Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc: (24 commits)
  MMC: Use timeout values from CSR
  MMC: CSD and CID timeout values
  sdhci: 'scratch' may be used uninitialized
  mmc: explicitly mention SDIO support in Kconfig
  mmc: remove redundant "depends on"
  Fix comment in include/linux/mmc/host.h
  sdio: high-speed support
  mmc_block: hard code 512 byte block size
  sdhci: force high speed capability on some controllers
  mmc_block: filter out PC requests
  mmc_block: indicate strict ordering
  mmc_block: inform block layer about sector count restriction
  sdio: give sdio irq thread a host specific name
  sdio: make sleep on error interruptable
  sdhci: reduce card detection delay
  sdhci: let the controller wait for busy state to end
  atmel-mci: Add missing flush_dcache_page() in PIO transfer code
  atmel-mci: Don't overwrite error bits when NOTBUSY is set
  atmel-mci: Add experimental DMA support
  atmel-mci: support multiple mmc slots
  ...

14 files changed, 1153 insertions, 475 deletions

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index c0b41e8bcd9..f2eeb38efa6 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -3,13 +3,14 @@
 #
 
 menuconfig MMC
-	tristate "MMC/SD card support"
+	tristate "MMC/SD/SDIO card support"
 	depends on HAS_IOMEM
 	help
-	  MMC is the "multi-media card" bus protocol.
+	  This selects MultiMediaCard, Secure Digital and Secure
+	  Digital I/O support.
 
-	  If you want MMC support, you should say Y here and also
-	  to the specific driver for your MMC interface.
+	  If you want MMC/SD/SDIO support, you should say Y here and
+	  also to your specific host controller driver.
 
 config MMC_DEBUG
 	bool "MMC debugging"
diff --git a/drivers/mmc/card/Kconfig b/drivers/mmc/card/Kconfig
index dd0f398ee2f..3f2a912659a 100644
--- a/drivers/mmc/card/Kconfig
+++ b/drivers/mmc/card/Kconfig
@@ -2,7 +2,7 @@
 # MMC/SD card drivers
 #
 
-comment "MMC/SD Card Drivers"
+comment "MMC/SD/SDIO Card Drivers"
 
 config MMC_BLOCK
 	tristate "MMC block device driver"
@@ -34,7 +34,6 @@ config MMC_BLOCK_BOUNCE
 
 config SDIO_UART
 	tristate "SDIO UART/GPS class support"
-	depends on MMC
 	help
 	  SDIO function driver for SDIO cards that implements the UART
 	  class, as well as the GPS class which appears like a UART.
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index efacee0404a..24c97d3d16b 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -58,7 +58,6 @@ struct mmc_blk_data {
 	struct mmc_queue queue;
 
 	unsigned int	usage;
-	unsigned int	block_bits;
 	unsigned int	read_only;
 };
 
@@ -216,8 +215,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 	struct mmc_blk_data *md = mq->data;
 	struct mmc_card *card = md->queue.card;
 	struct mmc_blk_request brq;
-	int ret = 1, data_size, i;
-	struct scatterlist *sg;
+	int ret = 1;
 
 	mmc_claim_host(card->host);
 
@@ -233,13 +231,11 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 		if (!mmc_card_blockaddr(card))
 			brq.cmd.arg <<= 9;
 		brq.cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
-		brq.data.blksz = 1 << md->block_bits;
+		brq.data.blksz = 512;
 		brq.stop.opcode = MMC_STOP_TRANSMISSION;
 		brq.stop.arg = 0;
 		brq.stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
-		brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
-		if (brq.data.blocks > card->host->max_blk_count)
-			brq.data.blocks = card->host->max_blk_count;
+		brq.data.blocks = req->nr_sectors;
 
 		if (brq.data.blocks > 1) {
 			/* SPI multiblock writes terminate using a special
@@ -271,24 +267,6 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 
 		mmc_queue_bounce_pre(mq);
 
-		/*
-		 * Adjust the sg list so it is the same size as the
-		 * request.
-		 */
-		if (brq.data.blocks !=
-		    (req->nr_sectors >> (md->block_bits - 9))) {
-			data_size = brq.data.blocks * brq.data.blksz;
-			for_each_sg(brq.data.sg, sg, brq.data.sg_len, i) {
-				data_size -= sg->length;
-				if (data_size <= 0) {
-					sg->length += data_size;
-					i++;
-					break;
-				}
-			}
-			brq.data.sg_len = i;
-		}
-
 		mmc_wait_for_req(card->host, &brq.mrq);
 
 		mmc_queue_bounce_post(mq);
@@ -373,16 +351,11 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 	if (rq_data_dir(req) != READ) {
 		if (mmc_card_sd(card)) {
 			u32 blocks;
-			unsigned int bytes;
 
 			blocks = mmc_sd_num_wr_blocks(card);
 			if (blocks != (u32)-1) {
-				if (card->csd.write_partial)
-					bytes = blocks << md->block_bits;
-				else
-					bytes = blocks << 9;
 				spin_lock_irq(&md->lock);
-				ret = __blk_end_request(req, 0, bytes);
+				ret = __blk_end_request(req, 0, blocks << 9);
 				spin_unlock_irq(&md->lock);
 			}
 		} else {
@@ -432,13 +405,6 @@ static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 	 */
 	md->read_only = mmc_blk_readonly(card);
 
-	/*
-	 * Both SD and MMC specifications state (although a bit
-	 * unclearly in the MMC case) that a block size of 512
-	 * bytes must always be supported by the card.
-	 */
-	md->block_bits = 9;
-
 	md->disk = alloc_disk(1 << MMC_SHIFT);
 	if (md->disk == NULL) {
 		ret = -ENOMEM;
@@ -476,7 +442,7 @@ static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 
 	sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 
-	blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
+	blk_queue_hardsect_size(md->queue.queue, 512);
 
 	if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) {
 		/*
@@ -514,7 +480,7 @@ mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 
 	mmc_claim_host(card->host);
 	cmd.opcode = MMC_SET_BLOCKLEN;
-	cmd.arg = 1 << md->block_bits;
+	cmd.arg = 512;
 	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
 	err = mmc_wait_for_cmd(card->host, &cmd, 5);
 	mmc_release_host(card->host);
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 3dee97e7d16..406989e992b 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -31,7 +31,7 @@ static int mmc_prep_request(struct request_queue *q, struct request *req)
 	/*
 	 * We only like normal block requests.
 	 */
-	if (!blk_fs_request(req) && !blk_pc_request(req)) {
+	if (!blk_fs_request(req)) {
 		blk_dump_rq_flags(req, "MMC bad request");
 		return BLKPREP_KILL;
 	}
@@ -131,6 +131,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
 	mq->req = NULL;
 
 	blk_queue_prep_rq(mq->queue, mmc_prep_request);
+	blk_queue_ordered(mq->queue, QUEUE_ORDERED_DRAIN, NULL);
 
 #ifdef CONFIG_MMC_BLOCK_BOUNCE
 	if (host->max_hw_segs == 1) {
@@ -142,12 +143,19 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
 			bouncesz = host->max_req_size;
 		if (bouncesz > host->max_seg_size)
 			bouncesz = host->max_seg_size;
+		if (bouncesz > (host->max_blk_count * 512))
+			bouncesz = host->max_blk_count * 512;
+
+		if (bouncesz > 512) {
+			mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
+			if (!mq->bounce_buf) {
+				printk(KERN_WARNING "%s: unable to "
+					"allocate bounce buffer\n",
+					mmc_card_name(card));
+			}
+		}
 
-		mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
-		if (!mq->bounce_buf) {
-			printk(KERN_WARNING "%s: unable to allocate "
-				"bounce buffer\n", mmc_card_name(card));
-		} else {
+		if (mq->bounce_buf) {
 			blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
 			blk_queue_max_sectors(mq->queue, bouncesz / 512);
 			blk_queue_max_phys_segments(mq->queue, bouncesz / 512);
@@ -175,7 +183,8 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
 
 	if (!mq->bounce_buf) {
 		blk_queue_bounce_limit(mq->queue, limit);
-		blk_queue_max_sectors(mq->queue, host->max_req_size / 512);
+		blk_queue_max_sectors(mq->queue,
+			min(host->max_blk_count, host->max_req_size / 512));
 		blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
 		blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
 		blk_queue_max_segment_size(mq->queue, host->max_seg_size);
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 64b05c6270f..9c50e6f1c23 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -248,8 +248,12 @@ mmc_send_cxd_data(struct mmc_card *card, struct mmc_host *host,
 
 	sg_init_one(&sg, data_buf, len);
 
-	if (card)
-		mmc_set_data_timeout(&data, card);
+	/*
+	 * The spec states that CSR and CID accesses have a timeout
+	 * of 64 clock cycles.
+	 */
+	data.timeout_ns = 0;
+	data.timeout_clks = 64;
 
 	mmc_wait_for_req(host, &mrq);
 
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 4eab79e09cc..fb99ccff908 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -165,6 +165,36 @@ static int sdio_enable_wide(struct mmc_card *card)
 }
 
 /*
+ * Test if the card supports high-speed mode and, if so, switch to it.
+ */
+static int sdio_enable_hs(struct mmc_card *card)
+{
+	int ret;
+	u8 speed;
+
+	if (!(card->host->caps & MMC_CAP_SD_HIGHSPEED))
+		return 0;
+
+	if (!card->cccr.high_speed)
+		return 0;
+
+	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
+	if (ret)
+		return ret;
+
+	speed |= SDIO_SPEED_EHS;
+
+	ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_SPEED, speed, NULL);
+	if (ret)
+		return ret;
+
+	mmc_card_set_highspeed(card);
+	mmc_set_timing(card->host, MMC_TIMING_SD_HS);
+
+	return 0;
+}
+
+/*
  * Host is being removed. Free up the current card.
  */
 static void mmc_sdio_remove(struct mmc_host *host)
@@ -333,10 +363,26 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr)
 		goto remove;
 
 	/*
-	 * No support for high-speed yet, so just set
-	 * the card's maximum speed.
+	 * Switch to high-speed (if supported).
 	 */
-	mmc_set_clock(host, card->cis.max_dtr);
+	err = sdio_enable_hs(card);
+	if (err)
+		goto remove;
+
+	/*
+	 * Change to the card's maximum speed.
+	 */
+	if (mmc_card_highspeed(card)) {
+		/*
+		 * The SDIO specification doesn't mention how
+		 * the CIS transfer speed register relates to
+		 * high-speed, but it seems that 50 MHz is
+		 * mandatory.
+		 */
+		mmc_set_clock(host, 50000000);
+	} else {
+		mmc_set_clock(host, card->cis.max_dtr);
+	}
 
 	/*
 	 * Switch to wider bus (if supported).
diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
index c292e124107..bb192f90e8e 100644
--- a/drivers/mmc/core/sdio_irq.c
+++ b/drivers/mmc/core/sdio_irq.c
@@ -5,6 +5,8 @@
  * Created:     June 18, 2007
  * Copyright:   MontaVista Software Inc.
  *
+ * Copyright 2008 Pierre Ossman
+ *
  * 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
@@ -107,11 +109,14 @@ static int sdio_irq_thread(void *_host)
 
 		/*
 		 * Give other threads a chance to run in the presence of
-		 * errors.  FIXME: determine if due to card removal and
-		 * possibly exit this thread if so.
+		 * errors.
 		 */
-		if (ret < 0)
-			ssleep(1);
+		if (ret < 0) {
+			set_current_state(TASK_INTERRUPTIBLE);
+			if (!kthread_should_stop())
+				schedule_timeout(HZ);
+			set_current_state(TASK_RUNNING);
+		}
 
 		/*
 		 * Adaptive polling frequency based on the assumption
@@ -154,7 +159,8 @@ static int sdio_card_irq_get(struct mmc_card *card)
 	if (!host->sdio_irqs++) {
 		atomic_set(&host->sdio_irq_thread_abort, 0);
 		host->sdio_irq_thread =
-			kthread_run(sdio_irq_thread, host, "ksdiorqd");
+			kthread_run(sdio_irq_thread, host, "ksdioirqd/%s",
+				mmc_hostname(host));
 		if (IS_ERR(host->sdio_irq_thread)) {
 			int err = PTR_ERR(host->sdio_irq_thread);
 			host->sdio_irqs--;
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index ea8d7a3490d..dfa585f7fea 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -2,7 +2,7 @@
 # MMC/SD host controller drivers
 #
 
-comment "MMC/SD Host Controller Drivers"
+comment "MMC/SD/SDIO Host Controller Drivers"
 
 config MMC_ARMMMCI
 	tristate "ARM AMBA Multimedia Card Interface support"
@@ -114,6 +114,17 @@ config MMC_ATMELMCI
 
 	  If unsure, say N.
 
+config MMC_ATMELMCI_DMA
+	bool "Atmel MCI DMA support (EXPERIMENTAL)"
+	depends on MMC_ATMELMCI && DMA_ENGINE && EXPERIMENTAL
+	help
+	  Say Y here to have the Atmel MCI driver use a DMA engine to
+	  do data transfers and thus increase the throughput and
+	  reduce the CPU utilization. Note that this is highly
+	  experimental and may cause the driver to lock up.
+
+	  If unsure, say N.
+
 config MMC_IMX
 	tristate "Motorola i.MX Multimedia Card Interface support"
 	depends on ARCH_IMX
@@ -141,21 +152,22 @@ config MMC_TIFM_SD
 	  module will be called tifm_sd.
 
 config MMC_SPI
-	tristate "MMC/SD over SPI"
-	depends on MMC && SPI_MASTER && !HIGHMEM && HAS_DMA
+	tristate "MMC/SD/SDIO over SPI"
+	depends on SPI_MASTER && !HIGHMEM && HAS_DMA
 	select CRC7
 	select CRC_ITU_T
 	help
-	  Some systems accss MMC/SD cards using a SPI controller instead of
-	  using a "native" MMC/SD controller.  This has a disadvantage of
-	  being relatively high overhead, but a compensating advantage of
-	  working on many systems without dedicated MMC/SD controllers.
+	  Some systems accss MMC/SD/SDIO cards using a SPI controller
+	  instead of using a "native" MMC/SD/SDIO controller.  This has a
+	  disadvantage of being relatively high overhead, but a compensating
+	  advantage of working on many systems without dedicated MMC/SD/SDIO
+	  controllers.
 
 	  If unsure, or if your system has no SPI master driver, say N.
 
 config MMC_S3C
 	tristate "Samsung S3C SD/MMC Card Interface support"
-	depends on ARCH_S3C2410 && MMC
+	depends on ARCH_S3C2410
 	help
 	  This selects a driver for the MCI interface found in
           Samsung's S3C2410, S3C2412, S3C2440, S3C2442 CPUs.
@@ -166,7 +178,7 @@ config MMC_S3C
 
 config MMC_SDRICOH_CS
 	tristate "MMC/SD driver for Ricoh Bay1Controllers (EXPERIMENTAL)"
-	depends on EXPERIMENTAL && MMC && PCI && PCMCIA
+	depends on EXPERIMENTAL && PCI && PCMCIA
 	help
 	  Say Y here if your Notebook reports a Ricoh Bay1Controller PCMCIA
 	  card whenever you insert a MMC or SD card into the card slot.
diff --git a/drivers/mmc/host/atmel-mci-regs.h b/drivers/mmc/host/atmel-mci-regs.h
index 26bd80e6503..b58364ed6bb 100644
--- a/drivers/mmc/host/atmel-mci-regs.h
+++ b/drivers/mmc/host/atmel-mci-regs.h
@@ -25,8 +25,10 @@
 #define MCI_SDCR		0x000c	/* SD Card / SDIO */
 # define MCI_SDCSEL_SLOT_A	(  0 <<  0)	/* Select SD slot A */
 # define MCI_SDCSEL_SLOT_B	(  1 <<  0)	/* Select SD slot A */
-# define MCI_SDCBUS_1BIT	(  0 <<  7)	/* 1-bit data bus */
-# define MCI_SDCBUS_4BIT	(  1 <<  7)	/* 4-bit data bus */
+# define MCI_SDCSEL_MASK	(  3 <<  0)
+# define MCI_SDCBUS_1BIT	(  0 <<  6)	/* 1-bit data bus */
+# define MCI_SDCBUS_4BIT	(  2 <<  6)	/* 4-bit data bus */
+# define MCI_SDCBUS_MASK	(  3 <<  6)
 #define MCI_ARGR		0x0010	/* Command Argument */
 #define MCI_CMDR		0x0014	/* Command */
 # define MCI_CMDR_CMDNB(x)	((x) <<  0)	/* Command Opcode */
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 00008967ef7..7a3f2436b01 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -11,6 +11,8 @@
 #include <linux/clk.h>
 #include <linux/debugfs.h>
 #include <linux/device.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
 #include <linux/err.h>
 #include <linux/gpio.h>
 #include <linux/init.h>
@@ -33,64 +35,178 @@
 #include "atmel-mci-regs.h"
 
 #define ATMCI_DATA_ERROR_FLAGS	(MCI_DCRCE | MCI_DTOE | MCI_OVRE | MCI_UNRE)
+#define ATMCI_DMA_THRESHOLD	16
 
 enum {
 	EVENT_CMD_COMPLETE = 0,
-	EVENT_DATA_ERROR,
-	EVENT_DATA_COMPLETE,
-	EVENT_STOP_SENT,
-	EVENT_STOP_COMPLETE,
 	EVENT_XFER_COMPLETE,
+	EVENT_DATA_COMPLETE,
+	EVENT_DATA_ERROR,
+};
+
+enum atmel_mci_state {
+	STATE_IDLE = 0,
+	STATE_SENDING_CMD,
+	STATE_SENDING_DATA,
+	STATE_DATA_BUSY,
+	STATE_SENDING_STOP,
+	STATE_DATA_ERROR,
+};
+
+struct atmel_mci_dma {
+#ifdef CONFIG_MMC_ATMELMCI_DMA
+	struct dma_client		client;
+	struct dma_chan			*chan;
+	struct dma_async_tx_descriptor	*data_desc;
+#endif
 };
 
+/**
+ * struct atmel_mci - MMC controller state shared between all slots
+ * @lock: Spinlock protecting the queue and associated data.
+ * @regs: Pointer to MMIO registers.
+ * @sg: Scatterlist entry currently being processed by PIO code, if any.
+ * @pio_offset: Offset into the current scatterlist entry.
+ * @cur_slot: The slot which is currently using the controller.
+ * @mrq: The request currently being processed on @cur_slot,
+ *	or NULL if the controller is idle.
+ * @cmd: The command currently being sent to the card, or NULL.
+ * @data: The data currently being transferred, or NULL if no data
+ *	transfer is in progress.
+ * @dma: DMA client state.
+ * @data_chan: DMA channel being used for the current data transfer.
+ * @cmd_status: Snapshot of SR taken upon completion of the current
+ *	command. Only valid when EVENT_CMD_COMPLETE is pending.
+ * @data_status: Snapshot of SR taken upon completion of the current
+ *	data transfer. Only valid when EVENT_DATA_COMPLETE or
+ *	EVENT_DATA_ERROR is pending.
+ * @stop_cmdr: Value to be loaded into CMDR when the stop command is
+ *	to be sent.
+ * @tasklet: Tasklet running the request state machine.
+ * @pending_events: Bitmask of events flagged by the interrupt handler
+ *	to be processed by the tasklet.
+ * @completed_events: Bitmask of events which the state machine has
+ *	processed.
+ * @state: Tasklet state.
+ * @queue: List of slots waiting for access to the controller.
+ * @need_clock_update: Update the clock rate before the next request.
+ * @need_reset: Reset controller before next request.
+ * @mode_reg: Value of the MR register.
+ * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus
+ *	rate and timeout calculations.
+ * @mapbase: Physical address of the MMIO registers.
+ * @mck: The peripheral bus clock hooked up to the MMC controller.
+ * @pdev: Platform device associated with the MMC controller.
+ * @slot: Slots sharing this MMC controller.
+ *
+ * Locking
+ * =======
+ *
+ * @lock is a softirq-safe spinlock protecting @queue as well as
+ * @cur_slot, @mrq and @state. These must always be updated
+ * at the same time while holding @lock.
+ *
+ * @lock also protects mode_reg and need_clock_update since these are
+ * used to synchronize mode register updates with the queue
+ * processing.
+ *
+ * The @mrq field of struct atmel_mci_slot is also protected by @lock,
+ * and must always be written at the same time as the slot is added to
+ * @queue.
+ *
+ * @pending_events and @completed_events are accessed using atomic bit
+ * operations, so they don't need any locking.
+ *
+ * None of the fields touched by the interrupt handler need any
+ * locking. However, ordering is important: Before EVENT_DATA_ERROR or
+ * EVENT_DATA_COMPLETE is set in @pending_events, all data-related
+ * interrupts must be disabled and @data_status updated with a
+ * snapshot of SR. Similarly, before EVENT_CMD_COMPLETE is set, the
+ * CMDRDY interupt must be disabled and @cmd_status updated with a
+ * snapshot of SR, and before EVENT_XFER_COMPLETE can be set, the
+ * bytes_xfered field of @data must be written. This is ensured by
+ * using barriers.
+ */
 struct atmel_mci {
-	struct mmc_host		*mmc;
+	spinlock_t		lock;
 	void __iomem		*regs;
 
 	struct scatterlist	*sg;
 	unsigned int		pio_offset;
 
+	struct atmel_mci_slot	*cur_slot;
 	struct mmc_request	*mrq;
 	struct mmc_command	*cmd;
 	struct mmc_data		*data;
 
+	struct atmel_mci_dma	dma;
+	struct dma_chan		*data_chan;
+
 	u32			cmd_status;
 	u32			data_status;
-	u32			stop_status;
 	u32			stop_cmdr;
 
-	u32			mode_reg;
-	u32			sdc_reg;
-
 	struct tasklet_struct	tasklet;
 	unsigned long		pending_events;
 	unsigned long		completed_events;
+	enum atmel_mci_state	state;
+	struct list_head	queue;
 
-	int			present;
-	int			detect_pin;
-	int			wp_pin;
-
-	/* For detect pin debouncing */
-	struct timer_list	detect_timer;
-
+	bool			need_clock_update;
+	bool			need_reset;
+	u32			mode_reg;
 	unsigned long		bus_hz;
 	unsigned long		mapbase;
 	struct clk		*mck;
 	struct platform_device	*pdev;
+
+	struct atmel_mci_slot	*slot[ATMEL_MCI_MAX_NR_SLOTS];
+};
+
+/**
+ * struct atmel_mci_slot - MMC slot state
+ * @mmc: The mmc_host representing this slot.
+ * @host: The MMC controller this slot is using.
+ * @sdc_reg: Value of SDCR to be written before using this slot.
+ * @mrq: mmc_request currently being processed or waiting to be
+ *	processed, or NULL when the slot is idle.
+ * @queue_node: List node for placing this node in the @queue list of
+ *	&struct atmel_mci.
+ * @clock: Clock rate configured by set_ios(). Protected by host->lock.
+ * @flags: Random state bits associated with the slot.
+ * @detect_pin: GPIO pin used for card detection, or negative if not
+ *	available.
+ * @wp_pin: GPIO pin used for card write protect sending, or negative
+ *	if not available.
+ * @detect_timer: Timer used for debouncing @detect_pin interrupts.
+ */
+struct atmel_mci_slot {
+	struct mmc_host		*mmc;
+	struct atmel_mci	*host;
+
+	u32			sdc_reg;
+
+	struct mmc_request	*mrq;
+	struct list_head	queue_node;
+
+	unsigned int		clock;
+	unsigned long		flags;
+#define ATMCI_CARD_PRESENT	0
+#define ATMCI_CARD_NEED_INIT	1
+#define ATMCI_SHUTDOWN		2
+
+	int			detect_pin;
+	int			wp_pin;
+
+	struct timer_list	detect_timer;
 };
 
-#define atmci_is_completed(host, event)				\
-	test_bit(event, &host->completed_events)
 #define atmci_test_and_clear_pending(host, event)		\
 	test_and_clear_bit(event, &host->pending_events)
-#define atmci_test_and_set_completed(host, event)		\
-	test_and_set_bit(event, &host->completed_events)
 #define atmci_set_completed(host, event)			\
 	set_bit(event, &host->completed_events)
 #define atmci_set_pending(host, event)				\
 	set_bit(event, &host->pending_events)
-#define atmci_clear_pending(host, event)			\
-	clear_bit(event, &host->pending_events)
 
 /*
  * The debugfs stuff below is mostly optimized away when
@@ -98,14 +214,15 @@ struct atmel_mci {
  */
 static int atmci_req_show(struct seq_file *s, void *v)
 {
-	struct atmel_mci	*host = s->private;
-	struct mmc_request	*mrq = host->mrq;
+	struct atmel_mci_slot	*slot = s->private;
+	struct mmc_request	*mrq;
 	struct mmc_command	*cmd;
 	struct mmc_command	*stop;
 	struct mmc_data		*data;
 
 	/* Make sure we get a consistent snapshot */
-	spin_lock_irq(&host->mmc->lock);
+	spin_lock_bh(&slot->host->lock);
+	mrq = slot->mrq;
 
 	if (mrq) {
 		cmd = mrq->cmd;
@@ -130,7 +247,7 @@ static int atmci_req_show(struct seq_file *s, void *v)
 				stop->resp[2], stop->error);
 	}
 
-	spin_unlock_irq(&host->mmc->lock);
+	spin_unlock_bh(&slot->host->lock);
 
 	return 0;
 }
@@ -193,12 +310,16 @@ static int atmci_regs_show(struct seq_file *s, void *v)
 	if (!buf)
 		return -ENOMEM;
 
-	/* Grab a more or less consistent snapshot */
-	spin_lock_irq(&host->mmc->lock);
+	/*
+	 * Grab a more or less consistent snapshot. Note that we're
+	 * not disabling interrupts, so IMR and SR may not be
+	 * consistent.
+	 */
+	spin_lock_bh(&host->lock);
 	clk_enable(host->mck);
 	memcpy_fromio(buf, host->regs, MCI_REGS_SIZE);
 	clk_disable(host->mck);
-	spin_unlock_irq(&host->mmc->lock);
+	spin_unlock_bh(&host->lock);
 
 	seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n",
 			buf[MCI_MR / 4],
@@ -236,13 +357,13 @@ static const struct file_operations atmci_regs_fops = {
 	.release	= single_release,
 };
 
-static void atmci_init_debugfs(struct atmel_mci *host)
+static void atmci_init_debugfs(struct atmel_mci_slot *slot)
 {
-	struct mmc_host	*mmc;
-	struct dentry	*root;
-	struct dentry	*node;
+	struct mmc_host		*mmc = slot->mmc;
+	struct atmel_mci	*host = slot->host;
+	struct dentry		*root;
+	struct dentry		*node;
 
-	mmc = host->mmc;
 	root = mmc->debugfs_root;
 	if (!root)
 		return;
@@ -254,7 +375,11 @@ static void atmci_init_debugfs(struct atmel_mci *host)
 	if (!node)
 		goto err;
 
-	node = debugfs_create_file("req", S_IRUSR, root, host, &atmci_req_fops);
+	node = debugfs_create_file("req", S_IRUSR, root, slot, &atmci_req_fops);
+	if (!node)
+		goto err;
+
+	node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state);
 	if (!node)
 		goto err;
 
@@ -271,25 +396,7 @@ static void atmci_init_debugfs(struct atmel_mci *host)
 	return;
 
 err:
-	dev_err(&host->pdev->dev,
-		"failed to initialize debugfs for controller\n");
-}
-
-static void atmci_enable(struct atmel_mci *host)
-{
-	clk_enable(host->mck);
-	mci_writel(host, CR, MCI_CR_MCIEN);
-	mci_writel(host, MR, host->mode_reg);
-	mci_writel(host, SDCR, host->sdc_reg);
-}
-
-static void atmci_disable(struct atmel_mci *host)
-{
-	mci_writel(host, CR, MCI_CR_SWRST);
-
-	/* Stall until write is complete, then disable the bus clock */
-	mci_readl(host, SR);
-	clk_disable(host->mck);
+	dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
 }
 
 static inline unsigned int ns_to_clocks(struct atmel_mci *host,
@@ -299,7 +406,7 @@ static inline unsigned int ns_to_clocks(struct atmel_mci *host,
 }
 
 static void atmci_set_timeout(struct atmel_mci *host,
-			      struct mmc_data *data)
+		struct atmel_mci_slot *slot, struct mmc_data *data)
 {
 	static unsigned	dtomul_to_shift[] = {
 		0, 4, 7, 8, 10, 12, 16, 20
@@ -322,7 +429,7 @@ static void atmci_set_timeout(struct atmel_mci *host,
 		dtocyc = 15;
 	}
 
-	dev_vdbg(&host->mmc->class_dev, "setting timeout to %u cycles\n",
+	dev_vdbg(&slot->mmc->class_dev, "setting timeout to %u cycles\n",
 			dtocyc << dtomul_to_shift[dtomul]);
 	mci_writel(host, DTOR, (MCI_DTOMUL(dtomul) | MCI_DTOCYC(dtocyc)));
 }
@@ -375,15 +482,12 @@ static u32 atmci_prepare_command(struct mmc_host *mmc,
 }
 
 static void atmci_start_command(struct atmel_mci *host,
-				struct mmc_command *cmd,
-				u32 cmd_flags)
+		struct mmc_command *cmd, u32 cmd_flags)
 {
-	/* Must read host->cmd after testing event flags */
-	smp_rmb();
 	WARN_ON(host->cmd);
 	host->cmd = cmd;
 
-	dev_vdbg(&host->mmc->class_dev,
+	dev_vdbg(&host->pdev->dev,
 			"start command: ARGR=0x%08x CMDR=0x%08x\n",
 			cmd->arg, cmd_flags);
 
@@ -391,34 +495,157 @@ static void atmci_start_command(struct atmel_mci *host,
 	mci_writel(host, CMDR, cmd_flags);
 }
 
-static void send_stop_cmd(struct mmc_host *mmc, struct mmc_data *data)
+static void send_stop_cmd(struct atmel_mci *host, struct mmc_data *data)
 {
-	struct atmel_mci *host = mmc_priv(mmc);
-
 	atmci_start_command(host, data->stop, host->stop_cmdr);
 	mci_writel(host, IER, MCI_CMDRDY);
 }
 
-static void atmci_request_end(struct mmc_host *mmc, struct mmc_request *mrq)
+#ifdef CONFIG_MMC_ATMELMCI_DMA
+static void atmci_dma_cleanup(struct atmel_mci *host)
 {
-	struct atmel_mci *host = mmc_priv(mmc);
+	struct mmc_data			*data = host->data;
 
-	WARN_ON(host->cmd || host->data);
-	host->mrq = NULL;
+	dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len,
+		     ((data->flags & MMC_DATA_WRITE)
+		      ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
+}
+
+static void atmci_stop_dma(struct atmel_mci *host)
+{
+	struct dma_chan *chan = host->data_chan;
+
+	if (chan) {
+		chan->device->device_terminate_all(chan);
+		atmci_dma_cleanup(host);
+	} else {
+		/* Data transfer was stopped by the interrupt handler */
+		atmci_set_pending(host, EVENT_XFER_COMPLETE);
+		mci_writel(host, IER, MCI_NOTBUSY);
+	}
+}
+
+/* This function is called by the DMA driver from tasklet context. */
+static void atmci_dma_complete(void *arg)
+{
+	struct atmel_mci	*host = arg;
+	struct mmc_data		*data = host->data;
+
+	dev_vdbg(&host->pdev->dev, "DMA complete\n");
+
+	atmci_dma_cleanup(host);
+
+	/*
+	 * If the card was removed, data will be NULL. No point trying
+	 * to send the stop command or waiting for NBUSY in this case.
+	 */
+	if (data) {
+		atmci_set_pending(host, EVENT_XFER_COMPLETE);
+		tasklet_schedule(&host->tasklet);
+
+		/*
+		 * Regardless of what the documentation says, we have
+		 * to wait for NOTBUSY even after block read
+		 * operations.
+		 *
+		 * When the DMA transfer is complete, the controller
+		 * may still be reading the CRC from the card, i.e.
+		 * the data transfer is still in progress and we
+		 * haven't seen all the potential error bits yet.
+		 *
+		 * The interrupt handler will schedule a different
+		 * tasklet to finish things up when the data transfer
+		 * is completely done.
+		 *
+		 * We may not complete the mmc request here anyway
+		 * because the mmc layer may call back and cause us to
+		 * violate the "don't submit new operations from the
+		 * completion callback" rule of the dma engine
+		 * framework.
+		 */
+		mci_writel(host, IER, MCI_NOTBUSY);
+	}
+}
+
+static int
+atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
+{
+	struct dma_chan			*chan;
+	struct dma_async_tx_descriptor	*desc;
+	struct scatterlist		*sg;
+	unsigned int			i;
+	enum dma_data_direction		direction;
+
+	/*
+	 * We don't do DMA on "complex" transfers, i.e. with
+	 * non-word-aligned buffers or lengths. Also, we don't bother
+	 * with all the DMA setup overhead for short transfers.
+	 */
+	if (data->blocks * data->blksz < ATMCI_DMA_THRESHOLD)
+		return -EINVAL;
+	if (data->blksz & 3)
+		return -EINVAL;
+
+	for_each_sg(data->sg, sg, data->sg_len, i) {
+		if (sg->offset & 3 || sg->length & 3)
+			return -EINVAL;
+	}
+
+	/* If we don't have a channel, we can't do DMA */
+	chan = host->dma.chan;
+	if (chan) {
+		dma_chan_get(chan);
+		host->data_chan = chan;
+	}
+
+	if (!chan)
+		return -ENODEV;
+
+	if (data->flags & MMC_DATA_READ)
+		direction = DMA_FROM_DEVICE;
+	else
+		direction = DMA_TO_DEVICE;
+
+	desc = chan->device->device_prep_slave_sg(chan,
+			data->sg, data->sg_len, direction,
+			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc)
+		return -ENOMEM;
 
-	atmci_disable(host);
+	host->dma.data_desc = desc;
+	desc->callback = atmci_dma_complete;
+	desc->callback_param = host;
+	desc->tx_submit(desc);
 
-	mmc_request_done(mmc, mrq);
+	/* Go! */
+	chan->device->device_issue_pending(chan);
+
+	return 0;
+}
+
+#else /* CONFIG_MMC_ATMELMCI_DMA */
+
+static int atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
+{