1 files changed, 149 insertions, 0 deletions
diff --git a/firmware/x300/lib/udp_uart.c b/firmware/x300/lib/udp_uart.c
new file mode 100644
index 000000000..d078aa2c3
--- /dev/null
+++ b/firmware/x300/lib/udp_uart.c
@@ -0,0 +1,149 @@
+/*
+ * Copyright 2011-2013 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 <wb_uart.h>
+#include <udp_uart.h>
+#include <u3_net_stack.h>
+
+/***********************************************************************
+ * Constants
+ **********************************************************************/
+#define MAX_NUM_UARTS 4
+
+static const size_t num_idle_cyc_b4_flush = 22;
+
+/***********************************************************************
+ * Globals
+ **********************************************************************/
+typedef struct
+{
+    uint32_t uart_base;
+    struct ip_addr host_addr;
+    int host_ethno;
+    uint16_t host_port;
+    uint16_t local_port;
+    __attribute__ ((aligned (16))) 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];
+
+static int udp_uart_lookup(const uint16_t port)
+{
+    for (size_t i = 0; i < MAX_NUM_UARTS; i++)
+    {
+        if (_states[i].local_port == port) return i;
+    }
+    return -1;
+}
+
+/***********************************************************************
+ * UDP handler for UARTs
+ **********************************************************************/
+static void handle_uart_data_packet(
+    const uint8_t ethno,
+    const struct ip_addr *src, const struct ip_addr *dst,
+    const uint16_t src_port, const uint16_t dst_port,
+    const void *buff, const size_t num_bytes
+){
+    //handle ICMP destination unreachable
+    if (buff == NULL)
+    {
+        const size_t which = udp_uart_lookup(src_port);
+        if (which == -1) return;
+        _states[which].host_port = 0;
+    }
+
+    //handle a regular blocking UART write
+    else
+    {
+        const size_t which = udp_uart_lookup(dst_port);
+        if (which == -1) return;
+        _states[which].host_ethno = ethno;
+        _states[which].host_addr = *src;
+        _states[which].host_port = src_port;
+        for (size_t i = 0; i < num_bytes; i++)
+        {
+            const char ch = ((const char *)buff)[i];
+            if (ch == '\n') wb_uart_putc(_states[which].uart_base, (int)'\r');
+            wb_uart_putc(_states[which].uart_base, (int)ch);
+            udp_uart_poll();
+        }
+    }
+}
+
+/***********************************************************************
+ * Public init function
+ **********************************************************************/
+void udp_uart_init(const uint32_t uart_base, const uint16_t udp_port)
+{
+    for (size_t i = 0; i < MAX_NUM_UARTS; i++)
+    {
+        if (_states[i].uart_base != 0) continue;
+        _states[i].uart_base = uart_base;
+        _states[i].local_port = udp_port;
+        _states[i].host_port = 0; //reset to null port
+        _states[i].len = 0;
+        _states[i].cyc = 0;
+        u3_net_stack_register_udp_handler(udp_port, &handle_uart_data_packet);
+        return;
+    }
+}
+
+/***********************************************************************
+ * Public poll function
+ **********************************************************************/
+void udp_uart_poll(void)
+{
+    for (size_t i = 0; i < MAX_NUM_UARTS; i++)
+    {
+        if (_states[i].uart_base == 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(state->buf); j++)
+        {
+            int ret = wb_uart_getc(state->uart_base);
+            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->host_port != 0) u3_net_stack_send_udp_pkt(
+                state->host_ethno,
+                &state->host_addr,
+                state->local_port,
+                state->host_port,
+                state->buf, state->len
+            );
+            state->len = 0;
+            state->cyc = 0;
+        }
+    }
+}