Prior to commit e6c9a037 ("i2c: xiic: Remove the disabling of
interrupts") IRQs where disabled when the initial __xiic_start_xfer() was
called. After the commit the interrupt is enabled while the function is
running, this means it is possible for the interrupt to be triggered while
the function is still running. When this happens the internal data
structures get corrupted and undefined behavior can occur like the
following crash:

	Internal error: Oops: 17 [#1] PREEMPT SMP ARM
	Modules linked in:
	CPU: 0 PID: 2040 Comm: i2cdetect Not tainted 4.0.0-02856-g047a308 #10956
	Hardware name: Xilinx Zynq Platform
	task: ee0c9500 ti: e99a2000 task.ti: e99a2000
	PC is at __xiic_start_xfer+0x6c4/0x7c8
	LR is at __xiic_start_xfer+0x690/0x7c8
	pc : [<c02bbffc>]    lr : [<c02bbfc8>]    psr: 800f0013
	sp : e99a3da8  ip : 00000000  fp : 00000000
	r10: 00000001  r9 : 600f0013  r8 : f0180000
	r7 : f0180000  r6 : c064e444  r5 : 00000017  r4 : ee031010
	r3 : 00000000  r2 : 00000000  r1 : 600f0013  r0 : 0000000f
	Flags: Nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
	Control: 18c5387d  Table: 29a5404a  DAC: 00000015
	Process i2cdetect (pid: 2040, stack limit = 0xe99a2210)
	Stack: (0xe99a3da8 to 0xe99a4000)
	3da0:                   ee031010 00000000 00000001 ee031020 ee031224 c02bc5ec
	3dc0: ee34c604 00000000 ee0c9500 e99a3dcc e99a3dd0 e99a3dd0 e99a3dd8 c069f0e8
	3de0: 00000000 ee031020 c064e100 ffff90bb e99a3e48 c02b6590 ee031020 00000001
	3e00: e99a3e48 ee031020 00000000 e99a3e63 00000001 c02b6ec4 00000000 00000000
	3e20: 00000000 c02b7320 e99a3ef0 00000000 00000000 e99e3df0 00000000 00000000
	3e40: 00000103 2814575f 0000003e c00a0000 e99a3e85 0001003e ee0c0000 e99a3e63
	3e60: eefd3578 c064e61c ee0c9500 c0041e04 0000056c e9a56db8 00006e5a b6f5c000
	3e80: ee0c9548 eefd0040 00000001 eefd3540 ee0c9500 eefd39a0 c064b540 ee0c9500
	3ea0: 00000000 ee92b000 00000000 bef4862c ee34c600 e99ecdc0 00000720 00000003
	3ec0: e99a2000 00000000 00000000 c02b8b30 00000000 00000000 00000000 e99a3f24
	3ee0: b6e80000 00000000 00000000 c04257e8 00000000 e99a3f24 c02b8f08 00000703
	3f00: 00000003 c02116bc ee935300 00000000 bef4862c ee34c600 e99ecdc0 c02b91f0
	3f20: e99ecdc0 00000720 bef4862c eeb725f8 e99ecdc0 c00c9e2c 00000003 00000003
	3f40: ee248dc0 00000000 ee248dc8 00000002 eeb7c1a8 00000000 00000000 c00bb360
	3f60: 00000000 00000000 00000003 ee248dc0 bef4862c e99ecdc0 e99ecdc0 00000720
	3f80: 00000003 e99a2000 00000000 c00c9f68 00000000 00000000 b6f22000 00000036
	3fa0: c000dfa4 c000de20 00000000 00000000 00000003 00000720 bef4862c bef4862c
	3fc0: 00000000 00000000 b6f22000 00000036 00000000 00000000 b6f60000 00000000
	3fe0: 00013040 bef48614 00008cab b6ecdbe6 400f0030 00000003 2f7fd821 2f7fdc21
	[<c02bbffc>] (__xiic_start_xfer) from [<c02bc5ec>] (xiic_xfer+0x94/0x168)
	[<c02bc5ec>] (xiic_xfer) from [<c02b6590>] (__i2c_transfer+0x4c/0x7c)
	[<c02b6590>] (__i2c_transfer) from [<c02b6ec4>] (i2c_transfer+0x9c/0xc4)
	[<c02b6ec4>] (i2c_transfer) from [<c02b7320>] (i2c_smbus_xfer+0x3a0/0x4ec)
	[<c02b7320>] (i2c_smbus_xfer) from [<c02b8b30>] (i2cdev_ioctl_smbus+0xb0/0x214)
	[<c02b8b30>] (i2cdev_ioctl_smbus) from [<c02b91f0>] (i2cdev_ioctl+0xa0/0x1d4)
	[<c02b91f0>] (i2cdev_ioctl) from [<c00c9e2c>] (do_vfs_ioctl+0x4b0/0x5b8)
	[<c00c9e2c>] (do_vfs_ioctl) from [<c00c9f68>] (SyS_ioctl+0x34/0x5c)
	[<c00c9f68>] (SyS_ioctl) from [<c000de20>] (ret_fast_syscall+0x0/0x34)
	Code: e283300c e5843210 eafffe64 e5943210 (e1d320b4)

The issue can easily be reproduced by performing I2C access under high
system load or IO load.

To fix the issue protect the invocation to __xiic_start_xfer() form
xiic_start_xfer() with the same lock that is used to protect the interrupt
handler.

Fixes: e6c9a037 ("i2c: xiic: Remove the disabling of interrupts")
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Reviewed-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Commit d701667b ("i2c: xiic: Do not reset controller before every
transfer") removed the reinitialization of the controller before the start
of each transfer. Apparently this change is not safe to make and the commit
results in random I2C bus failures.

An easy way to trigger the issue is to run i2cdetect.

Without the patch applied:
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
	 00:          -- -- -- -- -- -- -- -- -- -- -- -- --
	 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 30: -- -- -- -- -- -- -- -- UU UU -- UU 3c -- -- UU
	 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 70: -- -- -- -- -- -- -- --

With the patch applied every other or so invocation:
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
	 00:          03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
	 10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
	 20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
	 30: -- -- -- -- -- -- -- -- UU UU -- UU 3c -- -- UU
	 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 70: -- -- -- -- -- -- -- --

So revert the commit for now.

Fixes: d701667b ("i2c: xiic: Do not reset controller before every transfer")
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

In case of error conditions like Arbitration lost or NACK lets signal
the waiting process.

Handle error cases in the Rx path
Signed-off-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Currently only one interrupt is serviced in the isr.
In case the multiple interrupts happen simultenously we service and ack
only one of them. Check for all the causes in the isr and service them.
Signed-off-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Currently there is no slave mode support in the driver
also in the isr we just ack it and do nothing.
So disable the AAS interrupt.
Signed-off-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Remove the busy loop  while waiting for bus busy.
Instead let the processor sleep.
Signed-off-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Currently before every transfer the interrupts are disabled.
So incase the slave nacks in the middle of the transfer the
current transfer is not aborted. Upon enabling the interrupts
conditions like NACK , arbitration lost will not be masked.
Remove the disabling of the interrupts.
Signed-off-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Currently before every transfer the controller is reinitialised.
We are already resetting the controller upon errors so upon every
transfer is a performance kill.
Remove the same.
Signed-off-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The xiic_process is a 154 line code that runs in isr context currently
move it to thread context. Also the name xiic_process suggests that the
intension was to run in process context.
Signed-off-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
[wsa: initialized irqreturn_t to IRQ_NONE instead of IRQ_HANDLED]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Currently the interrupts are disabled at the start of the
isr and enabled at the end of the isr. Remove the same.

In case the slave device NACKs the transaction while in the isr
the transfer will continue and the NACK interrupt will arrive
only after the isr is serviced.
Signed-off-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

info(drivers/i2c/busses/i2c-xiic.c:55): Scanning doc for struct xiic_i2c
Warning(drivers/i2c/busses/i2c-xiic.c:79): No description found for parameter 'endianness'
Signed-off-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The driver tried to access device registers with the (little-endian)
iowrite/ioread functions. While this worked on little-endian machines
(e.g. Microblaze with AXI bus), it made the driver unusable on
big-endian machines (e.g. PPC405 with PLB).

During the probe function, the driver tried to write a 32-bit reset mask
into the reset register. This caused an error interrupt on big-endian
systems, because the device detected an invalid (byte-swapped) reset
mask. The result was an Oops.

The patch implements an endianness detection similar to the one used in
other Xilinx drivers like drivers/spi/spi-xilinx.c. It was tested on a
PPC405/PLB system.
Signed-off-by: NThomas Gessler <Thomas.Gessler@exp2.physik.uni-giessen.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

We have a central copy of the GPL for that. Some addresses were already
outdated.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This driver has been flagged to drop class based instantiation. The removal
improves boot-up time and is unneeded for embedded controllers. Users have been
warned to switch for some time now, so we can actually do the removal. Keep the
DEPRECATED flag, so the core can inform users that the behaviour finally
changed now. After another transition period, this flag can go, too.
While we are here, remove the indentation for the array setup because
such things always break after some time.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>.  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Simplified the probe and remove functions using devm_* functions
Signed-off-by: NKedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

IRQ handler has to be register first before IRQ
is enabled in xiic_reinit().
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Code changes to fix checkpatch warnings listed below.
- WARNING: please, no space before tabs
- WARNING: quoted string split across lines
Signed-off-by: NKedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

'of_match_ptr' is defined in linux/of.h. Include it explicitly to
avoid build breakage in the future.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Casting the return value which is a void pointer is redundant.
The conversion from void pointer to any other pointer type is
guaranteed by the C programming language.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

I2C of helpers used to live in of_i2c.c but experience (from SPI) shows
that it is much cleaner to have this in the core. This also removes a
circular dependency between the helpers and the core, and so we can
finally register child nodes in the core instead of doing this manually
in each driver. So, fix the drivers and documentation, too.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The TX_FIFO register is 10 bits wide.  The lower 8 bits are the data to be
written, while the upper two bits are flags to indicate stop/start.

The driver apparently attempted to optimize write access, by only writing a
byte in those cases where the stop/start bits are zero.  However, we have
seen cases where the lower byte is duplicated onto the upper byte by the
hardware, which causes inadvertent stop/starts.

This patch changes the write access to the transmit FIFO to always be 16 bits
wide.

Signed off by: Steven A. Falco <sfalco@harris.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

There is simply no reason to be manually setting the private driver
data to NULL in the remove/fail to probe cases.  This is just extra
cruft code that can be removed.

A few notes:
* Nothing relies on drvdata being set to NULL.
* The __device_release_driver() function eventually calls
  dev_set_drvdata(dev, NULL) anyway, so there's no need to do it
  twice.
* I verified that there were no cases where xxx_get_drvdata() was
  being called in these drivers and checking for / relying on the NULL
  return value.

This could be cleaned up kernel-wide but for now just take the baby
step and remove from the i2c subsystem.
Reported-by: NWolfram Sang <wsa@the-dreams.de>
Reported-by: NStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <wolfram@the-dreams.de>

CONFIG_HOTPLUG is going away as an option.  As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> (for ocores and mux-gpio)
Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com> (for i2c-gpio)
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> (for puf3)
Acked-by: Barry Song <baohua.song@csr.com> (for sirf)
Reviewed-by: NJean Delvare <khali@linux-fr.org>
[wsa: Fixed "foo* bar" flaws while we are here]
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Convert the drivers in drivers/i2c/busses/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Cc: Ben Dooks <ben-linux@fluff.org>
Acked-by: NJochen Friedrich <jochen@scram.de>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Cc: Manuel Lauss <manuel.lauss@googlemail.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Yong Zhang <yong.zhang0@gmail.com>
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

With the addition of a device platform mfd_cell pointer, MFD drivers
can go back to passing platform data back to their sub drivers.
This allows for an mfd_cell->mfd_data removal and thus keep the
sub drivers MFD agnostic. This is mostly needed for non MFD aware
sub drivers.
Acked-by: NRichard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

The cell's platform_data is now accessed with a helper function;
change clients to use that, and remove the now-unused data_size.

Note that the mfd's platform_data is marked __devinitdata.  This
is still correct in all cases except for the timbgpio driver, whose
remove hook has been changed to no longer reference the pdata.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

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: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

drivers/i2c/busses/i2c-xiic.c:493: error: implicit declaration of function 'mdelay'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: "Richard Röjfors" <richard.rojfors@pelagicore.com>
Cc: "Ben Dooks (embedded platforms)" <ben-linux@fluff.org>
Cc: linux-i2c@vger.kernel.org
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds support for the Xilinx XPS IIC Bus Interface.

The driver uses the dynamic mode, supporting to put several
I2C messages in the FIFO to reduce the number of interrupts.

It has the same feature as ocores, it can be passed a list
of devices that will be added when the bus is probed.
Signed-off-by: NRichard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>