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Diffstat (limited to 'cpukit/include/linux/spi/spidev.h')
-rw-r--r-- | cpukit/include/linux/spi/spidev.h | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/cpukit/include/linux/spi/spidev.h b/cpukit/include/linux/spi/spidev.h new file mode 100644 index 0000000000..e2fdb4b7e1 --- /dev/null +++ b/cpukit/include/linux/spi/spidev.h @@ -0,0 +1,268 @@ +/** + * @file + * + * @brief RTEMS Port of Linux SPI API + * + * @ingroup SPILinux + */ + +/* + * Copyright (c) 2016 embedded brains GmbH. All rights reserved. + * + * embedded brains GmbH + * Dornierstr. 4 + * 82178 Puchheim + * Germany + * <rtems@embedded-brains.de> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + +#ifndef _UAPI_LINUX_SPI_H +#define _UAPI_LINUX_SPI_H + +#include <sys/ioccom.h> +#include <stddef.h> +#include <stdint.h> + +/** + * @defgroup SPILinux Linux SPI User-Space API + * + * @ingroup SPI + * + * @brief RTEMS port of Linux SPI user-space API. + * + * Additional documentation is available through the Linux sources, see + * + * /usr/src/linux/include/uapi/linux/spidev.h. + * + * @{ + */ + +/** + * @name SPI Transfer Flags + * + * @{ + */ + +/** + * @brief SPI transfer flag which sets the clock phase. + */ +#define SPI_CPHA 0x01 + +/** + * @brief SPI transfer flag which sets the clock polarity. + */ +#define SPI_CPOL 0x02 + +/** + * @brief SPI transfer flag which sets SPI Mode 0 (clock starts low, sample on + * leading edge). + */ +#define SPI_MODE_0 0 + +/** + * @brief SPI transfer flag which sets SPI Mode 0 (clock starts low, sample on + * trailing edge). + */ +#define SPI_MODE_1 SPI_CPHA + +/** + * @brief SPI transfer flag which sets SPI Mode 0 (clock starts high, sample on + * leading edge). + */ +#define SPI_MODE_2 SPI_CPOL + +/** + * @brief SPI transfer flag which sets SPI Mode 0 (clock starts high, sample on + * trailing edge). + */ +#define SPI_MODE_3 (SPI_CPOL | SPI_CPHA) + +/** + * @brief SPI transfer flag which selects the device by setting the chip select + * line. + */ +#define SPI_CS_HIGH 0x04 + +/** + * @brief SPI transfer flag which triggers data transmission with the LSB being + * sent first. + */ +#define SPI_LSB_FIRST 0x08 + +/** + * @brief SPI transfer flag which uses a shared wire for master input/slave + * output as well as master output/slave input. + */ +#define SPI_3WIRE 0x10 + +/** + * @brief SPI transfer flag which initiates the loopback mode. + */ +#define SPI_LOOP 0x20 + +/** + * @brief SPI transfer flag which indicates that no chip select is needed due to + * only one device on the bus. + */ +#define SPI_NO_CS 0x40 + +/** + * @brief SPI transfer flag which pulls the slave to low level during pause. + */ +#define SPI_READY 0x80 + +/** + * @brief SPI transfer flag which sets up dual mode for transmission. + */ +#define SPI_TX_DUAL 0x100 + +/** + * @brief SPI transfer flag which sets up quad mode for transmission. + */ +#define SPI_TX_QUAD 0x200 + +/** + * @brief SPI transfer flag which sets up dual mode for reception. + */ +#define SPI_RX_DUAL 0x400 + +/** + * @brief SPI transfer flag which sets up quad mode for reception. + */ +#define SPI_RX_QUAD 0x800 + +/** @} */ + +#define SPI_IOC_MAGIC 's' + +/** + * @brief SPI transfer message. + */ +struct spi_ioc_transfer { + /** + * @brief Buffer for receive data. + */ + void *rx_buf; + + /** + * @brief Buffer for transmit data. + */ + const void *tx_buf; + + /** + * @brief Length of receive and transmit buffers in bytes. + */ + size_t len; + + /** + * @brief Sets the bit-rate of the device. + */ + uint32_t speed_hz; + + /** + * @brief Sets the delay after a transfer before the chip select status is + * changed and the next transfer is triggered. + */ + uint16_t delay_usecs; + + /** + * @brief Sets the device wordsize. + */ + uint8_t bits_per_word; + + /** + * @brief If true, device is deselected after transfer ended and before a new + * transfer is started. + */ + uint8_t cs_change; + + /** + * @brief Amount of bits that are used for reading. + */ + uint8_t rx_nbits; + + /** + * @brief Amount of bits that are used for writing. + */ + uint8_t tx_nbits; + + /** + * @brief Sets one of the possible modes that can be used for SPI transfers + * (dependent on clock phase and polarity). + */ + uint32_t mode; + + /** + * @brief Indicates which device is currently used. + */ + uint8_t cs; +}; + +/** + * @brief Calculates the size of the SPI message array. + */ +#define SPI_MSGSIZE(n) \ + (((n) * sizeof(struct spi_ioc_transfer) < IOCPARM_MAX) ? \ + (n) * sizeof(struct spi_ioc_transfer) : 0) + +/** + * @brief Transfers an array with SPI messages. + */ +#define SPI_IOC_MESSAGE(n) _IOW(SPI_IOC_MAGIC, 0, char[SPI_MSGSIZE(n)]) + +/** + * @brief Reads the least-significant 8-bits of the SPI default mode. + */ +#define SPI_IOC_RD_MODE _IOR(SPI_IOC_MAGIC, 1, uint8_t) + +/** + * @brief Writes the SPI default mode (the most-significant 24-bits of the mode are + * set to zero). + */ +#define SPI_IOC_WR_MODE _IOW(SPI_IOC_MAGIC, 1, uint8_t) + +/** + * @brief Reads the SPI default least-significant bit first setting. + */ +#define SPI_IOC_RD_LSB_FIRST _IOR(SPI_IOC_MAGIC, 2, uint8_t) + +/** + * @brief Writes the SPI default least-significant-bit first setting. + */ +#define SPI_IOC_WR_LSB_FIRST _IOW(SPI_IOC_MAGIC, 2, uint8_t) + +/** + * @brief Reads the SPI default bits per word. + */ +#define SPI_IOC_RD_BITS_PER_WORD _IOR(SPI_IOC_MAGIC, 3, uint8_t) + +/** + * @brief Writes the SPI default bits per word. + */ +#define SPI_IOC_WR_BITS_PER_WORD _IOW(SPI_IOC_MAGIC, 3, uint8_t) + +/** + * @brief Reads the SPI default speed in Hz. + */ +#define SPI_IOC_RD_MAX_SPEED_HZ _IOR(SPI_IOC_MAGIC, 4, uint32_t) + +/** + * @brief Writes the SPI default speed in Hz. + */ +#define SPI_IOC_WR_MAX_SPEED_HZ _IOW(SPI_IOC_MAGIC, 4, uint32_t) + +/** + * @brief Reads the full 32-bit SPI default mode. + */ +#define SPI_IOC_RD_MODE32 _IOR(SPI_IOC_MAGIC, 5, uint32_t) + +/** + * @brief Writes the full 32-bit SPI default mode. + */ +#define SPI_IOC_WR_MODE32 _IOW(SPI_IOC_MAGIC, 5, uint32_t) + +#endif /* _UAPI_LINUX_SPI_H */ |