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>
There is no meaningful code sharing between the PIO and DMA variants
(just the timeout calculation) so in order to make the code easier to
work with split the two cases.
Looking at the code it is not clear how the PIO version works for large
transmits, greater than FIFO size is only handled for RX.
Signed-off-by: Mark Brown <broonie@linaro.org>
The GPIO enable and disable is done in the core so does not need to be
replicated in the driver, delete the unneeded code. enable_cs() was not
referenced at all.
Signed-off-by: Mark Brown <broonie@linaro.org>
Use this new function to make code more comprehensible, since we are
reinitialzing the completion, not initializing.
[akpm@linux-foundation.org: linux-next resyncs]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix doubled clock disable and unprepare during PM suspend which triggered
the warnings:
WARNING: at drivers/clk/clk.c:800 clk_disable+0x18/0x24()
Modules linked in:
CPU: 0 PID: 1745 Comm: sh Not tainted 3.10.14-01211-ge2549bb-dirty #62
[<c0015980>] (unwind_backtrace+0x0/0x138) from [<c0012a44>] (show_stack+0x10/0x14)
[<c0012a44>] (show_stack+0x10/0x14) from [<c0022818>] (warn_slowpath_common+0x4c/0x68)
[<c0022818>] (warn_slowpath_common+0x4c/0x68) from [<c0022850>] (warn_slowpath_null+0x1c/0x24)
[<c0022850>] (warn_slowpath_null+0x1c/0x24) from [<c036e274>] (clk_disable+0x18/0x24)
[<c036e274>] (clk_disable+0x18/0x24) from [<c02d5f78>] (s3c64xx_spi_suspend+0x28/0x54)
[<c02d5f78>] (s3c64xx_spi_suspend+0x28/0x54) from [<c02b3a54>] (platform_pm_suspend+0x2c/0x5c)
[<c02b3a54>] (platform_pm_suspend+0x2c/0x5c) from [<c02b8a30>] (dpm_run_callback+0x44/0x7c)
[<c02b8a30>] (dpm_run_callback+0x44/0x7c) from [<c02b8b70>] (__device_suspend+0x108/0x300)
[<c02b8b70>] (__device_suspend+0x108/0x300) from [<c02ba4e0>] (dpm_suspend+0x54/0x208)
[<c02ba4e0>] (dpm_suspend+0x54/0x208) from [<c0066bcc>] (suspend_devices_and_enter+0x98/0x458)
[<c0066bcc>] (suspend_devices_and_enter+0x98/0x458) from [<c0067150>] (pm_suspend+0x1c4/0x25c)
[<c0067150>] (pm_suspend+0x1c4/0x25c) from [<c0066044>] (state_store+0x6c/0xbc)
[<c0066044>] (state_store+0x6c/0xbc) from [<c0203290>] (kobj_attr_store+0x14/0x20)
[<c0203290>] (kobj_attr_store+0x14/0x20) from [<c0157530>] (sysfs_write_file+0xfc/0x164)
[<c0157530>] (sysfs_write_file+0xfc/0x164) from [<c00fd6b0>] (vfs_write+0xbc/0x1bc)
[<c00fd6b0>] (vfs_write+0xbc/0x1bc) from [<c00fdaf0>] (SyS_write+0x40/0x68)
[<c00fdaf0>] (SyS_write+0x40/0x68) from [<c000ea80>] (ret_fast_syscall+0x0/0x3c)
The clocks may be already disabled before suspending. Check PM runtime
suspend status and disable clocks only if device is not suspended.
During resume do not enable the clocks if device is runtime suspended.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
During PM resume and suspend do not ignore the return value of
spi_master_suspend() or spi_master_resume(). Instead pass it further.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
pm_runtime_put() wasn't called if clock rate could not be set up in
s3c64xx_spi_setup() leading to invalid count of device pm_runtime usage.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Mark device as PM runtime active during initialization to reflect
actual device power/clocks state. This reduces the enable count for SPI
bus controller gate clock so it can be disabled when the bus controller
is not used.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
This is of very little value in itself but will be useful once the loop
iterating over the transfers is also factored out into the core.
Signed-off-by: Mark Brown <broonie@linaro.org>
The hardware level /CS handling is tied to the start of the data path so
is rolled into the same function as we use to manipulate GPIO /CS. In
order to support factoring out the /CS handling into the core separate the
two and explicitly start transfers separately to the /CS handling.
Signed-off-by: Mark Brown <broonie@linaro.org>
To help with bisection of future refactoring to share more of the code for
handling a spi_message pull the enabling of GPIO based /CS prior to all
the hardware setup for starting a transfer.
Signed-off-by: Mark Brown <broonie@linaro.org>
The hardware level /CS handling is tied to the start of the data path so
is rolled into the same function as we use to manipulate GPIO /CS. In
order to support factoring out the /CS handling into the core separate the
two and explicitly start transfers separately to the /CS handling.
Signed-off-by: Mark Brown <broonie@linaro.org>
Rather than using the driver custom platform data to store the chip select
GPIO use the cs_gpio field provided by the SPI core, supporting future
refectoring.
Signed-off-by: Mark Brown <broonie@linaro.org>
Ensure that the FIFOs are fully drained before we deassert /CS or do any
delays that have been requested in order to ensure that the behaviour
visible on the bus matches that which was requested by the caller.
Signed-off-by: Mark Brown <broonie@linaro.org>
Otherwise we may try to start transfers immediately and then fail to
runtime resume the device causing us not to have clocks enabled.
Signed-off-by: Mark Brown <broonie@linaro.org>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Conflicts:
drivers/spi/spi-s3c64xx.c
Add compatibles for s3c6410, s5pc100 and s5pc110/s5pv210 boards.
Signed-off-by: Mateusz Krawczuk <m.krawczuk@partner.samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Also improve the error reporting on failure and remove a duplicate put.
This provides a small code saving.
Signed-off-by: Mark Brown <broonie@linaro.org>
subsys_init_call() initializes driver too early.
It's preventing to move DMA channel allocation at the begining
(driver probe).
This patch reduces and simplifies initalization code by
using module_platform_driver() macro.
It's also efficiently delaying driver startup.
Signed-off-by: Lukasz Czerwinski <l.czerwinski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
We always need the device to be runtime PM enabled to use it so just skip
the DMA initialisation not the entire prepare when polling.
Signed-off-by: Mark Brown <broonie@linaro.org>
Since the driver supports only contiguous buffers, there is no need to
manually construct a scatterlist with just a single entry, when there is
a dedicated helper for this purpose.
This patch modifies prepare_dma() function to use available helper instead
of manually creating a scatterlist.
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Comments in linux/spi/spi.h and observed behavior show that .setup()
callback can be called multiple times without corresponding calls to
.cleanup(), what was incorrectly assumed by spi-s3c64xx driver, leading
to failures trying to request CS GPIO multiple times.
This patch modifies the behavior of spi-s3c64xx driver to request CS
GPIO only on first call to .setup() after last .cleanup().
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Not all fields of dma_slave_config struct are being initialized by
prepare_dma() function, leaving those which are not in undefined state,
which can confuse DMA drivers using them.
This patch adds call to memset() to zero the struct before initializing
a subset of its fields.
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
sdd->ops->request is unsigned int, not unsigned long.
Also, sdd->rx_dma.ch is a 'struct dma_chan *'.
Thus, (void *) is converted to (struct dma_chan *)(unsigned long),
in order to fix possible sparse warnings.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Fix the following build warnings when LPAE is enabled:
drivers/spi/spi-s3c64xx.c:1466:2: warning: format '%x' expects argument of type 'unsigned int', but argument 4 has type
'resource_size_t' [-Wformat]
drivers/spi/spi-s3c64xx.c:1466:2: warning: format '%x' expects argument of type 'unsigned int', but argument 5 has type
'resource_size_t' [-Wformat]
Use vsprintf extension %pR to format resource.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Fix the following checkpatch error and warnings:
ERROR: "(foo*)" should be "(foo *)"
WARNING: line over 80 characters
WARNING: quoted string split across lines
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Since the driver has been converted to use the core message pump code
the only use of the messsage queue in the driver is a check to see if
it is empty which will always succeed since nothing ever adds to the
queue. Just remove the queue.
Signed-off-by: Mark Brown <broonie@linaro.org>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Due to changes in mainline prior to submission the spi device detection
in polling mode breaks. This revealed the missing check for polling
during dma prepare. This patch adds the missing check.
Signed-off-by: Girish K S <ks.giri@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
After the patch "spi/s3c64xx: Fix non-dmaengine usage"
with commit id 563b444e33
submitted by Mark Brown, the spi device detection in polling
mode breaks. This revealed the missing check for polling during
dma prepare. This patch adds the missing check.
Signed-off-by: Girish K S <ks.giri@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
This should work with modern compilers, isn't that much of an issue if
it goes wrong and it ensures that the DT-only hardware variants don't
leave unreferenced parameters structures lying around.
Signed-off-by: Mark Brown <broonie@linaro.org>
This patch adds support for the exynos5440 spi controller.
The integration of the spi IP in exynos5440 is different from
other SoC's. The I/O pins are no more configured via gpio, they
have dedicated pins.
Signed-off-by: Girish K S <ks.giri@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
The existing driver supports gpio based /cs signal.
For controller's that have one device per controller,
the slave device's /cs signal might be internally controlled
by the chip select bit of slave select register. They are not
externally asserted/deasserted using gpio pin.
This patch adds support for controllers with dedicated /cs pin.
if "cs-gpio" property doesnt exist in a spi dts node, the controller
would treat the /cs pin as dedicated.
Signed-off-by: Girish K S <ks.giri@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
The 64xx spi driver supports partial polling mode.
Only the last chunk of the transfer length is transferred
or recieved in polling mode.
Some SoC's that adopt this controller might not have have dma
interface. This patch adds support for complete polling mode
and gives flexibity for the user to select poll/dma mode.
Signed-off-by: Girish K S <ks.giri@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Mark Brown