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/* Layer 1 - Receiving Normal Bursts */
/* (C) 2010 by Harald Welte <laforge@gnumonks.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.
*
*/
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <defines.h>
#include <debug.h>
#include <memory.h>
#include <byteorder.h>
#include <rffe.h>
#include <osmocom/gsm/gsm_utils.h>
#include <osmocom/core/msgb.h>
#include <calypso/dsp_api.h>
#include <calypso/irq.h>
#include <calypso/tpu.h>
#include <calypso/tsp.h>
#include <calypso/dsp.h>
#include <calypso/timer.h>
#include <comm/sercomm.h>
#include <layer1/sync.h>
#include <layer1/afc.h>
#include <layer1/toa.h>
#include <layer1/tdma_sched.h>
#include <layer1/mframe_sched.h>
#include <layer1/tpu_window.h>
#include <layer1/l23_api.h>
#include <layer1/rfch.h>
#include <layer1/prim.h>
#include <layer1/agc.h>
#include <l1ctl_proto.h>
struct l1s_rxnb_state {
struct l1s_meas_hdr meas[4];
struct msgb *msg;
struct l1ctl_info_dl *dl;
struct l1ctl_data_ind *di;
};
static struct l1s_rxnb_state rxnb;
static int l1s_nb_resp(__unused uint8_t p1, uint8_t burst_id, uint16_t p3)
{
struct gsm_time rx_time;
uint8_t mf_task_id = p3 & 0xff;
uint8_t mf_task_flags = p3 >> 8;
uint16_t rf_arfcn;
uint8_t tsc, tn;
putchart('n');
/* just for debugging, d_task_d should not be 0 */
if (dsp_api.db_r->d_task_d == 0) {
puts("EMPTY\n");
return 0;
}
/* DSP burst ID needs to correspond with what we expect */
if (dsp_api.db_r->d_burst_d != burst_id) {
printf("BURST ID %u!=%u\n", dsp_api.db_r->d_burst_d, burst_id);
return 0;
}
/* get radio parameters for _this_ burst */
gsm_fn2gsmtime(&rx_time, l1s.current_time.fn - 1);
rfch_get_params(&rx_time, &rf_arfcn, &tsc, &tn);
/* collect measurements */
rxnb.meas[burst_id].toa_qbit = dsp_api.db_r->a_serv_demod[D_TOA];
rxnb.meas[burst_id].pm_dbm8 =
agc_inp_dbm8_by_pm(dsp_api.db_r->a_serv_demod[D_PM] >> 3);
rxnb.meas[burst_id].freq_err =
ANGLE_TO_FREQ(dsp_api.db_r->a_serv_demod[D_ANGLE]);
rxnb.meas[burst_id].snr = dsp_api.db_r->a_serv_demod[D_SNR];
/* feed computed frequency error into AFC loop */
if (rxnb.meas[burst_id].snr > AFC_SNR_THRESHOLD)
afc_input(rxnb.meas[burst_id].freq_err, rf_arfcn, 1);
else
afc_input(rxnb.meas[burst_id].freq_err, rf_arfcn, 0);
/* feed computed TOA into TA loop */
toa_input(rxnb.meas[burst_id].toa_qbit << 2, rxnb.meas[burst_id].snr);
/* Tell the RF frontend to set the gain appropriately */
rffe_compute_gain(rxnb.meas[burst_id].pm_dbm8/8, CAL_DSP_TGT_BB_LVL);
/* 4th burst, get frame data */
if (dsp_api.db_r->d_burst_d == 3) {
uint8_t i;
uint16_t num_biterr;
uint32_t avg_snr = 0;
int32_t avg_dbm8 = 0;
/* Get radio parameters for the first burst */
gsm_fn2gsmtime(&rx_time, l1s.current_time.fn - 4);
rfch_get_params(&rx_time, &rf_arfcn, &tsc, &tn);
/* Set Channel Number depending on MFrame Task ID */
rxnb.dl->chan_nr = mframe_task2chan_nr(mf_task_id, tn);
/* Set SACCH indication in Link IDentifier */
if (mf_task_flags & MF_F_SACCH)
rxnb.dl->link_id = 0x40;
else
rxnb.dl->link_id = 0x00;
rxnb.dl->band_arfcn = htons(rf_arfcn);
rxnb.dl->frame_nr = htonl(rx_time.fn);
/* compute average snr and rx level */
for (i = 0; i < 4; ++i) {
avg_snr += rxnb.meas[i].snr;
avg_dbm8 += rxnb.meas[i].pm_dbm8;
}
rxnb.dl->snr = avg_snr / 4;
rxnb.dl->rx_level = dbm2rxlev(avg_dbm8 / (8*4));
num_biterr = dsp_api.ndb->a_cd[2] & 0xffff;
if (num_biterr > 0xff)
rxnb.dl->num_biterr = 0xff;
else
rxnb.dl->num_biterr = num_biterr;
rxnb.dl->fire_crc = ((dsp_api.ndb->a_cd[0] & 0xffff) & ((1 << B_FIRE1) | (1 << B_FIRE0))) >> B_FIRE0;
/* update rx level for pm report */
pu_update_rx_level(rxnb.dl->rx_level);
/* copy actual data, skipping the information block [0,1,2] */
dsp_memcpy_from_api(rxnb.di->data, &dsp_api.ndb->a_cd[3], 23, 0);
l1_queue_for_l2(rxnb.msg);
rxnb.msg = NULL; rxnb.dl = NULL; rxnb.di = NULL;
/* clear downlink task */
dsp_api.db_w->d_task_d = 0;
}
/* mark READ page as being used */
dsp_api.r_page_used = 1;
return 0;
}
static int l1s_nb_cmd(__unused uint8_t p1, uint8_t burst_id,
__unused uint16_t p3)
{
uint16_t arfcn;
uint8_t tsc, tn;
putchart('N');
if (burst_id == 1) {
/* allocate message only at 2nd burst in case of
* consecutive/overlapping normal burst RX tasks */
/* FIXME: we actually want all allocation out of L1S! */
if (rxnb.msg) {
/* Can happen when resetting ... */
printf("nb_cmd(0) and rxnb.msg != NULL\n");
msgb_free(rxnb.msg);
}
/* allocate msgb as needed. FIXME: from L1A ?? */
rxnb.msg = l1ctl_msgb_alloc(L1CTL_DATA_IND);
if (!rxnb.msg)
printf("nb_cmd(0): unable to allocate msgb\n");
rxnb.dl = (struct l1ctl_info_dl *) msgb_put(rxnb.msg, sizeof(*rxnb.dl));
rxnb.di = (struct l1ctl_data_ind *) msgb_put(rxnb.msg, sizeof(*rxnb.di));
}
rfch_get_params(&l1s.next_time, &arfcn, &tsc, &tn);
/* DDL_DSP_TASK, four normal bursts */
dsp_load_tch_param(&l1s.next_time,
SIG_ONLY_MODE, SDCCH_4, 0, 0, 0, tn);
dsp_load_rx_task(ALLC_DSP_TASK, burst_id, tsc);
l1s_rx_win_ctrl(arfcn, L1_RXWIN_NB, 0);
return 0;
}
const struct tdma_sched_item nb_sched_set[] = {
SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 0), SCHED_END_FRAME(),
SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 1), SCHED_END_FRAME(),
SCHED_ITEM(l1s_nb_resp, -4, 0, 0), SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 2), SCHED_END_FRAME(),
SCHED_ITEM(l1s_nb_resp, -4, 0, 1), SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 3), SCHED_END_FRAME(),
SCHED_ITEM(l1s_nb_resp, -4, 0, 2), SCHED_END_FRAME(),
SCHED_ITEM(l1s_nb_resp, -4, 0, 3), SCHED_END_FRAME(),
SCHED_END_SET()
};
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