blob: 0bab9029f3323feb3469ca9483c69df8adfcc623 [file] [log] [blame]
/*
* Copyright (c) 2022 Nordic Semiconductor ASA
*
* SPDX-License-Identifier: Apache-2.0
*/
/*
* Bus-specific functionality for BMI270s accessed via SPI.
*/
#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
#include "bmi270.h"
LOG_MODULE_DECLARE(bmi270, CONFIG_SENSOR_LOG_LEVEL);
static int bmi270_bus_check_spi(const union bmi270_bus *bus)
{
return spi_is_ready_dt(&bus->spi) ? 0 : -ENODEV;
}
static int bmi270_reg_read_spi(const union bmi270_bus *bus,
uint8_t start, uint8_t *data, uint16_t len)
{
int ret;
uint8_t addr;
uint8_t tmp[2];
const struct spi_buf tx_buf = {
.buf = &addr,
.len = 1
};
const struct spi_buf_set tx = {
.buffers = &tx_buf,
.count = 1
};
struct spi_buf rx_buf[2];
const struct spi_buf_set rx = {
.buffers = rx_buf,
.count = ARRAY_SIZE(rx_buf)
};
/* First byte we read should be discarded. */
rx_buf[0].buf = &tmp;
rx_buf[0].len = 2;
rx_buf[1].len = len;
rx_buf[1].buf = data;
addr = start | 0x80;
ret = spi_transceive_dt(&bus->spi, &tx, &rx);
if (ret < 0) {
LOG_DBG("spi_transceive failed %i", ret);
return ret;
}
k_usleep(BMI270_SPI_ACC_DELAY_US);
return 0;
}
static int bmi270_reg_write_spi(const union bmi270_bus *bus, uint8_t start,
const uint8_t *data, uint16_t len)
{
int ret;
uint8_t addr;
const struct spi_buf tx_buf[2] = {
{.buf = &addr, .len = sizeof(addr)},
{.buf = (uint8_t *)data, .len = len}
};
const struct spi_buf_set tx = {
.buffers = tx_buf,
.count = ARRAY_SIZE(tx_buf)
};
addr = start & BMI270_REG_MASK;
ret = spi_write_dt(&bus->spi, &tx);
if (ret < 0) {
LOG_ERR("spi_write_dt failed %i", ret);
return ret;
}
k_usleep(BMI270_SPI_ACC_DELAY_US);
return 0;
}
static int bmi270_bus_init_spi(const union bmi270_bus *bus)
{
uint8_t tmp;
/* Single read of SPI initializes the chip to SPI mode
*/
return bmi270_reg_read_spi(bus, BMI270_REG_CHIP_ID, &tmp, 1);
}
const struct bmi270_bus_io bmi270_bus_io_spi = {
.check = bmi270_bus_check_spi,
.read = bmi270_reg_read_spi,
.write = bmi270_reg_write_spi,
.init = bmi270_bus_init_spi,
};