len);
+
+			offset += len;
+			nbytes += len;
+
+			if (offset == sg->length) {
+				flush_dcache_page(sg_page(sg));
+				host->sg = sg = sg_next(sg);
+				if (!sg)
+					goto done;
+
+				offset = 0;
+				buf = sg_virt(sg);
+			}
+		} else {
+			unsigned int remaining = sg->length - offset;
+			host->pull_data(host, (void *)(buf + offset),
+					remaining);
+			nbytes += remaining;
+
+			flush_dcache_page(sg_page(sg));
+			host->sg = sg = sg_next(sg);
+			if (!sg)
+				goto done;
+
+			offset = len - remaining;
+			buf = sg_virt(sg);
+			host->pull_data(host, buf, offset);
+			nbytes += offset;
+		}
+
+		status = mci_readl(host, MINTSTS);
+		mci_writel(host, RINTSTS, SDMMC_INT_RXDR);
+		if (status & DW_MCI_DATA_ERROR_FLAGS) {
+			host->data_status = status;
+			data->bytes_xfered += nbytes;
+			smp_wmb();
+
+			set_bit(EVENT_DATA_ERROR, &host->pending_events);
+
+			tasklet_schedule(&host->tasklet);
+			return;
+		}
+		count++;
+	} while (status & SDMMC_INT_RXDR); /*if the RXDR is ready read again*/
+	len = SDMMC_GET_FCNT(mci_readl(host, STATUS));
+	host->pio_offset = offset;
+	data->bytes_xfered += nbytes;
+	return;
+
+done:
+	data->bytes_xfered += nbytes;
+	smp_wmb();
+	set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
+}
+
+static void dw_mci_write_data_pio(struct dw_mci *host)
+{
+	struct scatterlist *sg = host->sg;
+	void *buf = sg_virt(sg);
+	unsigned int offset = host->pio_offset;
+	struct mmc_data	*data = host->data;
+	int shift = host->data_shift;
+	u32 status;
+	unsigned int nbytes = 0, len;
+
+	do {
+		len = SDMMC_FIFO_SZ -
+			(SDMMC_GET_FCNT(mci_readl(host, STATUS)) << shift);
+		if (offset + len <= sg->length) {
+			host->push_data(host, (void *)(buf + offset), len);
+
+			offset += len;
+			nbytes += len;
+			if (offset == sg->length) {
+				host->sg = sg = sg_next(sg);
+				if (!sg)
+					goto done;
+
+				offset = 0;
+				buf = sg_virt(sg);
+			}
+		} else {
+			unsigned int remaining = sg->length - offset;
+
+			host->push_data(host, (void *)(buf + offset),
+					remaining);
+			nbytes += remaining;
+
+			host->sg = sg = sg_next(sg);
+			if (!sg)
+				goto done;
+
+			offset = len - remaining;
+			buf = sg_virt(sg);
+			host->push_data(host, (void *)buf, offset);
+			nbytes += offset;
+		}
+
+		status = mci_readl(host, MINTSTS);
+		mci_writel(host, RINTSTS, SDMMC_INT_TXDR);
+		if (status & DW_MCI_DATA_ERROR_FLAGS) {
+			host->data_status = status;
+			data->bytes_xfered += nbytes;
+