Audit and eliminate redundant #include directives from src/jtag.
[openocd.git] / src / jtag / bitbang.c
1 /***************************************************************************
2 * Copyright (C) 2005 by Dominic Rath *
3 * Dominic.Rath@gmx.de *
4 * *
5 * Copyright (C) 2007,2008 Øyvind Harboe *
6 * oyvind.harboe@zylin.com *
7 * *
8 * This program is free software; you can redistribute it and/or modify *
9 * it under the terms of the GNU General Public License as published by *
10 * the Free Software Foundation; either version 2 of the License, or *
11 * (at your option) any later version. *
12 * *
13 * This program is distributed in the hope that it will be useful, *
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16 * GNU General Public License for more details. *
17 * *
18 * You should have received a copy of the GNU General Public License *
19 * along with this program; if not, write to the *
20 * Free Software Foundation, Inc., *
21 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
22 ***************************************************************************/
23 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
26
27 #include "bitbang.h"
28 #include "jtag.h"
29
30 /**
31 * Function bitbang_stableclocks
32 * issues a number of clock cycles while staying in a stable state.
33 * Because the TMS value required to stay in the RESET state is a 1, whereas
34 * the TMS value required to stay in any of the other stable states is a 0,
35 * this function checks the current stable state to decide on the value of TMS
36 * to use.
37 */
38 static void bitbang_stableclocks(int num_cycles);
39
40
41 bitbang_interface_t *bitbang_interface;
42
43 /* DANGER!!!! clock absolutely *MUST* be 0 in idle or reset won't work!
44 *
45 * Set this to 1 and str912 reset halt will fail.
46 *
47 * If someone can submit a patch with an explanation it will be greatly
48 * appreciated, but as far as I can tell (ØH) DCLK is generated upon
49 * clk=0 in TAP_IDLE. Good luck deducing that from the ARM documentation!
50 * The ARM documentation uses the term "DCLK is asserted while in the TAP_IDLE
51 * state". With hardware there is no such thing as *while* in a state. There
52 * are only edges. So clk => 0 is in fact a very subtle state transition that
53 * happens *while* in the TAP_IDLE state. "#&¤"#¤&"#&"#&
54 *
55 * For "reset halt" the last thing that happens before srst is asserted
56 * is that the breakpoint is set up. If DCLK is not wiggled one last
57 * time before the reset, then the breakpoint is not set up and
58 * "reset halt" will fail to halt.
59 *
60 */
61 #define CLOCK_IDLE() 0
62
63
64 /* The bitbang driver leaves the TCK 0 when in idle */
65 static void bitbang_end_state(tap_state_t state)
66 {
67 if (tap_is_state_stable(state))
68 tap_set_end_state(state);
69 else
70 {
71 LOG_ERROR("BUG: %i is not a valid end state", state);
72 exit(-1);
73 }
74 }
75
76 static void bitbang_state_move(int skip)
77 {
78 int i=0, tms=0;
79 u8 tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
80
81 for (i = skip; i < 7; i++)
82 {
83 tms = (tms_scan >> i) & 1;
84 bitbang_interface->write(0, tms, 0);
85 bitbang_interface->write(1, tms, 0);
86 }
87 bitbang_interface->write(CLOCK_IDLE(), tms, 0);
88
89 tap_set_state(tap_get_end_state());
90 }
91
92 static void bitbang_path_move(pathmove_command_t *cmd)
93 {
94 int num_states = cmd->num_states;
95 int state_count;
96 int tms = 0;
97
98 state_count = 0;
99 while (num_states)
100 {
101 if (tap_state_transition(tap_get_state(), false) == cmd->path[state_count])
102 {
103 tms = 0;
104 }
105 else if (tap_state_transition(tap_get_state(), true) == cmd->path[state_count])
106 {
107 tms = 1;
108 }
109 else
110 {
111 LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(cmd->path[state_count]));
112 exit(-1);
113 }
114
115 bitbang_interface->write(0, tms, 0);
116 bitbang_interface->write(1, tms, 0);
117
118 tap_set_state(cmd->path[state_count]);
119 state_count++;
120 num_states--;
121 }
122
123 bitbang_interface->write(CLOCK_IDLE(), tms, 0);
124
125 tap_set_end_state(tap_get_state());
126 }
127
128 static void bitbang_runtest(int num_cycles)
129 {
130 int i;
131
132 tap_state_t saved_end_state = tap_get_end_state();
133
134 /* only do a state_move when we're not already in IDLE */
135 if (tap_get_state() != TAP_IDLE)
136 {
137 bitbang_end_state(TAP_IDLE);
138 bitbang_state_move(0);
139 }
140
141 /* execute num_cycles */
142 for (i = 0; i < num_cycles; i++)
143 {
144 bitbang_interface->write(0, 0, 0);
145 bitbang_interface->write(1, 0, 0);
146 }
147 bitbang_interface->write(CLOCK_IDLE(), 0, 0);
148
149 /* finish in end_state */
150 bitbang_end_state(saved_end_state);
151 if (tap_get_state() != tap_get_end_state())
152 bitbang_state_move(0);
153 }
154
155
156 static void bitbang_stableclocks(int num_cycles)
157 {
158 int tms = (tap_get_state() == TAP_RESET ? 1 : 0);
159 int i;
160
161 /* send num_cycles clocks onto the cable */
162 for (i = 0; i < num_cycles; i++)
163 {
164 bitbang_interface->write(1, tms, 0);
165 bitbang_interface->write(0, tms, 0);
166 }
167 }
168
169
170
171 static void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size)
172 {
173 tap_state_t saved_end_state = tap_get_end_state();
174 int bit_cnt;
175
176 if (!((!ir_scan && (tap_get_state() == TAP_DRSHIFT)) || (ir_scan && (tap_get_state() == TAP_IRSHIFT))))
177 {
178 if (ir_scan)
179 bitbang_end_state(TAP_IRSHIFT);
180 else
181 bitbang_end_state(TAP_DRSHIFT);
182
183 bitbang_state_move(0);
184 bitbang_end_state(saved_end_state);
185 }
186
187 for (bit_cnt = 0; bit_cnt < scan_size; bit_cnt++)
188 {
189 int val=0;
190 int tms=(bit_cnt==scan_size-1) ? 1 : 0;
191 int tdi;
192 int bytec=bit_cnt/8;
193 int bcval=1<<(bit_cnt % 8);
194
195 /* if we're just reading the scan, but don't care about the output
196 * default to outputting 'low', this also makes valgrind traces more readable,
197 * as it removes the dependency on an uninitialised value
198 */
199 tdi=0;
200 if ((type != SCAN_IN) && (buffer[bytec] & bcval))
201 tdi=1;
202
203 bitbang_interface->write(0, tms, tdi);
204
205 if (type!=SCAN_OUT)
206 val=bitbang_interface->read();
207
208 bitbang_interface->write(1, tms, tdi);
209
210 if (type != SCAN_OUT)
211 {
212 if (val)
213 buffer[bytec] |= bcval;
214 else
215 buffer[bytec] &= ~bcval;
216 }
217 }
218
219 if (tap_get_state() != tap_get_end_state())
220 {
221 /* we *KNOW* the above loop transitioned out of
222 * the shift state, so we skip the first state
223 * and move directly to the end state.
224 */
225 bitbang_state_move(1);
226 }
227 }
228
229 int bitbang_execute_queue(void)
230 {
231 jtag_command_t *cmd = jtag_command_queue; /* currently processed command */
232 int scan_size;
233 enum scan_type type;
234 u8 *buffer;
235 int retval;
236
237 if (!bitbang_interface)
238 {
239 LOG_ERROR("BUG: Bitbang interface called, but not yet initialized");
240 exit(-1);
241 }
242
243 /* return ERROR_OK, unless a jtag_read_buffer returns a failed check
244 * that wasn't handled by a caller-provided error handler
245 */
246 retval = ERROR_OK;
247
248 if(bitbang_interface->blink)
249 bitbang_interface->blink(1);
250
251 while (cmd)
252 {
253 switch (cmd->type)
254 {
255 case JTAG_END_STATE:
256 #ifdef _DEBUG_JTAG_IO_
257 LOG_DEBUG("end_state: %s", tap_state_name(cmd->cmd.end_state->end_state) );
258 #endif
259 if (cmd->cmd.end_state->end_state != TAP_INVALID)
260 bitbang_end_state(cmd->cmd.end_state->end_state);
261 break;
262 case JTAG_RESET:
263 #ifdef _DEBUG_JTAG_IO_
264 LOG_DEBUG("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst);
265 #endif
266 if ((cmd->cmd.reset->trst == 1) || (cmd->cmd.reset->srst && (jtag_reset_config & RESET_SRST_PULLS_TRST)))
267 {
268 tap_set_state(TAP_RESET);
269 }
270 bitbang_interface->reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
271 break;
272 case JTAG_RUNTEST:
273 #ifdef _DEBUG_JTAG_IO_
274 LOG_DEBUG("runtest %i cycles, end in %s", cmd->cmd.runtest->num_cycles, tap_state_name(cmd->cmd.runtest->end_state) );
275 #endif
276 if (cmd->cmd.runtest->end_state != TAP_INVALID)
277 bitbang_end_state(cmd->cmd.runtest->end_state);
278 bitbang_runtest(cmd->cmd.runtest->num_cycles);
279 break;
280
281 case JTAG_STABLECLOCKS:
282 /* this is only allowed while in a stable state. A check for a stable
283 * state was done in jtag_add_clocks()
284 */
285 bitbang_stableclocks(cmd->cmd.stableclocks->num_cycles);
286 break;
287
288 case JTAG_STATEMOVE:
289 #ifdef _DEBUG_JTAG_IO_
290 LOG_DEBUG("statemove end in %s", tap_state_name(cmd->cmd.statemove->end_state));
291 #endif
292 if (cmd->cmd.statemove->end_state != TAP_INVALID)
293 bitbang_end_state(cmd->cmd.statemove->end_state);
294 bitbang_state_move(0);
295 break;
296 case JTAG_PATHMOVE:
297 #ifdef _DEBUG_JTAG_IO_
298 LOG_DEBUG("pathmove: %i states, end in %s", cmd->cmd.pathmove->num_states,
299 tap_state_name(cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]));
300 #endif
301 bitbang_path_move(cmd->cmd.pathmove);
302 break;
303 case JTAG_SCAN:
304 #ifdef _DEBUG_JTAG_IO_
305 LOG_DEBUG("%s scan end in %s", (cmd->cmd.scan->ir_scan) ? "IR" : "DR", tap_state_name(cmd->cmd.scan->end_state) );
306 #endif
307 if (cmd->cmd.scan->end_state != TAP_INVALID)
308 bitbang_end_state(cmd->cmd.scan->end_state);
309 scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
310 type = jtag_scan_type(cmd->cmd.scan);
311 bitbang_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size);
312 if (jtag_read_buffer(buffer, cmd->cmd.scan) != ERROR_OK)
313 retval = ERROR_JTAG_QUEUE_FAILED;
314 if (buffer)
315 free(buffer);
316 break;
317 case JTAG_SLEEP:
318 #ifdef _DEBUG_JTAG_IO_
319 LOG_DEBUG("sleep %i", cmd->cmd.sleep->us);
320 #endif
321 jtag_sleep(cmd->cmd.sleep->us);
322 break;
323 default:
324 LOG_ERROR("BUG: unknown JTAG command type encountered");
325 exit(-1);
326 }
327 cmd = cmd->next;
328 }
329 if(bitbang_interface->blink)
330 bitbang_interface->blink(0);
331
332 return retval;
333 }