Force sane SRST and TRST initialization

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

diff --git a/src/jtag/core.c b/src/jtag/core.c
index 07eec64f46528ed31b0d58662ac9bcc4f5702db8..f7d55b79301624e889e909d41537593c6b5e66d2 100644 (file)
--- a/src/jtag/core.c
+++ b/src/jtag/core.c
@@ -1,16 +1,16 @@
 /***************************************************************************
- *   Copyright (C) 2005 by Dominic Rath                                    *
- *   Dominic.Rath@gmx.de                                                   *
+ *   Copyright (C) 2009 Zachary T Welch                                    *
+ *   zw@superlucidity.net                                                  *
  *                                                                         *
- *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
+ *   Copyright (C) 2007,2008,2009 Øyvind Harboe                            *
  *   oyvind.harboe@zylin.com                                               *
  *                                                                         *
  *   Copyright (C) 2009 SoftPLC Corporation                                *
  *       http://softplc.com                                                *
  *   dick@softplc.com                                                      *
  *                                                                         *
- *   Copyright (C) 2009 Zachary T Welch                                    *
- *   zw@superlucidity.net                                                  *
+ *   Copyright (C) 2005 by Dominic Rath                                    *
+ *   Dominic.Rath@gmx.de                                                   *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
@@ -68,10 +68,12 @@ static const char *jtag_event_strings[] =
 
 /*
  * JTAG adapters must initialize with TRST and SRST de-asserted
- * (they're negative logic, so that means *high*)
+ * (they're negative logic, so that means *high*).  But some
+ * hardware doesn't necessarily work that way ... so set things
+ * up so that jtag_init() always forces that state.
  */
-static int jtag_trst = 0;
-static int jtag_srst = 0;
+static int jtag_trst = -1;
+static int jtag_srst = -1;
 
 /**
  * List all TAPs that have been created.
@@ -1109,15 +1111,20 @@ static int jtag_validate_ircapture(void)
                }
 
                /* Validate the two LSBs, which must be 01 per JTAG spec.
-                * REVISIT we might be able to verify some MSBs too, using
-                * ircapture/irmask attributes.
+                *
+                * Or ... more bits could be provided by TAP declaration.
+                * Plus, some taps (notably in i.MX series chips) violate
+                * this part of the JTAG spec, so their capture mask/value
+                * attributes might disable this test.
                 */
                val = buf_get_u32(ir_test, chain_pos, tap->ir_length);
-               if ((val & 0x3) != 1) {
-                       LOG_ERROR("%s: IR capture error; saw 0x%0*x not 0x..1",
+               if ((val & tap->ir_capture_mask) != tap->ir_capture_value) {
+                       LOG_ERROR("%s: IR capture error; saw 0x%0*x not 0x%0*x",
                                        jtag_tap_name(tap),
                                        (tap->ir_length + 7) / tap->ir_length,
-                                       val);
+                                       val,
+                                       (tap->ir_length + 7) / tap->ir_length,
+                                       tap->ir_capture_value);
 
                        retval = ERROR_JTAG_INIT_FAILED;
                        goto done;
@@ -1230,7 +1237,7 @@ int jtag_interface_init(struct command_context_s *cmd_ctx)
        return ERROR_OK;
 }
 
-static int jtag_init_inner(struct command_context_s *cmd_ctx)
+int jtag_init_inner(struct command_context_s *cmd_ctx)
 {
        jtag_tap_t *tap;
        int retval;
@@ -1332,13 +1339,19 @@ int jtag_init_reset(struct command_context_s *cmd_ctx)
 int jtag_init(struct command_context_s *cmd_ctx)
 {
        int retval;
+
        if ((retval = jtag_interface_init(cmd_ctx)) != ERROR_OK)
                return retval;
-       if (jtag_init_inner(cmd_ctx) == ERROR_OK)
-       {
-               return ERROR_OK;
-       }
-       return jtag_init_reset(cmd_ctx);
+
+       /* guard against oddball hardware: force resets to be inactive */
+       jtag_add_reset(0, 0);
+       if ((retval = jtag_execute_queue()) != ERROR_OK)
+               return retval;
+
+       if (Jim_Eval_Named(interp, "jtag_init", __FILE__, __LINE__) != JIM_OK)
+               return ERROR_FAIL;
+
+       return ERROR_OK;
 }
 
 unsigned jtag_get_speed_khz(void)