sysmobts: Make it possible to slowly ramp up the output power

For systems with a bigger PA enabling the full output power at
once might draw more current than a power supply can provide. This
code will step up the output power in smaller steps to avoid this
situation.

7 files changed, 155 insertions, 12 deletions

diff --git a/src/osmo-bts-sysmo/main.c b/src/osmo-bts-sysmo/main.c
index bd11472b..fac45d9c 100644
--- a/src/osmo-bts-sysmo/main.c
+++ b/src/osmo-bts-sysmo/main.c
@@ -84,6 +84,11 @@ int bts_model_init(struct gsm_bts *bts)
 	}
 	bts->c0->nominal_power = rc;
 
+	/* Initial values for the power adjustments */
+	bts->c0->pa.max_initial_power = 23;
+	bts->c0->pa.step_size = 2;
+	bts->c0->pa.step_interval = 1;
+
 	bts_model_vty_init(bts);
 
 	return 0;
diff --git a/src/osmo-bts-sysmo/oml.c b/src/osmo-bts-sysmo/oml.c
index 4ebf6646..e5f9260b 100644
--- a/src/osmo-bts-sysmo/oml.c
+++ b/src/osmo-bts-sysmo/oml.c
@@ -271,6 +271,9 @@ static int trx_init_compl_cb(struct gsm_bts_trx *trx, struct msgb *l1_msg)
 		trx_rf_lock(trx, 1, trx_mute_on_init_cb);
 #endif
 
+	/* Begin to ramp up the power */
+	sysmobts_pa_maybe_step(trx);
+
 	return opstart_compl(&trx->mo, l1_msg);
 }
 
@@ -323,7 +326,10 @@ static int trx_init(struct gsm_bts_trx *trx)
 	dev_par->u16BcchArfcn = trx->bts->c0->arfcn;
 	dev_par->u8NbTsc = trx->bts->bsic & 7;
 	dev_par->fRxPowerLevel = fl1h->ul_power_target;
-	dev_par->fTxPowerLevel = sysmobts_get_power_trx(trx);
+
+	/* initialize the power */
+	sysmobts_pa_pwr_init(trx);
+	dev_par->fTxPowerLevel = trx->pa.current_power;
 	LOGP(DL1C, LOGL_NOTICE, "Init TRX (ARFCN %u, TSC %u, RxPower % 2f dBm, "
 		"TxPower % 2.2f dBm\n", dev_par->u16Arfcn, dev_par->u8NbTsc,
 		dev_par->fRxPowerLevel, dev_par->fTxPowerLevel);
@@ -1068,8 +1074,12 @@ static int chmod_txpower_compl_cb(struct gsm_bts_trx *trx, struct msgb *l1_msg)
 	LOGPC(DL1C, LOGL_INFO, "setTxPower %f dBm\n",
 		cc->cfgParams.setTxPowerLevel.fTxPowerLevel);
 
+	trx->pa.current_power = cc->cfgParams.setTxPowerLevel.fTxPowerLevel;
 	msgb_free(l1_msg);
 
+	/* Schedule the next step up */
+	sysmobts_pa_maybe_step(trx);
+
 	return 0;
 }
 
@@ -1543,8 +1553,10 @@ int bts_model_apply_oml(struct gsm_bts *bts, struct msgb *msg,
 		struct femtol1_hdl *fl1h = trx_femtol1_hdl(trx);
 
 		/* Did we go through MphInit yet? If yes fire and forget */
-		if (fl1h->hLayer1)
-			l1if_set_txpower(fl1h, sysmobts_get_power_trx(trx));
+		if (fl1h->hLayer1) {
+			sysmobts_pa_pwr_init(trx);
+			l1if_set_txpower(fl1h, (float) trx->pa.current_power);
+		}
 	}
 
 	/* FIXME: we actaully need to send a ACK or NACK for the OML message */
diff --git a/src/osmo-bts-sysmo/sysmobts_vty.c b/src/osmo-bts-sysmo/sysmobts_vty.c
index 690ffed9..ed90a234 100644
--- a/src/osmo-bts-sysmo/sysmobts_vty.c
+++ b/src/osmo-bts-sysmo/sysmobts_vty.c
@@ -254,6 +254,39 @@ DEFUN(cfg_trx_nominal_power, cfg_trx_nominal_power_cmd,
 	return CMD_SUCCESS;
 }
 
+#define PA_STR "Power-Amplifier settings"
+DEFUN(cfg_trx_pa_max_initial, cfg_trx_pa_max_initial_cmd,
+	"power-amplifier max-initial <0-100>",
+	PA_STR "Maximum initial power\n"
+	"Value in dBm\n")
+{
+	struct gsm_bts_trx *trx = vty->index;
+
+	trx->pa.max_initial_power = atoi(argv[0]);
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_trx_pa_step_size, cfg_trx_pa_step_size_cmd,
+	"power-amplifier step-size <1-100>",
+	PA_STR "Power increase by step\n"
+	"Step size in dB\n")
+{
+	struct gsm_bts_trx *trx = vty->index;
+
+	trx->pa.step_size = atoi(argv[0]);
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_trx_pa_step_interval, cfg_trx_pa_step_interval_cmd,
+	"power-amplifier step-interval <1-100>",
+	PA_STR "Power increase by step\n"
+	"Step time in seconds\n")
+{
+	struct gsm_bts_trx *trx = vty->index;
+
+	trx->pa.step_interval = atoi(argv[0]);
+	return CMD_SUCCESS;
+}
 
 /* runtime */
 
@@ -421,7 +454,9 @@ DEFUN(set_tx_power, set_tx_power_cmd,
 	struct gsm_bts_trx *trx = gsm_bts_trx_num(vty_bts, trx_nr);
 	struct femtol1_hdl *fl1h = trx_femtol1_hdl(trx);
 
-	l1if_set_txpower(fl1h, (float) power);
+	trx->pa.current_power = power;
+	osmo_timer_del(&trx->pa.step_timer);
+	l1if_set_txpower(fl1h, (float) trx->pa.current_power);
 
 	return CMD_SUCCESS;
 }
@@ -551,6 +586,12 @@ void bts_model_config_write_trx(struct vty *vty, struct gsm_bts_trx *trx)
 	if (trx->nominal_power != sysmobts_get_nominal_power(trx))
 		vty_out(vty, "  nominal-tx-power %d%s", trx->nominal_power,
 			VTY_NEWLINE);
+	vty_out(vty, "  power-amplifier max-initial %d%s",
+			trx->pa.max_initial_power, VTY_NEWLINE);
+	vty_out(vty, "  power-amplifier step-size %d%s",
+			trx->pa.step_size, VTY_NEWLINE);
+	vty_out(vty, "  power-amplifier step-interval %d%s",
+			trx->pa.step_interval, VTY_NEWLINE);
 
 	for (i = 0; i < 32; i++) {
 		if (fl1h->gsmtap_sapi_mask & (1 << i)) {
@@ -622,6 +663,9 @@ int bts_model_vty_init(struct gsm_bts *bts)
 	install_element(TRX_NODE, &cfg_trx_min_qual_rach_cmd);
 	install_element(TRX_NODE, &cfg_trx_min_qual_norm_cmd);
 	install_element(TRX_NODE, &cfg_trx_nominal_power_cmd);
+	install_element(TRX_NODE, &cfg_trx_pa_max_initial_cmd);
+	install_element(TRX_NODE, &cfg_trx_pa_step_size_cmd);
+	install_element(TRX_NODE, &cfg_trx_pa_step_interval_cmd);
 
 	return 0;
 }
diff --git a/src/osmo-bts-sysmo/utils.c b/src/osmo-bts-sysmo/utils.c
index 106d12bd..afca7730 100644
--- a/src/osmo-bts-sysmo/utils.c
+++ b/src/osmo-bts-sysmo/utils.c
@@ -137,13 +137,88 @@ int sysmobts_get_nominal_power(struct gsm_bts_trx *trx)
 	return -1;
 }
 
-int sysmobts_get_power_trx(struct gsm_bts_trx *trx)
+int sysmobts_get_target_power(struct gsm_bts_trx *trx)
 {
-	int power_transmitter = trx->nominal_power - trx->max_power_red;
-	power_transmitter -= trx->power_reduce;
+	int target_power = trx->nominal_power - trx->max_power_red;
+	target_power -= trx->power_reduce;
 
-	if (power_transmitter < 0)
-		power_transmitter = 0;
+	if (target_power < 0)
+		target_power = 0;
 
-	return power_transmitter;
+	return target_power;
+}
+
+void sysmobts_pa_pwr_init(struct gsm_bts_trx *trx)
+{
+	int target_power = sysmobts_get_target_power(trx);
+
+	/* Cancel any pending request */
+	osmo_timer_del(&trx->pa.step_timer);
+
+	/* is this below our initial target */
+	if (target_power <= trx->pa.max_initial_power) {
+		LOGP(DL1C, LOGL_NOTICE,
+			"PA target_power(%d) is below initial power.\n",
+			target_power);
+		trx->pa.current_power = target_power;
+		return;
+	}
+
+	/* is this below our current value? */
+	if (target_power <= trx->pa.current_power) {
+		LOGP(DL1C, LOGL_NOTICE,
+			"PA target_power(%d) is below current_power.\n",
+			target_power);
+		trx->pa.current_power = target_power;
+		return;
+	}
+
+	if (trx->pa.current_power > trx->pa.max_initial_power) {
+		LOGP(DL1C, LOGL_NOTICE,
+			"PA target_power(%d) starting from current_power.\n",
+			target_power);
+		return;
+	}
+
+	/* We need to step it up. Start from the initial value */
+	trx->pa.current_power = trx->pa.max_initial_power;
+	LOGP(DL1C, LOGL_NOTICE,
+		"PA target_power(%d) starting with %d dBm.\n",
+		target_power, trx->pa.current_power);
+}
+
+static void pa_trx_cb(void *_trx)
+{
+	struct gsm_bts_trx *trx = _trx;
+
+	LOGP(DL1C, LOGL_NOTICE,
+		"PA raising power to %d dBm.\n", trx->pa.current_power);
+	l1if_set_txpower(trx_femtol1_hdl(trx), (float) trx->pa.current_power);
+}
+
+void sysmobts_pa_maybe_step(struct gsm_bts_trx *trx)
+{
+	/* it can not have changed */
+	int target_power = sysmobts_get_target_power(trx);
+
+	/* We are done */
+	if (trx->pa.current_power >= target_power) {
+		LOGP(DL1C, LOGL_NOTICE,
+			"PA have reached target power: %d dBm.\n",
+			target_power);
+		return;
+	}
+
+	/* Step up the current power but clamp it */
+	trx->pa.current_power += trx->pa.step_size;
+	if (trx->pa.current_power > target_power)
+		trx->pa.current_power = target_power;
+
+	LOGP(DL1C, LOGL_NOTICE,
+		"PA scheduling to step to %d dBm.\n",
+		trx->pa.current_power);
+
+	trx->pa.step_timer.data = trx;
+	trx->pa.step_timer.cb = pa_trx_cb;
+	osmo_timer_schedule(&trx->pa.step_timer, trx->pa.step_interval, 0);
 }
diff --git a/src/osmo-bts-sysmo/utils.h b/src/osmo-bts-sysmo/utils.h
index aef774ca..cf5cf7af 100644
--- a/src/osmo-bts-sysmo/utils.h
+++ b/src/osmo-bts-sysmo/utils.h
@@ -12,5 +12,8 @@ int sysmobts_select_femto_band(struct gsm_bts_trx *trx, uint16_t arfcn);
 
 int sysmobts_get_nominal_power(struct gsm_bts_trx *trx);
 
-int sysmobts_get_power_trx(struct gsm_bts_trx *trx);
+int sysmobts_get_target_power(struct gsm_bts_trx *trx);
+
+void sysmobts_pa_pwr_init(struct gsm_bts_trx *trx);
+void sysmobts_pa_maybe_step(struct gsm_bts_trx *trx);
 #endif
diff --git a/tests/stubs.c b/tests/stubs.c
index 99961aad..184ae724 100644
--- a/tests/stubs.c
+++ b/tests/stubs.c
@@ -51,3 +51,6 @@ uint32_t trx_get_hlayer1(struct gsm_bts_trx *trx)
 
 int bts_model_oml_estab(struct gsm_bts *bts)
 { return 0; }
+
+int l1if_set_txpower(struct femtol1_hdl *fl1h, float tx_power)
+{ return 0; }
diff --git a/tests/sysmobts/Makefile.am b/tests/sysmobts/Makefile.am
index d884237b..17160ba5 100644
--- a/tests/sysmobts/Makefile.am
+++ b/tests/sysmobts/Makefile.am
@@ -5,5 +5,6 @@ LDADD = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) $(LIBOSMOVTY_LIBS) $(LIBOSMOTRAU_
 noinst_PROGRAMS = sysmobts_test
 EXTRA_DIST = sysmobts_test.ok
 
-sysmobts_test_SOURCES = sysmobts_test.c $(top_srcdir)/src/osmo-bts-sysmo/utils.c
+sysmobts_test_SOURCES = sysmobts_test.c $(top_srcdir)/src/osmo-bts-sysmo/utils.c \
+		$(srcdir)/../stubs.c
 sysmobts_test_LDADD = $(LDADD)