| /* ST Microelectronics STMEMS hal i/f |
| * |
| * Copyright (c) 2021 STMicroelectronics |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * zephyrproject-rtos/modules/hal/st/sensor/stmemsc/ |
| */ |
| |
| #include "stmemsc.h" |
| |
| #define SPI_READ (1 << 7) |
| |
| /* |
| * SPI read |
| */ |
| int stmemsc_spi_read(const struct spi_dt_spec *stmemsc, |
| uint8_t reg_addr, uint8_t *value, uint8_t len) |
| { |
| uint8_t buffer_tx[2] = { reg_addr | SPI_READ, 0 }; |
| |
| /* write 1 byte with reg addr (msb at 1) + 1 dummy byte */ |
| const struct spi_buf tx_buf = { .buf = buffer_tx, .len = 2, }; |
| const struct spi_buf_set tx = { .buffers = &tx_buf, .count = 1 }; |
| |
| /* |
| * transaction #1: dummy read to skip first byte |
| * transaction #2: read "len" byte of data |
| */ |
| const struct spi_buf rx_buf[2] = { |
| { .buf = NULL, .len = 1, }, |
| { .buf = value, .len = len, } |
| }; |
| const struct spi_buf_set rx = { .buffers = rx_buf, .count = 2 }; |
| |
| return spi_transceive_dt(stmemsc, &tx, &rx); |
| } |
| |
| /* |
| * SPI write |
| */ |
| int stmemsc_spi_write(const struct spi_dt_spec *stmemsc, |
| uint8_t reg_addr, uint8_t *value, uint8_t len) |
| { |
| uint8_t buffer_tx[1] = { reg_addr & ~SPI_READ }; |
| |
| /* |
| * transaction #1: write 1 byte with reg addr (msb at 0) |
| * transaction #2: write "len" byte of data |
| */ |
| const struct spi_buf tx_buf[2] = { |
| { .buf = buffer_tx, .len = 1, }, |
| { .buf = value, .len = len, } |
| }; |
| const struct spi_buf_set tx = { .buffers = tx_buf, .count = 2 }; |
| |
| return spi_write_dt(stmemsc, &tx); |
| } |