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36 Commits

Author SHA1 Message Date
Nicolas Ferre
ebb1fea9b3 mmc: atmel-mci: fix two parameters swapped
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>
2010-05-11 17:33:41 -07:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
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>
2010-03-30 22:02:32 +09:00
Nicolas Ferre
74791a2dc8 mmc: atmel-mci: new MCI2 module support in atmel-mci driver
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>
2009-12-15 08:53:35 -08:00
Nicolas Ferre
2635d1ba71 atmel-mci: change use of dma slave interface
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>
2009-12-15 08:53:35 -08:00
Linus Torvalds
a487b6705a Merge branch 'for-linus' of git://neil.brown.name/md
* '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
  ...
2009-09-24 07:55:29 -07:00
Rob Emanuele
04d699c364 atmel-mci: unified Atmel MCI drivers (AVR32 & AT91)
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>
2009-09-23 07:39:37 -07:00
Atsushi Nemoto
657a77fa72 dmaengine: Move all map_sg/unmap_sg for slave channel to its client
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>
2009-09-08 17:53:05 -07:00
Jonas Larsson
1c1452be2e atmel-mci: Add support for inverted detect pin
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>
2009-04-08 20:47:48 +02:00
Hans-Christian Egtvedt
32ab83a56f atmel-mci: fix sdc_reg typo
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>
2009-03-24 21:30:11 +01:00
Kay Sievers
89c8aa203e mmc: struct device - replace bus_id with dev_name(), dev_set_name()
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2009-03-24 21:29:57 +01:00
Dan Williams
287d859222 atmel-mci: fix initialization of dma slave data
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>
2009-02-18 15:37:55 -08:00
Linus Torvalds
d9e8a3a5b8 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx
* '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
  ...
2009-01-09 11:52:14 -08:00
Dan Williams
7dd6025101 dmaengine: kill enum dma_state_client
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>
2009-01-06 11:38:19 -07:00
Dan Williams
aa1e6f1a38 dmaengine: kill struct dma_client and supporting infrastructure
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>
2009-01-06 11:38:17 -07:00
Dan Williams
74465b4ff9 atmel-mci: convert to dma_request_channel and down-level dma_slave
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>
2009-01-06 11:38:16 -07:00
Dan Williams
6f49a57aa5 dmaengine: up-level reference counting to the module level
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>
2009-01-06 11:38:14 -07:00
Nicolas Ferre
c42aa775cc atmel-mci: move atmel-mci.h file to include/linux
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>
2009-01-05 16:35:31 +01:00
Haavard Skinnemoen
5e7184ae0d atmel-mci: Add missing flush_dcache_page() in PIO transfer code
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-10-05 20:39:21 +02:00
Haavard Skinnemoen
ca55f46e13 atmel-mci: Don't overwrite error bits when NOTBUSY is set
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>
2008-10-05 20:39:21 +02:00
Haavard Skinnemoen
65e8b083fc atmel-mci: Add experimental DMA support
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>
2008-10-05 20:39:21 +02:00
Haavard Skinnemoen
965ebf33ea atmel-mci: support multiple mmc slots
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>
2008-10-05 20:39:21 +02:00
Haavard Skinnemoen
6b918657b7 atmel-mci: Platform code for supporting multiple mmc slots
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>
2008-10-05 20:39:21 +02:00
Haavard Skinnemoen
945533b538 atmel-mci: Don't stop the clock between transfers
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>
2008-10-05 20:39:20 +02:00
Haavard Skinnemoen
c06ad2580d atmel-mci: Implement tasklet as a state machine
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>
2008-10-05 20:39:20 +02:00
Haavard Skinnemoen
a252e3e35e atmel-mci: Initialize BLKR before sending data transfer command
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>
2008-10-05 20:39:20 +02:00
Haavard Skinnemoen
da45b66ec8 atmel-mci: Set MMC_CAP_NEEDS_POLL if no detect_pin
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>
2008-09-20 12:12:23 +02:00
Haavard Skinnemoen
75d33cc751 atmel-mci: Fix bogus debugfs file size
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>
2008-09-20 12:12:09 +02:00
Haavard Skinnemoen
b17339a12c atmel-mci: Fix memory leak in atmci_regs_show
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>
2008-09-20 12:11:48 +02:00
Haavard Skinnemoen
87e60f2b80 atmel-mci: debugfs: enable clock before dumping regs
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>
2008-09-20 12:11:29 +02:00
Haavard Skinnemoen
3663b736a5 avr32: Use <mach/foo.h> instead of <asm/arch/foo.h>
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>
2008-08-05 14:36:57 +02:00
David Brownell
3c26e17032 avr32: some mmc/sd cleanups
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>
2008-07-27 13:57:36 +02:00
Haavard Skinnemoen
eda3d8f560 Merge commit 'upstream/master' 2008-07-27 13:54:08 +02:00
Haavard Skinnemoen
deec9ae31e atmel-mci: debugfs support
Create additional files under the host's debugfs directory containing
additional host-specific debug information.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2008-07-27 01:26:17 +02:00
Ben Nizette
fbfca4b878 avr32: clean up mci platform code
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>
2008-07-18 11:01:16 +02:00
Pierre Ossman
23af60398a mmc: remove multiwrite capability
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>
2008-07-15 14:14:49 +02:00
Haavard Skinnemoen
7d2be0749a atmel-mci: Driver for Atmel on-chip MMC controllers
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>
2008-07-15 14:14:49 +02:00