move ms_pwr utility function to gsm_utils.c

also, they should both take the gsm_band parameter, not a BTS

1 files changed, 76 insertions, 0 deletions

diff --git a/openbsc/src/gsm_utils.c b/openbsc/src/gsm_utils.c
index 0c25b28c6..185918ef9 100644
--- a/openbsc/src/gsm_utils.c
+++ b/openbsc/src/gsm_utils.c
@@ -21,9 +21,11 @@
  *
  */
 
+#include <openbsc/gsm_data.h>
 #include <openbsc/gsm_utils.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 
 /* GSM 03.38 6.2.1 Charachter packing */
 int gsm_7bit_decode(char *text, const u_int8_t *user_data, u_int8_t length)
@@ -71,3 +73,77 @@ int gsm_7bit_encode(u_int8_t *result, const char *data)
 
 	return out_length;
 }
+
+/* determine power control level for given dBm value, as indicated
+ * by the tables in chapter 4.1.1 of GSM TS 05.05 */
+int ms_pwr_ctl_lvl(enum gsm_band band, unsigned int dbm)
+{
+	switch (band) {
+	case GSM_BAND_400:
+	case GSM_BAND_900:
+	case GSM_BAND_850:
+		if (dbm >= 39)
+			return 0;
+		else if (dbm < 5)
+			return 19;
+		else
+			return 2 + ((39 - dbm) / 2);
+		break;
+	case GSM_BAND_1800:
+		if (dbm >= 36)
+			return 29;
+		else if (dbm >= 34)	
+			return 30;
+		else if (dbm >= 32)
+			return 31;
+		else
+			return (30 - dbm) / 2;
+		break;
+	case GSM_BAND_1900:
+		if (dbm >= 33)
+			return 30;
+		else if (dbm >= 32)
+			return 31;
+		else
+			return (30 - dbm) / 2;
+		break;
+	}
+	return -EINVAL;
+}
+
+int ms_pwr_dbm(enum gsm_band band, u_int8_t lvl)
+{
+	lvl &= 0x1f;
+
+	switch (band) {
+	case GSM_BAND_400:
+	case GSM_BAND_900:
+	case GSM_BAND_850:
+		if (lvl < 2)
+			return 39;
+		else if (lvl < 20)
+			return 39 - ((lvl - 2) * 2) ;
+		else
+			return 5;
+		break;
+	case GSM_BAND_1800:
+		if (lvl < 16)
+			return 30 - (lvl * 2);
+		else if (lvl < 29)
+			return 0;
+		else
+			return 36 - ((lvl - 29) * 2);
+		break;
+	case GSM_BAND_1900:
+		if (lvl < 16)
+			return 30 - (lvl * 2);
+		else if (lvl < 30)
+			return -EINVAL;
+		else
+			return 33 - (lvl - 30);
+		break;
+	}
+	return -EINVAL;
+}
+
+