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-rw-r--r--src/host/trxcon/src/sched_lchan_tchh.c622
1 files changed, 622 insertions, 0 deletions
diff --git a/src/host/trxcon/src/sched_lchan_tchh.c b/src/host/trxcon/src/sched_lchan_tchh.c
new file mode 100644
index 00000000..99e26808
--- /dev/null
+++ b/src/host/trxcon/src/sched_lchan_tchh.c
@@ -0,0 +1,622 @@
+/*
+ * OsmocomBB <-> SDR connection bridge
+ * TDMA scheduler: handlers for DL / UL bursts on logical channels
+ *
+ * (C) 2018-2022 by Vadim Yanitskiy <axilirator@gmail.com>
+ * (C) 2018 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2020-2023 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * 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.
+ *
+ */
+
+#include <errno.h>
+#include <string.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <osmocom/core/logging.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/bits.h>
+
+#include <osmocom/gsm/protocol/gsm_04_08.h>
+#include <osmocom/gsm/gsm_utils.h>
+#include <osmocom/gsm/gsm0502.h>
+
+#include <osmocom/coding/gsm0503_coding.h>
+#include <osmocom/coding/gsm0503_amr_dtx.h>
+#include <osmocom/codec/codec.h>
+
+#include <osmocom/bb/l1sched/l1sched.h>
+#include <osmocom/bb/l1sched/logging.h>
+
+/* Burst Payload LENgth (short alias) */
+#define BPLEN GSM_NBITS_NB_GMSK_PAYLOAD
+
+/* Burst BUFfer capacity (in BPLEN units) */
+#define BUFMAX 24
+
+/* Burst BUFfer position macros */
+#define BUFPOS(buf, n) &buf[(n) * BPLEN]
+#define BUFTAIL8(buf) BUFPOS(buf, (BUFMAX - 8))
+
+/* 3GPP TS 45.009, table 3.2.1.3-{2,4}: AMR on Downlink TCH/H.
+ *
+ * +---+---+---+---+---+---+
+ * | a | b | c | d | e | f | Burst 'a' received first
+ * +---+---+---+---+---+---+
+ * ^^^^^^^^^^^^^^^^^^^^^^^ FACCH frame (bursts 'a' .. 'f')
+ * ^^^^^^^^^^^^^^^ Speech frame (bursts 'a' .. 'd')
+ *
+ * TDMA frame number of burst 'f' is always used as the table index. */
+static const uint8_t sched_tchh_dl_amr_cmi_map[26] = {
+ [15] = 1, /* TCH/H(0): a=4 / d=10 / f=15 */
+ [23] = 1, /* TCH/H(0): a=13 / d=19 / f=23 */
+ [6] = 1, /* TCH/H(0): a=21 / d=2 / f=6 */
+
+ [16] = 1, /* TCH/H(1): a=5 / d=11 / f=16 */
+ [24] = 1, /* TCH/H(1): a=14 / d=20 / f=24 */
+ [7] = 1, /* TCH/H(1): a=22 / d=3 / f=7 */
+};
+
+/* TDMA frame number of burst 'a' is always used as the table index. */
+static const uint8_t sched_tchh_ul_amr_cmi_map[26] = {
+ [0] = 1, /* TCH/H(0): a=0 */
+ [8] = 1, /* TCH/H(0): a=8 */
+ [17] = 1, /* TCH/H(0): a=17 */
+
+ [1] = 1, /* TCH/H(1): a=1 */
+ [9] = 1, /* TCH/H(1): a=9 */
+ [18] = 1, /* TCH/H(1): a=18 */
+};
+
+static const uint8_t tch_h0_traffic_block_map[3][4] = {
+ /* B0(0,2,4,6), B1(4,6,8,10), B2(8,10,0,2) */
+ { 0, 2, 4, 6 },
+ { 4, 6, 8, 10 },
+ { 8, 10, 0, 2 },
+};
+
+static const uint8_t tch_h1_traffic_block_map[3][4] = {
+ /* B0(1,3,5,7), B1(5,7,9,11), B2(9,11,1,3) */
+ { 1, 3, 5, 7 },
+ { 5, 7, 9, 11 },
+ { 9, 11, 1, 3 },
+};
+
+static const uint8_t tch_h0_dl_facch_block_map[3][6] = {
+ /* B0(4,6,8,10,13,15), B1(13,15,17,19,21,23), B2(21,23,0,2,4,6) */
+ { 4, 6, 8, 10, 13, 15 },
+ { 13, 15, 17, 19, 21, 23 },
+ { 21, 23, 0, 2, 4, 6 },
+};
+
+static const uint8_t tch_h0_ul_facch_block_map[3][6] = {
+ /* B0(0,2,4,6,8,10), B1(8,10,13,15,17,19), B2(17,19,21,23,0,2) */
+ { 0, 2, 4, 6, 8, 10 },
+ { 8, 10, 13, 15, 17, 19 },
+ { 17, 19, 21, 23, 0, 2 },
+};
+
+static const uint8_t tch_h1_dl_facch_block_map[3][6] = {
+ /* B0(5,7,9,11,14,16), B1(14,16,18,20,22,24), B2(22,24,1,3,5,7) */
+ { 5, 7, 9, 11, 14, 16 },
+ { 14, 16, 18, 20, 22, 24 },
+ { 22, 24, 1, 3, 5, 7 },
+};
+
+const uint8_t tch_h1_ul_facch_block_map[3][6] = {
+ /* B0(1,3,5,7,9,11), B1(9,11,14,16,18,20), B2(18,20,22,24,1,3) */
+ { 1, 3, 5, 7, 9, 11 },
+ { 9, 11, 14, 16, 18, 20 },
+ { 18, 20, 22, 24, 1, 3 },
+};
+
+/* FACCH/H channel mapping for Downlink (see 3GPP TS 45.002, table 1).
+ * This mapping is valid for both FACCH/H(0) and FACCH/H(1).
+ * TDMA frame number of burst 'f' is used as the table index. */
+static const uint8_t sched_tchh_dl_facch_map[26] = {
+ [15] = 1, /* FACCH/H(0): B0(4,6,8,10,13,15) */
+ [16] = 1, /* FACCH/H(1): B0(5,7,9,11,14,16) */
+ [23] = 1, /* FACCH/H(0): B1(13,15,17,19,21,23) */
+ [24] = 1, /* FACCH/H(1): B1(14,16,18,20,22,24) */
+ [6] = 1, /* FACCH/H(0): B2(21,23,0,2,4,6) */
+ [7] = 1, /* FACCH/H(1): B2(22,24,1,3,5,7) */
+};
+
+/* 3GPP TS 45.002, table 2 in clause 7: Mapping tables for TCH/H2.4 and TCH/H4.8.
+ *
+ * +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
+ * | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v |
+ * +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
+ *
+ * TCH/H(0): B0(0,2,4,6,8,10,13,15,17,19,21,23,0,2,4,6,8,10,13,15,17,19)
+ * TCH/H(1): B0(1,3,5,7,9,11,14,16,18,20,22,24,1,3,5,7,9,11,14,16,18,20)
+ * TCH/H(0): B1(8,10,13,15,17,19,21,23,0,2,4,6,8,10,13,15,17,19,21,23,0,2)
+ * TCH/H(1): B1(9,11,14,16,18,20,22,24,1,3,5,7,9,11,14,16,18,20,22,24,1,3)
+ * TCH/H(0): B2(17,19,21,23,0,2,4,6,8,10,13,15,17,19,21,23,0,2,4,6,8,10)
+ * TCH/H(1): B2(18,20,22,24,1,3,5,7,9,11,14,16,18,20,22,24,1,3,5,7,9,11)
+ *
+ * TDMA frame number of burst 'a' % 26 is the table index.
+ * This mapping is valid for both TCH/H(0) and TCH/H(1). */
+static const uint8_t sched_tchh_ul_csd_map[26] = {
+ [0] = 1, /* TCH/H(0): B0(0 ... 19) */
+ [1] = 1, /* TCH/H(1): B0(1 ... 20) */
+ [8] = 1, /* TCH/H(0): B1(8 ... 2) */
+ [9] = 1, /* TCH/H(1): B1(9 ... 3) */
+ [17] = 1, /* TCH/H(0): B2(17 ... 10) */
+ [18] = 1, /* TCH/H(1): B2(18 ... 11) */
+};
+
+/* TDMA frame number of burst 'v' % 26 is the table index.
+ * This mapping is valid for both TCH/H(0) and TCH/H(1). */
+static const uint8_t sched_tchh_dl_csd_map[26] = {
+ [19] = 1, /* TCH/H(0): B0(0 ... 19) */
+ [20] = 1, /* TCH/H(1): B0(1 ... 20) */
+ [2] = 1, /* TCH/H(0): B1(8 ... 2) */
+ [3] = 1, /* TCH/H(1): B1(9 ... 3) */
+ [10] = 1, /* TCH/H(0): B2(17 ... 10) */
+ [11] = 1, /* TCH/H(1): B2(18 ... 11) */
+};
+
+/**
+ * Can a TCH/H block transmission be initiated / finished
+ * on a given frame number and a given channel type?
+ *
+ * See GSM 05.02, clause 7, table 1
+ *
+ * @param chan channel type (L1SCHED_TCHH_0 or L1SCHED_TCHH_1)
+ * @param fn the current frame number
+ * @param ul Uplink or Downlink?
+ * @param facch FACCH/H or traffic?
+ * @param start init or end of transmission?
+ * @return true (yes) or false (no)
+ */
+bool l1sched_tchh_block_map_fn(enum l1sched_lchan_type chan,
+ uint32_t fn, bool ul, bool facch, bool start)
+{
+ uint8_t fn_mf;
+ int i = 0;
+
+ /* Just to be sure */
+ OSMO_ASSERT(chan == L1SCHED_TCHH_0 || chan == L1SCHED_TCHH_1);
+
+ /* Calculate a modulo */
+ fn_mf = facch ? (fn % 26) : (fn % 13);
+
+#define MAP_GET_POS(map) \
+ (start ? 0 : ARRAY_SIZE(map[i]) - 1)
+
+#define BLOCK_MAP_FN(map) \
+ do { \
+ if (map[i][MAP_GET_POS(map)] == fn_mf) \
+ return true; \
+ } while (++i < ARRAY_SIZE(map))
+
+ /* Choose a proper block map */
+ if (facch) {
+ if (ul) {
+ if (chan == L1SCHED_TCHH_0)
+ BLOCK_MAP_FN(tch_h0_ul_facch_block_map);
+ else
+ BLOCK_MAP_FN(tch_h1_ul_facch_block_map);
+ } else {
+ if (chan == L1SCHED_TCHH_0)
+ BLOCK_MAP_FN(tch_h0_dl_facch_block_map);
+ else
+ BLOCK_MAP_FN(tch_h1_dl_facch_block_map);
+ }
+ } else {
+ if (chan == L1SCHED_TCHH_0)
+ BLOCK_MAP_FN(tch_h0_traffic_block_map);
+ else
+ BLOCK_MAP_FN(tch_h1_traffic_block_map);
+ }
+
+ return false;
+}
+
+static int decode_hr_facch(struct l1sched_lchan_state *lchan)
+{
+ uint8_t data[GSM_MACBLOCK_LEN];
+ int n_errors, n_bits_total;
+ int rc;
+
+ rc = gsm0503_tch_hr_facch_decode(&data[0], BUFTAIL8(lchan->rx_bursts),
+ &n_errors, &n_bits_total);
+ if (rc != GSM_MACBLOCK_LEN)
+ return rc;
+
+ /* calculate AVG of the measurements (FACCH/H takes 6 bursts) */
+ l1sched_lchan_meas_avg(lchan, 6);
+
+ l1sched_lchan_emit_data_ind(lchan, &data[0], GSM_MACBLOCK_LEN,
+ n_errors, n_bits_total, false);
+
+ return GSM_MACBLOCK_LEN;
+}
+
+int rx_tchh_fn(struct l1sched_lchan_state *lchan,
+ const struct l1sched_burst_ind *bi)
+{
+ int n_errors = -1, n_bits_total = 0, rc;
+ sbit_t *bursts_p, *burst;
+ uint8_t tch_data[240];
+ size_t tch_data_len;
+ uint32_t *mask;
+ int amr = 0;
+ uint8_t ft;
+
+ /* Set up pointers */
+ mask = &lchan->rx_burst_mask;
+ bursts_p = lchan->rx_bursts;
+
+ LOGP_LCHAND(lchan, LOGL_DEBUG,
+ "Traffic received: fn=%u bid=%u\n", bi->fn, bi->bid);
+
+ if (bi->bid == 0) {
+ /* Shift the burst buffer by 2 bursts leftwards */
+ memmove(BUFPOS(bursts_p, 0), BUFPOS(bursts_p, 2), 20 * BPLEN);
+ memset(BUFPOS(bursts_p, 20), 0, 2 * BPLEN);
+ *mask = *mask << 2;
+ }
+
+ if (*mask == 0x00) {
+ /* Align to the first burst */
+ if (bi->bid > 0)
+ return 0;
+
+ /* Align reception of the first FACCH/H frame */
+ if (lchan->tch_mode == GSM48_CMODE_SIGN) {
+ if (!l1sched_tchh_facch_start(lchan->type, bi->fn, 0))
+ return 0;
+ }
+ }
+
+ /* Update mask */
+ *mask |= (1 << bi->bid);
+
+ /* Store the measurements */
+ l1sched_lchan_meas_push(lchan, bi);
+
+ /* Copy burst to the end of buffer of 24 bursts */
+ burst = BUFPOS(bursts_p, 20 + bi->bid);
+ memcpy(burst, bi->burst + 3, 58);
+ memcpy(burst + 58, bi->burst + 87, 58);
+
+ /* Wait until the second burst */
+ if (bi->bid != 1)
+ return 0;
+
+ /* Wait for complete set of bursts */
+ switch (lchan->tch_mode) {
+ case GSM48_CMODE_SIGN:
+ /* FACCH/H is interleaved over 6 bursts */
+ if ((*mask & 0x3f) != 0x3f)
+ return 0;
+ break;
+ case GSM48_CMODE_DATA_6k0:
+ case GSM48_CMODE_DATA_3k6:
+ /* Data (CSD) is interleaved over 22 bursts */
+ if ((*mask & 0x3fffff) != 0x3fffff)
+ return 0;
+ if (!sched_tchh_dl_csd_map[bi->fn % 26])
+ return 0; /* CSD: skip decoding attempt, need 2 more bursts */
+ break;
+ default:
+ /* Speech is interleaved over 4 bursts */
+ if ((*mask & 0x0f) != 0x0f)
+ return 0;
+ break;
+ }
+
+ /* Skip decoding attempt in case of FACCH/H */
+ if (lchan->dl_ongoing_facch) {
+ /* Send BFI (DATA.ind without payload) for the 2nd stolen TCH frame */
+ l1sched_lchan_meas_avg(lchan, 4);
+ l1sched_lchan_emit_data_ind(lchan, NULL, 0, 0, 0, true);
+ lchan->dl_ongoing_facch = false;
+ return 0;
+ }
+
+ /* TCH/H: speech and signalling frames are interleaved over 4 and 6 bursts,
+ * respectively, while CSD frames are interleaved over 22 bursts. Unless
+ * we're in CSD mode, decode only the last 6 bursts to avoid introducing
+ * additional delays. */
+ switch (lchan->tch_mode) {
+ case GSM48_CMODE_SIGN:
+ case GSM48_CMODE_SPEECH_V1: /* HR */
+ rc = gsm0503_tch_hr_decode(&tch_data[0], BUFTAIL8(bursts_p),
+ !sched_tchh_dl_facch_map[bi->fn % 26],
+ &n_errors, &n_bits_total);
+ break;
+ case GSM48_CMODE_SPEECH_AMR: /* AMR */
+ /* See comment in function rx_tchf_fn() */
+ amr = 2;
+ rc = gsm0503_tch_ahs_decode_dtx(&tch_data[amr], BUFTAIL8(bursts_p),
+ !sched_tchh_dl_facch_map[bi->fn % 26],
+ !sched_tchh_dl_amr_cmi_map[bi->fn % 26],
+ lchan->amr.codec,
+ lchan->amr.codecs,
+ &lchan->amr.dl_ft,
+ &lchan->amr.dl_cmr,
+ &n_errors, &n_bits_total,
+ &lchan->amr.last_dtx);
+
+ /* only good speech frames get rtp header */
+ if (rc != GSM_MACBLOCK_LEN && rc >= 4) {
+ if (lchan->amr.last_dtx == AMR_OTHER) {
+ ft = lchan->amr.codec[lchan->amr.dl_ft];
+ } else {
+ /* SID frames will always get Frame Type Index 8 (AMR_SID) */
+ ft = AMR_SID;
+ }
+ rc = osmo_amr_rtp_enc(&tch_data[0],
+ lchan->amr.codec[lchan->amr.dl_cmr],
+ ft, AMR_GOOD);
+ if (rc < 0)
+ LOGP_LCHAND(lchan, LOGL_ERROR,
+ "osmo_amr_rtp_enc() returned rc=%d\n", rc);
+ }
+ break;
+ /* CSD (TCH/H4.8): 6.0 kbit/s radio interface rate */
+ case GSM48_CMODE_DATA_6k0:
+ /* FACCH/H does not steal TCH/H4.8 frames, but only disturbs some bits */
+ decode_hr_facch(lchan);
+ rc = gsm0503_tch_hr48_decode(&tch_data[0], BUFPOS(bursts_p, 0),
+ &n_errors, &n_bits_total);
+ break;
+ /* CSD (TCH/H2.4): 3.6 kbit/s radio interface rate */
+ case GSM48_CMODE_DATA_3k6:
+ /* FACCH/H does not steal TCH/H2.4 frames, but only disturbs some bits */
+ decode_hr_facch(lchan);
+ rc = gsm0503_tch_hr24_decode(&tch_data[0], BUFPOS(bursts_p, 0),
+ &n_errors, &n_bits_total);
+ break;
+ default:
+ LOGP_LCHAND(lchan, LOGL_ERROR, "Invalid TCH mode: %u\n", lchan->tch_mode);
+ return -EINVAL;
+ }
+
+ /* Check decoding result */
+ if (rc < 4) {
+ LOGP_LCHAND(lchan, LOGL_ERROR,
+ "Received bad frame (rc=%d, ber=%d/%d) at fn=%u\n",
+ rc, n_errors, n_bits_total, lchan->meas_avg.fn);
+
+ /* Send BFI (DATA.ind without payload) */
+ tch_data_len = 0;
+ } else if (rc == GSM_MACBLOCK_LEN) {
+ /* Skip decoding of the next 2 stolen bursts */
+ lchan->dl_ongoing_facch = true;
+
+ /* Calculate AVG of the measurements (FACCH/H takes 6 bursts) */
+ l1sched_lchan_meas_avg(lchan, 6);
+
+ /* FACCH/H received, forward to the higher layers */
+ l1sched_lchan_emit_data_ind(lchan, &tch_data[amr], GSM_MACBLOCK_LEN,
+ n_errors, n_bits_total, false);
+
+ /* Send BFI (DATA.ind without payload) for the 1st stolen TCH frame */
+ if (lchan->tch_mode == GSM48_CMODE_SIGN)
+ return 0;
+ tch_data_len = 0;
+ } else {
+ /* A good TCH frame received */
+ tch_data_len = rc;
+ }
+
+ /* Calculate AVG of the measurements (traffic takes 4 bursts) */
+ l1sched_lchan_meas_avg(lchan, 4);
+
+ /* Send a traffic frame to the higher layers */
+ return l1sched_lchan_emit_data_ind(lchan, &tch_data[0], tch_data_len,
+ n_errors, n_bits_total, true);
+}
+
+int tx_tchh_fn(struct l1sched_lchan_state *lchan,
+ struct l1sched_burst_req *br)
+{
+ struct msgb *msg_facch, *msg_tch, *msg;
+ ubit_t *bursts_p, *burst;
+ const uint8_t *tsc;
+ uint32_t *mask;
+ int rc;
+
+ /* Set up pointers */
+ mask = &lchan->tx_burst_mask;
+ bursts_p = lchan->tx_bursts;
+
+ if (br->bid > 0) {
+ if ((*mask & 0x01) != 0x01)
+ return -ENOENT;
+ goto send_burst;
+ }
+
+ if (*mask == 0x00) {
+ /* Align transmission of the first frame */
+ switch (lchan->tch_mode) {
+ case GSM48_CMODE_SIGN:
+ if (!l1sched_tchh_facch_start(lchan->type, br->fn, 1))
+ return 0;
+ break;
+ case GSM48_CMODE_DATA_6k0:
+ case GSM48_CMODE_DATA_3k6:
+ if (!sched_tchh_ul_csd_map[br->fn % 26])
+ return 0;
+ break;
+ }
+ }
+
+ /* Shift the burst buffer by 2 bursts leftwards for interleaving */
+ memmove(BUFPOS(bursts_p, 0), BUFPOS(bursts_p, 2), 20 * BPLEN);
+ memset(BUFPOS(bursts_p, 20), 0, 2 * BPLEN);
+ *mask = *mask << 2;
+
+ /* If FACCH/H blocks are still pending */
+ if (lchan->ul_facch_blocks > 2) {
+ struct msgb *msg = l1sched_lchan_prim_dequeue_tch(lchan, false);
+ msgb_free(msg); /* drop 2nd TCH/HS block */
+ goto send_burst;
+ }
+
+ switch (lchan->tch_mode) {
+ case GSM48_CMODE_DATA_6k0:
+ case GSM48_CMODE_DATA_3k6:
+ /* CSD: skip dequeueing/encoding, send 2 more bursts */
+ if (!sched_tchh_ul_csd_map[br->fn % 26])
+ goto send_burst;
+ break;
+ }
+
+ /* dequeue a pair of TCH and FACCH frames */
+ msg_tch = l1sched_lchan_prim_dequeue_tch(lchan, false);
+ if (l1sched_tchh_facch_start(lchan->type, br->fn, true))
+ msg_facch = l1sched_lchan_prim_dequeue_tch(lchan, true);
+ else
+ msg_facch = NULL;
+ /* prioritize FACCH over TCH */
+ msg = (msg_facch != NULL) ? msg_facch : msg_tch;
+
+ /* populate the buffer with bursts */
+ switch (lchan->tch_mode) {
+ case GSM48_CMODE_SIGN:
+ if (!l1sched_tchh_facch_start(lchan->type, br->fn, 1))
+ goto send_burst; /* XXX: should not happen */
+ if (msg == NULL)
+ msg = l1sched_lchan_prim_dummy_lapdm(lchan);
+ /* fall-through */
+ case GSM48_CMODE_SPEECH_V1:
+ if (msg == NULL) {
+ /* transmit a dummy speech block with inverted CRC3 */
+ gsm0503_tch_hr_encode(bursts_p, NULL, 0);
+ goto send_burst;
+ }
+ rc = gsm0503_tch_hr_encode(BUFPOS(bursts_p, 0),
+ msgb_l2(msg),
+ msgb_l2len(msg));
+ break;
+ case GSM48_CMODE_SPEECH_AMR:
+ {
+ bool amr_fn_is_cmr = !sched_tchh_ul_amr_cmi_map[br->fn % 26];
+ const uint8_t *data = msg ? msgb_l2(msg) : NULL;
+ size_t data_len = msg ? msgb_l2len(msg) : 0;
+
+ if (msg == NULL) {
+ /* TODO: It's not clear what to do for TCH/AHS.
+ * TODO: Send dummy FACCH maybe? */
+ goto send_burst; /* send garbage */
+ }
+
+ if (data_len != GSM_MACBLOCK_LEN) { /* TCH/AHS: speech */
+ if (!l1sched_lchan_amr_prim_is_valid(lchan, msg, amr_fn_is_cmr))
+ goto free_bad_msg;
+ /* pull the AMR header - sizeof(struct amr_hdr) */
+ data_len -= 2;
+ data += 2;
+ }
+
+ rc = gsm0503_tch_ahs_encode(BUFPOS(bursts_p, 0),
+ data, data_len,
+ amr_fn_is_cmr,
+ lchan->amr.codec,
+ lchan->amr.codecs,
+ lchan->amr.ul_ft,
+ lchan->amr.ul_cmr);
+ break;
+ }
+ /* CSD (TCH/H4.8): 6.0 kbit/s radio interface rate */
+ case GSM48_CMODE_DATA_6k0:
+ if ((msg = msg_tch) != NULL) {
+ OSMO_ASSERT(msgb_l2len(msg) == 4 * 60);
+ gsm0503_tch_hr48_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+ /* Confirm data sending (pass ownership of the msgb/prim) */
+ l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+ } else {
+ ubit_t idle[4 * 60];
+ memset(&idle[0], 0x01, sizeof(idle));
+ gsm0503_tch_hr48_encode(BUFPOS(bursts_p, 0), &idle[0]);
+ }
+ if ((msg = msg_facch) != NULL) {
+ gsm0503_tch_hr_facch_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+ /* Confirm FACCH sending (pass ownership of the msgb/prim) */
+ l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+ }
+ goto send_burst;
+ /* CSD (TCH/H2.4): 3.6 kbit/s radio interface rate */
+ case GSM48_CMODE_DATA_3k6:
+ if ((msg = msg_tch) != NULL) {
+ OSMO_ASSERT(msgb_l2len(msg) == 4 * 36);
+ gsm0503_tch_hr24_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+ /* Confirm data sending (pass ownership of the msgb/prim) */
+ l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+ } else {
+ ubit_t idle[4 * 36];
+ memset(&idle[0], 0x01, sizeof(idle));
+ gsm0503_tch_hr24_encode(BUFPOS(bursts_p, 0), &idle[0]);
+ }
+ if ((msg = msg_facch) != NULL) {
+ gsm0503_tch_hr_facch_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+ /* Confirm FACCH sending (pass ownership of the msgb/prim) */
+ l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+ }
+ goto send_burst;
+ default:
+ LOGP_LCHAND(lchan, LOGL_ERROR,
+ "TCH mode %s is unknown or not supported\n",
+ gsm48_chan_mode_name(lchan->tch_mode));
+ goto free_bad_msg;
+ }
+
+ if (rc) {
+ LOGP_LCHAND(lchan, LOGL_ERROR, "Failed to encode L2 payload (len=%u): %s\n",
+ msgb_l2len(msg), msgb_hexdump_l2(msg));
+free_bad_msg:
+ msgb_free(msg_facch);
+ msgb_free(msg_tch);
+ return -EINVAL;
+ }
+
+ if (msgb_l2len(msg) == GSM_MACBLOCK_LEN)
+ lchan->ul_facch_blocks = 6;
+
+ /* Confirm data / traffic sending (pass ownership of the msgb/prim) */
+ l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+ msgb_free((msg == msg_facch) ? msg_tch : msg_facch);
+
+send_burst:
+ /* Determine which burst should be sent */
+ burst = BUFPOS(bursts_p, br->bid);
+
+ /* Update mask */
+ *mask |= (1 << br->bid);
+
+ /* Choose proper TSC */
+ tsc = l1sched_nb_training_bits[lchan->tsc];
+
+ /* Compose a new burst */
+ memset(br->burst, 0, 3); /* TB */
+ memcpy(br->burst + 3, burst, 58); /* Payload 1/2 */
+ memcpy(br->burst + 61, tsc, 26); /* TSC */
+ memcpy(br->burst + 87, burst + 58, 58); /* Payload 2/2 */
+ memset(br->burst + 145, 0, 3); /* TB */
+ br->burst_len = GSM_NBITS_NB_GMSK_BURST;
+
+ LOGP_LCHAND(lchan, LOGL_DEBUG, "Scheduled fn=%u burst=%u\n", br->fn, br->bid);
+
+ /* In case of a FACCH/H frame, one block less */
+ if (lchan->ul_facch_blocks)
+ lchan->ul_facch_blocks--;
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-28 02:54:31 +0000