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stm32/spi: Add implementation of low-level SPI protocol.

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Can be used, for example, to configure external SPI flash using a hardware
SPI interface (code to be put in a board's bdev.c file):

    STATIC const spi_proto_cfg_t hard_spi_bus = {
        .spi = &spi_obj[5],
        .baudrate = 10000000,
        .polarity = 0,
        .phase = 0,
        .bits = 8,
        .firstbit = SPI_FIRSTBIT_MSB,
    };

    STATIC mp_spiflash_cache_t spi_bdev_cache;

    const mp_spiflash_config_t spiflash_config = {
        .bus_kind = MP_SPIFLASH_BUS_SPI,
        .bus.u_spi.cs = pin_A0,
        .bus.u_spi.data = (void*)&hard_spi_bus,
        .bus.u_spi.proto = &spi_proto,
        .cache = &spi_bdev_cache,
    };

    spi_bdev_t spi_bdev;
This commit is contained in:
Damien George 2018-08-14 22:05:20 +10:00
parent 01ce2e1682
commit 056e0b6293
2 changed files with 42 additions and 0 deletions
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31
ports/stm32/spi.c
View File

@ -563,3 +563,34 @@ const spi_t *spi_from_mp_obj(mp_obj_t o) {
mp_raise_TypeError("expecting an SPI object");
}
}
/******************************************************************************/
// Implementation of low-level SPI C protocol
STATIC int spi_proto_ioctl(void *self_in, uint32_t cmd) {
spi_proto_cfg_t *self = (spi_proto_cfg_t*)self_in;
switch (cmd) {
case MP_SPI_IOCTL_INIT:
spi_set_params(self->spi, 0xffffffff, self->baudrate,
self->polarity, self->phase, self->bits, self->firstbit);
spi_init(self->spi, false);
break;
case MP_SPI_IOCTL_DEINIT:
spi_deinit(self->spi);
break;
}
return 0;
}
STATIC void spi_proto_transfer(void *self_in, size_t len, const uint8_t *src, uint8_t *dest) {
spi_proto_cfg_t *self = (spi_proto_cfg_t*)self_in;
spi_transfer(self->spi, len, src, dest, SPI_TRANSFER_TIMEOUT(len));
}
const mp_spi_proto_t spi_proto = {
.ioctl = spi_proto_ioctl,
.transfer = spi_proto_transfer,
};

11
ports/stm32/spi.h
View File

@ -26,6 +26,7 @@
#ifndef MICROPY_INCLUDED_STM32_SPI_H
#define MICROPY_INCLUDED_STM32_SPI_H
#include "drivers/bus/spi.h"
#include "dma.h"
typedef struct _spi_t {
@ -34,6 +35,15 @@ typedef struct _spi_t {
const dma_descr_t *rx_dma_descr;
} spi_t;
typedef struct _spi_proto_cfg_t {
const spi_t *spi;
uint32_t baudrate;
uint8_t polarity;
uint8_t phase;
uint8_t bits;
uint8_t firstbit;
} spi_proto_cfg_t;
typedef struct _pyb_spi_obj_t {
mp_obj_base_t base;
const spi_t *spi;
@ -53,6 +63,7 @@ extern SPI_HandleTypeDef SPIHandle6;
extern const spi_t spi_obj[6];
extern const mp_spi_proto_t spi_proto;
extern const mp_obj_type_t pyb_spi_type;
extern const mp_obj_type_t machine_soft_spi_type;
extern const mp_obj_type_t machine_hard_spi_type;