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Gmane
From: Purushotam Kumar <purushotam-l0cyMroinI0 <at> public.gmane.org>
Subject: [PATCH 1/1] DaVinci: MMC: V4: MMC/SD controller driver for DaVinci family.
Newsgroups: gmane.linux.davinci
Date: Thursday 2nd April 2009 09:56:36 UTC (over 8 years ago)
From: Purshotam Kumar 

This patch adds support for MMC/SD controller driver for DaVinci family
SoC.
This patch will work for SoC like DM6446 and DM355. SoC like DM365 and
DA830 also has same controller with small variations and could
supported/added
easily by using this version of patch. It means that this version of patch
could be used for all SoC which has been derived from DaVinci family.

This patch has been generated against latest 2.6.29 mainline kernel. This
patch
will not compile currently because it depends notably on the EDMA utilities
and
chip/board setup, that will come at some point through the ARM tree. Please
use
currently DaVinci GIT tree for EDMA utilities and chip/board setup etc.

Many thanks to David Brownell
(david-b-yBeKhBN/[email protected]) for his all support.

This updated patch incorporates most of review comments given by 
Pierre Ossman. Many thanks for Pierre Ossman for reviewing.

Signed-off-by: Purshotam Kumar 
Acked-by: David Brownell

---
 arch/arm/mach-davinci/include/mach/mmc.h |   25 +
 drivers/mmc/host/Kconfig                 |    8 +
 drivers/mmc/host/Makefile                |    1 +
 drivers/mmc/host/davinci_mmc.c           | 1264
++++++++++++++++++++++++++++++
 4 files changed, 1298 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/mach-davinci/include/mach/mmc.h
 create mode 100644 drivers/mmc/host/davinci_mmc.c

diff --git a/arch/arm/mach-davinci/include/mach/mmc.h
b/arch/arm/mach-davinci/include/mach/mmc.h
new file mode 100644
index 0000000..8fee158
--- /dev/null
+++ b/arch/arm/mach-davinci/include/mach/mmc.h
@@ -0,0 +1,25 @@
+/*
+ *  Board-specific MMC configuration
+ */
+
+#ifndef _DAVINCI_MMC_H
+#define _DAVINCI_MMC_H
+
+#include 
+#include 
+
+struct davinci_mmc_config {
+	/* get_cd()/get_wp() may sleep */
+	int (*get_cd)(int module);
+	int (*get_ro)(int module);
+	/* wires == 0 is equivalent to wires == 4 (4-bit parallel) */
+	u8 wires;
+
+	u32 max_freq;
+
+	/* any additional host capabilities: OR'd in to mmc->f_caps */
+	u32 caps;
+};
+void davinci_setup_mmc(int module, struct davinci_mmc_config *config);
+
+#endif
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 99d4b28..311d00f 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -171,6 +171,14 @@ config MMC_TIFM_SD
           To compile this driver as a module, choose M here: the
 	  module will be called tifm_sd.
 
+config MMC_DAVINCI
+        tristate "TI DAVINCI Multimedia Card Interface support"
+        depends on ARCH_DAVINCI
+        help
+          This selects the TI DAVINCI Multimedia card Interface.
+          If you have an DAVINCI board with a Multimedia Card slot,
+          say Y or M here.  If unsure, say N.
+
 config MMC_SPI
 	tristate "MMC/SD/SDIO over SPI"
 	depends on SPI_MASTER && !HIGHMEM && HAS_DMA
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index dedec55..6bc91b1 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_MMC_OMAP_HS)	+= omap_hsmmc.o
 obj-$(CONFIG_MMC_AT91)		+= at91_mci.o
 obj-$(CONFIG_MMC_ATMELMCI)	+= atmel-mci.o
 obj-$(CONFIG_MMC_TIFM_SD)	+= tifm_sd.o
+obj-$(CONFIG_MMC_DAVINCI)       += davinci_mmc.o
 obj-$(CONFIG_MMC_SPI)		+= mmc_spi.o
 ifeq ($(CONFIG_OF),y)
 obj-$(CONFIG_MMC_SPI)		+= of_mmc_spi.o
diff --git a/drivers/mmc/host/davinci_mmc.c
b/drivers/mmc/host/davinci_mmc.c
new file mode 100644
index 0000000..eac74ff
--- /dev/null
+++ b/drivers/mmc/host/davinci_mmc.c
@@ -0,0 +1,1264 @@
+/*
+ * davinci_mmc.c - TI DaVinci MMC/SD/SDIO driver
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ *       Original author: Purushotam Kumar
+ * Copyright (C) 2009 David Brownell
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 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 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+#include 
+#include 
+
+/*
+ * Register Definitions
+ */
+#define DAVINCI_MMCCTL       0x00 /* Control Register                  */
+#define DAVINCI_MMCCLK       0x04 /* Memory Clock Control Register     */
+#define DAVINCI_MMCST0       0x08 /* Status Register 0                 */
+#define DAVINCI_MMCST1       0x0C /* Status Register 1                 */
+#define DAVINCI_MMCIM        0x10 /* Interrupt Mask Register           */
+#define DAVINCI_MMCTOR       0x14 /* Response Time-Out Register        */
+#define DAVINCI_MMCTOD       0x18 /* Data Read Time-Out Register       */
+#define DAVINCI_MMCBLEN      0x1C /* Block Length Register             */
+#define DAVINCI_MMCNBLK      0x20 /* Number of Blocks Register         */
+#define DAVINCI_MMCNBLC      0x24 /* Number of Blocks Counter Register */
+#define DAVINCI_MMCDRR       0x28 /* Data Receive Register             */
+#define DAVINCI_MMCDXR       0x2C /* Data Transmit Register            */
+#define DAVINCI_MMCCMD       0x30 /* Command Register                  */
+#define DAVINCI_MMCARGHL     0x34 /* Argument Register                 */
+#define DAVINCI_MMCRSP01     0x38 /* Response Register 0 and 1         */
+#define DAVINCI_MMCRSP23     0x3C /* Response Register 0 and 1         */
+#define DAVINCI_MMCRSP45     0x40 /* Response Register 0 and 1         */
+#define DAVINCI_MMCRSP67     0x44 /* Response Register 0 and 1         */
+#define DAVINCI_MMCDRSP      0x48 /* Data Response Register            */
+#define DAVINCI_MMCETOK      0x4C
+#define DAVINCI_MMCCIDX      0x50 /* Command Index Register            */
+#define DAVINCI_MMCCKC       0x54
+#define DAVINCI_MMCTORC      0x58
+#define DAVINCI_MMCTODC      0x5C
+#define DAVINCI_MMCBLNC      0x60
+#define DAVINCI_SDIOCTL      0x64
+#define DAVINCI_SDIOST0      0x68
+#define DAVINCI_SDIOEN       0x6C
+#define DAVINCI_SDIOST       0x70
+#define DAVINCI_MMCFIFOCTL   0x74 /* FIFO Control Register             */
+
+/* DAVINCI_MMCCTL definitions */
+#define MMCCTL_DATRST         (1 << 0)
+#define MMCCTL_CMDRST         (1 << 1)
+#define MMCCTL_WIDTH_4_BIT    (1 << 2)
+#define MMCCTL_DATEG_DISABLED (0 << 6)
+#define MMCCTL_DATEG_RISING   (1 << 6)
+#define MMCCTL_DATEG_FALLING  (2 << 6)
+#define MMCCTL_DATEG_BOTH     (3 << 6)
+#define MMCCTL_PERMDR_LE      (0 << 9)
+#define MMCCTL_PERMDR_BE      (1 << 9)
+#define MMCCTL_PERMDX_LE      (0 << 10)
+#define MMCCTL_PERMDX_BE      (1 << 10)
+
+/* DAVINCI_MMCCLK definitions */
+#define MMCCLK_CLKEN          (1 << 8)
+#define MMCCLK_CLKRT_MASK     (0xFF << 0)
+
+/* IRQ bit definitions, for DAVINCI_MMCST0 and DAVINCI_MMCIM */
+#define MMCST0_DATDNE         BIT(0)	/* data done */
+#define MMCST0_BSYDNE         BIT(1)	/* busy done */
+#define MMCST0_RSPDNE         BIT(2)	/* command done */
+#define MMCST0_TOUTRD         BIT(3)	/* data read timeout */
+#define MMCST0_TOUTRS         BIT(4)	/* command response timeout */
+#define MMCST0_CRCWR          BIT(5)	/* data write CRC error */
+#define MMCST0_CRCRD          BIT(6)	/* data read CRC error */
+#define MMCST0_CRCRS          BIT(7)	/* command response CRC error */
+#define MMCST0_DXRDY          BIT(9)	/* data transmit ready (fifo empty)
*/
+#define MMCST0_DRRDY          BIT(10)	/* data receive ready (data in
fifo)*/
+#define MMCST0_DATED          BIT(11)	/* DAT3 edge detect */
+#define MMCST0_TRNDNE         BIT(12)	/* transfer done */
+
+/* DAVINCI_MMCST1 definitions */
+#define MMCST1_BUSY           (1 << 0)
+
+/* DAVINCI_MMCCMD definitions */
+#define MMCCMD_CMD_MASK       (0x3F << 0)
+#define MMCCMD_PPLEN          (1 << 7)
+#define MMCCMD_BSYEXP         (1 << 8)
+#define MMCCMD_RSPFMT_MASK    (3 << 9)
+#define MMCCMD_RSPFMT_NONE    (0 << 9)
+#define MMCCMD_RSPFMT_R1456   (1 << 9)
+#define MMCCMD_RSPFMT_R2      (2 << 9)
+#define MMCCMD_RSPFMT_R3      (3 << 9)
+#define MMCCMD_DTRW           (1 << 11)
+#define MMCCMD_STRMTP         (1 << 12)
+#define MMCCMD_WDATX          (1 << 13)
+#define MMCCMD_INITCK         (1 << 14)
+#define MMCCMD_DCLR           (1 << 15)
+#define MMCCMD_DMATRIG        (1 << 16)
+
+/* DAVINCI_MMCFIFOCTL definitions */
+#define MMCFIFOCTL_FIFORST    (1 << 0)
+#define MMCFIFOCTL_FIFODIR_WR (1 << 1)
+#define MMCFIFOCTL_FIFODIR_RD (0 << 1)
+#define MMCFIFOCTL_FIFOLEV    (1 << 2) /* 0 = 128 bits, 1 = 256 bits */
+#define MMCFIFOCTL_ACCWD_4    (0 << 3) /* access width of 4 bytes    */
+#define MMCFIFOCTL_ACCWD_3    (1 << 3) /* access width of 3 bytes    */
+#define MMCFIFOCTL_ACCWD_2    (2 << 3) /* access width of 2 bytes    */
+#define MMCFIFOCTL_ACCWD_1    (3 << 3) /* access width of 1 byte     */
+
+
+/* MMCSD Init clock in Hz in opendrain mode */
+#define MMCSD_INIT_CLOCK		200000
+
+/*
+ * One scatterlist dma "segment" is at most MAX_CCNT rw_threshold units,
+ * and we handle up to NR_SG segments.  MMC_BLOCK_BOUNCE kicks in only
+ * for drivers with max_hw_segs == 1, making the segments bigger (64KB)
+ * than the page or two that's otherwise typical.  NR_SG == 16 gives at
+ * least the same throughput boost, using EDMA transfer linkage instead
+ * of spending CPU time copying pages.
+ */
+#define MAX_CCNT	((1 << 16) - 1)
+
+#define NR_SG		16
+
+#define DAVINCI_MMC_FIFO_SIZE_BYTE 32
+static unsigned rw_threshold = 32;
+static unsigned ns_in_one_cycle = 1;
+module_param(rw_threshold, uint, S_IRUGO);
+MODULE_PARM_DESC(rw_threshold,
+		"Read/Write threshold, can be 16/32. Default = 32");
+
+static unsigned __initdata use_dma = 1;
+module_param(use_dma, uint, 0);
+MODULE_PARM_DESC(use_dma, "Whether to use DMA or not. Default = 1");
+
+struct mmc_davinci_host {
+	struct mmc_command *cmd;
+	struct mmc_data *data;
+	struct mmc_host *mmc;
+	struct clk *clk;
+	unsigned int mmc_input_clk;
+	void __iomem *base;
+	struct resource *mem_res;
+	int irq;
+	unsigned char bus_mode;
+
+#define DAVINCI_MMC_DATADIR_NONE	0
+#define DAVINCI_MMC_DATADIR_READ	1
+#define DAVINCI_MMC_DATADIR_WRITE	2
+	unsigned char data_dir;
+
+	/* buffer is used during PIO of one scatterlist segment, and
+	 * is updated along with buffer_bytes_left.  bytes_left applies
+	 * to all N blocks of the PIO transfer.
+	 */
+	u8 *buffer;
+	u32 buffer_bytes_left;
+	u32 bytes_left;
+
+	u8 rxdma, txdma;
+	bool use_dma;
+	bool do_dma;
+
+	/* Scatterlist DMA uses one or more parameter RAM entries:
+	 * the main one (associated with rxdma or txdma) plus zero or
+	 * more links.  The entries for a given transfer differ only
+	 * by memory buffer (address, length) and link field.
+	 */
+	struct edmacc_param	tx_template;
+	struct edmacc_param	rx_template;
+	unsigned		n_link;
+	u8			links[NR_SG - 1];
+
+	/* For PIO we walk scatterlists one segment at a time. */
+	unsigned int		sg_len;
+};
+
+
+/* PIO only */
+static void mmc_davinci_sg_to_buf(struct mmc_davinci_host *host)
+{
+	struct scatterlist *sg;
+	sg = host->data->sg;
+	host->buffer_bytes_left = sg_dma_len(sg);
+	host->buffer = sg_virt(sg);
+	if (host->buffer_bytes_left > host->bytes_left)
+		host->buffer_bytes_left = host->bytes_left;
+}
+
+static void davinci_fifo_data_trans(struct mmc_davinci_host *host,
+					unsigned int n)
+{
+	u8 *p;
+	unsigned int i;
+
+	if (host->buffer_bytes_left == 0) {
+		host->data->sg = sg_next(host->data->sg);
+		mmc_davinci_sg_to_buf(host);
+	}
+
+	p = host->buffer;
+	if (n > host->buffer_bytes_left)
+		n = host->buffer_bytes_left;
+	host->buffer_bytes_left -= n;
+	host->bytes_left -= n;
+
+	/* NOTE:  we never transfer more than rw_threshold bytes
+	 * to/from the fifo here; there's no I/O overlap.
+	 * This also assumes that access width( i.e. ACCWD) is 4 bytes
+	 */
+	if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) {
+		for (i = 0; i < (n >> 2); i++) {
+			writel(*((u32 *)p), host->base + DAVINCI_MMCDXR);
+			p = p + 4;
+		}
+		if (n & 3) {
+			iowrite8_rep(host->base + DAVINCI_MMCDXR, p, (n & 3));
+			p = p + (n & 3);
+		}
+	} else {
+		for (i = 0; i < (n >> 2); i++) {
+			*((u32 *)p) = readl(host->base + DAVINCI_MMCDRR);
+			p  = p + 4;
+		}
+		if (n & 3) {
+			ioread8_rep(host->base + DAVINCI_MMCDRR, p, (n & 3));
+			p = p + (n & 3);
+		}
+	}
+	host->buffer = p;
+}
+
+static void mmc_davinci_start_command(struct mmc_davinci_host *host,
+		struct mmc_command *cmd)
+{
+	u32 cmd_reg = 0;
+	u32 im_val;
+
+	dev_dbg(mmc_dev(host->mmc), "CMD%d, arg 0x%08x%s\n",
+		cmd->opcode, cmd->arg,
+		({ char *s;
+		switch (mmc_resp_type(cmd)) {
+		case MMC_RSP_R1:
+			s = ", R1/R5/R6/R7 response";
+			break;
+		case MMC_RSP_R1B:
+			s = ", R1b response";
+			break;
+		case MMC_RSP_R2:
+			s = ", R2 response";
+			break;
+		case MMC_RSP_R3:
+			s = ", R3/R4 response";
+			break;
+		default:
+			s = ", (R? response)";
+			break;
+		}; s; }));
+	host->cmd = cmd;
+
+	switch (mmc_resp_type(cmd)) {
+	case MMC_RSP_R1B:
+		/* There's some spec confusion about when R1B is
+		 * allowed, but if the card doesn't issue a BUSY
+		 * then it's harmless for us to allow it.
+		 */
+		cmd_reg |= MMCCMD_BSYEXP;
+		/* FALLTHROUGH */
+	case MMC_RSP_R1:		/* 48 bits, CRC */
+		cmd_reg |= MMCCMD_RSPFMT_R1456;
+		break;
+	case MMC_RSP_R2:		/* 136 bits, CRC */
+		cmd_reg |= MMCCMD_RSPFMT_R2;
+		break;
+	case MMC_RSP_R3:		/* 48 bits, no CRC */
+		cmd_reg |= MMCCMD_RSPFMT_R3;
+		break;
+	default:
+		cmd_reg |= MMCCMD_RSPFMT_NONE;
+		dev_dbg(mmc_dev(host->mmc), "unknown resp_type %04x\n",
+			mmc_resp_type(cmd));
+		break;
+	}
+
+	/* Set command index */
+	cmd_reg |= cmd->opcode;
+
+	/* Enable EDMA transfer triggers */
+	if (host->do_dma)
+		cmd_reg |= MMCCMD_DMATRIG;
+
+	/* Setting whether command involves data transfer or not */
+	if (cmd->data)
+		cmd_reg |= MMCCMD_WDATX;
+
+	/* Setting whether stream or block transfer */
+	if (cmd->flags & MMC_DATA_STREAM)
+		cmd_reg |= MMCCMD_STRMTP;
+
+	/* Setting whether data read or write */
+	if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE)
+		cmd_reg |= MMCCMD_DTRW;
+
+	if (host->bus_mode == MMC_BUSMODE_PUSHPULL)
+		cmd_reg |= MMCCMD_PPLEN;
+
+	/* set Command timeout */
+	writel(0x1FFF, host->base + DAVINCI_MMCTOR);
+
+	/* Enable interrupt (calculate here, defer until FIFO is stuffed). */
+	im_val =  MMCST0_RSPDNE | MMCST0_CRCRS | MMCST0_TOUTRS;
+	if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) {
+		im_val |= MMCST0_DATDNE | MMCST0_CRCWR;
+
+		if (!host->do_dma)
+			im_val |= MMCST0_DXRDY;
+	} else if (host->data_dir == DAVINCI_MMC_DATADIR_READ) {
+		im_val |= MMCST0_DATDNE | MMCST0_CRCRD | MMCST0_TOUTRD;
+
+		if (!host->do_dma)
+			im_val |= MMCST0_DRRDY;
+	}
+
+	/*
+	 * Before non-DMA WRITE commands the controller needs priming:
+	 * FIFO should be populated with 32 bytes i.e. whatever is the FIFO size
+	 */
+	if (!host->do_dma && (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) &&
+		((cmd->opcode == MMC_WRITE_BLOCK) ||
+		(cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK)))
+		davinci_fifo_data_trans(host, DAVINCI_MMC_FIFO_SIZE_BYTE);
+
+	writel(cmd->arg, host->base + DAVINCI_MMCARGHL);
+	writel(cmd_reg,  host->base + DAVINCI_MMCCMD);
+	writel(im_val, host->base + DAVINCI_MMCIM);
+}
+
+/*----------------------------------------------------------------------*/
+
+/* DMA infrastructure */
+
+static void davinci_abort_dma(struct mmc_davinci_host *host)
+{
+	int sync_dev;
+
+	if (host->data_dir == DAVINCI_MMC_DATADIR_READ)
+		sync_dev = host->rxdma;
+	else
+		sync_dev = host->txdma;
+
+	edma_stop(sync_dev);
+	edma_clean_channel(sync_dev);
+}
+
+static void
+mmc_davinci_xfer_done(struct mmc_davinci_host *host, struct mmc_data
*data);
+
+static void mmc_davinci_dma_cb(unsigned channel, u16 ch_status, void
*data)
+{
+	if (DMA_COMPLETE != ch_status) {
+		struct mmc_davinci_host *host = data;
+
+		/* Currently means:  DMA Event Missed, or "null" transfer
+		 * request was seen.  In the future, TC errors (like bad
+		 * addresses) might be presented too.
+		 */
+		dev_warn(mmc_dev(host->mmc), "DMA %s error\n",
+			(host->data->flags & MMC_DATA_WRITE)
+				? "write" : "read");
+		host->data->error = -EIO;
+		mmc_davinci_xfer_done(host, host->data);
+	}
+}
+
+/* Set up tx or rx template, to be modified and updated later */
+static void __init mmc_davinci_dma_setup(struct mmc_davinci_host *host,
+		bool tx, struct edmacc_param *template)
+{
+	unsigned	sync_dev;
+	const u16	acnt = 4;
+	const u16	bcnt = rw_threshold >> 2;
+	const u16	ccnt = 0;
+	u32		src_port = 0;
+	u32		dst_port = 0;
+	s16		src_bidx, dst_bidx;
+	s16		src_cidx, dst_cidx;
+
+	/*
+	 * A-B Sync transfer:  each DMA request is for one "frame" of
+	 * rw_threshold bytes, broken into "acnt"-size chunks repeated
+	 * "bcnt" times.  Each segment needs "ccnt" such frames; since
+	 * we tell the block layer our mmc->max_seg_size limit, we can
+	 * trust (later) that it's within bounds.
+	 *
+	 * The FIFOs are read/written in 4-byte chunks (acnt == 4) and
+	 * EDMA will optimize memory operations to use larger bursts.
+	 */
+	if (tx) {
+		sync_dev = host->txdma;
+
+		/* src_prt, ccnt, and link to be set up later */
+		src_bidx = acnt;
+		src_cidx = acnt * bcnt;
+
+		dst_port = host->mem_res->start + DAVINCI_MMCDXR;
+		dst_bidx = 0;
+		dst_cidx = 0;
+	} else {
+		sync_dev = host->rxdma;
+
+		src_port = host->mem_res->start + DAVINCI_MMCDRR;
+		src_bidx = 0;
+		src_cidx = 0;
+
+		/* dst_prt, ccnt, and link to be set up later */
+		dst_bidx = acnt;
+		dst_cidx = acnt * bcnt;
+	}
+
+	/*
+	 * We can't use FIFO mode for the FIFOs because MMC FIFO addresses
+	 * are not 256-bit (32-byte) aligned.  So we use INCR, and the W8BIT
+	 * parameter is ignored.
+	 */
+	edma_set_src(sync_dev, src_port, INCR, W8BIT);
+	edma_set_dest(sync_dev, dst_port, INCR, W8BIT);
+
+	edma_set_src_index(sync_dev, src_bidx, src_cidx);
+	edma_set_dest_index(sync_dev, dst_bidx, dst_cidx);
+
+	edma_set_transfer_params(sync_dev, acnt, bcnt, ccnt, 8, ABSYNC);
+
+	edma_read_slot(sync_dev, template);
+
+	/* don't bother with irqs or chaining */
+	template->opt |= sync_dev << 12;
+}
+
+static void mmc_davinci_send_dma_request(struct mmc_davinci_host *host,
+		struct mmc_data *data)
+{
+	struct edmacc_param	*template;
+	int			channel, slot;
+	unsigned		link;
+	struct scatterlist	*sg;
+	unsigned		sg_len;
+	unsigned		bytes_left = host->bytes_left;
+	const unsigned		shift = (rw_threshold == 32) ? 5 : 4;
+
+	if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) {
+		template = &host->tx_template;
+		channel = host->txdma;
+	} else {
+		template = &host->rx_template;
+		channel = host->rxdma;
+	}
+
+	/* We know sg_len and ccnt will never be out of range because
+	 * we told the mmc layer which in turn tells the block layer
+	 * to ensure that it only hands us one scatterlist segment
+	 * per EDMA PARAM entry.  Update the PARAM
+	 * entries needed for each segment of this scatterlist.
+	 */
+	for (slot = channel, link = 0, sg = data->sg, sg_len = host->sg_len;
+			sg_len-- != 0 && bytes_left;
+			sg = sg_next(sg), slot = host->links[link++]) {
+		u32		buf = sg_dma_address(sg);
+		unsigned	count = sg_dma_len(sg);
+
+		template->link_bcntrld = sg_len
+				? (host->links[link] << 5)
+				: 0xffff;
+
+		if (count > bytes_left)
+			count = bytes_left;
+		bytes_left -= count;
+
+		if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE)
+			template->src = buf;
+		else
+			template->dst = buf;
+		template->ccnt = count >> shift;
+
+		edma_write_slot(slot, template);
+	}
+
+	edma_start(channel);
+}
+
+static int mmc_davinci_start_dma_transfer(struct mmc_davinci_host *host,
+		struct mmc_data *data)
+{
+	int i;
+	int mask = rw_threshold - 1;
+
+	host->sg_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+				((data->flags & MMC_DATA_WRITE)
+				? DMA_TO_DEVICE
+				: DMA_FROM_DEVICE));
+
+	/* no individual DMA segment should need a partial FIFO */
+	for (i = 0; i < host->sg_len; i++) {
+		if (sg_dma_len(data->sg + i) & mask) {
+			dma_unmap_sg(mmc_dev(host->mmc),
+					data->sg, data->sg_len,
+					(data->flags & MMC_DATA_WRITE)
+					? DMA_TO_DEVICE
+					: DMA_FROM_DEVICE);
+			return -1;
+		}
+	}
+
+	host->do_dma = 1;
+	mmc_davinci_send_dma_request(host, data);
+
+	return 0;
+}
+
+static void __init_or_module
+davinci_release_dma_channels(struct mmc_davinci_host *host)
+{
+	unsigned	i;
+
+	if (!host->use_dma)
+		return;
+
+	for (i = 0; i < host->n_link; i++)
+		edma_free_slot(host->links[i]);
+
+	edma_free_channel(host->txdma);
+	edma_free_channel(host->rxdma);
+}
+
+static int __init davinci_acquire_dma_channels(struct mmc_davinci_host
*host)
+{
+	int r, i;
+
+	/* Acquire master DMA write channel */
+	r = edma_alloc_channel(host->txdma, mmc_davinci_dma_cb, host,
+			EVENTQ_DEFAULT);
+	if (r < 0) {
+		dev_warn(mmc_dev(host->mmc), "alloc %s channel err %d\n",
+				"tx", r);
+		return r;
+	}
+	mmc_davinci_dma_setup(host, true, &host->tx_template);
+
+	/* Acquire master DMA read channel */
+	r = edma_alloc_channel(host->rxdma, mmc_davinci_dma_cb, host,
+			EVENTQ_DEFAULT);
+	if (r < 0) {
+		dev_warn(mmc_dev(host->mmc), "alloc %s channel err %d\n",
+				"rx", r);
+		goto free_master_write;
+	}
+	mmc_davinci_dma_setup(host, false, &host->rx_template);
+
+	/* Allocate parameter RAM slots, which will later be bound to a
+	 * channel as needed to handle a scatterlist.
+	 */
+	for (i = 0; i < ARRAY_SIZE(host->links); i++) {
+		r = edma_alloc_slot(EDMA_SLOT_ANY);
+		if (r < 0) {
+			dev_dbg(mmc_dev(host->mmc), "dma PaRAM alloc --> %d\n",
+				r);
+			break;
+		}
+		host->links[i] = r;
+	}
+	host->n_link = i;
+
+	return 0;
+
+free_master_write:
+	edma_free_channel(host->txdma);
+
+	return r;
+}
+
+/*----------------------------------------------------------------------*/
+
+static void
+mmc_davinci_prepare_data(struct mmc_davinci_host *host, struct mmc_request
*req)
+{
+	int fifo_lev = (rw_threshold == 32) ? MMCFIFOCTL_FIFOLEV : 0;
+	int timeout;
+	struct mmc_data *data = req->data;
+
+	host->data = data;
+	if (data == NULL) {
+		host->data_dir = DAVINCI_MMC_DATADIR_NONE;
+		writel(0, host->base + DAVINCI_MMCBLEN);
+		writel(0, host->base + DAVINCI_MMCNBLK);
+		return;
+	}
+
+	dev_dbg(mmc_dev(host->mmc), "%s %s, %d blocks of %d bytes\n",
+		(data->flags & MMC_DATA_STREAM) ? "stream" : "block",
+		(data->flags & MMC_DATA_WRITE) ? "write" : "read",
+		data->blocks, data->blksz);
+	dev_dbg(mmc_dev(host->mmc), "  DTO %d cycles + %d ns\n",
+		data->timeout_clks, data->timeout_ns);
+	timeout = data->timeout_clks + data->timeout_ns / ns_in_one_cycle;
+	if (timeout > 0xffff)
+		timeout = 0xffff;
+
+	writel(timeout, host->base + DAVINCI_MMCTOD);
+	writel(data->blocks, host->base + DAVINCI_MMCNBLK);
+	writel(data->blksz, host->base + DAVINCI_MMCBLEN);
+
+	/* Configure the FIFO */
+	switch (data->flags & MMC_DATA_WRITE) {
+	case MMC_DATA_WRITE:
+		host->data_dir = DAVINCI_MMC_DATADIR_WRITE;
+		writel(fifo_lev | MMCFIFOCTL_FIFODIR_WR | MMCFIFOCTL_FIFORST,
+			host->base + DAVINCI_MMCFIFOCTL);
+		writel(fifo_lev | MMCFIFOCTL_FIFODIR_WR,
+			host->base + DAVINCI_MMCFIFOCTL);
+		break;
+
+	default:
+		host->data_dir = DAVINCI_MMC_DATADIR_READ;
+		writel(fifo_lev | MMCFIFOCTL_FIFODIR_RD | MMCFIFOCTL_FIFORST,
+			host->base + DAVINCI_MMCFIFOCTL);
+		writel(fifo_lev | MMCFIFOCTL_FIFODIR_RD,
+			host->base + DAVINCI_MMCFIFOCTL);
+		break;
+	}
+
+	host->buffer = NULL;
+	host->bytes_left = data->blocks * data->blksz;
+
+	/* For now we try to use DMA whenever we won't need partial FIFO
+	 * reads or writes, either for the whole transfer (as tested here)
+	 * or for any individual scatterlist segment (tested when we call
+	 * start_dma_transfer).
+	 *
+	 * While we *could* change that, unusual block sizes are rarely
+	 * used.  The occasional fallback to PIO should't hurt.
+	 */
+	if (host->use_dma && (host->bytes_left & (rw_threshold - 1)) == 0
+			&& mmc_davinci_start_dma_transfer(host, data) == 0) {
+		/* zero this to ensure we take no PIO paths */
+		host->bytes_left = 0;
+	} else {
+		/* Revert to CPU Copy */
+		host->sg_len = data->sg_len;
+		mmc_davinci_sg_to_buf(host);
+	}
+}
+
+static void mmc_davinci_request(struct mmc_host *mmc, struct mmc_request
*req)
+{
+	struct mmc_davinci_host *host = mmc_priv(mmc);
+	unsigned long timeout = jiffies + msecs_to_jiffies(900);
+	u32 mmcst1 = 0;
+
+	/* Card may still be sending BUSY after a previous operation,
+	 * typically some kind of write.  If so, we can't proceed yet.
+	 */
+	while (time_before(jiffies, timeout)) {
+		mmcst1  = readl(host->base + DAVINCI_MMCST1);
+		if (!(mmcst1 & MMCST1_BUSY))
+			break;
+		cpu_relax();
+	}
+	if (mmcst1 & MMCST1_BUSY) {
+		dev_err(mmc_dev(host->mmc), "still BUSY? bad ... \n");
+		req->cmd->error = -ETIMEDOUT;
+		mmc_request_done(mmc, req);
+		return;
+	}
+
+	host->do_dma = 0;
+	mmc_davinci_prepare_data(host, req);
+	mmc_davinci_start_command(host, req->cmd);
+}
+
+static unsigned int calculate_freq_for_card(struct mmc_davinci_host *host,
+	unsigned int mmc_req_freq)
+{
+	unsigned int mmc_freq = 0, cpu_arm_clk = 0, mmc_push_pull = 0;
+
+	cpu_arm_clk = host->mmc_input_clk;
+	if (mmc_req_freq && cpu_arm_clk > (2 * mmc_req_freq))
+		mmc_push_pull = ((unsigned int)cpu_arm_clk
+				/ (2 * mmc_req_freq)) - 1;
+	else
+		mmc_push_pull = 0;
+
+	mmc_freq = (unsigned int)cpu_arm_clk / (2 * (mmc_push_pull + 1));
+
+	if (mmc_freq > mmc_req_freq)
+		mmc_push_pull = mmc_push_pull + 1;
+
+	/* Convert ns to clock cycles */
+	if (mmc_req_freq < 400000)
+		ns_in_one_cycle = 1000000 / ((cpu_arm_clk
+					/ (2 * (mmc_push_pull + 1)))/1000);
+	else
+		ns_in_one_cycle = 1000000 / ((cpu_arm_clk
+					/ (2 * (mmc_push_pull + 1)))/1000000);
+
+	return mmc_push_pull;
+}
+
+static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	unsigned int open_drain_freq = 0, cpu_arm_clk = 0;
+	unsigned int mmc_push_pull_freq = 0;
+	struct mmc_davinci_host *host = mmc_priv(mmc);
+
+	cpu_arm_clk = host->mmc_input_clk;
+	dev_dbg(mmc_dev(host->mmc),
+		"clock %dHz busmode %d powermode %d Vdd %04x\n",
+		ios->clock, ios->bus_mode, ios->power_mode,
+		ios->vdd);
+	if (ios->bus_width == MMC_BUS_WIDTH_4) {
+		dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
+		writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_WIDTH_4_BIT,
+			host->base + DAVINCI_MMCCTL);
+	} else {
+		dev_dbg(mmc_dev(host->mmc), "Disabling 4 bit mode\n");
+		writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_WIDTH_4_BIT,
+			host->base + DAVINCI_MMCCTL);
+	}
+
+	if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN) {
+		u32 temp;
+
+		/* Ignoring the init clock value passed for fixing the inter
+		 * operability with different cards.
+		 */
+		open_drain_freq = ((unsigned int)cpu_arm_clk
+				/ (2 * MMCSD_INIT_CLOCK)) - 1;
+
+		if (open_drain_freq > 0xFF)
+			open_drain_freq = 0xFF;
+
+		temp = readl(host->base + DAVINCI_MMCCLK) & ~MMCCLK_CLKRT_MASK;
+		temp |= open_drain_freq;
+		writel(temp, host->base + DAVINCI_MMCCLK);
+
+		/* Convert ns to clock cycles */
+		ns_in_one_cycle = (1000000) / (MMCSD_INIT_CLOCK/1000);
+	} else {
+		u32 temp;
+		mmc_push_pull_freq = calculate_freq_for_card(host, ios->clock);
+
+		temp = readl(host->base + DAVINCI_MMCCLK) & ~MMCCLK_CLKEN;
+		writel(temp, host->base + DAVINCI_MMCCLK);
+
+		udelay(10);
+
+		temp = readl(host->base + DAVINCI_MMCCLK) & ~MMCCLK_CLKRT_MASK;
+		temp |= mmc_push_pull_freq;
+		writel(temp, host->base + DAVINCI_MMCCLK);
+
+		writel(temp | MMCCLK_CLKEN, host->base + DAVINCI_MMCCLK);
+
+		udelay(10);
+	}
+
+	host->bus_mode = ios->bus_mode;
+	if (ios->power_mode == MMC_POWER_UP) {
+		unsigned long timeout = jiffies + msecs_to_jiffies(50);
+		bool lose = true;
+
+		/* Send clock cycles, poll completion */
+		writel(0, host->base + DAVINCI_MMCARGHL);
+		writel(MMCCMD_INITCK, host->base + DAVINCI_MMCCMD);
+		while (time_before(jiffies, timeout)) {
+			u32 tmp = readl(host->base + DAVINCI_MMCST0);
+
+			if (tmp & MMCST0_RSPDNE) {
+				lose = false;
+				break;
+			}
+			cpu_relax();
+		}
+		if (lose)
+			dev_warn(mmc_dev(host->mmc), "powerup timeout\n");
+	}
+
+	/* FIXME on power OFF, reset things ... */
+}
+
+static void
+mmc_davinci_xfer_done(struct mmc_davinci_host *host, struct mmc_data
*data)
+{
+	host->data = NULL;
+	host->data_dir = DAVINCI_MMC_DATADIR_NONE;
+
+	if (host->do_dma) {
+		davinci_abort_dma(host);
+
+		dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+			     (data->flags & MMC_DATA_WRITE)
+			     ? DMA_TO_DEVICE
+			     : DMA_FROM_DEVICE);
+		host->do_dma = false;
+	}
+
+	if (!data->stop || (host->cmd && host->cmd->error)) {
+		mmc_request_done(host->mmc, data->mrq);
+		writel(0, host->base + DAVINCI_MMCIM);
+	} else
+		mmc_davinci_start_command(host, data->stop);
+}
+
+static void mmc_davinci_cmd_done(struct mmc_davinci_host *host,
+				 struct mmc_command *cmd)
+{
+	host->cmd = NULL;
+
+	if (cmd->flags & MMC_RSP_PRESENT) {
+		if (cmd->flags & MMC_RSP_136) {
+			/* response type 2 */
+			cmd->resp[3] = readl(host->base + DAVINCI_MMCRSP01);
+			cmd->resp[2] = readl(host->base + DAVINCI_MMCRSP23);
+			cmd->resp[1] = readl(host->base + DAVINCI_MMCRSP45);
+			cmd->resp[0] = readl(host->base + DAVINCI_MMCRSP67);
+		} else {
+			/* response types 1, 1b, 3, 4, 5, 6 */
+			cmd->resp[0] = readl(host->base + DAVINCI_MMCRSP67);
+		}
+	}
+
+	if (host->data == NULL || cmd->error) {
+		if (cmd->error == -ETIMEDOUT)
+			cmd->mrq->cmd->retries = 0;
+		mmc_request_done(host->mmc, cmd->mrq);
+		writel(0, host->base + DAVINCI_MMCIM);
+	}
+}
+
+static void
+davinci_abort_data(struct mmc_davinci_host *host, struct mmc_data *data)
+{
+	u32 temp;
+
+	/* reset command and data state machines */
+	temp = readl(host->base + DAVINCI_MMCCTL);
+	writel(temp | MMCCTL_CMDRST | MMCCTL_DATRST,
+		host->base + DAVINCI_MMCCTL);
+
+	temp &= ~(MMCCTL_CMDRST | MMCCTL_DATRST);
+	udelay(10);
+	writel(temp, host->base + DAVINCI_MMCCTL);
+}
+
+static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
+{
+	struct mmc_davinci_host *host = (struct mmc_davinci_host *)dev_id;
+	unsigned int status, qstatus;
+	int end_command = 0;
+	int end_transfer = 0;
+	struct mmc_data *data = host->data;
+
+	if (host->cmd == NULL && host->data == NULL) {
+		status = readl(host->base + DAVINCI_MMCST0);
+		dev_dbg(mmc_dev(host->mmc),
+			"Spurious interrupt 0x%04x\n", status);
+		/* Disable the interrupt from mmcsd */
+		writel(0, host->base + DAVINCI_MMCIM);
+		return IRQ_NONE;
+	}
+
+	status = readl(host->base + DAVINCI_MMCST0);
+	qstatus = status;
+
+	/* handle FIFO first when using PIO for data.
+	 * bytes_left will decrease to zero as I/O progress and status will
+	 * read zero over iteration because this controller status
+	 * register(MMCST0) reports any status only once and it is cleared
+	 * by read. So, it is not unbouned loop even in the case of
+	 * non-dma.
+	 */
+	while (host->bytes_left && (status & (MMCST0_DXRDY | MMCST0_DRRDY))) {
+		davinci_fifo_data_trans(host, rw_threshold);
+		status = readl(host->base + DAVINCI_MMCST0);
+		if (!status)
+			break;
+		qstatus |= status;
+	}
+
+	if (qstatus & MMCST0_DATDNE) {
+		/* All blocks sent/received, and CRC checks passed */
+		if (data != NULL) {
+			if ((host->do_dma == 0) && (host->bytes_left > 0)) {
+				/* if datasize < rw_threshold
+				 * no RX ints are generated
+				 */
+				davinci_fifo_data_trans(host, host->bytes_left);
+			}
+			end_transfer = 1;
+			data->bytes_xfered = data->blocks * data->blksz;
+		} else {
+			dev_err(mmc_dev(host->mmc),
+					"DATDNE with no host->data\n");
+		}
+	}
+
+	if (qstatus & MMCST0_TOUTRD) {
+		/* Read data timeout */
+		data->error = -ETIMEDOUT;
+		end_transfer = 1;
+
+		dev_dbg(mmc_dev(host->mmc),
+			"read data timeout, status %x\n",
+			qstatus);
+
+		davinci_abort_data(host, data);
+	}
+
+	if (qstatus & (MMCST0_CRCWR | MMCST0_CRCRD)) {
+		/* Data CRC error */
+		data->error = -EILSEQ;
+		end_transfer = 1;
+
+		/* NOTE:  this controller uses CRCWR to report both CRC
+		 * errors and timeouts (on writes).  MMCDRSP values are
+		 * only weakly documented, but 0x9f was clearly a timeout
+		 * case and the two three-bit patterns in various SD specs
+		 * (101, 010) aren't part of it ...
+		 */
+		if (qstatus & MMCST0_CRCWR) {
+			u32 temp = readb(host->base + DAVINCI_MMCDRSP);
+
+			if (temp == 0x9f)
+				data->error = -ETIMEDOUT;
+		}
+		dev_dbg(mmc_dev(host->mmc), "data %s %s error\n",
+			(qstatus & MMCST0_CRCWR) ? "write" : "read",
+			(data->error == -ETIMEDOUT) ? "timeout" : "CRC");
+
+		davinci_abort_data(host, data);
+	}
+
+	if (qstatus & MMCST0_TOUTRS) {
+		/* Command timeout */
+		if (host->cmd) {
+			dev_dbg(mmc_dev(host->mmc),
+				"CMD%d timeout, status %x\n",
+				host->cmd->opcode, qstatus);
+			host->cmd->error = -ETIMEDOUT;
+			if (data) {
+				end_transfer = 1;
+				davinci_abort_data(host, data);
+			} else
+				end_command = 1;
+		}
+	}
+
+	if (qstatus & MMCST0_CRCRS) {
+		/* Command CRC error */
+		dev_dbg(mmc_dev(host->mmc), "Command CRC error\n");
+		if (host->cmd) {
+			host->cmd->error = -EILSEQ;
+			end_command = 1;
+		}
+	}
+
+	if (qstatus & MMCST0_RSPDNE) {
+		/* End of command phase */
+		end_command = (int) host->cmd;
+	}
+
+	if (end_command)
+		mmc_davinci_cmd_done(host, host->cmd);
+	if (end_transfer)
+		mmc_davinci_xfer_done(host, data);
+	return IRQ_HANDLED;
+}
+
+static int mmc_davinci_get_cd(struct mmc_host *mmc)
+{
+	struct platform_device *pdev = to_platform_device(mmc->parent);
+	struct davinci_mmc_config *config = pdev->dev.platform_data;
+
+	if (!config || !config->get_cd)
+		return -ENOSYS;
+	return config->get_cd(pdev->id);
+}
+
+static int mmc_davinci_get_ro(struct mmc_host *mmc)
+{
+	struct platform_device *pdev = to_platform_device(mmc->parent);
+	struct davinci_mmc_config *config = pdev->dev.platform_data;
+
+	if (!config || !config->get_ro)
+		return -ENOSYS;
+	return config->get_ro(pdev->id);
+}
+
+static struct mmc_host_ops mmc_davinci_ops = {
+	.request	= mmc_davinci_request,
+	.set_ios	= mmc_davinci_set_ios,
+	.get_cd		= mmc_davinci_get_cd,
+	.get_ro		= mmc_davinci_get_ro,
+};
+
+/*----------------------------------------------------------------------*/
+
+static void __init init_mmcsd_host(struct mmc_davinci_host *host)
+{
+	/* DAT line portion is diabled and in reset state */
+	writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_DATRST,
+		host->base + DAVINCI_MMCCTL);
+
+	/* CMD line portion is diabled and in reset state */
+	writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_CMDRST,
+		host->base + DAVINCI_MMCCTL);
+
+	udelay(10);
+
+	writel(0, host->base + DAVINCI_MMCCLK);
+	writel(MMCCLK_CLKEN, host->base + DAVINCI_MMCCLK);
+
+	writel(0x1FFF, host->base + DAVINCI_MMCTOR);
+	writel(0xFFFF, host->base + DAVINCI_MMCTOD);
+
+	writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_DATRST,
+		host->base + DAVINCI_MMCCTL);
+	writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_CMDRST,
+		host->base + DAVINCI_MMCCTL);
+
+	udelay(10);
+}
+
+static int __init davinci_mmcsd_probe(struct platform_device *pdev)
+{
+	struct davinci_mmc_config *pdata = pdev->dev.platform_data;
+	struct mmc_davinci_host *host = NULL;
+	struct mmc_host *mmc = NULL;
+	struct resource *r, *mem = NULL;
+	int ret = 0, irq = 0;
+	size_t mem_size;
+
+	/* REVISIT:  when we're fully converted, fail if pdata is NULL */
+
+	ret = -ENODEV;
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	irq = platform_get_irq(pdev, 0);
+	if (!r || irq == NO_IRQ)
+		goto out;
+
+	ret = -EBUSY;
+	mem_size = resource_size(r);
+	mem = request_mem_region(r->start, mem_size, pdev->name);
+	if (!mem)
+		goto out;
+
+	ret = -ENOMEM;
+	mmc = mmc_alloc_host(sizeof(struct mmc_davinci_host), &pdev->dev);
+	if (!mmc)
+		goto out;
+
+	host = mmc_priv(mmc);
+	host->mmc = mmc;	/* Important */
+
+	r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+	if (!r)
+		goto out;
+	host->rxdma = r->start;
+
+	r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
+	if (!r)
+		goto out;
+	host->txdma = r->start;
+
+	host->mem_res = mem;
+	host->base = ioremap(mem->start, mem_size);
+	if (!host->base)
+		goto out;
+
+	ret = -ENXIO;
+	host->clk = clk_get(&pdev->dev, "MMCSDCLK");
+	if (IS_ERR(host->clk)) {
+		ret = PTR_ERR(host->clk);
+		goto out;
+	}
+	clk_enable(host->clk);
+	host->mmc_input_clk = clk_get_rate(host->clk);
+
+	init_mmcsd_host(host);
+
+	host->use_dma = use_dma;
+	host->irq = irq;
+
+	if (host->use_dma && davinci_acquire_dma_channels(host) != 0)
+		host->use_dma = 0;
+
+	/* REVISIT:  someday, support IRQ-driven card detection.  */
+	mmc->caps |= MMC_CAP_NEEDS_POLL;
+
+	if (!pdata || pdata->wires == 4 || pdata->wires == 0)
+		mmc->caps |= MMC_CAP_4_BIT_DATA;
+
+	mmc->ops = &mmc_davinci_ops;
+	mmc->f_min = 312500;
+	mmc->f_max = 25000000;
+	if (pdata && pdata->max_freq)
+		mmc->f_max = pdata->max_freq;
+	if (pdata && pdata->caps)
+		mmc->caps |= pdata->caps;
+	mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
+
+	/* With no iommu coalescing pages, each phys_seg is a hw_seg.
+	 * Each hw_seg uses one EDMA parameter RAM slot, always one
+	 * channel and then usually some linked slots.
+	 */
+	mmc->max_hw_segs	= 1 + host->n_link;
+	mmc->max_phys_segs	= mmc->max_hw_segs;
+
+	/* EDMA limit per hw segment (one or two MBytes) */
+	mmc->max_seg_size	= MAX_CCNT * rw_threshold;
+
+	/* MMC/SD controller limits for multiblock requests */
+	mmc->max_blk_size	= 4095;  /* BLEN is 12 bits */
+	mmc->max_blk_count	= 65535; /* NBLK is 16 bits */
+	mmc->max_req_size	= mmc->max_blk_size * mmc->max_blk_count;
+
+	dev_dbg(mmc_dev(host->mmc), "max_phys_segs=%d\n", mmc->max_phys_segs);
+	dev_dbg(mmc_dev(host->mmc), "max_hw_segs=%d\n", mmc->max_hw_segs);
+	dev_dbg(mmc_dev(host->mmc), "max_blk_size=%d\n", mmc->max_blk_size);
+	dev_dbg(mmc_dev(host->mmc), "max_req_size=%d\n", mmc->max_req_size);
+	dev_dbg(mmc_dev(host->mmc), "max_seg_size=%d\n", mmc->max_seg_size);
+
+	platform_set_drvdata(pdev, host);
+
+	ret = mmc_add_host(mmc);
+	if (ret < 0)
+		goto out;
+
+	ret = request_irq(irq, mmc_davinci_irq, 0, mmc_hostname(mmc), host);
+	if (ret)
+		goto out;
+
+	rename_region(mem, mmc_hostname(mmc));
+
+	dev_info(mmc_dev(host->mmc), "Using %s, %d-bit mode\n",
+		host->use_dma ? "DMA" : "PIO",
+		(mmc->caps & MMC_CAP_4_BIT_DATA) ? 4 : 1);
+
+	return 0;
+
+out:
+	if (host) {
+		davinci_release_dma_channels(host);
+
+		if (host->clk) {
+			clk_disable(host->clk);
+			clk_put(host->clk);
+		}
+
+		if (host->base)
+			iounmap(host->base);
+	}
+
+	if (mmc)
+		mmc_free_host(mmc);
+
+	if (mem)
+		release_resource(mem);
+
+	dev_dbg(&pdev->dev, "probe err %d\n", ret);
+
+	return ret;
+}
+
+static int __exit davinci_mmcsd_remove(struct platform_device *pdev)
+{
+	struct mmc_davinci_host *host = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+	if (host) {
+		mmc_remove_host(host->mmc);
+		free_irq(host->irq, host);
+
+		davinci_release_dma_channels(host);
+
+		clk_disable(host->clk);
+		clk_put(host->clk);
+
+		iounmap(host->base);
+
+		release_resource(host->mem_res);
+
+		mmc_free_host(host->mmc);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int davinci_mmcsd_suspend(struct platform_device *pdev,
pm_message_t msg)
+{
+	struct mmc_davinci_host *host = platform_get_drvdata(pdev);
+
+	return mmc_suspend_host(host->mmc, msg);
+}
+
+static int davinci_mmcsd_resume(struct platform_device *pdev)
+{
+	struct mmc_davinci_host *host = platform_get_drvdata(pdev);
+
+	return mmc_resume_host(host->mmc);
+}
+#else
+#define davinci_mmcsd_suspend	NULL
+#define davinci_mmcsd_resume	NULL
+#endif
+
+static struct platform_driver davinci_mmcsd_driver = {
+	.driver		= {
+		.name	= "davinci_mmc",
+		.owner	= THIS_MODULE,
+	},
+	.remove		= __exit_p(davinci_mmcsd_remove),
+	.suspend	= davinci_mmcsd_suspend,
+	.resume		= davinci_mmcsd_resume,
+};
+
+static int __init davinci_mmcsd_init(void)
+{
+	return platform_driver_probe(&davinci_mmcsd_driver,
+				     davinci_mmcsd_probe);
+}
+module_init(davinci_mmcsd_init);
+
+static void __exit davinci_mmcsd_exit(void)
+{
+	platform_driver_unregister(&davinci_mmcsd_driver);
+}
+module_exit(davinci_mmcsd_exit);
+
+MODULE_AUTHOR("Texas Instruments India");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MMC/SD driver for Davinci MMC controller");
+
-- 
1.5.4.1
 
CD: 4ms