The spec for the pca9546 was missing. This chip is the same as the pca9545
except that it lacks interrupt lines. While the i2c_device_id table mapped
the pca9546 to the pca9545 definition the compatible table did not.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Peter Rosin <peda@axentia.se>
In ACPI world any ID should be carefully chosen and registered
officially. The commit bbf9d262a1 seems did a wrong assumption because
PCA is the registered PNP ID for "PHILIPS BU ADD ON CARD". I'm pretty
sure this prefix has nothing to do with the driver in question.
Moreover, newer ACPI specification has a support of _DSD method and
special device IDs to allow drivers be enumerated via compatible string.
The slight change to support this kind of enumeration will be added in
sequential patch against pca954x.c.
Revert the commit bbf9d262a1 for good.
Cc: Tin Huynh <tnhuynh@apm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Various muxes can aggregate multiple interrupts from each i2c bus.
All of the muxes with interrupt support combine the active low irq lines
using an internal 'and' function and generate a combined active low
output. The muxes do provide the ability to read a control register to
determine which irq is active. By making the mux an irq controller isr
latency can potentially be reduced by reading the status register and
then only calling the registered isr on that bus segment.
As there is no irq masking on the mux irq are disabled until irq_unmask is
called at least once.
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Peter Rosin <peda@axentia.se>
The spec for the pca954x was missing. This chip is the same as the pca9540
except that it has interrupt lines. While the i2c_device_id table mapped
the pca9542 to the pca9540 definition the compatible table did not. In
preparation for irq support add the pca9542 definition.
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Peter Rosin <peda@axentia.se>
The I2C core always reports a MODALIAS of the form i2c:<foo> even if the
device was registered via OF, this means that exporting the OF device ID
table device aliases in the module is not needed. But in order to change
how the core reports modaliases to user-space, it's better to export it.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The I2C core always reports a MODALIAS of the form i2c:<foo> even if the
device was registered via OF, this means that exporting the OF device ID
table device aliases in the module is not needed. But in order to change
how the core reports modaliases to user-space, it's better to export it.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Remove including <linux/version.h> that don't need it.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
smbus functions return -ve on error, 0 on success. However,
__i2c_transfer() have a different return signature - -ve on error, or
number of buffers transferred (which may be zero or greater).
The upshot of this is that the sense of the test is reversed when using
the mux on a bus supporting the master_xfer method: we cache the value
and never retry if we fail to transfer any buffers, but if we succeed,
we clear the cached value.
Fix this by making mlxcpld_mux_reg_write() return a -ve error code for
all failure cases, just as was done in commit 7f638c1cb0 ("i2c: mux:
pca954x: fix i2c mux selection caching").
This also aligns the implementations of these two muxes in this area.
Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
smbus functions return -ve on error, 0 on success. However,
__i2c_transfer() have a different return signature - -ve on error, or
number of buffers transferred (which may be zero or greater.)
The upshot of this is that the sense of the test is reversed when using
the mux on a bus supporting the master_xfer method: we cache the value
and never retry if we fail to transfer any buffers, but if we succeed,
we clear the cached value.
Fix this by making pca954x_reg_write() return a negative error code for
all failure cases.
Fixes: 463e8f845c ("i2c: mux: pca954x: retry updating the mux selection on failure")
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
- the first series of making i2c_device_id optional instead of
mandatory (in favor of alternatives like of_device_id).
This involves adding a new probe callback (probe_new) which removes
some peculiarities I2C had for a long time now. The new probe is
matching the other subsystems now and the old one will be removed
once all users are converted. It is expected to take a while but
there is ongoing interest in that.
- SMBus Host Notify introduced 4.9 got refactored. They are now using
interrupts instead of the alert callback which solves multiple
issues.
- new drivers for iMX LowPower I2C, Mellanox CPLD and its I2C mux
- significant refactoring for bcm2835 driver
- the usual set of driver updates and improvements
* 'i2c/for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (46 commits)
i2c: fsl-lpi2c: read lpi2c fifo size in probe()
i2c: octeon: thunderx: Remove double-check after interrupt
i2c: octeon: thunderx: TWSI software reset in recovery
i2c: cadence: Allow Cadence I2C to be selected for Cadence Xtensa CPUs
i2c: sh_mobile: Add per-Generation fallback bindings
i2c: rcar: Add per-Generation fallback bindings
i2c: imx-lpi2c: add low power i2c bus driver
dt-bindings: i2c: imx-lpi2c: add devicetree bindings
i2c: designware-pcidrv: Add 10bit address feature to medfield/merrifield
i2c: pxa: Add support for the I2C units found in Armada 3700
i2c: pxa: Add definition of fast and high speed modes via the regs layout
dt-bindings: i2c: pxa: Update the documentation for the Armada 3700
i2c: qup: support SMBus block read
i2c: qup: add ACPI support
i2c: designware: Consolidate default functionality bits
i2c: i2c-mux-gpio: update mux with gpiod_set_array_value_cansleep
i2c: mux: pca954x: Add ACPI support for pca954x
i2c: use an IRQ to report Host Notify events, not alert
i2c: i801: remove SMBNTFDDAT reads as they always seem to return 0
i2c: i801: use the BIT() macro for FEATURES_* also
...
If the gpio controller supports it and the gpio lines are concentrated
to one gpio chip, the mux controller pins will get updated simultaneously.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch enables ACPI support for mux-pca954x driver.
Signed-off-by: Tin Huynh <tnhuynh@apm.com>
Acked-by: Peter Rosin <peda@axentia.se>
[wsa: removed a trailing whitespace]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Deselect functionality can be ignored for device-trees with
"i2c-mux-idle-disconnect" entries if no platform_data is available.
By enabling the deselect functionality outside the platform_data
block the logic works as it did in previous kernels.
Fixes: 7fcac98071 ("i2c: i2c-mux-pca954x: convert to use an explicit i2c mux core")
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: Alex Hemme <ahemme@cisco.com>
Signed-off-by: Ziyang Wu <ziywu@cisco.com>
[touched up a few minor issues /peda]
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This driver allows I2C routing controlled through CPLD select registers on
a wide range of Mellanox systems (CPLD Lattice device).
MUX selection is provided by digital and analog HW. Analog part is not
under SW control.
Digital part is under CPLD control (channel selection/de-selection).
Connectivity schema.
.---. .-------------.
| l | | |-- i2cx1 -- i2cx8
| i |-- i2cn --+--| mlxcpld mux |
| n | | | |-- i2cy1 -- i2cy8
| u | | '-------------'
| x | | |
'---' '---------'
i2c-mux-mlxpcld does not necessarily require i2c-mlxcpld. It can be used
along with another bus driver, and still control i2c routing through CPLD
mux selection, in case the system is equipped with CPLD capable of mux
selection control.
The Kconfig currently controlling compilation of this code is:
drivers/i2c/muxes/Kconfig:config I2C_MUX_MLXCPLD
Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We get the following build error from UM Linux after adding
an entry to drivers/iio/gyro/Kconfig that issues "select I2C_MUX":
ERROR: "devm_ioremap_resource"
[drivers/i2c/muxes/i2c-mux-reg.ko] undefined!
ERROR: "of_address_to_resource"
[drivers/i2c/muxes/i2c-mux-reg.ko] undefined!
It appears that the I2C mux core code depends on HAS_IOMEM
for historical reasons, while CONFIG_I2C_MUX_REG does *not*
have a direct dependency on HAS_IOMEM.
This creates a situation where a allyesconfig or allmodconfig
for UM Linux will select I2C_MUX, and will implicitly enable
I2C_MUX_REG as well, and the compilation will fail for the
register driver.
Fix this up by making I2C_MUX_REG depend on HAS_IOMEM and
removing the dependency from I2C_MUX.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Jonathan Cameron <jic23@jic23.retrosnub.co.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Some drivers like i2c-gpio do not have dedicated pinctrl states. They
broke when error checking for pinctrl was added. Detect them now, and in
their case, simply skip over pinctrl configuration.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
"Here is the 4.9 pull request from I2C including:
- centralized error messages when registering to the core
- improved lockdep annotations to prevent false positives
- DT support for muxes, gates, and arbitrators
- bus speeds can now be obtained from ACPI
- i2c-octeon got refactored and now supports ThunderX SoCs, too
- i2c-tegra and i2c-designware got a bigger bunch of updates
- a couple of standard driver fixes and improvements"
* 'i2c/for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (71 commits)
i2c: axxia: disable clks in case of failure in probe
i2c: octeon: thunderx: Limit register access retries
i2c: uniphier-f: fix misdetection of incomplete STOP condition
gpio: pca953x: variable 'id' was used twice
i2c: i801: Add support for Kaby Lake PCH-H
gpio: pca953x: fix an incorrect lockdep warning
i2c: add a warning to i2c_adapter_depth()
lockdep: make MAX_LOCKDEP_SUBCLASSES unconditionally visible
i2c: export i2c_adapter_depth()
i2c: rk3x: Fix variable 'min_total_ns' unused warning
i2c: rk3x: Fix sparse warning
i2c / ACPI: Do not touch an I2C device if it belongs to another adapter
i2c: octeon: Fix high-level controller status check
i2c: octeon: Avoid sending STOP during recovery
i2c: octeon: Fix set SCL recovery function
i2c: rcar: add support for r8a7796 (R-Car M3-W)
i2c: imx: make bus recovery through pinctrl optional
i2c: meson: add gxbb compatible string
i2c: uniphier-f: set the adapter to master mode when probing
i2c: uniphier-f: avoid WARN_ON() of clk_disable() in failure path
...
The cached value of the last selected channel prevents retries on the
next call, even on failure to update the selected channel. Fix that.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
We can't use a static property for all the changesets, so we now create
dynamic ones for each changeset.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Fixes: 50a5ba8769 ("i2c: mux: demux-pinctrl: add driver")
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
No longer rely on the implicit matching with the i2c device name, use
an explicit compatible string instead.
Keep a direct pointer to the chip description instead of an index into
the chip description array.
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Peter Rosin <peda@axentia.se>
No longer rely on the implicit matching with the i2c device name, use
an explicit compatible string instead.
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Peter Rosin <peda@axentia.se>
The i2c mux core can then take appropriate action depending on if it is
used for an actual i2c mux, for a gate or for an arbitrator (the last
is the case for these drivers). This adds support for the new clearer
and more compact devicetree bindings that was added recently.
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Peter Rosin <peda@axentia.se>
Make sure the index to the active channel is invalidated when switching
fails.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We also need to revert the dynamic OF change, so we get a consistent
state again. Otherwise, we might have two devices enabled e.g. after
pinctrl setup fails.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
of_address_to_resource return 0 on successful call but
devm_ioremap_resource is called only if it returns non-zero value
Signed-off-by: Lukasz Gemborowski <lukasz.gemborowski@nokia.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
of_match_table was not filled which prevents device to be
instantiated from device tree node.
Signed-off-by: Lukasz Gemborowski <lukasz.gemborowski@nokia.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Add a mask to handle the case where not all child adapters should
cause a mux deselect to happen, now that there is a common deselect op
for all child adapters.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
sysfs attributes should use the same format for reads and writes,
rather than pretty-printing on read.
* Make the "cur_master" attribute read back as just the name of the
master
* Expose the list of all masters as a read-only "available_masters"
attribute, using space separators as in similar attributes of other
devices
Also, spell out "cur_master" in full as "current_master".
Fixes: 50a5ba8769 ("i2c: mux: demux-pinctrl: add driver")
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This driver allows an I2C bus to switch between multiple masters. This
is not hot-switching because connected I2C slaves will be
re-instantiated. It is meant to select the best I2C core at runtime once
the task is known. Example: Prefer i2c-gpio over another I2C core
because of HW errata affecting your use case.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Reading the register (if allowed) after writing is to ensure writing
is completed on a posted bus. The endianness of reading doesn't matter.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
With CONFIG_OF=n, the following warnings occur when compiling
drivers/i2c/muxes/i2c-mux-reg.c:
CC drivers/i2c/muxes/i2c-mux-reg.o
drivers/i2c/muxes/i2c-mux-reg.c:170:13: warning: ‘struct gpiomux’ declared inside parameter list [enabled by default]
struct platform_device *pdev)
^
drivers/i2c/muxes/i2c-mux-reg.c:170:13: warning: its scope
is only this definition or declaration, which is probably not what you want [enabled by default]
drivers/i2c/muxes/i2c-mux-reg.c: In function ‘i2c_mux_reg_probe’:
drivers/i2c/muxes/i2c-mux-reg.c:201:3: warning: passing argument 1 of ‘i2c_mux_reg_probe_dt’ from incompatible pointer type [enabled by default]
ret = i2c_mux_reg_probe_dt(mux, pdev);
^
Signed-off-by: Mike Rapoport <mike.rapoport@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Checking was done at three different locations, just do it once and
properly at probing time.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: York Sun <yorksun@freescale.com>
Every call of of_parse_phandle() increments user count of found device
node, if OF_DYNAMIC is enabled.
The change fixes all similar addressed cases in drivers/i2c.
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Based on i2c-mux-gpio driver, similarly the register-based mux
switch from one bus to another by setting a single register.
The register can be on PCIe bus, local bus, or any memory-mapped
address. The endianness of such register can be specified in device
tree if used, or in platform data.
Signed-off-by: York Sun <yorksun@freescale.com>
Acked-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This change is needed to properly lock I2C parent bus driver.
Prior to this change i2c_put_adapter() is misused, which may lead
to an overflow over zero of I2C bus driver user counter.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c_driver does not need to set an owner because i2c_register_driver()
will set it.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
pca9541 and pca954x are calling master_xfer() of the parent adapter directly
thus bypassing the quirks checks of the adapter. Use __i2c_transfer() instead.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: Łukasz Gemborowski <lukasz.gemborowski@nokia.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Fixes: b7f6258402 ("i2c: add quirk checks to core")
The GPIO subsystem provides dummy GPIO consumer functions if GPIOLIB is
not enabled. Hence drivers that depend on GPIOLIB, but use GPIO consumer
functionality only, can still be compiled if GPIOLIB is not enabled.
Relax the dependency on GPIOLIB if COMPILE_TEST is enabled, where
appropriate.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Probe deferral is not an error case. It happens only when
the necessary dependencies are not there yet.
The driver core is already printing a message when a driver
requests probe deferral, so this can be traced in the logs
without these error prints.
This patch removes the error messages for these deferral cases.
Signed-off-by: Ionut Nicu <ioan.nicu.ext@nokia.com>
Acked-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Since 39b2bbe3d7 (gpio: add flags argument to gpiod_get*() functions)
which appeared in v3.17-rc1, the gpiod_get* functions take an additional
parameter that allows to specify direction and initial value for
outputs.
Also there is an *_optional variant that serves well here. The sematics
is slightly changed here by using it. Now if a reset gpio is specified
and getting hold on it fails, pca954x_probe fails, too.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add i2c-mux-idle-disconnect device tree property to PCA954x mux driver. The new
property forces the multiplexer to disconnect child buses in idle state. This is
used, for example, when there are several multiplexers on the same bus and the
devices on the underlying buses might have same I2C addresses.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nsn.com>
[wsa: added a newline]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
