jtag: clean up TAP state name handling
authorDavid Brownell <dbrownell@users.sourceforge.net>
Fri, 23 Oct 2009 08:02:22 +0000 (01:02 -0700)
committerDavid Brownell <dbrownell@users.sourceforge.net>
Fri, 23 Oct 2009 08:02:22 +0000 (01:02 -0700)
Some cosmetic cleanup, and switch to a single table mapping
between state names and symbols (vs two routines which only
share that state with difficulty).

Get rid of TAP_NUM_STATES, and some related knowledge about
how TAP numbers are assigned.  Later on, this will help us
get rid of more such hardwired knowlege.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
src/jtag/interface.c
src/jtag/jtag.h
src/jtag/tcl.c

index fcdb8ee..e475b48 100644 (file)
@@ -73,20 +73,23 @@ tap_state_t tap_get_end_state()
 
 int tap_move_ndx(tap_state_t astate)
 {
-       /* given a stable state, return the index into the tms_seqs[] array within tap_get_tms_path() */
+       /* given a stable state, return the index into the tms_seqs[]
+        * array within tap_get_tms_path()
+        */
 
        int ndx;
 
        switch (astate)
        {
        case TAP_RESET:         ndx = 0;                        break;
+       case TAP_IDLE:          ndx = 1;                        break;
        case TAP_DRSHIFT:       ndx = 2;                        break;
        case TAP_DRPAUSE:       ndx = 3;                        break;
-       case TAP_IDLE:          ndx = 1;                        break;
        case TAP_IRSHIFT:       ndx = 4;                        break;
        case TAP_IRPAUSE:       ndx = 5;                        break;
        default:
-               LOG_ERROR("fatal: unstable state \"%s\" used in tap_move_ndx()", tap_state_name(astate));
+               LOG_ERROR("FATAL: unstable state \"%s\" in tap_move_ndx()",
+                               tap_state_name(astate));
                exit(1);
        }
 
@@ -95,12 +98,7 @@ int tap_move_ndx(tap_state_t astate)
 
 
 /* tap_move[i][j]: tap movement command to go from state i to state j
- * 0: Test-Logic-Reset
- * 1: Run-Test/Idle
- * 2: Shift-DR
- * 3: Pause-DR
- * 4: Shift-IR
- * 5: Pause-IR
+ * encodings of i and j are what tap_move_ndx() reports.
  *
  * DRSHIFT->DRSHIFT and IRSHIFT->IRSHIFT have to be caught in interface specific code
  */
@@ -108,7 +106,6 @@ struct tms_sequences
 {
        uint8_t bits;
        uint8_t bit_count;
-
 };
 
 /*
@@ -333,47 +330,54 @@ tap_state_t tap_state_transition(tap_state_t cur_state, bool tms)
        return new_state;
 }
 
-const char* tap_state_name(tap_state_t state)
+
+/* NOTE:  do not change these state names.  They're documented,
+ * and we rely on them to match SVF input (except for "RUN/IDLE").
+ */
+static const struct name_mapping {
+       enum tap_state  symbol;
+       const char      *name;
+} tap_name_mapping[] = {
+       { TAP_RESET,    "RESET", },
+       { TAP_IDLE,     "RUN/IDLE", },
+       { TAP_DRSELECT, "DRSELECT", },
+       { TAP_DRCAPTURE,"DRCAPTURE", },
+       { TAP_DRSHIFT,  "DRSHIFT", },
+       { TAP_DREXIT1,  "DREXIT1", },
+       { TAP_DRPAUSE,  "DRPAUSE", },
+       { TAP_DREXIT2,  "DREXIT2", },
+       { TAP_DRUPDATE, "DRUPDATE", },
+       { TAP_IRSELECT, "IRSELECT", },
+       { TAP_IRCAPTURE,"IRCAPTURE", },
+       { TAP_IRSHIFT,  "IRSHIFT", },
+       { TAP_IREXIT1,  "IREXIT1", },
+       { TAP_IRPAUSE,  "IRPAUSE", },
+       { TAP_IREXIT2,  "IREXIT2", },
+       { TAP_IRUPDATE, "IRUPDATE", },
+
+       /* only for input:  accept standard SVF name */
+       { TAP_IDLE,     "IDLE", },
+};
+
+const char *tap_state_name(tap_state_t state)
 {
-       const char* ret;
+       unsigned i;
 
-       switch (state)
-       {
-       case TAP_RESET:         ret = "RESET";                  break;
-       case TAP_IDLE:          ret = "RUN/IDLE";               break;
-       case TAP_DRSELECT:      ret = "DRSELECT";               break;
-       case TAP_DRCAPTURE: ret = "DRCAPTURE";          break;
-       case TAP_DRSHIFT:       ret = "DRSHIFT";                        break;
-       case TAP_DREXIT1:       ret = "DREXIT1";                        break;
-       case TAP_DRPAUSE:       ret = "DRPAUSE";                        break;
-       case TAP_DREXIT2:       ret = "DREXIT2";                        break;
-       case TAP_DRUPDATE:      ret = "DRUPDATE";               break;
-       case TAP_IRSELECT:      ret = "IRSELECT";               break;
-       case TAP_IRCAPTURE: ret = "IRCAPTURE";          break;
-       case TAP_IRSHIFT:       ret = "IRSHIFT";                        break;
-       case TAP_IREXIT1:       ret = "IREXIT1";                        break;
-       case TAP_IRPAUSE:       ret = "IRPAUSE";                        break;
-       case TAP_IREXIT2:       ret = "IREXIT2";                        break;
-       case TAP_IRUPDATE:      ret = "IRUPDATE";               break;
-       default:                                ret = "???";
+       for (i = 0; i < DIM(tap_name_mapping); i++) {
+               if (tap_name_mapping[i].symbol == state)
+                       return tap_name_mapping[i].name;
        }
-
-       return ret;
+       return "???";
 }
 
 tap_state_t tap_state_by_name(const char *name)
 {
-       tap_state_t x;
-
-       /* standard SVF name is "IDLE" */
-       if (0 == strcasecmp(name, "IDLE"))
-               return TAP_IDLE;
+       unsigned i;
 
-       for (x = 0 ; x < TAP_NUM_STATES ; x++) {
+       for (i = 0; i < DIM(tap_name_mapping); i++) {
                /* be nice to the human */
-               if (0 == strcasecmp(name, tap_state_name(x))) {
-                       return x;
-               }
+               if (strcasecmp(name, tap_name_mapping[i].name) == 0)
+                       return tap_name_mapping[i].symbol;
        }
        /* not found */
        return TAP_INVALID;
index 1dae00f..ca09f92 100644 (file)
  *
  * These definitions were gleaned from the ARM7TDMI-S Technical
  * Reference Manual and validated against several other ARM core
- * technical manuals.  tap_get_tms_path() is sensitive to this numbering
- * and ordering of the TAP states; furthermore, some interfaces require
- * specific numbers be used, as they are handed-off directly to their
- * hardware implementations.
+ * technical manuals.
+ *
+ * FIXME some interfaces require specific numbers be used, as they
+ * are handed-off directly to their hardware implementations.
+ * Fix those drivers to map as appropriate ... then pick some
+ * sane set of numbers here (where 0/uninitialized == INVALID).
  */
 typedef enum tap_state
 {
+       TAP_INVALID = -1,
+
 #if BUILD_ZY1000
        /* These are the old numbers. Leave as-is for now... */
        TAP_RESET    = 0, TAP_IDLE = 8,
@@ -72,7 +76,6 @@ typedef enum tap_state
        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,
@@ -92,9 +95,6 @@ typedef enum tap_state
        TAP_IRCAPTURE = 0xe,
        TAP_RESET = 0x0f,
 
-       TAP_NUM_STATES = 0x10,
-
-       TAP_INVALID = -1,
 #endif
 } tap_state_t;
 
index e080279..6a6e3ae 100644 (file)
@@ -1248,6 +1248,8 @@ static int handle_runtest_command(struct command_context_s *cmd_ctx,
  * For "irscan" or "drscan" commands, the "end" (really, "next") state
  * should be stable ... and *NOT* a shift state, otherwise free-running
  * jtag clocks could change the values latched by the update state.
+ * Not surprisingly, this is the same constraint as SVF; the "irscan"
+ * and "drscan" commands are a write-only subset of what SVF provides.
  */
 static bool scan_is_safe(tap_state_t state)
 {
@@ -1285,25 +1287,14 @@ static int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, c
        if (argc >= 4) {
                /* have at least one pair of numbers. */
                /* is last pair the magic text? */
-               if (0 == strcmp("-endstate", args[ argc - 2 ])) {
-                       const char *cpA;
-                       const char *cpS;
-                       cpA = args[ argc-1 ];
-                       for (endstate = 0 ; endstate < TAP_NUM_STATES ; endstate++) {
-                               cpS = tap_state_name(endstate);
-                               if (0 == strcmp(cpA, cpS)) {
-                                       break;
-                               }
-                       }
-                       if (endstate >= TAP_NUM_STATES) {
+               if (strcmp("-endstate", args[argc - 2]) == 0) {
+                       endstate = tap_state_by_name(args[argc - 1]);
+                       if (endstate == TAP_INVALID)
                                return ERROR_COMMAND_SYNTAX_ERROR;
-                       } else {
-                               if (!scan_is_safe(endstate))
-                                       LOG_WARNING("irscan with unsafe "
-                                                       "endstate \"%s\"", cpA);
-                               /* found - remove the last 2 args */
-                               argc -= 2;
-                       }
+                       if (!scan_is_safe(endstate))
+                               LOG_WARNING("unstable irscan endstate \"%s\"",
+                                               args[argc - 1]);
+                       argc -= 2;
                }
        }