git.rot13.org Git - goodfet/blob - firmware/apps/jtag/openocd.c

   1 /*! \file openocd.c
   2   \author Dave Huseby <dave at linuxprogrammer.org>
   3   \brief OpenOCD firmware
   4 */
   5
   6
   7 #include "platform.h"
   8 #include "command.h"
   9 #include "openocd.h"
  10 #include "jtag.h"
  11
  12 #define OPENOCD_APP
  13
  14 //! Handles a monitor command.
  15 void openocd_handle_fn(uint8_t const app,
  16                                            uint8_t const verb,
  17                                            uint32_t const len);
  18
  19 // define the openocd app's app_t
  20 app_t const openocd_app = {
  21
  22         /* app number */
  23         OPENOCD,
  24
  25         /* handle fn */
  26         openocd_handle_fn,
  27
  28         /* name */
  29         "OpenOCD",
  30
  31         /* desc */
  32         "\tThe OpenOCD app handles the OpenOCD bitbang protocol.\n"
  33 };
  34
  35 //! Clock the JTAG clock line
  36 static void openocd_tcktock()
  37 {
  38         CLRTCK;
  39         SETTCK;
  40 }
  41
  42 //! reset the cpu
  43 static void openocd_reset_cpu(void)
  44 {
  45         SETRST;
  46         msdelay(100);
  47         CLRRST;
  48         msdelay(100);
  49         SETRST;
  50         msdelay(100);
  51 }
  52
  53 //! reset the tap logic
  54 static void openocd_reset_test_logic(void)
  55 {
  56         CLRMOSI;
  57         SETTMS;
  58         openocd_tcktock();
  59         openocd_tcktock();
  60         openocd_tcktock();
  61         openocd_tcktock();
  62         openocd_tcktock(); // now in reset-test-logic
  63         CLRTMS;
  64         openocd_tcktock();  // now in run-test-idle state
  65 }
  66
  67 //! sets the LED value
  68 void openocd_led(int led)
  69 {
  70         if (led)
  71                 /* turn the LED on */
  72                 led_on();
  73         else
  74                 /* turn the LED off */
  75                 led_off();
  76 }
  77
  78 //! resets the device/JTAG logic
  79 void openocd_reset(int trst, int srst)
  80 {
  81         if(srst && trst)
  82         {
  83                 // we need to drive TST from low to high at
  84                 // the same time as the RST
  85                 SETTST;
  86                 SETRST;
  87                 msdelay(100);
  88                 CLRTST;
  89                 CLRRST;
  90                 msdelay(100);
  91                 SETTST;
  92                 SETRST;
  93                 msdelay(100);
  94         }
  95         else if (!srst && trst)
  96         {
  97                 openocd_reset_test_logic();
  98         }
  99         else if(srst && !trst)
 100         {
 101                 openocd_reset_cpu();
 102         }
 103 }
 104
 105 //! updates the tck, tms, and tdi values
 106 void openocd_write(int tck, int tms, int tdi)
 107 {
 108         if(tms)
 109                 SETTMS;
 110         else
 111                 CLRTMS;
 112
 113         if(tdi)
 114                 SETMOSI;
 115         else
 116                 CLRMOSI;
 117
 118         if(tck)
 119                 SETTCK;
 120         else
 121                 CLRTCK;
 122 }
 123
 124 //! Stop JTAG, release pins
 125 void openocd_stop()
 126 {
 127         P5OUT=0;
 128         P4OUT=0;
 129 }
 130
 131 //! Set up the pins for JTAG mode.
 132 void openocd_setup()
 133 {
 134         P5DIR|=MOSI+SCK+TMS;
 135         P5DIR&=~MISO;
 136         P4DIR|=TST;
 137         P2DIR|=RST;
 138         msdelay(100);
 139 }
 140
 141 //! handles OpenOCD commands
 142 void openocd_handle_fn(uint8_t const app,
 143                                            uint8_t const verb,
 144                                            uint32_t const len)
 145 {
 146         switch(verb)
 147         {
 148                 case START:
 149                         /* do nothing...*/
 150                         txdata(app,OK,0);
 151                         break;
 152
 153                 case STOP:
 154                         openocd_stop();
 155                         txdata(app,OK,0);
 156                         break;
 157
 158                 case SETUP:
 159                         openocd_setup();
 160                         txdata(app,OK,0);
 161                         break;
 162
 163                 case OPENOCD_RESET:
 164                         openocd_reset(cmddata[0], cmddata[1]);
 165                         txdata(app,OK,0);
 166                         break;
 167
 168                 case OPENOCD_READ:
 169                         cmddata[0] = READMISO;
 170                         txdata(app,OK,1);
 171                         break;
 172
 173                 case OPENOCD_WRITE:
 174                         openocd_write(cmddata[0], cmddata[1], cmddata[2]);
 175                         txdata(app,OK,0);
 176                         break;
 177
 178                 case OPENOCD_LED:
 179                         openocd_led(cmddata[0]);
 180                         txdata(app,OK,0);
 181                         break;
 182
 183                 default:
 184                         txdata(app,NOK,0);
 185         }
 186 }
 187
 188