include/uapi/linux/spi/spidev.h

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

File Facts

System
Linux kernel
Corpus path
include/uapi/linux/spi/spidev.h
Extension
.h
Size
4694 bytes
Lines
124
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

struct spi_ioc_transfer {
	__u64		tx_buf;
	__u64		rx_buf;

	__u32		len;
	__u32		speed_hz;

	__u16		delay_usecs;
	__u8		bits_per_word;
	__u8		cs_change;
	__u8		tx_nbits;
	__u8		rx_nbits;
	__u8		word_delay_usecs;
	__u8		pad;

	/* If the contents of 'struct spi_ioc_transfer' ever change
	 * incompatibly, then the ioctl number (currently 0) must change;
	 * ioctls with constant size fields get a bit more in the way of
	 * error checking than ones (like this) where that field varies.
	 *
	 * NOTE: struct layout is the same in 64bit and 32bit userspace.
	 */
};

/* not all platforms use <asm-generic/ioctl.h> or _IOC_TYPECHECK() ... */
#define SPI_MSGSIZE(N) \
	((((N)*(sizeof (struct spi_ioc_transfer))) < (1 << _IOC_SIZEBITS)) \
		? ((N)*(sizeof (struct spi_ioc_transfer))) : 0)
#define SPI_IOC_MESSAGE(N) _IOW(SPI_IOC_MAGIC, 0, char[SPI_MSGSIZE(N)])


/* Read / Write of SPI mode (SPI_MODE_0..SPI_MODE_3) (limited to 8 bits) */
#define SPI_IOC_RD_MODE			_IOR(SPI_IOC_MAGIC, 1, __u8)
#define SPI_IOC_WR_MODE			_IOW(SPI_IOC_MAGIC, 1, __u8)

/* Read / Write SPI bit justification */
#define SPI_IOC_RD_LSB_FIRST		_IOR(SPI_IOC_MAGIC, 2, __u8)
#define SPI_IOC_WR_LSB_FIRST		_IOW(SPI_IOC_MAGIC, 2, __u8)

/* Read / Write SPI device word length (1..N) */
#define SPI_IOC_RD_BITS_PER_WORD	_IOR(SPI_IOC_MAGIC, 3, __u8)
#define SPI_IOC_WR_BITS_PER_WORD	_IOW(SPI_IOC_MAGIC, 3, __u8)

/* Read / Write SPI device default max speed hz */
#define SPI_IOC_RD_MAX_SPEED_HZ		_IOR(SPI_IOC_MAGIC, 4, __u32)
#define SPI_IOC_WR_MAX_SPEED_HZ		_IOW(SPI_IOC_MAGIC, 4, __u32)

/* Read / Write of the SPI mode field */
#define SPI_IOC_RD_MODE32		_IOR(SPI_IOC_MAGIC, 5, __u32)
#define SPI_IOC_WR_MODE32		_IOW(SPI_IOC_MAGIC, 5, __u32)



#endif /* SPIDEV_H */

Annotation

Implementation Notes