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 <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
This commit is contained in:
Geert Uytterhoeven
2014-02-25 11:40:17 +01:00
committed by Mark Brown
parent e6456186ca
commit dc64d39b54
3 changed files with 33 additions and 6 deletions

View File

@@ -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