The patch adds support for Lenovo IdeaPad Z570 laptop. It makes all special
keys working, adds possibility to control fan like Windows does, controls
Touchpad Disabled LED, toggles touchpad state via keyboard controller and
corrects touchpad behavior on resume from suspend. It is new, modified
version of patch. Now it does not depend on psmouse and does not need patching
of input subsystem.
Signed-off-by: Maxim Mikityanskiy <maxtram95@gmail.com>

This is part 2 for touchpad toggle
Signed-off-by: Ike Panhc <ike.pan@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

The patch adds support for Lenovo IdeaPad Z570 laptop. It makes all special
keys working, adds possibility to control fan like Windows does, controls
Touchpad Disabled LED, toggles touchpad state via keyboard controller and
corrects touchpad behavior on resume from suspend. It is new, modified
version of patch. Now it does not depend on psmouse and does not need patching
of input subsystem.
Signed-off-by: Maxim Mikityanskiy <maxtram95@gmail.com>

This is part 1 for special button handling.
Signed-off-by: Ike Panhc <ike.pan@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

Due to commit cdda911c evdev only
becomes readable when the buffer contains an EV_SYN/SYN_REPORT event.

So in order to read the tablet sensor data as it happens we need to
ensure that we always call input_sync() after input_report_switch()
Signed-off-by: Carlos Alberto Lopez Perez <clopez@igalia.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

In the latest V-series bios DMI_PRODUCT_VERSION does not contain
the string Lenovo or Thinkpad, but is set to the model number, this
causes the thinkpad_acpi module to fail to load. Recognize laptop
as Lenovo using DMI_BIOS_VENDOR instead, which is set to Lenovo.

Test on V490u
=============
== After the patch ==

[ 1350.295757] thinkpad_acpi: ThinkPad ACPI Extras v0.24
[ 1350.295760] thinkpad_acpi: http://ibm-acpi.sf.net/
[ 1350.295761] thinkpad_acpi: ThinkPad BIOS H7ET21WW (1.00 ), EC unknown
[ 1350.295763] thinkpad_acpi: Lenovo LENOVO, model LV5DXXX
[ 1350.296086] thinkpad_acpi: detected a 8-level brightness capable ThinkPad
[ 1350.296694] thinkpad_acpi: radio switch found; radios are enabled
[ 1350.296703] thinkpad_acpi: possible tablet mode switch found; ThinkPad in laptop mode
[ 1350.306466] thinkpad_acpi: rfkill switch tpacpi_bluetooth_sw: radio is unblocked
[ 1350.307082] Registered led device: tpacpi::thinklight
[ 1350.307215] Registered led device: tpacpi::power
[ 1350.307255] Registered led device: tpacpi::standby
[ 1350.307294] Registered led device: tpacpi::thinkvantage
[ 1350.308160] thinkpad_acpi: Standard ACPI backlight interface available, not loading native one
[ 1350.308333] thinkpad_acpi: Console audio control enabled, mode: monitor (read only)
[ 1350.312287] input: ThinkPad Extra Buttons as /devices/platform/thinkpad_acpi/input/input14

== Before the patch ==
sudo modprobe thinkpad_acpi
FATAL: Error inserting thinkpad_acpi (/lib/modules/3.2.0-27-generic/kernel/drivers/platform/x86/thinkpad_acpi.ko): No such device

Test on B485
=============
This patch was also test in a B485 where the thinkpad_acpi module does not
have any issues loading. But, I tested it to make sure this patch does not
break on already functioning models of Lenovo products.

[13486.746359] thinkpad_acpi: ThinkPad ACPI Extras v0.24
[13486.746364] thinkpad_acpi: http://ibm-acpi.sf.net/
[13486.746368] thinkpad_acpi: ThinkPad BIOS HJET15WW(1.01), EC unknown
[13486.746373] thinkpad_acpi: Lenovo Lenovo LB485, model 814TR01
[13486.747300] thinkpad_acpi: detected a 8-level brightness capable ThinkPad
[13486.752435] thinkpad_acpi: rfkill switch tpacpi_bluetooth_sw: radio is unblocked
[13486.752883] Registered led device: tpacpi::thinklight
[13486.752915] thinkpad_acpi: Standard ACPI backlight interface available, not loading native one
[13486.753216] thinkpad_acpi: Console audio control enabled, mode: monitor (read only)
[13486.757147] input: ThinkPad Extra Buttons as /devices/platform/thinkpad_acpi/input/input15
Signed-off-by: Manoj Iyer <manoj.iyer@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

Fixed the typo introduced from the below commit
5f1e88f dell-laptop: Add 6 machines to touchpad led quirk
Reported-by: Carlos Alberto Lopez Perez <clopez@igalia.com>
Signed-off-by: AceLan Kao <acelan.kao@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

This callback is a no-op in nouveau, and the upcoming apple-gmux
switcheroo support won't require it either. Rather than forcing drivers
to stub it out, just make it optional and remove the callback from
nouveau.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

vga_switcheroo assumes that the handler will be registered before the
last client, otherwise switching will not be enabled. Likewise it's
assumed that the handler will not be unregistered without at least one
client also being unregistered, otherwise switching will remain enabled
despite no longer having a handler. These assumptions cannot be enforced
if the handler is in a separate driver from both clients, as with the
gmux found in Apple laptops. Remove this assumption.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

Add support for the gmux display muxing functionality and register a mux
handler with vga_switcheroo.
Signed-off-by: Andreas Heider <andreas@meetr.de>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

Fix the dependencies of apple-gmux to prevent it from being built-in
when one or more of its dependencies is built as a module. Otherwise it
can fail to build due to missing symbols.

v2: Add dependency on ACPI to fix build failure when ACPI=n
Reported-by: Arun Raghavan <arun.raghavan@collabora.co.uk>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

If the user bit is set, that mean BIOS can't set and record the wlan
status, it will report the value read from id ASUS_WMI_DEVID_WLAN_LED
(0x00010012) while we query the wlan status by id ASUS_WMI_DEVID_WLAN
(0x00010011) through WMI.
So, we have to record wlan status in id ASUS_WMI_DEVID_WLAN_LED
(0x00010012) while setting the wlan status through WMI.
This is also the behavior that windows app will do.

Quote from ASUS application engineer
===
When you call WMIMethod(DSTS, 0x00010011) to get WLAN status, it may return

(1) 0x00050001 (On)
(2) 0x00050000 (Off)
(3) 0x00030001 (On)
(4) 0x00030000 (Off)
(5) 0x00000002 (Unknown)

(1), (2) means that the model has hardware GPIO for WLAN, you can call
WMIMethod(DEVS, 0x00010011, 1 or 0) to turn WLAN on/off.
(3), (4) means that the model doesn’t have hardware GPIO, you need to use
API or driver library to turn WLAN on/off, and call
WMIMethod(DEVS, 0x00010012, 1 or 0) to set WLAN LED status.
After you set WLAN LED status, you can see the WLAN status is changed with
WMIMethod(DSTS, 0x00010011). Because the status is recorded lastly
(ex: Windows), you can use it for synchronization.
(5) means that the model doesn’t have WLAN device.

WLAN is the ONLY special case with upper rule.

For other device, like Bluetooth, you just need use
WMIMethod(DSTS, 0x00010013) to get, and WMIMethod(DEVS, 0x00010013, 1 or 0)
to set.
===
Signed-off-by: AceLan Kao <acelan.kao@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

We were only calling acpi_video_unregister() if ACPI video support was built
in, not if it was a module.
Signed-off-by: Matthew Garrett <mjg@redhat.com>

New gmux devices have a different method for accessing the registers.
Update the driver to cope. Incorporates feedback from Bernhard Froemel.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Bernhard Froemel <froemel@vmars.tuwien.ac.at>
Cc: Seth Forshee <seth.forshee@canonical.com>

Move the special-cased backlight update function to a generic gmux_write32
function.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Seth Forshee <seth.forshee@canonical.com>

Pull infiniband/rdma fixes from Roland Dreier:
 "Grab bag of InfiniBand/RDMA fixes:
   - IPoIB fixes for regressions introduced by path database conversion
   - mlx4 fixes for bugs with large memory systems and regressions from
     SR-IOV patches
   - RDMA CM fix for passing bad event up to userspace
   - Other minor fixes"

* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  IB/mlx4: Check iboe netdev pointer before dereferencing it
  mlx4_core: Clean up buddy bitmap allocation
  mlx4_core: Fix integer overflow issues around MTT table
  mlx4_core: Allow large mlx4_buddy bitmaps
  IB/srp: Fix a race condition
  IB/qib: Fix error return code in qib_init_7322_variables()
  IB: Fix typos in infiniband drivers
  IB/ipoib: Fix RCU pointer dereference of wrong object
  IB/ipoib: Add missing locking when CM object is deleted
  RDMA/ucma.c: Fix for events with wrong context on iWARP
  RDMA/ocrdma: Don't call vlan_dev_real_dev() for non-VLAN netdevs
  IB/mlx4: Fix possible deadlock on sm_lock spinlock

Pull TTY fixes from Greg Kroah-Hartman:
 "Here are 4 tiny patches, each fixing a serial driver problem that
  people have reported.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'tty-3.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  pmac_zilog,kdb: Fix console poll hook to return instead of loop
  serial: mxs-auart: fix the wrong RTS hardware flow control
  serial: ifx6x60: fix paging fault on spi_register_driver
  serial: Change Kconfig entry for CLPS711X-target

Pull staging fixes from Greg Kroah-Hartman:
 "Here are some staging driver fixes (and iio driver fixes, they get
  lumped in with the staging stuff due to dependancies) for your 3.6-rc3
  tree.

  Nothing major, just a bunch of fixes that people have reported.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'staging-3.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (26 commits)
  iio: lm3533-als: Fix build warnings
  staging:iio:ad7780: Mark channels as unsigned
  staging:iio:ad7192: Report offset and scale for temperature channel
  staging:iio:ad7192: Report channel offset
  staging:iio:ad7192: Mark channels as unsigned
  staging:iio:ad7192: Fix setting ACX
  staging:iio:ad7192: Add missing break in switch statement
  staging:iio:ad7793: Fix internal reference value
  staging:iio:ad7793: Follow new IIO naming spec
  staging:iio:ad7793: Fix temperature scale and offset
  staging:iio:ad7793: Report channel offset
  staging:iio:ad7793: Mark channels as unsigned
  staging:iio:ad7793: Add missing break in switch statement
  iio/adjd_s311: Fix potential memory leak in adjd_s311_update_scan_mode()
  iio: frequency: ADF4350: Fix potential reference div factor overflow.
  iio: staging: ad7298_ring: Fix maybe-uninitialized warning
  staging: comedi: usbduxfast: Declare MODULE_FIRMWARE usage
  staging: comedi: usbdux: Declare MODULE_FIRMWARE usage
  staging: comedi: usbduxsigma: Declare MODULE_FIRMWARE usage
  staging: csr: add INET dependancy
  ...

Pull driver core fixes from Greg Kroah-Hartman:
 "Here are two tiny patches, one fixing a dynamic debug problem that the
  printk rework turned up, and the other one fixing an extcon problem
  that people reported.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'driver-core-3.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  extcon: extcon_gpio: Replace gpio_request_one by devm_gpio_request_one
  drivers-core: make structured logging play nice with dynamic-debug

Pull Char / Misc driver fixes from Greg Kroah-Hartman:
 "Here are some small misc and w1 driver fixes for 3.6-rc3.  Nothing
  major, just some some bugfixes and a new device id for a w1 driver.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'char-misc-3.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  1-Wire: Add support for the maxim ds1825 temperature sensor
  ti-st: Fix check for pdata->chip_awake function pointer
  mei: add mei_quirk_probe function
  mei: fix device stall after wd is stopped

Pull USB patches from Greg Kroah-Hartman:
 "Here are a number of small USB patches for 3.6-rc3.

  The "large" one is just a number of device id updates to the option
  driver, done by the manufacturer, properly fixing up the device ids
  based on shipping devices.

  Other than that, some gadget driver fixes, the obligitary XHCI
  patches, and some other device ids and bugs fixed.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'usb-3.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (26 commits)
  USB: qcserial: fix port handling on Gobi 1K and 2K+
  USB: serial: Fix mos7840 timeout
  USB: option: add ZTE K5006-Z
  usb: gadget: u_ether: fix kworker 100% CPU issue with still used interfaces in eth_stop
  usb: host: tegra: fix warning messages in ehci_remove
  usb: host: mips: sead3: Update for EHCI register structure.
  usb: renesas_usbhs: fixup resume method for autonomy mode
  usb: renesas_usbhs: mod_host: add missing .bus_suspend/resume
  update MAINTAINERS for Oliver Neukum
  usb: usb_wwan: resume/suspend can be called after port is gone
  usb: serial: prevent suspend/resume from racing against probe/remove
  usb: usb_wwan: replace release and disconnect with a port_remove hook
  usb: serial: mos7840: Fixup mos7840_chars_in_buffer()
  USB: isp1362-hcd.c: usb message always saved in case of underrun
  OMAP: USB : Fix the EHCI enumeration and core retention issue
  usb: chipidea: fix and improve dependencies if usb host or gadget support is built as module
  USB: support the new interfaces of Huawei Data Card devices in option driver
  USB: ftdi_sio: Add VID/PID for Kondo Serial USB
  xhci: Switch PPT ports to EHCI on shutdown.
  xhci: Fix bug after deq ptr set to link TRB.
  ...

Fix fatal error in scripts/kernel-doc by ignoring the "__weak" attribute:

  Error(drivers/pci/pci.c:2820): cannot understand prototype: 'char * __weak pcibios_setup(char *str) '
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull a Yama bugfix from James Morris.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  Yama: access task_struct->comm directly

Pull C6X atomic64 support from Mark Salter:
 "Enable atomic64 ops in C6X
   - define L1_CACHE_SHIFT
   - select GENERIC_ATOMIC64"

* tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming:
  C6X: select GENERIC_ATOMIC64
  C6X: add Lx_CACHE_SHIFT defines

Pull ext4 bug fixes from Ted Ts'o:
 "The following are all bug fixes and regressions.  The most notable are
  the ones which cause problems for ext4 on RAID --- a performance
  problem when mounting very large filesystems, and a kernel OOPS when
  doing an rm -rf on large directory hierarchies on fast devices."

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix kernel BUG on large-scale rm -rf commands
  ext4: fix long mount times on very big file systems
  ext4: don't call ext4_error while block group is locked
  ext4: avoid kmemcheck complaint from reading uninitialized memory
  ext4: make sure the journal sb is written in ext4_clear_journal_err()

In some cases when an autofs indirect mount is contained in a file
system that is marked as shared (such as when systemd does the
equivalent of "mount --make-rshared /" early in the boot), mounts
stop expiring.

When this happens the first expiry check on a mountpoint dentry in
autofs_expire_indirect() sees a mountpoint dentry with a higher
than minimal reference count. Consequently the dentry is condidered
busy and the actual expiry check is never done.

This particular check was originally meant as an optimisation to
detect a path walk in progress but with the addition of rcu-walk
it can be ineffective anyway.

Removing the test allows automounts to expire again since the
actual expire check doesn't rely on the dentry reference count.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 968dee77: "ext4: fix hole punch failure when depth is greater
than 0" introduced a regression in v3.5.1/v3.6-rc1 which caused kernel
crashes when users ran run "rm -rf" on large directory hierarchy on
ext4 filesystems on RAID devices:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000028

    Process rm (pid: 18229, threadinfo ffff8801276bc000, task ffff880123631710)
    Call Trace:
     [<ffffffff81236483>] ? __ext4_handle_dirty_metadata+0x83/0x110
     [<ffffffff812353d3>] ext4_ext_truncate+0x193/0x1d0
     [<ffffffff8120a8cf>] ? ext4_mark_inode_dirty+0x7f/0x1f0
     [<ffffffff81207e05>] ext4_truncate+0xf5/0x100
     [<ffffffff8120cd51>] ext4_evict_inode+0x461/0x490
     [<ffffffff811a1312>] evict+0xa2/0x1a0
     [<ffffffff811a1513>] iput+0x103/0x1f0
     [<ffffffff81196d84>] do_unlinkat+0x154/0x1c0
     [<ffffffff8118cc3a>] ? sys_newfstatat+0x2a/0x40
     [<ffffffff81197b0b>] sys_unlinkat+0x1b/0x50
     [<ffffffff816135e9>] system_call_fastpath+0x16/0x1b
    Code: 8b 4d 20 0f b7 41 02 48 8d 04 40 48 8d 04 81 49 89 45 18 0f b7 49 02 48 83 c1 01 49 89 4d 00 e9 ae f8 ff ff 0f 1f 00 49 8b 45 28 <48> 8b 40 28 49 89 45 20 e9 85 f8 ff ff 0f 1f 80 00 00 00

    RIP  [<ffffffff81233164>] ext4_ext_remove_space+0xa34/0xdf0

This could be reproduced as follows:

The problem in commit 968dee77 was that caused the variable 'i' to
be left uninitialized if the truncate required more space than was
available in the journal.  This resulted in the function
ext4_ext_truncate_extend_restart() returning -EAGAIN, which caused
ext4_ext_remove_space() to restart the truncate operation after
starting a new jbd2 handle.
Reported-by: Maciej Żenczykowski <maze@google.com>
Reported-by: Marti Raudsepp <marti@juffo.org>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

Commit 8aeb00ff: "ext4: fix overhead calculation used by
ext4_statfs()" introduced a O(n**2) calculation which makes very large
file systems take forever to mount.  Fix this with an optimization for
non-bigalloc file systems.  (For bigalloc file systems the overhead
needs to be set in the the superblock.)
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

While in ext4_validate_block_bitmap(), if an block allocation bitmap
is found to be invalid, we call ext4_error() while the block group is
still locked.  This causes ext4_commit_super() to call a function
which might sleep while in an atomic context.

There's no need to keep the block group locked at this point, so hoist
the ext4_error() call up to ext4_validate_block_bitmap() and release
the block group spinlock before calling ext4_error().

The reported stack trace can be found at:

	http://article.gmane.org/gmane.comp.file-systems.ext4/33731Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

The core ptrace access checking routine holds a task lock, and when
reporting a failure, Yama takes a separate task lock. To avoid a
potential deadlock with two ptracers taking the opposite locks, do not
use get_task_comm() and just use ->comm directly since accuracy is not
important for the report.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
CC: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

Merge tag 'v3.6-rc1-iio-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus

IIO fixes for v3.6-rc1

These mostly consist of fixes from Lars-Peter Clausen that were
the first part of a large series reworking the drivers concerned.
Turns out these drivers had quite a wealth of minor bugs.

Also here are some build warning fixes for lm3533-als and
adjd_s111 (both new drives in this cycle).
Final elements are a a div factor overflow and a warning
related fix in a couple of Analog Devices drivers.

All in all nothing major, but a worthwhile bunch of short
fixes.

This patch adds support for maxim ds1825 based 1-wire temperature sensors.
Signed-off-by: Raphael Assenat <raph@8d.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ll_device_want_to_wakeup(): Fix the NULL pointer check on pdata->chip_awake,
which is performed on the wrong function pointer
Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix below build warnings:
  CC [M]  drivers/iio/light/lm3533-als.o
drivers/iio/light/lm3533-als.c:667:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/iio/light/lm3533-als.c:667:8: warning: (near initialization for 'dev_attr_in_illuminance0_thresh_either_en.show') [enabled by default]
drivers/iio/light/lm3533-als.c:667:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/iio/light/lm3533-als.c:667:8: warning: (near initialization for 'dev_attr_in_illuminance0_thresh_either_en.store') [enabled by default]
Signed-off-by: Axel Lin <axel.lin@gmail.com>

The values reported by the AD7780 are unsigned with a binary offset:

	0x000000 is negative fullscale
	0x800000 is zeroscale
	0xffffff is positive fullscale

So mark the channel in the channel spec as unsigned rather than signed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

The temperature channel reports values in degree Kelvin with sensitivity of 5630
codes per degree. If the chip is configured in bipolar mode there is an
additional binary offset of 0x800000 and the sensitivity is divided by two.

Currently the driver does the mapping from the raw value to degree Celsius when
doing a manual conversion. This has several disadvantages, the major one being
that it does not work for buffered mode, also by doing the division by the
sensitivity in the driver the precession of the reported value is needlessly
reduced.

Furthermore the current calculation only works in bipolar mode and the current
scale is of by a factor of 1000.

This patch modifies the driver to report correct offset and scale values in
both unipolar and bipolar mode and to report the raw temperature value
for manual conversions.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

In bipolar mode there is a a binary offset of 2**(N-1) (with N being the number
of bits) on the reported value. Currently this value is subtracted when doing a
manual read. While this works for manual channel readings it does not work for
buffered mode. So report the offset in the channels offset property, which will
work in both modes.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

The values reported by the AD7793 are unsigned.
	In uniploar mode:
			0x000000 is zeroscale
			0xffffff is fullscale
	In bipolar mode:
			0x000000 is negative fullscale
			0x800000 is zeroscale
			0xffffff is positive fullscale

In bipolar mode there is a binary offset, but the values are still unsigned.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Write to the correct register when setting the ACX bit.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Without the break statement we fall right through to the default case and return
an error value.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

The internal reference for the ad7793 and similar is 1.17V
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>