[ARM] 3457/1: i.MX: SD/MMC support for i.MX/MX1

Patch from Pavel Pisa

This patch adds support of i.MX/MX1 SD/MMC controller.
It has been significantly redesigned from the original Sascha Hauer's
version to support scatter-gather DMA, to conform to latest Pierre Ossman's
and Russell King's MMC-SD Linux 2.6.x infrastructure.
The handling of all events has been moved to the softirq context
and is designed with no busy-looping in mind. Unfortunately
some controller bugs has to be overcome by limited looping
about 2-20 usec but these are observed only for initial card
recognition phase.

There are still some missing/missed IRQs problems under heavy load.
Help of somebody with access to the full SDHC design information
is probably necessary.

Regenerated against 2.6.16-git-060402 to solve clash with other patches.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 1096 insertions, 0 deletions

diff --git a/drivers/mmc/imxmmc.c b/drivers/mmc/imxmmc.c
new file mode 100644
index 000000000000..ffb7f55d3467
--- /dev/null
+++ b/drivers/mmc/imxmmc.c
@@ -0,0 +1,1096 @@
+/*
+ *  linux/drivers/mmc/imxmmc.c - Motorola i.MX MMCI driver
+ *
+ *  Copyright (C) 2004 Sascha Hauer, Pengutronix <sascha@saschahauer.de>
+ *  Copyright (C) 2006 Pavel Pisa, PiKRON <ppisa@pikron.com>
+ *
+ *  derived from pxamci.c by Russell King
+ *
+ * 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.
+ *
+ *  2005-04-17 Pavel Pisa <pisa@cmp.felk.cvut.cz>
+ *             Changed to conform redesigned i.MX scatter gather DMA interface
+ *
+ *  2005-11-04 Pavel Pisa <pisa@cmp.felk.cvut.cz>
+ *             Updated for 2.6.14 kernel
+ *
+ *  2005-12-13 Jay Monkman <jtm@smoothsmoothie.com>
+ *             Found and corrected problems in the write path
+ *
+ *  2005-12-30 Pavel Pisa <pisa@cmp.felk.cvut.cz>
+ *             The event handling rewritten right way in softirq.
+ *             Added many ugly hacks and delays to overcome SDHC
+ *             deficiencies
+ *
+ */
+#include <linux/config.h>
+
+#ifdef CONFIG_MMC_DEBUG
+#define DEBUG
+#else
+#undef  DEBUG
+#endif
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/blkdev.h>
+#include <linux/dma-mapping.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/card.h>
+#include <linux/mmc/protocol.h>
+#include <linux/delay.h>
+
+#include <asm/dma.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/sizes.h>
+#include <asm/arch/mmc.h>
+#include <asm/arch/imx-dma.h>
+
+#include "imxmmc.h"
+
+#define DRIVER_NAME "imx-mmc"
+
+#define IMXMCI_INT_MASK_DEFAULT (INT_MASK_BUF_READY | INT_MASK_DATA_TRAN | \
+	              INT_MASK_WRITE_OP_DONE | INT_MASK_END_CMD_RES | \
+		      INT_MASK_AUTO_CARD_DETECT | INT_MASK_DAT0_EN | INT_MASK_SDIO)
+
+struct imxmci_host {
+	struct mmc_host		*mmc;
+	spinlock_t		lock;
+	struct resource		*res;
+	int			irq;
+	imx_dmach_t		dma;
+	unsigned int		clkrt;
+	unsigned int		cmdat;
+	volatile unsigned int	imask;
+	unsigned int		power_mode;
+	unsigned int		present;
+	struct imxmmc_platform_data *pdata;
+
+	struct mmc_request	*req;
+	struct mmc_command	*cmd;
+	struct mmc_data		*data;
+
+	struct timer_list	timer;
+	struct tasklet_struct	tasklet;
+	unsigned int		status_reg;
+	unsigned long		pending_events;
+	/* Next to fields are there for CPU driven transfers to overcome SDHC deficiencies */
+	u16			*data_ptr;
+	unsigned int		data_cnt;
+	atomic_t		stuck_timeout;
+
+	unsigned int		dma_nents;
+	unsigned int		dma_size;
+	unsigned int		dma_dir;
+	int			dma_allocated;
+
+	unsigned char		actual_bus_width;
+};
+
+#define IMXMCI_PEND_IRQ_b	0
+#define IMXMCI_PEND_DMA_END_b	1
+#define IMXMCI_PEND_DMA_ERR_b	2
+#define IMXMCI_PEND_WAIT_RESP_b	3
+#define IMXMCI_PEND_DMA_DATA_b	4
+#define IMXMCI_PEND_CPU_DATA_b	5
+#define IMXMCI_PEND_CARD_XCHG_b	6
+#define IMXMCI_PEND_SET_INIT_b	7
+
+#define IMXMCI_PEND_IRQ_m	(1 << IMXMCI_PEND_IRQ_b)
+#define IMXMCI_PEND_DMA_END_m	(1 << IMXMCI_PEND_DMA_END_b)
+#define IMXMCI_PEND_DMA_ERR_m	(1 << IMXMCI_PEND_DMA_ERR_b)
+#define IMXMCI_PEND_WAIT_RESP_m	(1 << IMXMCI_PEND_WAIT_RESP_b)
+#define IMXMCI_PEND_DMA_DATA_m	(1 << IMXMCI_PEND_DMA_DATA_b)
+#define IMXMCI_PEND_CPU_DATA_m	(1 << IMXMCI_PEND_CPU_DATA_b)
+#define IMXMCI_PEND_CARD_XCHG_m	(1 << IMXMCI_PEND_CARD_XCHG_b)
+#define IMXMCI_PEND_SET_INIT_m	(1 << IMXMCI_PEND_SET_INIT_b)
+
+static void imxmci_stop_clock(struct imxmci_host *host)
+{
+	int i = 0;
+	MMC_STR_STP_CLK &= ~STR_STP_CLK_START_CLK;
+	while(i < 0x1000) {
+	        if(!(i & 0x7f))
+			MMC_STR_STP_CLK |= STR_STP_CLK_STOP_CLK;
+
+		if(!(MMC_STATUS & STATUS_CARD_BUS_CLK_RUN)) {
+			/* Check twice before cut */
+			if(!(MMC_STATUS & STATUS_CARD_BUS_CLK_RUN))
+				return;
+		}
+
+		i++;
+	}
+	dev_dbg(mmc_dev(host->mmc), "imxmci_stop_clock blocked, no luck\n");
+}
+
+static void imxmci_start_clock(struct imxmci_host *host)
+{
+	int i = 0;
+	MMC_STR_STP_CLK &= ~STR_STP_CLK_STOP_CLK;
+	while(i < 0x1000) {
+	        if(!(i & 0x7f))
+			MMC_STR_STP_CLK |= STR_STP_CLK_START_CLK;
+
+		if(MMC_STATUS & STATUS_CARD_BUS_CLK_RUN) {
+			/* Check twice before cut */
+			if(MMC_STATUS & STATUS_CARD_BUS_CLK_RUN)
+				return;
+		}
+
+		i++;
+	}
+	dev_dbg(mmc_dev(host->mmc), "imxmci_start_clock blocked, no luck\n");
+}
+
+static void imxmci_softreset(void)
+{
+	/* reset sequence */
+	MMC_STR_STP_CLK = 0x8;
+	MMC_STR_STP_CLK = 0xD;
+	MMC_STR_STP_CLK = 0x5;
+	MMC_STR_STP_CLK = 0x5;
+	MMC_STR_STP_CLK = 0x5;
+	MMC_STR_STP_CLK = 0x5;
+	MMC_STR_STP_CLK = 0x5;
+	MMC_STR_STP_CLK = 0x5;
+	MMC_STR_STP_CLK = 0x5;
+	MMC_STR_STP_CLK = 0x5;
+
+	MMC_RES_TO = 0xff;
+	MMC_BLK_LEN = 512;
+	MMC_NOB = 1;
+}
+
+static int imxmci_busy_wait_for_status(struct imxmci_host *host,
+			unsigned int *pstat, unsigned int stat_mask,
+			int timeout, const char *where)
+{
+	int loops=0;
+	while(!(*pstat & stat_mask)) {
+		loops+=2;
+		if(loops >= timeout) {
+			dev_dbg(mmc_dev(host->mmc), "busy wait timeout in %s, STATUS = 0x%x (0x%x)\n",
+				where, *pstat, stat_mask);
+			return -1;
+		}
+		udelay(2);
+		*pstat |= MMC_STATUS;
+	}
+	if(!loops)
+		return 0;
+
+	dev_info(mmc_dev(host->mmc), "busy wait for %d usec in %s, STATUS = 0x%x (0x%x)\n",
+		loops, where, *pstat, stat_mask);
+	return loops;
+}
+
+static void imxmci_setup_data(struct imxmci_host *host, struct mmc_data *data)
+{
+	unsigned int nob = data->blocks;
+	unsigned int blksz = 1 << data->blksz_bits;
+	unsigned int datasz = nob * blksz;
+	int i;
+
+	if (data->flags & MMC_DATA_STREAM)
+		nob = 0xffff;
+
+	host->data = data;
+	data->bytes_xfered = 0;
+
+	MMC_NOB = nob;
+	MMC_BLK_LEN = blksz;
+
+	/*
+	 * DMA cannot be used for small block sizes, we have to use CPU driven transfers otherwise.
+	 * We are in big troubles for non-512 byte transfers according to note in the paragraph
+	 * 20.6.7 of User Manual anyway, but we need to be able to transfer SCR at least.
+	 * The situation is even more complex in reality. The SDHC in not able to handle wll
+	 * partial FIFO fills and reads. The length has to be rounded up to burst size multiple.
+	 * This is required for SCR read at least.
+	 */
+	if (datasz < 64) {
+		host->dma_size = datasz;
+		if (data->flags & MMC_DATA_READ) {
+			host->dma_dir = DMA_FROM_DEVICE;
+
+			/* Hack to enable read SCR */
+			if(datasz < 16) {
+				MMC_NOB = 1;
+				MMC_BLK_LEN = 16;
+			}
+		} else {
+			host->dma_dir = DMA_TO_DEVICE;
+		}
+
+		/* Convert back to virtual address */
+		host->data_ptr = (u16*)(page_address(data->sg->page) + data->sg->offset);
+		host->data_cnt = 0;
+
+		clear_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events);
+		set_bit(IMXMCI_PEND_CPU_DATA_b, &host->pending_events);
+
+		return;
+	}
+
+	if (data->flags & MMC_DATA_READ) {
+		host->dma_dir = DMA_FROM_DEVICE;
+		host->dma_nents = dma_map_sg(mmc_dev(host->mmc), data->sg,
+						data->sg_len,  host->dma_dir);
+
+		imx_dma_setup_sg(host->dma, data->sg, data->sg_len, datasz,
+			host->res->start + MMC_BUFFER_ACCESS_OFS, DMA_MODE_READ);
+
+		/*imx_dma_setup_mem2dev_ccr(host->dma, DMA_MODE_READ, IMX_DMA_WIDTH_16, CCR_REN);*/
+		CCR(host->dma) = CCR_DMOD_LINEAR | CCR_DSIZ_32 | CCR_SMOD_FIFO | CCR_SSIZ_16 | CCR_REN;
+	} else {
+		host->dma_dir = DMA_TO_DEVICE;
+
+		host->dma_nents = dma_map_sg(mmc_dev(host->mmc), data->sg,
+						data->sg_len,  host->dma_dir);
+
+		imx_dma_setup_sg(host->dma, data->sg, data->sg_len, datasz,
+			host->res->start + MMC_BUFFER_ACCESS_OFS, DMA_MODE_WRITE);
+
+		/*imx_dma_setup_mem2dev_ccr(host->dma, DMA_MODE_WRITE, IMX_DMA_WIDTH_16, CCR_REN);*/
+		CCR(host->dma) = CCR_SMOD_LINEAR | CCR_SSIZ_32 | CCR_DMOD_FIFO | CCR_DSIZ_16 | CCR_REN;
+	}
+
+#if 1	/* This code is there only for consistency checking and can be disabled in future */
+	host->dma_size = 0;
+	for(i=0; i<host->dma_nents; i++)
+		host->dma_size+=data->sg[i].length;
+
+	if (datasz > host->dma_size) {
+		dev_err(mmc_dev(host->mmc), "imxmci_setup_data datasz 0x%x > 0x%x dm_size\n",
+		       datasz, host->dma_size);
+	}
+#endif
+
+	host->dma_size = datasz;
+
+	wmb();
+
+	if(host->actual_bus_width == MMC_BUS_WIDTH_4)
+		BLR(host->dma) = 0;	/* burst 64 byte read / 64 bytes write */
+	else
+		BLR(host->dma) = 16;	/* burst 16 byte read / 16 bytes write */
+
+	RSSR(host->dma) = DMA_REQ_SDHC;
+
+	set_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events);
+	clear_bit(IMXMCI_PEND_CPU_DATA_b, &host->pending_events);
+
+	/* start DMA engine for read, write is delayed after initial response */
+	if (host->dma_dir == DMA_FROM_DEVICE) {
+		imx_dma_enable(host->dma);
+	}
+}
+
+static void imxmci_start_cmd(struct imxmci_host *host, struct mmc_command *cmd, unsigned int cmdat)
+{
+	unsigned long flags;
+	u32 imask;
+
+	WARN_ON(host->cmd != NULL);
+	host->cmd = cmd;
+
+	if (cmd->flags & MMC_RSP_BUSY)
+		cmdat |= CMD_DAT_CONT_BUSY;
+
+	switch (mmc_resp_type(cmd)) {
+	case MMC_RSP_R1: /* short CRC, OPCODE */
+	case MMC_RSP_R1B:/* short CRC, OPCODE, BUSY */
+		cmdat |= CMD_DAT_CONT_RESPONSE_FORMAT_R1;
+		break;
+	case MMC_RSP_R2: /* long 136 bit + CRC */
+		cmdat |= CMD_DAT_CONT_RESPONSE_FORMAT_R2;
+		break;
+	case MMC_RSP_R3: /* short */
+		cmdat |= CMD_DAT_CONT_RESPONSE_FORMAT_R3;
+		break;
+	case MMC_RSP_R6: /* short CRC */
+		cmdat |= CMD_DAT_CONT_RESPONSE_FORMAT_R6;
+		break;
+	default:
+		break;
+	}
+
+	if ( test_and_clear_bit(IMXMCI_PEND_SET_INIT_b, &host->pending_events) )
+		cmdat |= CMD_DAT_CONT_INIT; /* This command needs init */
+
+	if ( host->actual_bus_width == MMC_BUS_WIDTH_4 )
+		cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
+
+	MMC_CMD = cmd->opcode;
+	MMC_ARGH = cmd->arg >> 16;
+	MMC_ARGL = cmd->arg & 0xffff;
+	MMC_CMD_DAT_CONT = cmdat;
+
+	atomic_set(&host->stuck_timeout, 0);
+	set_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events);
+
+
+	imask = IMXMCI_INT_MASK_DEFAULT;
+	imask &= ~INT_MASK_END_CMD_RES;
+	if ( cmdat & CMD_DAT_CONT_DATA_ENABLE ) {
+		/*imask &= ~INT_MASK_BUF_READY;*/
+		imask &= ~INT_MASK_DATA_TRAN;
+		if ( cmdat & CMD_DAT_CONT_WRITE )
+			imask &= ~INT_MASK_WRITE_OP_DONE;
+		if(test_bit(IMXMCI_PEND_CPU_DATA_b, &host->pending_events))
+			imask &= ~INT_MASK_BUF_READY;
+	}
+
+	spin_lock_irqsave(&host->lock, flags);
+	host->imask = imask;
+	MMC_INT_MASK = host->imask;
+	spin_unlock_irqrestore(&host->lock, flags);
+
+	dev_dbg(mmc_dev(host->mmc), "CMD%02d (0x%02x) mask set to 0x%04x\n",
+		cmd->opcode, cmd->opcode, imask);
+
+	imxmci_start_clock(host);
+}
+
+static void imxmci_finish_request(struct imxmci_host *host, struct mmc_request *req)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->lock, flags);
+
+	host->pending_events &= ~(IMXMCI_PEND_WAIT_RESP_m | IMXMCI_PEND_DMA_END_m |
+			IMXMCI_PEND_DMA_DATA_m | IMXMCI_PEND_CPU_DATA_m);
+
+	host->imask = IMXMCI_INT_MASK_DEFAULT;
+	MMC_INT_MASK = host->imask;
+
+	spin_unlock_irqrestore(&host->lock, flags);
+
+	host->req = NULL;
+	host->cmd = NULL;
+	host->data = NULL;
+	mmc_request_done(host->mmc, req);
+}
+
+static int imxmci_finish_data(struct imxmci_host *host, unsigned int stat)
+{
+	struct mmc_data *data = host->data;
+	int data_error;
+
+	if(test_and_clear_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events)){
+		imx_dma_disable(host->dma);
+		dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->dma_nents,
+			     host->dma_dir);
+	}
+
+	if ( stat & STATUS_ERR_MASK ) {
+		dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n",stat);
+		if(stat & (STATUS_CRC_READ_ERR | STATUS_CRC_WRITE_ERR))
+			data->error = MMC_ERR_BADCRC;
+		else if(stat & STATUS_TIME_OUT_READ)
+			data->error = MMC_ERR_TIMEOUT;
+		else
+			data->error = MMC_ERR_FAILED;
+	} else {
+		data->bytes_xfered = host->dma_size;
+	}
+
+	data_error = data->error;
+
+	host->data = NULL;
+
+	return data_error;
+}
+
+static int imxmci_cmd_done(struct imxmci_host *host, unsigned int stat)
+{
+	struct mmc_command *cmd = host->cmd;
+	int i;
+	u32 a,b,c;
+	struct mmc_data *data = host->data;
+
+	if (!cmd)
+		return 0;
+
+	host->cmd = NULL;
+
+	if (stat & STATUS_TIME_OUT_RESP) {
+		dev_dbg(mmc_dev(host->mmc), "CMD TIMEOUT\n");
+		cmd->error = MMC_ERR_TIMEOUT;
+	} else if (stat & STATUS_RESP_CRC_ERR && cmd->flags & MMC_RSP_CRC) {
+		dev_dbg(mmc_dev(host->mmc), "cmd crc error\n");
+		cmd->error = MMC_ERR_BADCRC;
+	}
+
+	if(cmd->flags & MMC_RSP_PRESENT) {
+		if(cmd->flags & MMC_RSP_136) {
+			for (i = 0; i < 4; i++) {
+				u32 a = MMC_RES_FIFO & 0xffff;
+				u32 b = MMC_RES_FIFO & 0xffff;
+				cmd->resp[i] = a<<16 | b;
+			}
+		} else {
+			a = MMC_RES_FIFO & 0xffff;
+			b = MMC_RES_FIFO & 0xffff;
+			c = MMC_RES_FIFO & 0xffff;
+			cmd->resp[0] = a<<24 | b<<8 | c>>8;
+		}
+	}
+
+	dev_dbg(mmc_dev(host->mmc), "RESP 0x%08x, 0x%08x, 0x%08x, 0x%08x, error %d\n",
+		cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3], cmd->error);
+
+	if (data && (cmd->error == MMC_ERR_NONE) && !(stat & STATUS_ERR_MASK)) {
+		if (host->req->data->flags & MMC_DATA_WRITE) {
+
+			/* Wait for FIFO to be empty before starting DMA write */
+
+			stat = MMC_STATUS;
+			if(imxmci_busy_wait_for_status(host, &stat,
+				STATUS_APPL_BUFF_FE,
+				40, "imxmci_cmd_done DMA WR") < 0) {
+				cmd->error = MMC_ERR_FIFO;
+				imxmci_finish_data(host, stat);
+				if(host->req)
+					imxmci_finish_request(host, host->req);
+				dev_warn(mmc_dev(host->mmc), "STATUS = 0x%04x\n",
+				       stat);
+				return 0;
+			}
+
+			if(test_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events)) {
+				imx_dma_enable(host->dma);
+			}
+		}
+	} else {
+		struct mmc_request *req;
+		imxmci_stop_clock(host);
+		req = host->req;
+
+		if(data)
+			imxmci_finish_data(host, stat);
+
+		if( req ) {
+			imxmci_finish_request(host, req);
+		} else {
+			dev_warn(mmc_dev(host->mmc), "imxmci_cmd_done: no request to finish\n");
+		}
+	}
+
+	return 1;
+}
+
+static int imxmci_data_done(struct imxmci_host *host, unsigned int stat)
+{
+	struct mmc_data *data = host->data;
+	int data_error;
+
+	if (!data)
+		return 0;
+
+	data_error = imxmci_finish_data(host, stat);
+
+	if (host->req->stop && (data_error == MMC_ERR_NONE)) {
+		imxmci_stop_clock(host);
+		imxmci_start_cmd(host, host->req->stop, 0);
+	} else {
+		struct mmc_request *req;
+		req = host->req;
+		if( req ) {
+			imxmci_finish_request(host, req);
+		} else {
+			dev_warn(mmc_dev(host->mmc), "imxmci_data_done: no request to finish\n");
+		}
+	}
+
+	return 1;
+}
+
+static int imxmci_cpu_driven_data(struct imxmci_host *host, unsigned int *pstat)
+{
+	int i;
+	int burst_len;
+	int flush_len;
+	int trans_done = 0;
+	unsigned int stat = *pstat;
+
+	if(host->actual_bus_width == MMC_BUS_WIDTH_4)
+		burst_len = 16;
+	else
+		burst_len = 64;
+
+	/* This is unfortunately required */
+	dev_dbg(mmc_dev(host->mmc), "imxmci_cpu_driven_data running STATUS = 0x%x\n",
+		stat);
+
+	if(host->dma_dir == DMA_FROM_DEVICE) {
+		imxmci_busy_wait_for_status(host, &stat,
+				STATUS_APPL_BUFF_FF | STATUS_DATA_TRANS_DONE,
+				20, "imxmci_cpu_driven_data read");
+
+		while((stat & (STATUS_APPL_BUFF_FF |  STATUS_DATA_TRANS_DONE)) &&
+		      (host->data_cnt < host->dma_size)) {
+			if(burst_len >= host->dma_size - host->data_cnt) {
+				flush_len = burst_len;
+				burst_len = host->dma_size - host->data_cnt;
+				flush_len -= burst_len;
+				host->data_cnt = host->dma_size;
+				trans_done = 1;
+			} else {
+				flush_len = 0;
+				host->data_cnt += burst_len;
+			}
+
+			for(i = burst_len; i>=2 ; i-=2) {
+				*(host->data_ptr++) = MMC_BUFFER_ACCESS;
+				udelay(20);	/* required for clocks < 8MHz*/
+			}
+
+			if(i == 1)
+				*(u8*)(host->data_ptr) = MMC_BUFFER_ACCESS;
+
+			stat = MMC_STATUS;
+
+			/* Flush extra bytes from FIFO */
+			while(flush_len >= 2){
+				flush_len -= 2;
+				i = MMC_BUFFER_ACCESS;
+				stat = MMC_STATUS;
+				stat &= ~STATUS_CRC_READ_ERR; /* Stupid but required there */
+			}
+
+			dev_dbg(mmc_dev(host->mmc), "imxmci_cpu_driven_data read burst %d STATUS = 0x%x\n",
+				burst_len, stat);
+		}
+	} else {
+		imxmci_busy_wait_for_status(host, &stat,
+				STATUS_APPL_BUFF_FE,
+				20, "imxmci_cpu_driven_data write");
+
+		while((stat & STATUS_APPL_BUFF_FE) &&
+		      (host->data_cnt < host->dma_size)) {
+			if(burst_len >= host->dma_size - host->data_cnt) {
+				burst_len = host->dma_size - host->data_cnt;
+				host->data_cnt = host->dma_size;
+				trans_done = 1;
+			} else {
+				host->data_cnt += burst_len;
+			}
+
+			for(i = burst_len; i>0 ; i-=2)
+				MMC_BUFFER_ACCESS = *(host->data_ptr++);
+
+			stat = MMC_STATUS;
+
+			dev_dbg(mmc_dev(host->mmc), "imxmci_cpu_driven_data write burst %d STATUS = 0x%x\n",
+				burst_len, stat);
+		}
+	}
+
+	*pstat = stat;
+
+	return trans_done;
+}
+
+static void imxmci_dma_irq(int dma, void *devid, struct pt_regs *regs)
+{
+	struct imxmci_host *host = devid;
+	uint32_t stat = MMC_STATUS;
+
+	atomic_set(&host->stuck_timeout, 0);
+	host->status_reg = stat;
+	set_bit(IMXMCI_PEND_DMA_END_b, &host->pending_events);
+	tasklet_schedule(&host->tasklet);
+}
+
+static irqreturn_t imxmci_irq(int irq, void *devid, struct pt_regs *regs)
+{
+	struct imxmci_host *host = devid;
+	uint32_t stat = MMC_STATUS;
+	int handled = 1;
+
+	MMC_INT_MASK = host->imask | INT_MASK_SDIO | INT_MASK_AUTO_CARD_DETECT;
+
+	atomic_set(&host->stuck_timeout, 0);
+	host->status_reg = stat;
+	set_bit(IMXMCI_PEND_IRQ_b, &host->pending_events);
+	tasklet_schedule(&host->tasklet);
+
+	return IRQ_RETVAL(handled);;
+}
+
+static void imxmci_tasklet_fnc(unsigned long data)
+{
+	struct imxmci_host *host = (struct imxmci_host *)data;
+	u32 stat;
+	unsigned int data_dir_mask = 0;	/* STATUS_WR_CRC_ERROR_CODE_MASK */
+	int timeout = 0;
+
+	if(atomic_read(&host->stuck_timeout) > 4) {
+		char *what;
+		timeout = 1;
+		stat = MMC_STATUS;
+		host->status_reg = stat;
+		if (test_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events))
+			if (test_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events))
+				what = "RESP+DMA";
+			else
+				what = "RESP";
+		else
+			if (test_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events))
+				if(test_bit(IMXMCI_PEND_DMA_END_b, &host->pending_events))
+					what = "DATA";
+				else
+					what = "DMA";
+			else
+				what = "???";
+
+		dev_err(mmc_dev(host->mmc), "%s TIMEOUT, hardware stucked STATUS = 0x%04x IMASK = 0x%04x\n",
+		       what, stat, MMC_INT_MASK);
+		dev_err(mmc_dev(host->mmc), "CMD_DAT_CONT = 0x%04x, MMC_BLK_LEN = 0x%04x, MMC_NOB = 0x%04x, DMA_CCR = 0x%08x\n",
+		       MMC_CMD_DAT_CONT, MMC_BLK_LEN, MMC_NOB, CCR(host->dma));
+		dev_err(mmc_dev(host->mmc), "CMD%d, bus %d-bit, dma_size = 0x%x\n",
+		       host->cmd?host->cmd->opcode:0, 1<<host->actual_bus_width, host->dma_size);
+	}
+
+	if(!host->present || timeout)
+		host->status_reg = STATUS_TIME_OUT_RESP | STATUS_TIME_OUT_READ |
+				    STATUS_CRC_READ_ERR | STATUS_CRC_WRITE_ERR;
+
+	if(test_bit(IMXMCI_PEND_IRQ_b, &host->pending_events) || timeout) {
+		clear_bit(IMXMCI_PEND_IRQ_b, &host->pending_events);
+
+		stat = MMC_STATUS;
+		/*
+		 * This is not required in theory, but there is chance to miss some flag
+		 * which clears automatically by mask write, FreeScale original code keeps
+		 * stat from IRQ time so do I
+		 */
+		stat |= host->status_reg;
+
+		if(test_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events)) {
+			imxmci_busy_wait_for_status(host, &stat,
+					STATUS_END_CMD_RESP | STATUS_ERR_MASK,
+					20, "imxmci_tasklet_fnc resp (ERRATUM #4)");
+		}
+
+		if(stat & (STATUS_END_CMD_RESP | STATUS_ERR_MASK)) {
+			if(test_and_clear_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events))
+				imxmci_cmd_done(host, stat);
+			if(host->data && (stat & STATUS_ERR_MASK))
+				imxmci_data_done(host, stat);
+		}
+
+		if(test_bit(IMXMCI_PEND_CPU_DATA_b, &host->pending_events)) {
+			stat |= MMC_STATUS;
+			if(imxmci_cpu_driven_data(host, &stat)){
+				if(test_and_clear_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events))
+					imxmci_cmd_done(host, stat);
+				atomic_clear_mask(IMXMCI_PEND_IRQ_m|IMXMCI_PEND_CPU_DATA_m,
+							&host->pending_events);
+				imxmci_data_done(host, stat);
+			}
+		}
+	}
+
+	if(test_bit(IMXMCI_PEND_DMA_END_b, &host->pending_events) &&
+	   !test_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events)) {
+
+		stat = MMC_STATUS;
+		/* Same as above */
+		stat |= host->status_reg;
+
+		if(host->dma_dir == DMA_TO_DEVICE) {
+			data_dir_mask = STATUS_WRITE_OP_DONE;
+		} else {
+			data_dir_mask = STATUS_DATA_TRANS_DONE;
+		}
+
+		imxmci_busy_wait_for_status(host, &stat,
+				data_dir_mask,
+				50, "imxmci_tasklet_fnc data");
+
+		if(stat & data_dir_mask) {
+			clear_bit(IMXMCI_PEND_DMA_END_b, &host->pending_events);
+			imxmci_data_done(host, stat);
+		}
+	}
+
+	if(test_and_clear_bit(IMXMCI_PEND_CARD_XCHG_b, &host->pending_events)) {
+
+		if(host->cmd)
+			imxmci_cmd_done(host, STATUS_TIME_OUT_RESP);
+
+		if(host->data)
+			imxmci_data_done(host, STATUS_TIME_OUT_READ |
+					 STATUS_CRC_READ_ERR | STATUS_CRC_WRITE_ERR);
+
+		if(host->req)
+			imxmci_finish_request(host, host->req);
+
+		mmc_detect_change(host->mmc, msecs_to_jiffies(100));
+
+	}
+}
+
+static void imxmci_request(struct mmc_host *mmc, struct mmc_request *req)
+{
+	struct imxmci_host *host = mmc_priv(mmc);
+	unsigned int cmdat;
+
+	WARN_ON(host->req != NULL);
+
+	host->req = req;
+
+	cmdat = 0;
+
+	if (req->data) {
+		imxmci_setup_data(host, req->data);
+
+		cmdat |= CMD_DAT_CONT_DATA_ENABLE;
+
+		if (req->data->flags & MMC_DATA_WRITE)
+			cmdat |= CMD_DAT_CONT_WRITE;
+
+		if (req->data->flags & MMC_DATA_STREAM) {
+			cmdat |= CMD_DAT_CONT_STREAM_BLOCK;
+		}
+	}
+
+	imxmci_start_cmd(host, req->cmd, cmdat);
+}
+
+#define CLK_RATE 19200000
+
+static void imxmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct imxmci_host *host = mmc_priv(mmc);
+	int prescaler;
+
+	dev_dbg(mmc_dev(host->mmc), "clock %u power %u vdd %u width %u\n",
+		ios->clock, ios->power_mode, ios->vdd,
+		(ios->bus_width==MMC_BUS_WIDTH_4)?4:1);
+
+	if( ios->bus_width==MMC_BUS_WIDTH_4 ) {
+		host->actual_bus_width = MMC_BUS_WIDTH_4;
+		imx_gpio_mode(PB11_PF_SD_DAT3);
+	}else{
+		host->actual_bus_width = MMC_BUS_WIDTH_1;
+		imx_gpio_mode(GPIO_PORTB | GPIO_IN | GPIO_PUEN | 11);
+	}
+
+	if ( host->power_mode != ios->power_mode ) {
+		switch (ios->power_mode) {
+		case MMC_POWER_OFF:
+        		break;
+		case MMC_POWER_UP:
+			set_bit(IMXMCI_PEND_SET_INIT_b, &host->pending_events);
+        		break;
+		case MMC_POWER_ON:
+        		break;
+		}
+		host->power_mode = ios->power_mode;
+	}
+
+	if ( ios->clock ) {
+		unsigned int clk;
+
+		/* The prescaler is 5 for PERCLK2 equal to 96MHz
+		 * then 96MHz / 5 = 19.2 MHz
+		 */
+		clk=imx_get_perclk2();
+		prescaler=(clk+(CLK_RATE*7)/8)/CLK_RATE;
+		switch(prescaler) {
+		case 0:
+		case 1:	prescaler = 0;
+			break;
+		case 2:	prescaler = 1;
+			break;
+		case 3:	prescaler = 2;
+			break;
+		case 4:	prescaler = 4;
+			break;
+		default:
+		case 5:	prescaler = 5;
+			break;
+		}
+
+		dev_dbg(mmc_dev(host->mmc), "PERCLK2 %d MHz -> prescaler %d\n",
+			clk, prescaler);
+
+		for(clk=0; clk<8; clk++) {
+			int x;
+			x = CLK_RATE / (1<<clk);
+			if( x <= ios->clock)
+				break;
+		}
+
+		MMC_STR_STP_CLK |= STR_STP_CLK_ENABLE; /* enable controller */
+
+		imxmci_stop_clock(host);
+		MMC_CLK_RATE = (prescaler<<3) | clk;
+		imxmci_start_clock(host);
+
+		dev_dbg(mmc_dev(host->mmc), "MMC_CLK_RATE: 0x%08x\n", MMC_CLK_RATE);
+	} else {
+		imxmci_stop_clock(host);
+	}
+}
+
+static struct mmc_host_ops imxmci_ops = {
+	.request	= imxmci_request,
+	.set_ios	= imxmci_set_ios,
+};
+
+static struct resource *platform_device_resource(struct platform_device *dev, unsigned int mask, int nr)
+{
+	int i;
+
+	for (i = 0; i < dev->num_resources; i++)
+		if (dev->resource[i].flags == mask && nr-- == 0)
+			return &dev->resource[i];
+	return NULL;
+}
+
+static int platform_device_irq(struct platform_device *dev, int nr)
+{
+	int i;
+
+	for (i = 0; i < dev->num_resources; i++)
+		if (dev->resource[i].flags == IORESOURCE_IRQ && nr-- == 0)
+			return dev->resource[i].start;
+	return NO_IRQ;
+}
+
+static void imxmci_check_status(unsigned long data)
+{
+	struct imxmci_host *host = (struct imxmci_host *)data;
+
+	if( host->pdata->card_present() != host->present ) {
+		host->present ^= 1;
+		dev_info(mmc_dev(host->mmc), "card %s\n",
+		      host->present ? "inserted" : "removed");
+
+		set_bit(IMXMCI_PEND_CARD_XCHG_b, &host->pending_events);
+		tasklet_schedule(&host->tasklet);
+	}
+
+	if(test_bit(IMXMCI_PEND_WAIT_RESP_b, &host->pending_events) ||
+	   test_bit(IMXMCI_PEND_DMA_DATA_b, &host->pending_events)) {
+		atomic_inc(&host->stuck_timeout);
+		if(atomic_read(&host->stuck_timeout) > 4)
+			tasklet_schedule(&host->tasklet);
+	} else {
+		atomic_set(&host->stuck_timeout, 0);
+
+	}
+
+	mod_timer(&host->timer, jiffies + (HZ>>1));
+}
+
+static int imxmci_probe(struct platform_device *pdev)
+{
+	struct mmc_host *mmc;
+	struct imxmci_host *host = NULL;
+	struct resource *r;
+	int ret = 0, irq;
+
+	printk(KERN_INFO "i.MX mmc driver\n");
+
+	r = platform_device_resource(pdev, IORESOURCE_MEM, 0);
+	irq = platform_device_irq(pdev, 0);
+	if (!r || irq == NO_IRQ)
+		return -ENXIO;
+
+	r = request_mem_region(r->start, 0x100, "IMXMCI");
+	if (!r)
+		return -EBUSY;
+
+	mmc = mmc_alloc_host(sizeof(struct imxmci_host), &pdev->dev);
+	if (!mmc) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	mmc->ops = &imxmci_ops;
+	mmc->f_min = 150000;
+	mmc->f_max = CLK_RATE/2;
+	mmc->ocr_avail = MMC_VDD_32_33;
+	mmc->caps |= MMC_CAP_4_BIT_DATA;
+
+	/* MMC core transfer sizes tunable parameters */
+	mmc->max_hw_segs = 64;
+	mmc->max_phys_segs = 64;
+	mmc->max_sectors = 64;		/* default 1 << (PAGE_CACHE_SHIFT - 9) */
+	mmc->max_seg_size = 64*512;	/* default PAGE_CACHE_SIZE */
+
+	host = mmc_priv(mmc);
+	host->mmc = mmc;
+	host->dma_allocated = 0;
+	host->pdata = pdev->dev.platform_data;
+
+	spin_lock_init(&host->lock);
+	host->res = r;
+	host->irq = irq;
+
+	imx_gpio_mode(PB8_PF_SD_DAT0);
+	imx_gpio_mode(PB9_PF_SD_DAT1);
+	imx_gpio_mode(PB10_PF_SD_DAT2);
+	/* Configured as GPIO with pull-up to ensure right MCC card mode */
+	/* Switched to PB11_PF_SD_DAT3 if 4 bit bus is configured */
+	imx_gpio_mode(GPIO_PORTB | GPIO_IN | GPIO_PUEN | 11);
+	/* imx_gpio_mode(PB11_PF_SD_DAT3); */
+	imx_gpio_mode(PB12_PF_SD_CLK);
+	imx_gpio_mode(PB13_PF_SD_CMD);
+
+	imxmci_softreset();
+
+	if ( MMC_REV_NO != 0x390 ) {
+		dev_err(mmc_dev(host->mmc), "wrong rev.no. 0x%08x. aborting.\n",
+		        MMC_REV_NO);
+		goto out;
+	}
+
+	MMC_READ_TO = 0x2db4; /* recommended in data sheet */
+
+	host->imask = IMXMCI_INT_MASK_DEFAULT;
+	MMC_INT_MASK = host->imask;
+
+
+	if(imx_dma_request_by_prio(&host->dma, DRIVER_NAME, DMA_PRIO_LOW)<0){
+		dev_err(mmc_dev(host->mmc), "imx_dma_request_by_prio failed\n");
+		ret = -EBUSY;
+		goto out;
+	}
+	host->dma_allocated=1;
+	imx_dma_setup_handlers(host->dma, imxmci_dma_irq, NULL, host);
+
+	tasklet_init(&host->tasklet, imxmci_tasklet_fnc, (unsigned long)host);
+	host->status_reg=0;
+	host->pending_events=0;
+
+	ret = request_irq(host->irq, imxmci_irq, 0, DRIVER_NAME, host);
+	if (ret)
+		goto out;
+
+	host->present = host->pdata->card_present();
+	init_timer(&host->timer);
+	host->timer.data = (unsigned long)host;
+	host->timer.function = imxmci_check_status;
+	add_timer(&host->timer);
+	mod_timer(&host->timer, jiffies + (HZ>>1));
+
+	platform_set_drvdata(pdev, mmc);
+
+	mmc_add_host(mmc);
+
+	return 0;
+
+out:
+	if (host) {
+		if(host->dma_allocated){
+			imx_dma_free(host->dma);
+			host->dma_allocated=0;
+		}
+	}
+	if (mmc)
+		mmc_free_host(mmc);
+	release_resource(r);
+	return ret;
+}
+
+static int imxmci_remove(struct platform_device *pdev)
+{
+	struct mmc_host *mmc = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	if (mmc) {
+		struct imxmci_host *host = mmc_priv(mmc);
+
+		tasklet_disable(&host->tasklet);
+
+		del_timer_sync(&host->timer);
+		mmc_remove_host(mmc);
+
+		free_irq(host->irq, host);
+		if(host->dma_allocated){
+			imx_dma_free(host->dma);
+			host->dma_allocated=0;
+		}
+
+		tasklet_kill(&host->tasklet);
+
+		release_resource(host->res);
+
+		mmc_free_host(mmc);
+	}
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int imxmci_suspend(struct platform_device *dev, pm_message_t state)
+{
+	struct mmc_host *mmc = platform_get_drvdata(dev);
+	int ret = 0;
+
+	if (mmc)
+		ret = mmc_suspend_host(mmc, state);
+
+	return ret;
+}
+
+static int imxmci_resume(struct platform_device *dev)
+{
+	struct mmc_host *mmc = platform_get_drvdata(dev);
+	struct imxmci_host *host;
+	int ret = 0;
+
+	if (mmc) {
+		host = mmc_priv(mmc);
+		if(host)
+			set_bit(IMXMCI_PEND_SET_INIT_b, &host->pending_events);
+		ret = mmc_resume_host(mmc);
+	}
+
+	return ret;
+}
+#else
+#define imxmci_suspend  NULL
+#define imxmci_resume   NULL
+#endif /* CONFIG_PM */
+
+static struct platform_driver imxmci_driver = {
+	.probe		= imxmci_probe,
+	.remove		= imxmci_remove,
+	.suspend	= imxmci_suspend,
+	.resume		= imxmci_resume,
+	.driver		= {
+		.name		= DRIVER_NAME,
+	}
+};
+
+static int __init imxmci_init(void)
+{
+	return platform_driver_register(&imxmci_driver);
+}
+
+static void __exit imxmci_exit(void)
+{
+	platform_driver_unregister(&imxmci_driver);
+}
+
+module_init(imxmci_init);
+module_exit(imxmci_exit);
+
+MODULE_DESCRIPTION("i.MX Multimedia Card Interface Driver");
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_LICENSE("GPL");