1 files changed, 116 insertions, 0 deletions
diff --git a/firmware/usrp2/lib/udp_uart.c b/firmware/usrp2/lib/udp_uart.c
new file mode 100644
index 000000000..a3940c05f
--- /dev/null
+++ b/firmware/usrp2/lib/udp_uart.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright 2011 Ettus Research LLC
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "udp_uart.h"
+#include "hal_uart.h"
+#include "net_common.h"
+#include "compiler.h"
+#include <stdbool.h>
+
+/***********************************************************************
+ * Constants
+ **********************************************************************/
+#define MAX_NUM_UARTS 4
+#ifndef UDP_UART_MASK
+    #error missing definition for UDP_UART_MASK enable mask
+#endif
+static const size_t num_idle_cyc_b4_flush = 11; //small but lucky number
+
+/***********************************************************************
+ * Globals
+ **********************************************************************/
+static uint16_t _base_port;
+
+typedef struct{
+    struct socket_address dst;
+    _AL4 uint8_t buf[256];
+    size_t len; //length of buffer
+    size_t cyc; //idle cycle count
+} udp_uart_state_t;
+
+static udp_uart_state_t _states[MAX_NUM_UARTS];
+
+/***********************************************************************
+ * UDP handler for UARTs
+ **********************************************************************/
+static void handle_uart_data_packet(
+    struct socket_address src, struct socket_address dst,
+    unsigned char *payload, int payload_len
+){
+    //handle ICMP destination unreachable
+    if (payload == NULL){
+        const size_t which = src.port-_base_port;
+        if (which >= MAX_NUM_UARTS) return;
+        _states[which].dst.port = 0;
+    }
+
+    //handle a regular blocking UART write
+    else{
+        const size_t which = dst.port-_base_port;
+        if (which >= MAX_NUM_UARTS) return;
+        _states[which].dst = src;
+        for (size_t i = 0; i < payload_len; i++){
+            hal_uart_putc((hal_uart_name_t)which, (int)payload[i]);
+        }
+    }
+}
+
+/***********************************************************************
+ * Public init function
+ **********************************************************************/
+void udp_uart_init(const uint16_t base_port){
+    _base_port = base_port;
+    for(size_t i = 0; i < MAX_NUM_UARTS; i++){
+        _states[i].dst.port = 0; //reset to null port
+        _states[i].len = 0;
+        _states[i].cyc = 0;
+        register_udp_listener(_base_port+i, handle_uart_data_packet);
+    }
+}
+
+/***********************************************************************
+ * Public poll function
+ **********************************************************************/
+void udp_uart_poll(void){
+    for (size_t i = 0; i < MAX_NUM_UARTS; i++){
+        if (((UDP_UART_MASK) & (1 << i)) == 0) continue;
+
+        bool newline = false;
+        udp_uart_state_t *state = &_states[i];
+
+        //read all characters we can without blocking
+        for (size_t j = state->len; j < sizeof(_states[0].buf); j++){
+            int ret = hal_uart_getc_noblock((hal_uart_name_t)i);
+            if (ret == -1) break;
+            char ch = (char) ret;
+            if (ch == '\n' || ch == '\r') newline = true;
+            state->buf[j] = ch;
+            state->len++;
+            state->cyc = 0; //reset idle cycles
+        }
+
+        //nothing in buffer, continue to next uart
+        if (state->len == 0) continue;
+
+        //send out a message if newline or forced flush
+        if (newline || state->cyc++ > num_idle_cyc_b4_flush){
+            if (state->dst.port != 0) send_udp_pkt(_base_port+i, state->dst, state->buf, state->len);
+            state->len = 0;
+            state->cyc = 0;
+        }
+    }
+}