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