Initial import

1 files changed, 1172 insertions, 0 deletions

diff --git a/drivers/mmc/host/jz4740_mmc.c b/drivers/mmc/host/jz4740_mmc.c
new file mode 100644
index 000000000..76e8bce6f
--- /dev/null
+++ b/drivers/mmc/host/jz4740_mmc.c
@@ -0,0 +1,1172 @@
+/*
+ *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
+ *  JZ4740 SD/MMC controller driver
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ *
+ *  You should have received a copy of the  GNU General Public License along
+ *  with this program; if not, write  to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/mmc/host.h>
+#include <linux/mmc/slot-gpio.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/scatterlist.h>
+#include <linux/clk.h>
+
+#include <linux/bitops.h>
+#include <linux/gpio.h>
+#include <asm/mach-jz4740/gpio.h>
+#include <asm/cacheflush.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+
+#include <asm/mach-jz4740/dma.h>
+#include <asm/mach-jz4740/jz4740_mmc.h>
+
+#define JZ_REG_MMC_STRPCL	0x00
+#define JZ_REG_MMC_STATUS	0x04
+#define JZ_REG_MMC_CLKRT	0x08
+#define JZ_REG_MMC_CMDAT	0x0C
+#define JZ_REG_MMC_RESTO	0x10
+#define JZ_REG_MMC_RDTO		0x14
+#define JZ_REG_MMC_BLKLEN	0x18
+#define JZ_REG_MMC_NOB		0x1C
+#define JZ_REG_MMC_SNOB		0x20
+#define JZ_REG_MMC_IMASK	0x24
+#define JZ_REG_MMC_IREG		0x28
+#define JZ_REG_MMC_CMD		0x2C
+#define JZ_REG_MMC_ARG		0x30
+#define JZ_REG_MMC_RESP_FIFO	0x34
+#define JZ_REG_MMC_RXFIFO	0x38
+#define JZ_REG_MMC_TXFIFO	0x3C
+
+#define JZ_MMC_STRPCL_EXIT_MULTIPLE BIT(7)
+#define JZ_MMC_STRPCL_EXIT_TRANSFER BIT(6)
+#define JZ_MMC_STRPCL_START_READWAIT BIT(5)
+#define JZ_MMC_STRPCL_STOP_READWAIT BIT(4)
+#define JZ_MMC_STRPCL_RESET BIT(3)
+#define JZ_MMC_STRPCL_START_OP BIT(2)
+#define JZ_MMC_STRPCL_CLOCK_CONTROL (BIT(1) | BIT(0))
+#define JZ_MMC_STRPCL_CLOCK_STOP BIT(0)
+#define JZ_MMC_STRPCL_CLOCK_START BIT(1)
+
+
+#define JZ_MMC_STATUS_IS_RESETTING BIT(15)
+#define JZ_MMC_STATUS_SDIO_INT_ACTIVE BIT(14)
+#define JZ_MMC_STATUS_PRG_DONE BIT(13)
+#define JZ_MMC_STATUS_DATA_TRAN_DONE BIT(12)
+#define JZ_MMC_STATUS_END_CMD_RES BIT(11)
+#define JZ_MMC_STATUS_DATA_FIFO_AFULL BIT(10)
+#define JZ_MMC_STATUS_IS_READWAIT BIT(9)
+#define JZ_MMC_STATUS_CLK_EN BIT(8)
+#define JZ_MMC_STATUS_DATA_FIFO_FULL BIT(7)
+#define JZ_MMC_STATUS_DATA_FIFO_EMPTY BIT(6)
+#define JZ_MMC_STATUS_CRC_RES_ERR BIT(5)
+#define JZ_MMC_STATUS_CRC_READ_ERROR BIT(4)
+#define JZ_MMC_STATUS_TIMEOUT_WRITE BIT(3)
+#define JZ_MMC_STATUS_CRC_WRITE_ERROR BIT(2)
+#define JZ_MMC_STATUS_TIMEOUT_RES BIT(1)
+#define JZ_MMC_STATUS_TIMEOUT_READ BIT(0)
+
+#define JZ_MMC_STATUS_READ_ERROR_MASK (BIT(4) | BIT(0))
+#define JZ_MMC_STATUS_WRITE_ERROR_MASK (BIT(3) | BIT(2))
+
+
+#define JZ_MMC_CMDAT_IO_ABORT BIT(11)
+#define JZ_MMC_CMDAT_BUS_WIDTH_4BIT BIT(10)
+#define JZ_MMC_CMDAT_DMA_EN BIT(8)
+#define JZ_MMC_CMDAT_INIT BIT(7)
+#define JZ_MMC_CMDAT_BUSY BIT(6)
+#define JZ_MMC_CMDAT_STREAM BIT(5)
+#define JZ_MMC_CMDAT_WRITE BIT(4)
+#define JZ_MMC_CMDAT_DATA_EN BIT(3)
+#define JZ_MMC_CMDAT_RESPONSE_FORMAT (BIT(2) | BIT(1) | BIT(0))
+#define JZ_MMC_CMDAT_RSP_R1 1
+#define JZ_MMC_CMDAT_RSP_R2 2
+#define JZ_MMC_CMDAT_RSP_R3 3
+
+#define JZ_MMC_IRQ_SDIO BIT(7)
+#define JZ_MMC_IRQ_TXFIFO_WR_REQ BIT(6)
+#define JZ_MMC_IRQ_RXFIFO_RD_REQ BIT(5)
+#define JZ_MMC_IRQ_END_CMD_RES BIT(2)
+#define JZ_MMC_IRQ_PRG_DONE BIT(1)
+#define JZ_MMC_IRQ_DATA_TRAN_DONE BIT(0)
+
+
+#define JZ_MMC_CLK_RATE 24000000
+
+enum jz4740_mmc_state {
+	JZ4740_MMC_STATE_READ_RESPONSE,
+	JZ4740_MMC_STATE_TRANSFER_DATA,
+	JZ4740_MMC_STATE_SEND_STOP,
+	JZ4740_MMC_STATE_DONE,
+};
+
+struct jz4740_mmc_host_next {
+	int sg_len;
+	s32 cookie;
+};
+
+struct jz4740_mmc_host {
+	struct mmc_host *mmc;
+	struct platform_device *pdev;
+	struct jz4740_mmc_platform_data *pdata;
+	struct clk *clk;
+
+	int irq;
+	int card_detect_irq;
+
+	void __iomem *base;
+	struct resource *mem_res;
+	struct mmc_request *req;
+	struct mmc_command *cmd;
+
+	unsigned long waiting;
+
+	uint32_t cmdat;
+
+	uint16_t irq_mask;
+
+	spinlock_t lock;
+
+	struct timer_list timeout_timer;
+	struct sg_mapping_iter miter;
+	enum jz4740_mmc_state state;
+
+	/* DMA support */
+	struct dma_chan *dma_rx;
+	struct dma_chan *dma_tx;
+	struct jz4740_mmc_host_next next_data;
+	bool use_dma;
+	int sg_len;
+
+/* The DMA trigger level is 8 words, that is to say, the DMA read
+ * trigger is when data words in MSC_RXFIFO is >= 8 and the DMA write
+ * trigger is when data words in MSC_TXFIFO is < 8.
+ */
+#define JZ4740_MMC_FIFO_HALF_SIZE 8
+};
+
+/*----------------------------------------------------------------------------*/
+/* DMA infrastructure */
+
+static void jz4740_mmc_release_dma_channels(struct jz4740_mmc_host *host)
+{
+	if (!host->use_dma)
+		return;
+
+	dma_release_channel(host->dma_tx);
+	dma_release_channel(host->dma_rx);
+}
+
+static int jz4740_mmc_acquire_dma_channels(struct jz4740_mmc_host *host)
+{
+	dma_cap_mask_t mask;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	host->dma_tx = dma_request_channel(mask, NULL, host);
+	if (!host->dma_tx) {
+		dev_err(mmc_dev(host->mmc), "Failed to get dma_tx channel\n");
+		return -ENODEV;
+	}
+
+	host->dma_rx = dma_request_channel(mask, NULL, host);
+	if (!host->dma_rx) {
+		dev_err(mmc_dev(host->mmc), "Failed to get dma_rx channel\n");
+		goto free_master_write;
+	}
+
+	/* Initialize DMA pre request cookie */
+	host->next_data.cookie = 1;
+
+	return 0;
+
+free_master_write:
+	dma_release_channel(host->dma_tx);
+	return -ENODEV;
+}
+
+static inline int jz4740_mmc_get_dma_dir(struct mmc_data *data)
+{
+	return (data->flags & MMC_DATA_READ) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+}
+
+static inline struct dma_chan *jz4740_mmc_get_dma_chan(struct jz4740_mmc_host *host,
+						       struct mmc_data *data)
+{
+	return (data->flags & MMC_DATA_READ) ? host->dma_rx : host->dma_tx;
+}
+
+static void jz4740_mmc_dma_unmap(struct jz4740_mmc_host *host,
+				 struct mmc_data *data)
+{
+	struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
+	enum dma_data_direction dir = jz4740_mmc_get_dma_dir(data);
+
+	dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
+}
+
+/* Prepares DMA data for current/next transfer, returns non-zero on failure */
+static int jz4740_mmc_prepare_dma_data(struct jz4740_mmc_host *host,
+				       struct mmc_data *data,
+				       struct jz4740_mmc_host_next *next,
+				       struct dma_chan *chan)
+{
+	struct jz4740_mmc_host_next *next_data = &host->next_data;
+	enum dma_data_direction dir = jz4740_mmc_get_dma_dir(data);
+	int sg_len;
+
+	if (!next && data->host_cookie &&
+	    data->host_cookie != host->next_data.cookie) {
+		dev_warn(mmc_dev(host->mmc),
+			 "[%s] invalid cookie: data->host_cookie %d host->next_data.cookie %d\n",
+			 __func__,
+			 data->host_cookie,
+			 host->next_data.cookie);
+		data->host_cookie = 0;
+	}
+
+	/* Check if next job is already prepared */
+	if (next || data->host_cookie != host->next_data.cookie) {
+		sg_len = dma_map_sg(chan->device->dev,
+				    data->sg,
+				    data->sg_len,
+				    dir);
+
+	} else {
+		sg_len = next_data->sg_len;
+		next_data->sg_len = 0;
+	}
+
+	if (sg_len <= 0) {
+		dev_err(mmc_dev(host->mmc),
+			"Failed to map scatterlist for DMA operation\n");
+		return -EINVAL;
+	}
+
+	if (next) {
+		next->sg_len = sg_len;
+		data->host_cookie = ++next->cookie < 0 ? 1 : next->cookie;
+	} else
+		host->sg_len = sg_len;
+
+	return 0;
+}
+
+static int jz4740_mmc_start_dma_transfer(struct jz4740_mmc_host *host,
+					 struct mmc_data *data)
+{
+	int ret;
+	struct dma_chan *chan;
+	struct dma_async_tx_descriptor *desc;
+	struct dma_slave_config conf = {
+		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
+		.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
+		.src_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
+		.dst_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
+	};
+
+	if (data->flags & MMC_DATA_WRITE) {
+		conf.direction = DMA_MEM_TO_DEV;
+		conf.dst_addr = host->mem_res->start + JZ_REG_MMC_TXFIFO;
+		conf.slave_id = JZ4740_DMA_TYPE_MMC_TRANSMIT;
+		chan = host->dma_tx;
+	} else {
+		conf.direction = DMA_DEV_TO_MEM;
+		conf.src_addr = host->mem_res->start + JZ_REG_MMC_RXFIFO;
+		conf.slave_id = JZ4740_DMA_TYPE_MMC_RECEIVE;
+		chan = host->dma_rx;
+	}
+
+	ret = jz4740_mmc_prepare_dma_data(host, data, NULL, chan);
+	if (ret)
+		return ret;
+
+	dmaengine_slave_config(chan, &conf);
+	desc = dmaengine_prep_slave_sg(chan,
+				       data->sg,
+				       host->sg_len,
+				       conf.direction,
+				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		dev_err(mmc_dev(host->mmc),
+			"Failed to allocate DMA %s descriptor",
+			 conf.direction == DMA_MEM_TO_DEV ? "TX" : "RX");
+		goto dma_unmap;
+	}
+
+	dmaengine_submit(desc);
+	dma_async_issue_pending(chan);
+
+	return 0;
+
+dma_unmap:
+	jz4740_mmc_dma_unmap(host, data);
+	return -ENOMEM;
+}
+
+static void jz4740_mmc_pre_request(struct mmc_host *mmc,
+				   struct mmc_request *mrq,
+				   bool is_first_req)
+{
+	struct jz4740_mmc_host *host = mmc_priv(mmc);
+	struct mmc_data *data = mrq->data;
+	struct jz4740_mmc_host_next *next_data = &host->next_data;
+
+	BUG_ON(data->host_cookie);
+
+	if (host->use_dma) {
+		struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
+
+		if (jz4740_mmc_prepare_dma_data(host, data, next_data, chan))
+			data->host_cookie = 0;
+	}
+}
+
+static void jz4740_mmc_post_request(struct mmc_host *mmc,
+				    struct mmc_request *mrq,
+				    int err)
+{
+	struct jz4740_mmc_host *host = mmc_priv(mmc);
+	struct mmc_data *data = mrq->data;
+
+	if (host->use_dma && data->host_cookie) {
+		jz4740_mmc_dma_unmap(host, data);
+		data->host_cookie = 0;
+	}
+
+	if (err) {
+		struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
+
+		dmaengine_terminate_all(chan);
+	}
+}
+
+/*----------------------------------------------------------------------------*/
+
+static void jz4740_mmc_set_irq_enabled(struct jz4740_mmc_host *host,
+	unsigned int irq, bool enabled)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->lock, flags);
+	if (enabled)
+		host->irq_mask &= ~irq;
+	else
+		host->irq_mask |= irq;
+	spin_unlock_irqrestore(&host->lock, flags);
+
+	writew(host->irq_mask, host->base + JZ_REG_MMC_IMASK);
+}
+
+static void jz4740_mmc_clock_enable(struct jz4740_mmc_host *host,
+	bool start_transfer)
+{
+	uint16_t val = JZ_MMC_STRPCL_CLOCK_START;
+
+	if (start_transfer)
+		val |= JZ_MMC_STRPCL_START_OP;
+
+	writew(val, host->base + JZ_REG_MMC_STRPCL);
+}
+
+static void jz4740_mmc_clock_disable(struct jz4740_mmc_host *host)
+{
+	uint32_t status;
+	unsigned int timeout = 1000;
+
+	writew(JZ_MMC_STRPCL_CLOCK_STOP, host->base + JZ_REG_MMC_STRPCL);
+	do {
+		status = readl(host->base + JZ_REG_MMC_STATUS);
+	} while (status & JZ_MMC_STATUS_CLK_EN && --timeout);
+}
+
+static void jz4740_mmc_reset(struct jz4740_mmc_host *host)
+{
+	uint32_t status;
+	unsigned int timeout = 1000;
+
+	writew(JZ_MMC_STRPCL_RESET, host->base + JZ_REG_MMC_STRPCL);
+	udelay(10);
+	do {
+		status = readl(host->base + JZ_REG_MMC_STATUS);
+	} while (status & JZ_MMC_STATUS_IS_RESETTING && --timeout);
+}
+
+static void jz4740_mmc_request_done(struct jz4740_mmc_host *host)
+{
+	struct mmc_request *req;
+
+	req = host->req;
+	host->req = NULL;
+
+	mmc_request_done(host->mmc, req);
+}
+
+static unsigned int jz4740_mmc_poll_irq(struct jz4740_mmc_host *host,
+	unsigned int irq)
+{
+	unsigned int timeout = 0x800;
+	uint16_t status;
+
+	do {
+		status = readw(host->base + JZ_REG_MMC_IREG);
+	} while (!(status & irq) && --timeout);
+
+	if (timeout == 0) {
+		set_bit(0, &host->waiting);
+		mod_timer(&host->timeout_timer, jiffies + 5*HZ);
+		jz4740_mmc_set_irq_enabled(host, irq, true);
+		return true;
+	}
+
+	return false;
+}
+
+static void jz4740_mmc_transfer_check_state(struct jz4740_mmc_host *host,
+	struct mmc_data *data)
+{
+	int status;
+
+	status = readl(host->base + JZ_REG_MMC_STATUS);
+	if (status & JZ_MMC_STATUS_WRITE_ERROR_MASK) {
+		if (status & (JZ_MMC_STATUS_TIMEOUT_WRITE)) {
+			host->req->cmd->error = -ETIMEDOUT;
+			data->error = -ETIMEDOUT;
+		} else {
+			host->req->cmd->error = -EIO;
+			data->error = -EIO;
+		}
+	} else if (status & JZ_MMC_STATUS_READ_ERROR_MASK) {
+		if (status & (JZ_MMC_STATUS_TIMEOUT_READ)) {
+			host->req->cmd->error = -ETIMEDOUT;
+			data->error = -ETIMEDOUT;
+		} else {
+			host->req->cmd->error = -EIO;
+			data->error = -EIO;
+		}
+	}
+}
+
+static bool jz4740_mmc_write_data(struct jz4740_mmc_host *host,
+	struct mmc_data *data)
+{
+	struct sg_mapping_iter *miter = &host->miter;
+	void __iomem *fifo_addr = host->base + JZ_REG_MMC_TXFIFO;
+	uint32_t *buf;
+	bool timeout;
+	size_t i, j;
+
+	while (sg_miter_next(miter)) {
+		buf = miter->addr;
+		i = miter->length / 4;
+		j = i / 8;
+		i = i & 0x7;
+		while (j) {
+			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
+			if (unlikely(timeout))
+				goto poll_timeout;
+
+			writel(buf[0], fifo_addr);
+			writel(buf[1], fifo_addr);
+			writel(buf[2], fifo_addr);
+			writel(buf[3], fifo_addr);
+			writel(buf[4], fifo_addr);
+			writel(buf[5], fifo_addr);
+			writel(buf[6], fifo_addr);
+			writel(buf[7], fifo_addr);
+			buf += 8;
+			--j;
+		}
+		if (unlikely(i)) {
+			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
+			if (unlikely(timeout))
+				goto poll_timeout;
+
+			while (i) {
+				writel(*buf, fifo_addr);
+				++buf;
+				--i;
+			}
+		}
+		data->bytes_xfered += miter->length;
+	}
+	sg_miter_stop(miter);
+
+	return false;
+
+poll_timeout:
+	miter->consumed = (void *)buf - miter->addr;
+	data->bytes_xfered += miter->consumed;
+	sg_miter_stop(miter);
+
+	return true;
+}
+
+static bool jz4740_mmc_read_data(struct jz4740_mmc_host *host,
+				struct mmc_data *data)
+{
+	struct sg_mapping_iter *miter = &host->miter;
+	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RXFIFO;
+	uint32_t *buf;
+	uint32_t d;
+	uint16_t status;
+	size_t i, j;
+	unsigned int timeout;
+
+	while (sg_miter_next(miter)) {
+		buf = miter->addr;
+		i = miter->length;
+		j = i / 32;
+		i = i & 0x1f;
+		while (j) {
+			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
+			if (unlikely(timeout))
+				goto poll_timeout;
+
+			buf[0] = readl(fifo_addr);
+			buf[1] = readl(fifo_addr);
+			buf[2] = readl(fifo_addr);
+			buf[3] = readl(fifo_addr);
+			buf[4] = readl(fifo_addr);
+			buf[5] = readl(fifo_addr);
+			buf[6] = readl(fifo_addr);
+			buf[7] = readl(fifo_addr);
+
+			buf += 8;
+			--j;
+		}
+
+		if (unlikely(i)) {
+			timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
+			if (unlikely(timeout))
+				goto poll_timeout;
+
+			while (i >= 4) {
+				*buf++ = readl(fifo_addr);
+				i -= 4;
+			}
+			if (unlikely(i > 0)) {
+				d = readl(fifo_addr);
+				memcpy(buf, &d, i);
+			}
+		}
+		data->bytes_xfered += miter->length;
+
+		/* This can go away once MIPS implements
+		 * flush_kernel_dcache_page */
+		flush_dcache_page(miter->page);
+	}
+	sg_miter_stop(miter);
+
+	/* For whatever reason there is sometime one word more in the fifo then
+	 * requested */
+	timeout = 1000;
+	status = readl(host->base + JZ_REG_MMC_STATUS);
+	while (!(status & JZ_MMC_STATUS_DATA_FIFO_EMPTY) && --timeout) {
+		d = readl(fifo_addr);
+		status = readl(host->base + JZ_REG_MMC_STATUS);
+	}
+
+	return false;
+
+poll_timeout:
+	miter->consumed = (void *)buf - miter->addr;
+	data->bytes_xfered += miter->consumed;
+	sg_miter_stop(miter);
+
+	return true;
+}
+
+static void jz4740_mmc_timeout(unsigned long data)
+{
+	struct jz4740_mmc_host *host = (struct jz4740_mmc_host *)data;
+
+	if (!test_and_clear_bit(0, &host->waiting))
+		return;
+
+	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, false);
+
+	host->req->cmd->error = -ETIMEDOUT;
+	jz4740_mmc_request_done(host);
+}
+
+static void jz4740_mmc_read_response(struct jz4740_mmc_host *host,
+	struct mmc_command *cmd)
+{
+	int i;
+	uint16_t tmp;
+	void __iomem *fifo_addr = host->base + JZ_REG_MMC_RESP_FIFO;
+
+	if (cmd->flags & MMC_RSP_136) {
+		tmp = readw(fifo_addr);
+		for (i = 0; i < 4; ++i) {
+			cmd->resp[i] = tmp << 24;
+			tmp = readw(fifo_addr);
+			cmd->resp[i] |= tmp << 8;
+			tmp = readw(fifo_addr);
+			cmd->resp[i] |= tmp >> 8;
+		}
+	} else {
+		cmd->resp[0] = readw(fifo_addr) << 24;
+		cmd->resp[0] |= readw(fifo_addr) << 8;
+		cmd->resp[0] |= readw(fifo_addr) & 0xff;
+	}
+}
+
+static void jz4740_mmc_send_command(struct jz4740_mmc_host *host,
+	struct mmc_command *cmd)
+{
+	uint32_t cmdat = host->cmdat;
+
+	host->cmdat &= ~JZ_MMC_CMDAT_INIT;
+	jz4740_mmc_clock_disable(host);
+
+	host->cmd = cmd;
+
+	if (cmd->flags & MMC_RSP_BUSY)
+		cmdat |= JZ_MMC_CMDAT_BUSY;
+
+	switch (mmc_resp_type(cmd)) {
+	case MMC_RSP_R1B:
+	case MMC_RSP_R1:
+		cmdat |= JZ_MMC_CMDAT_RSP_R1;
+		break;
+	case MMC_RSP_R2:
+		cmdat |= JZ_MMC_CMDAT_RSP_R2;
+		break;
+	case MMC_RSP_R3:
+		cmdat |= JZ_MMC_CMDAT_RSP_R3;
+		break;
+	default:
+		break;
+	}
+
+	if (cmd->data) {
+		cmdat |= JZ_MMC_CMDAT_DATA_EN;
+		if (cmd->data->flags & MMC_DATA_WRITE)
+			cmdat |= JZ_MMC_CMDAT_WRITE;
+		if (cmd->data->flags & MMC_DATA_STREAM)
+			cmdat |= JZ_MMC_CMDAT_STREAM;
+		if (host->use_dma)
+			cmdat |= JZ_MMC_CMDAT_DMA_EN;
+
+		writew(cmd->data->blksz, host->base + JZ_REG_MMC_BLKLEN);
+		writew(cmd->data->blocks, host->base + JZ_REG_MMC_NOB);
+	}
+
+	writeb(cmd->opcode, host->base + JZ_REG_MMC_CMD);
+	writel(cmd->arg, host->base + JZ_REG_MMC_ARG);
+	writel(cmdat, host->base + JZ_REG_MMC_CMDAT);
+
+	jz4740_mmc_clock_enable(host, 1);
+}
+
+static void jz_mmc_prepare_data_transfer(struct jz4740_mmc_host *host)
+{
+	struct mmc_command *cmd = host->req->cmd;
+	struct mmc_data *data = cmd->data;
+	int direction;
+
+	if (data->flags & MMC_DATA_READ)
+		direction = SG_MITER_TO_SG;
+	else
+		direction = SG_MITER_FROM_SG;
+
+	sg_miter_start(&host->miter, data->sg, data->sg_len, direction);
+}
+
+
+static irqreturn_t jz_mmc_irq_worker(int irq, void *devid)
+{
+	struct jz4740_mmc_host *host = (struct jz4740_mmc_host *)devid;
+	struct mmc_command *cmd = host->req->cmd;
+	struct mmc_request *req = host->req;
+	struct mmc_data *data = cmd->data;
+	bool timeout = false;
+
+	if (cmd->error)
+		host->state = JZ4740_MMC_STATE_DONE;
+
+	switch (host->state) {
+	case JZ4740_MMC_STATE_READ_RESPONSE:
+		if (cmd->flags & MMC_RSP_PRESENT)
+			jz4740_mmc_read_response(host, cmd);
+
+		if (!data)
+			break;
+
+		jz_mmc_prepare_data_transfer(host);
+
+	case JZ4740_MMC_STATE_TRANSFER_DATA:
+		if (host->use_dma) {
+			/* Use DMA if enabled.
+			 * Data transfer direction is defined later by
+			 * relying on data flags in
+			 * jz4740_mmc_prepare_dma_data() and
+			 * jz4740_mmc_start_dma_transfer().
+			 */
+			timeout = jz4740_mmc_start_dma_transfer(host, data);
+			data->bytes_xfered = data->blocks * data->blksz;
+		} else if (data->flags & MMC_DATA_READ)
+			/* Use PIO if DMA is not enabled.
+			 * Data transfer direction was defined before
+			 * by relying on data flags in
+			 * jz_mmc_prepare_data_transfer().
+			 */
+			timeout = jz4740_mmc_read_data(host, data);
+		else
+			timeout = jz4740_mmc_write_data(host, data);
+
+		if (unlikely(timeout)) {
+			host->state = JZ4740_MMC_STATE_TRANSFER_DATA;
+			break;
+		}
+
+		jz4740_mmc_transfer_check_state(host, data);
+
+		timeout = jz4740_mmc_poll_irq(host, JZ_MMC_IRQ_DATA_TRAN_DONE);
+		if (unlikely(timeout)) {
+			host->state = JZ4740_MMC_STATE_SEND_STOP;
+			break;
+		}
+		writew(JZ_MMC_IRQ_DATA_TRAN_DONE, host->base + JZ_REG_MMC_IREG);
+
+	case JZ4740_MMC_STATE_SEND_STOP:
+		if (!req->stop)
+			break;
+
+		jz4740_mmc_send_command(host, req->stop);
+
+		if (mmc_resp_type(req->stop) & MMC_RSP_BUSY) {
+			timeout = jz4740_mmc_poll_irq(host,
+						      JZ_MMC_IRQ_PRG_DONE);
+			if (timeout) {
+				host->state = JZ4740_MMC_STATE_DONE;
+				break;
+			}
+		}
+	case JZ4740_MMC_STATE_DONE:
+		break;
+	}
+
+	if (!timeout)
+		jz4740_mmc_request_done(host);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t jz_mmc_irq(int irq, void *devid)
+{
+	struct jz4740_mmc_host *host = devid;
+	struct mmc_command *cmd = host->cmd;
+	uint16_t irq_reg, status, tmp;
+
+	irq_reg = readw(host->base + JZ_REG_MMC_IREG);
+
+	tmp = irq_reg;
+	irq_reg &= ~host->irq_mask;
+
+	tmp &= ~(JZ_MMC_IRQ_TXFIFO_WR_REQ | JZ_MMC_IRQ_RXFIFO_RD_REQ |
+		JZ_MMC_IRQ_PRG_DONE | JZ_MMC_IRQ_DATA_TRAN_DONE);
+
+	if (tmp != irq_reg)
+		writew(tmp & ~irq_reg, host->base + JZ_REG_MMC_IREG);
+
+	if (irq_reg & JZ_MMC_IRQ_SDIO) {
+		writew(JZ_MMC_IRQ_SDIO, host->base + JZ_REG_MMC_IREG);
+		mmc_signal_sdio_irq(host->mmc);
+		irq_reg &= ~JZ_MMC_IRQ_SDIO;
+	}
+
+	if (host->req && cmd && irq_reg) {
+		if (test_and_clear_bit(0, &host->waiting)) {
+			del_timer(&host->timeout_timer);
+
+			status = readl(host->base + JZ_REG_MMC_STATUS);
+
+			if (status & JZ_MMC_STATUS_TIMEOUT_RES) {
+					cmd->error = -ETIMEDOUT;
+			} else if (status & JZ_MMC_STATUS_CRC_RES_ERR) {
+					cmd->error = -EIO;
+			} else if (status & (JZ_MMC_STATUS_CRC_READ_ERROR |
+				    JZ_MMC_STATUS_CRC_WRITE_ERROR)) {
+					if (cmd->data)
+							cmd->data->error = -EIO;
+					cmd->error = -EIO;
+			}
+
+			jz4740_mmc_set_irq_enabled(host, irq_reg, false);
+			writew(irq_reg, host->base + JZ_REG_MMC_IREG);
+
+			return IRQ_WAKE_THREAD;
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int jz4740_mmc_set_clock_rate(struct jz4740_mmc_host *host, int rate)
+{
+	int div = 0;
+	int real_rate;
+
+	jz4740_mmc_clock_disable(host);
+	clk_set_rate(host->clk, JZ_MMC_CLK_RATE);
+
+	real_rate = clk_get_rate(host->clk);
+
+	while (real_rate > rate && div < 7) {
+		++div;
+		real_rate >>= 1;
+	}
+
+	writew(div, host->base + JZ_REG_MMC_CLKRT);
+	return real_rate;
+}
+
+static void jz4740_mmc_request(struct mmc_host *mmc, struct mmc_request *req)
+{
+	struct jz4740_mmc_host *host = mmc_priv(mmc);
+
+	host->req = req;
+
+	writew(0xffff, host->base + JZ_REG_MMC_IREG);
+
+	writew(JZ_MMC_IRQ_END_CMD_RES, host->base + JZ_REG_MMC_IREG);
+	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, true);
+
+	host->state = JZ4740_MMC_STATE_READ_RESPONSE;
+	set_bit(0, &host->waiting);
+	mod_timer(&host->timeout_timer, jiffies + 5*HZ);
+	jz4740_mmc_send_command(host, req->cmd);
+}
+
+static void jz4740_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct jz4740_mmc_host *host = mmc_priv(mmc);
+	if (ios->clock)
+		jz4740_mmc_set_clock_rate(host, ios->clock);
+
+	switch (ios->power_mode) {
+	case MMC_POWER_UP:
+		jz4740_mmc_reset(host);
+		if (gpio_is_valid(host->pdata->gpio_power))
+			gpio_set_value(host->pdata->gpio_power,
+					!host->pdata->power_active_low);
+		host->cmdat |= JZ_MMC_CMDAT_INIT;
+		clk_prepare_enable(host->clk);
+		break;
+	case MMC_POWER_ON:
+		break;
+	default:
+		if (gpio_is_valid(host->pdata->gpio_power))
+			gpio_set_value(host->pdata->gpio_power,
+					host->pdata->power_active_low);
+		clk_disable_unprepare(host->clk);
+		break;
+	}
+
+	switch (ios->bus_width) {
+	case MMC_BUS_WIDTH_1:
+		host->cmdat &= ~JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
+		break;
+	case MMC_BUS_WIDTH_4:
+		host->cmdat |= JZ_MMC_CMDAT_BUS_WIDTH_4BIT;
+		break;
+	default:
+		break;
+	}
+}
+
+static void jz4740_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+	struct jz4740_mmc_host *host = mmc_priv(mmc);
+	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_SDIO, enable);
+}
+
+static const struct mmc_host_ops jz4740_mmc_ops = {
+	.request	= jz4740_mmc_request,
+	.pre_req	= jz4740_mmc_pre_request,
+	.post_req	= jz4740_mmc_post_request,
+	.set_ios	= jz4740_mmc_set_ios,
+	.get_ro		= mmc_gpio_get_ro,
+	.get_cd		= mmc_gpio_get_cd,
+	.enable_sdio_irq = jz4740_mmc_enable_sdio_irq,
+};
+
+static const struct jz_gpio_bulk_request jz4740_mmc_pins[] = {
+	JZ_GPIO_BULK_PIN(MSC_CMD),
+	JZ_GPIO_BULK_PIN(MSC_CLK),
+	JZ_GPIO_BULK_PIN(MSC_DATA0),
+	JZ_GPIO_BULK_PIN(MSC_DATA1),
+	JZ_GPIO_BULK_PIN(MSC_DATA2),
+	JZ_GPIO_BULK_PIN(MSC_DATA3),
+};
+
+static int jz4740_mmc_request_gpio(struct device *dev, int gpio,
+	const char *name, bool output, int value)
+{
+	int ret;
+
+	if (!gpio_is_valid(gpio))
+		return 0;
+
+	ret = gpio_request(gpio, name);
+	if (ret) {
+		dev_err(dev, "Failed to request %s gpio: %d\n", name, ret);
+		return ret;
+	}
+
+	if (output)
+		gpio_direction_output(gpio, value);
+	else
+		gpio_direction_input(gpio);
+
+	return 0;
+}
+
+static int jz4740_mmc_request_gpios(struct mmc_host *mmc,
+	struct platform_device *pdev)
+{
+	struct jz4740_mmc_platform_data *pdata = pdev->dev.platform_data;
+	int ret = 0;
+
+	if (!pdata)
+		return 0;
+
+	if (!pdata->card_detect_active_low)
+		mmc->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
+	if (!pdata->read_only_active_low)
+		mmc->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
+
+	if (gpio_is_valid(pdata->gpio_card_detect)) {
+		ret = mmc_gpio_request_cd(mmc, pdata->gpio_card_detect, 0);
+		if (ret)
+			return ret;
+	}
+
+	if (gpio_is_valid(pdata->gpio_read_only)) {
+		ret = mmc_gpio_request_ro(mmc, pdata->gpio_read_only);
+		if (ret)
+			return ret;
+	}
+
+	return jz4740_mmc_request_gpio(&pdev->dev, pdata->gpio_power,
+			"MMC read only", true, pdata->power_active_low);
+}
+
+static void jz4740_mmc_free_gpios(struct platform_device *pdev)
+{
+	struct jz4740_mmc_platform_data *pdata = pdev->dev.platform_data;
+
+	if (!pdata)
+		return;
+
+	if (gpio_is_valid(pdata->gpio_power))
+		gpio_free(pdata->gpio_power);
+}
+
+static inline size_t jz4740_mmc_num_pins(struct jz4740_mmc_host *host)
+{
+	size_t num_pins = ARRAY_SIZE(jz4740_mmc_pins);
+	if (host->pdata && host->pdata->data_1bit)
+		num_pins -= 3;
+
+	return num_pins;
+}
+
+static int jz4740_mmc_probe(struct platform_device* pdev)
+{
+	int ret;
+	struct mmc_host *mmc;
+	struct jz4740_mmc_host *host;
+	struct jz4740_mmc_platform_data *pdata;
+
+	pdata = pdev->dev.platform_data;
+
+	mmc = mmc_alloc_host(sizeof(struct jz4740_mmc_host), &pdev->dev);
+	if (!mmc) {
+		dev_err(&pdev->dev, "Failed to alloc mmc host structure\n");
+		return -ENOMEM;
+	}
+
+	host = mmc_priv(mmc);
+	host->pdata = pdata;
+
+	host->irq = platform_get_irq(pdev, 0);
+	if (host->irq < 0) {
+		ret = host->irq;
+		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
+		goto err_free_host;
+	}
+
+	host->clk = devm_clk_get(&pdev->dev, "mmc");
+	if (IS_ERR(host->clk)) {
+		ret = PTR_ERR(host->clk);
+		dev_err(&pdev->dev, "Failed to get mmc clock\n");
+		goto err_free_host;
+	}
+
+	host->mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	host->base = devm_ioremap_resource(&pdev->dev, host->mem_res);
+	if (IS_ERR(host->base)) {
+		ret = PTR_ERR(host->base);
+		dev_err(&pdev->dev, "Failed to ioremap base memory\n");
+		goto err_free_host;
+	}
+
+	ret = jz_gpio_bulk_request(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request mmc pins: %d\n", ret);
+		goto err_free_host;
+	}
+
+	ret = jz4740_mmc_request_gpios(mmc, pdev);
+	if (ret)
+		goto err_gpio_bulk_free;
+
+	mmc->ops = &jz4740_mmc_ops;
+	mmc->f_min = JZ_MMC_CLK_RATE / 128;
+	mmc->f_max = JZ_MMC_CLK_RATE;
+	mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
+	mmc->caps = (pdata && pdata->data_1bit) ? 0 : MMC_CAP_4_BIT_DATA;
+	mmc->caps |= MMC_CAP_SDIO_IRQ;
+
+	mmc->max_blk_size = (1 << 10) - 1;
+	mmc->max_blk_count = (1 << 15) - 1;
+	mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
+
+	mmc->max_segs = 128;
+	mmc->max_seg_size = mmc->max_req_size;
+
+	host->mmc = mmc;
+	host->pdev = pdev;
+	spin_lock_init(&host->lock);
+	host->irq_mask = 0xffff;
+
+	ret = request_threaded_irq(host->irq, jz_mmc_irq, jz_mmc_irq_worker, 0,
+			dev_name(&pdev->dev), host);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
+		goto err_free_gpios;
+	}
+
+	jz4740_mmc_reset(host);
+	jz4740_mmc_clock_disable(host);
+	setup_timer(&host->timeout_timer, jz4740_mmc_timeout,
+			(unsigned long)host);
+	/* It is not important when it times out, it just needs to timeout. */
+	set_timer_slack(&host->timeout_timer, HZ);
+
+	host->use_dma = true;
+	if (host->use_dma && jz4740_mmc_acquire_dma_channels(host) != 0)
+		host->use_dma = false;
+
+	platform_set_drvdata(pdev, host);
+	ret = mmc_add_host(mmc);
+
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add mmc host: %d\n", ret);
+		goto err_free_irq;
+	}
+	dev_info(&pdev->dev, "JZ SD/MMC card driver registered\n");
+
+	dev_info(&pdev->dev, "Using %s, %d-bit mode\n",
+		 host->use_dma ? "DMA" : "PIO",
+		 (mmc->caps & MMC_CAP_4_BIT_DATA) ? 4 : 1);
+
+	return 0;
+
+err_free_irq:
+	free_irq(host->irq, host);
+err_free_gpios:
+	jz4740_mmc_free_gpios(pdev);
+err_gpio_bulk_free:
+	if (host->use_dma)
+		jz4740_mmc_release_dma_channels(host);
+	jz_gpio_bulk_free(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
+err_free_host:
+	mmc_free_host(mmc);
+
+	return ret;
+}
+
+static int jz4740_mmc_remove(struct platform_device *pdev)
+{
+	struct jz4740_mmc_host *host = platform_get_drvdata(pdev);
+
+	del_timer_sync(&host->timeout_timer);
+	jz4740_mmc_set_irq_enabled(host, 0xff, false);
+	jz4740_mmc_reset(host);
+
+	mmc_remove_host(host->mmc);
+
+	free_irq(host->irq, host);
+
+	jz4740_mmc_free_gpios(pdev);
+	jz_gpio_bulk_free(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
+
+	if (host->use_dma)
+		jz4740_mmc_release_dma_channels(host);
+
+	mmc_free_host(host->mmc);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int jz4740_mmc_suspend(struct device *dev)
+{
+	struct jz4740_mmc_host *host = dev_get_drvdata(dev);
+
+	jz_gpio_bulk_suspend(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
+
+	return 0;
+}
+
+static int jz4740_mmc_resume(struct device *dev)
+{
+	struct jz4740_mmc_host *host = dev_get_drvdata(dev);
+
+	jz_gpio_bulk_resume(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(jz4740_mmc_pm_ops, jz4740_mmc_suspend,
+	jz4740_mmc_resume);
+#define JZ4740_MMC_PM_OPS (&jz4740_mmc_pm_ops)
+#else
+#define JZ4740_MMC_PM_OPS NULL
+#endif
+
+static struct platform_driver jz4740_mmc_driver = {
+	.probe = jz4740_mmc_probe,
+	.remove = jz4740_mmc_remove,
+	.driver = {
+		.name = "jz4740-mmc",
+		.pm = JZ4740_MMC_PM_OPS,
+	},
+};
+
+module_platform_driver(jz4740_mmc_driver);
+
+MODULE_DESCRIPTION("JZ4740 SD/MMC controller driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");