]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
Blackfin SPI Driver: Make mmc_spi driver work on Blackfin
authorWolfgang Muees <wolfgang.mues@auerswald.de>
Tue, 7 Apr 2009 02:00:53 +0000 (19:00 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 7 Apr 2009 15:31:06 +0000 (08:31 -0700)
commit93b61bddc13d9acf1fe341b39d826e80f3182d1e
tree54a5b574ada4b619a9cba845bee1e4205d62176c
parent42c78b2bf51bafb4cfa98dfecc28dd9b8bcd04b0
Blackfin SPI Driver: Make mmc_spi driver work on Blackfin

1. Rewrite of the non-dma data transfer functions to use only ONE mode
   of TIMOD (TIMOD=0x1).  With TIMOD=0, it was not possible to set the TX
   bit pattern.  So the TDBR = 0xFFFF inside the read calls won't work.

2. Clear SPI_RDBR before reading and before duplex transfer.
   Otherwise the garbage data in RDBR will get read.  Since mmc_spi uses a
   lot of duplex transfers, this is the main cause of mmc_spi failure.

3. Poll RXS for transfer completion.  Polling SPIF or TXS cannot
   guarantee transfer completion.  This may interrupt a transfer before it
   is finished.  Also this may leave garbage data in buffer and affect
   next transfer.

[Yi Li <yi.li@analog.com>: add a field "u16 idle_tx_val" in "struct
bfin5xx_spi_chip" to specify the value to transmit if no TX value
is supplied.]
Signed-off-by: Wolfgang Muees <wolfgang.mues@auerswald.de>
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/blackfin/include/asm/bfin5xx_spi.h
drivers/spi/spi_bfin5xx.c