mirror of https://github.com/qmk/qmk_firmware
259 lines
9.2 KiB
C
259 lines
9.2 KiB
C
/*
|
|
LUFA Library
|
|
Copyright (C) Dean Camera, 2017.
|
|
|
|
dean [at] fourwalledcubicle [dot] com
|
|
www.lufa-lib.org
|
|
*/
|
|
|
|
/*
|
|
Copyright 2017 Dean Camera (dean [at] fourwalledcubicle [dot] com)
|
|
|
|
Permission to use, copy, modify, distribute, and sell this
|
|
software and its documentation for any purpose is hereby granted
|
|
without fee, provided that the above copyright notice appear in
|
|
all copies and that both that the copyright notice and this
|
|
permission notice and warranty disclaimer appear in supporting
|
|
documentation, and that the name of the author not be used in
|
|
advertising or publicity pertaining to distribution of the
|
|
software without specific, written prior permission.
|
|
|
|
The author disclaims all warranties with regard to this
|
|
software, including all implied warranties of merchantability
|
|
and fitness. In no event shall the author be liable for any
|
|
special, indirect or consequential damages or any damages
|
|
whatsoever resulting from loss of use, data or profits, whether
|
|
in an action of contract, negligence or other tortious action,
|
|
arising out of or in connection with the use or performance of
|
|
this software.
|
|
*/
|
|
|
|
/** \file
|
|
* \brief SPI Peripheral Driver (AVR8)
|
|
*
|
|
* On-chip SPI driver for the 8-bit AVR microcontrollers.
|
|
*
|
|
* \note This file should not be included directly. It is automatically included as needed by the SPI driver
|
|
* dispatch header located in LUFA/Drivers/Peripheral/SPI.h.
|
|
*/
|
|
|
|
/** \ingroup Group_SPI
|
|
* \defgroup Group_SPI_AVR8 SPI Peripheral Driver (AVR8)
|
|
*
|
|
* \section Sec_SPI_AVR8_ModDescription Module Description
|
|
* Driver for the hardware SPI port available on most 8-bit AVR microcontroller models. This
|
|
* module provides an easy to use driver for the setup and transfer of data over the
|
|
* AVR's SPI port.
|
|
*
|
|
* \note This file should not be included directly. It is automatically included as needed by the SPI driver
|
|
* dispatch header located in LUFA/Drivers/Peripheral/SPI.h.
|
|
*
|
|
* \section Sec_SPI_AVR8_ExampleUsage Example Usage
|
|
* The following snippet is an example of how this module may be used within a typical
|
|
* application.
|
|
*
|
|
* \code
|
|
* // Initialize the SPI driver before first use
|
|
* SPI_Init(SPI_SPEED_FCPU_DIV_2 | SPI_ORDER_MSB_FIRST | SPI_SCK_LEAD_FALLING |
|
|
* SPI_SAMPLE_TRAILING | SPI_MODE_MASTER);
|
|
*
|
|
* // Send several bytes, ignoring the returned data
|
|
* SPI_SendByte(0x01);
|
|
* SPI_SendByte(0x02);
|
|
* SPI_SendByte(0x03);
|
|
*
|
|
* // Receive several bytes, sending a dummy 0x00 byte each time
|
|
* uint8_t Byte1 = SPI_ReceiveByte();
|
|
* uint8_t Byte2 = SPI_ReceiveByte();
|
|
* uint8_t Byte3 = SPI_ReceiveByte();
|
|
*
|
|
* // Send a byte, and store the received byte from the same transaction
|
|
* uint8_t ResponseByte = SPI_TransferByte(0xDC);
|
|
* \endcode
|
|
*
|
|
* @{
|
|
*/
|
|
|
|
#ifndef __SPI_AVR8_H__
|
|
#define __SPI_AVR8_H__
|
|
|
|
/* Includes: */
|
|
#include "../../../Common/Common.h"
|
|
|
|
/* Enable C linkage for C++ Compilers: */
|
|
#if defined(__cplusplus)
|
|
extern "C" {
|
|
#endif
|
|
|
|
/* Preprocessor Checks: */
|
|
#if !defined(__INCLUDE_FROM_SPI_H)
|
|
#error Do not include this file directly. Include LUFA/Drivers/Peripheral/SPI.h instead.
|
|
#endif
|
|
|
|
/* Private Interface - For use in library only: */
|
|
#if !defined(__DOXYGEN__)
|
|
/* Macros: */
|
|
#define SPI_USE_DOUBLESPEED (1 << SPE)
|
|
#endif
|
|
|
|
/* Public Interface - May be used in end-application: */
|
|
/* Macros: */
|
|
/** \name SPI Prescaler Configuration Masks */
|
|
//@{
|
|
/** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 2. */
|
|
#define SPI_SPEED_FCPU_DIV_2 SPI_USE_DOUBLESPEED
|
|
|
|
/** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 4. */
|
|
#define SPI_SPEED_FCPU_DIV_4 0
|
|
|
|
/** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 8. */
|
|
#define SPI_SPEED_FCPU_DIV_8 (SPI_USE_DOUBLESPEED | (1 << SPR0))
|
|
|
|
/** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 16. */
|
|
#define SPI_SPEED_FCPU_DIV_16 (1 << SPR0)
|
|
|
|
/** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 32. */
|
|
#define SPI_SPEED_FCPU_DIV_32 (SPI_USE_DOUBLESPEED | (1 << SPR1))
|
|
|
|
/** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 64. */
|
|
#define SPI_SPEED_FCPU_DIV_64 (SPI_USE_DOUBLESPEED | (1 << SPR1) | (1 << SPR0))
|
|
|
|
/** SPI prescaler mask for \ref SPI_Init(). Divides the system clock by a factor of 128. */
|
|
#define SPI_SPEED_FCPU_DIV_128 ((1 << SPR1) | (1 << SPR0))
|
|
//@}
|
|
|
|
/** \name SPI SCK Polarity Configuration Masks */
|
|
//@{
|
|
/** SPI clock polarity mask for \ref SPI_Init(). Indicates that the SCK should lead on the rising edge. */
|
|
#define SPI_SCK_LEAD_RISING (0 << CPOL)
|
|
|
|
/** SPI clock polarity mask for \ref SPI_Init(). Indicates that the SCK should lead on the falling edge. */
|
|
#define SPI_SCK_LEAD_FALLING (1 << CPOL)
|
|
//@}
|
|
|
|
/** \name SPI Sample Edge Configuration Masks */
|
|
//@{
|
|
/** SPI data sample mode mask for \ref SPI_Init(). Indicates that the data should sampled on the leading edge. */
|
|
#define SPI_SAMPLE_LEADING (0 << CPHA)
|
|
|
|
/** SPI data sample mode mask for \ref SPI_Init(). Indicates that the data should be sampled on the trailing edge. */
|
|
#define SPI_SAMPLE_TRAILING (1 << CPHA)
|
|
//@}
|
|
|
|
/** \name SPI Data Ordering Configuration Masks */
|
|
//@{
|
|
/** SPI data order mask for \ref SPI_Init(). Indicates that data should be shifted out MSB first. */
|
|
#define SPI_ORDER_MSB_FIRST (0 << DORD)
|
|
|
|
/** SPI data order mask for \ref SPI_Init(). Indicates that data should be shifted out LSB first. */
|
|
#define SPI_ORDER_LSB_FIRST (1 << DORD)
|
|
//@}
|
|
|
|
/** \name SPI Mode Configuration Masks */
|
|
//@{
|
|
/** SPI mode mask for \ref SPI_Init(). Indicates that the SPI interface should be initialized into slave mode. */
|
|
#define SPI_MODE_SLAVE (0 << MSTR)
|
|
|
|
/** SPI mode mask for \ref SPI_Init(). Indicates that the SPI interface should be initialized into master mode. */
|
|
#define SPI_MODE_MASTER (1 << MSTR)
|
|
//@}
|
|
|
|
/* Inline Functions: */
|
|
/** Initializes the SPI subsystem, ready for transfers. Must be called before calling any other
|
|
* SPI routines.
|
|
*
|
|
* \param[in] SPIOptions SPI Options, a mask consisting of one of each of the \c SPI_SPEED_*,
|
|
* \c SPI_SCK_*, \c SPI_SAMPLE_*, \c SPI_ORDER_* and \c SPI_MODE_* masks.
|
|
*/
|
|
static inline void SPI_Init(const uint8_t SPIOptions);
|
|
static inline void SPI_Init(const uint8_t SPIOptions)
|
|
{
|
|
/* Prevent high rise times on PB.0 (/SS) from forcing a change to SPI slave mode */
|
|
DDRB |= (1 << 0);
|
|
PORTB |= (1 << 0);
|
|
|
|
DDRB |= ((1 << 1) | (1 << 2));
|
|
DDRB &= ~(1 << 3);
|
|
PORTB |= (1 << 3);
|
|
|
|
if (SPIOptions & SPI_USE_DOUBLESPEED)
|
|
SPSR |= (1 << SPI2X);
|
|
else
|
|
SPSR &= ~(1 << SPI2X);
|
|
|
|
/* Switch /SS to input mode after configuration to allow for forced mode changes */
|
|
DDRB &= ~(1 << 0);
|
|
|
|
SPCR = ((1 << SPE) | SPIOptions);
|
|
}
|
|
|
|
/** Turns off the SPI driver, disabling and returning used hardware to their default configuration. */
|
|
static inline void SPI_Disable(void);
|
|
static inline void SPI_Disable(void)
|
|
{
|
|
DDRB &= ~((1 << 1) | (1 << 2));
|
|
PORTB &= ~((1 << 0) | (1 << 3));
|
|
|
|
SPCR = 0;
|
|
SPSR = 0;
|
|
}
|
|
|
|
/** Retrieves the currently selected SPI mode, once the SPI interface has been configured.
|
|
*
|
|
* \return \ref SPI_MODE_MASTER if the interface is currently in SPI Master mode, \ref SPI_MODE_SLAVE otherwise
|
|
*/
|
|
static inline uint8_t SPI_GetCurrentMode(void) ATTR_ALWAYS_INLINE;
|
|
static inline uint8_t SPI_GetCurrentMode(void)
|
|
{
|
|
return (SPCR & SPI_MODE_MASTER);
|
|
}
|
|
|
|
/** Sends and receives a byte through the SPI interface, blocking until the transfer is complete.
|
|
*
|
|
* \param[in] Byte Byte to send through the SPI interface.
|
|
*
|
|
* \return Response byte from the attached SPI device.
|
|
*/
|
|
static inline uint8_t SPI_TransferByte(const uint8_t Byte) ATTR_ALWAYS_INLINE;
|
|
static inline uint8_t SPI_TransferByte(const uint8_t Byte)
|
|
{
|
|
SPDR = Byte;
|
|
while (!(SPSR & (1 << SPIF)));
|
|
return SPDR;
|
|
}
|
|
|
|
/** Sends a byte through the SPI interface, blocking until the transfer is complete. The response
|
|
* byte sent to from the attached SPI device is ignored.
|
|
*
|
|
* \param[in] Byte Byte to send through the SPI interface.
|
|
*/
|
|
static inline void SPI_SendByte(const uint8_t Byte) ATTR_ALWAYS_INLINE;
|
|
static inline void SPI_SendByte(const uint8_t Byte)
|
|
{
|
|
SPDR = Byte;
|
|
while (!(SPSR & (1 << SPIF)));
|
|
}
|
|
|
|
/** Sends a dummy byte through the SPI interface, blocking until the transfer is complete. The response
|
|
* byte from the attached SPI device is returned.
|
|
*
|
|
* \return The response byte from the attached SPI device.
|
|
*/
|
|
static inline uint8_t SPI_ReceiveByte(void) ATTR_ALWAYS_INLINE ATTR_WARN_UNUSED_RESULT;
|
|
static inline uint8_t SPI_ReceiveByte(void)
|
|
{
|
|
SPDR = 0x00;
|
|
while (!(SPSR & (1 << SPIF)));
|
|
return SPDR;
|
|
}
|
|
|
|
/* Disable C linkage for C++ Compilers: */
|
|
#if defined(__cplusplus)
|
|
}
|
|
#endif
|
|
|
|
#endif
|
|
|
|
/** @} */
|
|
|