These DMA drain buffer implementations in drivers are pretty horrible
to do in terms of manipulating the scatterlist.  Plus they're being
done at least in drivers/ide and drivers/ata, so we now have code
duplication.

The one use case for this, as I understand it is AHCI controllers doing
PIO mode to mmc devices but translating this to DMA at the controller
level.

So, what about adding a callback to the block layer that permits the
adding of the drain buffer for the problem devices.  The idea is that
you'd do this in slave_configure after you find one of these devices.

The beauty of doing it in the block layer is that it quietly adds the
drain buffer to the end of the sg list, so it automatically gets mapped
(and unmapped) without anything unusual having to be done to the
scatterlist in driver/scsi or drivers/ata and without any alteration to
the transfer length.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

If the users sets a new ->bi_bdev on the bio after __bio_clone() has
returned it, the "segment counts valid" flag still remains even though
it may be different with the new target. So don't calculate segment
counts in __bio_clone().
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Let queue_dma_alignment return 0 if it was specifically set to 0.
This permits devices with no particular alignment restrictions to
use arbitrary user space buffers without copying.
Signed-off-by: Pete Wyckoff <pw@osc.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Since the SCSI layer uses the request queues from the block layer, blktrace can
also be used to trace the requests to all SCSI devices (like SCSI tape drives),
not only disks. The only missing part is the ioctl interface to start and stop
tracing.

This patch adds the SETUP, START, STOP and TEARDOWN ioctls from blktrace to the
sg device files. With this change, blktrace can be used for SCSI devices like
for disks, e.g.: blktrace -d /dev/sg1 -o - | blkparse -i -
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6: (54 commits)
  MAINTIANERS: just use Mike gmail e-mail for contact and pawn the serial driver off onto Sonic
  [Blackfin] arch: remove old I2C BF54x porting.
  [Blackfin] arch: Add the semtimedop syscall.  Upstream uClibc doesn't compile without it.
  [Blackfin] arch: fix bug kernel boot message: memory information is not reasonable
  [Blackfin] arch: use common flash driver to setup partitions rather than the bf5xx-flash driver
  [Blackfin] arch: Fix bug - kernel build with Debug option enabled fails to boot up
  [Blackfin] arch: Fix bug Only RTC interrupt can wake up deeper sleep core.
  [Blackfin] arch: Add proper SW System Reset delay sequence
  [Blackfin] arch: Update copyright date
  [Blackfin] arch: GPIO API cleanup and anomaly update
  [Blackfin] arch: Fix BUG gpio_direction_output API is not compatitable with GENERIC_GPIO API interface
  [Blackfin] arch: Initial checkin of the memory protection support.
  [Blackfin] arch: set_bfin_dma_config shouldnt set SYNC or RESTART by default - add argument or option
  [Blackfin] arch: Add some comments - fix semicolons
  [Blackfin] arch: move all code related to CPLB handling into a new subdirectory under kernel/
  [Blackfin] arch: print out list of modules if kernel is crashing and tell people if the kernel is tainted 
  [Blackfin] arch: enable generic GPIO based I2C driver in STAMP-BF533, EZKIT-BF533 and EZKIT-BF561 boards
  [Blackfin] arch: Don't oops_in_progress if single step is comming from the kernel
  [Blackfin] arch: Fix BUG - kernel sometimes would stuck with KEYBOARD_GPIO on
  [Blackfin] arch: update to latest anomaly sheets
  ...

All the users of this driver explicitly specify the I2C bus numbers
to be used in their platform data. Make the driver respect that.
Signed-off-by: Kalle Pokki <kalle.pokki@eke.fi>
Cc: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Convert the i2c-au1550 bus driver to platform driver, and
register a platform device for the Alchemy Db/Pb series of
boards.
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Zero-bytes transfers would leave the bus transaction unfinished
(no i2c stop is sent), with the following transfer actually
sending the slave address to the previously addressed device,
resulting in weird device failures (e.g. reset minute register
values in my RTC).
This patch instructs the controller to send an I2C STOP right after
the slave address in case of a zero-byte transfer.
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Propagate the error values returned by i2c_wait() instead of overriding
them with a meaningless -1.
Signed-off-by: Jon Smirl <jonsmirl@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

This adds a i2c_new_dummy() primitive to help work with devices
that consume multiple addresses, which include many I2C eeproms
and at least one RTC.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

It is no longer required to hold adapter->clist_lock to call
i2c_check_addr.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>

We only need to hold adapter->clist_lock when we touch the client list.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

This goes on top of the patch removing most i2c_adapter.clients usage,
updating i2c_attach_client:

 - Don't call device_register() while holding clist_lock.  This
   removes a self-deadlock when on the i2c_driver.probe() path,
   for drivers that need to attach new devices (e.g. dummies).

 - Remove a redundant address check.  The driver model core does
   this as a consequence of guaranteeing unique names.

 - Move the "device registered" diagnostic so that it never lies;
   previously, on error paths it would falsely report success.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

The redundant i2c client list maintained by i2c-core is going away
soon, so drivers should stop using it now. Instead, they can use the
standard iterator provided by the device driver model
(device_for_each_child).
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Michael Hunold <michael@mihu.de>

The i2c_adapter.clients list of i2c_client nodes duplicates driver
model state.  This patch starts removing that list, letting us remove
most existing users of those i2c-core lists.

 * The core I2C code now iterates over the driver model's list instead
   of the i2c-internal one in some places where it's safe:
      - Passing a command/ioctl to each client, a mechanims
        used almost exclusively by DVB adapters;
      - Device address checking, in both i2c-core and i2c-dev.

 * Provide i2c_verify_client() to use with driver model iterators.

 * Flag the relevant i2c_adapter and i2c_client fields as deprecated,
   to help prevent new users from appearing.

For the moment the list needs to stick around, since some issues show
up when deleting devices created by legacy I2C drivers.  (They don't
follow standard driver model rules.  Removing those devices can cause
self-deadlocks.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Add support for another variant of the VT8237. I couldn't test
I2C block support but I assume it is present as well.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Checking the PCI function number doesn't add any value, and it makes
adding dynamic IDs to the driver more difficult. Drop this check.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

The i2c-amd756 and i2c-viapro drivers make use of the driver_data
field of the PCI device ID. When adding device IDs dynamically (by
writing to the new_id sysfs file) you cannot set the value of this
field by default. It has to be allowed explicitly. Do that, and
check the value so that the user can't crash the kernel accidentally.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

Add polling I2C transfer implementation for PXA I2C. This is needed
for cases where I2C transactions have to occur at times interrups are
disabled.
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Acked-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Allow i2c_transfer to be called in contexts where sleeping is not allowed.
It is the reponsability of the caller to ensure that the underlying i2c bus
driver will not sleep either.
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

The implementation is unsafe, and anyway one can achieve the same from
userspace using i2c-dev + i2cdetect.

Also tag i2c_sibyte_add_bus __init.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Ralf Baechle <ralf@linux-mips.org>

Discard all I2C driver IDs that aren't used anywhere. That's not just a
couple of them, but more like 49 or one quarter of all defined IDs! And
this is just a first pass, next will come all IDs that are set but
never used, or used but never set.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

I2C block read is supported since the ICH5. I couldn't get it to work
using the block buffer, so it's using the old-style byte-by-byte mode
for now.

Note: I'm also updating the driver author... The i2c-i801 driver was
really written by Mark Studebaker, even though he based his work on
the i2c-piix4 driver which was written by Philip Edelbrock.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Clear special mode bits (PEC, block buffer) at driver load time,
you never know in which state the device was left by its last user.

Also make sure that we reset the block buffer mode at the end of every
transaction, not only when PEC was used.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Use separate flags with explicit names to describe the features of
the ICH chip.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Provide a clearer documentation of which additional features each
ICH chip support, and which of these the driver supports.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Move the tps65010 header file from the OMAP arch directory to the
more generic <linux/i2c/...> directory, and remove the spurious
dependency of this driver on OMAP.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Rename the main mutex in i2c-core from core_lists to core_lock. This
makes more sense now that the redundant lists are gone.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

i2c_driver.list is superfluous, this list duplicates the one
maintained by the driver core. Drop it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>

i2c_adapter.list is superfluous, this list duplicates the one
maintained by the driver core. Drop it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>

Use more standard prototypes for i2c_use_client() and
i2c_release_client(). The former now returns a pointer to the client,
and the latter no longer returns anything. This matches what all other
subsystems do.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>

Don't implement our own reference counting mechanism for i2c clients
when the driver model already has one.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>

The framebuffer drivers for these pieces of hardware include support
for the DDC/I2C buses, so there is no need for separate drivers.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

I2C adapter drivers are supposed to handle retries on nack by themselves
if they do, so there's no point in setting .retries if they don't.

As this retry mechanism is going away (at least in its current form),
clean this up now so that we don't get build failures later.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

I2C driver IDs are optional, so if you don't need one, just omit it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Signed-off-by: Jean Delvare <khali@linux-fr.org>

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it>

This patch allows much of the I2C client address data to move from initdata
into text.
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

The 10-bit address support in i2c-algo-pcf is so heavily broken that
it can't have ever been used. Nobody ever complained, so I'll take it
that nobody needs it. Let's just delete it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Update comments and logging on return path for byte writes.  NAK is
an error, to be reported or optionally ignored.  Timeouts are always
errors.  Lost arbitration is not currently handled, so don't even list
it as an option in the error message.

Don't return bogus EFAULT code for inappropriate NAK; EIO is better,
there is no bad userspace address in question.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>