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 <l1a_l23_interface.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_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         if ((chan_nr2mf_task(ul->chan_nr) >= MF_TASK_SDCCH8_4) &&
 177             (chan_nr2mf_task(ul->chan_nr) <= MF_TASK_SDCCH8_7)) {
 178                 /* FIXME: TX while RX prevents SDCCH8 [4..7] */
 179                 puts("We don't support SDCCH8 [4..7] yet\n");
 180                 return;
 181         }
 182
 183         /* configure dedicated channel state */
 184         l1s.dedicated.type = chan_nr2dchan_type(ul->chan_nr);
 185         l1s.dedicated.tsc  = est_req->tsc;
 186         l1s.dedicated.tn   = ul->chan_nr & 0x7;
 187         l1s.dedicated.h    = est_req->h;
 188
 189         if (est_req->h) {
 190                 int i;
 191                 l1s.dedicated.h1.hsn  = est_req->h1.hsn;
 192                 l1s.dedicated.h1.maio = est_req->h1.maio;
 193                 l1s.dedicated.h1.n    = est_req->h1.n;
 194                 for (i=0; i<est_req->h1.n; i++)
 195                         l1s.dedicated.h1.ma[i] = ntohs(est_req->h1.ma[i]);
 196         } else {
 197                 l1s.dedicated.h0.arfcn = ntohs(est_req->h0.band_arfcn);
 198         }
 199
 200         /* figure out which MF tasks to enable */
 201         l1a_mftask_set(1 << chan_nr2mf_task(ul->chan_nr));
 202 }
 203
 204 /* receive a L1CTL_DM_REL_REQ from L23 */
 205 static void l1ctl_rx_dm_rel_req(struct msgb *msg)
 206 {
 207         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 208         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 209
 210         printd("L1CTL_DM_REL_REQ\n");
 211         l1a_mftask_set(0);
 212         l1s.dedicated.type = GSM_DCHAN_NONE;
 213 }
 214
 215 /* receive a L1CTL_RACH_REQ from L23 */
 216 static void l1ctl_rx_param_req(struct msgb *msg)
 217 {
 218         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 219         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 220         struct l1ctl_par_req *par_req = (struct l1ctl_par_req *) ul->payload;
 221
 222         printd("L1CTL_PARAM_REQ (ta=%d, tx_power=%d)\n", par_req->ta,
 223                 par_req->tx_power);
 224
 225         l1s.ta = par_req->ta;
 226         // FIXME: set power
 227 }
 228
 229 /* receive a L1CTL_RACH_REQ from L23 */
 230 static void l1ctl_rx_rach_req(struct msgb *msg)
 231 {
 232         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 233         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 234         struct l1ctl_rach_req *rach_req = (struct l1ctl_rach_req *) ul->payload;
 235
 236         printd("L1CTL_RACH_REQ (ra=0x%02x, fn51=%d, mf_off=%d)\n", rach_req->ra, rach_req->fn51, rach_req->mf_off);
 237
 238         l1a_rach_req(rach_req->fn51, rach_req->mf_off, rach_req->ra);
 239 }
 240
 241 /* receive a L1CTL_DATA_REQ from L23 */
 242 static void l1ctl_rx_data_req(struct msgb *msg)
 243 {
 244         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 245         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 246         struct l1ctl_data_ind *data_ind = (struct l1ctl_data_ind *) ul->payload;
 247         struct llist_head *tx_queue;
 248
 249         printd("L1CTL_DATA_REQ (link_id=0x%02x)\n", ul->link_id);
 250
 251         msg->l3h = data_ind->data;
 252         tx_queue = (ul->link_id & 0x40) ?
 253                         &l1s.tx_queue[L1S_CHAN_SACCH] :
 254                         &l1s.tx_queue[L1S_CHAN_MAIN];
 255
 256         printd("ul=%p, ul->payload=%p, data_ind=%p, data_ind->data=%p l3h=%p\n",
 257                 ul, ul->payload, data_ind, data_ind->data, msg->l3h);
 258
 259         l1a_txq_msgb_enq(tx_queue, msg);
 260 }
 261
 262 /* receive a L1CTL_PM_REQ from L23 */
 263 static void l1ctl_rx_pm_req(struct msgb *msg)
 264 {
 265         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 266         struct l1ctl_pm_req *pm_req = (struct l1ctl_pm_req *) l1h->data;
 267
 268         switch (pm_req->type) {
 269         case 1:
 270                 l1s.pm.mode = 1;
 271                 l1s.pm.range.arfcn_start =
 272                                 ntohs(pm_req->range.band_arfcn_from);
 273                 l1s.pm.range.arfcn_next =
 274                                 ntohs(pm_req->range.band_arfcn_from);
 275                 l1s.pm.range.arfcn_end =
 276                                 ntohs(pm_req->range.band_arfcn_to);
 277                 printf("L1CTL_PM_REQ start=%u end=%u\n",
 278                         l1s.pm.range.arfcn_start, l1s.pm.range.arfcn_end);
 279                 break;
 280         }
 281
 282         l1s_pm_test(1, l1s.pm.range.arfcn_next);
 283 }
 284
 285 /* Transmit a L1CTL_RESET_IND or L1CTL_RESET_CONF */
 286 void l1ctl_tx_reset(uint8_t msg_type, uint8_t reset_type)
 287 {
 288         struct msgb *msg = l1ctl_msgb_alloc(msg_type);
 289         struct l1ctl_reset *reset_resp;
 290         reset_resp = (struct l1ctl_reset *)
 291                                 msgb_put(msg, sizeof(*reset_resp));
 292         reset_resp->type = reset_type;
 293
 294         l1_queue_for_l2(msg);
 295 }
 296
 297 /* receive a L1CTL_RESET_REQ from L23 */
 298 static void l1ctl_rx_reset_req(struct msgb *msg)
 299 {
 300         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 301         struct l1ctl_reset *reset_req =
 302                                 (struct l1ctl_reset *) l1h->data;
 303
 304         switch (reset_req->type) {
 305         case L1CTL_RES_T_FULL:
 306                 printf("L1CTL_RESET_REQ: FULL!\n");
 307                 l1s_reset();
 308                 l1s_reset_hw();
 309                 l1ctl_tx_reset(L1CTL_RESET_CONF, reset_req->type);
 310                 break;
 311         case L1CTL_RES_T_SCHED:
 312                 printf("L1CTL_RESET_REQ: SCHED!\n");
 313                 l1ctl_tx_reset(L1CTL_RESET_CONF, reset_req->type);
 314                 sched_gsmtime_reset();
 315                 break;
 316         default:
 317                 printf("unknown L1CTL_RESET_REQ type\n");
 318                 break;
 319         }
 320 }
 321
 322 /* Transmit a L1CTL_CCCH_MODE_CONF */
 323 static void l1ctl_tx_ccch_mode_conf(uint8_t ccch_mode)
 324 {
 325         struct msgb *msg = l1ctl_msgb_alloc(L1CTL_CCCH_MODE_CONF);
 326         struct l1ctl_ccch_mode_conf *mode_conf;
 327         mode_conf = (struct l1ctl_ccch_mode_conf *)
 328                                 msgb_put(msg, sizeof(*mode_conf));
 329         mode_conf->ccch_mode = ccch_mode;
 330
 331         l1_queue_for_l2(msg);
 332 }
 333
 334 /* receive a L1CTL_CCCH_MODE_REQ from L23 */
 335 static void l1ctl_rx_ccch_mode_req(struct msgb *msg)
 336 {
 337         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 338         struct l1ctl_ccch_mode_req *ccch_mode_req =
 339                 (struct l1ctl_ccch_mode_req *) l1h->data;
 340         uint8_t ccch_mode = ccch_mode_req->ccch_mode;
 341
 342         /* pre-set the CCCH mode */
 343         l1s.serving_cell.ccch_mode = ccch_mode;
 344
 345         /* Update task */
 346         mframe_disable(MF_TASK_CCCH_COMB);
 347         mframe_disable(MF_TASK_CCCH);
 348
 349         if (ccch_mode == CCCH_MODE_COMBINED)
 350                 mframe_enable(MF_TASK_CCCH_COMB);
 351         else if (ccch_mode == CCCH_MODE_NON_COMBINED)
 352                 mframe_enable(MF_TASK_CCCH);
 353
 354         l1ctl_tx_ccch_mode_conf(ccch_mode);
 355 }
 356
 357 /* callback from SERCOMM when L2 sends a message to L1 */
 358 static void l1a_l23_rx_cb(uint8_t dlci, struct msgb *msg)
 359 {
 360         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 361
 362 #if 0
 363         {
 364                 int i;
 365                 printf("l1a_l23_rx_cb (%u): ", msg->len);
 366                 for (i = 0; i < msg->len; i++)
 367                         printf("%02x ", msg->data[i]);
 368                 puts("\n");
 369         }
 370 #endif
 371
 372         msg->l1h = msg->data;
 373
 374         if (sizeof(*l1h) > msg->len) {
 375                 printf("l1a_l23_cb: Short message. %u\n", msg->len);
 376                 goto exit_msgbfree;
 377         }
 378
 379         switch (l1h->msg_type) {
 380         case L1CTL_FBSB_REQ:
 381                 l1ctl_rx_fbsb_req(msg);
 382                 break;
 383         case L1CTL_DM_EST_REQ:
 384                 l1ctl_rx_dm_est_req(msg);
 385                 break;
 386         case L1CTL_DM_REL_REQ:
 387                 l1ctl_rx_dm_rel_req(msg);
 388                 break;
 389         case L1CTL_PARAM_REQ:
 390                 l1ctl_rx_param_req(msg);
 391                 break;
 392         case L1CTL_RACH_REQ:
 393                 l1ctl_rx_rach_req(msg);
 394                 break;
 395         case L1CTL_DATA_REQ:
 396                 l1ctl_rx_data_req(msg);
 397                 /* we have to keep the msgb, not free it! */
 398                 goto exit_nofree;
 399         case L1CTL_PM_REQ:
 400                 l1ctl_rx_pm_req(msg);
 401                 break;
 402         case L1CTL_RESET_REQ:
 403                 l1ctl_rx_reset_req(msg);
 404                 break;
 405         case L1CTL_CCCH_MODE_REQ:
 406                 l1ctl_rx_ccch_mode_req(msg);
 407                 break;
 408         }
 409
 410 exit_msgbfree:
 411         msgb_free(msg);
 412 exit_nofree:
 413         return;
 414 }
 415
 416 void l1a_l23api_init(void)
 417 {
 418         sercomm_register_rx_cb(SC_DLCI_L1A_L23, l1a_l23_rx_cb);
 419 }