boards: arm: Add support for Silicon Labs EFM32PG-STK3402A

The EFM32 Pearl Gecko Starter Kit contains sensors and
peripherals demonstrating the usage of the EFM32PG MCU
family. This patch adds basic support for this board
and is copied from EFM32WG-STK3800.

Signed-off-by: Gil Benkö <gil.benkoe@pm.me>
Signed-off-by: Christian Taedcke <hacking@taedcke.com>

boards/arm/efm32pg_stk3402a/CMakeLists.txt

@@ -0,0 +1,5 @@
+if(CONFIG_UART_GECKO)
+  zephyr_library()
+  zephyr_library_sources(board.c)
+  zephyr_library_include_directories(${PROJECT_SOURCE_DIR}/drivers)
+endif()

boards/arm/efm32pg_stk3402a/Kconfig

@@ -0,0 +1,19 @@
+# Kconfig - EFM32PG STK3402A board configuration
+#
+# Copyright (c) 2018 Christian Taedcke
+#
+# SPDX-License-Identifier: Apache-2.0
+
+if BOARD_EFM32PG_STK3402A
+
+config BOARD_INIT_PRIORITY
+	int
+
+	# omit prompt to signify a "hidden" option
+	default KERNEL_INIT_PRIORITY_DEFAULT
+	depends on GPIO
+	help
+	  Board initialization priority. This must be bigger than
+	  GPIO_GECKO_COMMON_INIT_PRIORITY.
+
+endif # BOARD_EFM32PG_STK3402A

boards/arm/efm32pg_stk3402a/Kconfig.board

@@ -0,0 +1,12 @@
+# Kconfig - EFM32PG STK3402A board
+#
+# Copyright (c) 2018, Christian Taedcke
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+config BOARD_EFM32PG_STK3402A
+	bool "SiLabs EFM32PG-STK3402A (Pearl Gecko)"
+	depends on SOC_SERIES_EFM32PG12B
+	select SOC_PART_NUMBER_EFM32PG12B500F1024GL125
+	select HAS_DTS_I2C

boards/arm/efm32pg_stk3402a/Kconfig.defconfig

@@ -0,0 +1,62 @@
+# Kconfig - EFM32PG STK3402A board
+#
+# Copyright (c) 2018, Christian Taedcke
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+if BOARD_EFM32PG_STK3402A
+
+config BOARD
+	default "efm32pg_stk3402a"
+
+config CMU_HFXO_FREQ
+	default 40000000
+
+config CMU_LFXO_FREQ
+	default 32768
+
+if GPIO_GECKO
+
+config GPIO_GECKO_PORTA
+	default y
+
+config GPIO_GECKO_PORTB
+	default y
+
+config GPIO_GECKO_PORTC
+	default n
+
+config GPIO_GECKO_PORTD
+	default y
+
+config GPIO_GECKO_PORTE
+	default n
+
+config GPIO_GECKO_PORTF
+	default y
+
+endif # GPIO_GECKO
+
+if UART_GECKO
+
+config USART_GECKO_0
+	default y
+
+endif # UART_GECKO
+
+if LEUART_GECKO
+
+config LEUART_GECKO_0
+	default y
+
+endif # LEUART_GECKO
+
+if I2C_GECKO
+
+config I2C_0
+	default y
+
+endif # I2C_GECKO
+
+endif # BOARD_EFM32PG_STK3402A

boards/arm/efm32pg_stk3402a/board.c

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2018 Christian Taedcke
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <init.h>
+#include "board.h"
+#include <gpio.h>
+#include <misc/printk.h>
+
+static int efm32pg_stk3402a_init(struct device *dev)
+{
+	struct device *bce_dev; /* Board Controller Enable Gpio Device */
+
+	ARG_UNUSED(dev);
+
+	/* Enable the board controller to be able to use the serial port */
+	bce_dev = device_get_binding(BC_ENABLE_GPIO_NAME);
+
+	if (!bce_dev) {
+		printk("Board controller gpio port was not found!\n");
+		return -ENODEV;
+	}
+
+	gpio_pin_configure(bce_dev, BC_ENABLE_GPIO_PIN, GPIO_DIR_OUT);
+	gpio_pin_write(bce_dev, BC_ENABLE_GPIO_PIN, 1);
+
+	return 0;
+}
+
+/* needs to be done after GPIO driver init */
+SYS_INIT(efm32pg_stk3402a_init, PRE_KERNEL_1, CONFIG_BOARD_INIT_PRIORITY);

boards/arm/efm32pg_stk3402a/board.cmake

@@ -0,0 +1,8 @@
+#
+# Copyright (c) 2018, Christian Taedcke
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+board_runner_args(jlink "--device=EFM32PG12BxxxF1024")
+include(${ZEPHYR_BASE}/boards/common/jlink.board.cmake)

boards/arm/efm32pg_stk3402a/board.h

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2018 Christian Taedcke
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef __INC_BOARD_H
+#define __INC_BOARD_H
+
+/* This pin is used to enable the serial port using the board controller */
+#define BC_ENABLE_GPIO_NAME  DT_GPIO_GECKO_PORTA_NAME
+#define BC_ENABLE_GPIO_PIN   5
+
+#endif /* __INC_BOARD_H */

boards/arm/efm32pg_stk3402a/doc/efm32pg_stk3402a.rst

@@ -0,0 +1,189 @@
+.. _efm32pg_stk3402a:
+
+EFM32 Pearl Gecko Starter Kit
+#############################
+
+Overview
+********
+
+The EFM32 Pearl Gecko Starter Kit EFM32PG-STK3402A contains an MCU from the
+EFM32PG family built on an ARM® Cortex®-M4F processor with excellent low
+power capabilities.
+
+.. figure:: slstk3402a-pearl-gecko-pg12-stk.png
+   :width: 375px
+   :align: center
+   :alt: EFM32PG-SLSTK3402A
+
+   EFM32PG-SLSTK3402A (image courtesy of Silicon Labs)
+
+Hardware
+********
+
+- Advanced Energy Monitoring provides real-time information about the energy
+  consumption of an application or prototype design.
+- Ultra low power 128x128 pixel Memory-LCD
+- 2 user buttons, 2 LEDs and a touch slider
+- Humidity, temperature, and inductive-capacitive metal sensor
+- On-board Segger J-Link USB debugger
+
+For more information about the EFM32PG SoC and EFM32PG-STK3402A board:
+
+- `EFM32PG Website`_
+- `EFM32PG12 Datasheet`_
+- `EFM32PG12 Reference Manual`_
+- `EFM32PG-STK3402A Website`_
+- `EFM32PG-STK3402A User Guide`_
+- `EFM32PG-STK3402A Schematics`_
+
+Supported Features
+==================
+
+The efm32pg_stk3402a board configuration supports the following hardware features:
+
++-----------+------------+-------------------------------------+
+| Interface | Controller | Driver/Component                    |
++===========+============+=====================================+
+| NVIC      | on-chip    | nested vector interrupt controller  |
++-----------+------------+-------------------------------------+
+| SYSTICK   | on-chip    | systick                             |
++-----------+------------+-------------------------------------+
+| FLASH     | on-chip    | flash memory                        |
++-----------+------------+-------------------------------------+
+| GPIO      | on-chip    | gpio                                |
++-----------+------------+-------------------------------------+
+| UART      | on-chip    | serial port-polling;                |
+|           |            | serial port-interrupt               |
++-----------+------------+-------------------------------------+
+| I2C       | on-chip    | i2c port-polling                    |
++-----------+------------+-------------------------------------+
+
+The default configuration can be found in the defconfig file:
+
+	``boards/arm/efm32pg_stk3402a/efm32pg_stk3402a_defconfig``
+
+Other hardware features are currently not supported by the port.
+
+Connections and IOs
+===================
+
+The EFM32PG12 SoC has twelve GPIO controllers (PORTA to PORTL), but only four
+are currently enabled (PORTA, PORTB, PORTD and PORTF) for the EFM32PG-STK3402A
+board.
+
+In the following table, the column **Name** contains pin names. For example, PE2
+means pin number 2 on PORTE, as used in the board's datasheets and manuals.
+
++-------+-------------+-------------------------------------+
+| Name  | Function    | Usage                               |
++=======+=============+=====================================+
+| PF4   | GPIO        | LED0                                |
++-------+-------------+-------------------------------------+
+| PF5   | GPIO        | LED1                                |
++-------+-------------+-------------------------------------+
+| PF6   | GPIO        | Push Button PB0                     |
++-------+-------------+-------------------------------------+
+| PF7   | GPIO        | Push Button PB1                     |
++-------+-------------+-------------------------------------+
+| PA5   | GPIO        | Board Controller Enable             |
+|       |             | EFM_BC_EN                           |
++-------+-------------+-------------------------------------+
+| PA0   | UART_TX     | UART TX Console VCOM_TX US0_TX #0   |
++-------+-------------+-------------------------------------+
+| PA1   | UART_RX     | UART RX Console VCOM_RX US0_RX #0   |
++-------+-------------+-------------------------------------+
+| PD10  | UART_TX     | EXP12_UART_TX LEU0_TX #18           |
++-------+-------------+-------------------------------------+
+| PD11  | UART_RX     | EXP14_UART_RX LEU0_RX #18           |
++-------+-------------+-------------------------------------+
+| PC10  | I2C_SDA     | ENV_I2C_SDA I2C0_SDA #15            |
++-------+-------------+-------------------------------------+
+| PC11  | I2C_SCL     | ENV_I2C_SCL I2C0_SCL #15            |
++-------+-------------+-------------------------------------+
+
+
+System Clock
+============
+
+The EFM32PG SoC is configured to use the 40 MHz external oscillator on the
+board.
+
+Serial Port
+===========
+
+The EFM32PG SoC has four USARTs and one Low Energy UART (LEUART).
+
+Programming and Debugging
+*************************
+
+.. note::
+   Before using the kit the first time, you should update the J-Link firmware
+   from `J-Link-Downloads`_
+
+Flashing
+========
+
+The EFM32PG-STK3402A includes an `J-Link`_ serial and debug adaptor built into the
+board. The adaptor provides:
+
+- A USB connection to the host computer, which exposes a mass storage device and a
+  USB serial port.
+- A serial flash device, which implements the USB flash disk file storage.
+- A physical UART connection which is relayed over interface USB serial port.
+
+Flashing an application to EFM32PG-STK3402A
+-------------------------------------------
+
+The sample application :ref:`hello_world` is used for this example.
+Build the Zephyr kernel and application:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/hello_world
+   :board: efm32pg_stk3402a
+   :goals: build
+
+Connect the EFM32PG-STK3402A to your host computer using the USB port and you
+should see a USB connection which exposes a mass storage device(STK3402A).
+Copy the generated zephyr.bin to the STK3402A drive.
+
+Use a USB-to-UART converter such as an FT232/CP2102 to connect to the UART on the
+expansion header.
+
+Open a serial terminal (minicom, putty, etc.) with the following settings:
+
+- Speed: 115200
+- Data: 8 bits
+- Parity: None
+- Stop bits: 1
+
+Reset the board and you'll see the following message on the corresponding serial port
+terminal session:
+
+.. code-block:: console
+
+   Hello World! arm
+
+
+.. _EFM32PG-STK3402A Website:
+   https://www.silabs.com/products/development-tools/mcu/32-bit/efm32-pearl-gecko-pg12-starter-kit
+
+.. _EFM32PG-STK3402A User Guide:
+   https://www.silabs.com/documents/public/user-guides/ug257-stk3402-usersguide.pdf
+
+.. _EFM32PG-STK3402A Schematics:
+   https://www.silabs.com/documents/public/schematic-files/EFM32PG12-BRD2501A-A01-schematic.pdf
+
+.. _EFM32PG Website:
+   https://www.silabs.com/products/mcu/32-bit/efm32-pearl-gecko
+
+.. _EFM32PG12 Datasheet:
+   https://www.silabs.com/documents/public/data-sheets/efm32pg12-datasheet.pdf
+
+.. _EFM32PG12 Reference Manual:
+   https://www.silabs.com/documents/public/reference-manuals/efm32pg12-rm.pdf
+
+.. _J-Link:
+   https://www.segger.com/jlink-debug-probes.html
+
+.. _J-Link-Downloads:
+   https://www.segger.com/downloads/jlink

boards/arm/efm32pg_stk3402a/efm32pg_stk3402a.dts

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2017 Christian Taedcke
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/dts-v1/;
+#include <silabs/efm32pg12b500f1024gl125.dtsi>
+
+/ {
+	model = "Silicon Labs EFM32PG STK3402A board";
+	compatible = "silabs,efm32pg_stk3402a", "silabs,efm32pg12b";
+
+	chosen {
+		zephyr,console = &usart0;
+		zephyr,sram = &sram0;
+		zephyr,flash = &flash0;
+	};
+
+	/* These aliases are provided for compatibility with samples */
+	aliases {
+		i2c-0  = &i2c0;
+		usart-0 = &usart0;
+		leuart-0 = &leuart0;
+		led0 = &led0;
+		led1 = &led1;
+		sw0 = &button0;
+		sw1 = &button1;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+		led0: led_0 {
+			gpios = <&gpiof 4 0>;
+			label = "LED 0";
+		};
+		led1: led_1 {
+			gpios = <&gpiof 5 0>;
+			label = "LED 1";
+		};
+	};
+
+	buttons {
+		compatible = "gpio-keys";
+		button0: button_0 {
+			/* gpio flags need validation */
+			gpios = <&gpiof 6 GPIO_INT_ACTIVE_LOW>;
+			label = "User Push Button 0";
+		};
+		button1: button_1 {
+			/* gpio flags need validation */
+			gpios = <&gpiof 7 GPIO_INT_ACTIVE_LOW>;
+			label = "User Push Button 1";
+		};
+	};
+};
+
+&usart0 {
+	current-speed = <115200>;
+	location = <0>;
+	status = "ok";
+};
+
+&leuart0 {
+	current-speed = <9600>;
+	location = <18>;
+	status = "ok";
+};
+
+&i2c0 {
+	location = <15>;
+	status = "ok";
+};

boards/arm/efm32pg_stk3402a/efm32pg_stk3402a.yaml

@@ -0,0 +1,16 @@
+identifier: efm32pg_stk3402a
+name: EFM32PG-STK3402A
+type: mcu
+arch: arm
+ram: 256
+flash: 1024
+toolchain:
+  - zephyr
+  - gccarmemb
+supported:
+  - i2c
+  - gpio
+testing:
+  ignore_tags:
+    - net
+    - bluetooth

boards/arm/efm32pg_stk3402a/efm32pg_stk3402a_defconfig

@@ -0,0 +1,11 @@
+CONFIG_ARM=y
+CONFIG_SOC_FAMILY_EXX32=y
+CONFIG_SOC_SERIES_EFM32PG12B=y
+CONFIG_BOARD_EFM32PG_STK3402A=y
+CONFIG_CONSOLE=y
+CONFIG_UART_CONSOLE=y
+CONFIG_SERIAL=y
+CONFIG_CORTEX_M_SYSTICK=y
+CONFIG_GPIO=y
+CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC=40000000
+CONFIG_CMU_HFCLK_HFXO=y