arm64: dts: imx8mp: Enable SAI audio on Data Modul i.MX8M Plus eDM SBC

Add SAI I2S and audio bindings to Data Modul i.MX8M Plus eDM SBC.

The SGTL5000 is attached to SAI3, however the SGTL5000 codec MCLK
must be supplied even if the SAI3 is not in use and is controlled
separately by the codec. The MCLK is also used to drive the codec
I2C block, so without MCLK, I2C access to the codec would not be
possible.

To provide such flexible MCLK control, use PWM4 with period 1 and
duty cycle 50% as 12 MHz clock source, as there is no direct way
to route MX8MP CCM clock to the MCLK pin. Use codec as bitclock
and frame clock master, so that the SGTL5000 PLL can be used to
generate derived clock.

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

diff --git a/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc.dts b/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc.dts
index 336180ebfb094bafe322d1781473a64a51361068..43ca2ae5eaa672de67b809eb67b70230dff085aa 100644 (file)
--- a/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc.dts
@@ -46,6 +46,19 @@
                clock-frequency = <25000000>;
        };
 
+       clk_pwm4: clock-pwm4 {
+               compatible = "pwm-clock";
+               #clock-cells = <0>;
+               clock-frequency = <12000000>;
+               clock-output-names = "codec-pwm4";
+               /*
+                * 1 / 83 ns ~= 12 MHz , but since the PWM input clock is 24 MHz
+                * and the calculated PWM period is 1 and duty cycle is 50%, the
+                * result is exactly 12 MHz, which is fine for SGTL5000 MCLK.
+                */
+               pwms = <&pwm4 0 83 0>;
+       };
+
        panel: panel {
                /* Compatible string is filled in by panel board DT Overlay. */
                backlight = <&backlight>;
@@ -83,6 +96,24 @@
                vin-supply = <&buck4>;
        };
 
+       sound {
+               compatible = "simple-audio-card";
+               simple-audio-card,name = "SGTL5000-Card";
+               simple-audio-card,format = "i2s";
+               simple-audio-card,bitclock-master = <&codec_dai>;
+               simple-audio-card,frame-master = <&codec_dai>;
+               simple-audio-card,widgets = "Headphone", "Headphone Jack";
+               simple-audio-card,routing = "Headphone Jack", "HP_OUT";
+
+               cpu_dai: simple-audio-card,cpu {
+                       sound-dai = <&sai3>;
+               };
+
+               codec_dai: simple-audio-card,codec {
+                       sound-dai = <&sgtl5000>;
+               };
+       };
+
        watchdog { /* TPS3813 */
                compatible = "linux,wdt-gpio";
                pinctrl-names = "default";
@@ -289,6 +320,15 @@
        sda-gpios = <&gpio5 15 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
        status = "okay";
 
+       sgtl5000: audio-codec@a {
+               compatible = "fsl,sgtl5000";
+               reg = <0x0a>;
+               #sound-dai-cells = <0>;
+               clocks = <&clk_pwm4>;
+               VDDA-supply = <&buck4>;
+               VDDIO-supply = <&buck4>;
+       };
+
        usb-hub@2c {
                compatible = "microchip,usb2514bi";
                reg = <0x2c>;
@@ -452,6 +492,23 @@
        status = "disabled";
 };
 
+&pwm4 {
+       pinctrl-names = "default";
+       pinctrl-0 = <&pinctrl_pwm4>;
+       status = "okay";
+};
+
+&sai3 {
+       #clock-cells = <0>;
+       #sound-dai-cells = <0>;
+       assigned-clocks = <&clk IMX8MP_CLK_SAI3>;
+       assigned-clock-parents = <&clk IMX8MP_AUDIO_PLL1_OUT>;
+       assigned-clock-rates = <12288000>;
+       pinctrl-names = "default";
+       pinctrl-0 = <&pinctrl_sai3>;
+       status = "okay";
+};
+
 /* SD slot */
 &usdhc2 {
        pinctrl-names = "default", "state_100mhz", "state_200mhz";
@@ -801,6 +858,12 @@
                >;
        };
 
+       pinctrl_pwm4: pwm4-grp {
+               fsl,pins = <
+                       MX8MP_IOMUXC_SAI3_MCLK__PWM4_OUT                0xd6
+               >;
+       };
+
        pinctrl_rtc: rtc-grp {
                fsl,pins = <
                        /* RTC_IRQ# */
@@ -832,7 +895,6 @@
                        MX8MP_IOMUXC_SAI3_TXFS__AUDIOMIX_SAI3_TX_SYNC   0xd6
                        MX8MP_IOMUXC_SAI3_TXD__AUDIOMIX_SAI3_TX_DATA00  0xd6
                        MX8MP_IOMUXC_SAI3_TXC__AUDIOMIX_SAI3_TX_BCLK    0xd6
-                       MX8MP_IOMUXC_SAI3_MCLK__AUDIOMIX_SAI3_MCLK      0xd6
                        MX8MP_IOMUXC_SAI3_RXD__AUDIOMIX_SAI3_RX_DATA00  0xd6
                >;
        };