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 <osmocore/gsm_utils.h>
33 #include <osmocore/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/tdma_sched.h>
45 #include <layer1/mframe_sched.h>
46 #include <layer1/tpu_window.h>
47 #include <layer1/l23_api.h>
48 #include <layer1/rfch.h>
49 #include <layer1/prim.h>
51 #include <l1ctl_proto.h>
53 struct l1s_rxnb_state {
54 struct l1s_meas_hdr meas[4];
57 struct l1ctl_info_dl *dl;
58 struct l1ctl_data_ind *di;
61 static struct l1s_rxnb_state rxnb;
63 static int l1s_nb_resp(__unused uint8_t p1, uint8_t burst_id, uint16_t p3)
65 struct gsm_time rx_time;
66 uint8_t mf_task_id = p3 & 0xff;
67 uint8_t mf_task_flags = p3 >> 8;
73 /* just for debugging, d_task_d should not be 0 */
74 if (dsp_api.db_r->d_task_d == 0) {
79 /* DSP burst ID needs to corespond with what we expect */
80 if (dsp_api.db_r->d_burst_d != burst_id) {
81 printf("BURST ID %u!=%u\n", dsp_api.db_r->d_burst_d, burst_id);
85 /* get radio parameters for _this_ burst */
86 gsm_fn2gsmtime(&rx_time, l1s.current_time.fn - 1);
87 rfch_get_params(&rx_time, &rf_arfcn, &tsc, &tn);
89 /* collect measurements */
90 rxnb.meas[burst_id].toa_qbit = dsp_api.db_r->a_serv_demod[D_TOA];
91 rxnb.meas[burst_id].pm_dbm8 =
92 agc_inp_dbm8_by_pm(dsp_api.db_r->a_serv_demod[D_PM] >> 3);
93 rxnb.meas[burst_id].freq_err =
94 ANGLE_TO_FREQ(dsp_api.db_r->a_serv_demod[D_ANGLE]);
95 rxnb.meas[burst_id].snr = dsp_api.db_r->a_serv_demod[D_SNR];
97 /* feed computed frequency error into AFC loop */
98 if (rxnb.meas[burst_id].snr > AFC_SNR_THRESHOLD)
99 afc_input(rxnb.meas[burst_id].freq_err, rf_arfcn, 1);
101 afc_input(rxnb.meas[burst_id].freq_err, rf_arfcn, 0);
103 /* Tell the RF frontend to set the gain appropriately */
104 rffe_set_gain(rxnb.meas[burst_id].pm_dbm8/8, CAL_DSP_TGT_BB_LVL);
106 /* 4th burst, get frame data */
107 if (dsp_api.db_r->d_burst_d == 3) {
110 uint32_t avg_snr = 0;
111 int32_t avg_dbm8 = 0;
113 /* Get radio parameters for the first burst */
114 gsm_fn2gsmtime(&rx_time, l1s.current_time.fn - 4);
115 rfch_get_params(&rx_time, &rf_arfcn, &tsc, &tn);
117 /* Set Channel Number depending on MFrame Task ID */
118 rxnb.dl->chan_nr = mframe_task2chan_nr(mf_task_id, tn);
120 /* Set SACCH indication in Link IDentifier */
121 if (mf_task_flags & MF_F_SACCH)
122 rxnb.dl->link_id = 0x40;
124 rxnb.dl->link_id = 0x00;
126 rxnb.dl->band_arfcn = htons(rf_arfcn);
128 rxnb.dl->frame_nr = htonl(rx_time.fn);
130 /* compute average snr and rx level */
131 for (i = 0; i < 4; ++i) {
132 avg_snr += rxnb.meas[i].snr;
133 avg_dbm8 += rxnb.meas[i].pm_dbm8;
135 rxnb.dl->snr = avg_snr / 4;
136 rxnb.dl->rx_level = (avg_dbm8 / (8*4)) + 110;
138 num_biterr = dsp_api.ndb->a_cd[2] & 0xffff;
139 if (num_biterr > 0xff)
140 rxnb.dl->num_biterr = 0xff;
142 rxnb.dl->num_biterr = num_biterr;
144 rxnb.dl->fire_crc = ((dsp_api.ndb->a_cd[0] & 0xffff) & ((1 << B_FIRE1) | (1 << B_FIRE0))) >> B_FIRE0;
146 /* update rx level for pm report */
147 pu_update_rx_level(rxnb.dl->rx_level);
149 /* copy actual data, skipping the information block [0,1,2] */
150 dsp_memcpy_from_api(rxnb.di->data, &dsp_api.ndb->a_cd[3], 23, 0);
152 l1_queue_for_l2(rxnb.msg);
153 rxnb.msg = NULL; rxnb.dl = NULL; rxnb.di = NULL;
155 /* clear downlink task */
156 dsp_api.db_w->d_task_d = 0;
159 /* mark READ page as being used */
160 dsp_api.r_page_used = 1;
165 static int l1s_nb_cmd(__unused uint8_t p1, uint8_t burst_id,
166 __unused uint16_t p3)
174 /* allocate message only at 2nd burst in case of
175 * consecutive/overlapping normal burst RX tasks */
176 /* FIXME: we actually want all allocation out of L1S! */
178 /* Can happen when resetting ... */
179 printf("nb_cmd(0) and rxnb.msg != NULL\n");
182 /* allocate msgb as needed. FIXME: from L1A ?? */
183 rxnb.msg = l1ctl_msgb_alloc(L1CTL_DATA_IND);
185 printf("nb_cmd(0): unable to allocate msgb\n");
186 rxnb.dl = (struct l1ctl_info_dl *) msgb_put(rxnb.msg, sizeof(*rxnb.dl));
187 rxnb.di = (struct l1ctl_data_ind *) msgb_put(rxnb.msg, sizeof(*rxnb.di));
190 rfch_get_params(&l1s.next_time, &arfcn, &tsc, &tn);
192 /* DDL_DSP_TASK, four normal bursts */
193 dsp_load_tch_param(&l1s.next_time,
194 SIG_ONLY_MODE, SDCCH_4, 0, 0, 0, tn);
196 dsp_load_rx_task(ALLC_DSP_TASK, burst_id, tsc);
198 l1s_rx_win_ctrl(arfcn, L1_RXWIN_NB, 0);
203 const struct tdma_sched_item nb_sched_set[] = {
204 SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 0), SCHED_END_FRAME(),
205 SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 1), SCHED_END_FRAME(),
206 SCHED_ITEM(l1s_nb_resp, -4, 0, 0), SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 2), SCHED_END_FRAME(),
207 SCHED_ITEM(l1s_nb_resp, -4, 0, 1), SCHED_ITEM_DT(l1s_nb_cmd, 0, 0, 3), SCHED_END_FRAME(),
208 SCHED_ITEM(l1s_nb_resp, -4, 0, 2), SCHED_END_FRAME(),
209 SCHED_ITEM(l1s_nb_resp, -4, 0, 3), SCHED_END_FRAME(),