soc/samr21: Initial support

CODEOWNERS

@@ -149,6 +149,7 @@
 /drivers/i2c/i2c_rv32m1_lpi2c*            @henrikbrixandersen
 /drivers/wifi/                            @jukkar @tbursztyka @pfalcon
 /drivers/wifi/eswifi/                     @loicpoulain
+/dts/arm/atmel/samr21.dtsi                @benpicco
 /dts/arm/st/                              @erwango
 /dts/arm/nordic/                          @ioannisg @carlescufi
 /dts/arm/nxp/                             @MaureenHelm
@@ -161,6 +162,7 @@
 /dts/bindings/sensor/ams,ens210.yaml      @alexanderwachter
 /dts/bindings/sensor/ams,iaqcore.yaml     @alexanderwachter
 /ext/fs/                                  @nashif @wentongwu
+/ext/hal/atmel/asf/sam0/include/samr21/   @benpicco
 /ext/hal/cmsis/                           @MaureenHelm @galak
 /ext/hal/libmetal/                        @galak
 /ext/hal/nordic/                          @carlescufi @anangl

boards/arm/atsamr21_xpro/CMakeLists.txt

@@ -0,0 +1,6 @@
+# Copyright (c) 2019 Benjamin Valentin
+# SPDX-License-Identifier: Apache-2.0
+if(CONFIG_PINMUX_SAM0)
+  zephyr_library()
+  zephyr_library_sources(pinmux.c)
+endif()

boards/arm/atsamr21_xpro/Kconfig.board

@@ -0,0 +1,8 @@
+# Kconfig - SAM R21 Xplained Pro Board configuration
+#
+# Copyright (c) 2019 Benjamin Valentin
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_ATSAMR21_XPRO
+	bool "SAM R21 Xplained Pro"
+	depends on SOC_PART_NUMBER_SAMR21G18A

boards/arm/atsamr21_xpro/Kconfig.defconfig

@@ -0,0 +1,11 @@
+# Kconfig - SAM R21 Xplained Pro board configuration
+#
+# Copyright (c) 2019 Benjamin Valentin
+# SPDX-License-Identifier: Apache-2.0
+
+if BOARD_ATSAMR21_XPRO
+
+config BOARD
+	default "atsamr21_xpro"
+
+endif # BOARD_ATSAMR21_XPRO

boards/arm/atsamr21_xpro/atsamr21_xpro.dts

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2019 Benjamin Valentin
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/dts-v1/;
+#include <atmel/samr21.dtsi>
+
+/ {
+	model = "SAM R21 Xplained Pro";
+	compatible = "atsamr21,xpro", "atmel,samr21g18a", "atmel,samr21";
+
+	chosen {
+		zephyr,console = &sercom0;
+		zephyr,shell-uart = &sercom0;
+		zephyr,sram = &sram0;
+		zephyr,flash = &flash0;
+	};
+
+	/* These aliases are provided for compatibility with samples */
+	aliases {
+		led0 = &led0;
+		sw0 = &user_button;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+		led0: led_0 {
+			gpios = <&porta 19 0>;
+			label = "Yellow LED";
+		};
+	};
+
+	buttons {
+		compatible = "gpio-keys";
+		user_button: button_0 {
+			gpios = <&porta 28 (GPIO_PUD_PULL_UP | GPIO_INT_ACTIVE_LOW)>;
+			label = "SW0";
+		};
+	};
+};
+
+&sercom0 {
+	status = "ok";
+	compatible = "atmel,sam0-uart";
+	current-speed = <115200>;
+	rxpo = <1>;
+	txpo = <0>;
+};
+
+&sercom5 {
+	status = "ok";
+	compatible = "atmel,sam0-spi";
+	dipo = <0>;
+	dopo = <2>;
+	label = "SPI_0";
+};
+
+&usb0 {
+	status = "ok";
+};
+
+&rtc {
+	status = "ok";
+};

boards/arm/atsamr21_xpro/atsamr21_xpro.yaml

@@ -0,0 +1,16 @@
+# Copyright (c) 2019 Benjamin Valentin
+# SPDX-License-Identifier: Apache-2.0
+identifier: atsamr21_xpro
+name: SAM R21 Xplained Pro
+type: mcu
+arch: arm
+ram: 32
+flash: 256
+toolchain:
+  - zephyr
+  - gnuarmemb
+  - xtools
+supported:
+  - gpio
+  - spi
+  - usb_device

boards/arm/atsamr21_xpro/atsamr21_xpro_defconfig

@@ -0,0 +1,21 @@
+# Copyright (c) 2019 Benjamin Valentin
+# SPDX-License-Identifier: Apache-2.0
+CONFIG_ARM=y
+CONFIG_SOC_FAMILY_SAM0=y
+CONFIG_SOC_SERIES_SAMR21=y
+CONFIG_SOC_PART_NUMBER_SAMR21G18A=y
+CONFIG_BOARD_ATSAMR21_XPRO=y
+CONFIG_CORTEX_M_SYSTICK=y
+CONFIG_CONSOLE=y
+CONFIG_UART_CONSOLE=y
+CONFIG_SERIAL=y
+CONFIG_UART_SAM0=y
+CONFIG_UART_INTERRUPT_DRIVEN=y
+CONFIG_GPIO=y
+CONFIG_GPIO_SAM0=y
+CONFIG_WATCHDOG=y
+CONFIG_WDT_SAM0=y
+CONFIG_SOC_ATMEL_SAMD_XOSC32K=y
+CONFIG_SOC_ATMEL_SAMD_XOSC32K_AS_MAIN=y
+CONFIG_PINMUX=y
+CONFIG_PINMUX_SAM0=y

boards/arm/atsamr21_xpro/board.cmake

@@ -0,0 +1,4 @@
+# Copyright (c) 2019 Benjamin Valentin
+# SPDX-License-Identifier: Apache-2.0
+
+include(${ZEPHYR_BASE}/boards/common/openocd.board.cmake)

boards/arm/atsamr21_xpro/doc/index.rst

@@ -0,0 +1,207 @@
+.. _atsamr21_xpro:
+
+SAM R21 Xplained Pro Evaluation Kit
+###################################
+
+Overview
+********
+
+The SAM R21 Xplained Pro is a compact evaluation board by Atmel featuring a
+ATSAMR21G18A SoC. The SoC includes a SAMR21 ARM Cortex-M0+ micro-controller
+bundled with Atmel's AT86RF233, a 2.4GHz IEEE802.15.4 compatible radio.
+The kit includes Atmel’s Embedded Debugger (EDBG), which provides a full
+debug interface without the need for additional hardware.
+
+.. image:: img/atsamr21_xpro.png
+     :width: 500px
+     :align: center
+     :alt: ATSAMR21-XPRO
+
+Hardware
+********
+
+- ATSAMR21G18A ARM Cortex-M0+ processor at 48 MHz
+- 32.768 kHz crystal oscillator
+- 256 KiB flash memory and 32 KiB of RAM
+- One yellow user LED
+- One mechanical user push button
+- One reset button
+- On-board USB based EDBG unit with serial console
+
+Supported Features
+==================
+
+The atsamr21_xpro board configuration supports the following hardware
+features:
+
++-----------+------------+--------------------------------------+
+| Interface | Controller | Driver/Component                     |
++===========+============+======================================+
+| NVIC      | on-chip    | nested vector interrupt controller   |
++-----------+------------+--------------------------------------+
+| 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    |
++-----------+------------+--------------------------------------+
+
+Other hardware features are not currently supported by Zephyr.
+
+The default configuration can be found in the Kconfig
+``boards/arm/atsamr21_xpro/atsamr21_xpro_defconfig``.
+
+Pin Mapping
+===========
+
+The SAM R21 Xplained Pro evaluation kit has 3 GPIO controllers. These
+controllers are responsible for pin muxing, input/output, pull-up, etc.
+
+For mode details please refer to `SAM R21 Family Datasheet`_ and the `SAM R21
+Xplained Pro Schematic`_.
+
+.. image:: img/ATSAMR21-XPRO-pinout.png
+     :width: 500px
+     :align: center
+     :alt: ATSAMR21-XPRO-pinout
+
+Default Zephyr Peripheral Mapping:
+----------------------------------
+- SERCOM0 USART TX : PA5
+- SERCOM0 USART RX : PA4
+- SERCOM5 SPI MISO : PB02
+- SERCOM5 SPI MOSI : PB22
+- SERCOM5 SPI SCK  : PB23
+- GPIO SPI CS      : PB03
+- GPIO LED0        : PB17
+
+System Clock
+============
+
+The SAMR21 MCU is configured to use the 32.768 kHz external oscillator
+with the on-chip PLL generating the 48 MHz system clock.
+
+Serial Port
+===========
+
+The SAMR21 MCU has six SERCOM based USARTs with two configured as USARTs in
+this BSP. SERCOM0 is the default Zephyr console.
+
+- SERCOM0 115200 8n1 connected to the onboard Atmel Embedded Debugger (EDBG)
+
+SPI Port
+========
+
+The SAMR21 MCU has 6 SERCOM based SPIs.
+
+- SERCOM5 is exposed via Xplained Pro Standard Extension Header
+
+I2C Port
+========
+
+When connecting an I2C device and a logic analyzer to an I2C port at the same
+time, the internal pull-up resistors are not sufficient for stable bus
+operation. You probably have to connect external pull-ups to both bus lines. 10K
+is a good value to start with.
+
+
+Radio
+=====
+
+The SAMR21 SoC includes an on-chip AT86RF233 radio. It is internally
+connected via SPI and some GPIO pins and behaves the same way as
+externally connected SPI devices.
+
++-------------+------------------------------------------------------------------------------------------+
+| Sensor      | AT86RF233                                                                                |
++=============+==========================================================================================+
+| Type        | 2.4GHz IEEE802.15.4 radio                                                                |
++-------------+------------------------------------------------------------------------------------------+
+| Vendor      | Atmel                                                                                    |
++-------------+------------------------------------------------------------------------------------------+
+| Datasheet   |`Datasheet <http://www.atmel.com/images/atmel-8351-mcu_wireless-at86rf233_datasheet.pdf>`_|
++-------------+------------------------------------------------------------------------------------------+
+| connected to| SPI_0                                                                                    |
++-------------+------------------------------------------------------------------------------------------+
+| Pin Config:                                                                                            |
++-------------+------------------------------------------------------------------------------------------+
+| Device      | SERCOM4                                                                                  |
++-------------+------------------------------------------------------------------------------------------+
+| MOSI        | PB30 (OUT, SPI mosi)                                                                     |
++-------------+------------------------------------------------------------------------------------------+
+| MISO        | PC19 (IN, SPI miso)                                                                      |
++-------------+------------------------------------------------------------------------------------------+
+| SCLK        | PC18 (OUT, SPI sclk)                                                                     |
++-------------+------------------------------------------------------------------------------------------+
+| CS          | PB31 (OUT, GPIO output)                                                                  |
++-------------+------------------------------------------------------------------------------------------+
+| IRQ         | PB00 (IN, GPIO external interrupt)                                                       |
++-------------+------------------------------------------------------------------------------------------+
+| RSTN        | PB15 (OUT, GPIO output)                                                                  |
++-------------+------------------------------------------------------------------------------------------+
+| SLP_TR      | PA20 (OUT, GPIO output)                                                                  |
++-------------+------------------------------------------------------------------------------------------+
+
+Programming and Debugging
+*************************
+
+The SAM R21 Xplained Pro comes with a Atmel Embedded Debugger (EDBG).  This
+provides a debug interface to the SAMR21 chip and is supported by
+OpenOCD.
+
+Flashing
+========
+
+#. Build the Zephyr kernel and the :ref:`hello_world` sample application:
+
+   .. zephyr-app-commands::
+      :zephyr-app: samples/hello_world
+      :board: atsamr21_xpro
+      :goals: build
+      :compact:
+
+#. Connect the SAM R21 Xplained Pro to your host computer using the USB debug
+   port.
+
+#. Run your favorite terminal program to listen for output. Under Linux the
+   terminal should be :code:`/dev/ttyACM0`. For example:
+
+   .. code-block:: console
+
+      $ minicom -D /dev/ttyACM0 -o
+
+   The -o option tells minicom not to send the modem initialization
+   string. Connection should be configured as follows:
+
+   - Speed: 115200
+   - Data: 8 bits
+   - Parity: None
+   - Stop bits: 1
+
+#. To flash an image:
+
+   .. zephyr-app-commands::
+      :zephyr-app: samples/hello_world
+      :board: atsamr21_xpro
+      :goals: flash
+      :compact:
+
+   You should see "Hello World! arm" in your terminal.
+
+References
+**********
+
+.. target-notes::
+
+.. _Microchip website:
+    http://www.microchip.com/DevelopmentTools/ProductDetails.aspx?PartNO=ATSAMR21-XPRO
+
+.. _SAM R21 Family Datasheet:
+    http://ww1.microchip.com/downloads/en/devicedoc/sam-r21_datasheet.pdf
+
+.. _SAM R21 Xplained Pro Schematic:
+    http://ww1.microchip.com/downloads/en/DeviceDoc/SAMR21-Xplained-Pro_Design-Documentation.zip