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| author |   Jan Kundrát <jan.kundrat@cesnet.cz> | 2019-03-07 15:29:42 +0100 |
|---|---|---|
| committer |   Mark Brown <broonie@kernel.org> | 2019-03-18 12:18:28 +0000 |
| commit | 2ed6692e8ce924346c3aab5585b07005adb30625 (patch) | |
| tree | 9c77ba50e365714bc1d4e5cfd5dfee6382cc416b /include/uapi/linux/spi | |
| parent | spi: lpspi: Code cleanup (diff) | |
| download | wireguard-linux-2ed6692e8ce924346c3aab5585b07005adb30625.tar.xz wireguard-linux-2ed6692e8ce924346c3aab5585b07005adb30625.zip | |
spi: spidev: Enable control of inter-word delays
Commit b7bb367afa4b added support for inserting delays in between
individual words within a single SPI transaction. This makes it
accessible from userspace.
WARNING: This delay is silently ignored unless the SPI controller
implements extra support for it. This is similar to how the in-kernel
users handle the other existing property, spi_transfer->word_delay.
Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'include/uapi/linux/spi')
| -rw-r--r-- | include/uapi/linux/spi/spidev.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/uapi/linux/spi/spidev.h b/include/uapi/linux/spi/spidev.h index c4253f0090d8..ee0f2460bff6 100644 --- a/include/uapi/linux/spi/spidev.h +++ b/include/uapi/linux/spi/spidev.h @@ -66,6 +66,9 @@ * @delay_usecs: If nonzero, how long to delay after the last bit transfer * before optionally deselecting the device before the next transfer. * @cs_change: True to deselect device before starting the next transfer. + * @word_delay_usecs: If nonzero, how long to wait between words within one + * transfer. This property needs explicit support in the SPI controller, + * otherwise it is silently ignored. * * This structure is mapped directly to the kernel spi_transfer structure; * the fields have the same meanings, except of course that the pointers @@ -100,7 +103,8 @@ struct spi_ioc_transfer { __u8 cs_change; __u8 tx_nbits; __u8 rx_nbits; - __u16 pad; + __u8 word_delay_usecs; + __u8 pad; /* If the contents of 'struct spi_ioc_transfer' ever change * incompatibly, then the ioctl number (currently 0) must change; |