Commit Graph

5 Commits

Author SHA1 Message Date
Hector Palacios
95b1ed2ac7 spi: spidev_test gives error upon 1-byte transfer
The sample application spidev_test.c is using SPI_IOC_MESSAGE ioctl to do
an SPI transfer.  This ioctl returns the number of bytes successfully
transmitted or a negative error code upon erroneous completion.  The
application however is returning an error if the result of the ioclt if
the return value is 1.  This makes the application to fail upon 1-byte
length transfers.

Signed-off-by: Hector Palacios <hector.palacios@digi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-04-29 16:40:30 -06:00
Ladinu Chandrasinghe
b7ed698cc9 Documentation/: fix warnings from -Wmissing-prototypes in HOSTCFLAGS
Fix up -Wmissing-prototypes in compileable userspace code, mainly under
Documentation/.

Signed-off-by: Ladinu Chandrasinghe <ladinu.pub@gmail.com>
Signed-off-by: Trevor Keith <tsrk@tsrk.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 07:39:28 -07:00
David Brownell
b55f627fee spi: new spi->mode bits
Add two new spi_device.mode bits to accomodate more protocol options, and
pass them through to usermode drivers:

 * SPI_NO_CS ... a second 3-wire variant, where the chipselect
   line is removed instead of a data line; transfers are still
   full duplex.

   This obviously has STRONG protocol implications since the
   chipselect transitions can't be used to synchronize state
   transitions with the SPI master.

 * SPI_READY ... defines open drain signal that's pulled low
   to pause the clock.  This defines a 5-wire variant (normal
   4-wire SPI plus READY) and two 4-wire variants (READY plus
   each of the 3-wire flavors).

   Such hardware flow control can be a big win.  There are ADC
   converters and flash chips that expose READY signals, but not
   many host controllers support it today.

The spi_bitbang code should be changed to use SPI_NO_CS instead of its
current nonportable hack.  That's a mode most hardware can easily support
(unlike SPI_READY).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Paulraj, Sandeep" <s-paulraj@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-30 18:56:00 -07:00
WANG Cong
cd58310d77 Documentation/spi/spidev_test.c: constify some variables
Constify two char pointers and a struct in Documentation/spi/spidev_test.c.

Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:10 -07:00
Anton Vorontsov
22b238bdb9 spidev_test utility
This is a simple utility used to test SPI functionality.  It could stand
growing options to support using other test data patterns; this initial
version only issues full duplex transfers, which rules out 3WIRE or
Microwire links.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:40 -07:00