egprs: Add CPS tables from TS 04.60

Includes EGPRS coding and puncturing scheme (CPS) tables from 3GPP
TS 04.60. Currently osmo-bts-trx is the only user of CPS table
values, but this may change with gprsdecode and other utilities.

Change-Id: I09fe6514a0e2e51bb3206f8387633f7e0255345f

1 files changed, 106 insertions, 0 deletions

diff --git a/src/gsm/gprs_rlc.c b/src/gsm/gprs_rlc.c
new file mode 100644
index 00000000..d6ccbbe4
--- /dev/null
+++ b/src/gsm/gprs_rlc.c
@@ -0,0 +1,106 @@
+#include <errno.h>
+#include <string.h>
+
+#include <osmocom/gprs/gprs_rlc.h>
+#include <osmocom/gprs/protocol/gsm_04_60.h>
+
+#define EGPRS_CPS_TYPE1_TBL_SZ		29
+#define EGPRS_CPS_TYPE2_TBL_SZ		8
+#define EGPRS_CPS_TYPE3_TBL_SZ		16
+
+/* 3GPP TS 44.060 10.4.8a.1.1 "Header type 1" */
+static const struct egprs_cps egprs_cps_table_type1[EGPRS_CPS_TYPE1_TBL_SZ] = {
+	{ .bits =  0, .mcs = 9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } },
+	{ .bits =  1, .mcs = 9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } },
+	{ .bits =  2, .mcs = 9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } },
+	{ .bits =  3, .mcs = 0, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } },
+	{ .bits =  4, .mcs = 9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } },
+	{ .bits =  5, .mcs = 9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } },
+	{ .bits =  6, .mcs = 9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } },
+	{ .bits =  7, .mcs = 0, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } },
+	{ .bits =  8, .mcs = 9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } },
+	{ .bits =  9, .mcs = 9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } },
+	{ .bits = 10, .mcs = 9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } },
+	{ .bits = 11, .mcs = 8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } },
+	{ .bits = 12, .mcs = 8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } },
+	{ .bits = 13, .mcs = 8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } },
+	{ .bits = 14, .mcs = 8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } },
+	{ .bits = 15, .mcs = 8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } },
+	{ .bits = 16, .mcs = 8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } },
+	{ .bits = 17, .mcs = 8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } },
+	{ .bits = 18, .mcs = 8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } },
+	{ .bits = 19, .mcs = 8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } },
+	{ .bits = 20, .mcs = 7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } },
+	{ .bits = 21, .mcs = 7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } },
+	{ .bits = 22, .mcs = 7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } },
+	{ .bits = 23, .mcs = 7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } },
+	{ .bits = 24, .mcs = 7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } },
+	{ .bits = 25, .mcs = 7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } },
+	{ .bits = 26, .mcs = 7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } },
+	{ .bits = 27, .mcs = 7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } },
+	{ .bits = 28, .mcs = 7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } },
+};
+
+/*
+ * 3GPP TS 44.060 10.4.8a.2.1
+ * "Header type 2 in EGPRS TBF or uplink EGPRS2-A TBF"
+ */
+static const struct egprs_cps egprs_cps_table_type2[EGPRS_CPS_TYPE2_TBL_SZ] = {
+	{ .bits =  0, .mcs = 6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
+	{ .bits =  1, .mcs = 6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
+	{ .bits =  2, .mcs = 6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
+	{ .bits =  3, .mcs = 6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
+	{ .bits =  4, .mcs = 5, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
+	{ .bits =  5, .mcs = 5, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
+	{ .bits =  6, .mcs = 6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
+	{ .bits =  7, .mcs = 6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
+};
+
+/* 3GPP TS 44.060 10.4.8a.3 "Header type 3" */
+static const struct egprs_cps egprs_cps_table_type3[EGPRS_CPS_TYPE3_TBL_SZ] = {
+	{ .bits =  0, .mcs = 4, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
+	{ .bits =  1, .mcs = 4, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
+	{ .bits =  2, .mcs = 4, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } },
+	{ .bits =  3, .mcs = 3, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
+	{ .bits =  4, .mcs = 3, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
+	{ .bits =  5, .mcs = 3, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } },
+	{ .bits =  6, .mcs = 3, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
+	{ .bits =  7, .mcs = 3, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
+	{ .bits =  8, .mcs = 3, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } },
+	{ .bits =  9, .mcs = 2, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
+	{ .bits = 10, .mcs = 2, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
+	{ .bits = 11, .mcs = 1, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
+	{ .bits = 12, .mcs = 1, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
+	{ .bits = 13, .mcs = 2, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
+	{ .bits = 14, .mcs = 2, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
+	{ .bits = 15, .mcs = 0, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } },
+};
+
+int egprs_get_cps(struct egprs_cps *cps, uint8_t type, uint8_t bits)
+{
+	const struct egprs_cps *table_cps;
+
+	switch (type) {
+	case EGPRS_HDR_TYPE1:
+		if (bits >= EGPRS_CPS_TYPE1_TBL_SZ)
+			return -EINVAL;
+		table_cps = &egprs_cps_table_type1[bits];
+		break;
+	case EGPRS_HDR_TYPE2:
+		if (bits >= EGPRS_CPS_TYPE2_TBL_SZ)
+			return -EINVAL;
+		table_cps = &egprs_cps_table_type2[bits];
+		break;
+	case EGPRS_HDR_TYPE3:
+		if (bits >= EGPRS_CPS_TYPE3_TBL_SZ)
+			return -EINVAL;
+		table_cps = &egprs_cps_table_type3[bits];
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	memcpy(cps, table_cps, sizeof *cps);
+
+	return 0;
+}