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 <osmocore/protocol/gsm_04_08.h>
  34 #include <comm/sercomm.h>
  35
  36 #include <layer1/sync.h>
  37 #include <layer1/async.h>
  38 #include <layer1/mframe_sched.h>
  39 #include <layer1/prim.h>
  40 #include <layer1/tpu_window.h>
  41
  42 #include <rf/trf6151.h>
  43
  44 #include <l1ctl_proto.h>
  45
  46 /* the size we will allocate struct msgb* for HDLC */
  47 #define L3_MSG_HEAD 4
  48 #define L3_MSG_SIZE (sizeof(struct l1ctl_hdr)+sizeof(struct l1ctl_info_dl)+sizeof(struct l1ctl_data_ind) + L3_MSG_HEAD)
  49
  50 void l1_queue_for_l2(struct msgb *msg)
  51 {
  52         /* forward via serial for now */
  53         sercomm_sendmsg(SC_DLCI_L1A_L23, msg);
  54 }
  55
  56 static enum mframe_task chan_nr2mf_task(uint8_t chan_nr)
  57 {
  58         uint8_t cbits = chan_nr >> 3;
  59         uint8_t tn = chan_nr & 0x7;
  60         uint8_t lch_idx;
  61
  62         if (cbits == 0x01) {
  63                 lch_idx = 0;
  64                 return (tn & 1) ? MF_TASK_TCH_F_ODD : MF_TASK_TCH_F_EVEN;
  65         } else if ((cbits & 0x1e) == 0x02) {
  66                 lch_idx = cbits & 0x1;
  67                 return MF_TASK_TCH_H_0 + lch_idx;
  68         } else if ((cbits & 0x1c) == 0x04) {
  69                 lch_idx = cbits & 0x3;
  70                 return MF_TASK_SDCCH4_0 + lch_idx;
  71         } else if ((cbits & 0x18) == 0x08) {
  72                 lch_idx = cbits & 0x7;
  73                 return MF_TASK_SDCCH8_0 + lch_idx;
  74 #if 0
  75         } else if (cbits == 0x10) {
  76                 /* FIXME: when to do extended BCCH? */
  77                 return MF_TASK_BCCH_NORM;
  78         } else if (cbits == 0x11 || cbits == 0x12) {
  79                 /* FIXME: how to decide CCCH norm/extd? */
  80                 return MF_TASK_BCCH_CCCH;
  81 #endif
  82         }
  83         return 0;
  84 }
  85
  86 static int  chan_nr2dchan_type(uint8_t chan_nr)
  87 {
  88         uint8_t cbits = chan_nr >> 3;
  89
  90         if (cbits == 0x01) {
  91                 return GSM_DCHAN_TCH_F;
  92         } else if ((cbits & 0x1e) == 0x02) {
  93                 return GSM_DCHAN_TCH_H;
  94         } else if ((cbits & 0x1c) == 0x04) {
  95                 return GSM_DCHAN_SDCCH_4;
  96         } else if ((cbits & 0x18) == 0x08) {
  97                 return GSM_DCHAN_SDCCH_8;
  98         }
  99         return GSM_DCHAN_UNKNOWN;
 100 }
 101
 102 static int chan_nr_is_tch(uint8_t chan_nr)
 103 {
 104         return ((chan_nr >> 3) == 0x01 ||               /* TCH/F */
 105                 ((chan_nr >> 3) & 0x1e) == 0x02);       /* TCH/H */
 106 }
 107
 108 struct msgb *l1ctl_msgb_alloc(uint8_t msg_type)
 109 {
 110         struct msgb *msg;
 111         struct l1ctl_hdr *l1h;
 112
 113         msg = msgb_alloc_headroom(L3_MSG_SIZE, L3_MSG_HEAD, "l1ctl");
 114         if (!msg) {
 115                 while (1) {
 116                         puts("OOPS. Out of buffers...\n");
 117                 }
 118
 119                 return NULL;
 120         }
 121         l1h = (struct l1ctl_hdr *) msgb_put(msg, sizeof(*l1h));
 122         l1h->msg_type = msg_type;
 123         l1h->flags = 0;
 124
 125         msg->l1h = (uint8_t *)l1h;
 126
 127         return msg;
 128 }
 129
 130 struct msgb *l1_create_l2_msg(int msg_type, uint32_t fn, uint16_t snr,
 131                               uint16_t arfcn)
 132 {
 133         struct l1ctl_info_dl *dl;
 134         struct msgb *msg = l1ctl_msgb_alloc(msg_type);
 135
 136         dl = (struct l1ctl_info_dl *) msgb_put(msg, sizeof(*dl));
 137         dl->frame_nr = htonl(fn);
 138         dl->snr = snr;
 139         dl->band_arfcn = htons(arfcn);
 140
 141         return msg;
 142 }
 143
 144 /* receive a L1CTL_FBSB_REQ from L23 */
 145 static void l1ctl_rx_fbsb_req(struct msgb *msg)
 146 {
 147         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 148         struct l1ctl_fbsb_req *sync_req = (struct l1ctl_fbsb_req *) l1h->data;
 149
 150         if (sizeof(*sync_req) > msg->len) {
 151                 printf("Short sync msg. %u\n", msg->len);
 152                 return;
 153         }
 154
 155         printd("L1CTL_FBSB_REQ (arfcn=%u, flags=0x%x)\n",
 156                 ntohs(sync_req->band_arfcn), sync_req->flags);
 157
 158         /* reset scheduler and hardware */
 159         l1s_reset();
 160
 161         /* pre-set the CCCH mode */
 162         l1s.serving_cell.ccch_mode = sync_req->ccch_mode;
 163
 164         printd("Starting FCCH Recognition\n");
 165         l1s_fbsb_req(1, sync_req);
 166 }
 167
 168 /* receive a L1CTL_DM_EST_REQ from L23 */
 169 static void l1ctl_rx_dm_est_req(struct msgb *msg)
 170 {
 171         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 172         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 173         struct l1ctl_dm_est_req *est_req = (struct l1ctl_dm_est_req *) ul->payload;
 174
 175         printd("L1CTL_DM_EST_REQ (arfcn=%u, chan_nr=0x%02x, tsc=%u)\n",
 176                 ntohs(est_req->h0.band_arfcn), ul->chan_nr, est_req->tsc);
 177
 178         /* configure dedicated channel state */
 179         l1s.dedicated.type = chan_nr2dchan_type(ul->chan_nr);
 180         l1s.dedicated.tsc  = est_req->tsc;
 181         l1s.dedicated.tn   = ul->chan_nr & 0x7;
 182         l1s.dedicated.h    = est_req->h;
 183
 184         if (est_req->h) {
 185                 int i;
 186                 l1s.dedicated.h1.hsn  = est_req->h1.hsn;
 187                 l1s.dedicated.h1.maio = est_req->h1.maio;
 188                 l1s.dedicated.h1.n    = est_req->h1.n;
 189                 for (i=0; i<est_req->h1.n; i++)
 190                         l1s.dedicated.h1.ma[i] = ntohs(est_req->h1.ma[i]);
 191         } else {
 192                 l1s.dedicated.h0.arfcn = ntohs(est_req->h0.band_arfcn);
 193         }
 194
 195         /* TCH config */
 196         if (chan_nr_is_tch(ul->chan_nr)) {
 197                 /* Mode */
 198                 l1a_tch_mode_set(est_req->tch_mode);
 199
 200                 /* Sync */
 201                 l1s.tch_sync = 1;       /* can be set without locking */
 202         }
 203
 204         /* figure out which MF tasks to enable */
 205         l1a_mftask_set(1 << chan_nr2mf_task(ul->chan_nr));
 206 }
 207
 208 /* receive a L1CTL_DM_FREQ_REQ from L23 */
 209 static void l1ctl_rx_dm_freq_req(struct msgb *msg)
 210 {
 211         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 212         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 213         struct l1ctl_dm_freq_req *freq_req =
 214                         (struct l1ctl_dm_freq_req *) ul->payload;
 215
 216         printd("L1CTL_DM_FREQ_REQ (arfcn=%u, tsc=%u)\n",
 217                 ntohs(freq_req->h0.band_arfcn), freq_req->tsc);
 218
 219         /* configure dedicated channel state */
 220         l1s.dedicated.st_tsc  = freq_req->tsc;
 221         l1s.dedicated.st_h    = freq_req->h;
 222
 223         if (freq_req->h) {
 224                 int i;
 225                 l1s.dedicated.st_h1.hsn  = freq_req->h1.hsn;
 226                 l1s.dedicated.st_h1.maio = freq_req->h1.maio;
 227                 l1s.dedicated.st_h1.n    = freq_req->h1.n;
 228                 for (i=0; i<freq_req->h1.n; i++)
 229                         l1s.dedicated.st_h1.ma[i] = ntohs(freq_req->h1.ma[i]);
 230         } else {
 231                 l1s.dedicated.st_h0.arfcn = ntohs(freq_req->h0.band_arfcn);
 232         }
 233
 234         l1a_freq_req(ntohs(freq_req->fn));
 235 }
 236
 237 /* receive a L1CTL_CRYPTO_REQ from L23 */
 238 static void l1ctl_rx_crypto_req(struct msgb *msg)
 239 {
 240         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 241         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 242         struct l1ctl_crypto_req *cr = (struct l1ctl_crypto_req *) ul->payload;
 243         uint8_t key_len = msg->len - sizeof(*l1h) - sizeof(*ul) - sizeof(*cr);
 244
 245         printd("L1CTL_CRYPTO_REQ (algo=A5/%u, len=%u)\n", cr->algo, key_len);
 246
 247         if (cr->algo && key_len != 8) {
 248                 printd("L1CTL_CRYPTO_REQ -> Invalid key\n");
 249                 return;
 250         }
 251
 252         dsp_load_ciph_param(cr->algo, cr->key);
 253 }
 254
 255 /* receive a L1CTL_DM_REL_REQ from L23 */
 256 static void l1ctl_rx_dm_rel_req(struct msgb *msg)
 257 {
 258         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 259         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 260
 261         printd("L1CTL_DM_REL_REQ\n");
 262         l1a_mftask_set(0);
 263         l1s.dedicated.type = GSM_DCHAN_NONE;
 264         l1a_txq_msgb_flush(&l1s.tx_queue[L1S_CHAN_MAIN]);
 265         l1a_txq_msgb_flush(&l1s.tx_queue[L1S_CHAN_SACCH]);
 266         l1a_meas_msgb_set(NULL);
 267         dsp_load_ciph_param(0, NULL);
 268         l1a_tch_mode_set(GSM48_CMODE_SIGN);
 269 }
 270
 271 /* receive a L1CTL_PARAM_REQ from L23 */
 272 static void l1ctl_rx_param_req(struct msgb *msg)
 273 {
 274         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 275         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 276         struct l1ctl_par_req *par_req = (struct l1ctl_par_req *) ul->payload;
 277
 278         printd("L1CTL_PARAM_REQ (ta=%d, tx_power=%d)\n", par_req->ta,
 279                 par_req->tx_power);
 280
 281         l1s.ta = par_req->ta;
 282         l1s.tx_power = par_req->tx_power;
 283 }
 284
 285 /* receive a L1CTL_RACH_REQ from L23 */
 286 static void l1ctl_rx_rach_req(struct msgb *msg)
 287 {
 288         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 289         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 290         struct l1ctl_rach_req *rach_req = (struct l1ctl_rach_req *) ul->payload;
 291
 292         printd("L1CTL_RACH_REQ (ra=0x%02x, fn51=%d, mf_off=%d)\n", rach_req->ra, rach_req->fn51, rach_req->mf_off);
 293
 294         l1a_rach_req(rach_req->fn51, rach_req->mf_off, rach_req->ra);
 295 }
 296
 297 /* receive a L1CTL_DATA_REQ from L23 */
 298 static void l1ctl_rx_data_req(struct msgb *msg)
 299 {
 300         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 301         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 302         struct l1ctl_data_ind *data_ind = (struct l1ctl_data_ind *) ul->payload;
 303         struct llist_head *tx_queue;
 304
 305         printd("L1CTL_DATA_REQ (link_id=0x%02x)\n", ul->link_id);
 306
 307         msg->l3h = data_ind->data;
 308         if (ul->link_id & 0x40) {
 309                 struct gsm48_hdr *gh = (struct gsm48_hdr *)(data_ind->data + 5);
 310                 if (gh->proto_discr == GSM48_PDISC_RR
 311                  && gh->msg_type == GSM48_MT_RR_MEAS_REP) {
 312                         printd("updating measurement report\n");
 313                         l1a_meas_msgb_set(msg);
 314                         return;
 315                 }
 316                 tx_queue = &l1s.tx_queue[L1S_CHAN_SACCH];
 317         } else
 318                 tx_queue = &l1s.tx_queue[L1S_CHAN_MAIN];
 319
 320         printd("ul=%p, ul->payload=%p, data_ind=%p, data_ind->data=%p l3h=%p\n",
 321                 ul, ul->payload, data_ind, data_ind->data, msg->l3h);
 322
 323         l1a_txq_msgb_enq(tx_queue, msg);
 324 }
 325
 326 /* receive a L1CTL_PM_REQ from L23 */
 327 static void l1ctl_rx_pm_req(struct msgb *msg)
 328 {
 329         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 330         struct l1ctl_pm_req *pm_req = (struct l1ctl_pm_req *) l1h->data;
 331
 332         switch (pm_req->type) {
 333         case 1:
 334                 l1s.pm.mode = 1;
 335                 l1s.pm.range.arfcn_start =
 336                                 ntohs(pm_req->range.band_arfcn_from);
 337                 l1s.pm.range.arfcn_next =
 338                                 ntohs(pm_req->range.band_arfcn_from);
 339                 l1s.pm.range.arfcn_end =
 340                                 ntohs(pm_req->range.band_arfcn_to);
 341                 printf("L1CTL_PM_REQ start=%u end=%u\n",
 342                         l1s.pm.range.arfcn_start, l1s.pm.range.arfcn_end);
 343                 break;
 344         }
 345
 346         l1s_pm_test(1, l1s.pm.range.arfcn_next);
 347 }
 348
 349 /* Transmit a L1CTL_RESET_IND or L1CTL_RESET_CONF */
 350 void l1ctl_tx_reset(uint8_t msg_type, uint8_t reset_type)
 351 {
 352         struct msgb *msg = l1ctl_msgb_alloc(msg_type);
 353         struct l1ctl_reset *reset_resp;
 354         reset_resp = (struct l1ctl_reset *)
 355                                 msgb_put(msg, sizeof(*reset_resp));
 356         reset_resp->type = reset_type;
 357
 358         l1_queue_for_l2(msg);
 359 }
 360
 361 /* receive a L1CTL_RESET_REQ from L23 */
 362 static void l1ctl_rx_reset_req(struct msgb *msg)
 363 {
 364         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 365         struct l1ctl_reset *reset_req =
 366                                 (struct l1ctl_reset *) l1h->data;
 367
 368         switch (reset_req->type) {
 369         case L1CTL_RES_T_FULL:
 370                 printf("L1CTL_RESET_REQ: FULL!\n");
 371                 l1s_reset();
 372                 l1s_reset_hw();
 373                 l1ctl_tx_reset(L1CTL_RESET_CONF, reset_req->type);
 374                 break;
 375         case L1CTL_RES_T_SCHED:
 376                 printf("L1CTL_RESET_REQ: SCHED!\n");
 377                 l1ctl_tx_reset(L1CTL_RESET_CONF, reset_req->type);
 378                 sched_gsmtime_reset();
 379                 break;
 380         default:
 381                 printf("unknown L1CTL_RESET_REQ type\n");
 382                 break;
 383         }
 384 }
 385
 386 /* Transmit a L1CTL_CCCH_MODE_CONF */
 387 static void l1ctl_tx_ccch_mode_conf(uint8_t ccch_mode)
 388 {
 389         struct msgb *msg = l1ctl_msgb_alloc(L1CTL_CCCH_MODE_CONF);
 390         struct l1ctl_ccch_mode_conf *mode_conf;
 391         mode_conf = (struct l1ctl_ccch_mode_conf *)
 392                                 msgb_put(msg, sizeof(*mode_conf));
 393         mode_conf->ccch_mode = ccch_mode;
 394
 395         l1_queue_for_l2(msg);
 396 }
 397
 398 /* receive a L1CTL_CCCH_MODE_REQ from L23 */
 399 static void l1ctl_rx_ccch_mode_req(struct msgb *msg)
 400 {
 401         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 402         struct l1ctl_ccch_mode_req *ccch_mode_req =
 403                 (struct l1ctl_ccch_mode_req *) l1h->data;
 404         uint8_t ccch_mode = ccch_mode_req->ccch_mode;
 405
 406         /* pre-set the CCCH mode */
 407         l1s.serving_cell.ccch_mode = ccch_mode;
 408
 409         /* Update task */
 410         mframe_disable(MF_TASK_CCCH_COMB);
 411         mframe_disable(MF_TASK_CCCH);
 412
 413         if (ccch_mode == CCCH_MODE_COMBINED)
 414                 mframe_enable(MF_TASK_CCCH_COMB);
 415         else if (ccch_mode == CCCH_MODE_NON_COMBINED)
 416                 mframe_enable(MF_TASK_CCCH);
 417
 418         l1ctl_tx_ccch_mode_conf(ccch_mode);
 419 }
 420
 421 /* Transmit a L1CTL_TCH_MODE_CONF */
 422 static void l1ctl_tx_tch_mode_conf(uint8_t tch_mode)
 423 {
 424         struct msgb *msg = l1ctl_msgb_alloc(L1CTL_TCH_MODE_CONF);
 425         struct l1ctl_tch_mode_conf *mode_conf;
 426         mode_conf = (struct l1ctl_tch_mode_conf *)
 427                                 msgb_put(msg, sizeof(*mode_conf));
 428         mode_conf->tch_mode = tch_mode;
 429
 430         l1_queue_for_l2(msg);
 431 }
 432
 433 /* receive a L1CTL_TCH_MODE_REQ from L23 */
 434 static void l1ctl_rx_tch_mode_req(struct msgb *msg)
 435 {
 436         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 437         struct l1ctl_tch_mode_req *tch_mode_req =
 438                 (struct l1ctl_tch_mode_req *) l1h->data;
 439         uint8_t tch_mode = tch_mode_req->tch_mode;
 440
 441         printd("L1CTL_TCH_MODE_REQ (mode=0x%02x)\n", tch_mode);
 442         tch_mode = l1a_tch_mode_set(tch_mode);
 443
 444         l1ctl_tx_tch_mode_conf(tch_mode);
 445 }
 446
 447 /* callback from SERCOMM when L2 sends a message to L1 */
 448 static void l1a_l23_rx_cb(uint8_t dlci, struct msgb *msg)
 449 {
 450         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 451
 452 #if 0
 453         {
 454                 int i;
 455                 printf("l1a_l23_rx_cb (%u): ", msg->len);
 456                 for (i = 0; i < msg->len; i++)
 457                         printf("%02x ", msg->data[i]);
 458                 puts("\n");
 459         }
 460 #endif
 461
 462         msg->l1h = msg->data;
 463
 464         if (sizeof(*l1h) > msg->len) {
 465                 printf("l1a_l23_cb: Short message. %u\n", msg->len);
 466                 goto exit_msgbfree;
 467         }
 468
 469         switch (l1h->msg_type) {
 470         case L1CTL_FBSB_REQ:
 471                 l1ctl_rx_fbsb_req(msg);
 472                 break;
 473         case L1CTL_DM_EST_REQ:
 474                 l1ctl_rx_dm_est_req(msg);
 475                 break;
 476         case L1CTL_DM_REL_REQ:
 477                 l1ctl_rx_dm_rel_req(msg);
 478                 break;
 479         case L1CTL_PARAM_REQ:
 480                 l1ctl_rx_param_req(msg);
 481                 break;
 482         case L1CTL_DM_FREQ_REQ:
 483                 l1ctl_rx_dm_freq_req(msg);
 484                 break;
 485         case L1CTL_CRYPTO_REQ:
 486                 l1ctl_rx_crypto_req(msg);
 487                 break;
 488         case L1CTL_RACH_REQ:
 489                 l1ctl_rx_rach_req(msg);
 490                 break;
 491         case L1CTL_DATA_REQ:
 492                 l1ctl_rx_data_req(msg);
 493                 /* we have to keep the msgb, not free it! */
 494                 goto exit_nofree;
 495         case L1CTL_PM_REQ:
 496                 l1ctl_rx_pm_req(msg);
 497                 break;
 498         case L1CTL_RESET_REQ:
 499                 l1ctl_rx_reset_req(msg);
 500                 break;
 501         case L1CTL_CCCH_MODE_REQ:
 502                 l1ctl_rx_ccch_mode_req(msg);
 503                 break;
 504         case L1CTL_TCH_MODE_REQ:
 505                 l1ctl_rx_tch_mode_req(msg);
 506                 break;
 507         }
 508
 509 exit_msgbfree:
 510         msgb_free(msg);
 511 exit_nofree:
 512         return;
 513 }
 514
 515 void l1a_l23api_init(void)
 516 {
 517         sercomm_register_rx_cb(SC_DLCI_L1A_L23, l1a_l23_rx_cb);
 518 }