diff --git a/legacy_tests/app_test_i2s_loopback/Makefile b/legacy_tests/app_test_i2s_loopback/Makefile
index 81a8e145..c3e3ab40 100644
--- a/legacy_tests/app_test_i2s_loopback/Makefile
+++ b/legacy_tests/app_test_i2s_loopback/Makefile
@@ -1,7 +1,5 @@
-# Copyright (c) 2016, XMOS Ltd, All rights reserved
 TARGET = xk-audio-216-mc.xn
-USED_MODULES = lib_xua \
-               module_i2c_shared module_i2c_single_port lib_logging 
+USED_MODULES = lib_xua lib_i2c lib_logging
 
 BUILD_FLAGS = -O0 -g -lflash -DXUD_SERIES_SUPPORT=4 -DXUD_CORE_CLOCK=600 -fxscope -save-temps -march=xs2a -DUSB_TILE=tile[1]
 
diff --git a/legacy_tests/app_test_i2s_loopback/xk_216_mc/audiohw.xc b/legacy_tests/app_test_i2s_loopback/xk_216_mc/audiohw.xc
index 3a8cde53..ed1d5f7e 100644
--- a/legacy_tests/app_test_i2s_loopback/xk_216_mc/audiohw.xc
+++ b/legacy_tests/app_test_i2s_loopback/xk_216_mc/audiohw.xc
@@ -1,4 +1,4 @@
-// Copyright 2016-2021 XMOS LIMITED.
+// Copyright 2016-2022 XMOS LIMITED.
 // This Software is subject to the terms of the XMOS Public Licence: Version 1.
 #ifdef HARDWARE
 
@@ -8,7 +8,7 @@
 #include "devicedefines.h"
 #include <platform.h>
 #include "gpio_access.h"
-#include "i2c_shared.h"
+#include "i2c.h"
 #include "cs4384.h"
 #include "cs5368.h"
 #include "cs2100.h"
@@ -25,16 +25,10 @@
 
 on tile[0] : out port p_gpio = XS1_PORT_8C;
 
-#ifndef IAP
-/* If IAP not enabled, i2c ports not declared - still needs for DAC config */
-on tile [0] : struct r_i2c r_i2c = {XS1_PORT_4A};
-#else
-extern struct r_i2c r_i2c;
-#endif
+port p_i2c = on tile[0]:PORT_I2C;
 
-#define DAC_REGWRITE(reg, val) {data[0] = val; i2c_shared_master_write_reg(r_i2c, CS4384_I2C_ADDR, reg, data, 1);}
-#define DAC_REGREAD(reg, val)  {i2c_shared_master_read_reg(r_i2c, CS4384_I2C_ADDR, reg, val, 1);}
-#define ADC_REGWRITE(reg, val) {data[0] = val; i2c_shared_master_write_reg(r_i2c, CS5368_I2C_ADDR, reg, data, 1);}
+#define DAC_REGWRITE(reg, val) {result = i2c.write_reg(CS4384_I2C_ADDR, reg, val);}
+#define ADC_REGWRITE(reg, val) {result = i2c.write_reg(CS5368_I2C_ADDR, reg, val);}
 
 #ifdef USE_FRACTIONAL_N
 
@@ -45,14 +39,15 @@ extern struct r_i2c r_i2c;
 #define PLL_SYNC_FREQ 300
 #endif
 
-#define CS2100_REGREAD(reg, data)  {data[0] = 0xAA; i2c_master_read_reg(CS2100_I2C_DEVICE_ADDR, reg, data, 1, r_i2c);}
-#define CS2100_REGREAD_ASSERT(reg, data, expected)  {data[0] = 0xAA; i2c_master_read_reg(CS2100_I2C_DEVICE_ADDR, reg, data, 1, r_i2c); assert(data[0] == expected);}
-#define CS2100_REGWRITE(reg, val) {data[0] = val; i2c_master_write_reg(CS2100_I2C_DEVICE_ADDR, reg, data, 1, r_i2c);}
+#define CS2100_REGREAD(reg, data) {data[0] = i2c.read_reg(CS2100_I2C_DEVICE_ADDR, reg, result);}
+#define CS2100_REGREAD_ASSERT(reg, data, expected) {data[0] = i2c.read_reg(CS2100_I2C_DEVICE_ADDR, reg, result); assert(data[0] == expected);}
+#define CS2100_REGWRITE(reg, val) {result = i2c.write_reg(CS2100_I2C_DEVICE_ADDR, reg, val);}
 
 /* Init of CS2100 */
-void PllInit(void)
+void PllInit(client interface i2c_master_if i2c)
 {
     unsigned char data[1] = {0};
+    i2c_regop_res_t result;
 
 #if XCORE_200_MC_AUDIO_HW_VERSION < 2
     /* Enable init */
@@ -73,12 +68,15 @@ void PllInit(void)
     CS2100_REGREAD_ASSERT(CS2100_GLOBAL_CONFIG, data, 0x01);
     CS2100_REGREAD_ASSERT(CS2100_FUNC_CONFIG_1, data, 0x08);
     CS2100_REGREAD_ASSERT(CS2100_FUNC_CONFIG_2, data, 0x00);
+
+    i2c.shutdown();
 }
 
 /* Setup PLL multiplier */
-void PllMult(unsigned output, unsigned ref)
+void PllMult(unsigned output, unsigned ref, client interface i2c_master_if i2c)
 {
     unsigned char data[1] = {0};
+    i2c_regop_res_t result;
 
     /* PLL expects 12:20 format, convert output and ref to 12:20 */
     /* Shift up the dividend by 12 to retain format... */
@@ -120,9 +118,6 @@ void AudioHwInit(chanend ?c_codec)
     start_clock(clk_pll_sync);
 #endif
 
-    /* Init the i2c module */
-    i2c_shared_master_init(r_i2c);
-
     /* Assert reset to ADC and DAC */
     set_gpio(P_GPIO_DAC_RST_N, 0);
     set_gpio(P_GPIO_ADC_RST_N, 0);
@@ -143,7 +138,12 @@ void AudioHwInit(chanend ?c_codec)
     set_gpio(P_GPIO_PLL_SEL, 1);
 
      /* Initialise external PLL */
-    PllInit();
+    i2c_master_if i2c[1];
+    par
+    {
+        i2c_master_single_port(i2c, 1, p_i2c, 10, 0, 1, 0);
+        PllInit(i2c[0]);
+    }
 #endif
 
 #ifdef IAP
@@ -155,10 +155,11 @@ void AudioHwInit(chanend ?c_codec)
 /* Configures the external audio hardware for the required sample frequency.
  * See gpio.h for I2C helper functions and gpio access
  */
-void AudioHwConfig(unsigned samFreq, unsigned mClk, chanend ?c_codec, unsigned dsdMode,
-    unsigned sampRes_DAC, unsigned sampRes_ADC)
+void AudioHwConfig2(unsigned samFreq, unsigned mClk, chanend ?c_codec, unsigned dsdMode,
+    unsigned sampRes_DAC, unsigned sampRes_ADC, client interface i2c_master_if i2c)
 {
-	unsigned char data[1] = {0};
+    unsigned char data[1] = {0};
+    i2c_regop_res_t result;
 
     /* Put ADC and DAC into reset */
 	set_gpio(P_GPIO_ADC_RST_N, 0);
@@ -167,7 +168,7 @@ void AudioHwConfig(unsigned samFreq, unsigned mClk, chanend ?c_codec, unsigned d
     /* Set master clock select appropriately */
 #if defined(USE_FRACTIONAL_N)
     /* Configure external fractional-n clock multiplier for 300Hz -> mClkFreq */
-    PllMult(mClk, PLL_SYNC_FREQ);
+    PllMult(mClk, PLL_SYNC_FREQ, i2c);
 #endif
     /* Allow some time for mclk to lock and MCLK to stabilise - this is important to avoid glitches at start of stream */
     {
@@ -365,8 +366,20 @@ void AudioHwConfig(unsigned samFreq, unsigned mClk, chanend ?c_codec, unsigned d
         DAC_REGWRITE(CS4384_MODE_CTRL, 0b10000000);
     }
 #endif
+
+    i2c.shutdown();
     return;
 }
-//:
+
+void AudioHwConfig(unsigned samFreq, unsigned mClk, chanend ?c_codec, unsigned dsdMode,
+    unsigned sampRes_DAC, unsigned sampRes_ADC)
+{
+    i2c_master_if i2c[1];
+    par
+    {
+        i2c_master_single_port(i2c, 1, p_i2c, 10, 0, 1, 0);
+        AudioHwConfig2(samFreq, mClk, c_codec, dsdMode, sampRes_DAC, sampRes_ADC, i2c[0]);
+    }
+}
 
 #endif
diff --git a/module_locks/README.rst b/module_locks/README.rst
deleted file mode 100644
index ecde319a..00000000
--- a/module_locks/README.rst
+++ /dev/null
@@ -1,7 +0,0 @@
-module_locks Readme
-===================
-
-:scope: Dummy module
-:description: Allows compiling legacy_tests in lib_xua with lib_locks. sc_i2c is used in the tests and it requires module_locks from sc_util, but the definitions in sc_utils conflict with the ones in lib_locks.
-:keywords: dummy
-:boards: XMOS Dev Kit
diff --git a/module_locks/module_build_info b/module_locks/module_build_info
deleted file mode 100644
index d90ffd43..00000000
--- a/module_locks/module_build_info
+++ /dev/null
@@ -1 +0,0 @@
-# Dummy module used in legacy_tests. See README.rst for more details.