move MS power control handling from sysmobts to common part

MS uplink power control is required in pretty much any BTS, and we
cannot assume that they PHY / L1 will always take care of it by
itself.   So the correspondign code is moved to common/power_control.c
and called from the generic part of L1SAP.

The corresponding VTY paramter has been moved from the sysmobts-specific
trx VTY node to the common BTS VTY node.

5 files changed, 118 insertions, 1 deletions

diff --git a/src/common/Makefile.am b/src/common/Makefile.am
index 56648b14..d2580f93 100644
--- a/src/common/Makefile.am
+++ b/src/common/Makefile.am
@@ -8,4 +8,4 @@ libbts_a_SOURCES = gsm_data_shared.c sysinfo.c logging.c abis.c oml.c bts.c \
 		   load_indication.c pcu_sock.c handover.c msg_utils.c \
 		   load_indication.c pcu_sock.c handover.c msg_utils.c \
 		   tx_power.c bts_ctrl_commands.c bts_ctrl_lookup.c \
-		   l1sap.c cbch.c
+		   l1sap.c cbch.c power_control.c
diff --git a/src/common/bts.c b/src/common/bts.c
index 9abbe121..77302e2f 100644
--- a/src/common/bts.c
+++ b/src/common/bts.c
@@ -99,6 +99,7 @@ int bts_init(struct gsm_bts *bts)
 
 	/* configurable via VTY */
 	btsb->paging_state = paging_init(btsb, 200, 0);
+	btsb->ul_power_target = -75;	/* dBm default */
 
 	/* configurable via OML */
 	btsb->load.ccch.load_ind_period = 112;
diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index ca785fe4..1cb752e3 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -783,6 +783,8 @@ static int l1sap_ph_data_ind(struct gsm_bts_trx *trx,
 		lchan->meas.l1_info[0] |= ((data[0] >> 5) & 1) << 2;
 		lchan->meas.l1_info[1] = data[1];
 		lchan->meas.flags |= LC_UL_M_F_L1_VALID;
+
+		lchan_ms_pwr_ctrl(lchan, data[0] & 0x1f, data_ind->rssi);
 	} else
 		le = &lchan->lapdm_ch.lapdm_dcch;
 
diff --git a/src/common/power_control.c b/src/common/power_control.c
new file mode 100644
index 00000000..78d2702b
--- /dev/null
+++ b/src/common/power_control.c
@@ -0,0 +1,99 @@
+/* MS Power Control Loop L1 */
+
+/* (C) 2014 by Holger Hans Peter Freyther
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdint.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <osmo-bts/logging.h>
+#include <osmo-bts/bts.h>
+#include <osmo-bts/gsm_data.h>
+#include <osmo-bts/measurement.h>
+#include <osmo-bts/bts_model.h>
+#include <osmo-bts/l1sap.h>
+
+/*
+ * Check if manual power control is needed
+ * Check if fixed power was selected
+ * Check if the MS is already using our level if not
+ * the value is bogus..
+ * TODO: Add a timeout.. e.g. if the ms is not capable of reaching
+ * the value we have set.
+ */
+int lchan_ms_pwr_ctrl(struct gsm_lchan *lchan,
+		      const uint8_t ms_power, const int rxLevel)
+{
+	int rx;
+	int cur_dBm, new_dBm, new_pwr;
+	struct gsm_bts *bts = lchan->ts->trx->bts;
+	struct gsm_bts_role_bts *btsb = bts_role_bts(bts);
+	const enum gsm_band band = bts->band;
+
+	if (!trx_ms_pwr_ctrl_is_osmo(lchan->ts->trx))
+		return 0;
+	if (lchan->ms_power_ctrl.fixed)
+		return 0;
+
+	/* The phone hasn't reached the power level yet */
+	if (lchan->ms_power_ctrl.current != ms_power)
+		return 0;
+
+	/*
+	 * What is the difference between what we want and received?
+	 * Ignore a margin that is within the range of measurement
+	 * and MS output issues.
+	 */
+	rx = btsb->ul_power_target - rxLevel;
+	if (rx >= 0 && rx < 1)
+		return 0;
+	if (rx < 0 && rx > -1)
+		return 0;
+
+	/* We don't really care about the truncation of int + float */
+	cur_dBm = ms_pwr_dbm(band, ms_power);
+	new_dBm = cur_dBm + rx;
+
+	/* Clamp negative values and do it depending on the band */
+	if (new_dBm < 0)
+		new_dBm = 0;
+
+	switch (band) {
+	case GSM_BAND_1800:
+		/* If MS_TX_PWR_MAX_CCH is set the values 29,
+		 * 30, 31 are not used. Avoid specifying a dBm
+		 * that would lead to these power levels. The
+		 * phone might not be able to reach them. */
+		if (new_dBm > 30)
+			new_dBm = 30;
+		break;
+	default:
+		break;
+	}
+
+	new_pwr = ms_pwr_ctl_lvl(band, new_dBm);
+	if (lchan->ms_power_ctrl.current != new_pwr) {
+		lchan->ms_power_ctrl.current = new_pwr;
+		bts_model_adjst_ms_pwr(lchan);
+		return 1;
+	}
+
+	return 0;
+}
diff --git a/src/common/vty.c b/src/common/vty.c
index 8479e5a0..e3fd57df 100644
--- a/src/common/vty.c
+++ b/src/common/vty.c
@@ -207,6 +207,7 @@ static void config_write_bts_single(struct vty *vty, struct gsm_bts *bts)
 		VTY_NEWLINE);
 	vty_out(vty, " paging lifetime %u%s", paging_get_lifetime(btsb->paging_state),
 		VTY_NEWLINE);
+	vty_out(vty, " uplink-power-target %d%s", btsb->ul_power_target, VTY_NEWLINE);
 	if (btsb->agch_queue_thresh_level != GSM_BTS_AGCH_QUEUE_THRESH_LEVEL_DEFAULT
 		 || btsb->agch_queue_low_level != GSM_BTS_AGCH_QUEUE_LOW_LEVEL_DEFAULT
 		 || btsb->agch_queue_high_level != GSM_BTS_AGCH_QUEUE_HIGH_LEVEL_DEFAULT)
@@ -441,6 +442,19 @@ DEFUN(cfg_bts_agch_queue_mgmt_default,
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_bts_ul_power_target, cfg_bts_ul_power_target_cmd,
+	"uplink-power-target <-110-0>",
+	"Set the nominal target Rx Level for uplink power control loop\n"
+	"Target uplink Rx level in dBm\n")
+{
+	struct gsm_bts *bts = vty->index;
+	struct gsm_bts_role_bts *btsb = bts_role_bts(bts);
+
+	btsb->ul_power_target = atoi(argv[0]);
+
+	return CMD_SUCCESS;
+}
+
 #define DB_DBM_STR 							\
 	"Unit is dB (decibels)\n"					\
 	"Unit is mdB (milli-decibels, or rather 1/10000 bel)\n"
@@ -782,6 +796,7 @@ int bts_vty_init(struct gsm_bts *bts, const struct log_info *cat)
 	install_element(BTS_NODE, &cfg_bts_paging_lifetime_cmd);
 	install_element(BTS_NODE, &cfg_bts_agch_queue_mgmt_default_cmd);
 	install_element(BTS_NODE, &cfg_bts_agch_queue_mgmt_params_cmd);
+	install_element(BTS_NODE, &cfg_bts_ul_power_target_cmd);
 
 	install_element(BTS_NODE, &cfg_trx_gsmtap_sapi_cmd);
 	install_element(BTS_NODE, &cfg_trx_no_gsmtap_sapi_cmd);