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authorWolfgang Muees <wolfgang.mues@auerswald.de>2009-04-06 22:00:53 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-04-07 11:31:06 -0400
commit93b61bddc13d9acf1fe341b39d826e80f3182d1e (patch)
tree54a5b574ada4b619a9cba845bee1e4205d62176c /arch
parent42c78b2bf51bafb4cfa98dfecc28dd9b8bcd04b0 (diff)
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/blackfin/include/asm/bfin5xx_spi.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/bfin5xx_spi.h b/arch/blackfin/include/asm/bfin5xx_spi.h
index 8c5f8a977a66..aaeb4df10d57 100644
--- a/arch/blackfin/include/asm/bfin5xx_spi.h
+++ b/arch/blackfin/include/asm/bfin5xx_spi.h
@@ -125,6 +125,8 @@ struct bfin5xx_spi_chip {
125 u8 cs_change_per_word; 125 u8 cs_change_per_word;
126 u16 cs_chg_udelay; /* Some devices require 16-bit delays */ 126 u16 cs_chg_udelay; /* Some devices require 16-bit delays */
127 u32 cs_gpio; 127 u32 cs_gpio;
128 /* Value to send if no TX value is supplied, usually 0x0 or 0xFFFF */
129 u16 idle_tx_val;
128}; 130};
129 131
130#endif /* _SPI_CHANNEL_H_ */ 132#endif /* _SPI_CHANNEL_H_ */