From cf14939ccad9ba40e239c12b4daf395e5930c05b Mon Sep 17 00:00:00 2001
From: Jon Trulson <jtrulson@ics.com>
Date: Wed, 29 Apr 2015 16:08:36 -0600
Subject: [PATCH] uart: add uart device read and write functionality

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
---
 api/mraa/uart.h   | 21 +++++++++++++++++++++
 api/mraa/uart.hpp | 26 ++++++++++++++++++++++++++
 src/uart/uart.c   | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+)

diff --git a/api/mraa/uart.h b/api/mraa/uart.h
index 79aa732..e321d6a 100644
--- a/api/mraa/uart.h
+++ b/api/mraa/uart.h
@@ -93,6 +93,27 @@ mraa_result_t mraa_uart_open_dev(mraa_uart_context dev, speed_t baud);
  */
 mraa_result_t mraa_uart_close_dev(mraa_uart_context dev);
 
+/**
+ * Read bytes from the device into a buffer
+ *
+ * @param dev uart context
+ * @param buf buffer pointer
+ * @param len maximum size of buffer
+ * @return the number of bytes read, or -1 if an error occurred
+ */
+int mraa_uart_read(mraa_uart_context dev, char *buf, size_t len);
+
+/**
+ * Write bytes in buffer to a device
+ *
+ * @param dev uart context
+ * @param buf buffer pointer
+ * @param len maximum size of buffer
+ * @return the number of bytes written, or -1 if an error occurred
+ */
+int mraa_uart_write(mraa_uart_context dev, char *buf, size_t len);
+
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/api/mraa/uart.hpp b/api/mraa/uart.hpp
index e976c87..d158d52 100644
--- a/api/mraa/uart.hpp
+++ b/api/mraa/uart.hpp
@@ -102,6 +102,32 @@ class Uart
         return mraa_uart_close_dev(m_uart);
     }
 
+    /**
+     * Read bytes from the device into a buffer
+     *
+     * @param buf buffer pointer
+     * @param len maximum size of buffer
+     * @return the number of bytes read, or -1 if an error occurred
+     */
+    int
+    read(char *buf, size_t len)
+    {
+        return mraa_uart_read(m_uart, buf, len);
+    }
+
+    /**
+     * Write bytes in buffer to a device
+     *
+     * @param buf buffer pointer
+     * @param len maximum size of buffer
+     * @return the number of bytes written, or -1 if an error occurred
+     */
+    int
+    write(char *buf, size_t len)
+    {
+        return mraa_uart_write(m_uart, buf, len);
+    }
+
   private:
     mraa_uart_context m_uart;
 };
diff --git a/src/uart/uart.c b/src/uart/uart.c
index d933f0a..416cf71 100644
--- a/src/uart/uart.c
+++ b/src/uart/uart.c
@@ -172,3 +172,35 @@ mraa_uart_close_dev(mraa_uart_context dev)
     dev->fd = -1;
     return MRAA_SUCCESS;
 }
+
+int
+mraa_uart_read(mraa_uart_context dev, char *buf, size_t len)
+{
+    if (!dev) {
+        syslog(LOG_ERR, "uart: read: context is NULL");
+        return MRAA_ERROR_INVALID_HANDLE;
+    }
+
+    if (dev->fd < 0) {
+        syslog(LOG_ERR, "uart: port is not open");
+        return MRAA_ERROR_INVALID_RESOURCE;
+    }
+
+    return read(dev->fd, buf, len);
+}
+
+int
+mraa_uart_write(mraa_uart_context dev, char *buf, size_t len)
+{
+    if (!dev) {
+        syslog(LOG_ERR, "uart: write: context is NULL");
+        return MRAA_ERROR_INVALID_HANDLE;
+    }
+
+    if (dev->fd < 0) {
+        syslog(LOG_ERR, "uart: port is not open");
+        return MRAA_ERROR_INVALID_RESOURCE;
+    }
+
+    return write(dev->fd, buf, len);
+}