1 /* Layer 1 - Receiving Normal Bursts */
3 /* (C) 2010 by Harald Welte <laforge@gnumonks.org>
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.
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.
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.
31 #include <byteorder.h>
32 #include <osmocom/gsm/gsm_utils.h>
33 #include <osmocom/core/msgb.h>
34 #include <calypso/dsp_api.h>
35 #include <calypso/irq.h>
36 #include <calypso/tpu.h>
37 #include <calypso/tsp.h>
38 #include <calypso/dsp.h>
39 #include <calypso/timer.h>
40 #include <comm/sercomm.h>
42 #include <layer1/sync.h>
43 #include <layer1/afc.h>
44 #include <layer1/toa.h>
45 #include <layer1/tdma_sched.h>
46 #include <layer1/mframe_sched.h>
47 #include <layer1/tpu_window.h>
48 #include <layer1/l23_api.h>
49 #include <layer1/rfch.h>
50 #include <layer1/prim.h>
52 #include <l1ctl_proto.h>
54 struct l1s_rxnb_state {
55 struct l1s_meas_hdr meas[4];
58 struct l1ctl_info_dl *dl;
59 struct l1ctl_data_ind *di;
62 static struct l1s_rxnb_state rxnb;
64 static int l1s_nb_resp(__unused uint8_t p1, uint8_t burst_id, uint16_t p3)
66 struct gsm_time rx_time;
67 uint8_t mf_task_id = p3 & 0xff;
68 uint8_t mf_task_flags = p3 >> 8;
74 /* just for debugging, d_task_d should not be 0 */
75 if (dsp_api.db_r->d_task_d == 0) {
80 /* DSP burst ID needs to correspond with what we expect */
81 if (dsp_api.db_r->d_burst_d != burst_id) {
82 printf("BURST ID %u!=%u\n", dsp_api.db_r->d_burst_d, burst_id);
86 /* get radio parameters for _this_ burst */
87 gsm_fn2gsmtime(&rx_time, l1s.current_time.fn - 1);
88 rfch_get_params(&rx_time, &rf_arfcn, &tsc, &tn);
90 /* collect measurements */
91 rxnb.meas[burst_id].toa_qbit = dsp_api.db_r->a_serv_demod[D_TOA];
92 rxnb.meas[burst_id].pm_dbm8 =
93 agc_inp_dbm8_by_pm(dsp_api.db_r->a_serv_demod[D_PM] >> 3);
94 rxnb.meas[burst_id].freq_err =
95 ANGLE_TO_FREQ(dsp_api.db_r->a_serv_demod[D_ANGLE]);
96 rxnb.meas[burst_id].snr = dsp_api.db_r->a_serv_demod[D_SNR];
98 /* feed computed frequency error into AFC loop */
99 if (rxnb.meas[burst_id].snr > AFC_SNR_THRESHOLD)
100 afc_input(rxnb.meas[burst_id].freq_err, rf_arfcn, 1);
102 afc_input(rxnb.meas[burst_id].freq_err, rf_arfcn, 0);
104 /* feed computed TOA into TA loop */
105 toa_input(rxnb.meas[burst_id].toa_qbit << 2, rxnb.meas[burst_id].snr);
107 /* Tell the RF frontend to set the gain appropriately */
108 rffe_set_gain(rxnb.meas[burst_id].pm_dbm8/8, CAL_DSP_TGT_BB_LVL);
110 /* 4th burst, get frame data */
111 if (dsp_api.db_r->d_burst_d == 3) {
114 uint32_t avg_snr = 0;
115 int32_t avg_dbm8 = 0;
117 /* Get radio parameters for the first burst */
118 gsm_fn2gsmtime(&rx_time, l1s.current_time.fn - 4);
119 rfch_get_params(&rx_time, &rf_arfcn, &tsc, &tn);
121 /* Set Channel Number depending on MFrame Task ID */
122 rxnb.dl->chan_nr = mframe_task2chan_nr(mf_task_id, tn);
124 /* Set SACCH indication in Link IDentifier */
125 if (mf_task_flags & MF_F_SACCH)
126 rxnb.dl->link_id = 0x40;
128 rxnb.dl->link_id = 0x00;
130 rxnb.dl->band_arfcn = htons(rf_arfcn);
132 rxnb.dl->frame_nr = htonl(rx_time.fn);
134 /* compute average snr and rx level */
135 for (i = 0; i < 4; ++i) {
136 avg_snr += rxnb.meas[i].snr;
137 avg_dbm8 += rxnb.meas[i].pm_dbm8;
139 rxnb.dl->snr = avg_snr / 4;
140 rxnb.dl->rx_level = dbm2rxlev(avg_dbm8 / (8*4));
142 num_biterr = dsp_api.ndb->a_cd[2] & 0xffff;
143 if (num_biterr > 0xff)
144 rxnb.dl->num_biterr = 0xff;
146 rxnb.dl->num_biterr = num_biterr;
148 rxnb.dl->fire_crc = ((dsp_api.ndb->a_cd[0] & 0xffff) & ((1 << B_FIRE1) | (1 << B_FIRE0))) >> B_FIRE0;
150 /* update rx level for pm report */
151 pu_update_rx_level(rxnb.dl->rx_level);
153 /* copy actual data, skipping the information block [0,1,2] */
154 dsp_memcpy_from_api(rxnb.di->data, &dsp_api.ndb->a_cd[3], 23, 0);
156 l1_queue_for_l2(rxnb.msg);
157 rxnb.msg = NULL; rxnb.dl = NULL; rxnb.di = NULL;
159 /* clear downlink task */
160 dsp_api.db_w->d_task_d = 0;
163 /* mark READ page as being used */
164 dsp_api.r_page_used = 1;
169 static int l1s_nb_cmd(__unused uint8_t p1, uint8_t burst_id,
170 __unused uint16_t p3)
178 /* allocate message only at 2nd burst in case of
179 * consecutive/overlapping normal burst RX tasks */
180 /* FIXME: we actually want all allocation out of L1S! */
182 /* Can happen when resetting ... */
183 printf("nb_cmd(0) and rxnb.msg != NULL\n");
186 /* allocate msgb as needed. FIXME: from L1A ?? */
187 rxnb.msg = l1ctl_msgb_alloc(L1CTL_DATA_IND);
189 printf("nb_cmd(0): unable to allocate msgb\n");
190 rxnb.dl = (struct l1ctl_info_dl *) msgb_put(rxnb.msg, sizeof(*rxnb.dl));
191 rxnb.di = (struct l1ctl_data_ind *) msgb_put(rxnb.msg, sizeof(*rxnb.di));
194 rfch_get_params(&l1s.next_time, &arfcn, &tsc, &tn);
196 /* DDL_DSP_TASK, four normal bursts */
197 dsp_load_tch_param(&l1s.next_time,
198 SIG_ONLY_MODE, SDCCH_4, 0, 0, 0, tn);
200 dsp_load_rx_task(ALLC_DSP_TASK, burst_id, tsc);
202 l1s_rx_win_ctrl(arfcn, L1_RXWIN_NB, 0);
207 const struct tdma_sched_item nb_sched_set[] = {
208 SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 0), SCHED_END_FRAME(),
209 SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 1), SCHED_END_FRAME(),
210 SCHED_ITEM(l1s_nb_resp, -4, 0, 0), SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 2), SCHED_END_FRAME(),
211 SCHED_ITEM(l1s_nb_resp, -4, 0, 1), SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 3), SCHED_END_FRAME(),
212 SCHED_ITEM(l1s_nb_resp, -4, 0, 2), SCHED_END_FRAME(),
213 SCHED_ITEM(l1s_nb_resp, -4, 0, 3), SCHED_END_FRAME(),