[PATCH v3 0/4] arm64: dts: freescale: Add IMX-AUD-IO add-on board support

[PATCH v3 0/4] arm64: dts: freescale: Add IMX-AUD-IO add-on board support

[Chancel Liu]

From: Chancel Liu <chancel.liu@nxp.com>

This patch series adds support for the IMX-AUD-IO[1] audio expansion
card on the i.MX95 19x19 EVK and i.MX952 EVK platforms.

A connector is present on the base board to attach the IMX-AUD-IO card.
This connector is described by the fsl,aud-io-slot binding. It acts as
a nexus that exposes a constrained set of I/O resources, such as GPIOs,
clocks and interrupts, through fixed electrical wiring. All actual
hardware providers reside on the base board.

Also update the EVK base Device Trees to describe the connector and
required board-level resources. Add a DTS overlay to enable the
IMX-AUD-IO board.

The approach used here is inspired by the discussion[2] where a
connector is described as a nexus mapping board-level resources. One
important difference in this case is that the IMX-AUD-IO add-on board
is not a hot-pluggable device. The board is connected to the connector
before boot and remains present for the lifetime of the system. As a
result, the connector is modeled to describe fixed, boot-time hardware
wiring rather than runtime attachment or hot-plug handling.

This series depends on the clock nexus support from Miquel Raynal[3],
in particular the clock-nexus-node.yaml binding that defines clock-map,
e.g. commit e0be7b4eedd3 ("dt-bindings: clock: Introduce nexus nodes").

[1]https://www.nxp.com/part/IMX-AUD-IO
[2]https://lore.kernel.org/linux-devicetree/20250902105710.00512c6d@booty/
[3]https://lore.kernel.org/all/20260807-schneider-v7-2-rc1-eip201-upstream-v5-0-8785f9531cf0@bootlin.com/

Changes in v3:
- Drop unneeded clock-map-mask and clock-map-pass-thru from the binding.
- Constrain gpio-map/clock-map/interrupt-map maxItems to the number of
  signals the connector actually provides instead of a loose upper bound.
- Narrow gpio-map-mask/interrupt-map-mask from 0xffff to 0xf.
Link to v2: https://lore.kernel.org/r/20260629074734.3643227-1-chancel.liu@oss.nxp.com

Changes in v2:
- Drop [PATCH 1/5] clk: Add support for clock nexus dt bindings. Same
  change is already present in Miquel Raynal's ongoing series
- Drop PWM properties from binding. This connector carries no PWM signals
- Rename compatible from fsl,io-connector to board-specific compatibles:
  fsl,imx95-19x19-evk-aud-io and fsl,imx952-evk-aud-io. The i.MX952 EVK
  uses fsl,imx95-19x19-evk-aud-io as fallback
- Add property constraints instead of redefining common types
- Fix inconsistent quote style for '#interrupt-cells' in binding
- Add required GPIO nexus properties and reference gpio-nexus-node.yaml
  and clock-nexus-node.yaml
- Make gpio-map-pass-thru a const value to pass through only polarity
  bit (bit 0)
- Modify dts accordingly and some commit messages

Chancel Liu (4):
  dt-bindings: connector: Add fsl,aud-io-slot binding
  arm64: dts: freescale: imx95-19x19-evk: Add IMX-AUD-IO board support
  arm64: dts: freescale: imx952-evk: Add IMX-AUD-IO board support
  arm64: dts: freescale: Add common DTS overlay for IMX-AUD-IO add-on
    board

 .../bindings/connector/fsl,aud-io-slot.yaml   | 106 ++++++++++++++++++
 arch/arm64/boot/dts/freescale/Makefile        |   4 +
 arch/arm64/boot/dts/freescale/imx-aud-io.dtso |  57 ++++++++++
 .../boot/dts/freescale/imx95-19x19-evk.dts    |  54 ++++++++-
 arch/arm64/boot/dts/freescale/imx952-evk.dts  |  69 +++++++++++-
 5 files changed, 286 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml
 create mode 100644 arch/arm64/boot/dts/freescale/imx-aud-io.dtso

--
2.50.1

[PATCH v3 1/4] dt-bindings: connector: Add fsl,aud-io-slot binding

[Chancel Liu]

From: Chancel Liu <chancel.liu@nxp.com>

The NXP AUD-IO slot represents a physically present I/O connector on
the base board. It acts as a nexus that exposes a constrained set of
I/O resources, such as GPIOs, clocks and interrupts, through fixed
electrical wiring. All actual hardware providers reside on the base
board. The connector node only defines index-based mappings to those
providers.

This connector type is present on i.MX95 19x19 EVK and i.MX952 EVK,
where it is used to attach the IMX-AUD-IO audio expansion card[1]. The
same add-on board can be reused across different base boards that carry
this connector.

[1]https://www.nxp.com/part/IMX-AUD-IO

Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
---
 .../bindings/connector/fsl,aud-io-slot.yaml   | 106 ++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml

diff --git a/Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml b/Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml
new file mode 100644
index 000000000000..fc3896d0fafa
--- /dev/null
+++ b/Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml
@@ -0,0 +1,106 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/connector/fsl,aud-io-slot.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP AUD-IO Slot
+
+maintainers:
+  - Frank Li <Frank.Li@nxp.com>
+  - Chancel Liu <chancel.liu@nxp.com>
+
+description:
+  The NXP AUD-IO slot represents a physically present I/O connector on
+  the base board. It acts as a nexus that exposes a constrained set of
+  I/O resources, such as GPIOs, clocks and interrupts, through fixed
+  electrical wiring. All actual hardware providers reside on the base
+  board. The connector node only defines index-based mappings to those
+  providers. This connector type is present on i.MX95 19x19 EVK and
+  i.MX952 EVK, where it is used to attach the IMX-AUD-IO expansion card.
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - fsl,imx952-evk-aud-io
+          - const: fsl,imx95-19x19-evk-aud-io
+      - const: fsl,imx95-19x19-evk-aud-io
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+  gpio-map:
+    minItems: 1
+    maxItems: 3
+
+  gpio-map-mask:
+    items:
+      - const: 0xf
+      - const: 0x0
+
+  gpio-map-pass-thru:
+    items:
+      - const: 0x0
+      - const: 0x1
+
+  '#clock-cells':
+    const: 1
+
+  clock-map:
+    minItems: 1
+    maxItems: 2
+
+  '#address-cells':
+    const: 0
+
+  interrupt-controller: true
+
+  '#interrupt-cells':
+    const: 2
+
+  interrupt-map:
+    minItems: 1
+    maxItems: 2
+
+  interrupt-map-mask:
+    items:
+      - const: 0xf
+      - const: 0x0
+
+allOf:
+  - $ref: /schemas/gpio/gpio-nexus-node.yaml#
+  - $ref: /schemas/clock/clock-nexus-node.yaml#
+
+required:
+  - compatible
+  - gpio-controller
+  - '#gpio-cells'
+  - gpio-map
+  - gpio-map-mask
+  - gpio-map-pass-thru
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    connector {
+      compatible = "fsl,imx95-19x19-evk-aud-io";
+      gpio-controller;
+      #gpio-cells = <2>;
+      gpio-map = <0 0 &gpio1 8 1>;
+      gpio-map-mask = <0xf 0x0>;
+      gpio-map-pass-thru = <0x0 0x1>;
+      #clock-cells = <1>;
+      clock-map = <0 &clk 1>;
+      #address-cells = <0>;
+      interrupt-controller;
+      #interrupt-cells = <2>;
+      interrupt-map-mask = <0xf 0x0>;
+      interrupt-map = <0 0 &gpio2 27 IRQ_TYPE_LEVEL_LOW>;
+    };
-- 
2.50.1

[PATCH v3 2/4] arm64: dts: freescale: imx95-19x19-evk: Add IMX-AUD-IO board support

[Chancel Liu]

From: Chancel Liu <chancel.liu@nxp.com>

IMX-AUD-IO is an add-on board which can be connected to i.MX95 19x19
EVK through a physical connector. This connector is described as a
fsl,aud-io-slot connector to expose a constrained subset of GPIO and
clock resources to the add-on board using fixed electrical wiring.

Also add required regulator, sound CPU DAI and I2C bus configuration to
support IMX-AUD-IO on this base board.

Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
---
 .../boot/dts/freescale/imx95-19x19-evk.dts    | 54 ++++++++++++++++++-
 1 file changed, 52 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/freescale/imx95-19x19-evk.dts b/arch/arm64/boot/dts/freescale/imx95-19x19-evk.dts
index 47ed0ef67611..ddc5aed2ea8a 100644
--- a/arch/arm64/boot/dts/freescale/imx95-19x19-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx95-19x19-evk.dts
@@ -43,6 +43,18 @@ aliases {
 		serial4 = &lpuart5;
 	};
 
+	aud_io_slot: connector {
+		compatible = "fsl,imx95-19x19-evk-aud-io";
+		gpio-controller;
+		#gpio-cells = <2>;
+		gpio-map = <0 0 &i2c6_pcal6416 8 1>;
+		gpio-map-mask = <0xf 0x0>;
+		/* Only pass through GPIO polarity flag bit 0. */
+		gpio-map-pass-thru = <0x0 0x1>;
+		#clock-cells = <1>;
+		clock-map = <0 &scmi_clk IMX95_CLK_SAI2>;
+	};
+
 	bt_sco_codec: audio-codec-bt-sco {
 		#sound-dai-cells = <1>;
 		compatible = "linux,bt-sco";
@@ -161,7 +173,7 @@ flexcan2_phy: can-phy1 {
 		standby-gpios = <&i2c4_gpio_expander_21 3 GPIO_ACTIVE_LOW>;
 	};
 
-	reg_vref_1v8: regulator-1p8v {
+	aud_io_reg_1v8: reg_vref_1v8: regulator-1p8v {
 		compatible = "regulator-fixed";
 		regulator-max-microvolt = <1800000>;
 		regulator-min-microvolt = <1800000>;
@@ -175,6 +187,22 @@ reg_3p3v: regulator-3p3v {
 		regulator-name = "+V3.3_SW";
 	};
 
+	aud_io_reg_3v3: regulator-aud-io-3v3 {
+		compatible = "regulator-fixed";
+		regulator-name = "aud-io-3v3";
+		regulator-max-microvolt = <3300000>;
+		regulator-min-microvolt = <3300000>;
+		gpio = <&i2c6_pcal6416 11 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+	};
+
+	aud_io_reg_5v: regulator-aud-io-5v {
+		compatible = "regulator-fixed";
+		regulator-name = "aud-io-5v";
+		regulator-max-microvolt = <5000000>;
+		regulator-min-microvolt = <5000000>;
+	};
+
 	reg_audio_pwr: regulator-audio-pwr {
 		compatible = "regulator-fixed";
 		regulator-name = "audio-pwr";
@@ -449,7 +477,7 @@ i2c5_pcal6408: gpio@21 {
 	};
 };
 
-&lpi2c6 {
+aud_io_i2c: &lpi2c6 {
 	clock-frequency = <100000>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_lpi2c6>;
@@ -671,6 +699,28 @@ &sai1 {
 	status = "okay";
 };
 
+aud_io_cpu: &sai2 {
+	#sound-dai-cells = <0>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_sai2>;
+	clocks = <&scmi_clk IMX95_CLK_BUSNETCMIX>, <&dummy>,
+		 <&scmi_clk IMX95_CLK_SAI2>, <&dummy>,
+		 <&dummy>, <&scmi_clk IMX95_CLK_AUDIOPLL1>,
+		 <&scmi_clk IMX95_CLK_AUDIOPLL2>;
+	clock-names = "bus", "mclk0", "mclk1", "mclk2", "mclk3", "pll8k", "pll11k";
+	assigned-clocks = <&scmi_clk IMX95_CLK_AUDIOPLL1_VCO>,
+			  <&scmi_clk IMX95_CLK_AUDIOPLL2_VCO>,
+			  <&scmi_clk IMX95_CLK_AUDIOPLL1>,
+			  <&scmi_clk IMX95_CLK_AUDIOPLL2>,
+			  <&scmi_clk IMX95_CLK_SAI2>;
+	assigned-clock-parents = <0>, <0>, <0>, <0>,
+				 <&scmi_clk IMX95_CLK_AUDIOPLL1>;
+	assigned-clock-rates = <3932160000>, <3612672000>,
+			       <393216000>, <361267200>, <12288000>;
+	fsl,sai-mclk-direction-output;
+	fsl,sai-asynchronous;
+};
+
 &sai3 {
 	#sound-dai-cells = <0>;
 	pinctrl-names = "default";
-- 
2.50.1

[PATCH v3 3/4] arm64: dts: freescale: imx952-evk: Add IMX-AUD-IO board support

[Chancel Liu]

From: Chancel Liu <chancel.liu@nxp.com>

IMX-AUD-IO is an add-on board which can be connected to i.MX952 EVK
through a physical connector. This connector is described as a
fsl,aud-io-slot connector to expose a constrained subset of GPIO and
clock resources to the add-on board using fixed electrical wiring.

Also add required regulator, sound CPU DAI and I2C bus configuration to
support IMX-AUD-IO on this base board.

Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
---
 arch/arm64/boot/dts/freescale/imx952-evk.dts | 69 +++++++++++++++++++-
 1 file changed, 67 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/freescale/imx952-evk.dts b/arch/arm64/boot/dts/freescale/imx952-evk.dts
index 047dfde20718..401e16b7e4a0 100644
--- a/arch/arm64/boot/dts/freescale/imx952-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx952-evk.dts
@@ -49,6 +49,18 @@ amp_mqs1: audio-amplifier {
 		VCC-supply = <&reg_3p3v>;
 	};
 
+	aud_io_slot: connector {
+		compatible = "fsl,imx952-evk-aud-io", "fsl,imx95-19x19-evk-aud-io";
+		gpio-controller;
+		#gpio-cells = <2>;
+		gpio-map = <0 0 &pcal6416 8 1>;
+		gpio-map-mask = <0xf 0x0>;
+		/* Only pass through GPIO polarity flag bit 0. */
+		gpio-map-pass-thru = <0x0 0x1>;
+		#clock-cells = <1>;
+		clock-map = <0 &scmi_clk IMX952_CLK_SAI2>;
+	};
+
 	bt_sco_codec: audio-codec-bt-sco {
 		#sound-dai-cells = <1>;
 		compatible = "linux,bt-sco";
@@ -190,13 +202,29 @@ reg_1p8v: regulator-1p8v {
 		regulator-name = "+V1.8_SW";
 	};
 
-	reg_vref_1v8: regulator-adc-vref {
+	aud_io_reg_1v8: reg_vref_1v8: regulator-adc-vref {
 		compatible = "regulator-fixed";
 		regulator-name = "vref_1v8";
 		regulator-min-microvolt = <1800000>;
 		regulator-max-microvolt = <1800000>;
 	};
 
+	aud_io_reg_3v3: regulator-aud-io-3v3 {
+		compatible = "regulator-fixed";
+		regulator-name = "aud-io-3v3";
+		regulator-max-microvolt = <3300000>;
+		regulator-min-microvolt = <3300000>;
+		gpio = <&pcal6416 11 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+	};
+
+	aud_io_reg_5v: regulator-aud-io-5v {
+		compatible = "regulator-fixed";
+		regulator-name = "aud-io-5v";
+		regulator-max-microvolt = <5000000>;
+		regulator-min-microvolt = <5000000>;
+	};
+
 	reg_audio_pwr: regulator-audio-pwr {
 		compatible = "regulator-fixed";
 		regulator-name = "audio-pwr";
@@ -409,7 +437,7 @@ i2c4_pcal6408: gpio@21 {
 	};
 };
 
-&lpi2c6 {
+aud_io_i2c: &lpi2c6 {
 	clock-frequency = <100000>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_lpi2c6>;
@@ -556,6 +584,27 @@ &sai1 {
 	status = "okay";
 };
 
+aud_io_cpu: &sai2 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_sai2>;
+	clocks = <&scmi_clk IMX952_CLK_BUSNETCMIX>, <&clk_dummy>,
+		 <&scmi_clk IMX952_CLK_SAI2>, <&clk_dummy>,
+		 <&clk_dummy>, <&scmi_clk IMX952_CLK_AUDIOPLL1>,
+		 <&scmi_clk IMX952_CLK_AUDIOPLL2>;
+	clock-names = "bus", "mclk0", "mclk1", "mclk2", "mclk3", "pll8k", "pll11k";
+	assigned-clocks = <&scmi_clk IMX952_CLK_AUDIOPLL1_VCO>,
+			  <&scmi_clk IMX952_CLK_AUDIOPLL2_VCO>,
+			  <&scmi_clk IMX952_CLK_AUDIOPLL1>,
+			  <&scmi_clk IMX952_CLK_AUDIOPLL2>,
+			  <&scmi_clk IMX952_CLK_SAI2>;
+	assigned-clock-parents = <0>, <0>, <0>, <0>,
+				 <&scmi_clk IMX952_CLK_AUDIOPLL1>;
+	assigned-clock-rates = <3932160000>, <3612672000>,
+			       <393216000>, <361267200>, <12288000>;
+	fsl,sai-mclk-direction-output;
+	fsl,sai-asynchronous;
+};
+
 &sai3 {
 	assigned-clocks = <&scmi_clk IMX952_CLK_AUDIOPLL1_VCO>,
 			  <&scmi_clk IMX952_CLK_AUDIOPLL2_VCO>,
@@ -783,6 +832,22 @@ IMX952_PAD_SAI1_TXD0__AONMIX_TOP_GPIO1_IO_13		0x51e
 		>;
 	};
 
+	pinctrl_sai2: sai2grp {
+		fsl,pins = <
+			IMX952_PAD_ENET2_MDIO__NETCMIX_TOP_SAI2_RX_BCLK		0x31e
+			IMX952_PAD_ENET2_MDC__NETCMIX_TOP_SAI2_RX_SYNC		0x31e
+			IMX952_PAD_ENET2_TD3__NETCMIX_TOP_SAI2_RX_DATA_0	0x31e
+			IMX952_PAD_ENET2_TD2__NETCMIX_TOP_SAI2_RX_DATA_1	0x31e
+			IMX952_PAD_ENET2_TXC__NETCMIX_TOP_SAI2_TX_BCLK		0x31e
+			IMX952_PAD_ENET2_TX_CTL__NETCMIX_TOP_SAI2_TX_SYNC	0x31e
+			IMX952_PAD_ENET2_RX_CTL__NETCMIX_TOP_SAI2_TX_DATA_0	0x31e
+			IMX952_PAD_ENET2_RXC__NETCMIX_TOP_SAI2_TX_DATA_1	0x31e
+			IMX952_PAD_ENET2_RD0__NETCMIX_TOP_SAI2_TX_DATA_2	0x31e
+			IMX952_PAD_ENET2_RD1__NETCMIX_TOP_SAI2_TX_DATA_3	0x31e
+			IMX952_PAD_ENET2_RD2__NETCMIX_TOP_SAI2_MCLK		0x31e
+		>;
+	};
+
 	pinctrl_sai3: sai3grp {
 		fsl,pins = <
 			IMX952_PAD_GPIO_IO17__WAKEUPMIX_TOP_SAI3_MCLK			0x31e
-- 
2.50.1

[PATCH v3 4/4] arm64: dts: freescale: Add common DTS overlay for IMX-AUD-IO add-on board

[Chancel Liu]

From: Chancel Liu <chancel.liu@nxp.com>

Add common DTS overlay for the IMX-AUD-IO add-on board[1] which
connects to the base board through a fsl,aud-io-slot connector.

This board features a CS42888 codec providing 2 microphone inputs, 2
line inputs and 6 channels audio output capability.

[1]https://www.nxp.com/part/IMX-AUD-IO

Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
---
 arch/arm64/boot/dts/freescale/Makefile        |  4 ++
 arch/arm64/boot/dts/freescale/imx-aud-io.dtso | 57 +++++++++++++++++++
 2 files changed, 61 insertions(+)
 create mode 100644 arch/arm64/boot/dts/freescale/imx-aud-io.dtso

diff --git a/arch/arm64/boot/dts/freescale/Makefile b/arch/arm64/boot/dts/freescale/Makefile
index a80cccf34eb5..aaf546cec0c8 100644
--- a/arch/arm64/boot/dts/freescale/Makefile
+++ b/arch/arm64/boot/dts/freescale/Makefile
@@ -994,6 +994,8 @@ dtb-$(CONFIG_ARCH_MXC) += imx95-15x15-evk-mqs.dtb
 imx95-19x19-evk-pcie0-ep-dtbs += imx95-19x19-evk.dtb imx-pcie0-ep.dtbo
 imx95-19x19-evk-pcie1-ep-dtbs += imx95-19x19-evk.dtb imx-pcie1-ep.dtbo
 dtb-$(CONFIG_ARCH_MXC) += imx95-19x19-evk-pcie0-ep.dtb imx95-19x19-evk-pcie1-ep.dtb
+imx95-19x19-evk-aud-io-dtbs += imx95-19x19-evk.dtb imx-aud-io.dtbo
+dtb-$(CONFIG_ARCH_MXC) += imx95-19x19-evk-aud-io.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx95-libra-rdk-fpsc.dtb
 
 dtb-$(CONFIG_ARCH_MXC) += imx95-19x19-verdin-evk.dtb
@@ -1001,6 +1003,8 @@ dtb-$(CONFIG_ARCH_MXC) += imx95-19x19-verdin-evk.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx952-evk.dtb
 imx952-evk-mqs-dtbs += imx952-evk.dtb imx9-mqs.dtbo
 dtb-$(CONFIG_ARCH_MXC) += imx952-evk-mqs.dtb
+imx952-evk-aud-io-dtbs += imx952-evk.dtb imx-aud-io.dtbo
+dtb-$(CONFIG_ARCH_MXC) += imx952-evk-aud-io.dtb
 
 dtb-$(CONFIG_ARCH_MXC) += imx952-frdm.dtb
 
diff --git a/arch/arm64/boot/dts/freescale/imx-aud-io.dtso b/arch/arm64/boot/dts/freescale/imx-aud-io.dtso
new file mode 100644
index 000000000000..311b7f984576
--- /dev/null
+++ b/arch/arm64/boot/dts/freescale/imx-aud-io.dtso
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Common Device Tree for the IMX-AUD-IO add-on board[1].
+ * It connects to the base board through an AUD-IO slot.
+ *
+ * [1]https://www.nxp.com/part/IMX-AUD-IO
+ *
+ * Copyright 2026 NXP
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/gpio/gpio.h>
+
+&{/} {
+	aud-io-sound-cs42888 {
+		compatible = "fsl,imx-audio-card";
+		model = "imx-cs42888";
+
+		pri-dai-link {
+			link-name = "cs42888";
+			format = "i2s";
+			fsl,mclk-equal-bclk;
+
+			codec {
+				sound-dai = <&audio_io_codec>;
+			};
+
+			cpu {
+				sound-dai = <&aud_io_cpu>;
+			};
+		};
+	};
+};
+
+&aud_io_i2c {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	audio_io_codec: codec@48 {
+		compatible = "cirrus,cs42888";
+		reg = <0x48>;
+		clocks = <&aud_io_slot 0>;
+		clock-names = "mclk";
+		VA-supply = <&aud_io_reg_5v>;
+		VD-supply = <&aud_io_reg_3v3>;
+		VLS-supply = <&aud_io_reg_1v8>;
+		VLC-supply = <&aud_io_reg_1v8>;
+		#sound-dai-cells = <0>;
+		reset-gpios = <&aud_io_slot 0 GPIO_ACTIVE_LOW>;
+	};
+};
+
+&aud_io_cpu {
+	status = "okay";
+};
-- 
2.50.1

Re: [PATCH v3 1/4] dt-bindings: connector: Add fsl,aud-io-slot binding

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [Medium] dt-bindings: connector: controller properties on passive nexus node
- [Low] dt-bindings: connector: reference to non-existent gpio-nexus-node.yaml
- [Low] dt-bindings: connector: 2-space indent and raw GPIO flag in example
--

commit e914717ab225094e8907a50041ee664ef2ac92f2
Author: Chancel Liu <chancel.liu@nxp.com>

dt-bindings: connector: Add fsl,aud-io-slot binding

This patch adds a Device Tree binding schema for the NXP AUD-IO slot
connector found on the i.MX95 19x19 EVK and i.MX952 EVK base boards. The
connector acts as a nexus node that remaps GPIOs, clocks, and interrupts
to base board providers for the IMX-AUD-IO expansion card.

> diff --git a/Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml b/Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml
> new file mode 100644
> index 0000000000000..fc3896d0fafab
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml
> @@ -0,0 +1,106 @@

[ ... ]

> +  gpio-controller: true
> +
> +  '#gpio-cells':
> +    const: 2
> +
> +  gpio-map:
> +    minItems: 1
> +    maxItems: 3
> +
> +  gpio-map-mask:
> +    items:
> +      - const: 0xf
> +      - const: 0x0
> +
> +  gpio-map-pass-thru:
> +    items:
> +      - const: 0x0
> +      - const: 0x1
> +
> +  '#clock-cells':
> +    const: 1
> +
> +  clock-map:
> +    minItems: 1
> +    maxItems: 2
> +
> +  '#address-cells':
> +    const: 0
> +
> +  interrupt-controller: true
> +
> +  '#interrupt-cells':
> +    const: 2
> +
> +  interrupt-map:
> +    minItems: 1
> +    maxItems: 2
> +
> +  interrupt-map-mask:
> +    items:
> +      - const: 0xf
> +      - const: 0x0
> +
> +allOf:
> +  - $ref: /schemas/gpio/gpio-nexus-node.yaml#
> +  - $ref: /schemas/clock/clock-nexus-node.yaml#

[Severity: Low]
Will this cause dt_binding_check to fail when resolving the allOf references?

There is no Documentation/devicetree/bindings/gpio/gpio-nexus-node.yaml in
the kernel tree or in dtschema (where gpio-map, gpio-map-mask, and
gpio-map-pass-thru are defined in schemas/gpio/gpio.yaml).

Also, Documentation/devicetree/bindings/clock/clock-nexus-node.yaml defines
select: true so it is applied globally by dtschema rather than being
referenced via allOf in individual bindings. Should the allOf block be
dropped here?

> +
> +required:
> +  - compatible
> +  - gpio-controller

[Severity: Medium]
Should a passive connector nexus node declare or require gpio-controller and
interrupt-controller?

The binding description notes that all actual hardware providers reside on
the base board and the connector node only defines index-based mappings via
gpio-map, clock-map, and interrupt-map. Per the Devicetree Specification, a
nexus node that remaps specifiers is not itself a controller.

In the kernel, gpio_shared_of_traverse() in drivers/gpio/gpiolib-shared.c
calls of_parse_phandle_with_args() (which does not traverse gpio-map) and
checks for gpio-controller to identify the backing hardware controller:

drivers/gpio/gpiolib-shared.c:gpio_shared_of_traverse() {
    ...
    ret = of_parse_phandle_with_args(curr, prop->name,
                                     "#gpio-cells", i,
                                     &args);
    if (ret)
        continue;

    np = args.np;

    if (!of_property_present(np, "gpio-controller"))
        continue;
    ...
}

When gpio-controller is present on the connector node, gpiolib-shared
records the passive connector node as the GPIO controller device instead of
the actual GPIO controller on the base board.

Similarly, in of_irq_parse_raw() in drivers/of/irq.c:

drivers/of/irq.c:of_irq_parse_raw() {
    ...
    bool intc = of_property_read_bool(ipar, "interrupt-controller");

    imap = of_get_property(ipar, "interrupt-map", &imaplen);
    if (intc &&
        (!imap || of_device_compatible_match(ipar, of_irq_imap_abusers))) {
        pr_debug(" -> got it !\n");
        return 0;
    }
    ...
}

If a node sets interrupt-controller without interrupt-map (which is optional
in this schema), interrupt resolution stops at the passive connector node
where no irq_domain exists.

Could gpio-controller and interrupt-controller be removed from properties,
required, and the example?

> +  - '#gpio-cells'
> +  - gpio-map
> +  - gpio-map-mask
> +  - gpio-map-pass-thru
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +
> +    connector {
> +      compatible = "fsl,imx95-19x19-evk-aud-io";
> +      gpio-controller;
> +      #gpio-cells = <2>;
> +      gpio-map = <0 0 &gpio1 8 1>;
> +      gpio-map-mask = <0xf 0x0>;
> +      gpio-map-pass-thru = <0x0 0x1>;
> +      #clock-cells = <1>;
> +      clock-map = <0 &clk 1>;
> +      #address-cells = <0>;
> +      interrupt-controller;
> +      #interrupt-cells = <2>;
> +      interrupt-map-mask = <0xf 0x0>;
> +      interrupt-map = <0 0 &gpio2 27 IRQ_TYPE_LEVEL_LOW>;
> +    };

[Severity: Low]
This isn't a bug, but the properties inside the connector node in the
example use 2-space indentation instead of 4-space indentation, which
triggers a warning in scripts/dtc/dt-check-style --mode=strict. Also,
could gpio-map include dt-bindings/gpio/gpio.h and use a symbolic GPIO flag
macro instead of the raw integer 1?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261103070433.2307145-1-chancel.liu@oss.nxp.com?part=1

Re: [PATCH v3 1/4] dt-bindings: connector: Add fsl,aud-io-slot binding

[Frank Li]

On Tue, Nov 03, 2026 at 04:04:30PM +0900, Chancel Liu wrote:
> From: Chancel Liu <chancel.liu@nxp.com>
>
> The NXP AUD-IO slot represents a physically present I/O connector on
> the base board. It acts as a nexus that exposes a constrained set of
> I/O resources, such as GPIOs, clocks and interrupts, through fixed
> electrical wiring. All actual hardware providers reside on the base
> board. The connector node only defines index-based mappings to those
> providers.
>
> This connector type is present on i.MX95 19x19 EVK and i.MX952 EVK,
> where it is used to attach the IMX-AUD-IO audio expansion card[1]. The
> same add-on board can be reused across different base boards that carry
> this connector.
>
> [1]https://www.nxp.com/part/IMX-AUD-IO
>
> Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
> ---
>  .../bindings/connector/fsl,aud-io-slot.yaml   | 106 ++++++++++++++++++
>  1 file changed, 106 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml
>
> diff --git a/Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml b/Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml
> new file mode 100644
> index 000000000000..fc3896d0fafa
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/connector/fsl,aud-io-slot.yaml
> @@ -0,0 +1,106 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/connector/fsl,aud-io-slot.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NXP AUD-IO Slot
> +
> +maintainers:
> +  - Frank Li <Frank.Li@nxp.com>
> +  - Chancel Liu <chancel.liu@nxp.com>
> +
> +description:
> +  The NXP AUD-IO slot represents a physically present I/O connector on
> +  the base board. It acts as a nexus that exposes a constrained set of
> +  I/O resources, such as GPIOs, clocks and interrupts, through fixed
> +  electrical wiring. All actual hardware providers reside on the base
> +  board. The connector node only defines index-based mappings to those
> +  providers. This connector type is present on i.MX95 19x19 EVK and
> +  i.MX952 EVK, where it is used to attach the IMX-AUD-IO expansion card.
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - items:
> +          - enum:
> +              - fsl,imx952-evk-aud-io
> +          - const: fsl,imx95-19x19-evk-aud-io
> +      - const: fsl,imx95-19x19-evk-aud-io
> +
> +  gpio-controller: true

I remember Rob said needn't gpio-controller if gpio-map exist

> +
> +  '#gpio-cells':
> +    const: 2
> +
> +  gpio-map:
> +    minItems: 1
> +    maxItems: 3
> +
> +  gpio-map-mask:
> +    items:
> +      - const: 0xf
> +      - const: 0x0
> +
> +  gpio-map-pass-thru:
> +    items:
> +      - const: 0x0
> +      - const: 0x1

I think you should pass thru whole u32 0xffffffff in case GPIO add
new flags in future.

> +
> +  '#clock-cells':
> +    const: 1
> +
> +  clock-map:
> +    minItems: 1
> +    maxItems: 2
> +
> +  '#address-cells':
> +    const: 0

There are not child node, why need #address-cells?

> +
> +  interrupt-controller: true
> +
> +  '#interrupt-cells':
> +    const: 2
> +
> +  interrupt-map:
> +    minItems: 1
> +    maxItems: 2
> +
> +  interrupt-map-mask:
> +    items:
> +      - const: 0xf
> +      - const: 0x0
> +
> +allOf:
> +  - $ref: /schemas/gpio/gpio-nexus-node.yaml#
> +  - $ref: /schemas/clock/clock-nexus-node.yaml#
> +
> +required:
> +  - compatible
> +  - gpio-controller
> +  - '#gpio-cells'
> +  - gpio-map
> +  - gpio-map-mask
> +  - gpio-map-pass-thru
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +
> +    connector {
> +      compatible = "fsl,imx95-19x19-evk-aud-io";
> +      gpio-controller;
> +      #gpio-cells = <2>;
> +      gpio-map = <0 0 &gpio1 8 1>;
> +      gpio-map-mask = <0xf 0x0>;
> +      gpio-map-pass-thru = <0x0 0x1>;
> +      #clock-cells = <1>;
> +      clock-map = <0 &clk 1>;
> +      #address-cells = <0>;
> +      interrupt-controller;
> +      #interrupt-cells = <2>;
> +      interrupt-map-mask = <0xf 0x0>;
> +      interrupt-map = <0 0 &gpio2 27 IRQ_TYPE_LEVEL_LOW>;
                                                          ^  missed count?

Frank

> +    };
> --
> 2.50.1
>
>