- added "init" command. "init" and "reset" at end of startup script is equivalent

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

diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c
index c73e0c9aa879663b1056e796215d2b2591c44a78..291c40107c791e4e6c9b5298c9be8bbc2445ed2a 100644 (file)
--- a/src/jtag/jtag.c
+++ b/src/jtag/jtag.c
@@ -898,6 +898,23 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
        int trst_with_tlr = 0;
        int retval;
        
+       /* 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)&&
+                       ((jtag_reset_config & RESET_TRST_PULLS_SRST)==0))
+       {
+               if (((req_tlr_or_trst&&!jtag_trst)||
+                               (!req_tlr_or_trst&&jtag_trst))&&
+                               ((req_srst&&!jtag_srst)||
+                                               (!req_srst&&jtag_srst)))
+               {
+                       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))
@@ -1477,7 +1494,7 @@ int jtag_interface_init(struct command_context_s *cmd_ctx)
        return ERROR_OK;
 }
 
-int jtag_init(struct command_context_s *cmd_ctx)
+static int jtag_init_inner(struct command_context_s *cmd_ctx)
 {
        int validate_tries = 0;
        jtag_device_t *device;
@@ -1521,6 +1538,56 @@ int jtag_init(struct command_context_s *cmd_ctx)
        return ERROR_OK;
 }
 
+int jtag_init_reset(struct command_context_s *cmd_ctx)
+{
+       int retval;
+       LOG_DEBUG("Trying to bring the JTAG controller to life by asserting TRST / tms");
+
+       /* Reset can happen after a power cycle.
+        * 
+        * Ideally we would only assert TRST or run tms before the target reset.
+        * 
+        * However w/srst_pulls_trst, trst is asserted together with the target
+        * reset whether we want it or not.
+        * 
+        * NB! Some targets have JTAG circuitry disabled until a 
+        * trst & srst has been asserted.
+        * 
+        * NB! here we assume nsrst/ntrst delay are sufficient!
+        * 
+        * NB! order matters!!!! srst *can* disconnect JTAG circuitry
+        * 
+        */
+       jtag_add_reset(1, 0); /* TMS or TRST */
+       if (jtag_reset_config & RESET_HAS_SRST)
+       {
+               jtag_add_reset(1, 1);
+               if ((jtag_reset_config & RESET_SRST_PULLS_TRST)==0)
+                       jtag_add_reset(0, 1);
+       }
+       jtag_add_reset(0, 0);
+       if ((retval = jtag_execute_queue()) != ERROR_OK)
+               return retval;
+       
+       /* Check that we can communication on the JTAG chain + eventually we want to
+        * be able to perform enumeration only after OpenOCD has started 
+        * telnet and GDB server
+        * 
+        * That would allow users to more easily perform any magic they need to before
+        * reset happens.
+        */
+       return jtag_init_inner(cmd_ctx);
+}
+
+int jtag_init(struct command_context_s *cmd_ctx)
+{
+       if (jtag_init_inner(cmd_ctx)==ERROR_OK)
+       {
+               return ERROR_OK;
+       }
+       return jtag_init_reset(cmd_ctx);
+}
+
 
 static int default_khz(int khz, int *jtag_speed)
 {