boards: arm: mimxrt595_evk_cm33: enable DMIC0 channels 0 and 1

Enable L/R channel pair for DMIC0 on the RT595 EVK. The RT595 EVK has a
pair of MEMS microphones wired to PDM channel 0 and 1, so these channels
are configured with appropriate gain and filter settings for the MEMS
microphones.

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>
Co-authored-by: Yves Vandervennet <yves.vandervennet@nxp.com>

boards/arm/mimxrt595_evk/doc/index.rst

@@ -113,6 +113,8 @@ already supported, which can also be re-used on this mimxrt595_evk board:
 |           |            | :ref:`rk055hdmipi4ma0`, and         |
 |           |            | :ref:`g1120b0mipi` display shields  |
 +-----------+------------+-------------------------------------+
+| DMIC      | on-chip    | dmic                                |
++-----------+------------+-------------------------------------+
 
 The default configuration can be found in the defconfig file:
 

boards/arm/mimxrt595_evk/mimxrt595_evk_cm33-pinctrl.dtsi

@@ -46,6 +46,16 @@
 		};
 	};
 
+	pinmux_dmic0: pinmux_dmic0 {
+		group0 {
+			pinmux = <DMIC0_DATA23_PIO3_1>, <DMIC0_DATA01_PIO5_8>,
+			       <DMIC0_CLK01_PIO5_4>;
+			slew-rate = "normal";
+			drive-strength = "normal";
+			input-enable;
+		};
+	};
+
 	pinmux_flexcomm4_i2c: pinmux_flexcomm4_i2c {
 		group0 {
 			pinmux = <FC4_TXD_SCL_MISO_WS_PIO0_29>,

boards/arm/mimxrt595_evk/mimxrt595_evk_cm33.dts

@@ -28,6 +28,7 @@
 		accel0 = &fxos8700;
 		sdhc0 = &usdhc0;
 		pwm-0 = &sc_timer;
+		dmic-dev = &dmic0;
 	};
 
 	chosen {
@@ -482,6 +483,30 @@ zephyr_udc0: &usbhs {
 	dma-names = "smartdma";
 };
 
+&dmic0 {
+	status = "okay";
+	pinctrl-0 = <&pinmux_dmic0>;
+	pinctrl-names = "default";
+	use2fs;
+};
+
+/* Configure pdm channels 0 and 1 with gain, and cutoff settings
+ * appropriate for the attached MEMS microphones.
+ */
+&pdmc0 {
+	status = "okay";
+	gainshift = <3>;
+	dc-cutoff = "155hz";
+	dc-gain = <1>;
+};
+
+&pdmc1 {
+	status = "okay";
+	gainshift = <3>;
+	dc-cutoff = "155hz";
+	dc-gain = <1>;
+};
+
 &mrt_channel0 {
 	status = "okay";
 };

boards/arm/mimxrt595_evk/mimxrt595_evk_cm33.yaml

@@ -28,4 +28,5 @@ supported:
   - sdhc
   - pwm
   - i2s
+  - dmic
 vendor: nxp

samples/drivers/audio/dmic/boards/mimxrt595_evk_cm33.overlay

@@ -0,0 +1,3 @@
+dmic_dev: &dmic0 {
+        status = "okay";
+};