dwc_scan_descriptors scans all descriptors from active_list in case transfer is
not completed.  It compares first_desc->lli.llp, and then all childrens of its
tx_list. But it doesn't compare its own address, i.e. first_desc->txd.phys, as
this is what we have initially programmed into the controller register. So this
causes dma to stop and finish a transfer, which was never started. And thus
fail.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

This patch sets default Burst length for all transfer to 16. This will
enhance performance when user doesn't have any chan->private data.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Msize or Burst Size is peripheral dependent in case of prep_slave_sg and
cyclic_prep transfers, and in case of memcpy transfers it is platform dependent.
So msize configuration must come from platform data.

Also some peripherals (ex: JPEG), need to be flow controller for dma transfers,
so this information in case of slave_sg & cyclic_prep transfers must come from
platform data.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

In Synopsys designware, channel priority is programmable. This patch adds
support for passing channel priority through platform data. By default Ascending
channel priority will be followed, i.e. channel 0 will get highest priority and
channel 7 will get lowest.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

In SPEAr Platform channels 4-7 have more Fifo depth. So we must get better
channel first. This patch introduces concept of channel allocation order in
dw_dmac. If user doesn't pass anything or 0, than normal (ascending) channel
allocation will follow, else channels will be allocated in descending order.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

dwc_desc_get checks all descriptors for DMA_CTRL_ACK before allocating them for
transfers. And descriptors are not marked with DMA_CRTL_ACK after transfer
finishes. Thus descriptor once used is not usable again. This patch marks
descriptors with DMA_CRTL_ACK after dma xfer finishes
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Every descriptor can transfer a maximum count of 4095 (12 bits, in control reg),
So we must have DWC_MAX_COUNT as 4095 instead of 2048.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Lock must be taken before calling dwc_scan_descriptors, as this may
access/modify shared data and queues. dwc_tx_status wasn't taking lock before
calling this routine. This patch add code that takes lock before calling
dwc_scan_descriptors.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

dwc_complete_all and other routines was removing all descriptors from dwc->queue
and pushing them to dwc->active_list. Only one was required to be removed. Also
we are calling dwc_dostart, once list is fixed.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

In some cases users of dw_dmac are initialized before dw_dmac, and if they try
to use dw_dmac, they simply fail. So its better we register init() routine
of driver using subsys_initcall() instead of module_init(), so that dma driver
is available at the earliest possible.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Some platforms (e.g. Picochip PC3XX) have multiple DMA controllers
where some may be used for slave transfers and others for general
purpose memcpy type transfers. Add a .is_private boolean to the
platform data structure so that controllers can be marked as private
so that the DMA_PRIVATE capability will be set for that controller.
Signed-off-by: NJamie Iles <jamie.iles@picochip.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Some platforms have flexible mastering capabilities and this needs
to be selected at runtime. If the platform has specified private
data in the form of the dw_dma_slave then fetch the source and
destination masters from here. If this isn't present, default to
the previous of 0 and 1.

v2: cleanup whitespace
Acked-by: NHans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Signed-off-by: NJamie Iles <jamie.iles@picochip.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Some hardware (picoChip picoXCell in particular) sometimes has
the block transfer complete bit being set for a channel after the
whole transfer has completed. If we don't have any transfers in the
active list then don't bother to scan the descriptors. This often
happens in normal operation and doesn't require the channel to be
reset.

v2: cleanup whitespace
Signed-off-by: NJamie Iles <jamie.iles@picochip.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This adds an argument to the DMAengine control function, so that
we can later provide control commands that need some external data
passed in through an argument akin to the ioctl() operation
prototype.

[dan.j.williams@intel.com: fix up some missed conversions]
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Simple conditional struct filler to cut out some duplicated code.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Convert the device_is_tx_complete() operation on the
DMA engine to a generic device_tx_status()operation which
can return three states, DMA_TX_RUNNING, DMA_TX_COMPLETE,
DMA_TX_PAUSED.

[dan.j.williams@intel.com: update for timberdale]
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Li Yang <leoli@freescale.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Magnus Damm <damm@opensource.se>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Joe Perches <joe@perches.com>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Convert the device_terminate_all() operation on the
DMA engine to a generic device_control() operation
which can now optionally support also pausing and
resuming DMA on a certain channel. Implemented for the
COH 901 318 DMAC as an example.

[dan.j.williams@intel.com: update for timberdale]
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Li Yang <leoli@freescale.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Magnus Damm <damm@opensource.se>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Joe Perches <joe@perches.com>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

memset of 0 is not needed after kzalloc

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x;
statement S;
@@

x = kzalloc(...);
if (x == NULL) S
... when != x
-memset(x,0,...);// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Dan Williams wrote:
... DMA-slave clients request specific channels and know the hardware
details at a low level, so it should not be too high an expectation to
push dma mapping responsibility to the client.

Also this patch includes DMA_COMPL_{SRC,DEST}_UNMAP_SINGLE support for
dw_dmac driver.
Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Drop dw_dmac's use of tx_list from struct dma_async_tx_descriptor in
preparation for removal of this field.

Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This patch reworks platform driver power management code
for dw_dmac from legacy late/early callbacks to dev_pm_ops.

The callbacks are converted for CONFIG_SUSPEND like this:
  suspend_late() -> suspend_noirq()
  resume_early() -> resume_noirq()
Signed-off-by: NMagnus Damm <damm@igel.co.jp>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

This patch adds a cyclic DMA interface to the DW DMA driver. This is
very useful if you want to use the DMA controller in combination with a
sound device which uses cyclic buffers.

Using a DMA channel for cyclic DMA will disable the possibility to use
it as a normal DMA engine until the user calls the cyclic free function
on the DMA channel. Also a cyclic DMA list can not be prepared if the
channel is already active.
Signed-off-by: NHans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Acked-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Centralize this common initialization (and one case where ipu_idmac is
duplicating ->chan initialization).
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Cc: Dan Williams <dan.j.williams@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>

The conversion of atmel-mci to dma_request_channel missed the
initialization of the channel dma_slave information.  The filter_fn passed
to dma_request_channel is responsible for initializing the channel's
private data.  This implementation has the additional benefit of enabling
a generic client-channel data passing mechanism.
Reviewed-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Resolves:
WARNING: at drivers/base/core.c:122 device_release+0x4d/0x52()
Device 'dma0chan0' does not have a release() function, it is broken and must be fixed.

The dma_chan_dev object is introduced to gear-match sysfs kobject and
dmaengine channel lifetimes.  When a channel is removed access to the
sysfs entries return -ENODEV until the kobject can be released.

The bulk of the change is updates to existing code to handle the extra
layer of indirection between a dma_chan and its struct device.
Reported-by: NAlexander Beregalov <a.beregalov@gmail.com>
Acked-by: NStephen Hemminger <shemminger@vyatta.com>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

All users have been converted to either the general-purpose allocator,
dma_find_channel, or dma_request_channel.
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

dma_request_channel provides an exclusive channel, so we no longer need to
pass slave data through dmaengine.

Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Simply, if a client wants any dmaengine channel then prevent all dmaengine
modules from being removed.  Once the clients are done re-enable module
removal.

Why?, beyond reducing complication:
1/ Tracking reference counts per-transaction in an efficient manner, as
   is currently done, requires a complicated scheme to avoid cache-line
   bouncing effects.
2/ Per-transaction ref-counting gives the false impression that a
   dma-driver can be gracefully removed ahead of its user (net, md, or
   dma-slave)
3/ None of the in-tree dma-drivers talk to hot pluggable hardware, but
   if such an engine were built one day we still would not need to notify
   clients of remove events.  The driver can simply return NULL to a
   ->prep() request, something that is much easier for a client to handle.
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The tasklet checks RAW.BLOCK twice, and does not check RAW.XFER. This is
obviously wrong, and could theoretically cause the driver to hang.
Reported-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds a driver for the Synopsys DesignWare DMA controller (aka
DMACA on AVR32 systems.) This DMA controller can be found integrated
on the AT32AP7000 chip and is primarily meant for peripheral DMA
transfer, but can also be used for memory-to-memory transfers.

This patch is based on a driver from David Brownell which was based on
an older version of the DMA Engine framework. It also implements the
proposed extensions to the DMA Engine API for slave DMA operations.

The dmatest client shows no problems, but there may still be room for
improvement performance-wise. DMA slave transfer performance is
definitely "good enough"; reading 100 MiB from an SD card running at ~20
MHz yields ~7.2 MiB/s average transfer rate.

Full documentation for this controller can be found in the Synopsys
DW AHB DMAC Databook:

http://www.synopsys.com/designware/docs/iip/DW_ahb_dmac/latest/doc/dw_ahb_dmac_db.pdf

The controller has lots of implementation options, so it's usually a
good idea to check the data sheet of the chip it's intergrated on as
well. The AT32AP7000 data sheet can be found here:

http://www.atmel.com/dyn/products/datasheets.asp?family_id=682


Changes since v4:
  * Use client_count instead of dma_chan_is_in_use()
  * Add missing include
  * Unmap buffers unless client told us not to

Changes since v3:
  * Update to latest DMA engine and DMA slave APIs
  * Embed the hw descriptor into the sw descriptor
  * Clean up and update MODULE_DESCRIPTION, copyright date, etc.

Changes since v2:
  * Dequeue all pending transfers in terminate_all()
  * Rename dw_dmac.h -> dw_dmac_regs.h
  * Define and use controller-specific dma_slave data
  * Fix up a few outdated comments
  * Define hardware registers as structs (doesn't generate better
    code, unfortunately, but it looks nicer.)
  * Get number of channels from platform_data instead of hardcoding it
    based on CONFIG_WHATEVER_CPU.
  * Give slave clients exclusive access to the channel

Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>,
Signed-off-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>