mmc: SD/MMC Host Controller for Wondermedia WM8505/WM8650

This patch adds support for the SD/MMC host controller found
on Wondermedia 8xxx series SoCs, currently supported under
arm/arch-vt8500.

A binding document is also included, based on mmc.txt with
additional properties.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Chris Ball <cjb@laptop.org>

5 files changed, 1065 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/mmc/vt8500-sdmmc.txt b/Documentation/devicetree/bindings/mmc/vt8500-sdmmc.txt
new file mode 100644
index 000000000000..d7fb6abb3eb8
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/vt8500-sdmmc.txt
@@ -0,0 +1,23 @@
+* Wondermedia WM8505/WM8650 SD/MMC Host Controller
+
+This file documents differences between the core properties described
+by mmc.txt and the properties used by the wmt-sdmmc driver.
+
+Required properties:
+- compatible: Should be "wm,wm8505-sdhc".
+- interrupts: Two interrupts are required - regular irq and dma irq.
+
+Optional properties:
+- sdon-inverted: SD_ON bit is inverted on the controller
+
+Examples:
+
+sdhc@d800a000 {
+	compatible = "wm,wm8505-sdhc";
+	reg = <0xd800a000 0x1000>;
+	interrupts = <20 21>;
+	clocks = <&sdhc>;
+	bus-width = <4>;
+	sdon-inverted;
+};
+
diff --git a/MAINTAINERS b/MAINTAINERS
index d2189fb78dcb..cfafe1b6b004 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1221,6 +1221,7 @@ F:	drivers/video/wm8505fb*
 F:	drivers/video/wmt_ge_rops.*
 F:	drivers/tty/serial/vt8500_serial.c
 F:	drivers/rtc/rtc-vt8500-c
+F:	drivers/mmc/host/wmt-sdmmc.c
 
 ARM/ZIPIT Z2 SUPPORT
 M:	Marek Vasut <marek.vasut@gmail.com>
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 5c7c846e03ef..83eb1e06ff76 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -601,3 +601,14 @@ config MMC_USHC
 
 	  Note: These controllers only support SDIO cards and do not
 	  support MMC or SD memory cards.
+
+config MMC_WMT
+	tristate "Wondermedia SD/MMC Host Controller support"
+	depends on ARCH_VT8500
+	default y
+	help
+	  This selects support for the SD/MMC Host Controller on
+	  Wondermedia WM8505/WM8650 based SoCs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called wmt-sdmmc.
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index cd64b5df9703..39d5e1234709 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_MMC_SH_MMCIF)	+= sh_mmcif.o
 obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
 obj-$(CONFIG_MMC_VUB300)	+= vub300.o
 obj-$(CONFIG_MMC_USHC)		+= ushc.o
+obj-$(CONFIG_MMC_WMT)		+= wmt-sdmmc.o
 
 obj-$(CONFIG_MMC_SDHCI_PLTFM)		+= sdhci-pltfm.o
 obj-$(CONFIG_MMC_SDHCI_CNS3XXX)		+= sdhci-cns3xxx.o
diff --git a/drivers/mmc/host/wmt-sdmmc.c b/drivers/mmc/host/wmt-sdmmc.c
new file mode 100644
index 000000000000..5ba4605e4f80
--- /dev/null
+++ b/drivers/mmc/host/wmt-sdmmc.c
@@ -0,0 +1,1029 @@
+/*
+ *  WM8505/WM8650 SD/MMC Host Controller
+ *
+ *  Copyright (C) 2010 Tony Prisk
+ *  Copyright (C) 2008 WonderMedia Technologies, Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/ioport.h>
+#include <linux/errno.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/clk.h>
+#include <linux/gpio.h>
+
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_device.h>
+
+#include <linux/mmc/host.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/sd.h>
+
+#include <asm/byteorder.h>
+
+
+#define DRIVER_NAME "wmt-sdhc"
+
+
+/* MMC/SD controller registers */
+#define SDMMC_CTLR			0x00
+#define SDMMC_CMD			0x01
+#define SDMMC_RSPTYPE			0x02
+#define SDMMC_ARG			0x04
+#define SDMMC_BUSMODE			0x08
+#define SDMMC_BLKLEN			0x0C
+#define SDMMC_BLKCNT			0x0E
+#define SDMMC_RSP			0x10
+#define SDMMC_CBCR			0x20
+#define SDMMC_INTMASK0			0x24
+#define SDMMC_INTMASK1			0x25
+#define SDMMC_STS0			0x28
+#define SDMMC_STS1			0x29
+#define SDMMC_STS2			0x2A
+#define SDMMC_STS3			0x2B
+#define SDMMC_RSPTIMEOUT		0x2C
+#define SDMMC_CLK			0x30	/* VT8500 only */
+#define SDMMC_EXTCTRL			0x34
+#define SDMMC_SBLKLEN			0x38
+#define SDMMC_DMATIMEOUT		0x3C
+
+
+/* SDMMC_CTLR bit fields */
+#define CTLR_CMD_START			0x01
+#define CTLR_CMD_WRITE			0x04
+#define CTLR_FIFO_RESET			0x08
+
+/* SDMMC_BUSMODE bit fields */
+#define BM_SPI_MODE			0x01
+#define BM_FOURBIT_MODE			0x02
+#define BM_EIGHTBIT_MODE		0x04
+#define BM_SD_OFF			0x10
+#define BM_SPI_CS			0x20
+#define BM_SD_POWER			0x40
+#define BM_SOFT_RESET			0x80
+#define BM_ONEBIT_MASK			0xFD
+
+/* SDMMC_BLKLEN bit fields */
+#define BLKL_CRCERR_ABORT		0x0800
+#define BLKL_CD_POL_HIGH		0x1000
+#define BLKL_GPI_CD			0x2000
+#define BLKL_DATA3_CD			0x4000
+#define BLKL_INT_ENABLE			0x8000
+
+/* SDMMC_INTMASK0 bit fields */
+#define INT0_MBLK_TRAN_DONE_INT_EN	0x10
+#define INT0_BLK_TRAN_DONE_INT_EN	0x20
+#define INT0_CD_INT_EN			0x40
+#define INT0_DI_INT_EN			0x80
+
+/* SDMMC_INTMASK1 bit fields */
+#define INT1_CMD_RES_TRAN_DONE_INT_EN	0x02
+#define INT1_CMD_RES_TOUT_INT_EN	0x04
+#define INT1_MBLK_AUTO_STOP_INT_EN	0x08
+#define INT1_DATA_TOUT_INT_EN		0x10
+#define INT1_RESCRC_ERR_INT_EN		0x20
+#define INT1_RCRC_ERR_INT_EN		0x40
+#define INT1_WCRC_ERR_INT_EN		0x80
+
+/* SDMMC_STS0 bit fields */
+#define STS0_WRITE_PROTECT		0x02
+#define STS0_CD_DATA3			0x04
+#define STS0_CD_GPI			0x08
+#define STS0_MBLK_DONE			0x10
+#define STS0_BLK_DONE			0x20
+#define STS0_CARD_DETECT		0x40
+#define STS0_DEVICE_INS			0x80
+
+/* SDMMC_STS1 bit fields */
+#define STS1_SDIO_INT			0x01
+#define STS1_CMDRSP_DONE		0x02
+#define STS1_RSP_TIMEOUT		0x04
+#define STS1_AUTOSTOP_DONE		0x08
+#define STS1_DATA_TIMEOUT		0x10
+#define STS1_RSP_CRC_ERR		0x20
+#define STS1_RCRC_ERR			0x40
+#define STS1_WCRC_ERR			0x80
+
+/* SDMMC_STS2 bit fields */
+#define STS2_CMD_RES_BUSY		0x10
+#define STS2_DATARSP_BUSY		0x20
+#define STS2_DIS_FORCECLK		0x80
+
+
+/* MMC/SD DMA Controller Registers */
+#define SDDMA_GCR			0x100
+#define SDDMA_IER			0x104
+#define SDDMA_ISR			0x108
+#define SDDMA_DESPR			0x10C
+#define SDDMA_RBR			0x110
+#define SDDMA_DAR			0x114
+#define SDDMA_BAR			0x118
+#define SDDMA_CPR			0x11C
+#define SDDMA_CCR			0x120
+
+
+/* SDDMA_GCR bit fields */
+#define DMA_GCR_DMA_EN			0x00000001
+#define DMA_GCR_SOFT_RESET		0x00000100
+
+/* SDDMA_IER bit fields */
+#define DMA_IER_INT_EN			0x00000001
+
+/* SDDMA_ISR bit fields */
+#define DMA_ISR_INT_STS			0x00000001
+
+/* SDDMA_RBR bit fields */
+#define DMA_RBR_FORMAT			0x40000000
+#define DMA_RBR_END			0x80000000
+
+/* SDDMA_CCR bit fields */
+#define DMA_CCR_RUN			0x00000080
+#define DMA_CCR_IF_TO_PERIPHERAL	0x00000000
+#define DMA_CCR_PERIPHERAL_TO_IF	0x00400000
+
+/* SDDMA_CCR event status */
+#define DMA_CCR_EVT_NO_STATUS		0x00000000
+#define DMA_CCR_EVT_UNDERRUN		0x00000001
+#define DMA_CCR_EVT_OVERRUN		0x00000002
+#define DMA_CCR_EVT_DESP_READ		0x00000003
+#define DMA_CCR_EVT_DATA_RW		0x00000004
+#define DMA_CCR_EVT_EARLY_END		0x00000005
+#define DMA_CCR_EVT_SUCCESS		0x0000000F
+
+#define PDMA_READ			0x00
+#define PDMA_WRITE			0x01
+
+#define WMT_SD_POWER_OFF		0
+#define WMT_SD_POWER_ON			1
+
+struct wmt_dma_descriptor {
+	u32 flags;
+	u32 data_buffer_addr;
+	u32 branch_addr;
+	u32 reserved1;
+};
+
+struct wmt_mci_caps {
+	unsigned int	f_min;
+	unsigned int	f_max;
+	u32		ocr_avail;
+	u32		caps;
+	u32		max_seg_size;
+	u32		max_segs;
+	u32		max_blk_size;
+};
+
+struct wmt_mci_priv {
+	struct mmc_host *mmc;
+	void __iomem *sdmmc_base;
+
+	int irq_regular;
+	int irq_dma;
+
+	void *dma_desc_buffer;
+	dma_addr_t dma_desc_device_addr;
+
+	struct completion cmdcomp;
+	struct completion datacomp;
+
+	struct completion *comp_cmd;
+	struct completion *comp_dma;
+
+	struct mmc_request *req;
+	struct mmc_command *cmd;
+
+	struct clk *clk_sdmmc;
+	struct device *dev;
+
+	u8 power_inverted;
+	u8 cd_inverted;
+};
+
+static void wmt_set_sd_power(struct wmt_mci_priv *priv, int enable)
+{
+	u32 reg_tmp;
+	if (enable) {
+		if (priv->power_inverted) {
+			reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
+			writeb(reg_tmp | BM_SD_OFF,
+			       priv->sdmmc_base + SDMMC_BUSMODE);
+		} else {
+			reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
+			writeb(reg_tmp & (~BM_SD_OFF),
+			       priv->sdmmc_base + SDMMC_BUSMODE);
+		}
+	} else {
+		if (priv->power_inverted) {
+			reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
+			writeb(reg_tmp & (~BM_SD_OFF),
+			       priv->sdmmc_base + SDMMC_BUSMODE);
+		} else {
+			reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
+			writeb(reg_tmp | BM_SD_OFF,
+			       priv->sdmmc_base + SDMMC_BUSMODE);
+		}
+	}
+}
+
+static void wmt_mci_read_response(struct mmc_host *mmc)
+{
+	struct wmt_mci_priv *priv;
+	int idx1, idx2;
+	u8 tmp_resp;
+	u32 response;
+
+	priv = mmc_priv(mmc);
+
+	for (idx1 = 0; idx1 < 4; idx1++) {
+		response = 0;
+		for (idx2 = 0; idx2 < 4; idx2++) {
+			if ((idx1 == 3) && (idx2 == 3))
+				tmp_resp = readb(priv->sdmmc_base + SDMMC_RSP);
+			else
+				tmp_resp = readb(priv->sdmmc_base + SDMMC_RSP +
+						 (idx1*4) + idx2 + 1);
+			response |= (tmp_resp << (idx2 * 8));
+		}
+		priv->cmd->resp[idx1] = cpu_to_be32(response);
+	}
+}
+
+static void wmt_mci_start_command(struct wmt_mci_priv *priv)
+{
+	u32 reg_tmp;
+
+	reg_tmp = readb(priv->sdmmc_base + SDMMC_CTLR);
+	writeb(reg_tmp | CTLR_CMD_START, priv->sdmmc_base + SDMMC_CTLR);
+}
+
+static int wmt_mci_send_command(struct mmc_host *mmc, u8 command, u8 cmdtype,
+				u32 arg, u8 rsptype)
+{
+	struct wmt_mci_priv *priv;
+	u32 reg_tmp;
+
+	priv = mmc_priv(mmc);
+
+	/* write command, arg, resptype registers */
+	writeb(command, priv->sdmmc_base + SDMMC_CMD);
+	writel(arg, priv->sdmmc_base + SDMMC_ARG);
+	writeb(rsptype, priv->sdmmc_base + SDMMC_RSPTYPE);
+
+	/* reset response FIFO */
+	reg_tmp = readb(priv->sdmmc_base + SDMMC_CTLR);
+	writeb(reg_tmp | CTLR_FIFO_RESET, priv->sdmmc_base + SDMMC_CTLR);
+
+	/* ensure clock enabled - VT3465 */
+	wmt_set_sd_power(priv, WMT_SD_POWER_ON);
+
+	/* clear status bits */
+	writeb(0xFF, priv->sdmmc_base + SDMMC_STS0);
+	writeb(0xFF, priv->sdmmc_base + SDMMC_STS1);
+	writeb(0xFF, priv->sdmmc_base + SDMMC_STS2);
+	writeb(0xFF, priv->sdmmc_base + SDMMC_STS3);
+
+	/* set command type */
+	reg_tmp = readb(priv->sdmmc_base + SDMMC_CTLR);
+	writeb((reg_tmp & 0x0F) | (cmdtype << 4),
+	       priv->sdmmc_base + SDMMC_CTLR);
+
+	return 0;
+}
+
+static void wmt_mci_disable_dma(struct wmt_mci_priv *priv)
+{
+	writel(DMA_ISR_INT_STS, priv->sdmmc_base + SDDMA_ISR);
+	writel(0, priv->sdmmc_base + SDDMA_IER);
+}
+
+static void wmt_complete_data_request(struct wmt_mci_priv *priv)
+{
+	struct mmc_request *req;
+	req = priv->req;
+
+	req->data->bytes_xfered = req->data->blksz * req->data->blocks;
+
+	/* unmap the DMA pages used for write data */
+	if (req->data->flags & MMC_DATA_WRITE)
+		dma_unmap_sg(mmc_dev(priv->mmc), req->data->sg,
+			     req->data->sg_len, DMA_TO_DEVICE);
+	else
+		dma_unmap_sg(mmc_dev(priv->mmc), req->data->sg,
+			     req->data->sg_len, DMA_FROM_DEVICE);
+
+	/* Check if the DMA ISR returned a data error */
+	if ((req->cmd->error) || (req->data->error))
+		mmc_request_done(priv->mmc, req);
+	else {
+		wmt_mci_read_response(priv->mmc);
+		if (!req->data->stop) {
+			/* single-block read/write requests end here */
+			mmc_request_done(priv->mmc, req);
+		} else {
+			/*
+			 * we change the priv->cmd variable so the response is
+			 * stored in the stop struct rather than the original
+			 * calling command struct
+			 */
+			priv->comp_cmd = &priv->cmdcomp;
+			init_completion(priv->comp_cmd);
+			priv->cmd = req->data->stop;
+			wmt_mci_send_command(priv->mmc, req->data->stop->opcode,
+					     7, req->data->stop->arg, 9);
+			wmt_mci_start_command(priv);
+		}
+	}
+}
+
+static irqreturn_t wmt_mci_dma_isr(int irq_num, void *data)
+{
+	struct mmc_host *mmc;
+	struct wmt_mci_priv *priv;
+
+	int status;
+
+	priv = (struct wmt_mci_priv *)data;
+	mmc = priv->mmc;
+
+	status = readl(priv->sdmmc_base + SDDMA_CCR) & 0x0F;
+
+	if (status != DMA_CCR_EVT_SUCCESS) {
+		dev_err(priv->dev, "DMA Error: Status = %d\n", status);
+		priv->req->data->error = -ETIMEDOUT;
+		complete(priv->comp_dma);
+		return IRQ_HANDLED;
+	}
+
+	priv->req->data->error = 0;
+
+	wmt_mci_disable_dma(priv);
+
+	complete(priv->comp_dma);
+
+	if (priv->comp_cmd) {
+		if (completion_done(priv->comp_cmd)) {
+			/*
+			 * if the command (regular) interrupt has already
+			 * completed, finish off the request otherwise we wait
+			 * for the command interrupt and finish from there.
+			 */
+			wmt_complete_data_request(priv);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t wmt_mci_regular_isr(int irq_num, void *data)
+{
+	struct wmt_mci_priv *priv;
+	u32 status0;
+	u32 status1;
+	u32 status2;
+	u32 reg_tmp;
+	int cmd_done;
+
+	priv = (struct wmt_mci_priv *)data;
+	cmd_done = 0;
+	status0 = readb(priv->sdmmc_base + SDMMC_STS0);
+	status1 = readb(priv->sdmmc_base + SDMMC_STS1);
+	status2 = readb(priv->sdmmc_base + SDMMC_STS2);
+
+	/* Check for card insertion */
+	reg_tmp = readb(priv->sdmmc_base + SDMMC_INTMASK0);
+	if ((reg_tmp & INT0_DI_INT_EN) && (status0 & STS0_DEVICE_INS)) {
+		mmc_detect_change(priv->mmc, 0);
+		if (priv->cmd)
+			priv->cmd->error = -ETIMEDOUT;
+		if (priv->comp_cmd)
+			complete(priv->comp_cmd);
+		if (priv->comp_dma) {
+			wmt_mci_disable_dma(priv);
+			complete(priv->comp_dma);
+		}
+		writeb(STS0_DEVICE_INS, priv->sdmmc_base + SDMMC_STS0);
+		return IRQ_HANDLED;
+	}
+
+	if ((!priv->req->data) ||
+	    ((priv->req->data->stop) && (priv->cmd == priv->req->data->stop))) {
+		/* handle non-data & stop_transmission requests */
+		if (status1 & STS1_CMDRSP_DONE) {
+			priv->cmd->error = 0;
+			cmd_done = 1;
+		} else if ((status1 & STS1_RSP_TIMEOUT) ||
+			   (status1 & STS1_DATA_TIMEOUT)) {
+			priv->cmd->error = -ETIMEDOUT;
+			cmd_done = 1;
+		}
+
+		if (cmd_done) {
+			priv->comp_cmd = NULL;
+
+			if (!priv->cmd->error)
+				wmt_mci_read_response(priv->mmc);
+
+			priv->cmd = NULL;
+
+			mmc_request_done(priv->mmc, priv->req);
+		}
+	} else {
+		/* handle data requests */
+		if (status1 & STS1_CMDRSP_DONE) {
+			if (priv->cmd)
+				priv->cmd->error = 0;
+			if (priv->comp_cmd)
+				complete(priv->comp_cmd);
+		}
+
+		if ((status1 & STS1_RSP_TIMEOUT) ||
+		    (status1 & STS1_DATA_TIMEOUT)) {
+			if (priv->cmd)
+				priv->cmd->error = -ETIMEDOUT;
+			if (priv->comp_cmd)
+				complete(priv->comp_cmd);
+			if (priv->comp_dma) {
+				wmt_mci_disable_dma(priv);
+				complete(priv->comp_dma);
+			}
+		}
+
+		if (priv->comp_dma) {
+			/*
+			 * If the dma interrupt has already completed, finish
+			 * off the request; otherwise we wait for the DMA
+			 * interrupt and finish from there.
+			 */
+			if (completion_done(priv->comp_dma))
+				wmt_complete_data_request(priv);
+		}
+	}
+
+	writeb(status0, priv->sdmmc_base + SDMMC_STS0);
+	writeb(status1, priv->sdmmc_base + SDMMC_STS1);
+	writeb(status2, priv->sdmmc_base + SDMMC_STS2);
+
+	return IRQ_HANDLED;
+}
+
+static void wmt_reset_hardware(struct mmc_host *mmc)
+{
+	struct wmt_mci_priv *priv;
+	u32 reg_tmp;
+
+	priv = mmc_priv(mmc);
+
+	/* reset controller */
+	reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
+	writeb(reg_tmp | BM_SOFT_RESET, priv->sdmmc_base + SDMMC_BUSMODE);
+
+	/* reset response FIFO */
+	reg_tmp = readb(priv->sdmmc_base + SDMMC_CTLR);
+	writeb(reg_tmp | CTLR_FIFO_RESET, priv->sdmmc_base + SDMMC_CTLR);
+
+	/* enable GPI pin to detect card */
+	writew(BLKL_INT_ENABLE | BLKL_GPI_CD, priv->sdmmc_base + SDMMC_BLKLEN);
+
+	/* clear interrupt status */
+	writeb(0xFF, priv->sdmmc_base + SDMMC_STS0);
+	writeb(0xFF, priv->sdmmc_base + SDMMC_STS1);
+
+	/* setup interrupts */
+	writeb(INT0_CD_INT_EN | INT0_DI_INT_EN, priv->sdmmc_base +
+	       SDMMC_INTMASK0);
+	writeb(INT1_DATA_TOUT_INT_EN | INT1_CMD_RES_TRAN_DONE_INT_EN |
+	       INT1_CMD_RES_TOUT_INT_EN, priv->sdmmc_base + SDMMC_INTMASK1);
+
+	/* set the DMA timeout */
+	writew(8191, priv->sdmmc_base + SDMMC_DMATIMEOUT);
+
+	/* auto clock freezing enable */
+	reg_tmp = readb(priv->sdmmc_base + SDMMC_STS2);
+	writeb(reg_tmp | STS2_DIS_FORCECLK, priv->sdmmc_base + SDMMC_STS2);
+
+	/* set a default clock speed of 400Khz */
+	clk_set_rate(priv->clk_sdmmc, 400000);
+}
+
+static int wmt_dma_init(struct mmc_host *mmc)
+{
+	struct wmt_mci_priv *priv;
+
+	priv = mmc_priv(mmc);
+
+	writel(DMA_GCR_SOFT_RESET, priv->sdmmc_base + SDDMA_GCR);
+	writel(DMA_GCR_DMA_EN, priv->sdmmc_base + SDDMA_GCR);
+	if ((readl(priv->sdmmc_base + SDDMA_GCR) & DMA_GCR_DMA_EN) != 0)
+		return 0;
+	else
+		return 1;
+}
+
+static void wmt_dma_init_descriptor(struct wmt_dma_descriptor *desc,
+		u16 req_count, u32 buffer_addr, u32 branch_addr, int end)
+{
+	desc->flags = 0x40000000 | req_count;
+	if (end)
+		desc->flags |= 0x80000000;
+	desc->data_buffer_addr = buffer_addr;
+	desc->branch_addr = branch_addr;
+}
+
+static void wmt_dma_config(struct mmc_host *mmc, u32 descaddr, u8 dir)
+{
+	struct wmt_mci_priv *priv;
+	u32 reg_tmp;
+
+	priv = mmc_priv(mmc);
+
+	/* Enable DMA Interrupts */
+	writel(DMA_IER_INT_EN, priv->sdmmc_base + SDDMA_IER);
+
+	/* Write DMA Descriptor Pointer Register */
+	writel(descaddr, priv->sdmmc_base + SDDMA_DESPR);
+
+	writel(0x00, priv->sdmmc_base + SDDMA_CCR);
+
+	if (dir == PDMA_WRITE) {
+		reg_tmp = readl(priv->sdmmc_base + SDDMA_CCR);
+		writel(reg_tmp & DMA_CCR_IF_TO_PERIPHERAL, priv->sdmmc_base +
+		       SDDMA_CCR);
+	} else {
+		reg_tmp = readl(priv->sdmmc_base + SDDMA_CCR);
+		writel(reg_tmp | DMA_CCR_PERIPHERAL_TO_IF, priv->sdmmc_base +
+		       SDDMA_CCR);
+	}
+}
+
+static void wmt_dma_start(struct wmt_mci_priv *priv)
+{
+	u32 reg_tmp;
+
+	reg_tmp = readl(priv->sdmmc_base + SDDMA_CCR);
+	writel(reg_tmp | DMA_CCR_RUN, priv->sdmmc_base + SDDMA_CCR);
+}
+
+static void wmt_mci_request(struct mmc_host *mmc, struct mmc_request *req)
+{
+	struct wmt_mci_priv *priv;
+	struct wmt_dma_descriptor *desc;
+	u8 command;
+	u8 cmdtype;
+	u32 arg;
+	u8 rsptype;
+	u32 reg_tmp;
+
+	struct scatterlist *sg;
+	int i;
+	int sg_cnt;
+	int offset;
+	u32 dma_address;
+	int desc_cnt;
+
+	priv = mmc_priv(mmc);
+	priv->req = req;
+
+	/*
+	 * Use the cmd variable to pass a pointer to the resp[] structure
+	 * This is required on multi-block requests to pass the pointer to the
+	 * stop command
+	 */
+	priv->cmd = req->cmd;
+
+	command = req->cmd->opcode;
+	arg = req->cmd->arg;
+	rsptype = mmc_resp_type(req->cmd);
+	cmdtype = 0;
+
+	/* rsptype=7 only valid for SPI commands - should be =2 for SD */
+	if (rsptype == 7)
+		rsptype = 2;
+	/* rsptype=21 is R1B, convert for controller */
+	if (rsptype == 21)
+		rsptype = 9;
+
+	if (!req->data) {
+		wmt_mci_send_command(mmc, command, cmdtype, arg, rsptype);
+		wmt_mci_start_command(priv);
+		/* completion is now handled in the regular_isr() */
+	}
+	if (req->data) {
+		priv->comp_cmd = &priv->cmdcomp;
+		init_completion(priv->comp_cmd);
+
+		wmt_dma_init(mmc);
+
+		/* set controller data length */
+		reg_tmp = readw(priv->sdmmc_base + SDMMC_BLKLEN);
+		writew((reg_tmp & 0xF800) | (req->data->blksz - 1),
+		       priv->sdmmc_base + SDMMC_BLKLEN);
+
+		/* set controller block count */
+		writew(req->data->blocks, priv->sdmmc_base + SDMMC_BLKCNT);
+
+		desc = (struct wmt_dma_descriptor *)priv->dma_desc_buffer;
+
+		if (req->data->flags & MMC_DATA_WRITE) {
+			sg_cnt = dma_map_sg(mmc_dev(mmc), req->data->sg,
+					    req->data->sg_len, DMA_TO_DEVICE);
+			cmdtype = 1;
+			if (req->data->blocks > 1)
+				cmdtype = 3;
+		} else {
+			sg_cnt = dma_map_sg(mmc_dev(mmc), req->data->sg,
+					    req->data->sg_len, DMA_FROM_DEVICE);
+			cmdtype = 2;
+			if (req->data->blocks > 1)
+				cmdtype = 4;
+		}
+
+		dma_address = priv->dma_desc_device_addr + 16;
+		desc_cnt = 0;
+
+		for_each_sg(req->data->sg, sg, sg_cnt, i) {
+			offset = 0;
+			while (offset < sg_dma_len(sg)) {
+				wmt_dma_init_descriptor(desc, req->data->blksz,
+						sg_dma_address(sg)+offset,
+						dma_address, 0);
+				desc++;
+				desc_cnt++;
+				offset += req->data->blksz;
+				dma_address += 16;
+				if (desc_cnt == req->data->blocks)
+					break;
+			}
+		}
+		desc--;
+		desc->flags |= 0x80000000;
+
+		if (req->data->flags & MMC_DATA_WRITE)
+			wmt_dma_config(mmc, priv->dma_desc_device_addr,
+				       PDMA_WRITE);
+		else
+			wmt_dma_config(mmc, priv->dma_desc_device_addr,
+				       PDMA_READ);
+
+		wmt_mci_send_command(mmc, command, cmdtype, arg, rsptype);
+
+		priv->comp_dma = &priv->datacomp;
+		init_completion(priv->comp_dma);
+
+		wmt_dma_start(priv);
+		wmt_mci_start_command(priv);
+	}
+}
+
+static void wmt_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct wmt_mci_priv *priv;
+	u32 reg_tmp;
+
+	priv = mmc_priv(mmc);
+
+	if (ios->power_mode == MMC_POWER_UP) {
+		wmt_reset_hardware(mmc);
+
+		wmt_set_sd_power(priv, WMT_SD_POWER_ON);
+	}
+	if (ios->power_mode == MMC_POWER_OFF)
+		wmt_set_sd_power(priv, WMT_SD_POWER_OFF);
+
+	if (ios->clock != 0)
+		clk_set_rate(priv->clk_sdmmc, ios->clock);
+
+	switch (ios->bus_width) {
+	case MMC_BUS_WIDTH_8:
+		reg_tmp = readb(priv->sdmmc_base + SDMMC_EXTCTRL);
+		writeb(reg_tmp | 0x04, priv->sdmmc_base + SDMMC_EXTCTRL);
+		break;
+	case MMC_BUS_WIDTH_4:
+		reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
+		writeb(reg_tmp | BM_FOURBIT_MODE, priv->sdmmc_base +
+		       SDMMC_BUSMODE);
+
+		reg_tmp = readb(priv->sdmmc_base + SDMMC_EXTCTRL);
+		writeb(reg_tmp & 0xFB, priv->sdmmc_base + SDMMC_EXTCTRL);
+		break;
+	case MMC_BUS_WIDTH_1:
+		reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
+		writeb(reg_tmp & BM_ONEBIT_MASK, priv->sdmmc_base +
+		       SDMMC_BUSMODE);
+
+		reg_tmp = readb(priv->sdmmc_base + SDMMC_EXTCTRL);
+		writeb(reg_tmp & 0xFB, priv->sdmmc_base + SDMMC_EXTCTRL);
+		break;
+	}
+}
+
+static int wmt_mci_get_ro(struct mmc_host *mmc)
+{
+	struct wmt_mci_priv *priv = mmc_priv(mmc);
+
+	return !(readb(priv->sdmmc_base + SDMMC_STS0) & STS0_WRITE_PROTECT);
+}
+
+static int wmt_mci_get_cd(struct mmc_host *mmc)
+{
+	struct wmt_mci_priv *priv = mmc_priv(mmc);
+	u32 cd = (readb(priv->sdmmc_base + SDMMC_STS0) & STS0_CD_GPI) >> 3;
+
+	return !(cd ^ priv->cd_inverted);
+}
+
+static struct mmc_host_ops wmt_mci_ops = {
+	.request = wmt_mci_request,
+	.set_ios = wmt_mci_set_ios,
+	.get_ro = wmt_mci_get_ro,
+	.get_cd = wmt_mci_get_cd,
+};
+
+/* Controller capabilities */
+static struct wmt_mci_caps wm8505_caps = {
+	.f_min = 390425,
+	.f_max = 50000000,
+	.ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34,
+	.caps = MMC_CAP_4_BIT_DATA | MMC_CAP_MMC_HIGHSPEED |
+		MMC_CAP_SD_HIGHSPEED,
+	.max_seg_size = 65024,
+	.max_segs = 128,
+	.max_blk_size = 2048,
+};
+
+static struct of_device_id wmt_mci_dt_ids[] = {
+	{ .compatible = "wm,wm8505-sdhc", .data = &wm8505_caps },
+	{ /* Sentinel */ },
+};
+
+static int __devinit wmt_mci_probe(struct platform_device *pdev)
+{
+	struct mmc_host *mmc;
+	struct wmt_mci_priv *priv;
+	struct device_node *np = pdev->dev.of_node;
+	const struct of_device_id *of_id =
+		of_match_device(wmt_mci_dt_ids, &pdev->dev);
+	const struct wmt_mci_caps *wmt_caps = of_id->data;
+	int ret;
+	int regular_irq, dma_irq;
+
+	if (!of_id || !of_id->data) {
+		dev_err(&pdev->dev, "Controller capabilities data missing\n");
+		return -EFAULT;
+	}
+
+	if (!np) {
+		dev_err(&pdev->dev, "Missing SDMMC description in devicetree\n");
+		return -EFAULT;
+	}
+
+	regular_irq = irq_of_parse_and_map(np, 0);
+	dma_irq = irq_of_parse_and_map(np, 1);
+
+	if (!regular_irq || !dma_irq) {
+		dev_err(&pdev->dev, "Getting IRQs failed!\n");
+		ret = -ENXIO;
+		goto fail1;
+	}
+
+	mmc = mmc_alloc_host(sizeof(struct wmt_mci_priv), &pdev->dev);
+	if (!mmc) {
+		dev_err(&pdev->dev, "Failed to allocate mmc_host\n");
+		ret = -ENOMEM;
+		goto fail1;
+	}
+
+	mmc->ops = &wmt_mci_ops;
+	mmc->f_min = wmt_caps->f_min;
+	mmc->f_max = wmt_caps->f_max;
+	mmc->ocr_avail = wmt_caps->ocr_avail;
+	mmc->caps = wmt_caps->caps;
+
+	mmc->max_seg_size = wmt_caps->max_seg_size;
+	mmc->max_segs = wmt_caps->max_segs;
+	mmc->max_blk_size = wmt_caps->max_blk_size;
+
+	mmc->max_req_size = (16*512*mmc->max_segs);
+	mmc->max_blk_count = mmc->max_req_size / 512;
+
+	priv = mmc_priv(mmc);
+	priv->mmc = mmc;
+	priv->dev = &pdev->dev;
+
+	priv->power_inverted = 0;
+	priv->cd_inverted = 0;
+
+	if (of_get_property(np, "sdon-inverted", NULL))
+		priv->power_inverted = 1;
+	if (of_get_property(np, "cd-inverted", NULL))
+		priv->cd_inverted = 1;
+
+	priv->sdmmc_base = of_iomap(np, 0);
+	if (!priv->sdmmc_base) {
+		dev_err(&pdev->dev, "Failed to map IO space\n");
+		ret = -ENOMEM;
+		goto fail2;
+	}
+
+	priv->irq_regular = regular_irq;
+	priv->irq_dma = dma_irq;
+
+	ret = request_irq(regular_irq, wmt_mci_regular_isr, 0, "sdmmc", priv);
+	if (ret) {
+		dev_err(&pdev->dev, "Register regular IRQ fail\n");
+		goto fail3;
+	}
+
+	ret = request_irq(dma_irq, wmt_mci_dma_isr, 32, "sdmmc", priv);
+	if (ret) {
+		dev_err(&pdev->dev, "Register DMA IRQ fail\n");
+		goto fail4;
+	}
+
+	/* alloc some DMA buffers for descriptors/transfers */
+	priv->dma_desc_buffer = dma_alloc_coherent(&pdev->dev,
+						   mmc->max_blk_count * 16,
+						   &priv->dma_desc_device_addr,
+						   208);
+	if (!priv->dma_desc_buffer) {
+		dev_err(&pdev->dev, "DMA alloc fail\n");
+		ret = -EPERM;
+		goto fail5;
+	}
+
+	platform_set_drvdata(pdev, mmc);
+
+	priv->clk_sdmmc = of_clk_get(np, 0);
+	if (IS_ERR(priv->clk_sdmmc)) {
+		dev_err(&pdev->dev, "Error getting clock\n");
+		ret = PTR_ERR(priv->clk_sdmmc);
+		goto fail5;
+	}
+
+	clk_prepare_enable(priv->clk_sdmmc);
+
+	/* configure the controller to a known 'ready' state */
+	wmt_reset_hardware(mmc);
+
+	mmc_add_host(mmc);
+
+	dev_info(&pdev->dev, "WMT SDHC Controller initialized\n");
+
+	return 0;
+fail5:
+	free_irq(dma_irq, priv);
+fail4:
+	free_irq(regular_irq, priv);
+fail3:
+	iounmap(priv->sdmmc_base);
+fail2:
+	mmc_free_host(mmc);
+fail1:
+	return ret;
+}
+
+static int __devexit wmt_mci_remove(struct platform_device *pdev)
+{
+	struct mmc_host *mmc;
+	struct wmt_mci_priv *priv;
+	struct resource *res;
+	u32 reg_tmp;
+
+	mmc = platform_get_drvdata(pdev);
+	priv = mmc_priv(mmc);
+
+	/* reset SD controller */
+	reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
+	writel(reg_tmp | BM_SOFT_RESET, priv->sdmmc_base + SDMMC_BUSMODE);
+	reg_tmp = readw(priv->sdmmc_base + SDMMC_BLKLEN);
+	writew(reg_tmp & ~(0xA000), priv->sdmmc_base + SDMMC_BLKLEN);
+	writeb(0xFF, priv->sdmmc_base + SDMMC_STS0);
+	writeb(0xFF, priv->sdmmc_base + SDMMC_STS1);
+
+	/* release the dma buffers */
+	dma_free_coherent(&pdev->dev, priv->mmc->max_blk_count * 16,
+			  priv->dma_desc_buffer, priv->dma_desc_device_addr);
+
+	mmc_remove_host(mmc);
+
+	free_irq(priv->irq_regular, priv);
+	free_irq(priv->irq_dma, priv);
+
+	iounmap(priv->sdmmc_base);
+
+	clk_disable_unprepare(priv->clk_sdmmc);
+	clk_put(priv->clk_sdmmc);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	release_mem_region(res->start, res->end - res->start + 1);
+
+	mmc_free_host(mmc);
+
+	platform_set_drvdata(pdev, NULL);
+
+	dev_info(&pdev->dev, "WMT MCI device removed\n");
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int wmt_mci_suspend(struct device *dev)
+{
+	u32 reg_tmp;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct mmc_host *mmc = platform_get_drvdata(pdev);
+	struct wmt_mci_priv *priv;
+	int ret;
+
+	if (!mmc)
+		return 0;
+
+	priv = mmc_priv(mmc);
+	ret = mmc_suspend_host(mmc);
+
+	if (!ret) {
+		reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
+		writeb(reg_tmp | BM_SOFT_RESET, priv->sdmmc_base +
+		       SDMMC_BUSMODE);
+
+		reg_tmp = readw(priv->sdmmc_base + SDMMC_BLKLEN);
+		writew(reg_tmp & 0x5FFF, priv->sdmmc_base + SDMMC_BLKLEN);
+
+		writeb(0xFF, priv->sdmmc_base + SDMMC_STS0);
+		writeb(0xFF, priv->sdmmc_base + SDMMC_STS1);
+
+		clk_disable(priv->clk_sdmmc);
+	}
+	return ret;
+}
+
+static int wmt_mci_resume(struct device *dev)
+{
+	u32 reg_tmp;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct mmc_host *mmc = platform_get_drvdata(pdev);
+	struct wmt_mci_priv *priv;
+	int ret = 0;
+
+	if (mmc) {
+		priv = mmc_priv(mmc);
+		clk_enable(priv->clk_sdmmc);
+
+		reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
+		writeb(reg_tmp | BM_SOFT_RESET, priv->sdmmc_base +
+		       SDMMC_BUSMODE);
+
+		reg_tmp = readw(priv->sdmmc_base + SDMMC_BLKLEN);
+		writew(reg_tmp | (BLKL_GPI_CD | BLKL_INT_ENABLE),
+		       priv->sdmmc_base + SDMMC_BLKLEN);
+
+		reg_tmp = readb(priv->sdmmc_base + SDMMC_INTMASK0);
+		writeb(reg_tmp | INT0_DI_INT_EN, priv->sdmmc_base +
+		       SDMMC_INTMASK0);
+
+		ret = mmc_resume_host(mmc);
+	}
+
+	return ret;
+}
+
+static const struct dev_pm_ops wmt_mci_pm = {
+	.suspend        = wmt_mci_suspend,
+	.resume         = wmt_mci_resume,
+};
+
+#define wmt_mci_pm_ops (&wmt_mci_pm)
+
+#else	/* !CONFIG_PM */
+
+#define wmt_mci_pm_ops NULL
+
+#endif
+
+static struct platform_driver wmt_mci_driver = {
+	.probe = wmt_mci_probe,
+	.remove = __exit_p(wmt_mci_remove),
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+		.pm = wmt_mci_pm_ops,
+		.of_match_table = wmt_mci_dt_ids,
+	},
+};
+
+module_platform_driver(wmt_mci_driver);
+
+MODULE_DESCRIPTION("Wondermedia MMC/SD Driver");
+MODULE_AUTHOR("Tony Prisk");
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(of, wmt_mci_dt_ids);