1 files changed, 86 insertions, 0 deletions
diff --git a/firmware/e300/battery/spi.c b/firmware/e300/battery/spi.c
new file mode 100644
index 000000000..ae42c6e40
--- /dev/null
+++ b/firmware/e300/battery/spi.c
@@ -0,0 +1,86 @@
+/* USRP E310 Firmware Atmel AVR SPI driver
+ * Copyright (C) 2014 Ettus Research
+ * This file is part of the USRP E310 Firmware
+ * The USRP E310 Firmware 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 of the License, or
+ * (at your option) any later version.
+ * The USRP E310 Firmware 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 the USRP E310 Firmware. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "mcu_settings.h"
+#include "io.h"
+#include "spi.h"
+#include "utils.h"
+
+#include <avr/io.h>
+#include <stdlib.h>
+#include <util/delay.h>
+
+static io_pin_t AVR_CS = IO_PB(2);
+static io_pin_t AVR_MOSI = IO_PB(3);
+static io_pin_t AVR_MISO = IO_PB(4);
+static io_pin_t AVR_SCK = IO_PB(5);
+
+void spi_init(spi_type_t type, spi_order_t order, spi_mode_t mode, spi_speed_t speed)
+{
+	uint8_t val;
+
+	io_output_pin(AVR_CS);
+	io_output_pin(AVR_MOSI);
+	io_input_pin(AVR_MISO);
+	io_output_pin(AVR_SCK);
+
+	/* slave select is low active */
+	io_set_pin(AVR_CS);
+
+	/* SPCR looks like this: [SPIE | SPE | DORD | MSTR | CPOL | CPHA | SPR1 | SPR0] */
+	val = BIT(SPE);
+	val |= (order == SPI_LSB_FIRST) ? BIT(DORD) : 0;
+	val |= (type == SPI_TYPE_MASTER) ? BIT(MSTR) : 0;
+	val |= mode << CPHA;
+	val |= speed << SPR0;
+
+	SPCR = val;
+}
+
+uint8_t spi_transact(uint8_t data)
+{
+	uint8_t ret;
+
+	io_clear_pin(AVR_CS);
+	SPDR = data;
+	ret = SPDR;
+	io_set_pin(AVR_CS);
+	return ret;
+}
+
+void spi_transact_buf(uint8_t *in, uint8_t *out, uint8_t size)
+{
+	uint8_t i;
+
+	io_clear_pin(AVR_CS);
+
+	for (i = 0; i < size; i++) {
+		SPDR = in[i];
+		spi_wait_till_done();
+		out[i] = SPDR;
+	}
+
+	io_set_pin(AVR_CS);
+}
+
+void spi_wait_till_done(void)
+{
+	uint8_t timeout = 100;
+
+	do {
+		_delay_us(10);
+		timeout--;
+	} while (timeout && !(SPSR & BIT(SPIF)));
+}