cinterion: implement power off

Powering off Cinterion modems is done with the AT^SMSO command. Once this
command is sent to the device, ModemManager still needs to wait to get an
unsolicited ^SHUTDOWN message from the modem, which is when the shutdown
is considered complete.

Newer Cinterion devices, though, don't seem to follow this rule and just
reply OK to AT^SMSO (i.e. no ^SHUTDOWN), but instead, they will remove the
tty ports.

plugins/cinterion/mm-broadband-modem-cinterion.c

@@ -276,6 +276,158 @@ modem_power_down (MMIfaceModem *self,
             result);
 }
 
+/*****************************************************************************/
+/* Modem Power Off */
+
+#define MAX_POWER_OFF_WAIT_TIME_SECS 20
+
+typedef struct {
+    MMBroadbandModemCinterion *self;
+    MMPortSerialAt *port;
+    GSimpleAsyncResult *result;
+    GRegex *shutdown_regex;
+    gboolean shutdown_received;
+    gboolean smso_replied;
+    gboolean serial_open;
+    guint timeout_id;
+} PowerOffContext;
+
+static void
+power_off_context_complete_and_free (PowerOffContext *ctx)
+{
+    if (ctx->serial_open)
+        mm_port_serial_close (MM_PORT_SERIAL (ctx->port));
+    if (ctx->timeout_id)
+        g_source_remove (ctx->timeout_id);
+    mm_port_serial_at_add_unsolicited_msg_handler (ctx->port, ctx->shutdown_regex, NULL, NULL, NULL);
+    g_object_unref (ctx->port);
+    g_object_unref (ctx->self);
+    g_regex_unref (ctx->shutdown_regex);
+    g_simple_async_result_complete_in_idle (ctx->result);
+    g_object_unref (ctx->result);
+    g_slice_free (PowerOffContext, ctx);
+}
+
+static gboolean
+modem_power_off_finish (MMIfaceModem *self,
+                        GAsyncResult *res,
+                        GError **error)
+{
+    return !g_simple_async_result_propagate_error (G_SIMPLE_ASYNC_RESULT (res), error);
+}
+
+static void
+complete_power_off (PowerOffContext *ctx)
+{
+    if (!ctx->shutdown_received || !ctx->smso_replied)
+        return;
+
+    g_simple_async_result_set_op_res_gboolean (ctx->result, TRUE);
+    power_off_context_complete_and_free (ctx);
+}
+
+static void
+smso_ready (MMBaseModem *self,
+            GAsyncResult *res,
+            PowerOffContext *ctx)
+{
+    GError *error = NULL;
+
+    mm_base_modem_at_command_full_finish (MM_BASE_MODEM (self), res, &error);
+    if (error) {
+        g_simple_async_result_take_error (ctx->result, error);
+        power_off_context_complete_and_free (ctx);
+        return;
+    }
+
+    /* Set as replied */
+    ctx->smso_replied = TRUE;
+    complete_power_off (ctx);
+}
+
+static void
+shutdown_received (MMPortSerialAt *port,
+                   GMatchInfo *match_info,
+                   PowerOffContext *ctx)
+{
+    /* Cleanup handler */
+    mm_port_serial_at_add_unsolicited_msg_handler (port, ctx->shutdown_regex, NULL, NULL, NULL);
+    /* Set as received */
+    ctx->shutdown_received = TRUE;
+    complete_power_off (ctx);
+}
+
+static gboolean
+power_off_timeout_cb (PowerOffContext *ctx)
+{
+    ctx->timeout_id = 0;
+
+    /* The SMSO reply should have come earlier */
+    g_warn_if_fail (ctx->smso_replied == TRUE);
+
+    g_simple_async_result_set_error (ctx->result,
+                                     MM_CORE_ERROR,
+                                     MM_CORE_ERROR_FAILED,
+                                     "Power off operation timed out");
+    power_off_context_complete_and_free (ctx);
+
+    return FALSE;
+}
+
+static void
+modem_power_off (MMIfaceModem *self,
+                 GAsyncReadyCallback callback,
+                 gpointer user_data)
+{
+    PowerOffContext *ctx;
+    GError *error = NULL;
+
+    ctx = g_slice_new0 (PowerOffContext);
+    ctx->self = g_object_ref (self);
+    ctx->port = mm_base_modem_get_port_primary (MM_BASE_MODEM (self));
+    ctx->result = g_simple_async_result_new (G_OBJECT (self),
+                                             callback,
+                                             user_data,
+                                             modem_power_off);
+    ctx->shutdown_regex = g_regex_new ("\\r\\n\\^SHUTDOWN\\r\\n",
+                                       G_REGEX_RAW | G_REGEX_OPTIMIZE, 0, NULL);
+    ctx->timeout_id = g_timeout_add_seconds (MAX_POWER_OFF_WAIT_TIME_SECS,
+                                             (GSourceFunc)power_off_timeout_cb,
+                                             ctx);
+
+    /* We'll need to wait for a ^SHUTDOWN before returning the action, which is
+     * when the modem tells us that it is ready to be shutdown */
+    mm_port_serial_at_add_unsolicited_msg_handler (
+        ctx->port,
+        ctx->shutdown_regex,
+        (MMPortSerialAtUnsolicitedMsgFn)shutdown_received,
+        ctx,
+        NULL);
+
+    /* In order to get the ^SHUTDOWN notification, we must keep the port open
+     * during the wait time */
+    ctx->serial_open = mm_port_serial_open (MM_PORT_SERIAL (ctx->port), &error);
+    if (G_UNLIKELY (error)) {
+        g_simple_async_result_take_error (ctx->result, error);
+        power_off_context_complete_and_free (ctx);
+        return;
+    }
+
+    /* Note: we'll use a timeout < MAX_POWER_OFF_WAIT_TIME_SECS for the AT command,
+     * so we're sure that the AT command reply will always come before the timeout
+     * fires */
+    g_assert (MAX_POWER_OFF_WAIT_TIME_SECS > 5);
+    mm_base_modem_at_command_full (MM_BASE_MODEM (self),
+                                   ctx->port,
+                                   "^SMSO",
+                                   5,
+                                   FALSE, /* allow_cached */
+                                   FALSE, /* is_raw */
+                                   NULL, /* cancellable */
+                                   (GAsyncReadyCallback)smso_ready,
+                                   ctx);
+}
+
 /*****************************************************************************/
 /* ACCESS TECHNOLOGIES */
 
@@ -1283,6 +1435,8 @@ iface_modem_init (MMIfaceModem *iface)
     iface->setup_flow_control_finish = setup_flow_control_finish;
     iface->modem_power_down = modem_power_down;
     iface->modem_power_down_finish = modem_power_down_finish;
+    iface->modem_power_off = modem_power_off;
+    iface->modem_power_off_finish = modem_power_off_finish;
 }
 
 static void