From 64e63cd1bbd5866e41f1dc548ea52714d2e16a93 Mon Sep 17 00:00:00 2001
From: Gabriel Mariano Marcelino <gabriel.mm8@gmail.com>
Date: Tue, 11 Jul 2023 21:57:00 -0300
Subject: [PATCH] firmware: drivers: uart: Minor improvements and adding
 doxygen documentation #43

---
 firmware/drivers/uart/uart.c | 13 +++++-----
 firmware/drivers/uart/uart.h | 50 ++++++++++++++++++------------------
 2 files changed, 31 insertions(+), 32 deletions(-)

diff --git a/firmware/drivers/uart/uart.c b/firmware/drivers/uart/uart.c
index 56e9a95..bfb12fd 100644
--- a/firmware/drivers/uart/uart.c
+++ b/firmware/drivers/uart/uart.c
@@ -166,12 +166,11 @@ int uart_init(uart_config_t config)
 int uart_write(uart_config_t config, uint16_t *data, uint16_t len)
 {
     int err = ERRNO_SUCCESS;
-    uint32_t usart;
 
     uint16_t i = 0U;
     for(i = 0U; i < len; i++)
     {
-        err = uart_send_byte(config, *(data + i));
+        err = uart_send_byte(config, data[i]);
     }
 
     return err;
@@ -179,7 +178,7 @@ int uart_write(uart_config_t config, uint16_t *data, uint16_t len)
 
 int uart_read(uart_config_t config, uint16_t *data, uint16_t len)
 {
-    int err;
+    int err = ERRNO_SUCCESS;
     uint16_t num_bytes = len;
     uint16_t i = 0U;
     queue_t *uart_rx_buffer;
@@ -216,8 +215,8 @@ int uart_rx_enable(uart_config_t config)
 
 int uart_rx_disable(uart_config_t config)
 {
-    int err;
-    uint32_t usart;
+    int err = -1;
+    uint32_t usart = UINT32_MAX;
 
     err  = uart_select_port_address(config, &usart);
     usart_disable_rx_interrupt(usart);
@@ -240,7 +239,7 @@ uint16_t uart_read_available(uart_config_t config)
 
 int uart_flush(uart_config_t config)
 {
-    int err;
+    int err = ERRNO_SUCCESS;
 
     queue_t *uart_rx_buffer;
 
@@ -258,7 +257,7 @@ int uart_flush(uart_config_t config)
 
 static inline int uart_send_byte(uart_config_t config, uint16_t c)
 {
-    int err = 0;
+    int err = ERRNO_SUCCESS;
 
     uint32_t usart;
 
diff --git a/firmware/drivers/uart/uart.h b/firmware/drivers/uart/uart.h
index c925840..c679f83 100644
--- a/firmware/drivers/uart/uart.h
+++ b/firmware/drivers/uart/uart.h
@@ -77,10 +77,10 @@ typedef enum
  */
 typedef enum 
 {
-    UART_SB_0_5=0,          /**< . */
-    UART_SB_1,              /**< . */
-    UART_SB_1_5,            /**< . */
-    UART_SB_2               /**< . */
+    UART_SB_0_5=0,          /**< 0.5 stop bit. */
+    UART_SB_1,              /**< 1 stop bit. */
+    UART_SB_1_5,            /**< 1.5 stop bit. */
+    UART_SB_2               /**< 2 stop bits. */
 } uart_sb_t;
 
 /**
@@ -124,71 +124,71 @@ typedef struct
 } uart_config_t;
 
 /**
- * \brief .
+ * \brief Initializes a given UART port.
  *
- * \param[in] config .
+ * \param[in] config are the configuration parameters of the given UART port.
  *
- * \return .
+ * \return The status/error code.
  */
 int uart_init(uart_config_t config);
 
 /**
- * \brief .
+ * \brief Writes data to a given UART port.
  *
- * \param[in] config .
+ * \param[in] config are the configuration parameters of the given UART port.
  *
- * \param[in] data .
+ * \param[in] data is the array of bytes to be written.
  *
- * \param[in] len .
+ * \param[in] len is the number of bytes to be written.
  *
- * \return .
+ * \return The status/error code.
  */
 int uart_write(uart_config_t config, uint16_t *data, uint16_t len);
 
 /**
- * \brief .
+ * \brief Reads data from a given UART port.
  *
- * \param[in] config .
+ * \param[in] config are the configuration parameters of the given UART port.
  *
- * \param[in,out] data .
+ * \param[in,out] data is a pointer to store the read data.
  *
- * \param[in] len .
+ * \param[in] len is the number of bytes to read.
  *
- * \return .
+ * \return The status/error code.
  */
 int uart_read(uart_config_t config, uint16_t *data, uint16_t len);
 
 /**
- * \brief .
+ * \brief Enables the RX of a given UART port.
  *
- * \param[in] config .
+ * \param[in] config are the configuration parameters of the given UART port.
  *
  * \return The status/error code.
  */
 int uart_rx_enable(uart_config_t config);
 
 /**
- * \brief .
+ * \brief Disables the RX of a given UART port.
  *
- * \param[in] config .
+ * \param[in] config are the configuration parameters of the given UART port.
  *
  * \return The status/error code.
  */
 int uart_rx_disable(uart_config_t config);
 
 /**
- * \brief .
+ * \brief Checks if there is available data to read from a given UART port.
  *
- * \param[in] config .
+ * \param[in] config are the configuration parameters of the given UART port.
  *
  * \return The status/error code.
  */
 uint16_t uart_read_available(uart_config_t config);
 
 /**
- * \brief .
+ * \brief Flushes the RX buffer of a given UART port.
  *
- * \param[in] config .
+ * \param[in] config are the configuration parameters of the given UART port.
  *
  * \return The status/error code.
  */