Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1229 insertions, 0 deletions

diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c
new file mode 100644
index 0000000000..5b3ab0e205
--- /dev/null
+++ b/drivers/mmc/host/mxcmmc.c
@@ -0,0 +1,1229 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/drivers/mmc/host/mxcmmc.c - Freescale i.MX MMCI driver
+ *
+ *  This is a driver for the SDHC controller found in Freescale MX2/MX3
+ *  SoCs. It is basically the same hardware as found on MX1 (imxmmc.c).
+ *  Unlike the hardware found on MX1, this hardware just works and does
+ *  not need all the quirks found in imxmmc.c, hence the separate driver.
+ *
+ *  Copyright (C) 2008 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
+ *  Copyright (C) 2006 Pavel Pisa, PiKRON <ppisa@pikron.com>
+ *
+ *  derived from pxamci.c by Russell King
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+#include <linux/highmem.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/blkdev.h>
+#include <linux/dma-mapping.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/card.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/regulator/consumer.h>
+#include <linux/dmaengine.h>
+#include <linux/types.h>
+#include <linux/of.h>
+#include <linux/of_dma.h>
+#include <linux/mmc/slot-gpio.h>
+
+#include <asm/dma.h>
+#include <asm/irq.h>
+#include <linux/platform_data/mmc-mxcmmc.h>
+
+#include <linux/dma/imx-dma.h>
+
+#define DRIVER_NAME "mxc-mmc"
+#define MXCMCI_TIMEOUT_MS 10000
+
+#define MMC_REG_STR_STP_CLK		0x00
+#define MMC_REG_STATUS			0x04
+#define MMC_REG_CLK_RATE		0x08
+#define MMC_REG_CMD_DAT_CONT		0x0C
+#define MMC_REG_RES_TO			0x10
+#define MMC_REG_READ_TO			0x14
+#define MMC_REG_BLK_LEN			0x18
+#define MMC_REG_NOB			0x1C
+#define MMC_REG_REV_NO			0x20
+#define MMC_REG_INT_CNTR		0x24
+#define MMC_REG_CMD			0x28
+#define MMC_REG_ARG			0x2C
+#define MMC_REG_RES_FIFO		0x34
+#define MMC_REG_BUFFER_ACCESS		0x38
+
+#define STR_STP_CLK_RESET               (1 << 3)
+#define STR_STP_CLK_START_CLK           (1 << 1)
+#define STR_STP_CLK_STOP_CLK            (1 << 0)
+
+#define STATUS_CARD_INSERTION		(1 << 31)
+#define STATUS_CARD_REMOVAL		(1 << 30)
+#define STATUS_YBUF_EMPTY		(1 << 29)
+#define STATUS_XBUF_EMPTY		(1 << 28)
+#define STATUS_YBUF_FULL		(1 << 27)
+#define STATUS_XBUF_FULL		(1 << 26)
+#define STATUS_BUF_UND_RUN		(1 << 25)
+#define STATUS_BUF_OVFL			(1 << 24)
+#define STATUS_SDIO_INT_ACTIVE		(1 << 14)
+#define STATUS_END_CMD_RESP		(1 << 13)
+#define STATUS_WRITE_OP_DONE		(1 << 12)
+#define STATUS_DATA_TRANS_DONE		(1 << 11)
+#define STATUS_READ_OP_DONE		(1 << 11)
+#define STATUS_WR_CRC_ERROR_CODE_MASK	(3 << 10)
+#define STATUS_CARD_BUS_CLK_RUN		(1 << 8)
+#define STATUS_BUF_READ_RDY		(1 << 7)
+#define STATUS_BUF_WRITE_RDY		(1 << 6)
+#define STATUS_RESP_CRC_ERR		(1 << 5)
+#define STATUS_CRC_READ_ERR		(1 << 3)
+#define STATUS_CRC_WRITE_ERR		(1 << 2)
+#define STATUS_TIME_OUT_RESP		(1 << 1)
+#define STATUS_TIME_OUT_READ		(1 << 0)
+#define STATUS_ERR_MASK			0x2f
+
+#define CMD_DAT_CONT_CMD_RESP_LONG_OFF	(1 << 12)
+#define CMD_DAT_CONT_STOP_READWAIT	(1 << 11)
+#define CMD_DAT_CONT_START_READWAIT	(1 << 10)
+#define CMD_DAT_CONT_BUS_WIDTH_4	(2 << 8)
+#define CMD_DAT_CONT_INIT		(1 << 7)
+#define CMD_DAT_CONT_WRITE		(1 << 4)
+#define CMD_DAT_CONT_DATA_ENABLE	(1 << 3)
+#define CMD_DAT_CONT_RESPONSE_48BIT_CRC	(1 << 0)
+#define CMD_DAT_CONT_RESPONSE_136BIT	(2 << 0)
+#define CMD_DAT_CONT_RESPONSE_48BIT	(3 << 0)
+
+#define INT_SDIO_INT_WKP_EN		(1 << 18)
+#define INT_CARD_INSERTION_WKP_EN	(1 << 17)
+#define INT_CARD_REMOVAL_WKP_EN		(1 << 16)
+#define INT_CARD_INSERTION_EN		(1 << 15)
+#define INT_CARD_REMOVAL_EN		(1 << 14)
+#define INT_SDIO_IRQ_EN			(1 << 13)
+#define INT_DAT0_EN			(1 << 12)
+#define INT_BUF_READ_EN			(1 << 4)
+#define INT_BUF_WRITE_EN		(1 << 3)
+#define INT_END_CMD_RES_EN		(1 << 2)
+#define INT_WRITE_OP_DONE_EN		(1 << 1)
+#define INT_READ_OP_EN			(1 << 0)
+
+enum mxcmci_type {
+	IMX21_MMC,
+	IMX31_MMC,
+	MPC512X_MMC,
+};
+
+struct mxcmci_host {
+	struct mmc_host		*mmc;
+	void __iomem		*base;
+	dma_addr_t		phys_base;
+	int			detect_irq;
+	struct dma_chan		*dma;
+	struct dma_async_tx_descriptor *desc;
+	int			do_dma;
+	int			default_irq_mask;
+	int			use_sdio;
+	unsigned int		power_mode;
+	struct imxmmc_platform_data *pdata;
+
+	struct mmc_request	*req;
+	struct mmc_command	*cmd;
+	struct mmc_data		*data;
+
+	unsigned int		datasize;
+	unsigned int		dma_dir;
+
+	u16			rev_no;
+	unsigned int		cmdat;
+
+	struct clk		*clk_ipg;
+	struct clk		*clk_per;
+
+	int			clock;
+
+	struct work_struct	datawork;
+	spinlock_t		lock;
+
+	int			burstlen;
+	int			dmareq;
+	struct dma_slave_config dma_slave_config;
+	struct imx_dma_data	dma_data;
+
+	struct timer_list	watchdog;
+	enum mxcmci_type	devtype;
+};
+
+static const struct of_device_id mxcmci_of_match[] = {
+	{
+		.compatible = "fsl,imx21-mmc",
+		.data = (void *) IMX21_MMC,
+	}, {
+		.compatible = "fsl,imx31-mmc",
+		.data = (void *) IMX31_MMC,
+	}, {
+		.compatible = "fsl,mpc5121-sdhc",
+		.data = (void *) MPC512X_MMC,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, mxcmci_of_match);
+
+static inline int is_imx31_mmc(struct mxcmci_host *host)
+{
+	return host->devtype == IMX31_MMC;
+}
+
+static inline int is_mpc512x_mmc(struct mxcmci_host *host)
+{
+	return host->devtype == MPC512X_MMC;
+}
+
+static inline u32 mxcmci_readl(struct mxcmci_host *host, int reg)
+{
+	if (IS_ENABLED(CONFIG_PPC_MPC512x))
+		return ioread32be(host->base + reg);
+	else
+		return readl(host->base + reg);
+}
+
+static inline void mxcmci_writel(struct mxcmci_host *host, u32 val, int reg)
+{
+	if (IS_ENABLED(CONFIG_PPC_MPC512x))
+		iowrite32be(val, host->base + reg);
+	else
+		writel(val, host->base + reg);
+}
+
+static inline u16 mxcmci_readw(struct mxcmci_host *host, int reg)
+{
+	if (IS_ENABLED(CONFIG_PPC_MPC512x))
+		return ioread32be(host->base + reg);
+	else
+		return readw(host->base + reg);
+}
+
+static inline void mxcmci_writew(struct mxcmci_host *host, u16 val, int reg)
+{
+	if (IS_ENABLED(CONFIG_PPC_MPC512x))
+		iowrite32be(val, host->base + reg);
+	else
+		writew(val, host->base + reg);
+}
+
+static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios);
+
+static void mxcmci_set_power(struct mxcmci_host *host, unsigned int vdd)
+{
+	if (!IS_ERR(host->mmc->supply.vmmc)) {
+		if (host->power_mode == MMC_POWER_UP)
+			mmc_regulator_set_ocr(host->mmc,
+					      host->mmc->supply.vmmc, vdd);
+		else if (host->power_mode == MMC_POWER_OFF)
+			mmc_regulator_set_ocr(host->mmc,
+					      host->mmc->supply.vmmc, 0);
+	}
+
+	if (host->pdata && host->pdata->setpower)
+		host->pdata->setpower(mmc_dev(host->mmc), vdd);
+}
+
+static inline int mxcmci_use_dma(struct mxcmci_host *host)
+{
+	return host->do_dma;
+}
+
+static void mxcmci_softreset(struct mxcmci_host *host)
+{
+	int i;
+
+	dev_dbg(mmc_dev(host->mmc), "mxcmci_softreset\n");
+
+	/* reset sequence */
+	mxcmci_writew(host, STR_STP_CLK_RESET, MMC_REG_STR_STP_CLK);
+	mxcmci_writew(host, STR_STP_CLK_RESET | STR_STP_CLK_START_CLK,
+			MMC_REG_STR_STP_CLK);
+
+	for (i = 0; i < 8; i++)
+		mxcmci_writew(host, STR_STP_CLK_START_CLK, MMC_REG_STR_STP_CLK);
+
+	mxcmci_writew(host, 0xff, MMC_REG_RES_TO);
+}
+
+#if IS_ENABLED(CONFIG_PPC_MPC512x)
+static inline void buffer_swap32(u32 *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < ((len + 3) / 4); i++) {
+		*buf = swab32(*buf);
+		buf++;
+	}
+}
+
+static void mxcmci_swap_buffers(struct mmc_data *data)
+{
+	struct scatterlist *sg;
+	int i;
+
+	for_each_sg(data->sg, sg, data->sg_len, i)
+		buffer_swap32(sg_virt(sg), sg->length);
+}
+#else
+static inline void mxcmci_swap_buffers(struct mmc_data *data) {}
+#endif
+
+static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
+{
+	unsigned int nob = data->blocks;
+	unsigned int blksz = data->blksz;
+	unsigned int datasize = nob * blksz;
+	struct scatterlist *sg;
+	enum dma_transfer_direction slave_dirn;
+	int i, nents;
+
+	host->data = data;
+	data->bytes_xfered = 0;
+
+	mxcmci_writew(host, nob, MMC_REG_NOB);
+	mxcmci_writew(host, blksz, MMC_REG_BLK_LEN);
+	host->datasize = datasize;
+
+	if (!mxcmci_use_dma(host))
+		return 0;
+
+	for_each_sg(data->sg, sg, data->sg_len, i) {
+		if (sg->offset & 3 || sg->length & 3 || sg->length < 512) {
+			host->do_dma = 0;
+			return 0;
+		}
+	}
+
+	if (data->flags & MMC_DATA_READ) {
+		host->dma_dir = DMA_FROM_DEVICE;
+		slave_dirn = DMA_DEV_TO_MEM;
+	} else {
+		host->dma_dir = DMA_TO_DEVICE;
+		slave_dirn = DMA_MEM_TO_DEV;
+
+		mxcmci_swap_buffers(data);
+	}
+
+	nents = dma_map_sg(host->dma->device->dev, data->sg,
+				     data->sg_len,  host->dma_dir);
+	if (nents != data->sg_len)
+		return -EINVAL;
+
+	host->desc = dmaengine_prep_slave_sg(host->dma,
+		data->sg, data->sg_len, slave_dirn,
+		DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+
+	if (!host->desc) {
+		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
+				host->dma_dir);
+		host->do_dma = 0;
+		return 0; /* Fall back to PIO */
+	}
+	wmb();
+
+	dmaengine_submit(host->desc);
+	dma_async_issue_pending(host->dma);
+
+	mod_timer(&host->watchdog, jiffies + msecs_to_jiffies(MXCMCI_TIMEOUT_MS));
+
+	return 0;
+}
+
+static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat);
+static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat);
+
+static void mxcmci_dma_callback(void *data)
+{
+	struct mxcmci_host *host = data;
+	u32 stat;
+
+	del_timer(&host->watchdog);
+
+	stat = mxcmci_readl(host, MMC_REG_STATUS);
+
+	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
+
+	mxcmci_data_done(host, stat);
+}
+
+static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_command *cmd,
+		unsigned int cmdat)
+{
+	u32 int_cntr = host->default_irq_mask;
+	unsigned long flags;
+
+	WARN_ON(host->cmd != NULL);
+	host->cmd = cmd;
+
+	switch (mmc_resp_type(cmd)) {
+	case MMC_RSP_R1: /* short CRC, OPCODE */
+	case MMC_RSP_R1B:/* short CRC, OPCODE, BUSY */
+		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT_CRC;
+		break;
+	case MMC_RSP_R2: /* long 136 bit + CRC */
+		cmdat |= CMD_DAT_CONT_RESPONSE_136BIT;
+		break;
+	case MMC_RSP_R3: /* short */
+		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT;
+		break;
+	case MMC_RSP_NONE:
+		break;
+	default:
+		dev_err(mmc_dev(host->mmc), "unhandled response type 0x%x\n",
+				mmc_resp_type(cmd));
+		cmd->error = -EINVAL;
+		return -EINVAL;
+	}
+
+	int_cntr = INT_END_CMD_RES_EN;
+
+	if (mxcmci_use_dma(host)) {
+		if (host->dma_dir == DMA_FROM_DEVICE) {
+			host->desc->callback = mxcmci_dma_callback;
+			host->desc->callback_param = host;
+		} else {
+			int_cntr |= INT_WRITE_OP_DONE_EN;
+		}
+	}
+
+	spin_lock_irqsave(&host->lock, flags);
+	if (host->use_sdio)
+		int_cntr |= INT_SDIO_IRQ_EN;
+	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
+	spin_unlock_irqrestore(&host->lock, flags);
+
+	mxcmci_writew(host, cmd->opcode, MMC_REG_CMD);
+	mxcmci_writel(host, cmd->arg, MMC_REG_ARG);
+	mxcmci_writew(host, cmdat, MMC_REG_CMD_DAT_CONT);
+
+	return 0;
+}
+
+static void mxcmci_finish_request(struct mxcmci_host *host,
+		struct mmc_request *req)
+{
+	u32 int_cntr = host->default_irq_mask;
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->lock, flags);
+	if (host->use_sdio)
+		int_cntr |= INT_SDIO_IRQ_EN;
+	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
+	spin_unlock_irqrestore(&host->lock, flags);
+
+	host->req = NULL;
+	host->cmd = NULL;
+	host->data = NULL;
+
+	mmc_request_done(host->mmc, req);
+}
+
+static int mxcmci_finish_data(struct mxcmci_host *host, unsigned int stat)
+{
+	struct mmc_data *data = host->data;
+	int data_error;
+
+	if (mxcmci_use_dma(host)) {
+		dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
+				host->dma_dir);
+		mxcmci_swap_buffers(data);
+	}
+
+	if (stat & STATUS_ERR_MASK) {
+		dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n",
+				stat);
+		if (stat & STATUS_CRC_READ_ERR) {
+			dev_err(mmc_dev(host->mmc), "%s: -EILSEQ\n", __func__);
+			data->error = -EILSEQ;
+		} else if (stat & STATUS_CRC_WRITE_ERR) {
+			u32 err_code = (stat >> 9) & 0x3;
+			if (err_code == 2) { /* No CRC response */
+				dev_err(mmc_dev(host->mmc),
+					"%s: No CRC -ETIMEDOUT\n", __func__);
+				data->error = -ETIMEDOUT;
+			} else {
+				dev_err(mmc_dev(host->mmc),
+					"%s: -EILSEQ\n", __func__);
+				data->error = -EILSEQ;
+			}
+		} else if (stat & STATUS_TIME_OUT_READ) {
+			dev_err(mmc_dev(host->mmc),
+				"%s: read -ETIMEDOUT\n", __func__);
+			data->error = -ETIMEDOUT;
+		} else {
+			dev_err(mmc_dev(host->mmc), "%s: -EIO\n", __func__);
+			data->error = -EIO;
+		}
+	} else {
+		data->bytes_xfered = host->datasize;
+	}
+
+	data_error = data->error;
+
+	host->data = NULL;
+
+	return data_error;
+}
+
+static void mxcmci_read_response(struct mxcmci_host *host, unsigned int stat)
+{
+	struct mmc_command *cmd = host->cmd;
+	int i;
+	u32 a, b, c;
+
+	if (!cmd)
+		return;
+
+	if (stat & STATUS_TIME_OUT_RESP) {
+		dev_dbg(mmc_dev(host->mmc), "CMD TIMEOUT\n");
+		cmd->error = -ETIMEDOUT;
+	} else if (stat & STATUS_RESP_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
+		dev_dbg(mmc_dev(host->mmc), "cmd crc error\n");
+		cmd->error = -EILSEQ;
+	}
+
+	if (cmd->flags & MMC_RSP_PRESENT) {
+		if (cmd->flags & MMC_RSP_136) {
+			for (i = 0; i < 4; i++) {
+				a = mxcmci_readw(host, MMC_REG_RES_FIFO);
+				b = mxcmci_readw(host, MMC_REG_RES_FIFO);
+				cmd->resp[i] = a << 16 | b;
+			}
+		} else {
+			a = mxcmci_readw(host, MMC_REG_RES_FIFO);
+			b = mxcmci_readw(host, MMC_REG_RES_FIFO);
+			c = mxcmci_readw(host, MMC_REG_RES_FIFO);
+			cmd->resp[0] = a << 24 | b << 8 | c >> 8;
+		}
+	}
+}
+
+static int mxcmci_poll_status(struct mxcmci_host *host, u32 mask)
+{
+	u32 stat;
+	unsigned long timeout = jiffies + HZ;
+
+	do {
+		stat = mxcmci_readl(host, MMC_REG_STATUS);
+		if (stat & STATUS_ERR_MASK)
+			return stat;
+		if (time_after(jiffies, timeout)) {
+			mxcmci_softreset(host);
+			mxcmci_set_clk_rate(host, host->clock);
+			return STATUS_TIME_OUT_READ;
+		}
+		if (stat & mask)
+			return 0;
+		cpu_relax();
+	} while (1);
+}
+
+static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes)
+{
+	unsigned int stat;
+	u32 *buf = _buf;
+
+	while (bytes > 3) {
+		stat = mxcmci_poll_status(host,
+				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
+		if (stat)
+			return stat;
+		*buf++ = cpu_to_le32(mxcmci_readl(host, MMC_REG_BUFFER_ACCESS));
+		bytes -= 4;
+	}
+
+	if (bytes) {
+		u8 *b = (u8 *)buf;
+		u32 tmp;
+
+		stat = mxcmci_poll_status(host,
+				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
+		if (stat)
+			return stat;
+		tmp = cpu_to_le32(mxcmci_readl(host, MMC_REG_BUFFER_ACCESS));
+		memcpy(b, &tmp, bytes);
+	}
+
+	return 0;
+}
+
+static int mxcmci_push(struct mxcmci_host *host, void *_buf, int bytes)
+{
+	unsigned int stat;
+	u32 *buf = _buf;
+
+	while (bytes > 3) {
+		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
+		if (stat)
+			return stat;
+		mxcmci_writel(host, cpu_to_le32(*buf++), MMC_REG_BUFFER_ACCESS);
+		bytes -= 4;
+	}
+
+	if (bytes) {
+		u8 *b = (u8 *)buf;
+		u32 tmp;
+
+		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
+		if (stat)
+			return stat;
+
+		memcpy(&tmp, b, bytes);
+		mxcmci_writel(host, cpu_to_le32(tmp), MMC_REG_BUFFER_ACCESS);
+	}
+
+	return mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
+}
+
+static int mxcmci_transfer_data(struct mxcmci_host *host)
+{
+	struct mmc_data *data = host->req->data;
+	struct scatterlist *sg;
+	int stat, i;
+
+	host->data = data;
+	host->datasize = 0;
+
+	if (data->flags & MMC_DATA_READ) {
+		for_each_sg(data->sg, sg, data->sg_len, i) {
+			stat = mxcmci_pull(host, sg_virt(sg), sg->length);
+			if (stat)
+				return stat;
+			host->datasize += sg->length;
+		}
+	} else {
+		for_each_sg(data->sg, sg, data->sg_len, i) {
+			stat = mxcmci_push(host, sg_virt(sg), sg->length);
+			if (stat)
+				return stat;
+			host->datasize += sg->length;
+		}
+		stat = mxcmci_poll_status(host, STATUS_WRITE_OP_DONE);
+		if (stat)
+			return stat;
+	}
+	return 0;
+}
+
+static void mxcmci_datawork(struct work_struct *work)
+{
+	struct mxcmci_host *host = container_of(work, struct mxcmci_host,
+						  datawork);
+	int datastat = mxcmci_transfer_data(host);
+
+	mxcmci_writel(host, STATUS_READ_OP_DONE | STATUS_WRITE_OP_DONE,
+		MMC_REG_STATUS);
+	mxcmci_finish_data(host, datastat);
+
+	if (host->req->stop) {
+		if (mxcmci_start_cmd(host, host->req->stop, 0)) {
+			mxcmci_finish_request(host, host->req);
+			return;
+		}
+	} else {
+		mxcmci_finish_request(host, host->req);
+	}
+}
+
+static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat)
+{
+	struct mmc_request *req;
+	int data_error;
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->lock, flags);
+
+	if (!host->data) {
+		spin_unlock_irqrestore(&host->lock, flags);
+		return;
+	}
+
+	if (!host->req) {
+		spin_unlock_irqrestore(&host->lock, flags);
+		return;
+	}
+
+	req = host->req;
+	if (!req->stop)
+		host->req = NULL; /* we will handle finish req below */
+
+	data_error = mxcmci_finish_data(host, stat);
+
+	spin_unlock_irqrestore(&host->lock, flags);
+
+	if (data_error)
+		return;
+
+	mxcmci_read_response(host, stat);
+	host->cmd = NULL;
+
+	if (req->stop) {
+		if (mxcmci_start_cmd(host, req->stop, 0)) {
+			mxcmci_finish_request(host, req);
+			return;
+		}
+	} else {
+		mxcmci_finish_request(host, req);
+	}
+}
+
+static void mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat)
+{
+	mxcmci_read_response(host, stat);
+	host->cmd = NULL;
+
+	if (!host->data && host->req) {
+		mxcmci_finish_request(host, host->req);
+		return;
+	}
+
+	/* For the DMA case the DMA engine handles the data transfer
+	 * automatically. For non DMA we have to do it ourselves.
+	 * Don't do it in interrupt context though.
+	 */
+	if (!mxcmci_use_dma(host) && host->data)
+		schedule_work(&host->datawork);
+
+}
+
+static irqreturn_t mxcmci_irq(int irq, void *devid)
+{
+	struct mxcmci_host *host = devid;
+	bool sdio_irq;
+	u32 stat;
+
+	stat = mxcmci_readl(host, MMC_REG_STATUS);
+	mxcmci_writel(host,
+		stat & ~(STATUS_SDIO_INT_ACTIVE | STATUS_DATA_TRANS_DONE |
+			 STATUS_WRITE_OP_DONE),
+		MMC_REG_STATUS);
+
+	dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);
+
+	spin_lock(&host->lock);
+	sdio_irq = (stat & STATUS_SDIO_INT_ACTIVE) && host->use_sdio;
+	spin_unlock(&host->lock);
+
+	if (mxcmci_use_dma(host) && (stat & (STATUS_WRITE_OP_DONE)))
+		mxcmci_writel(host, STATUS_WRITE_OP_DONE, MMC_REG_STATUS);
+
+	if (sdio_irq) {
+		mxcmci_writel(host, STATUS_SDIO_INT_ACTIVE, MMC_REG_STATUS);
+		mmc_signal_sdio_irq(host->mmc);
+	}
+
+	if (stat & STATUS_END_CMD_RESP)
+		mxcmci_cmd_done(host, stat);
+
+	if (mxcmci_use_dma(host) && (stat & STATUS_WRITE_OP_DONE)) {
+		del_timer(&host->watchdog);
+		mxcmci_data_done(host, stat);
+	}
+
+	if (host->default_irq_mask &&
+		  (stat & (STATUS_CARD_INSERTION | STATUS_CARD_REMOVAL)))
+		mmc_detect_change(host->mmc, msecs_to_jiffies(200));
+
+	return IRQ_HANDLED;
+}
+
+static void mxcmci_request(struct mmc_host *mmc, struct mmc_request *req)
+{
+	struct mxcmci_host *host = mmc_priv(mmc);
+	unsigned int cmdat = host->cmdat;
+	int error;
+
+	WARN_ON(host->req != NULL);
+
+	host->req = req;
+	host->cmdat &= ~CMD_DAT_CONT_INIT;
+
+	if (host->dma)
+		host->do_dma = 1;
+
+	if (req->data) {
+		error = mxcmci_setup_data(host, req->data);
+		if (error) {
+			req->cmd->error = error;
+			goto out;
+		}
+
+
+		cmdat |= CMD_DAT_CONT_DATA_ENABLE;
+
+		if (req->data->flags & MMC_DATA_WRITE)
+			cmdat |= CMD_DAT_CONT_WRITE;
+	}
+
+	error = mxcmci_start_cmd(host, req->cmd, cmdat);
+
+out:
+	if (error)
+		mxcmci_finish_request(host, req);
+}
+
+static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios)
+{
+	unsigned int divider;
+	int prescaler = 0;
+	unsigned int clk_in = clk_get_rate(host->clk_per);
+
+	while (prescaler <= 0x800) {
+		for (divider = 1; divider <= 0xF; divider++) {
+			int x;
+
+			x = (clk_in / (divider + 1));
+
+			if (prescaler)
+				x /= (prescaler * 2);
+
+			if (x <= clk_ios)
+				break;
+		}
+		if (divider < 0x10)
+			break;
+
+		if (prescaler == 0)
+			prescaler = 1;
+		else
+			prescaler <<= 1;
+	}
+
+	mxcmci_writew(host, (prescaler << 4) | divider, MMC_REG_CLK_RATE);
+
+	dev_dbg(mmc_dev(host->mmc), "scaler: %d divider: %d in: %d out: %d\n",
+			prescaler, divider, clk_in, clk_ios);
+}
+
+static int mxcmci_setup_dma(struct mmc_host *mmc)
+{
+	struct mxcmci_host *host = mmc_priv(mmc);
+	struct dma_slave_config *config = &host->dma_slave_config;
+
+	config->dst_addr = host->phys_base + MMC_REG_BUFFER_ACCESS;
+	config->src_addr = host->phys_base + MMC_REG_BUFFER_ACCESS;
+	config->dst_addr_width = 4;
+	config->src_addr_width = 4;
+	config->dst_maxburst = host->burstlen;
+	config->src_maxburst = host->burstlen;
+	config->device_fc = false;
+
+	return dmaengine_slave_config(host->dma, config);
+}
+
+static void mxcmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct mxcmci_host *host = mmc_priv(mmc);
+	int burstlen, ret;
+
+	/*
+	 * use burstlen of 64 (16 words) in 4 bit mode (--> reg value  0)
+	 * use burstlen of 16 (4 words) in 1 bit mode (--> reg value 16)
+	 */
+	if (ios->bus_width == MMC_BUS_WIDTH_4)
+		burstlen = 16;
+	else
+		burstlen = 4;
+
+	if (mxcmci_use_dma(host) && burstlen != host->burstlen) {
+		host->burstlen = burstlen;
+		ret = mxcmci_setup_dma(mmc);
+		if (ret) {
+			dev_err(mmc_dev(host->mmc),
+				"failed to config DMA channel. Falling back to PIO\n");
+			dma_release_channel(host->dma);
+			host->do_dma = 0;
+			host->dma = NULL;
+		}
+	}
+
+	if (ios->bus_width == MMC_BUS_WIDTH_4)
+		host->cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
+	else
+		host->cmdat &= ~CMD_DAT_CONT_BUS_WIDTH_4;
+
+	if (host->power_mode != ios->power_mode) {
+		host->power_mode = ios->power_mode;
+		mxcmci_set_power(host, ios->vdd);
+
+		if (ios->power_mode == MMC_POWER_ON)
+			host->cmdat |= CMD_DAT_CONT_INIT;
+	}
+
+	if (ios->clock) {
+		mxcmci_set_clk_rate(host, ios->clock);
+		mxcmci_writew(host, STR_STP_CLK_START_CLK, MMC_REG_STR_STP_CLK);
+	} else {
+		mxcmci_writew(host, STR_STP_CLK_STOP_CLK, MMC_REG_STR_STP_CLK);
+	}
+
+	host->clock = ios->clock;
+}
+
+static irqreturn_t mxcmci_detect_irq(int irq, void *data)
+{
+	struct mmc_host *mmc = data;
+
+	dev_dbg(mmc_dev(mmc), "%s\n", __func__);
+
+	mmc_detect_change(mmc, msecs_to_jiffies(250));
+	return IRQ_HANDLED;
+}
+
+static int mxcmci_get_ro(struct mmc_host *mmc)
+{
+	struct mxcmci_host *host = mmc_priv(mmc);
+
+	if (host->pdata && host->pdata->get_ro)
+		return !!host->pdata->get_ro(mmc_dev(mmc));
+	/*
+	 * If board doesn't support read only detection (no mmc_gpio
+	 * context or gpio is invalid), then let the mmc core decide
+	 * what to do.
+	 */
+	return mmc_gpio_get_ro(mmc);
+}
+
+static void mxcmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+	struct mxcmci_host *host = mmc_priv(mmc);
+	unsigned long flags;
+	u32 int_cntr;
+
+	spin_lock_irqsave(&host->lock, flags);
+	host->use_sdio = enable;
+	int_cntr = mxcmci_readl(host, MMC_REG_INT_CNTR);
+
+	if (enable)
+		int_cntr |= INT_SDIO_IRQ_EN;
+	else
+		int_cntr &= ~INT_SDIO_IRQ_EN;
+
+	mxcmci_writel(host, int_cntr, MMC_REG_INT_CNTR);
+	spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void mxcmci_init_card(struct mmc_host *host, struct mmc_card *card)
+{
+	struct mxcmci_host *mxcmci = mmc_priv(host);
+
+	/*
+	 * MX3 SoCs have a silicon bug which corrupts CRC calculation of
+	 * multi-block transfers when connected SDIO peripheral doesn't
+	 * drive the BUSY line as required by the specs.
+	 * One way to prevent this is to only allow 1-bit transfers.
+	 */
+
+	if (is_imx31_mmc(mxcmci) && mmc_card_sdio(card))
+		host->caps &= ~MMC_CAP_4_BIT_DATA;
+	else
+		host->caps |= MMC_CAP_4_BIT_DATA;
+}
+
+static bool filter(struct dma_chan *chan, void *param)
+{
+	struct mxcmci_host *host = param;
+
+	if (!imx_dma_is_general_purpose(chan))
+		return false;
+
+	chan->private = &host->dma_data;
+
+	return true;
+}
+
+static void mxcmci_watchdog(struct timer_list *t)
+{
+	struct mxcmci_host *host = from_timer(host, t, watchdog);
+	struct mmc_request *req = host->req;
+	unsigned int stat = mxcmci_readl(host, MMC_REG_STATUS);
+
+	if (host->dma_dir == DMA_FROM_DEVICE) {
+		dmaengine_terminate_all(host->dma);
+		dev_err(mmc_dev(host->mmc),
+			"%s: read time out (status = 0x%08x)\n",
+			__func__, stat);
+	} else {
+		dev_err(mmc_dev(host->mmc),
+			"%s: write time out (status = 0x%08x)\n",
+			__func__, stat);
+		mxcmci_softreset(host);
+	}
+
+	/* Mark transfer as erroneus and inform the upper layers */
+
+	if (host->data)
+		host->data->error = -ETIMEDOUT;
+	host->req = NULL;
+	host->cmd = NULL;
+	host->data = NULL;
+	mmc_request_done(host->mmc, req);
+}
+
+static const struct mmc_host_ops mxcmci_ops = {
+	.request		= mxcmci_request,
+	.set_ios		= mxcmci_set_ios,
+	.get_ro			= mxcmci_get_ro,
+	.enable_sdio_irq	= mxcmci_enable_sdio_irq,
+	.init_card		= mxcmci_init_card,
+};
+
+static int mxcmci_probe(struct platform_device *pdev)
+{
+	struct mmc_host *mmc;
+	struct mxcmci_host *host;
+	struct resource *res;
+	int ret = 0, irq;
+	bool dat3_card_detect = false;
+	dma_cap_mask_t mask;
+	struct imxmmc_platform_data *pdata = pdev->dev.platform_data;
+
+	pr_info("i.MX/MPC512x SDHC driver\n");
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	mmc = mmc_alloc_host(sizeof(*host), &pdev->dev);
+	if (!mmc)
+		return -ENOMEM;
+
+	host = mmc_priv(mmc);
+
+	host->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(host->base)) {
+		ret = PTR_ERR(host->base);
+		goto out_free;
+	}
+
+	host->phys_base = res->start;
+
+	ret = mmc_of_parse(mmc);
+	if (ret)
+		goto out_free;
+	mmc->ops = &mxcmci_ops;
+
+	/* For devicetree parsing, the bus width is read from devicetree */
+	if (pdata)
+		mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
+	else
+		mmc->caps |= MMC_CAP_SDIO_IRQ;
+
+	/* MMC core transfer sizes tunable parameters */
+	mmc->max_blk_size = 2048;
+	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;
+
+	host->devtype = (uintptr_t)of_device_get_match_data(&pdev->dev);
+
+	/* adjust max_segs after devtype detection */
+	if (!is_mpc512x_mmc(host))
+		mmc->max_segs = 64;
+
+	host->mmc = mmc;
+	host->pdata = pdata;
+	spin_lock_init(&host->lock);
+
+	if (pdata)
+		dat3_card_detect = pdata->dat3_card_detect;
+	else if (mmc_card_is_removable(mmc)
+			&& !of_property_read_bool(pdev->dev.of_node, "cd-gpios"))
+		dat3_card_detect = true;
+
+	ret = mmc_regulator_get_supply(mmc);
+	if (ret)
+		goto out_free;
+
+	if (!mmc->ocr_avail) {
+		if (pdata && pdata->ocr_avail)
+			mmc->ocr_avail = pdata->ocr_avail;
+		else
+			mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
+	}
+
+	if (dat3_card_detect)
+		host->default_irq_mask =
+			INT_CARD_INSERTION_EN | INT_CARD_REMOVAL_EN;
+	else
+		host->default_irq_mask = 0;
+
+	host->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+	if (IS_ERR(host->clk_ipg)) {
+		ret = PTR_ERR(host->clk_ipg);
+		goto out_free;
+	}
+
+	host->clk_per = devm_clk_get(&pdev->dev, "per");
+	if (IS_ERR(host->clk_per)) {
+		ret = PTR_ERR(host->clk_per);
+		goto out_free;
+	}
+
+	ret = clk_prepare_enable(host->clk_per);
+	if (ret)
+		goto out_free;
+
+	ret = clk_prepare_enable(host->clk_ipg);
+	if (ret)
+		goto out_clk_per_put;
+
+	mxcmci_softreset(host);
+
+	host->rev_no = mxcmci_readw(host, MMC_REG_REV_NO);
+	if (host->rev_no != 0x400) {
+		ret = -ENODEV;
+		dev_err(mmc_dev(host->mmc), "wrong rev.no. 0x%08x. aborting.\n",
+			host->rev_no);
+		goto out_clk_put;
+	}
+
+	mmc->f_min = clk_get_rate(host->clk_per) >> 16;
+	mmc->f_max = clk_get_rate(host->clk_per) >> 1;
+
+	/* recommended in data sheet */
+	mxcmci_writew(host, 0x2db4, MMC_REG_READ_TO);
+
+	mxcmci_writel(host, host->default_irq_mask, MMC_REG_INT_CNTR);
+
+	if (!host->pdata) {
+		host->dma = dma_request_chan(&pdev->dev, "rx-tx");
+		if (IS_ERR(host->dma)) {
+			if (PTR_ERR(host->dma) == -EPROBE_DEFER) {
+				ret = -EPROBE_DEFER;
+				goto out_clk_put;
+			}
+
+			/* Ignore errors to fall back to PIO mode */
+			host->dma = NULL;
+		}
+	} else {
+		res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+		if (res) {
+			host->dmareq = res->start;
+			host->dma_data.peripheral_type = IMX_DMATYPE_SDHC;
+			host->dma_data.priority = DMA_PRIO_LOW;
+			host->dma_data.dma_request = host->dmareq;
+			dma_cap_zero(mask);
+			dma_cap_set(DMA_SLAVE, mask);
+			host->dma = dma_request_channel(mask, filter, host);
+		}
+	}
+	if (host->dma)
+		mmc->max_seg_size = dma_get_max_seg_size(
+				host->dma->device->dev);
+	else
+		dev_info(mmc_dev(host->mmc), "dma not available. Using PIO\n");
+
+	INIT_WORK(&host->datawork, mxcmci_datawork);
+
+	ret = devm_request_irq(&pdev->dev, irq, mxcmci_irq, 0,
+			       dev_name(&pdev->dev), host);
+	if (ret)
+		goto out_free_dma;
+
+	platform_set_drvdata(pdev, mmc);
+
+	if (host->pdata && host->pdata->init) {
+		ret = host->pdata->init(&pdev->dev, mxcmci_detect_irq,
+				host->mmc);
+		if (ret)
+			goto out_free_dma;
+	}
+
+	timer_setup(&host->watchdog, mxcmci_watchdog, 0);
+
+	ret = mmc_add_host(mmc);
+	if (ret)
+		goto out_free_dma;
+
+	return 0;
+
+out_free_dma:
+	if (host->dma)
+		dma_release_channel(host->dma);
+
+out_clk_put:
+	clk_disable_unprepare(host->clk_ipg);
+out_clk_per_put:
+	clk_disable_unprepare(host->clk_per);
+
+out_free:
+	mmc_free_host(mmc);
+
+	return ret;
+}
+
+static void mxcmci_remove(struct platform_device *pdev)
+{
+	struct mmc_host *mmc = platform_get_drvdata(pdev);
+	struct mxcmci_host *host = mmc_priv(mmc);
+
+	mmc_remove_host(mmc);
+
+	if (host->pdata && host->pdata->exit)
+		host->pdata->exit(&pdev->dev, mmc);
+
+	if (host->dma)
+		dma_release_channel(host->dma);
+
+	clk_disable_unprepare(host->clk_per);
+	clk_disable_unprepare(host->clk_ipg);
+
+	mmc_free_host(mmc);
+}
+
+static int mxcmci_suspend(struct device *dev)
+{
+	struct mmc_host *mmc = dev_get_drvdata(dev);
+	struct mxcmci_host *host = mmc_priv(mmc);
+
+	clk_disable_unprepare(host->clk_per);
+	clk_disable_unprepare(host->clk_ipg);
+	return 0;
+}
+
+static int mxcmci_resume(struct device *dev)
+{
+	struct mmc_host *mmc = dev_get_drvdata(dev);
+	struct mxcmci_host *host = mmc_priv(mmc);
+	int ret;
+
+	ret = clk_prepare_enable(host->clk_per);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(host->clk_ipg);
+	if (ret)
+		clk_disable_unprepare(host->clk_per);
+
+	return ret;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(mxcmci_pm_ops, mxcmci_suspend, mxcmci_resume);
+
+static struct platform_driver mxcmci_driver = {
+	.probe		= mxcmci_probe,
+	.remove_new	= mxcmci_remove,
+	.driver		= {
+		.name		= DRIVER_NAME,
+		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
+		.pm	= pm_sleep_ptr(&mxcmci_pm_ops),
+		.of_match_table	= mxcmci_of_match,
+	}
+};
+
+module_platform_driver(mxcmci_driver);
+
+MODULE_DESCRIPTION("i.MX Multimedia Card Interface Driver");
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mxc-mmc");