bcm27xx: add linux 5.4 support

Tested on bcm2710 (Raspberry Pi 3B).

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 2482 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.4/950-0044-Adding-bcm2835-sdhost-driver-and-an-overlay-to-enabl.patch b/target/linux/bcm27xx/patches-5.4/950-0044-Adding-bcm2835-sdhost-driver-and-an-overlay-to-enabl.patch
new file mode 100644
index 0000000000..ff219e3d01
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0044-Adding-bcm2835-sdhost-driver-and-an-overlay-to-enabl.patch
@@ -0,0 +1,2482 @@
+From 4b99e30ff67c5c6a471ef276cf5166016beb24ea Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+Date: Wed, 25 Mar 2015 17:49:47 +0000
+Subject: [PATCH] Adding bcm2835-sdhost driver, and an overlay to
+ enable it
+
+BCM2835 has two SD card interfaces. This driver uses the other one.
+
+bcm2835-sdhost: Error handling fix, and code clarification
+
+bcm2835-sdhost: 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 sdhost interface is restricted to integer divisions of
+core_freq, and the highest sensible option for a core_freq of 250MHz
+is 84 (250/3 = 83.3MHz), the next being 125 (250/2) which is much too
+high.
+
+Use at your own risk.
+
+bcm2835-sdhost: Round up the overclock, so 62 works for 62.5Mhz
+
+Also only warn once for each overclock setting.
+
+bcm2835-sdhost: Improve error handling and recovery
+
+1) Expose the hw_reset method to the MMC framework, removing many
+   internal calls by the driver.
+
+2) Reduce overclock setting on error.
+
+3) Increase timeout to cope with high capacity cards.
+
+4) Add properties and parameters to control pio_limit and debug.
+
+5) Reduce messages at probe time.
+
+bcm2835-sdhost: Further improve overclock back-off
+
+bcm2835-sdhost: Clear HBLC for PIO mode
+
+Also update pio_limit default in overlay README.
+
+bcm2835-sdhost: Add the ERASE capability
+
+See: https://github.com/raspberrypi/linux/issues/1076
+
+bcm2835-sdhost: Ignore CRC7 for MMC CMD1
+
+It seems that the sdhost interface returns CRC7 errors for CMD1,
+which is the MMC-specific SEND_OP_COND. Returning these errors to
+the MMC layer causes a downward spiral, but ignoring them seems
+to be harmless.
+
+bcm2835-mmc/sdhost: Remove ARCH_BCM2835 differences
+
+The bcm2835-mmc driver (and -sdhost driver that copied from it)
+contains code to handle SDIO interrupts in a threaded interrupt
+handler rather than waking the MMC framework thread. The change
+follows a patch from Russell King that adds the facility as the
+preferred way of working.
+
+However, the new code path is only present in ARCH_BCM2835
+builds, which I have taken to be a way of testing the waters
+rather than making the change across the board; I can't see
+any technical reason why it wouldn't be enabled for MACH_BCM270X
+builds. So this patch standardises on the ARCH_BCM2835 code,
+removing the old code paths.
+
+bcm2835-sdhost: Don't log timeout errors unless debug=1
+
+The MMC card-discovery process generates timeouts. This is
+expected behaviour, so reporting it to the user serves no purpose.
+Suppress the reporting of timeout errors unless the debug flag
+is on.
+
+bcm2835-sdhost: Add workaround for odd behaviour on some cards
+
+For reasons not understood, the sdhost driver fails when reading
+sectors very near the end of some SD cards. The problem could
+be related to the similar issue that reading the final sector
+of any card as part of a multiple read never completes, and the
+workaround is an extension of the mechanism introduced to solve
+that problem which ensures those sectors are always read singly.
+
+bcm2835-sdhost: Major revision
+
+This is a significant revision of the bcm2835-sdhost driver. It
+improves on the original in a number of ways:
+
+1) Through the use of CMD23 for reads it appears to avoid problems
+   reading some sectors on certain high speed cards.
+2) Better atomicity to prevent crashes.
+3) Higher performance.
+4) Activity logging included, for easier diagnosis in the event
+   of a problem.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+bcm2835-sdhost: Restore ATOMIC flag to PIO sg mapping
+
+Allocation problems have been seen in a wireless driver, and
+this is the only change which might have been responsible.
+
+SQUASH: bcm2835-sdhost: Only claim one DMA channel
+
+With both MMC controllers enabled there are few DMA channels left. The
+bcm2835-sdhost 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>
+
+bcm2835-sdhost: Workaround for "slow" sectors
+
+Some cards have been seen to cause timeouts after certain sectors are
+read. This workaround enforces a minimum delay between the stop after
+reading one of those sectors and a subsequent data command.
+
+Using CMD23 (SET_BLOCK_COUNT) avoids this problem, so good cards will
+not be penalised by this workaround.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+bcm2835-sdhost: Firmware manages the clock divisor
+
+The bcm2835-sdhost driver hands control of the CDIV clock divisor
+register to matching firmware, allowing it to adjust to a changing
+core clock. This removes the need to use the performance governor or
+to enable io_is_busy on the on-demand governor in order to get the
+best SD performance.
+
+N.B. As SD clocks must be an integer divisor of the core clock, it is
+possible that the SD clock for "turbo" mode can be different (even
+lower) than "normal" mode.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+bcm2835-sdhost: Reset the clock in task context
+
+Since reprogramming the clock can now involve a round-trip to the
+firmware it must not be done at atomic context, and a tasklet
+is not a task.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+bcm2835-sdhost: Don't exit cmd wait loop on error
+
+The FAIL flag can be set in the CMD register before command processing
+is complete, leading to spurious "failed to complete" errors. This has
+the effect of promoting harmless CRC7 errors during CMD1 processing
+into errors that can delay and even prevent booting.
+
+Also:
+1) Convert the last KERN_ERROR message in the register dumping to
+   KERN_INFO.
+2) Remove an unnecessary reset call from  bcm2835_sdhost_add_host.
+
+See: https://github.com/raspberrypi/linux/pull/1492
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+bcm2835-sdhost: mmc_card_blockaddr fix
+
+Get the definition of mmc_card_blockaddr from drivers/mmc/core/card.h.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+bcm2835-sdhost: New timer API
+
+mmc: bcm2835-sdhost: Support underclocking
+
+Support underclocking of the SD bus in two ways:
+1. using the max-frequency DT property (which currently has no DT
+   parameter), and
+2. using the exiting sd_overclock parameter.
+
+The two methods differ slightly - in the former the MMC subsystem is
+aware of the underclocking, while in the latter it isn't - but the
+end results should be the same.
+
+See: https://github.com/raspberrypi/linux/issues/2350
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+mmc: bcm2835-sdhost: Add include
+
+highmem.h (needed for kmap_atomic) is pulled in by one of the other
+include files, but only with some CONFIG settings. Make the inclusion
+explicit to cater for cases where the CONFIG setting is absent.
+
+See: https://github.com/raspberrypi/linux/issues/2366
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+mmc/bcm2835-sdhost: Recover from MMC_SEND_EXT_CSD
+
+If the user issues an "mmc extcsd read", the SD controller receives
+what it thinks is a SEND_IF_COND command with an unexpected data block.
+The resulting operations leave the FSM stuck in READWAIT, a state which
+persists until the MMC framework resets the controller, by which point
+the root filesystem is likely to have been unmounted.
+
+A less heavyweight solution is to detect the condition and nudge the
+FSM by asserting the (self-clearing) FORCE_DATA_MODE bit.
+
+N.B. This workaround was essentially discovered by accident and without
+a full understanding the inner workings of the controller, so it is
+fortunate that the "fix" only modifies error paths.
+
+See: https://github.com/raspberrypi/linux/issues/2728
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+mmc: bcm2835-sdhost: Fix warnings on arm64
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+bcm2835-sdhost: Allow for sg entries that cross pages
+
+The dma_complete handling code calculates a virtual address for a page
+then adds an offset, but if the offset is more than a page and HIGHMEM
+is in use then the summed address could be in an unmapped (or just
+incorrect) page.
+
+The upstream SDHOST driver allows for this possibility - copy the code
+that does so.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+bcm2835-sdhost: Fix DMA channel leak on error/remove
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+
+mmc: bcm2835-sdhost: Support 64-bit physical addresses
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+---
+ drivers/mmc/host/Kconfig          |   10 +
+ drivers/mmc/host/Makefile         |    1 +
+ drivers/mmc/host/bcm2835-sdhost.c | 2204 +++++++++++++++++++++++++++++
+ 3 files changed, 2215 insertions(+)
+ create mode 100644 drivers/mmc/host/bcm2835-sdhost.c
+
+--- a/drivers/mmc/host/Kconfig
++++ b/drivers/mmc/host/Kconfig
+@@ -34,6 +34,16 @@ config MMC_BCM2835_PIO_DMA_BARRIER
+ 
+ 	  If unsure, say 2 here.
+ 
++config MMC_BCM2835_SDHOST
++	tristate "Support for the SDHost controller on BCM2708/9"
++	depends on ARCH_BCM2835
++	help
++	  This selects the SDHost controller on BCM2835/6.
++
++	  If you have a controller with this interface, say Y or M here.
++
++	  If unsure, say N.
++
+ config MMC_DEBUG
+ 	bool "MMC host drivers debugging"
+ 	depends on MMC != n
+--- a/drivers/mmc/host/Makefile
++++ b/drivers/mmc/host/Makefile
+@@ -24,6 +24,7 @@ obj-$(CONFIG_MMC_SDHCI_F_SDH30)	+= sdhci
+ obj-$(CONFIG_MMC_SDHCI_SPEAR)	+= sdhci-spear.o
+ obj-$(CONFIG_MMC_SDHCI_AM654)	+= sdhci_am654.o
+ obj-$(CONFIG_MMC_BCM2835_MMC)	+= bcm2835-mmc.o
++obj-$(CONFIG_MMC_BCM2835_SDHOST)	+= bcm2835-sdhost.o
+ obj-$(CONFIG_MMC_WBSD)		+= wbsd.o
+ obj-$(CONFIG_MMC_AU1X)		+= au1xmmc.o
+ obj-$(CONFIG_MMC_ALCOR)	+= alcor.o
+--- /dev/null
++++ b/drivers/mmc/host/bcm2835-sdhost.c
+@@ -0,0 +1,2204 @@
++/*
++ * BCM2835 SD host driver.
++ *
++ * Author:      Phil Elwell <phil@raspberrypi.org>
++ *              Copyright (C) 2015-2016 Raspberry Pi (Trading) Ltd.
++ *
++ * Based on
++ *  mmc-bcm2835.c by Gellert Weisz
++ * which is, in turn, 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/>.
++ */
++
++#define FIFO_READ_THRESHOLD     4
++#define FIFO_WRITE_THRESHOLD    4
++#define ALLOW_CMD23_READ        1
++#define ALLOW_CMD23_WRITE       0
++#define ENABLE_LOG              1
++#define SDDATA_FIFO_PIO_BURST   8
++#define CMD_DALLY_US            1
++
++#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/mmc/sdio.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 <linux/time.h>
++#include <linux/workqueue.h>
++#include <linux/interrupt.h>
++#include <linux/highmem.h>
++#include <soc/bcm2835/raspberrypi-firmware.h>
++
++/* For mmc_card_blockaddr */
++#include "../core/card.h"
++
++#define DRIVER_NAME "sdhost-bcm2835"
++
++#define SDCMD  0x00 /* Command to SD card              - 16 R/W */
++#define SDARG  0x04 /* Argument to SD card             - 32 R/W */
++#define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
++#define SDCDIV 0x0c /* Start value for clock divider   - 11 R/W */
++#define SDRSP0 0x10 /* SD card response (31:0)         - 32 R   */
++#define SDRSP1 0x14 /* SD card response (63:32)        - 32 R   */
++#define SDRSP2 0x18 /* SD card response (95:64)        - 32 R   */
++#define SDRSP3 0x1c /* SD card response (127:96)       - 32 R   */
++#define SDHSTS 0x20 /* SD host status                  - 11 R   */
++#define SDVDD  0x30 /* SD card power control           -  1 R/W */
++#define SDEDM  0x34 /* Emergency Debug Mode            - 13 R/W */
++#define SDHCFG 0x38 /* Host configuration              -  2 R/W */
++#define SDHBCT 0x3c /* Host byte count (debug)         - 32 R/W */
++#define SDDATA 0x40 /* Data to/from SD card            - 32 R/W */
++#define SDHBLC 0x50 /* Host block count (SDIO/SDHC)    -  9 R/W */
++
++#define SDCMD_NEW_FLAG                  0x8000
++#define SDCMD_FAIL_FLAG                 0x4000
++#define SDCMD_BUSYWAIT                  0x800
++#define SDCMD_NO_RESPONSE               0x400
++#define SDCMD_LONG_RESPONSE             0x200
++#define SDCMD_WRITE_CMD                 0x80
++#define SDCMD_READ_CMD                  0x40
++#define SDCMD_CMD_MASK                  0x3f
++
++#define SDCDIV_MAX_CDIV                 0x7ff
++
++#define SDHSTS_BUSY_IRPT                0x400
++#define SDHSTS_BLOCK_IRPT               0x200
++#define SDHSTS_SDIO_IRPT                0x100
++#define SDHSTS_REW_TIME_OUT             0x80
++#define SDHSTS_CMD_TIME_OUT             0x40
++#define SDHSTS_CRC16_ERROR              0x20
++#define SDHSTS_CRC7_ERROR               0x10
++#define SDHSTS_FIFO_ERROR               0x08
++/* Reserved */
++/* Reserved */
++#define SDHSTS_DATA_FLAG                0x01
++
++#define SDHSTS_TRANSFER_ERROR_MASK      (SDHSTS_CRC7_ERROR|SDHSTS_CRC16_ERROR|SDHSTS_REW_TIME_OUT|SDHSTS_FIFO_ERROR)
++#define SDHSTS_ERROR_MASK               (SDHSTS_CMD_TIME_OUT|SDHSTS_TRANSFER_ERROR_MASK)
++
++#define SDHCFG_BUSY_IRPT_EN     (1<<10)
++#define SDHCFG_BLOCK_IRPT_EN    (1<<8)
++#define SDHCFG_SDIO_IRPT_EN     (1<<5)
++#define SDHCFG_DATA_IRPT_EN     (1<<4)
++#define SDHCFG_SLOW_CARD        (1<<3)
++#define SDHCFG_WIDE_EXT_BUS     (1<<2)
++#define SDHCFG_WIDE_INT_BUS     (1<<1)
++#define SDHCFG_REL_CMD_LINE     (1<<0)
++
++#define SDEDM_FORCE_DATA_MODE   (1<<19)
++#define SDEDM_CLOCK_PULSE       (1<<20)
++#define SDEDM_BYPASS            (1<<21)
++
++#define SDEDM_WRITE_THRESHOLD_SHIFT 9
++#define SDEDM_READ_THRESHOLD_SHIFT 14
++#define SDEDM_THRESHOLD_MASK     0x1f
++
++#define SDEDM_FSM_MASK           0xf
++#define SDEDM_FSM_IDENTMODE      0x0
++#define SDEDM_FSM_DATAMODE       0x1
++#define SDEDM_FSM_READDATA       0x2
++#define SDEDM_FSM_WRITEDATA      0x3
++#define SDEDM_FSM_READWAIT       0x4
++#define SDEDM_FSM_READCRC        0x5
++#define SDEDM_FSM_WRITECRC       0x6
++#define SDEDM_FSM_WRITEWAIT1     0x7
++#define SDEDM_FSM_POWERDOWN      0x8
++#define SDEDM_FSM_POWERUP        0x9
++#define SDEDM_FSM_WRITESTART1    0xa
++#define SDEDM_FSM_WRITESTART2    0xb
++#define SDEDM_FSM_GENPULSES      0xc
++#define SDEDM_FSM_WRITEWAIT2     0xd
++#define SDEDM_FSM_STARTPOWDOWN   0xf
++
++#define SDDATA_FIFO_WORDS        16
++
++#define USE_CMD23_FLAGS          ((ALLOW_CMD23_READ * MMC_DATA_READ) | \
++				  (ALLOW_CMD23_WRITE * MMC_DATA_WRITE))
++
++#define MHZ 1000000
++
++
++struct bcm2835_host {
++	spinlock_t		lock;
++
++	void __iomem		*ioaddr;
++	phys_addr_t		bus_addr;
++
++	struct mmc_host		*mmc;
++
++	u32			pio_timeout;	/* In jiffies */
++
++	int			clock;		/* Current clock speed */
++
++	bool			slow_card;	/* Force 11-bit divisor */
++
++	unsigned int		max_clk;	/* Max possible freq */
++
++	struct tasklet_struct	finish_tasklet;	/* Tasklet structures */
++
++	struct work_struct	cmd_wait_wq;	/* Workqueue function */
++
++	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			cmd_quick_poll_retries;
++	u32			ns_per_fifo_word;
++
++	/* cached registers */
++	u32			hcfg;
++	u32			cdiv;
++
++	struct mmc_request		*mrq;			/* Current request */
++	struct mmc_command		*cmd;			/* Current command */
++	struct mmc_data			*data;			/* Current data request */
++	unsigned int			data_complete:1;	/* Data finished before cmd */
++
++	unsigned int			flush_fifo:1;		/* Drain the fifo when finishing */
++
++	unsigned int			use_busy:1;		/* Wait for busy interrupt */
++
++	unsigned int			use_sbc:1;		/* Send CMD23 */
++
++	unsigned int			debug:1;		/* Enable debug output */
++	unsigned int			firmware_sets_cdiv:1;	/* Let the firmware manage the clock */
++	unsigned int			reset_clock:1;		/* Reset the clock fore the next request */
++
++	/*DMA part*/
++	struct dma_chan			*dma_chan_rxtx;		/* DMA channel for reads and writes */
++	struct dma_chan			*dma_chan;		/* Channel in use */
++	struct dma_slave_config		dma_cfg_rx;
++	struct dma_slave_config		dma_cfg_tx;
++	struct dma_async_tx_descriptor	*dma_desc;
++	u32				dma_dir;
++	u32				drain_words;
++	struct page 			*drain_page;
++	u32				drain_offset;
++
++	bool				allow_dma;
++	bool				use_dma;
++	/*end of DMA part*/
++
++	int				max_delay;	/* maximum length of time spent waiting */
++	struct timeval			stop_time;	/* when the last stop was issued */
++	u32				delay_after_stop; /* minimum time between stop and subsequent data transfer */
++	u32				delay_after_this_stop; /* minimum time between this stop and subsequent data transfer */
++	u32				user_overclock_50; /* User's preferred frequency to use when 50MHz is requested (in MHz) */
++	u32				overclock_50;	/* frequency to use when 50MHz is requested (in MHz) */
++	u32				overclock;	/* Current frequency if overclocked, else zero */
++	u32				pio_limit;	/* Maximum block count for PIO (0 = always DMA) */
++
++	u32				sectors;	/* Cached card size in sectors */
++};
++
++#if ENABLE_LOG
++
++struct log_entry_struct {
++	char event[4];
++	u32 timestamp;
++	u32 param1;
++	u32 param2;
++};
++
++typedef struct log_entry_struct LOG_ENTRY_T;
++
++LOG_ENTRY_T *sdhost_log_buf;
++dma_addr_t sdhost_log_addr;
++static u32 sdhost_log_idx;
++static spinlock_t log_lock;
++static void __iomem *timer_base;
++
++#define LOG_ENTRIES (256*1)
++#define LOG_SIZE (sizeof(LOG_ENTRY_T)*LOG_ENTRIES)
++
++static void log_init(struct device *dev, u32 bus_to_phys)
++{
++	spin_lock_init(&log_lock);
++	sdhost_log_buf = dma_alloc_coherent(dev, LOG_SIZE, &sdhost_log_addr,
++					     GFP_KERNEL);
++	if (sdhost_log_buf) {
++		pr_info("sdhost: log_buf @ %p (%llx)\n",
++			sdhost_log_buf, (u64)sdhost_log_addr);
++		timer_base = ioremap_nocache(bus_to_phys + 0x7e003000, SZ_4K);
++		if (!timer_base)
++			pr_err("sdhost: failed to remap timer\n");
++	}
++	else
++		pr_err("sdhost: failed to allocate log buf\n");
++}
++
++static void log_event_impl(const char *event, u32 param1, u32 param2)
++{
++	if (sdhost_log_buf) {
++		LOG_ENTRY_T *entry;
++		unsigned long flags;
++
++		spin_lock_irqsave(&log_lock, flags);
++
++		entry = sdhost_log_buf + sdhost_log_idx;
++		memcpy(entry->event, event, 4);
++		entry->timestamp = (readl(timer_base + 4) & 0x3fffffff) +
++			(smp_processor_id()<<30);
++		entry->param1 = param1;
++		entry->param2 = param2;
++		sdhost_log_idx = (sdhost_log_idx + 1) % LOG_ENTRIES;
++
++		spin_unlock_irqrestore(&log_lock, flags);
++	}
++}
++
++static void log_dump(void)
++{
++	if (sdhost_log_buf) {
++		LOG_ENTRY_T *entry;
++		unsigned long flags;
++		int idx;
++
++		spin_lock_irqsave(&log_lock, flags);
++
++		idx = sdhost_log_idx;
++		do {
++			entry = sdhost_log_buf + idx;
++			if (entry->event[0] != '\0')
++				pr_info("[%08x] %.4s %x %x\n",
++				       entry->timestamp,
++				       entry->event,
++				       entry->param1,
++				       entry->param2);
++			idx = (idx + 1) % LOG_ENTRIES;
++		} while (idx != sdhost_log_idx);
++
++		spin_unlock_irqrestore(&log_lock, flags);
++	}
++}
++
++#define log_event(event, param1, param2) log_event_impl(event, (u32)(uintptr_t)param1, (u32)(uintptr_t)param2)
++
++#else
++
++#define log_init(x) (void)0
++#define log_event(event, param1, param2) (void)0
++#define log_dump() (void)0
++
++#endif
++
++static inline void do_gettimeofday(struct timeval *tv)
++{
++	struct timespec64 now;
++
++	ktime_get_real_ts64(&now);
++	tv->tv_sec = now.tv_sec;
++	tv->tv_usec = now.tv_nsec/1000;
++}
++
++static inline void bcm2835_sdhost_write(struct bcm2835_host *host, u32 val, int reg)
++{
++	writel(val, host->ioaddr + reg);
++}
++
++static inline u32 bcm2835_sdhost_read(struct bcm2835_host *host, int reg)
++{
++	return readl(host->ioaddr + reg);
++}
++
++static inline u32 bcm2835_sdhost_read_relaxed(struct bcm2835_host *host, int reg)
++{
++	return readl_relaxed(host->ioaddr + reg);
++}
++
++static void bcm2835_sdhost_dumpcmd(struct bcm2835_host *host,
++				   struct mmc_command *cmd,
++				   const char *label)
++{
++	if (cmd)
++		pr_info("%s:%c%s op %d arg 0x%x flags 0x%x - resp %08x %08x %08x %08x, err %d\n",
++			mmc_hostname(host->mmc),
++			(cmd == host->cmd) ? '>' : ' ',
++			label, cmd->opcode, cmd->arg, cmd->flags,
++			cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3],
++			cmd->error);
++}
++
++static void bcm2835_sdhost_dumpregs(struct bcm2835_host *host)
++{
++	if (host->mrq)
++	{
++		bcm2835_sdhost_dumpcmd(host, host->mrq->sbc, "sbc");
++		bcm2835_sdhost_dumpcmd(host, host->mrq->cmd, "cmd");
++		if (host->mrq->data)
++			pr_info("%s: data blocks %x blksz %x - err %d\n",
++			       mmc_hostname(host->mmc),
++			       host->mrq->data->blocks,
++			       host->mrq->data->blksz,
++			       host->mrq->data->error);
++		bcm2835_sdhost_dumpcmd(host, host->mrq->stop, "stop");
++	}
++
++	pr_info("%s: =========== REGISTER DUMP ===========\n",
++		mmc_hostname(host->mmc));
++
++	pr_info("%s: SDCMD  0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDCMD));
++	pr_info("%s: SDARG  0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDARG));
++	pr_info("%s: SDTOUT 0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDTOUT));
++	pr_info("%s: SDCDIV 0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDCDIV));
++	pr_info("%s: SDRSP0 0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDRSP0));
++	pr_info("%s: SDRSP1 0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDRSP1));
++	pr_info("%s: SDRSP2 0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDRSP2));
++	pr_info("%s: SDRSP3 0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDRSP3));
++	pr_info("%s: SDHSTS 0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDHSTS));
++	pr_info("%s: SDVDD  0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDVDD));
++	pr_info("%s: SDEDM  0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDEDM));
++	pr_info("%s: SDHCFG 0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDHCFG));
++	pr_info("%s: SDHBCT 0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDHBCT));
++	pr_info("%s: SDHBLC 0x%08x\n",
++		mmc_hostname(host->mmc),
++		bcm2835_sdhost_read(host, SDHBLC));
++
++	pr_info("%s: ===========================================\n",
++		mmc_hostname(host->mmc));
++}
++
++static void bcm2835_sdhost_set_power(struct bcm2835_host *host, bool on)
++{
++	bcm2835_sdhost_write(host, on ? 1 : 0, SDVDD);
++}
++
++static void bcm2835_sdhost_reset_internal(struct bcm2835_host *host)
++{
++	u32 temp;
++
++	if (host->debug)
++		pr_info("%s: reset\n", mmc_hostname(host->mmc));
++
++	bcm2835_sdhost_set_power(host, false);
++
++	bcm2835_sdhost_write(host, 0, SDCMD);
++	bcm2835_sdhost_write(host, 0, SDARG);
++	bcm2835_sdhost_write(host, 0xf00000, SDTOUT);
++	bcm2835_sdhost_write(host, 0, SDCDIV);
++	bcm2835_sdhost_write(host, 0x7f8, SDHSTS); /* Write 1s to clear */
++	bcm2835_sdhost_write(host, 0, SDHCFG);
++	bcm2835_sdhost_write(host, 0, SDHBCT);
++	bcm2835_sdhost_write(host, 0, SDHBLC);
++
++	/* Limit fifo usage due to silicon bug */
++	temp = bcm2835_sdhost_read(host, SDEDM);
++	temp &= ~((SDEDM_THRESHOLD_MASK<<SDEDM_READ_THRESHOLD_SHIFT) |
++		  (SDEDM_THRESHOLD_MASK<<SDEDM_WRITE_THRESHOLD_SHIFT));
++	temp |= (FIFO_READ_THRESHOLD << SDEDM_READ_THRESHOLD_SHIFT) |
++		(FIFO_WRITE_THRESHOLD << SDEDM_WRITE_THRESHOLD_SHIFT);
++	bcm2835_sdhost_write(host, temp, SDEDM);
++	mdelay(10);
++	bcm2835_sdhost_set_power(host, true);
++	mdelay(10);
++	host->clock = 0;
++	host->sectors = 0;
++	bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
++	bcm2835_sdhost_write(host, SDCDIV_MAX_CDIV, SDCDIV);
++}
++
++static void bcm2835_sdhost_reset(struct mmc_host *mmc)
++{
++	struct bcm2835_host *host = mmc_priv(mmc);
++	unsigned long flags;
++	spin_lock_irqsave(&host->lock, flags);
++	log_event("RST<", 0, 0);
++
++	bcm2835_sdhost_reset_internal(host);
++
++	spin_unlock_irqrestore(&host->lock, flags);
++}
++
++static void bcm2835_sdhost_set_ios(struct mmc_host *mmc, struct mmc_ios *ios);
++
++static void bcm2835_sdhost_init(struct bcm2835_host *host, int soft)
++{
++	pr_debug("bcm2835_sdhost_init(%d)\n", soft);
++
++	/* Set interrupt enables */
++	host->hcfg = SDHCFG_BUSY_IRPT_EN;
++
++	bcm2835_sdhost_reset_internal(host);
++
++	if (soft) {
++		/* force clock reconfiguration */
++		host->clock = 0;
++		bcm2835_sdhost_set_ios(host->mmc, &host->mmc->ios);
++	}
++}
++
++static void bcm2835_sdhost_wait_transfer_complete(struct bcm2835_host *host)
++{
++	int timediff;
++	u32 alternate_idle;
++	u32 edm;
++
++	alternate_idle = (host->mrq->data->flags & MMC_DATA_READ) ?
++		SDEDM_FSM_READWAIT : SDEDM_FSM_WRITESTART1;
++
++	edm = bcm2835_sdhost_read(host, SDEDM);
++
++	log_event("WTC<", edm, 0);
++
++	timediff = 0;
++
++	while (1) {
++		u32 fsm = edm & SDEDM_FSM_MASK;
++		if ((fsm == SDEDM_FSM_IDENTMODE) ||
++		    (fsm == SDEDM_FSM_DATAMODE))
++			break;
++		if (fsm == alternate_idle) {
++			bcm2835_sdhost_write(host,
++					     edm | SDEDM_FORCE_DATA_MODE,
++					     SDEDM);
++			break;
++		}
++
++		timediff++;
++		if (timediff == 100000) {
++			pr_err("%s: wait_transfer_complete - still waiting after %d retries\n",
++			       mmc_hostname(host->mmc),
++			       timediff);
++			log_dump();
++			bcm2835_sdhost_dumpregs(host);
++			host->mrq->data->error = -ETIMEDOUT;
++			log_event("WTC!", edm, 0);
++			return;
++		}
++		cpu_relax();
++		edm = bcm2835_sdhost_read(host, SDEDM);
++	}
++	log_event("WTC>", edm, 0);
++}
++
++static void bcm2835_sdhost_finish_data(struct bcm2835_host *host);
++
++static void bcm2835_sdhost_dma_complete(void *param)
++{
++	struct bcm2835_host *host = param;
++	struct mmc_data *data = host->data;
++	unsigned long flags;
++
++	spin_lock_irqsave(&host->lock, flags);
++	log_event("DMA<", host->data, bcm2835_sdhost_read(host, SDHSTS));
++	log_event("DMA ", bcm2835_sdhost_read(host, SDCMD),
++		  bcm2835_sdhost_read(host, SDEDM));
++
++	if (host->dma_chan) {
++		dma_unmap_sg(host->dma_chan->device->dev,
++			     data->sg, data->sg_len,
++			     host->dma_dir);
++
++		host->dma_chan = NULL;
++	}
++
++	if (host->drain_words) {
++		void *page;
++		u32 *buf;
++
++		if (host->drain_offset & PAGE_MASK) {
++			host->drain_page += host->drain_offset >> PAGE_SHIFT;
++			host->drain_offset &= ~PAGE_MASK;
++		}
++
++		page = kmap_atomic(host->drain_page);
++		buf = page + host->drain_offset;
++
++		while (host->drain_words) {
++			u32 edm = bcm2835_sdhost_read(host, SDEDM);
++			if ((edm >> 4) & 0x1f)
++				*(buf++) = bcm2835_sdhost_read(host,
++							       SDDATA);
++			host->drain_words--;
++		}
++
++		kunmap_atomic(page);
++	}
++
++	bcm2835_sdhost_finish_data(host);
++
++	log_event("DMA>", host->data, 0);
++	spin_unlock_irqrestore(&host->lock, flags);
++}
++
++static void bcm2835_sdhost_read_block_pio(struct bcm2835_host *host)
++{
++	unsigned long flags;
++	size_t blksize, len;
++	u32 *buf;
++	unsigned long wait_max;
++
++	blksize = host->data->blksz;
++
++	wait_max = jiffies + msecs_to_jiffies(host->pio_timeout);
++
++	local_irq_save(flags);
++
++	while (blksize) {
++		int copy_words;
++		u32 hsts = 0;
++
++		if (!sg_miter_next(&host->sg_miter)) {
++			host->data->error = -EINVAL;
++			break;
++		}
++
++		len = min(host->sg_miter.length, blksize);
++		if (len % 4) {
++			host->data->error = -EINVAL;
++			break;
++		}
++
++		blksize -= len;
++		host->sg_miter.consumed = len;
++
++		buf = (u32 *)host->sg_miter.addr;
++
++		copy_words = len/4;
++
++		while (copy_words) {
++			int burst_words, words;
++			u32 edm;
++
++			burst_words = SDDATA_FIFO_PIO_BURST;
++			if (burst_words > copy_words)
++				burst_words = copy_words;
++			edm = bcm2835_sdhost_read(host, SDEDM);
++			words = ((edm >> 4) & 0x1f);
++
++			if (words < burst_words) {
++				int fsm_state = (edm & SDEDM_FSM_MASK);
++				if ((fsm_state != SDEDM_FSM_READDATA) &&
++				    (fsm_state != SDEDM_FSM_READWAIT) &&
++				    (fsm_state != SDEDM_FSM_READCRC)) {
++					hsts = bcm2835_sdhost_read(host,
++								   SDHSTS);
++					pr_info("%s: fsm %x, hsts %x\n",
++					       mmc_hostname(host->mmc),
++					       fsm_state, hsts);
++					if (hsts & SDHSTS_ERROR_MASK)
++						break;
++				}
++
++				if (time_after(jiffies, wait_max)) {
++					pr_err("%s: PIO read timeout - EDM %x\n",
++					       mmc_hostname(host->mmc),
++					       edm);
++					hsts = SDHSTS_REW_TIME_OUT;
++					break;
++				}
++				ndelay((burst_words - words) *
++				       host->ns_per_fifo_word);
++				continue;
++			} else if (words > copy_words) {
++				words = copy_words;
++			}
++
++			copy_words -= words;
++
++			while (words) {
++				*(buf++) = bcm2835_sdhost_read(host, SDDATA);
++				words--;
++			}
++		}
++
++		if (hsts & SDHSTS_ERROR_MASK)
++			break;
++	}
++
++	sg_miter_stop(&host->sg_miter);
++
++	local_irq_restore(flags);
++}
++
++static void bcm2835_sdhost_write_block_pio(struct bcm2835_host *host)
++{
++	unsigned long flags;
++	size_t blksize, len;
++	u32 *buf;
++	unsigned long wait_max;
++
++	blksize = host->data->blksz;
++
++	wait_max = jiffies + msecs_to_jiffies(host->pio_timeout);
++
++	local_irq_save(flags);
++
++	while (blksize) {
++		int copy_words;
++		u32 hsts = 0;
++
++		if (!sg_miter_next(&host->sg_miter)) {
++			host->data->error = -EINVAL;
++			break;
++		}
++
++		len = min(host->sg_miter.length, blksize);
++		if (len % 4) {
++			host->data->error = -EINVAL;
++			break;
++		}
++
++		blksize -= len;
++		host->sg_miter.consumed = len;
++
++		buf = (u32 *)host->sg_miter.addr;
++
++		copy_words = len/4;
++
++		while (copy_words) {
++			int burst_words, words;
++			u32 edm;
++
++			burst_words = SDDATA_FIFO_PIO_BURST;
++			if (burst_words > copy_words)
++				burst_words = copy_words;
++			edm = bcm2835_sdhost_read(host, SDEDM);
++			words = SDDATA_FIFO_WORDS - ((edm >> 4) & 0x1f);
++
++			if (words < burst_words) {
++				int fsm_state = (edm & SDEDM_FSM_MASK);
++				if ((fsm_state != SDEDM_FSM_WRITEDATA) &&
++				    (fsm_state != SDEDM_FSM_WRITESTART1) &&
++				    (fsm_state != SDEDM_FSM_WRITESTART2)) {
++					hsts = bcm2835_sdhost_read(host,
++								   SDHSTS);
++					pr_info("%s: fsm %x, hsts %x\n",
++					       mmc_hostname(host->mmc),
++					       fsm_state, hsts);
++					if (hsts & SDHSTS_ERROR_MASK)
++						break;
++				}
++
++				if (time_after(jiffies, wait_max)) {
++					pr_err("%s: PIO write timeout - EDM %x\n",
++					       mmc_hostname(host->mmc),
++					       edm);
++					hsts = SDHSTS_REW_TIME_OUT;
++					break;
++				}
++				ndelay((burst_words - words) *
++				       host->ns_per_fifo_word);
++				continue;
++			} else if (words > copy_words) {
++				words = copy_words;
++			}
++
++			copy_words -= words;
++
++			while (words) {
++				bcm2835_sdhost_write(host, *(buf++), SDDATA);
++				words--;
++			}
++		}
++
++		if (hsts & SDHSTS_ERROR_MASK)
++			break;
++	}
++
++	sg_miter_stop(&host->sg_miter);
++
++	local_irq_restore(flags);
++}
++
++static void bcm2835_sdhost_transfer_pio(struct bcm2835_host *host)
++{
++	u32 sdhsts;
++	bool is_read;
++	BUG_ON(!host->data);
++	log_event("XFP<", host->data, host->blocks);
++
++	is_read = (host->data->flags & MMC_DATA_READ) != 0;
++	if (is_read)
++		bcm2835_sdhost_read_block_pio(host);
++	else
++		bcm2835_sdhost_write_block_pio(host);
++
++	sdhsts = bcm2835_sdhost_read(host, SDHSTS);
++	if (sdhsts & (SDHSTS_CRC16_ERROR |
++		      SDHSTS_CRC7_ERROR |
++		      SDHSTS_FIFO_ERROR)) {
++		pr_err("%s: %s transfer error - HSTS %x\n",
++		       mmc_hostname(host->mmc),
++		       is_read ? "read" : "write",
++		       sdhsts);
++		host->data->error = -EILSEQ;
++	} else if ((sdhsts & (SDHSTS_CMD_TIME_OUT |
++			      SDHSTS_REW_TIME_OUT))) {
++		pr_err("%s: %s timeout error - HSTS %x\n",
++		       mmc_hostname(host->mmc),
++		       is_read ? "read" : "write",
++		       sdhsts);
++		host->data->error = -ETIMEDOUT;
++	}
++	log_event("XFP>", host->data, host->blocks);
++}
++
++static void bcm2835_sdhost_prepare_dma(struct bcm2835_host *host,
++	struct mmc_data *data)
++{
++	int len, dir_data, dir_slave;
++	struct dma_async_tx_descriptor *desc = NULL;
++	struct dma_chan *dma_chan;
++
++	log_event("PRD<", data, 0);
++	pr_debug("bcm2835_sdhost_prepare_dma()\n");
++
++	dma_chan = host->dma_chan_rxtx;
++	if (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;
++	}
++	log_event("PRD1", dma_chan, 0);
++
++	BUG_ON(!dma_chan->device);
++	BUG_ON(!dma_chan->device->dev);
++	BUG_ON(!data->sg);
++
++	/* The block doesn't manage the FIFO DREQs properly for multi-block
++	   transfers, so don't attempt to DMA the final few words.
++	   Unfortunately this requires the final sg entry to be trimmed.
++	   N.B. This code demands that the overspill is contained in
++	   a single sg entry.
++	*/
++
++	host->drain_words = 0;
++	if ((data->blocks > 1) && (dir_data == DMA_FROM_DEVICE)) {
++		struct scatterlist *sg;
++		u32 len;
++		int i;
++
++		len = min((u32)(FIFO_READ_THRESHOLD - 1) * 4,
++			  (u32)data->blocks * data->blksz);
++
++		for_each_sg(data->sg, sg, data->sg_len, i) {
++			if (sg_is_last(sg)) {
++				BUG_ON(sg->length < len);
++				sg->length -= len;
++				host->drain_page = sg_page(sg);
++				host->drain_offset = sg->offset + sg->length;
++			}
++		}
++		host->drain_words = len/4;
++	}
++
++	/* 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);
++
++	len = dma_map_sg(dma_chan->device->dev, data->sg, data->sg_len,
++			 dir_data);
++
++	log_event("PRD2", len, 0);
++	if (len > 0)
++		desc = dmaengine_prep_slave_sg(dma_chan, data->sg,
++					       len, dir_slave,
++					       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
++	log_event("PRD3", desc, 0);
++
++	if (desc) {
++		desc->callback = bcm2835_sdhost_dma_complete;
++		desc->callback_param = host;
++		host->dma_desc = desc;
++		host->dma_chan = dma_chan;
++		host->dma_dir = dir_data;
++	}
++	log_event("PDM>", data, 0);
++}
++
++static void bcm2835_sdhost_start_dma(struct bcm2835_host *host)
++{
++	log_event("SDMA", host->data, host->dma_chan);
++	dmaengine_submit(host->dma_desc);
++	dma_async_issue_pending(host->dma_chan);
++}
++
++static void bcm2835_sdhost_set_transfer_irqs(struct bcm2835_host *host)
++{
++	u32 all_irqs = SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN |
++		SDHCFG_BUSY_IRPT_EN;
++	if (host->dma_desc)
++		host->hcfg = (host->hcfg & ~all_irqs) |
++			SDHCFG_BUSY_IRPT_EN;
++	else
++		host->hcfg = (host->hcfg & ~all_irqs) |
++			SDHCFG_DATA_IRPT_EN |
++			SDHCFG_BUSY_IRPT_EN;
++
++	bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
++}
++
++static void bcm2835_sdhost_prepare_data(struct bcm2835_host *host, struct mmc_command *cmd)
++{
++	struct mmc_data *data = cmd->data;
++
++	WARN_ON(host->data);
++
++	host->data = data;
++	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_complete = 0;
++	host->flush_fifo = 0;
++	host->data->bytes_xfered = 0;
++
++	if (!host->sectors && host->mmc->card) {
++		struct mmc_card *card = host->mmc->card;
++		if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) {
++			/*
++			 * The EXT_CSD sector count is in number of 512 byte
++			 * sectors.
++			 */
++			host->sectors = card->ext_csd.sectors;
++		} else {
++			/*
++			 * The CSD capacity field is in units of read_blkbits.
++			 * set_capacity takes units of 512 bytes.
++			 */
++			host->sectors = card->csd.capacity <<
++				(card->csd.read_blkbits - 9);
++		}
++	}
++
++	if (!host->dma_desc) {
++		/* Use PIO */
++		int flags = SG_MITER_ATOMIC;
++
++		if (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;
++	}
++
++	bcm2835_sdhost_set_transfer_irqs(host);
++
++	bcm2835_sdhost_write(host, data->blksz, SDHBCT);
++	bcm2835_sdhost_write(host, data->blocks, SDHBLC);
++
++	BUG_ON(!host->data);
++}
++
++bool bcm2835_sdhost_send_command(struct bcm2835_host *host,
++				 struct mmc_command *cmd)
++{
++	u32 sdcmd, sdhsts;
++	unsigned long timeout;
++	int delay;
++
++	WARN_ON(host->cmd);
++	log_event("CMD<", cmd->opcode, cmd->arg);
++
++	if (cmd->data)
++		pr_debug("%s: send_command %d 0x%x "
++			 "(flags 0x%x) - %s %d*%d\n",
++			 mmc_hostname(host->mmc),
++			 cmd->opcode, cmd->arg, cmd->flags,
++			 (cmd->data->flags & MMC_DATA_READ) ?
++			 "read" : "write", cmd->data->blocks,
++			 cmd->data->blksz);
++	else
++		pr_debug("%s: send_command %d 0x%x (flags 0x%x)\n",
++			 mmc_hostname(host->mmc),
++			 cmd->opcode, cmd->arg, cmd->flags);
++
++	/* Wait max 100 ms */
++	timeout = 10000;
++
++	while (bcm2835_sdhost_read(host, SDCMD) & SDCMD_NEW_FLAG) {
++		if (timeout == 0) {
++			pr_warn("%s: previous command never completed.\n",
++				mmc_hostname(host->mmc));
++			if (host->debug)
++				bcm2835_sdhost_dumpregs(host);
++			cmd->error = -EILSEQ;
++			tasklet_schedule(&host->finish_tasklet);
++			return false;
++		}
++		timeout--;
++		udelay(10);
++	}
++
++	delay = (10000 - timeout)/100;
++	if (delay > host->max_delay) {
++		host->max_delay = delay;
++		pr_warning("%s: controller hung for %d ms\n",
++			   mmc_hostname(host->mmc),
++			   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;
++
++	/* Clear any error flags */
++	sdhsts = bcm2835_sdhost_read(host, SDHSTS);
++	if (sdhsts & SDHSTS_ERROR_MASK)
++		bcm2835_sdhost_write(host, sdhsts, SDHSTS);
++
++	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 false;
++	}
++
++	bcm2835_sdhost_prepare_data(host, cmd);
++
++	bcm2835_sdhost_write(host, cmd->arg, SDARG);
++
++	sdcmd = cmd->opcode & SDCMD_CMD_MASK;
++
++	host->use_busy = 0;
++	if (!(cmd->flags & MMC_RSP_PRESENT)) {
++		sdcmd |= SDCMD_NO_RESPONSE;
++	} else {
++		if (cmd->flags & MMC_RSP_136)
++			sdcmd |= SDCMD_LONG_RESPONSE;
++		if (cmd->flags & MMC_RSP_BUSY) {
++			sdcmd |= SDCMD_BUSYWAIT;
++			host->use_busy = 1;
++		}
++	}
++
++	if (cmd->data) {
++		log_event("CMDD", cmd->data->blocks, cmd->data->blksz);
++		if (host->delay_after_this_stop) {
++			struct timeval now;
++			int time_since_stop;
++			do_gettimeofday(&now);
++			time_since_stop = (now.tv_sec - host->stop_time.tv_sec);
++			if (time_since_stop < 2) {
++				/* Possibly less than one second */
++				time_since_stop = time_since_stop * 1000000 +
++					(now.tv_usec - host->stop_time.tv_usec);
++				if (time_since_stop <
++				    host->delay_after_this_stop)
++					udelay(host->delay_after_this_stop -
++					       time_since_stop);
++			}
++		}
++
++		host->delay_after_this_stop = host->delay_after_stop;
++		if ((cmd->data->flags & MMC_DATA_READ) && !host->use_sbc) {
++			/* See if read crosses one of the hazardous sectors */
++			u32 first_blk, last_blk;
++
++			/* Intentionally include the following sector because
++			   without CMD23/SBC the read may run on. */
++			first_blk = host->mrq->cmd->arg;
++			last_blk = first_blk + cmd->data->blocks;
++
++			if (((last_blk >= (host->sectors - 64)) &&
++			     (first_blk <= (host->sectors - 64))) ||
++			    ((last_blk >= (host->sectors - 32)) &&
++			     (first_blk <= (host->sectors - 32)))) {
++				host->delay_after_this_stop =
++					max(250u, host->delay_after_stop);
++			}
++		}
++
++		if (cmd->data->flags & MMC_DATA_WRITE)
++			sdcmd |= SDCMD_WRITE_CMD;
++		if (cmd->data->flags & MMC_DATA_READ)
++			sdcmd |= SDCMD_READ_CMD;
++	}
++
++	bcm2835_sdhost_write(host, sdcmd | SDCMD_NEW_FLAG, SDCMD);
++
++	return true;
++}
++
++static void bcm2835_sdhost_finish_command(struct bcm2835_host *host,
++					  unsigned long *irq_flags);
++static void bcm2835_sdhost_transfer_complete(struct bcm2835_host *host);
++
++static void bcm2835_sdhost_finish_data(struct bcm2835_host *host)
++{
++	struct mmc_data *data;
++
++	data = host->data;
++	BUG_ON(!data);
++
++	log_event("FDA<", host->mrq, host->cmd);
++	pr_debug("finish_data(error %d, stop %d, sbc %d)\n",
++	       data->error, data->stop ? 1 : 0,
++	       host->mrq->sbc ? 1 : 0);
++
++	host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
++	bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
++
++	data->bytes_xfered = data->error ? 0 : (data->blksz * data->blocks);
++
++	host->data_complete = 1;
++
++	if (host->cmd) {
++		/*
++		 * Data managed to finish before the
++		 * command completed. Make sure we do
++		 * things in the proper order.
++		 */
++		pr_debug("Finished early - HSTS %x\n",
++			 bcm2835_sdhost_read(host, SDHSTS));
++	}
++	else
++		bcm2835_sdhost_transfer_complete(host);
++	log_event("FDA>", host->mrq, host->cmd);
++}
++
++static void bcm2835_sdhost_transfer_complete(struct bcm2835_host *host)
++{
++	struct mmc_data *data;
++
++	BUG_ON(host->cmd);
++	BUG_ON(!host->data);
++	BUG_ON(!host->data_complete);
++
++	data = host->data;
++	host->data = NULL;
++
++	log_event("TCM<", data, data->error);
++	pr_debug("transfer_complete(error %d, stop %d)\n",
++	       data->error, data->stop ? 1 : 0);
++
++	/*
++	 * Need to send CMD12 if -
++	 * a) open-ended multiblock transfer (no CMD23)
++	 * b) error in multiblock transfer
++	 */
++	if (host->mrq->stop && (data->error || !host->use_sbc)) {
++		if (bcm2835_sdhost_send_command(host, host->mrq->stop)) {
++			/* No busy, so poll for completion */
++			if (!host->use_busy)
++				bcm2835_sdhost_finish_command(host, NULL);
++
++			if (host->delay_after_this_stop)
++				do_gettimeofday(&host->stop_time);
++		}
++	} else {
++		bcm2835_sdhost_wait_transfer_complete(host);
++		tasklet_schedule(&host->finish_tasklet);
++	}
++	log_event("TCM>", data, 0);
++}
++
++/* If irq_flags is valid, the caller is in a thread context and is allowed
++   to sleep */
++static void bcm2835_sdhost_finish_command(struct bcm2835_host *host,
++					  unsigned long *irq_flags)
++{
++	u32 sdcmd;
++	u32 retries;
++#ifdef DEBUG
++	struct timeval before, after;
++	int timediff = 0;
++#endif
++
++	log_event("FCM<", host->mrq, host->cmd);
++	pr_debug("finish_command(%x)\n", bcm2835_sdhost_read(host, SDCMD));
++
++	BUG_ON(!host->cmd || !host->mrq);
++
++	/* Poll quickly at first */
++
++	retries = host->cmd_quick_poll_retries;
++	if (!retries) {
++		/* Work out how many polls take 1us by timing 10us */
++		struct timeval start, now;
++		int us_diff;
++
++		retries = 1;
++		do {
++			int i;
++
++			retries *= 2;
++
++			do_gettimeofday(&start);
++
++			for (i = 0; i < retries; i++) {
++				cpu_relax();
++				sdcmd = bcm2835_sdhost_read(host, SDCMD);
++			}
++
++			do_gettimeofday(&now);
++			us_diff = (now.tv_sec - start.tv_sec) * 1000000 +
++				(now.tv_usec - start.tv_usec);
++		} while (us_diff < 10);
++
++		host->cmd_quick_poll_retries = ((retries * us_diff + 9)*CMD_DALLY_US)/10 + 1;
++		retries = 1; // We've already waited long enough this time
++	}
++
++	for (sdcmd = bcm2835_sdhost_read(host, SDCMD);
++	     (sdcmd & SDCMD_NEW_FLAG) && retries;
++	     retries--) {
++		cpu_relax();
++		sdcmd = bcm2835_sdhost_read(host, SDCMD);
++	}
++
++	if (!retries) {
++		unsigned long wait_max;
++
++		if (!irq_flags) {
++			/* Schedule the work */
++			log_event("CWWQ", 0, 0);
++			schedule_work(&host->cmd_wait_wq);
++			return;
++		}
++
++		/* Wait max 100 ms */
++		wait_max = jiffies + msecs_to_jiffies(100);
++		while (time_before(jiffies, wait_max)) {
++			spin_unlock_irqrestore(&host->lock, *irq_flags);
++			usleep_range(1, 10);
++			spin_lock_irqsave(&host->lock, *irq_flags);
++			sdcmd = bcm2835_sdhost_read(host, SDCMD);
++			if (!(sdcmd & SDCMD_NEW_FLAG))
++				break;
++		}
++	}
++
++	/* Check for errors */
++	if (sdcmd & SDCMD_NEW_FLAG) {
++		if (host->debug) {
++			pr_err("%s: command %d never completed.\n",
++			       mmc_hostname(host->mmc), host->cmd->opcode);
++			bcm2835_sdhost_dumpregs(host);
++		}
++		host->cmd->error = -EILSEQ;
++		tasklet_schedule(&host->finish_tasklet);
++		return;
++	} else if (sdcmd & SDCMD_FAIL_FLAG) {
++		u32 sdhsts = bcm2835_sdhost_read(host, SDHSTS);
++
++		/* Clear the errors */
++		bcm2835_sdhost_write(host, SDHSTS_ERROR_MASK, SDHSTS);
++
++		if (host->debug)
++			pr_info("%s: error detected - CMD %x, HSTS %03x, EDM %x\n",
++				mmc_hostname(host->mmc), sdcmd, sdhsts,
++				bcm2835_sdhost_read(host, SDEDM));
++
++		if ((sdhsts & SDHSTS_CRC7_ERROR) &&
++		    (host->cmd->opcode == 1)) {
++			if (host->debug)
++				pr_info("%s: ignoring CRC7 error for CMD1\n",
++					mmc_hostname(host->mmc));
++		} else {
++			u32 edm, fsm;
++
++			if (sdhsts & SDHSTS_CMD_TIME_OUT) {
++				if (host->debug)
++					pr_warn("%s: command %d timeout\n",
++					       mmc_hostname(host->mmc),
++					       host->cmd->opcode);
++				host->cmd->error = -ETIMEDOUT;
++			} else {
++				pr_warn("%s: unexpected command %d error\n",
++				       mmc_hostname(host->mmc),
++				       host->cmd->opcode);
++				host->cmd->error = -EILSEQ;
++			}
++
++			edm = readl(host->ioaddr + SDEDM);
++			fsm = edm & SDEDM_FSM_MASK;
++			if (fsm == SDEDM_FSM_READWAIT ||
++			    fsm == SDEDM_FSM_WRITESTART1)
++				writel(edm | SDEDM_FORCE_DATA_MODE,
++				       host->ioaddr + SDEDM);
++			tasklet_schedule(&host->finish_tasklet);
++			return;
++		}
++	}
++
++	if (host->cmd->flags & MMC_RSP_PRESENT) {
++		if (host->cmd->flags & MMC_RSP_136) {
++			int i;
++			for (i = 0; i < 4; i++)
++				host->cmd->resp[3 - i] = bcm2835_sdhost_read(host, SDRSP0 + i*4);
++			pr_debug("%s: finish_command %08x %08x %08x %08x\n",
++				 mmc_hostname(host->mmc),
++				 host->cmd->resp[0], host->cmd->resp[1], host->cmd->resp[2], host->cmd->resp[3]);
++			log_event("RSP ", host->cmd->resp[0], host->cmd->resp[1]);
++		} else {
++			host->cmd->resp[0] = bcm2835_sdhost_read(host, SDRSP0);
++			pr_debug("%s: finish_command %08x\n",
++				 mmc_hostname(host->mmc),
++				 host->cmd->resp[0]);
++			log_event("RSP ", host->cmd->resp[0], 0);
++		}
++	}
++
++	if (host->cmd == host->mrq->sbc) {
++		/* Finished CMD23, now send actual command. */
++		host->cmd = NULL;
++		if (bcm2835_sdhost_send_command(host, host->mrq->cmd)) {
++			if (host->data && host->dma_desc)
++				/* DMA transfer starts now, PIO starts after irq */
++				bcm2835_sdhost_start_dma(host);
++
++			if (!host->use_busy)
++				bcm2835_sdhost_finish_command(host, NULL);
++		}
++	} else if (host->cmd == host->mrq->stop) {
++		/* Finished CMD12 */
++		tasklet_schedule(&host->finish_tasklet);
++	} else {
++		/* Processed actual command. */
++		host->cmd = NULL;
++		if (!host->data)
++			tasklet_schedule(&host->finish_tasklet);
++		else if (host->data_complete)
++			bcm2835_sdhost_transfer_complete(host);
++	}
++	log_event("FCM>", host->mrq, host->cmd);
++}
++
++static void bcm2835_sdhost_timeout(struct timer_list *t)
++{
++	struct bcm2835_host *host = from_timer(host, t, timer);
++	unsigned long flags;
++
++	spin_lock_irqsave(&host->lock, flags);
++	log_event("TIM<", 0, 0);
++
++	if (host->mrq) {
++		pr_err("%s: timeout waiting for hardware interrupt.\n",
++			mmc_hostname(host->mmc));
++		log_dump();
++		bcm2835_sdhost_dumpregs(host);
++
++		if (host->data) {
++			host->data->error = -ETIMEDOUT;
++			bcm2835_sdhost_finish_data(host);
++		} else {
++			if (host->cmd)
++				host->cmd->error = -ETIMEDOUT;
++			else
++				host->mrq->cmd->error = -ETIMEDOUT;
++
++			pr_debug("timeout_timer tasklet_schedule\n");
++			tasklet_schedule(&host->finish_tasklet);
++		}
++	}
++
++	spin_unlock_irqrestore(&host->lock, flags);
++}
++
++static void bcm2835_sdhost_busy_irq(struct bcm2835_host *host, u32 intmask)
++{
++	log_event("IRQB", host->cmd, intmask);
++	if (!host->cmd) {
++		pr_err("%s: got command busy interrupt 0x%08x even "
++			"though no command operation was in progress.\n",
++			mmc_hostname(host->mmc), (unsigned)intmask);
++		bcm2835_sdhost_dumpregs(host);
++		return;
++	}
++
++	if (!host->use_busy) {
++		pr_err("%s: got command busy interrupt 0x%08x even "
++			"though not expecting one.\n",
++			mmc_hostname(host->mmc), (unsigned)intmask);
++		bcm2835_sdhost_dumpregs(host);
++		return;
++	}
++	host->use_busy = 0;
++
++	if (intmask & SDHSTS_ERROR_MASK)
++	{
++		pr_err("sdhost_busy_irq: intmask %x, data %p\n", intmask, host->mrq->data);
++		if (intmask & SDHSTS_CRC7_ERROR)
++			host->cmd->error = -EILSEQ;
++		else if (intmask & (SDHSTS_CRC16_ERROR |
++				    SDHSTS_FIFO_ERROR)) {
++			if (host->mrq->data)
++				host->mrq->data->error = -EILSEQ;
++			else
++				host->cmd->error = -EILSEQ;
++		} else if (intmask & SDHSTS_REW_TIME_OUT) {
++			if (host->mrq->data)
++				host->mrq->data->error = -ETIMEDOUT;
++			else
++				host->cmd->error = -ETIMEDOUT;
++		} else if (intmask & SDHSTS_CMD_TIME_OUT)
++			host->cmd->error = -ETIMEDOUT;
++
++		if (host->debug) {
++			log_dump();
++			bcm2835_sdhost_dumpregs(host);
++		}
++	}
++	else
++		bcm2835_sdhost_finish_command(host, NULL);
++}
++
++static void bcm2835_sdhost_data_irq(struct bcm2835_host *host, u32 intmask)
++{
++	/* There are no dedicated data/space available interrupt
++	   status bits, so it is necessary to use the single shared
++	   data/space available FIFO status bits. It is therefore not
++	   an error to get here when there is no data transfer in
++	   progress. */
++	log_event("IRQD", host->data, intmask);
++	if (!host->data)
++		return;
++
++	if (intmask & (SDHSTS_CRC16_ERROR |
++		       SDHSTS_FIFO_ERROR |
++		       SDHSTS_REW_TIME_OUT)) {
++		if (intmask & (SDHSTS_CRC16_ERROR |
++			       SDHSTS_FIFO_ERROR))
++			host->data->error = -EILSEQ;
++		else
++			host->data->error = -ETIMEDOUT;
++
++		if (host->debug) {
++			log_dump();
++			bcm2835_sdhost_dumpregs(host);
++		}
++	}
++
++	if (host->data->error) {
++		bcm2835_sdhost_finish_data(host);
++	} else if (host->data->flags & MMC_DATA_WRITE) {
++		/* Use the block interrupt for writes after the first block */
++		host->hcfg &= ~(SDHCFG_DATA_IRPT_EN);
++		host->hcfg |= SDHCFG_BLOCK_IRPT_EN;
++		bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
++		bcm2835_sdhost_transfer_pio(host);
++	} else {
++		bcm2835_sdhost_transfer_pio(host);
++		host->blocks--;
++		if ((host->blocks == 0) || host->data->error)
++			bcm2835_sdhost_finish_data(host);
++	}
++}
++
++static void bcm2835_sdhost_block_irq(struct bcm2835_host *host, u32 intmask)
++{
++	log_event("IRQK", host->data, intmask);
++	if (!host->data) {
++		pr_err("%s: got block interrupt 0x%08x even "
++			"though no data operation was in progress.\n",
++			mmc_hostname(host->mmc), (unsigned)intmask);
++		bcm2835_sdhost_dumpregs(host);
++		return;
++	}
++
++	if (intmask & (SDHSTS_CRC16_ERROR |
++		       SDHSTS_FIFO_ERROR |
++		       SDHSTS_REW_TIME_OUT)) {
++		if (intmask & (SDHSTS_CRC16_ERROR |
++			       SDHSTS_FIFO_ERROR))
++			host->data->error = -EILSEQ;
++		else
++			host->data->error = -ETIMEDOUT;
++
++		if (host->debug) {
++			log_dump();
++			bcm2835_sdhost_dumpregs(host);
++		}
++	}
++
++	if (!host->dma_desc) {
++		BUG_ON(!host->blocks);
++		if (host->data->error || (--host->blocks == 0)) {
++			bcm2835_sdhost_finish_data(host);
++		} else {
++			bcm2835_sdhost_transfer_pio(host);
++		}
++	} else if (host->data->flags & MMC_DATA_WRITE) {
++		bcm2835_sdhost_finish_data(host);
++	}
++}
++
++static irqreturn_t bcm2835_sdhost_irq(int irq, void *dev_id)
++{
++	irqreturn_t result = IRQ_NONE;
++	struct bcm2835_host *host = dev_id;
++	u32 intmask;
++
++	spin_lock(&host->lock);
++
++	intmask = bcm2835_sdhost_read(host, SDHSTS);
++	log_event("IRQ<", intmask, 0);
++
++	bcm2835_sdhost_write(host,
++			     SDHSTS_BUSY_IRPT |
++			     SDHSTS_BLOCK_IRPT |
++			     SDHSTS_SDIO_IRPT |
++			     SDHSTS_DATA_FLAG,
++			     SDHSTS);
++
++	if (intmask & SDHSTS_BLOCK_IRPT) {
++		bcm2835_sdhost_block_irq(host, intmask);
++		result = IRQ_HANDLED;
++	}
++
++	if (intmask & SDHSTS_BUSY_IRPT) {
++		bcm2835_sdhost_busy_irq(host, intmask);
++		result = IRQ_HANDLED;
++	}
++
++	/* There is no true data interrupt status bit, so it is
++	   necessary to qualify the data flag with the interrupt
++	   enable bit */
++	if ((intmask & SDHSTS_DATA_FLAG) &&
++	    (host->hcfg & SDHCFG_DATA_IRPT_EN)) {
++		bcm2835_sdhost_data_irq(host, intmask);
++		result = IRQ_HANDLED;
++	}
++
++	log_event("IRQ>", bcm2835_sdhost_read(host, SDHSTS), 0);
++	spin_unlock(&host->lock);
++
++	return result;
++}
++
++void bcm2835_sdhost_set_clock(struct bcm2835_host *host, unsigned int clock)
++{
++	int div = 0; /* Initialized for compiler warning */
++	unsigned int input_clock = clock;
++	unsigned long flags;
++
++	if (host->debug)
++		pr_info("%s: set_clock(%d)\n", mmc_hostname(host->mmc), clock);
++
++	if (host->overclock_50 && (clock == 50*MHZ))
++		clock = host->overclock_50 * MHZ + (MHZ - 1);
++
++	/* The SDCDIV register has 11 bits, and holds (div - 2).
++	   But in data mode the max is 50MHz wihout a minimum, and only the
++	   bottom 3 bits are used. Since the switch over is automatic (unless
++	   we have marked the card as slow...), chosen values have to make
++	   sense in both modes.
++	   Ident mode must be 100-400KHz, so can range check the requested
++	   clock. CMD15 must be used to return to data mode, so this can be
++	   monitored.
++
++	   clock 250MHz -> 0->125MHz, 1->83.3MHz, 2->62.5MHz, 3->50.0MHz
++                           4->41.7MHz, 5->35.7MHz, 6->31.3MHz, 7->27.8MHz
++
++			 623->400KHz/27.8MHz
++			 reset value (507)->491159/50MHz
++
++	   BUT, the 3-bit clock divisor in data mode is too small if the
++	   core clock is higher than 250MHz, so instead use the SLOW_CARD
++	   configuration bit to force the use of the ident clock divisor
++	   at all times.
++	*/
++
++	host->mmc->actual_clock = 0;
++
++	if (host->firmware_sets_cdiv) {
++		u32 msg[3] = { clock, 0, 0 };
++
++		rpi_firmware_property(rpi_firmware_get(NULL),
++				      RPI_FIRMWARE_SET_SDHOST_CLOCK,
++				      &msg, sizeof(msg));
++
++		clock = max(msg[1], msg[2]);
++		spin_lock_irqsave(&host->lock, flags);
++	} else {
++		spin_lock_irqsave(&host->lock, flags);
++		if (clock < 100000) {
++			/* Can't stop the clock, but make it as slow as
++			 * possible to show willing
++			 */
++			host->cdiv = SDCDIV_MAX_CDIV;
++			bcm2835_sdhost_write(host, host->cdiv, SDCDIV);
++			spin_unlock_irqrestore(&host->lock, flags);
++			return;
++		}
++
++		div = host->max_clk / clock;
++		if (div < 2)
++			div = 2;
++		if ((host->max_clk / div) > clock)
++			div++;
++		div -= 2;
++
++		if (div > SDCDIV_MAX_CDIV)
++			div = SDCDIV_MAX_CDIV;
++
++		clock = host->max_clk / (div + 2);
++
++		host->cdiv = div;
++		bcm2835_sdhost_write(host, host->cdiv, SDCDIV);
++
++		if (host->debug)
++			pr_info("%s: clock=%d -> max_clk=%d, cdiv=%x "
++				"(actual clock %d)\n",
++				mmc_hostname(host->mmc), input_clock,
++				host->max_clk, host->cdiv,
++				clock);
++	}
++
++	/* Calibrate some delays */
++
++	host->ns_per_fifo_word = (1000000000/clock) *
++		((host->mmc->caps & MMC_CAP_4_BIT_DATA) ? 8 : 32);
++
++	if (input_clock == 50 * MHZ) {
++		if (clock > input_clock) {
++			/* Save the closest value, to make it easier
++			   to reduce in the event of error */
++			host->overclock_50 = (clock/MHZ);
++
++			if (clock != host->overclock) {
++				pr_info("%s: overclocking to %dHz\n",
++					mmc_hostname(host->mmc), clock);
++				host->overclock = clock;
++			}
++		} else if (host->overclock) {
++			host->overclock = 0;
++			if (clock == 50 * MHZ)
++				pr_warn("%s: cancelling overclock\n",
++					mmc_hostname(host->mmc));
++		}
++	} else if (input_clock == 0) {
++		/* Reset the preferred overclock when the clock is stopped.
++		 * This always happens during initialisation. */
++		host->overclock_50 = host->user_overclock_50;
++		host->overclock = 0;
++	}
++
++	/* Set the timeout to 500ms */
++	bcm2835_sdhost_write(host, clock/2, SDTOUT);
++
++	host->mmc->actual_clock = clock;
++	host->clock = input_clock;
++	host->reset_clock = 0;
++
++	spin_unlock_irqrestore(&host->lock, flags);
++}
++
++static void bcm2835_sdhost_request(struct mmc_host *mmc, struct mmc_request *mrq)
++{
++	struct bcm2835_host *host;
++	unsigned long flags;
++	u32 edm, fsm;
++
++	host = mmc_priv(mmc);
++
++	if (host->debug) {
++		struct mmc_command *cmd = mrq->cmd;
++		BUG_ON(!cmd);
++		if (cmd->data)
++			pr_info("%s: cmd %d 0x%x (flags 0x%x) - %s %d*%d\n",
++				mmc_hostname(mmc),
++				cmd->opcode, cmd->arg, cmd->flags,
++				(cmd->data->flags & MMC_DATA_READ) ?
++				"read" : "write", cmd->data->blocks,
++				cmd->data->blksz);
++		else
++			pr_info("%s: cmd %d 0x%x (flags 0x%x)\n",
++				mmc_hostname(mmc),
++				cmd->opcode, cmd->arg, cmd->flags);
++	}
++
++	/* Reset the error statuses in case this is a retry */
++	if (mrq->sbc)
++		mrq->sbc->error = 0;
++	if (mrq->cmd)
++		mrq->cmd->error = 0;
++	if (mrq->data)
++		mrq->data->error = 0;
++	if (mrq->stop)
++		mrq->stop->error = 0;
++
++	if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
++		pr_err("%s: unsupported block size (%d bytes)\n",
++		       mmc_hostname(mmc), mrq->data->blksz);
++		mrq->cmd->error = -EINVAL;
++		mmc_request_done(mmc, mrq);
++		return;
++	}
++
++	if (host->use_dma && mrq->data &&
++	    (mrq->data->blocks > host->pio_limit))
++		bcm2835_sdhost_prepare_dma(host, mrq->data);
++
++	if (host->reset_clock)
++	    bcm2835_sdhost_set_clock(host, host->clock);
++
++	spin_lock_irqsave(&host->lock, flags);
++
++	WARN_ON(host->mrq != NULL);
++	host->mrq = mrq;
++
++	edm = bcm2835_sdhost_read(host, SDEDM);
++	fsm = edm & SDEDM_FSM_MASK;
++
++	log_event("REQ<", mrq, edm);
++	if ((fsm != SDEDM_FSM_IDENTMODE) &&
++	    (fsm != SDEDM_FSM_DATAMODE)) {
++		log_event("REQ!", mrq, edm);
++		if (host->debug) {
++			pr_warn("%s: previous command (%d) not complete (EDM %x)\n",
++			       mmc_hostname(host->mmc),
++			       bcm2835_sdhost_read(host, SDCMD) & SDCMD_CMD_MASK,
++			       edm);
++			log_dump();
++			bcm2835_sdhost_dumpregs(host);
++		}
++		mrq->cmd->error = -EILSEQ;
++		tasklet_schedule(&host->finish_tasklet);
++		spin_unlock_irqrestore(&host->lock, flags);
++		return;
++	}
++
++	host->use_sbc = !!mrq->sbc &&
++		(host->mrq->data->flags & USE_CMD23_FLAGS);
++	if (host->use_sbc) {
++		if (bcm2835_sdhost_send_command(host, mrq->sbc)) {
++			if (!host->use_busy)
++				bcm2835_sdhost_finish_command(host, &flags);
++		}
++	} else if (bcm2835_sdhost_send_command(host, mrq->cmd)) {
++		if (host->data && host->dma_desc)
++			/* DMA transfer starts now, PIO starts after irq */
++			bcm2835_sdhost_start_dma(host);
++
++		if (!host->use_busy)
++			bcm2835_sdhost_finish_command(host, &flags);
++	}
++
++	log_event("CMD ", mrq->cmd->opcode,
++		   mrq->data ? (u32)mrq->data->blksz : 0);
++
++	log_event("REQ>", mrq, 0);
++	spin_unlock_irqrestore(&host->lock, flags);
++}
++
++static void bcm2835_sdhost_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
++{
++
++	struct bcm2835_host *host = mmc_priv(mmc);
++	unsigned long flags;
++
++	if (host->debug)
++		pr_info("%s: ios clock %d, pwr %d, bus_width %d, "
++			"timing %d, vdd %d, drv_type %d\n",
++			mmc_hostname(mmc),
++			ios->clock, ios->power_mode, ios->bus_width,
++			ios->timing, ios->signal_voltage, ios->drv_type);
++
++	spin_lock_irqsave(&host->lock, flags);
++
++	log_event("IOS<", ios->clock, 0);
++
++	/* set bus width */
++	host->hcfg &= ~SDHCFG_WIDE_EXT_BUS;
++	if (ios->bus_width == MMC_BUS_WIDTH_4)
++		host->hcfg |= SDHCFG_WIDE_EXT_BUS;
++
++	host->hcfg |= SDHCFG_WIDE_INT_BUS;
++
++	/* Disable clever clock switching, to cope with fast core clocks */
++	host->hcfg |= SDHCFG_SLOW_CARD;
++
++	bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
++
++	spin_unlock_irqrestore(&host->lock, flags);
++
++	if (!ios->clock || ios->clock != host->clock)
++		bcm2835_sdhost_set_clock(host, ios->clock);
++}
++
++static struct mmc_host_ops bcm2835_sdhost_ops = {
++	.request = bcm2835_sdhost_request,
++	.set_ios = bcm2835_sdhost_set_ios,
++	.hw_reset = bcm2835_sdhost_reset,
++};
++
++static void bcm2835_sdhost_cmd_wait_work(struct work_struct *work)
++{
++	struct bcm2835_host *host;
++	unsigned long flags;
++
++	host = container_of(work, struct bcm2835_host, cmd_wait_wq);
++
++	spin_lock_irqsave(&host->lock, flags);
++
++	log_event("CWK<", host->cmd, host->mrq);
++
++	/*
++	 * 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;
++	}
++
++	bcm2835_sdhost_finish_command(host, &flags);
++
++	log_event("CWK>", host->cmd, 0);
++
++	spin_unlock_irqrestore(&host->lock, flags);
++}
++
++static void bcm2835_sdhost_tasklet_finish(unsigned long param)
++{
++	struct bcm2835_host *host;
++	unsigned long flags;
++	struct mmc_request *mrq;
++	struct dma_chan *terminate_chan = NULL;
++
++	host = (struct bcm2835_host *)param;
++
++	spin_lock_irqsave(&host->lock, flags);
++
++	log_event("TSK<", host->mrq, 0);
++	/*
++	 * 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;
++
++	/* Drop the overclock after any data corruption, or after any
++	 * error while overclocked. Ignore errors for status commands,
++	 * as they are likely when a card is ejected. */
++	if (host->overclock) {
++		if ((mrq->cmd && mrq->cmd->error &&
++		     (mrq->cmd->opcode != MMC_SEND_STATUS)) ||
++		    (mrq->data && mrq->data->error) ||
++		    (mrq->stop && mrq->stop->error) ||
++		    (mrq->sbc && mrq->sbc->error)) {
++			host->overclock_50--;
++			pr_warn("%s: reducing overclock due to errors\n",
++				mmc_hostname(host->mmc));
++			host->reset_clock = 1;
++			mrq->cmd->error = -ETIMEDOUT;
++			mrq->cmd->retries = 1;
++		}
++	}
++
++	host->mrq = NULL;
++	host->cmd = NULL;
++	host->data = NULL;
++
++	host->dma_desc = NULL;
++	terminate_chan = host->dma_chan;
++	host->dma_chan = NULL;
++
++	spin_unlock_irqrestore(&host->lock, flags);
++
++	if (terminate_chan)
++	{
++		int err = dmaengine_terminate_all(terminate_chan);
++		if (err)
++			pr_err("%s: failed to terminate DMA (%d)\n",
++			       mmc_hostname(host->mmc), err);
++	}
++
++	/* The SDHOST block doesn't report any errors for a disconnected
++	   interface. All cards and SDIO devices should report some supported
++	   voltage range, so a zero response to SEND_OP_COND, IO_SEND_OP_COND
++	   or APP_SEND_OP_COND can be treated as an error. */
++	if (((mrq->cmd->opcode == MMC_SEND_OP_COND) ||
++	     (mrq->cmd->opcode == SD_IO_SEND_OP_COND) ||
++	     (mrq->cmd->opcode == SD_APP_OP_COND)) &&
++	    (mrq->cmd->error == 0) &&
++	    (mrq->cmd->resp[0] == 0)) {
++		mrq->cmd->error = -ETIMEDOUT;
++		if (host->debug)
++			pr_info("%s: faking timeout due to zero OCR\n",
++				mmc_hostname(host->mmc));
++	}
++
++	mmc_request_done(host->mmc, mrq);
++	log_event("TSK>", mrq, 0);
++}
++
++int bcm2835_sdhost_add_host(struct bcm2835_host *host)
++{
++	struct mmc_host *mmc;
++	struct dma_slave_config cfg;
++	char pio_limit_string[20];
++	int ret;
++
++	mmc = host->mmc;
++
++	if (!mmc->f_max || mmc->f_max > host->max_clk)
++		mmc->f_max = host->max_clk;
++	mmc->f_min = host->max_clk / SDCDIV_MAX_CDIV;
++
++	mmc->max_busy_timeout =  (~(unsigned int)0)/(mmc->f_max/1000);
++
++	pr_debug("f_max %d, f_min %d, max_busy_timeout %d\n",
++		 mmc->f_max, mmc->f_min, mmc->max_busy_timeout);
++
++	/* host controller capabilities */
++	mmc->caps |=
++		MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED |
++		MMC_CAP_NEEDS_POLL | MMC_CAP_HW_RESET | MMC_CAP_ERASE |
++		((ALLOW_CMD23_READ|ALLOW_CMD23_WRITE) * MMC_CAP_CMD23);
++
++	spin_lock_init(&host->lock);
++
++	if (host->allow_dma) {
++		if (IS_ERR_OR_NULL(host->dma_chan_rxtx)) {
++			pr_err("%s: unable to initialise DMA channel. "
++			       "Falling back to PIO\n",
++			       mmc_hostname(mmc));
++			host->use_dma = false;
++		} else {
++			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
++			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
++			cfg.slave_id = 13;		/* DREQ channel */
++
++			/* Validate the slave configurations */
++
++			cfg.direction = DMA_MEM_TO_DEV;
++			cfg.src_addr = 0;
++			cfg.dst_addr = host->bus_addr + SDDATA;
++
++			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 + SDDATA;
++				cfg.dst_addr = 0;
++
++				ret = dmaengine_slave_config(host->dma_chan_rxtx, &cfg);
++			}
++
++			if (ret == 0) {
++				host->dma_cfg_rx = cfg;
++
++				host->use_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->use_dma = false;
++			}
++		}
++	} else {
++		host->use_dma = false;
++	}
++
++	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_sdhost_tasklet_finish, (unsigned long)host);
++
++	INIT_WORK(&host->cmd_wait_wq, bcm2835_sdhost_cmd_wait_work);
++
++	timer_setup(&host->timer, bcm2835_sdhost_timeout, 0);
++
++	bcm2835_sdhost_init(host, 0);
++
++	ret = request_irq(host->irq, bcm2835_sdhost_irq, 0 /*IRQF_SHARED*/,
++				  mmc_hostname(mmc), host);
++	if (ret) {
++		pr_err("%s: failed to request IRQ %d: %d\n",
++		       mmc_hostname(mmc), host->irq, ret);
++		goto untasklet;
++	}
++
++	mmc_add_host(mmc);
++
++	pio_limit_string[0] = '\0';
++	if (host->use_dma && (host->pio_limit > 0))
++		sprintf(pio_limit_string, " (>%d)", host->pio_limit);
++	pr_info("%s: %s loaded - DMA %s%s\n",
++		mmc_hostname(mmc), DRIVER_NAME,
++		host->use_dma ? "enabled" : "disabled",
++		pio_limit_string);
++
++	return 0;
++
++untasklet:
++	tasklet_kill(&host->finish_tasklet);
++
++	return ret;
++}
++
++static int bcm2835_sdhost_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;
++	u32 msg[3];
++	int na;
++	int ret;
++
++	pr_debug("bcm2835_sdhost_probe\n");
++	mmc = mmc_alloc_host(sizeof(*host), dev);
++	if (!mmc)
++		return -ENOMEM;
++
++	mmc->ops = &bcm2835_sdhost_ops;
++	host = mmc_priv(mmc);
++	host->mmc = mmc;
++	host->pio_timeout = msecs_to_jiffies(500);
++	host->pio_limit = 1;
++	host->max_delay = 1; /* Warn if over 1ms */
++	host->allow_dma = 1;
++	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;
++	}
++
++	na = of_n_addr_cells(node);
++	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 = (phys_addr_t)of_read_number(addr, na);
++	pr_debug(" - ioaddr %lx, iomem->start %lx, bus_addr %lx\n",
++		 (unsigned long)host->ioaddr,
++		 (unsigned long)iomem->start,
++		 (unsigned long)host->bus_addr);
++
++	if (node) {
++		/* Read any custom properties */
++		of_property_read_u32(node,
++				     "brcm,delay-after-stop",
++				     &host->delay_after_stop);
++		of_property_read_u32(node,
++				     "brcm,overclock-50",
++				     &host->user_overclock_50);
++		of_property_read_u32(node,
++				     "brcm,pio-limit",
++				     &host->pio_limit);
++		host->allow_dma =
++			!of_property_read_bool(node, "brcm,force-pio");
++		host->debug = of_property_read_bool(node, "brcm,debug");
++	}
++
++	host->dma_chan = NULL;
++	host->dma_desc = NULL;
++
++	/* Formally recognise the other way of disabling DMA */
++	if (host->pio_limit == 0x7fffffff)
++		host->allow_dma = false;
++
++	if (host->allow_dma) {
++		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);
++		}
++	}
++
++	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;
++	}
++
++	pr_debug(" - max_clk %lx, irq %d\n",
++		 (unsigned long)host->max_clk,
++		 (int)host->irq);
++
++	log_init(dev, iomem->start - host->bus_addr);
++
++	if (node)
++		mmc_of_parse(mmc);
++	else
++		mmc->caps |= MMC_CAP_4_BIT_DATA;
++
++	msg[0] = 0;
++	msg[1] = ~0;
++	msg[2] = ~0;
++
++	rpi_firmware_property(rpi_firmware_get(NULL),
++			      RPI_FIRMWARE_SET_SDHOST_CLOCK,
++			      &msg, sizeof(msg));
++
++	host->firmware_sets_cdiv = (msg[1] != ~0);
++
++	ret = bcm2835_sdhost_add_host(host);
++	if (ret)
++		goto err;
++
++	platform_set_drvdata(pdev, host);
++
++	pr_debug("bcm2835_sdhost_probe -> OK\n");
++
++	return 0;
++
++err:
++	pr_debug("bcm2835_sdhost_probe -> err %d\n", ret);
++	if (host->dma_chan_rxtx)
++		dma_release_channel(host->dma_chan_rxtx);
++	mmc_free_host(mmc);
++
++	return ret;
++}
++
++static int bcm2835_sdhost_remove(struct platform_device *pdev)
++{
++	struct bcm2835_host *host = platform_get_drvdata(pdev);
++
++	pr_debug("bcm2835_sdhost_remove\n");
++
++	mmc_remove_host(host->mmc);
++
++	bcm2835_sdhost_set_power(host, false);
++
++	free_irq(host->irq, host);
++
++	del_timer_sync(&host->timer);
++
++	tasklet_kill(&host->finish_tasklet);
++	if (host->dma_chan_rxtx)
++		dma_release_channel(host->dma_chan_rxtx);
++	mmc_free_host(host->mmc);
++	platform_set_drvdata(pdev, NULL);
++
++	pr_debug("bcm2835_sdhost_remove - OK\n");
++	return 0;
++}
++
++static const struct of_device_id bcm2835_sdhost_match[] = {
++	{ .compatible = "brcm,bcm2835-sdhost" },
++	{ }
++};
++MODULE_DEVICE_TABLE(of, bcm2835_sdhost_match);
++
++static struct platform_driver bcm2835_sdhost_driver = {
++	.probe      = bcm2835_sdhost_probe,
++	.remove     = bcm2835_sdhost_remove,
++	.driver     = {
++		.name		= DRIVER_NAME,
++		.owner		= THIS_MODULE,
++		.of_match_table	= bcm2835_sdhost_match,
++	},
++};
++module_platform_driver(bcm2835_sdhost_driver);
++
++MODULE_ALIAS("platform:sdhost-bcm2835");
++MODULE_DESCRIPTION("BCM2835 SDHost driver");
++MODULE_LICENSE("GPL v2");
++MODULE_AUTHOR("Phil Elwell");