1 /***************************************************************************
2 * Copyright (C) 2005 by Dominic Rath *
3 * Dominic.Rath@gmx.de *
5 * Copyright (C) 2007,2008 Øyvind Harboe *
6 * oyvind.harboe@zylin.com *
8 * This program is free software; you can redistribute it and/or modify *
9 * it under the terms of the GNU General Public License as published by *
10 * the Free Software Foundation; either version 2 of the License, or *
11 * (at your option) any later version. *
13 * This program is distributed in the hope that it will be useful, *
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16 * GNU General Public License for more details. *
18 * You should have received a copy of the GNU General Public License *
19 * along with this program; if not, write to the *
20 * Free Software Foundation, Inc., *
21 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
22 ***************************************************************************/
26 #include <helper/binarybuffer.h>
27 #include <helper/log.h>
29 #ifdef _DEBUG_JTAG_IO_
30 #define DEBUG_JTAG_IO(expr ...) \
31 do { if (1) LOG_DEBUG(expr); } while (0)
33 #define DEBUG_JTAG_IO(expr ...) \
34 do { if (0) LOG_DEBUG(expr); } while (0)
37 #ifndef DEBUG_JTAG_IOZ
38 #define DEBUG_JTAG_IOZ 64
41 /*-----</Macros>-------------------------------------------------*/
44 * Defines JTAG Test Access Port states.
46 * These definitions were gleaned from the ARM7TDMI-S Technical
47 * Reference Manual and validated against several other ARM core
50 * FIXME some interfaces require specific numbers be used, as they
51 * are handed-off directly to their hardware implementations.
52 * Fix those drivers to map as appropriate ... then pick some
53 * sane set of numbers here (where 0/uninitialized == INVALID).
55 typedef enum tap_state
60 /* These are the old numbers. Leave as-is for now... */
61 TAP_RESET
= 0, TAP_IDLE
= 8,
62 TAP_DRSELECT
= 1, TAP_DRCAPTURE
= 2, TAP_DRSHIFT
= 3, TAP_DREXIT1
= 4,
63 TAP_DRPAUSE
= 5, TAP_DREXIT2
= 6, TAP_DRUPDATE
= 7,
64 TAP_IRSELECT
= 9, TAP_IRCAPTURE
= 10, TAP_IRSHIFT
= 11, TAP_IREXIT1
= 12,
65 TAP_IRPAUSE
= 13, TAP_IREXIT2
= 14, TAP_IRUPDATE
= 15,
68 /* Proper ARM recommended numbers */
90 * Function tap_state_name
91 * Returns a string suitable for display representing the JTAG tap_state
93 const char *tap_state_name(tap_state_t state
);
95 /// Provides user-friendly name lookup of TAP states.
96 tap_state_t
tap_state_by_name(const char *name
);
98 /// The current TAP state of the pending JTAG command queue.
99 extern tap_state_t cmd_queue_cur_state
;
102 * This structure defines a single scan field in the scan. It provides
103 * fields for the field's width and pointers to scan input and output
106 * In addition, this structure includes a value and mask that is used by
107 * jtag_add_dr_scan_check() to validate the value that was scanned out.
109 * The allocated, modified, and intmp fields are internal work space.
112 /// A pointer to the tap structure to which this field refers.
113 struct jtag_tap
* tap
;
115 /// The number of bits this field specifies (up to 32)
117 /// A pointer to value to be scanned into the device
119 /// A pointer to a 32-bit memory location for data scanned out
122 /// The value used to check the data scanned out.
123 uint8_t* check_value
;
124 /// The mask to go with check_value
127 /// in_value has been allocated for the queue
129 /// Indicates we modified the in_value.
131 /// temporary storage for performing value checks synchronously
138 const char* dotted_name
;
139 int abs_chain_position
;
140 /// Is this TAP disabled after JTAG reset?
141 bool disabled_after_reset
;
142 /// Is this TAP currently enabled?
144 int ir_length
; /**< size of instruction register */
145 uint32_t ir_capture_value
;
146 uint8_t* expected
; /**< Capture-IR expected value */
147 uint32_t ir_capture_mask
;
148 uint8_t* expected_mask
; /**< Capture-IR expected mask */
149 uint32_t idcode
; /**< device identification code */
150 /** not all devices have idcode,
151 * we'll discover this during chain examination */
154 /// Array of expected identification codes */
155 uint32_t* expected_ids
;
156 /// Number of expected identification codes
157 uint8_t expected_ids_cnt
;
159 /// Flag saying whether to ignore version field in expected_ids[]
162 /// current instruction
164 /// Bypass register selected
167 struct jtag_tap_event_action
*event_action
;
169 struct jtag_tap
* next_tap
;
172 void jtag_tap_init(struct jtag_tap
*tap
);
173 void jtag_tap_free(struct jtag_tap
*tap
);
175 struct jtag_tap
* jtag_all_taps(void);
176 const char *jtag_tap_name(const struct jtag_tap
*tap
);
177 struct jtag_tap
* jtag_tap_by_string(const char* dotted_name
);
178 struct jtag_tap
* jtag_tap_by_jim_obj(Jim_Interp
* interp
, Jim_Obj
* obj
);
179 struct jtag_tap
* jtag_tap_next_enabled(struct jtag_tap
* p
);
180 unsigned jtag_tap_count_enabled(void);
181 unsigned jtag_tap_count(void);
185 * - TRST_ASSERTED triggers two sets of callbacks, after operations to
186 * reset the scan chain -- via TMS+TCK signaling, or deasserting the
187 * nTRST signal -- are queued:
189 * + Callbacks in C code fire first, patching internal state
190 * + Then post-reset event scripts fire ... activating JTAG circuits
191 * via TCK cycles, exiting SWD mode via TMS sequences, etc
193 * During those callbacks, scan chain contents have not been validated.
194 * JTAG operations that address a specific TAP (primarily DR/IR scans)
195 * must *not* be queued.
197 * - TAP_EVENT_SETUP is reported after TRST_ASSERTED, and after the scan
198 * chain has been validated. JTAG operations including scans that
199 * target specific TAPs may be performed.
201 * - TAP_EVENT_ENABLE and TAP_EVENT_DISABLE implement TAP activation and
202 * deactivation outside the core using scripted code that understands
203 * the specific JTAG router type. They might be triggered indirectly
204 * from EVENT_SETUP operations.
208 JTAG_TAP_EVENT_SETUP
,
209 JTAG_TAP_EVENT_ENABLE
,
210 JTAG_TAP_EVENT_DISABLE
,
213 struct jtag_tap_event_action
215 /// The event for which this action will be triggered.
216 enum jtag_event event
;
217 /// The interpreter to use for evaluating the @c body.
219 /// Contains a script to 'eval' when the @c event is triggered.
221 // next action in linked list
222 struct jtag_tap_event_action
*next
;
226 * Defines the function signature requide for JTAG event callback
227 * functions, which are added with jtag_register_event_callback()
228 * and removed jtag_unregister_event_callback().
229 * @param event The event to handle.
230 * @param prive A pointer to data that was passed to
231 * jtag_register_event_callback().
232 * @returns Must return ERROR_OK on success, or an error code on failure.
234 * @todo Change to return void or define a use for its return code.
236 typedef int (*jtag_event_handler_t
)(enum jtag_event event
, void* priv
);
238 int jtag_register_event_callback(jtag_event_handler_t f
, void *x
);
239 int jtag_unregister_event_callback(jtag_event_handler_t f
, void *x
);
241 int jtag_call_event_callbacks(enum jtag_event event
);
244 /// @returns The current JTAG speed setting.
245 int jtag_get_speed(void);
248 * Given a @a speed setting, use the interface @c speed_div callback to
249 * adjust the setting.
250 * @param speed The speed setting to convert back to readable KHz.
251 * @returns ERROR_OK if the interface has not been initialized or on success;
252 * otherwise, the error code produced by the @c speed_div callback.
254 int jtag_get_speed_readable(int *speed
);
256 /// Attempt to configure the interface for the specified KHz.
257 int jtag_config_khz(unsigned khz
);
260 * Attempt to enable RTCK/RCLK. If that fails, fallback to the
261 * specified frequency.
263 int jtag_config_rclk(unsigned fallback_speed_khz
);
265 /// Retreives the clock speed of the JTAG interface in KHz.
266 unsigned jtag_get_speed_khz(void);
271 RESET_HAS_TRST
= 0x1,
272 RESET_HAS_SRST
= 0x2,
273 RESET_TRST_AND_SRST
= 0x3,
274 RESET_SRST_PULLS_TRST
= 0x4,
275 RESET_TRST_PULLS_SRST
= 0x8,
276 RESET_TRST_OPEN_DRAIN
= 0x10,
277 RESET_SRST_PUSH_PULL
= 0x20,
278 RESET_SRST_NO_GATING
= 0x40,
281 enum reset_types
jtag_get_reset_config(void);
282 void jtag_set_reset_config(enum reset_types type
);
284 void jtag_set_nsrst_delay(unsigned delay
);
285 unsigned jtag_get_nsrst_delay(void);
287 void jtag_set_ntrst_delay(unsigned delay
);
288 unsigned jtag_get_ntrst_delay(void);
290 void jtag_set_nsrst_assert_width(unsigned delay
);
291 unsigned jtag_get_nsrst_assert_width(void);
293 void jtag_set_ntrst_assert_width(unsigned delay
);
294 unsigned jtag_get_ntrst_assert_width(void);
296 /// @returns The current state of TRST.
297 int jtag_get_trst(void);
298 /// @returns The current state of SRST.
299 int jtag_get_srst(void);
301 /// Enable or disable data scan verification checking.
302 void jtag_set_verify(bool enable
);
303 /// @returns True if data scan verification will be performed.
304 bool jtag_will_verify(void);
306 /// Enable or disable verification of IR scan checking.
307 void jtag_set_verify_capture_ir(bool enable
);
308 /// @returns True if IR scan verification will be performed.
309 bool jtag_will_verify_capture_ir(void);
312 * Initialize interface upon startup. Return a successful no-op upon
313 * subsequent invocations.
315 int jtag_interface_init(struct command_context
* cmd_ctx
);
317 /// Shutdown the JTAG interface upon program exit.
318 int jtag_interface_quit(void);
321 * Initialize JTAG chain using only a RESET reset. If init fails,
324 int jtag_init(struct command_context
* cmd_ctx
);
326 /// reset, then initialize JTAG chain
327 int jtag_init_reset(struct command_context
* cmd_ctx
);
328 int jtag_register_commands(struct command_context
* cmd_ctx
);
329 int jtag_init_inner(struct command_context
*cmd_ctx
);
333 * The JTAG interface can be implemented with a software or hardware fifo.
335 * TAP_DRSHIFT and TAP_IRSHIFT are illegal end states; however,
336 * TAP_DRSHIFT/IRSHIFT can be emulated as end states, by using longer
339 * Code that is relatively insensitive to the path taken through state
340 * machine (as long as it is JTAG compliant) can use @a endstate for
341 * jtag_add_xxx_scan(). Otherwise, the pause state must be specified as
342 * end state and a subsequent jtag_add_pathmove() must be issued.
346 * Generate an IR SCAN with a list of scan fields with one entry for
349 * If the input field list contains an instruction value for a TAP then
350 * that is used otherwise the TAP is set to bypass.
352 * TAPs for which no fields are passed are marked as bypassed for
353 * subsequent DR SCANs.
356 void jtag_add_ir_scan(int num_fields
,
357 struct scan_field
* fields
, tap_state_t endstate
);
359 * The same as jtag_add_ir_scan except no verification is performed out
362 void jtag_add_ir_scan_noverify(int num_fields
,
363 const struct scan_field
*fields
, tap_state_t state
);
365 * Duplicate the scan fields passed into the function into an IR SCAN
366 * command. This function assumes that the caller handles extra fields
369 void jtag_add_plain_ir_scan(int num_fields
,
370 const struct scan_field
* fields
, tap_state_t endstate
);
374 * Set in_value to point to 32 bits of memory to scan into. This
375 * function is a way to handle the case of synchronous and asynchronous
378 * In the event of an asynchronous queue execution the queue buffer
379 * allocation method is used, for the synchronous case the temporary 32
380 * bits come from the input field itself.
382 void jtag_alloc_in_value32(struct scan_field
*field
);
385 * Generate a DR SCAN using the fields passed to the function.
386 * For connected TAPs, the function checks in_fields and uses fields
387 * specified there. For bypassed TAPs, the function generates a dummy
388 * 1-bit field. The bypass status of TAPs is set by jtag_add_ir_scan().
390 void jtag_add_dr_scan(int num_fields
,
391 const struct scan_field
* fields
, tap_state_t endstate
);
392 /// A version of jtag_add_dr_scan() that uses the check_value/mask fields
393 void jtag_add_dr_scan_check(int num_fields
,
394 struct scan_field
* fields
, tap_state_t endstate
);
396 * Duplicate the scan fields passed into the function into a DR SCAN
397 * command. Unlike jtag_add_dr_scan(), this function assumes that the
398 * caller handles extra fields for bypassed TAPs.
400 void jtag_add_plain_dr_scan(int num_fields
,
401 const struct scan_field
* fields
, tap_state_t endstate
);
404 * Defines the type of data passed to the jtag_callback_t interface.
405 * The underlying type must allow storing an @c int or pointer type.
407 typedef intptr_t jtag_callback_data_t
;
410 * Defines a simple JTAG callback that can allow conversions on data
411 * scanned in from an interface.
413 * This callback should only be used for conversion that cannot fail.
414 * For conversion types or checks that can fail, use the more complete
415 * variant: jtag_callback_t.
417 typedef void (*jtag_callback1_t
)(jtag_callback_data_t data0
);
419 /// A simpler version of jtag_add_callback4().
420 void jtag_add_callback(jtag_callback1_t
, jtag_callback_data_t data0
);
424 * Defines the interface of the JTAG callback mechanism. Such
425 * callbacks can be executed once the queue has been flushed.
427 * The JTAG queue can be executed synchronously or asynchronously.
428 * Typically for USB, the queue is executed asynchronously. For
429 * low-latency interfaces, the queue may be executed synchronously.
431 * The callback mechanism is very general and does not make many
432 * assumptions about what the callback does or what its arguments are.
433 * These callbacks are typically executed *after* the *entire* JTAG
434 * queue has been executed for e.g. USB interfaces, and they are
435 * guaranteeed to be invoked in the order that they were queued.
437 * If the execution of the queue fails before the callbacks, then --
438 * depending on driver implementation -- the callbacks may or may not be
441 * @todo Make that behavior consistent.
443 * @param data0 Typically used to point to the data to operate on.
444 * Frequently this will be the data clocked in during a shift operation.
445 * @param data1 An integer big enough to use as an @c int or a pointer.
446 * @param data2 An integer big enough to use as an @c int or a pointer.
447 * @param data3 An integer big enough to use as an @c int or a pointer.
448 * @returns an error code
450 typedef int (*jtag_callback_t
)(jtag_callback_data_t data0
,
451 jtag_callback_data_t data1
,
452 jtag_callback_data_t data2
,
453 jtag_callback_data_t data3
);
456 * Run a TAP_RESET reset where the end state is TAP_RESET,
457 * regardless of the start state.
459 void jtag_add_tlr(void);
462 * Application code *must* assume that interfaces will
463 * implement transitions between states with different
464 * paths and path lengths through the state diagram. The
465 * path will vary across interface and also across versions
466 * of the same interface over time. Even if the OpenOCD code
467 * is unchanged, the actual path taken may vary over time
468 * and versions of interface firmware or PCB revisions.
470 * Use jtag_add_pathmove() when specific transition sequences
473 * Do not use jtag_add_pathmove() unless you need to, but do use it
476 * DANGER! If the target is dependent upon a particular sequence
477 * of transitions for things to work correctly(e.g. as a workaround
478 * for an errata that contradicts the JTAG standard), then pathmove
479 * must be used, even if some jtag interfaces happen to use the
480 * desired path. Worse, the jtag interface used for testing a
481 * particular implementation, could happen to use the "desired"
482 * path when transitioning to/from end
485 * A list of unambigious single clock state transitions, not
486 * all drivers can support this, but it is required for e.g.
487 * XScale and Xilinx support
489 * Note! TAP_RESET must not be used in the path!
491 * Note that the first on the list must be reachable
492 * via a single transition from the current state.
494 * All drivers are required to implement jtag_add_pathmove().
495 * However, if the pathmove sequence can not be precisely
496 * executed, an interface_jtag_add_pathmove() or jtag_execute_queue()
497 * must return an error. It is legal, but not recommended, that
498 * a driver returns an error in all cases for a pathmove if it
499 * can only implement a few transitions and therefore
500 * a partial implementation of pathmove would have little practical
503 * If an error occurs, jtag_error will contain one of these error codes:
504 * - ERROR_JTAG_NOT_STABLE_STATE -- The final state was not stable.
505 * - ERROR_JTAG_STATE_INVALID -- The path passed through TAP_RESET.
506 * - ERROR_JTAG_TRANSITION_INVALID -- The path includes invalid
509 void jtag_add_pathmove(int num_states
, const tap_state_t
* path
);
512 * jtag_add_statemove() moves from the current state to @a goal_state.
514 * @param goal_state The final TAP state.
515 * @return ERROR_OK on success, or an error code on failure.
517 * Moves from the current state to the goal \a state.
518 * Both states must be stable.
520 int jtag_add_statemove(tap_state_t goal_state
);
523 * Goes to TAP_IDLE (if we're not already there), cycle
524 * precisely num_cycles in the TAP_IDLE state, after which move
525 * to @a endstate (unless it is also TAP_IDLE).
527 * @param num_cycles Number of cycles in TAP_IDLE state. This argument
528 * may be 0, in which case this routine will navigate to @a endstate
530 * @param endstate The final state.
532 void jtag_add_runtest(int num_cycles
, tap_state_t endstate
);
535 * A reset of the TAP state machine can be requested.
537 * Whether tms or trst reset is used depends on the capabilities of
538 * the target and jtag interface(reset_config command configures this).
540 * srst can driver a reset of the TAP state machine and vice
543 * Application code may need to examine value of jtag_reset_config
544 * to determine the proper codepath
546 * DANGER! Even though srst drives trst, trst might not be connected to
547 * the interface, and it might actually be *harmful* to assert trst in this case.
549 * This is why combinations such as "reset_config srst_only srst_pulls_trst"
552 * only req_tlr_or_trst and srst can have a transition for a
553 * call as the effects of transitioning both at the "same time"
554 * are undefined, but when srst_pulls_trst or vice versa,
555 * then trst & srst *must* be asserted together.
557 void jtag_add_reset(int req_tlr_or_trst
, int srst
);
561 * Function jtag_set_end_state
563 * Set a global variable to \a state if \a state != TAP_INVALID.
565 * Return the value of the global variable.
568 tap_state_t
jtag_set_end_state(tap_state_t state
);
570 * Function jtag_get_end_state
572 * Return the value of the global variable for end state
575 tap_state_t
jtag_get_end_state(void);
576 void jtag_add_sleep(uint32_t us
);
580 * Function jtag_add_stable_clocks
581 * first checks that the state in which the clocks are to be issued is
582 * stable, then queues up clock_count clocks for transmission.
584 void jtag_add_clocks(int num_cycles
);
588 * For software FIFO implementations, the queued commands can be executed
589 * during this call or earlier. A sw queue might decide to push out
590 * some of the jtag_add_xxx() operations once the queue is "big enough".
592 * This fn will return an error code if any of the prior jtag_add_xxx()
593 * calls caused a failure, e.g. check failure. Note that it does not
594 * matter if the operation was executed *before* jtag_execute_queue(),
595 * jtag_execute_queue() will still return an error code.
597 * All jtag_add_xxx() calls that have in_handler != NULL will have been
598 * executed when this fn returns, but if what has been queued only
599 * clocks data out, without reading anything back, then JTAG could
600 * be running *after* jtag_execute_queue() returns. The API does
601 * not define a way to flush a hw FIFO that runs *after*
602 * jtag_execute_queue() returns.
604 * jtag_add_xxx() commands can either be executed immediately or
605 * at some time between the jtag_add_xxx() fn call and jtag_execute_queue().
607 int jtag_execute_queue(void);
609 /// same as jtag_execute_queue() but does not clear the error flag
610 void jtag_execute_queue_noclear(void);
612 /// @returns the number of times the scan queue has been flushed
613 int jtag_get_flush_queue_count(void);
615 /// Report Tcl event to all TAPs
616 void jtag_notify_event(enum jtag_event
);
619 /* can be implemented by hw + sw */
620 int jtag_power_dropout(int* dropout
);
621 int jtag_srst_asserted(int* srst_asserted
);
623 /* JTAG support functions */
626 * Execute jtag queue and check value with an optional mask.
627 * @param field Pointer to scan field.
628 * @param value Pointer to scan value.
629 * @param mask Pointer to scan mask; may be NULL.
630 * @returns Nothing, but calls jtag_set_error() on any error.
632 void jtag_check_value_mask(struct scan_field
*field
, uint8_t *value
, uint8_t *mask
);
634 void jtag_sleep(uint32_t us
);
637 * The JTAG subsystem defines a number of error codes,
638 * using codes between -100 and -199.
640 #define ERROR_JTAG_INIT_FAILED (-100)
641 #define ERROR_JTAG_INVALID_INTERFACE (-101)
642 #define ERROR_JTAG_NOT_IMPLEMENTED (-102)
643 #define ERROR_JTAG_TRST_ASSERTED (-103)
644 #define ERROR_JTAG_QUEUE_FAILED (-104)
645 #define ERROR_JTAG_NOT_STABLE_STATE (-105)
646 #define ERROR_JTAG_DEVICE_ERROR (-107)
647 #define ERROR_JTAG_STATE_INVALID (-108)
648 #define ERROR_JTAG_TRANSITION_INVALID (-109)
649 #define ERROR_JTAG_INIT_SOFT_FAIL (-110)
652 * jtag_add_dr_out() is a version of jtag_add_dr_scan() which
653 * only scans data out. It operates on 32 bit integers instead
654 * of 8 bit, which makes it a better impedance match with
655 * the calling code which often operate on 32 bit integers.
657 * Current or end_state can not be TAP_RESET. end_state can be TAP_INVALID
659 * num_bits[i] is the number of bits to clock out from value[i] LSB first.
661 * If the device is in bypass, then that is an error condition in
662 * the caller code that is not detected by this fn, whereas
663 * jtag_add_dr_scan() does detect it. Similarly if the device is not in
664 * bypass, data must be passed to it.
666 * If anything fails, then jtag_error will be set and jtag_execute() will
667 * return an error. There is no way to determine if there was a failure
668 * during this function call.
670 * This is an inline fn to speed up embedded hosts. Also note that
671 * interface_jtag_add_dr_out() can be a *small* inline function for
674 * There is no jtag_add_dr_outin() version of this fn that also allows
675 * clocking data back in. Patches gladly accepted!
680 * Set the current JTAG core execution error, unless one was set
681 * by a previous call previously. Driver or application code must
682 * use jtag_error_clear to reset jtag_error once this routine has been
683 * called with a non-zero error code.
685 void jtag_set_error(int error
);
686 /// @returns The current value of jtag_error
687 int jtag_get_error(void);
689 * Resets jtag_error to ERROR_OK, returning its previous value.
690 * @returns The previous value of @c jtag_error.
692 int jtag_error_clear(void);
695 * Return true if it's safe for a background polling task to access the
696 * JTAG scan chain. Polling may be explicitly disallowed, and is also
697 * unsafe while nTRST is active or the JTAG clock is gated off.,
699 bool is_jtag_poll_safe(void);
702 * Return flag reporting whether JTAG polling is disallowed.
704 bool jtag_poll_get_enabled(void);
707 * Assign flag reporting whether JTAG polling is disallowed.
709 void jtag_poll_set_enabled(bool value
);
712 /* The minidriver may have inline versions of some of the low
713 * level APIs that are used in inner loops. */
714 #include <jtag/minidriver.h>