linux/spi/spi.h

50  *                 transfer bytes histogramm
116  *	The spi_transfer.speed_hz can override this for each transfer.
122  *	each word in a transfer (by specifying SPI_LSB_FIRST).
128  *	The spi_transfer.bits_per_word can override this for each transfer.
146  *	words of a transfer
335  *	supported. If set, the SPI core will reject any transfer with an
338  * @min_speed_hz: Lowest supported transfer speed
339  * @max_speed_hz: Highest supported transfer speed
342  * @max_transfer_size: function that returns the max transfer size for
358  * @transfer: adds a message to the controller's transfer queue.
380  * @max_dma_len: Maximum length of a DMA transfer for the device.
382  *	so the subsystem requests the driver to prepare the transfer hardware
384  * @transfer_one_message: the subsystem calls the driver to transfer a single
395  * @prepare_message: set up the controller to transfer a single message,
398  * @transfer_one: transfer a single spi_transfer.
400  *                  - return 0 if the transfer is finished,
401  *                  - return 1 if the transfer is still in progress. When
402  *                    the driver is finished with this transfer it must
404  *                    can issue the next transfer. Note: transfer_one and
414  * @slave_abort: abort the ongoing transfer request on an SPI slave controller
452  * @fallback: fallback to pio if dma transfer return failure with
500 	/* limits on transfer speed */
518 	 * on some hardware transfer / message size may be constrained
519 	 * the limit may depend on device transfer settings
555 	 * + The transfer() method may not sleep; its main role is
572 	int			(*transfer)(struct spi_device *spi,  member
580 	 * exists and returns true then the transfer will be mapped
591 	 * controller transfer queueing mechanism. If these are used, the
592 	 * transfer() function above must NOT be specified by the driver.
630 			    struct spi_transfer *transfer);
710 /* Helper calls for driver to timestamp transfer */
803  * The spi_messages themselves consist of a series of read+write transfer
826  *      transfer. If 0 the default (from @spi_device) is used.
828  *      for this transfer. If 0 the default (from @spi_device) is used.
829  * @cs_change: affects chipselect after this transfer completes
832  * @delay: delay to be introduced after this transfer before
834  *	the next transfer or completing this @spi_message.
835  * @delay_usecs: microseconds to delay after this transfer before
837  *	the next transfer or completing this @spi_message.
841  *      transfer this transfer. Set to 0 if the spi bus driver does
848  *	snapshot for this transfer begins. Upon completing the SPI transfer,
850  *	on the available snapshotting resolution (DMA transfer,
856  *	@ptp_sts_word_post to the length of the transfer. This is done
858  *	that a transfer-level snapshot taken from within the driver may still
862  *	hardware has some sort of assist for retrieving exact transfer timing,
869  * @timestamped: true if the transfer has been timestamped
890  * When the word size of the SPI transfer is not a power-of-two multiple
896  * it stays selected until after the last transfer in a message.  Drivers
899  * (i) If the transfer isn't the last one in the message, this flag is
905  * (ii) When the transfer is the last one in the message, the chip may
906  * stay selected until the next transfer.  On multi-device SPI busses
915  * When SPI can transfer in 1x,2x or 4x. It can get this transfer information
917  * two should both be set. User can set transfer mode with SPI_NBITS_SINGLE(1x)
918  * SPI_NBITS_DUAL(2x) and SPI_NBITS_QUAD(4x) to support these three transfer.
944 #define	SPI_NBITS_SINGLE	0x01 /* 1bit transfer */
945 #define	SPI_NBITS_DUAL		0x02 /* 2bits transfer */
946 #define	SPI_NBITS_QUAD		0x04 /* 4bits transfer */
971  * @transfers: list of transfer segments in this transaction
974  *	addresses for each transfer buffer
989  * a single programmed DMA transfer.  On all systems, these messages are
1007 	 * last transfer ... allowing things like "read 16 bit length L"
1151 	/* transfer size limit must not be greater than messsage size limit */  in spi_max_transfer_size()
1177 /* SPI transfer replacement methods which make use of spi_res */
1192  * @replaced_after:     the transfer after which the @replaced_transfers
1222 /* SPI transfer transformation methods */
1231 /* All these synchronous SPI transfer routines are utilities layered
1232  * over the core async transfer primitive.  Here, "synchronous" means
1233  * they will sleep uninterruptibly until the async transfer completes.
1242  * spi_sync_transfer - synchronous SPI data transfer
1248  * Does a synchronous SPI data transfer of the given spi_transfer array.
1428  * as the default transfer wordsize) is not included here.