ee63d39058
* Move default config to .c file * Explicitly define PAL modes for boards with custom init * Unify spi_master headers
116 lines
3.5 KiB
C
116 lines
3.5 KiB
C
// Copyright 2025 QMK
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// SPDX-License-Identifier: GPL-2.0-or-later
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#pragma once
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#include <stdint.h>
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#include <stdbool.h>
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#include "gpio.h"
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/**
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* \file
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*
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* \defgroup spi_master SPI Master API
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*
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* \brief API to communicate with SPI devices.
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* \{
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*/
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// Hardware SS pin is defined in the header so that user code can refer to it
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#ifdef __AVR__
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# if defined(__AVR_AT90USB162__) || defined(__AVR_ATmega16U2__) || defined(__AVR_ATmega32U2__) || defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__)
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# define SPI_SS_PIN B0
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# elif defined(__AVR_ATmega32A__)
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# define SPI_SS_PIN B4
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# elif defined(__AVR_ATmega328P__) || defined(__AVR_ATmega328__)
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# define SPI_SS_PIN B2
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# endif
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#endif
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typedef int16_t spi_status_t;
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#define SPI_STATUS_SUCCESS (0)
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#define SPI_STATUS_ERROR (-1)
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#define SPI_STATUS_TIMEOUT (-2)
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#define SPI_TIMEOUT_IMMEDIATE (0)
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#define SPI_TIMEOUT_INFINITE (0xFFFF)
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#ifdef __cplusplus
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extern "C" {
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#endif
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typedef struct spi_start_config_t {
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pin_t slave_pin;
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bool lsb_first;
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uint8_t mode;
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uint16_t divisor;
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bool cs_active_low;
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} spi_start_config_t;
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/**
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* \brief Initialize the SPI driver. This function must be called only once, before any of the below functions can be called.
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*/
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void spi_init(void);
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/**
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* \brief Start an SPI transaction.
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*
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* \param slavePin The GPIO pin connected to the desired device's `SS` line.
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* \param lsbFirst Determines the endianness of the transmission. If `true`, the least significant bit of each byte is sent first.
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* \param mode The SPI mode to use.
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* \param divisor The SPI clock divisor.
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*
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* \return `true` if the operation was successful, otherwise `false` if the supplied parameters are invalid or the SPI peripheral is already in use.
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*/
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bool spi_start(pin_t slavePin, bool lsbFirst, uint8_t mode, uint16_t divisor);
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bool spi_start_extended(spi_start_config_t *start_config);
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/**
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* \brief Write a byte to the selected SPI device.
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*
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* \param data The byte to write.
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*
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* \return `SPI_STATUS_TIMEOUT` if the timeout period elapses, or `SPI_STATUS_SUCCESS`.
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*/
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spi_status_t spi_write(uint8_t data);
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/**
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* \brief Read a byte from the selected SPI device.
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*
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* \return `SPI_STATUS_TIMEOUT` if the timeout period elapses, otherwise the byte read from the device.
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*/
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spi_status_t spi_read(void);
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/**
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* \brief Send multiple bytes to the selected SPI device.
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*
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* \param data A pointer to the data to write from.
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* \param length The number of bytes to write. Take care not to overrun the length of `data`.
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*
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* \return `SPI_STATUS_TIMEOUT` if the timeout period elapses, `SPI_STATUS_ERROR` if some other error occurs, otherwise `SPI_STATUS_SUCCESS`.
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*/
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spi_status_t spi_transmit(const uint8_t *data, uint16_t length);
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/**
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* \brief Receive multiple bytes from the selected SPI device.
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*
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* \param data A pointer to a buffer to read into.
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* \param length The number of bytes to read. Take care not to overrun the length of `data`.
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*
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* \return `SPI_STATUS_TIMEOUT` if the timeout period elapses, `SPI_STATUS_ERROR` if some other error occurs, otherwise `SPI_STATUS_SUCCESS`.
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*/
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spi_status_t spi_receive(uint8_t *data, uint16_t length);
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/**
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* \brief End the current SPI transaction. This will deassert the slave select pin and reset the endianness, mode and divisor configured by `spi_start()`.
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*
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*/
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void spi_stop(void);
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#ifdef __cplusplus
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}
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#endif
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/** \} */
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