boards/b-l475e-iot01a: Add SPI2 and SPI3 buses

[dp1]

Contribution description

This PR adds support for the missing SPI2 and SPI3 buses on the b-l4753-iot0a1 board.
SPI2 is exposed on the PMOD connector, SPI3 is used internally to communicate with the radio modules onboard

Testing procedure

SPI3 was tested by interfacing with the bluetooth module with the following code:

#include <stdio.h>

#include "clk.h"
#include "board.h"
#include "periph_conf.h"
#include "timex.h"
#include "xtimer.h"
#include "periph/gpio.h"
#include "periph/spi.h"
#include "fmt.h"

spi_t spi = SPI_DEV(2);
gpio_t cs = GPIO_PIN(PORT_D, 13);
gpio_t rst = GPIO_PIN(PORT_A, 8);
gpio_t ble_int = GPIO_PIN(PORT_E, 6);


uint8_t txbuf[256];
uint8_t rxbuf[256];
char hexbuf[256];

void ble_int_cb(void *arg) {
    (void)arg;

    puts("Interrupt called");
}

bool ble_data_present(void) {
    return gpio_read(ble_int) != 0;
}

void ble_init(void) {
    // Keep BLE in reset
    gpio_init(rst, GPIO_OUT);
    gpio_write(rst, 0);
    xtimer_usleep(5000);

    spi_init(spi);
    spi_init_cs(spi, cs);

    gpio_init_int(ble_int, GPIO_IN_PD, GPIO_RISING, ble_int_cb, NULL);
    gpio_irq_enable(ble_int);

    // Take BLE out of reset
    gpio_set(rst);
    xtimer_usleep(5000);
}

int main(void) {

    ble_init();

    txbuf[0] = 0x0A;
    txbuf[1] = 0;
    txbuf[2] = 0;
    txbuf[3] = 0;
    txbuf[4] = 0;

    while(1) {
        spi_acquire(spi, cs, SPI_MODE_0, SPI_CLK_5MHZ);
        spi_transfer_bytes(spi, cs, false, txbuf, rxbuf, 5);
        spi_release(spi);

        printf("data present: %d\n", ble_data_present());
        fmt_bytes_hex(hexbuf, txbuf, 5);
        printf("TX: %s\n", hexbuf);
        fmt_bytes_hex(hexbuf, rxbuf, 5);
        printf("RX: %s\n", hexbuf);
        puts("");

        xtimer_sleep(1);
    }
}

[aabadie]

Nice. Are you planning to write a driver for BLE ?

[dp1]

Indeed that's the plan, by adding the SPI/HCI interface used by the chip to NimBLE which seems to be quite feature rich already (and already handles another chip via SPI, so it shouldn't be too hard).

[dp1]

I added a new commit to disable the warnings about undocumented macros, just like it's done for the DMA_[0-3]_ISR macros

[aabadie]

Also you should update your last commit message to something like tools/doccheck: update exclude patterns for b-l475e-iot01a. This way we clearly know what it is about.

[aabadie]

ACK

Thanks!

[dp1]

Indeed that's the plan, by adding the SPI/HCI interface used by the chip to NimBLE which seems to be quite feature rich already (and already handles another chip via SPI, so it shouldn't be too hard).

Just as an FYI if somebody finds this PR and is looking for SPBTLE-RF support: Integrating the chip in NimBLE proved to be harder than I thought. Given the limited time I had, I ended up porting another library to RIOT, which you can find here: SPBTLE-RF-RIOT. It doesn't support all the roles, but if you need Beacon and Observer functionality it's good to go