boards: stm32g0316-disco: add support for the ST STM32G0316-DISCO board

Add support for the ST STM32G0316-DISCO development board. This board
features an ST STM32G031J6 MCU on a breakable SO8 to DIL8 module, a user
LED and a button.

Signed-off-by: Filip Brozovic <fbrozovic@gmail.com>

boards/arm/stm32g0316_disco/CMakeLists.txt

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: Apache-2.0
+
+if(CONFIG_PINMUX)
+zephyr_library()
+zephyr_library_sources(pinmux.c)
+zephyr_library_include_directories(${ZEPHYR_BASE}/drivers)
+endif()

boards/arm/stm32g0316_disco/Kconfig.board

@@ -0,0 +1,8 @@
+# STM32G0316 Discovery board configuration
+
+# Copyright (c) 2019 SEAL AG
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_STM32G0316_DISCO
+	bool "STM32G0316 Discovery Development Board"
+	depends on SOC_STM32G031XX

boards/arm/stm32g0316_disco/Kconfig.defconfig

@@ -0,0 +1,18 @@
+# STM32G0316 Discovery board configuration
+
+# Copyright (c) 2019 SEAL AG
+# SPDX-License-Identifier: Apache-2.0
+
+if BOARD_STM32G0316_DISCO
+
+config BOARD
+	default "stm32g0316_disco"
+
+if UART_CONSOLE
+
+config UART_1
+	default y
+
+endif # UART_CONSOLE
+
+endif # BOARD_STM32G0316_DISCO

boards/arm/stm32g0316_disco/board.cmake

@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: Apache-2.0
+board_runner_args(pyocd "--target=stm32g031j6mx")
+
+include(${ZEPHYR_BASE}/boards/common/pyocd.board.cmake)

boards/arm/stm32g0316_disco/doc/index.rst

@@ -0,0 +1,132 @@
+.. _stm32g0316_disco_board:
+
+STM32G0316-DISCO
+################
+
+Overview
+********
+
+The STM32G0316-DISCO Discovery kit helps to discover features of STM32G0 in SO8 package.
+This discovery kit offers an SO8 to DIL8 module designed with the STM32G031J6 microcontroller
+and allows the user to develop applications. It includes an on-board ST-LINK/V2-1 to debug
+and program the embedded STM32 microcontroller.
+
+.. image:: img/stm32g0316-disco.jpg
+   :width: 670px
+   :align: center
+   :alt: STM32G0316-DISCO
+
+Hardware
+********
+
+- STM32G031J6 Arm |reg| Cortex |reg|-M0+ core-based microcontroller,
+  featuring 32 Kbytes of Flash memory and 8 Kbytes of SRAM, in an SO8 package
+- 1 user LED
+- 1 reset/user push-button
+- Individual and breakable STM32 SO8 to DIL8 module
+- ST-LINK Micro-B USB connector
+- DIL8 socket to ease programming of the STM32 MCU
+- On-board ST-LINK/V2-1 debugger/programmer
+
+For more information about the STM32G03x SoC and the STM32G0316-DISCO board, see these ST reference documents:
+
+- `STM32G031J6 website`_
+- `STM32G031 datasheet`_
+- `STM32G0x1 reference manual`_
+- `STM32G0316-DISCO website`_
+
+Supported Features
+==================
+
+The Zephyr stm32g0316_disco board configuration supports the following hardware features:
+
++-----------+------------+-------------------------------------+
+| Interface | Controller | Driver/Component                    |
++===========+============+=====================================+
+| NVIC      | on-chip    | nested vector interrupt controller  |
++-----------+------------+-------------------------------------+
+| UART      | on-chip    | serial port-polling;                |
+|           |            | serial port-interrupt               |
++-----------+------------+-------------------------------------+
+| PINMUX    | on-chip    | pinmux                              |
++-----------+------------+-------------------------------------+
+| GPIO      | on-chip    | gpio                                |
++-----------+------------+-------------------------------------+
+| CLOCK     | on-chip    | reset and clock control             |
++-----------+------------+-------------------------------------+
+
+Other hardware features are not currently supported by the port.
+
+The default configuration can be found in the defconfig file:
+``boards/arm/stm32g0316_disco/stm32g0316_disco_defconfig``
+
+Connections and IOs
+===================
+
+Due to the small number of I/O pins on the SO8 package, multiple die I/Os are bonded
+to the same package pins to maximize the number of peripherals which can be used.
+Care must be taken not to set two I/Os which are connected together to conflicting
+states (e.g. both as outputs, one low, the other high).
+
+Default Zephyr Peripheral Mapping:
+----------------------------------
+
+.. rst-class:: rst-columns
+
+- UART_1 TX/RX : PA9/PB7 (pins 5/1)
+- USER_PB : PA0 (pin 4)
+- LD2 : PA12 (pin 6)
+
+Programming and Debugging
+*************************
+
+Applications for the ``stm32g0316_disco`` board configuration can be built the
+usual way (see :ref:`build_an_application` and :ref:`application_run` for more details).
+
+Flashing
+========
+
+The STM32G0316-DISCO board includes an ST-LINK/V2-1 embedded debug tool
+interface. This interface is not yet supported by the openocd version included in
+the Zephyr SDK. Instead, support can be enabled on pyocd by adding "pack" support with
+the following pyocd command:
+
+.. code-block:: console
+
+   $ pyocd pack --install stm32g031j6
+
+Flashing an application to the STM32G0316-DISCO
+-----------------------------------------------
+
+Here is an example for the :ref:`blinky-sample` application.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/basic/blinky
+   :board: stm32g0316_disco
+   :goals: build flash
+
+You should see the LED blinking every second.
+
+Debugging
+=========
+
+You can debug an application in the usual way.  Here is an example for the
+:ref:`hello_world` application.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/hello_world
+   :board: stm32g0316_disco
+   :maybe-skip-config:
+   :goals: debug
+
+.. _STM32G031J6 website:
+   https://www.st.com/en/microcontrollers-microprocessors/stm32g031j6.html
+
+.. _STM32G031 datasheet:
+   https://www.st.com/resource/en/datasheet/stm32g031j6.pdf
+
+.. _STM32G0x1 reference manual:
+   https://www.st.com/resource/en/reference_manual/dm00371828.pdf
+
+.. _STM32G0316-DISCO website:
+   https://www.st.com/en/evaluation-tools/stm32g0316-disco.html

boards/arm/stm32g0316_disco/pinmux.c

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2019 SEAL AG
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <init.h>
+#include <soc.h>
+
+#include <pinmux/stm32/pinmux_stm32.h>
+
+/* pin assignments for STM32G0316-DISCO board */
+static const struct pin_config pinconf[] = {
+#ifdef CONFIG_UART_1
+	{STM32_PIN_PA9, STM32G0_PINMUX_FUNC_PA9_USART1_TX},
+	{STM32_PIN_PB7, STM32G0_PINMUX_FUNC_PB7_USART1_RX},
+#endif /* CONFIG_UART_1 */
+};
+
+static int pinmux_stm32_init(struct device *port)
+{
+	ARG_UNUSED(port);
+
+#ifdef CONFIG_UART_1
+	/* Remap PA11 to PA9 */
+	LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_SYSCFG);
+	LL_SYSCFG_EnablePinRemap(LL_SYSCFG_PIN_RMP_PA11);
+#endif /* CONFIG_UART_1 */
+
+	stm32_setup_pins(pinconf, ARRAY_SIZE(pinconf));
+
+	return 0;
+}
+
+SYS_INIT(pinmux_stm32_init, PRE_KERNEL_1,
+	 CONFIG_PINMUX_STM32_DEVICE_INITIALIZATION_PRIORITY);

boards/arm/stm32g0316_disco/stm32g0316_disco.dts

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2019 SEAL AG
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/dts-v1/;
+#include <st/g0/stm32g031X6.dtsi>
+
+/ {
+	model = "STMicroelectronics STM32G0316 Discovery board";
+	compatible = "st,stm32g0316-disco", "st,stm32g031";
+
+	aliases {
+		led0 = &green_led_1;
+		sw0 = &user_button;
+	};
+
+	chosen {
+		zephyr,console = &usart1;
+		zephyr,shell-uart = &usart1;
+		zephyr,sram = &sram0;
+		zephyr,flash = &flash0;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+		green_led_1: led_2 {
+			gpios = <&gpioa 12 GPIO_INT_ACTIVE_LOW>;
+			label = "User LD2";
+		};
+	};
+
+	gpio_keys {
+		compatible = "gpio-keys";
+		user_button: button {
+			label = "User";
+			gpios = <&gpioa 0 GPIO_INT_ACTIVE_LOW>;
+		};
+	};
+};
+
+&usart1 {
+	current-speed = <115200>;
+	status = "okay";
+};

boards/arm/stm32g0316_disco/stm32g0316_disco.yaml

@@ -0,0 +1,13 @@
+identifier: stm32g0316_disco
+name: STM32G0316-DISCO
+type: mcu
+arch: arm
+toolchain:
+  - zephyr
+  - gnuarmemb
+  - xtools
+ram: 8
+flash: 32
+supported:
+  - gpio
+  - uart

boards/arm/stm32g0316_disco/stm32g0316_disco_defconfig

@@ -0,0 +1,42 @@
+# Zephyr Kernel Configuration
+CONFIG_ARM=y
+CONFIG_SOC_SERIES_STM32G0X=y
+CONFIG_SOC_STM32G031XX=y
+CONFIG_CORTEX_M_SYSTICK=y
+CONFIG_BOARD_STM32G0316_DISCO=y
+
+# 64MHz system clock
+CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC=64000000
+
+# Kernel Options due to Low Memory (8k)
+CONFIG_MAIN_STACK_SIZE=640
+CONFIG_IDLE_STACK_SIZE=200
+CONFIG_ISR_STACK_SIZE=512
+
+# Serial Drivers
+CONFIG_SERIAL=y
+CONFIG_UART_INTERRUPT_DRIVEN=y
+# enable console
+CONFIG_CONSOLE=y
+CONFIG_UART_CONSOLE=y
+
+# Pinmux Driver
+CONFIG_PINMUX=y
+
+# GPIO Controller
+CONFIG_GPIO=y
+
+# Clock configuration
+CONFIG_CLOCK_CONTROL=y
+# SYSCLK selection
+CONFIG_CLOCK_STM32_SYSCLK_SRC_PLL=y
+# PLL configuration
+CONFIG_CLOCK_STM32_PLL_SRC_HSI=y
+# produce 64MHz clock at PLL output
+CONFIG_CLOCK_STM32_PLL_M_DIVISOR=1
+CONFIG_CLOCK_STM32_PLL_N_MULTIPLIER=8
+CONFIG_CLOCK_STM32_PLL_P_DIVISOR=2
+CONFIG_CLOCK_STM32_PLL_Q_DIVISOR=2
+CONFIG_CLOCK_STM32_PLL_R_DIVISOR=2
+CONFIG_CLOCK_STM32_AHB_PRESCALER=1
+CONFIG_CLOCK_STM32_APB1_PRESCALER=1

drivers/pinmux/stm32/pinmux_stm32g0.h

@@ -16,6 +16,8 @@
 #define STM32G0_PINMUX_FUNC_PA3_USART2_RX \
 	(STM32_PINMUX_ALT_FUNC_1 | STM32_PUPDR_NO_PULL)
 
+#define STM32G0_PINMUX_FUNC_PA9_USART1_TX \
+	(STM32_PINMUX_ALT_FUNC_1 | STM32_PUSHPULL_NOPULL)
 #define STM32G0_PINMUX_FUNC_PB6_USART1_TX \
 	(STM32_PINMUX_ALT_FUNC_0 | STM32_PUSHPULL_NOPULL)
 #define STM32G0_PINMUX_FUNC_PB7_USART1_RX \