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jtag.h

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    oharboe authored
    git-svn-id: svn://svn.berlios.de/openocd/trunk@1766 b42882b7-edfa-0310-969c-e2dbd0fdcd60
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    jtag.h 30.63 KiB
    /***************************************************************************
    *   Copyright (C) 2005 by Dominic Rath                                    *
    *   Dominic.Rath@gmx.de                                                   *
    *                                                                         *
    *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
    *   oyvind.harboe@zylin.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; either version 2 of the License, or     *
    *   (at your option) any later version.                                   *
    *                                                                         *
    *   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.,                                       *
    *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
    ***************************************************************************/
    #ifndef JTAG_H
    #define JTAG_H
    
    #include "binarybuffer.h"
    #include "log.h"
    
    
    #ifdef _DEBUG_JTAG_IO_
    #define DEBUG_JTAG_IO(expr ...)		LOG_DEBUG(expr)
    #else
    #define DEBUG_JTAG_IO(expr ...)
    #endif
    
    #ifndef DEBUG_JTAG_IOZ
    #define DEBUG_JTAG_IOZ 64
    #endif
    
    /*-----<Macros>--------------------------------------------------*/
    
    /** When given an array, compute its DIMension, i.e. number of elements in the array */
    #define DIM(x)					(sizeof(x)/sizeof((x)[0]))
    
    /** Calculate the number of bytes required to hold @a n TAP scan bits */
    #define TAP_SCAN_BYTES(n)		CEIL(n, 8)
    
    /*-----</Macros>-------------------------------------------------*/
    
    
    
    /*
     * Tap states from ARM7TDMI-S Technical reference manual.
     * Also, validated against several other ARM core technical manuals.
     *
     * N.B. tap_get_tms_path() was changed to reflect this corrected
     * numbering and ordering of the TAP states.
     *
     * DANGER!!!! some interfaces care about the actual numbers used
     * as they are handed off directly to hardware implementations.
     */
    
    typedef enum tap_state
    {
    #if BUILD_ECOSBOARD
    /* These are the old numbers. Leave as-is for now... */
    	TAP_RESET    = 0, TAP_IDLE = 8,
    	TAP_DRSELECT = 1, TAP_DRCAPTURE = 2, TAP_DRSHIFT = 3, TAP_DREXIT1 = 4,
    	TAP_DRPAUSE  = 5, TAP_DREXIT2 = 6, TAP_DRUPDATE = 7,
    	TAP_IRSELECT = 9, TAP_IRCAPTURE = 10, TAP_IRSHIFT = 11, TAP_IREXIT1 = 12,
    	TAP_IRPAUSE  = 13, TAP_IREXIT2 = 14, TAP_IRUPDATE = 15,
    
    	TAP_NUM_STATES = 16, TAP_INVALID = -1,
    #else
    	/* Proper ARM recommended numbers */
    	TAP_DREXIT2 = 0x0,
    	TAP_DREXIT1 = 0x1,
    	TAP_DRSHIFT = 0x2,
    	TAP_DRPAUSE = 0x3,
    	TAP_IRSELECT = 0x4,
    	TAP_DRUPDATE = 0x5,
    	TAP_DRCAPTURE = 0x6,
    	TAP_DRSELECT = 0x7,
    	TAP_IREXIT2 = 0x8,
    	TAP_IREXIT1 = 0x9,
    	TAP_IRSHIFT = 0xa,
    	TAP_IRPAUSE = 0xb,
    	TAP_IDLE = 0xc,
    	TAP_IRUPDATE = 0xd,
    	TAP_IRCAPTURE = 0xe,
    	TAP_RESET = 0x0f,
    
    	TAP_NUM_STATES = 0x10,
    
    	TAP_INVALID = -1,
    #endif
    } tap_state_t;
    
    typedef struct tap_transition_s
    {
    	tap_state_t high;
    	tap_state_t low;
    } tap_transition_t;
    
    //extern tap_transition_t tap_transitions[16];    /* describe the TAP state diagram */
    
    
    /*-----<Cable Helper API>-------------------------------------------*/
    
    /* The "Cable Helper API" is what the cable drivers can use to help implement
     * their "Cable API".  So a Cable Helper API is a set of helper functions used by
     * cable drivers, and this is different from a Cable API.  A "Cable API" is what
     * higher level code used to talk to a cable.
     */
    
    
    /** implementation of wrapper function tap_set_state() */
    void tap_set_state_impl(tap_state_t new_state);
    
    /**
     * Function tap_set_state
     * sets the state of a "state follower" which tracks the state of the TAPs connected to the
     * cable.  The state follower is hopefully always in the same state as the actual
     * TAPs in the jtag chain, and will be so if there are no bugs in the tracking logic within that
     * cable driver. All the cable drivers call this function to indicate the state they think
     * the TAPs attached to their cables are in.  Because this function can also log transitions,
     * it will be helpful to call this function with every transition that the TAPs being manipulated
     * are expected to traverse, not just end points of a multi-step state path.
     * @param new_state is the state we think the TAPs are currently in or are about to enter.
     */
    #if defined(_DEBUG_JTAG_IO_)
    #define tap_set_state(new_state) \
    	do { \
    		LOG_DEBUG( "tap_set_state(%s)", tap_state_name(new_state) ); \
    		tap_set_state_impl(new_state); \
    	} while (0)
    #else
    static inline void tap_set_state(tap_state_t new_state)
    {
    	tap_set_state_impl(new_state);
    }
    
    #endif
    
    /**
     * Function tap_get_state
     * gets the state of the "state follower" which tracks the state of the TAPs connected to
     * the cable.
     * @see tap_set_state
     * @return tap_state_t - The state the TAPs are in now.
     */
    tap_state_t tap_get_state(void);
    
    /**
     * Function tap_set_end_state
     * sets the state of an "end state follower" which tracks the state that any cable driver
     * thinks will be the end (resultant) state of the current TAP SIR or SDR operation.  At completion
     * of that TAP operation this value is copied into the state follower via tap_set_state().
     * @param new_end_state is that state the TAPs should enter at completion of a pending TAP operation.
     */
    void        tap_set_end_state(tap_state_t new_end_state);
    
    /**
     * Function tap_get_end_state
     * @see tap_set_end_state
     * @return tap_state_t - The state the TAPs should be in at completion of the current TAP operation.
     */
    tap_state_t tap_get_end_state(void);
    
    /**
     * Function tap_get_tms_path
     * returns a 7 bit long "bit sequence" indicating what has to be done with TMS
     * during a sequence of seven TAP clock cycles in order to get from
     * state \a "from" to state \a "to".
     * @param from is the starting state
     * @param to is the resultant or final state
     * @return int - a 7 bit sequence, with the first bit in the sequence at bit 0.
     */
    int tap_get_tms_path(tap_state_t from, tap_state_t to);
    
    
    /**
     * Function int tap_get_tms_path_len
     * returns the total number of bits that represents a TMS path
     * transition as given by the function tap_get_tms_path().
     *
     * For at least one interface (JLink) it's not OK to simply "pad" TMS sequences
     * to fit a whole byte.  (I suspect this is a general TAP problem within OOCD.)
     * Padding TMS causes all manner of instability that's not easily
     * discovered.  Using this routine we can apply EXACTLY the state transitions
     * required to make something work - no more - no less.
     *
     * @param from is the starting state
     * @param to is the resultant or final state
     * @return int - the total number of bits in a transition.
     */
    int tap_get_tms_path_len(tap_state_t from, tap_state_t to);
    
    
    /**
     * Function tap_move_ndx
     * when given a stable state, returns an index from 0-5.  The index corresponds to a
     * sequence of stable states which are given in this order: <p>
     * { TAP_RESET, TAP_IDLE, TAP_DRSHIFT, TAP_DRPAUSE, TAP_IRSHIFT, TAP_IRPAUSE }
     * <p>
     * This sequence corresponds to look up tables which are used in some of the
     * cable drivers.
     * @param astate is the stable state to find in the sequence.  If a non stable
     *  state is passed, this may cause the program to output an error message
     *  and terminate.
     * @return int - the array (or sequence) index as described above
     */
    int tap_move_ndx(tap_state_t astate);
    
    /**
     * Function tap_is_state_stable
     * returns true if the \a astate is stable.
     */
    bool tap_is_state_stable(tap_state_t astate);
    
    /**
     * Function tap_state_transition
     * takes a current TAP state and returns the next state according to the tms value.
     * @param current_state is the state of a TAP currently.
     * @param tms is either zero or non-zero, just like a real TMS line in a jtag interface.
     * @return tap_state_t - the next state a TAP would enter.
     */
    tap_state_t tap_state_transition(tap_state_t current_state, bool tms);
    
    /**
     * Function tap_state_name
     * Returns a string suitable for display representing the JTAG tap_state
     */
    const char* tap_state_name(tap_state_t state);
    
    #ifdef _DEBUG_JTAG_IO_
    /**
     * @brief Prints verbose TAP state transitions for the given TMS/TDI buffers.
     * @param tms_buf must points to a buffer containing the TMS bitstream.
     * @param tdi_buf must points to a buffer containing the TDI bitstream.
     * @param tap_len must specify the length of the TMS/TDI bitstreams.
     * @param start_tap_state must specify the current TAP state.
     * @returns the final TAP state; pass as @a start_tap_state in following call.
     */
    tap_state_t jtag_debug_state_machine(const void *tms_buf, const void *tdi_buf,
    		unsigned tap_len, tap_state_t start_tap_state);
    #else
    static inline tap_state_t jtag_debug_state_machine(const void *tms_buf,
    		const void *tdi_buf, unsigned tap_len, tap_state_t start_tap_state)
    {
    	return start_tap_state;
    }
    #endif // _DEBUG_JTAG_IO_
    
    /*-----</Cable Helper API>------------------------------------------*/
    
    
    extern tap_state_t cmd_queue_end_state;         /* finish DR scans in dr_end_state */
    extern tap_state_t cmd_queue_cur_state;         /* current TAP state */
    
    typedef void* error_handler_t;  /* Later on we can delete error_handler_t, but keep it for now to make patches more readable */
    
    struct scan_field_s;
    typedef int (*in_handler_t)(u8* in_value, void* priv, struct scan_field_s* field);
    
    typedef struct scan_field_s
    {
    	jtag_tap_t* tap;                /* tap pointer this instruction refers to */
    	int         num_bits;           /* number of bits this field specifies (up to 32) */
    	u8*         out_value;          /* value to be scanned into the device */
    	u8*         in_value;           /* pointer to a 32-bit memory location to take data scanned out */
    
    	u8*         check_value;        /* Used together with jtag_add_dr_scan_check() to check data clocked
    	                                   in */
    	u8*         check_mask;         /* mask to go with check_value */
    
    	/* internal work space */
    	int			allocated;			/* in_value has been allocated for the queue */
    	int			modified;			/* did we modify the in_value? */
    	u8			intmp[4];			/* temporary storage for checking synchronously */
    } scan_field_t;
    
    enum scan_type {
    	/* IN: from device to host, OUT: from host to device */
    	SCAN_IN = 1, SCAN_OUT = 2, SCAN_IO = 3
    };
    
    typedef struct scan_command_s
    {
    	int           ir_scan;      /* instruction/not data scan */
    	int           num_fields;   /* number of fields in *fields array */
    	scan_field_t* fields;       /* pointer to an array of data scan fields */
    	tap_state_t   end_state;    /* TAP state in which JTAG commands should finish */
    } scan_command_t;
    
    typedef struct statemove_command_s
    {
    	tap_state_t end_state;   /* TAP state in which JTAG commands should finish */
    } statemove_command_t;
    
    typedef struct pathmove_command_s
    {
    	int          num_states;    /* number of states in *path */
    	tap_state_t* path;          /* states that have to be passed */
    } pathmove_command_t;
    
    typedef struct runtest_command_s
    {
    	int         num_cycles;     /* number of cycles that should be spent in Run-Test/Idle */
    	tap_state_t end_state;      /* TAP state in which JTAG commands should finish */
    } runtest_command_t;
    
    
    typedef struct stableclocks_command_s
    {
    	int num_cycles;             /* number of clock cycles that should be sent */
    } stableclocks_command_t;
    
    
    typedef struct reset_command_s
    {
    	int trst;           /* trst/srst 0: deassert, 1: assert, -1: don't change */
    	int srst;
    } reset_command_t;
    
    typedef struct end_state_command_s
    {
    	tap_state_t end_state;   /* TAP state in which JTAG commands should finish */
    } end_state_command_t;
    
    typedef struct sleep_command_s
    {
    	u32 us;     /* number of microseconds to sleep */
    } sleep_command_t;
    
    typedef union jtag_command_container_u
    {
    	scan_command_t*         scan;
    	statemove_command_t*    statemove;
    	pathmove_command_t*     pathmove;
    	runtest_command_t*      runtest;
    	stableclocks_command_t* stableclocks;
    	reset_command_t*        reset;
    	end_state_command_t*    end_state;
    	sleep_command_t* sleep;
    } jtag_command_container_t;
    
    enum jtag_command_type {
    	JTAG_SCAN         = 1,
    	JTAG_STATEMOVE    = 2,
    	JTAG_RUNTEST      = 3,
    	JTAG_RESET        = 4,
    	JTAG_END_STATE    = 5,
    	JTAG_PATHMOVE     = 6,
    	JTAG_SLEEP        = 7,
    	JTAG_STABLECLOCKS = 8
    };
    
    typedef struct jtag_command_s
    {
    	jtag_command_container_t cmd;
    	enum jtag_command_type   type;
    	struct jtag_command_s*   next;
    } jtag_command_t;
    
    extern jtag_command_t* jtag_command_queue;
    
    /* forward declaration */
    typedef struct jtag_tap_event_action_s jtag_tap_event_action_t;
    
    /* this is really: typedef jtag_tap_t */
    /* But - the typedef is done in "types.h" */
    /* due to "forward decloration reasons" */
    struct jtag_tap_s
    {
    	const char* chip;
    	const char* tapname;
    	const char* dotted_name;
    	int         abs_chain_position;
    	int         enabled;
    	int         ir_length;          /* size of instruction register */
    	u32         ir_capture_value;
    	u8*         expected;           /* Capture-IR expected value */
    	u32         ir_capture_mask;
    	u8*         expected_mask;      /* Capture-IR expected mask */
    	u32         idcode;             /* device identification code */
    	u32*        expected_ids;       /* Array of expected identification codes */
    	u8          expected_ids_cnt;   /* Number of expected identification codes */
    	u8*         cur_instr;          /* current instruction */
    	int         bypass;             /* bypass register selected */
    
    	jtag_tap_event_action_t* event_action;
    
    	jtag_tap_t* next_tap;
    };
    extern jtag_tap_t* jtag_AllTaps(void);
    extern jtag_tap_t* jtag_TapByPosition(int n);
    extern jtag_tap_t* jtag_TapByString(const char* dotted_name);
    extern jtag_tap_t* jtag_TapByJimObj(Jim_Interp* interp, Jim_Obj* obj);
    extern jtag_tap_t* jtag_TapByAbsPosition(int abs_position);
    extern int         jtag_NumEnabledTaps(void);
    extern int         jtag_NumTotalTaps(void);
    
    static __inline__ jtag_tap_t* jtag_NextEnabledTap(jtag_tap_t* p)
    {
    	if (p == NULL)
    	{
    		/* start at the head of list */
    		p = jtag_AllTaps();
    	}
    	else
    	{
    		/* start *after* this one */
    		p = p->next_tap;
    	}
    	while (p)
    	{
    		if (p->enabled)
    		{
    			break;
    		}
    		else
    		{
    			p = p->next_tap;
    		}
    	}
    
    	return p;
    }
    
    
    enum reset_line_mode {
    	LINE_OPEN_DRAIN = 0x0,
    	LINE_PUSH_PULL  = 0x1,
    };
    
    typedef struct jtag_interface_s
    {
    	char* name;
    
    	/* queued command execution
    	 */
    	int (*execute_queue)(void);
    
    	/* interface initalization
    	 */
    	int (*speed)(int speed);
    	int (*register_commands)(struct command_context_s* cmd_ctx);
    	int (*init)(void);
    	int (*quit)(void);
    
    	/* returns JTAG maxium speed for KHz. 0=RTCK. The function returns
    	 *  a failure if it can't support the KHz/RTCK.
    	 *
    	 *  WARNING!!!! if RTCK is *slow* then think carefully about
    	 *  whether you actually want to support this in the driver.
    	 *  Many target scripts are written to handle the absence of RTCK
    	 *  and use a fallback kHz TCK.
    	 */
    	int (*khz)(int khz, int* jtag_speed);
    
    	/* returns the KHz for the provided JTAG speed. 0=RTCK. The function returns
    	 *  a failure if it can't support the KHz/RTCK. */
    	int (*speed_div)(int speed, int* khz);
    
    	/* Read and clear the power dropout flag. Note that a power dropout
    	 *  can be transitionary, easily much less than a ms.
    	 *
    	 *  So to find out if the power is *currently* on, you must invoke
    	 *  this method twice. Once to clear the power dropout flag and a
    	 *  second time to read the current state.
    	 *
    	 *  Currently the default implementation is never to detect power dropout.
    	 */
    	int (*power_dropout)(int* power_dropout);
    
    	/* Read and clear the srst asserted detection flag.
    	 *
    	 * NB!!!! like power_dropout this does *not* read the current
    	 * state. srst assertion is transitionary and *can* be much
    	 * less than 1ms.
    	 */
    	int (*srst_asserted)(int* srst_asserted);
    } jtag_interface_t;
    
    enum jtag_event {
    	JTAG_TRST_ASSERTED
    };
    
    extern char* jtag_event_strings[];
    
    enum jtag_tap_event {
    	JTAG_TAP_EVENT_ENABLE,
    	JTAG_TAP_EVENT_DISABLE
    };
    
    extern const Jim_Nvp nvp_jtag_tap_event[];
    
    struct jtag_tap_event_action_s
    {
    	enum jtag_tap_event      event;
    	Jim_Obj*                 body;
    	jtag_tap_event_action_t* next;
    };
    
    extern int jtag_trst;
    extern int jtag_srst;
    
    typedef struct jtag_event_callback_s
    {
    	int (*callback)(enum jtag_event event, void* priv);
    	void*                         priv;
    	struct jtag_event_callback_s* next;
    } jtag_event_callback_t;
    
    extern jtag_event_callback_t* jtag_event_callbacks;
    
    extern jtag_interface_t*      jtag; /* global pointer to configured JTAG interface */
    
    extern int jtag_speed;
    extern int jtag_speed_post_reset;
    
    enum reset_types {
    	RESET_NONE            = 0x0,
    	RESET_HAS_TRST        = 0x1,
    	RESET_HAS_SRST        = 0x2,
    	RESET_TRST_AND_SRST   = 0x3,
    	RESET_SRST_PULLS_TRST = 0x4,
    	RESET_TRST_PULLS_SRST = 0x8,
    	RESET_TRST_OPEN_DRAIN = 0x10,
    	RESET_SRST_PUSH_PULL  = 0x20,
    };
    
    extern enum reset_types jtag_reset_config;
    
    /* initialize interface upon startup. A successful no-op
     * upon subsequent invocations
     */
    extern int  jtag_interface_init(struct command_context_s* cmd_ctx);
    
    /* initialize JTAG chain using only a RESET reset. If init fails,
     * try reset + init.
     */
    extern int  jtag_init(struct command_context_s* cmd_ctx);
    
    /* reset, then initialize JTAG chain */
    extern int  jtag_init_reset(struct command_context_s* cmd_ctx);
    extern int  jtag_register_commands(struct command_context_s* cmd_ctx);
    
    /* JTAG interface, can be implemented with a software or hardware fifo
     *
     * TAP_DRSHIFT and TAP_IRSHIFT are illegal end states. TAP_DRSHIFT/IRSHIFT as end states
     * can be emulated by using a larger scan.
     *
     * Code that is relatively insensitive to the path(as long
     * as it is JTAG compliant) taken through state machine can use
     * endstate for jtag_add_xxx_scan(). Otherwise the pause state must be
     * specified as end state and a subsequent jtag_add_pathmove() must
     * be issued.
     *
     */
    extern void jtag_add_ir_scan(int num_fields, scan_field_t* fields, tap_state_t endstate);
    /* same as jtag_add_ir_scan except no verify is performed */
    extern void jtag_add_ir_scan_noverify(int num_fields, scan_field_t *fields, tap_state_t state);
    extern int  interface_jtag_add_ir_scan(int num_fields, scan_field_t* fields, tap_state_t endstate);
    extern void jtag_add_dr_scan(int num_fields, scan_field_t* fields, tap_state_t endstate);
    
    /* set in_value to point to 32 bits of memory to scan into. This function
     * is a way to handle the case of synchronous and asynchronous
     * JTAG queues.
     *
     * In the event of an asynchronous queue execution the queue buffer
     * allocation method is used, for the synchronous case the temporary 32 bits come
     * from the input field itself.
     */
    
    #ifndef HAVE_JTAG_MINIDRIVER_H
    extern void jtag_alloc_in_value32(scan_field_t *field);
    #else
    static __inline__ void jtag_alloc_in_value32(scan_field_t *field)
    {
    	field->in_value=field->intmp;
    }
    #endif
    
    
    
    /* This version of jtag_add_dr_scan() uses the check_value/mask fields */
    extern void jtag_add_dr_scan_check(int num_fields, scan_field_t* fields, tap_state_t endstate);
    extern int  interface_jtag_add_dr_scan(int num_fields, scan_field_t* fields, tap_state_t endstate);
    extern void jtag_add_plain_ir_scan(int num_fields, scan_field_t* fields, tap_state_t endstate);
    extern int  interface_jtag_add_plain_ir_scan(int num_fields, scan_field_t* fields, tap_state_t endstate);
    extern void jtag_add_plain_dr_scan(int num_fields, scan_field_t* fields, tap_state_t endstate);
    extern int  interface_jtag_add_plain_dr_scan(int num_fields, scan_field_t* fields, tap_state_t endstate);
    
    
    /* Simplest/typical callback - do some conversion on the data clocked in.
     * This callback is for such conversion that can not fail.
     * For conversion types or checks that can
     * fail, use the jtag_callback_t variant */
    typedef void (*jtag_callback1_t)(u8 *in);
    
    #ifndef HAVE_JTAG_MINIDRIVER_H
    /* A simpler version of jtag_add_callback4 */
    extern void jtag_add_callback(jtag_callback1_t, u8 *in);
    #else
    /* implemented by minidriver */
    #endif
    
    
    /* This type can store an integer safely by a normal cast on 64 and
     * 32 bit systems. */
    typedef intptr_t jtag_callback_data_t;
    
    /* The generic callback mechanism.
     *
     * The callback is invoked with three arguments. The first argument is
     * the pointer to the data clocked in.
     */
    typedef int (*jtag_callback_t)(u8 *in, jtag_callback_data_t data1, jtag_callback_data_t data2, jtag_callback_data_t data3);
    
    
    /* This callback can be executed immediately the queue has been flushed. Note that
     * the JTAG queue can either be executed synchronously or asynchronously. Typically
     * for USB the queue is executed asynchronously. For low latency interfaces, the
     * queue may be executed synchronously.
     *
     * These callbacks are typically executed *after* the *entire* JTAG queue has been
     * executed for e.g. USB interfaces.
     *
     * The callbacks are guaranteeed to be invoked in the order that they were queued.
     *
     * The strange name is due to C's lack of overloading using function arguments
     *
     * The callback mechansim is very general and does not really make any assumptions
     * about what the callback does and what the arguments are.
     *
     * in - typically used to point to the data to operate on. More often than not
     * this will be the data clocked in during a shift operation
     *
     * data1 - an integer that is big enough to be used either as an 'int' or
     * cast to/from a pointer
     *
     * data2 - an integer that is big enough to be used either as an 'int' or
     * cast to/from a pointer
     *
     * Why stop at 'data2' for arguments? Somewhat historical reasons. This is
     * sufficient to implement the jtag_check_value_mask(), besides the
     * line is best drawn somewhere...
     *
     * If the execution of the queue fails before the callbacks, then the
     * callbacks may or may not be invoked depending on driver implementation.
     */
    #ifndef HAVE_JTAG_MINIDRIVER_H
    extern void jtag_add_callback4(jtag_callback_t, u8 *in, jtag_callback_data_t data1, jtag_callback_data_t data2, jtag_callback_data_t data3);
    #else
    /* implemented by minidriver */
    #endif
    
    
    /* run a TAP_RESET reset. End state is TAP_RESET, regardless
     * of start state.
     */
    extern void jtag_add_tlr(void);
    extern int  interface_jtag_add_tlr(void);
    
    /* Application code *must* assume that interfaces will
     * implement transitions between states with different
     * paths and path lengths through the state diagram. The
     * path will vary across interface and also across versions
     * of the same interface over time. Even if the OpenOCD code
     * is unchanged, the actual path taken may vary over time
     * and versions of interface firmware or PCB revisions.
     *
     * Use jtag_add_pathmove() when specific transition sequences
     * are required.
     *
     * Do not use jtag_add_pathmove() unless you need to, but do use it
     * if you have to.
     *
     * DANGER! If the target is dependent upon a particular sequence
     * of transitions for things to work correctly(e.g. as a workaround
     * for an errata that contradicts the JTAG standard), then pathmove
     * must be used, even if some jtag interfaces happen to use the
     * desired path. Worse, the jtag interface used for testing a
     * particular implementation, could happen to use the "desired"
     * path when transitioning to/from end
     * state.
     *
     * A list of unambigious single clock state transitions, not
     * all drivers can support this, but it is required for e.g.
     * XScale and Xilinx support
     *
     * Note! TAP_RESET must not be used in the path!
     *
     * Note that the first on the list must be reachable
     * via a single transition from the current state.
     *
     * All drivers are required to implement jtag_add_pathmove().
     * However, if the pathmove sequence can not be precisely
     * executed, an interface_jtag_add_pathmove() or jtag_execute_queue()
     * must return an error. It is legal, but not recommended, that
     * a driver returns an error in all cases for a pathmove if it
     * can only implement a few transitions and therefore
     * a partial implementation of pathmove would have little practical
     * application.
     */
    extern void jtag_add_pathmove(int num_states, tap_state_t* path);
    extern int  interface_jtag_add_pathmove(int num_states, tap_state_t* path);
    
    /* go to TAP_IDLE, if we're not already there and cycle
     * precisely num_cycles in the TAP_IDLE after which move
     * to the end state, if it is != TAP_IDLE
     *
     * nb! num_cycles can be 0, in which case the fn will navigate
     * to endstate via TAP_IDLE
     */
    extern void jtag_add_runtest(int num_cycles, tap_state_t endstate);
    extern int  interface_jtag_add_runtest(int num_cycles, tap_state_t endstate);
    
    /* A reset of the TAP state machine can be requested.
     *
     * Whether tms or trst reset is used depends on the capabilities of
     * the target and jtag interface(reset_config  command configures this).
     *
     * srst can driver a reset of the TAP state machine and vice
     * versa
     *
     * Application code may need to examine value of jtag_reset_config
     * to determine the proper codepath
     *
     * DANGER! Even though srst drives trst, trst might not be connected to
     * the interface, and it might actually be *harmful* to assert trst in this case.
     *
     * This is why combinations such as "reset_config srst_only srst_pulls_trst"
     * are supported.
     *
     * only req_tlr_or_trst and srst can have a transition for a
     * call as the effects of transitioning both at the "same time"
     * are undefined, but when srst_pulls_trst or vice versa,
     * then trst & srst *must* be asserted together.
     */
    extern void jtag_add_reset(int req_tlr_or_trst, int srst);
    
    /* this drives the actual srst and trst pins. srst will always be 0
     * if jtag_reset_config & RESET_SRST_PULLS_TRST != 0 and ditto for
     * trst.
     *
     * the higher level jtag_add_reset will invoke jtag_add_tlr() if
     * approperiate
     */
    extern int  interface_jtag_add_reset(int trst, int srst);
    extern void jtag_add_end_state(tap_state_t endstate);
    extern int  interface_jtag_add_end_state(tap_state_t endstate);
    extern void jtag_add_sleep(u32 us);
    extern int  interface_jtag_add_sleep(u32 us);
    
    
    /**
     * Function jtag_add_stable_clocks
     * first checks that the state in which the clocks are to be issued is
     * stable, then queues up clock_count clocks for transmission.
     */
    void jtag_add_clocks(int num_cycles);
    int  interface_jtag_add_clocks(int num_cycles);
    
    
    /*
     * For software FIFO implementations, the queued commands can be executed
     * during this call or earlier. A sw queue might decide to push out
     * some of the jtag_add_xxx() operations once the queue is "big enough".
     *
     * This fn will return an error code if any of the prior jtag_add_xxx()
     * calls caused a failure, e.g. check failure. Note that it does not
     * matter if the operation was executed *before* jtag_execute_queue(),
     * jtag_execute_queue() will still return an error code.
     *
     * All jtag_add_xxx() calls that have in_handler!=NULL will have been
     * executed when this fn returns, but if what has been queued only
     * clocks data out, without reading anything back, then JTAG could
     * be running *after* jtag_execute_queue() returns. The API does
     * not define a way to flush a hw FIFO that runs *after*
     * jtag_execute_queue() returns.
     *
     * jtag_add_xxx() commands can either be executed immediately or
     * at some time between the jtag_add_xxx() fn call and jtag_execute_queue().
     */
    extern int            jtag_execute_queue(void);
    
    /* same as jtag_execute_queue() but does not clear the error flag */
    extern void jtag_execute_queue_noclear(void);
    
    /* this flag is set when an error occurs while executing the queue. cleared
     * by jtag_execute_queue()
     *
     * this flag can also be set from application code if some error happens
     * during processing that should be reported during jtag_execute_queue().
     */
    extern int jtag_error;
    
    static __inline__ void jtag_set_error(int error)
    {
    	if ((error==ERROR_OK)||(jtag_error!=ERROR_OK))
    	{
    		/* keep first error */
    		return;
    	}
    	jtag_error=error;
    }
    
    
    
    /* can be implemented by hw+sw */
    extern int            interface_jtag_execute_queue(void);
    extern int            jtag_power_dropout(int* dropout);
    extern int            jtag_srst_asserted(int* srst_asserted);
    
    /* JTAG support functions */
    struct invalidstruct
    {
    
    };
    
    /* execute jtag queue and check value and use mask if mask is != NULL. invokes
     * jtag_set_error() with any error. */
    extern void jtag_check_value_mask(scan_field_t *field, u8 *value, u8 *mask);
    extern enum scan_type jtag_scan_type(scan_command_t* cmd);
    extern int            jtag_scan_size(scan_command_t* cmd);
    extern int            jtag_read_buffer(u8* buffer, scan_command_t* cmd);
    extern int            jtag_build_buffer(scan_command_t* cmd, u8** buffer);
    
    extern void           jtag_sleep(u32 us);
    extern int            jtag_call_event_callbacks(enum jtag_event event);
    extern int            jtag_register_event_callback(int (* callback)(enum jtag_event event, void* priv), void* priv);
    
    extern int jtag_verify_capture_ir;
    
    void jtag_tap_handle_event(jtag_tap_t* tap, enum jtag_tap_event e);
    
    /* error codes
     * JTAG subsystem uses codes between -100 and -199 */
    
    #define ERROR_JTAG_INIT_FAILED       (-100)
    #define ERROR_JTAG_INVALID_INTERFACE (-101)
    #define ERROR_JTAG_NOT_IMPLEMENTED   (-102)
    #define ERROR_JTAG_TRST_ASSERTED     (-103)
    #define ERROR_JTAG_QUEUE_FAILED      (-104)
    #define ERROR_JTAG_NOT_STABLE_STATE  (-105)
    #define ERROR_JTAG_DEVICE_ERROR      (-107)
    
    
    /* this allows JTAG devices to implement the entire jtag_xxx() layer in hw/sw */
    #ifdef HAVE_JTAG_MINIDRIVER_H
    /* Here a #define MINIDRIVER() and an inline version of hw fifo interface_jtag_add_dr_out can be defined */
    #include "jtag_minidriver.h"
    #define MINIDRIVER(a) notused ## a
    #else
    #define MINIDRIVER(a) a
    
    /* jtag_add_dr_out() is a faster version of jtag_add_dr_scan()
     *
     * Current or end_state can not be TAP_RESET. end_state can be TAP_INVALID
     *
     * num_bits[i] is the number of bits to clock out from value[i] LSB first.
     *
     * If the device is in bypass, then that is an error condition in
     * the caller code that is not detected by this fn, whereas jtag_add_dr_scan()
     * does detect it. Similarly if the device is not in bypass, data must
     * be passed to it.
     *
     * If anything fails, then jtag_error will be set and jtag_execute() will
     * return an error. There is no way to determine if there was a failure
     * during this function call.
     *
     * Note that this jtag_add_dr_out can be defined as an inline function.
     */
    extern void interface_jtag_add_dr_out(jtag_tap_t* tap, int num_fields, const int* num_bits, const u32* value,
    		tap_state_t end_state);
    
    #endif
    
    static __inline__ void jtag_add_dr_out(jtag_tap_t* tap, int num_fields, const int* num_bits, const u32* value,
    		tap_state_t end_state)
    {
    	if (end_state != TAP_INVALID)
    		cmd_queue_end_state = end_state;
    	cmd_queue_cur_state = cmd_queue_end_state;
    	interface_jtag_add_dr_out(tap, num_fields, num_bits, value, cmd_queue_end_state);
    }
    
    
    #endif /* JTAG_H */