port arfcn range encode support from osmo-bsc

As part of fixing issue OS#3075, we want to migrate support
for encoding system information from osmo-bsc to libosmocore.

This change ports one of the prerequisites for doing so:
osmo-bsc code for range-encoding ARFCNs, including tests.

An osmo_gsm48_ prefix has been prepended to public symbols in
order to avoid clashes with existing symbols in osmo-bsc code.

Change-Id: Ia220764fba451be5e975ae7c5eefb1a25ac2bf2c
Related: OS#3075

1 files changed, 25 insertions, 0 deletions

diff --git a/include/osmocom/gsm/gsm48_arfcn_range_encode.h b/include/osmocom/gsm/gsm48_arfcn_range_encode.h
new file mode 100644
index 00000000..146c8534
--- /dev/null
+++ b/include/osmocom/gsm/gsm48_arfcn_range_encode.h
@@ -0,0 +1,25 @@
+/*! \file gsm48_arfcn_range_encode.h */
+
+#pragma once
+
+#include <stdint.h>
+
+enum osmo_gsm48_range {
+	OSMO_GSM48_ARFCN_RANGE_INVALID	= -1,
+	OSMO_GSM48_ARFCN_RANGE_128		= 127,
+	OSMO_GSM48_ARFCN_RANGE_256		= 255,
+	OSMO_GSM48_ARFCN_RANGE_512		= 511,
+	OSMO_GSM48_ARFCN_RANGE_1024		= 1023,
+};
+
+#define OSMO_GSM48_RANGE_ENC_MAX_ARFCNS	29
+
+int osmo_gsm48_range_enc_determine_range(const int *arfcns, int size, int *f0_out);
+int osmo_gsm48_range_enc_arfcns(enum osmo_gsm48_range rng, const int *arfcns, int sze, int *out, int idx);
+int osmo_gsm48_range_enc_find_index(enum osmo_gsm48_range rng, const int *arfcns, int size);
+int osmo_gsm48_range_enc_filter_arfcns(int *arfcns, const int sze, const int f0, int *f0_included);
+
+int osmo_gsm48_range_enc_128(uint8_t *chan_list, int f0, int *w);
+int osmo_gsm48_range_enc_256(uint8_t *chan_list, int f0, int *w);
+int osmo_gsm48_range_enc_512(uint8_t *chan_list, int f0, int *w);
+int osmo_gsm48_range_enc_1024(uint8_t *chan_list, int f0, int f0_incl, int *w);