From 96da55d83aeadd92ac9e57dec9a38057b1b35f67 Mon Sep 17 00:00:00 2001
From: Jared Boone <jboone@earfeast.com>
Date: Wed, 10 Aug 2016 10:34:14 -0700
Subject: [PATCH] wait_for_buffer() now handles TX buffers.

Feels a bit awkward to read LLI src/dest to determine if RX or TX. But it works.
---
 firmware/baseband/baseband_dma.cpp    | 7 +++++--
 firmware/baseband/baseband_dma.hpp    | 2 +-
 firmware/baseband/baseband_thread.cpp | 2 +-
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/firmware/baseband/baseband_dma.cpp b/firmware/baseband/baseband_dma.cpp
index d86bef72e..4fc1fdd8f 100644
--- a/firmware/baseband/baseband_dma.cpp
+++ b/firmware/baseband/baseband_dma.cpp
@@ -156,12 +156,15 @@ void disable() {
 	gpdma_channel_sgpio.disable();
 }
 
-baseband::buffer_t wait_for_rx_buffer() {
+baseband::buffer_t wait_for_buffer() {
 	const auto next_index = thread_wait.sleep();
 	
 	if( next_index >= 0 ) {
 		const size_t free_index = (next_index + transfers_per_buffer - 2) & transfers_mask;
-		return { reinterpret_cast<sample_t*>(lli_loop[free_index].destaddr), transfer_samples };
+		const auto src = lli_loop[free_index].srcaddr;
+		const auto dst = lli_loop[free_index].destaddr;
+		const auto p = (src == reinterpret_cast<uint32_t>(&LPC_SGPIO->REG_SS[0])) ? dst : src;
+		return { reinterpret_cast<sample_t*>(p), transfer_samples };
 	} else {
 		return { };
 	}
diff --git a/firmware/baseband/baseband_dma.hpp b/firmware/baseband/baseband_dma.hpp
index 94827d4bc..56752ddcc 100644
--- a/firmware/baseband/baseband_dma.hpp
+++ b/firmware/baseband/baseband_dma.hpp
@@ -42,7 +42,7 @@ bool is_enabled();
 
 void disable();
 
-baseband::buffer_t wait_for_rx_buffer();
+baseband::buffer_t wait_for_buffer();
 
 } /* namespace dma */
 } /* namespace baseband */
diff --git a/firmware/baseband/baseband_thread.cpp b/firmware/baseband/baseband_thread.cpp
index 0784d9bd6..926e4fb0f 100644
--- a/firmware/baseband/baseband_thread.cpp
+++ b/firmware/baseband/baseband_thread.cpp
@@ -77,7 +77,7 @@ void BasebandThread::run() {
 
 	while( !chThdShouldTerminate() ) {
 		// TODO: Place correct sampling rate into buffer returned here:
-		const auto buffer_tmp = baseband::dma::wait_for_rx_buffer();
+		const auto buffer_tmp = baseband::dma::wait_for_buffer();
 		if( buffer_tmp ) {
 			buffer_c8_t buffer {
 				buffer_tmp.p, buffer_tmp.count, sampling_rate