boards/serpente: add serpente board

See https://serpente.solder.party

boards/serpente/Makefile

@@ -0,0 +1,5 @@
+MODULE = board
+
+DIRS = $(RIOTBOARD)/common/samd21-arduino-bootloader
+
+include $(RIOTBASE)/Makefile.base

boards/serpente/Makefile.dep

@@ -0,0 +1,18 @@
+ifneq (,$(filter mtd,$(USEMODULE)))
+  USEMODULE += mtd_spi_nor
+endif
+
+ifneq (,$(filter saul_default,$(USEMODULE)))
+  USEMODULE += saul_gpio
+endif
+
+# use arduino-bootloader only if no other stdio_% other than stdio_cdc_acm
+# is requested
+ifeq (,$(filter-out stdio_cdc_acm,$(filter stdio_%,$(USEMODULE))))
+  USEMODULE += boards_common_samd21-arduino-bootloader
+endif
+
+ifneq (,$(filter boards_common_samd21-arduino-bootloader,$(USEMODULE)))
+  # setup the samd21 arduino bootloader related dependencies
+  include $(RIOTBOARD)/common/samd21-arduino-bootloader/Makefile.dep
+endif

boards/serpente/Makefile.features

@@ -0,0 +1,13 @@
+CPU = samd21
+CPU_MODEL = samd21e18a
+
+# Put defined MCU peripherals here (in alphabetical order)
+FEATURES_PROVIDED += bootloader_arduino
+FEATURES_PROVIDED += periph_adc
+FEATURES_PROVIDED += periph_i2c
+FEATURES_PROVIDED += periph_rtc
+FEATURES_PROVIDED += periph_rtt
+FEATURES_PROVIDED += periph_spi
+FEATURES_PROVIDED += periph_timer
+FEATURES_PROVIDED += periph_uart
+FEATURES_PROVIDED += periph_usbdev

boards/serpente/Makefile.include

@@ -0,0 +1,20 @@
+PORT_LINUX ?= /dev/ttyACM0
+PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.usbmodem*)))
+
+CONFIG_USB_VID=0x239A
+CONFIG_USB_PID=0x0057
+
+CFLAGS += -DBOOTLOADER_UF2
+
+# setup serial terminal
+include $(RIOTMAKE)/tools/serial.inc.mk
+
+# setup the flash tool used
+ifeq ($(PROGRAMMER),jlink)
+  # in case J-Link is attached to SWD pins, use a plain CPU memory model
+  JLINK_DEVICE := atsamd21
+  include $(RIOTMAKE)/tools/jlink.inc.mk
+endif
+
+# Include all definitions for flashing with bossa other USB
+include $(RIOTBOARD)/common/samd21-arduino-bootloader/Makefile.include

boards/serpente/board.c

@@ -0,0 +1,72 @@
+/*
+ * Copyright (C)  2020 Benjamin Valentin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     boards_serpente
+ * @{
+ *
+ * @file
+ * @brief       Board specific implementations for the Serpente board
+ *
+ * @author      Benjamin Valentin <benpicco@googlemail.com>
+ *
+ * @}
+ */
+
+#include "cpu.h"
+#include "board.h"
+#include "mtd.h"
+#include "mtd_spi_nor.h"
+#include "periph/gpio.h"
+#include "periph/spi.h"
+#include "timex.h"
+
+#ifdef MODULE_MTD
+/* GD25Q32C */
+static const mtd_spi_nor_params_t _serpente_nor_params = {
+    .opcode = &mtd_spi_nor_opcode_default,
+    .wait_chip_erase = 15LU * US_PER_SEC,
+    .wait_32k_erase = 250LU * US_PER_MS,
+    .wait_sector_erase = 50LU * US_PER_MS,
+    .wait_4k_erase = 150LU * US_PER_MS,
+    .wait_chip_wake_up = 1LU * US_PER_MS,
+    .clk = SERPENTE_NOR_SPI_CLK,
+    .flag = SERPENTE_NOR_FLAGS,
+    .spi = SERPENTE_NOR_SPI_DEV,
+    .mode = SERPENTE_NOR_SPI_MODE,
+    .cs = SERPENTE_NOR_SPI_CS,
+    .addr_width = 3,
+};
+
+static mtd_spi_nor_t serpente_nor_dev = {
+    .base = {
+        .driver = &mtd_spi_nor_driver,
+        .page_size = SERPENTE_NOR_PAGE_SIZE,
+        .pages_per_sector = SERPENTE_NOR_PAGES_PER_SECTOR,
+        .sector_count = SERPENTE_NOR_SECTOR_COUNT,
+    },
+    .params = &_serpente_nor_params,
+};
+
+mtd_dev_t *mtd0 = (mtd_dev_t *)&serpente_nor_dev;
+#endif /* MODULE_MTD */
+
+void board_init(void)
+{
+    /* initialize the CPU */
+    cpu_init();
+
+    /* initialize the on-board red LEDs */
+    gpio_init(LED0_PIN, GPIO_OUT);
+    gpio_init(LED1_PIN, GPIO_OUT);
+    gpio_init(LED2_PIN, GPIO_OUT);
+
+    LED0_OFF;
+    LED1_OFF;
+    LED2_OFF;
+}

boards/serpente/doc.txt

@@ -0,0 +1,45 @@
+/**
+@defgroup    boards_serpente Serpente R2
+@ingroup     boards
+@brief       Support for the Serpente board.
+
+### General information
+
+The [Serpente boards](https://serpente.solder.party/) are low-cost development boards designed
+to be used with Adafruit’s CircuitPython.
+
+Three versions of the board board exist, but they all the same except for the USB connector.
+The standard Serpente board contains a female USB Type-C connector, the Serpente Plug C
+contains a male USB Type-C connector, and the Serpente Plug uses the board itself as a Type-A USB plug.
+
+If you are familiar with the Digispark boards, you may notice some similarities.
+This fact is of course not incidental, the Serpente boards are inspired by the Digispark,
+both in form-factor as well as use-cases. The Serpente boards are meant to be used as quick
+and dirty, yet flexible, prototyping tools.
+
+### Pinout
+
+\image html https://serpente.solder.party/r2/pinout.png width=66%
+
+### Flash the board
+
+Use `BOARD=serpente` with the `make` command.<br/>
+Example with `micropython` application:
+```
+     make BOARD=serpente -C examples/micropython flash
+```
+
+RIOT will automatically trigger a reset to the bootloader, but this only works if RIOT is still
+running on the board.
+If your application has crashed or got erased, `make flash` will not be able to trigger a bootloader reset.
+
+To manually enter the bootloader, quickly press the Reset button twice.
+You know you've successfully entered the bootloader when the LED begins flashing blue.
+
+Sometimes flashing fails and the board gets stuck in the bootloader.
+In this case, just run `make flash` again when the device is not busy anymore.
+
+### Accessing STDIO via UART
+
+STDIO of RIOT is directly available over the USB port.
+ */

boards/serpente/include/board.h

@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2020 Benjamin Valentin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     boards_serpente
+ * @brief       Support for the Serpente board.
+ * @{
+ *
+ * @file
+ * @brief       Board specific definitions for the Serpente
+ *              board
+ *
+ * @author      Benjamin Valentin <benpicco@googlemail.com>
+ */
+
+#ifndef BOARD_H
+#define BOARD_H
+
+#include "cpu.h"
+#include "periph_conf.h"
+#include "mtd.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @name    LED pin definitions and handlers
+ * @{
+ */
+#define LED_PORT            PORT->Group[PA]
+
+#define LED0_PIN            GPIO_PIN(PA, 22)
+#define LED0_MASK           (1 << 22)
+#define LED0_NAME           "LED(Red)"
+
+#define LED0_OFF            (LED_PORT.OUTSET.reg = LED0_MASK)
+#define LED0_ON             (LED_PORT.OUTCLR.reg = LED0_MASK)
+#define LED0_TOGGLE         (LED_PORT.OUTTGL.reg = LED0_MASK)
+
+#define LED1_PIN            GPIO_PIN(PA, 19)
+#define LED1_MASK           (1 << 19)
+#define LED1_NAME           "LED(Green)"
+
+#define LED1_OFF            (LED_PORT.OUTSET.reg = LED1_MASK)
+#define LED1_ON             (LED_PORT.OUTCLR.reg = LED1_MASK)
+#define LED1_TOGGLE         (LED_PORT.OUTTGL.reg = LED1_MASK)
+
+#define LED2_PIN            GPIO_PIN(PA, 23)
+#define LED2_MASK           (1 << 23)
+#define LED2_NAME           "LED(Blue)"
+
+#define LED2_OFF            (LED_PORT.OUTSET.reg = LED2_MASK)
+#define LED2_ON             (LED_PORT.OUTCLR.reg = LED2_MASK)
+#define LED2_TOGGLE         (LED_PORT.OUTTGL.reg = LED2_MASK)
+/** @} */
+
+/**
+ * @name Serpente NOR flash hardware configuration
+ * @{
+ */
+#define SERPENTE_NOR_PAGE_SIZE          (256)
+#define SERPENTE_NOR_PAGES_PER_SECTOR   (16)
+#define SERPENTE_NOR_SECTOR_COUNT       (1024)
+#define SERPENTE_NOR_FLAGS              (SPI_NOR_F_SECT_4K | SPI_NOR_F_SECT_32K)
+#define SERPENTE_NOR_SPI_DEV            SPI_DEV(0)
+#define SERPENTE_NOR_SPI_CLK            SPI_CLK_10MHZ
+#define SERPENTE_NOR_SPI_CS             GPIO_PIN(PA, 15)
+#define SERPENTE_NOR_SPI_MODE           SPI_MODE_3
+/** @} */
+
+/**
+ * @name MTD configuration
+ * @{
+ */
+extern mtd_dev_t *mtd0;
+#define MTD_0 mtd0
+/** @} */
+
+/**
+ * @brief   Initialize board specific hardware, including clock, LEDs and std-IO
+ */
+void board_init(void);
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BOARD_H */
+/** @} */

boards/serpente/include/gpio_params.h

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C)  2020 Benjamin Valentin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     boards_serpente
+ * @{
+ *
+ * @file
+ * @brief       Board specific configuration of direct mapped GPIOs
+ *
+ * @author      Benjamin Valentin <benpicco@googlemail.com>
+ */
+
+#ifndef GPIO_PARAMS_H
+#define GPIO_PARAMS_H
+
+#include "board.h"
+#include "saul/periph.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief    GPIO pin configuration
+ */
+static const  saul_gpio_params_t saul_gpio_params[] =
+{
+    {
+        .name = LED0_NAME,
+        .pin = LED0_PIN,
+        .mode = GPIO_OUT,
+        .flags = SAUL_GPIO_INVERTED,
+    },
+    {
+        .name = LED1_NAME,
+        .pin = LED1_PIN,
+        .mode = GPIO_OUT,
+        .flags = SAUL_GPIO_INVERTED,
+    },
+    {
+        .name = LED2_NAME,
+        .pin = LED2_PIN,
+        .mode = GPIO_OUT,
+        .flags = SAUL_GPIO_INVERTED,
+    },
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GPIO_PARAMS_H */
+/** @} */

boards/serpente/include/periph_conf.h

@@ -0,0 +1,259 @@
+/*
+ * Copyright (C)  2020 Benjamin Valentin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     boards_serpente
+ * @{
+ *
+ * @file
+ * @brief       Configuration of CPU peripherals for the Serpente board
+ *
+ * @author      Benjamin Valentin <benpicco@googlemail.com>
+ */
+
+#ifndef PERIPH_CONF_H
+#define PERIPH_CONF_H
+
+#include <stdint.h>
+
+#include "cpu.h"
+#include "periph_cpu.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @name    External oscillator and clock configuration
+ *
+ * For selection of the used CORECLOCK, we have implemented two choices:
+ *
+ * - usage of the PLL fed by the internal 8MHz oscillator divided by 8
+ * - usage of the internal 8MHz oscillator directly, divided by N if needed
+ *
+ *
+ * The PLL option allows for the usage of a wider frequency range and a more
+ * stable clock with less jitter. This is why we use this option as default.
+ *
+ * The target frequency is computed from the PLL multiplier and the PLL divisor.
+ * Use the following formula to compute your values:
+ *
+ * CORECLOCK = ((PLL_MUL + 1) * 1MHz) / PLL_DIV
+ *
+ * NOTE: The PLL circuit does not run with less than 32MHz while the maximum PLL
+ *       frequency is 96MHz. So PLL_MULL must be between 31 and 95!
+ *
+ *
+ * The internal Oscillator used directly can lead to a slightly better power
+ * efficiency to the cost of a less stable clock. Use this option when you know
+ * what you are doing! The actual core frequency is adjusted as follows:
+ *
+ * CORECLOCK = 8MHz / DIV
+ *
+ * NOTE: A core clock frequency below 1MHz is not recommended
+ *
+ * @{
+ */
+#define CLOCK_USE_PLL       (1)
+
+#if CLOCK_USE_PLL
+/* edit these values to adjust the PLL output frequency */
+#define CLOCK_PLL_MUL       (47U)               /* must be >= 31 & <= 95 */
+#define CLOCK_PLL_DIV       (1U)                /* adjust to your needs */
+#define CLOCK_CORECLOCK     (((CLOCK_PLL_MUL + 1) * 1000000U) / CLOCK_PLL_DIV)
+#else
+/* edit this value to your needs */
+#define CLOCK_DIV           (1U)
+/* generate the actual core clock frequency */
+#define CLOCK_CORECLOCK     (8000000 / CLOCK_DIV)
+#endif
+/** @} */
+
+/**
+ * @name    Timer peripheral configuration
+ * @{
+ */
+static const tc32_conf_t timer_config[] = {
+    {   /* Timer 0 - System Clock */
+        .dev            = TC3,
+        .irq            = TC3_IRQn,
+        .pm_mask        = PM_APBCMASK_TC3,
+        .gclk_ctrl      = GCLK_CLKCTRL_ID_TCC2_TC3,
+#if CLOCK_USE_PLL || CLOCK_USE_XOSC32_DFLL
+        .gclk_src       = SAM0_GCLK_1MHZ,
+        .prescaler      = TC_CTRLA_PRESCALER_DIV1,
+#else
+        .gclk_src       = SAM0_GCLK_MAIN,
+        .prescaler      = TC_CTRLA_PRESCALER_DIV8,
+#endif
+        .flags          = TC_CTRLA_MODE_COUNT16,
+    },
+    {   /* Timer 1 */
+        .dev            = TC4,
+        .irq            = TC4_IRQn,
+        .pm_mask        = PM_APBCMASK_TC4 | PM_APBCMASK_TC5,
+        .gclk_ctrl      = GCLK_CLKCTRL_ID_TC4_TC5,
+#if CLOCK_USE_PLL || CLOCK_USE_XOSC32_DFLL
+        .gclk_src       = SAM0_GCLK_1MHZ,
+        .prescaler      = TC_CTRLA_PRESCALER_DIV1,
+#else
+        .gclk_src       = SAM0_GCLK_MAIN,
+        .prescaler      = TC_CTRLA_PRESCALER_DIV8,
+#endif
+        .flags          = TC_CTRLA_MODE_COUNT32,
+    }
+};
+
+#define TIMER_0_MAX_VALUE   0xffff
+
+/* interrupt function name mapping */
+#define TIMER_0_ISR         isr_tc3
+#define TIMER_1_ISR         isr_tc4
+
+#define TIMER_NUMOF         ARRAY_SIZE(timer_config)
+/** @} */
+
+/**
+ * @name    UART configuration
+ * @{
+ */
+static const uart_conf_t uart_config[] = {
+    {
+        .dev      = &SERCOM2->USART,
+        .rx_pin   = GPIO_PIN(PA, 9),    /* D5 */
+        .tx_pin   = GPIO_PIN(PA, 8),    /* D4 */
+        .mux      = GPIO_MUX_D,
+        .rx_pad   = UART_PAD_RX_1,
+        .tx_pad   = UART_PAD_TX_0,
+        .flags    = UART_FLAG_NONE,
+        .gclk_src = SAM0_GCLK_MAIN,
+    },
+    {
+        .dev      = &SERCOM0->USART,
+        .rx_pin   = GPIO_PIN(PA, 5),    /* D1 */
+        .tx_pin   = GPIO_PIN(PA, 4),    /* D0 */
+        .mux      = GPIO_MUX_D,
+        .rx_pad   = UART_PAD_RX_1,
+        .tx_pad   = UART_PAD_TX_0,
+        .flags    = UART_FLAG_NONE,
+        .gclk_src = SAM0_GCLK_MAIN,
+    }
+};
+
+/* interrupt function name mapping */
+#define UART_0_ISR          isr_sercom2
+#define UART_1_ISR          isr_sercom0
+
+#define UART_NUMOF          ARRAY_SIZE(uart_config)
+/** @} */
+
+/**
+ * @name SPI configuration
+ * @{
+ */
+static const spi_conf_t spi_config[] = {
+    {   /* Flash */
+        .dev      = &SERCOM1->SPI,
+        .miso_pin = GPIO_PIN(PA, 18),
+        .mosi_pin = GPIO_PIN(PA, 16),
+        .clk_pin  = GPIO_PIN(PA, 17),
+        .miso_mux = GPIO_MUX_C,
+        .mosi_mux = GPIO_MUX_C,
+        .clk_mux  = GPIO_MUX_C,
+        .miso_pad = SPI_PAD_MISO_2,
+        .mosi_pad = SPI_PAD_MOSI_0_SCK_1,
+        .gclk_src = SAM0_GCLK_MAIN,
+    },
+    {   /* D0 … D2 (user pins) */
+        .dev      = &SERCOM0->SPI,
+        .miso_pin = GPIO_PIN(PA, 6),    /* D2 */
+        .mosi_pin = GPIO_PIN(PA, 4),    /* D0 */
+        .clk_pin  = GPIO_PIN(PA, 5),    /* D1 */
+        .miso_mux = GPIO_MUX_D,
+        .mosi_mux = GPIO_MUX_D,
+        .clk_mux  = GPIO_MUX_D,
+        .miso_pad = SPI_PAD_MISO_2,
+        .mosi_pad = SPI_PAD_MOSI_0_SCK_1,
+        .gclk_src = SAM0_GCLK_MAIN,
+    },
+};
+
+#define SPI_NUMOF           ARRAY_SIZE(spi_config)
+/** @} */
+
+/**
+ * @name    I2C configuration
+ * @{
+ */
+static const i2c_conf_t i2c_config[] = {
+    {
+        .dev      = &(SERCOM2->I2CM),
+        .speed    = I2C_SPEED_NORMAL,
+        .scl_pin  = GPIO_PIN(PA, 9),    /* D5 */
+        .sda_pin  = GPIO_PIN(PA, 8),    /* D4 */
+        .mux      = GPIO_MUX_D,
+        .gclk_src = SAM0_GCLK_MAIN,
+        .flags    = I2C_FLAG_NONE
+     }
+};
+#define I2C_NUMOF           ARRAY_SIZE(i2c_config)
+/** @} */
+
+/**
+ * @name    RTT configuration
+ * @{
+ */
+#define RTT_MAX_VALUE       (0xffffffff)
+#define RTT_FREQUENCY       (32768U)    /* in Hz. For changes see `rtt.c` */
+/** @} */
+
+/**
+ * @name    ADC Default values
+ * @{
+ */
+#define ADC_PRESCALER                       ADC_CTRLB_PRESCALER_DIV512
+
+#define ADC_NEG_INPUT                       ADC_INPUTCTRL_MUXNEG_GND
+#define ADC_GAIN_FACTOR_DEFAULT             ADC_INPUTCTRL_GAIN_1X
+#define ADC_REF_DEFAULT                     ADC_REFCTRL_REFSEL_INT1V
+
+static const adc_conf_chan_t adc_channels[] = {
+    /* port, pin, muxpos */
+    {GPIO_PIN(PA, 4), ADC_INPUTCTRL_MUXPOS_PIN4},
+    {GPIO_PIN(PA, 5), ADC_INPUTCTRL_MUXPOS_PIN5},
+    {GPIO_PIN(PA, 6), ADC_INPUTCTRL_MUXPOS_PIN6},
+    {GPIO_PIN(PA, 7), ADC_INPUTCTRL_MUXPOS_PIN7},
+    {GPIO_PIN(PA, 8), ADC_INPUTCTRL_MUXPOS_PIN16},
+    {GPIO_PIN(PA, 9), ADC_INPUTCTRL_MUXPOS_PIN17},
+};
+
+#define ADC_NUMOF           ARRAY_SIZE(adc_channels)
+/** @} */
+
+
+/**
+ * @name USB peripheral configuration
+ * @{
+ */
+static const sam0_common_usb_config_t sam_usbdev_config[] = {
+    {
+        .dm     = GPIO_PIN(PA, 24),
+        .dp     = GPIO_PIN(PA, 25),
+        .d_mux  = GPIO_MUX_G,
+        .device = &USB->DEVICE,
+        .gclk_src = SAM0_GCLK_MAIN,
+    }
+};
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PERIPH_CONF_H */
+/** @} */

examples/lua_REPL/Makefile.ci

@@ -66,6 +66,7 @@ BOARD_INSUFFICIENT_MEMORY := \
     samr34-xpro \
     seeeduino_arch-pro \
     sensebox_samd21 \
+    serpente \
     slstk3401a \
     sltb001a \
     slwstk6000b-slwrb4150a \

tests/bench_xtimer/Makefile.ci

@@ -1,4 +1,5 @@
 BOARD_INSUFFICIENT_MEMORY := \
     im880b \
     olimexino-stm32 \
+    serpente \
     #