1 /***************************************************************************
2 * Copyright (C) 2008 by Øyvind Harboe *
3 * oyvind.harboe@zylin.com *
5 * This program is free software; you can redistribute it and/or modify *
6 * it under the terms of the GNU General Public License as published by *
7 * the Free Software Foundation; either version 2 of the License, or *
8 * (at your option) any later version. *
10 * This program is distributed in the hope that it will be useful, *
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
13 * GNU General Public License for more details. *
15 * You should have received a copy of the GNU General Public License *
16 * along with this program; if not, write to the *
17 * Free Software Foundation, Inc., *
18 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
19 ***************************************************************************/
24 #define INCLUDE_JTAG_INTERFACE_H
29 /* my private tap controller state, which tracks state for calling code */
30 static tap_state_t dummy_state = TAP_RESET;
32 static int dummy_clock; /* edge detector */
34 static int clock_count; /* count clocks in any stable state, only stable states */
36 static u32 dummy_data;
39 static int dummy_speed(int speed);
40 static int dummy_register_commands(struct command_context_s *cmd_ctx);
41 static int dummy_init(void);
42 static int dummy_quit(void);
43 static int dummy_khz(int khz, int *jtag_speed);
44 static int dummy_speed_div(int speed, int *khz);
47 /* The dummy driver is used to easily check the code path
48 * where the target is unresponsive.
50 jtag_interface_t dummy_interface =
54 .execute_queue = bitbang_execute_queue,
57 .register_commands = dummy_register_commands,
59 .speed_div = dummy_speed_div,
65 static int dummy_read(void);
66 static void dummy_write(int tck, int tms, int tdi);
67 static void dummy_reset(int trst, int srst);
68 static void dummy_led(int on);
70 static bitbang_interface_t dummy_bitbang =
78 static int dummy_read(void)
80 int data = 1 & dummy_data;
81 dummy_data = (dummy_data >> 1) | (1<<31);
86 static void dummy_write(int tck, int tms, int tdi)
88 /* TAP standard: "state transitions occur on rising edge of clock" */
89 if( tck != dummy_clock )
93 tap_state_t old_state = dummy_state;
94 dummy_state = tap_state_transition( old_state, tms );
96 if( old_state != dummy_state )
100 LOG_DEBUG("dummy_tap: %d stable clocks", clock_count);
104 LOG_DEBUG("dummy_tap: %s", tap_state_name(dummy_state) );
107 if(dummy_state == TAP_DRCAPTURE)
108 dummy_data = 0x01255043;
113 /* this is a stable state clock edge, no change of state here,
114 * simply increment clock_count for subsequent logging
123 static void dummy_reset(int trst, int srst)
127 if (trst || (srst && (jtag_reset_config & RESET_SRST_PULLS_TRST)))
128 dummy_state = TAP_RESET;
130 LOG_DEBUG("reset to: %s", tap_state_name(dummy_state) );
133 static int dummy_khz(int khz, int *jtag_speed)
141 *jtag_speed=64000/khz;
146 static int dummy_speed_div(int speed, int *khz)
160 static int dummy_speed(int speed)
165 static int dummy_register_commands(struct command_context_s *cmd_ctx)
170 static int dummy_init(void)
172 bitbang_interface = &dummy_bitbang;
177 static int dummy_quit(void)
182 static void dummy_led(int on)