text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*
   * 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.
   */
  
  #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/iopoll.h>
  #include <linux/ioport.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/pm_runtime.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/card.h>
  #include <linux/mmc/host.h>
  #include <linux/mmc/mmc.h>
  #include <linux/mmc/sd.h>
  #include <linux/mmc/sdio.h>
  #include <linux/bitops.h>
  #include <linux/regulator/consumer.h>
  #include <linux/of.h>
  #include <linux/of_gpio.h>
  #include <linux/mmc/slot-gpio.h>
  
  #include "dw_mmc.h"
  
  /* Common flag combinations */
  #define DW_MCI_DATA_ERROR_FLAGS	(SDMMC_INT_DRTO | SDMMC_INT_DCRC | \
  				 SDMMC_INT_HTO | SDMMC_INT_SBE  | \
  				 SDMMC_INT_EBE | SDMMC_INT_HLE)
  #define DW_MCI_CMD_ERROR_FLAGS	(SDMMC_INT_RTO | SDMMC_INT_RCRC | \
  				 SDMMC_INT_RESP_ERR | SDMMC_INT_HLE)
  #define DW_MCI_ERROR_FLAGS	(DW_MCI_DATA_ERROR_FLAGS | \
  				 DW_MCI_CMD_ERROR_FLAGS)
  #define DW_MCI_SEND_STATUS	1
  #define DW_MCI_RECV_STATUS	2
  #define DW_MCI_DMA_THRESHOLD	16
  
  #define DW_MCI_FREQ_MAX	200000000	/* unit: HZ */
  #define DW_MCI_FREQ_MIN	100000		/* unit: HZ */
  
  #define IDMAC_INT_CLR		(SDMMC_IDMAC_INT_AI | SDMMC_IDMAC_INT_NI | \
  				 SDMMC_IDMAC_INT_CES | SDMMC_IDMAC_INT_DU | \
  				 SDMMC_IDMAC_INT_FBE | SDMMC_IDMAC_INT_RI | \
  				 SDMMC_IDMAC_INT_TI)
  
  #define DESC_RING_BUF_SZ	PAGE_SIZE
  
  struct idmac_desc_64addr {
  	u32		des0;	/* Control Descriptor */
  #define IDMAC_OWN_CLR64(x) \
  	!((x) & cpu_to_le32(IDMAC_DES0_OWN))
  
  	u32		des1;	/* Reserved */
  
  	u32		des2;	/*Buffer sizes */
  #define IDMAC_64ADDR_SET_BUFFER1_SIZE(d, s) \
  	((d)->des2 = ((d)->des2 & cpu_to_le32(0x03ffe000)) | \
  	 ((cpu_to_le32(s)) & cpu_to_le32(0x1fff)))
  
  	u32		des3;	/* Reserved */
  
  	u32		des4;	/* Lower 32-bits of Buffer Address Pointer 1*/
  	u32		des5;	/* Upper 32-bits of Buffer Address Pointer 1*/
  
  	u32		des6;	/* Lower 32-bits of Next Descriptor Address */
  	u32		des7;	/* Upper 32-bits of Next Descriptor Address */
  };
  
  struct idmac_desc {
  	__le32		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)
  
  	__le32		des1;	/* Buffer sizes */
  #define IDMAC_SET_BUFFER1_SIZE(d, s) \
  	((d)->des1 = ((d)->des1 & cpu_to_le32(0x03ffe000)) | (cpu_to_le32((s) & 0x1fff)))
  
  	__le32		des2;	/* buffer 1 physical address */
  
  	__le32		des3;	/* buffer 2 physical address */
  };
  
  /* Each descriptor can transfer up to 4KB of data in chained mode */
  #define DW_MCI_DESC_DATA_LENGTH	0x1000
  
  #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;
  }
  DEFINE_SHOW_ATTRIBUTE(dw_mci_req);
  
  static int dw_mci_regs_show(struct seq_file *s, void *v)
  {
  	struct dw_mci *host = s->private;
  
  	pm_runtime_get_sync(host->dev);
  
  	seq_printf(s, "STATUS:\t0x%08x\n", mci_readl(host, STATUS));
  	seq_printf(s, "RINTSTS:\t0x%08x\n", mci_readl(host, RINTSTS));
  	seq_printf(s, "CMD:\t0x%08x\n", mci_readl(host, CMD));
  	seq_printf(s, "CTRL:\t0x%08x\n", mci_readl(host, CTRL));
  	seq_printf(s, "INTMASK:\t0x%08x\n", mci_readl(host, INTMASK));
  	seq_printf(s, "CLKENA:\t0x%08x\n", mci_readl(host, CLKENA));
  
  	pm_runtime_put_autosuspend(host->dev);
  
  	return 0;
  }
  DEFINE_SHOW_ATTRIBUTE(dw_mci_regs);
  
  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;
  
  	root = mmc->debugfs_root;
  	if (!root)
  		return;
  
  	debugfs_create_file("regs", S_IRUSR, root, host, &dw_mci_regs_fops);
  	debugfs_create_file("req", S_IRUSR, root, slot, &dw_mci_req_fops);
  	debugfs_create_u32("state", S_IRUSR, root, &host->state);
  	debugfs_create_xul("pending_events", S_IRUSR, root,
  			   &host->pending_events);
  	debugfs_create_xul("completed_events", S_IRUSR, root,
  			   &host->completed_events);
  }
  #endif /* defined(CONFIG_DEBUG_FS) */
  
  static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset)
  {
  	u32 ctrl;
  
  	ctrl = mci_readl(host, CTRL);
  	ctrl |= reset;
  	mci_writel(host, CTRL, ctrl);
  
  	/* wait till resets clear */
  	if (readl_poll_timeout_atomic(host->regs + SDMMC_CTRL, ctrl,
  				      !(ctrl & reset),
  				      1, 500 * USEC_PER_MSEC)) {
  		dev_err(host->dev,
  			"Timeout resetting block (ctrl reset %#x)\n",
  			ctrl & reset);
  		return false;
  	}
  
  	return true;
  }
  
  static void dw_mci_wait_while_busy(struct dw_mci *host, u32 cmd_flags)
  {
  	u32 status;
  
  	/*
  	 * Databook says that before issuing a new data transfer command
  	 * we need to check to see if the card is busy.  Data transfer commands
  	 * all have SDMMC_CMD_PRV_DAT_WAIT set, so we'll key off that.
  	 *
  	 * ...also allow sending for SDMMC_CMD_VOLT_SWITCH where busy is
  	 * expected.
  	 */
  	if ((cmd_flags & SDMMC_CMD_PRV_DAT_WAIT) &&
  	    !(cmd_flags & SDMMC_CMD_VOLT_SWITCH)) {
  		if (readl_poll_timeout_atomic(host->regs + SDMMC_STATUS,
  					      status,
  					      !(status & SDMMC_STATUS_BUSY),
  					      10, 500 * USEC_PER_MSEC))
  			dev_err(host->dev, "Busy; trying anyway\n");
  	}
  }
  
  static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
  {
  	struct dw_mci *host = slot->host;
  	unsigned int cmd_status = 0;
  
  	mci_writel(host, CMDARG, arg);
  	wmb(); /* drain writebuffer */
  	dw_mci_wait_while_busy(host, cmd);
  	mci_writel(host, CMD, SDMMC_CMD_START | cmd);
  
  	if (readl_poll_timeout_atomic(host->regs + SDMMC_CMD, cmd_status,
  				      !(cmd_status & SDMMC_CMD_START),
  				      1, 500 * USEC_PER_MSEC))
  		dev_err(&slot->mmc->class_dev,
  			"Timeout sending command (cmd %#x arg %#x status %#x)\n",
  			cmd, arg, cmd_status);
  }
  
  static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	struct dw_mci *host = slot->host;
  	u32 cmdr;
  
  	cmd->error = -EINPROGRESS;
  	cmdr = cmd->opcode;
  
  	if (cmd->opcode == MMC_STOP_TRANSMISSION ||
  	    cmd->opcode == MMC_GO_IDLE_STATE ||
  	    cmd->opcode == MMC_GO_INACTIVE_STATE ||
  	    (cmd->opcode == SD_IO_RW_DIRECT &&
  	     ((cmd->arg >> 9) & 0x1FFFF) == SDIO_CCCR_ABORT))
  		cmdr |= SDMMC_CMD_STOP;
  	else if (cmd->opcode != MMC_SEND_STATUS && cmd->data)
  		cmdr |= SDMMC_CMD_PRV_DAT_WAIT;
  
  	if (cmd->opcode == SD_SWITCH_VOLTAGE) {
  		u32 clk_en_a;
  
  		/* Special bit makes CMD11 not die */
  		cmdr |= SDMMC_CMD_VOLT_SWITCH;
  
  		/* Change state to continue to handle CMD11 weirdness */
  		WARN_ON(slot->host->state != STATE_SENDING_CMD);
  		slot->host->state = STATE_SENDING_CMD11;
  
  		/*
  		 * We need to disable low power mode (automatic clock stop)
  		 * while doing voltage switch so we don't confuse the card,
  		 * since stopping the clock is a specific part of the UHS
  		 * voltage change dance.
  		 *
  		 * Note that low power mode (SDMMC_CLKEN_LOW_PWR) will be
  		 * unconditionally turned back on in dw_mci_setup_bus() if it's
  		 * ever called with a non-zero clock.  That shouldn't happen
  		 * until the voltage change is all done.
  		 */
  		clk_en_a = mci_readl(host, CLKENA);
  		clk_en_a &= ~(SDMMC_CLKEN_LOW_PWR << slot->id);
  		mci_writel(host, CLKENA, clk_en_a);
  		mci_send_cmd(slot, SDMMC_CMD_UPD_CLK |
  			     SDMMC_CMD_PRV_DAT_WAIT, 0);
  	}
  
  	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;
  
  	if (cmd->data) {
  		cmdr |= SDMMC_CMD_DAT_EXP;
  		if (cmd->data->flags & MMC_DATA_WRITE)
  			cmdr |= SDMMC_CMD_DAT_WR;
  	}
  
  	if (!test_bit(DW_MMC_CARD_NO_USE_HOLD, &slot->flags))
  		cmdr |= SDMMC_CMD_USE_HOLD_REG;
  
  	return cmdr;
  }
  
  static u32 dw_mci_prep_stop_abort(struct dw_mci *host, struct mmc_command *cmd)
  {
  	struct mmc_command *stop;
  	u32 cmdr;
  
  	if (!cmd->data)
  		return 0;
  
  	stop = &host->stop_abort;
  	cmdr = cmd->opcode;
  	memset(stop, 0, sizeof(struct mmc_command));
  
  	if (cmdr == MMC_READ_SINGLE_BLOCK ||
  	    cmdr == MMC_READ_MULTIPLE_BLOCK ||
  	    cmdr == MMC_WRITE_BLOCK ||
  	    cmdr == MMC_WRITE_MULTIPLE_BLOCK ||
  	    cmdr == MMC_SEND_TUNING_BLOCK ||
  	    cmdr == MMC_SEND_TUNING_BLOCK_HS200) {
  		stop->opcode = MMC_STOP_TRANSMISSION;
  		stop->arg = 0;
  		stop->flags = MMC_RSP_R1B | MMC_CMD_AC;
  	} else if (cmdr == SD_IO_RW_EXTENDED) {
  		stop->opcode = SD_IO_RW_DIRECT;
  		stop->arg |= (1 << 31) | (0 << 28) | (SDIO_CCCR_ABORT << 9) |
  			     ((cmd->arg >> 28) & 0x7);
  		stop->flags = MMC_RSP_SPI_R5 | MMC_RSP_R5 | MMC_CMD_AC;
  	} else {
  		return 0;
  	}
  
  	cmdr = stop->opcode | SDMMC_CMD_STOP |
  		SDMMC_CMD_RESP_CRC | SDMMC_CMD_RESP_EXP;
  
  	if (!test_bit(DW_MMC_CARD_NO_USE_HOLD, &host->slot->flags))
  		cmdr |= SDMMC_CMD_USE_HOLD_REG;
  
  	return cmdr;
  }
  
  static inline void dw_mci_set_cto(struct dw_mci *host)
  {
  	unsigned int cto_clks;
  	unsigned int cto_div;
  	unsigned int cto_ms;
  	unsigned long irqflags;
  
  	cto_clks = mci_readl(host, TMOUT) & 0xff;
  	cto_div = (mci_readl(host, CLKDIV) & 0xff) * 2;
  	if (cto_div == 0)
  		cto_div = 1;
  
  	cto_ms = DIV_ROUND_UP_ULL((u64)MSEC_PER_SEC * cto_clks * cto_div,
  				  host->bus_hz);
  
  	/* add a bit spare time */
  	cto_ms += 10;
  
  	/*
  	 * The durations we're working with are fairly short so we have to be
  	 * extra careful about synchronization here.  Specifically in hardware a
  	 * command timeout is _at most_ 5.1 ms, so that means we expect an
  	 * interrupt (either command done or timeout) to come rather quickly
  	 * after the mci_writel.  ...but just in case we have a long interrupt
  	 * latency let's add a bit of paranoia.
  	 *
  	 * In general we'll assume that at least an interrupt will be asserted
  	 * in hardware by the time the cto_timer runs.  ...and if it hasn't
  	 * been asserted in hardware by that time then we'll assume it'll never
  	 * come.
  	 */
  	spin_lock_irqsave(&host->irq_lock, irqflags);
  	if (!test_bit(EVENT_CMD_COMPLETE, &host->pending_events))
  		mod_timer(&host->cto_timer,
  			jiffies + msecs_to_jiffies(cto_ms) + 1);
  	spin_unlock_irqrestore(&host->irq_lock, irqflags);
  }
  
  static void dw_mci_start_command(struct dw_mci *host,
  				 struct mmc_command *cmd, u32 cmd_flags)
  {
  	host->cmd = cmd;
  	dev_vdbg(host->dev,
  		 "start command: ARGR=0x%08x CMDR=0x%08x\n",
  		 cmd->arg, cmd_flags);
  
  	mci_writel(host, CMDARG, cmd->arg);
  	wmb(); /* drain writebuffer */
  	dw_mci_wait_while_busy(host, cmd_flags);
  
  	mci_writel(host, CMD, cmd_flags | SDMMC_CMD_START);
  
  	/* response expected command only */
  	if (cmd_flags & SDMMC_CMD_RESP_EXP)
  		dw_mci_set_cto(host);
  }
  
  static inline void send_stop_abort(struct dw_mci *host, struct mmc_data *data)
  {
  	struct mmc_command *stop = &host->stop_abort;
  
  	dw_mci_start_command(host, stop, host->stop_cmdr);
  }
  
  /* DMA interface functions */
  static void dw_mci_stop_dma(struct dw_mci *host)
  {
  	if (host->using_dma) {
  		host->dma_ops->stop(host);
  		host->dma_ops->cleanup(host);
  	}
  
  	/* Data transfer was stopped by the interrupt handler */
  	set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
  }
  
  static void dw_mci_dma_cleanup(struct dw_mci *host)
  {
  	struct mmc_data *data = host->data;
  
  	if (data && data->host_cookie == COOKIE_MAPPED) {
  		dma_unmap_sg(host->dev,
  			     data->sg,
  			     data->sg_len,
  			     mmc_get_dma_dir(data));
  		data->host_cookie = COOKIE_UNMAPPED;
  	}
  }
  
  static void dw_mci_idmac_reset(struct dw_mci *host)
  {
  	u32 bmod = mci_readl(host, BMOD);
  	/* Software reset of DMA */
  	bmod |= SDMMC_IDMAC_SWRESET;
  	mci_writel(host, BMOD, bmod);
  }
  
  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 | SDMMC_IDMAC_FB);
  	temp |= SDMMC_IDMAC_SWRESET;
  	mci_writel(host, BMOD, temp);
  }
  
  static void dw_mci_dmac_complete_dma(void *arg)
  {
  	struct dw_mci *host = arg;
  	struct mmc_data *data = host->data;
  
  	dev_vdbg(host->dev, "DMA complete\n");
  
  	if ((host->use_dma == TRANS_MODE_EDMAC) &&
  	    data && (data->flags & MMC_DATA_READ))
  		/* Invalidate cache after read */
  		dma_sync_sg_for_cpu(mmc_dev(host->slot->mmc),
  				    data->sg,
  				    data->sg_len,
  				    DMA_FROM_DEVICE);
  
  	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 int dw_mci_idmac_init(struct dw_mci *host)
  {
  	int i;
  
  	if (host->dma_64bit_address == 1) {
  		struct idmac_desc_64addr *p;
  		/* Number of descriptors in the ring buffer */
  		host->ring_size =
  			DESC_RING_BUF_SZ / sizeof(struct idmac_desc_64addr);
  
  		/* Forward link the descriptor list */
  		for (i = 0, p = host->sg_cpu; i < host->ring_size - 1;
  								i++, p++) {
  			p->des6 = (host->sg_dma +
  					(sizeof(struct idmac_desc_64addr) *
  							(i + 1))) & 0xffffffff;
  
  			p->des7 = (u64)(host->sg_dma +
  					(sizeof(struct idmac_desc_64addr) *
  							(i + 1))) >> 32;
  			/* Initialize reserved and buffer size fields to "0" */
  			p->des0 = 0;
  			p->des1 = 0;
  			p->des2 = 0;
  			p->des3 = 0;
  		}
  
  		/* Set the last descriptor as the end-of-ring descriptor */
  		p->des6 = host->sg_dma & 0xffffffff;
  		p->des7 = (u64)host->sg_dma >> 32;
  		p->des0 = IDMAC_DES0_ER;
  
  	} else {
  		struct idmac_desc *p;
  		/* Number of descriptors in the ring buffer */
  		host->ring_size =
  			DESC_RING_BUF_SZ / 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 = cpu_to_le32(host->sg_dma +
  					(sizeof(struct idmac_desc) * (i + 1)));
  			p->des0 = 0;
  			p->des1 = 0;
  		}
  
  		/* Set the last descriptor as the end-of-ring descriptor */
  		p->des3 = cpu_to_le32(host->sg_dma);
  		p->des0 = cpu_to_le32(IDMAC_DES0_ER);
  	}
  
  	dw_mci_idmac_reset(host);
  
  	if (host->dma_64bit_address == 1) {
  		/* Mask out interrupts - get Tx & Rx complete only */
  		mci_writel(host, IDSTS64, IDMAC_INT_CLR);
  		mci_writel(host, IDINTEN64, SDMMC_IDMAC_INT_NI |
  				SDMMC_IDMAC_INT_RI | SDMMC_IDMAC_INT_TI);
  
  		/* Set the descriptor base address */
  		mci_writel(host, DBADDRL, host->sg_dma & 0xffffffff);
  		mci_writel(host, DBADDRU, (u64)host->sg_dma >> 32);
  
  	} else {
  		/* Mask out interrupts - get Tx & Rx complete only */
  		mci_writel(host, IDSTS, IDMAC_INT_CLR);
  		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 inline int dw_mci_prepare_desc64(struct dw_mci *host,
  					 struct mmc_data *data,
  					 unsigned int sg_len)
  {
  	unsigned int desc_len;
  	struct idmac_desc_64addr *desc_first, *desc_last, *desc;
  	u32 val;
  	int i;
  
  	desc_first = desc_last = desc = host->sg_cpu;
  
  	for (i = 0; i < sg_len; i++) {
  		unsigned int length = sg_dma_len(&data->sg[i]);
  
  		u64 mem_addr = sg_dma_address(&data->sg[i]);
  
  		for ( ; length ; desc++) {
  			desc_len = (length <= DW_MCI_DESC_DATA_LENGTH) ?
  				   length : DW_MCI_DESC_DATA_LENGTH;
  
  			length -= desc_len;
  
  			/*
  			 * Wait for the former clear OWN bit operation
  			 * of IDMAC to make sure that this descriptor
  			 * isn't still owned by IDMAC as IDMAC's write
  			 * ops and CPU's read ops are asynchronous.
  			 */
  			if (readl_poll_timeout_atomic(&desc->des0, val,
  						!(val & IDMAC_DES0_OWN),
  						10, 100 * USEC_PER_MSEC))
  				goto err_own_bit;
  
  			/*
  			 * Set the OWN bit and disable interrupts
  			 * for this descriptor
  			 */
  			desc->des0 = IDMAC_DES0_OWN | IDMAC_DES0_DIC |
  						IDMAC_DES0_CH;
  
  			/* Buffer length */
  			IDMAC_64ADDR_SET_BUFFER1_SIZE(desc, desc_len);
  
  			/* Physical address to DMA to/from */
  			desc->des4 = mem_addr & 0xffffffff;
  			desc->des5 = mem_addr >> 32;
  
  			/* Update physical address for the next desc */
  			mem_addr += desc_len;
  
  			/* Save pointer to the last descriptor */
  			desc_last = desc;
  		}
  	}
  
  	/* Set first descriptor */
  	desc_first->des0 |= IDMAC_DES0_FD;
  
  	/* Set last descriptor */
  	desc_last->des0 &= ~(IDMAC_DES0_CH | IDMAC_DES0_DIC);
  	desc_last->des0 |= IDMAC_DES0_LD;
  
  	return 0;
  err_own_bit:
  	/* restore the descriptor chain as it's polluted */
  	dev_dbg(host->dev, "descriptor is still owned by IDMAC.\n");
  	memset(host->sg_cpu, 0, DESC_RING_BUF_SZ);
  	dw_mci_idmac_init(host);
  	return -EINVAL;
  }
  
  
  static inline int dw_mci_prepare_desc32(struct dw_mci *host,
  					 struct mmc_data *data,
  					 unsigned int sg_len)
  {
  	unsigned int desc_len;
  	struct idmac_desc *desc_first, *desc_last, *desc;
  	u32 val;
  	int i;
  
  	desc_first = desc_last = desc = host->sg_cpu;
  
  	for (i = 0; i < sg_len; i++) {
  		unsigned int length = sg_dma_len(&data->sg[i]);
  
  		u32 mem_addr = sg_dma_address(&data->sg[i]);
  
  		for ( ; length ; desc++) {
  			desc_len = (length <= DW_MCI_DESC_DATA_LENGTH) ?
  				   length : DW_MCI_DESC_DATA_LENGTH;
  
  			length -= desc_len;
  
  			/*
  			 * Wait for the former clear OWN bit operation
  			 * of IDMAC to make sure that this descriptor
  			 * isn't still owned by IDMAC as IDMAC's write
  			 * ops and CPU's read ops are asynchronous.
  			 */
  			if (readl_poll_timeout_atomic(&desc->des0, val,
  						      IDMAC_OWN_CLR64(val),
  						      10,
  						      100 * USEC_PER_MSEC))
  				goto err_own_bit;
  
  			/*
  			 * Set the OWN bit and disable interrupts
  			 * for this descriptor
  			 */
  			desc->des0 = cpu_to_le32(IDMAC_DES0_OWN |
  						 IDMAC_DES0_DIC |
  						 IDMAC_DES0_CH);
  
  			/* Buffer length */
  			IDMAC_SET_BUFFER1_SIZE(desc, desc_len);
  
  			/* Physical address to DMA to/from */
  			desc->des2 = cpu_to_le32(mem_addr);
  
  			/* Update physical address for the next desc */
  			mem_addr += desc_len;
  
  			/* Save pointer to the last descriptor */
  			desc_last = desc;
  		}
  	}
  
  	/* Set first descriptor */
  	desc_first->des0 |= cpu_to_le32(IDMAC_DES0_FD);
  
  	/* Set last descriptor */
  	desc_last->des0 &= cpu_to_le32(~(IDMAC_DES0_CH |
  				       IDMAC_DES0_DIC));
  	desc_last->des0 |= cpu_to_le32(IDMAC_DES0_LD);
  
  	return 0;
  err_own_bit:
  	/* restore the descriptor chain as it's polluted */
  	dev_dbg(host->dev, "descriptor is still owned by IDMAC.\n");
  	memset(host->sg_cpu, 0, DESC_RING_BUF_SZ);
  	dw_mci_idmac_init(host);
  	return -EINVAL;
  }
  
  static int dw_mci_idmac_start_dma(struct dw_mci *host, unsigned int sg_len)
  {
  	u32 temp;
  	int ret;
  
  	if (host->dma_64bit_address == 1)
  		ret = dw_mci_prepare_desc64(host, host->data, sg_len);
  	else
  		ret = dw_mci_prepare_desc32(host, host->data, sg_len);
  
  	if (ret)
  		goto out;
  
  	/* drain writebuffer */
  	wmb();
  
  	/* Make sure to reset DMA in case we did PIO before this */
  	dw_mci_ctrl_reset(host, SDMMC_CTRL_DMA_RESET);
  	dw_mci_idmac_reset(host);
  
  	/* Select IDMAC interface */
  	temp = mci_readl(host, CTRL);
  	temp |= SDMMC_CTRL_USE_IDMAC;
  	mci_writel(host, CTRL, temp);
  
  	/* drain writebuffer */
  	wmb();
  
  	/* Enable the IDMAC */
  	temp = mci_readl(host, BMOD);
  	temp |= SDMMC_IDMAC_ENABLE | SDMMC_IDMAC_FB;
  	mci_writel(host, BMOD, temp);
  
  	/* Start it running */
  	mci_writel(host, PLDMND, 1);
  
  out:
  	return ret;
  }
  
  static const 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_dmac_complete_dma,
  	.cleanup = dw_mci_dma_cleanup,
  };
  
  static void dw_mci_edmac_stop_dma(struct dw_mci *host)
  {
  	dmaengine_terminate_async(host->dms->ch);
  }
  
  static int dw_mci_edmac_start_dma(struct dw_mci *host,
  					    unsigned int sg_len)
  {
  	struct dma_slave_config cfg;
  	struct dma_async_tx_descriptor *desc = NULL;
  	struct scatterlist *sgl = host->data->sg;
  	static const u32 mszs[] = {1, 4, 8, 16, 32, 64, 128, 256};
  	u32 sg_elems = host->data->sg_len;
  	u32 fifoth_val;
  	u32 fifo_offset = host->fifo_reg - host->regs;
  	int ret = 0;
  
  	/* Set external dma config: burst size, burst width */
  	cfg.dst_addr = host->phy_regs + fifo_offset;
  	cfg.src_addr = cfg.dst_addr;
  	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
  	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
  
  	/* Match burst msize with external dma config */
  	fifoth_val = mci_readl(host, FIFOTH);
  	cfg.dst_maxburst = mszs[(fifoth_val >> 28) & 0x7];
  	cfg.src_maxburst = cfg.dst_maxburst;
  
  	if (host->data->flags & MMC_DATA_WRITE)
  		cfg.direction = DMA_MEM_TO_DEV;
  	else
  		cfg.direction = DMA_DEV_TO_MEM;
  
  	ret = dmaengine_slave_config(host->dms->ch, &cfg);
  	if (ret) {
  		dev_err(host->dev, "Failed to config edmac.\n");
  		return -EBUSY;
  	}
  
  	desc = dmaengine_prep_slave_sg(host->dms->ch, sgl,
  				       sg_len, cfg.direction,
  				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
  	if (!desc) {
  		dev_err(host->dev, "Can't prepare slave sg.\n");
  		return -EBUSY;
  	}
  
  	/* Set dw_mci_dmac_complete_dma as callback */
  	desc->callback = dw_mci_dmac_complete_dma;
  	desc->callback_param = (void *)host;
  	dmaengine_submit(desc);
  
  	/* Flush cache before write */
  	if (host->data->flags & MMC_DATA_WRITE)
  		dma_sync_sg_for_device(mmc_dev(host->slot->mmc), sgl,
  				       sg_elems, DMA_TO_DEVICE);
  
  	dma_async_issue_pending(host->dms->ch);
  
  	return 0;
  }
  
  static int dw_mci_edmac_init(struct dw_mci *host)
  {
  	/* Request external dma channel */
  	host->dms = kzalloc(sizeof(struct dw_mci_dma_slave), GFP_KERNEL);
  	if (!host->dms)
  		return -ENOMEM;
  
  	host->dms->ch = dma_request_chan(host->dev, "rx-tx");
  	if (IS_ERR(host->dms->ch)) {
  		int ret = PTR_ERR(host->dms->ch);
  
  		dev_err(host->dev, "Failed to get external DMA channel.\n");
  		kfree(host->dms);
  		host->dms = NULL;
  		return ret;
  	}
  
  	return 0;
  }
  
  static void dw_mci_edmac_exit(struct dw_mci *host)
  {
  	if (host->dms) {
  		if (host->dms->ch) {
  			dma_release_channel(host->dms->ch);
  			host->dms->ch = NULL;
  		}
  		kfree(host->dms);
  		host->dms = NULL;
  	}
  }
  
  static const struct dw_mci_dma_ops dw_mci_edmac_ops = {
  	.init = dw_mci_edmac_init,
  	.exit = dw_mci_edmac_exit,
  	.start = dw_mci_edmac_start_dma,
  	.stop = dw_mci_edmac_stop_dma,
  	.complete = dw_mci_dmac_complete_dma,
  	.cleanup = dw_mci_dma_cleanup,
  };
  
  static int dw_mci_pre_dma_transfer(struct dw_mci *host,
  				   struct mmc_data *data,
  				   int cookie)
  {
  	struct scatterlist *sg;
  	unsigned int i, sg_len;
  
  	if (data->host_cookie == COOKIE_PRE_MAPPED)
  		return data->sg_len;
  
  	/*
  	 * 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;
  	}
  
  	sg_len = dma_map_sg(host->dev,
  			    data->sg,
  			    data->sg_len,
  			    mmc_get_dma_dir(data));
  	if (sg_len == 0)
  		return -EINVAL;
  
  	data->host_cookie = cookie;
  
  	return sg_len;
  }
  
  static void dw_mci_pre_req(struct mmc_host *mmc,
  			   struct mmc_request *mrq)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	struct mmc_data *data = mrq->data;
  
  	if (!slot->host->use_dma || !data)
  		return;
  
  	/* This data might be unmapped at this time */
  	data->host_cookie = COOKIE_UNMAPPED;
  
  	if (dw_mci_pre_dma_transfer(slot->host, mrq->data,
  				COOKIE_PRE_MAPPED) < 0)
  		data->host_cookie = COOKIE_UNMAPPED;
  }
  
  static void dw_mci_post_req(struct mmc_host *mmc,
  			    struct mmc_request *mrq,
  			    int err)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	struct mmc_data *data = mrq->data;
  
  	if (!slot->host->use_dma || !data)
  		return;
  
  	if (data->host_cookie != COOKIE_UNMAPPED)
  		dma_unmap_sg(slot->host->dev,
  			     data->sg,
  			     data->sg_len,
  			     mmc_get_dma_dir(data));
  	data->host_cookie = COOKIE_UNMAPPED;
  }
  
  static int dw_mci_get_cd(struct mmc_host *mmc)
  {
  	int present;
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	struct dw_mci *host = slot->host;
  	int gpio_cd = mmc_gpio_get_cd(mmc);
  
  	/* Use platform get_cd function, else try onboard card detect */
  	if (((mmc->caps & MMC_CAP_NEEDS_POLL)
  				|| !mmc_card_is_removable(mmc))) {
  		present = 1;
  
  		if (!test_bit(DW_MMC_CARD_PRESENT, &slot->flags)) {
  			if (mmc->caps & MMC_CAP_NEEDS_POLL) {
  				dev_info(&mmc->class_dev,
  					"card is polling.\n");
  			} else {
  				dev_info(&mmc->class_dev,
  					"card is non-removable.\n");
  			}
  			set_bit(DW_MMC_CARD_PRESENT, &slot->flags);
  		}
  
  		return present;
  	} else if (gpio_cd >= 0)
  		present = gpio_cd;
  	else
  		present = (mci_readl(slot->host, CDETECT) & (1 << slot->id))
  			== 0 ? 1 : 0;
  
  	spin_lock_bh(&host->lock);
  	if (present && !test_and_set_bit(DW_MMC_CARD_PRESENT, &slot->flags))
  		dev_dbg(&mmc->class_dev, "card is present\n");
  	else if (!present &&
  			!test_and_clear_bit(DW_MMC_CARD_PRESENT, &slot->flags))
  		dev_dbg(&mmc->class_dev, "card is not present\n");
  	spin_unlock_bh(&host->lock);
  
  	return present;
  }
  
  static void dw_mci_adjust_fifoth(struct dw_mci *host, struct mmc_data *data)
  {
  	unsigned int blksz = data->blksz;
  	static const u32 mszs[] = {1, 4, 8, 16, 32, 64, 128, 256};
  	u32 fifo_width = 1 << host->data_shift;
  	u32 blksz_depth = blksz / fifo_width, fifoth_val;
  	u32 msize = 0, rx_wmark = 1, tx_wmark, tx_wmark_invers;
  	int idx = ARRAY_SIZE(mszs) - 1;
  
  	/* pio should ship this scenario */
  	if (!host->use_dma)
  		return;
  
  	tx_wmark = (host->fifo_depth) / 2;
  	tx_wmark_invers = host->fifo_depth - tx_wmark;
  
  	/*
  	 * MSIZE is '1',
  	 * if blksz is not a multiple of the FIFO width
  	 */
  	if (blksz % fifo_width)
  		goto done;
  
  	do {
  		if (!((blksz_depth % mszs[idx]) ||
  		     (tx_wmark_invers % mszs[idx]))) {
  			msize = idx;
  			rx_wmark = mszs[idx] - 1;
  			break;
  		}
  	} while (--idx > 0);
  	/*
  	 * If idx is '0', it won't be tried
  	 * Thus, initial values are uesed
  	 */
  done:
  	fifoth_val = SDMMC_SET_FIFOTH(msize, rx_wmark, tx_wmark);
  	mci_writel(host, FIFOTH, fifoth_val);
  }
  
  static void dw_mci_ctrl_thld(struct dw_mci *host, struct mmc_data *data)
  {
  	unsigned int blksz = data->blksz;
  	u32 blksz_depth, fifo_depth;
  	u16 thld_size;
  	u8 enable;
  
  	/*
  	 * CDTHRCTL doesn't exist prior to 240A (in fact that register offset is
  	 * in the FIFO region, so we really shouldn't access it).
  	 */
  	if (host->verid < DW_MMC_240A ||
  		(host->verid < DW_MMC_280A && data->flags & MMC_DATA_WRITE))
  		return;
  
  	/*
  	 * Card write Threshold is introduced since 2.80a
  	 * It's used when HS400 mode is enabled.
  	 */
  	if (data->flags & MMC_DATA_WRITE &&
  		host->timing != MMC_TIMING_MMC_HS400)
  		goto disable;
  
  	if (data->flags & MMC_DATA_WRITE)
  		enable = SDMMC_CARD_WR_THR_EN;
  	else
  		enable = SDMMC_CARD_RD_THR_EN;
  
  	if (host->timing != MMC_TIMING_MMC_HS200 &&
  	    host->timing != MMC_TIMING_UHS_SDR104 &&
  	    host->timing != MMC_TIMING_MMC_HS400)
  		goto disable;
  
  	blksz_depth = blksz / (1 << host->data_shift);
  	fifo_depth = host->fifo_depth;
  
  	if (blksz_depth > fifo_depth)
  		goto disable;
  
  	/*
  	 * If (blksz_depth) >= (fifo_depth >> 1), should be 'thld_size <= blksz'
  	 * If (blksz_depth) <  (fifo_depth >> 1), should be thld_size = blksz
  	 * Currently just choose blksz.
  	 */
  	thld_size = blksz;
  	mci_writel(host, CDTHRCTL, SDMMC_SET_THLD(thld_size, enable));
  	return;
  
  disable:
  	mci_writel(host, CDTHRCTL, 0);
  }
  
  static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
  {
  	unsigned long irqflags;
  	int sg_len;
  	u32 temp;
  
  	host->using_dma = 0;
  
  	/* If we don't have a channel, we can't do DMA */
  	if (!host->use_dma)
  		return -ENODEV;
  
  	sg_len = dw_mci_pre_dma_transfer(host, data, COOKIE_MAPPED);
  	if (sg_len < 0) {
  		host->dma_ops->stop(host);
  		return sg_len;
  	}
  
  	host->using_dma = 1;
  
  	if (host->use_dma == TRANS_MODE_IDMAC)
  		dev_vdbg(host->dev,
  			 "sd sg_cpu: %#lx sg_dma: %#lx sg_len: %d\n",
  			 (unsigned long)host->sg_cpu,
  			 (unsigned long)host->sg_dma,
  			 sg_len);
  
  	/*
  	 * Decide the MSIZE and RX/TX Watermark.
  	 * If current block size is same with previous size,
  	 * no need to update fifoth.
  	 */
  	if (host->prev_blksz != data->blksz)
  		dw_mci_adjust_fifoth(host, data);
  
  	/* 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 */
  	spin_lock_irqsave(&host->irq_lock, irqflags);
  	temp = mci_readl(host, INTMASK);
  	temp  &= ~(SDMMC_INT_RXDR | SDMMC_INT_TXDR);
  	mci_writel(host, INTMASK, temp);
  	spin_unlock_irqrestore(&host->irq_lock, irqflags);
  
  	if (host->dma_ops->start(host, sg_len)) {
  		host->dma_ops->stop(host);
  		/* We can't do DMA, try PIO for this one */
  		dev_dbg(host->dev,
  			"%s: fall back to PIO mode for current transfer\n",
  			__func__);
  		return -ENODEV;
  	}
  
  	return 0;
  }
  
  static void dw_mci_submit_data(struct dw_mci *host, struct mmc_data *data)
  {
  	unsigned long irqflags;
  	int flags = SG_MITER_ATOMIC;
  	u32 temp;
  
  	data->error = -EINPROGRESS;
  
  	WARN_ON(host->data);
  	host->sg = NULL;
  	host->data = data;
  
  	if (data->flags & MMC_DATA_READ)
  		host->dir_status = DW_MCI_RECV_STATUS;
  	else
  		host->dir_status = DW_MCI_SEND_STATUS;
  
  	dw_mci_ctrl_thld(host, data);
  
  	if (dw_mci_submit_data_dma(host, data)) {
  		if (host->data->flags & MMC_DATA_READ)
  			flags |= SG_MITER_TO_SG;
  		else
  			flags |= SG_MITER_FROM_SG;
  
  		sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
  		host->sg = data->sg;
  		host->part_buf_start = 0;
  		host->part_buf_count = 0;
  
  		mci_writel(host, RINTSTS, SDMMC_INT_TXDR | SDMMC_INT_RXDR);
  
  		spin_lock_irqsave(&host->irq_lock, irqflags);
  		temp = mci_readl(host, INTMASK);
  		temp |= SDMMC_INT_TXDR | SDMMC_INT_RXDR;
  		mci_writel(host, INTMASK, temp);
  		spin_unlock_irqrestore(&host->irq_lock, irqflags);
  
  		temp = mci_readl(host, CTRL);
  		temp &= ~SDMMC_CTRL_DMA_ENABLE;
  		mci_writel(host, CTRL, temp);
  
  		/*
  		 * Use the initial fifoth_val for PIO mode. If wm_algined
  		 * is set, we set watermark same as data size.
  		 * If next issued data may be transfered by DMA mode,
  		 * prev_blksz should be invalidated.
  		 */
  		if (host->wm_aligned)
  			dw_mci_adjust_fifoth(host, data);
  		else
  			mci_writel(host, FIFOTH, host->fifoth_val);
  		host->prev_blksz = 0;
  	} else {
  		/*
  		 * Keep the current block size.
  		 * It will be used to decide whether to update
  		 * fifoth register next time.
  		 */
  		host->prev_blksz = data->blksz;
  	}
  }
  
  static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
  {
  	struct dw_mci *host = slot->host;
  	unsigned int clock = slot->clock;
  	u32 div;
  	u32 clk_en_a;
  	u32 sdmmc_cmd_bits = SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT;
  
  	/* We must continue to set bit 28 in CMD until the change is complete */
  	if (host->state == STATE_WAITING_CMD11_DONE)
  		sdmmc_cmd_bits |= SDMMC_CMD_VOLT_SWITCH;
  
  	slot->mmc->actual_clock = 0;
  
  	if (!clock) {
  		mci_writel(host, CLKENA, 0);
  		mci_send_cmd(slot, sdmmc_cmd_bits, 0);
  	} else if (clock != host->current_speed || force_clkinit) {
  		div = host->bus_hz / clock;
  		if (host->bus_hz % clock && host->bus_hz > clock)
  			/*
  			 * move the + 1 after the divide to prevent
  			 * over-clocking the card.
  			 */
  			div += 1;
  
  		div = (host->bus_hz != clock) ? DIV_ROUND_UP(div, 2) : 0;
  
  		if ((clock != slot->__clk_old &&
  			!test_bit(DW_MMC_CARD_NEEDS_POLL, &slot->flags)) ||
  			force_clkinit) {
  			/* Silent the verbose log if calling from PM context */
  			if (!force_clkinit)
  				dev_info(&slot->mmc->class_dev,
  					 "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ div = %d)\n",
  					 slot->id, host->bus_hz, clock,
  					 div ? ((host->bus_hz / div) >> 1) :
  					 host->bus_hz, div);
  
  			/*
  			 * If card is polling, display the message only
  			 * one time at boot time.
  			 */
  			if (slot->mmc->caps & MMC_CAP_NEEDS_POLL &&
  					slot->mmc->f_min == clock)
  				set_bit(DW_MMC_CARD_NEEDS_POLL, &slot->flags);
  		}
  
  		/* disable clock */
  		mci_writel(host, CLKENA, 0);
  		mci_writel(host, CLKSRC, 0);
  
  		/* inform CIU */
  		mci_send_cmd(slot, sdmmc_cmd_bits, 0);
  
  		/* set clock to desired speed */
  		mci_writel(host, CLKDIV, div);
  
  		/* inform CIU */
  		mci_send_cmd(slot, sdmmc_cmd_bits, 0);
  
  		/* enable clock; only low power if no SDIO */
  		clk_en_a = SDMMC_CLKEN_ENABLE << slot->id;
  		if (!test_bit(DW_MMC_CARD_NO_LOW_PWR, &slot->flags))
  			clk_en_a |= SDMMC_CLKEN_LOW_PWR << slot->id;
  		mci_writel(host, CLKENA, clk_en_a);
  
  		/* inform CIU */
  		mci_send_cmd(slot, sdmmc_cmd_bits, 0);
  
  		/* keep the last clock value that was requested from core */
  		slot->__clk_old = clock;
  		slot->mmc->actual_clock = div ? ((host->bus_hz / div) >> 1) :
  					  host->bus_hz;
  	}
  
  	host->current_speed = clock;
  
  	/* Set the current slot bus width */
  	mci_writel(host, CTYPE, (slot->ctype << slot->id));
  }
  
  static void __dw_mci_start_request(struct dw_mci *host,
  				   struct dw_mci_slot *slot,
  				   struct mmc_command *cmd)
  {
  	struct mmc_request *mrq;
  	struct mmc_data	*data;
  	u32 cmdflags;
  
  	mrq = slot->mrq;
  
  	host->mrq = mrq;
  
  	host->pending_events = 0;
  	host->completed_events = 0;
  	host->cmd_status = 0;
  	host->data_status = 0;
  	host->dir_status = 0;
  
  	data = cmd->data;
  	if (data) {
  		mci_writel(host, TMOUT, 0xFFFFFFFF);
  		mci_writel(host, BYTCNT, data->blksz*data->blocks);
  		mci_writel(host, BLKSIZ, data->blksz);
  	}
  
  	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(); /* drain writebuffer */
  	}
  
  	dw_mci_start_command(host, cmd, cmdflags);
  
  	if (cmd->opcode == SD_SWITCH_VOLTAGE) {
  		unsigned long irqflags;
  
  		/*
  		 * Databook says to fail after 2ms w/ no response, but evidence
  		 * shows that sometimes the cmd11 interrupt takes over 130ms.
  		 * We'll set to 500ms, plus an extra jiffy just in case jiffies
  		 * is just about to roll over.
  		 *
  		 * We do this whole thing under spinlock and only if the
  		 * command hasn't already completed (indicating the the irq
  		 * already ran so we don't want the timeout).
  		 */
  		spin_lock_irqsave(&host->irq_lock, irqflags);
  		if (!test_bit(EVENT_CMD_COMPLETE, &host->pending_events))
  			mod_timer(&host->cmd11_timer,
  				jiffies + msecs_to_jiffies(500) + 1);
  		spin_unlock_irqrestore(&host->irq_lock, irqflags);
  	}
  
  	host->stop_cmdr = dw_mci_prep_stop_abort(host, cmd);
  }
  
  static void dw_mci_start_request(struct dw_mci *host,
  				 struct dw_mci_slot *slot)
  {
  	struct mmc_request *mrq = slot->mrq;
  	struct mmc_command *cmd;
  
  	cmd = mrq->sbc ? mrq->sbc : mrq->cmd;
  	__dw_mci_start_request(host, slot, cmd);
  }
  
  /* must be called with host->lock held */
  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);
  
  	slot->mrq = mrq;
  
  	if (host->state == STATE_WAITING_CMD11_DONE) {
  		dev_warn(&slot->mmc->class_dev,
  			 "Voltage change didn't complete\n");
  		/*
  		 * this case isn't expected to happen, so we can
  		 * either crash here or just try to continue on
  		 * in the closest possible state
  		 */
  		host->state = STATE_IDLE;
  	}
  
  	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);
  	}
  }
  
  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);
  
  	/*
  	 * The check for card presence and queueing of the request must be
  	 * atomic, otherwise the card could be removed in between and the
  	 * request wouldn't fail until another card was inserted.
  	 */
  
  	if (!dw_mci_get_cd(mmc)) {
  		mrq->cmd->error = -ENOMEDIUM;
  		mmc_request_done(mmc, mrq);
  		return;
  	}
  
  	spin_lock_bh(&host->lock);
  
  	dw_mci_queue_request(host, slot, mrq);
  
  	spin_unlock_bh(&host->lock);
  }
  
  static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	const struct dw_mci_drv_data *drv_data = slot->host->drv_data;
  	u32 regs;
  	int ret;
  
  	switch (ios->bus_width) {
  	case MMC_BUS_WIDTH_4:
  		slot->ctype = SDMMC_CTYPE_4BIT;
  		break;
  	case MMC_BUS_WIDTH_8:
  		slot->ctype = SDMMC_CTYPE_8BIT;
  		break;
  	default:
  		/* set default 1 bit mode */
  		slot->ctype = SDMMC_CTYPE_1BIT;
  	}
  
  	regs = mci_readl(slot->host, UHS_REG);
  
  	/* DDR mode set */
  	if (ios->timing == MMC_TIMING_MMC_DDR52 ||
  	    ios->timing == MMC_TIMING_UHS_DDR50 ||
  	    ios->timing == MMC_TIMING_MMC_HS400)
  		regs |= ((0x1 << slot->id) << 16);
  	else
  		regs &= ~((0x1 << slot->id) << 16);
  
  	mci_writel(slot->host, UHS_REG, regs);
  	slot->host->timing = ios->timing;
  
  	/*
  	 * Use mirror of ios->clock to prevent race with mmc
  	 * core ios update when finding the minimum.
  	 */
  	slot->clock = ios->clock;
  
  	if (drv_data && drv_data->set_ios)
  		drv_data->set_ios(slot->host, ios);
  
  	switch (ios->power_mode) {
  	case MMC_POWER_UP:
  		if (!IS_ERR(mmc->supply.vmmc)) {
  			ret = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc,
  					ios->vdd);
  			if (ret) {
  				dev_err(slot->host->dev,
  					"failed to enable vmmc regulator\n");
  				/*return, if failed turn on vmmc*/
  				return;
  			}
  		}
  		set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
  		regs = mci_readl(slot->host, PWREN);
  		regs |= (1 << slot->id);
  		mci_writel(slot->host, PWREN, regs);
  		break;
  	case MMC_POWER_ON:
  		if (!slot->host->vqmmc_enabled) {
  			if (!IS_ERR(mmc->supply.vqmmc)) {
  				ret = regulator_enable(mmc->supply.vqmmc);
  				if (ret < 0)
  					dev_err(slot->host->dev,
  						"failed to enable vqmmc\n");
  				else
  					slot->host->vqmmc_enabled = true;
  
  			} else {
  				/* Keep track so we don't reset again */
  				slot->host->vqmmc_enabled = true;
  			}
  
  			/* Reset our state machine after powering on */
  			dw_mci_ctrl_reset(slot->host,
  					  SDMMC_CTRL_ALL_RESET_FLAGS);
  		}
  
  		/* Adjust clock / bus width after power is up */
  		dw_mci_setup_bus(slot, false);
  
  		break;
  	case MMC_POWER_OFF:
  		/* Turn clock off before power goes down */
  		dw_mci_setup_bus(slot, false);
  
  		if (!IS_ERR(mmc->supply.vmmc))
  			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
  
  		if (!IS_ERR(mmc->supply.vqmmc) && slot->host->vqmmc_enabled)
  			regulator_disable(mmc->supply.vqmmc);
  		slot->host->vqmmc_enabled = false;
  
  		regs = mci_readl(slot->host, PWREN);
  		regs &= ~(1 << slot->id);
  		mci_writel(slot->host, PWREN, regs);
  		break;
  	default:
  		break;
  	}
  
  	if (slot->host->state == STATE_WAITING_CMD11_DONE && ios->clock != 0)
  		slot->host->state = STATE_IDLE;
  }
  
  static int dw_mci_card_busy(struct mmc_host *mmc)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	u32 status;
  
  	/*
  	 * Check the busy bit which is low when DAT[3:0]
  	 * (the data lines) are 0000
  	 */
  	status = mci_readl(slot->host, STATUS);
  
  	return !!(status & SDMMC_STATUS_BUSY);
  }
  
  static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	struct dw_mci *host = slot->host;
  	const struct dw_mci_drv_data *drv_data = host->drv_data;
  	u32 uhs;
  	u32 v18 = SDMMC_UHS_18V << slot->id;
  	int ret;
  
  	if (drv_data && drv_data->switch_voltage)
  		return drv_data->switch_voltage(mmc, ios);
  
  	/*
  	 * Program the voltage.  Note that some instances of dw_mmc may use
  	 * the UHS_REG for this.  For other instances (like exynos) the UHS_REG
  	 * does no harm but you need to set the regulator directly.  Try both.
  	 */
  	uhs = mci_readl(host, UHS_REG);
  	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
  		uhs &= ~v18;
  	else
  		uhs |= v18;
  
  	if (!IS_ERR(mmc->supply.vqmmc)) {
  		ret = mmc_regulator_set_vqmmc(mmc, ios);
  		if (ret < 0) {
  			dev_dbg(&mmc->class_dev,
  					 "Regulator set error %d - %s V\n",
  					 ret, uhs & v18 ? "1.8" : "3.3");
  			return ret;
  		}
  	}
  	mci_writel(host, UHS_REG, uhs);
  
  	return 0;
  }
  
  static int dw_mci_get_ro(struct mmc_host *mmc)
  {
  	int read_only;
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	int gpio_ro = mmc_gpio_get_ro(mmc);
  
  	/* Use platform get_ro function, else try on board write protect */
  	if (gpio_ro >= 0)
  		read_only = gpio_ro;
  	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 void dw_mci_hw_reset(struct mmc_host *mmc)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	struct dw_mci *host = slot->host;
  	int reset;
  
  	if (host->use_dma == TRANS_MODE_IDMAC)
  		dw_mci_idmac_reset(host);
  
  	if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_DMA_RESET |
  				     SDMMC_CTRL_FIFO_RESET))
  		return;
  
  	/*
  	 * According to eMMC spec, card reset procedure:
  	 * tRstW >= 1us:   RST_n pulse width
  	 * tRSCA >= 200us: RST_n to Command time
  	 * tRSTH >= 1us:   RST_n high period
  	 */
  	reset = mci_readl(host, RST_N);
  	reset &= ~(SDMMC_RST_HWACTIVE << slot->id);
  	mci_writel(host, RST_N, reset);
  	usleep_range(1, 2);
  	reset |= SDMMC_RST_HWACTIVE << slot->id;
  	mci_writel(host, RST_N, reset);
  	usleep_range(200, 300);
  }
  
  static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	struct dw_mci *host = slot->host;
  
  	/*
  	 * Low power mode will stop the card clock when idle.  According to the
  	 * description of the CLKENA register we should disable low power mode
  	 * for SDIO cards if we need SDIO interrupts to work.
  	 */
  	if (mmc->caps & MMC_CAP_SDIO_IRQ) {
  		const u32 clken_low_pwr = SDMMC_CLKEN_LOW_PWR << slot->id;
  		u32 clk_en_a_old;
  		u32 clk_en_a;
  
  		clk_en_a_old = mci_readl(host, CLKENA);
  
  		if (card->type == MMC_TYPE_SDIO ||
  		    card->type == MMC_TYPE_SD_COMBO) {
  			set_bit(DW_MMC_CARD_NO_LOW_PWR, &slot->flags);
  			clk_en_a = clk_en_a_old & ~clken_low_pwr;
  		} else {
  			clear_bit(DW_MMC_CARD_NO_LOW_PWR, &slot->flags);
  			clk_en_a = clk_en_a_old | clken_low_pwr;
  		}
  
  		if (clk_en_a != clk_en_a_old) {
  			mci_writel(host, CLKENA, clk_en_a);
  			mci_send_cmd(slot, SDMMC_CMD_UPD_CLK |
  				     SDMMC_CMD_PRV_DAT_WAIT, 0);
  		}
  	}
  }
  
  static void __dw_mci_enable_sdio_irq(struct dw_mci_slot *slot, int enb)
  {
  	struct dw_mci *host = slot->host;
  	unsigned long irqflags;
  	u32 int_mask;
  
  	spin_lock_irqsave(&host->irq_lock, irqflags);
  
  	/* Enable/disable Slot Specific SDIO interrupt */
  	int_mask = mci_readl(host, INTMASK);
  	if (enb)
  		int_mask |= SDMMC_INT_SDIO(slot->sdio_id);
  	else
  		int_mask &= ~SDMMC_INT_SDIO(slot->sdio_id);
  	mci_writel(host, INTMASK, int_mask);
  
  	spin_unlock_irqrestore(&host->irq_lock, irqflags);
  }
  
  static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	struct dw_mci *host = slot->host;
  
  	__dw_mci_enable_sdio_irq(slot, enb);
  
  	/* Avoid runtime suspending the device when SDIO IRQ is enabled */
  	if (enb)
  		pm_runtime_get_noresume(host->dev);
  	else
  		pm_runtime_put_noidle(host->dev);
  }
  
  static void dw_mci_ack_sdio_irq(struct mmc_host *mmc)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  
  	__dw_mci_enable_sdio_irq(slot, 1);
  }
  
  static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	struct dw_mci *host = slot->host;
  	const struct dw_mci_drv_data *drv_data = host->drv_data;
  	int err = -EINVAL;
  
  	if (drv_data && drv_data->execute_tuning)
  		err = drv_data->execute_tuning(slot, opcode);
  	return err;
  }
  
  static int dw_mci_prepare_hs400_tuning(struct mmc_host *mmc,
  				       struct mmc_ios *ios)
  {
  	struct dw_mci_slot *slot = mmc_priv(mmc);
  	struct dw_mci *host = slot->host;
  	const struct dw_mci_drv_data *drv_data = host->drv_data;
  
  	if (drv_data && drv_data->prepare_hs400_tuning)
  		return drv_data->prepare_hs400_tuning(host, ios);
  
  	return 0;
  }
  
  static bool dw_mci_reset(struct dw_mci *host)
  {
  	u32 flags = SDMMC_CTRL_RESET | SDMMC_CTRL_FIFO_RESET;
  	bool ret = false;
  	u32 status = 0;
  
  	/*
  	 * Resetting generates a block interrupt, hence setting
  	 * the scatter-gather pointer to NULL.
  	 */
  	if (host->sg) {
  		sg_miter_stop(&host->sg_miter);
  		host->sg = NULL;
  	}
  
  	if (host->use_dma)
  		flags |= SDMMC_CTRL_DMA_RESET;
  
  	if (dw_mci_ctrl_reset(host, flags)) {
  		/*
  		 * In all cases we clear the RAWINTS
  		 * register to clear any interrupts.
  		 */
  		mci_writel(host, RINTSTS, 0xFFFFFFFF);
  
  		if (!host->use_dma) {
  			ret = true;
  			goto ciu_out;
  		}
  
  		/* Wait for dma_req to be cleared */
  		if (readl_poll_timeout_atomic(host->regs + SDMMC_STATUS,
  					      status,
  					      !(status & SDMMC_STATUS_DMA_REQ),
  					      1, 500 * USEC_PER_MSEC)) {
  			dev_err(host->dev,
  				"%s: Timeout waiting for dma_req to be cleared\n",
  				__func__);
  			goto ciu_out;
  		}
  
  		/* when using DMA next we reset the fifo again */
  		if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_FIFO_RESET))
  			goto ciu_out;
  	} else {
  		/* if the controller reset bit did clear, then set clock regs */
  		if (!(mci_readl(host, CTRL) & SDMMC_CTRL_RESET)) {
  			dev_err(host->dev,
  				"%s: fifo/dma reset bits didn't clear but ciu was reset, doing clock update\n",
  				__func__);
  			goto ciu_out;
  		}
  	}
  
  	if (host->use_dma == TRANS_MODE_IDMAC)
  		/* It is also required that we reinit idmac */
  		dw_mci_idmac_init(host);
  
  	ret = true;
  
  ciu_out:
  	/* After a CTRL reset we need to have CIU set clock registers  */
  	mci_send_cmd(host->slot, SDMMC_CMD_UPD_CLK, 0);
  
  	return ret;
  }
  
  static const struct mmc_host_ops dw_mci_ops = {
  	.request		= dw_mci_request,
  	.pre_req		= dw_mci_pre_req,
  	.post_req		= dw_mci_post_req,
  	.set_ios		= dw_mci_set_ios,
  	.get_ro			= dw_mci_get_ro,
  	.get_cd			= dw_mci_get_cd,
  	.hw_reset               = dw_mci_hw_reset,
  	.enable_sdio_irq	= dw_mci_enable_sdio_irq,
  	.ack_sdio_irq		= dw_mci_ack_sdio_irq,
  	.execute_tuning		= dw_mci_execute_tuning,
  	.card_busy		= dw_mci_card_busy,
  	.start_signal_voltage_switch = dw_mci_switch_voltage,
  	.init_card		= dw_mci_init_card,
  	.prepare_hs400_tuning	= dw_mci_prepare_hs400_tuning,
  };
  
  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->slot->mmc;
  
  	WARN_ON(host->cmd || host->data);
  
  	host->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->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->dev, "list empty\n");
  
  		if (host->state == STATE_SENDING_CMD11)
  			host->state = STATE_WAITING_CMD11_DONE;
  		else
  			host->state = STATE_IDLE;
  	}
  
  	spin_unlock(&host->lock);
  	mmc_request_done(prev_mmc, mrq);
  	spin_lock(&host->lock);
  }
  
  static int 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;
  
  	return cmd->error;
  }
  
  static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data)
  {
  	u32 status = host->data_status;
  
  	if (status & DW_MCI_DATA_ERROR_FLAGS) {
  		if (status & SDMMC_INT_DRTO) {
  			data->error = -ETIMEDOUT;
  		} else if (status & SDMMC_INT_DCRC) {
  			data->error = -EILSEQ;
  		} else if (status & SDMMC_INT_EBE) {
  			if (host->dir_status ==
  				DW_MCI_SEND_STATUS) {
  				/*
  				 * No data CRC status was returned.
  				 * The number of bytes transferred
  				 * will be exaggerated in PIO mode.
  				 */
  				data->bytes_xfered = 0;
  				data->error = -ETIMEDOUT;
  			} else if (host->dir_status ==
  					DW_MCI_RECV_STATUS) {
  				data->error = -EILSEQ;
  			}
  		} else {
  			/* SDMMC_INT_SBE is included */
  			data->error = -EILSEQ;
  		}
  
  		dev_dbg(host->dev, "data error, status 0x%08x\n", status);
  
  		/*
  		 * After an error, there may be data lingering
  		 * in the FIFO
  		 */
  		dw_mci_reset(host);
  	} else {
  		data->bytes_xfered = data->blocks * data->blksz;
  		data->error = 0;
  	}
  
  	return data->error;
  }
  
  static void dw_mci_set_drto(struct dw_mci *host)
  {
  	unsigned int drto_clks;
  	unsigned int drto_div;
  	unsigned int drto_ms;
  	unsigned long irqflags;
  
  	drto_clks = mci_readl(host, TMOUT) >> 8;
  	drto_div = (mci_readl(host, CLKDIV) & 0xff) * 2;
  	if (drto_div == 0)
  		drto_div = 1;
  
  	drto_ms = DIV_ROUND_UP_ULL((u64)MSEC_PER_SEC * drto_clks * drto_div,
  				   host->bus_hz);
  
  	/* add a bit spare time */
  	drto_ms += 10;
  
  	spin_lock_irqsave(&host->irq_lock, irqflags);
  	if (!test_bit(EVENT_DATA_COMPLETE, &host->pending_events))
  		mod_timer(&host->dto_timer,
  			  jiffies + msecs_to_jiffies(drto_ms));
  	spin_unlock_irqrestore(&host->irq_lock, irqflags);
  }
  
  static bool dw_mci_clear_pending_cmd_complete(struct dw_mci *host)
  {
  	if (!test_bit(EVENT_CMD_COMPLETE, &host->pending_events))
  		return false;
  
  	/*
  	 * Really be certain that the timer has stopped.  This is a bit of
  	 * paranoia and could only really happen if we had really bad
  	 * interrupt latency and the interrupt routine and timeout were
  	 * running concurrently so that the del_timer() in the interrupt
  	 * handler couldn't run.
  	 */
  	WARN_ON(del_timer_sync(&host->cto_timer));
  	clear_bit(EVENT_CMD_COMPLETE, &host->pending_events);
  
  	return true;
  }
  
  static bool dw_mci_clear_pending_data_complete(struct dw_mci *host)
  {
  	if (!test_bit(EVENT_DATA_COMPLETE, &host->pending_events))
  		return false;
  
  	/* Extra paranoia just like dw_mci_clear_pending_cmd_complete() */
  	WARN_ON(del_timer_sync(&host->dto_timer));
  	clear_bit(EVENT_DATA_COMPLETE, &host->pending_events);
  
  	return true;
  }
  
  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;
  	struct mmc_request *mrq;
  	enum dw_mci_state state;
  	enum dw_mci_state prev_state;
  	unsigned int err;
  
  	spin_lock(&host->lock);
  
  	state = host->state;
  	data = host->data;
  	mrq = host->mrq;
  
  	do {
  		prev_state = state;
  
  		switch (state) {
  		case STATE_IDLE:
  		case STATE_WAITING_CMD11_DONE:
  			break;
  
  		case STATE_SENDING_CMD11:
  		case STATE_SENDING_CMD:
  			if (!dw_mci_clear_pending_cmd_complete(host))
  				break;
  
  			cmd = host->cmd;
  			host->cmd = NULL;
  			set_bit(EVENT_CMD_COMPLETE, &host->completed_events);
  			err = dw_mci_command_complete(host, cmd);
  			if (cmd == mrq->sbc && !err) {
  				__dw_mci_start_request(host, host->slot,
  						       mrq->cmd);
  				goto unlock;
  			}
  
  			if (cmd->data && err) {
  				/*
  				 * During UHS tuning sequence, sending the stop
  				 * command after the response CRC error would
  				 * throw the system into a confused state
  				 * causing all future tuning phases to report
  				 * failure.
  				 *
  				 * In such case controller will move into a data
  				 * transfer state after a response error or
  				 * response CRC error. Let's let that finish
  				 * before trying to send a stop, so we'll go to
  				 * STATE_SENDING_DATA.
  				 *
  				 * Although letting the data transfer take place
  				 * will waste a bit of time (we already know
  				 * the command was bad), it can't cause any
  				 * errors since it's possible it would have
  				 * taken place anyway if this tasklet got
  				 * delayed. Allowing the transfer to take place
  				 * avoids races and keeps things simple.
  				 */
  				if (err != -ETIMEDOUT) {
  					state = STATE_SENDING_DATA;
  					continue;
  				}
  
  				dw_mci_stop_dma(host);
  				send_stop_abort(host, data);
  				state = STATE_SENDING_STOP;
  				break;
  			}
  
  			if (!cmd->data || err) {
  				dw_mci_request_end(host, mrq);
  				goto unlock;
  			}
  
  			prev_state = state = STATE_SENDING_DATA;
  			/* fall through */
  
  		case STATE_SENDING_DATA:
  			/*
  			 * We could get a data error and never a transfer
  			 * complete so we'd better check for it here.
  			 *
  			 * Note that we don't really care if we also got a
  			 * transfer complete; stopping the DMA and sending an
  			 * abort won't hurt.
  			 */
  			if (test_and_clear_bit(EVENT_DATA_ERROR,
  					       &host->pending_events)) {
  				dw_mci_stop_dma(host);
  				if (!(host->data_status & (SDMMC_INT_DRTO |
  							   SDMMC_INT_EBE)))
  					send_stop_abort(host, data);
  				state = STATE_DATA_ERROR;
  				break;
  			}
  
  			if (!test_and_clear_bit(EVENT_XFER_COMPLETE,
  						&host->pending_events)) {
  				/*
  				 * If all data-related interrupts don't come
  				 * within the given time in reading data state.
  				 */
  				if (host->dir_status == DW_MCI_RECV_STATUS)
  					dw_mci_set_drto(host);
  				break;
  			}
  
  			set_bit(EVENT_XFER_COMPLETE, &host->completed_events);
  
  			/*
  			 * Handle an EVENT_DATA_ERROR that might have shown up
  			 * before the transfer completed.  This might not have
  			 * been caught by the check above because the interrupt
  			 * could have gone off between the previous check and
  			 * the check for transfer complete.
  			 *
  			 * Technically this ought not be needed assuming we
  			 * get a DATA_COMPLETE eventually (we'll notice the
  			 * error and end the request), but it shouldn't hurt.
  			 *
  			 * This has the advantage of sending the stop command.
  			 */
  			if (test_and_clear_bit(EVENT_DATA_ERROR,
  					       &host->pending_events)) {
  				dw_mci_stop_dma(host);
  				if (!(host->data_status & (SDMMC_INT_DRTO |
  							   SDMMC_INT_EBE)))
  					send_stop_abort(host, data);
  				state = STATE_DATA_ERROR;
  				break;
  			}
  			prev_state = state = STATE_DATA_BUSY;
  
  			/* fall through */
  
  		case STATE_DATA_BUSY:
  			if (!dw_mci_clear_pending_data_complete(host)) {
  				/*
  				 * If data error interrupt comes but data over
  				 * interrupt doesn't come within the given time.
  				 * in reading data state.
  				 */
  				if (host->dir_status == DW_MCI_RECV_STATUS)
  					dw_mci_set_drto(host);
  				break;
  			}
  
  			host->data = NULL;
  			set_bit(EVENT_DATA_COMPLETE, &host->completed_events);
  			err = dw_mci_data_complete(host, data);
  
  			if (!err) {
  				if (!data->stop || mrq->sbc) {
  					if (mrq->sbc && data->stop)
  						data->stop->error = 0;
  					dw_mci_request_end(host, mrq);
  					goto unlock;
  				}
  
  				/* stop command for open-ended transfer*/
  				if (data->stop)
  					send_stop_abort(host, data);
  			} else {
  				/*
  				 * If we don't have a command complete now we'll
  				 * never get one since we just reset everything;
  				 * better end the request.
  				 *
  				 * If we do have a command complete we'll fall
  				 * through to the SENDING_STOP command and
  				 * everything will be peachy keen.
  				 */
  				if (!test_bit(EVENT_CMD_COMPLETE,
  					      &host->pending_events)) {
  					host->cmd = NULL;
  					dw_mci_request_end(host, mrq);
  					goto unlock;
  				}
  			}
  
  			/*
  			 * If err has non-zero,
  			 * stop-abort command has been already issued.
  			 */
  			prev_state = state = STATE_SENDING_STOP;
  
  			/* fall through */
  
  		case STATE_SENDING_STOP:
  			if (!dw_mci_clear_pending_cmd_complete(host))
  				break;
  
  			/* CMD error in data command */
  			if (mrq->cmd->error && mrq->data)
  				dw_mci_reset(host);
  
  			host->cmd = NULL;
  			host->data = NULL;
  
  			if (!mrq->sbc && mrq->stop)
  				dw_mci_command_complete(host, mrq->stop);
  			else
  				host->cmd_status = 0;
  
  			dw_mci_request_end(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);
  
  }
  
  /* push final bytes to part_buf, only use during push */
  static void dw_mci_set_part_bytes(struct dw_mci *host, void *buf, int cnt)
  {
  	memcpy((void *)&host->part_buf, buf, cnt);
  	host->part_buf_count = cnt;
  }
  
  /* append bytes to part_buf, only use during push */
  static int dw_mci_push_part_bytes(struct dw_mci *host, void *buf, int cnt)
  {
  	cnt = min(cnt, (1 << host->data_shift) - host->part_buf_count);
  	memcpy((void *)&host->part_buf + host->part_buf_count, buf, cnt);
  	host->part_buf_count += cnt;
  	return cnt;
  }
  
  /* pull first bytes from part_buf, only use during pull */
  static int dw_mci_pull_part_bytes(struct dw_mci *host, void *buf, int cnt)
  {
  	cnt = min_t(int, cnt, host->part_buf_count);
  	if (cnt) {
  		memcpy(buf, (void *)&host->part_buf + host->part_buf_start,
  		       cnt);
  		host->part_buf_count -= cnt;
  		host->part_buf_start += cnt;
  	}
  	return cnt;
  }
  
  /* pull final bytes from the part_buf, assuming it's just been filled */
  static void dw_mci_pull_final_bytes(struct dw_mci *host, void *buf, int cnt)
  {
  	memcpy(buf, &host->part_buf, cnt);
  	host->part_buf_start = cnt;
  	host->part_buf_count = (1 << host->data_shift) - cnt;
  }
  
  static void dw_mci_push_data16(struct dw_mci *host, void *buf, int cnt)
  {
  	struct mmc_data *data = host->data;
  	int init_cnt = cnt;
  
  	/* try and push anything in the part_buf */
  	if (unlikely(host->part_buf_count)) {
  		int len = dw_mci_push_part_bytes(host, buf, cnt);
  
  		buf += len;
  		cnt -= len;
  		if (host->part_buf_count == 2) {
  			mci_fifo_writew(host->fifo_reg, host->part_buf16);
  			host->part_buf_count = 0;
  		}
  	}
  #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  	if (unlikely((unsigned long)buf & 0x1)) {
  		while (cnt >= 2) {
  			u16 aligned_buf[64];
  			int len = min(cnt & -2, (int)sizeof(aligned_buf));
  			int items = len >> 1;
  			int i;
  			/* memcpy from input buffer into aligned buffer */
  			memcpy(aligned_buf, buf, len);
  			buf += len;
  			cnt -= len;
  			/* push data from aligned buffer into fifo */
  			for (i = 0; i < items; ++i)
  				mci_fifo_writew(host->fifo_reg, aligned_buf[i]);
  		}
  	} else
  #endif
  	{
  		u16 *pdata = buf;
  
  		for (; cnt >= 2; cnt -= 2)
  			mci_fifo_writew(host->fifo_reg, *pdata++);
  		buf = pdata;
  	}
  	/* put anything remaining in the part_buf */
  	if (cnt) {
  		dw_mci_set_part_bytes(host, buf, cnt);
  		 /* Push data if we have reached the expected data length */
  		if ((data->bytes_xfered + init_cnt) ==
  		    (data->blksz * data->blocks))
  			mci_fifo_writew(host->fifo_reg, host->part_buf16);
  	}
  }
  
  static void dw_mci_pull_data16(struct dw_mci *host, void *buf, int cnt)
  {
  #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  	if (unlikely((unsigned long)buf & 0x1)) {
  		while (cnt >= 2) {
  			/* pull data from fifo into aligned buffer */
  			u16 aligned_buf[64];
  			int len = min(cnt & -2, (int)sizeof(aligned_buf));
  			int items = len >> 1;
  			int i;
  
  			for (i = 0; i < items; ++i)
  				aligned_buf[i] = mci_fifo_readw(host->fifo_reg);
  			/* memcpy from aligned buffer into output buffer */
  			memcpy(buf, aligned_buf, len);
  			buf += len;
  			cnt -= len;
  		}
  	} else
  #endif
  	{
  		u16 *pdata = buf;
  
  		for (; cnt >= 2; cnt -= 2)
  			*pdata++ = mci_fifo_readw(host->fifo_reg);
  		buf = pdata;
  	}
  	if (cnt) {
  		host->part_buf16 = mci_fifo_readw(host->fifo_reg);
  		dw_mci_pull_final_bytes(host, buf, cnt);
  	}
  }
  
  static void dw_mci_push_data32(struct dw_mci *host, void *buf, int cnt)
  {
  	struct mmc_data *data = host->data;
  	int init_cnt = cnt;
  
  	/* try and push anything in the part_buf */
  	if (unlikely(host->part_buf_count)) {
  		int len = dw_mci_push_part_bytes(host, buf, cnt);
  
  		buf += len;
  		cnt -= len;
  		if (host->part_buf_count == 4) {
  			mci_fifo_writel(host->fifo_reg,	host->part_buf32);
  			host->part_buf_count = 0;
  		}
  	}
  #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  	if (unlikely((unsigned long)buf & 0x3)) {
  		while (cnt >= 4) {
  			u32 aligned_buf[32];
  			int len = min(cnt & -4, (int)sizeof(aligned_buf));
  			int items = len >> 2;
  			int i;
  			/* memcpy from input buffer into aligned buffer */
  			memcpy(aligned_buf, buf, len);
  			buf += len;
  			cnt -= len;
  			/* push data from aligned buffer into fifo */
  			for (i = 0; i < items; ++i)
  				mci_fifo_writel(host->fifo_reg,	aligned_buf[i]);
  		}
  	} else
  #endif
  	{
  		u32 *pdata = buf;
  
  		for (; cnt >= 4; cnt -= 4)
  			mci_fifo_writel(host->fifo_reg, *pdata++);
  		buf = pdata;
  	}
  	/* put anything remaining in the part_buf */
  	if (cnt) {
  		dw_mci_set_part_bytes(host, buf, cnt);
  		 /* Push data if we have reached the expected data length */
  		if ((data->bytes_xfered + init_cnt) ==
  		    (data->blksz * data->blocks))
  			mci_fifo_writel(host->fifo_reg, host->part_buf32);
  	}
  }
  
  static void dw_mci_pull_data32(struct dw_mci *host, void *buf, int cnt)
  {
  #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  	if (unlikely((unsigned long)buf & 0x3)) {
  		while (cnt >= 4) {
  			/* pull data from fifo into aligned buffer */
  			u32 aligned_buf[32];
  			int len = min(cnt & -4, (int)sizeof(aligned_buf));
  			int items = len >> 2;
  			int i;
  
  			for (i = 0; i < items; ++i)
  				aligned_buf[i] = mci_fifo_readl(host->fifo_reg);
  			/* memcpy from aligned buffer into output buffer */
  			memcpy(buf, aligned_buf, len);
  			buf += len;
  			cnt -= len;
  		}
  	} else
  #endif
  	{
  		u32 *pdata = buf;
  
  		for (; cnt >= 4; cnt -= 4)
  			*pdata++ = mci_fifo_readl(host->fifo_reg);
  		buf = pdata;
  	}
  	if (cnt) {
  		host->part_buf32 = mci_fifo_readl(host->fifo_reg);
  		dw_mci_pull_final_bytes(host, buf, cnt);
  	}
  }
  
  static void dw_mci_push_data64(struct dw_mci *host, void *buf, int cnt)
  {
  	struct mmc_data *data = host->data;
  	int init_cnt = cnt;
  
  	/* try and push anything in the part_buf */
  	if (unlikely(host->part_buf_count)) {
  		int len = dw_mci_push_part_bytes(host, buf, cnt);
  
  		buf += len;
  		cnt -= len;
  
  		if (host->part_buf_count == 8) {
  			mci_fifo_writeq(host->fifo_reg,	host->part_buf);
  			host->part_buf_count = 0;
  		}
  	}
  #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  	if (unlikely((unsigned long)buf & 0x7)) {
  		while (cnt >= 8) {
  			u64 aligned_buf[16];
  			int len = min(cnt & -8, (int)sizeof(aligned_buf));
  			int items = len >> 3;
  			int i;
  			/* memcpy from input buffer into aligned buffer */
  			memcpy(aligned_buf, buf, len);
  			buf += len;
  			cnt -= len;
  			/* push data from aligned buffer into fifo */
  			for (i = 0; i < items; ++i)
  				mci_fifo_writeq(host->fifo_reg,	aligned_buf[i]);
  		}
  	} else
  #endif
  	{
  		u64 *pdata = buf;
  
  		for (; cnt >= 8; cnt -= 8)
  			mci_fifo_writeq(host->fifo_reg, *pdata++);
  		buf = pdata;
  	}
  	/* put anything remaining in the part_buf */
  	if (cnt) {
  		dw_mci_set_part_bytes(host, buf, cnt);
  		/* Push data if we have reached the expected data length */
  		if ((data->bytes_xfered + init_cnt) ==
  		    (data->blksz * data->blocks))
  			mci_fifo_writeq(host->fifo_reg, host->part_buf);
  	}
  }
  
  static void dw_mci_pull_data64(struct dw_mci *host, void *buf, int cnt)
  {
  #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  	if (unlikely((unsigned long)buf & 0x7)) {
  		while (cnt >= 8) {
  			/* pull data from fifo into aligned buffer */
  			u64 aligned_buf[16];
  			int len = min(cnt & -8, (int)sizeof(aligned_buf));
  			int items = len >> 3;
  			int i;
  
  			for (i = 0; i < items; ++i)
  				aligned_buf[i] = mci_fifo_readq(host->fifo_reg);
  
  			/* memcpy from aligned buffer into output buffer */
  			memcpy(buf, aligned_buf, len);
  			buf += len;
  			cnt -= len;
  		}
  	} else
  #endif
  	{
  		u64 *pdata = buf;
  
  		for (; cnt >= 8; cnt -= 8)
  			*pdata++ = mci_fifo_readq(host->fifo_reg);
  		buf = pdata;
  	}
  	if (cnt) {
  		host->part_buf = mci_fifo_readq(host->fifo_reg);
  		dw_mci_pull_final_bytes(host, buf, cnt);
  	}
  }
  
  static void dw_mci_pull_data(struct dw_mci *host, void *buf, int cnt)
  {
  	int len;
  
  	/* get remaining partial bytes */
  	len = dw_mci_pull_part_bytes(host, buf, cnt);
  	if (unlikely(len == cnt))
  		return;
  	buf += len;
  	cnt -= len;
  
  	/* get the rest of the data */
  	host->pull_data(host, buf, cnt);
  }
  
  static void dw_mci_read_data_pio(struct dw_mci *host, bool dto)
  {
  	struct sg_mapping_iter *sg_miter = &host->sg_miter;
  	void *buf;
  	unsigned int offset;
  	struct mmc_data	*data = host->data;
  	int shift = host->data_shift;
  	u32 status;
  	unsigned int len;
  	unsigned int remain, fcnt;
  
  	do {
  		if (!sg_miter_next(sg_miter))
  			goto done;
  
  		host->sg = sg_miter->piter.sg;
  		buf = sg_miter->addr;
  		remain = sg_miter->length;
  		offset = 0;
  
  		do {
  			fcnt = (SDMMC_GET_FCNT(mci_readl(host, STATUS))
  					<< shift) + host->part_buf_count;
  			len = min(remain, fcnt);
  			if (!len)
  				break;
  			dw_mci_pull_data(host, (void *)(buf + offset), len);
  			data->bytes_xfered += len;
  			offset += len;
  			remain -= len;
  		} while (remain);
  
  		sg_miter->consumed = offset;
  		status = mci_readl(host, MINTSTS);
  		mci_writel(host, RINTSTS, SDMMC_INT_RXDR);
  	/* if the RXDR is ready read again */
  	} while ((status & SDMMC_INT_RXDR) ||
  		 (dto && SDMMC_GET_FCNT(mci_readl(host, STATUS))));
  
  	if (!remain) {
  		if (!sg_miter_next(sg_miter))
  			goto done;
  		sg_miter->consumed = 0;
  	}
  	sg_miter_stop(sg_miter);
  	return;
  
  done:
  	sg_miter_stop(sg_miter);
  	host->sg = NULL;
  	smp_wmb(); /* drain writebuffer */
  	set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
  }
  
  static void dw_mci_write_data_pio(struct dw_mci *host)
  {
  	struct sg_mapping_iter *sg_miter = &host->sg_miter;
  	void *buf;
  	unsigned int offset;
  	struct mmc_data	*data = host->data;
  	int shift = host->data_shift;
  	u32 status;
  	unsigned int len;
  	unsigned int fifo_depth = host->fifo_depth;
  	unsigned int remain, fcnt;
  
  	do {
  		if (!sg_miter_next(sg_miter))
  			goto done;
  
  		host->sg = sg_miter->piter.sg;
  		buf = sg_miter->addr;
  		remain = sg_miter->length;
  		offset = 0;
  
  		do {
  			fcnt = ((fifo_depth -
  				 SDMMC_GET_FCNT(mci_readl(host, STATUS)))
  					<< shift) - host->part_buf_count;
  			len = min(remain, fcnt);
  			if (!len)
  				break;
  			host->push_data(host, (void *)(buf + offset), len);
  			data->bytes_xfered += len;
  			offset += len;
  			remain -= len;
  		} while (remain);
  
  		sg_miter->consumed = offset;
  		status = mci_readl(host, MINTSTS);
  		mci_writel(host, RINTSTS, SDMMC_INT_TXDR);
  	} while (status & SDMMC_INT_TXDR); /* if TXDR write again */
  
  	if (!remain) {
  		if (!sg_miter_next(sg_miter))
  			goto done;
  		sg_miter->consumed = 0;
  	}
  	sg_miter_stop(sg_miter);
  	return;
  
  done:
  	sg_miter_stop(sg_miter);
  	host->sg = NULL;
  	smp_wmb(); /* drain writebuffer */
  	set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
  }
  
  static void dw_mci_cmd_interrupt(struct dw_mci *host, u32 status)
  {
  	del_timer(&host->cto_timer);
  
  	if (!host->cmd_status)
  		host->cmd_status = status;
  
  	smp_wmb(); /* drain writebuffer */
  
  	set_bit(EVENT_CMD_COMPLETE, &host->pending_events);
  	tasklet_schedule(&host->tasklet);
  }
  
  static void dw_mci_handle_cd(struct dw_mci *host)
  {
  	struct dw_mci_slot *slot = host->slot;
  
  	if (slot->mmc->ops->card_event)
  		slot->mmc->ops->card_event(slot->mmc);
  	mmc_detect_change(slot->mmc,
  		msecs_to_jiffies(host->pdata->detect_delay_ms));
  }
  
  static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
  {
  	struct dw_mci *host = dev_id;
  	u32 pending;
  	struct dw_mci_slot *slot = host->slot;
  	unsigned long irqflags;
  
  	pending = mci_readl(host, MINTSTS); /* read-only mask reg */
  
  	if (pending) {
  		/* Check volt switch first, since it can look like an error */
  		if ((host->state == STATE_SENDING_CMD11) &&
  		    (pending & SDMMC_INT_VOLT_SWITCH)) {
  			mci_writel(host, RINTSTS, SDMMC_INT_VOLT_SWITCH);
  			pending &= ~SDMMC_INT_VOLT_SWITCH;
  
  			/*
  			 * Hold the lock; we know cmd11_timer can't be kicked
  			 * off after the lock is released, so safe to delete.
  			 */
  			spin_lock_irqsave(&host->irq_lock, irqflags);
  			dw_mci_cmd_interrupt(host, pending);
  			spin_unlock_irqrestore(&host->irq_lock, irqflags);
  
  			del_timer(&host->cmd11_timer);
  		}
  
  		if (pending & DW_MCI_CMD_ERROR_FLAGS) {
  			spin_lock_irqsave(&host->irq_lock, irqflags);
  
  			del_timer(&host->cto_timer);
  			mci_writel(host, RINTSTS, DW_MCI_CMD_ERROR_FLAGS);
  			host->cmd_status = pending;
  			smp_wmb(); /* drain writebuffer */
  			set_bit(EVENT_CMD_COMPLETE, &host->pending_events);
  
  			spin_unlock_irqrestore(&host->irq_lock, irqflags);
  		}
  
  		if (pending & DW_MCI_DATA_ERROR_FLAGS) {
  			/* if there is an error report DATA_ERROR */
  			mci_writel(host, RINTSTS, DW_MCI_DATA_ERROR_FLAGS);
  			host->data_status = pending;
  			smp_wmb(); /* drain writebuffer */
  			set_bit(EVENT_DATA_ERROR, &host->pending_events);
  			tasklet_schedule(&host->tasklet);
  		}
  
  		if (pending & SDMMC_INT_DATA_OVER) {
  			spin_lock_irqsave(&host->irq_lock, irqflags);
  
  			del_timer(&host->dto_timer);
  
  			mci_writel(host, RINTSTS, SDMMC_INT_DATA_OVER);
  			if (!host->data_status)
  				host->data_status = pending;
  			smp_wmb(); /* drain writebuffer */
  			if (host->dir_status == DW_MCI_RECV_STATUS) {
  				if (host->sg != NULL)
  					dw_mci_read_data_pio(host, true);
  			}
  			set_bit(EVENT_DATA_COMPLETE, &host->pending_events);
  			tasklet_schedule(&host->tasklet);
  
  			spin_unlock_irqrestore(&host->irq_lock, irqflags);
  		}
  
  		if (pending & SDMMC_INT_RXDR) {
  			mci_writel(host, RINTSTS, SDMMC_INT_RXDR);
  			if (host->dir_status == DW_MCI_RECV_STATUS && host->sg)
  				dw_mci_read_data_pio(host, false);
  		}
  
  		if (pending & SDMMC_INT_TXDR) {
  			mci_writel(host, RINTSTS, SDMMC_INT_TXDR);
  			if (host->dir_status == DW_MCI_SEND_STATUS && host->sg)
  				dw_mci_write_data_pio(host);
  		}
  
  		if (pending & SDMMC_INT_CMD_DONE) {
  			spin_lock_irqsave(&host->irq_lock, irqflags);
  
  			mci_writel(host, RINTSTS, SDMMC_INT_CMD_DONE);
  			dw_mci_cmd_interrupt(host, pending);
  
  			spin_unlock_irqrestore(&host->irq_lock, irqflags);
  		}
  
  		if (pending & SDMMC_INT_CD) {
  			mci_writel(host, RINTSTS, SDMMC_INT_CD);
  			dw_mci_handle_cd(host);
  		}
  
  		if (pending & SDMMC_INT_SDIO(slot->sdio_id)) {
  			mci_writel(host, RINTSTS,
  				   SDMMC_INT_SDIO(slot->sdio_id));
  			__dw_mci_enable_sdio_irq(slot, 0);
  			sdio_signal_irq(slot->mmc);
  		}
  
  	}
  
  	if (host->use_dma != TRANS_MODE_IDMAC)
  		return IRQ_HANDLED;
  
  	/* Handle IDMA interrupts */
  	if (host->dma_64bit_address == 1) {
  		pending = mci_readl(host, IDSTS64);
  		if (pending & (SDMMC_IDMAC_INT_TI | SDMMC_IDMAC_INT_RI)) {
  			mci_writel(host, IDSTS64, SDMMC_IDMAC_INT_TI |
  							SDMMC_IDMAC_INT_RI);
  			mci_writel(host, IDSTS64, SDMMC_IDMAC_INT_NI);
  			if (!test_bit(EVENT_DATA_ERROR, &host->pending_events))
  				host->dma_ops->complete((void *)host);
  		}
  	} else {
  		pending = mci_readl(host, IDSTS);
  		if (pending & (SDMMC_IDMAC_INT_TI | SDMMC_IDMAC_INT_RI)) {
  			mci_writel(host, IDSTS, SDMMC_IDMAC_INT_TI |
  							SDMMC_IDMAC_INT_RI);
  			mci_writel(host, IDSTS, SDMMC_IDMAC_INT_NI);
  			if (!test_bit(EVENT_DATA_ERROR, &host->pending_events))
  				host->dma_ops->complete((void *)host);
  		}
  	}
  
  	return IRQ_HANDLED;
  }
  
  static int dw_mci_init_slot_caps(struct dw_mci_slot *slot)
  {
  	struct dw_mci *host = slot->host;
  	const struct dw_mci_drv_data *drv_data = host->drv_data;
  	struct mmc_host *mmc = slot->mmc;
  	int ctrl_id;
  
  	if (host->pdata->caps)
  		mmc->caps = host->pdata->caps;
  
  	if (host->pdata->pm_caps)
  		mmc->pm_caps = host->pdata->pm_caps;
  
  	if (host->dev->of_node) {
  		ctrl_id = of_alias_get_id(host->dev->of_node, "mshc");
  		if (ctrl_id < 0)
  			ctrl_id = 0;
  	} else {
  		ctrl_id = to_platform_device(host->dev)->id;
  	}
  
  	if (drv_data && drv_data->caps) {
  		if (ctrl_id >= drv_data->num_caps) {
  			dev_err(host->dev, "invalid controller id %d\n",
  				ctrl_id);
  			return -EINVAL;
  		}
  		mmc->caps |= drv_data->caps[ctrl_id];
  	}
  
  	if (host->pdata->caps2)
  		mmc->caps2 = host->pdata->caps2;
  
  	mmc->f_min = DW_MCI_FREQ_MIN;
  	if (!mmc->f_max)
  		mmc->f_max = DW_MCI_FREQ_MAX;
  
  	/* Process SDIO IRQs through the sdio_irq_work. */
  	if (mmc->caps & MMC_CAP_SDIO_IRQ)
  		mmc->caps2 |= MMC_CAP2_SDIO_IRQ_NOTHREAD;
  
  	return 0;
  }
  
  static int dw_mci_init_slot(struct dw_mci *host)
  {
  	struct mmc_host *mmc;
  	struct dw_mci_slot *slot;
  	int ret;
  
  	mmc = mmc_alloc_host(sizeof(struct dw_mci_slot), host->dev);
  	if (!mmc)
  		return -ENOMEM;
  
  	slot = mmc_priv(mmc);
  	slot->id = 0;
  	slot->sdio_id = host->sdio_id0 + slot->id;
  	slot->mmc = mmc;
  	slot->host = host;
  	host->slot = slot;
  
  	mmc->ops = &dw_mci_ops;
  
  	/*if there are external regulators, get them*/
  	ret = mmc_regulator_get_supply(mmc);
  	if (ret)
  		goto err_host_allocated;
  
  	if (!mmc->ocr_avail)
  		mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
  
  	ret = mmc_of_parse(mmc);
  	if (ret)
  		goto err_host_allocated;
  
  	ret = dw_mci_init_slot_caps(slot);
  	if (ret)
  		goto err_host_allocated;
  
  	/* Useful defaults if platform data is unset. */
  	if (host->use_dma == TRANS_MODE_IDMAC) {
  		mmc->max_segs = host->ring_size;
  		mmc->max_blk_size = 65535;
  		mmc->max_seg_size = 0x1000;
  		mmc->max_req_size = mmc->max_seg_size * host->ring_size;
  		mmc->max_blk_count = mmc->max_req_size / 512;
  	} else if (host->use_dma == TRANS_MODE_EDMAC) {
  		mmc->max_segs = 64;
  		mmc->max_blk_size = 65535;
  		mmc->max_blk_count = 65535;
  		mmc->max_req_size =
  				mmc->max_blk_size * mmc->max_blk_count;
  		mmc->max_seg_size = mmc->max_req_size;
  	} else {
  		/* TRANS_MODE_PIO */
  		mmc->max_segs = 64;
  		mmc->max_blk_size = 65535; /* BLKSIZ is 16 bits */
  		mmc->max_blk_count = 512;
  		mmc->max_req_size = mmc->max_blk_size *
  				    mmc->max_blk_count;
  		mmc->max_seg_size = mmc->max_req_size;
  	}
  
  	dw_mci_get_cd(mmc);
  
  	ret = mmc_add_host(mmc);
  	if (ret)
  		goto err_host_allocated;
  
  #if defined(CONFIG_DEBUG_FS)
  	dw_mci_init_debugfs(slot);
  #endif
  
  	return 0;
  
  err_host_allocated:
  	mmc_free_host(mmc);
  	return ret;
  }
  
  static void dw_mci_cleanup_slot(struct dw_mci_slot *slot)
  {
  	/* Debugfs stuff is cleaned up by mmc core */
  	mmc_remove_host(slot->mmc);
  	slot->host->slot = NULL;
  	mmc_free_host(slot->mmc);
  }
  
  static void dw_mci_init_dma(struct dw_mci *host)
  {
  	int addr_config;
  	struct device *dev = host->dev;
  
  	/*
  	* Check tansfer mode from HCON[17:16]
  	* Clear the ambiguous description of dw_mmc databook:
  	* 2b'00: No DMA Interface -> Actually means using Internal DMA block
  	* 2b'01: DesignWare DMA Interface -> Synopsys DW-DMA block
  	* 2b'10: Generic DMA Interface -> non-Synopsys generic DMA block
  	* 2b'11: Non DW DMA Interface -> pio only
  	* Compared to DesignWare DMA Interface, Generic DMA Interface has a
  	* simpler request/acknowledge handshake mechanism and both of them
  	* are regarded as external dma master for dw_mmc.
  	*/
  	host->use_dma = SDMMC_GET_TRANS_MODE(mci_readl(host, HCON));
  	if (host->use_dma == DMA_INTERFACE_IDMA) {
  		host->use_dma = TRANS_MODE_IDMAC;
  	} else if (host->use_dma == DMA_INTERFACE_DWDMA ||
  		   host->use_dma == DMA_INTERFACE_GDMA) {
  		host->use_dma = TRANS_MODE_EDMAC;
  	} else {
  		goto no_dma;
  	}
  
  	/* Determine which DMA interface to use */
  	if (host->use_dma == TRANS_MODE_IDMAC) {
  		/*
  		* Check ADDR_CONFIG bit in HCON to find
  		* IDMAC address bus width
  		*/
  		addr_config = SDMMC_GET_ADDR_CONFIG(mci_readl(host, HCON));
  
  		if (addr_config == 1) {
  			/* host supports IDMAC in 64-bit address mode */
  			host->dma_64bit_address = 1;
  			dev_info(host->dev,
  				 "IDMAC supports 64-bit address mode.\n");
  			if (!dma_set_mask(host->dev, DMA_BIT_MASK(64)))
  				dma_set_coherent_mask(host->dev,
  						      DMA_BIT_MASK(64));
  		} else {
  			/* host supports IDMAC in 32-bit address mode */
  			host->dma_64bit_address = 0;
  			dev_info(host->dev,
  				 "IDMAC supports 32-bit address mode.\n");
  		}
  
  		/* Alloc memory for sg translation */
  		host->sg_cpu = dmam_alloc_coherent(host->dev,
  						   DESC_RING_BUF_SZ,
  						   &host->sg_dma, GFP_KERNEL);
  		if (!host->sg_cpu) {
  			dev_err(host->dev,
  				"%s: could not alloc DMA memory\n",
  				__func__);
  			goto no_dma;
  		}
  
  		host->dma_ops = &dw_mci_idmac_ops;
  		dev_info(host->dev, "Using internal DMA controller.\n");
  	} else {
  		/* TRANS_MODE_EDMAC: check dma bindings again */
  		if ((device_property_read_string_array(dev, "dma-names",
  						       NULL, 0) < 0) ||
  		    !device_property_present(dev, "dmas")) {
  			goto no_dma;
  		}
  		host->dma_ops = &dw_mci_edmac_ops;
  		dev_info(host->dev, "Using external DMA controller.\n");
  	}
  
  	if (host->dma_ops->init && host->dma_ops->start &&
  	    host->dma_ops->stop && host->dma_ops->cleanup) {
  		if (host->dma_ops->init(host)) {
  			dev_err(host->dev, "%s: Unable to initialize DMA Controller.\n",
  				__func__);
  			goto no_dma;
  		}
  	} else {
  		dev_err(host->dev, "DMA initialization not found.\n");
  		goto no_dma;
  	}
  
  	return;
  
  no_dma:
  	dev_info(host->dev, "Using PIO mode.\n");
  	host->use_dma = TRANS_MODE_PIO;
  }
  
  static void dw_mci_cmd11_timer(struct timer_list *t)
  {
  	struct dw_mci *host = from_timer(host, t, cmd11_timer);
  
  	if (host->state != STATE_SENDING_CMD11) {
  		dev_warn(host->dev, "Unexpected CMD11 timeout\n");
  		return;
  	}
  
  	host->cmd_status = SDMMC_INT_RTO;
  	set_bit(EVENT_CMD_COMPLETE, &host->pending_events);
  	tasklet_schedule(&host->tasklet);
  }
  
  static void dw_mci_cto_timer(struct timer_list *t)
  {
  	struct dw_mci *host = from_timer(host, t, cto_timer);
  	unsigned long irqflags;
  	u32 pending;
  
  	spin_lock_irqsave(&host->irq_lock, irqflags);
  
  	/*
  	 * If somehow we have very bad interrupt latency it's remotely possible
  	 * that the timer could fire while the interrupt is still pending or
  	 * while the interrupt is midway through running.  Let's be paranoid
  	 * and detect those two cases.  Note that this is paranoia is somewhat
  	 * justified because in this function we don't actually cancel the
  	 * pending command in the controller--we just assume it will never come.
  	 */
  	pending = mci_readl(host, MINTSTS); /* read-only mask reg */
  	if (pending & (DW_MCI_CMD_ERROR_FLAGS | SDMMC_INT_CMD_DONE)) {
  		/* The interrupt should fire; no need to act but we can warn */
  		dev_warn(host->dev, "Unexpected interrupt latency\n");
  		goto exit;
  	}
  	if (test_bit(EVENT_CMD_COMPLETE, &host->pending_events)) {
  		/* Presumably interrupt handler couldn't delete the timer */
  		dev_warn(host->dev, "CTO timeout when already completed\n");
  		goto exit;
  	}
  
  	/*
  	 * Continued paranoia to make sure we're in the state we expect.
  	 * This paranoia isn't really justified but it seems good to be safe.
  	 */
  	switch (host->state) {
  	case STATE_SENDING_CMD11:
  	case STATE_SENDING_CMD:
  	case STATE_SENDING_STOP:
  		/*
  		 * If CMD_DONE interrupt does NOT come in sending command
  		 * state, we should notify the driver to terminate current
  		 * transfer and report a command timeout to the core.
  		 */
  		host->cmd_status = SDMMC_INT_RTO;
  		set_bit(EVENT_CMD_COMPLETE, &host->pending_events);
  		tasklet_schedule(&host->tasklet);
  		break;
  	default:
  		dev_warn(host->dev, "Unexpected command timeout, state %d\n",
  			 host->state);
  		break;
  	}
  
  exit:
  	spin_unlock_irqrestore(&host->irq_lock, irqflags);
  }
  
  static void dw_mci_dto_timer(struct timer_list *t)
  {
  	struct dw_mci *host = from_timer(host, t, dto_timer);
  	unsigned long irqflags;
  	u32 pending;
  
  	spin_lock_irqsave(&host->irq_lock, irqflags);
  
  	/*
  	 * The DTO timer is much longer than the CTO timer, so it's even less
  	 * likely that we'll these cases, but it pays to be paranoid.
  	 */
  	pending = mci_readl(host, MINTSTS); /* read-only mask reg */
  	if (pending & SDMMC_INT_DATA_OVER) {
  		/* The interrupt should fire; no need to act but we can warn */
  		dev_warn(host->dev, "Unexpected data interrupt latency\n");
  		goto exit;
  	}
  	if (test_bit(EVENT_DATA_COMPLETE, &host->pending_events)) {
  		/* Presumably interrupt handler couldn't delete the timer */
  		dev_warn(host->dev, "DTO timeout when already completed\n");
  		goto exit;
  	}
  
  	/*
  	 * Continued paranoia to make sure we're in the state we expect.
  	 * This paranoia isn't really justified but it seems good to be safe.
  	 */
  	switch (host->state) {
  	case STATE_SENDING_DATA:
  	case STATE_DATA_BUSY:
  		/*
  		 * If DTO interrupt does NOT come in sending data state,
  		 * we should notify the driver to terminate current transfer
  		 * and report a data timeout to the core.
  		 */
  		host->data_status = SDMMC_INT_DRTO;
  		set_bit(EVENT_DATA_ERROR, &host->pending_events);
  		set_bit(EVENT_DATA_COMPLETE, &host->pending_events);
  		tasklet_schedule(&host->tasklet);
  		break;
  	default:
  		dev_warn(host->dev, "Unexpected data timeout, state %d\n",
  			 host->state);
  		break;
  	}
  
  exit:
  	spin_unlock_irqrestore(&host->irq_lock, irqflags);
  }
  
  #ifdef CONFIG_OF
  static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
  {
  	struct dw_mci_board *pdata;
  	struct device *dev = host->dev;
  	const struct dw_mci_drv_data *drv_data = host->drv_data;
  	int ret;
  	u32 clock_frequency;
  
  	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
  	if (!pdata)
  		return ERR_PTR(-ENOMEM);
  
  	/* find reset controller when exist */
  	pdata->rstc = devm_reset_control_get_optional_exclusive(dev, "reset");
  	if (IS_ERR(pdata->rstc)) {
  		if (PTR_ERR(pdata->rstc) == -EPROBE_DEFER)
  			return ERR_PTR(-EPROBE_DEFER);
  	}
  
  	if (device_property_read_u32(dev, "fifo-depth", &pdata->fifo_depth))
  		dev_info(dev,
  			 "fifo-depth property not found, using value of FIFOTH register as default\n");
  
  	device_property_read_u32(dev, "card-detect-delay",
  				 &pdata->detect_delay_ms);
  
  	device_property_read_u32(dev, "data-addr", &host->data_addr_override);
  
  	if (device_property_present(dev, "fifo-watermark-aligned"))
  		host->wm_aligned = true;
  
  	if (!device_property_read_u32(dev, "clock-frequency", &clock_frequency))
  		pdata->bus_hz = clock_frequency;
  
  	if (drv_data && drv_data->parse_dt) {
  		ret = drv_data->parse_dt(host);
  		if (ret)
  			return ERR_PTR(ret);
  	}
  
  	return pdata;
  }
  
  #else /* CONFIG_OF */
  static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
  {
  	return ERR_PTR(-EINVAL);
  }
  #endif /* CONFIG_OF */
  
  static void dw_mci_enable_cd(struct dw_mci *host)
  {
  	unsigned long irqflags;
  	u32 temp;
  
  	/*
  	 * No need for CD if all slots have a non-error GPIO
  	 * as well as broken card detection is found.
  	 */
  	if (host->slot->mmc->caps & MMC_CAP_NEEDS_POLL)
  		return;
  
  	if (mmc_gpio_get_cd(host->slot->mmc) < 0) {
  		spin_lock_irqsave(&host->irq_lock, irqflags);
  		temp = mci_readl(host, INTMASK);
  		temp  |= SDMMC_INT_CD;
  		mci_writel(host, INTMASK, temp);
  		spin_unlock_irqrestore(&host->irq_lock, irqflags);
  	}
  }
  
  int dw_mci_probe(struct dw_mci *host)
  {
  	const struct dw_mci_drv_data *drv_data = host->drv_data;
  	int width, i, ret = 0;
  	u32 fifo_size;
  
  	if (!host->pdata) {
  		host->pdata = dw_mci_parse_dt(host);
  		if (PTR_ERR(host->pdata) == -EPROBE_DEFER) {
  			return -EPROBE_DEFER;
  		} else if (IS_ERR(host->pdata)) {
  			dev_err(host->dev, "platform data not available\n");
  			return -EINVAL;
  		}
  	}
  
  	host->biu_clk = devm_clk_get(host->dev, "biu");
  	if (IS_ERR(host->biu_clk)) {
  		dev_dbg(host->dev, "biu clock not available\n");
  	} else {
  		ret = clk_prepare_enable(host->biu_clk);
  		if (ret) {
  			dev_err(host->dev, "failed to enable biu clock\n");
  			return ret;
  		}
  	}
  
  	host->ciu_clk = devm_clk_get(host->dev, "ciu");
  	if (IS_ERR(host->ciu_clk)) {
  		dev_dbg(host->dev, "ciu clock not available\n");
  		host->bus_hz = host->pdata->bus_hz;
  	} else {
  		ret = clk_prepare_enable(host->ciu_clk);
  		if (ret) {
  			dev_err(host->dev, "failed to enable ciu clock\n");
  			goto err_clk_biu;
  		}
  
  		if (host->pdata->bus_hz) {
  			ret = clk_set_rate(host->ciu_clk, host->pdata->bus_hz);
  			if (ret)
  				dev_warn(host->dev,
  					 "Unable to set bus rate to %uHz\n",
  					 host->pdata->bus_hz);
  		}
  		host->bus_hz = clk_get_rate(host->ciu_clk);
  	}
  
  	if (!host->bus_hz) {
  		dev_err(host->dev,
  			"Platform data must supply bus speed\n");
  		ret = -ENODEV;
  		goto err_clk_ciu;
  	}
  
  	if (!IS_ERR(host->pdata->rstc)) {
  		reset_control_assert(host->pdata->rstc);
  		usleep_range(10, 50);
  		reset_control_deassert(host->pdata->rstc);
  	}
  
  	if (drv_data && drv_data->init) {
  		ret = drv_data->init(host);
  		if (ret) {
  			dev_err(host->dev,
  				"implementation specific init failed\n");
  			goto err_clk_ciu;
  		}
  	}
  
  	timer_setup(&host->cmd11_timer, dw_mci_cmd11_timer, 0);
  	timer_setup(&host->cto_timer, dw_mci_cto_timer, 0);
  	timer_setup(&host->dto_timer, dw_mci_dto_timer, 0);
  
  	spin_lock_init(&host->lock);
  	spin_lock_init(&host->irq_lock);
  	INIT_LIST_HEAD(&host->queue);
  
  	/*
  	 * Get the host data width - this assumes that HCON has been set with
  	 * the correct values.
  	 */
  	i = SDMMC_GET_HDATA_WIDTH(mci_readl(host, HCON));
  	if (!i) {
  		host->push_data = dw_mci_push_data16;
  		host->pull_data = dw_mci_pull_data16;
  		width = 16;
  		host->data_shift = 1;
  	} else if (i == 2) {
  		host->push_data = dw_mci_push_data64;
  		host->pull_data = dw_mci_pull_data64;
  		width = 64;
  		host->data_shift = 3;
  	} else {
  		/* Check for a reserved value, and warn if it is */
  		WARN((i != 1),
  		     "HCON reports a reserved host data width!\n"
  		     "Defaulting to 32-bit access.\n");
  		host->push_data = dw_mci_push_data32;
  		host->pull_data = dw_mci_pull_data32;
  		width = 32;
  		host->data_shift = 2;
  	}
  
  	/* Reset all blocks */
  	if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
  		ret = -ENODEV;
  		goto err_clk_ciu;
  	}
  
  	host->dma_ops = host->pdata->dma_ops;
  	dw_mci_init_dma(host);
  
  	/* Clear the interrupts for the host controller */
  	mci_writel(host, RINTSTS, 0xFFFFFFFF);
  	mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */
  
  	/* Put in max timeout */
  	mci_writel(host, TMOUT, 0xFFFFFFFF);
  
  	/*
  	 * FIFO threshold settings  RxMark  = fifo_size / 2 - 1,
  	 *                          Tx Mark = fifo_size / 2 DMA Size = 8
  	 */
  	if (!host->pdata->fifo_depth) {
  		/*
  		 * Power-on value of RX_WMark is FIFO_DEPTH-1, but this may
  		 * have been overwritten by the bootloader, just like we're
  		 * about to do, so if you know the value for your hardware, you
  		 * should put it in the platform data.
  		 */
  		fifo_size = mci_readl(host, FIFOTH);
  		fifo_size = 1 + ((fifo_size >> 16) & 0xfff);
  	} else {
  		fifo_size = host->pdata->fifo_depth;
  	}
  	host->fifo_depth = fifo_size;
  	host->fifoth_val =
  		SDMMC_SET_FIFOTH(0x2, fifo_size / 2 - 1, fifo_size / 2);
  	mci_writel(host, FIFOTH, host->fifoth_val);
  
  	/* disable clock to CIU */
  	mci_writel(host, CLKENA, 0);
  	mci_writel(host, CLKSRC, 0);
  
  	/*
  	 * In 2.40a spec, Data offset is changed.
  	 * Need to check the version-id and set data-offset for DATA register.
  	 */
  	host->verid = SDMMC_GET_VERID(mci_readl(host, VERID));
  	dev_info(host->dev, "Version ID is %04x\n", host->verid);
  
  	if (host->data_addr_override)
  		host->fifo_reg = host->regs + host->data_addr_override;
  	else if (host->verid < DW_MMC_240A)
  		host->fifo_reg = host->regs + DATA_OFFSET;
  	else
  		host->fifo_reg = host->regs + DATA_240A_OFFSET;
  
  	tasklet_init(&host->tasklet, dw_mci_tasklet_func, (unsigned long)host);
  	ret = devm_request_irq(host->dev, host->irq, dw_mci_interrupt,
  			       host->irq_flags, "dw-mci", host);
  	if (ret)
  		goto err_dmaunmap;
  
  	/*
  	 * Enable interrupts for command done, data over, data empty,
  	 * receive ready and error such as transmit, receive timeout, crc error
  	 */
  	mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
  		   SDMMC_INT_TXDR | SDMMC_INT_RXDR |
  		   DW_MCI_ERROR_FLAGS);
  	/* Enable mci interrupt */
  	mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);
  
  	dev_info(host->dev,
  		 "DW MMC controller at irq %d,%d bit host data width,%u deep fifo\n",
  		 host->irq, width, fifo_size);
  
  	/* We need at least one slot to succeed */
  	ret = dw_mci_init_slot(host);
  	if (ret) {
  		dev_dbg(host->dev, "slot %d init failed\n", i);
  		goto err_dmaunmap;
  	}
  
  	/* Now that slots are all setup, we can enable card detect */
  	dw_mci_enable_cd(host);
  
  	return 0;
  
  err_dmaunmap:
  	if (host->use_dma && host->dma_ops->exit)
  		host->dma_ops->exit(host);
  
  	if (!IS_ERR(host->pdata->rstc))
  		reset_control_assert(host->pdata->rstc);
  
  err_clk_ciu:
  	clk_disable_unprepare(host->ciu_clk);
  
  err_clk_biu:
  	clk_disable_unprepare(host->biu_clk);
  
  	return ret;
  }
  EXPORT_SYMBOL(dw_mci_probe);
  
  void dw_mci_remove(struct dw_mci *host)
  {
  	dev_dbg(host->dev, "remove slot\n");
  	if (host->slot)
  		dw_mci_cleanup_slot(host->slot);
  
  	mci_writel(host, RINTSTS, 0xFFFFFFFF);
  	mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */
  
  	/* disable clock to CIU */
  	mci_writel(host, CLKENA, 0);
  	mci_writel(host, CLKSRC, 0);
  
  	if (host->use_dma && host->dma_ops->exit)
  		host->dma_ops->exit(host);
  
  	if (!IS_ERR(host->pdata->rstc))
  		reset_control_assert(host->pdata->rstc);
  
  	clk_disable_unprepare(host->ciu_clk);
  	clk_disable_unprepare(host->biu_clk);
  }
  EXPORT_SYMBOL(dw_mci_remove);
  
  
  
  #ifdef CONFIG_PM
  int dw_mci_runtime_suspend(struct device *dev)
  {
  	struct dw_mci *host = dev_get_drvdata(dev);
  
  	if (host->use_dma && host->dma_ops->exit)
  		host->dma_ops->exit(host);
  
  	clk_disable_unprepare(host->ciu_clk);
  
  	if (host->slot &&
  	    (mmc_can_gpio_cd(host->slot->mmc) ||
  	     !mmc_card_is_removable(host->slot->mmc)))
  		clk_disable_unprepare(host->biu_clk);
  
  	return 0;
  }
  EXPORT_SYMBOL(dw_mci_runtime_suspend);
  
  int dw_mci_runtime_resume(struct device *dev)
  {
  	int ret = 0;
  	struct dw_mci *host = dev_get_drvdata(dev);
  
  	if (host->slot &&
  	    (mmc_can_gpio_cd(host->slot->mmc) ||
  	     !mmc_card_is_removable(host->slot->mmc))) {
  		ret = clk_prepare_enable(host->biu_clk);
  		if (ret)
  			return ret;
  	}
  
  	ret = clk_prepare_enable(host->ciu_clk);
  	if (ret)
  		goto err;
  
  	if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
  		clk_disable_unprepare(host->ciu_clk);
  		ret = -ENODEV;
  		goto err;
  	}
  
  	if (host->use_dma && host->dma_ops->init)
  		host->dma_ops->init(host);
  
  	/*
  	 * Restore the initial value at FIFOTH register
  	 * And Invalidate the prev_blksz with zero
  	 */
  	mci_writel(host, FIFOTH, host->fifoth_val);
  	host->prev_blksz = 0;
  
  	/* Put in max timeout */
  	mci_writel(host, TMOUT, 0xFFFFFFFF);
  
  	mci_writel(host, RINTSTS, 0xFFFFFFFF);
  	mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
  		   SDMMC_INT_TXDR | SDMMC_INT_RXDR |
  		   DW_MCI_ERROR_FLAGS);
  	mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);
  
  
  	if (host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER)
  		dw_mci_set_ios(host->slot->mmc, &host->slot->mmc->ios);
  
  	/* Force setup bus to guarantee available clock output */
  	dw_mci_setup_bus(host->slot, true);
  
  	/* Re-enable SDIO interrupts. */
  	if (sdio_irq_claimed(host->slot->mmc))
  		__dw_mci_enable_sdio_irq(host->slot, 1);
  
  	/* Now that slots are all setup, we can enable card detect */
  	dw_mci_enable_cd(host);
  
  	return 0;
  
  err:
  	if (host->slot &&
  	    (mmc_can_gpio_cd(host->slot->mmc) ||
  	     !mmc_card_is_removable(host->slot->mmc)))
  		clk_disable_unprepare(host->biu_clk);
  
  	return ret;
  }
  EXPORT_SYMBOL(dw_mci_runtime_resume);
  #endif /* CONFIG_PM */
  
  static int __init dw_mci_init(void)
  {
  	pr_info("Synopsys Designware Multimedia Card Interface Driver\n");
  	return 0;
  }
  
  static void __exit dw_mci_exit(void)
  {
  }
  
  module_init(dw_mci_init);
  module_exit(dw_mci_exit);
  
  MODULE_DESCRIPTION("DW Multimedia Card Interface driver");
  MODULE_AUTHOR("NXP Semiconductor VietNam");
  MODULE_AUTHOR("Imagination Technologies Ltd");
  MODULE_LICENSE("GPL v2");
  