linux/arch
Brian Niebuhr c29e3c60e7 spi: davinci: always start transmit DMA
Due to the full duplex nature of the SPI bus, the SPI master
on DaVinci needs transmit to be active even if the tranfer is
only meant to collect receive data.

The current code achieves this by using a temporary zeroed buffer
to provide DMA data in case the transfer does not have a transmit
buffer provided.

However, the transmit DMA is started only if transmit buffer is
provided rendering the temporary buffer unused. Instead the code
relies on a write to SPIDAT1 register to trigger transmit operation.
This however only sends two bytes of data.

Fix this by starting transmit DMA always.

This changes exposes a bug on DM355 where the CSHOLD bit in
SPIDAT1 needs to be written to in between transfers. Handle
that by introducing a "cshold_bug" platform data which is
set to true for DM355.

Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
2010-11-18 18:38:33 +05:30
..
alpha Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
arm spi: davinci: always start transmit DMA 2010-11-18 18:38:33 +05:30
avr32 Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
blackfin BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
cris Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
frv BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
h8300 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
ia64 SCSI host lock push-down 2010-11-16 13:33:23 -08:00
m32r Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
m68k BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
m68knommu BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
microblaze Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
mips Merge git://git.infradead.org/mtd-2.6 2010-10-30 08:31:35 -07:00
mn10300 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
parisc BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
powerpc BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
s390 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
score Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
sh Merge branches 'sh/pio-death', 'sh/nommu', 'sh/clkfwk', 'sh/core' and 'sh/intc-extension' into sh-fixes-for-linus 2010-11-08 09:42:43 +09:00
sparc BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
tile BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
um BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
x86 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
xtensa Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:16:39 -07:00
.gitignore
Kconfig jump label: Add work around to i386 gcc asm goto bug 2010-10-29 14:45:29 -04:00