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comparison ft16/subslot_rx.c @ 2:5c18cd38c8ad

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ft16: import from ice1-trau-tester/abis
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 29 Aug 2024 13:07:16 +0000
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1:e5527fc2050b 2:5c18cd38c8ad
1 /*
2 * Here we are going to implement Abis subslot Rx.
3 */
4
5 #include <stdint.h>
6 #include <stdbool.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <string.h>
10
11 #include <osmocom/core/select.h>
12 #include <osmocom/core/utils.h>
13 #include <osmocom/isdn/i460_mux.h>
14 #include <osmocom/trau/trau_sync.h>
15
16 #include "globals.h"
17 #include "submux.h"
18
19 void i460_rx_func(struct osmo_i460_subchan *schan, void *user_data,
20 const ubit_t *bits, unsigned int num_bits)
21 {
22 struct abis_subslot *ab = user_data;
23
24 osmo_trau_sync_rx_ubits(ab->sync, bits, num_bits);
25 }
26
27 static void sync_lost(struct abis_subslot *ab)
28 {
29 if (!ab->got_sync)
30 return;
31 printf("Subslot %d lost frame sync\n", ab->nr);
32 ab->got_sync = false;
33 }
34
35 /* function copied from libosmo-abis/src/trau/trau_frame.c */
36 static uint32_t get_bits(const ubit_t *bitbuf, int offset, int num)
37 {
38 int i;
39 uint32_t ret = 0;
40
41 for (i = offset; i < offset + num; i++) {
42 ret = ret << 1;
43 if (bitbuf[i])
44 ret |= 1;
45 }
46 return ret;
47 }
48
49 void sync_rx_func(void *user_data, const ubit_t *bits, unsigned int num_bits)
50 {
51 struct abis_subslot *ab = user_data;
52 uint8_t ft;
53
54 if (!bits) {
55 sync_lost(ab);
56 return;
57 }
58 OSMO_ASSERT(num_bits == 320);
59 ft = get_bits(bits, 17, 5);
60 if (!ab->got_sync) {
61 printf("Subslot %d got frame sync with FT=0x%02X\n",
62 ab->nr, ft);
63 ab->got_sync = true;
64 ab->frame_type = ft;
65 return;
66 }
67 if (ft == ab->frame_type)
68 return;
69 printf("Subslot %d changed frame type from 0x%02X to 0x%02X\n", ab->nr,
70 ab->frame_type, ft);
71 ab->frame_type = ft;
72 }