From 4b9e3235931ba3c3a144f43fffa9eec9c3644779 Mon Sep 17 00:00:00 2001
From: Sam Chesney <samc@xmos.com>
Date: Wed, 7 Dec 2016 11:41:05 +0000
Subject: [PATCH] Move defines and checks to expected places

---
 module_usb_audio/audio_io/audio_io.xc | 26 --------------------
 module_usb_audio/devicedefines.h      | 35 +++++++++++++++++++++++++++
 module_usb_audio/warnings.xc          |  6 +++++
 3 files changed, 41 insertions(+), 26 deletions(-)

diff --git a/module_usb_audio/audio_io/audio_io.xc b/module_usb_audio/audio_io/audio_io.xc
index 2f6fb0e2..ba067156 100755
--- a/module_usb_audio/audio_io/audio_io.xc
+++ b/module_usb_audio/audio_io/audio_io.xc
@@ -32,32 +32,6 @@
 #include "commands.h"
 #include "xc_ptr.h"
 
-#ifndef I2S_DOWNSAMPLE_FACTOR
-#define I2S_DOWNSAMPLE_FACTOR (1)
-#endif
-
-#ifndef I2S_DOWNSAMPLE_MONO
-#define I2S_DOWNSAMPLE_MONO (0)
-#endif
-
-#if (I2S_DOWNSAMPLE_MONO == 1)
-#define I2S_DOWNSAMPLE_CHANS (I2S_CHANS_DAC/2)
-#else
-#define I2S_DOWNSAMPLE_CHANS I2S_CHANS_DAC
-#endif
-
-#if (I2S_DOWNSAMPLE_FACTOR != 1) && (I2S_DOWNSAMPLE_FACTOR != 3)
-#error "Unsupported I2S downsampling configuration"
-#endif
-
-#if (NUM_USB_CHAN_IN && (NUM_USB_CHAN_IN < (I2S_CHANS_ADC + NUM_PDM_MICS)))
-#error "Not enough USB input channels to support number of I2S and PDM inputs"
-#endif
-
-#if (NUM_USB_CHAN_IN && (NUM_USB_CHAN_IN < (NUM_PDM_MICS + PDM_MIC_INDEX)))
-#error "PDM mic inputs mapping exceeds bounds of USB input channel"
-#endif
-
 /* TODO 32 is max expected channels */
 static unsigned samplesOut[32];
 
diff --git a/module_usb_audio/devicedefines.h b/module_usb_audio/devicedefines.h
index ffc11fde..ca7ac85c 100644
--- a/module_usb_audio/devicedefines.h
+++ b/module_usb_audio/devicedefines.h
@@ -121,6 +121,41 @@
 #define I2S_WIRES_ADC            (I2S_CHANS_ADC / I2S_CHANS_PER_FRAME)
 #endif
 
+/**
+ * @brief Incoming I2S (device to host) channels can be downsampled by a factor of 3.
+ *
+ * Default: 1 i.e. downsampling is disabled.
+ */
+#ifndef I2S_DOWNSAMPLE_FACTOR
+#define I2S_DOWNSAMPLE_FACTOR (1)
+#else
+    #if (I2S_DOWNSAMPLE_FACTOR != 3)
+        #error Unsupported I2S downsampling configuration
+    #endif
+#endif
+
+/**
+ * @brief Only downsample one channel per I2S frame.
+ *
+ * Default: 0 i.e. mono mode is disabled, all channels will be downsampled.
+ */
+#ifndef I2S_DOWNSAMPLE_MONO
+#define I2S_DOWNSAMPLE_MONO (0)
+#endif
+
+/**
+ * @brief Number of incoming (device to host) I2S channels to downsample.
+ *
+ * Default: The number of I2S incoming channels, or half this if mono downsampling is enabled.
+ */
+#if (I2S_DOWNSAMPLE_MONO == 1)
+    #define I2S_DOWNSAMPLE_CHANS (I2S_CHANS_ADC / 2)
+    #if ((I2S_DOWNSAMPLE_FACTOR > 1) && (I2S_MODE_TDM == 1))
+        #error Mono I2S downsampling is not avaliable in TDM mode
+    #endif
+#else
+#define I2S_DOWNSAMPLE_CHANS I2S_CHANS_ADC
+#endif
 
 /**
  * @brief Max supported sample frequency for device (Hz). Default: 192000
diff --git a/module_usb_audio/warnings.xc b/module_usb_audio/warnings.xc
index c1646213..7c0f753d 100644
--- a/module_usb_audio/warnings.xc
+++ b/module_usb_audio/warnings.xc
@@ -72,4 +72,10 @@ Warnings relating to configuration defines located in this XC source file rather
 #error NUM_USB_CHAN_IN_FS expected to be less than or equal to NUM_USB_CHAN_IN
 #endif
 
+#if (NUM_USB_CHAN_IN && (NUM_USB_CHAN_IN < (I2S_CHANS_ADC + NUM_PDM_MICS)))
+#error Not enough USB input channels to support number of I2S and PDM inputs
+#endif
 
+#if (NUM_USB_CHAN_IN && (NUM_USB_CHAN_IN < (NUM_PDM_MICS + PDM_MIC_INDEX)))
+#error PDM mic inputs mapping exceeds bounds of USB input channel
+#endif