mraa.c: add a by-name lookup function also for UARTs

Signed-off-by: Tapani Utriainen <tapani@technexion.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

api/mraa/common.h

@@ -265,6 +265,14 @@ int mraa_spi_lookup(const char* spi_name);
  */
 int mraa_pwm_lookup(const char* pwm_name);
 
+/**
+ * Get UART index by name, board must be initialised.
+ *
+ * @param uart_name: Name of UART. Eg:UART1
+ * @return int of MRAA index for UART, or -1 if not found.
+ */
+int mraa_uart_lookup(const char* uart_name);
+
 /**
  * Get default i2c bus, board must be initialised.
  *

api/mraa/common.hpp

@@ -300,6 +300,27 @@ getPwmLookup(std::string pwm_name)
     return index;
 }
 
+/**
+ * Get UART index by UART name, board must be initialised.
+ *
+ * @param pwm_name: Name of the UART. Eg: UART2
+ * @throws std::invalid_argument if name is not found
+ * @return MRAA index for the UART
+ */
+inline int
+getUartLookup(std::string uart_name)
+{
+    int index = mraa_uart_lookup(uart_name.c_str());
+
+    if (index < 0) {
+        std::ostringstream oss;
+        oss << "UART name " << uart_name << " is not valid";
+        throw std::invalid_argument(oss.str());
+    }
+
+    return index;
+}
+
 /**
  * Sets the log level to use from 0-7 where 7 is very verbose. These are the
  * syslog log levels, see syslog(3) for more information on the levels.