diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/jtag/jtag.h | 2 | ||||
| -rw-r--r-- | src/jtag/tcl.c | 107 | ||||
| -rw-r--r-- | src/target/arm7_9_common.c | 15 |
3 files changed, 106 insertions, 18 deletions
diff --git a/src/jtag/jtag.h b/src/jtag/jtag.h index 786b2b83..60774589 100644 --- a/src/jtag/jtag.h +++ b/src/jtag/jtag.h @@ -286,7 +286,7 @@ enum reset_types { RESET_TRST_PULLS_SRST = 0x8, RESET_TRST_OPEN_DRAIN = 0x10, RESET_SRST_PUSH_PULL = 0x20, - RESET_SRST_GATES_JTAG = 0x40, + RESET_SRST_NO_GATING = 0x40, }; enum reset_types jtag_get_reset_config(void); diff --git a/src/jtag/tcl.c b/src/jtag/tcl.c index 9101d31e..e080279a 100644 --- a/src/jtag/tcl.c +++ b/src/jtag/tcl.c @@ -631,7 +631,12 @@ int jtag_register_commands(struct command_context_s *cmd_ctx) COMMAND_CONFIG, "(DEPRECATED) jtag_device <ir_length> <ir_expected> <ir_mask>"); register_command(cmd_ctx, NULL, "reset_config", handle_reset_config_command, COMMAND_ANY, - "[none/trst_only/srst_only/trst_and_srst] [srst_pulls_trst/trst_pulls_srst] [combined/separate] [trst_push_pull/trst_open_drain] [srst_push_pull/srst_open_drain]"); + "reset_config " + "[none|trst_only|srst_only|trst_and_srst] " + "[srst_pulls_trst|trst_pulls_srst|combined|separate] " + "[srst_gates_jtag|srst_nogate] " + "[trst_push_pull|trst_open_drain] " + "[srst_push_pull|srst_open_drain]"); register_command(cmd_ctx, NULL, "jtag_nsrst_delay", handle_jtag_nsrst_delay_command, COMMAND_ANY, "jtag_nsrst_delay <ms> - delay after deasserting srst in ms"); register_command(cmd_ctx, NULL, "jtag_ntrst_delay", handle_jtag_ntrst_delay_command, @@ -851,9 +856,6 @@ static int handle_reset_config_command(struct command_context_s *cmd_ctx, char * int new_cfg = 0; int mask = 0; - if (argc < 1) - return ERROR_COMMAND_SYNTAX_ERROR; - /* Original versions cared about the order of these tokens: * reset_config signals [combination [trst_type [srst_type]]] * They also clobbered the previous configuration even on error. @@ -865,13 +867,21 @@ static int handle_reset_config_command(struct command_context_s *cmd_ctx, char * int tmp = 0; int m; - m = RESET_SRST_GATES_JTAG; - tmp = 0; + /* gating */ + m = RESET_SRST_NO_GATING; if (strcmp(*args, "srst_gates_jtag") == 0) - { - tmp = RESET_SRST_GATES_JTAG; - goto next; + /* default: don't use JTAG while SRST asserted */; + else if (strcmp(*args, "srst_nogate") == 0) + tmp = RESET_SRST_NO_GATING; + else + m = 0; + if (mask & m) { + LOG_ERROR("extra reset_config %s spec (%s)", + "gating", *args); + return ERROR_INVALID_ARGUMENTS; } + if (m) + goto next; /* signals */ m = RESET_HAS_TRST | RESET_HAS_SRST; @@ -958,10 +968,81 @@ next: } /* clear previous values of those bits, save new values */ - enum reset_types old_cfg = jtag_get_reset_config(); - old_cfg &= ~mask; - new_cfg |= old_cfg; - jtag_set_reset_config(new_cfg); + if (mask) { + int old_cfg = jtag_get_reset_config(); + + old_cfg &= ~mask; + new_cfg |= old_cfg; + jtag_set_reset_config(new_cfg); + } else + new_cfg = jtag_get_reset_config(); + + + /* + * Display the (now-)current reset mode + */ + char *modes[5]; + + /* minimal JTAG has neither SRST nor TRST (so that's the default) */ + switch (new_cfg & (RESET_HAS_TRST | RESET_HAS_SRST)) { + case RESET_HAS_SRST: + modes[0] = "srst_only"; + break; + case RESET_HAS_TRST: + modes[0] = "trst_only"; + break; + case RESET_TRST_AND_SRST: + modes[0] = "trst_and_srst"; + break; + default: + modes[0] = "none"; + break; + } + + /* normally SRST and TRST are decoupled; but bugs happen ... */ + switch (new_cfg & (RESET_SRST_PULLS_TRST | RESET_TRST_PULLS_SRST)) { + case RESET_SRST_PULLS_TRST: + modes[1] = "srst_pulls_trst"; + break; + case RESET_TRST_PULLS_SRST: + modes[1] = "trst_pulls_srst"; + break; + case RESET_SRST_PULLS_TRST | RESET_TRST_PULLS_SRST: + modes[1] = "combined"; + break; + default: + modes[1] = "separate"; + break; + } + + /* TRST-less connectors include Altera, Xilinx, and minimal JTAG */ + if (new_cfg & RESET_HAS_TRST) { + if (new_cfg & RESET_TRST_OPEN_DRAIN) + modes[3] = " trst_open_drain"; + else + modes[3] = " trst_push_pull"; + } else + modes[3] = ""; + + /* SRST-less connectors include TI-14, Xilinx, and minimal JTAG */ + if (new_cfg & RESET_HAS_SRST) { + if (new_cfg & RESET_SRST_NO_GATING) + modes[2] = " srst_nogate"; + else + modes[2] = " srst_gates_jtag"; + + if (new_cfg & RESET_SRST_PUSH_PULL) + modes[4] = " srst_push_pull"; + else + modes[4] = " srst_open_drain"; + } else { + modes[2] = ""; + modes[4] = ""; + } + + command_print(cmd_ctx, "%s %s%s%s%s", + modes[0], modes[1], + modes[2], modes[3], modes[4]); return ERROR_OK; } diff --git a/src/target/arm7_9_common.c b/src/target/arm7_9_common.c index 40dddda6..2b064f23 100644 --- a/src/target/arm7_9_common.c +++ b/src/target/arm7_9_common.c @@ -1021,12 +1021,19 @@ int arm7_9_assert_reset(target_t *target) return ERROR_FAIL; } - /* at this point trst has been asserted/deasserted once. We want to - * program embedded ice while SRST is asserted, but some CPUs gate - * the JTAG clock while SRST is asserted + /* At this point trst has been asserted/deasserted once. We would + * like to program EmbeddedICE while SRST is asserted, instead of + * depending on SRST to leave that module alone. However, many CPUs + * gate the JTAG clock while SRST is asserted; or JTAG may need + * clock stability guarantees (adaptive clocking might help). + * + * So we assume JTAG access during SRST is off the menu unless it's + * been specifically enabled. */ bool srst_asserted = false; - if (((jtag_reset_config & RESET_SRST_PULLS_TRST) == 0) && ((jtag_reset_config & RESET_SRST_GATES_JTAG) == 0)) + + if (((jtag_reset_config & RESET_SRST_PULLS_TRST) == 0) + && (jtag_reset_config & RESET_SRST_NO_GATING)) { jtag_add_reset(0, 1); srst_asserted = true; |