With many drivers converting to using generic device properties, it is
useful to provide array of device properties when instantiating new i2c
client via i2c_board_info and have them automatically added to the device
in question.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When using devicetree i2c_board_info.type is set to the compatible
string with the vendor prefix removed. For I2C devices described via
ACPI the i2c_board_info.type string is set to the ACPI device name. When
using ACPI and DT ids this string ends up something like "PRP0001:00".

If the of_compatible property is present try to use that instead. This
makes it easier to instantiate i2c drivers through ACPI with DT ids.
Signed-off-by: NDan O'Donovan <dan@emutex.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Trivial fix to spelling mistake in WARN message, insufficient has
an insufficient number of i's in the spelling.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

In of_i2c_register_device(), when the check for
device address validity fails we print the info.addr,
which has not been assigned properly.

Fix this by printing the actual invalid address.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Fixes: b4e2f6ac ("i2c: apply DT flags when probing")
Cc: stable@kernel.org

Falling back unconditionally to HostNotify as primary client's interrupt
breaks some drivers which alter their functionality depending on whether
interrupt is present or not, so let's introduce a board flag telling I2C
core explicitly if we want wired interrupt or HostNotify-based one:
I2C_CLIENT_HOST_NOTIFY.

For DT-based systems we introduce "host-notify" property that we convert
to I2C_CLIENT_HOST_NOTIFY board flag.
Tested-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: NPali Rohár <pali.rohar@gmail.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.
Requested-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some tracepoints have a registration function that gets enabled when the
tracepoint is enabled. There may be cases that the registraction function
must fail (for example, can't allocate enough memory). In this case, the
tracepoint should also fail to register, otherwise the user would not know
why the tracepoint is not working.

Cc: David Howells <dhowells@redhat.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The current SMBus Host Notify implementation relies on .alert() to
relay its notifications. However, the use cases where SMBus Host
Notify is needed currently is to signal data ready on touchpads.

This is closer to an IRQ than a custom API through .alert().
Given that the 2 touchpad manufacturers (Synaptics and Elan) that
use SMBus Host Notify don't put any data in the SMBus payload, the
concept actually matches one to one.

Benefits are multiple:
- simpler code and API: the client will just have an IRQ, and
  nothing needs to be added in the adapter beside internally
  enabling it.
- no more specific workqueue, the threading is handled by IRQ core
  directly (when required)
- no more races when removing the device (the drivers are already
  required to disable irq on remove)
- simpler handling for drivers: use plain regular IRQs
- no more dependency on i2c-smbus for i2c-i801 (and any other adapter)
- the IRQ domain is created automatically when the adapter exports
  the Host Notify capability
- the IRQ are assign only if ACPI, OF and the caller did not assign
  one already
- the domain is automatically destroyed on remove
- fewer lines of code (minus 20, yeah!)
Signed-off-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This will aid the seamless removal of the current probe()'s, more
commonly unused than used second parameter.  Most I2C drivers can
simply switch over to the new interface, others which have DT
support can use its own matching instead and others can call
i2c_match_id() themselves.  This brings I2C's device probe method
into line with other similar interfaces in the kernel and prevents
the requirement to pass an i2c_device_id table.
Suggested-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
[Kieran: fix rebase conflicts and adapt for dev_pm_domain_{attach,detach}]
Tested-by: NKieran Bingham <kieran@bingham.xyz>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NKieran Bingham <kieran@bingham.xyz>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

When there was no other way to match a I2C device to driver i2c_match_id()
was exclusively used.  However, now there are other types of tables which
are commonly supplied, matching on an i2c_device_id table is used less
frequently.  Instead of _always_ calling i2c_match_id() from within the
framework, we only need to do so from drivers which have no other way of
matching.  This patch makes i2c_match_id() available to the aforementioned
device drivers.
Acked-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Tested-by: NKieran Bingham <kieran@bingham.xyz>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NKieran Bingham <kieran@bingham.xyz>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Currently the I2C framework insists on devices supplying an I2C ID
table.  Many of the devices which do so unnecessarily adding quite a
few wasted lines to kernel code.  This patch allows drivers a means
to 'not' supply the aforementioned table and match on DT match tables
instead.
Acked-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Tested-by: NKieran Bingham <kieran@bingham.xyz>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NKieran Bingham <kieran@bingham.xyz>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This function provides a single call for all I2C devices which need to
match firstly using traditional OF means i.e by of_node, then if that
fails we attempt to match using the supplied I2C client name with a
list of supplied compatible strings with the '<vendor>,' string
removed.  The latter is required due to the unruly naming conventions
used currently by I2C devices.
Acked-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
[Kieran: Fix static inline usage on !CONFIG_OF]
Tested-by: NKieran Bingham <kieran@bingham.xyz>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NKieran Bingham <kieran@bingham.xyz>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

A great deal of I2C devices are currently matched via DT node name, and
as such the compatible naming convention of '<vendor>,<device>' has gone
somewhat awry - some nodes don't supply one, some supply an arbitrary
string and others the correct device name with an arbitrary vendor prefix.

In an effort to correct this problem we have to supply a mechanism to
match a device by compatible string AND by simple device name.  This
function strips off the '<vendor>,' part of a supplied compatible string
and attempts to match without it.

It is also used for sysfs, where a user can choose to instantiate a
device on an i2c bus using the sysfs interface by providing a string and
address to match and communicate with the device on the bus. Presently
this string is only matched against the old i2c device id style strings,
even in the presence of full device tree compatible strings with vendor
prefixes.

Providing a vendor-prefixed string to the sysfs interface will not match
against the device tree of_match_device() calls as there is no device
tree node to parse from the sysfs interface.

This function can match both vendor prefixed and stripped compatible
strings on the sysfs interface.
Acked-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NKieran Bingham <kieran@bingham.xyz>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Here we're providing dereference protection for i2c_match_id(), which
saves us having to do it each time it's called.  We're also stripping
out the (now) needless checks in i2c_device_match().  This patch paves
the way for other, similar code trimming.
Acked-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Tested-by: NKieran Bingham <kieran@bingham.xyz>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NKieran Bingham <kieran@bingham.xyz>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Race condition between registering an I2C device driver and
deregistering an I2C adapter device which is assumed to manage that
I2C device may lead to a NULL pointer dereference due to the
uninitialized list head of driver clients.

The root cause of the issue is that the I2C bus may know about the
registered device driver and thus it is matched by bus_for_each_drv(),
but the list of clients is not initialized and commonly it is NULL,
because I2C device drivers define struct i2c_driver as static and
clients field is expected to be initialized by I2C core:

  i2c_register_driver()             i2c_del_adapter()
    driver_register()                 ...
      bus_add_driver()                ...
        ...                           bus_for_each_drv(..., __process_removed_adapter)
      ...                               i2c_do_del_adapter()
    ...                                   list_for_each_entry_safe(..., &driver->clients, ...)
    INIT_LIST_HEAD(&driver->clients);

To solve the problem it is sufficient to do clients list head
initialization before calling driver_register().

The problem was found while using an I2C device driver with a sluggish
registration routine on a bus provided by a physically detachable I2C
master controller, but practically the oops may be reproduced under
the race between arbitraty I2C device driver registration and managing
I2C bus device removal e.g. by unbinding the latter over sysfs:

% echo 21a4000.i2c > /sys/bus/platform/drivers/imx-i2c/unbind
  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  Internal error: Oops: 17 [#1] SMP ARM
  CPU: 2 PID: 533 Comm: sh Not tainted 4.9.0-rc3+ #61
  Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
  task: e5ada400 task.stack: e4936000
  PC is at i2c_do_del_adapter+0x20/0xcc
  LR is at __process_removed_adapter+0x14/0x1c
  Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
  Control: 10c5387d  Table: 35bd004a  DAC: 00000051
  Process sh (pid: 533, stack limit = 0xe4936210)
  Stack: (0xe4937d28 to 0xe4938000)
  Backtrace:
  [<c0667be0>] (i2c_do_del_adapter) from [<c0667cc0>] (__process_removed_adapter+0x14/0x1c)
  [<c0667cac>] (__process_removed_adapter) from [<c0516998>] (bus_for_each_drv+0x6c/0xa0)
  [<c051692c>] (bus_for_each_drv) from [<c06685ec>] (i2c_del_adapter+0xbc/0x284)
  [<c0668530>] (i2c_del_adapter) from [<bf0110ec>] (i2c_imx_remove+0x44/0x164 [i2c_imx])
  [<bf0110a8>] (i2c_imx_remove [i2c_imx]) from [<c051a838>] (platform_drv_remove+0x2c/0x44)
  [<c051a80c>] (platform_drv_remove) from [<c05183d8>] (__device_release_driver+0x90/0x12c)
  [<c0518348>] (__device_release_driver) from [<c051849c>] (device_release_driver+0x28/0x34)
  [<c0518474>] (device_release_driver) from [<c0517150>] (unbind_store+0x80/0x104)
  [<c05170d0>] (unbind_store) from [<c0516520>] (drv_attr_store+0x28/0x34)
  [<c05164f8>] (drv_attr_store) from [<c0298acc>] (sysfs_kf_write+0x50/0x54)
  [<c0298a7c>] (sysfs_kf_write) from [<c029801c>] (kernfs_fop_write+0x100/0x214)
  [<c0297f1c>] (kernfs_fop_write) from [<c0220130>] (__vfs_write+0x34/0x120)
  [<c02200fc>] (__vfs_write) from [<c0221088>] (vfs_write+0xa8/0x170)
  [<c0220fe0>] (vfs_write) from [<c0221e74>] (SyS_write+0x4c/0xa8)
  [<c0221e28>] (SyS_write) from [<c0108a20>] (ret_fast_syscall+0x0/0x1c)
Signed-off-by: NVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

Instantiated I2C device nodes are marked with OF_POPULATE. This was
introduced in 4f001fd3. On unloading, loaded device nodes will of
course be unmarked. The problem are nodes that fail during
initialisation: If a node fails, it won't be unloaded and hence not be
unmarked.

If a I2C driver module is unloaded and reloaded, it will skip nodes that
failed before.

Skip device nodes that are already populated and mark them only in case
of success.

Fixes: 4f001fd3 ("i2c: Mark instantiated device nodes with OF_POPULATE")
Signed-off-by: NRalf Ramsauer <ralf@ramses-pyramidenbau.de>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NPantelis Antoniou <pantelis.antoniou@konsulko.com>
[wsa: use 14-digit commit sha]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

This routine is only used together with lockdep for nested locking.
The number of lock subclasses is limited to 8 as defined in lockdep.h

Emit a warning if the adapter depth exceeds the maximum number of
lockdep subclasses.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: NPeter Rosin <peda@axentia.se>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

For crazy setups in which an i2c gpio expander is behind an i2c gpio
multiplexer controlled by a gpio provided a second expander using the
same device driver we need to explicitly tell lockdep how to handle
nested locking.

Export i2c_adapter_depth() as public API to be reused outside of i2c
core code.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: NPeter Rosin <peda@axentia.se>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

When enumerating I2C devices connected to an I2C adapter we scan the whole
namespace (as it is possible to have devices anywhere in that namespace,
not just below the I2C adapter device) and add each found device to the I2C
bus in question.

Now after commit 525e6fab ("i2c / ACPI: add support for ACPI
reconfigure notifications") checking of the adapter handle to the one found
in the I2cSerialBus() resource was moved to happen after resources of the
I2C device has been parsed. This means that if the I2cSerialBus() resource
points to an adapter that does not exists in the system we still parse
those resources. This is problematic in particular because
acpi_dev_resource_interrupt() tries to configure GSI if the device also has
an Interrupt() resource. Failing to do that results errrors like this to be
printed on the console:

  [   10.409490] ERROR: Unable to locate IOAPIC for GSI 37

To fix this we pass the I2C adapter to i2c_acpi_get_info() and make sure
the handle matches the one in the I2cSerialBus() resource before doing
anything else to the device.
Reported-by: NNicolai Stange <nicstange@gmail.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NNicolai Stange <nicstange@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

It's better to have strings in the code like they appeared in the output.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This makes it trivial to constify them, so do that.
Signed-off-by: NPeter Rosin <peda@axentia.se>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

ACPI 5 specification doesn't have property for the I2C bus speed but
I2cSerialBus resource descriptor which define each controller-slave
connection define the maximum speed supported by that connection.

Thus finding the maximum safe speed for the bus is to walk through all
I2cSerialBus resources that are associated to I2C controller and use the
speed of slowest connection.

Add function i2c_acpi_find_bus_speed() to the i2c-core that adapter
drivers can call prior registering itself to core.

This implies two-step walk through the I2cSerialBus resources: call to
i2c_acpi_find_bus_speed() does the first scan and finds the safe bus
speed that adapter drivers can set up. Adapter driver registration does
the second scan when i2c-core creates the I2C slaves by calling the
i2c_acpi_register_devices(). In that way the bus speed is set in case
slave device probe gets called during registration and does communication.

Previous version commit 55d38d06 ("i2c: core: Add function for finding
the bus speed from ACPI") got reverted due merge conflicts from
commit 525e6fab ("i2c / ACPI: add support for ACPI reconfigure
notifications").

This version is a bit bigger than previous version but is still sharing
the lowest and complicated part of I2cSerialBus lookup routines with the
existing code.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

I2C ACPI enumeration was originally implemented in another module under
drivers/acpi/ but was later moved into i2c-core with added support for
I2C ACPI operation region.

Rename these acpi_i2c_ prefixed functions, structures and defines in
i2c-core to i2c_acpi_ in order to have more consistent name space.

This is updated version from commit a7003b65 ("i2c: core: Cleanup I2C
ACPI namespace") that got reverted due merge conflicts from
commit 525e6fab ("i2c / ACPI: add support for ACPI reconfigure
notifications").
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This unifies usage with i2c_lock_bus and i2c_unlock_bus, and paves the
way for the next patch which looks a bit saner with this preparatory
work taken care of beforehand.
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This reverts commit a7003b65.There were
too heavy merge conflicts and the driver code making use of this was not
ready yet anyhow. So, we wait one cycle.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This reverts commit 55d38d06. There were
too heavy merge conflicts and the driver code making use of this was not
ready yet anyhow. So, we wait one cycle.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

ACPI 5 specification doesn't have property for the I2C bus speed but
I2cSerialBus resource descriptors which define each controller-slave
connection define the maximum speed supported by that connection.

Thus finding the maximum safe speed for the bus is to walk all
I2cSerialBus resources that are associated to I2C controller and use
the speed of slowest connection.

Add function i2c_acpi_find_bus_speed() to the i2c-core that adapter
drivers can call prior registering itself to core.

This implies two-step walk through the I2cSerialBus resources: call to
i2c_acpi_find_bus_speed() does the first scan and finds the safe bus
speed that adapter drivers can set up. Adapter driver registration does
the second scan when i2c-core creates the I2C slaves by calling the
i2c_acpi_register_devices(). In that way the bus speed is set in case
slave device probe gets called during registration and does
communication.

Implement this by reusing the existing ACPI I2C walk routines in the
i2c-core. Extend them so that slowest connection speed is saved during
the walk and I2C slaves are registered only when calling through the
i2c_acpi_register_devices() with the i2c_adapter pointer.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

I2C ACPI enumeration was originally implemented in another module under
drivers/acpi/ but was later moved into i2c-core with added support for
I2C ACPI operation region.

Rename these acpi_i2c_ prefixed functions, structures and defines in
i2c-core to i2c_acpi_ in order to have more consistent name space.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Now that we revisited all error messages, we can use pr_fmt for the
remaining pr_* messages to ensure consistent output.
Signed-off-by: NWolfram Sang <wsa-dev@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Use a warning loglevel instead of info and switch to dev_* for device
info. Also print which client was accessed.
Signed-off-by: NWolfram Sang <wsa-dev@sang-engineering.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Use dev_err instead of pr_err for more details.
Signed-off-by: NWolfram Sang <wsa-dev@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Fix some whitespace issues while here.
Signed-off-by: NWolfram Sang <wsa-dev@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Switch to WARN if no adapter name is given, otherwise we won't know who
missed to do that. Add error message if device registration fails.
Update error message for missing algo to match style of the others.
Signed-off-by: NWolfram Sang <wsa-dev@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Move recovery init to a seperate function to let have
i2c_register_adapter() less lines and to avoid goto and a label.
Refactor string handling there for consistency and to save some bytes.
Signed-off-by: NWolfram Sang <wsa-dev@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

On error, we should give idr back to the pool in any case.
Signed-off-by: NWolfram Sang <wsa-dev@sang-engineering.com>
Reviewed-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This patch adds supports for I2C device enumeration and removal via
ACPI reconfiguration notifications that are send as a result of an
ACPI table load or unload operation.

The code is very similar with the device tree reconfiguration code
with only small differences in the way we test and set the enumerated
state of the device:

 * the equivalent of device tree's OF_POPULATED flag is the
   flags.visited field in the ACPI device and the following
   wrappers are used to manipulate it: acpi_device_enumerated(),
   acpi_device_set_enumerated() and acpi_device_clear_enumerated()

 * the device tree code checks of status of the OF_POPULATED flag to
   avoid trying to create duplicate Linux devices in two places: once
   when the controller is probed, and once when the reconfigure event
   is received; in the ACPI code the check is performed only once when
   the ACPI namespace is searched because this code path is invoked in
   both of the two mentioned cases

The rest of the enumeration handling is similar with device tree: when
the Linux device is unregistered the ACPI device is marked as not
enumerated; also, when a device remove notification is received we
check that the device is in the enumerated state before continuing
with the removal of the Linux device.
Signed-off-by: NOctavian Purdila <octavian.purdila@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If the 'i2c-bus' device-tree node is present for an I2C adapter then
parse this subnode for I2C slaves.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NThierry Reding <treding@nvidia.com>

Some I2C devices have multiple addresses assigned, for example each address
corresponding to a different internal register map page of the device.
So far drivers which need support for this have handled this with a driver
specific and non-generic implementation, e.g. passing the additional address
via platform data.

This patch provides a new helper function called i2c_new_secondary_device()
which is intended to provide a generic way to get the secondary address
as well as instantiate a struct i2c_client for the secondary address.

The function expects a pointer to the primary i2c_client, a name
for the secondary address and an optional default address. The name is used
as a handle to specify which secondary address to get.

The default address is used as a fallback in case no secondary address
was explicitly specified. In case no secondary address and no default
address were specified the function returns NULL.

For now the function only supports look-up of the secondary address
from devicetree, but it can be extended in the future
to for example support board files and/or ACPI.
Signed-off-by: NJean-Michel Hautbois <jean-michel.hautbois@veo-labs.com>
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

A custom recovery function doesn't need these pointers to be populated
because it may work differently internally.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NPeter Griffin <peter.griffin@linaro.org>

With a i2c topology like the following

                       GPIO ---|  ------ BAT1
                        |      v /
   I2C  -----+----------+---- MUX
             |                   \
           EEPROM                 ------ BAT2

there is a locking problem with the GPIO controller since it is a client
on the same i2c bus that it muxes. Transfers to the mux clients (e.g. BAT1)
will lock the whole i2c bus prior to attempting to switch the mux to the
correct i2c segment. In the above case, the GPIO device is an I/O expander
with an i2c interface, and since the GPIO subsystem knows nothing (and
rightfully so) about the lockless needs of the i2c mux code, this results
in a deadlock when the GPIO driver issues i2c transfers to modify the
mux.

So, observing that while it is needed to have the i2c bus locked during the
actual MUX update in order to avoid random garbage on the slave side, it
is not strictly a must to have it locked over the whole sequence of a full
select-transfer-deselect mux client operation. The mux itself needs to be
locked, so transfers to clients behind the mux are serialized, and the mux
needs to be stable during all i2c traffic (otherwise individual mux slave
segments might see garbage, or worse).

Introduce this new locking concept as "mux-locked" muxes, and call the
pre-existing mux locking scheme "parent-locked".

Modify the i2c mux locking so that muxes that are "mux-locked" locks only
the muxes on the parent adapter instead of the whole i2c bus when there is
a transfer to the slave side of the mux. This lock serializes transfers to
the slave side of the muxes on the parent adapter.

Add code to i2c-mux-gpio and i2c-mux-pinctrl that checks if all involved
gpio/pinctrl devices have a parent that is an i2c adapter in the same
adapter tree that is muxed, and request a "mux-locked mux" if that is the
case.

Modify the select-transfer-deselect code for "mux-locked" muxes so
that each of the select-transfer-deselect ops locks the mux parent
adapter individually.
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>