Initial firmware commit.

firmware/application/rffc507x_spi.cpp

@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
+ *
+ * This file is part of PortaPack.
+ *
+ * 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 2, 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; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "rffc507x_spi.hpp"
+
+#include "utility.hpp"
+
+#include "hackrf_gpio.hpp"
+using namespace hackrf::one;
+
+namespace rffc507x {
+namespace spi {
+
+void SPI::init() {
+	gpio_rffc5072_select.set();
+	gpio_rffc5072_clock.clear();
+
+	gpio_rffc5072_select.output();
+	gpio_rffc5072_clock.output();
+	gpio_rffc5072_data.input();
+
+	gpio_rffc5072_data.clear();
+}
+
+inline void SPI::select(const bool active) {
+	gpio_rffc5072_select.write(!active);
+}
+
+inline void SPI::direction_out() {
+	gpio_rffc5072_data.output();
+}
+
+inline void SPI::direction_in() {
+	gpio_rffc5072_data.input();
+}
+
+inline void SPI::write_bit(const bit_t value) {
+	gpio_rffc5072_data.write(value);
+}
+
+inline bit_t SPI::read_bit() {
+	return gpio_rffc5072_data.read() & 1;
+}
+
+inline bit_t SPI::transfer_bit(const bit_t bit_out) {
+	gpio_rffc5072_clock.clear();
+	write_bit(bit_out);
+	const bit_t bit_in = read_bit();
+	gpio_rffc5072_clock.set();
+	return bit_in;
+}
+
+data_t SPI::transfer_bits(const data_t data_out, const size_t count) {
+	data_t data_in = 0;
+	for(size_t i=0; i<count; i++) {
+		data_in = (data_in << 1) | transfer_bit((data_out >> (count - i - 1)) & 1);
+	}
+	return data_in;
+}
+
+data_t SPI::transfer_word(const Direction direction, const address_t address, const data_t data_out) {
+	select(true);
+
+	const data_t address_word =
+		  ((direction == Direction::Read) ? (1 << 7) : 0)
+		| (address & 0x7f)
+		;
+
+	direction_out();
+	transfer_bits(address_word, 9);
+
+	if( direction == Direction::Read ) {
+		direction_in();
+		transfer_bits(0, 2);
+	}
+
+	const data_t data_in = transfer_bits(data_out, 16);
+
+	if( direction == Direction::Write ) {
+		direction_in();
+	}
+
+	select(false);
+
+	transfer_bits(0, 2);
+
+	return data_in;
+}
+
+}
+}