[PATCH v3] MMC: Add JZ4740 mmc driver

[Lars-Peter Clausen <lars@metafoo.de>]

This patch adds support for the mmc controller on JZ4740 SoCs.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matt Fleming <matt@console-pimps.org>
Cc: linux-mmc@vger.kernel.org

---
Changes since v1
- Do not request IRQ with IRQF_DISABLED since it is a noop now
- Use a generous slack for the timeout timer. It does not need to be accurate.
Changes since v2
- Use sg_mapping_to iterate over sg elements in mmc read and write functions
- Use bitops instead of a spinlock and a variable for testing whether a request
  has been finished.
- Rework irq and timeout handling in order to get rid of locking in hot paths
---
 drivers/mmc/host/Kconfig       |    8 +
 drivers/mmc/host/Makefile      |    1 +
 drivers/mmc/host/jz4740_mmc.c  |  969 ++++++++++++++++++++++++++++++++++++++++
 include/linux/mmc/jz4740_mmc.h |   15 +
 4 files changed, 993 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mmc/host/jz4740_mmc.c
 create mode 100644 include/linux/mmc/jz4740_mmc.h

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index f06d06e..546fc49 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -81,6 +81,14 @@ config MMC_RICOH_MMC
 
 	  If unsure, say Y.
 
+config MMC_JZ4740
+	tristate "JZ4740 SD/Multimedia Card Interface support"
+	depends on MACH_JZ4740
+	help
+	  This selects the Ingenic Z4740 SD/Multimedia card Interface.
+	  If you have an ngenic platform with a Multimedia Card slot,
+	  say Y or M here.
+
 config MMC_SDHCI_OF
 	tristate "SDHCI support on OpenFirmware platforms"
 	depends on MMC_SDHCI && PPC_OF
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index e30c2ee..f4e53c9 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_MMC_CB710)	+= cb710-mmc.o
 obj-$(CONFIG_MMC_VIA_SDMMC)	+= via-sdmmc.o
 obj-$(CONFIG_SDH_BFIN)		+= bfin_sdh.o
 obj-$(CONFIG_MMC_SH_MMCIF)	+= sh_mmcif.o
+obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
 
 obj-$(CONFIG_MMC_SDHCI_OF)	+= sdhci-of.o
 sdhci-of-y				:= sdhci-of-core.o
diff --git a/drivers/mmc/host/jz4740_mmc.c b/drivers/mmc/host/jz4740_mmc.c
new file mode 100644
index 0000000..b34f25b
--- /dev/null
+++ b/drivers/mmc/host/jz4740_mmc.c
@@ -0,0 +1,969 @@
+/*
+ *  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/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/mmc/jz4740_mmc.h>
+
+#include <linux/bitops.h>
+#include <linux/gpio.h>
+#include <asm/mach-jz4740/gpio.h>
+#include <asm/cacheflush.h>
+#include <linux/dma-mapping.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
+
+#define JZ4740_MMC_MAX_TIMEOUT 10000000
+
+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;
+
+	struct resource *mem;
+	void __iomem *base;
+	struct mmc_request *req;
+	struct mmc_command *cmd;
+
+	unsigned long waiting;
+
+	int max_clock;
+	uint32_t cmdat;
+
+	uint16_t irq_mask;
+
+	spinlock_t lock;
+
+	struct timer_list timeout_timer;
+};
+
+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;
+
+	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);
+}
+
+static void jz4740_mmc_reset(struct jz4740_mmc_host *host)
+{
+	uint32_t status;
+
+	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);
+}
+
+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 inline unsigned int jz4740_mmc_wait_irq(struct jz4740_mmc_host *host,
+	unsigned int irq)
+{
+	unsigned int timeout = JZ4740_MMC_MAX_TIMEOUT;
+	uint16_t status;
+
+	do {
+		status = readw(host->base + JZ_REG_MMC_IREG);
+	} while (!(status & irq) && --timeout);
+
+	return timeout;
+}
+
+static void jz4740_mmc_write_data(struct jz4740_mmc_host *host,
+	struct mmc_data *data)
+{
+	struct sg_mapping_iter miter;
+	uint32_t *buf;
+	int status;
+	unsigned int timeout;
+	size_t i, j;
+
+	sg_miter_start(&miter, data->sg, data->sg_len, SG_MITER_FROM_SG);
+	while (sg_miter_next(&miter)) {
+		buf = miter.addr;
+		i = miter.length / 4;
+		j = i >> 3;
+		i = i & 0x7;
+		while (j) {
+			timeout = jz4740_mmc_wait_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
+			if (unlikely(timeout == 0)) {
+				sg_miter_stop(&miter);
+				goto err_timeout;
+			}
+
+			writel(buf[0], host->base + JZ_REG_MMC_TXFIFO);
+			writel(buf[1], host->base + JZ_REG_MMC_TXFIFO);
+			writel(buf[2], host->base + JZ_REG_MMC_TXFIFO);
+			writel(buf[3], host->base + JZ_REG_MMC_TXFIFO);
+			writel(buf[4], host->base + JZ_REG_MMC_TXFIFO);
+			writel(buf[5], host->base + JZ_REG_MMC_TXFIFO);
+			writel(buf[6], host->base + JZ_REG_MMC_TXFIFO);
+			writel(buf[7], host->base + JZ_REG_MMC_TXFIFO);
+			buf += 8;
+			--j;
+		}
+		if (unlikely(i)) {
+			timeout = jz4740_mmc_wait_irq(host, JZ_MMC_IRQ_TXFIFO_WR_REQ);
+			if (unlikely(timeout == 0)) {
+				sg_miter_stop(&miter);
+				goto err_timeout;
+			}
+
+			while (i) {
+				writel(*buf, host->base + JZ_REG_MMC_TXFIFO);
+				++buf;
+				--i;
+			}
+		}
+		data->bytes_xfered += miter.length;
+	}
+	sg_miter_stop(&miter);
+
+	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;
+		}
+		return;
+	}
+
+	timeout = JZ4740_MMC_MAX_TIMEOUT;
+	do {
+		status = readl(host->base + JZ_REG_MMC_STATUS);
+	} while ((status & JZ_MMC_STATUS_DATA_TRAN_DONE) == 0 && --timeout);
+
+	if (unlikely(timeout == 0))
+		goto err_timeout;
+	writew(JZ_MMC_IRQ_DATA_TRAN_DONE, host->base + JZ_REG_MMC_IREG);
+
+	return;
+
+err_timeout:
+	host->req->cmd->error = -ETIMEDOUT;
+	data->error = -ETIMEDOUT;
+}
+
+static void jz4740_mmc_read_data(struct jz4740_mmc_host *host,
+				struct mmc_data *data)
+{
+	struct sg_mapping_iter miter;
+	uint32_t *buf;
+	uint32_t d;
+	uint16_t status = 0;
+	size_t i, j;
+	unsigned int timeout;
+
+	sg_miter_start(&miter, data->sg, data->sg_len, SG_MITER_TO_SG);
+	while (sg_miter_next(&miter)) {
+		buf = miter.addr;
+		i = miter.length;
+		j = i >> 5;
+		i = i & 0x1f;
+		while (j) {
+			timeout = jz4740_mmc_wait_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
+			if (unlikely(timeout == 0)) {
+				sg_miter_stop(&miter);
+				goto err_timeout;
+			}
+
+			buf[0] = readl(host->base + JZ_REG_MMC_RXFIFO);
+			buf[1] = readl(host->base + JZ_REG_MMC_RXFIFO);
+			buf[2] = readl(host->base + JZ_REG_MMC_RXFIFO);
+			buf[3] = readl(host->base + JZ_REG_MMC_RXFIFO);
+			buf[4] = readl(host->base + JZ_REG_MMC_RXFIFO);
+			buf[5] = readl(host->base + JZ_REG_MMC_RXFIFO);
+			buf[6] = readl(host->base + JZ_REG_MMC_RXFIFO);
+			buf[7] = readl(host->base + JZ_REG_MMC_RXFIFO);
+
+			buf += 8;
+			--j;
+		}
+
+		while (i >= 4) {
+			timeout = jz4740_mmc_wait_irq(host, JZ_MMC_IRQ_RXFIFO_RD_REQ);
+			if (unlikely(timeout == 0)) {
+				sg_miter_stop(&miter);
+				goto err_timeout;
+			}
+
+			*buf++ = readl(host->base + JZ_REG_MMC_RXFIFO);
+			i -= 4;
+		}
+		if (unlikely(i > 0)) {
+			d = readl(host->base + JZ_REG_MMC_RXFIFO);
+			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);
+
+	status = readl(host->base + JZ_REG_MMC_STATUS);
+	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;
+		}
+		return;
+	}
+
+	/* For whatever reason there is sometime one word more in the fifo then
+	 * requested */
+	while ((status & JZ_MMC_STATUS_DATA_FIFO_EMPTY) == 0 && --timeout) {
+		d = readl(host->base + JZ_REG_MMC_RXFIFO);
+		status = readl(host->base + JZ_REG_MMC_STATUS);
+	}
+	return;
+
+err_timeout:
+	host->req->cmd->error = -ETIMEDOUT;
+	data->error = -ETIMEDOUT;
+}
+
+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;
+
+	if (cmd->flags & MMC_RSP_136) {
+		tmp = readw(host->base + JZ_REG_MMC_RESP_FIFO);
+		for (i = 0; i < 4; ++i) {
+			cmd->resp[i] = tmp << 24;
+			cmd->resp[i] |= readw(host->base + JZ_REG_MMC_RESP_FIFO) << 8;
+			tmp = readw(host->base + JZ_REG_MMC_RESP_FIFO);
+			cmd->resp[i] |= tmp >> 8;
+		}
+	} else {
+		cmd->resp[0] = readw(host->base + JZ_REG_MMC_RESP_FIFO) << 24;
+		cmd->resp[0] |= readw(host->base + JZ_REG_MMC_RESP_FIFO) << 8;
+		cmd->resp[0] |= readw(host->base + JZ_REG_MMC_RESP_FIFO) & 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;
+
+		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 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;
+	unsigned int timeout = JZ4740_MMC_MAX_TIMEOUT;
+	uint32_t status;
+
+	if (cmd->error)
+		goto done;
+
+	if (cmd->flags & MMC_RSP_PRESENT)
+		jz4740_mmc_read_response(host, cmd);
+
+	if (cmd->data) {
+		if (cmd->data->flags & MMC_DATA_READ)
+			jz4740_mmc_read_data(host, cmd->data);
+		else
+			jz4740_mmc_write_data(host, cmd->data);
+	}
+
+	if (req->stop) {
+		jz4740_mmc_send_command(host, req->stop);
+		do {
+			status = readw(host->base + JZ_REG_MMC_IREG);
+		} while ((status & JZ_MMC_IRQ_PRG_DONE) == 0 && --timeout);
+		writew(JZ_MMC_IRQ_PRG_DONE, host->base + JZ_REG_MMC_IREG);
+	}
+
+	if (unlikely(timeout == 0))
+		req->stop->error = -ETIMEDOUT;
+
+done:
+	jz4740_mmc_request_done(host);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t jz_mmc_irq(int irq, void *devid)
+{
+	struct jz4740_mmc_host *host = devid;
+	uint16_t irq_reg, status, tmp;
+	irqreturn_t ret = IRQ_HANDLED;
+
+	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);
+	}
+
+	if (!host->req || !host->cmd)
+		goto handled;
+
+	if (!(irq_reg & JZ_MMC_IRQ_END_CMD_RES))
+		goto handled;
+
+	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) {
+			host->cmd->error = -ETIMEDOUT;
+		} else if (status & JZ_MMC_STATUS_CRC_RES_ERR) {
+			host->cmd->error = -EIO;
+		} else if (status & (JZ_MMC_STATUS_CRC_READ_ERROR |
+			    JZ_MMC_STATUS_CRC_WRITE_ERROR)) {
+			host->cmd->data->error = -EIO;
+		} else if (status & (JZ_MMC_STATUS_CRC_READ_ERROR |
+				JZ_MMC_STATUS_CRC_WRITE_ERROR)) {
+			host->cmd->data->error = -EIO;
+		}
+
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_END_CMD_RES, false);
+	writew(JZ_MMC_IRQ_END_CMD_RES, host->base + JZ_REG_MMC_IREG);
+
+handled:
+	return ret;
+}
+
+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);
+
+	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_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(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 int jz4740_mmc_get_ro(struct mmc_host *mmc)
+{
+	struct jz4740_mmc_host *host = mmc_priv(mmc);
+	if (!gpio_is_valid(host->pdata->gpio_read_only))
+		return -ENOSYS;
+
+	return gpio_get_value(host->pdata->gpio_read_only) ^
+		host->pdata->read_only_active_low;
+}
+
+static int jz4740_mmc_get_cd(struct mmc_host *mmc)
+{
+	struct jz4740_mmc_host *host = mmc_priv(mmc);
+	if (!gpio_is_valid(host->pdata->gpio_card_detect))
+		return -ENOSYS;
+
+	return gpio_get_value(host->pdata->gpio_card_detect) ^
+			host->pdata->card_detect_active_low;
+}
+
+static irqreturn_t jz4740_mmc_card_detect_irq(int irq, void *devid)
+{
+	struct jz4740_mmc_host *host = devid;
+
+	mmc_detect_change(host->mmc, HZ / 3);
+
+	return IRQ_HANDLED;
+}
+
+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,
+	.set_ios	= jz4740_mmc_set_ios,
+	.get_ro		= jz4740_mmc_get_ro,
+	.get_cd		= jz4740_mmc_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 __devinit jz4740_mmc_request_gpios(struct platform_device *pdev)
+{
+	int ret;
+	struct jz4740_mmc_platform_data *pdata = pdev->dev.platform_data;
+
+	if (!pdata)
+		return 0;
+
+	if (gpio_is_valid(pdata->gpio_card_detect)) {
+		ret = gpio_request(pdata->gpio_card_detect, "MMC detect change");
+		if (ret) {
+			dev_err(&pdev->dev, "Failed to request detect change gpio\n");
+			goto err;
+		}
+		gpio_direction_input(pdata->gpio_card_detect);
+	}
+
+	if (gpio_is_valid(pdata->gpio_read_only)) {
+		ret = gpio_request(pdata->gpio_read_only, "MMC read only");
+		if (ret) {
+			dev_err(&pdev->dev, "Failed to request read only gpio: %d\n", ret);
+			goto err_free_gpio_card_detect;
+		}
+		gpio_direction_input(pdata->gpio_read_only);
+	}
+
+	if (gpio_is_valid(pdata->gpio_power)) {
+		ret = gpio_request(pdata->gpio_power, "MMC power");
+		if (ret) {
+			dev_err(&pdev->dev, "Failed to request power gpio: %d\n", ret);
+			goto err_free_gpio_read_only;
+		}
+		gpio_direction_output(pdata->gpio_power, pdata->power_active_low);
+	}
+
+	return 0;
+
+err_free_gpio_read_only:
+	if (gpio_is_valid(pdata->gpio_read_only))
+		gpio_free(pdata->gpio_read_only);
+err_free_gpio_card_detect:
+	if (gpio_is_valid(pdata->gpio_card_detect))
+		gpio_free(pdata->gpio_card_detect);
+err:
+	return ret;
+}
+
+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);
+	if (gpio_is_valid(pdata->gpio_read_only))
+		gpio_free(pdata->gpio_read_only);
+	if (gpio_is_valid(pdata->gpio_card_detect))
+		gpio_free(pdata->gpio_card_detect);
+}
+
+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 __devinit 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 = clk_get(&pdev->dev, "mmc");
+	if (!host->clk) {
+		ret = -ENOENT;
+		dev_err(&pdev->dev, "Failed to get mmc clock\n");
+		goto err_free_host;
+	}
+
+	host->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!host->mem) {
+		ret = -ENOENT;
+		dev_err(&pdev->dev, "Failed to get base platform memory\n");
+		goto err_clk_put;
+	}
+
+	host->mem = request_mem_region(host->mem->start,
+					resource_size(host->mem), pdev->name);
+	if (!host->mem) {
+		ret = -EBUSY;
+		dev_err(&pdev->dev, "Failed to request base memory region\n");
+		goto err_clk_put;
+	}
+
+	host->base = ioremap_nocache(host->mem->start, resource_size(host->mem));
+	if (!host->base) {
+		ret = -EBUSY;
+		dev_err(&pdev->dev, "Failed to ioremap base memory\n");
+		goto err_release_mem_region;
+	}
+
+	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_iounmap;
+	}
+
+	ret = jz4740_mmc_request_gpios(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_phys_segs = 128;
+	mmc->max_hw_segs = 128;
+	mmc->max_seg_size = mmc->max_req_size;
+
+	host->mmc = mmc;
+	host->pdev = pdev;
+	host->max_clock = JZ_MMC_CLK_RATE;
+	spin_lock_init(&host->lock);
+	host->irq_mask = 0xffff;
+
+	host->card_detect_irq = gpio_to_irq(pdata->gpio_card_detect);
+
+	if (host->card_detect_irq < 0) {
+		dev_warn(&pdev->dev, "Failed to get irq for card detect gpio\n");
+	} else {
+		ret = request_irq(host->card_detect_irq,
+			jz4740_mmc_card_detect_irq,
+			IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+			"MMC card detect", host);
+
+		if (ret) {
+			dev_err(&pdev->dev, "Failed to request card detect irq");
+			goto err_free_gpios;
+		}
+	}
+
+	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_card_detect_irq;
+	}
+
+	jz4740_mmc_reset(host);
+	jz4740_mmc_clock_disable(host);
+	setup_timer(&host->timeout_timer, jz4740_mmc_timeout,
+			(unsigned long)host);
+	/* It is not that important when it times out, it just needs to timeout. */
+	set_timer_slack(&host->timeout_timer, HZ);
+
+	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");
+
+	return 0;
+
+err_free_irq:
+	free_irq(host->irq, host);
+err_free_card_detect_irq:
+	if (host->card_detect_irq >= 0)
+		free_irq(host->card_detect_irq, host);
+err_free_gpios:
+	jz4740_mmc_free_gpios(pdev);
+err_gpio_bulk_free:
+	jz_gpio_bulk_free(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
+err_iounmap:
+	iounmap(host->base);
+err_release_mem_region:
+	release_mem_region(host->mem->start, resource_size(host->mem));
+err_clk_put:
+	clk_put(host->clk);
+err_free_host:
+	platform_set_drvdata(pdev, NULL);
+	mmc_free_host(mmc);
+
+	return ret;
+}
+
+static int __devexit 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);
+	if (host->card_detect_irq >= 0)
+		free_irq(host->card_detect_irq, host);
+
+	jz4740_mmc_free_gpios(pdev);
+	jz_gpio_bulk_free(jz4740_mmc_pins, jz4740_mmc_num_pins(host));
+
+	iounmap(host->base);
+	release_mem_region(host->mem->start, resource_size(host->mem));
+
+	clk_put(host->clk);
+
+	platform_set_drvdata(pdev, NULL);
+	mmc_free_host(host->mmc);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int jz4740_mmc_suspend(struct device *dev)
+{
+	struct jz4740_mmc_host *host = dev_get_drvdata(dev);
+
+	mmc_suspend_host(host->mmc);
+
+	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));
+
+	mmc_resume_host(host->mmc);
+
+	return 0;
+}
+
+const struct dev_pm_ops jz4740_mmc_pm_ops = {
+	.suspend	= jz4740_mmc_suspend,
+	.resume		= jz4740_mmc_resume,
+	.poweroff	= jz4740_mmc_suspend,
+	.restore	= 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 = __devexit_p(jz4740_mmc_remove),
+	.driver = {
+		.name = "jz4740-mmc",
+		.owner = THIS_MODULE,
+		.pm = JZ4740_MMC_PM_OPS,
+	},
+};
+
+static int __init jz4740_mmc_init(void)
+{
+	return platform_driver_register(&jz4740_mmc_driver);
+}
+module_init(jz4740_mmc_init);
+
+static void __exit jz4740_mmc_exit(void)
+{
+	platform_driver_unregister(&jz4740_mmc_driver);
+}
+module_exit(jz4740_mmc_exit);
+
+MODULE_DESCRIPTION("JZ4740 SD/MMC controller driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
diff --git a/include/linux/mmc/jz4740_mmc.h b/include/linux/mmc/jz4740_mmc.h
new file mode 100644
index 0000000..8543f43
--- /dev/null
+++ b/include/linux/mmc/jz4740_mmc.h
@@ -0,0 +1,15 @@
+#ifndef __LINUX_MMC_JZ4740_MMC
+#define __LINUX_MMC_JZ4740_MMC
+
+struct jz4740_mmc_platform_data {
+	int gpio_power;
+	int gpio_card_detect;
+	int gpio_read_only;
+	unsigned card_detect_active_low:1;
+	unsigned read_only_active_low:1;
+	unsigned power_active_low:1;
+
+	unsigned data_1bit:1;
+};
+
+#endif
-- 
1.5.6.5