Let general purpose I2C/SMBus bus drivers add SPD to their class. Once
this is done, we will be able to tell the eeprom driver to only probe
for SPD EEPROMs and similar on these buses.

Note that I took a conservative approach here, adding I2C_CLASS_SPD to
many drivers that have no idea whether they can host SPD EEPROMs or not.
This is to make sure that the eeprom driver doesn't stop probing buses
where SPD EEPROMs or equivalent live.

So, bus driver maintainers and users should feel free to remove the SPD
class from drivers those buses never have SPD EEPROMs or they don't
want the eeprom driver to bind to them. Likewise, feel free to add the
SPD class to any bus driver I might have missed.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Bugfixes to the i2c-cpm driver

- enable correct interrupts (I2CER_TXE instead of I2CER_BUSY)
- replace forgotten iic with i2c
- prefix debug-output on init with 0x and add frequency
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Acked-by: NJochen Friedrich <jochen@scram.de>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This driver uses the port of 2.4 code from Vitaly Bordug
<vitb@kernel.crashing.org> and the actual algorithm used by the i2c
driver of the DBox code on cvs.tuxboc.org from Felix Domke
(tmbinc@gmx.net) and Gillem (htoa@gmx.net) converted to an
of_platform_driver. Tested on CPM1 (MPC823 on dbox2 hardware) and
CPM2 (MPC8272).
Signed-off-by: NJochen Friedrich <jochen@scram.de>
Tested-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This is part of the effort to get rid of the BKL.

[JD: In fact i2c-dev doesn't need more locking than is already done
for the other i2c drivers, so we can simply switch to unlocked_ioctl.]
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

New i2c bus driver for the Intel SCH chipsets (AF82US15W, AF82US15L,
AF82UL11L).
Signed-off-by: NAlek Du <alek.du@intel.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

i2c_del_driver() can be simplified a bit.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Use list_for_each_entry_safe() in i2c_del_adapter() and i2c_del_driver().
Signed-off-by: NMatthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Fix errorcode to be more descriptive when ioremap fails.
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Give a more concrete error code, when the bus is not idle.
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Many PC SMBus host controller drivers don't properly handle the case
where they are requested to achieve a transaction they do not support.
Update them so that the consistently print a warning message and
return a single error value in this case.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The i2c-piix4 driver was used recently as a model to write a new SMBus
host controller driver and this made me realize that the code of this
old driver wasn't exactly good. So, here are many cleanups and minor
fixes to this driver, so that these minor mistakes aren't duplicated
again:

* Delete unused structure.
* Delete needless forward function declaration.
* Properly announce the SMBus host controller as we find it.
* Spell it SMBus not SMB.
* Return -EBUSY instead of -ENODEV when the I/O region is already in
  use.
* Drop useless masks on the 7-bit address and the R/W bit.
* Reject block transaction requests with an invalid block length.
* Check and report block transaction replies with an invalid block
  length.
* Delete a useless comment.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Tighten error paths used by various i2c adapters (mostly x86) so
they return real fault/errno codes instead of a "-1" (which is
most often interpreted as "-EPERM").  Build tested, with eyeball
review.

One minor initial goal is to have adapters consistently return
the code "-ENXIO" when addressing a device doesn't get an ACK
response, at least in the probe paths where they are already
good at stifling related logspam.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Defend the i2c refcount calls against NULL pointers, as is important
(and conventional) for such calls.  Note that none of the current
callers of i2c_use_client() use its return value.

[JD: I hate this but apparently all the other subsystems do it so...]
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Provide kerneldoc for most of the I2C and SMBus I/O calls.  Add a
comment summarizing some fault reporting issues which affect the
ability to provide clean fault reports through I2C master transfer
calls.  (Making it hard to precisely specify their return values...)
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Function i2c_smbus_write_quick has no users left, so we can delete it.

Also update the list of these helper functions which are gone but
could be added back if needed.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The list of I2C/SMBus bus drivers is growing and it is sometimes
difficult for the users to figure out what drivers they should enable.
By grouping the drivers by type, I hope to make the selection easier.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

More updates to the I2C stack's fault reporting:  make the core stop
returning "-1" (usually "-EPERM") for all faults.  Instead, pass lower
level fault code up the stack, or return some appropriate errno.

This patch happens to touch almost exclusively SMBus calls.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

i2c-core doesn't use seq files, so doesn't need to include
<linux/seq_file.h>.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Since only a few Blackfins lack TWI, just list them in a depends
statement.
Signed-off-by: NMike Frysinger <vapier.adi@gmail.com>
Signed-off-by: NBryan Wu <cooloney@kernel.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This patch contains the scheduled removal of i2c-i810, i2c-prosavage
and i2c-savage4.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Just like the Tyan S4882, the S4985 uses a multiplexer to give access
to all 16 memory module SPD EEPROMs. This specific i2c-nforce2-s4985
driver adds support for this. It is heavily based on the older
i2c-amd756-s4882 driver.

As more mainboards will use multiplexer chips, we will have to find a
way to support them without having to write a new specfic driver for
each. The recent changes to the i2c subsystem should help us, and the
new gpio subsystem might help, too.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

If an interrupt happens before an I2c master read/write,
complete is called on uninitialized structure.
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NKevin Hilman <khilman@mvista.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

If wait_for_completion_interruptible_timeout exits due
to a signal, the i2c bus was locking up.
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NKevin Hilman <khilman@mvista.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Interrupts are enabled at the point where the DAVINCI_I2C_IVR_REG is read,
so unless an interrupt happened just at that moment, no interrupt would be
pending. Even though documentation implies you should do this, I see no
reason. If slave support is added, this read would cause a hard to
reproduce bug.
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NKevin Hilman <khilman@mvista.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Previously the dev_dbg only printed if no error.
Printing also on an error is more useful
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NKevin Hilman <khilman@mvista.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Ensure psc value gives a clock between 7-12 MHz
Signed-off-by: NTroy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: NKevin Hilman <khilman@mvista.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Use class_for_each_device for iteration.
Signed-off-by: NDave Young <hidave.darkstar@gmail.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Add a MODULE_ALIAS() statement for the i2c-s3c2410 controller
to ensure that it can be autoloaded on the S3C2440 systems that
we support.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

The driver should be returning -ENXIO for transfers that do not
pass the initial address byte stage.

Note, also small tidyups to the driver comments in the area.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

We should check for the reception of an ACK after transmitting each
data byte. The address send has been correctly checking this, but the
data write byte state should have also been checking for these failures.

As part of the same fix, we remove the ACK checking from the receive
path where it should not have been checking for an ACK which our hardware
was sending.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

i2c-core takes care of the possible corruption of 24RF08 chips for
quite some times, so device devices no longer need to do it. And they
really should not, as applying the prevention twice voids it.

I thought that I had fixed all drivers long ago but apparently I had
missed that one.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Ben Gardner <bgardner@wabtec.com>

The i2c-amd756 driver pretends to support SMBus process call
transactions but actually does not. Fix it.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Remove the old driver_name/type scheme for i2c driver matching. Only the
standard aliasing model will be used from now on.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

There is a strange chip at 0x2e on the second SMBus channel of the
DFI Lanparty NF4 Expert motherboard. Accessing the chip reboots the
system. As there's nothing interesting on this SMBus channel, the
easiest and safest thing to do is to disable it on that board.

This is a better fix to bug #5889 than the it87 driver update that was
done originally:
http://bugzilla.kernel.org/show_bug.cgi?id=5889Signed-off-by: NJean Delvare <khali@linux-fr.org>

The Alchemy platform code registers the SMBus device using the virtual
address of its registers instead of the physical one -- fix this, taking
into account that actually the whole megabyte is decoded by any of the
programmable serial controllers (one of which is SMBus), and that all the
Alchemy peripherals are directly mappable into KSEG1 kernel space and
therefore ioremap() call would just boil down to CKSEG1ADDR() invocation.
Signed-off-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

As the old driver_name/type matching scheme is going away soon, change
the dummy device mechanism to use the new matching scheme.

This has the downside that dummy i2c clients can no longer choose
their name, they'll all appear as "dummy" in sysfs and in log
messages. I don't think it is a problem in practice though, as there
is little reason to use these i2c clients to log messages.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The i2c_sibyte_add_bus() function is not called, nor meant to, from 
outside, so mark it as static; fixing a sparse warning too.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The frequency may have been once hardcoded to 100 kHz, but currently it is
passed as an argument to i2c_sibyte_add_bus(), so update the comment to
match code.  While at it, reformat a nearby comment for consistency.  No
functional changes.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

We had a report that running sensors-detect on a Sapphire AM2RD790
motherbord killed the CPU. While the exact cause is still unknown,
I'd rather play it safe and prevent any access to the SMBus on that
machine by not letting the i2c-piix4 driver attach to the SMBus host
device on that machine. Also blacklist a similar board made by DFI.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Per the PIIX4 errata, there maybe a delay between setting the
start bit in the Smbus Host Controller Register and the transaction
actually starting. If the driver doesn't delay long enough, it
may appear that the transaction is complete when actually it
hasn't started, this may lead to bus collisions.

While 1 ms appears to be enough for most chips, the ServerWorks CSB5
wants 2 ms.
Signed-off-by: NDavid Milburn <dmilburn@redhat.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>