host/trxcon: integrate osmo-fsm framework

This change introduces the following state machines:

  - trxcon_app_fsm - main application state machine.

    This state machine handles different events, raised
    from program modules (such as trx_if.c or l1ctl.c).

  - l1ctl_link_fsm - L1CTL server state machine.

  - trx_interface_fsm - TRX interface state machine.

The program modules (such as trx_if.c or l1ctl.c) should be as
much independent from each other as possible. In other words,
one module should not call methods from another, e.g. L1CTL
handlers are not able to send any command to transceiver directly.

Instead of that, they should use shared event set to notify the
main state machine about something. Depending on current state
and received event, main state machine 'decides' what to do. This
approach would allow to easily reuse the source code almost 'as is'
anywhere outside the project.

Change-Id: I7ee6fc891abe5f775f5b7ebbf093181a97950dea

1 files changed, 66 insertions, 0 deletions

diff --git a/src/host/trxcon/trxcon.c b/src/host/trxcon/trxcon.c
index 781942a6..5874560d 100644
--- a/src/host/trxcon/trxcon.c
+++ b/src/host/trxcon/trxcon.c
@@ -29,12 +29,14 @@
 #include <unistd.h>
 #include <signal.h>
 
+#include <osmocom/core/fsm.h>
 #include <osmocom/core/msgb.h>
 #include <osmocom/core/talloc.h>
 #include <osmocom/core/signal.h>
 #include <osmocom/core/select.h>
 #include <osmocom/core/application.h>
 
+#include "trxcon.h"
 #include "trx_if.h"
 #include "logging.h"
 #include "l1ctl_link.h"
@@ -62,6 +64,62 @@ static struct {
 } app_data;
 
 void *tall_trx_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) {
+			trx_if_flush_ctrl(app_data.trx);
+			trx_if_cmd_poweroff(app_data.trx);
+		}
+		break;
+	case TRX_EVENT_RESET_IND:
+	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_RESET_IND) |
+			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 struct osmo_fsm trxcon_fsm_def = {
+	.name = "trxcon_app_fsm",
+	.states = trxcon_fsm_states,
+	.num_states = ARRAY_SIZE(trxcon_fsm_states),
+	.log_subsys = DAPP,
+};
 
 static void print_usage(const char *app)
 {
@@ -175,6 +233,11 @@ int main(int argc, char **argv)
 	/* Init logging system */
 	trx_log_init(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_trx_ctx,
+		NULL, LOGL_DEBUG, "main");
+
 	/* Init L1CTL server */
 	rc = l1ctl_link_init(&app_data.l1l, app_data.bind_socket);
 	if (rc)
@@ -203,6 +266,9 @@ exit:
 	l1ctl_link_shutdown(app_data.l1l);
 	trx_if_close(app_data.trx);
 
+	/* Shutdown main state machine */
+	osmo_fsm_inst_free(trxcon_fsm);
+
 	/* Make Valgrind happy */
 	log_fini();
 	talloc_free(tall_trx_ctx);