linux/spi/spi.h

64  *                 transfer bytes histogram
138  *	The spi_transfer.speed_hz can override this for each transfer.
145  *	each word in a transfer (by specifying SPI_LSB_FIRST).
151  *	The spi_transfer.bits_per_word can override this for each transfer.
168  *	words of a transfer
402  *	supported. If set, the SPI core will reject any transfer with an
405  * @min_speed_hz: Lowest supported transfer speed
406  * @max_speed_hz: Highest supported transfer speed
411  * @max_transfer_size: function that returns the max transfer size for
428  * @transfer: adds a message to the controller's transfer queue.
447  * @fallback: fallback to PIO if DMA transfer return failure with
460  * @max_dma_len: Maximum length of a DMA transfer for the device.
462  *	so the subsystem requests the driver to prepare the transfer hardware
464  * @transfer_one_message: the subsystem calls the driver to transfer a single
477  * @prepare_message: set up the controller to transfer a single message,
480  * @transfer_one: transfer a single spi_transfer.
482  *                  - return 0 if the transfer is finished,
483  *                  - return 1 if the transfer is still in progress. When
484  *                    the driver is finished with this transfer it must
486  *                    can issue the next transfer. If the transfer fails, the
504  * @target_abort: abort the ongoing transfer request on an SPI target controller
586 	/* Limits on transfer speed */
616 	 * On some hardware transfer / message size may be constrained
617 	 * the limit may depend on device transfer settings.
657 	 * + The transfer() method may not sleep; its main role is
674 	int			(*transfer)(struct spi_device *spi,  member
682 	 * exists and returns true then the transfer will be mapped
696 	 * controller transfer queueing mechanism. If these are used, the
697 	 * transfer() function above must NOT be specified by the driver.
738 			    struct spi_transfer *transfer);
822 /* Helper calls for driver to timestamp transfer */
929  * The spi_messages themselves consist of a series of read+write transfer
952  *      transfer. If 0 the default (from @spi_device) is used.
954  *      for this transfer. If 0 the default (from @spi_device) is used.
955  * @dummy_data: indicates transfer is dummy bytes transfer.
956  * @cs_off: performs the transfer with chipselect off.
957  * @cs_change: affects chipselect after this transfer completes
960  * @delay: delay to be introduced after this transfer before
962  *	the next transfer or completing this @spi_message.
966  *      transfer this transfer. Set to 0 if the SPI bus driver does
977  *	snapshot for this transfer begins. Upon completing the SPI transfer,
979  *	on the available snapshotting resolution (DMA transfer,
985  *	@ptp_sts_word_post to the length of the transfer. This is done
987  *	that a transfer-level snapshot taken from within the driver may still
991  *	hardware has some sort of assist for retrieving exact transfer timing,
998  * @timestamped: true if the transfer has been timestamped
1019  * When the word size of the SPI transfer is not a power-of-two multiple
1025  * it stays selected until after the last transfer in a message.  Drivers
1028  * (i) If the transfer isn't the last one in the message, this flag is
1034  * (ii) When the transfer is the last one in the message, the chip may
1035  * stay selected until the next transfer.  On multi-device SPI busses
1044  * When SPI can transfer in 1x,2x or 4x. It can get this transfer information
1046  * two should both be set. User can set transfer mode with SPI_NBITS_SINGLE(1x)
1047  * SPI_NBITS_DUAL(2x) and SPI_NBITS_QUAD(4x) to support these three transfer.
1083 #define	SPI_NBITS_SINGLE	0x01 /* 1-bit transfer */
1084 #define	SPI_NBITS_DUAL		0x02 /* 2-bit transfer */
1085 #define	SPI_NBITS_QUAD		0x04 /* 4-bit transfer */
1086 #define	SPI_NBITS_OCTAL	0x08 /* 8-bit transfer */
1108  * @transfers: list of transfer segments in this transaction
1129  * a single programmed DMA transfer.  On all systems, these messages are
1154 	 * last transfer ... allowing things like "read 16 bit length L"
1301 	/* Transfer size limit must not be greater than message size limit */  in spi_max_transfer_size()
1328  * @xfer: Transfer descriptor
1330  * Compute a relevant timeout value for the given transfer. We derive the time
1334  * Returns: Transfer timeout value in milliseconds.
1344 /* SPI transfer replacement methods which make use of spi_res */
1359  * @replaced_after:     the transfer after which the @replaced_transfers
1380 /* SPI transfer transformation methods */
1392  * All these synchronous SPI transfer routines are utilities layered
1393  * over the core async transfer primitive.  Here, "synchronous" means
1394  * they will sleep uninterruptibly until the async transfer completes.
1403  * spi_sync_transfer - synchronous SPI data transfer
1409  * Does a synchronous SPI data transfer of the given spi_transfer array.
1589  * as the default transfer wordsize) is not included here.