1SPI_SYNC(9)             Serial Peripheral Interface (S             SPI_SYNC(9)
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NAME

6       spi_sync - blocking/synchronous SPI data transfers
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SYNOPSIS

9       int spi_sync(struct spi_device * spi, struct spi_message * message);
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ARGUMENTS

12       spi
13           device with which data will be exchanged
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15       message
16           describes the data transfers
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CONTEXT

19       can sleep
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DESCRIPTION

22       This call may only be used from a context that may sleep. The sleep is
23       non-interruptible, and has no timeout. Low-overhead controller drivers
24       may DMA directly into and out of the message buffers.
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26       Note that the SPI device's chip select is active during the message,
27       and then is normally disabled between messages. Drivers for some
28       frequently-used devices may want to minimize costs of selecting a chip,
29       by leaving it selected in anticipation that the next message will go to
30       the same chip. (That may increase power usage.)
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32       Also, the caller is guaranteeing that the memory associated with the
33       message will not be freed before this call returns.
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35       It returns zero on success, else a negative error code.
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38Kernel Hackers Manual 3.10         June 2019                       SPI_SYNC(9)
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