boards: hsdk: add cy8c95xx I/O expander, LEDs support

hsdk has an on board cy8c95xx I/O expander, and 4 on
board LEDs use the expander GPIO. Add the I/O expander
and LEDs in hsdk dts, then add documents for them.

Signed-off-by: Watson Zeng <zhiwei@synopsys.com>

boards/arc/hsdk/Kconfig.defconfig

@@ -37,4 +37,18 @@ endif # SPI_DW
 
 endif # SPI
 
+if I2C
+
+config I2C_DW
+	default y
+
+if I2C_DW
+
+config I2C_DW_CLOCK_SPEED
+	default 200
+
+endif #I2C_DW
+
+endif #I2C
+
 endif # BOARD_HSDK

boards/arc/hsdk/doc/index.rst

@@ -8,7 +8,7 @@ Overview
 
 The DesignWare(R) ARC(R) HS Development Kit is a ready-to-use platform for
 rapid software development on the ARC HS3x family of processors. It supports
-single- and multi-core ARC HS34, HS36 and HS38 processors and offers a wide
+single-core and multi-core ARC HS34, HS36 and HS38 processors and offers a wide
 range of interfaces including Ethernet, WiFi, Bluetooth, USB, SDIO, I2C, SPI,
 UART, I2S, ADC, PWM and GPIO. A Vivante GPU is also contained in the ARC
 Development System SoC. This allows developers to build and debug complex
@@ -298,6 +298,56 @@ using the CREG_GPIO_MUX register (see Pinmux ). After a reset, all ports are con
 | IO13  | gpio[15]   | -               | spi2_clk   |
 +-------+------------+-----------------+------------+
 
+I/O expander
+============
+
+The ARC HSDK board includes a CY8C9520A I/O expander from `Cypress CY8C9520A
+<https://www.cypress.com/file/37971/download>`__. The I/O
+expander offers additional GPIO signals and board control signals and can be accessed
+through the on-board I2C bus, we have implemented a basic driver for it.
+Tables below shows an overview of relevant I/O signals.
+
++------------+---------------------------------------------+
+| Pins       | Usage                                       |
++------------+---------------------------------------------+
+| port0_bit0 | RS9113 Bluetooth I2S RX enable (active low) |
++------------+---------------------------------------------+
+| port0_bit1 | mikroBUS Reset (active low)                 |
++------------+---------------------------------------------+
+| port0_bit2 | GPIO for Arduino AD0                        |
++------------+---------------------------------------------+
+| port0_bit3 | GPIO for Arduino AD1                        |
++------------+---------------------------------------------+
+| port0_bit4 | GPIO for Arduino AD2                        |
++------------+---------------------------------------------+
+| port0_bit5 | GPIO for Arduino AD3                        |
++------------+---------------------------------------------+
+| port1_bit4 | On-board user LED0                          |
++------------+---------------------------------------------+
+| port1_bit5 | On-board user LED1                          |
++------------+---------------------------------------------+
+| port1_bit6 | On-board user LED2                          |
++------------+---------------------------------------------+
+| port1_bit7 | On-board user LED3                          |
++------------+---------------------------------------------+
+
+On-board user LEDS
+==================
+
+The ARC HSDK includes 4 user LEDs(active high), which can be controlled through the I/O expander pins.
+
++-------+-----------------+
+| LEDs  | PINs            |
++-------+-----------------+
+| LED0  | GPX_port1_bit4  |
++-------+-----------------+
+| LED1  | GPX_port1_bit5  |
++-------+-----------------+
+| LED2  | GPX_port1_bit6  |
++-------+-----------------+
+| LED3  | GPX_port1_bit7  |
++-------+-----------------+
+
 For hardware feature details, refer to : `Designware HS Development Kit website
 <https://www.synopsys.com/dw/ipdir.php?ds=arc-hs-development-kit>`__.
 

boards/arc/hsdk/hsdk.dtsi

@@ -12,6 +12,30 @@
 
 	aliases {
 		uart-0 = &uart0;
+		led0 = &led0;
+		led1 = &led1;
+		led2 = &led2;
+		led3 = &led3;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+		led0: led_0 {
+			gpios = <&cy8c95xx_port1 4 GPIO_ACTIVE_HIGH>;
+			label = "LED 0";
+		};
+		led1: led_1 {
+			gpios = <&cy8c95xx_port1 5 GPIO_ACTIVE_HIGH>;
+			label = "LED 1";
+		};
+		led2: led_2 {
+			gpios = <&cy8c95xx_port1 6 GPIO_ACTIVE_HIGH>;
+			label = "LED 2";
+		};
+		led3: led_3 {
+			gpios = <&cy8c95xx_port1 7 GPIO_ACTIVE_HIGH>;
+			label = "LED 3";
+		};
 	};
 
 	chosen {
@@ -45,3 +69,38 @@
 	status = "okay";
 	clock-frequency = <33333333>;
 };
+
+&i2c0 {
+	status = "okay";
+	clock-frequency = <I2C_BITRATE_STANDARD>;
+
+	cy8c95xx: cy8c95xx@20 {
+		compatible = "cypress,cy8c95xx-gpio";
+		reg = <0x20>;
+		label = "cy8c95xx_gpio";
+
+		ranges;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cy8c95xx_port0: cy8c95xx_port@0 {
+			compatible = "cypress,cy8c95xx-gpio-port";
+			reg = <0x00>;
+			label = "cy8c95xx_port0";
+			gpio-controller;
+			#gpio-cells = <2>;
+			ngpios = <8>;
+			status = "okay";
+		};
+
+		cy8c95xx_port1: cy8c95xx_port@1 {
+			compatible = "cypress,cy8c95xx-gpio-port";
+			reg = <0x01>;
+			label = "cy8c95xx_port1";
+			gpio-controller;
+			#gpio-cells = <2>;
+			ngpios = <8>;
+			status = "okay";
+		};
+	};
+};

boards/arc/hsdk/hsdk_defconfig

@@ -18,3 +18,5 @@ CONFIG_GPIO=y
 CONFIG_SPI=y
 CONFIG_SMP=y
 CONFIG_MP_NUM_CPUS=4
+CONFIG_I2C=y
+CONFIG_GPIO_CY8C95XX=y