Some devices such as AVR will return 0xffffffff instead of the TDI

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

diff --git a/src/jtag/dummy.c b/src/jtag/dummy.c
index 0565edafb098953d8f84d75d10d7c2b0e705bfee..49161a607c80b0dd6dd198348ecb1b75f4aac35f 100644 (file)
--- a/src/jtag/dummy.c
+++ b/src/jtag/dummy.c
@@ -26,32 +26,49 @@
 #include "jtag.h"\r
 #include "bitbang.h"\r
 \r
-int dummy_speed(int speed);\r
-int dummy_register_commands(struct command_context_s *cmd_ctx);\r
-int dummy_init(void);\r
-int dummy_quit(void);\r
 \r
-/* The dummy driver is used to easily check the code path \r
+/* my private tap controller state, which tracks state for calling code */\r
+static tap_state_t dummy_state = TAP_RESET;\r
+\r
+static int dummy_clock;         /* edge detector */\r
+\r
+static int clock_count;         /* count clocks in any stable state, only stable states */\r
+\r
+static u32 dummy_data;\r
+\r
+\r
+static int dummy_speed(int speed);\r
+static int dummy_register_commands(struct command_context_s *cmd_ctx);\r
+static int dummy_init(void);\r
+static int dummy_quit(void);\r
+static int dummy_khz(int khz, int *jtag_speed);\r
+static int dummy_speed_div(int speed, int *khz);\r
+\r
+\r
+/* The dummy driver is used to easily check the code path\r
  * where the target is unresponsive.\r
  */\r
-jtag_interface_t dummy_interface = \r
+jtag_interface_t dummy_interface =\r
 {\r
        .name = "dummy",\r
-       \r
+\r
        .execute_queue = bitbang_execute_queue,\r
 \r
-       .speed = dummy_speed,   \r
+       .speed = dummy_speed,\r
        .register_commands = dummy_register_commands,\r
+       .khz = dummy_khz,\r
+       .speed_div = dummy_speed_div,\r
+\r
        .init = dummy_init,\r
        .quit = dummy_quit,\r
 };\r
 \r
-int dummy_read(void);\r
-void dummy_write(int tck, int tms, int tdi);\r
-void dummy_reset(int trst, int srst);\r
-void dummy_led(int on);\r
+static int dummy_read(void);\r
+static void dummy_write(int tck, int tms, int tdi);\r
+static void dummy_reset(int trst, int srst);\r
+static void dummy_led(int on);\r
 \r
-bitbang_interface_t dummy_bitbang =\r
+static bitbang_interface_t dummy_bitbang =\r
 {\r
        .read = dummy_read,\r
        .write = dummy_write,\r
@@ -59,41 +76,111 @@ bitbang_interface_t dummy_bitbang =
        .blink = dummy_led\r
 };\r
 \r
-int dummy_read(void)\r
+static int dummy_read(void)\r
 {\r
-       return 1;\r
+       int data = 1 & dummy_data;\r
+       dummy_data = (dummy_data >> 1) | (1<<31);\r
+       return data;\r
 }\r
 \r
-void dummy_write(int tck, int tms, int tdi)\r
+\r
+static void dummy_write(int tck, int tms, int tdi)\r
 {\r
+       /* TAP standard: "state transitions occur on rising edge of clock" */\r
+       if( tck != dummy_clock )\r
+       {\r
+               if( tck )\r
+               {\r
+                       tap_state_t old_state = dummy_state;\r
+                       dummy_state = tap_state_transition( old_state, tms );\r
+\r
+                       if( old_state != dummy_state )\r
+                       {\r
+                               if( clock_count )\r
+                               {\r
+                                       LOG_DEBUG("dummy_tap: %d stable clocks", clock_count);\r
+                                       clock_count = 0;\r
+                               }\r
+\r
+                               LOG_DEBUG("dummy_tap: %s", tap_state_name(dummy_state) );\r
+\r
+#if defined(DEBUG)\r
+                               if(dummy_state == TAP_DRCAPTURE)\r
+                                       dummy_data = 0x01255043;\r
+#endif\r
+                       }\r
+                       else\r
+                       {\r
+                               /* this is a stable state clock edge, no change of state here,\r
+                                * simply increment clock_count for subsequent logging\r
+                                */\r
+                               ++clock_count;\r
+                       }\r
+               }\r
+               dummy_clock = tck;\r
+       }\r
 }\r
 \r
-void dummy_reset(int trst, int srst)\r
+static void dummy_reset(int trst, int srst)\r
 {\r
+       dummy_clock = 0;\r
+\r
+       if (trst || (srst && (jtag_reset_config & RESET_SRST_PULLS_TRST)))\r
+               dummy_state = TAP_RESET;\r
+\r
+       LOG_DEBUG("reset to: %s", tap_state_name(dummy_state) );\r
 }\r
 \r
-int dummy_speed(int speed)\r
+static int dummy_khz(int khz, int *jtag_speed)\r
 {\r
+       if (khz==0)\r
+       {\r
+               *jtag_speed=0;\r
+       }\r
+       else\r
+       {\r
+               *jtag_speed=64000/khz;\r
+       }\r
        return ERROR_OK;\r
 }\r
 \r
-int dummy_register_commands(struct command_context_s *cmd_ctx)\r
+static int dummy_speed_div(int speed, int *khz)\r
 {\r
+       if (speed==0)\r
+       {\r
+               *khz = 0;\r
+       }\r
+       else\r
+       {\r
+               *khz=64000/speed;\r
+       }\r
+\r
        return ERROR_OK;\r
 }\r
 \r
-int dummy_init(void)\r
+static int dummy_speed(int speed)\r
 {\r
-       bitbang_interface = &dummy_bitbang;     \r
+       return ERROR_OK;\r
+}\r
 \r
+static int dummy_register_commands(struct command_context_s *cmd_ctx)\r
+{\r
        return ERROR_OK;\r
 }\r
 \r
-int dummy_quit(void)\r
+static int dummy_init(void)\r
 {\r
+       bitbang_interface = &dummy_bitbang;\r
+\r
        return ERROR_OK;\r
 }\r
 \r
-void dummy_led(int on)\r
+static int dummy_quit(void)\r
 {\r
+       return ERROR_OK;\r
 }\r
+\r
+static void dummy_led(int on)\r
+{\r
+}\r
+\r