git.sur5r.net Git - openocd/blob - src/jtag/dummy.c

   1 /***************************************************************************\r
   2  *   Copyright (C) 2008 by Øyvind Harboe                                   *\r
   3  *   oyvind.harboe@zylin.com                                               *\r
   4  *                                                                         *\r
   5  *   This program is free software; you can redistribute it and/or modify  *\r
   6  *   it under the terms of the GNU General Public License as published by  *\r
   7  *   the Free Software Foundation; either version 2 of the License, or     *\r
   8  *   (at your option) any later version.                                   *\r
   9  *                                                                         *\r
  10  *   This program is distributed in the hope that it will be useful,       *\r
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *\r
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *\r
  13  *   GNU General Public License for more details.                          *\r
  14  *                                                                         *\r
  15  *   You should have received a copy of the GNU General Public License     *\r
  16  *   along with this program; if not, write to the                         *\r
  17  *   Free Software Foundation, Inc.,                                       *\r
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *\r
  19  ***************************************************************************/\r
  20 #ifdef HAVE_CONFIG_H\r
  21 #include "config.h"\r
  22 #endif\r
  23 \r
  24 #include "replacements.h"\r
  25 \r
  26 #include "jtag.h"\r
  27 #include "bitbang.h"\r
  28 \r
  29 \r
  30 /* my private tap controller state, which tracks state for calling code */\r
  31 static tap_state_t dummy_state = TAP_RESET;\r
  32 \r
  33 static int dummy_clock;         /* edge detector */\r
  34 \r
  35 static int clock_count;         /* count clocks in any stable state, only stable states */\r
  36 \r
  37 static u32 dummy_data;\r
  38 \r
  39 \r
  40 static int dummy_speed(int speed);\r
  41 static int dummy_register_commands(struct command_context_s *cmd_ctx);\r
  42 static int dummy_init(void);\r
  43 static int dummy_quit(void);\r
  44 static int dummy_khz(int khz, int *jtag_speed);\r
  45 static int dummy_speed_div(int speed, int *khz);\r
  46 \r
  47 \r
  48 /* The dummy driver is used to easily check the code path\r
  49  * where the target is unresponsive.\r
  50  */\r
  51 jtag_interface_t dummy_interface =\r
  52 {\r
  53         .name = "dummy",\r
  54 \r
  55         .execute_queue = bitbang_execute_queue,\r
  56 \r
  57         .speed = dummy_speed,\r
  58         .register_commands = dummy_register_commands,\r
  59         .khz = dummy_khz,\r
  60         .speed_div = dummy_speed_div,\r
  61 \r
  62         .init = dummy_init,\r
  63         .quit = dummy_quit,\r
  64 };\r
  65 \r
  66 static int dummy_read(void);\r
  67 static void dummy_write(int tck, int tms, int tdi);\r
  68 static void dummy_reset(int trst, int srst);\r
  69 static void dummy_led(int on);\r
  70 \r
  71 static bitbang_interface_t dummy_bitbang =\r
  72 {\r
  73         .read = dummy_read,\r
  74         .write = dummy_write,\r
  75         .reset = dummy_reset,\r
  76         .blink = dummy_led\r
  77 };\r
  78 \r
  79 static int dummy_read(void)\r
  80 {\r
  81         int data = 1 & dummy_data;\r
  82         dummy_data = (dummy_data >> 1) | (1<<31);\r
  83         return data;\r
  84 }\r
  85 \r
  86 \r
  87 static void dummy_write(int tck, int tms, int tdi)\r
  88 {\r
  89         /* TAP standard: "state transitions occur on rising edge of clock" */\r
  90         if( tck != dummy_clock )\r
  91         {\r
  92                 if( tck )\r
  93                 {\r
  94                         tap_state_t old_state = dummy_state;\r
  95                         dummy_state = tap_state_transition( old_state, tms );\r
  96 \r
  97                         if( old_state != dummy_state )\r
  98                         {\r
  99                                 if( clock_count )\r
 100                                 {\r
 101                                         LOG_DEBUG("dummy_tap: %d stable clocks", clock_count);\r
 102                                         clock_count = 0;\r
 103                                 }\r
 104 \r
 105                                 LOG_DEBUG("dummy_tap: %s", tap_state_name(dummy_state) );\r
 106 \r
 107 #if defined(DEBUG)\r
 108                                 if(dummy_state == TAP_DRCAPTURE)\r
 109                                         dummy_data = 0x01255043;\r
 110 #endif\r
 111                         }\r
 112                         else\r
 113                         {\r
 114                                 /* this is a stable state clock edge, no change of state here,\r
 115                                  * simply increment clock_count for subsequent logging\r
 116                                  */\r
 117                                 ++clock_count;\r
 118                         }\r
 119                 }\r
 120                 dummy_clock = tck;\r
 121         }\r
 122 }\r
 123 \r
 124 static void dummy_reset(int trst, int srst)\r
 125 {\r
 126         dummy_clock = 0;\r
 127 \r
 128         if (trst || (srst && (jtag_reset_config & RESET_SRST_PULLS_TRST)))\r
 129                 dummy_state = TAP_RESET;\r
 130 \r
 131         LOG_DEBUG("reset to: %s", tap_state_name(dummy_state) );\r
 132 }\r
 133 \r
 134 static int dummy_khz(int khz, int *jtag_speed)\r
 135 {\r
 136         if (khz==0)\r
 137         {\r
 138                 *jtag_speed=0;\r
 139         }\r
 140         else\r
 141         {\r
 142                 *jtag_speed=64000/khz;\r
 143         }\r
 144         return ERROR_OK;\r
 145 }\r
 146 \r
 147 static int dummy_speed_div(int speed, int *khz)\r
 148 {\r
 149         if (speed==0)\r
 150         {\r
 151                 *khz = 0;\r
 152         }\r
 153         else\r
 154         {\r
 155                 *khz=64000/speed;\r
 156         }\r
 157 \r
 158         return ERROR_OK;\r
 159 }\r
 160 \r
 161 static int dummy_speed(int speed)\r
 162 {\r
 163         return ERROR_OK;\r
 164 }\r
 165 \r
 166 static int dummy_register_commands(struct command_context_s *cmd_ctx)\r
 167 {\r
 168         return ERROR_OK;\r
 169 }\r
 170 \r
 171 static int dummy_init(void)\r
 172 {\r
 173         bitbang_interface = &dummy_bitbang;\r
 174 \r
 175         return ERROR_OK;\r
 176 }\r
 177 \r
 178 static int dummy_quit(void)\r
 179 {\r
 180         return ERROR_OK;\r
 181 }\r
 182 \r
 183 static void dummy_led(int on)\r
 184 {\r
 185 }\r
 186 \r