include/uapi/linux/spi/spi.h

Source file repositories/reference/linux-study-clean/include/uapi/linux/spi/spi.h

File Facts

System
Linux kernel
Corpus path
include/uapi/linux/spi/spi.h
Extension
.h
Size
2004 bytes
Lines
45
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _UAPI_SPI_H
#define _UAPI_SPI_H

#include <linux/const.h>

#define	SPI_CPHA		_BITUL(0)	/* clock phase */
#define	SPI_CPOL		_BITUL(1)	/* clock polarity */

#define	SPI_MODE_0		(0|0)		/* (original MicroWire) */
#define	SPI_MODE_1		(0|SPI_CPHA)
#define	SPI_MODE_2		(SPI_CPOL|0)
#define	SPI_MODE_3		(SPI_CPOL|SPI_CPHA)
#define	SPI_MODE_X_MASK		(SPI_CPOL|SPI_CPHA)

#define	SPI_CS_HIGH		_BITUL(2)	/* chipselect active high? */
#define	SPI_LSB_FIRST		_BITUL(3)	/* per-word bits-on-wire */
#define	SPI_3WIRE		_BITUL(4)	/* SI/SO signals shared */
#define	SPI_LOOP		_BITUL(5)	/* loopback mode */
#define	SPI_NO_CS		_BITUL(6)	/* 1 dev/bus, no chipselect */
#define	SPI_READY		_BITUL(7)	/* slave pulls low to pause */
#define	SPI_TX_DUAL		_BITUL(8)	/* transmit with 2 wires */
#define	SPI_TX_QUAD		_BITUL(9)	/* transmit with 4 wires */
#define	SPI_RX_DUAL		_BITUL(10)	/* receive with 2 wires */
#define	SPI_RX_QUAD		_BITUL(11)	/* receive with 4 wires */
#define	SPI_CS_WORD		_BITUL(12)	/* toggle cs after each word */
#define	SPI_TX_OCTAL		_BITUL(13)	/* transmit with 8 wires */
#define	SPI_RX_OCTAL		_BITUL(14)	/* receive with 8 wires */
#define	SPI_3WIRE_HIZ		_BITUL(15)	/* high impedance turnaround */
#define	SPI_RX_CPHA_FLIP	_BITUL(16)	/* flip CPHA on Rx only xfer */
#define SPI_MOSI_IDLE_LOW	_BITUL(17)	/* leave MOSI line low when idle */
#define SPI_MOSI_IDLE_HIGH	_BITUL(18)	/* leave MOSI line high when idle */

/*
 * All the bits defined above should be covered by SPI_MODE_USER_MASK.
 * The SPI_MODE_USER_MASK has the SPI_MODE_KERNEL_MASK counterpart in
 * 'include/linux/spi/spi.h'. The bits defined here are from bit 0 upwards
 * while in SPI_MODE_KERNEL_MASK they are from the other end downwards.
 * These bits must not overlap. A static assert check should make sure of that.
 * If adding extra bits, make sure to increase the bit index below as well.
 */
#define SPI_MODE_USER_MASK	(_BITUL(19) - 1)

#endif /* _UAPI_SPI_H */

Annotation

Implementation Notes