ev11l78a: initial import of the UPD301C Basic Sink board.

This board is a relatively inexpensive development kit for USB-PD
controllers, using an UPD301C controller.

This Zephyr config includes support for:

 * UART (present on he debug header of the board), tested with the
   hello_world sample application;
 * the one standalone LED (CAP_MIS), tested with the blinky sample
   application;
 * the rotary encoder (PDO_SEL), via ADC, tested with the adc sample
   application;
 * the current sense amplifier (I_SENSE), currently untested;
 * the SPI bus, connected internally in the UPD301C to the UPD350;
 * the I2C bus, exposed on the debug header, currently untested.

Note that the drivers.uart.async_api.rtt has to be disabled, as it is
for other m0 boards with no dma or it fails to build.

Signed-off-by: Diego Elio Pettenò <flameeyes@meta.com>

boards/arm/ev11l78a/Kconfig.board

@@ -0,0 +1,8 @@
+# Microchip EV11L78A Board configuration
+
+# Copyright (c) 2023 Meta Platforms, Inc. and its affiliates.
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_EV11L78A
+	bool "Microchip EV11L78A"
+	depends on SOC_PART_NUMBER_SAMD20E16

boards/arm/ev11l78a/Kconfig.defconfig

@@ -0,0 +1,8 @@
+# Microchip EV11L78A Board configuration
+
+# Copyright (c) 2023 Meta Platforms, Inc. and its affiliates.
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD
+	default "ev11l78a"
+	depends on BOARD_EV11L78A

boards/arm/ev11l78a/board.cmake

@@ -0,0 +1,4 @@
+# Copyright (c) 2018 Sean Nyekjaer
+# SPDX-License-Identifier: Apache-2.0
+
+include(${ZEPHYR_BASE}/boards/common/openocd.board.cmake)

boards/arm/ev11l78a/doc/index.rst

@@ -0,0 +1,92 @@
+.. _ev11l78a:
+
+UPD301C Basic Sink Application Example
+######################################
+
+Overview
+********
+
+The UPD301C Basic Sink Application Example Evaluation Kit (EV11L78A)
+is a low-cost evaluation platform for Microchip's UPD301C Standalone
+Programmable USB Power Delivery (PD) Controller. This RoHS-compliant
+evaluation platform comes in a small form factor and adheres to the
+USB Type-C™ Connector Specification and USB PD 3.0 specification.
+
+.. figure:: img/ev11l78a.jpg
+    :width: 500px
+    :align: center
+    :alt: EV11L78A
+
+    UPD301C Basic Sink Application Example (Credit: `Microchip Technology`_)
+
+Hardware
+********
+
+- ATSAMD20E16 ARM Cortex-M0+ processor at 48 MHz
+- UPD301C combines a SAMD20 core and a UPD350 USB-PD controller
+- Sink PDO Selector Switch
+- Onboard LED Voltmeter
+
+Supported Features
+==================
+
+The ev11l78a board configuration supports the following hardware
+features:
+
++-----------+------------+------------------------------------------+
+| Interface | Controller | Driver/Component                         |
++===========+============+==========================================+
+| NVIC      | on-chip    | nested vector interrupt controller       |
++-----------+------------+------------------------------------------+
+| Flash     | on-chip    | Can be used with LittleFS to store files |
++-----------+------------+------------------------------------------+
+| SYSTICK   | on-chip    | systick                                  |
++-----------+------------+------------------------------------------+
+| WDT       | on-chip    | Watchdog                                 |
++-----------+------------+------------------------------------------+
+| GPIO      | on-chip    | I/O ports                                |
++-----------+------------+------------------------------------------+
+| USART     | on-chip    | Serial ports                             |
++-----------+------------+------------------------------------------+
+| SPI       | on-chip    | Serial Peripheral Interface ports        |
++-----------+------------+------------------------------------------+
+| I2C       | on-chip    | I²C ports                                |
++-----------+------------+------------------------------------------+
+| ADC       | on-chip    | Analog-to-Digital Converter              |
++-----------+------------+------------------------------------------+
+
+Other hardware features are not currently supported by Zephyr.
+
+Refer to the `EV11L78A Schematics`_ for a detailed hardware diagram.
+
+The default configuration can be found in the Kconfig
+:zephyr_file:`boards/arm/ev11l78a/ev11l78a_defconfig`.
+
+Serial Port
+===========
+
+The SAMD20 MCU has 6 SERCOM based USARTs. One of the USARTs
+(SERCOM1) is available on the Debug/Status header.
+
+SPI Port
+========
+
+The SAMD20 MCU has 6 SERCOM based SPIs. One of the SPIs (SERCOM0)
+is internally connected between the SAMD20 core and the UPD350.
+
+I²C Port
+========
+
+The SAMD20 MCU has 6 SERCOM based I2Cs. One of the I2Cs (SERCOM3)
+is available on the Debug/Status header.
+
+References
+**********
+
+.. target-notes::
+
+.. _Microchip Technology:
+    https://www.microchip.com/en-us/development-tool/ev11l78a
+
+.. _EV11L78A Schematics:
+    https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/SupportingCollateral/03-00056-R1.0.PDF

boards/arm/ev11l78a/ev11l78a-pinctrl.dtsi

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2023, Meta Platforms, Inc. and its affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <dt-bindings/pinctrl/samd20eXab-pinctrl.h>
+
+&pinctrl {
+	sercom0_spi_default: sercom0_spi_default {
+		group1 {
+			pinmux = <PA8C_SERCOM0_PAD0>,
+				 <PA9C_SERCOM0_PAD1>,
+				 <PA11C_SERCOM0_PAD3>;
+		};
+	};
+
+	sercom1_uart_default: sercom1_uart_default {
+		group1 {
+			pinmux = <PA18C_SERCOM1_PAD2>,
+				 <PA19C_SERCOM1_PAD3>;
+		};
+	};
+
+	sercom3_i2c_default: sercom3_i2c_default {
+		group1 {
+			pinmux = <PA17D_SERCOM3_PAD1>,
+				 <PA18D_SERCOM3_PAD2>;
+		};
+	};
+
+	adc_default: adc_default {
+		group1 {
+			pinmux = <PA4B_ADC_AIN4>,
+				 <PA5B_ADC_AIN5>;
+		};
+	};
+};

boards/arm/ev11l78a/ev11l78a.dts

@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2023, Meta Platforms, Inc. and its affiliates.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/dts-v1/;
+#include <freq.h>
+#include <atmel/samd20.dtsi>
+#include "ev11l78a-pinctrl.dtsi"
+
+/ {
+	model = "Microchip EV11L78A";
+	compatible = "atmel,samd20e16", "atmel,samd20";
+
+	aliases {
+		led0 = &cap_mis_led;
+		spi0 = &sercom0;
+		i2c0 = &sercom3;
+	};
+
+	chosen {
+		zephyr,console = &sercom1;
+		zephyr,shell-uart = &sercom1;
+		zephyr,sram = &sram0;
+		zephyr,flash = &flash0;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+		cap_mis_led: led_0 {
+			gpios = <&porta 23 GPIO_ACTIVE_HIGH>;
+			label = "CAP_MIS";
+		};
+	};
+
+	csa_i_sense: i_sense {
+		compatible = "current-sense-amplifier";
+		io-channels = <&adc 5>;
+		sense-resistor-micro-ohms = <4000>;
+		sense-gain-mult = <100>;
+	};
+
+};
+
+&cpu0 {
+	clock-frequency = <DT_FREQ_M(48)>;
+};
+
+&sercom0 {
+	status = "okay";
+	compatible = "atmel,sam0-spi";
+	dipo = <0>;
+	dopo = <2>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	cs-gpios = <&porta 10 GPIO_ACTIVE_LOW>;
+
+	pinctrl-0 = <&sercom0_spi_default>;
+	pinctrl-names = "default";
+};
+
+&sercom1 {
+	status = "okay";
+	compatible = "atmel,sam0-uart";
+	current-speed = <115200>;
+	rxpo = <3>;
+	txpo = <1>;
+
+	pinctrl-0 = <&sercom1_uart_default>;
+	pinctrl-names = "default";
+};
+
+&sercom3 {
+	status = "okay";
+	compatible = "atmel,sam0-i2c";
+	clock-frequency = <I2C_BITRATE_HIGH>;
+
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	pinctrl-0 = <&sercom3_i2c_default>;
+	pinctrl-names = "default";
+};
+
+&flash0 {
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		/*
+		 * The final 16 KiB is reserved for the application.
+		 * Storage partition will be used by FCB/LittleFS/NVS
+		 * if enabled.
+		 */
+		storage_partition: partition@3c000 {
+			label = "storage";
+			reg = <0x0003c000 0x00004000>;
+		};
+	};
+};
+
+&adc {
+	status = "okay";
+	prescaler = <32>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	channel@4 {
+		reg = <4>;
+		zephyr,gain = "ADC_GAIN_1_2";
+		zephyr,reference = "ADC_REF_VDD_1_2";
+		zephyr,vref-mv = <1650>;
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,resolution = <12>;
+		zephyr,input-positive = <4>;
+	};
+
+	pinctrl-0 = <&adc_default>;
+	pinctrl-names = "default";
+};

boards/arm/ev11l78a/ev11l78a.yaml

@@ -0,0 +1,16 @@
+identifier: ev11l78a
+name: UPD301C Basic Sink Application Example
+type: mcu
+arch: arm
+ram: 32
+flash: 64
+toolchain:
+  - zephyr
+  - gnuarmemb
+  - xtools
+supported:
+  - adc
+  - gpio
+  - i2c
+  - spi
+  - uart

boards/arm/ev11l78a/ev11l78a_defconfig

@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_SOC_SERIES_SAMD20=y
+CONFIG_SOC_PART_NUMBER_SAMD20E16=y
+CONFIG_SOC_ATMEL_SAMD_OSC8M=y
+CONFIG_SOC_ATMEL_SAMD_OSC8M_AS_MAIN=y
+CONFIG_BOARD_EV11L78A=y
+CONFIG_BUILD_OUTPUT_HEX=y
+CONFIG_CONSOLE=y
+CONFIG_GPIO=y
+CONFIG_SERIAL=y
+CONFIG_UART_CONSOLE=y
+CONFIG_UART_INTERRUPT_DRIVEN=y

boards/arm/ev11l78a/pre_dt_board.cmake

@@ -0,0 +1,7 @@
+# Copyright (c) 2021 Linaro Limited
+# SPDX-License-Identifier: Apache-2.0
+
+# Suppress "unique_unit_address_if_enabled" to handle the following overlaps:
+# - /soc/pinmux@41004400 & /soc/gpio@41004400
+# - /soc/pinmux@41004480 & /soc/gpio@41004480
+list(APPEND EXTRA_DTC_FLAGS "-Wno-unique_unit_address_if_enabled")

boards/arm/ev11l78a/support/openocd.cfg

@@ -0,0 +1,22 @@
+source [find interface/jlink.cfg]
+transport select swd
+
+# chip name
+set CHIPNAME at91samd20e16
+set ENDIAN little
+set CPUTAPID 0x0bc11477
+
+source [find target/at91samdXX.cfg]
+
+reset_config trst_and_srst separate
+
+$_TARGETNAME configure -event gdb-attach {
+	echo "Debugger attaching: halting execution"
+	reset halt
+	gdb_breakpoint_override hard
+}
+
+$_TARGETNAME configure -event gdb-detach {
+	echo "Debugger detaching: resuming execution"
+	resume
+}

samples/drivers/adc/boards/ev11l78a.overlay

@@ -0,0 +1,11 @@
+/*
+ * Copyright (c) 2023, Meta Platforms, Inc. and its affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	zephyr,user {
+		/* pin 4 ADC(+) */
+		io-channels = <&adc 4>;
+	};
+};

tests/drivers/adc/adc_api/boards/ev11l78a.overlay

@@ -0,0 +1,11 @@
+/*
+ * Copyright (c) 2023, Meta Platforms, Inc. and its affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	zephyr,user {
+		/* pin 4 ADC(+) */
+		io-channels = <&adc 4>;
+	};
+};

tests/drivers/uart/uart_async_api/testcase.yaml

@@ -20,6 +20,7 @@ common:
     - wio_terminal
     - xiao_esp32c3
     - atsamd20_xpro
+    - ev11l78a
   tags:
     - drivers
     - uart