iio: adc: Add Phytium ADC support

Phytium Pe220x SoCs includes an 8-channel, 10-bit single ended ADC.
This patch add this ADC's driver support.

Signed-off-by: Yang Liu <yangliu2021@phytium.com.cn>
Signed-off-by: Zhou Yulin <zhouyulin1283@phytium.com.cn>
Signed-off-by: Chen Baozi <chenbaozi@phytium.com.cn>
Signed-off-by: Wang Yinfeng <wangyinfeng@phytium.com.cn>
Signed-off-by: Hu Yeqing <huyeqing2074@phytium.com.cn>

Author: Hu Yeqing

Documentation/devicetree/bindings/iio/adc/phytium,adc.yaml

@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2019 Analog Devices Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/phytium,adi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Phytium ADC
+
+maintainers:
+  - Chen Baozi <chenbaozi@phytium.com.cn>
+
+description: |
+  This device is a 10-bit converter for 8 voltage channels. All inputs are
+  single ended.
+
+properties:
+  compatible:
+    const: phytium,adc
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+    description: Input clock used to derive the sample clock.
+
+  interrupts:
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - interrupts
+  - '#address-cells'
+  - '#size-cells'
+
+examples:
+  - |
+    adc0: adc@2807b000 {
+      compatible = "phytium,adc";
+      reg = <0x0 0x2807b000 0x0 0x1000>;
+      interrupts = <GIC_SPI 232 IRQ_TYPE_LEVEL_HIGH>;
+      clocks = <&sysclk_48mhz>;
+
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      channel@0 {
+        reg = <0>;
+      };
+      channel@1 {
+        reg = <1>;
+      };
+      channel@2 {
+        reg = <2>;
+      };
+      channel@3 {
+        reg = <3>;
+      };
+      channel@4 {
+       reg = <4>;
+      };
+      channel@5 {
+        reg = <5>;
+      };
+      channel@6 {
+        reg = <5>;
+      };
+      channel@7 {
+        reg = <7>;
+      };
+    };

drivers/iio/adc/Kconfig

@@ -886,6 +886,18 @@ config PALMAS_GPADC
 	  is used in smartphones and tablets and supports a 16 channel
 	  general purpose ADC.
 
+config PHYTIUM_ADC
+	tristate "Phytium ADC driver"
+	depends on ARCH_PHYTIUM || COMPILE_TEST
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Phytium analog to digital
+	  converters (ADC).
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called phytium-adc.
+
 config QCOM_VADC_COMMON
 	tristate
 

drivers/iio/adc/Makefile

@@ -82,6 +82,7 @@ obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o
 obj-$(CONFIG_NAU7802) += nau7802.o
 obj-$(CONFIG_NPCM_ADC) += npcm_adc.o
 obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
+obj-$(CONFIG_PHYTIUM_ADC) += phytium-adc.o
 obj-$(CONFIG_QCOM_SPMI_ADC5) += qcom-spmi-adc5.o
 obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
 obj-$(CONFIG_QCOM_SPMI_RRADC) += qcom-spmi-rradc.o