src/target/firmware/layer1/l23_api.c

   1 /* Synchronous part of GSM Layer 1: API to Layer2+ */
   2
   3 /* (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
   4  *
   5  * All Rights Reserved
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  */
  22
  23 #define DEBUG
  24
  25 #include <stdint.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28
  29 #include <debug.h>
  30 #include <byteorder.h>
  31
  32 #include <osmocore/msgb.h>
  33 #include <comm/sercomm.h>
  34
  35 #include <layer1/sync.h>
  36 #include <layer1/async.h>
  37 #include <layer1/mframe_sched.h>
  38 #include <layer1/tpu_window.h>
  39
  40 #include <rf/trf6151.h>
  41
  42 #include <l1ctl_proto.h>
  43
  44 /* the size we will allocate struct msgb* for HDLC */
  45 #define L3_MSG_HEAD 4
  46 #define L3_MSG_SIZE (sizeof(struct l1ctl_hdr)+sizeof(struct l1ctl_info_dl)+sizeof(struct l1ctl_data_ind) + L3_MSG_HEAD)
  47
  48 void l1_queue_for_l2(struct msgb *msg)
  49 {
  50         /* forward via serial for now */
  51         sercomm_sendmsg(SC_DLCI_L1A_L23, msg);
  52 }
  53
  54 static enum mframe_task chan_nr2mf_task(uint8_t chan_nr)
  55 {
  56         uint8_t cbits = chan_nr >> 3;
  57         uint8_t lch_idx;
  58
  59         if (cbits == 0x01) {
  60                 lch_idx = 0;
  61                 /* FIXME: TCH/F */
  62         } else if ((cbits & 0x1e) == 0x02) {
  63                 lch_idx = cbits & 0x1;
  64                 /* FIXME: TCH/H */
  65         } else if ((cbits & 0x1c) == 0x04) {
  66                 lch_idx = cbits & 0x3;
  67                 return MF_TASK_SDCCH4_0 + lch_idx;
  68         } else if ((cbits & 0x18) == 0x08) {
  69                 lch_idx = cbits & 0x7;
  70                 return MF_TASK_SDCCH8_0 + lch_idx;
  71 #if 0
  72         } else if (cbits == 0x10) {
  73                 /* FIXME: when to do extended BCCH? */
  74                 return MF_TASK_BCCH_NORM;
  75         } else if (cbits == 0x11 || cbits == 0x12) {
  76                 /* FIXME: how to decide CCCH norm/extd? */
  77                 return MF_TASK_BCCH_CCCH;
  78 #endif
  79         }
  80         return 0;
  81 }
  82
  83 static int  chan_nr2dchan_type(uint8_t chan_nr)
  84 {
  85         uint8_t cbits = chan_nr >> 3;
  86
  87         if (cbits == 0x01) {
  88                 return GSM_DCHAN_TCH_F;
  89         } else if ((cbits & 0x1e) == 0x02) {
  90                 return GSM_DCHAN_TCH_H;
  91         } else if ((cbits & 0x1c) == 0x04) {
  92                 return GSM_DCHAN_SDCCH_4;
  93         } else if ((cbits & 0x18) == 0x08) {
  94                 return GSM_DCHAN_SDCCH_8;
  95         }
  96         return GSM_DCHAN_UNKNOWN;
  97 }
  98
  99 struct msgb *l1ctl_msgb_alloc(uint8_t msg_type)
 100 {
 101         struct msgb *msg;
 102         struct l1ctl_hdr *l1h;
 103
 104         msg = msgb_alloc_headroom(L3_MSG_SIZE, L3_MSG_HEAD, "l1ctl");
 105         if (!msg) {
 106                 while (1) {
 107                         puts("OOPS. Out of buffers...\n");
 108                 }
 109
 110                 return NULL;
 111         }
 112         l1h = (struct l1ctl_hdr *) msgb_put(msg, sizeof(*l1h));
 113         l1h->msg_type = msg_type;
 114         l1h->flags = 0;
 115
 116         msg->l1h = (uint8_t *)l1h;
 117
 118         return msg;
 119 }
 120
 121 struct msgb *l1_create_l2_msg(int msg_type, uint32_t fn, uint16_t snr,
 122                               uint16_t arfcn)
 123 {
 124         struct l1ctl_info_dl *dl;
 125         struct msgb *msg = l1ctl_msgb_alloc(msg_type);
 126
 127         dl = (struct l1ctl_info_dl *) msgb_put(msg, sizeof(*dl));
 128         dl->frame_nr = htonl(fn);
 129         dl->snr = snr;
 130         dl->band_arfcn = htons(arfcn);
 131
 132         return msg;
 133 }
 134
 135 /* receive a L1CTL_FBSB_REQ from L23 */
 136 static void l1ctl_rx_fbsb_req(struct msgb *msg)
 137 {
 138         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 139         struct l1ctl_fbsb_req *sync_req = (struct l1ctl_fbsb_req *) l1h->data;
 140
 141         if (sizeof(*sync_req) > msg->len) {
 142                 printf("Short sync msg. %u\n", msg->len);
 143                 return;
 144         }
 145
 146         printd("L1CTL_FBSB_REQ (arfcn=%u, flags=0x%x)\n",
 147                 ntohs(sync_req->band_arfcn), sync_req->flags);
 148
 149         /* reset scheduler and hardware */
 150         l1s_reset();
 151
 152         /* pre-set the CCCH mode */
 153         l1s.serving_cell.ccch_mode = sync_req->ccch_mode;
 154
 155         printd("Starting FCCH Recognition\n");
 156         l1s_fbsb_req(1, sync_req);
 157 }
 158
 159 /* receive a L1CTL_DM_EST_REQ from L23 */
 160 static void l1ctl_rx_dm_est_req(struct msgb *msg)
 161 {
 162         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 163         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 164         struct l1ctl_dm_est_req *est_req = (struct l1ctl_dm_est_req *) ul->payload;
 165
 166         printd("L1CTL_DM_EST_REQ (arfcn=%u, chan_nr=0x%02x, tsc=%u)\n",
 167                 ntohs(est_req->h0.band_arfcn), ul->chan_nr, est_req->tsc);
 168
 169         /* Current limitations */
 170         if ((ul->chan_nr & 0x7) > 4) {
 171                 /* FIXME: Timeslot */
 172                 puts("We don't support TS > 4 yet\n");
 173                 return;
 174         }
 175
 176         /* configure dedicated channel state */
 177         l1s.dedicated.type = chan_nr2dchan_type(ul->chan_nr);
 178         l1s.dedicated.tsc  = est_req->tsc;
 179         l1s.dedicated.tn   = ul->chan_nr & 0x7;
 180         l1s.dedicated.h    = est_req->h;
 181
 182         if (est_req->h) {
 183                 int i;
 184                 l1s.dedicated.h1.hsn  = est_req->h1.hsn;
 185                 l1s.dedicated.h1.maio = est_req->h1.maio;
 186                 l1s.dedicated.h1.n    = est_req->h1.n;
 187                 for (i=0; i<est_req->h1.n; i++)
 188                         l1s.dedicated.h1.ma[i] = ntohs(est_req->h1.ma[i]);
 189         } else {
 190                 l1s.dedicated.h0.arfcn = ntohs(est_req->h0.band_arfcn);
 191         }
 192
 193         /* figure out which MF tasks to enable */
 194         l1a_mftask_set(1 << chan_nr2mf_task(ul->chan_nr));
 195 }
 196
 197 /* receive a L1CTL_DM_FREQ_REQ from L23 */
 198 static void l1ctl_rx_dm_freq_req(struct msgb *msg)
 199 {
 200         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 201         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 202         struct l1ctl_dm_freq_req *freq_req =
 203                         (struct l1ctl_dm_freq_req *) ul->payload;
 204
 205         printd("L1CTL_DM_FREQ_REQ (arfcn=%u, tsc=%u)\n",
 206                 ntohs(freq_req->h0.band_arfcn), freq_req->tsc);
 207
 208         /* configure dedicated channel state */
 209         l1s.dedicated.st_tsc  = freq_req->tsc;
 210         l1s.dedicated.st_h    = freq_req->h;
 211
 212         if (freq_req->h) {
 213                 int i;
 214                 l1s.dedicated.st_h1.hsn  = freq_req->h1.hsn;
 215                 l1s.dedicated.st_h1.maio = freq_req->h1.maio;
 216                 l1s.dedicated.st_h1.n    = freq_req->h1.n;
 217                 for (i=0; i<freq_req->h1.n; i++)
 218                         l1s.dedicated.st_h1.ma[i] = ntohs(freq_req->h1.ma[i]);
 219         } else {
 220                 l1s.dedicated.st_h0.arfcn = ntohs(freq_req->h0.band_arfcn);
 221         }
 222
 223         l1a_freq_req(ntohs(freq_req->fn));
 224 }
 225
 226 /* receive a L1CTL_CRYPTO_REQ from L23 */
 227 static void l1ctl_rx_crypto_req(struct msgb *msg)
 228 {
 229         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 230         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 231         struct l1ctl_crypto_req *cr = (struct l1ctl_crypto_req *) ul->payload;
 232         uint8_t key_len = msg->len - sizeof(*l1h) - sizeof(*ul) - sizeof(*cr);
 233
 234         printd("L1CTL_CRYPTO_REQ (algo=A5/%u, len=%u)\n", cr->algo, key_len);
 235
 236         // for dieter: (cr->alog, cr->key, key_len);
 237
 238 }
 239
 240 /* receive a L1CTL_DM_REL_REQ from L23 */
 241 static void l1ctl_rx_dm_rel_req(struct msgb *msg)
 242 {
 243         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 244         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 245
 246         printd("L1CTL_DM_REL_REQ\n");
 247         l1a_mftask_set(0);
 248         l1s.dedicated.type = GSM_DCHAN_NONE;
 249         l1a_txq_msgb_flush(&l1s.tx_queue[L1S_CHAN_MAIN]);
 250         l1a_txq_msgb_flush(&l1s.tx_queue[L1S_CHAN_SACCH]);
 251 }
 252
 253 /* receive a L1CTL_RACH_REQ from L23 */
 254 static void l1ctl_rx_param_req(struct msgb *msg)
 255 {
 256         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 257         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 258         struct l1ctl_par_req *par_req = (struct l1ctl_par_req *) ul->payload;
 259
 260         printd("L1CTL_PARAM_REQ (ta=%d, tx_power=%d)\n", par_req->ta,
 261                 par_req->tx_power);
 262
 263         l1s.ta = par_req->ta;
 264         // FIXME: set power
 265 }
 266
 267 /* receive a L1CTL_RACH_REQ from L23 */
 268 static void l1ctl_rx_rach_req(struct msgb *msg)
 269 {
 270         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 271         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 272         struct l1ctl_rach_req *rach_req = (struct l1ctl_rach_req *) ul->payload;
 273
 274         printd("L1CTL_RACH_REQ (ra=0x%02x, fn51=%d, mf_off=%d)\n", rach_req->ra, rach_req->fn51, rach_req->mf_off);
 275
 276         l1a_rach_req(rach_req->fn51, rach_req->mf_off, rach_req->ra);
 277 }
 278
 279 /* receive a L1CTL_DATA_REQ from L23 */
 280 static void l1ctl_rx_data_req(struct msgb *msg)
 281 {
 282         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 283         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 284         struct l1ctl_data_ind *data_ind = (struct l1ctl_data_ind *) ul->payload;
 285         struct llist_head *tx_queue;
 286
 287         printd("L1CTL_DATA_REQ (link_id=0x%02x)\n", ul->link_id);
 288
 289         msg->l3h = data_ind->data;
 290         tx_queue = (ul->link_id & 0x40) ?
 291                         &l1s.tx_queue[L1S_CHAN_SACCH] :
 292                         &l1s.tx_queue[L1S_CHAN_MAIN];
 293
 294         printd("ul=%p, ul->payload=%p, data_ind=%p, data_ind->data=%p l3h=%p\n",
 295                 ul, ul->payload, data_ind, data_ind->data, msg->l3h);
 296
 297         l1a_txq_msgb_enq(tx_queue, msg);
 298 }
 299
 300 /* receive a L1CTL_PM_REQ from L23 */
 301 static void l1ctl_rx_pm_req(struct msgb *msg)
 302 {
 303         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 304         struct l1ctl_pm_req *pm_req = (struct l1ctl_pm_req *) l1h->data;
 305
 306         switch (pm_req->type) {
 307         case 1:
 308                 l1s.pm.mode = 1;
 309                 l1s.pm.range.arfcn_start =
 310                                 ntohs(pm_req->range.band_arfcn_from);
 311                 l1s.pm.range.arfcn_next =
 312                                 ntohs(pm_req->range.band_arfcn_from);
 313                 l1s.pm.range.arfcn_end =
 314                                 ntohs(pm_req->range.band_arfcn_to);
 315                 printf("L1CTL_PM_REQ start=%u end=%u\n",
 316                         l1s.pm.range.arfcn_start, l1s.pm.range.arfcn_end);
 317                 break;
 318         }
 319
 320         l1s_pm_test(1, l1s.pm.range.arfcn_next);
 321 }
 322
 323 /* Transmit a L1CTL_RESET_IND or L1CTL_RESET_CONF */
 324 void l1ctl_tx_reset(uint8_t msg_type, uint8_t reset_type)
 325 {
 326         struct msgb *msg = l1ctl_msgb_alloc(msg_type);
 327         struct l1ctl_reset *reset_resp;
 328         reset_resp = (struct l1ctl_reset *)
 329                                 msgb_put(msg, sizeof(*reset_resp));
 330         reset_resp->type = reset_type;
 331
 332         l1_queue_for_l2(msg);
 333 }
 334
 335 /* receive a L1CTL_RESET_REQ from L23 */
 336 static void l1ctl_rx_reset_req(struct msgb *msg)
 337 {
 338         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 339         struct l1ctl_reset *reset_req =
 340                                 (struct l1ctl_reset *) l1h->data;
 341
 342         switch (reset_req->type) {
 343         case L1CTL_RES_T_FULL:
 344                 printf("L1CTL_RESET_REQ: FULL!\n");
 345                 l1s_reset();
 346                 l1s_reset_hw();
 347                 l1ctl_tx_reset(L1CTL_RESET_CONF, reset_req->type);
 348                 break;
 349         case L1CTL_RES_T_SCHED:
 350                 printf("L1CTL_RESET_REQ: SCHED!\n");
 351                 l1ctl_tx_reset(L1CTL_RESET_CONF, reset_req->type);
 352                 sched_gsmtime_reset();
 353                 break;
 354         default:
 355                 printf("unknown L1CTL_RESET_REQ type\n");
 356                 break;
 357         }
 358 }
 359
 360 /* Transmit a L1CTL_CCCH_MODE_CONF */
 361 static void l1ctl_tx_ccch_mode_conf(uint8_t ccch_mode)
 362 {
 363         struct msgb *msg = l1ctl_msgb_alloc(L1CTL_CCCH_MODE_CONF);
 364         struct l1ctl_ccch_mode_conf *mode_conf;
 365         mode_conf = (struct l1ctl_ccch_mode_conf *)
 366                                 msgb_put(msg, sizeof(*mode_conf));
 367         mode_conf->ccch_mode = ccch_mode;
 368
 369         l1_queue_for_l2(msg);
 370 }
 371
 372 /* receive a L1CTL_CCCH_MODE_REQ from L23 */
 373 static void l1ctl_rx_ccch_mode_req(struct msgb *msg)
 374 {
 375         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 376         struct l1ctl_ccch_mode_req *ccch_mode_req =
 377                 (struct l1ctl_ccch_mode_req *) l1h->data;
 378         uint8_t ccch_mode = ccch_mode_req->ccch_mode;
 379
 380         /* pre-set the CCCH mode */
 381         l1s.serving_cell.ccch_mode = ccch_mode;
 382
 383         /* Update task */
 384         mframe_disable(MF_TASK_CCCH_COMB);
 385         mframe_disable(MF_TASK_CCCH);
 386
 387         if (ccch_mode == CCCH_MODE_COMBINED)
 388                 mframe_enable(MF_TASK_CCCH_COMB);
 389         else if (ccch_mode == CCCH_MODE_NON_COMBINED)
 390                 mframe_enable(MF_TASK_CCCH);
 391
 392         l1ctl_tx_ccch_mode_conf(ccch_mode);
 393 }
 394
 395 /* callback from SERCOMM when L2 sends a message to L1 */
 396 static void l1a_l23_rx_cb(uint8_t dlci, struct msgb *msg)
 397 {
 398         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 399
 400 #if 0
 401         {
 402                 int i;
 403                 printf("l1a_l23_rx_cb (%u): ", msg->len);
 404                 for (i = 0; i < msg->len; i++)
 405                         printf("%02x ", msg->data[i]);
 406                 puts("\n");
 407         }
 408 #endif
 409
 410         msg->l1h = msg->data;
 411
 412         if (sizeof(*l1h) > msg->len) {
 413                 printf("l1a_l23_cb: Short message. %u\n", msg->len);
 414                 goto exit_msgbfree;
 415         }
 416
 417         switch (l1h->msg_type) {
 418         case L1CTL_FBSB_REQ:
 419                 l1ctl_rx_fbsb_req(msg);
 420                 break;
 421         case L1CTL_DM_EST_REQ:
 422                 l1ctl_rx_dm_est_req(msg);
 423                 break;
 424         case L1CTL_DM_REL_REQ:
 425                 l1ctl_rx_dm_rel_req(msg);
 426                 break;
 427         case L1CTL_PARAM_REQ:
 428                 l1ctl_rx_param_req(msg);
 429                 break;
 430         case L1CTL_DM_FREQ_REQ:
 431                 l1ctl_rx_dm_freq_req(msg);
 432                 break;
 433         case L1CTL_CRYPTO_REQ:
 434                 l1ctl_rx_crypto_req(msg);
 435                 break;
 436         case L1CTL_RACH_REQ:
 437                 l1ctl_rx_rach_req(msg);
 438                 break;
 439         case L1CTL_DATA_REQ:
 440                 l1ctl_rx_data_req(msg);
 441                 /* we have to keep the msgb, not free it! */
 442                 goto exit_nofree;
 443         case L1CTL_PM_REQ:
 444                 l1ctl_rx_pm_req(msg);
 445                 break;
 446         case L1CTL_RESET_REQ:
 447                 l1ctl_rx_reset_req(msg);
 448                 break;
 449         case L1CTL_CCCH_MODE_REQ:
 450                 l1ctl_rx_ccch_mode_req(msg);
 451                 break;
 452         }
 453
 454 exit_msgbfree:
 455         msgb_free(msg);
 456 exit_nofree:
 457         return;
 458 }
 459
 460 void l1a_l23api_init(void)
 461 {
 462         sercomm_register_rx_cb(SC_DLCI_L1A_L23, l1a_l23_rx_cb);
 463 }