spi: add software implementation for SPI_CS_WORD
authorDavid Lechner <david@lechnology.com>
Thu, 13 Sep 2018 00:39:18 +0000 (19:39 -0500)
committerMark Brown <broonie@kernel.org>
Mon, 17 Sep 2018 21:14:18 +0000 (14:14 -0700)
commitcbaa62e0094a840fecc853910e0c0454529cec03
tree20c73652bd2be26568a889b055befcbde7b1b7eb
parent0baf9eb25572eea0cf48249c1d152d8373956a7c
spi: add software implementation for SPI_CS_WORD

This adds a default software implementation for the SPI_CS_WORD flag for
controllers that don't have such a feature.

The SPI_CS_WORD flag indicates that the CS line should be toggled
between each word sent, not just between each transfer. The
implementation works by using existing functions to split transfers into
one-word-sized transfers and sets the cs_change bit for each of the
new transfers.

Signed-off-by: David Lechner <david@lechnology.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
drivers/spi/spi.c