[MMC] Add OMAP MMC host driver

Adds OMAP MMC driver.

Signed-off-by: Juha Yrj�l� <[e-mail]>
Signed-off-by: Tony Lindgren <[e-mail]>
Signed-off-by: Carlos Aguiar <[e-mail]>
Signed-off-by: Russell King <[e-mail]>

drivers/mmc/Kconfig

···
 
 	  If unsure, say N.
 
+config MMC_OMAP
+	tristate "TI OMAP Multimedia Card Interface support"
+	depends on ARCH_OMAP && MMC
+	select TPS65010 if MACH_OMAP_H2
+	help
+	  This selects the TI OMAP Multimedia card Interface.
+	  If you have an OMAP board with a Multimedia Card slot,
+	  say Y or M here.
+
+	  If unsure, say N.
+
 config MMC_WBSD
 	tristate "Winbond W83L51xD SD/MMC Card Interface support"
 	depends on MMC && ISA_DMA_API

drivers/mmc/Makefile

···
 obj-$(CONFIG_MMC_SDHCI)		+= sdhci.o
 obj-$(CONFIG_MMC_WBSD)		+= wbsd.o
 obj-$(CONFIG_MMC_AU1X)		+= au1xmmc.o
+obj-$(CONFIG_MMC_OMAP)		+= omap.o
 
 mmc_core-y := mmc.o mmc_queue.o mmc_sysfs.o

drivers/mmc/omap.c

···
+/*
+ *  linux/drivers/media/mmc/omap.c
+ *
+ *  Copyright (C) 2004 Nokia Corporation
+ *  Written by Tuukka Tikkanen and Juha Yrj�l�<[e-mail]>
+ *  Misc hacks here and there by Tony Lindgren <[e-mail]>
+ *  Other hacks (DMA, SD, etc) by David Brownell
+ *
+ * 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/config.h>
+
+#ifdef CONFIG_MMC_DEBUG
+#define DEBUG	/* for dev_dbg(), pr_debug(), etc */
+#endif
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/protocol.h>
+#include <linux/mmc/card.h>
+#include <linux/clk.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/scatterlist.h>
+#include <asm/mach-types.h>
+
+#include <asm/arch/board.h>
+#include <asm/arch/gpio.h>
+#include <asm/arch/dma.h>
+#include <asm/arch/mux.h>
+#include <asm/arch/fpga.h>
+#include <asm/arch/tps65010.h>
+
+#include "omap.h"
+
+#define DRIVER_NAME "mmci-omap"
+#define RSP_TYPE(x)	((x) & ~(MMC_RSP_BUSY|MMC_RSP_OPCODE))
+
+/* Specifies how often in millisecs to poll for card status changes
+ * when the cover switch is open */
+#define OMAP_MMC_SWITCH_POLL_DELAY	500
+
+static int mmc_omap_enable_poll = 1;
+
+struct mmc_omap_host {
+	int			initialized;
+	int			suspended;
+	struct mmc_request *	mrq;
+	struct mmc_command *	cmd;
+	struct mmc_data *	data;
+	struct mmc_host *	mmc;
+	struct device *		dev;
+	unsigned char		id; /* 16xx chips have 2 MMC blocks */
+	struct clk *		iclk;
+	struct clk *		fclk;
+	void __iomem		*base;
+	int			irq;
+	unsigned char		bus_mode;
+	unsigned char		hw_bus_mode;
+
+	unsigned int		sg_len;
+	int			sg_idx;
+	u16 *			buffer;
+	u32			buffer_bytes_left;
+	u32			total_bytes_left;
+
+	unsigned		use_dma:1;
+	unsigned		brs_received:1, dma_done:1;
+	unsigned		dma_is_read:1;
+	unsigned		dma_in_use:1;
+	int			dma_ch;
+	spinlock_t		dma_lock;
+	struct timer_list	dma_timer;
+	unsigned		dma_len;
+
+	short			power_pin;
+	short			wp_pin;
+
+	int			switch_pin;
+	struct work_struct	switch_work;
+	struct timer_list	switch_timer;
+	int			switch_last_state;
+};
+
+static inline int
+mmc_omap_cover_is_open(struct mmc_omap_host *host)
+{
+	if (host->switch_pin < 0)
+		return 0;
+	return omap_get_gpio_datain(host->switch_pin);
+}
+
+static ssize_t
+mmc_omap_show_cover_switch(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct mmc_omap_host *host = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%s\n", mmc_omap_cover_is_open(host) ? "open" :
+			"closed");
+}
+
+static DEVICE_ATTR(cover_switch, S_IRUGO, mmc_omap_show_cover_switch, NULL);
+
+static ssize_t
+mmc_omap_show_enable_poll(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%d\n", mmc_omap_enable_poll);
+}
+
+static ssize_t
+mmc_omap_store_enable_poll(struct device *dev,
+	struct device_attribute *attr, const char *buf,
+	size_t size)
+{
+	int enable_poll;
+
+	if (sscanf(buf, "%10d", &enable_poll) != 1)
+		return -EINVAL;
+
+	if (enable_poll != mmc_omap_enable_poll) {
+		struct mmc_omap_host *host = dev_get_drvdata(dev);
+
+		mmc_omap_enable_poll = enable_poll;
+		if (enable_poll && host->switch_pin >= 0)
+			schedule_work(&host->switch_work);
+	}
+	return size;
+}
+
+static DEVICE_ATTR(enable_poll, 0664,
+		   mmc_omap_show_enable_poll, mmc_omap_store_enable_poll);
+
+static void
+mmc_omap_start_command(struct mmc_omap_host *host, struct mmc_command *cmd)
+{
+	u32 cmdreg;
+	u32 resptype;
+	u32 cmdtype;
+
+	host->cmd = cmd;
+
+	resptype = 0;
+	cmdtype = 0;
+
+	/* Our hardware needs to know exact type */
+	switch (RSP_TYPE(mmc_resp_type(cmd))) {
+	case RSP_TYPE(MMC_RSP_R1):
+		/* resp 1, resp 1b */
+		resptype = 1;
+		break;
+	case RSP_TYPE(MMC_RSP_R2):
+		resptype = 2;
+		break;
+	case RSP_TYPE(MMC_RSP_R3):
+		resptype = 3;
+		break;
+	default:
+		break;
+	}
+
+	if (mmc_cmd_type(cmd) == MMC_CMD_ADTC) {
+		cmdtype = OMAP_MMC_CMDTYPE_ADTC;
+	} else if (mmc_cmd_type(cmd) == MMC_CMD_BC) {
+		cmdtype = OMAP_MMC_CMDTYPE_BC;
+	} else if (mmc_cmd_type(cmd) == MMC_CMD_BCR) {
+		cmdtype = OMAP_MMC_CMDTYPE_BCR;
+	} else {
+		cmdtype = OMAP_MMC_CMDTYPE_AC;
+	}
+
+	cmdreg = cmd->opcode | (resptype << 8) | (cmdtype << 12);
+
+	if (host->bus_mode == MMC_BUSMODE_OPENDRAIN)
+		cmdreg |= 1 << 6;
+
+	if (cmd->flags & MMC_RSP_BUSY)
+		cmdreg |= 1 << 11;
+
+	if (host->data && !(host->data->flags & MMC_DATA_WRITE))
+		cmdreg |= 1 << 15;
+
+	clk_enable(host->fclk);
+
+	OMAP_MMC_WRITE(host->base, CTO, 200);
+	OMAP_MMC_WRITE(host->base, ARGL, cmd->arg & 0xffff);
+	OMAP_MMC_WRITE(host->base, ARGH, cmd->arg >> 16);
+	OMAP_MMC_WRITE(host->base, IE,
+		       OMAP_MMC_STAT_A_EMPTY    | OMAP_MMC_STAT_A_FULL    |
+		       OMAP_MMC_STAT_CMD_CRC    | OMAP_MMC_STAT_CMD_TOUT  |
+		       OMAP_MMC_STAT_DATA_CRC   | OMAP_MMC_STAT_DATA_TOUT |
+		       OMAP_MMC_STAT_END_OF_CMD | OMAP_MMC_STAT_CARD_ERR  |
+		       OMAP_MMC_STAT_END_OF_DATA);
+	OMAP_MMC_WRITE(host->base, CMD, cmdreg);
+}
+
+static void
+mmc_omap_xfer_done(struct mmc_omap_host *host, struct mmc_data *data)
+{
+	if (host->dma_in_use) {
+		enum dma_data_direction dma_data_dir;
+
+		BUG_ON(host->dma_ch < 0);
+		if (data->error != MMC_ERR_NONE)
+			omap_stop_dma(host->dma_ch);
+		/* Release DMA channel lazily */
+		mod_timer(&host->dma_timer, jiffies + HZ);
+		if (data->flags & MMC_DATA_WRITE)
+			dma_data_dir = DMA_TO_DEVICE;
+		else
+			dma_data_dir = DMA_FROM_DEVICE;
+		dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->sg_len,
+			     dma_data_dir);
+	}
+	host->data = NULL;
+	host->sg_len = 0;
+	clk_disable(host->fclk);
+
+	/* NOTE:  MMC layer will sometimes poll-wait CMD13 next, issuing
+	 * dozens of requests until the card finishes writing data.
+	 * It'd be cheaper to just wait till an EOFB interrupt arrives...
+	 */
+
+	if (!data->stop) {
+		host->mrq = NULL;
+		mmc_request_done(host->mmc, data->mrq);
+		return;
+	}
+
+	mmc_omap_start_command(host, data->stop);
+}
+
+static void
+mmc_omap_end_of_data(struct mmc_omap_host *host, struct mmc_data *data)
+{
+	unsigned long flags;
+	int done;
+
+	if (!host->dma_in_use) {
+		mmc_omap_xfer_done(host, data);
+		return;
+	}
+	done = 0;
+	spin_lock_irqsave(&host->dma_lock, flags);
+	if (host->dma_done)
+		done = 1;
+	else
+		host->brs_received = 1;
+	spin_unlock_irqrestore(&host->dma_lock, flags);
+	if (done)
+		mmc_omap_xfer_done(host, data);
+}
+
+static void
+mmc_omap_dma_timer(unsigned long data)
+{
+	struct mmc_omap_host *host = (struct mmc_omap_host *) data;
+
+	BUG_ON(host->dma_ch < 0);
+	omap_free_dma(host->dma_ch);
+	host->dma_ch = -1;
+}
+
+static void
+mmc_omap_dma_done(struct mmc_omap_host *host, struct mmc_data *data)
+{
+	unsigned long flags;
+	int done;
+
+	done = 0;
+	spin_lock_irqsave(&host->dma_lock, flags);
+	if (host->brs_received)
+		done = 1;
+	else
+		host->dma_done = 1;
+	spin_unlock_irqrestore(&host->dma_lock, flags);
+	if (done)
+		mmc_omap_xfer_done(host, data);
+}
+
+static void
+mmc_omap_cmd_done(struct mmc_omap_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] =
+				OMAP_MMC_READ(host->base, RSP0) |
+				(OMAP_MMC_READ(host->base, RSP1) << 16);
+			cmd->resp[2] =
+				OMAP_MMC_READ(host->base, RSP2) |
+				(OMAP_MMC_READ(host->base, RSP3) << 16);
+			cmd->resp[1] =
+				OMAP_MMC_READ(host->base, RSP4) |
+				(OMAP_MMC_READ(host->base, RSP5) << 16);
+			cmd->resp[0] =
+				OMAP_MMC_READ(host->base, RSP6) |
+				(OMAP_MMC_READ(host->base, RSP7) << 16);
+		} else {
+			/* response types 1, 1b, 3, 4, 5, 6 */
+			cmd->resp[0] =
+				OMAP_MMC_READ(host->base, RSP6) |
+				(OMAP_MMC_READ(host->base, RSP7) << 16);
+		}
+	}
+
+	if (host->data == NULL || cmd->error != MMC_ERR_NONE) {
+		host->mrq = NULL;
+		clk_disable(host->fclk);
+		mmc_request_done(host->mmc, cmd->mrq);
+	}
+}
+
+/* PIO only */
+static void
+mmc_omap_sg_to_buf(struct mmc_omap_host *host)
+{
+	struct scatterlist *sg;
+
+	sg = host->data->sg + host->sg_idx;
+	host->buffer_bytes_left = sg->length;
+	host->buffer = page_address(sg->page) + sg->offset;
+	if (host->buffer_bytes_left > host->total_bytes_left)
+		host->buffer_bytes_left = host->total_bytes_left;
+}
+
+/* PIO only */
+static void
+mmc_omap_xfer_data(struct mmc_omap_host *host, int write)
+{
+	int n;
+	void __iomem *reg;
+	u16 *p;
+
+	if (host->buffer_bytes_left == 0) {
+		host->sg_idx++;
+		BUG_ON(host->sg_idx == host->sg_len);
+		mmc_omap_sg_to_buf(host);
+	}
+	n = 64;
+	if (n > host->buffer_bytes_left)
+		n = host->buffer_bytes_left;
+	host->buffer_bytes_left -= n;
+	host->total_bytes_left -= n;
+	host->data->bytes_xfered += n;
+
+	if (write) {
+		__raw_writesw(host->base + OMAP_MMC_REG_DATA, host->buffer, n);
+	} else {
+		__raw_readsw(host->base + OMAP_MMC_REG_DATA, host->buffer, n);
+	}
+}
+
+static inline void mmc_omap_report_irq(u16 status)
+{
+	static const char *mmc_omap_status_bits[] = {
+		"EOC", "CD", "CB", "BRS", "EOFB", "DTO", "DCRC", "CTO",
+		"CCRC", "CRW", "AF", "AE", "OCRB", "CIRQ", "CERR"
+	};
+	int i, c = 0;
+
+	for (i = 0; i < ARRAY_SIZE(mmc_omap_status_bits); i++)
+		if (status & (1 << i)) {
+			if (c)
+				printk(" ");
+			printk("%s", mmc_omap_status_bits[i]);
+			c++;
+		}
+}
+
+static irqreturn_t mmc_omap_irq(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct mmc_omap_host * host = (struct mmc_omap_host *)dev_id;
+	u16 status;
+	int end_command;
+	int end_transfer;
+	int transfer_error;
+
+	if (host->cmd == NULL && host->data == NULL) {
+		status = OMAP_MMC_READ(host->base, STAT);
+		dev_info(mmc_dev(host->mmc),"spurious irq 0x%04x\n", status);
+		if (status != 0) {
+			OMAP_MMC_WRITE(host->base, STAT, status);
+			OMAP_MMC_WRITE(host->base, IE, 0);
+		}
+		return IRQ_HANDLED;
+	}
+
+	end_command = 0;
+	end_transfer = 0;
+	transfer_error = 0;
+
+	while ((status = OMAP_MMC_READ(host->base, STAT)) != 0) {
+		OMAP_MMC_WRITE(host->base, STAT, status);
+#ifdef CONFIG_MMC_DEBUG
+		dev_dbg(mmc_dev(host->mmc), "MMC IRQ %04x (CMD %d): ",
+			status, host->cmd != NULL ? host->cmd->opcode : -1);
+		mmc_omap_report_irq(status);
+		printk("\n");
+#endif
+		if (host->total_bytes_left) {
+			if ((status & OMAP_MMC_STAT_A_FULL) ||
+			    (status & OMAP_MMC_STAT_END_OF_DATA))
+				mmc_omap_xfer_data(host, 0);
+			if (status & OMAP_MMC_STAT_A_EMPTY)
+				mmc_omap_xfer_data(host, 1);
+		}
+
+		if (status & OMAP_MMC_STAT_END_OF_DATA) {
+			end_transfer = 1;
+		}
+
+		if (status & OMAP_MMC_STAT_DATA_TOUT) {
+			dev_dbg(mmc_dev(host->mmc), "data timeout\n");
+			if (host->data) {
+				host->data->error |= MMC_ERR_TIMEOUT;
+				transfer_error = 1;
+			}
+		}
+
+		if (status & OMAP_MMC_STAT_DATA_CRC) {
+			if (host->data) {
+				host->data->error |= MMC_ERR_BADCRC;
+				dev_dbg(mmc_dev(host->mmc),
+					 "data CRC error, bytes left %d\n",
+					host->total_bytes_left);
+				transfer_error = 1;
+			} else {
+				dev_dbg(mmc_dev(host->mmc), "data CRC error\n");
+			}
+		}
+
+		if (status & OMAP_MMC_STAT_CMD_TOUT) {
+			/* Timeouts are routine with some commands */
+			if (host->cmd) {
+				if (host->cmd->opcode != MMC_ALL_SEND_CID &&
+						host->cmd->opcode !=
+						MMC_SEND_OP_COND &&
+						host->cmd->opcode !=
+						MMC_APP_CMD &&
+						!mmc_omap_cover_is_open(host))
+					dev_err(mmc_dev(host->mmc),
+						"command timeout, CMD %d\n",
+						host->cmd->opcode);
+				host->cmd->error = MMC_ERR_TIMEOUT;
+				end_command = 1;
+			}
+		}
+
+		if (status & OMAP_MMC_STAT_CMD_CRC) {
+			if (host->cmd) {
+				dev_err(mmc_dev(host->mmc),
+					"command CRC error (CMD%d, arg 0x%08x)\n",
+					host->cmd->opcode, host->cmd->arg);
+				host->cmd->error = MMC_ERR_BADCRC;
+				end_command = 1;
+			} else
+				dev_err(mmc_dev(host->mmc),
+					"command CRC error without cmd?\n");
+		}
+
+		if (status & OMAP_MMC_STAT_CARD_ERR) {
+			if (host->cmd && host->cmd->opcode == MMC_STOP_TRANSMISSION) {
+				u32 response = OMAP_MMC_READ(host->base, RSP6)
+					| (OMAP_MMC_READ(host->base, RSP7) << 16);
+				/* STOP sometimes sets must-ignore bits */
+				if (!(response & (R1_CC_ERROR
+								| R1_ILLEGAL_COMMAND
+								| R1_COM_CRC_ERROR))) {
+					end_command = 1;
+					continue;
+				}
+			}
+
+			dev_dbg(mmc_dev(host->mmc), "card status error (CMD%d)\n",
+				host->cmd->opcode);
+			if (host->cmd) {
+				host->cmd->error = MMC_ERR_FAILED;
+				end_command = 1;
+			}
+			if (host->data) {
+				host->data->error = MMC_ERR_FAILED;
+				transfer_error = 1;
+			}
+		}
+
+		/*
+		 * NOTE: On 1610 the END_OF_CMD may come too early when
+		 * starting a write 
+		 */
+		if ((status & OMAP_MMC_STAT_END_OF_CMD) &&
+		    (!(status & OMAP_MMC_STAT_A_EMPTY))) {
+			end_command = 1;
+		}
+	}
+
+	if (end_command) {
+		mmc_omap_cmd_done(host, host->cmd);
+	}
+	if (transfer_error)
+		mmc_omap_xfer_done(host, host->data);
+	else if (end_transfer)
+		mmc_omap_end_of_data(host, host->data);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mmc_omap_switch_irq(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct mmc_omap_host *host = (struct mmc_omap_host *) dev_id;
+
+	schedule_work(&host->switch_work);
+
+	return IRQ_HANDLED;
+}
+
+static void mmc_omap_switch_timer(unsigned long arg)
+{
+	struct mmc_omap_host *host = (struct mmc_omap_host *) arg;
+
+	schedule_work(&host->switch_work);
+}
+
+/* FIXME: Handle card insertion and removal properly. Maybe use a mask
+ * for MMC state? */
+static void mmc_omap_switch_callback(unsigned long data, u8 mmc_mask)
+{
+}
+
+static void mmc_omap_switch_handler(void *data)
+{
+	struct mmc_omap_host *host = (struct mmc_omap_host *) data;
+	struct mmc_card *card;
+	static int complained = 0;
+	int cards = 0, cover_open;
+
+	if (host->switch_pin == -1)
+		return;
+	cover_open = mmc_omap_cover_is_open(host);
+	if (cover_open != host->switch_last_state) {
+		kobject_uevent(&host->dev->kobj, KOBJ_CHANGE);
+		host->switch_last_state = cover_open;
+	}
+	mmc_detect_change(host->mmc, 0);
+	list_for_each_entry(card, &host->mmc->cards, node) {
+		if (mmc_card_present(card))
+			cards++;
+	}
+	if (mmc_omap_cover_is_open(host)) {
+		if (!complained) {
+			dev_info(mmc_dev(host->mmc), "cover is open");
+			complained = 1;
+		}
+		if (mmc_omap_enable_poll)
+			mod_timer(&host->switch_timer, jiffies +
+				msecs_to_jiffies(OMAP_MMC_SWITCH_POLL_DELAY));
+	} else {
+		complained = 0;
+	}
+}
+
+/* Prepare to transfer the next segment of a scatterlist */
+static void
+mmc_omap_prepare_dma(struct mmc_omap_host *host, struct mmc_data *data)
+{
+	int dma_ch = host->dma_ch;
+	unsigned long data_addr;
+	u16 buf, frame;
+	u32 count;
+	struct scatterlist *sg = &data->sg[host->sg_idx];
+	int src_port = 0;
+	int dst_port = 0;
+	int sync_dev = 0;
+
+	data_addr = io_v2p((u32) host->base) + OMAP_MMC_REG_DATA;
+	frame = 1 << data->blksz_bits;
+	count = sg_dma_len(sg);
+
+	if ((data->blocks == 1) && (count > (1 << data->blksz_bits)))
+		count = frame;
+
+	host->dma_len = count;
+
+	/* FIFO is 16x2 bytes on 15xx, and 32x2 bytes on 16xx and 24xx.
+	 * Use 16 or 32 word frames when the blocksize is at least that large.
+	 * Blocksize is usually 512 bytes; but not for some SD reads.
+	 */
+	if (cpu_is_omap15xx() && frame > 32)
+		frame = 32;
+	else if (frame > 64)
+		frame = 64;
+	count /= frame;
+	frame >>= 1;
+
+	if (!(data->flags & MMC_DATA_WRITE)) {
+		buf = 0x800f | ((frame - 1) << 8);
+
+		if (cpu_class_is_omap1()) {
+			src_port = OMAP_DMA_PORT_TIPB;
+			dst_port = OMAP_DMA_PORT_EMIFF;
+		}
+		if (cpu_is_omap24xx())
+			sync_dev = OMAP24XX_DMA_MMC1_RX;
+
+		omap_set_dma_src_params(dma_ch, src_port,
+					OMAP_DMA_AMODE_CONSTANT,
+					data_addr, 0, 0);
+		omap_set_dma_dest_params(dma_ch, dst_port,
+					 OMAP_DMA_AMODE_POST_INC,
+					 sg_dma_address(sg), 0, 0);
+		omap_set_dma_dest_data_pack(dma_ch, 1);
+		omap_set_dma_dest_burst_mode(dma_ch, OMAP_DMA_DATA_BURST_4);
+	} else {
+		buf = 0x0f80 | ((frame - 1) << 0);
+
+		if (cpu_class_is_omap1()) {
+			src_port = OMAP_DMA_PORT_EMIFF;
+			dst_port = OMAP_DMA_PORT_TIPB;
+		}
+		if (cpu_is_omap24xx())
+			sync_dev = OMAP24XX_DMA_MMC1_TX;
+
+		omap_set_dma_dest_params(dma_ch, dst_port,
+					 OMAP_DMA_AMODE_CONSTANT,
+					 data_addr, 0, 0);
+		omap_set_dma_src_params(dma_ch, src_port,
+					OMAP_DMA_AMODE_POST_INC,
+					sg_dma_address(sg), 0, 0);
+		omap_set_dma_src_data_pack(dma_ch, 1);
+		omap_set_dma_src_burst_mode(dma_ch, OMAP_DMA_DATA_BURST_4);
+	}
+
+	/* Max limit for DMA frame count is 0xffff */
+	if (unlikely(count > 0xffff))
+		BUG();
+
+	OMAP_MMC_WRITE(host->base, BUF, buf);
+	omap_set_dma_transfer_params(dma_ch, OMAP_DMA_DATA_TYPE_S16,
+				     frame, count, OMAP_DMA_SYNC_FRAME,
+				     sync_dev, 0);
+}
+
+/* A scatterlist segment completed */
+static void mmc_omap_dma_cb(int lch, u16 ch_status, void *data)
+{
+	struct mmc_omap_host *host = (struct mmc_omap_host *) data;
+	struct mmc_data *mmcdat = host->data;
+
+	if (unlikely(host->dma_ch < 0)) {
+		dev_err(mmc_dev(host->mmc), "DMA callback while DMA not
+				enabled\n");
+		return;
+	}
+	/* FIXME: We really should do something to _handle_ the errors */
+	if (ch_status & OMAP_DMA_TOUT_IRQ) {
+		dev_err(mmc_dev(host->mmc),"DMA timeout\n");
+		return;
+	}
+	if (ch_status & OMAP_DMA_DROP_IRQ) {
+		dev_err(mmc_dev(host->mmc), "DMA sync error\n");
+		return;
+	}
+	if (!(ch_status & OMAP_DMA_BLOCK_IRQ)) {
+		return;
+	}
+	mmcdat->bytes_xfered += host->dma_len;
+	host->sg_idx++;
+	if (host->sg_idx < host->sg_len) {
+		mmc_omap_prepare_dma(host, host->data);
+		omap_start_dma(host->dma_ch);
+	} else
+		mmc_omap_dma_done(host, host->data);
+}
+
+static int mmc_omap_get_dma_channel(struct mmc_omap_host *host, struct mmc_data *data)
+{
+	const char *dev_name;
+	int sync_dev, dma_ch, is_read, r;
+
+	is_read = !(data->flags & MMC_DATA_WRITE);
+	del_timer_sync(&host->dma_timer);
+	if (host->dma_ch >= 0) {
+		if (is_read == host->dma_is_read)
+			return 0;
+		omap_free_dma(host->dma_ch);
+		host->dma_ch = -1;
+	}
+
+	if (is_read) {
+		if (host->id == 1) {
+			sync_dev = OMAP_DMA_MMC_RX;
+			dev_name = "MMC1 read";
+		} else {
+			sync_dev = OMAP_DMA_MMC2_RX;
+			dev_name = "MMC2 read";
+		}
+	} else {
+		if (host->id == 1) {
+			sync_dev = OMAP_DMA_MMC_TX;
+			dev_name = "MMC1 write";
+		} else {
+			sync_dev = OMAP_DMA_MMC2_TX;
+			dev_name = "MMC2 write";
+		}
+	}
+	r = omap_request_dma(sync_dev, dev_name, mmc_omap_dma_cb,
+			     host, &dma_ch);
+	if (r != 0) {
+		dev_dbg(mmc_dev(host->mmc), "omap_request_dma() failed with %d\n", r);
+		return r;
+	}
+	host->dma_ch = dma_ch;
+	host->dma_is_read = is_read;
+
+	return 0;
+}
+
+static inline void set_cmd_timeout(struct mmc_omap_host *host, struct mmc_request *req)
+{
+	u16 reg;
+
+	reg = OMAP_MMC_READ(host->base, SDIO);
+	reg &= ~(1 << 5);
+	OMAP_MMC_WRITE(host->base, SDIO, reg);
+	/* Set maximum timeout */
+	OMAP_MMC_WRITE(host->base, CTO, 0xff);
+}
+
+static inline void set_data_timeout(struct mmc_omap_host *host, struct mmc_request *req)
+{
+	int timeout;
+	u16 reg;
+
+	/* Convert ns to clock cycles by assuming 20MHz frequency
+	 * 1 cycle at 20MHz = 500 ns
+	 */
+	timeout = req->data->timeout_clks + req->data->timeout_ns / 500;
+
+	/* Check if we need to use timeout multiplier register */
+	reg = OMAP_MMC_READ(host->base, SDIO);
+	if (timeout > 0xffff) {
+		reg |= (1 << 5);
+		timeout /= 1024;
+	} else
+		reg &= ~(1 << 5);
+	OMAP_MMC_WRITE(host->base, SDIO, reg);
+	OMAP_MMC_WRITE(host->base, DTO, timeout);
+}
+
+static void
+mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req)
+{
+	struct mmc_data *data = req->data;
+	int i, use_dma, block_size;
+	unsigned sg_len;
+
+	host->data = data;
+	if (data == NULL) {
+		OMAP_MMC_WRITE(host->base, BLEN, 0);
+		OMAP_MMC_WRITE(host->base, NBLK, 0);
+		OMAP_MMC_WRITE(host->base, BUF, 0);
+		host->dma_in_use = 0;
+		set_cmd_timeout(host, req);
+		return;
+	}
+
+
+	block_size = 1 << data->blksz_bits;
+
+	OMAP_MMC_WRITE(host->base, NBLK, data->blocks - 1);
+	OMAP_MMC_WRITE(host->base, BLEN, block_size - 1);
+	set_data_timeout(host, req);
+
+	/* cope with calling layer confusion; it issues "single
+	 * block" writes using multi-block scatterlists.
+	 */
+	sg_len = (data->blocks == 1) ? 1 : data->sg_len;
+
+	/* Only do DMA for entire blocks */
+	use_dma = host->use_dma;
+	if (use_dma) {
+		for (i = 0; i < sg_len; i++) {
+			if ((data->sg[i].length % block_size) != 0) {
+				use_dma = 0;
+				break;
+			}
+		}
+	}
+
+	host->sg_idx = 0;
+	if (use_dma) {
+		if (mmc_omap_get_dma_channel(host, data) == 0) {
+			enum dma_data_direction dma_data_dir;
+
+			if (data->flags & MMC_DATA_WRITE)
+				dma_data_dir = DMA_TO_DEVICE;
+			else
+				dma_data_dir = DMA_FROM_DEVICE;
+
+			host->sg_len = dma_map_sg(mmc_dev(host->mmc), data->sg,
+						sg_len, dma_data_dir);
+			host->total_bytes_left = 0;
+			mmc_omap_prepare_dma(host, req->data);
+			host->brs_received = 0;
+			host->dma_done = 0;
+			host->dma_in_use = 1;
+		} else
+			use_dma = 0;
+	}
+
+	/* Revert to PIO? */
+	if (!use_dma) {
+		OMAP_MMC_WRITE(host->base, BUF, 0x1f1f);
+		host->total_bytes_left = data->blocks * block_size;
+		host->sg_len = sg_len;
+		mmc_omap_sg_to_buf(host);
+		host->dma_in_use = 0;
+	}
+}
+
+static void mmc_omap_request(struct mmc_host *mmc, struct mmc_request *req)
+{
+	struct mmc_omap_host *host = mmc_priv(mmc);
+
+	WARN_ON(host->mrq != NULL);
+
+	host->mrq = req;
+
+	/* only touch fifo AFTER the controller readies it */
+	mmc_omap_prepare_data(host, req);
+	mmc_omap_start_command(host, req->cmd);
+	if (host->dma_in_use)
+		omap_start_dma(host->dma_ch);
+}
+
+static void innovator_fpga_socket_power(int on)
+{
+#if defined(CONFIG_MACH_OMAP_INNOVATOR) && defined(CONFIG_ARCH_OMAP15XX)
+
+	if (on) {
+		fpga_write(fpga_read(OMAP1510_FPGA_POWER) | (1 << 3),
+		     OMAP1510_FPGA_POWER);
+	} else {
+		fpga_write(fpga_read(OMAP1510_FPGA_POWER) & ~(1 << 3),
+		     OMAP1510_FPGA_POWER);
+	}
+#endif
+}
+
+/*
+ * Turn the socket power on/off. Innovator uses FPGA, most boards
+ * probably use GPIO.
+ */
+static void mmc_omap_power(struct mmc_omap_host *host, int on)
+{
+	if (on) {
+		if (machine_is_omap_innovator())
+			innovator_fpga_socket_power(1);
+		else if (machine_is_omap_h2())
+			tps65010_set_gpio_out_value(GPIO3, HIGH);
+		else if (machine_is_omap_h3())
+			/* GPIO 4 of TPS65010 sends SD_EN signal */
+			tps65010_set_gpio_out_value(GPIO4, HIGH);
+		else if (cpu_is_omap24xx()) {
+			u16 reg = OMAP_MMC_READ(host->base, CON);
+			OMAP_MMC_WRITE(host->base, CON, reg | (1 << 11));
+		} else
+			if (host->power_pin >= 0)
+				omap_set_gpio_dataout(host->power_pin, 1);
+	} else {
+		if (machine_is_omap_innovator())
+			innovator_fpga_socket_power(0);
+		else if (machine_is_omap_h2())
+			tps65010_set_gpio_out_value(GPIO3, LOW);
+		else if (machine_is_omap_h3())
+			tps65010_set_gpio_out_value(GPIO4, LOW);
+		else if (cpu_is_omap24xx()) {
+			u16 reg = OMAP_MMC_READ(host->base, CON);
+			OMAP_MMC_WRITE(host->base, CON, reg & ~(1 << 11));
+		} else
+			if (host->power_pin >= 0)
+				omap_set_gpio_dataout(host->power_pin, 0);
+	}
+}
+
+static void mmc_omap_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct mmc_omap_host *host = mmc_priv(mmc);
+	int dsor;
+	int realclock, i;
+
+	realclock = ios->clock;
+
+	if (ios->clock == 0)
+		dsor = 0;
+	else {
+		int func_clk_rate = clk_get_rate(host->fclk);
+
+		dsor = func_clk_rate / realclock;
+		if (dsor < 1)
+			dsor = 1;
+
+		if (func_clk_rate / dsor > realclock)
+			dsor++;
+
+		if (dsor > 250)
+			dsor = 250;
+		dsor++;
+
+		if (ios->bus_width == MMC_BUS_WIDTH_4)
+			dsor |= 1 << 15;
+	}
+
+	switch (ios->power_mode) {
+	case MMC_POWER_OFF:
+		mmc_omap_power(host, 0);
+		break;
+	case MMC_POWER_UP:
+	case MMC_POWER_ON:
+		mmc_omap_power(host, 1);
+		dsor |= 1<<11;
+		break;
+	}
+
+	host->bus_mode = ios->bus_mode;
+	host->hw_bus_mode = host->bus_mode;
+
+	clk_enable(host->fclk);
+
+	/* On insanely high arm_per frequencies something sometimes
+	 * goes somehow out of sync, and the POW bit is not being set,
+	 * which results in the while loop below getting stuck.
+	 * Writing to the CON register twice seems to do the trick. */
+	for (i = 0; i < 2; i++)
+		OMAP_MMC_WRITE(host->base, CON, dsor);
+	if (ios->power_mode == MMC_POWER_UP) {
+		/* Send clock cycles, poll completion */
+		OMAP_MMC_WRITE(host->base, IE, 0);
+		OMAP_MMC_WRITE(host->base, STAT, 0xffff);
+		OMAP_MMC_WRITE(host->base, CMD, 1<<7);
+		while (0 == (OMAP_MMC_READ(host->base, STAT) & 1));
+		OMAP_MMC_WRITE(host->base, STAT, 1);
+	}
+	clk_disable(host->fclk);
+}
+
+static int mmc_omap_get_ro(struct mmc_host *mmc)
+{
+	struct mmc_omap_host *host = mmc_priv(mmc);
+
+	return host->wp_pin && omap_get_gpio_datain(host->wp_pin);
+}
+
+static struct mmc_host_ops mmc_omap_ops = {
+	.request	= mmc_omap_request,
+	.set_ios	= mmc_omap_set_ios,
+	.get_ro		= mmc_omap_get_ro,
+};
+
+static int __init mmc_omap_probe(struct platform_device *pdev)
+{
+	struct omap_mmc_conf *minfo = pdev->dev.platform_data;
+	struct mmc_host *mmc;
+	struct mmc_omap_host *host = NULL;
+	int ret = 0;
+	
+	if (platform_get_resource(pdev, IORESOURCE_MEM, 0) ||
+			platform_get_irq(pdev, IORESOURCE_IRQ, 0)) {
+		dev_err(&pdev->dev, "mmc_omap_probe: invalid resource type\n");
+		return -ENODEV;
+	}
+
+	if (!request_mem_region(pdev->resource[0].start,
+				pdev->resource[0].end - pdev->resource[0].start + 1,
+				pdev->name)) {
+		dev_dbg(&pdev->dev, "request_mem_region failed\n");
+		return -EBUSY;
+	}
+
+	mmc = mmc_alloc_host(sizeof(struct mmc_omap_host), &pdev->dev);
+	if (!mmc) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	host = mmc_priv(mmc);
+	host->mmc = mmc;
+
+	spin_lock_init(&host->dma_lock);
+	init_timer(&host->dma_timer);
+	host->dma_timer.function = mmc_omap_dma_timer;
+	host->dma_timer.data = (unsigned long) host;
+
+	host->id = pdev->id;
+
+	if (cpu_is_omap24xx()) {
+		host->iclk = clk_get(&pdev->dev, "mmc_ick");
+		if (IS_ERR(host->iclk))
+			goto out;
+		clk_enable(host->iclk);
+	}
+
+	if (!cpu_is_omap24xx())
+		host->fclk = clk_get(&pdev->dev, "mmc_ck");
+	else
+		host->fclk = clk_get(&pdev->dev, "mmc_fck");
+
+	if (IS_ERR(host->fclk)) {
+		ret = PTR_ERR(host->fclk);
+		goto out;
+	}
+
+	/* REVISIT:
+	 * Also, use minfo->cover to decide how to manage
+	 * the card detect sensing.
+	 */
+	host->power_pin = minfo->power_pin;
+	host->switch_pin = minfo->switch_pin;
+	host->wp_pin = minfo->wp_pin;
+	host->use_dma = 1;
+	host->dma_ch = -1;
+
+	host->irq = pdev->resource[1].start;
+	host->base = ioremap(pdev->res.start, SZ_4K);
+	if (!host->base) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	 if (minfo->wire4)
+		 mmc->caps |= MMC_CAP_4_BIT_DATA;
+
+	mmc->ops = &mmc_omap_ops;
+	mmc->f_min = 400000;
+	mmc->f_max = 24000000;
+	mmc->ocr_avail = MMC_VDD_32_33|MMC_VDD_33_34;
+
+	/* Use scatterlist DMA to reduce per-transfer costs.
+	 * NOTE max_seg_size assumption that small blocks aren't
+	 * normally used (except e.g. for reading SD registers).
+	 */
+	mmc->max_phys_segs = 32;
+	mmc->max_hw_segs = 32;
+	mmc->max_sectors = 256; /* NBLK max 11-bits, OMAP also limited by DMA */
+	mmc->max_seg_size = mmc->max_sectors * 512;
+
+	if (host->power_pin >= 0) {
+		if ((ret = omap_request_gpio(host->power_pin)) != 0) {
+			dev_err(mmc_dev(host->mmc), "Unable to get GPIO
+					pin for MMC power\n");
+			goto out;
+		}
+		omap_set_gpio_direction(host->power_pin, 0);
+	}
+
+	ret = request_irq(host->irq, mmc_omap_irq, 0, DRIVER_NAME, host);
+	if (ret)
+		goto out;
+
+	host->dev = &pdev->dev;
+	platform_set_drvdata(pdev, host);
+
+	mmc_add_host(mmc);
+
+	if (host->switch_pin >= 0) {
+		INIT_WORK(&host->switch_work, mmc_omap_switch_handler, host);
+		init_timer(&host->switch_timer);
+		host->switch_timer.function = mmc_omap_switch_timer;
+		host->switch_timer.data = (unsigned long) host;
+		if (omap_request_gpio(host->switch_pin) != 0) {
+			dev_warn(mmc_dev(host->mmc), "Unable to get GPIO pin for MMC cover switch\n");
+			host->switch_pin = -1;
+			goto no_switch;
+		}
+
+		omap_set_gpio_direction(host->switch_pin, 1);
+		ret = request_irq(OMAP_GPIO_IRQ(host->switch_pin),
+				  mmc_omap_switch_irq, SA_TRIGGER_RISING, DRIVER_NAME, host);
+		if (ret) {
+			dev_warn(mmc_dev(host->mmc), "Unable to get IRQ for MMC cover switch\n");
+			omap_free_gpio(host->switch_pin);
+			host->switch_pin = -1;
+			goto no_switch;
+		}
+		ret = device_create_file(&pdev->dev, &dev_attr_cover_switch);
+		if (ret == 0) {
+			ret = device_create_file(&pdev->dev, &dev_attr_enable_poll);
+			if (ret != 0)
+				device_remove_file(&pdev->dev, &dev_attr_cover_switch);
+		}
+		if (ret) {
+			dev_wan(mmc_dev(host->mmc), "Unable to create sysfs attributes\n");
+			free_irq(OMAP_GPIO_IRQ(host->switch_pin), host);
+			omap_free_gpio(host->switch_pin);
+			host->switch_pin = -1;
+			goto no_switch;
+		}
+		if (mmc_omap_enable_poll && mmc_omap_cover_is_open(host))
+			schedule_work(&host->switch_work);
+	}
+
+no_switch:
+	return 0;
+
+out:
+	/* FIXME: Free other resources too. */
+	if (host) {
+		if (host->iclk && !IS_ERR(host->iclk))
+			clk_put(host->iclk);
+		if (host->fclk && !IS_ERR(host->fclk))
+			clk_put(host->fclk);
+		mmc_free_host(host->mmc);
+	}
+	return ret;
+}
+
+static int mmc_omap_remove(struct platform_device *pdev)
+{
+	struct mmc_omap_host *host = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	if (host) {
+		mmc_remove_host(host->mmc);
+		free_irq(host->irq, host);
+
+		if (host->power_pin >= 0)
+			omap_free_gpio(host->power_pin);
+		if (host->switch_pin >= 0) {
+			device_remove_file(&pdev->dev, &dev_attr_enable_poll);
+			device_remove_file(&pdev->dev, &dev_attr_cover_switch);
+			free_irq(OMAP_GPIO_IRQ(host->switch_pin), host);
+			omap_free_gpio(host->switch_pin);
+			host->switch_pin = -1;
+			del_timer_sync(&host->switch_timer);
+			flush_scheduled_work();
+		}
+		if (host->iclk && !IS_ERR(host->iclk))
+			clk_put(host->iclk);
+		if (host->fclk && !IS_ERR(host->fclk))
+			clk_put(host->fclk);
+		mmc_free_host(host->mmc);
+	}
+
+	release_mem_region(pdev->resource[0].start,
+			pdev->resource[0].end - pdev->resource[0].start + 1);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int mmc_omap_suspend(struct platform_device *pdev, pm_message_t mesg)
+{
+	int ret = 0;
+	struct mmc_omap_host *host = platform_get_drvdata(pdev);
+
+	if (host && host->suspended)
+		return 0;
+
+	if (host) {
+		ret = mmc_suspend_host(host->mmc, mesg);
+		if (ret == 0)
+			host->suspended = 1;
+	}
+	return ret;
+}
+
+static int mmc_omap_resume(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct mmc_omap_host *host = platform_get_drvdata(pdev);
+
+	if (host && !host->suspended)
+		return 0;
+
+	if (host) {
+		ret = mmc_resume_host(host->mmc);
+		if (ret == 0)
+			host->suspended = 0;
+	}
+
+	return ret;
+}
+#else
+#define mmc_omap_suspend	NULL
+#define mmc_omap_resume		NULL
+#endif
+
+static struct platform_driver mmc_omap_driver = {
+	.probe		= mmc_omap_probe,
+	.remove		= mmc_omap_remove,
+	.suspend	= mmc_omap_suspend,
+	.resume		= mmc_omap_resume,
+	.driver		= {
+		.name	= DRIVER_NAME,
+	},
+};
+
+static int __init mmc_omap_init(void)
+{
+	return platform_driver_register(&mmc_omap_driver);
+}
+
+static void __exit mmc_omap_exit(void)
+{
+	platform_driver_unregister(&mmc_omap_driver);
+}
+
+module_init(mmc_omap_init);
+module_exit(mmc_omap_exit);
+
+MODULE_DESCRIPTION("OMAP Multimedia Card driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS(DRIVER_NAME);
+MODULE_AUTHOR("Juha Yrj�l�");

drivers/mmc/omap.h

···
+#ifndef	DRIVERS_MEDIA_MMC_OMAP_H
+#define	DRIVERS_MEDIA_MMC_OMAP_H
+
+#define	OMAP_MMC_REG_CMD	0x00
+#define	OMAP_MMC_REG_ARGL	0x04
+#define	OMAP_MMC_REG_ARGH	0x08
+#define	OMAP_MMC_REG_CON	0x0c
+#define	OMAP_MMC_REG_STAT	0x10
+#define	OMAP_MMC_REG_IE		0x14
+#define	OMAP_MMC_REG_CTO	0x18
+#define	OMAP_MMC_REG_DTO	0x1c
+#define	OMAP_MMC_REG_DATA	0x20
+#define	OMAP_MMC_REG_BLEN	0x24
+#define	OMAP_MMC_REG_NBLK	0x28
+#define	OMAP_MMC_REG_BUF	0x2c
+#define OMAP_MMC_REG_SDIO	0x34
+#define	OMAP_MMC_REG_REV	0x3c
+#define	OMAP_MMC_REG_RSP0	0x40
+#define	OMAP_MMC_REG_RSP1	0x44
+#define	OMAP_MMC_REG_RSP2	0x48
+#define	OMAP_MMC_REG_RSP3	0x4c
+#define	OMAP_MMC_REG_RSP4	0x50
+#define	OMAP_MMC_REG_RSP5	0x54
+#define	OMAP_MMC_REG_RSP6	0x58
+#define	OMAP_MMC_REG_RSP7	0x5c
+#define	OMAP_MMC_REG_IOSR	0x60
+#define	OMAP_MMC_REG_SYSC	0x64
+#define	OMAP_MMC_REG_SYSS	0x68
+
+#define	OMAP_MMC_STAT_CARD_ERR		(1 << 14)
+#define	OMAP_MMC_STAT_CARD_IRQ		(1 << 13)
+#define	OMAP_MMC_STAT_OCR_BUSY		(1 << 12)
+#define	OMAP_MMC_STAT_A_EMPTY		(1 << 11)
+#define	OMAP_MMC_STAT_A_FULL		(1 << 10)
+#define	OMAP_MMC_STAT_CMD_CRC		(1 <<  8)
+#define	OMAP_MMC_STAT_CMD_TOUT		(1 <<  7)
+#define	OMAP_MMC_STAT_DATA_CRC		(1 <<  6)
+#define	OMAP_MMC_STAT_DATA_TOUT		(1 <<  5)
+#define	OMAP_MMC_STAT_END_BUSY		(1 <<  4)
+#define	OMAP_MMC_STAT_END_OF_DATA	(1 <<  3)
+#define	OMAP_MMC_STAT_CARD_BUSY		(1 <<  2)
+#define	OMAP_MMC_STAT_END_OF_CMD	(1 <<  0)
+
+#define OMAP_MMC_READ(base, reg)	__raw_readw((base) + OMAP_MMC_REG_##reg)
+#define OMAP_MMC_WRITE(base, reg, val)	__raw_writew((val), (base) + OMAP_MMC_REG_##reg)
+
+/*
+ * Command types
+ */
+#define OMAP_MMC_CMDTYPE_BC	0
+#define OMAP_MMC_CMDTYPE_BCR	1
+#define OMAP_MMC_CMDTYPE_AC	2
+#define OMAP_MMC_CMDTYPE_ADTC	3
+
+#endif