Matt Hsu <matt@0xlab.org> and Holger Hans Peter Freyther <zecke@selfish.org> Before...

[openocd.git] / src / jtag / core.c

diff --git a/src/jtag/core.c b/src/jtag/core.c
index 611ea7d6596de74fb62bbee5c1478c63ecfa6034..e23cbaa2e19db0f11eaa9730a496b30487e81396 100644 (file)
--- a/src/jtag/core.c
+++ b/src/jtag/core.c
@@ -585,9 +585,31 @@ void jtag_add_clocks(int num_cycles)
 void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 {
        int trst_with_tlr = 0;
-       int new_srst;
+       int new_srst = 0;
        int new_trst = 0;
 
+       /* Without SRST, we must use target-specific JTAG operations
+        * on each target; callers should not be requesting SRST when
+        * that signal doesn't exist.
+        *
+        * RESET_SRST_PULLS_TRST is a board or chip level quirk, which
+        * can kick in even if the JTAG adapter can't drive TRST.
+        */
+       if (req_srst) {
+               if (!(jtag_reset_config & RESET_HAS_SRST)) {
+                       LOG_ERROR("BUG: can't assert SRST");
+                       jtag_set_error(ERROR_FAIL);
+                       return;
+               }
+               if ((jtag_reset_config & RESET_SRST_PULLS_TRST) != 0
+                               && !req_tlr_or_trst) {
+                       LOG_ERROR("BUG: can't assert only SRST");
+                       jtag_set_error(ERROR_FAIL);
+                       return;
+               }
+               new_srst = 1;
+       }
+
        /* JTAG reset (entry to TAP_RESET state) can always be achieved
         * using TCK and TMS; that may go through a TAP_{IR,DR}UPDATE
         * state first.  TRST accelerates it, and bypasses those states.
@@ -605,41 +627,6 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
                        new_trst = 1;
        }
 
-       /* FIX!!! there are *many* different cases here. A better
-        * approach is needed for legal combinations of transitions...
-        */
-       if ((jtag_reset_config & RESET_HAS_SRST)&&
-                       (jtag_reset_config & RESET_HAS_TRST)&&
-                       ((jtag_reset_config & RESET_SRST_PULLS_TRST) == 0))
-       {
-               if (((req_tlr_or_trst&&!jtag_trst)||
-                               (!req_tlr_or_trst && jtag_trst))&&
-                               ((req_srst&&!jtag_srst)||
-                                               (!req_srst && jtag_srst)))
-               {
-                       /* FIX!!! srst_pulls_trst allows 1,1 => 0,0 transition.... */
-                       //LOG_ERROR("BUG: transition of req_tlr_or_trst and req_srst in the same jtag_add_reset() call is undefined");
-               }
-       }
-
-       /* Make sure that jtag_reset_config allows the requested reset */
-       /* if SRST pulls TRST, we can't fulfill srst == 1 with trst == 0 */
-       if (((jtag_reset_config & RESET_SRST_PULLS_TRST) && (req_srst == 1)) && (!req_tlr_or_trst))
-       {
-               LOG_ERROR("BUG: requested reset would assert trst");
-               jtag_set_error(ERROR_FAIL);
-               return;
-       }
-
-       if (req_srst && !(jtag_reset_config & RESET_HAS_SRST))
-       {
-               LOG_ERROR("BUG: requested SRST assertion, but the current configuration doesn't support this");
-               jtag_set_error(ERROR_FAIL);
-               return;
-       }
-
-       new_srst = req_srst;
-
        /* Maybe change TRST and/or SRST signal state */
        if (jtag_srst != new_srst || jtag_trst != new_trst) {
                int retval;
@@ -952,7 +939,7 @@ static bool jtag_examine_chain_match_tap(const struct jtag_tap_s *tap)
        /* If none of the expected ids matched, log an error */
        if (ii != tap->expected_ids_cnt)
        {
-               LOG_INFO("JTAG Tap/device matched");
+               LOG_DEBUG("JTAG Tap/device matched");
                return true;
        }
        jtag_examine_chain_display(LOG_LVL_ERROR, "got",
@@ -988,20 +975,26 @@ int jtag_examine_chain(void)
                return ERROR_JTAG_INIT_FAILED;
        }
 
-       for (unsigned bit_count = 0; bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;)
+       for (unsigned bit_count = 0;
+                       tap && bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;
+                       tap = jtag_tap_next_enabled(tap))
        {
                uint32_t idcode = buf_get_u32(idcode_buffer, bit_count, 32);
+
                if ((idcode & 1) == 0)
                {
                        /* LSB must not be 0, this indicates a device in bypass */
                        LOG_WARNING("Tap/Device does not have IDCODE");
                        idcode = 0;
+                       tap->hasidcode = false;
 
                        bit_count += 1;
                }
                else
                {
-                       /*
+                       tap->hasidcode = true;
+
+                       /*
                         * End of chain (invalid manufacturer ID) some devices, such
                         * as AVR will output all 1's instead of TDI input value at
                         * end of chain.
@@ -1026,10 +1019,8 @@ int jtag_examine_chain(void)
                tap->idcode = idcode;
 
                // ensure the TAP ID does matches what was expected
-               if (!jtag_examine_chain_match_tap(tap))
+               if (!jtag_examine_chain_match_tap(tap))
                        return ERROR_JTAG_INIT_FAILED;
-
-               tap = jtag_tap_next_enabled(tap);
        }
 
        /* see if number of discovered devices matches configuration */
@@ -1075,7 +1066,10 @@ int jtag_validate_chain(void)
 
 
        jtag_add_plain_ir_scan(1, &field, TAP_RESET);
-       jtag_execute_queue();
+       int retval;
+       retval = jtag_execute_queue();
+       if (retval != ERROR_OK)
+               return retval;
 
        tap = NULL;
        chain_pos = 0;
@@ -1087,7 +1081,8 @@ int jtag_validate_chain(void)
                }
 
                val = buf_get_u32(ir_test, chain_pos, 2);
-               if (val != 0x1)
+               /* Only fail this check if we have IDCODE for this device */
+               if ((val != 0x1)&&(tap->hasidcode))
                {
                        char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
                        LOG_ERROR("Could not validate JTAG scan chain, IR mismatch, scan returned 0x%s. tap=%s pos=%d expected 0x1 got %0x", cbuf, jtag_tap_name(tap), chain_pos, val);