tests: drivers: i2s: Test different length transmission

Add test that verifies I2S/TDM communication (single instance with
GPIO loopback from DOUT to DIN) at different configuration.
Verify:
- mono / stereo configuration;
- 8/16/32 bit word size;
- 8/16/24 bytes long data buffer.

Signed-off-by: Sebastian Głąb <[email protected]>

Author: nordic-segl

scripts/ci/license_allow_list.yaml

@@ -49,6 +49,7 @@ Apache-2.0: |
   ^nrf/modules/openthread/
   ^nrf/samples/net/http_server/src/main.c
   ^nrf/tests/benchmarks/kernel_freq_change/src/kernel_context.c
+  ^nrf/tests/drivers/i2s/i2s_buffer/src/i2s_buffer.c
   ^nrf/tests/subsys/suit/common/tls_config/user-tls-conf.h
   ^nrf/subsys/settings/
   ^nrf/subsys/mgmt/mcumgr/grp/img_mgmt/src/img_mgmt.c

tests/drivers/i2s/i2s_buffer/CMakeLists.txt

@@ -0,0 +1,13 @@
+#
+# Copyright (c) 2025 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(i2s_buffer)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})

tests/drivers/i2s/i2s_buffer/Kconfig

@@ -0,0 +1,43 @@
+#
+# Copyright (c) 2025 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+mainmenu "I2S Buffer Test"
+
+config I2S_TEST_ALLOWED_DATA_OFFSET
+	int "Allowed offset in received data"
+	default 2 if DT_HAS_NORDIC_NRF_I2S_ENABLED
+	default 0
+	help
+	  Maximum allowed offset between sent and received samples.
+	  Value is in "full" audio samples.
+	  Offset of 1 "full" audio sample is:
+	  - 1 byte for mono 8 bit word size.
+	  - 2 bytes for stereo 8 bit word size.
+	  - 2 bytes for mono 16 bit word size.
+	  - 4 bytes for stereo 16 bit word size.
+	  - 4 bytes for mono 32 bit word size.
+	  - 8 bytes for stereo 32 bit word size.
+
+config I2S_TEST_BUFFER_SIZE
+	int "Number of bytes send in one transaction"
+	default 16
+	help
+	  Value has to be a multiple of 8 bytes. Test supports up to 32 bytes.
+
+config I2S_TEST_WORD_SIZE_32_BIT_UNSUPPORTED
+	bool "32 bit word size is not supported by the driver"
+	help
+	  When set to 'y' testing 32 bit word size is skipped.
+
+config I2S_TEST_BLOCK_SIZE_8_UNSUPPORTED
+	bool "Block_size of 8 bytes is not supported by the driver"
+	default y if DT_HAS_NORDIC_NRF_TDM_ENABLED
+	help
+	  When set to 'y', test that use 8 bytes of data check if
+	  i2s_configure() returns -EINVAL.
+	  When set to 'n', test will do the I2S transmission.
+
+source "Kconfig.zephyr"

tests/drivers/i2s/i2s_buffer/boards/nrf52840dk_nrf52840.conf

@@ -0,0 +1 @@
+CONFIG_I2S_TEST_WORD_SIZE_32_BIT_UNSUPPORTED=y

tests/drivers/i2s/i2s_buffer/boards/nrf52840dk_nrf52840.overlay

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+/* Test requires GPIO loopback:
+ * P1.01 - P1.02
+ */
+
+/ {
+	aliases {
+		i2s-node0 = &i2s0;
+	};
+};
+
+&pinctrl {
+	i2s0_default_alt: i2s0_default_alt {
+		group1 {
+			psels = <NRF_PSEL(I2S_SCK_M, 1, 5)>,
+				<NRF_PSEL(I2S_LRCK_M, 1, 6)>,
+				<NRF_PSEL(I2S_SDOUT, 1, 1)>,
+				<NRF_PSEL(I2S_SDIN, 1, 2)>;
+		};
+	};
+};
+
+&i2s0 {
+	status = "okay";
+	pinctrl-0 = <&i2s0_default_alt>;
+	pinctrl-names = "default";
+};

tests/drivers/i2s/i2s_buffer/boards/nrf5340dk_nrf5340_cpuapp.overlay

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+/* Test requires GPIO loopback:
+ * P0.04 - P0.05
+ */
+
+/ {
+	aliases {
+		i2s-node0 = &i2s0;
+	};
+};
+
+&pinctrl {
+	i2s0_default_alt: i2s0_default_alt {
+		group1 {
+			psels = <NRF_PSEL(I2S_SCK_M, 1, 6)>,
+				<NRF_PSEL(I2S_LRCK_M, 1, 7)>,
+				<NRF_PSEL(I2S_SDOUT, 0, 4)>,
+				<NRF_PSEL(I2S_SDIN, 0, 5)>;
+		};
+	};
+};
+
+&uart1 {
+	status = "disabled";
+};
+
+&i2s0 {
+	status = "okay";
+	pinctrl-0 = <&i2s0_default_alt>;
+	pinctrl-names = "default";
+};

tests/drivers/i2s/i2s_buffer/boards/nrf5340dk_nrf5340_cpuapp_aclk.overlay

@@ -0,0 +1,9 @@
+/* Drive i2s peripheral from ACLK. */
+
+&clock {
+	hfclkaudio-frequency = <11289600>;
+};
+
+&i2s0 {
+	clock-source = "ACLK";
+};

tests/drivers/i2s/i2s_buffer/boards/nrf54h20dk_nrf54h20_cpuapp.overlay

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+/* Test requires GPIO loopback:
+ * P1.04 - P1.05
+ */
+
+/ {
+	aliases {
+		i2s-node0 = &tdm130;
+	};
+};
+
+&pinctrl {
+	tdm130_default_alt: tdm130_default_alt {
+		group1 {
+			psels = <NRF_PSEL(TDM_SCK_M, 1, 3)>,
+				<NRF_PSEL(TDM_FSYNC_M, 1, 6)>,
+				<NRF_PSEL(TDM_SDOUT, 1, 4)>,
+				<NRF_PSEL(TDM_SDIN, 1, 5)>;
+		};
+	};
+};
+
+&tdm130 {
+	status = "okay";
+	pinctrl-0 = <&tdm130_default_alt>;
+	pinctrl-names = "default";
+	memory-regions = <&cpuapp_dma_region>;
+};

tests/drivers/i2s/i2s_buffer/boards/nrf54l15dk_nrf54l15_cpuapp.overlay

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+/* Test requires GPIO loopback:
+ * P1.08 - P1.09
+ */
+
+/ {
+	aliases {
+		i2s-node0 = &i2s20;
+	};
+};
+
+&pinctrl {
+	i2s20_default_alt: i2s20_default_alt {
+		group1 {
+			psels = <NRF_PSEL(I2S_SCK_M, 1, 11)>,
+				<NRF_PSEL(I2S_LRCK_M, 1, 12)>,
+				<NRF_PSEL(I2S_SDOUT, 1, 8)>,
+				<NRF_PSEL(I2S_SDIN, 1, 9)>;
+		};
+	};
+};
+
+&i2s20 {
+	status = "okay";
+	pinctrl-0 = <&i2s20_default_alt>;
+	pinctrl-names = "default";
+};

tests/drivers/i2s/i2s_buffer/boards/nrf54lm20dk_nrf54lm20a_cpuapp.overlay

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+/* Test requires GPIO loopback:
+ * P1.30 - P1.31
+ */
+
+/ {
+	aliases {
+		i2s-node0 = &tdm;
+	};
+};
+
+&pinctrl {
+	tdm_default_alt: tdm_default_alt {
+		group1 {
+			psels = <NRF_PSEL(TDM_SCK_M, 1, 23)>,
+				<NRF_PSEL(TDM_FSYNC_M, 1, 14)>,
+				<NRF_PSEL(TDM_SDOUT, 1, 30)>,
+				<NRF_PSEL(TDM_SDIN, 1, 31)>;
+		};
+	};
+};
+
+&tdm {
+	status = "okay";
+	pinctrl-0 = <&tdm_default_alt>;
+	pinctrl-names = "default";
+};