Move some common spi_setup() error checks into the SPI framework from the
spi_master controller drivers:
- Add a new "mode_bits" field to spi_master
- Use that in spi_setup to validate the spi->mode value being
requested. Setting this new field is now mandatory for any
controller supporting more than vanilla SPI_MODE_0.
- Update all spi_master drivers to:
* Initialize that field
* Remove current spi_setup() checks using that value.
This is a net minor code shrink.
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>
Start moving some spi_setup() functionality into the SPI core from the
various spi_master controller drivers:
- Make that function stop being an inline;
- Move two common idioms from drivers into that new function:
* Default bits_per_word to 8 if that field isn't set
* Issue a standardized dev_dbg() message
This is a net minor source code shrink, and supports enhancments found in
some follow-up patches.
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>
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>
According to comments in linux/spi/spi.h:
* All SPI transfers start with the relevant chipselect active. Normally
* it stays selected until after the last transfer in a message. Drivers
* can affect the chipselect signal using cs_change.
*
* (i) If the transfer isn't the last one in the message, this flag is
* used to make the chipselect briefly go inactive in the middle of the
* message. Toggling chipselect in this way may be needed to terminate
* a chip command, letting a single spi_message perform all of group of
* chip transactions together.
*
* (ii) When the transfer is the last one in the message, the chip may
* stay selected until the next transfer. On multi-device SPI busses
* with nothing blocking messages going to other devices, this is just
* a performance hint; starting a message to another device deselects
* this one. But in other cases, this can be used to ensure correctness.
* Some devices need protocol transactions to be built from a series of
* spi_message submissions, where the content of one message is determined
* by the results of previous messages and where the whole transaction
* ends when the chipselect goes intactive.
Signed-off-by: Yi Li <yi.li@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>
This bug can be observed when two SPI devices are sharing the spi bus: One
device is set as SPI CS 7, another one is using SPI CS 4.
In spi_bfin5xx.c: cs_active(), cs_deactive() are used to control SPI_FLG
register. From the debug bellow:
cs_active: flag: 0x7f91, chip->flag: 0x7f80, cs: 7
cs_active: flag: 0xef91, chip->flag: 0xef10, cs: 4
When device A (cs_7) activate CS 7, SPI_FLG is set as 0x7f91 (however,
SPI_FLG should be set as 0x7f80, or 0x6f91 if in broadcast mode).
Due to some HW bug (very possibly), if SPI_FLG is set as 0x7f91, SPISSEL7
is asserted, however SPISSEL4 will be asserted too (I can see this using
the scope). This is unreasonable according to HRM.
Signed-off-by: Yi Li <yi.li@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>
When using a BF533-STAMP here with a W25X10 SPI flash. It works fine when
enable_dma is disabled, but doesn't work at all when turning DMA on. We
get just 0xff bytes back when trying to read the device.
Change the code around so that it programs the SPI first and then enables
DMA, it seems to work a lot better ...
Signed-off-by: Mike Frysinger <vapier.adi@gmail.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>
Since 43cc71eed1, the platform modalias is
prefixed with "platform:". Add MODULE_ALIAS() to the hotpluggable SPI
platform drivers, to allow module auto loading.
[dbrownell@users.sourceforge.net: more drivers: registration fixes]
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
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>
PBX 2 SPI devices need the nonstandard "cs change per word" mechanism.
This patch is one of three updating this driver to make the last data bits get
sent before advancing the transfer ... in this case, before the chipselect
gets deactivated.
Signed-off-by: Bryan Wu <bryan.wu@analog.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>
- reconfigure SPI baud from speed_hz of each spi transfer
- according to spi_transfer.bits_per_word to reprogram register and setup
correct SPI operation handlers
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
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>
Remove some sort of bloaty code, try to get these pin_req arrays built at compile-time
- move this static things to the blackfin board file
- add pin_req array to struct bfin5xx_spi_master
- tested on BF537/BF548 with SPI flash
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
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 SPI driver to work with SPI flash ST M25P16 on bf548
Currently the SPI driver enables the SPI controller and sets the SPI baud
register for each SPI transfer. But they should never be changed within a SPI
message session, in which several SPI transfers are pumped.
This patch moves SPI setting to the begining of a message session, and
never disables SPI controller until an error occurs.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.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>
