OctoClock firmware upgrade, added host driver

* OctoClock can communicate with UHD over Ethernet
* Can read NMEA strings from GPSDO and send to host
* Added multi_usrp_clock class for clock devices
* uhd::device can now filter to return only USRP devices or clock devices
* New OctoClock bootloader can accept firmware download over Ethernet
* Added octoclock_burn_eeprom,octoclock_firmware_burner utilities
* Added test_clock_synch example to show clock API

1 files changed, 156 insertions, 0 deletions

diff --git a/firmware/octoclock/lib/serial.c b/firmware/octoclock/lib/serial.c
new file mode 100644
index 000000000..298cdff8d
--- /dev/null
+++ b/firmware/octoclock/lib/serial.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright 2014 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 <stdbool.h>
+
+#include <octoclock.h>
+#include <serial.h>
+
+#include <avr/pgmspace.h>
+#include <util/delay.h>
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+void serial_init(volatile uint8_t* port, uint8_t index){
+    *port |= _BV(index);
+}
+
+static void _serial_tx_send(uint8_t* buffer, volatile uint8_t* port, uint8_t index){
+    const uint8_t delay = BAUD_115200_DELAY;
+    uint8_t countdown;
+
+    for(uint8_t i = 0; i < 10; ++i){
+        if(buffer[i]) *port |= _BV(index);
+        else *port &= ~_BV(index);
+
+        countdown = delay;
+        while(--countdown) asm("nop");
+    }
+}
+
+static void _serial_tx_char(char c, volatile uint8_t* port, uint8_t index){
+	uint8_t buffer[10];
+	uint8_t i = 0;
+
+	buffer[i++] = 0;	// START
+	for (int idx = 0; idx < 8; ++idx)
+	buffer[i++] = (((uint8_t)(c) & ((uint8_t)1<<((idx)))) ? 0x01 : 0x00);	// Endianness: 7-
+	buffer[i++] = 1;	// STOP
+
+	_serial_tx_send(buffer, port, index);
+}
+
+void serial_tx_P(const char* message, volatile uint8_t* port, uint8_t index, bool newline){
+    char c = pgm_read_byte(message);
+    if(c == '\0') return;
+
+    do{
+        _serial_tx_char(c, port, index);
+        c = pgm_read_byte(++message);
+    } while(c != '\0');
+
+    if(newline){
+        _serial_tx_char('\r', port, index);
+        _serial_tx_char('\n', port, index);
+    }
+
+    *port |= _BV(index);
+}
+
+void serial_tx(const char* message, volatile uint8_t* port, uint8_t index, bool newline){
+    if (message[0] == '\0')
+    return;
+
+    do
+    {
+        _serial_tx_char(*message, port, index);
+    } while (*(++message) != '\0');
+
+    if (newline){
+        _serial_tx_char('\r', port, index);
+        _serial_tx_char('\n', port, index);
+    }
+
+    *port |= _BV(index);
+}
+
+void serial_tx_byte(uint8_t byte, volatile uint8_t* port, uint8_t index, bool newline){
+    char ch[4];
+    ch[0] = '0' + (byte / 100);
+    ch[1] = '0' + ((byte % 100) / 10);
+    ch[2] = '0' + (byte % 10);
+    ch[3] = '\0';
+    serial_tx(ch, port, index, newline);
+}
+
+void serial_tx_hex(uint8_t byte, volatile uint8_t* port, uint8_t index, bool newline){
+    char ch[3];
+    uint8_t _byte = byte >> 4;
+    if (_byte < 10)
+        ch[0] = '0' + _byte;
+    else
+        ch[0] = 'A' + (_byte - 10);
+    byte &= 0x0F;
+    if (byte < 10)
+        ch[1] = '0' + byte;
+    else
+        ch[1] = 'A' + (byte - 10);
+    ch[2] = '\0';
+    serial_tx(ch, port, index, newline);
+}
+
+char serial_rx_char(volatile uint8_t* port, uint8_t index){
+    char c = 0;
+    const uint8_t delay = BAUD_115200_DELAY;
+    uint8_t countdown;
+
+    //Wait for character to appear, 0 will act as start marker
+    while(*port & _BV(index));
+
+    //With start marker there, wait for next bit
+    countdown = delay;
+    while(--countdown) asm("nop");
+
+    for(uint8_t i = 0; i < 8; ++i){
+        if(*port & _BV(index)) c &= (uint8_t)(1 << i);
+
+        countdown = delay;
+        while(--countdown) asm("nop");
+    }
+
+    return c;
+}
+
+//Assume ready (probably risky)
+char serial_rx_char_nowait(volatile uint8_t* port, uint8_t index){
+    char c = 0;
+    const uint8_t delay = BAUD_115200_DELAY;
+    uint8_t countdown;
+
+    //Wait for start marker to pass
+    countdown = delay;
+    while(--countdown) asm("nop");
+
+    for(uint8_t i = 0; i < 8; ++i){
+        if(*port & _BV(index)) c &= (uint8_t)(1 << i);
+
+        countdown = delay;
+        while(--countdown) asm("nop");
+    }
+
+    return c;
+}