From 34b01d89af4515e0bfbc54758c8a0190ef17473e Mon Sep 17 00:00:00 2001
From: Jared Boone <jboone@earfeast.com>
Date: Sat, 7 Dec 2013 15:29:14 -0800
Subject: [PATCH] Add SGPIO DMA configuration code.

---
 firmware/common/sgpio_dma.c | 142 ++++++++++++++++++++++++++++++++++++
 firmware/common/sgpio_dma.h |  35 +++++++++
 2 files changed, 177 insertions(+)
 create mode 100644 firmware/common/sgpio_dma.c
 create mode 100644 firmware/common/sgpio_dma.h

diff --git a/firmware/common/sgpio_dma.c b/firmware/common/sgpio_dma.c
new file mode 100644
index 00000000..b0383250
--- /dev/null
+++ b/firmware/common/sgpio_dma.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright 2013 Jared Boone <jared@sharebrained.com>
+ *
+ * This file is part of HackRF.
+ *
+ * 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 <sgpio_dma.h>
+
+#include <libopencm3/lpc43xx/creg.h>
+#include <libopencm3/lpc43xx/gpdma.h>
+#include <libopencm3/lpc43xx/scu.h>
+#include <libopencm3/lpc43xx/sgpio.h>
+
+#include <sgpio.h>
+#include <gpdma.h>
+
+#define LLI_COUNT 4
+
+static void configure_dma_lli(gpdma_lli_t* const lli, const bool direction_transmit, void* const buffer, const size_t byte_count) {
+	const size_t transfer_count = LLI_COUNT;
+	const size_t transfer_bytes = 4;
+	const size_t transfer_size = byte_count / transfer_count / transfer_bytes;
+	const size_t transfer_size_bytes = transfer_size * transfer_bytes;
+
+	for(size_t i=0; i<transfer_count; i++) {
+		void* const peripheral_address = (void*)&SGPIO_REG_SS(0);
+		void* const memory_address = buffer + (transfer_size_bytes * i);
+		
+		const uint_fast8_t source_master = direction_transmit ? 1 : 0;
+		const uint_fast8_t destination_master = direction_transmit ? 0 : 1;
+		const uint_fast8_t lli_fetch_master = direction_transmit ? 0 : 1;
+		const uint_fast8_t interrupt_after_this_lli = i & 1;
+
+		lli[i].csrcaddr = direction_transmit ? memory_address : peripheral_address;
+		lli[i].cdestaddr = direction_transmit ? peripheral_address : memory_address;
+		lli[i].clli = (gpdma_lli_t*)((uint32_t)&lli[(i + 1) % transfer_count] | lli_fetch_master);
+		lli[i].ccontrol =
+			GPDMA_CCONTROL_TRANSFERSIZE(transfer_size) |
+			GPDMA_CCONTROL_SBSIZE(0) |
+			GPDMA_CCONTROL_DBSIZE(0) |
+			GPDMA_CCONTROL_SWIDTH(2) |
+			GPDMA_CCONTROL_DWIDTH(2) |
+			GPDMA_CCONTROL_S(source_master) |
+			GPDMA_CCONTROL_D(destination_master) |
+			GPDMA_CCONTROL_SI(direction_transmit ? 1 : 0) |
+			GPDMA_CCONTROL_DI(direction_transmit ? 0 : 1) |
+			GPDMA_CCONTROL_PROT1(0) |
+			GPDMA_CCONTROL_PROT2(0) |
+			GPDMA_CCONTROL_PROT3(0) |
+			GPDMA_CCONTROL_I(interrupt_after_this_lli)
+			;
+	}
+}
+
+static void sgpio_dma_enable(const uint_fast8_t channel, const gpdma_lli_t* const lli, const bool direction_transmit) {
+	gpdma_channel_disable(channel);
+	gpdma_channel_interrupt_tc_clear(channel);
+	gpdma_channel_interrupt_error_clear(channel);
+
+	GPDMA_CSRCADDR(channel) = (uint32_t)lli[0].csrcaddr;
+	GPDMA_CDESTADDR(channel) = (uint32_t)lli[0].cdestaddr;
+	GPDMA_CLLI(channel) = (uint32_t)lli[0].clli;
+	GPDMA_CCONTROL(channel) = lli[0].ccontrol;
+
+	/* 1: Memory -> Peripheral
+	 * 2: Peripheral -> Memory */
+	const uint_fast8_t flowcntrl = direction_transmit ? 1 : 2;
+
+	GPDMA_CCONFIG(channel) =
+		GPDMA_CCONFIG_E(0) |
+		GPDMA_CCONFIG_SRCPERIPHERAL(0) |
+		GPDMA_CCONFIG_DESTPERIPHERAL(0) |
+		GPDMA_CCONFIG_FLOWCNTRL(flowcntrl) |
+		GPDMA_CCONFIG_IE(1) |
+		GPDMA_CCONFIG_ITC(1) |
+		GPDMA_CCONFIG_L(0) |
+		GPDMA_CCONFIG_H(0)
+		;
+
+	gpdma_channel_enable(channel);
+}
+
+static gpdma_lli_t lli_rx[LLI_COUNT];
+static gpdma_lli_t lli_tx[LLI_COUNT];
+
+void sgpio_dma_init(void* const buffer, const size_t byte_count) {
+	configure_dma_lli(lli_rx, false, buffer, byte_count);
+	configure_dma_lli(lli_tx, true, buffer, byte_count);
+
+	/* DMA peripheral/source 0, option 2 (SGPIO14) -- BREQ */
+	CREG_DMAMUX &= ~(CREG_DMAMUX_DMAMUXPER0_MASK);
+	CREG_DMAMUX |= CREG_DMAMUX_DMAMUXPER0(0x2);
+
+	// Disable sync, maybe it is causing max speed (10MT/sec) glitches?
+	//GPDMA_DMACSYNC = (1 << 0);
+	//GPDMA_SYNC = GPDMA_SYNC_DMACSYNC(0xFFFF); // TODO: Don't do this, I'm just going nuts here.
+
+	gpdma_controller_enable();
+}
+
+static const uint_fast8_t dma_channel_sgpio = 0;
+
+void sgpio_dma_rx_start() {
+	sgpio_dma_enable(dma_channel_sgpio, lli_rx, false);
+}
+
+void sgpio_dma_tx_start() {
+	sgpio_dma_enable(dma_channel_sgpio, lli_tx, true);
+}
+
+void sgpio_dma_irq_tc_acknowledge() {
+	gpdma_channel_interrupt_tc_clear(dma_channel_sgpio);
+}
+
+void sgpio_dma_stop() {
+	gpdma_channel_disable(dma_channel_sgpio);
+}
+
+size_t sgpio_dma_current_transfer_index() {
+	const gpdma_lli_t* const next_lli = (gpdma_lli_t*)GPDMA_CLLI(dma_channel_sgpio);
+	for(size_t i=0; i<LLI_COUNT; i++) {
+		if( (lli_rx[i].clli == next_lli) || (lli_tx[i].clli == next_lli) ) {
+			return i;
+		}
+	}
+	return 0;
+}
diff --git a/firmware/common/sgpio_dma.h b/firmware/common/sgpio_dma.h
new file mode 100644
index 00000000..b3103651
--- /dev/null
+++ b/firmware/common/sgpio_dma.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2013 Jared Boone <jared@sharebrained.com>
+ *
+ * This file is part of HackRF.
+ *
+ * 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.
+ */
+
+#ifndef __SGPIO_DMA_H__
+#define __SGPIO_DMA_H__
+
+#include <stddef.h>
+
+void sgpio_dma_init(void* const buffer, const size_t byte_count);
+void sgpio_dma_rx_start();
+void sgpio_dma_tx_start();
+void sgpio_dma_irq_tc_acknowledge();
+void sgpio_dma_stop();
+
+size_t sgpio_dma_current_transfer_index();
+
+#endif/*__SGPIO_DMA_H__*/