ARM64: dts: meson: meson-gx: add the SAR ADC

Add the SAR ADC to meson-gxbb.dtsi and meson-gxl.dtsi. GXBB provides a
10-bit ADC while GXL and GXM provide a 12-bit ADC.
Some boards use resistor ladder buttons connected through one of the ADC
channels. On newer devices (GXL and GXM) some boards use pull-ups/downs
to change the resistance (and thus the ADC value) on one of the ADC
channels to indicate the board revision.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-gx.dtsi

@@ -237,6 +237,14 @@
 				status = "disabled";
 			};
 
+			saradc: adc@8680 {
+				compatible = "amlogic,meson-saradc";
+				reg = <0x0 0x8680 0x0 0x34>;
+				#io-channel-cells = <1>;
+				interrupts = <GIC_SPI 73 IRQ_TYPE_EDGE_RISING>;
+				status = "disabled";
+			};
+
 			pwm_ef: pwm@86c0 {
 				compatible = "amlogic,meson-gx-pwm", "amlogic,meson-gxbb-pwm";
 				reg = <0x0 0x086c0 0x0 0x10>;

arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi

@@ -490,6 +490,16 @@
 	clocks = <&clkc CLKID_I2C>;
 };
 
+&saradc {
+	compatible = "amlogic,meson-gxbb-saradc", "amlogic,meson-saradc";
+	clocks = <&xtal>,
+		 <&clkc CLKID_SAR_ADC>,
+		 <&clkc CLKID_SANA>,
+		 <&clkc CLKID_SAR_ADC_CLK>,
+		 <&clkc CLKID_SAR_ADC_SEL>;
+	clock-names = "clkin", "core", "sana", "adc_clk", "adc_sel";
+};
+
 &sd_emmc_a {
 	clocks = <&clkc CLKID_SD_EMMC_A>,
 		 <&xtal>,

arch/arm64/boot/dts/amlogic/meson-gxl.dtsi

@@ -347,6 +347,16 @@
 	clocks = <&clkc CLKID_I2C>;
 };
 
+&saradc {
+	compatible = "amlogic,meson-gxl-saradc", "amlogic,meson-saradc";
+	clocks = <&xtal>,
+		 <&clkc CLKID_SAR_ADC>,
+		 <&clkc CLKID_SANA>,
+		 <&clkc CLKID_SAR_ADC_CLK>,
+		 <&clkc CLKID_SAR_ADC_SEL>;
+	clock-names = "clkin", "core", "sana", "adc_clk", "adc_sel";
+};
+
 &sd_emmc_a {
 	clocks = <&clkc CLKID_SD_EMMC_A>,
 		 <&xtal>,

arch/arm64/boot/dts/amlogic/meson-gxm.dtsi

@@ -117,6 +117,10 @@
 	};
 };
 
+&saradc {
+	compatible = "amlogic,meson-gxm-saradc", "amlogic,meson-saradc";
+};
+
 &scpi_dvfs {
 	clock-indices = <0 1>;
 	clock-output-names = "vbig", "vlittle";