The 16-bit DMA support doesn't fit well within the SPI core DMA framework,
as it needs to manage its own double-sized temporary buffers, for handling
the interleaved data.
Remove it, as there is no in-tree board code that sets
rspi_plat_data.dma_width_16bit.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
Spi v3 controller is not only used on Blackfin. So rename it
and use ioread/iowrite api to make it work on other platform.
Signed-off-by: Scott Jiang <scott.jiang.linux@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
This patch fix spelling typo in Documentation/DocBook.
It is because .html and .xml files are generated by make htmldocs,
I have to fix a typo within the source files.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
We cannot unconditionally use dma_map_single() to map data for use with
SPI since transfers may exceed a page and virtual addresses may not be
provided with physically contiguous pages. Further, addresses allocated
using vmalloc() need to be mapped differently to other addresses.
Currently only the MXS driver handles all this, a few drivers do handle
the possibility that buffers may not be physically contiguous which is
the main potential problem but many don't even do that. Factoring this
out into the core will make it easier for drivers to do a good job so if
the driver is using the core DMA code then generate a scatterlist
instead of mapping to a single address so do that.
This code is mainly based on a combination of the existing code in the MXS
and PXA2xx drivers. In future we should be able to extend it to allow the
core to concatenate adjacent transfers if they are compatible, improving
performance.
Currently for simplicity clients are not allowed to use the scatterlist
when they do DMA mapping, in the future the existing single address
mappings will be replaced with use of the scatterlist most likely as
part of pre-verifying transfers.
This change makes it mandatory to use scatterlists when using the core DMA
mapping so update the s3c64xx driver to do this when used with dmaengine.
Doing so makes the code more ugly but it is expected that the old s3c-dma
code can be removed very soon.
Signed-off-by: Mark Brown <broonie@linaro.org>
It is fairly common for SPI devices to require that one or both transfer
directions is always active. Currently drivers open code this in various
ways with varying degrees of efficiency. Start factoring this out by
providing flags SPI_MASTER_MUST_TX and SPI_MASTER_MUST_RX. These will cause
the core to provide buffers for the requested direction if none are
specified in the underlying transfer.
Currently this is fairly inefficient since we actually allocate a data
buffer which may get large, support for mapping transfers using a
scatterlist will allow us to avoid this for DMA based transfers.
Signed-off-by: Mark Brown <broonie@linaro.org>
The process of DMA mapping buffers for SPI transfers does not vary between
devices so in order to save duplication of code in drivers this can be
factored out into the core, allowing it to be integrated with the work that
is being done on factoring out the common elements from the data path
including more sharing of dmaengine code.
In order to use this masters need to provide a can_dma() operation and while
the hardware is prepared they should ensure that DMA channels are provided
in tx_dma and rx_dma. The core will then ensure that the buffers are mapped
for DMA prior to calling transfer_one_message().
Currently the cleanup on error is not complete, this needs to be improved.
Signed-off-by: Mark Brown <broonie@linaro.org>
The transfer_one_message callback handles messages, not transfers.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Mark Brown <broonie@linaro.org>
Explicitly note the transfer_one and transfer_one_message are mutually
exclusive, to make the text a little more newcomers friendly.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Mark Brown <broonie@linaro.org>
Pull spi updates from Mark Brown:
"A respun version of the merges for the pull request previously sent
with a few additional fixes. The last two merges were fixed up by
hand since the branches have moved on and currently have the prior
merge in them.
Quite a busy release for the SPI subsystem, mostly in cleanups big and
small scattered through the stack rather than anything else:
- New driver for the Broadcom BC63xx HSSPI controller
- Fix duplicate device registration for ACPI
- Conversion of s3c64xx to DMAEngine (this pulls in platform and DMA
changes upon which the transiton depends)
- Some small optimisations to reduce the amount of time we hold locks
in the datapath, eliminate some redundant checks and the size of a
spi_transfer
- Lots of fixes, cleanups and general enhancements to drivers,
especially the rspi and Atmel drivers"
* tag 'spi-v3.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (112 commits)
spi: core: Fix transfer failure when master->transfer_one returns positive value
spi: Correct set_cs() documentation
spi: Clarify transfer_one() w.r.t. spi_finalize_current_transfer()
spi: Spelling s/finised/finished/
spi: sc18is602: Convert to use bits_per_word_mask
spi: Remove duplicate code to set default bits_per_word setting
spi/pxa2xx: fix compilation warning when !CONFIG_PM_SLEEP
spi: clps711x: Add MODULE_ALIAS to support module auto-loading
spi: rspi: Add missing clk_disable() calls in error and cleanup paths
spi: rspi: Spelling s/transmition/transmission/
spi: rspi: Add support for specifying CPHA/CPOL
spi/pxa2xx: initialize DMA channels to -1 to prevent inadvertent match
spi: rspi: Add more QSPI register documentation
spi: rspi: Add more RSPI register documentation
spi: rspi: Remove dependency on DMAE for SHMOBILE
spi/s3c64xx: Correct indentation
spi: sh: Use spi_sh_clear_bit() instead of open-coded
spi: bitbang: Grammar s/make to make/to make/
spi: sh-hspi: Spelling s/recive/receive/
spi: core: Improve tx/rx_nbits check comments
...
The documentation for spi_master.set_cs() says:
assert or deassert chip select, true to assert
i.e. its "enable" parameter uses assertion-level logic.
This does not match the implementation of spi_set_cs(), which calls
spi_master.set_cs() with the wanted logic level of the chip select line,
which depends on the polarity of the chip select signal.
Correct the documentation to match the implementation.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
spi_write_then_read() takes a "void *" for rxbuf, so there's no need to
cast the buffer pointer to "u8 *".
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Trent Piepho observed that since the current realistic maximum number of
data lines is four we can pack the spi_transfer struct more efficiently
if we use a bitfield for the number of bits, allowing the fields to fit
in a single byte along with cs_change.
If space becomes an issue further optimiation is possible by only using
the constants and packing the values chosen for them.
Reported-by: Trent Piepho <tpiepho@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
fiq.h contains only a function declaration and is not used by anyone
else. Move the declaration to the driver header file and remove the
unnecessary platform dependency from the driver.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Now that spi_device->mode is a u16, the chip_select, bits_per_mode,
and mode fields pack poorly, taking 8 bytes: four data and four
padding. By moving (u8)bits_per_word up one position, to after
(u8)chip_select, they pack better and only use 4 bytes.
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Reviewed-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>g
Signed-off-by: Mark Brown <broonie@linaro.org>
Commit 20bc4d5d56
(gpio: 74x164: Add support for the daisy-chaining) introduce check
for DT for the driver, so driver cannot be used without DT.
There are no in-tree users of this driver, so remove non-DT support
completely.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
