From dc64d39b54c1e9db97a6fb1ca52598c981728157 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 25 Feb 2014 11:40:17 +0100 Subject: spi: spidev: Add support for Dual/Quad SPI Transfers Add support for Dual/Quad SPI Transfers to the spidev API. As this uses SPI mode bits that don't fit in a single byte, two new ioctls (SPI_IOC_RD_MODE32 and SPI_IOC_WR_MODE32) are introduced. Signed-off-by: Geert Uytterhoeven Signed-off-by: Mark Brown --- Documentation/spi/spidev | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/spi') diff --git a/Documentation/spi/spidev b/Documentation/spi/spidev index ed2da5e5b28a..3d14035b1766 100644 --- a/Documentation/spi/spidev +++ b/Documentation/spi/spidev @@ -85,6 +85,12 @@ settings for data transfer parameters: SPI_MODE_0..SPI_MODE_3; or if you prefer you can combine SPI_CPOL (clock polarity, idle high iff this is set) or SPI_CPHA (clock phase, sample on trailing edge iff this is set) flags. + Note that this request is limited to SPI mode flags that fit in a + single byte. + + SPI_IOC_RD_MODE32, SPI_IOC_WR_MODE32 ... pass a pointer to a uin32_t + which will return (RD) or assign (WR) the full SPI transfer mode, + not limited to the bits that fit in one byte. SPI_IOC_RD_LSB_FIRST, SPI_IOC_WR_LSB_FIRST ... pass a pointer to a byte which will return (RD) or assign (WR) the bit justification used to -- cgit v1.2.3