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