boards: 96b_carbon_nrf51: add support for 96Boards Carbon nRF51 chip

This adds support for the nRF51 chip on the board.

If you'd like to run Zephyr on the STM32F4 chip on Carbon, you need to
use the 96b_carbon board instead.

The current SPI Bluetooth protocol only uses 5 wires, so we use the
remaining pin as UART TX.

Signed-off-by: Ricardo Salveti <ricardo.salveti@linaro.org>
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>

boards/arm/96b_carbon_nrf51/96b_carbon_nrf51_defconfig

@@ -0,0 +1,34 @@
+CONFIG_ARM=y
+CONFIG_SOC_FAMILY_NRF5=y
+CONFIG_SOC_SERIES_NRF51X=y
+CONFIG_SOC_NRF51822_QFAC=y
+CONFIG_BOARD_96B_CARBON_NRF51=y
+
+# enable uart driver
+CONFIG_SERIAL=y
+CONFIG_UART_NRF5=y
+CONFIG_UART_NRF5_GPIO_TX_PIN=29
+CONFIG_UART_NRF5_GPIO_RX_PIN=11
+
+# enable console
+CONFIG_CONSOLE=y
+CONFIG_UART_CONSOLE=y
+
+# bluetooth
+CONFIG_BLUETOOTH=y
+CONFIG_BLUETOOTH_CONTROLLER=y
+
+# spi
+CONFIG_SPI=y
+CONFIG_SPI_1=y
+CONFIG_SPI_1_NAME="SPI_1"
+CONFIG_SPI_1_IRQ_PRI=1
+CONFIG_SPI_NRF5=y
+CONFIG_SPIS1_NRF5=y
+CONFIG_SPIS1_NRF5_GPIO_SCK_PIN=7
+CONFIG_SPIS1_NRF5_GPIO_MOSI_PIN=0
+CONFIG_SPIS1_NRF5_GPIO_MISO_PIN=30
+CONFIG_SPIS1_NRF5_GPIO_CSN_PIN=25
+
+#enable DTS
+CONFIG_HAS_DTS=y

boards/arm/96b_carbon_nrf51/Kconfig.board

@@ -0,0 +1,9 @@
+# Kconfig - 96Boards Carbon nRF51 board configuration
+#
+# Copyright (c) 2016, 2017 Linaro Limited.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_96B_CARBON_NRF51
+	bool "96Boards Carbon (nRF51)"
+	depends on SOC_NRF51822_QFAC

boards/arm/96b_carbon_nrf51/Kconfig.defconfig

@@ -0,0 +1,25 @@
+# Kconfig - 96Boards Carbon nRF51 board default configuration
+#
+# Copyright (c) 2016, 2017 Linaro Limited.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+if BOARD_96B_CARBON_NRF51
+
+config BOARD
+	default 96b_carbon_nrf51
+
+if UART_NRF5
+
+config GPIO
+	default y
+
+config GPIO_NRF5
+	default y
+
+config GPIO_NRF5_P0
+	default y
+
+endif # UART_NRF5
+
+endif # BOARD_96B_CARBON_NRF51

boards/arm/96b_carbon_nrf51/Makefile

@@ -0,0 +1 @@
+obj- += dummy.o

boards/arm/96b_carbon_nrf51/board.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2016, 2017 Linaro Limited.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef __INC_BOARD_H
+#define __INC_BOARD_H
+
+#include <soc.h>
+
+#endif /* __INC_BOARD_H */

boards/arm/96b_carbon_nrf51/doc/96b_carbon_nrf51.rst

@@ -0,0 +1,136 @@
+.. _96b_carbon_nrf51_board:
+
+96Boards Carbon nRF51
+#####################
+
+.. note::
+
+   If you're looking to reprogram the main STMicro part, see
+   :ref:`96b_carbon_board`. Users should not use this configuration
+   unless they want to reprogram the secondary chip which provides
+   Bluetooth connectivity.
+
+Overview
+********
+
+Zephyr applications use the 96b_carbon_nrf51 configuration to run on
+the secondary nRF51822 chip on the 96Boards Carbon. This chip provides
+Bluetooth functionality to the main STM32F401RET chip via SPI.
+
+Hardware
+********
+
+The 96Boards Carbon nRF51 has two external oscillators. The frequency
+of the slow clock is 32.768 kHz. The frequency of the main clock is 16
+MHz.
+
+See :ref:`96b_carbon_board` for other general information about the
+board; that configuration is for the same physical board, just a
+different chip.
+
+Supported Features
+==================
+
++-----------+------------+-------------------------------------+
+| Interface | Controller | Driver/Component                    |
++===========+============+=====================================+
+| NVIC      | on-chip    | nested vector interrupt controller  |
++-----------+------------+-------------------------------------+
+| RTC       | on-chip    | system clock                        |
++-----------+------------+-------------------------------------+
+| UART      | on-chip    | serial port                         |
++-----------+------------+-------------------------------------+
+| GPIO      | on-chip    | gpio                                |
++-----------+------------+-------------------------------------+
+| FLASH     | on-chip    | flash                               |
++-----------+------------+-------------------------------------+
+| SPIS      | on-chip    | SPI slave                           |
++-----------+------------+-------------------------------------+
+| RADIO     | on-chip    | bluetooth                           |
++-----------+------------+-------------------------------------+
+
+The default configuration can be found in the defconfig file:
+
+        ``boards/arm/96b_carbon_nrf51/96b_carbon_nrf51_defconfig``
+
+Connections and IOs
+===================
+
+The SWD debug pins are broken out to an external header; all other
+connected pins are to the main STM32F401RET chip.
+
+Programming and Debugging
+*************************
+
+Flashing
+========
+
+The 96Boards Carbon nRF51 can be flashed using an external SWD
+debugger, via the debug header labeled "BLE" on the board's
+silkscreen. The header is not populated; 0.1" male header must be
+soldered on first.
+
+.. figure:: img/96b-carbon-nrf51-debug.png
+     :align: center
+     :alt: 96Boards Carbon nRF51 Debug
+
+     96Boards Carbon nRF51 Debug
+
+The following example assumes a Zephyr binary ``zephyr.elf`` will be
+flashed to the board.
+
+It uses the `Black Magic Debug Probe`_ as an SWD programmer, which can
+be connected to the BLE debug header using flying leads and its 20 Pin
+JTAG Adapter Board Kit. When plugged into your host PC, the Black
+Magic Debug Probe enumerates as a USB serial device as documented on
+its `Getting started page`_.
+
+It also uses the GDB binary provided with the Zephyr SDK,
+``arm-zephyr-eabi-gdb``. Other GDB binaries, such as the GDB from GCC
+ARM Embedded, can be used as well.
+
+.. code-block:: console
+
+   $ arm-zephyr-eabi-gdb -q zephyr.elf
+   (gdb) target extended-remote /dev/ttyACM0
+   Remote debugging using /dev/ttyACM0
+   (gdb) monitor swdp_scan
+   Target voltage: 3.3V
+   Available Targets:
+   No. Att Driver
+    1      nRF51
+   (gdb) attach 1
+   Attaching to Remote target
+   0xabcdef12 in ?? ()
+   (gdb) load
+
+Debugging
+=========
+
+After you've flashed the chip, you can keep debugging using the same
+GDB instance. To reattach, just follow the same steps above, but don't
+run "load". You can then debug as usual with GDB. In particular, type
+"run" at the GDB prompt to restart the program you've flashed.
+
+As an aid to debugging, this board configuration directs a console
+output to a currently unused pin connected to the STM32F401RET. Users
+who are experienced in electronics rework can remove a resistor (R22)
+on the board and attach a wire to the nRF51822's UART output.
+
+References
+**********
+
+- `Board documentation from 96Boards`_
+- `nRF51822 information from Nordic Semiconductor`_
+
+.. _Black Magic Debug Probe:
+   https://github.com/blacksphere/blackmagic/wiki
+
+.. _Getting started page:
+   https://github.com/blacksphere/blackmagic/wiki/Getting-Started
+
+.. _Board documentation from 96Boards:
+   http://www.96boards.org/product/carbon/
+
+.. _nRF51822 information from Nordic Semiconductor:
+   https://www.nordicsemi.com/eng/Products/Bluetooth-low-energy/nRF51822

dts/arm/96b_carbon_nrf51.dts

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2017 Linaro Limited
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/dts-v1/;
+#include <nordic/nrf51822.dtsi>
+
+/ {
+	model = "Seeed Studio Carbon nRF51 96board";
+	compatible = "seeed,carbon_nrf51", "nordic,nrf51822-qfac",
+		     "nordic,nrf51822";
+
+	chosen {
+		zephyr,console = &uart0;
+		zephyr,sram = &sram0;
+		zephyr,flash = &flash0;
+	};
+};
+
+&uart0 {
+	current-speed = <115200>;
+	status = "ok";
+};

dts/arm/96b_carbon_nrf51.fixup

@@ -0,0 +1,3 @@
+#define CONFIG_NUM_IRQ_PRIO_BITS	ARM_V6M_NVIC_E000E100_ARM_NUM_IRQ_PRIORITY_BITS
+#define CONFIG_UART_NRF5_IRQ_PRI	NORDIC_NRF_UART_40002000_IRQ_0_PRIORITY
+#define CONFIG_UART_NRF5_BAUD_RATE	NORDIC_NRF_UART_40002000_CURRENT_SPEED

dts/arm/Makefile

@@ -13,6 +13,7 @@ dtb-$(CONFIG_BOARD_V2M_BEETLE)		=	v2m_beetle.dts_compiled
 dtb-$(CONFIG_BOARD_MPS2_AN385)		=	mps2_an385.dts_compiled
 dtb-$(CONFIG_BOARD_OLIMEXINO_STM32)	=	olimexino_stm32.dts_compiled
 dtb-$(CONFIG_BOARD_96B_CARBON)		=	96b_carbon.dts_compiled
+dtb-$(CONFIG_BOARD_96B_CARBON_NRF51)	=	96b_carbon_nrf51.dts_compiled
 dtb-$(CONFIG_BOARD_NUCLEO_F401RE)	=	nucleo_f401re.dts_compiled
 dtb-$(CONFIG_BOARD_NUCLEO_F411RE)	=	nucleo_f411re.dts_compiled
 dtb-$(CONFIG_BOARD_NUCLEO_F103RB)	=	nucleo_f103rb.dts_compiled