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>
Add support for GPIO controlled SPI Chip Selects. To make use of this
feature, set chip_select = 0 and add a proper cs_gpio to your
controller_data.
struct spi_board_info
.chip_select = 0
struct bfin5xx_spi_chip
.cs_gpio = GPIO_P###
There are various SPI devices that require SPI MODE_0, and need to have
the Chip Selects asserted during the entire transfer. Consider using
SPI_MODE_3 (SPI_CPHA | SPI_CPOL) if your device allows it.
Signed-off-by: Michael Hennerich <michael.hennerich@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>
Fix erroneous SPI Clock divisor calculation. Make sure SPI_BAUD is always
>= 2. Writing a value of 0 or 1 to the SPI_BAUD register disables the
serial clock.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
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>
use scm changelog rather than comment blocks in files
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
