drivers: modem: Add function to wait for sem and handle error

Add a helper function that waits for a semaphore and handles the
error conditions that may arise.

Signed-off-by: Joakim Andersson <joerchan@gmail.com>

Author: joerchan

drivers/modem/modem_cmd_handler.c

@@ -486,6 +486,20 @@ int modem_cmd_handler_update_cmds(struct modem_cmd_handler_data *data,
 	return 0;
 }
 
+int modem_cmd_handler_await(struct modem_cmd_handler_data *data,
+			    struct k_sem *sem, k_timeout_t timeout)
+{
+	int ret = k_sem_take(sem, timeout);
+
+	if (ret == 0) {
+		ret = modem_cmd_handler_get_error(data);
+	} else if (ret == -EAGAIN) {
+		ret = -ETIMEDOUT;
+	}
+
+	return ret;
+}
+
 int modem_cmd_send_data_nolock(struct modem_iface *iface,
 			       const uint8_t *buf, size_t len)
 {

drivers/modem/modem_cmd_handler.h

@@ -158,6 +158,21 @@ int modem_cmd_handler_update_cmds(struct modem_cmd_handler_data *data,
 				  size_t handler_cmds_len,
 				  bool reset_error_flag);
 
+/**
+ * @brief  Wait until semaphore is given
+ *
+ * This function does the same wait behavior as @ref modem_cmd_send, but can wait without sending
+ * any command first. Useful for waiting for asynchronous responses.
+ *
+ * @param  data: handler data to use
+ * @param  sem: wait for semaphore.
+ * @param  timeout: wait timeout.
+ *
+ * @retval 0 if ok, < 0 if error.
+ */
+int modem_cmd_handler_await(struct modem_cmd_handler_data *data,
+			    struct k_sem *sem, k_timeout_t timeout);
+
 /**
  * @brief  send data directly to interface w/o TX lock.
  *