mips: code clean up in mips_m4k_debug_entry() function
[fw/openocd] / src / target / mips_ejtag.c
1 /***************************************************************************
2  *   Copyright (C) 2008 by Spencer Oliver                                  *
3  *   spen@spen-soft.co.uk                                                  *
4  *                                                                         *
5  *   Copyright (C) 2008 by David T.L. Wong                                 *
6  *                                                                         *
7  *   Copyright (C) 2009 by David N. Claffey <dnclaffey@gmail.com>          *
8  *                                                                         *
9  *   This program is free software; you can redistribute it and/or modify  *
10  *   it under the terms of the GNU General Public License as published by  *
11  *   the Free Software Foundation; either version 2 of the License, or     *
12  *   (at your option) any later version.                                   *
13  *                                                                         *
14  *   This program is distributed in the hope that it will be useful,       *
15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
17  *   GNU General Public License for more details.                          *
18  *                                                                         *
19  *   You should have received a copy of the GNU General Public License     *
20  *   along with this program; if not, write to the                         *
21  *   Free Software Foundation, Inc.,                                       *
22  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
23  ***************************************************************************/
24
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28
29 #include "mips32.h"
30 #include "mips_ejtag.h"
31
32 void mips_ejtag_set_instr(struct mips_ejtag *ejtag_info, int new_instr)
33 {
34         struct jtag_tap *tap;
35
36         tap = ejtag_info->tap;
37         assert(tap != NULL);
38
39         if (buf_get_u32(tap->cur_instr, 0, tap->ir_length) != (uint32_t)new_instr) {
40                 struct scan_field field;
41                 uint8_t t[4];
42
43                 field.num_bits = tap->ir_length;
44                 field.out_value = t;
45                 buf_set_u32(t, 0, field.num_bits, new_instr);
46                 field.in_value = NULL;
47
48                 jtag_add_ir_scan(tap, &field, TAP_IDLE);
49         }
50 }
51
52 int mips_ejtag_get_idcode(struct mips_ejtag *ejtag_info, uint32_t *idcode)
53 {
54         struct scan_field field;
55         uint8_t r[4];
56
57         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_IDCODE);
58
59         field.num_bits = 32;
60         field.out_value = NULL;
61         field.in_value = r;
62
63         jtag_add_dr_scan(ejtag_info->tap, 1, &field, TAP_IDLE);
64
65         int retval;
66         retval = jtag_execute_queue();
67         if (retval != ERROR_OK) {
68                 LOG_ERROR("register read failed");
69                 return retval;
70         }
71
72         *idcode = buf_get_u32(field.in_value, 0, 32);
73
74         return ERROR_OK;
75 }
76
77 static int mips_ejtag_get_impcode(struct mips_ejtag *ejtag_info, uint32_t *impcode)
78 {
79         struct scan_field field;
80         uint8_t r[4];
81
82         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_IMPCODE);
83
84         field.num_bits = 32;
85         field.out_value = NULL;
86         field.in_value = r;
87
88         jtag_add_dr_scan(ejtag_info->tap, 1, &field, TAP_IDLE);
89
90         int retval;
91         retval = jtag_execute_queue();
92         if (retval != ERROR_OK) {
93                 LOG_ERROR("register read failed");
94                 return retval;
95         }
96
97         *impcode = buf_get_u32(field.in_value, 0, 32);
98
99         return ERROR_OK;
100 }
101
102 int mips_ejtag_drscan_32(struct mips_ejtag *ejtag_info, uint32_t *data)
103 {
104         struct jtag_tap *tap;
105         tap  = ejtag_info->tap;
106         assert(tap != NULL);
107
108         struct scan_field field;
109         uint8_t t[4], r[4];
110         int retval;
111
112         field.num_bits = 32;
113         field.out_value = t;
114         buf_set_u32(t, 0, field.num_bits, *data);
115         field.in_value = r;
116
117         jtag_add_dr_scan(tap, 1, &field, TAP_IDLE);
118
119         retval = jtag_execute_queue();
120         if (retval != ERROR_OK) {
121                 LOG_ERROR("register read failed");
122                 return retval;
123         }
124
125         *data = buf_get_u32(field.in_value, 0, 32);
126
127         keep_alive();
128
129         return ERROR_OK;
130 }
131
132 void mips_ejtag_drscan_32_out(struct mips_ejtag *ejtag_info, uint32_t data)
133 {
134         uint8_t t[4];
135         struct jtag_tap *tap;
136         tap  = ejtag_info->tap;
137         assert(tap != NULL);
138
139         struct scan_field field;
140
141         field.num_bits = 32;
142         field.out_value = t;
143         buf_set_u32(t, 0, field.num_bits, data);
144
145         field.in_value = NULL;
146
147         jtag_add_dr_scan(tap, 1, &field, TAP_IDLE);
148 }
149
150 int mips_ejtag_drscan_8(struct mips_ejtag *ejtag_info, uint32_t *data)
151 {
152         struct jtag_tap *tap;
153         tap  = ejtag_info->tap;
154         assert(tap != NULL);
155
156         struct scan_field field;
157         uint8_t t[4] = {0, 0, 0, 0}, r[4];
158         int retval;
159
160         field.num_bits = 8;
161         field.out_value = t;
162         buf_set_u32(t, 0, field.num_bits, *data);
163         field.in_value = r;
164
165         jtag_add_dr_scan(tap, 1, &field, TAP_IDLE);
166
167         retval = jtag_execute_queue();
168         if (retval != ERROR_OK) {
169                 LOG_ERROR("register read failed");
170                 return retval;
171         }
172
173         *data = buf_get_u32(field.in_value, 0, 32);
174
175         return ERROR_OK;
176 }
177
178 void mips_ejtag_drscan_8_out(struct mips_ejtag *ejtag_info, uint8_t data)
179 {
180         struct jtag_tap *tap;
181         tap  = ejtag_info->tap;
182         assert(tap != NULL);
183
184         struct scan_field field;
185
186         field.num_bits = 8;
187         field.out_value = &data;
188         field.in_value = NULL;
189
190         jtag_add_dr_scan(tap, 1, &field, TAP_IDLE);
191 }
192
193 /* Set (to enable) or clear (to disable stepping) the SSt bit (bit 8) in Cp0 Debug reg (reg 23, sel 0) */
194 int mips_ejtag_config_step(struct mips_ejtag *ejtag_info, int enable_step)
195 {
196         int code_len = enable_step ? 6 : 7;
197
198         uint32_t *code = malloc(code_len * sizeof(uint32_t));
199         if (code == NULL) {
200                 LOG_ERROR("Out of memory");
201                 return ERROR_FAIL;
202         }
203         uint32_t *code_p = code;
204
205         *code_p++ = MIPS32_MTC0(1, 31, 0);                      /* move $1 to COP0 DeSave */
206         *code_p++ = MIPS32_MFC0(1, 23, 0),                      /* move COP0 Debug to $1 */
207         *code_p++ = MIPS32_ORI(1, 1, 0x0100);                   /* set SSt bit in debug reg */
208         if (!enable_step)
209                 *code_p++ = MIPS32_XORI(1, 1, 0x0100);          /* clear SSt bit in debug reg */
210
211         *code_p++ = MIPS32_MTC0(1, 23, 0);                      /* move $1 to COP0 Debug */
212         *code_p++ = MIPS32_B(NEG16((code_len - 1)));            /* jump to start */
213         *code_p = MIPS32_MFC0(1, 31, 0);                        /* move COP0 DeSave to $1 */
214
215         int retval = mips32_pracc_exec(ejtag_info, code_len, code, 0, NULL, 0, NULL, 1);
216
217         free(code);
218         return retval;
219 }
220
221 int mips_ejtag_enter_debug(struct mips_ejtag *ejtag_info)
222 {
223         uint32_t ejtag_ctrl;
224         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL);
225
226         /* set debug break bit */
227         ejtag_ctrl = ejtag_info->ejtag_ctrl | EJTAG_CTRL_JTAGBRK;
228         mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
229
230         /* break bit will be cleared by hardware */
231         ejtag_ctrl = ejtag_info->ejtag_ctrl;
232         mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
233         LOG_DEBUG("ejtag_ctrl: 0x%8.8" PRIx32 "", ejtag_ctrl);
234         if ((ejtag_ctrl & EJTAG_CTRL_BRKST) == 0) {
235                 LOG_ERROR("Failed to enter Debug Mode!");
236                 return ERROR_FAIL;
237         }
238
239         return ERROR_OK;
240 }
241
242 int mips_ejtag_exit_debug(struct mips_ejtag *ejtag_info)
243 {
244         uint32_t inst;
245         inst = MIPS32_DRET;
246
247         /* execute our dret instruction */
248         return mips32_pracc_exec(ejtag_info, 1, &inst, 0, NULL, 0, NULL, 0);
249 }
250
251 int mips_ejtag_init(struct mips_ejtag *ejtag_info)
252 {
253         uint32_t ejtag_version;
254         int retval;
255
256         retval = mips_ejtag_get_impcode(ejtag_info, &ejtag_info->impcode);
257         if (retval != ERROR_OK)
258                 return retval;
259         LOG_DEBUG("impcode: 0x%8.8" PRIx32 "", ejtag_info->impcode);
260
261         /* get ejtag version */
262         ejtag_version = ((ejtag_info->impcode >> 29) & 0x07);
263
264         switch (ejtag_version) {
265                 case 0:
266                         LOG_DEBUG("EJTAG: Version 1 or 2.0 Detected");
267                         break;
268                 case 1:
269                         LOG_DEBUG("EJTAG: Version 2.5 Detected");
270                         break;
271                 case 2:
272                         LOG_DEBUG("EJTAG: Version 2.6 Detected");
273                         break;
274                 case 3:
275                         LOG_DEBUG("EJTAG: Version 3.1 Detected");
276                         break;
277                 default:
278                         LOG_DEBUG("EJTAG: Unknown Version Detected");
279                         break;
280         }
281         LOG_DEBUG("EJTAG: features:%s%s%s%s%s%s%s",
282                 ejtag_info->impcode & EJTAG_IMP_R3K ? " R3k" : " R4k",
283                 ejtag_info->impcode & EJTAG_IMP_DINT ? " DINT" : "",
284                 ejtag_info->impcode & (1 << 22) ? " ASID_8" : "",
285                 ejtag_info->impcode & (1 << 21) ? " ASID_6" : "",
286                 ejtag_info->impcode & EJTAG_IMP_MIPS16 ? " MIPS16" : "",
287                 ejtag_info->impcode & EJTAG_IMP_NODMA ? " noDMA" : " DMA",
288                 ejtag_info->impcode & EJTAG_DCR_MIPS64  ? " MIPS64" : " MIPS32");
289
290         if ((ejtag_info->impcode & EJTAG_IMP_NODMA) == 0)
291                 LOG_DEBUG("EJTAG: DMA Access Mode Support Enabled");
292
293         /* set initial state for ejtag control reg */
294         ejtag_info->ejtag_ctrl = EJTAG_CTRL_ROCC | EJTAG_CTRL_PRACC | EJTAG_CTRL_PROBEN | EJTAG_CTRL_SETDEV;
295         ejtag_info->fast_access_save = -1;
296
297         return ERROR_OK;
298 }
299
300 int mips_ejtag_fastdata_scan(struct mips_ejtag *ejtag_info, int write_t, uint32_t *data)
301 {
302         struct jtag_tap *tap;
303
304         tap = ejtag_info->tap;
305         assert(tap != NULL);
306
307         struct scan_field fields[2];
308         uint8_t spracc = 0;
309         uint8_t t[4] = {0, 0, 0, 0};
310
311         /* fastdata 1-bit register */
312         fields[0].num_bits = 1;
313         fields[0].out_value = &spracc;
314         fields[0].in_value = NULL;
315
316         /* processor access data register 32 bit */
317         fields[1].num_bits = 32;
318         fields[1].out_value = t;
319
320         if (write_t) {
321                 fields[1].in_value = NULL;
322                 buf_set_u32(t, 0, 32, *data);
323         } else
324                 fields[1].in_value = (void *) data;
325
326         jtag_add_dr_scan(tap, 2, fields, TAP_IDLE);
327
328         if (!write_t && data)
329                 jtag_add_callback(mips_le_to_h_u32,
330                         (jtag_callback_data_t) data);
331
332         keep_alive();
333
334         return ERROR_OK;
335 }