Initial test FW app for MIDI

tests/test_midi/src/hwsupport.xc

@@ -0,0 +1,43 @@
+// Copyright 2017-2024 XMOS LIMITED.
+// This Software is subject to the terms of the XMOS Public Licence: Version 1.
+#include <xs1.h>
+#include <platform.h>
+#include "xua.h"
+
+
+on tile[0]: out port p_ctrl = XS1_PORT_8D;
+
+/* p_ctrl:
+ * [0:3] - Unused
+ * [4]   - EN_3v3_N
+ * [5]   - EN_3v3A
+ * [6]   - EXT_PLL_SEL (CS2100:0, SI: 1)
+ * [7]   - MCLK_DIR    (Out:0, In: 1)
+ */
+#define EXT_PLL_SEL__MCLK_DIR    (0x80)
+
+/* Note, this runs on Tile[0] */
+void ctrlPort()
+{
+    // Drive control port to turn on 3V3 and set MCLK_DIR
+    // Note, "soft-start" to reduce current spike
+    // Note, 3v3_EN is inverted
+    for (int i = 0; i < 30; i++)
+    {
+        p_ctrl <: EXT_PLL_SEL__MCLK_DIR | 0x30; /* 3v3: off, 3v3A: on */
+        delay_microseconds(5);
+        p_ctrl <: EXT_PLL_SEL__MCLK_DIR | 0x20; /* 3v3: on, 3v3A: on */
+        delay_microseconds(5);
+    }
+}
+
+/* Configures the external audio hardware at startup. Note this runs on Tile[1] */
+void AudioHwInit()
+{
+}
+
+/* Configures the external audio hardware for the required sample frequency */
+void AudioHwConfig(unsigned samFreq, unsigned mClk, unsigned dsdMode, unsigned sampRes_DAC, unsigned sampRes_ADC)
+{
+}
+