USB: Support for addressing a USB device under xHCI

[deliverable/linux.git] / drivers / usb / host / xhci.h

/*
 * xHCI host controller driver
 *
 * Copyright (C) 2008 Intel Corp.
 *
 * Author: Sarah Sharp
 * Some code borrowed from the Linux EHCI driver.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that 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, write to the Free Software Foundation,
 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef __LINUX_XHCI_HCD_H
#define __LINUX_XHCI_HCD_H

#include <linux/usb.h>
#include <linux/timer.h>

#include "../core/hcd.h"
/* Code sharing between pci-quirks and xhci hcd */
#include	"xhci-ext-caps.h"

/* xHCI PCI Configuration Registers */
#define XHCI_SBRN_OFFSET	(0x60)

/* Max number of USB devices for any host controller - limit in section 6.1 */
#define MAX_HC_SLOTS		256
/* Section 5.3.3 - MaxPorts */
#define MAX_HC_PORTS		127

/*
 * xHCI register interface.
 * This corresponds to the eXtensible Host Controller Interface (xHCI)
 * Revision 0.95 specification
 *
 * Registers should always be accessed with double word or quad word accesses.
 *
 * Some xHCI implementations may support 64-bit address pointers.  Registers
 * with 64-bit address pointers should be written to with dword accesses by
 * writing the low dword first (ptr[0]), then the high dword (ptr[1]) second.
 * xHCI implementations that do not support 64-bit address pointers will ignore
 * the high dword, and write order is irrelevant.
 */

/**
 * struct xhci_cap_regs - xHCI Host Controller Capability Registers.
 * @hc_capbase:		length of the capabilities register and HC version number
 * @hcs_params1:	HCSPARAMS1 - Structural Parameters 1
 * @hcs_params2:	HCSPARAMS2 - Structural Parameters 2
 * @hcs_params3:	HCSPARAMS3 - Structural Parameters 3
 * @hcc_params:		HCCPARAMS - Capability Parameters
 * @db_off:		DBOFF - Doorbell array offset
 * @run_regs_off:	RTSOFF - Runtime register space offset
 */
struct xhci_cap_regs {
	u32	hc_capbase;
	u32	hcs_params1;
	u32	hcs_params2;
	u32	hcs_params3;
	u32	hcc_params;
	u32	db_off;
	u32	run_regs_off;
	/* Reserved up to (CAPLENGTH - 0x1C) */
} __attribute__ ((packed));

/* hc_capbase bitmasks */
/* bits 7:0 - how long is the Capabilities register */
#define HC_LENGTH(p)		XHCI_HC_LENGTH(p)
/* bits 31:16	*/
#define HC_VERSION(p)		(((p) >> 16) & 0xffff)

/* HCSPARAMS1 - hcs_params1 - bitmasks */
/* bits 0:7, Max Device Slots */
#define HCS_MAX_SLOTS(p)	(((p) >> 0) & 0xff)
#define HCS_SLOTS_MASK		0xff
/* bits 8:18, Max Interrupters */
#define HCS_MAX_INTRS(p)	(((p) >> 8) & 0x7ff)
/* bits 24:31, Max Ports - max value is 0x7F = 127 ports */
#define HCS_MAX_PORTS(p)	(((p) >> 24) & 0x7f)

/* HCSPARAMS2 - hcs_params2 - bitmasks */
/* bits 0:3, frames or uframes that SW needs to queue transactions
 * ahead of the HW to meet periodic deadlines */
#define HCS_IST(p)		(((p) >> 0) & 0xf)
/* bits 4:7, max number of Event Ring segments */
#define HCS_ERST_MAX(p)		(((p) >> 4) & 0xf)
/* bit 26 Scratchpad restore - for save/restore HW state - not used yet */
/* bits 27:31 number of Scratchpad buffers SW must allocate for the HW */

/* HCSPARAMS3 - hcs_params3 - bitmasks */
/* bits 0:7, Max U1 to U0 latency for the roothub ports */
#define HCS_U1_LATENCY(p)	(((p) >> 0) & 0xff)
/* bits 16:31, Max U2 to U0 latency for the roothub ports */
#define HCS_U2_LATENCY(p)	(((p) >> 16) & 0xffff)

/* HCCPARAMS - hcc_params - bitmasks */
/* true: HC can use 64-bit address pointers */
#define HCC_64BIT_ADDR(p)	((p) & (1 << 0))
/* true: HC can do bandwidth negotiation */
#define HCC_BANDWIDTH_NEG(p)	((p) & (1 << 1))
/* true: HC uses 64-byte Device Context structures
 * FIXME 64-byte context structures aren't supported yet.
 */
#define HCC_64BYTE_CONTEXT(p)	((p) & (1 << 2))
/* true: HC has port power switches */
#define HCC_PPC(p)		((p) & (1 << 3))
/* true: HC has port indicators */
#define HCS_INDICATOR(p)	((p) & (1 << 4))
/* true: HC has Light HC Reset Capability */
#define HCC_LIGHT_RESET(p)	((p) & (1 << 5))
/* true: HC supports latency tolerance messaging */
#define HCC_LTC(p)		((p) & (1 << 6))
/* true: no secondary Stream ID Support */
#define HCC_NSS(p)		((p) & (1 << 7))
/* Max size for Primary Stream Arrays - 2^(n+1), where n is bits 12:15 */
#define HCC_MAX_PSA		(1 << ((((p) >> 12) & 0xf) + 1))
/* Extended Capabilities pointer from PCI base - section 5.3.6 */
#define HCC_EXT_CAPS(p)		XHCI_HCC_EXT_CAPS(p)

/* db_off bitmask - bits 0:1 reserved */
#define	DBOFF_MASK	(~0x3)

/* run_regs_off bitmask - bits 0:4 reserved */
#define	RTSOFF_MASK	(~0x1f)


/* Number of registers per port */
#define	NUM_PORT_REGS	4

/**
 * struct xhci_op_regs - xHCI Host Controller Operational Registers.
 * @command:		USBCMD - xHC command register
 * @status:		USBSTS - xHC status register
 * @page_size:		This indicates the page size that the host controller
 * 			supports.  If bit n is set, the HC supports a page size
 * 			of 2^(n+12), up to a 128MB page size.
 * 			4K is the minimum page size.
 * @cmd_ring:		CRP - 64-bit Command Ring Pointer
 * @dcbaa_ptr:		DCBAAP - 64-bit Device Context Base Address Array Pointer
 * @config_reg:		CONFIG - Configure Register
 * @port_status_base:	PORTSCn - base address for Port Status and Control
 * 			Each port has a Port Status and Control register,
 * 			followed by a Port Power Management Status and Control
 * 			register, a Port Link Info register, and a reserved
 * 			register.
 * @port_power_base:	PORTPMSCn - base address for
 * 			Port Power Management Status and Control
 * @port_link_base:	PORTLIn - base address for Port Link Info (current
 * 			Link PM state and control) for USB 2.1 and USB 3.0
 * 			devices.
 */
struct xhci_op_regs {
	u32	command;
	u32	status;
	u32	page_size;
	u32	reserved1;
	u32	reserved2;
	u32	dev_notification;
	u32	cmd_ring[2];
	/* rsvd: offset 0x20-2F */
	u32	reserved3[4];
	u32	dcbaa_ptr[2];
	u32	config_reg;
	/* rsvd: offset 0x3C-3FF */
	u32	reserved4[241];
	/* port 1 registers, which serve as a base address for other ports */
	u32	port_status_base;
	u32	port_power_base;
	u32	port_link_base;
	u32	reserved5;
	/* registers for ports 2-255 */
	u32	reserved6[NUM_PORT_REGS*254];
} __attribute__ ((packed));

/* USBCMD - USB command - command bitmasks */
/* start/stop HC execution - do not write unless HC is halted*/
#define CMD_RUN		XHCI_CMD_RUN
/* Reset HC - resets internal HC state machine and all registers (except
 * PCI config regs).  HC does NOT drive a USB reset on the downstream ports.
 * The xHCI driver must reinitialize the xHC after setting this bit.
 */
#define CMD_RESET	(1 << 1)
/* Event Interrupt Enable - a '1' allows interrupts from the host controller */
#define CMD_EIE		XHCI_CMD_EIE
/* Host System Error Interrupt Enable - get out-of-band signal for HC errors */
#define CMD_HSEIE	XHCI_CMD_HSEIE
/* bits 4:6 are reserved (and should be preserved on writes). */
/* light reset (port status stays unchanged) - reset completed when this is 0 */
#define CMD_LRESET	(1 << 7)
/* FIXME: ignoring host controller save/restore state for now. */
#define CMD_CSS		(1 << 8)
#define CMD_CRS		(1 << 9)
/* Enable Wrap Event - '1' means xHC generates an event when MFINDEX wraps. */
#define CMD_EWE		XHCI_CMD_EWE
/* MFINDEX power management - '1' means xHC can stop MFINDEX counter if all root
 * hubs are in U3 (selective suspend), disconnect, disabled, or powered-off.
 * '0' means the xHC can power it off if all ports are in the disconnect,
 * disabled, or powered-off state.
 */
#define CMD_PM_INDEX	(1 << 11)
/* bits 12:31 are reserved (and should be preserved on writes). */

/* USBSTS - USB status - status bitmasks */
/* HC not running - set to 1 when run/stop bit is cleared. */
#define STS_HALT	XHCI_STS_HALT
/* serious error, e.g. PCI parity error.  The HC will clear the run/stop bit. */
#define STS_FATAL	(1 << 2)
/* event interrupt - clear this prior to clearing any IP flags in IR set*/
#define STS_EINT	(1 << 3)
/* port change detect */
#define STS_PORT	(1 << 4)
/* bits 5:7 reserved and zeroed */
/* save state status - '1' means xHC is saving state */
#define STS_SAVE	(1 << 8)
/* restore state status - '1' means xHC is restoring state */
#define STS_RESTORE	(1 << 9)
/* true: save or restore error */
#define STS_SRE		(1 << 10)
/* true: Controller Not Ready to accept doorbell or op reg writes after reset */
#define STS_CNR		XHCI_STS_CNR
/* true: internal Host Controller Error - SW needs to reset and reinitialize */
#define STS_HCE		(1 << 12)
/* bits 13:31 reserved and should be preserved */

/*
 * DNCTRL - Device Notification Control Register - dev_notification bitmasks
 * Generate a device notification event when the HC sees a transaction with a
 * notification type that matches a bit set in this bit field.
 */
#define	DEV_NOTE_MASK		(0xffff)
#define ENABLE_DEV_NOTE(x)	(1 << x)
/* Most of the device notification types should only be used for debug.
 * SW does need to pay attention to function wake notifications.
 */
#define	DEV_NOTE_FWAKE		ENABLE_DEV_NOTE(1)

/* CRCR - Command Ring Control Register - cmd_ring bitmasks */
/* bit 0 is the command ring cycle state */
/* stop ring operation after completion of the currently executing command */
#define CMD_RING_PAUSE		(1 << 1)
/* stop ring immediately - abort the currently executing command */
#define CMD_RING_ABORT		(1 << 2)
/* true: command ring is running */
#define CMD_RING_RUNNING	(1 << 3)
/* bits 4:5 reserved and should be preserved */
/* Command Ring pointer - bit mask for the lower 32 bits. */
#define CMD_RING_ADDR_MASK	(0xffffffc0)

/* CONFIG - Configure Register - config_reg bitmasks */
/* bits 0:7 - maximum number of device slots enabled (NumSlotsEn) */
#define MAX_DEVS(p)	((p) & 0xff)
/* bits 8:31 - reserved and should be preserved */

/* PORTSC - Port Status and Control Register - port_status_base bitmasks */
/* true: device connected */
#define PORT_CONNECT	(1 << 0)
/* true: port enabled */
#define PORT_PE		(1 << 1)
/* bit 2 reserved and zeroed */
/* true: port has an over-current condition */
#define PORT_OC		(1 << 3)
/* true: port reset signaling asserted */
#define PORT_RESET	(1 << 4)
/* Port Link State - bits 5:8
 * A read gives the current link PM state of the port,
 * a write with Link State Write Strobe set sets the link state.
 */
/* true: port has power (see HCC_PPC) */
#define PORT_POWER	(1 << 9)
/* bits 10:13 indicate device speed:
 * 0 - undefined speed - port hasn't be initialized by a reset yet
 * 1 - full speed
 * 2 - low speed
 * 3 - high speed
 * 4 - super speed
 * 5-15 reserved
 */
#define DEV_SPEED_MASK		(0xf<<10)
#define DEV_UNDEFSPEED(p)	(((p) & DEV_SPEED_MASK) == (0x0<<10))
#define DEV_FULLSPEED(p)	(((p) & DEV_SPEED_MASK) == (0x1<<10))
#define DEV_LOWSPEED(p)		(((p) & DEV_SPEED_MASK) == (0x2<<10))
#define DEV_HIGHSPEED(p)	(((p) & DEV_SPEED_MASK) == (0x3<<10))
#define DEV_SUPERSPEED(p)	(((p) & DEV_SPEED_MASK) == (0x4<<10))
/* Port Indicator Control */
#define PORT_LED_OFF	(0 << 14)
#define PORT_LED_AMBER	(1 << 14)
#define PORT_LED_GREEN	(2 << 14)
#define PORT_LED_MASK	(3 << 14)
/* Port Link State Write Strobe - set this when changing link state */
#define PORT_LINK_STROBE	(1 << 16)
/* true: connect status change */
#define PORT_CSC	(1 << 17)
/* true: port enable change */
#define PORT_PEC	(1 << 18)
/* true: warm reset for a USB 3.0 device is done.  A "hot" reset puts the port
 * into an enabled state, and the device into the default state.  A "warm" reset
 * also resets the link, forcing the device through the link training sequence.
 * SW can also look at the Port Reset register to see when warm reset is done.
 */
#define PORT_WRC	(1 << 19)
/* true: over-current change */
#define PORT_OCC	(1 << 20)
/* true: reset change - 1 to 0 transition of PORT_RESET */
#define PORT_RC		(1 << 21)
/* port link status change - set on some port link state transitions:
 *  Transition				Reason
 *  ------------------------------------------------------------------------------
 *  - U3 to Resume			Wakeup signaling from a device
 *  - Resume to Recovery to U0		USB 3.0 device resume
 *  - Resume to U0			USB 2.0 device resume
 *  - U3 to Recovery to U0		Software resume of USB 3.0 device complete
 *  - U3 to U0				Software resume of USB 2.0 device complete
 *  - U2 to U0				L1 resume of USB 2.1 device complete
 *  - U0 to U0 (???)			L1 entry rejection by USB 2.1 device
 *  - U0 to disabled			L1 entry error with USB 2.1 device
 *  - Any state to inactive		Error on USB 3.0 port
 */
#define PORT_PLC	(1 << 22)
/* port configure error change - port failed to configure its link partner */
#define PORT_CEC	(1 << 23)
/* bit 24 reserved */
/* wake on connect (enable) */
#define PORT_WKCONN_E	(1 << 25)
/* wake on disconnect (enable) */
#define PORT_WKDISC_E	(1 << 26)
/* wake on over-current (enable) */
#define PORT_WKOC_E	(1 << 27)
/* bits 28:29 reserved */
/* true: device is removable - for USB 3.0 roothub emulation */
#define PORT_DEV_REMOVE	(1 << 30)
/* Initiate a warm port reset - complete when PORT_WRC is '1' */
#define PORT_WR		(1 << 31)

/* Port Power Management Status and Control - port_power_base bitmasks */
/* Inactivity timer value for transitions into U1, in microseconds.
 * Timeout can be up to 127us.  0xFF means an infinite timeout.
 */
#define PORT_U1_TIMEOUT(p)	((p) & 0xff)
/* Inactivity timer value for transitions into U2 */
#define PORT_U2_TIMEOUT(p)	(((p) & 0xff) << 8)
/* Bits 24:31 for port testing */


/**
 * struct intr_reg - Interrupt Register Set
 * @irq_pending:	IMAN - Interrupt Management Register.  Used to enable
 *			interrupts and check for pending interrupts.
 * @irq_control:	IMOD - Interrupt Moderation Register.
 * 			Used to throttle interrupts.
 * @erst_size:		Number of segments in the Event Ring Segment Table (ERST).
 * @erst_base:		ERST base address.
 * @erst_dequeue:	Event ring dequeue pointer.
 *
 * Each interrupter (defined by a MSI-X vector) has an event ring and an Event
 * Ring Segment Table (ERST) associated with it.  The event ring is comprised of
 * multiple segments of the same size.  The HC places events on the ring and
 * "updates the Cycle bit in the TRBs to indicate to software the current
 * position of the Enqueue Pointer." The HCD (Linux) processes those events and
 * updates the dequeue pointer.
 */
struct intr_reg {
	u32	irq_pending;
	u32	irq_control;
	u32	erst_size;
	u32	rsvd;
	u32	erst_base[2];
	u32	erst_dequeue[2];
} __attribute__ ((packed));

/* irq_pending bitmasks */
#define	ER_IRQ_PENDING(p)	((p) & 0x1)
/* bits 2:31 need to be preserved */
/* THIS IS BUGGY - FIXME - IP IS WRITE 1 TO CLEAR */
#define	ER_IRQ_CLEAR(p)		((p) & 0xfffffffe)
#define	ER_IRQ_ENABLE(p)	((ER_IRQ_CLEAR(p)) | 0x2)
#define	ER_IRQ_DISABLE(p)	((ER_IRQ_CLEAR(p)) & ~(0x2))

/* irq_control bitmasks */
/* Minimum interval between interrupts (in 250ns intervals).  The interval
 * between interrupts will be longer if there are no events on the event ring.
 * Default is 4000 (1 ms).
 */
#define ER_IRQ_INTERVAL_MASK	(0xffff)
/* Counter used to count down the time to the next interrupt - HW use only */
#define ER_IRQ_COUNTER_MASK	(0xffff << 16)

/* erst_size bitmasks */
/* Preserve bits 16:31 of erst_size */
#define	ERST_SIZE_MASK		(0xffff << 16)

/* erst_dequeue bitmasks */
/* Dequeue ERST Segment Index (DESI) - Segment number (or alias)
 * where the current dequeue pointer lies.  This is an optional HW hint.
 */
#define ERST_DESI_MASK		(0x7)
/* Event Handler Busy (EHB) - is the event ring scheduled to be serviced by
 * a work queue (or delayed service routine)?
 */
#define ERST_EHB		(1 << 3)
#define ERST_PTR_MASK		(0xf)

/**
 * struct xhci_run_regs
 * @microframe_index:
 * 		MFINDEX - current microframe number
 *
 * Section 5.5 Host Controller Runtime Registers:
 * "Software should read and write these registers using only Dword (32 bit)
 * or larger accesses"
 */
struct xhci_run_regs {
	u32	microframe_index;
	u32	rsvd[7];
	struct intr_reg	ir_set[128];
} __attribute__ ((packed));

/**
 * struct doorbell_array
 *
 * Section 5.6
 */
struct xhci_doorbell_array {
	u32	doorbell[256];
} __attribute__ ((packed));

#define	DB_TARGET_MASK		0xFFFFFF00
#define	DB_STREAM_ID_MASK	0x0000FFFF
#define	DB_TARGET_HOST		0x0
#define	DB_STREAM_ID_HOST	0x0
#define	DB_MASK			(0xff << 8)


/**
 * struct xhci_slot_ctx
 * @dev_info:	Route string, device speed, hub info, and last valid endpoint
 * @dev_info2:	Max exit latency for device number, root hub port number
 * @tt_info:	tt_info is used to construct split transaction tokens
 * @dev_state:	slot state and device address
 *
 * Slot Context - section 6.2.1.1.  This assumes the HC uses 32-byte context
 * structures.  If the HC uses 64-byte contexts, there is an additional 32 bytes
 * reserved at the end of the slot context for HC internal use.
 */
struct xhci_slot_ctx {
	u32	dev_info;
	u32	dev_info2;
	u32	tt_info;
	u32	dev_state;
	/* offset 0x10 to 0x1f reserved for HC internal use */
	u32	reserved[4];
} __attribute__ ((packed));

/* dev_info bitmasks */
/* Route String - 0:19 */
#define ROUTE_STRING_MASK	(0xfffff)
/* Device speed - values defined by PORTSC Device Speed field - 20:23 */
#define DEV_SPEED	(0xf << 20)
/* bit 24 reserved */
/* Is this LS/FS device connected through a HS hub? - bit 25 */
#define DEV_MTT		(0x1 << 25)
/* Set if the device is a hub - bit 26 */
#define DEV_HUB		(0x1 << 26)
/* Index of the last valid endpoint context in this device context - 27:31 */
#define LAST_EP_MASK	(0x1f << 27)
#define LAST_EP(p)	((p) << 27)

/* dev_info2 bitmasks */
/* Max Exit Latency (ms) - worst case time to wake up all links in dev path */
#define MAX_EXIT	(0xffff)
/* Root hub port number that is needed to access the USB device */
#define ROOT_HUB_PORT	(0xff << 16)

/* tt_info bitmasks */
/*
 * TT Hub Slot ID - for low or full speed devices attached to a high-speed hub
 * The Slot ID of the hub that isolates the high speed signaling from
 * this low or full-speed device.  '0' if attached to root hub port.
 */
#define TT_SLOT		(0xff)
/*
 * The number of the downstream facing port of the high-speed hub
 * '0' if the device is not low or full speed.
 */
#define TT_PORT		(0xff << 8)

/* dev_state bitmasks */
/* USB device address - assigned by the HC */
#define DEV_ADDR	(0xff)
/* bits 8:26 reserved */
/* Slot state */
#define SLOT_STATE	(0x1f << 27)


/**
 * struct xhci_ep_ctx
 * @ep_info:	endpoint state, streams, mult, and interval information.
 * @ep_info2:	information on endpoint type, max packet size, max burst size,
 * 		error count, and whether the HC will force an event for all
 * 		transactions.
 * @ep_ring:	64-bit ring address.  If the endpoint only defines one flow,
 * 		this points to the endpoint transfer ring.  Otherwise, it points
 * 		to a flow context array, which has a ring pointer for each flow.
 * @intr_target:
 * 		64-bit address of the Interrupter Target that will receive
 * 		events from this endpoint.
 *
 * Endpoint Context - section 6.2.1.2.  This assumes the HC uses 32-byte context
 * structures.  If the HC uses 64-byte contexts, there is an additional 32 bytes
 * reserved at the end of the endpoint context for HC internal use.
 */
struct xhci_ep_ctx {
	u32	ep_info;
	u32	ep_info2;
	/* 64-bit endpoint ring address */
	u32	ep_ring[2];
	/* 64-bit address of the interrupter target */
	u32	intr_target[2];
	/* offset 0x14 - 0x1f reserved for HC internal use */
	u32	reserved[2];
} __attribute__ ((packed));

/* ep_info bitmasks */
/*
 * Endpoint State - bits 0:2
 * 0 - disabled
 * 1 - running
 * 2 - halted due to halt condition - ok to manipulate endpoint ring
 * 3 - stopped
 * 4 - TRB error
 * 5-7 - reserved
 */
#define EP_STATE	(0xf)
/* Mult - Max number of burtst within an interval, in EP companion desc. */
#define EP_MULT(p)		((p & 0x3) << 8)
/* bits 10:14 are Max Primary Streams */
/* bit 15 is Linear Stream Array */
/* Interval - period between requests to an endpoint - 125u increments. */
#define EP_INTERVAL	(0xff << 16)

/* ep_info2 bitmasks */
/*
 * Force Event - generate transfer events for all TRBs for this endpoint
 * This will tell the HC to ignore the IOC and ISP flags (for debugging only).
 */
#define	FORCE_EVENT	(0x1)
#define ERROR_COUNT(p)	(((p) & 0x3) << 1)
#define EP_TYPE(p)	((p) << 3)
#define ISOC_OUT_EP	1
#define BULK_OUT_EP	2
#define INT_OUT_EP	3
#define CTRL_EP		4
#define ISOC_IN_EP	5
#define BULK_IN_EP	6
#define INT_IN_EP	7
/* bit 6 reserved */
/* bit 7 is Host Initiate Disable - for disabling stream selection */
#define MAX_BURST(p)	(((p)&0xff) << 8)
#define MAX_PACKET(p)	(((p)&0xffff) << 16)


/**
 * struct xhci_device_control
 * Input/Output context; see section 6.2.5.
 *
 * @drop_context:	set the bit of the endpoint context you want to disable
 * @add_context:	set the bit of the endpoint context you want to enable
 */
struct xhci_device_control {
	u32	drop_flags;
	u32	add_flags;
	u32	rsvd[6];
	struct xhci_slot_ctx	slot;
	struct xhci_ep_ctx	ep[31];
} __attribute__ ((packed));

/* drop context bitmasks */
#define	DROP_EP(x)	(0x1 << x)
/* add context bitmasks */
#define	ADD_EP(x)	(0x1 << x)


/**
 * struct xhci_device_context_array
 * @dev_context_ptr	array of 64-bit DMA addresses for device contexts
 */
struct xhci_device_context_array {
	/* 64-bit device addresses; we only write 32-bit addresses */
	u32			dev_context_ptrs[2*MAX_HC_SLOTS];
	/* private xHCD pointers */
	dma_addr_t	dma;
} __attribute__ ((packed));
/* TODO: write function to set the 64-bit device DMA address */
/*
 * TODO: change this to be dynamically sized at HC mem init time since the HC
 * might not be able to handle the maximum number of devices possible.
 */


struct xhci_stream_ctx {
	/* 64-bit stream ring address, cycle state, and stream type */
	u32	stream_ring[2];
	/* offset 0x14 - 0x1f reserved for HC internal use */
	u32	reserved[2];
} __attribute__ ((packed));


struct xhci_transfer_event {
	/* 64-bit buffer address, or immediate data */
	u32	buffer[2];
	u32	transfer_len;
	/* This field is interpreted differently based on the type of TRB */
	u32	flags;
} __attribute__ ((packed));

/* Completion Code - only applicable for some types of TRBs */
#define	COMP_CODE_MASK		(0xff << 24)
#define GET_COMP_CODE(p)	(((p) & COMP_CODE_MASK) >> 24)
#define COMP_SUCCESS	1
/* Data Buffer Error */
#define COMP_DB_ERR	2
/* Babble Detected Error */
#define COMP_BABBLE	3
/* USB Transaction Error */
#define COMP_TX_ERR	4
/* TRB Error - some TRB field is invalid */
#define COMP_TRB_ERR	5
/* Stall Error - USB device is stalled */
#define COMP_STALL	6
/* Resource Error - HC doesn't have memory for that device configuration */
#define COMP_ENOMEM	7
/* Bandwidth Error - not enough room in schedule for this dev config */
#define COMP_BW_ERR	8
/* No Slots Available Error - HC ran out of device slots */
#define COMP_ENOSLOTS	9
/* Invalid Stream Type Error */
#define COMP_STREAM_ERR	10
/* Slot Not Enabled Error - doorbell rung for disabled device slot */
#define COMP_EBADSLT	11
/* Endpoint Not Enabled Error */
#define COMP_EBADEP	12
/* Short Packet */
#define COMP_SHORT_TX	13
/* Ring Underrun - doorbell rung for an empty isoc OUT ep ring */
#define COMP_UNDERRUN	14
/* Ring Overrun - isoc IN ep ring is empty when ep is scheduled to RX */
#define COMP_OVERRUN	15
/* Virtual Function Event Ring Full Error */
#define COMP_VF_FULL	16
/* Parameter Error - Context parameter is invalid */
#define COMP_EINVAL	17
/* Bandwidth Overrun Error - isoc ep exceeded its allocated bandwidth */
#define COMP_BW_OVER	18
/* Context State Error - illegal context state transition requested */
#define COMP_CTX_STATE	19
/* No Ping Response Error - HC didn't get PING_RESPONSE in time to TX */
#define COMP_PING_ERR	20
/* Event Ring is full */
#define COMP_ER_FULL	21
/* Missed Service Error - HC couldn't service an isoc ep within interval */
#define COMP_MISSED_INT	23
/* Successfully stopped command ring */
#define COMP_CMD_STOP	24
/* Successfully aborted current command and stopped command ring */
#define COMP_CMD_ABORT	25
/* Stopped - transfer was terminated by a stop endpoint command */
#define COMP_STOP	26
/* Same as COMP_EP_STOPPED, but the transfered length in the event is invalid */
#define COMP_STOP_INVAL	27
/* Control Abort Error - Debug Capability - control pipe aborted */
#define COMP_DBG_ABORT	28
/* TRB type 29 and 30 reserved */
/* Isoc Buffer Overrun - an isoc IN ep sent more data than could fit in TD */
#define COMP_BUFF_OVER	31
/* Event Lost Error - xHC has an "internal event overrun condition" */
#define COMP_ISSUES	32
/* Undefined Error - reported when other error codes don't apply */
#define COMP_UNKNOWN	33
/* Invalid Stream ID Error */
#define COMP_STRID_ERR	34
/* Secondary Bandwidth Error - may be returned by a Configure Endpoint cmd */
/* FIXME - check for this */
#define COMP_2ND_BW_ERR	35
/* Split Transaction Error */
#define	COMP_SPLIT_ERR	36

struct xhci_link_trb {
	/* 64-bit segment pointer*/
	u32 segment_ptr[2];
	u32 intr_target;
	u32 control;
} __attribute__ ((packed));

/* control bitfields */
#define LINK_TOGGLE	(0x1<<1)

/* Command completion event TRB */
struct xhci_event_cmd {
	/* Pointer to command TRB, or the value passed by the event data trb */
	u32 cmd_trb[2];
	u32 status;
	u32 flags;
} __attribute__ ((packed));


/* Port Status Change Event TRB fields */
/* Port ID - bits 31:24 */
#define GET_PORT_ID(p)		(((p) & (0xff << 24)) >> 24)

/* Normal TRB fields */
/* transfer_len bitmasks - bits 0:16 */
#define	TRB_LEN(p)		((p) & 0x1ffff)
/* TD size - number of bytes remaining in the TD (including this TRB):
 * bits 17 - 21.  Shift the number of bytes by 10. */
#define TD_REMAINDER(p)		((((p) >> 10) & 0x1f) << 17)
/* Interrupter Target - which MSI-X vector to target the completion event at */
#define TRB_INTR_TARGET(p)	(((p) & 0x3ff) << 22)
#define GET_INTR_TARGET(p)	(((p) >> 22) & 0x3ff)

/* Cycle bit - indicates TRB ownership by HC or HCD */
#define TRB_CYCLE		(1<<0)
/*
 * Force next event data TRB to be evaluated before task switch.
 * Used to pass OS data back after a TD completes.
 */
#define TRB_ENT			(1<<1)
/* Interrupt on short packet */
#define TRB_ISP			(1<<2)
/* Set PCIe no snoop attribute */
#define TRB_NO_SNOOP		(1<<3)
/* Chain multiple TRBs into a TD */
#define TRB_CHAIN		(1<<4)
/* Interrupt on completion */
#define TRB_IOC			(1<<5)
/* The buffer pointer contains immediate data */
#define TRB_IDT			(1<<6)


/* Control transfer TRB specific fields */
#define TRB_DIR_IN		(1<<16)

struct xhci_generic_trb {
	u32 field[4];
} __attribute__ ((packed));

union xhci_trb {
	struct xhci_link_trb		link;
	struct xhci_transfer_event	trans_event;
	struct xhci_event_cmd		event_cmd;
	struct xhci_generic_trb		generic;
};

/* TRB bit mask */
#define	TRB_TYPE_BITMASK	(0xfc00)
#define TRB_TYPE(p)		((p) << 10)
/* TRB type IDs */
/* bulk, interrupt, isoc scatter/gather, and control data stage */
#define TRB_NORMAL		1
/* setup stage for control transfers */
#define TRB_SETUP		2
/* data stage for control transfers */
#define TRB_DATA		3
/* status stage for control transfers */
#define TRB_STATUS		4
/* isoc transfers */
#define TRB_ISOC		5
/* TRB for linking ring segments */
#define TRB_LINK		6
#define TRB_EVENT_DATA		7
/* Transfer Ring No-op (not for the command ring) */
#define TRB_TR_NOOP		8
/* Command TRBs */
/* Enable Slot Command */
#define TRB_ENABLE_SLOT		9
/* Disable Slot Command */
#define TRB_DISABLE_SLOT	10
/* Address Device Command */
#define TRB_ADDR_DEV		11
/* Configure Endpoint Command */
#define TRB_CONFIG_EP		12
/* Evaluate Context Command */
#define TRB_EVAL_CONTEXT	13
/* Reset Transfer Ring Command */
#define TRB_RESET_RING		14
/* Stop Transfer Ring Command */
#define TRB_STOP_RING		15
/* Set Transfer Ring Dequeue Pointer Command */
#define TRB_SET_DEQ		16
/* Reset Device Command */
#define TRB_RESET_DEV		17
/* Force Event Command (opt) */
#define TRB_FORCE_EVENT		18
/* Negotiate Bandwidth Command (opt) */
#define TRB_NEG_BANDWIDTH	19
/* Set Latency Tolerance Value Command (opt) */
#define TRB_SET_LT		20
/* Get port bandwidth Command */
#define TRB_GET_BW		21
/* Force Header Command - generate a transaction or link management packet */
#define TRB_FORCE_HEADER	22
/* No-op Command - not for transfer rings */
#define TRB_CMD_NOOP		23
/* TRB IDs 24-31 reserved */
/* Event TRBS */
/* Transfer Event */
#define TRB_TRANSFER		32
/* Command Completion Event */
#define TRB_COMPLETION		33
/* Port Status Change Event */
#define TRB_PORT_STATUS		34
/* Bandwidth Request Event (opt) */
#define TRB_BANDWIDTH_EVENT	35
/* Doorbell Event (opt) */
#define TRB_DOORBELL		36
/* Host Controller Event */
#define TRB_HC_EVENT		37
/* Device Notification Event - device sent function wake notification */
#define TRB_DEV_NOTE		38
/* MFINDEX Wrap Event - microframe counter wrapped */
#define TRB_MFINDEX_WRAP	39
/* TRB IDs 40-47 reserved, 48-63 is vendor-defined */

/*
 * TRBS_PER_SEGMENT must be a multiple of 4,
 * since the command ring is 64-byte aligned.
 * It must also be greater than 16.
 */
#define TRBS_PER_SEGMENT	64
#define SEGMENT_SIZE		(TRBS_PER_SEGMENT*16)

struct xhci_segment {
	union xhci_trb		*trbs;
	/* private to HCD */
	struct xhci_segment	*next;
	dma_addr_t		dma;
} __attribute__ ((packed));

struct xhci_ring {
	struct xhci_segment	*first_seg;
	union  xhci_trb		*enqueue;
	struct xhci_segment	*enq_seg;
	unsigned int		enq_updates;
	union  xhci_trb		*dequeue;
	struct xhci_segment	*deq_seg;
	unsigned int		deq_updates;
	/*
	 * Write the cycle state into the TRB cycle field to give ownership of
	 * the TRB to the host controller (if we are the producer), or to check
	 * if we own the TRB (if we are the consumer).  See section 4.9.1.
	 */
	u32			cycle_state;
};

struct xhci_erst_entry {
	/* 64-bit event ring segment address */
	u32	seg_addr[2];
	u32	seg_size;
	/* Set to zero */
	u32	rsvd;
} __attribute__ ((packed));

struct xhci_erst {
	struct xhci_erst_entry	*entries;
	unsigned int		num_entries;
	/* xhci->event_ring keeps track of segment dma addresses */
	dma_addr_t		erst_dma_addr;
	/* Num entries the ERST can contain */
	unsigned int		erst_size;
};

/*
 * Each segment table entry is 4*32bits long.  1K seems like an ok size:
 * (1K bytes * 8bytes/bit) / (4*32 bits) = 64 segment entries in the table,
 * meaning 64 ring segments.
 * Initial allocated size of the ERST, in number of entries */
#define	ERST_NUM_SEGS	1
/* Initial allocated size of the ERST, in number of entries */
#define	ERST_SIZE	64
/* Initial number of event segment rings allocated */
#define	ERST_ENTRIES	1
/* Poll every 60 seconds */
#define	POLL_TIMEOUT	60
/* XXX: Make these module parameters */


/* There is one ehci_hci structure per controller */
struct xhci_hcd {
	/* glue to PCI and HCD framework */
	struct xhci_cap_regs __iomem *cap_regs;
	struct xhci_op_regs __iomem *op_regs;
	struct xhci_run_regs __iomem *run_regs;
	struct xhci_doorbell_array __iomem *dba;
	/* Our HCD's current interrupter register set */
	struct	intr_reg __iomem *ir_set;

	/* Cached register copies of read-only HC data */
	__u32		hcs_params1;
	__u32		hcs_params2;
	__u32		hcs_params3;
	__u32		hcc_params;

	spinlock_t	lock;

	/* packed release number */
	u8		sbrn;
	u16		hci_version;
	u8		max_slots;
	u8		max_interrupters;
	u8		max_ports;
	u8		isoc_threshold;
	int		event_ring_max;
	int		addr_64;
	/* 4KB min, 128MB max */
	int		page_size;
	/* Valid values are 12 to 20, inclusive */
	int		page_shift;
	/* only one MSI vector for now, but might need more later */
	int		msix_count;
	struct msix_entry	*msix_entries;
	/* data structures */
	struct xhci_device_context_array *dcbaa;
	struct xhci_ring	*cmd_ring;
	struct xhci_ring	*event_ring;
	struct xhci_erst	erst;

	/* DMA pools */
	struct dma_pool	*device_pool;
	struct dma_pool	*segment_pool;

#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
	/* Poll the rings - for debugging */
	struct timer_list	event_ring_timer;
	int			zombie;
#endif
	/* Statistics */
	int			noops_submitted;
	int			noops_handled;
	int			error_bitmask;
};

/* For testing purposes */
#define NUM_TEST_NOOPS	0

/* convert between an HCD pointer and the corresponding EHCI_HCD */
static inline struct xhci_hcd *hcd_to_xhci(struct usb_hcd *hcd)
{
	return (struct xhci_hcd *) (hcd->hcd_priv);
}

static inline struct usb_hcd *xhci_to_hcd(struct xhci_hcd *xhci)
{
	return container_of((void *) xhci, struct usb_hcd, hcd_priv);
}

#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
#define XHCI_DEBUG	1
#else
#define XHCI_DEBUG	0
#endif

#define xhci_dbg(xhci, fmt, args...) \
	do { if (XHCI_DEBUG) dev_dbg(xhci_to_hcd(xhci)->self.controller , fmt , ## args); } while (0)
#define xhci_info(xhci, fmt, args...) \
	do { if (XHCI_DEBUG) dev_info(xhci_to_hcd(xhci)->self.controller , fmt , ## args); } while (0)
#define xhci_err(xhci, fmt, args...) \
	dev_err(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
#define xhci_warn(xhci, fmt, args...) \
	dev_warn(xhci_to_hcd(xhci)->self.controller , fmt , ## args)

/* TODO: copied from ehci.h - can be refactored? */
/* xHCI spec says all registers are little endian */
static inline unsigned int xhci_readl(const struct xhci_hcd *xhci,
		__u32 __iomem *regs)
{
	return readl(regs);
}
static inline void xhci_writel(const struct xhci_hcd *xhci,
		const unsigned int val, __u32 __iomem *regs)
{
	if (!in_interrupt())
		xhci_dbg(xhci, "`MEM_WRITE_DWORD(3'b000, 32'h%0x, 32'h%0x, 4'hf);\n",
				(unsigned int) regs, val);
	writel(val, regs);
}

/* xHCI debugging */
void xhci_print_ir_set(struct xhci_hcd *xhci, struct intr_reg *ir_set, int set_num);
void xhci_print_registers(struct xhci_hcd *xhci);
void xhci_dbg_regs(struct xhci_hcd *xhci);
void xhci_print_run_regs(struct xhci_hcd *xhci);
void xhci_debug_segment(struct xhci_hcd *xhci, struct xhci_segment *seg);
void xhci_debug_ring(struct xhci_hcd *xhci, struct xhci_ring *ring);
void xhci_dbg_erst(struct xhci_hcd *xhci, struct xhci_erst *erst);
void xhci_dbg_cmd_ptrs(struct xhci_hcd *xhci);
void xhci_dbg_ring_ptrs(struct xhci_hcd *xhci, struct xhci_ring *ring);

/* xHCI memory managment */
void xhci_mem_cleanup(struct xhci_hcd *xhci);
int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags);

#ifdef CONFIG_PCI
/* xHCI PCI glue */
int xhci_register_pci(void);
void xhci_unregister_pci(void);
#endif

/* xHCI host controller glue */
int xhci_halt(struct xhci_hcd *xhci);
int xhci_reset(struct xhci_hcd *xhci);
int xhci_init(struct usb_hcd *hcd);
int xhci_run(struct usb_hcd *hcd);
void xhci_stop(struct usb_hcd *hcd);
void xhci_shutdown(struct usb_hcd *hcd);
int xhci_get_frame(struct usb_hcd *hcd);
irqreturn_t xhci_irq(struct usb_hcd *hcd);

/* xHCI ring, segment, TRB, and TD functions */
dma_addr_t trb_virt_to_dma(struct xhci_segment *seg, union xhci_trb *trb);
void ring_cmd_db(struct xhci_hcd *xhci);
void *setup_one_noop(struct xhci_hcd *xhci);
void handle_event(struct xhci_hcd *xhci);
void set_hc_event_deq(struct xhci_hcd *xhci);

/* xHCI roothub code */
int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, u16 wIndex,
		char *buf, u16 wLength);
int xhci_hub_status_data(struct usb_hcd *hcd, char *buf);

#endif /* __LINUX_XHCI_HCD_H */