277 lines
7.0 KiB
C
277 lines
7.0 KiB
C
/* Synchronous part of GSM Layer 1: API to Layer2+ */
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/* (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
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*
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* All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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*/
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#define DEBUG
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#include <stdint.h>
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#include <stdio.h>
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#include <debug.h>
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#include <byteorder.h>
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#include <osmocore/msgb.h>
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#include <comm/sercomm.h>
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#include <layer1/sync.h>
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#include <layer1/async.h>
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#include <layer1/mframe_sched.h>
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#include <layer1/tpu_window.h>
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#include <rf/trf6151.h>
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#include <l1a_l23_interface.h>
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/* the size we will allocate struct msgb* for HDLC */
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#define L3_MSG_HEAD 4
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#define L3_MSG_SIZE (sizeof(struct l1ctl_info_dl)+sizeof(struct l1ctl_data_ind) + L3_MSG_HEAD)
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void l1_queue_for_l2(struct msgb *msg)
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{
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/* forward via serial for now */
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sercomm_sendmsg(SC_DLCI_L1A_L23, msg);
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}
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static enum mframe_task chan_nr2mf_task(uint8_t chan_nr)
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{
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uint8_t cbits = chan_nr >> 3;
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uint8_t lch_idx;
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if (cbits == 0x01) {
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lch_idx = 0;
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/* FIXME: TCH/F */
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} else if ((cbits & 0x1e) == 0x02) {
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lch_idx = cbits & 0x1;
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/* FIXME: TCH/H */
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} else if ((cbits & 0x1c) == 0x04) {
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lch_idx = cbits & 0x3;
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return MF_TASK_SDCCH4_0 + lch_idx;
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} else if ((cbits & 0x18) == 0x08) {
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lch_idx = cbits & 0x7;
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return MF_TASK_SDCCH8_0 + lch_idx;
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#if 0
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} else if (cbits == 0x10) {
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/* FIXME: when to do extended BCCH? */
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return MF_TASK_BCCH_NORM;
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} else if (cbits == 0x11 || cbits == 0x12) {
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/* FIXME: how to decide CCCH norm/extd? */
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return MF_TASK_BCCH_CCCH;
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#endif
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}
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return 0;
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}
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struct msgb *l1ctl_msgb_alloc(uint8_t msg_type)
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{
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struct msgb *msg;
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struct l1ctl_hdr *l1h;
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msg = msgb_alloc_headroom(L3_MSG_SIZE, L3_MSG_HEAD, "l1ctl");
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if (!msg) {
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while (1) {
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puts("OOPS. Out of buffers...\n");
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}
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return NULL;
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}
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l1h = (struct l1ctl_hdr *) msgb_put(msg, sizeof(*l1h));
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l1h->msg_type = msg_type;
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l1h->flags = 0;
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msg->l1h = l1h;
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return msg;
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}
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struct msgb *l1_create_l2_msg(int msg_type, uint32_t fn, uint16_t snr,
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uint16_t arfcn)
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{
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struct l1ctl_info_dl *dl;
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struct msgb *msg = l1ctl_msgb_alloc(msg_type);
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dl = (struct l1ctl_info_dl *) msgb_put(msg, sizeof(*dl));
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dl->frame_nr = htonl(fn);
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dl->snr = snr;
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dl->band_arfcn = htons(arfcn);
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return msg;
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}
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/* receive a L1CTL_PM_REQ from L23 */
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void l1ctl_rx_pm_req(struct msgb *msg)
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{
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struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
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struct l1ctl_pm_req *pm_req = (struct l1ctl_pm_req *) l1h->data;
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switch (pm_req->type) {
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case 1:
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l1s.pm.mode = 1;
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l1s.pm.range.arfcn_start =
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ntohs(pm_req->range.band_arfcn_from);
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l1s.pm.range.arfcn_next =
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ntohs(pm_req->range.band_arfcn_from);
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l1s.pm.range.arfcn_end =
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ntohs(pm_req->range.band_arfcn_to);
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printf("L1CTL_PM_REQ start=%u end=%u\n",
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l1s.pm.range.arfcn_start, l1s.pm.range.arfcn_end);
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break;
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}
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l1s_pm_test(1, l1s.pm.range.arfcn_next);
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}
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/* Transmit a L1CTL_RESET_IND or L1CTL_RESET_CONF */
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void l1ctl_tx_reset(uint8_t msg_type, uint8_t reset_type)
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{
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struct msgb *msg = l1ctl_msgb_alloc(msg_type);
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struct l1ctl_reset *reset_resp;
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reset_resp = (struct l1ctl_reset *)
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msgb_put(msg, sizeof(*reset_resp));
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reset_resp->type = reset_type;
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l1_queue_for_l2(msg);
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}
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/* receive a L1CTL_RESET_REQ from L23 */
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static void l1ctl_rx_reset_req(struct msgb *msg)
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{
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struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
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struct l1ctl_reset *reset_req =
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(struct l1ctl_reset *) l1h->data;
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switch (reset_req->type) {
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case L1CTL_RES_T_FULL:
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printf("L1CTL_RESET_REQ: FULL!\n");
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l1s_reset();
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l1s_reset_hw();
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l1ctl_tx_reset(L1CTL_RESET_CONF, reset_req->type);
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break;
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default:
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printf("unknown L1CTL_RESET_REQ type\n");
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break;
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}
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}
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/* callback from SERCOMM when L2 sends a message to L1 */
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static void l1a_l23_rx_cb(uint8_t dlci, struct msgb *msg)
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{
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struct l1ctl_hdr *l1h = (struct l1ctl_hdr *) msg->data;
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struct l1ctl_info_ul *ul = (struct l1ctl_info_ul *) l1h->data;
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struct l1ctl_fbsb_req *sync_req;
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struct l1ctl_rach_req *rach_req;
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struct l1ctl_dm_est_req *est_req;
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struct l1ctl_data_ind *data_ind;
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struct llist_head *tx_queue;
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#if 0
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{
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int i;
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printf("l1a_l23_rx_cb (%u): ", msg->len);
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for (i = 0; i < msg->len; i++)
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printf("%02x ", msg->data[i]);
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puts("\n");
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}
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#endif
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msg->l1h = msg->data;
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if (sizeof(*l1h) > msg->len) {
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printf("l1a_l23_cb: Short message. %u\n", msg->len);
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goto exit_msgbfree;
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}
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switch (l1h->msg_type) {
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case L1CTL_FBSB_REQ:
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if (sizeof(*sync_req) > msg->len) {
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printf("Short sync msg. %u\n", msg->len);
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break;
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}
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sync_req = (struct l1ctl_fbsb_req *) l1h->data;
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printd("L1CTL_FBSB_REQ (arfcn=%u, flags=0x%x)\n",
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ntohs(sync_req->band_arfcn), sync_req->flags);
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/* reset scheduler and hardware */
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l1s_reset();
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/* tune to specified frequency */
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trf6151_rx_window(0, ntohs(sync_req->band_arfcn), 40, 0);
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tpu_end_scenario();
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printd("Starting FCCH Recognition\n");
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l1s_fbsb_req(1, sync_req);
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break;
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case L1CTL_DM_EST_REQ:
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est_req = (struct l1ctl_dm_est_req *) ul->payload;
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printd("L1CTL_DM_EST_REQ (arfcn=%u, chan_nr=0x%02x)\n",
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ntohs(est_req->band_arfcn), ul->chan_nr);
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if (ntohs(est_req->band_arfcn) != l1s.serving_cell.arfcn) {
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/* FIXME: ARFCN */
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puts("We don't support ARFCN switches yet\n");
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break;
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}
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if (ul->chan_nr & 0x7) {
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/* FIXME: Timeslot */
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puts("We don't support non-0 TS yet\n");
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break;
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}
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if (est_req->h0.h) {
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puts("We don't support frequency hopping yet\n");
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break;
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}
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/* FIXME: set TSC of ded chan according to est_req.h0.tsc */
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/* figure out which MF tasks to enable */
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l1a_mftask_set(1 << chan_nr2mf_task(ul->chan_nr));
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break;
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case L1CTL_RACH_REQ:
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rach_req = (struct l1ctl_rach_req *) ul->payload;
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printd("L1CTL_RACH_REQ (ra=0x%02x)\n", rach_req->ra);
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l1a_rach_req(27, rach_req->ra);
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break;
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case L1CTL_DATA_REQ:
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data_ind = (struct l1ctl_data_ind *) ul->payload;
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printd("L1CTL_DATA_REQ (link_id=0x%02x)\n", ul->link_id);
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if (ul->link_id & 0x40)
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tx_queue = &l1s.tx_queue[L1S_CHAN_SACCH];
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else
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tx_queue = &l1s.tx_queue[L1S_CHAN_MAIN];
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msg->l3h = data_ind->data;
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printd("ul=%p, ul->payload=%p, data_ind=%p, data_ind->data=%p l3h=%p\n",
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ul, ul->payload, data_ind, data_ind->data, msg->l3h);
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l1a_txq_msgb_enq(tx_queue, msg);
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/* we have to keep the msgb, not free it! */
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goto exit_nofree;
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case L1CTL_PM_REQ:
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l1ctl_rx_pm_req(msg);
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break;
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case L1CTL_RESET_REQ:
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l1ctl_rx_reset_req(msg);
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}
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exit_msgbfree:
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msgb_free(msg);
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exit_nofree:
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return;
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}
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void l1a_l23api_init(void)
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{
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sercomm_register_rx_cb(SC_DLCI_L1A_L23, l1a_l23_rx_cb);
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}
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