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-rw-r--r--src/host/trxcon/sched_lchan_tchh.c319
1 files changed, 319 insertions, 0 deletions
diff --git a/src/host/trxcon/sched_lchan_tchh.c b/src/host/trxcon/sched_lchan_tchh.c
index 316f995b..7fb2809d 100644
--- a/src/host/trxcon/sched_lchan_tchh.c
+++ b/src/host/trxcon/sched_lchan_tchh.c
@@ -3,6 +3,7 @@
* TDMA scheduler: handlers for DL / UL bursts on logical channels
*
* (C) 2018 by Vadim Yanitskiy <axilirator@gmail.com>
+ * (C) 2018 by Harald Welte <laforge@gnumonks.org>
*
* All Rights Reserved
*
@@ -23,11 +24,27 @@
*/
#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/coding/gsm0503_coding.h>
+#include <osmocom/codec/codec.h>
+
+#include "l1ctl_proto.h"
#include "scheduler.h"
#include "sched_trx.h"
+#include "logging.h"
+#include "trx_if.h"
+#include "trxcon.h"
+#include "l1ctl.h"
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) */
@@ -181,3 +198,305 @@ uint32_t sched_tchh_block_dl_first_fn(enum trx_lchan_type chan,
/* Couldn't calculate the first fn, return the last */
return last_fn;
}
+
+int rx_tchh_fn(struct trx_instance *trx, struct trx_ts *ts,
+ struct trx_lchan_state *lchan, uint32_t fn, uint8_t bid,
+ sbit_t *bits, int8_t rssi, int16_t toa256)
+{
+ const struct trx_lchan_desc *lchan_desc;
+ int n_errors = -1, n_bits_total, rc;
+ sbit_t *buffer, *offset;
+ uint8_t l2[128], *mask;
+ size_t l2_len;
+
+ /* Set up pointers */
+ lchan_desc = &trx_lchan_desc[lchan->type];
+ mask = &lchan->rx_burst_mask;
+ buffer = lchan->rx_bursts;
+
+ LOGP(DSCHD, LOGL_DEBUG, "Traffic received on %s: fn=%u ts=%u bid=%u\n",
+ lchan_desc->name, fn, ts->index, bid);
+
+ if (*mask == 0x00) {
+ /* Align to the first burst */
+ if (bid > 0)
+ return 0;
+
+ /* Align reception of the first FACCH/H frame */
+ if (lchan->tch_mode == GSM48_CMODE_SIGN) {
+ if (!sched_tchh_facch_start(lchan->type, fn, 0))
+ return 0;
+ } else { /* or TCH/H traffic frame */
+ if (!sched_tchh_traffic_start(lchan->type, fn, 0))
+ return 0;
+ }
+ }
+
+ /* Update mask */
+ *mask |= (1 << bid);
+
+ /**
+ * FIXME: properly update measurements
+ *
+ * Since TCH/H channel is using block-diagonal interleaving,
+ * a single burst may carry 57 bits of one encoded frame,
+ * and 57 bits of another. This should be taken into account.
+ */
+ lchan->meas.rssi_sum += rssi;
+ lchan->meas.toa256_sum += toa256;
+ lchan->meas.rssi_num++;
+ lchan->meas.toa256_num++;
+
+ /* Copy burst to the end of buffer of 6 bursts */
+ offset = buffer + bid * 116 + 464;
+ memcpy(offset, bits + 3, 58);
+ memcpy(offset + 58, bits + 87, 58);
+
+ /* Wait until the second burst */
+ if (bid != 1)
+ return 0;
+
+ /* Wait for complete set of bursts */
+ if (lchan->tch_mode == GSM48_CMODE_SIGN) {
+ /* FACCH/H is interleaved over 6 bursts */
+ if ((*mask & 0x3f) != 0x3f)
+ goto bfi_shift;
+ } else {
+ /* Traffic is interleaved over 4 bursts */
+ if ((*mask & 0x0f) != 0x0f)
+ goto bfi_shift;
+ }
+
+ /* Skip decoding attempt in case of FACCH/H */
+ if (lchan->dl_ongoing_facch) {
+ lchan->dl_ongoing_facch = false;
+ goto bfi_shift; /* 2/2 BFI */
+ }
+
+ switch (lchan->tch_mode) {
+ case GSM48_CMODE_SIGN:
+ case GSM48_CMODE_SPEECH_V1: /* HR */
+ rc = gsm0503_tch_hr_decode(l2, buffer,
+ !sched_tchh_facch_end(lchan->type, fn, 0),
+ &n_errors, &n_bits_total);
+ break;
+ case GSM48_CMODE_SPEECH_AMR: /* AMR */
+ /**
+ * TODO: AMR requires a dedicated loop,
+ * which will be implemented later...
+ */
+ LOGP(DSCHD, LOGL_ERROR, "AMR isn't supported yet\n");
+ return -ENOTSUP;
+ default:
+ LOGP(DSCHD, LOGL_ERROR, "Invalid TCH mode: %u\n", lchan->tch_mode);
+ return -EINVAL;
+ }
+
+ /* Shift buffer by 4 bursts for interleaving */
+ memcpy(buffer, buffer + 232, 232);
+ memcpy(buffer + 232, buffer + 464, 232);
+
+ /* Shift burst mask */
+ *mask = *mask << 2;
+
+ /* Check decoding result */
+ if (rc < 4) {
+ LOGP(DSCHD, LOGL_ERROR, "Received bad TCH frame ending at "
+ "fn=%u on %s (rc=%d)\n", fn, lchan_desc->name, rc);
+
+ /* Send BFI */
+ goto bfi;
+ } else if (rc == GSM_MACBLOCK_LEN) {
+ /* Skip decoding of the next 2 stolen bursts */
+ lchan->dl_ongoing_facch = true;
+
+ /* Calculate TDMA frame number of the first burst */
+ lchan->rx_first_fn = sched_tchh_block_dl_first_fn(lchan->type,
+ fn, true); /* FACCH/H */
+
+ /* FACCH/H received, forward to the higher layers */
+ sched_send_dt_ind(trx, ts, lchan, l2, GSM_MACBLOCK_LEN,
+ n_errors, false, false);
+
+ /* 1/2 BFI */
+ goto bfi;
+ } else {
+ /* A good TCH frame received */
+ l2_len = rc;
+ }
+
+ /* Calculate TDMA frame number of the first burst */
+ lchan->rx_first_fn = sched_tchh_block_dl_first_fn(lchan->type,
+ fn, false); /* TCH/H */
+
+ /* Send a traffic frame to the higher layers */
+ return sched_send_dt_ind(trx, ts, lchan, l2, l2_len,
+ n_errors, false, true);
+
+bfi_shift:
+ /* Shift buffer */
+ memcpy(buffer, buffer + 232, 232);
+ memcpy(buffer + 232, buffer + 464, 232);
+
+ /* Shift burst mask */
+ *mask = *mask << 2;
+
+bfi:
+ /* Didn't try to decode */
+ if (n_errors < 0)
+ n_errors = 116 * 2;
+
+ /* Calculate TDMA frame number of the first burst */
+ lchan->rx_first_fn = sched_tchh_block_dl_first_fn(lchan->type,
+ fn, false); /* TCH/H */
+
+ /* BFI is not applicable in signalling mode */
+ if (lchan->tch_mode == GSM48_CMODE_SIGN)
+ return sched_send_dt_ind(trx, ts, lchan, NULL, 0,
+ n_errors, true, false);
+
+ /* Bad frame indication */
+ l2_len = sched_bad_frame_ind(l2, lchan);
+
+ /* Send a BFI frame to the higher layers */
+ return sched_send_dt_ind(trx, ts, lchan, l2, l2_len,
+ n_errors, true, true);
+}
+
+int tx_tchh_fn(struct trx_instance *trx, struct trx_ts *ts,
+ struct trx_lchan_state *lchan, uint32_t fn, uint8_t bid)
+{
+ const struct trx_lchan_desc *lchan_desc;
+ ubit_t burst[GSM_BURST_LEN];
+ ubit_t *buffer, *offset;
+ const uint8_t *tsc;
+ uint8_t *mask;
+ size_t l2_len;
+ int rc;
+
+ /* Set up pointers */
+ lchan_desc = &trx_lchan_desc[lchan->type];
+ mask = &lchan->tx_burst_mask;
+ buffer = lchan->tx_bursts;
+
+ if (bid > 0) {
+ /* Align to the first burst */
+ if (*mask == 0x00)
+ return 0;
+ goto send_burst;
+ }
+
+ if (*mask == 0x00) {
+ /* Align transmission of the first FACCH/H frame */
+ if (lchan->tch_mode == GSM48_CMODE_SIGN)
+ if (!sched_tchh_facch_start(lchan->type, fn, 1))
+ return 0;
+ }
+
+ /* Shift buffer by 2 bursts back for interleaving */
+ memcpy(buffer, buffer + 232, 232);
+
+ /* Also shift TX burst mask */
+ *mask = *mask << 2;
+
+ /* If FACCH/H blocks are still pending */
+ if (lchan->ul_facch_blocks > 2) {
+ memcpy(buffer + 232, buffer + 464, 232);
+ goto send_burst;
+ }
+
+ /* Check the current TCH mode */
+ switch (lchan->tch_mode) {
+ case GSM48_CMODE_SIGN:
+ case GSM48_CMODE_SPEECH_V1: /* HR */
+ l2_len = GSM_HR_BYTES + 1;
+ break;
+ case GSM48_CMODE_SPEECH_AMR: /* AMR */
+ /**
+ * TODO: AMR requires a dedicated loop,
+ * which will be implemented later...
+ */
+ LOGP(DSCHD, LOGL_ERROR, "AMR isn't supported yet, "
+ "dropping frame...\n");
+
+ /* Forget this primitive */
+ sched_prim_drop(lchan);
+ return -ENOTSUP;
+ default:
+ LOGP(DSCHD, LOGL_ERROR, "Invalid TCH mode: %u, "
+ "dropping frame...\n", lchan->tch_mode);
+
+ /* Forget this primitive */
+ sched_prim_drop(lchan);
+ return -EINVAL;
+ }
+
+ /* Determine payload length */
+ if (PRIM_IS_FACCH(lchan->prim)) {
+ l2_len = GSM_MACBLOCK_LEN; /* FACCH */
+ } else if (lchan->prim->payload_len != l2_len) {
+ LOGP(DSCHD, LOGL_ERROR, "Primitive has odd length %zu "
+ "(expected %zu for TCH or %u for FACCH), so dropping...\n",
+ lchan->prim->payload_len, l2_len, GSM_MACBLOCK_LEN);
+
+ /* Forget this primitive */
+ sched_prim_drop(lchan);
+ return -EINVAL;
+ }
+
+ /* Encode the payload */
+ rc = gsm0503_tch_hr_encode(buffer, lchan->prim->payload, l2_len);
+ if (rc) {
+ LOGP(DSCHD, LOGL_ERROR, "Failed to encode L2 payload\n");
+
+ /* Forget this primitive */
+ sched_prim_drop(lchan);
+ return -EINVAL;
+ }
+
+ /* A FACCH/H frame occupies 6 bursts */
+ if (PRIM_IS_FACCH(lchan->prim))
+ lchan->ul_facch_blocks = 6;
+
+send_burst:
+ /* Determine which burst should be sent */
+ offset = buffer + bid * 116;
+
+ /* Update mask */
+ *mask |= (1 << bid);
+
+ /* Choose proper TSC */
+ tsc = sched_nb_training_bits[trx->tsc];
+
+ /* Compose a new burst */
+ memset(burst, 0, 3); /* TB */
+ memcpy(burst + 3, offset, 58); /* Payload 1/2 */
+ memcpy(burst + 61, tsc, 26); /* TSC */
+ memcpy(burst + 87, offset + 58, 58); /* Payload 2/2 */
+ memset(burst + 145, 0, 3); /* TB */
+
+ LOGP(DSCHD, LOGL_DEBUG, "Transmitting %s fn=%u ts=%u burst=%u\n",
+ lchan_desc->name, fn, ts->index, bid);
+
+ /* Forward burst to transceiver */
+ sched_trx_handle_tx_burst(trx, ts, lchan, fn, burst);
+
+ /* In case of a FACCH/H frame, one block less */
+ if (lchan->ul_facch_blocks)
+ lchan->ul_facch_blocks--;
+
+ if ((*mask & 0x0f) == 0x0f) {
+ /**
+ * If no more FACCH/H blocks pending,
+ * confirm data / traffic sending
+ */
+ if (!lchan->ul_facch_blocks)
+ sched_send_dt_conf(trx, ts, lchan, fn,
+ PRIM_IS_TCH(lchan->prim));
+
+ /* Forget processed primitive */
+ sched_prim_drop(lchan);
+ }
+
+ return 0;
+}