In DMA support, The received data is not pushed to tty until the DMA buffer
is filled. But some megabyte rate chips such as BT expect fast response and
data should be pushed immediately. In order to fix this issue, We suggest
the use of the timer for polling DMA buffer.
In our test, no data loss occurred at high-baudrate as compared with interrupt-
driven (We tested with 3Mbps).
We changes:
- We add timer for polling. If we set poll_timer to 10, every 10ms,
timer handler checks the residue in the dma buffer and transfer data
to the tty. Also, last_residue is updated for the next polling.
- poll_timeout is used to prevent the timer's system cost.
If poll_timeout is set to 3000 and no data is received in 3 seconds,
we inactivate poll timer and driver falls back to interrupt-driven.
When data is received again in FIFO and UART irq is occurred, we switch
back to DMA mode and start polling.
- We use consistent DMA mappings to avoid from the frequent cache operation
of the timer function for default.
- pl011_dma_rx_chars is modified. the pending size is recalculated because
data can be taken by polling.
- the polling time is adjusted if dma rx poll is enabled but no rate is
specified. Ideal polling interval to push 1 character at every interval
is the reciprocal of 'baud rate / 10 line bits per character / 1000 ms
per sec'. But It is very aggressive to system. Experimentally,
'10000000 / baud' is suitable to receive dozens of characters. the poll rate
can be specified statically by dma_rx_poll_rate of the platform data as well.
Changes compared to v1:
- Use of consistent DMA mappings.
- Added dma_rx_poll_rate in platform data to specify the polling interval.
- Added dma_rx_poll_timeout in platform data to specify the polling timeout.
Changes compared to v2:
- Use of consistent DMA mappings for default.
- Added dma_rx_poll_enable in platform data to adjust the polling time
according to the baud rate.
- remove unnecessary lock from the polling function.
Signed-off-by: Chanho Min <chanho.min@lge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull slave-dmaengine updates from Vinod Koul:
"This is fairly big pull by my standards as I had missed last merge
window. So we have the support for device tree for slave-dmaengine,
large updates to dw_dmac driver from Andy for reusing on different
architectures. Along with this we have fixes on bunch of the drivers"
Fix up trivial conflicts, usually due to #include line movement next to
each other.
* 'next' of git://git.infradead.org/users/vkoul/slave-dma: (111 commits)
Revert "ARM: SPEAr13xx: Pass DW DMAC platform data from DT"
ARM: dts: pl330: Add #dma-cells for generic dma binding support
DMA: PL330: Register the DMA controller with the generic DMA helpers
DMA: PL330: Add xlate function
DMA: PL330: Add new pl330 filter for DT case.
dma: tegra20-apb-dma: remove unnecessary assignment
edma: do not waste memory for dma_mask
dma: coh901318: set residue only if dma is in progress
dma: coh901318: avoid unbalanced locking
dmaengine.h: remove redundant else keyword
dma: of-dma: protect list write operation by spin_lock
dmaengine: ste_dma40: do not remove descriptors for cyclic transfers
dma: of-dma.c: fix memory leakage
dw_dmac: apply default dma_mask if needed
dmaengine: ioat - fix spare sparse complain
dmaengine: move drivers/of/dma.c -> drivers/dma/of-dma.c
ioatdma: fix race between updating ioat->head and IOAT_COMPLETION_PENDING
dw_dmac: add support for Lynxpoint DMA controllers
dw_dmac: return proper residue value
dw_dmac: fill individual length of descriptor
...
The header is used by drivers/dma/amba-pl08x.c, which can be compiled
under x86, where PL080 exists under a PCI-to-AMBA bridge. This patche
moves it where it can be accessed by other architectures, and fixes
all users.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This creates amba_apb_device_add_res() and
amba_ahb_device_add_res() respectively, to add devices with
another parent than iomem_resource. This is needed to specify
that a device is contained in a specific IO range.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull spi updates from Mark Brown:
"No framework work here, only a bunch of driver updates of varying
sizes:
- Factoring out of the core hardware support from the MXS MMC driver
by Marek Vasut to allow the hardware to also be used for SPI.
- Lots of error handling cleanups from Guenter Roeck
- Removal of the existing Tegra driver which is quite comprehensively
broken as detailed in the changelog for the removal.
- DT suppport for the PL022 and GPIO drivers.
- pinctrl support for OMAP and PL022."
Pulling from Mark Brown as Grant Likely is still busy moving.
* tag 'spi-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/misc: (53 commits)
spi: remove completely broken Tegra driver
spi/imx: set the inactive state of the clock according to the clock polarity
spi/pl022: get/put resources on suspend/resume
spi/pl022: use more managed resources
spi/pl022: Devicetree support w/o platform data
spi/s3c64xx: Don't free controller_data on non-dt platforms
spi: omap2-mcspi: add pinctrl support
spi/pl022: adopt pinctrl support
spi: omap2-mcspi: Cleanup the omap2_mcspi_txrx_dma function
spi/gpio: Fix stub for spi_gpio_probe_dt()
spi/mxs: Make the SPI block clock speed configurable via DT
spi: spi-sh-hspi: drop frees of devm_ alloc'd data
spi/pl022: Fix chipselects pointer computation
spi: spi-tle62x0: Use module_spi_driver macro
mxs/spi: Rework the mxs_ssp_timeout to be more readable
mxs/spi: Decrement the DMA/PIO border
mxs/spi: Increment the transfer length only if transfer succeeded
mxs/spi: Fix issues when doing long continuous transfer
spi: spi-gpio: Add DT bindings
spi: spi-gpio: store chipselect information in private structure
...
This patch adds the ability for the driver to control the chip select directly.
This enables independence from cs_control callbacks. Configurable via
platform_data, to be extended as DT in the following patch.
Based on the initial patch by Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Signed-off-by: Roland Stigge <stigge@antcom.de>
Acked-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Pull ARM DMA engine updates from Russell King:
"This looks scary at first glance, but what it is is:
- a rework of the sa11x0 DMA engine driver merged during the previous
cycle, to extract a common set of helper functions for DMA engine
implementations.
- conversion of amba-pl08x.c to use these helper functions.
- addition of OMAP DMA engine driver (using these helper functions),
and conversion of some of the OMAP DMA users to use DMA engine.
Nothing in the helper functions is ARM specific, so I hope that other
implementations can consolidate some of their code by making use of
these helpers.
This has been sitting in linux-next most of the merge cycle, and has
been tested by several OMAP folk. I've tested it on sa11x0 platforms,
and given it my best shot on my broken platforms which have the
amba-pl08x controller.
The last point is the addition to feature-removal-schedule.txt, which
will have a merge conflict. Between myself and TI, we're planning to
remove the old TI DMA implementation next year."
Fix up trivial add/add conflicts in Documentation/feature-removal-schedule.txt
and drivers/dma/{Kconfig,Makefile}
* 'dmaengine' of git://git.linaro.org/people/rmk/linux-arm: (53 commits)
ARM: 7481/1: OMAP2+: omap2plus_defconfig: enable OMAP DMA engine
ARM: 7464/1: mmc: omap_hsmmc: ensure probe returns error if DMA channel request fails
Add feature removal of old OMAP private DMA implementation
mtd: omap2: remove private DMA API implementation
mtd: omap2: add DMA engine support
spi: omap2-mcspi: remove private DMA API implementation
spi: omap2-mcspi: add DMA engine support
ARM: omap: remove mmc platform data dma_mask and initialization
mmc: omap: remove private DMA API implementation
mmc: omap: add DMA engine support
mmc: omap_hsmmc: remove private DMA API implementation
mmc: omap_hsmmc: add DMA engine support
dmaengine: omap: add support for cyclic DMA
dmaengine: omap: add support for setting fi
dmaengine: omap: add support for returning residue in tx_state method
dmaengine: add OMAP DMA engine driver
dmaengine: sa11x0-dma: add cyclic DMA support
dmaengine: sa11x0-dma: fix DMA residue support
dmaengine: PL08x: ensure all descriptors are freed when channel is released
dmaengine: PL08x: get rid of write only pool_ctr and free_txd locking
...
Remove the unused fields from struct ssp_config_chip that was removed
before
Add bus_id documentation to pl022_ssp_controller
Signed-off-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Signed-off-by: Roland Stigge <stigge@antcom.de>
Get rid of the unnecessary checks in dma_slave_config utilizing
the DMA direction. This allows us to move the computation of
cctl to the prepare function.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Try to avoid dereferencing the DMA engine's channel struct in these
platform helpers; instead, pass a pointer to the channel data into
get_signal(), and the returned signal number to put_signal().
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Circular buffers are not handled in this way; we have a separate API
call now to setup circular buffers. So lets not mislead people with
this bool.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull slave-dmaengine updates from Vinod Koul:
"Nothing exciting this time, odd fixes in a bunch of drivers"
* 'next' of git://git.infradead.org/users/vkoul/slave-dma:
dmaengine: at_hdmac: take maxburst from slave configuration
dmaengine: at_hdmac: remove ATC_DEFAULT_CTRLA constant
dmaengine: at_hdmac: remove some at_dma_slave comments
dma: imx-sdma: make channel0 operations atomic
dmaengine: Fixup dmaengine_prep_slave_single() to be actually useful
dmaengine: Use dma_sg_len(sg) instead of sg->length
dmaengine: Use sg_dma_address instead of sg_phys
DMA: PL330: Remove duplicate header file inclusion
dma: imx-sdma: keep the callbacks invoked in the tasklet
dmaengine: dw_dma: add Device Tree probing capability
dmaengine: dw_dmac: Add clk_{un}prepare() support
dma/amba-pl08x: add support for the Nomadik variant
dma/amba-pl08x: check for terminal count status only
Add two functions to add APB and AHB devices to the amba (PrimeCell)
bus dynamically. This is modeled after the static definition
macros recently introduced into <linux/amba/bus.h> and can
help us in factoring out a bunch of code across the kernel.
Since a lot of call sites seem to be using a returned struct
amba device* pointer, let's use that.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull ARM fixes from Russell King:
"Nothing too disasterous, the biggest thing being the removal of the
regulator support for vcore in the AMBA driver; only one SoC was using
this and it got broken during the last merge window, which then
started causing problems for other people. Mutual agreement was
reached for it to be removed."
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
ARM: 7386/1: jump_label: fixup for rename to static_key
ARM: 7384/1: ThumbEE: Disable userspace TEEHBR access for !CONFIG_ARM_THUMBEE
ARM: 7382/1: mm: truncate memory banks to fit in 4GB space for classic MMU
ARM: 7359/2: smp_twd: Only wait for reprogramming on active cpus
ARM: 7383/1: nommu: populate vectors page from paging_init
ARM: 7381/1: nommu: fix typo in mm/Kconfig
ARM: 7380/1: DT: do not add a zero-sized memory property
ARM: 7379/1: DT: fix atags_to_fdt() second call site
ARM: 7366/3: amba: Remove AMBA level regulator support
ARM: 7377/1: vic: re-read status register before dispatching each IRQ handler
ARM: 7368/1: fault.c: correct how the tsk->[maj|min]_flt gets incremented
The AMBA bus regulator support is being used to model on/off switches
for power domains which isn't terribly idiomatic for modern kernels with
the generic power domain code and creates integration problems on platforms
which don't use regulators for their power domains as it's hard to tell
the difference between a regulator that is needed but failed to be provided
and one that isn't supposed to be there (though DT does make that easier).
Platforms that wish to use the regulator API to manage their power domains
can indirect via the power domain interface.
This feature is only used with the vape supply of the db8500 PRCMU
driver which supplies the UARTs and MMC controllers, none of which have
support for managing vcore at runtime in mainline (only pl022 SPI
controller does). Update that supply to have an always_on constraint
until the power domain support for the system is updated so that it is
enabled for these users, this is likely to have no impact on practical
systems as probably at least one of these devices will be active and
cause AMBA to hold the supply on anyway.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
linux/pl022.h uses definitions like, u8, u16, etc, which have dependency of
types.h file, which isn't included in it. So, we get compilation warnings.
This patch includes types.h there to fix these warnings.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Pull slave-dmaengine update from Vinod Koul:
"This includes the cookie cleanup by Russell, the addition of context
parameter for dmaengine APIs, more arm dmaengine driver cleanup by
moving code to dmaengine, this time for imx by Javier and pl330 by
Boojin along with the usual driver fixes."
Fix up some fairly trivial conflicts with various other cleanups.
* 'next' of git://git.infradead.org/users/vkoul/slave-dma: (67 commits)
dmaengine: imx: fix the build failure on x86_64
dmaengine: i.MX: Fix merge of cookie branch.
dmaengine: i.MX: Add support for interleaved transfers.
dmaengine: imx-dma: use 'dev_dbg' and 'dev_warn' for messages.
dmaengine: imx-dma: remove 'imx_dmav1_baseaddr' and 'dma_clk'.
dmaengine: imx-dma: remove unused arg of imxdma_sg_next.
dmaengine: imx-dma: remove internal structure.
dmaengine: imx-dma: remove 'resbytes' field of 'internal' structure.
dmaengine: imx-dma: remove 'in_use' field of 'internal' structure.
dmaengine: imx-dma: remove sg member from internal structure.
dmaengine: imx-dma: remove 'imxdma_setup_sg_hw' function.
dmaengine: imx-dma: remove 'imxdma_config_channel_hw' function.
dmaengine: imx-dma: remove 'imxdma_setup_mem2mem_hw' function.
dmaengine: imx-dma: remove dma_mode member of internal structure.
dmaengine: imx-dma: remove data member from internal structure.
dmaengine: imx-dma: merge old dma-v1.c with imx-dma.c
dmaengine: at_hdmac: add slave config operation
dmaengine: add context parameter to prep_slave_sg and prep_dma_cyclic
dmaengine/dma_slave: introduce inline wrappers
dma: imx-sdma: Treat firmware messages as warnings instead of erros
...
Pull <linux/device.h> avoidance patches from Paul Gortmaker:
"Nearly every subsystem has some kind of header with a proto like:
void foo(struct device *dev);
and yet there is no reason for most of these guys to care about the
sub fields within the device struct. This allows us to significantly
reduce the scope of headers including headers. For this instance, a
reduction of about 40% is achieved by replacing the include with the
simple fact that the device is some kind of a struct.
Unlike the much larger module.h cleanup, this one is simply two
commits. One to fix the implicit <linux/device.h> users, and then one
to delete the device.h includes from the linux/include/ dir wherever
possible."
* tag 'device-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
device.h: audit and cleanup users in main include dir
device.h: cleanup users outside of linux/include (C files)
Pull #2 ARM updates from Russell King:
"Further ARM AMBA primecell updates which aren't included directly in
the previous commit. I wanted to keep these separate as they're
touching stuff outside arch/arm/."
* 'amba' of git://git.linaro.org/people/rmk/linux-arm:
ARM: 7362/1: AMBA: Add module_amba_driver() helper macro for amba_driver
ARM: 7335/1: mach-u300: do away with MMC config files
ARM: 7280/1: mmc: mmci: Cache MMCICLOCK and MMCIPOWER register
ARM: 7309/1: realview: fix unconnected interrupts on EB11MP
ARM: 7230/1: mmc: mmci: Fix PIO read for small SDIO packets
ARM: 7227/1: mmc: mmci: Prepare for SDIO before setting up DMA job
ARM: 7223/1: mmc: mmci: Fixup use of runtime PM and use autosuspend
ARM: 7221/1: mmc: mmci: Change from using legacy suspend
ARM: 7219/1: mmc: mmci: Change vdd_handler to a generic ios_handler
ARM: 7218/1: mmc: mmci: Provide option to configure bus signal direction
ARM: 7217/1: mmc: mmci: Put power register deviations in variant data
ARM: 7216/1: mmc: mmci: Do not release spinlock in request_end
ARM: 7215/1: mmc: mmci: Increase max_segs from 16 to 128
Pull #1 ARM updates from Russell King:
"This one covers stuff which Arnd is waiting for me to push, as this is
shared between both our trees and probably other trees elsewhere.
Essentially, this contains:
- AMBA primecell device initializer updates - mostly shrinking the
size of the device declarations in platform code to something more
reasonable.
- Getting rid of the NO_IRQ crap from AMBA primecell stuff.
- Nicolas' idle cleanups. This in combination with the restart
cleanups from the last merge window results in a great many
mach/system.h files being deleted."
Yay: ~80 files, ~2000 lines deleted.
* 'for-armsoc' of git://git.linaro.org/people/rmk/linux-arm: (60 commits)
ARM: remove disable_fiq and arch_ret_to_user macros
ARM: make entry-macro.S depend on !MULTI_IRQ_HANDLER
ARM: rpc: make default fiq handler run-time installed
ARM: make arch_ret_to_user macro optional
ARM: amba: samsung: use common amba device initializers
ARM: amba: spear: use common amba device initializers
ARM: amba: nomadik: use common amba device initializers
ARM: amba: u300: use common amba device initializers
ARM: amba: lpc32xx: use common amba device initializers
ARM: amba: netx: use common amba device initializers
ARM: amba: bcmring: use common amba device initializers
ARM: amba: ep93xx: use common amba device initializers
ARM: amba: omap2: use common amba device initializers
ARM: amba: integrator: use common amba device initializers
ARM: amba: realview: get rid of private platform amba_device initializer
ARM: amba: versatile: get rid of private platform amba_device initializer
ARM: amba: vexpress: get rid of private platform amba_device initializer
ARM: amba: provide common initializers for static amba devices
ARM: amba: make use of -1 IRQs warn
ARM: amba: u300: get rid of NO_IRQ initializers
...
