mmc: Add new VUB300 USB-to-SD/SDIO/MMC driver

Add a driver for Elan Digital System's VUB300 chip which is a USB
connected SDIO/SDmem/MMC host controller.  A VUB300 chip enables a USB 2.0
or USB 1.1 connected host computer to use SDIO/SD/MMC cards without the
need for a directly connected, for example via PCI, SDIO host controller.

Signed-off-by: Anthony F Olech <tony.olech@elandigitalsystems.com>
[cjb: various punctuation and style fixes]
Tested-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

3 files changed, 2538 insertions, 0 deletions

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index b981715130c..56dbf3f6ad0 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -535,6 +535,37 @@ config MMC_JZ4740
 	  If you have a board based on such a SoC and with a SD/MMC slot,
 	  say Y or M here.
 
+config MMC_VUB300
+	tristate "VUB300 USB to SDIO/SD/MMC Host Controller support"
+	depends on USB
+	help
+	  This selects support for Elan Digital Systems' VUB300 chip.
+
+	  The VUB300 is a USB-SDIO Host Controller Interface chip
+	  that enables the host computer to use SDIO/SD/MMC cards
+	  via a USB 2.0 or USB 1.1 host.
+
+	  The VUB300 chip will be found in both physically separate
+	  USB to SDIO/SD/MMC adapters and embedded on some motherboards.
+
+	  The VUB300 chip supports SD and MMC memory cards in addition
+	  to single and multifunction SDIO cards.
+
+	  Some SDIO cards will need a firmware file to be loaded and
+	  sent to VUB300 chip in order to achieve better data throughput.
+	  Download these "Offload Pseudocode" from Elan Digital Systems'
+	  web-site http://www.elandigitalsystems.com/support/downloads.php
+	  and put them in /lib/firmware. Note that without these additional
+	  firmware files the VUB300 chip will still function, but not at
+	  the best obtainable data rate.
+
+	  To compile this mmc host controller driver as a module,
+	  choose M here: the module will be called vub300.
+
+	  If you have a computer with an embedded VUB300 chip
+	  or if you intend connecting a USB adapter based on a
+	  VUB300 chip say Y or M here.
+
 config MMC_USHC
 	tristate "USB SD Host Controller (USHC) support"
 	depends on USB
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 4f1df0aae57..58a5cf73d6e 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_SDH_BFIN)		+= bfin_sdh.o
 obj-$(CONFIG_MMC_DW)		+= dw_mmc.o
 obj-$(CONFIG_MMC_SH_MMCIF)	+= sh_mmcif.o
 obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
+obj-$(CONFIG_MMC_VUB300)	+= vub300.o
 obj-$(CONFIG_MMC_USHC)		+= ushc.o
 
 obj-$(CONFIG_MMC_SDHCI_PLTFM)			+= sdhci-platform.o
diff --git a/drivers/mmc/host/vub300.c b/drivers/mmc/host/vub300.c
new file mode 100644
index 00000000000..cbb03305b77
--- /dev/null
+++ b/drivers/mmc/host/vub300.c
@@ -0,0 +1,2506 @@
+/*
+ * Remote VUB300 SDIO/SDmem Host Controller Driver
+ *
+ * Copyright (C) 2010 Elan Digital Systems Limited
+ *
+ * based on USB Skeleton driver - 2.2
+ *
+ * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2
+ *
+ * VUB300: is a USB 2.0 client device with a single SDIO/SDmem/MMC slot
+ *         Any SDIO/SDmem/MMC device plugged into the VUB300 will appear,
+ *         by virtue of this driver, to have been plugged into a local
+ *         SDIO host controller, similar to, say, a PCI Ricoh controller
+ *         This is because this kernel device driver is both a USB 2.0
+ *         client device driver AND an MMC host controller driver. Thus
+ *         if there is an existing driver for the inserted SDIO/SDmem/MMC
+ *         device then that driver will be used by the kernel to manage
+ *         the device in exactly the same fashion as if it had been
+ *         directly plugged into, say, a local pci bus Ricoh controller
+ *
+ * RANT: this driver was written using a display 128x48 - converting it
+ *       to a line width of 80 makes it very difficult to support. In
+ *       particular functions have been broken down into sub functions
+ *       and the original meaningful names have been shortened into
+ *       cryptic ones.
+ *       The problem is that executing a fragment of code subject to
+ *       two conditions means an indentation of 24, thus leaving only
+ *       56 characters for a C statement. And that is quite ridiculous!
+ *
+ * Data types: data passed to/from the VUB300 is fixed to a number of
+ *             bits and driver data fields reflect that limit by using
+ *             u8, u16, u32
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/kref.h>
+#include <linux/uaccess.h>
+#include <linux/usb.h>
+#include <linux/mutex.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/card.h>
+#include <linux/mmc/sdio_func.h>
+#include <linux/mmc/sdio_ids.h>
+#include <linux/workqueue.h>
+#include <linux/ctype.h>
+#include <linux/firmware.h>
+#include <linux/scatterlist.h>
+
+struct host_controller_info {
+	u8 info_size;
+	u16 firmware_version;
+	u8 number_of_ports;
+} __packed;
+
+#define FIRMWARE_BLOCK_BOUNDARY 1024
+struct sd_command_header {
+	u8 header_size;
+	u8 header_type;
+	u8 port_number;
+	u8 command_type; /* Bit7 - Rd/Wr */
+	u8 command_index;
+	u8 transfer_size[4]; /* ReadSize + ReadSize */
+	u8 response_type;
+	u8 arguments[4];
+	u8 block_count[2];
+	u8 block_size[2];
+	u8 block_boundary[2];
+	u8 reserved[44]; /* to pad out to 64 bytes */
+} __packed;
+
+struct sd_irqpoll_header {
+	u8 header_size;
+	u8 header_type;
+	u8 port_number;
+	u8 command_type; /* Bit7 - Rd/Wr */
+	u8 padding[16]; /* don't ask why !! */
+	u8 poll_timeout_msb;
+	u8 poll_timeout_lsb;
+	u8 reserved[42]; /* to pad out to 64 bytes */
+} __packed;
+
+struct sd_common_header {
+	u8 header_size;
+	u8 header_type;
+	u8 port_number;
+} __packed;
+
+struct sd_response_header {
+	u8 header_size;
+	u8 header_type;
+	u8 port_number;
+	u8 command_type;
+	u8 command_index;
+	u8 command_response[0];
+} __packed;
+
+struct sd_status_header {
+	u8 header_size;
+	u8 header_type;
+	u8 port_number;
+	u16 port_flags;
+	u32 sdio_clock;
+	u16 host_header_size;
+	u16 func_header_size;
+	u16 ctrl_header_size;
+} __packed;
+
+struct sd_error_header {
+	u8 header_size;
+	u8 header_type;
+	u8 port_number;
+	u8 error_code;
+} __packed;
+
+struct sd_interrupt_header {
+	u8 header_size;
+	u8 header_type;
+	u8 port_number;
+} __packed;
+
+struct offload_registers_access {
+	u8 command_byte[4];
+	u8 Respond_Byte[4];
+} __packed;
+
+#define INTERRUPT_REGISTER_ACCESSES 15
+struct sd_offloaded_interrupt {
+	u8 header_size;
+	u8 header_type;
+	u8 port_number;
+	struct offload_registers_access reg[INTERRUPT_REGISTER_ACCESSES];
+} __packed;
+
+struct sd_register_header {
+	u8 header_size;
+	u8 header_type;
+	u8 port_number;
+	u8 command_type;
+	u8 command_index;
+	u8 command_response[6];
+} __packed;
+
+#define PIGGYBACK_REGISTER_ACCESSES 14
+struct sd_offloaded_piggyback {
+	struct sd_register_header sdio;
+	struct offload_registers_access reg[PIGGYBACK_REGISTER_ACCESSES];
+} __packed;
+
+union sd_response {
+	struct sd_common_header common;
+	struct sd_status_header status;
+	struct sd_error_header error;
+	struct sd_interrupt_header interrupt;
+	struct sd_response_header response;
+	struct sd_offloaded_interrupt irq;
+	struct sd_offloaded_piggyback pig;
+} __packed;
+
+union sd_command {
+	struct sd_command_header head;
+	struct sd_irqpoll_header poll;
+} __packed;
+
+enum SD_RESPONSE_TYPE {
+	SDRT_UNSPECIFIED = 0,
+	SDRT_NONE,
+	SDRT_1,
+	SDRT_1B,
+	SDRT_2,
+	SDRT_3,
+	SDRT_4,
+	SDRT_5,
+	SDRT_5B,
+	SDRT_6,
+	SDRT_7,
+};
+
+#define RESPONSE_INTERRUPT			0x01
+#define RESPONSE_ERROR				0x02
+#define RESPONSE_STATUS				0x03
+#define RESPONSE_IRQ_DISABLED			0x05
+#define RESPONSE_IRQ_ENABLED			0x06
+#define RESPONSE_PIGGYBACKED			0x07
+#define RESPONSE_NO_INTERRUPT			0x08
+#define RESPONSE_PIG_DISABLED			0x09
+#define RESPONSE_PIG_ENABLED			0x0A
+#define SD_ERROR_1BIT_TIMEOUT			0x01
+#define SD_ERROR_4BIT_TIMEOUT			0x02
+#define SD_ERROR_1BIT_CRC_WRONG			0x03
+#define SD_ERROR_4BIT_CRC_WRONG			0x04
+#define SD_ERROR_1BIT_CRC_ERROR			0x05
+#define SD_ERROR_4BIT_CRC_ERROR			0x06
+#define SD_ERROR_NO_CMD_ENDBIT			0x07
+#define SD_ERROR_NO_1BIT_DATEND			0x08
+#define SD_ERROR_NO_4BIT_DATEND			0x09
+#define SD_ERROR_1BIT_UNEXPECTED_TIMEOUT	0x0A
+#define SD_ERROR_4BIT_UNEXPECTED_TIMEOUT	0x0B
+#define SD_ERROR_ILLEGAL_COMMAND		0x0C
+#define SD_ERROR_NO_DEVICE			0x0D
+#define SD_ERROR_TRANSFER_LENGTH		0x0E
+#define SD_ERROR_1BIT_DATA_TIMEOUT		0x0F
+#define SD_ERROR_4BIT_DATA_TIMEOUT		0x10
+#define SD_ERROR_ILLEGAL_STATE			0x11
+#define SD_ERROR_UNKNOWN_ERROR			0x12
+#define SD_ERROR_RESERVED_ERROR			0x13
+#define SD_ERROR_INVALID_FUNCTION		0x14
+#define SD_ERROR_OUT_OF_RANGE			0x15
+#define SD_ERROR_STAT_CMD			0x16
+#define SD_ERROR_STAT_DATA			0x17
+#define SD_ERROR_STAT_CMD_TIMEOUT		0x18
+#define SD_ERROR_SDCRDY_STUCK			0x19
+#define SD_ERROR_UNHANDLED			0x1A
+#define SD_ERROR_OVERRUN			0x1B
+#define SD_ERROR_PIO_TIMEOUT			0x1C
+
+#define FUN(c) (0x000007 & (c->arg>>28))
+#define REG(c) (0x01FFFF & (c->arg>>9))
+
+static int limit_speed_to_24_MHz;
+module_param(limit_speed_to_24_MHz, bool, 0644);
+MODULE_PARM_DESC(limit_speed_to_24_MHz, "Limit Max SDIO Clock Speed to 24 MHz");
+
+static int pad_input_to_usb_pkt;
+module_param(pad_input_to_usb_pkt, bool, 0644);
+MODULE_PARM_DESC(pad_input_to_usb_pkt,
+		 "Pad USB data input transfers to whole USB Packet");
+
+static int disable_offload_processing;
+module_param(disable_offload_processing, bool, 0644);
+MODULE_PARM_DESC(disable_offload_processing, "Disable Offload Processing");
+
+static int force_1_bit_data_xfers;
+module_param(force_1_bit_data_xfers, bool, 0644);
+MODULE_PARM_DESC(force_1_bit_data_xfers,
+		 "Force SDIO Data Transfers to 1-bit Mode");
+
+static int force_polling_for_irqs;
+module_param(force_polling_for_irqs, bool, 0644);
+MODULE_PARM_DESC(force_polling_for_irqs, "Force Polling for SDIO interrupts");
+
+static int firmware_irqpoll_timeout = 1024;
+module_param(firmware_irqpoll_timeout, int, 0644);
+MODULE_PARM_DESC(firmware_irqpoll_timeout, "VUB300 firmware irqpoll timeout");
+
+static int force_max_req_size = 128;
+module_param(force_max_req_size, int, 0644);
+MODULE_PARM_DESC(force_max_req_size, "set max request size in kBytes");
+
+#ifdef SMSC_DEVELOPMENT_BOARD
+static int firmware_rom_wait_states = 0x04;
+#else
+static int firmware_rom_wait_states = 0x1C;
+#endif
+
+module_param(firmware_rom_wait_states, bool, 0644);
+MODULE_PARM_DESC(firmware_rom_wait_states,
+		 "ROM wait states byte=RRRIIEEE (Reserved Internal External)");
+
+#define ELAN_VENDOR_ID		0x2201
+#define VUB300_VENDOR_ID	0x0424
+#define VUB300_PRODUCT_ID	0x012C
+static struct usb_device_id vub300_table[] = {
+	{USB_DEVICE(ELAN_VENDOR_ID, VUB300_PRODUCT_ID)},
+	{USB_DEVICE(VUB300_VENDOR_ID, VUB300_PRODUCT_ID)},
+	{} /* Terminating entry */
+};
+MODULE_DEVICE_TABLE(usb, vub300_table);
+
+static struct workqueue_struct *cmndworkqueue;
+static struct workqueue_struct *pollworkqueue;
+static struct workqueue_struct *deadworkqueue;
+
+static inline int interface_to_InterfaceNumber(struct usb_interface *interface)
+{
+	if (!interface)
+		return -1;
+	if (!interface->cur_altsetting)
+		return -1;
+	return interface->cur_altsetting->desc.bInterfaceNumber;
+}
+
+struct sdio_register {
+	unsigned func_num:3;
+	unsigned sdio_reg:17;
+	unsigned activate:1;
+	unsigned prepared:1;
+	unsigned regvalue:8;
+	unsigned response:8;
+	unsigned sparebit:26;
+};
+
+struct vub300_mmc_host {
+	struct usb_device *udev;
+	struct usb_interface *interface;
+	struct kref kref;
+	struct mutex cmd_mutex;
+	struct mutex irq_mutex;
+	char vub_name[3 + (9 * 8) + 4 + 1]; /* max of 7 sdio fn's */
+	u8 cmnd_out_ep; /* EndPoint for commands */
+	u8 cmnd_res_ep; /* EndPoint for responses */
+	u8 data_out_ep; /* EndPoint for out data */
+	u8 data_inp_ep; /* EndPoint for inp data */
+	bool card_powered;
+	bool card_present;
+	bool read_only;
+	bool large_usb_packets;
+	bool app_spec; /* ApplicationSpecific */
+	bool irq_enabled; /* by the MMC CORE */
+	bool irq_disabled; /* in the firmware */
+	unsigned bus_width:4;
+	u8 total_offload_count;
+	u8 dynamic_register_count;
+	u8 resp_len;
+	u32 datasize;
+	int errors;
+	int usb_transport_fail;
+	int usb_timed_out;
+	int irqs_queued;
+	struct sdio_register sdio_register[16];
+	struct offload_interrupt_function_register {
+#define MAXREGBITS 4
+#define MAXREGS (1<<MAXREGBITS)
+#define MAXREGMASK (MAXREGS-1)
+		u8 offload_count;
+		u32 offload_point;
+		struct offload_registers_access reg[MAXREGS];
+	} fn[8];
+	u16 fbs[8]; /* Function Block Size */
+	struct mmc_command *cmd;
+	struct mmc_request *req;
+	struct mmc_data *data;
+	struct mmc_host *mmc;
+	struct urb *urb;
+	struct urb *command_out_urb;
+	struct urb *command_res_urb;
+	struct completion command_complete;
+	struct completion irqpoll_complete;
+	union sd_command cmnd;
+	union sd_response resp;
+	struct timer_list sg_transfer_timer;
+	struct usb_sg_request sg_request;
+	struct timer_list inactivity_timer;
+	struct work_struct deadwork;
+	struct work_struct cmndwork;
+	struct delayed_work pollwork;
+	struct host_controller_info hc_info;
+	struct sd_status_header system_port_status;
+	u8 padded_buffer[64];
+};
+
+#define kref_to_vub300_mmc_host(d) container_of(d, struct vub300_mmc_host, kref)
+#define SET_TRANSFER_PSEUDOCODE		21
+#define SET_INTERRUPT_PSEUDOCODE	20
+#define SET_FAILURE_MODE		18
+#define SET_ROM_WAIT_STATES		16
+#define SET_IRQ_ENABLE			13
+#define SET_CLOCK_SPEED			11
+#define SET_FUNCTION_BLOCK_SIZE		9
+#define SET_SD_DATA_MODE		6
+#define SET_SD_POWER			4
+#define ENTER_DFU_MODE			3
+#define GET_HC_INF0			1
+#define GET_SYSTEM_PORT_STATUS		0
+
+static void vub300_delete(struct kref *kref)
+{				/* kref callback - softirq */
+	struct vub300_mmc_host *vub300 = kref_to_vub300_mmc_host(kref);
+	struct mmc_host *mmc = vub300->mmc;
+	usb_free_urb(vub300->command_out_urb);
+	vub300->command_out_urb = NULL;
+	usb_free_urb(vub300->command_res_urb);
+	vub300->command_res_urb = NULL;
+	usb_put_dev(vub300->udev);
+	mmc_free_host(mmc);
+	/*
+	 * and hence also frees vub300
+	 * which is contained at the end of struct mmc
+	 */
+}
+
+static void vub300_queue_cmnd_work(struct vub300_mmc_host *vub300)
+{
+	kref_get(&vub300->kref);
+	if (queue_work(cmndworkqueue, &vub300->cmndwork)) {
+		/*
+		 * then the cmndworkqueue was not previously
+		 * running and the above get ref is obvious
+		 * required and will be put when the thread
+		 * terminates by a specific call
+		 */
+	} else {
+		/*
+		 * the cmndworkqueue was already running from
+		 * a previous invocation and thus to keep the
+		 * kref counts correct we must undo the get
+		 */
+		kref_put(&vub300->kref, vub300_delete);
+	}
+}
+
+static void vub300_queue_poll_work(struct vub300_mmc_host *vub300, int delay)
+{
+	kref_get(&vub300->kref);
+	if (queue_delayed_work(pollworkqueue, &vub300->pollwork, delay)) {
+		/*
+		 * then the pollworkqueue was not previously
+		 * running and the above get ref is obvious
+		 * required and will be put when the thread
+		 * terminates by a specific call
+		 */
+	} else {
+		/*
+		 * the pollworkqueue was already running from
+		 * a previous invocation and thus to keep the
+		 * kref counts correct we must undo the get
+		 */
+		kref_put(&vub300->kref, vub300_delete);
+	}
+}
+
+static void vub300_queue_dead_work(struct vub300_mmc_host *vub300)
+{
+	kref_get(&vub300->kref);
+	if (queue_work(deadworkqueue, &vub300->deadwork)) {
+		/*
+		 * then the deadworkqueue was not previously
+		 * running and the above get ref is obvious
+		 * required and will be put when the thread
+		 * terminates by a specific call
+		 */
+	} else {
+		/*
+		 * the deadworkqueue was already running from
+		 * a previous invocation and thus to keep the
+		 * kref counts correct we must undo the get
+		 */
+		kref_put(&vub300->kref, vub300_delete);
+	}
+}
+
+static void irqpoll_res_completed(struct urb *urb)
+{				/* urb completion handler - hardirq */
+	struct vub300_mmc_host *vub300 = (struct vub300_mmc_host *)urb->context;
+	if (urb->status)
+		vub300->usb_transport_fail = urb->status;
+	complete(&vub300->irqpoll_complete);
+}
+
+static void irqpoll_out_completed(struct urb *urb)
+{				/* urb completion handler - hardirq */
+	struct vub300_mmc_host *vub300 = (struct vub300_mmc_host *)urb->context;
+	if (urb->status) {
+		vub300->usb_transport_fail = urb->status;
+		complete(&vub300->irqpoll_complete);
+		return;
+	} else {
+		int ret;
+		unsigned int pipe =
+			usb_rcvbulkpipe(vub300->udev, vub300->cmnd_res_ep);
+		usb_fill_bulk_urb(vub300->command_res_urb, vub300->udev, pipe,
+				  &vub300->resp, sizeof(vub300->resp),
+				  irqpoll_res_completed, vub300);
+		vub300->command_res_urb->actual_length = 0;
+		ret = usb_submit_urb(vub300->command_res_urb, GFP_ATOMIC);
+		if (ret) {
+			vub300->usb_transport_fail = ret;
+			complete(&vub300->irqpoll_complete);
+		}
+		return;
+	}
+}
+
+static void send_irqpoll(struct vub300_mmc_host *vub300)
+{
+	/* cmd_mutex is held by vub300_pollwork_thread */
+	int retval;
+	int timeout = 0xFFFF & (0x0001FFFF - firmware_irqpoll_timeout);
+	vub300->cmnd.poll.header_size = 22;
+	vub300->cmnd.poll.header_type = 1;
+	vub300->cmnd.poll.port_number = 0;
+	vub300->cmnd.poll.command_type = 2;
+	vub300->cmnd.poll.poll_timeout_lsb = 0xFF & (unsigned)timeout;
+	vub300->cmnd.poll.poll_timeout_msb = 0xFF & (unsigned)(timeout >> 8);
+	usb_fill_bulk_urb(vub300->command_out_urb, vub300->udev,
+			  usb_sndbulkpipe(vub300->udev, vub300->cmnd_out_ep)
+			  , &vub300->cmnd, sizeof(vub300->cmnd)
+			  , irqpoll_out_completed, vub300);
+	retval = usb_submit_urb(vub300->command_out_urb, GFP_KERNEL);
+	if (0 > retval) {
+		vub300->usb_transport_fail = retval;
+		vub300_queue_poll_work(vub300, 1);
+		complete(&vub300->irqpoll_complete);
+		return;
+	} else {
+		return;
+	}
+}
+
+static void new_system_port_status(struct vub300_mmc_host *vub300)
+{
+	int old_card_present = vub300->card_present;
+	int new_card_present =
+		(0x0001 & vub300->system_port_status.port_flags) ? 1 : 0;
+	vub300->read_only =
+		(0x0010 & vub300->system_port_status.port_flags) ? 1 : 0;
+	if (new_card_present && !old_card_present) {
+		dev_info(&vub300->udev->dev, "card just inserted\n");
+		vub300->card_present = 1;
+		vub300->bus_width = 0;
+		if (disable_offload_processing)
+			strncpy(vub300->vub_name, "EMPTY Processing Disabled",
+				sizeof(vub300->vub_name));
+		else
+			vub300->vub_name[0] = 0;
+		mmc_detect_change(vub300->mmc, 1);
+	} else if (!new_card_present && old_card_present) {
+		dev_info(&vub300->udev->dev, "card just ejected\n");
+		vub300->card_present = 0;
+		mmc_detect_change(vub300->mmc, 0);
+	} else {
+		/* no change */
+	}
+}
+
+static void __add_offloaded_reg_to_fifo(struct vub300_mmc_host *vub300,
+					struct offload_registers_access
+					*register_access, u8 func)
+{
+	u8 r = vub300->fn[func].offload_point + vub300->fn[func].offload_count;
+	memcpy(&vub300->fn[func].reg[MAXREGMASK & r], register_access,
+	       sizeof(struct offload_registers_access));
+	vub300->fn[func].offload_count += 1;
+	vub300->total_offload_count += 1;
+}
+
+static void add_offloaded_reg(struct vub300_mmc_host *vub300,
+			      struct offload_registers_access *register_access)
+{
+	u32 Register = ((0x03 & register_access->command_byte[0]) << 15)
+			| ((0xFF & register_access->command_byte[1]) << 7)
+			| ((0xFE & register_access->command_byte[2]) >> 1);
+	u8 func = ((0x70 & register_access->command_byte[0]) >> 4);
+	u8 regs = vub300->dynamic_register_count;
+	u8 i = 0;
+	while (0 < regs-- && 1 == vub300->sdio_register[i].activate) {
+		if (vub300->sdio_register[i].func_num == func &&
+		    vub300->sdio_register[i].sdio_reg == Register) {
+			if (vub300->sdio_register[i].prepared == 0)
+				vub300->sdio_register[i].prepared = 1;
+			vub300->sdio_register[i].response =
+				register_access->Respond_Byte[2];
+			vub300->sdio_register[i].regvalue =
+				register_access->Respond_Byte[3];
+			return;
+		} else {
+			i += 1;
+			continue;
+		}
+	};
+	__add_offloaded_reg_to_fifo(vub300, register_access, func);
+}
+
+static void check_vub300_port_status(struct vub300_mmc_host *vub300)
+{
+	/*
+	 * cmd_mutex is held by vub300_pollwork_thread,
+	 * vub300_deadwork_thread or vub300_cmndwork_thread
+	 */
+	int retval;
+	retval =
+		usb_control_msg(vub300->udev, usb_rcvctrlpipe(vub300->udev, 0),
+				GET_SYSTEM_PORT_STATUS,
+				USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+				0x0000, 0x0000, &vub300->system_port_status,
+				sizeof(vub300->system_port_status), HZ);
+	if (sizeof(vub300->system_port_status) == retval)
+		new_system_port_status(vub300);
+}
+
+static void __vub300_irqpoll_response(struct vub300_mmc_host *vub300)
+{
+	/* cmd_mutex is held by vub300_pollwork_thread */
+	if (vub300->command_res_urb->actual_length == 0)
+		return;
+
+	switch (vub300->resp.common.header_type) {
+	case RESPONSE_INTERRUPT:
+		mutex_lock(&vub300->irq_mutex);
+		if (vub300->irq_enabled)
+			mmc_signal_sdio_irq(vub300->mmc);
+		else
+			vub300->irqs_queued += 1;
+		vub300->irq_disabled = 1;
+		mutex_unlock(&vub300->irq_mutex);
+		break;
+	case RESPONSE_ERROR:
+		if (vub300->resp.error.error_code == SD_ERROR_NO_DEVICE)
+			check_vub300_port_status(vub300);
+		break;
+	case RESPONSE_STATUS:
+		vub300->system_port_status = vub300->resp.status;
+		new_system_port_status(vub300);
+		if (!vub300->card_present)
+			vub300_queue_poll_work(vub300, HZ / 5);
+		break;
+	case RESPONSE_IRQ_DISABLED:
+	{
+		int offloaded_data_length = vub300->resp.common.header_size - 3;
+		int register_count = offloaded_data_length >> 3;
+		int ri = 0;
+		while (register_count--) {
+			add_offloaded_reg(vub300, &vub300->resp.irq.reg[ri]);
+			ri += 1;
+		}
+		mutex_lock(&vub300->irq_mutex);
+		if (vub300->irq_enabled)
+			mmc_signal_sdio_irq(vub300->mmc);
+		else
+			vub300->irqs_queued += 1;
+		vub300->irq_disabled = 1;
+		mutex_unlock(&vub300->irq_mutex);
+		break;
+	}
+	case RESPONSE_IRQ_ENABLED:
+	{
+		int offloaded_data_length = vub300->resp.common.header_size - 3;
+		int register_count = offloaded_data_length >> 3;
+		int ri = 0;
+		while (register_count--) {
+			add_offloaded_reg(vub300, &vub300->resp.irq.reg[ri]);
+			ri += 1;
+		}
+		mutex_lock(&vub300->irq_mutex);
+		if (vub300->irq_enabled)
+			mmc_signal_sdio_irq(vub300->mmc);
+		else if (vub300->irqs_queued)
+			vub300->irqs_queued += 1;
+		else
+			vub300->irqs_queued += 1;
+		vub300->irq_disabled = 0;
+		mutex_unlock(&vub300->irq_mutex);
+		break;
+	}
+	case RESPONSE_NO_INTERRUPT:
+		vub300_queue_poll_work(vub300, 1);
+		break;
+	default:
+		break;
+	}
+}
+
+static void __do_poll(struct vub300_mmc_host *vub300)
+{
+	/* cmd_mutex is held by vub300_pollwork_thread */
+	long commretval;
+	mod_timer(&vub300->inactivity_timer, jiffies + HZ);
+	init_completion(&vub300->irqpoll_complete);
+	send_irqpoll(vub300);
+	commretval = wait_for_completion_timeout(&vub300->irqpoll_complete,
+						 msecs_to_jiffies(500));
+	if (vub300->usb_transport_fail) {
+		/* no need to do anything */
+	} else if (commretval == 0) {
+		vub300->usb_timed_out = 1;
+		usb_kill_urb(vub300->command_out_urb);
+		usb_kill_urb(vub300->command_res_urb);
+	} else if (commretval < 0) {
+		vub300_queue_poll_work(vub300, 1);
+	} else { /* commretval > 0 */
+		__vub300_irqpoll_response(vub300);
+	}
+}
+
+/* this thread runs only when the driver
+ * is trying to poll the device for an IRQ
+ */
+static void vub300_pollwork_thread(struct work_struct *work)
+{				/* NOT irq */
+	struct vub300_mmc_host *vub300 = container_of(work,
+			      struct vub300_mmc_host, pollwork.work);
+	if (!vub300->interface) {
+		kref_put(&vub300->kref, vub300_delete);
+		return;
+	}
+	mutex_lock(&vub300->cmd_mutex);
+	if (vub300->cmd) {
+		vub300_queue_poll_work(vub300, 1);
+	} else if (!vub300->card_present) {
+		/* no need to do anything */
+	} else { /* vub300->card_present */
+		mutex_lock(&vub300->irq_mutex);
+		if (!vub300->irq_enabled) {
+			mutex_unlock(&vub300->irq_mutex);
+		} else if (vub300->irqs_queued) {
+			vub300->irqs_queued -= 1;
+			mmc_signal_sdio_irq(vub300->mmc);
+			mod_timer(&vub300->inactivity_timer, jiffies + HZ);
+			mutex_unlock(&vub300->irq_mutex);
+		} else { /* NOT vub300->irqs_queued */
+			mutex_unlock(&vub300->irq_mutex);
+			__do_poll(vub300);
+		}
+	}
+	mutex_unlock(&vub300->cmd_mutex);
+	kref_put(&vub300->kref, vub300_delete);
+}
+
+static void vub300_deadwork_thread(struct work_struct *work)
+{				/* NOT irq */
+	struct vub300_mmc_host *vub300 =
+		container_of(work, struct vub300_mmc_host, deadwork);
+	if (!vub300->interface) {
+		kref_put(&vub300->kref, vub300_delete);
+		return;
+	}
+	mutex_lock(&vub300->cmd_mutex);
+	if (vub300->cmd) {
+		/*
+		 * a command got in as the inactivity
+		 * timer expired - so we just let the
+		 * processing of the command show if
+		 * the device is dead
+		 */
+	} else if (vub300->card_present) {
+		check_vub300_port_status(vub300);
+	} else if (vub300->mmc && vub300->mmc->card &&
+		   mmc_card_present(vub300->mmc->card)) {
+		/*
+		 * the MMC core must not have responded
+		 * to the previous indication - lets
+		 * hope that it eventually does so we
+		 * will just ignore this for now
+		 */
+	} else {
+		check_vub300_port_status(vub300);
+	}
+	mod_timer(&vub300->inactivity_timer, jiffies + HZ);
+	mutex_unlock(&vub300->cmd_mutex);
+	kref_put(&vub300->kref, vub300_delete);
+}
+
+static void vub300_inactivity_timer_expired(unsigned long data)
+{				/* softirq */
+	struct vub300_mmc_host *vub300 = (struct vub300_mmc_host *)data;
+	if (!vub300->interface) {
+		kref_put(&vub300->kref, vub300_delete);
+	} else if (vub300->cmd) {
+		mod_timer(&vub300->inactivity_timer, jiffies + HZ);
+	} else {
+		vub300_queue_dead_work(vub300);
+		mod_timer(&vub300->inactivity_timer, jiffies + HZ);
+	}
+}
+
+static int vub300_response_error(u8 error_code)
+{
+	switch (error_code) {
+	case SD_ERROR_PIO_TIMEOUT:
+	case SD_ERROR_1BIT_TIMEOUT:
+	case SD_ERROR_4BIT_TIMEOUT:
+		return -ETIMEDOUT;
+	case SD_ERROR_STAT_DATA:
+	case SD_ERROR_OVERRUN:
+	case SD_ERROR_STAT_CMD:
+	case SD_ERROR_STAT_CMD_TIMEOUT:
+	case SD_ERROR_SDCRDY_STUCK:
+	case SD_ERROR_UNHANDLED:
+	case SD_ERROR_1BIT_CRC_WRONG:
+	case SD_ERROR_4BIT_CRC_WRONG:
+	case SD_ERROR_1BIT_CRC_ERROR:
+	case SD_ERROR_4BIT_CRC_ERROR:
+	case SD_ERROR_NO_CMD_ENDBIT:
+	case SD_ERROR_NO_1BIT_DATEND:
+	case SD_ERROR_NO_4BIT_DATEND:
+	case SD_ERROR_1BIT_DATA_TIMEOUT:
+	case SD_ERROR_4BIT_DATA_TIMEOUT:
+	case SD_ERROR_1BIT_UNEXPECTED_TIMEOUT:
+	case SD_ERROR_4BIT_UNEXPECTED_TIMEOUT:
+		return -EILSEQ;
+	case 33:
+		return -EILSEQ;
+	case SD_ERROR_ILLEGAL_COMMAND:
+		return -EINVAL;
+	case SD_ERROR_NO_DEVICE:
+		return -ENOMEDIUM;
+	default:
+		return -ENODEV;
+	}
+}
+
+static void command_res_completed(struct urb *urb)
+{				/* urb completion handler - hardirq */
+	struct vub300_mmc_host *vub300 = (struct vub300_mmc_host *)urb->context;
+	if (urb->status) {
+		/* we have to let the initiator handle the error */
+	} else if (vub300->command_res_urb->actual_length == 0) {
+		/*
+		 * we have seen this happen once or twice and
+		 * we suspect a buggy USB host controller
+		 */
+	} else if (!vub300->data) {
+		/* this means that the command (typically CMD52) suceeded */
+	} else if (vub300->resp.common.header_type != 0x02) {
+		/*
+		 * this is an error response from the VUB300 chip
+		 * and we let the initiator handle it
+		 */
+	} else if (vub300->urb) {
+		vub300->cmd->error =
+			vub300_response_error(vub300->resp.error.error_code);
+		usb_unlink_urb(vub300->urb);
+	} else {
+		vub300->cmd->error =
+			vub300_response_error(vub300->resp.error.error_code);
+		usb_sg_cancel(&vub300->sg_request);
+	}
+	complete(&vub300->command_complete);	/* got_response_in */
+}
+
+static void command_out_completed(struct urb *urb)
+{				/* urb completion handler - hardirq */
+	struct vub300_mmc_host *vub300 = (struct vub300_mmc_host *)urb->context;
+	if (urb->status) {
+		complete(&vub300->command_complete);
+	} else {
+		int ret;
+		unsigned int pipe =
+			usb_rcvbulkpipe(vub300->udev, vub300->cmnd_res_ep);
+		usb_fill_bulk_urb(vub300->command_res_urb, vub300->udev, pipe,
+				  &vub300->resp, sizeof(vub300->resp),
+				  command_res_completed, vub300);
+		vub300->command_res_urb->actual_length = 0;
+		ret = usb_submit_urb(vub300->command_res_urb, GFP_ATOMIC);
+		if (ret == 0) {
+			/*
+			 * the urb completion handler will call
+			 * our completion handler
+			 */
+		} else {
+			/*
+			 * and thus we only call it directly
+			 * when it will not be called
+			 */
+			complete(&vub300->command_complete);
+		}
+	}
+}
+
+/*
+ * the STUFF bits are masked out for the comparisons
+ */
+static void snoop_block_size_and_bus_width(struct vub300_mmc_host *vub300,
+					   u32 cmd_arg)
+{
+	if ((0xFBFFFE00 & cmd_arg) == 0x80022200)
+		vub300->fbs[1] = (cmd_arg << 8) | (0x00FF & vub300->fbs[1]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x80022000)
+		vub300->fbs[1] = (0xFF & cmd_arg) | (0xFF00 & vub300->fbs[1]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x80042200)
+		vub300->fbs[2] = (cmd_arg << 8) | (0x00FF & vub300->fbs[2]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x80042000)
+		vub300->fbs[2] = (0xFF & cmd_arg) | (0xFF00 & vub300->fbs[2]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x80062200)
+		vub300->fbs[3] = (cmd_arg << 8) | (0x00FF & vub300->fbs[3]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x80062000)
+		vub300->fbs[3] = (0xFF & cmd_arg) | (0xFF00 & vub300->fbs[3]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x80082200)
+		vub300->fbs[4] = (cmd_arg << 8) | (0x00FF & vub300->fbs[4]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x80082000)
+		vub300->fbs[4] = (0xFF & cmd_arg) | (0xFF00 & vub300->fbs[4]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x800A2200)
+		vub300->fbs[5] = (cmd_arg << 8) | (0x00FF & vub300->fbs[5]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x800A2000)
+		vub300->fbs[5] = (0xFF & cmd_arg) | (0xFF00 & vub300->fbs[5]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x800C2200)
+		vub300->fbs[6] = (cmd_arg << 8) | (0x00FF & vub300->fbs[6]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x800C2000)
+		vub300->fbs[6] = (0xFF & cmd_arg) | (0xFF00 & vub300->fbs[6]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x800E2200)
+		vub300->fbs[7] = (cmd_arg << 8) | (0x00FF & vub300->fbs[7]);
+	else if ((0xFBFFFE00 & cmd_arg) == 0x800E2000)
+		vub300->fbs[7] = (0xFF & cmd_arg) | (0xFF00 & vub300->fbs[7]);
+	else if ((0xFBFFFE03 & cmd_arg) == 0x80000E00)
+		vub300->bus_width = 1;
+	else if ((0xFBFFFE03 & cmd_arg) == 0x80000E02)
+		vub300->bus_width = 4;
+}
+
+static void send_command(struct vub300_mmc_host *vub300)
+{
+	/* cmd_mutex is held by vub300_cmndwork_thread */
+	struct mmc_command *cmd = vub300->cmd;
+	struct mmc_data *data = vub300->data;
+	int retval;
+	int i;
+	u8 response_type;
+	if (vub300->app_spec) {
+		switch (cmd->opcode) {
+		case 6:
+			response_type = SDRT_1;
+			vub300->resp_len = 6;
+			if (0x00000000 == (0x00000003 & cmd->arg))
+				vub300->bus_width = 1;
+			else if (0x00000002 == (0x00000003 & cmd->arg))
+				vub300->bus_width = 4;
+			else
+				dev_err(&vub300->udev->dev,
+					"unexpected ACMD6 bus_width=%d\n",
+					0x00000003 & cmd->arg);
+			break;
+		case 13:
+			response_type = SDRT_1;
+			vub300->resp_len = 6;
+			break;
+		case 22:
+			response_type = SDRT_1;
+			vub300->resp_len = 6;
+			break;
+		case 23:
+			response_type = SDRT_1;
+			vub300->resp_len = 6;
+			break;
+		case 41:
+			response_type = SDRT_3;
+			vub300->resp_len = 6;
+			break;
+		case 42:
+			response_type = SDRT_1;
+			vub300->resp_len = 6;
+			break;
+		case 51:
+			response_type = SDRT_1;
+			vub300->resp_len = 6;
+			break;
+		case 55:
+			response_type = SDRT_1;
+			vub300->resp_len = 6;
+			break;
+		default:
+			vub300->resp_len = 0;
+			cmd->error = -EINVAL;
+			complete(&vub300->command_complete);
+			return;
+		}
+		vub300->app_spec = 0;
+	} else {
+		switch (cmd->opcode) {
+		case 0:
+			response_type = SDRT_NONE;
+			vub300->resp_len = 0;
+			break;
+		case 1:
+			response_type = SDRT_3;
+			vub300->resp_len = 6;
+			break;
+		case 2:
+			response_type = SDRT_2;
+			vub300->resp_len = 17;
+			break;
+		case 3:
+			response_type = SDRT_6;
+			vub300->resp_len = 6;
+			break;
+		case 4:
+			response_type = SDRT_NONE;
+			vub300->resp_len = 0;
+			break;
+		case 5:
+			response_type = SDRT_4;
+			vub300->resp_len = 6;
+			break;
+		case 6:
+			response_type = SDRT_1;
+			vub300->resp_len = 6;
+			break;
+		case 7:
+			response_type = SDRT_1B;
+			vub300->resp_len = 6;
+			break;
+		case 8:
+			response_type = SDRT_7;
+			vub300->resp_len = 6;
+			break;
+		case 9:
+			response_type = SDRT_2;
+			vub300->resp_len = 17;
+			break;
+		case 10:
+			response_type = SDRT_2;
+			vub300->resp_len = 17;
+			break;
+		case 12:
+			response_type = SDRT_1B;
+			vub300->resp_len = 6;