spi: document the transfer_one spi_master callback (18cc0adb) · Commits · e / devices / android_kernel_teracube_emerald

Documentation/spi/spi-summary

+15 −0

Original line number	Original line	Diff line number	Diff line
	@@ -545,6 +545,21 @@ SPI MASTER METHODS
	spi_finalize_current_message() so the subsystem can issue the next		spi_finalize_current_message() so the subsystem can issue the next
	transfer. This may sleep.		transfer. This may sleep.

			master->transfer_one(struct spi_master master, struct spi_device spi,
			struct spi_transfer *transfer)
			The subsystem calls the driver to transfer a single transfer while
			queuing transfers that arrive in the meantime. When the driver is
			finished with this transfer, it must call
			spi_finalize_current_transfer() so the subsystem can issue the next
			transfer. This may sleep. Note: transfer_one and transfer_one_message
			are mutually exclusive; when both are set, the generic subsystem does
			not call your transfer_one callback.

			Return values:
			negative errno: error
			0: transfer is finished
			1: transfer is still in progress

	DEPRECATED METHODS		DEPRECATED METHODS

	master->transfer(struct spi_device spi, struct spi_message message)		master->transfer(struct spi_device spi, struct spi_message message)