riscv-openocd/src/jtag/jtag.h

/***************************************************************************
 *   Copyright (C) 2005 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   Copyright (C) 2007,2008 <EFBFBD>yvind 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 "types.h"
#include "binarybuffer.h"
#include "log.h"

#include "command.h"

#if 0
#define _DEBUG_JTAG_IO_
#endif

/* 16 Tap States, from page 21 of ASSET InterTech, Inc.'s svf.pdf
 */
enum tap_state
{
	TAP_RESET = 0x0, TAP_IDLE = 0x8,
	TAP_DRSELECT = 0x1, TAP_DRCAPTURE = 0x2, TAP_DRSHIFT = 0x3, TAP_DREXIT1 = 0x4,
	TAP_DRPAUSE = 0x5, TAP_DREXIT2 = 0x6, TAP_DRUPDATE = 0x7,
	TAP_IRSELECT = 0x9, TAP_IRCAPTURE = 0xa, TAP_IRSHIFT = 0xb, TAP_IREXIT1 = 0xc,
	TAP_IRPAUSE = 0xd, TAP_IREXIT2 = 0xe, TAP_IRUPDATE = 0xf
};

typedef struct tap_transition_s
{
	enum tap_state high;
	enum tap_state low;
} tap_transition_t;

extern char* tap_state_strings[16];
extern int tap_move_map[16];	/* map 16 TAP states to 6 stable states */
extern u8 tap_move[6][6];		/* value scanned to TMS to move from one of six stable states to another */
extern tap_transition_t tap_transitions[16];	/* describe the TAP state diagram */

extern enum tap_state end_state;		/* finish DR scans in dr_end_state */
extern enum tap_state cur_state;		/* current TAP state */

extern enum tap_state cmd_queue_end_state;		/* finish DR scans in dr_end_state */
extern enum tap_state cmd_queue_cur_state;		/* current TAP state */

#define TAP_MOVE(from, to) tap_move[tap_move_map[from]][tap_move_map[to]]

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 *out_mask;		/* only masked bits care */
	u8 *in_value;		/* pointer to a 32-bit memory location to take data scanned out */
	/* in_check_value/mask, in_handler_error_handler, in_handler_priv can be used by the in handler, otherwise they contain garbage  */
	u8 *in_check_value;	/* used to validate scan results */
	u8 *in_check_mask;	/* check specified bits against check_value */
	in_handler_t in_handler;	    /* process received buffer using this handler */
	void *in_handler_priv;	/* additional information for the in_handler */
} 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 */
	enum tap_state end_state;	/* TAP state in which JTAG commands should finish */
} scan_command_t;

typedef struct statemove_command_s
{
	enum tap_state 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 */
	enum tap_state *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 */
	enum tap_state end_state;	/* TAP state in which JTAG commands should finish */
} runtest_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
{
	enum tap_state 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;
	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
};

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;

// 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_t *next_tap;
};
extern jtag_tap_t *jtag_AllTaps(void);
extern jtag_tap_t *jtag_TapByPosition(int n);
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[];

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 enum tap_state end_state;
extern enum tap_state cur_state;

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, enum tap_state endstate);
extern int interface_jtag_add_ir_scan(int num_fields, scan_field_t *fields, enum tap_state endstate);
extern void jtag_add_dr_scan(int num_fields, scan_field_t *fields, enum tap_state endstate);
extern int interface_jtag_add_dr_scan(int num_fields, scan_field_t *fields, enum tap_state endstate);
extern void jtag_add_plain_ir_scan(int num_fields, scan_field_t *fields, enum tap_state endstate);
extern int interface_jtag_add_plain_ir_scan(int num_fields, scan_field_t *fields, enum tap_state endstate);
extern void jtag_add_plain_dr_scan(int num_fields, scan_field_t *fields, enum tap_state endstate);
extern int interface_jtag_add_plain_dr_scan(int num_fields, scan_field_t *fields, enum tap_state endstate);
/* 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);
/* 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, enum tap_state *path);
extern int interface_jtag_add_pathmove(int num_states, enum tap_state *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, enum tap_state endstate);
extern int interface_jtag_add_runtest(int num_cycles, enum tap_state 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(enum tap_state endstate);
extern int interface_jtag_add_end_state(enum tap_state endstate);
extern void jtag_add_sleep(u32 us);
extern int interface_jtag_add_sleep(u32 us);



/*
 * 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);
/* 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 */
extern void jtag_set_check_value(scan_field_t *field, u8 *value,  u8 *mask, error_handler_t *in_error_handler);
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;

/* 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_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 -1
 *
 * 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,
		enum tap_state end_state);
#endif




static __inline__ void jtag_add_dr_out(jtag_tap_t *tap,
		int num_fields,
		const int *num_bits,
		const u32 *value,
		enum tap_state end_state)
{
	if (end_state != -1)
		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 */