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struct_spi_message(9) [centos man page]

SPI_MESSAGE(9) Serial Peripheral Interface (S STRUCT SPI_MESSAGE(9) NAME
struct_spi_message - one multi-segment SPI transaction SYNOPSIS
struct spi_message { struct list_head transfers; struct spi_device * spi; unsigned is_dma_mapped:1; void (* complete) (void *context); void * context; unsigned actual_length; int status; struct list_head queue; void * state; }; MEMBERS
transfers list of transfer segments in this transaction spi SPI device to which the transaction is queued is_dma_mapped if true, the caller provided both dma and cpu virtual addresses for each transfer buffer complete called to report transaction completions context the argument to complete when it's called actual_length the total number of bytes that were transferred in all successful segments status zero for success, else negative errno queue for use by whichever driver currently owns the message state for use by whichever driver currently owns the message DESCRIPTION
A spi_message is used to execute an atomic sequence of data transfers, each represented by a struct spi_transfer. The sequence is "atomic" in the sense that no other spi_message may use that SPI bus until that sequence completes. On some systems, many such sequences can execute as as single programmed DMA transfer. On all systems, these messages are queued, and might complete after transactions to other devices. Messages sent to a given spi_device are alway executed in FIFO order. The code that submits an spi_message (and its spi_transfers) to the lower layers is responsible for managing its memory. Zero-initialize every field you don't set up explicitly, to insulate against future API updates. After you submit a message and its transfers, ignore them until its completion callback. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 STRUCT SPI_MESSAGE(9)

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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)
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