spi_async(9) [centos man page]

SPI_ASYNC(9)						  Serial Peripheral Interface (S					      SPI_ASYNC(9)

NAME

       spi_async - asynchronous SPI transfer

SYNOPSIS

       int spi_async(struct spi_device * spi, struct spi_message * message);

ARGUMENTS

       spi
	   device with which data will be exchanged

       message
	   describes the data transfers, including completion callback

CONTEXT

       any (irqs may be blocked, etc)

DESCRIPTION

       This call may be used in_irq and other contexts which can't sleep, as well as from task contexts which can sleep.

       The completion callback is invoked in a context which can't sleep. Before that invocation, the value of message->status is undefined. When
       the callback is issued, message->status holds either zero (to indicate complete success) or a negative error code. After that callback
       returns, the driver which issued the transfer request may deallocate the associated memory; it's no longer in use by any SPI core or
       controller driver code.

       Note that although all messages to a spi_device are handled in FIFO order, messages may go to different devices in other orders. Some
       device might be higher priority, or have various "hard" access time requirements, for example.

       On detection of any fault during the transfer, processing of the entire message is aborted, and the device is deselected. Until returning
       from the associated message completion callback, no other spi_message queued to that device will be processed. (This rule applies equally
       to all the synchronous transfer calls, which are wrappers around this core asynchronous primitive.)

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014							      SPI_ASYNC(9)

STRUCT 
SPI_DRIVER(9)					  Serial Peripheral Interface (S				      STRUCT SPI_DRIVER(9)

NAME

       struct_spi_driver - Host side "protocol" driver

SYNOPSIS

       struct spi_driver {
	 const struct spi_device_id * id_table;
	 int (* probe) (struct spi_device *spi);
	 int (* remove) (struct spi_device *spi);
	 void (* shutdown) (struct spi_device *spi);
	 int (* suspend) (struct spi_device *spi, pm_message_t mesg);
	 int (* resume) (struct spi_device *spi);
	 struct device_driver driver;
       };

MEMBERS

       id_table
	   List of SPI devices supported by this driver

       probe
	   Binds this driver to the spi device. Drivers can verify that the device is actually present, and may need to configure characteristics
	   (such as bits_per_word) which weren't needed for the initial configuration done during system setup.

       remove
	   Unbinds this driver from the spi device

       shutdown
	   Standard shutdown callback used during system state transitions such as powerdown/halt and kexec

       suspend
	   Standard suspend callback used during system state transitions

       resume
	   Standard resume callback used during system state transitions

       driver
	   SPI device drivers should initialize the name and owner field of this structure.

DESCRIPTION

       This represents the kind of device driver that uses SPI messages to interact with the hardware at the other end of a SPI link. It's called
       a "protocol" driver because it works through messages rather than talking directly to SPI hardware (which is what the underlying SPI
       controller driver does to pass those messages). These protocols are defined in the specification for the device(s) supported by the driver.

       As a rule, those device protocols represent the lowest level interface supported by a driver, and it will support upper level interfaces
       too. Examples of such upper levels include frameworks like MTD, networking, MMC, RTC, filesystem character device nodes, and hardware
       monitoring.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						      STRUCT SPI_DRIVER(9)