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         if (ntohs(est_req->h0.band_arfcn) != l1s.serving_cell.arfcn) {
 170                 /* FIXME: ARFCN */
 171                 puts("We don't support ARFCN switches yet\n");
 172                 return;
 173         }
 174         if (ul->chan_nr & 0x7) {
 175                 /* FIXME: Timeslot */
 176                 puts("We don't support non-0 TS yet\n");
 177                 return;
 178         }
 179         if (est_req->h) {
 180                 puts("We don't support frequency hopping yet\n");
 181                 return;
 182         }
 183
 184         /* configure dedicated channel state */
 185         l1s.dedicated.type = chan_nr2dchan_type(ul->chan_nr);
 186         l1s.dedicated.tsc  = est_req->tsc;
 187         l1s.dedicated.tn   = ul->chan_nr & 0x7;
 188         l1s.dedicated.h    = est_req->h;
 189
 190         if (est_req->h) {
 191                 int i;
 192                 l1s.dedicated.h1.hsn  = est_req->h1.hsn;
 193                 l1s.dedicated.h1.maio = est_req->h1.maio;
 194                 l1s.dedicated.h1.n    = est_req->h1.n;
 195                 for (i=0; i<est_req->h1.n; i++)
 196                         l1s.dedicated.h1.ma[i] = ntohs(est_req->h1.ma[i]);
 197         } else {
 198                 l1s.dedicated.h0.arfcn = ntohs(est_req->h0.band_arfcn);
 199         }
 200
 201         /* figure out which MF tasks to enable */
 202         l1a_mftask_set(1 << chan_nr2mf_task(ul->chan_nr));
 203 }
 204
 205 /* receive a L1CTL_DM_REL_REQ from L23 */
 206 static void l1ctl_rx_dm_rel_req(struct msgb *msg)
 207 {
 208         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 209         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 210
 211         l1a_mftask_set(0);
 212 }
 213
 214 /* receive a L1CTL_RACH_REQ from L23 */
 215 static void l1ctl_rx_rach_req(struct msgb *msg)
 216 {
 217         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 218         struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
 219         struct l1ctl_rach_req *rach_req = (struct l1ctl_rach_req *) ul->payload;
 220
 221         printd("L1CTL_RACH_REQ (ra=0x%02x)\n", rach_req->ra);
 222
 223         l1a_rach_req(27, rach_req->ra);
 224 }
 225
 226 /* receive a L1CTL_DATA_REQ from L23 */
 227 static void l1ctl_rx_data_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_data_ind *data_ind = (struct l1ctl_data_ind *) ul->payload;
 232         struct llist_head *tx_queue;
 233
 234         printd("L1CTL_DATA_REQ (link_id=0x%02x)\n", ul->link_id);
 235
 236         msg->l3h = data_ind->data;
 237         tx_queue = (ul->link_id & 0x40) ?
 238                         &l1s.tx_queue[L1S_CHAN_SACCH] :
 239                         &l1s.tx_queue[L1S_CHAN_MAIN];
 240
 241         printd("ul=%p, ul->payload=%p, data_ind=%p, data_ind->data=%p l3h=%p\n",
 242                 ul, ul->payload, data_ind, data_ind->data, msg->l3h);
 243
 244         l1a_txq_msgb_enq(tx_queue, msg);
 245 }
 246
 247 /* receive a L1CTL_PM_REQ from L23 */
 248 static void l1ctl_rx_pm_req(struct msgb *msg)
 249 {
 250         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 251         struct l1ctl_pm_req *pm_req = (struct l1ctl_pm_req *) l1h->data;
 252
 253         switch (pm_req->type) {
 254         case 1:
 255                 l1s.pm.mode = 1;
 256                 l1s.pm.range.arfcn_start =
 257                                 ntohs(pm_req->range.band_arfcn_from);
 258                 l1s.pm.range.arfcn_next =
 259                                 ntohs(pm_req->range.band_arfcn_from);
 260                 l1s.pm.range.arfcn_end =
 261                                 ntohs(pm_req->range.band_arfcn_to);
 262                 printf("L1CTL_PM_REQ start=%u end=%u\n",
 263                         l1s.pm.range.arfcn_start, l1s.pm.range.arfcn_end);
 264                 break;
 265         }
 266
 267         l1s_pm_test(1, l1s.pm.range.arfcn_next);
 268 }
 269
 270 /* Transmit a L1CTL_RESET_IND or L1CTL_RESET_CONF */
 271 void l1ctl_tx_reset(uint8_t msg_type, uint8_t reset_type)
 272 {
 273         struct msgb *msg = l1ctl_msgb_alloc(msg_type);
 274         struct l1ctl_reset *reset_resp;
 275         reset_resp = (struct l1ctl_reset *)
 276                                 msgb_put(msg, sizeof(*reset_resp));
 277         reset_resp->type = reset_type;
 278
 279         l1_queue_for_l2(msg);
 280 }
 281
 282 /* receive a L1CTL_RESET_REQ from L23 */
 283 static void l1ctl_rx_reset_req(struct msgb *msg)
 284 {
 285         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 286         struct l1ctl_reset *reset_req =
 287                                 (struct l1ctl_reset *) l1h->data;
 288
 289         switch (reset_req->type) {
 290         case L1CTL_RES_T_FULL:
 291                 printf("L1CTL_RESET_REQ: FULL!\n");
 292                 l1s_reset();
 293                 l1s_reset_hw();
 294                 l1ctl_tx_reset(L1CTL_RESET_CONF, reset_req->type);
 295                 break;
 296         default:
 297                 printf("unknown L1CTL_RESET_REQ type\n");
 298                 break;
 299         }
 300 }
 301
 302 /* Transmit a L1CTL_CCCH_MODE_CONF */
 303 static void l1ctl_tx_ccch_mode_conf(uint8_t ccch_mode)
 304 {
 305         struct msgb *msg = l1ctl_msgb_alloc(L1CTL_CCCH_MODE_CONF);
 306         struct l1ctl_ccch_mode_conf *mode_conf;
 307         mode_conf = (struct l1ctl_ccch_mode_conf *)
 308                                 msgb_put(msg, sizeof(*mode_conf));
 309         mode_conf->ccch_mode = ccch_mode;
 310
 311         l1_queue_for_l2(msg);
 312 }
 313
 314 /* receive a L1CTL_CCCH_MODE_REQ from L23 */
 315 static void l1ctl_rx_ccch_mode_req(struct msgb *msg)
 316 {
 317         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 318         struct l1ctl_ccch_mode_req *ccch_mode_req =
 319                 (struct l1ctl_ccch_mode_req *) l1h->data;
 320         uint8_t ccch_mode = ccch_mode_req->ccch_mode;
 321
 322         /* pre-set the CCCH mode */
 323         l1s.serving_cell.ccch_mode = ccch_mode;
 324
 325         /* Update task */
 326         mframe_disable(MF_TASK_CCCH_COMB);
 327         mframe_disable(MF_TASK_CCCH);
 328
 329         if (ccch_mode == CCCH_MODE_COMBINED)
 330                 mframe_enable(MF_TASK_CCCH_COMB);
 331         else if (ccch_mode == CCCH_MODE_NON_COMBINED)
 332                 mframe_enable(MF_TASK_CCCH);
 333
 334         l1ctl_tx_ccch_mode_conf(ccch_mode);
 335 }
 336
 337 /* callback from SERCOMM when L2 sends a message to L1 */
 338 static void l1a_l23_rx_cb(uint8_t dlci, struct msgb *msg)
 339 {
 340         struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
 341
 342 #if 0
 343         {
 344                 int i;
 345                 printf("l1a_l23_rx_cb (%u): ", msg->len);
 346                 for (i = 0; i < msg->len; i++)
 347                         printf("%02x ", msg->data[i]);
 348                 puts("\n");
 349         }
 350 #endif
 351
 352         msg->l1h = msg->data;
 353
 354         if (sizeof(*l1h) > msg->len) {
 355                 printf("l1a_l23_cb: Short message. %u\n", msg->len);
 356                 goto exit_msgbfree;
 357         }
 358
 359         switch (l1h->msg_type) {
 360         case L1CTL_FBSB_REQ:
 361                 l1ctl_rx_fbsb_req(msg);
 362                 break;
 363         case L1CTL_DM_EST_REQ:
 364                 l1ctl_rx_dm_est_req(msg);
 365                 break;
 366         case L1CTL_DM_REL_REQ:
 367                 l1ctl_rx_dm_rel_req(msg);
 368                 break;
 369         case L1CTL_RACH_REQ:
 370                 l1ctl_rx_rach_req(msg);
 371                 break;
 372         case L1CTL_DATA_REQ:
 373                 l1ctl_rx_data_req(msg);
 374                 /* we have to keep the msgb, not free it! */
 375                 goto exit_nofree;
 376         case L1CTL_PM_REQ:
 377                 l1ctl_rx_pm_req(msg);
 378                 break;
 379         case L1CTL_RESET_REQ:
 380                 l1ctl_rx_reset_req(msg);
 381                 break;
 382         case L1CTL_CCCH_MODE_REQ:
 383                 l1ctl_rx_ccch_mode_req(msg);
 384                 break;
 385         }
 386
 387 exit_msgbfree:
 388         msgb_free(msg);
 389 exit_nofree:
 390         return;
 391 }
 392
 393 void l1a_l23api_init(void)
 394 {
 395         sercomm_register_rx_cb(SC_DLCI_L1A_L23, l1a_l23_rx_cb);
 396 }