Atmel-mci support for SDIO interrupts. This adds the enable_sdio_irq()
function and the configuration of sdio irq mask per slot. With this irq
mask information, we keep the idea of multiple slot per sd/mmc host (not
only A and B). MMC_CAP_SDIO_IRQ is added according to slot configuration.
A new little function is added to run mmc_signal_sdio_irq() during
interrupt handling routine.
Signed-off-by: Anders Grahn <anders.grahn@hd-wireless.se>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable high speed support for atmel-mci driver. This support is dependent
of the revision of the IP and, of course, the capacity of the SD card
used.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
DMAENGINE: extend the control command to include an arg
async_tx: trim dma_async_tx_descriptor in 'no channel switch' case
DMAENGINE: DMA40 fix for allocation of logical channel 0
DMAENGINE: DMA40 support paused channel status
dmaengine: mpc512x: Use resource_size
DMA ENGINE: Do not reset 'private' of channel
ioat: Remove duplicated devm_kzalloc() calls for ioatdma_device
ioat3: disable cacheline-unaligned transfers for raid operations
ioat2,3: convert to producer/consumer locking
ioat: convert to circ_buf
DMAENGINE: Support for ST-Ericssons DMA40 block v3
async_tx: use of kzalloc/kfree requires the include of slab.h
dmaengine: provide helper for setting txstate
DMAENGINE: generic channel status v2
DMAENGINE: generic slave control v2
dma: timb-dma: Update comment and fix compiler warning
dma: Add timb-dma
DMAENGINE: COH 901 318 fix bytesleft
DMAENGINE: COH 901 318 rename confusing vars
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: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
In debugfs, printing of command response reports resp[2] twice: fix it to
resp[3].
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Disable data error interrupts while we are actually recording that there
is not such errors. This will prevent, in some cases, the warning message
printed at new request queuing (in atmci_start_request()).
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The removing of an SD card in certain circumstances can lead to a kernel
oops if we do not make sure that the "data" field of the host structure is
valid. This patch adds a test in atmci_dma_cleanup() function and also
calls atmci_stop_dma() before throwing away the reference to data.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Two parameters were swapped in the calls to atmci_init_slot().
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Reported-by: Anders Grahn <anders.grahn@hd-wireless.se>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.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: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Mark 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: Dan Williams <dan.j.williams@intel.com>
This new revision of the IP adds some improvements to the MCI already
present in several Atmel SOC.
Some new registers are added and a particular way of handling DMA
interaction lead to a new sequence in function call which is backward
compatible: On MCI2, we must set the DMAEN bit to enable the DMA
handshaking interface. This must happen before the data transfer command
is sent.
A new function is able to differentiate MCI2 code and is based on
knowledge of processor id (cpu_is_xxx()).
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow the use of another DMA controller driver in atmel-mci sd/mmc driver.
This adds a generic dma_slave pointer to the mci platform structure where
we can store DMA controller information. In atmel-mci we use information
provided by this structure to initialize the driver (with new helper
functions that are architecture dependant).
This also adds at32/avr32 chip modifications to cope with this new access
method.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://neil.brown.name/md: (97 commits)
md: raid-1/10: fix RW bits manipulation
md: remove unnecessary memset from multipath.
md: report device as congested when suspended
md: Improve name of threads created by md_register_thread
md: remove sparse warnings about lock context.
md: remove sparse waring "symbol xxx shadows an earlier one"
async_tx/raid6: add missing dma_unmap calls to the async fail case
ioat3: fix uninitialized var warnings
drivers/dma/ioat/dma_v2.c: fix warnings
raid6test: fix stack overflow
ioat2: clarify ring size limits
md/raid6: cleanup ops_run_compute6_2
md/raid6: eliminate BUG_ON with side effect
dca: module load should not be an error message
ioat: driver version 4.0
dca: registering requesters in multiple dca domains
async_tx: remove HIGHMEM64G restriction
dmaengine: sh: Add Support SuperH DMA Engine driver
dmaengine: Move all map_sg/unmap_sg for slave channel to its client
fsldma: Add DMA_SLAVE support
...
Unification of the atmel-mci driver to support the AT91 processors MCI
interface. The atmel-mci driver currently supports the AVR32 and this
patch adds AT91 support.
Add read/write proof selection switch dependent on chip availability of
this feature.
To use this new driver on a at91 the platform driver for your board needs
to be updated.
[nicolas.ferre@atmel.com indent, Kconfig comment and one printk modification]
Signed-off-by: Rob Emanuele <rob@emanuele.us>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Same patch as before, modified to use bool. Also adds description of
the new field in struct atmel_mci that I missed in the first patch.
This patch adds Atmel MCI support for inverted detect pins.
Signed-off-by: Jonas Larsson <jonas.larsson@martinsson.se>
Acked-by: Pierre Ossman <pierre@ossman.eu>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
This fixes a bug when setting the sdc_reg for 4-bit bus width
transactions.
Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
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: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (22 commits)
ioat: fix self test for multi-channel case
dmaengine: bump initcall level to arch_initcall
dmaengine: advertise all channels on a device to dma_filter_fn
dmaengine: use idr for registering dma device numbers
dmaengine: add a release for dma class devices and dependent infrastructure
ioat: do not perform removal actions at shutdown
iop-adma: enable module removal
iop-adma: kill debug BUG_ON
iop-adma: let devm do its job, don't duplicate free
dmaengine: kill enum dma_state_client
dmaengine: remove 'bigref' infrastructure
dmaengine: kill struct dma_client and supporting infrastructure
dmaengine: replace dma_async_client_register with dmaengine_get
atmel-mci: convert to dma_request_channel and down-level dma_slave
dmatest: convert to dma_request_channel
dmaengine: introduce dma_request_channel and private channels
net_dma: convert to dma_find_channel
dmaengine: provide a common 'issue_pending_all' implementation
dmaengine: centralize channel allocation, introduce dma_find_channel
dmaengine: up-level reference counting to the module level
...
DMA_NAK is now useless. We can just use a bool instead.
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan 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: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Needed to use the atmel-mci driver in an architecture
independant maner.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
After a data error, we wait for the NOTBUSY bit to be set so that we can
be sure the data transfer is completely finished. However, when NOTBUSY
is set, the interrupt handler copies the contents of SR into
data_status, overwriting any error bits we may have detected earlier.
To avoid this, initialize data_status to 0 before starting a request, and
don't overwrite it unless it still contains 0.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
This adds support for DMA transfers through the generic DMA engine
framework with the DMA slave extensions.
The driver has been tested using mmc-block and ext3fs on several SD,
SDHC and MMC+ cards. Reads and writes work fine, with read transfer
rates up to 7.5 MiB/s on fast cards with debugging disabled.
Unfortunately, the driver has been known to lock up from time to time
with DMA enabled, so DMA support is currently optional and marked
EXPERIMENTAL. However, I didn't see any problems while testing 13
different cards (MMC, SD and SDHC of different brands and sizes), so I
suspect the "Initialize BLKR before sending data transfer command" fix
that was posted earlier fixed this as well.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
The Atmel MCI controller can drive multiple cards through separate sets
of pins, but only one at a time. This patch adds support for
multiplexing access to the controller so that multiple card slots can be
used as if they were hooked up to separate mmc controllers.
The atmel-mci driver registers each slot as a separate mmc_host. Both
access the same common controller state, but they also have some state
on their own for card detection/write protect handling, and separate
shadows of the MR and SDCR registers.
When one of the slots receives a request from the mmc core, the common
controller state is checked. If it's idle, the request is submitted
immediately. If not, the request is added to a queue. When a request is
done, the queue is checked and if there is a queued request, it is
submitted before the completion callback is called.
This patch also includes a few cleanups and fixes, including a locking
overhaul. I had to change the locking extensively in any case, so I
might as well try to get it right. The driver no longer takes any
irq-safe locks, which may or may not improve the overall system
performance.
This patch also adds a bit of documentation of the internal data
structures.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Add the necessary platform infrastructure to support multiple mmc/sdcard
slots all at once through a single controller. Currently, the driver
will use the first valid slot it finds and stick with that, but later
patches will add support for switching between several slots on the fly.
Extend the platform data structure with per-slot information: MMC/SDcard
bus width and card detect/write protect pins. This will affect the pin
muxing as well as the capabilities announced to the mmc core.
Note that board code is now required to supply a mci_platform_data
struct to at32_add_device_mci().
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Some cards might get upset if we turn off the clock for extended periods
of time. So keep the clock running until the mmc core tells us to turn
it off.
Also, don't reset the controller between each transfer. That was an
attempt to work around earlier bugs, and it never really worked very
well.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
With the current system of completed/pending events, things may get
handled in different order depending on which event triggers first. For
example, if the data transfer is complete before the command, the stop
command must be sent after the command is complete, not the data. This
creates a bit of complexity around the stop command.
By having the tasklet go through a sequence of clearly defined states,
things always happen in a certain order even if the events come at
different times, so the stop command can simply be sent when we exit the
"sending data" state because we will never enter that state before the
command has been sent successfully.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
The atmel-mci driver sometimes fails data transfers like this:
mmcblk0: error -5 transferring data
end_request: I/O error, dev mmcblk0, sector 2749769
end_request: I/O error, dev mmcblk0, sector 2749777
It turns out that this might be caused by the BLKR register (which
contains the block size and the number of blocks being transfered) being
initialized too late. This patch moves the initialization of BLKR so
that it contains the correct value before the block transfer command is
sent.
This error is difficult to reproduce, but if you insert a long delay
(mdelay(10) or thereabouts) between the calls to atmci_start_command()
and atmci_submit_data(), all transfers seem to fail without this patch,
while I haven't seen any failures with this patch.
Reported-by: Hein_Tibosch <hein_tibosch@yahoo.es>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
This allows the mmc core to detect card insertion/removal for slots that
don't have any CD pin wired up.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
We used to store a binary register snapshot in the "regs" file, so we
set the file size to be the size of this snapshot. This is no longer
valid since we switched to using seq_file.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The debugfs hook atmci_regs_show allocates a temporary buffer for
storing a register snapshot, but it doesn't free it before returning.
Plug this leak.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Make sure that the peripheral clock is enabled before reading the MMIO
registers for the debugfs "regs" dump.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Update all avr32-specific files to use the new platform-specific header
locations. Drivers shared with ARM are left alone for now.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Minor cleanups for the MMC/SD support on avr32:
- Make at32_add_device_mci() properly initialize "missing"
platform data ... so boards like STK1002 won't try GPIO 0.
- Switch over to gpio_is_valid() instead of testing for only
one designated value.
- Provide STK1002 platform data for the unlikely case that
switches are set so first Ethernet controller isn't in use.
(That's the only way to get card detect and writeprotect
switch sensing on the STK1000.)
And get rid of one "unused variable" warning.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
This patch does a few small cleanups around the atmel mci platform code
and in the atmel-mci driver. The platform changes simply removes an
unused variable, uses the fact that by the end we always have some form
of platform data and notes that GPIO_PIN_NONE != 0. This last point
could cause the incorrect attempt to twice reserve pin PA0.
While we've got the hood up, add linux/err.h to the atmel-mci.c include
list. It needs it and generally pulls it by voodoo but I did once
stumble across a config which don't build.
This is against Linus' latest git.
Signed-off-by: Ben Nizette <bn@niasdigital.com>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Relax requirements on host controllers and only require that they do not
report a transfer count than is larger than the actual one (i.e. a lower
value is okay). This is how many other parts of the kernel behaves so
upper layers should already be prepared to handle that scenario. This
gives us a performance boost on MMC cards.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This is a driver for the MMC controller on the AP7000 chips from
Atmel. It should in theory work on AT91 systems too with some
tweaking, but since the DMA interface is quite different, it's not
entirely clear if it's worth merging this with the at91_mci driver.
This driver has been around for a while in BSPs and kernel sources
provided by Atmel, but this particular version uses the generic DMA
Engine framework (with the slave extensions) instead of an
avr32-only DMA controller framework.
This driver can also use PIO transfers when no DMA channels are
available, and for transfers where using DMA may be difficult or
impractical for some reason (e.g. the DMA setup overhead is usually
not worth it for very short transfers, and badly aligned buffers or
lengths are difficult to handle.)
Currently, the driver only support PIO transfers. DMA support has been
split out to a separate patch to hopefully make it easier to review.
The driver has been tested using mmc-block and ext3fs on several SD,
SDHC and MMC+ cards. Reads and writes work fine, with read transfer
rates up to 3.5 MiB/s on fast cards with debugging disabled.
The driver has also been tested using the mmc_test module on the same
cards. All tests except 7, 9, 15 and 17 succeed. The first two are
unsupported by all the cards I have, so I don't know if the driver
handles this correctly. The last two fail because the hardware flags a
Data CRC Error instead of a Data Timeout error. I'm not sure how to deal
with that.
Documentation for this controller can be found in many data sheets from
Atmel, including the AT32AP7000 data sheet which can be found here:
http://www.atmel.com/dyn/products/datasheets.asp?family_id=682
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
