- Fixes '<<' whitespace
[openocd.git] / src / jtag / dummy.c
1 /***************************************************************************
2 * Copyright (C) 2008 by √ėyvind Harboe *
3 * oyvind.harboe@zylin.com *
4 * *
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. *
9 * *
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. *
14 * *
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 ***************************************************************************/
20 #ifdef HAVE_CONFIG_H
21 #include "config.h"
22 #endif
23
24 #include "interface.h"
25 #include "bitbang.h"
26
27
28 /* my private tap controller state, which tracks state for calling code */
29 static tap_state_t dummy_state = TAP_RESET;
30
31 static int dummy_clock; /* edge detector */
32
33 static int clock_count; /* count clocks in any stable state, only stable states */
34
35 static uint32_t dummy_data;
36
37
38 static int dummy_speed(int speed);
39 static int dummy_register_commands(struct command_context_s *cmd_ctx);
40 static int dummy_init(void);
41 static int dummy_quit(void);
42 static int dummy_khz(int khz, int *jtag_speed);
43 static int dummy_speed_div(int speed, int *khz);
44
45
46 /* The dummy driver is used to easily check the code path
47 * where the target is unresponsive.
48 */
49 jtag_interface_t dummy_interface =
50 {
51 .name = "dummy",
52
53 .execute_queue = bitbang_execute_queue,
54
55 .speed = dummy_speed,
56 .register_commands = dummy_register_commands,
57 .khz = dummy_khz,
58 .speed_div = dummy_speed_div,
59
60 .init = dummy_init,
61 .quit = dummy_quit,
62 };
63
64 static int dummy_read(void);
65 static void dummy_write(int tck, int tms, int tdi);
66 static void dummy_reset(int trst, int srst);
67 static void dummy_led(int on);
68
69 static bitbang_interface_t dummy_bitbang =
70 {
71 .read = dummy_read,
72 .write = dummy_write,
73 .reset = dummy_reset,
74 .blink = dummy_led
75 };
76
77 static int dummy_read(void)
78 {
79 int data = 1 & dummy_data;
80 dummy_data = (dummy_data >> 1) | (1 << 31);
81 return data;
82 }
83
84
85 static void dummy_write(int tck, int tms, int tdi)
86 {
87 /* TAP standard: "state transitions occur on rising edge of clock" */
88 if ( tck != dummy_clock )
89 {
90 if ( tck )
91 {
92 tap_state_t old_state = dummy_state;
93 dummy_state = tap_state_transition( old_state, tms );
94
95 if ( old_state != dummy_state )
96 {
97 if ( clock_count )
98 {
99 LOG_DEBUG("dummy_tap: %d stable clocks", clock_count);
100 clock_count = 0;
101 }
102
103 LOG_DEBUG("dummy_tap: %s", tap_state_name(dummy_state) );
104
105 #if defined(DEBUG)
106 if (dummy_state == TAP_DRCAPTURE)
107 dummy_data = 0x01255043;
108 #endif
109 }
110 else
111 {
112 /* this is a stable state clock edge, no change of state here,
113 * simply increment clock_count for subsequent logging
114 */
115 ++clock_count;
116 }
117 }
118 dummy_clock = tck;
119 }
120 }
121
122 static void dummy_reset(int trst, int srst)
123 {
124 dummy_clock = 0;
125
126 if (trst || (srst && (jtag_get_reset_config() & RESET_SRST_PULLS_TRST)))
127 dummy_state = TAP_RESET;
128
129 LOG_DEBUG("reset to: %s", tap_state_name(dummy_state) );
130 }
131
132 static int dummy_khz(int khz, int *jtag_speed)
133 {
134 if (khz==0)
135 {
136 *jtag_speed=0;
137 }
138 else
139 {
140 *jtag_speed=64000/khz;
141 }
142 return ERROR_OK;
143 }
144
145 static int dummy_speed_div(int speed, int *khz)
146 {
147 if (speed==0)
148 {
149 *khz = 0;
150 }
151 else
152 {
153 *khz=64000/speed;
154 }
155
156 return ERROR_OK;
157 }
158
159 static int dummy_speed(int speed)
160 {
161 return ERROR_OK;
162 }
163
164 static int dummy_register_commands(struct command_context_s *cmd_ctx)
165 {
166 return ERROR_OK;
167 }
168
169 static int dummy_init(void)
170 {
171 bitbang_interface = &dummy_bitbang;
172
173 return ERROR_OK;
174 }
175
176 static int dummy_quit(void)
177 {
178 return ERROR_OK;
179 }
180
181 static void dummy_led(int on)
182 {
183 }
184