netdev: Represent RSSI as int16_t

drivers/include/net/netdev.h

@@ -245,7 +245,7 @@ typedef enum {
  * May be different for certain radios.
  */
 struct netdev_radio_rx_info {
-    uint8_t rssi;       /**< RSSI of a received packet */
+    int16_t rssi;       /**< RSSI of a received packet in dBm */
     uint8_t lqi;        /**< LQI of a received packet */
 };
 

sys/include/net/gnrc/netif/hdr.h

@@ -85,7 +85,7 @@ typedef struct {
     uint8_t dst_l2addr_len;     /**< length of l2 destination address in byte */
     kernel_pid_t if_pid;        /**< PID of network interface */
     uint8_t flags;              /**< flags as defined above */
-    uint8_t rssi;               /**< rssi of received packet (optional) */
+    int16_t rssi;               /**< rssi of received packet in dBm (optional) */
     uint8_t lqi;                /**< lqi of received packet (optional) */
 } gnrc_netif_hdr_t;
 

sys/net/gnrc/netif/hdr/gnrc_netif_hdr_print.c

@@ -23,7 +23,7 @@ void gnrc_netif_hdr_print(gnrc_netif_hdr_t *hdr)
     char addr_str[GNRC_NETIF_HDR_L2ADDR_PRINT_LEN];
 
     printf("if_pid: %u  ", (unsigned) hdr->if_pid);
-    printf("rssi: %u  ", (unsigned) hdr->rssi);
+    printf("rssi: %d  ", (signed) hdr->rssi);
     printf("lqi: %u\n", (unsigned) hdr->lqi);
     printf("flags: ");