trxcon: refactor trxcon_fsm finite state machine

Change-Id: I035b2cb701e2d0b3fedec4d569507b79d400df5b

6 files changed, 161 insertions, 86 deletions

diff --git a/src/host/trxcon/Makefile.am b/src/host/trxcon/Makefile.am
index b51db02f..76254c5e 100644
--- a/src/host/trxcon/Makefile.am
+++ b/src/host/trxcon/Makefile.am
@@ -22,6 +22,7 @@ AM_CFLAGS = \
 bin_PROGRAMS = trxcon
 
 trxcon_SOURCES = \
+	trxcon_fsm.c \
 	l1ctl_link.c \
 	l1ctl.c \
 	trx_if.c \
diff --git a/src/host/trxcon/l1ctl_link.c b/src/host/trxcon/l1ctl_link.c
index b7ea262a..0b01d729 100644
--- a/src/host/trxcon/l1ctl_link.c
+++ b/src/host/trxcon/l1ctl_link.c
@@ -176,8 +176,8 @@ static int l1ctl_link_accept(struct osmo_fd *bfd, unsigned int flags)
 		return -1;
 	}
 
-	osmo_fsm_inst_dispatch(trxcon_fsm, L1CTL_EVENT_CONNECT, l1l);
 	osmo_fsm_inst_state_chg(l1l->fsm, L1CTL_STATE_CONNECTED, 0, 0);
+	osmo_fsm_inst_dispatch(trxcon_fsm, TRXCON_EV_L1CTL_CONNECT, NULL);
 
 	LOGP(DL1C, LOGL_NOTICE, "L1CTL has a new connection\n");
 
@@ -223,8 +223,8 @@ int l1ctl_link_close_conn(struct l1ctl_link *l1l)
 	/* Clear pending messages */
 	osmo_wqueue_clear(&l1l->wq);
 
-	osmo_fsm_inst_dispatch(trxcon_fsm, L1CTL_EVENT_DISCONNECT, l1l);
 	osmo_fsm_inst_state_chg(l1l->fsm, L1CTL_STATE_IDLE, 0, 0);
+	osmo_fsm_inst_dispatch(trxcon_fsm, TRXCON_EV_L1CTL_DISCONNECT, NULL);
 
 	return 0;
 }
diff --git a/src/host/trxcon/trx_if.c b/src/host/trxcon/trx_if.c
index 4c10da6c..79df6873 100644
--- a/src/host/trxcon/trx_if.c
+++ b/src/host/trxcon/trx_if.c
@@ -173,7 +173,7 @@ static void trx_ctrl_timer_cb(void *data)
 	if (++tcm->retry_cnt > 3) {
 		LOGP(DTRX, LOGL_NOTICE, "Transceiver offline\n");
 		osmo_fsm_inst_state_chg(trx->fsm, TRX_STATE_OFFLINE, 0, 0);
-		osmo_fsm_inst_dispatch(trxcon_fsm, TRX_EVENT_OFFLINE, trx);
+		osmo_fsm_inst_dispatch(trxcon_fsm, TRXCON_EV_TRX_DISCONNECT, NULL);
 		return;
 	}
 
@@ -514,7 +514,7 @@ static int trx_ctrl_read_cb(struct osmo_fd *ofd, unsigned int what)
 
 rsp_error:
 	/* Notify higher layers about the problem */
-	osmo_fsm_inst_dispatch(trxcon_fsm, TRX_EVENT_RSP_ERROR, trx);
+	osmo_fsm_inst_dispatch(trxcon_fsm, TRXCON_EV_TRX_CTRL_ERROR, NULL);
 	return -EIO;
 }
 
diff --git a/src/host/trxcon/trxcon.c b/src/host/trxcon/trxcon.c
index 8e371df1..8b177ba5 100644
--- a/src/host/trxcon/trxcon.c
+++ b/src/host/trxcon/trxcon.c
@@ -1,7 +1,7 @@
 /*
  * OsmocomBB <-> SDR connection bridge
  *
- * (C) 2016-2017 by Vadim Yanitskiy <axilirator@gmail.com>
+ * (C) 2016-2019 by Vadim Yanitskiy <axilirator@gmail.com>
  *
  * All Rights Reserved
  *
@@ -77,72 +77,6 @@ static struct {
 static void *tall_trxcon_ctx = NULL;
 struct osmo_fsm_inst *trxcon_fsm;
 
-static void trxcon_fsm_idle_action(struct osmo_fsm_inst *fi,
-	uint32_t event, void *data)
-{
-	if (event == L1CTL_EVENT_CONNECT)
-		osmo_fsm_inst_state_chg(trxcon_fsm, TRXCON_STATE_MANAGED, 0, 0);
-}
-
-static void trxcon_fsm_managed_action(struct osmo_fsm_inst *fi,
-	uint32_t event, void *data)
-{
-	switch (event) {
-	case L1CTL_EVENT_DISCONNECT:
-		osmo_fsm_inst_state_chg(trxcon_fsm, TRXCON_STATE_IDLE, 0, 0);
-
-		if (app_data.trx->fsm->state != TRX_STATE_OFFLINE) {
-			/* Reset scheduler and clock counter */
-			sched_trx_reset(app_data.trx, true);
-
-			/* TODO: implement trx_if_reset() */
-			trx_if_cmd_poweroff(app_data.trx);
-			trx_if_cmd_echo(app_data.trx);
-		}
-		break;
-	case TRX_EVENT_RSP_ERROR:
-	case TRX_EVENT_OFFLINE:
-		/* TODO: notify L2 & L3 about that */
-		break;
-	default:
-		LOGPFSML(fi, LOGL_ERROR, "Unhandled event %u\n", event);
-	}
-}
-
-static struct osmo_fsm_state trxcon_fsm_states[] = {
-	[TRXCON_STATE_IDLE] = {
-		.in_event_mask = GEN_MASK(L1CTL_EVENT_CONNECT),
-		.out_state_mask = GEN_MASK(TRXCON_STATE_MANAGED),
-		.name = "IDLE",
-		.action = trxcon_fsm_idle_action,
-	},
-	[TRXCON_STATE_MANAGED] = {
-		.in_event_mask = (
-			GEN_MASK(L1CTL_EVENT_DISCONNECT) |
-			GEN_MASK(TRX_EVENT_RSP_ERROR) |
-			GEN_MASK(TRX_EVENT_OFFLINE)),
-		.out_state_mask = GEN_MASK(TRXCON_STATE_IDLE),
-		.name = "MANAGED",
-		.action = trxcon_fsm_managed_action,
-	},
-};
-
-static const struct value_string app_evt_names[] = {
-	OSMO_VALUE_STRING(L1CTL_EVENT_CONNECT),
-	OSMO_VALUE_STRING(L1CTL_EVENT_DISCONNECT),
-	OSMO_VALUE_STRING(TRX_EVENT_OFFLINE),
-	OSMO_VALUE_STRING(TRX_EVENT_RSP_ERROR),
-	{ 0, NULL }
-};
-
-static struct osmo_fsm trxcon_fsm_def = {
-	.name = "trxcon_app_fsm",
-	.states = trxcon_fsm_states,
-	.num_states = ARRAY_SIZE(trxcon_fsm_states),
-	.log_subsys = DAPP,
-	.event_names = app_evt_names,
-};
-
 static void print_usage(const char *app)
 {
 	printf("Usage: %s\n", app);
@@ -273,10 +207,11 @@ int main(int argc, char **argv)
 	/* Init logging system */
 	trx_log_init(tall_trxcon_ctx, app_data.debug_mask);
 
-	/* Allocate the application state machine */
-	osmo_fsm_register(&trxcon_fsm_def);
-	trxcon_fsm = osmo_fsm_inst_alloc(&trxcon_fsm_def, tall_trxcon_ctx,
-		NULL, LOGL_DEBUG, "main");
+	/* Allocate a trxcon state machine */
+	trxcon_fsm = osmo_fsm_inst_alloc(&trxcon_fsm_def,
+		tall_trxcon_ctx, NULL, LOGL_DEBUG, "main");
+	if (trxcon_fsm == NULL)
+		goto exit;
 
 	/* Init L1CTL server */
 	app_data.l1l = l1ctl_link_init(tall_trxcon_ctx,
@@ -323,7 +258,8 @@ exit:
 	trx_if_close(app_data.trx);
 
 	/* Shutdown main state machine */
-	osmo_fsm_inst_free(trxcon_fsm);
+	if (trxcon_fsm != NULL)
+		osmo_fsm_inst_free(trxcon_fsm);
 
 	/* Deinitialize logging */
 	log_fini();
diff --git a/src/host/trxcon/trxcon.h b/src/host/trxcon/trxcon.h
index f66a6285..0b113915 100644
--- a/src/host/trxcon/trxcon.h
+++ b/src/host/trxcon/trxcon.h
@@ -1,20 +1,35 @@
 #pragma once
 
+#include <osmocom/core/utils.h>
+#include <osmocom/core/fsm.h>
+
 #define GEN_MASK(state) (0x01 << state)
 
+extern const struct value_string trxcon_fsm_event_names[];
 extern struct osmo_fsm_inst *trxcon_fsm;
+extern struct osmo_fsm trxcon_fsm_def;
 
-enum trxcon_fsm_states {
-	TRXCON_STATE_IDLE = 0,
-	TRXCON_STATE_MANAGED,
+enum trxcon_fsm_state_type {
+	TRXCON_ST_IDLE = 0,
+	TRXCON_ST_MANAGED,
 };
 
-enum trxcon_fsm_events {
-	/* L1CTL specific events */
-	L1CTL_EVENT_CONNECT,
-	L1CTL_EVENT_DISCONNECT,
+enum trxcon_event_type {
+	/* Events coming from L1CTL interface */
+	TRXCON_EV_L1CTL_DISCONNECT,	/*!< L1CTL interface has lost a connection */
+	TRXCON_EV_L1CTL_CONNECT,	/*!< L1CTL interface has got a connection */
+	TRXCON_EV_L1CTL_REQ,		/*!< L1CTL request message from a client */
+
+	/* Events coming from TRX interface */
+	TRXCON_EV_TRX_DISCONNECT,	/*!< TRX interface has lost connection */
+	TRXCON_EV_TRX_CTRL_ERROR,	/*!< TRXC (CTRL) error from transceiver */
+	TRXCON_EV_TRX_CTRL_RSP,		/*!< TRXC (CTRL) response from transceiver */
+	TRXCON_EV_TRX_DL_BURST,		/*!< TRXD (DATA) DL burst from transceiver */
 
-	/* TRX specific events */
-	TRX_EVENT_RSP_ERROR,
-	TRX_EVENT_OFFLINE,
+	/* Events coming from scheduler */
+	TRXCON_EV_SCHED_CLCK_LOSS,	/*!< No more clock from transceiver */
+	TRXCON_EV_SCHED_DL_DF_IND,	/*!< DL Data Frame INDication */
+	TRXCON_EV_SCHED_UL_DF_CONF,	/*!< UL Data Frame CONFirmation */
+	TRXCON_EV_SCHED_DL_TF_IND,	/*!< DL Traffic Frame INDication */
+	TRXCON_EV_SCHED_UL_TF_CONF,	/*!< UL Traffic Frame CONFirmation */
 };
diff --git a/src/host/trxcon/trxcon_fsm.c b/src/host/trxcon/trxcon_fsm.c
new file mode 100644
index 00000000..69a2da1b
--- /dev/null
+++ b/src/host/trxcon/trxcon_fsm.c
@@ -0,0 +1,123 @@
+/*
+ * OsmocomBB <-> SDR connection bridge
+ * trxcon state machine definition
+ *
+ * (C) 2019 by Vadim Yanitskiy <axilirator@gmail.com>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/fsm.h>
+
+#include <logging.h>
+#include <trxcon.h>
+
+static void trxcon_fsm_idle_action(struct osmo_fsm_inst *fi,
+	uint32_t event, void *data)
+{
+	switch ((enum trxcon_event_type) event) {
+	case TRXCON_EV_L1CTL_CONNECT:
+		osmo_fsm_inst_state_chg(fi, TRXCON_ST_MANAGED, 0, 0);
+		break;
+	default:
+		LOGPFSML(fi, LOGL_ERROR, "Unhandled event '%s'\n",
+			osmo_fsm_event_name(&trxcon_fsm_def, event));
+	}
+}
+
+static void trxcon_fsm_managed_action(struct osmo_fsm_inst *fi,
+	uint32_t event, void *data)
+{
+	switch ((enum trxcon_event_type) event) {
+	case TRXCON_EV_L1CTL_DISCONNECT:
+		/* TODO: reset TRX interface */
+		osmo_fsm_inst_state_chg(fi, TRXCON_ST_IDLE, 0, 0);
+		break;
+	case TRXCON_EV_TRX_DISCONNECT:
+		/* TODO: notify L1CTL interface */
+		osmo_fsm_inst_state_chg(fi, TRXCON_ST_IDLE, 0, 0);
+		break;
+	default:
+		LOGPFSML(fi, LOGL_ERROR, "Unhandled event '%s'\n",
+			osmo_fsm_event_name(&trxcon_fsm_def, event));
+	}
+}
+
+/* Generates mask for a single state or event */
+#define S(x) (1 << x)
+
+static const struct osmo_fsm_state trxcon_fsm_states[] = {
+	[TRXCON_ST_IDLE] = {
+		.name = "IDLE",
+		.out_state_mask = S(TRXCON_ST_MANAGED),
+		.in_event_mask  = S(TRXCON_EV_L1CTL_CONNECT),
+		.action = &trxcon_fsm_idle_action,
+	},
+	[TRXCON_ST_MANAGED] = {
+		.name = "MANAGED",
+		.out_state_mask = S(TRXCON_ST_IDLE),
+		.in_event_mask  = S(TRXCON_EV_L1CTL_DISCONNECT)
+				| S(TRXCON_EV_L1CTL_CONNECT)
+				| S(TRXCON_EV_L1CTL_REQ)
+				| S(TRXCON_EV_TRX_DISCONNECT)
+				| S(TRXCON_EV_TRX_CTRL_ERROR)
+				| S(TRXCON_EV_TRX_CTRL_RSP)
+				| S(TRXCON_EV_TRX_DL_BURST)
+				| S(TRXCON_EV_SCHED_CLCK_LOSS)
+				| S(TRXCON_EV_SCHED_DL_DF_IND)
+				| S(TRXCON_EV_SCHED_UL_DF_CONF)
+				| S(TRXCON_EV_SCHED_DL_TF_IND)
+				| S(TRXCON_EV_SCHED_UL_TF_CONF)
+				,
+		.action = &trxcon_fsm_managed_action,
+	},
+};
+
+const struct value_string trxcon_fsm_event_names[] = {
+	OSMO_VALUE_STRING(TRXCON_EV_L1CTL_DISCONNECT),
+	OSMO_VALUE_STRING(TRXCON_EV_L1CTL_CONNECT),
+	OSMO_VALUE_STRING(TRXCON_EV_L1CTL_REQ),
+
+	OSMO_VALUE_STRING(TRXCON_EV_TRX_DISCONNECT),
+	OSMO_VALUE_STRING(TRXCON_EV_TRX_CTRL_ERROR),
+	OSMO_VALUE_STRING(TRXCON_EV_TRX_CTRL_RSP),
+	OSMO_VALUE_STRING(TRXCON_EV_TRX_DL_BURST),
+
+	OSMO_VALUE_STRING(TRXCON_EV_SCHED_CLCK_LOSS),
+	OSMO_VALUE_STRING(TRXCON_EV_SCHED_DL_DF_IND),
+	OSMO_VALUE_STRING(TRXCON_EV_SCHED_UL_DF_CONF),
+	OSMO_VALUE_STRING(TRXCON_EV_SCHED_DL_TF_IND),
+	OSMO_VALUE_STRING(TRXCON_EV_SCHED_UL_TF_CONF),
+
+	{ 0, NULL }
+};
+
+struct osmo_fsm trxcon_fsm_def = {
+	.name = "trxcon_fsm",
+	.states = trxcon_fsm_states,
+	.num_states = ARRAY_SIZE(trxcon_fsm_states),
+	.event_names = trxcon_fsm_event_names,
+	.log_subsys = DAPP,
+};
+
+static __attribute__((constructor)) void on_dso_load(void)
+{
+	/* Register our FSM */
+	OSMO_ASSERT(osmo_fsm_register(&trxcon_fsm_def) == 0);
+}