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From e567a7eb59832a76c36cf531967a56d3ff906584 Mon Sep 17 00:00:00 2001
From: gellert <gellert@raspberrypi.org>
Date: Fri, 15 Aug 2014 16:35:06 +0100
Subject: [PATCH 040/454] MMC: added alternative MMC driver
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

mmc: Disable CMD23 transfers on all cards

Pending wire-level investigation of these types of transfers
and associated errors on bcm2835-mmc, disable for now. Fallback of
CMD18/CMD25 transfers will be used automatically by the MMC layer.

Reported/Tested-by: Gellert Weisz <gellert@raspberrypi.org>

mmc: bcm2835-mmc: enable DT support for all architectures

Both ARCH_BCM2835 and ARCH_BCM270x are built with OF now.
Enable Device Tree support for all architectures.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

mmc: bcm2835-mmc: fix probe error handling

Probe error handling is broken in several places.
Simplify error handling by using device managed functions.
Replace pr_{err,info} with dev_{err,info}.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

bcm2835-mmc: Add locks when accessing sdhost registers

bcm2835-mmc: Add range of debug options for slowing things down

bcm2835-mmc: Add option to disable some delays

bcm2835-mmc: Add option to disable MMC_QUIRK_BLK_NO_CMD23

bcm2835-mmc: Default to disabling MMC_QUIRK_BLK_NO_CMD23

bcm2835-mmc: Adding overclocking option

Allow a different clock speed to be substitued for a requested 50MHz.
This option is exposed using the "overclock_50" DT parameter.
Note that the mmc interface is restricted to EVEN integer divisions of
250MHz, and the highest sensible option is 63 (250/4 = 62.5), the
next being 125 (250/2) which is much too high.

Use at your own risk.

bcm2835-mmc: Round up the overclock, so 62 works for 62.5Mhz

Also only warn once for each overclock setting.

mmc: bcm2835-mmc: Make available on ARCH_BCM2835

Make the bcm2835-mmc driver available for use on ARCH_BCM2835.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

BCM270x_DT: add bcm2835-mmc entry

Add Device Tree entry for bcm2835-mmc.
In non-DT mode, don't add the device in the board file.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

bcm2835-mmc: Don't overwrite MMC capabilities from DT

bcm2835-mmc: Don't override bus width capabilities from devicetree

Take out the force setting of the MMC_CAP_4_BIT_DATA host capability
so that the result read from devicetree via mmc_of_parse() is
preserved.

bcm2835-mmc: Only claim one DMA channel

With both MMC controllers enabled there are few DMA channels left. The
bcm2835-mmc driver only uses DMA in one direction at a time, so it
doesn't need to claim two channels.

See: https://github.com/raspberrypi/linux/issues/1327

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
---
 drivers/mmc/core/block.c       |   28 +-
 drivers/mmc/core/core.c        |    3 +-
 drivers/mmc/core/host.c        |   17 +-
 drivers/mmc/core/quirks.h      |    8 +
 drivers/mmc/host/Kconfig       |   29 +
 drivers/mmc/host/Makefile      |    1 +
 drivers/mmc/host/bcm2835-mmc.c | 1584 ++++++++++++++++++++++++++++++++
 include/linux/mmc/card.h       |    2 +
 8 files changed, 1667 insertions(+), 5 deletions(-)
 create mode 100644 drivers/mmc/host/bcm2835-mmc.c

--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -131,6 +131,13 @@ static DEFINE_MUTEX(open_lock);
 module_param(perdev_minors, int, 0444);
 MODULE_PARM_DESC(perdev_minors, "Minors numbers to allocate per device");
 
+/*
+ * Allow quirks to be overridden for the current card
+ */
+static char *card_quirks;
+module_param(card_quirks, charp, 0644);
+MODULE_PARM_DESC(card_quirks, "Force the use of the indicated quirks (a bitfield)");
+
 static inline int mmc_blk_part_switch(struct mmc_card *card,
                                      unsigned int part_type);
 
@@ -2514,6 +2521,7 @@ static int mmc_blk_probe(struct mmc_card
 {
        struct mmc_blk_data *md, *part_md;
        char cap_str[10];
+       char quirk_str[24];
 
        /*
         * Check that the card supports the command class(es) we need.
@@ -2521,7 +2529,16 @@ static int mmc_blk_probe(struct mmc_card
        if (!(card->csd.cmdclass & CCC_BLOCK_READ))
                return -ENODEV;
 
-       mmc_fixup_device(card, mmc_blk_fixups);
+       if (card_quirks) {
+               unsigned long quirks;
+               if (kstrtoul(card_quirks, 0, &quirks) == 0)
+                       card->quirks = (unsigned int)quirks;
+               else
+                       pr_err("mmc_block: Invalid card_quirks parameter '%s'\n",
+                              card_quirks);
+       }
+       else
+               mmc_fixup_device(card, mmc_blk_fixups);
 
        md = mmc_blk_alloc(card);
        if (IS_ERR(md))
@@ -2529,9 +2546,14 @@ static int mmc_blk_probe(struct mmc_card
 
        string_get_size((u64)get_capacity(md->disk), 512, STRING_UNITS_2,
                        cap_str, sizeof(cap_str));
-       pr_info("%s: %s %s %s %s\n",
+       if (card->quirks)
+               snprintf(quirk_str, sizeof(quirk_str),
+                        " (quirks 0x%08x)", card->quirks);
+       else
+               quirk_str[0] = '\0';
+       pr_info("%s: %s %s %s%s%s\n",
                md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
-               cap_str, md->read_only ? "(ro)" : "");
+               cap_str, md->read_only ? " (ro)" : "", quirk_str);
 
        if (mmc_blk_alloc_parts(card, md))
                goto out;
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2210,7 +2210,8 @@ EXPORT_SYMBOL(mmc_erase);
 int mmc_can_erase(struct mmc_card *card)
 {
        if ((card->host->caps & MMC_CAP_ERASE) &&
-           (card->csd.cmdclass & CCC_ERASE) && card->erase_size)
+           (card->csd.cmdclass & CCC_ERASE) && card->erase_size &&
+           !(card->quirks & MMC_QUIRK_ERASE_BROKEN))
                return 1;
        return 0;
 }
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -350,15 +350,30 @@ struct mmc_host *mmc_alloc_host(int extr
 {
        int err;
        struct mmc_host *host;
+       int id;
 
        host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
        if (!host)
                return NULL;
 
+       /* If OF aliases exist, start dynamic assignment after highest */
+       id = of_alias_get_highest_id("mmc");
+       id = (id < 0) ? 0 : id + 1;
+
+       /* If this devices has OF node, maybe it has an alias */
+       if (dev->of_node) {
+               int of_id = of_alias_get_id(dev->of_node, "mmc");
+
+               if (of_id < 0)
+                       dev_warn(dev, "/aliases ID not available\n");
+               else
+                       id = of_id;
+       }
+
        /* scanning will be enabled when we're ready */
        host->rescan_disable = 1;
 
-       err = ida_simple_get(&mmc_host_ida, 0, 0, GFP_KERNEL);
+       err = ida_simple_get(&mmc_host_ida, id, 0, GFP_KERNEL);
        if (err < 0) {
                kfree(host);
                return NULL;
--- a/drivers/mmc/core/quirks.h
+++ b/drivers/mmc/core/quirks.h
@@ -99,6 +99,14 @@ static const struct mmc_fixup mmc_blk_fi
        MMC_FIXUP("V10016", CID_MANFID_KINGSTON, CID_OEMID_ANY, add_quirk_mmc,
                  MMC_QUIRK_TRIM_BROKEN),
 
+       /*
+        *  On some Kingston SD cards, multiple erases of less than 64
+        *  sectors can cause corruption.
+        */
+       MMC_FIXUP("SD16G", 0x41, 0x3432, add_quirk, MMC_QUIRK_ERASE_BROKEN),
+       MMC_FIXUP("SD32G", 0x41, 0x3432, add_quirk, MMC_QUIRK_ERASE_BROKEN),
+       MMC_FIXUP("SD64G", 0x41, 0x3432, add_quirk, MMC_QUIRK_ERASE_BROKEN),
+
        END_FIXUP
 };
 
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -4,6 +4,35 @@
 
 comment "MMC/SD/SDIO Host Controller Drivers"
 
+config MMC_BCM2835_MMC
+       tristate "MMC support on BCM2835"
+       depends on MACH_BCM2708 || MACH_BCM2709 || ARCH_BCM2835
+       help
+         This selects the MMC Interface on BCM2835.
+
+         If you have a controller with this interface, say Y or M here.
+
+         If unsure, say N.
+
+config MMC_BCM2835_DMA
+       bool "DMA support on BCM2835 Arasan controller"
+       depends on MMC_BCM2835_MMC
+       help
+         Enable DMA support on the Arasan SDHCI controller in Broadcom 2708
+         based chips.
+
+         If unsure, say N.
+
+config MMC_BCM2835_PIO_DMA_BARRIER
+       int "Block count limit for PIO transfers"
+       depends on MMC_BCM2835_MMC && MMC_BCM2835_DMA
+       range 0 256
+       default 2
+       help
+         The inclusive limit in bytes under which PIO will be used instead of DMA
+
+         If unsure, say 2 here.
+
 config MMC_DEBUG
        bool "MMC host drivers debugging"
        depends on MMC != n
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_MMC_SDHCI_S3C)   += sdhci-s3c
 obj-$(CONFIG_MMC_SDHCI_SIRF)           += sdhci-sirf.o
 obj-$(CONFIG_MMC_SDHCI_F_SDH30)        += sdhci_f_sdh30.o
 obj-$(CONFIG_MMC_SDHCI_SPEAR)  += sdhci-spear.o
+obj-$(CONFIG_MMC_BCM2835_MMC)  += bcm2835-mmc.o
 obj-$(CONFIG_MMC_WBSD)         += wbsd.o
 obj-$(CONFIG_MMC_AU1X)         += au1xmmc.o
 obj-$(CONFIG_MMC_MTK)          += mtk-sd.o
--- /dev/null
+++ b/drivers/mmc/host/bcm2835-mmc.c
@@ -0,0 +1,1584 @@
+/*
+ * BCM2835 MMC host driver.
+ *
+ * Author:      Gellert Weisz <gellert@raspberrypi.org>
+ *              Copyright 2014
+ *
+ * Based on
+ *  sdhci-bcm2708.c by Broadcom
+ *  sdhci-bcm2835.c by Stephen Warren and Oleksandr Tymoshenko
+ *  sdhci.c and sdhci-pci.c by Pierre Ossman
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/sd.h>
+#include <linux/scatterlist.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/blkdev.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/of_dma.h>
+
+#include "sdhci.h"
+
+
+#define DRIVER_NAME "mmc-bcm2835"
+
+#define DBG(f, x...) \
+pr_debug(DRIVER_NAME " [%s()]: " f, __func__, ## x)
+
+#ifndef CONFIG_MMC_BCM2835_DMA
+ #define FORCE_PIO
+#endif
+
+
+/* the inclusive limit in bytes under which PIO will be used instead of DMA */
+#ifdef CONFIG_MMC_BCM2835_PIO_DMA_BARRIER
+#define PIO_DMA_BARRIER CONFIG_MMC_BCM2835_PIO_DMA_BARRIER
+#else
+#define PIO_DMA_BARRIER 00
+#endif
+
+#define MIN_FREQ 400000
+#define TIMEOUT_VAL 0xE
+#define BCM2835_SDHCI_WRITE_DELAY(f)   (((2 * 1000000) / f) + 1)
+
+
+unsigned mmc_debug;
+unsigned mmc_debug2;
+
+struct bcm2835_host {
+       spinlock_t                              lock;
+
+       void __iomem                    *ioaddr;
+       u32                                             bus_addr;
+
+       struct mmc_host                 *mmc;
+
+       u32                                             timeout;
+
+       int                                             clock;  /* Current clock speed */
+       u8                                              pwr;    /* Current voltage */
+
+       unsigned int                    max_clk;                /* Max possible freq */
+       unsigned int                    timeout_clk;    /* Timeout freq (KHz) */
+       unsigned int                    clk_mul;                /* Clock Muliplier value */
+
+       struct tasklet_struct   finish_tasklet;         /* Tasklet structures */
+
+       struct timer_list               timer;                  /* Timer for timeouts */
+
+       struct sg_mapping_iter  sg_miter;               /* SG state for PIO */
+       unsigned int                    blocks;                 /* remaining PIO blocks */
+
+       int                                             irq;                    /* Device IRQ */
+
+
+       u32                                             ier;                    /* cached registers */
+
+       struct mmc_request              *mrq;                   /* Current request */
+       struct mmc_command              *cmd;                   /* Current command */
+       struct mmc_data                 *data;                  /* Current data request */
+       unsigned int                    data_early:1;           /* Data finished before cmd */
+
+       wait_queue_head_t               buf_ready_int;          /* Waitqueue for Buffer Read Ready interrupt */
+
+       u32                                             thread_isr;
+
+       u32                                             shadow;
+
+       /*DMA part*/
+       struct dma_chan                 *dma_chan_rxtx;         /* DMA channel for reads and writes */
+       struct dma_slave_config         dma_cfg_rx;
+       struct dma_slave_config         dma_cfg_tx;
+       struct dma_async_tx_descriptor  *tx_desc;       /* descriptor */
+
+       bool                                    have_dma;
+       bool                                    use_dma;
+       bool                                    wait_for_dma;
+       /*end of DMA part*/
+
+       int                                             max_delay;      /* maximum length of time spent waiting */
+
+       int                                             flags;                          /* Host attributes */
+#define SDHCI_REQ_USE_DMA      (1<<2)  /* Use DMA for this req. */
+#define SDHCI_DEVICE_DEAD      (1<<3)  /* Device unresponsive */
+#define SDHCI_AUTO_CMD12       (1<<6)  /* Auto CMD12 support */
+#define SDHCI_AUTO_CMD23       (1<<7)  /* Auto CMD23 support */
+#define SDHCI_SDIO_IRQ_ENABLED (1<<9)  /* SDIO irq enabled */
+
+       u32                             overclock_50;   /* frequency to use when 50MHz is requested (in MHz) */
+       u32                             max_overclock;  /* Highest reported */
+};
+
+
+static inline void bcm2835_mmc_writel(struct bcm2835_host *host, u32 val, int reg, int from)
+{
+       unsigned delay;
+       lockdep_assert_held_once(&host->lock);
+       writel(val, host->ioaddr + reg);
+       udelay(BCM2835_SDHCI_WRITE_DELAY(max(host->clock, MIN_FREQ)));
+
+       delay = ((mmc_debug >> 16) & 0xf) << ((mmc_debug >> 20) & 0xf);
+       if (delay && !((1<<from) & mmc_debug2))
+               udelay(delay);
+}
+
+static inline void mmc_raw_writel(struct bcm2835_host *host, u32 val, int reg)
+{
+       unsigned delay;
+       lockdep_assert_held_once(&host->lock);
+       writel(val, host->ioaddr + reg);
+
+       delay = ((mmc_debug >> 24) & 0xf) << ((mmc_debug >> 28) & 0xf);
+       if (delay)
+               udelay(delay);
+}
+
+static inline u32 bcm2835_mmc_readl(struct bcm2835_host *host, int reg)
+{
+       lockdep_assert_held_once(&host->lock);
+       return readl(host->ioaddr + reg);
+}
+
+static inline void bcm2835_mmc_writew(struct bcm2835_host *host, u16 val, int reg)
+{
+       u32 oldval = (reg == SDHCI_COMMAND) ? host->shadow :
+               bcm2835_mmc_readl(host, reg & ~3);
+       u32 word_num = (reg >> 1) & 1;
+       u32 word_shift = word_num * 16;
+       u32 mask = 0xffff << word_shift;
+       u32 newval = (oldval & ~mask) | (val << word_shift);
+
+       if (reg == SDHCI_TRANSFER_MODE)
+               host->shadow = newval;
+       else
+               bcm2835_mmc_writel(host, newval, reg & ~3, 0);
+
+}
+
+static inline void bcm2835_mmc_writeb(struct bcm2835_host *host, u8 val, int reg)
+{
+       u32 oldval = bcm2835_mmc_readl(host, reg & ~3);
+       u32 byte_num = reg & 3;
+       u32 byte_shift = byte_num * 8;
+       u32 mask = 0xff << byte_shift;
+       u32 newval = (oldval & ~mask) | (val << byte_shift);
+
+       bcm2835_mmc_writel(host, newval, reg & ~3, 1);
+}
+
+
+static inline u16 bcm2835_mmc_readw(struct bcm2835_host *host, int reg)
+{
+       u32 val = bcm2835_mmc_readl(host, (reg & ~3));
+       u32 word_num = (reg >> 1) & 1;
+       u32 word_shift = word_num * 16;
+       u32 word = (val >> word_shift) & 0xffff;
+
+       return word;
+}
+
+static inline u8 bcm2835_mmc_readb(struct bcm2835_host *host, int reg)
+{
+       u32 val = bcm2835_mmc_readl(host, (reg & ~3));
+       u32 byte_num = reg & 3;
+       u32 byte_shift = byte_num * 8;
+       u32 byte = (val >> byte_shift) & 0xff;
+
+       return byte;
+}
+
+static void bcm2835_mmc_unsignal_irqs(struct bcm2835_host *host, u32 clear)
+{
+       u32 ier;
+
+       ier = bcm2835_mmc_readl(host, SDHCI_SIGNAL_ENABLE);
+       ier &= ~clear;
+       /* change which requests generate IRQs - makes no difference to
+          the content of SDHCI_INT_STATUS, or the need to acknowledge IRQs */
+       bcm2835_mmc_writel(host, ier, SDHCI_SIGNAL_ENABLE, 2);
+}
+
+
+static void bcm2835_mmc_dumpregs(struct bcm2835_host *host)
+{
+       pr_debug(DRIVER_NAME ": =========== REGISTER DUMP (%s)===========\n",
+               mmc_hostname(host->mmc));
+
+       pr_debug(DRIVER_NAME ": Sys addr: 0x%08x | Version:  0x%08x\n",
+               bcm2835_mmc_readl(host, SDHCI_DMA_ADDRESS),
+               bcm2835_mmc_readw(host, SDHCI_HOST_VERSION));
+       pr_debug(DRIVER_NAME ": Blk size: 0x%08x | Blk cnt:  0x%08x\n",
+               bcm2835_mmc_readw(host, SDHCI_BLOCK_SIZE),
+               bcm2835_mmc_readw(host, SDHCI_BLOCK_COUNT));
+       pr_debug(DRIVER_NAME ": Argument: 0x%08x | Trn mode: 0x%08x\n",
+               bcm2835_mmc_readl(host, SDHCI_ARGUMENT),
+               bcm2835_mmc_readw(host, SDHCI_TRANSFER_MODE));
+       pr_debug(DRIVER_NAME ": Present:  0x%08x | Host ctl: 0x%08x\n",
+               bcm2835_mmc_readl(host, SDHCI_PRESENT_STATE),
+               bcm2835_mmc_readb(host, SDHCI_HOST_CONTROL));
+       pr_debug(DRIVER_NAME ": Power:    0x%08x | Blk gap:  0x%08x\n",
+               bcm2835_mmc_readb(host, SDHCI_POWER_CONTROL),
+               bcm2835_mmc_readb(host, SDHCI_BLOCK_GAP_CONTROL));
+       pr_debug(DRIVER_NAME ": Wake-up:  0x%08x | Clock:    0x%08x\n",
+               bcm2835_mmc_readb(host, SDHCI_WAKE_UP_CONTROL),
+               bcm2835_mmc_readw(host, SDHCI_CLOCK_CONTROL));
+       pr_debug(DRIVER_NAME ": Timeout:  0x%08x | Int stat: 0x%08x\n",
+               bcm2835_mmc_readb(host, SDHCI_TIMEOUT_CONTROL),
+               bcm2835_mmc_readl(host, SDHCI_INT_STATUS));
+       pr_debug(DRIVER_NAME ": Int enab: 0x%08x | Sig enab: 0x%08x\n",
+               bcm2835_mmc_readl(host, SDHCI_INT_ENABLE),
+               bcm2835_mmc_readl(host, SDHCI_SIGNAL_ENABLE));
+       pr_debug(DRIVER_NAME ": AC12 err: 0x%08x | Slot int: 0x%08x\n",
+               bcm2835_mmc_readw(host, SDHCI_ACMD12_ERR),
+               bcm2835_mmc_readw(host, SDHCI_SLOT_INT_STATUS));
+       pr_debug(DRIVER_NAME ": Caps:     0x%08x | Caps_1:   0x%08x\n",
+               bcm2835_mmc_readl(host, SDHCI_CAPABILITIES),
+               bcm2835_mmc_readl(host, SDHCI_CAPABILITIES_1));
+       pr_debug(DRIVER_NAME ": Cmd:      0x%08x | Max curr: 0x%08x\n",
+               bcm2835_mmc_readw(host, SDHCI_COMMAND),
+               bcm2835_mmc_readl(host, SDHCI_MAX_CURRENT));
+       pr_debug(DRIVER_NAME ": Host ctl2: 0x%08x\n",
+               bcm2835_mmc_readw(host, SDHCI_HOST_CONTROL2));
+
+       pr_debug(DRIVER_NAME ": ===========================================\n");
+}
+
+
+static void bcm2835_mmc_reset(struct bcm2835_host *host, u8 mask)
+{
+       unsigned long timeout;
+       unsigned long flags;
+
+       spin_lock_irqsave(&host->lock, flags);
+       bcm2835_mmc_writeb(host, mask, SDHCI_SOFTWARE_RESET);
+
+       if (mask & SDHCI_RESET_ALL)
+               host->clock = 0;
+
+       /* Wait max 100 ms */
+       timeout = 100;
+
+       /* hw clears the bit when it's done */
+       while (bcm2835_mmc_readb(host, SDHCI_SOFTWARE_RESET) & mask) {
+               if (timeout == 0) {
+                       pr_err("%s: Reset 0x%x never completed.\n",
+                               mmc_hostname(host->mmc), (int)mask);
+                       bcm2835_mmc_dumpregs(host);
+                       return;
+               }
+               timeout--;
+               spin_unlock_irqrestore(&host->lock, flags);
+               mdelay(1);
+               spin_lock_irqsave(&host->lock, flags);
+       }
+
+       if (100-timeout > 10 && 100-timeout > host->max_delay) {
+               host->max_delay = 100-timeout;
+               pr_warning("Warning: MMC controller hung for %d ms\n", host->max_delay);
+       }
+       spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void bcm2835_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios);
+
+static void bcm2835_mmc_init(struct bcm2835_host *host, int soft)
+{
+       unsigned long flags;
+       if (soft)
+               bcm2835_mmc_reset(host, SDHCI_RESET_CMD|SDHCI_RESET_DATA);
+       else
+               bcm2835_mmc_reset(host, SDHCI_RESET_ALL);
+
+       host->ier = SDHCI_INT_BUS_POWER | SDHCI_INT_DATA_END_BIT |
+                   SDHCI_INT_DATA_CRC | SDHCI_INT_DATA_TIMEOUT |
+                   SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC |
+                   SDHCI_INT_TIMEOUT | SDHCI_INT_DATA_END |
+                   SDHCI_INT_RESPONSE;
+
+       spin_lock_irqsave(&host->lock, flags);
+       bcm2835_mmc_writel(host, host->ier, SDHCI_INT_ENABLE, 3);
+       bcm2835_mmc_writel(host, host->ier, SDHCI_SIGNAL_ENABLE, 3);
+       spin_unlock_irqrestore(&host->lock, flags);
+
+       if (soft) {
+               /* force clock reconfiguration */
+               host->clock = 0;
+               bcm2835_mmc_set_ios(host->mmc, &host->mmc->ios);
+       }
+}
+
+
+
+static void bcm2835_mmc_finish_data(struct bcm2835_host *host);
+
+static void bcm2835_mmc_dma_complete(void *param)
+{
+       struct bcm2835_host *host = param;
+       struct dma_chan *dma_chan;
+       unsigned long flags;
+       u32 dir_data;
+
+       spin_lock_irqsave(&host->lock, flags);
+
+       host->use_dma = false;
+
+       if (host->data && !(host->data->flags & MMC_DATA_WRITE)) {
+               /* otherwise handled in SDHCI IRQ */
+               dma_chan = host->dma_chan_rxtx;
+               dir_data = DMA_FROM_DEVICE;
+
+               dma_unmap_sg(dma_chan->device->dev,
+                    host->data->sg, host->data->sg_len,
+                    dir_data);
+
+               bcm2835_mmc_finish_data(host);
+       } else if (host->wait_for_dma) {
+               host->wait_for_dma = false;
+               tasklet_schedule(&host->finish_tasklet);
+       }
+
+       spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void bcm2835_bcm2835_mmc_read_block_pio(struct bcm2835_host *host)
+{
+       unsigned long flags;
+       size_t blksize, len, chunk;
+
+       u32 uninitialized_var(scratch);
+       u8 *buf;
+
+       blksize = host->data->blksz;
+       chunk = 0;
+
+       local_irq_save(flags);
+
+       while (blksize) {
+               if (!sg_miter_next(&host->sg_miter))
+                       BUG();
+
+               len = min(host->sg_miter.length, blksize);
+
+               blksize -= len;
+               host->sg_miter.consumed = len;
+
+               buf = host->sg_miter.addr;
+
+               while (len) {
+                       if (chunk == 0) {
+                               scratch = bcm2835_mmc_readl(host, SDHCI_BUFFER);
+                               chunk = 4;
+                       }
+
+                       *buf = scratch & 0xFF;
+
+                       buf++;
+                       scratch >>= 8;
+                       chunk--;
+                       len--;
+               }
+       }
+
+       sg_miter_stop(&host->sg_miter);
+
+       local_irq_restore(flags);
+}
+
+static void bcm2835_bcm2835_mmc_write_block_pio(struct bcm2835_host *host)
+{
+       unsigned long flags;
+       size_t blksize, len, chunk;
+       u32 scratch;
+       u8 *buf;
+
+       blksize = host->data->blksz;
+       chunk = 0;
+       chunk = 0;
+       scratch = 0;
+
+       local_irq_save(flags);
+
+       while (blksize) {
+               if (!sg_miter_next(&host->sg_miter))
+                       BUG();
+
+               len = min(host->sg_miter.length, blksize);
+
+               blksize -= len;
+               host->sg_miter.consumed = len;
+
+               buf = host->sg_miter.addr;
+
+               while (len) {
+                       scratch |= (u32)*buf << (chunk * 8);
+
+                       buf++;
+                       chunk++;
+                       len--;
+
+                       if ((chunk == 4) || ((len == 0) && (blksize == 0))) {
+                               mmc_raw_writel(host, scratch, SDHCI_BUFFER);
+                               chunk = 0;
+                               scratch = 0;
+                       }
+               }
+       }
+
+       sg_miter_stop(&host->sg_miter);
+
+       local_irq_restore(flags);
+}
+
+
+static void bcm2835_mmc_transfer_pio(struct bcm2835_host *host)
+{
+       u32 mask;
+
+       BUG_ON(!host->data);
+
+       if (host->blocks == 0)
+               return;
+
+       if (host->data->flags & MMC_DATA_READ)
+               mask = SDHCI_DATA_AVAILABLE;
+       else
+               mask = SDHCI_SPACE_AVAILABLE;
+
+       while (bcm2835_mmc_readl(host, SDHCI_PRESENT_STATE) & mask) {
+
+               if (host->data->flags & MMC_DATA_READ)
+                       bcm2835_bcm2835_mmc_read_block_pio(host);
+               else
+                       bcm2835_bcm2835_mmc_write_block_pio(host);
+
+               host->blocks--;
+
+               /* QUIRK used in sdhci.c removes the 'if' */
+               /* but it seems this is unnecessary */
+               if (host->blocks == 0)
+                       break;
+
+
+       }
+}
+
+
+static void bcm2835_mmc_transfer_dma(struct bcm2835_host *host)
+{
+       u32 len, dir_data, dir_slave;
+       struct dma_async_tx_descriptor *desc = NULL;
+       struct dma_chan *dma_chan;
+
+
+       WARN_ON(!host->data);
+
+       if (!host->data)
+               return;
+
+       if (host->blocks == 0)
+               return;
+
+       dma_chan = host->dma_chan_rxtx;
+       if (host->data->flags & MMC_DATA_READ) {
+               dir_data = DMA_FROM_DEVICE;
+               dir_slave = DMA_DEV_TO_MEM;
+       } else {
+               dir_data = DMA_TO_DEVICE;
+               dir_slave = DMA_MEM_TO_DEV;
+       }
+
+       /* The parameters have already been validated, so this will not fail */
+       (void)dmaengine_slave_config(dma_chan,
+                                    (dir_data == DMA_FROM_DEVICE) ?
+                                    &host->dma_cfg_rx :
+                                    &host->dma_cfg_tx);
+
+       BUG_ON(!dma_chan->device);
+       BUG_ON(!dma_chan->device->dev);
+       BUG_ON(!host->data->sg);
+
+       len = dma_map_sg(dma_chan->device->dev, host->data->sg,
+                        host->data->sg_len, dir_data);
+       if (len > 0) {
+               desc = dmaengine_prep_slave_sg(dma_chan, host->data->sg,
+                                              len, dir_slave,
+                                              DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+       } else {
+               dev_err(mmc_dev(host->mmc), "dma_map_sg returned zero length\n");
+       }
+       if (desc) {
+               unsigned long flags;
+               spin_lock_irqsave(&host->lock, flags);
+               bcm2835_mmc_unsignal_irqs(host, SDHCI_INT_DATA_AVAIL |
+                                                   SDHCI_INT_SPACE_AVAIL);
+               host->tx_desc = desc;
+               desc->callback = bcm2835_mmc_dma_complete;
+               desc->callback_param = host;
+               spin_unlock_irqrestore(&host->lock, flags);
+               dmaengine_submit(desc);
+               dma_async_issue_pending(dma_chan);
+       }
+
+}
+
+
+
+static void bcm2835_mmc_set_transfer_irqs(struct bcm2835_host *host)
+{
+       u32 pio_irqs = SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL;
+       u32 dma_irqs = SDHCI_INT_DMA_END | SDHCI_INT_ADMA_ERROR;
+
+       if (host->use_dma)
+               host->ier = (host->ier & ~pio_irqs) | dma_irqs;
+       else
+               host->ier = (host->ier & ~dma_irqs) | pio_irqs;
+
+       bcm2835_mmc_writel(host, host->ier, SDHCI_INT_ENABLE, 4);
+       bcm2835_mmc_writel(host, host->ier, SDHCI_SIGNAL_ENABLE, 4);
+}
+
+
+static void bcm2835_mmc_prepare_data(struct bcm2835_host *host, struct mmc_command *cmd)
+{
+       u8 count;
+       struct mmc_data *data = cmd->data;
+
+       WARN_ON(host->data);
+
+       if (data || (cmd->flags & MMC_RSP_BUSY)) {
+               count = TIMEOUT_VAL;
+               bcm2835_mmc_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
+       }
+
+       if (!data)
+               return;
+
+       /* Sanity checks */
+       BUG_ON(data->blksz * data->blocks > 524288);
+       BUG_ON(data->blksz > host->mmc->max_blk_size);
+       BUG_ON(data->blocks > 65535);
+
+       host->data = data;
+       host->data_early = 0;
+       host->data->bytes_xfered = 0;
+
+
+       if (!(host->flags & SDHCI_REQ_USE_DMA)) {
+               int flags;
+
+               flags = SG_MITER_ATOMIC;
+               if (host->data->flags & MMC_DATA_READ)
+                       flags |= SG_MITER_TO_SG;
+               else
+                       flags |= SG_MITER_FROM_SG;
+               sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
+               host->blocks = data->blocks;
+       }
+
+       host->use_dma = host->have_dma && data->blocks > PIO_DMA_BARRIER;
+
+       bcm2835_mmc_set_transfer_irqs(host);
+
+       /* Set the DMA boundary value and block size */
+       bcm2835_mmc_writew(host, SDHCI_MAKE_BLKSZ(SDHCI_DEFAULT_BOUNDARY_ARG,
+               data->blksz), SDHCI_BLOCK_SIZE);
+       bcm2835_mmc_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
+
+       BUG_ON(!host->data);
+}
+
+static void bcm2835_mmc_set_transfer_mode(struct bcm2835_host *host,
+       struct mmc_command *cmd)
+{
+       u16 mode;
+       struct mmc_data *data = cmd->data;
+
+       if (data == NULL) {
+               /* clear Auto CMD settings for no data CMDs */
+               mode = bcm2835_mmc_readw(host, SDHCI_TRANSFER_MODE);
+               bcm2835_mmc_writew(host, mode & ~(SDHCI_TRNS_AUTO_CMD12 |
+                               SDHCI_TRNS_AUTO_CMD23), SDHCI_TRANSFER_MODE);
+               return;
+       }
+
+       WARN_ON(!host->data);
+
+       mode = SDHCI_TRNS_BLK_CNT_EN;
+
+       if ((mmc_op_multi(cmd->opcode) || data->blocks > 1)) {
+               mode |= SDHCI_TRNS_MULTI;
+
+               /*
+                * If we are sending CMD23, CMD12 never gets sent
+                * on successful completion (so no Auto-CMD12).
+                */
+               if (!host->mrq->sbc && (host->flags & SDHCI_AUTO_CMD12))
+                       mode |= SDHCI_TRNS_AUTO_CMD12;
+               else if (host->mrq->sbc && (host->flags & SDHCI_AUTO_CMD23)) {
+                       mode |= SDHCI_TRNS_AUTO_CMD23;
+                       bcm2835_mmc_writel(host, host->mrq->sbc->arg, SDHCI_ARGUMENT2, 5);
+               }
+       }
+
+       if (data->flags & MMC_DATA_READ)
+               mode |= SDHCI_TRNS_READ;
+       if (host->flags & SDHCI_REQ_USE_DMA)
+               mode |= SDHCI_TRNS_DMA;
+
+       bcm2835_mmc_writew(host, mode, SDHCI_TRANSFER_MODE);
+}
+
+void bcm2835_mmc_send_command(struct bcm2835_host *host, struct mmc_command *cmd)
+{
+       int flags;
+       u32 mask;
+       unsigned long timeout;
+
+       WARN_ON(host->cmd);
+
+       /* Wait max 10 ms */
+       timeout = 1000;
+
+       mask = SDHCI_CMD_INHIBIT;
+       if ((cmd->data != NULL) || (cmd->flags & MMC_RSP_BUSY))
+               mask |= SDHCI_DATA_INHIBIT;
+
+       /* We shouldn't wait for data inihibit for stop commands, even
+          though they might use busy signaling */
+       if (host->mrq->data && (cmd == host->mrq->data->stop))
+               mask &= ~SDHCI_DATA_INHIBIT;
+
+       while (bcm2835_mmc_readl(host, SDHCI_PRESENT_STATE) & mask) {
+               if (timeout == 0) {
+                       pr_err("%s: Controller never released inhibit bit(s).\n",
+                               mmc_hostname(host->mmc));
+                       bcm2835_mmc_dumpregs(host);
+                       cmd->error = -EIO;
+                       tasklet_schedule(&host->finish_tasklet);
+                       return;
+               }
+               timeout--;
+               udelay(10);
+       }
+
+       if ((1000-timeout)/100 > 1 && (1000-timeout)/100 > host->max_delay) {
+               host->max_delay = (1000-timeout)/100;
+               pr_warning("Warning: MMC controller hung for %d ms\n", host->max_delay);
+       }
+
+       timeout = jiffies;
+       if (!cmd->data && cmd->busy_timeout > 9000)
+               timeout += DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ;
+       else
+               timeout += 10 * HZ;
+       mod_timer(&host->timer, timeout);
+
+       host->cmd = cmd;
+       host->use_dma = false;
+
+       bcm2835_mmc_prepare_data(host, cmd);
+
+       bcm2835_mmc_writel(host, cmd->arg, SDHCI_ARGUMENT, 6);
+
+       bcm2835_mmc_set_transfer_mode(host, cmd);
+
+       if ((cmd->flags & MMC_RSP_136) && (cmd->flags & MMC_RSP_BUSY)) {
+               pr_err("%s: Unsupported response type!\n",
+                       mmc_hostname(host->mmc));
+               cmd->error = -EINVAL;
+               tasklet_schedule(&host->finish_tasklet);
+               return;
+       }
+
+       if (!(cmd->flags & MMC_RSP_PRESENT))
+               flags = SDHCI_CMD_RESP_NONE;
+       else if (cmd->flags & MMC_RSP_136)
+               flags = SDHCI_CMD_RESP_LONG;
+       else if (cmd->flags & MMC_RSP_BUSY)
+               flags = SDHCI_CMD_RESP_SHORT_BUSY;
+       else
+               flags = SDHCI_CMD_RESP_SHORT;
+
+       if (cmd->flags & MMC_RSP_CRC)
+               flags |= SDHCI_CMD_CRC;
+       if (cmd->flags & MMC_RSP_OPCODE)
+               flags |= SDHCI_CMD_INDEX;
+
+       if (cmd->data)
+               flags |= SDHCI_CMD_DATA;
+
+       bcm2835_mmc_writew(host, SDHCI_MAKE_CMD(cmd->opcode, flags), SDHCI_COMMAND);
+}
+
+
+static void bcm2835_mmc_finish_data(struct bcm2835_host *host)
+{
+       struct mmc_data *data;
+
+       BUG_ON(!host->data);
+
+       data = host->data;
+       host->data = NULL;
+
+       if (data->error)
+               data->bytes_xfered = 0;
+       else
+               data->bytes_xfered = data->blksz * data->blocks;
+
+       /*
+        * Need to send CMD12 if -
+        * a) open-ended multiblock transfer (no CMD23)
+        * b) error in multiblock transfer
+        */
+       if (data->stop &&
+           (data->error ||
+            !host->mrq->sbc)) {
+
+               /*
+                * The controller needs a reset of internal state machines
+                * upon error conditions.
+                */
+               if (data->error) {
+                       bcm2835_mmc_reset(host, SDHCI_RESET_CMD);
+                       bcm2835_mmc_reset(host, SDHCI_RESET_DATA);
+               }
+
+               bcm2835_mmc_send_command(host, data->stop);
+       } else if (host->use_dma) {
+               host->wait_for_dma = true;
+       } else {
+               tasklet_schedule(&host->finish_tasklet);
+       }
+}
+
+static void bcm2835_mmc_finish_command(struct bcm2835_host *host)
+{
+       int i;
+
+       BUG_ON(host->cmd == NULL);
+
+       if (host->cmd->flags & MMC_RSP_PRESENT) {
+               if (host->cmd->flags & MMC_RSP_136) {
+                       /* CRC is stripped so we need to do some shifting. */
+                       for (i = 0; i < 4; i++) {
+                               host->cmd->resp[i] = bcm2835_mmc_readl(host,
+                                       SDHCI_RESPONSE + (3-i)*4) << 8;
+                               if (i != 3)
+                                       host->cmd->resp[i] |=
+                                               bcm2835_mmc_readb(host,
+                                               SDHCI_RESPONSE + (3-i)*4-1);
+                       }
+               } else {
+                       host->cmd->resp[0] = bcm2835_mmc_readl(host, SDHCI_RESPONSE);
+               }
+       }
+
+       host->cmd->error = 0;
+
+       /* Finished CMD23, now send actual command. */
+       if (host->cmd == host->mrq->sbc) {
+               host->cmd = NULL;
+               bcm2835_mmc_send_command(host, host->mrq->cmd);
+
+               if (host->mrq->cmd->data && host->use_dma) {
+                       /* DMA transfer starts now, PIO starts after interrupt */
+                       bcm2835_mmc_transfer_dma(host);
+               }
+       } else {
+
+               /* Processed actual command. */
+               if (host->data && host->data_early)
+                       bcm2835_mmc_finish_data(host);
+
+               if (!host->cmd->data)
+                       tasklet_schedule(&host->finish_tasklet);
+
+               host->cmd = NULL;
+       }
+}
+
+
+static void bcm2835_mmc_timeout_timer(unsigned long data)
+{
+       struct bcm2835_host *host;
+       unsigned long flags;
+
+       host = (struct bcm2835_host *)data;
+
+       spin_lock_irqsave(&host->lock, flags);
+
+       if (host->mrq) {
+               pr_err("%s: Timeout waiting for hardware interrupt.\n",
+                       mmc_hostname(host->mmc));
+               bcm2835_mmc_dumpregs(host);
+
+               if (host->data) {
+                       host->data->error = -ETIMEDOUT;
+                       bcm2835_mmc_finish_data(host);
+               } else {
+                       if (host->cmd)
+                               host->cmd->error = -ETIMEDOUT;
+                       else
+                               host->mrq->cmd->error = -ETIMEDOUT;
+
+                       tasklet_schedule(&host->finish_tasklet);
+               }
+       }
+
+       mmiowb();
+       spin_unlock_irqrestore(&host->lock, flags);
+}
+
+
+static void bcm2835_mmc_enable_sdio_irq_nolock(struct bcm2835_host *host, int enable)
+{
+       if (!(host->flags & SDHCI_DEVICE_DEAD)) {
+               if (enable)
+                       host->ier |= SDHCI_INT_CARD_INT;
+               else
+                       host->ier &= ~SDHCI_INT_CARD_INT;
+
+               bcm2835_mmc_writel(host, host->ier, SDHCI_INT_ENABLE, 7);
+               bcm2835_mmc_writel(host, host->ier, SDHCI_SIGNAL_ENABLE, 7);
+               mmiowb();
+       }
+}
+
+static void bcm2835_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+       struct bcm2835_host *host = mmc_priv(mmc);
+       unsigned long flags;
+
+       spin_lock_irqsave(&host->lock, flags);
+       if (enable)
+               host->flags |= SDHCI_SDIO_IRQ_ENABLED;
+       else
+               host->flags &= ~SDHCI_SDIO_IRQ_ENABLED;
+
+       bcm2835_mmc_enable_sdio_irq_nolock(host, enable);
+       spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void bcm2835_mmc_cmd_irq(struct bcm2835_host *host, u32 intmask)
+{
+
+       BUG_ON(intmask == 0);
+
+       if (!host->cmd) {
+               pr_err("%s: Got command interrupt 0x%08x even "
+                       "though no command operation was in progress.\n",
+                       mmc_hostname(host->mmc), (unsigned)intmask);
+               bcm2835_mmc_dumpregs(host);
+               return;
+       }
+
+       if (intmask & SDHCI_INT_TIMEOUT)
+               host->cmd->error = -ETIMEDOUT;
+       else if (intmask & (SDHCI_INT_CRC | SDHCI_INT_END_BIT |
+                       SDHCI_INT_INDEX)) {
+                       host->cmd->error = -EILSEQ;
+       }
+
+       if (host->cmd->error) {
+               tasklet_schedule(&host->finish_tasklet);
+               return;
+       }
+
+       if (intmask & SDHCI_INT_RESPONSE)
+               bcm2835_mmc_finish_command(host);
+
+}
+
+static void bcm2835_mmc_data_irq(struct bcm2835_host *host, u32 intmask)
+{
+       struct dma_chan *dma_chan;
+       u32 dir_data;
+
+       BUG_ON(intmask == 0);
+
+       if (!host->data) {
+               /*
+                * The "data complete" interrupt is also used to
+                * indicate that a busy state has ended. See comment
+                * above in sdhci_cmd_irq().
+                */
+               if (host->cmd && (host->cmd->flags & MMC_RSP_BUSY)) {
+                       if (intmask & SDHCI_INT_DATA_END) {
+                               bcm2835_mmc_finish_command(host);
+                               return;
+                       }
+               }
+
+               pr_debug("%s: Got data interrupt 0x%08x even "
+                       "though no data operation was in progress.\n",
+                       mmc_hostname(host->mmc), (unsigned)intmask);
+               bcm2835_mmc_dumpregs(host);
+
+               return;
+       }
+
+       if (intmask & SDHCI_INT_DATA_TIMEOUT)
+               host->data->error = -ETIMEDOUT;
+       else if (intmask & SDHCI_INT_DATA_END_BIT)
+               host->data->error = -EILSEQ;
+       else if ((intmask & SDHCI_INT_DATA_CRC) &&
+               SDHCI_GET_CMD(bcm2835_mmc_readw(host, SDHCI_COMMAND))
+                       != MMC_BUS_TEST_R)
+               host->data->error = -EILSEQ;
+
+       if (host->use_dma) {
+               if  (host->data->flags & MMC_DATA_WRITE) {
+                       /* IRQ handled here */
+
+                       dma_chan = host->dma_chan_rxtx;
+                       dir_data = DMA_TO_DEVICE;
+                       dma_unmap_sg(dma_chan->device->dev,
+                                host->data->sg, host->data->sg_len,
+                                dir_data);
+
+                       bcm2835_mmc_finish_data(host);
+               }
+
+       } else {
+               if (host->data->error)
+                       bcm2835_mmc_finish_data(host);
+               else {
+                       if (intmask & (SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL))
+                               bcm2835_mmc_transfer_pio(host);
+
+                       if (intmask & SDHCI_INT_DATA_END) {
+                               if (host->cmd) {
+                                       /*
+                                        * Data managed to finish before the
+                                        * command completed. Make sure we do
+                                        * things in the proper order.
+                                        */
+                                       host->data_early = 1;
+                               } else {
+                                       bcm2835_mmc_finish_data(host);
+                               }
+                       }
+               }
+       }
+}
+
+
+static irqreturn_t bcm2835_mmc_irq(int irq, void *dev_id)
+{
+       irqreturn_t result = IRQ_NONE;
+       struct bcm2835_host *host = dev_id;
+       u32 intmask, mask, unexpected = 0;
+       int max_loops = 16;
+
+       spin_lock(&host->lock);
+
+       intmask = bcm2835_mmc_readl(host, SDHCI_INT_STATUS);
+
+       if (!intmask || intmask == 0xffffffff) {
+               result = IRQ_NONE;
+               goto out;
+       }
+
+       do {
+               /* Clear selected interrupts. */
+               mask = intmask & (SDHCI_INT_CMD_MASK | SDHCI_INT_DATA_MASK |
+                                 SDHCI_INT_BUS_POWER);
+               bcm2835_mmc_writel(host, mask, SDHCI_INT_STATUS, 8);
+
+
+               if (intmask & SDHCI_INT_CMD_MASK)
+                       bcm2835_mmc_cmd_irq(host, intmask & SDHCI_INT_CMD_MASK);
+
+               if (intmask & SDHCI_INT_DATA_MASK)
+                       bcm2835_mmc_data_irq(host, intmask & SDHCI_INT_DATA_MASK);
+
+               if (intmask & SDHCI_INT_BUS_POWER)
+                       pr_err("%s: Card is consuming too much power!\n",
+                               mmc_hostname(host->mmc));
+
+               if (intmask & SDHCI_INT_CARD_INT) {
+                       bcm2835_mmc_enable_sdio_irq_nolock(host, false);
+                       host->thread_isr |= SDHCI_INT_CARD_INT;
+                       result = IRQ_WAKE_THREAD;
+               }
+
+               intmask &= ~(SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE |
+                            SDHCI_INT_CMD_MASK | SDHCI_INT_DATA_MASK |
+                            SDHCI_INT_ERROR | SDHCI_INT_BUS_POWER |
+                            SDHCI_INT_CARD_INT);
+
+               if (intmask) {
+                       unexpected |= intmask;
+                       bcm2835_mmc_writel(host, intmask, SDHCI_INT_STATUS, 9);
+               }
+
+               if (result == IRQ_NONE)
+                       result = IRQ_HANDLED;
+
+               intmask = bcm2835_mmc_readl(host, SDHCI_INT_STATUS);
+       } while (intmask && --max_loops);
+out:
+       spin_unlock(&host->lock);
+
+       if (unexpected) {
+               pr_err("%s: Unexpected interrupt 0x%08x.\n",
+                          mmc_hostname(host->mmc), unexpected);
+               bcm2835_mmc_dumpregs(host);
+       }
+
+       return result;
+}
+
+static irqreturn_t bcm2835_mmc_thread_irq(int irq, void *dev_id)
+{
+       struct bcm2835_host *host = dev_id;
+       unsigned long flags;
+       u32 isr;
+
+       spin_lock_irqsave(&host->lock, flags);
+       isr = host->thread_isr;
+       host->thread_isr = 0;
+       spin_unlock_irqrestore(&host->lock, flags);
+
+       if (isr & SDHCI_INT_CARD_INT) {
+               sdio_run_irqs(host->mmc);
+
+               spin_lock_irqsave(&host->lock, flags);
+               if (host->flags & SDHCI_SDIO_IRQ_ENABLED)
+                       bcm2835_mmc_enable_sdio_irq_nolock(host, true);
+               spin_unlock_irqrestore(&host->lock, flags);
+       }
+
+       return isr ? IRQ_HANDLED : IRQ_NONE;
+}
+
+
+
+void bcm2835_mmc_set_clock(struct bcm2835_host *host, unsigned int clock)
+{
+       int div = 0; /* Initialized for compiler warning */
+       int real_div = div, clk_mul = 1;
+       u16 clk = 0;
+       unsigned long timeout;
+       unsigned int input_clock = clock;
+
+       if (host->overclock_50 && (clock == 50000000))
+               clock = host->overclock_50 * 1000000 + 999999;
+
+       host->mmc->actual_clock = 0;
+
+       bcm2835_mmc_writew(host, 0, SDHCI_CLOCK_CONTROL);
+
+       if (clock == 0)
+               return;
+
+       /* Version 3.00 divisors must be a multiple of 2. */
+       if (host->max_clk <= clock)
+               div = 1;
+       else {
+               for (div = 2; div < SDHCI_MAX_DIV_SPEC_300;
+                        div += 2) {
+                       if ((host->max_clk / div) <= clock)
+                               break;
+               }
+       }
+
+       real_div = div;
+       div >>= 1;
+
+       if (real_div)
+               clock = (host->max_clk * clk_mul) / real_div;
+       host->mmc->actual_clock = clock;
+
+       if ((clock > input_clock) && (clock > host->max_overclock)) {
+               pr_warn("%s: Overclocking to %dHz\n",
+                       mmc_hostname(host->mmc), clock);
+               host->max_overclock = clock;
+       }
+
+       clk |= (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
+       clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)
+               << SDHCI_DIVIDER_HI_SHIFT;
+       clk |= SDHCI_CLOCK_INT_EN;
+       bcm2835_mmc_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+       /* Wait max 20 ms */
+       timeout = 20;
+       while (!((clk = bcm2835_mmc_readw(host, SDHCI_CLOCK_CONTROL))
+               & SDHCI_CLOCK_INT_STABLE)) {
+               if (timeout == 0) {
+                       pr_err("%s: Internal clock never "
+                               "stabilised.\n", mmc_hostname(host->mmc));
+                       bcm2835_mmc_dumpregs(host);
+                       return;
+               }
+               timeout--;
+               mdelay(1);
+       }
+
+       if (20-timeout > 10 && 20-timeout > host->max_delay) {
+               host->max_delay = 20-timeout;
+               pr_warning("Warning: MMC controller hung for %d ms\n", host->max_delay);
+       }
+
+       clk |= SDHCI_CLOCK_CARD_EN;
+       bcm2835_mmc_writew(host, clk, SDHCI_CLOCK_CONTROL);
+}
+
+static void bcm2835_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+       struct bcm2835_host *host;
+       unsigned long flags;
+
+       host = mmc_priv(mmc);
+
+       spin_lock_irqsave(&host->lock, flags);
+
+       WARN_ON(host->mrq != NULL);
+
+       host->mrq = mrq;
+
+       if (mrq->sbc && !(host->flags & SDHCI_AUTO_CMD23))
+               bcm2835_mmc_send_command(host, mrq->sbc);
+       else
+               bcm2835_mmc_send_command(host, mrq->cmd);
+
+       mmiowb();
+       spin_unlock_irqrestore(&host->lock, flags);
+
+       if (!(mrq->sbc && !(host->flags & SDHCI_AUTO_CMD23)) && mrq->cmd->data && host->use_dma) {
+               /* DMA transfer starts now, PIO starts after interrupt */
+               bcm2835_mmc_transfer_dma(host);
+       }
+}
+
+
+static void bcm2835_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+
+       struct bcm2835_host *host = mmc_priv(mmc);
+       unsigned long flags;
+       u8 ctrl;
+       u16 clk, ctrl_2;
+
+       pr_debug("bcm2835_mmc_set_ios: clock %d, pwr %d, bus_width %d, timing %d, vdd %d, drv_type %d\n",
+                ios->clock, ios->power_mode, ios->bus_width,
+                ios->timing, ios->signal_voltage, ios->drv_type);
+
+       spin_lock_irqsave(&host->lock, flags);
+
+       if (!ios->clock || ios->clock != host->clock) {
+               bcm2835_mmc_set_clock(host, ios->clock);
+               host->clock = ios->clock;
+       }
+
+       if (host->pwr != SDHCI_POWER_330) {
+               host->pwr = SDHCI_POWER_330;
+               bcm2835_mmc_writeb(host, SDHCI_POWER_330 | SDHCI_POWER_ON, SDHCI_POWER_CONTROL);
+       }
+
+       ctrl = bcm2835_mmc_readb(host, SDHCI_HOST_CONTROL);
+
+       /* set bus width */
+       ctrl &= ~SDHCI_CTRL_8BITBUS;
+       if (ios->bus_width == MMC_BUS_WIDTH_4)
+               ctrl |= SDHCI_CTRL_4BITBUS;
+       else
+               ctrl &= ~SDHCI_CTRL_4BITBUS;
+
+       ctrl &= ~SDHCI_CTRL_HISPD; /* NO_HISPD_BIT */
+
+
+       bcm2835_mmc_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+       /*
+        * We only need to set Driver Strength if the
+        * preset value enable is not set.
+        */
+       ctrl_2 = bcm2835_mmc_readw(host, SDHCI_HOST_CONTROL2);
+       ctrl_2 &= ~SDHCI_CTRL_DRV_TYPE_MASK;
+       if (ios->drv_type == MMC_SET_DRIVER_TYPE_A)
+               ctrl_2 |= SDHCI_CTRL_DRV_TYPE_A;
+       else if (ios->drv_type == MMC_SET_DRIVER_TYPE_C)
+               ctrl_2 |= SDHCI_CTRL_DRV_TYPE_C;
+
+       bcm2835_mmc_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
+
+       /* Reset SD Clock Enable */
+       clk = bcm2835_mmc_readw(host, SDHCI_CLOCK_CONTROL);
+       clk &= ~SDHCI_CLOCK_CARD_EN;
+       bcm2835_mmc_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+       /* Re-enable SD Clock */
+       bcm2835_mmc_set_clock(host, host->clock);
+       bcm2835_mmc_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+
+       mmiowb();
+
+       spin_unlock_irqrestore(&host->lock, flags);
+}
+
+
+static struct mmc_host_ops bcm2835_ops = {
+       .request = bcm2835_mmc_request,
+       .set_ios = bcm2835_mmc_set_ios,
+       .enable_sdio_irq = bcm2835_mmc_enable_sdio_irq,
+};
+
+
+static void bcm2835_mmc_tasklet_finish(unsigned long param)
+{
+       struct bcm2835_host *host;
+       unsigned long flags;
+       struct mmc_request *mrq;
+
+       host = (struct bcm2835_host *)param;
+
+       spin_lock_irqsave(&host->lock, flags);
+
+       /*
+        * If this tasklet gets rescheduled while running, it will
+        * be run again afterwards but without any active request.
+        */
+       if (!host->mrq) {
+               spin_unlock_irqrestore(&host->lock, flags);
+               return;
+       }
+
+       del_timer(&host->timer);
+
+       mrq = host->mrq;
+
+       /*
+        * The controller needs a reset of internal state machines
+        * upon error conditions.
+        */
+       if (!(host->flags & SDHCI_DEVICE_DEAD) &&
+           ((mrq->cmd && mrq->cmd->error) ||
+                (mrq->data && (mrq->data->error ||
+                 (mrq->data->stop && mrq->data->stop->error))))) {
+
+               spin_unlock_irqrestore(&host->lock, flags);
+               bcm2835_mmc_reset(host, SDHCI_RESET_CMD);
+               bcm2835_mmc_reset(host, SDHCI_RESET_DATA);
+               spin_lock_irqsave(&host->lock, flags);
+       }
+
+       host->mrq = NULL;
+       host->cmd = NULL;
+       host->data = NULL;
+
+       mmiowb();
+
+       spin_unlock_irqrestore(&host->lock, flags);
+       mmc_request_done(host->mmc, mrq);
+}
+
+
+
+static int bcm2835_mmc_add_host(struct bcm2835_host *host)
+{
+       struct mmc_host *mmc = host->mmc;
+       struct device *dev = mmc->parent;
+#ifndef FORCE_PIO
+       struct dma_slave_config cfg;
+#endif
+       int ret;
+
+       bcm2835_mmc_reset(host, SDHCI_RESET_ALL);
+
+       host->clk_mul = 0;
+
+       mmc->f_max = host->max_clk;
+       mmc->f_max = host->max_clk;
+       mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300;
+
+       /* SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK */
+       host->timeout_clk = mmc->f_max / 1000;
+       mmc->max_busy_timeout = (1 << 27) / host->timeout_clk;
+
+       /* host controller capabilities */
+       mmc->caps |= MMC_CAP_CMD23 | MMC_CAP_ERASE | MMC_CAP_NEEDS_POLL |
+               MMC_CAP_SDIO_IRQ | MMC_CAP_SD_HIGHSPEED |
+               MMC_CAP_MMC_HIGHSPEED;
+
+       mmc->caps2 |= MMC_CAP2_SDIO_IRQ_NOTHREAD;
+
+       host->flags = SDHCI_AUTO_CMD23;
+
+       dev_info(dev, "mmc_debug:%x mmc_debug2:%x\n", mmc_debug, mmc_debug2);
+#ifdef FORCE_PIO
+       dev_info(dev, "Forcing PIO mode\n");
+       host->have_dma = false;
+#else
+       if (IS_ERR_OR_NULL(host->dma_chan_rxtx)) {
+               dev_err(dev, "%s: Unable to initialise DMA channel. Falling back to PIO\n",
+                       DRIVER_NAME);
+               host->have_dma = false;
+       } else {
+               dev_info(dev, "DMA channel allocated");
+
+               cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+               cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+               cfg.slave_id = 11;              /* DREQ channel */
+
+               /* Validate the slave configurations */
+
+               cfg.direction = DMA_MEM_TO_DEV;
+               cfg.src_addr = 0;
+               cfg.dst_addr = host->bus_addr + SDHCI_BUFFER;
+
+               ret = dmaengine_slave_config(host->dma_chan_rxtx, &cfg);
+
+               if (ret == 0) {
+                       host->dma_cfg_tx = cfg;
+
+                       cfg.direction = DMA_DEV_TO_MEM;
+                       cfg.src_addr = host->bus_addr + SDHCI_BUFFER;
+                       cfg.dst_addr = 0;
+
+                       ret = dmaengine_slave_config(host->dma_chan_rxtx, &cfg);
+               }
+
+               if (ret == 0) {
+                       host->dma_cfg_rx = cfg;
+
+                       host->have_dma = true;
+               } else {
+                       pr_err("%s: unable to configure DMA channel. "
+                              "Falling back to PIO\n",
+                              mmc_hostname(mmc));
+                       dma_release_channel(host->dma_chan_rxtx);
+                       host->dma_chan_rxtx = NULL;
+                       host->have_dma = false;
+               }
+       }
+#endif
+       mmc->max_segs = 128;
+       mmc->max_req_size = 524288;
+       mmc->max_seg_size = mmc->max_req_size;
+       mmc->max_blk_size = 512;
+       mmc->max_blk_count =  65535;
+
+       /* report supported voltage ranges */
+       mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
+
+       tasklet_init(&host->finish_tasklet,
+               bcm2835_mmc_tasklet_finish, (unsigned long)host);
+
+       setup_timer(&host->timer, bcm2835_mmc_timeout_timer, (unsigned long)host);
+       init_waitqueue_head(&host->buf_ready_int);
+
+       bcm2835_mmc_init(host, 0);
+       ret = devm_request_threaded_irq(dev, host->irq, bcm2835_mmc_irq,
+                                       bcm2835_mmc_thread_irq, IRQF_SHARED,
+                                       mmc_hostname(mmc), host);
+       if (ret) {
+               dev_err(dev, "Failed to request IRQ %d: %d\n", host->irq, ret);
+               goto untasklet;
+       }
+
+       mmiowb();
+       mmc_add_host(mmc);
+
+       return 0;
+
+untasklet:
+       tasklet_kill(&host->finish_tasklet);
+
+       return ret;
+}
+
+static int bcm2835_mmc_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct device_node *node = dev->of_node;
+       struct clk *clk;
+       struct resource *iomem;
+       struct bcm2835_host *host;
+       struct mmc_host *mmc;
+       const __be32 *addr;
+       int ret;
+
+       mmc = mmc_alloc_host(sizeof(*host), dev);
+       if (!mmc)
+               return -ENOMEM;
+
+       mmc->ops = &bcm2835_ops;
+       host = mmc_priv(mmc);
+       host->mmc = mmc;
+       host->timeout = msecs_to_jiffies(1000);
+       spin_lock_init(&host->lock);
+
+       iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       host->ioaddr = devm_ioremap_resource(dev, iomem);
+       if (IS_ERR(host->ioaddr)) {
+               ret = PTR_ERR(host->ioaddr);
+               goto err;
+       }
+
+       addr = of_get_address(node, 0, NULL, NULL);
+       if (!addr) {
+               dev_err(dev, "could not get DMA-register address\n");
+               return -ENODEV;
+       }
+       host->bus_addr = be32_to_cpup(addr);
+       pr_debug(" - ioaddr %lx, iomem->start %lx, bus_addr %lx\n",
+                (unsigned long)host->ioaddr,
+                (unsigned long)iomem->start,
+                (unsigned long)host->bus_addr);
+
+#ifndef FORCE_PIO
+       if (node) {
+               host->dma_chan_rxtx = dma_request_slave_channel(dev, "rx-tx");
+               if (!host->dma_chan_rxtx)
+                       host->dma_chan_rxtx =
+                               dma_request_slave_channel(dev, "tx");
+               if (!host->dma_chan_rxtx)
+                       host->dma_chan_rxtx =
+                               dma_request_slave_channel(dev, "rx");
+       } else {
+               dma_cap_mask_t mask;
+
+               dma_cap_zero(mask);
+               /* we don't care about the channel, any would work */
+               dma_cap_set(DMA_SLAVE, mask);
+               host->dma_chan_rxtx = dma_request_channel(mask, NULL, NULL);
+       }
+#endif
+       clk = devm_clk_get(dev, NULL);
+       if (IS_ERR(clk)) {
+               ret = PTR_ERR(clk);
+               if (ret == -EPROBE_DEFER)
+                       dev_info(dev, "could not get clk, deferring probe\n");
+               else
+                       dev_err(dev, "could not get clk\n");
+               goto err;
+       }
+
+       host->max_clk = clk_get_rate(clk);
+
+       host->irq = platform_get_irq(pdev, 0);
+       if (host->irq <= 0) {
+               dev_err(dev, "get IRQ failed\n");
+               ret = -EINVAL;
+               goto err;
+       }
+
+       if (node) {
+               mmc_of_parse(mmc);
+
+               /* Read any custom properties */
+               of_property_read_u32(node,
+                                    "brcm,overclock-50",
+                                    &host->overclock_50);
+       } else {
+               mmc->caps |= MMC_CAP_4_BIT_DATA;
+       }
+
+       ret = bcm2835_mmc_add_host(host);
+       if (ret)
+               goto err;
+
+       platform_set_drvdata(pdev, host);
+
+       return 0;
+err:
+       mmc_free_host(mmc);
+
+       return ret;
+}
+
+static int bcm2835_mmc_remove(struct platform_device *pdev)
+{
+       struct bcm2835_host *host = platform_get_drvdata(pdev);
+       unsigned long flags;
+       int dead;
+       u32 scratch;
+
+       dead = 0;
+       scratch = bcm2835_mmc_readl(host, SDHCI_INT_STATUS);
+       if (scratch == (u32)-1)
+               dead = 1;
+
+
+       if (dead) {
+               spin_lock_irqsave(&host->lock, flags);
+
+               host->flags |= SDHCI_DEVICE_DEAD;
+
+               if (host->mrq) {
+                       pr_err("%s: Controller removed during "
+                               " transfer!\n", mmc_hostname(host->mmc));
+
+                       host->mrq->cmd->error = -ENOMEDIUM;
+                       tasklet_schedule(&host->finish_tasklet);
+               }
+
+               spin_unlock_irqrestore(&host->lock, flags);
+       }
+
+       mmc_remove_host(host->mmc);
+
+       if (!dead)
+               bcm2835_mmc_reset(host, SDHCI_RESET_ALL);
+
+       free_irq(host->irq, host);
+
+       del_timer_sync(&host->timer);
+
+       tasklet_kill(&host->finish_tasklet);
+
+       mmc_free_host(host->mmc);
+       platform_set_drvdata(pdev, NULL);
+
+       return 0;
+}
+
+
+static const struct of_device_id bcm2835_mmc_match[] = {
+       { .compatible = "brcm,bcm2835-mmc" },
+       { }
+};
+MODULE_DEVICE_TABLE(of, bcm2835_mmc_match);
+
+
+
+static struct platform_driver bcm2835_mmc_driver = {
+       .probe      = bcm2835_mmc_probe,
+       .remove     = bcm2835_mmc_remove,
+       .driver     = {
+               .name           = DRIVER_NAME,
+               .owner          = THIS_MODULE,
+               .of_match_table = bcm2835_mmc_match,
+       },
+};
+module_platform_driver(bcm2835_mmc_driver);
+
+module_param(mmc_debug, uint, 0644);
+module_param(mmc_debug2, uint, 0644);
+MODULE_ALIAS("platform:mmc-bcm2835");
+MODULE_DESCRIPTION("BCM2835 SDHCI driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Gellert Weisz");
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -269,6 +269,8 @@ struct mmc_card {
 #define MMC_QUIRK_TRIM_BROKEN  (1<<12)         /* Skip trim */
 #define MMC_QUIRK_BROKEN_HPI   (1<<13)         /* Disable broken HPI support */
 
+#define MMC_QUIRK_ERASE_BROKEN (1<<31)         /* Skip erase */
+
        bool                    reenable_cmdq;  /* Re-enable Command Queue */
 
        unsigned int            erase_size;     /* erase size in sectors */