Commit Graph

102 Commits

Author SHA1 Message Date
Wolfram Sang 465b2c4ab8 Merge branch 'i2c-mux/for-next' of https://github.com/peda-r/i2c-mux into i2c/for-4.11 2017-02-10 12:51:23 +01:00
Phil Reid f2114795f7 i2c: mux: pca954x: Add interrupt controller support
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>
2017-02-10 08:23:51 +01:00
Phil Reid f8251f1dfd i2c: mux: pca954x: Add missing pca9542 definition to chip_desc
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>
2017-02-10 08:23:50 +01:00
Javier Martinez Canillas e278d64190 i2c: mux: pca9541: Export OF device ID table as module aliases
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>
2017-02-09 17:31:05 +01:00
Javier Martinez Canillas acf6ef1d6c i2c: mux: pca954x: Export OF device ID table as module aliases
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>
2017-02-09 17:31:05 +01:00
Wei Yongjun 1da8726700 i2c: mux: mlxcpld: remove unused including <linux/version.h>
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>
2017-02-09 17:29:21 +01:00
Peter Rosin 649ac63a9a i2c: mux: mlxcpld: fix i2c mux selection caching
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>
2016-12-18 08:54:38 +01:00
Russell King 7f638c1cb0 i2c: mux: pca954x: fix i2c mux selection caching
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>
2016-12-17 19:29:44 +01:00
Linus Torvalds 8600b697cd Merge branch 'i2c/for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
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
  ...
2016-12-15 12:56:35 -08:00
Peter Rosin feff5c0a27 i2c: i2c-mux-gpio: update mux with gpiod_set_array_value_cansleep
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>
2016-11-29 20:10:59 +01:00
tnhuynh@apm.com bbf9d262a1 i2c: mux: pca954x: Add ACPI support for pca954x
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>
2016-11-29 20:06:47 +01:00
Alex Hemme ad092de60f i2c: i2c-mux-pca954x: fix deselect enabling for device-tree
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>
2016-11-19 21:49:29 +01:00
Vadim Pasternak c02b7bf532 i2c: mux: mellanox: add driver
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>
2016-11-17 23:19:00 +01:00
Linus Walleij 93d710a65e i2c: mux: fix up dependencies
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
2016-11-14 18:23:30 +01:00
Wolfram Sang d052db11c1 i2c: mux: demux-pinctrl: make drivers with no pinctrl work again
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>
2016-11-10 21:12:47 +01:00
Linus Torvalds 87840a2b7e Merge branch 'i2c/for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
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
  ...
2016-10-07 14:12:21 -07:00
Peter Rosin 463e8f845c i2c: mux: pca954x: retry updating the mux selection on failure
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
2016-09-21 23:10:21 +02:00
Wolfram Sang e35478eac0 i2c: mux: demux-pinctrl: run properly with multiple instances
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>
2016-09-08 16:56:21 +02:00
Peter Rosin 8a191a7ad4 i2c: pca954x: add device tree binding
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>
2016-08-25 22:11:04 +02:00
Peter Rosin a1cbf338ab i2c: pca9541: add device tree binding
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>
2016-08-25 22:11:03 +02:00
Peter Rosin 40839590f8 i2c: mux: inform the i2c mux core about how it is used
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>
2016-08-25 22:11:03 +02:00
Wolfram Sang 9a5382e8ff i2c: mux: demux-pinctrl: invalidate properly when switching fails
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>
2016-08-25 18:41:34 +02:00
Wolfram Sang ce8cb803d8 i2c: mux: demux-pinctrl: properly roll back when adding adapter fails
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
2016-08-15 00:55:07 +02:00
Lukasz Gemborowski 22ebf00eb5 i2c: mux: reg: wrong condition checked for of_address_to_resource return value
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
2016-07-06 00:33:49 +09:00
Lukasz Gemborowski 9f05e62190 i2c: mux: reg: Provide of_match_table
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>
2016-06-09 22:38:16 +02:00
Peter Rosin 6ef91fcca8 i2c: mux: relax locking of the top i2c adapter during mux-locked muxing
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>
2016-05-04 22:39:17 +02:00
Wolfram Sang 2c89e5d884 i2c: mux: pinctrl: fix indentation for better readability
smatch rightfully says:

drivers/i2c/muxes/i2c-mux-pinctrl.c:175 i2c_mux_pinctrl_probe() warn: inconsistent indenting

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-24 23:11:41 +02:00
Peter Rosin 193304aef8 i2c: i2c-mux-reg: convert to use an explicit i2c mux core
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>
2016-04-22 14:56:41 +02:00
Peter Rosin 7fcac98071 i2c: i2c-mux-pca954x: convert to use an explicit i2c mux core
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>
2016-04-22 14:56:40 +02:00
Peter Rosin ab88b97c69 i2c: i2c-mux-pca9541: convert to use an explicit i2c mux core
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>
2016-04-22 14:56:39 +02:00
Peter Rosin 8aacd90166 i2c: i2c-arb-gpio-challenge: convert to use an explicit i2c mux core
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>
2016-04-22 14:56:38 +02:00
Peter Rosin 4bbe7fb0a2 i2c: i2c-mux-pinctrl: convert to use an explicit i2c mux core
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>
2016-04-22 14:56:37 +02:00
Peter Rosin bb44814763 i2c: i2c-mux-gpio: convert to use an explicit i2c mux core
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>
2016-04-22 14:56:36 +02:00
Ben Hutchings c0c508a418 i2c: mux: demux-pinctrl: Clean up sysfs attributes
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>
2016-04-01 13:00:07 +02:00
Wolfram Sang 50a5ba8769 i2c: mux: demux-pinctrl: add driver
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>
2016-02-12 19:16:04 +01:00
York Sun 5a73882fd2 i2c: mux: reg Change ioread endianness for readback
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>
2015-09-03 11:58:42 +02:00
Mike Rapoport a05a34e7f6 i2c: mux: reg: fix compilation warnings
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>
2015-09-03 11:56:23 +02:00
Wolfram Sang fce388afd6 i2c: mux: reg: simplify register size checking
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>
2015-09-03 11:54:41 +02:00
Vladimir Zapolskiy bdbf4a29ee i2c: muxes: fix leaked i2c adapter device node references
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>
2015-08-31 22:40:34 +02:00
York Sun b3fdd32799 i2c: mux: Add register-based mux i2c-mux-reg
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>
2015-08-24 14:05:18 +02:00
Vladimir Zapolskiy 0d1ad98dd8 i2c: arb-gpio-challenge: use of_get_i2c_adapter_by_node interface
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>
2015-08-10 08:37:36 +02:00
Krzysztof Kozlowski 069d5b745b i2c: Drop owner assignment from i2c_driver
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>
2015-08-10 08:37:35 +02:00
Alexander Sverdlin 0a8237ae31 i2c: mux: pca954x: Use __i2c_transfer because of quirks
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")
2015-06-17 14:35:38 +02:00
Geert Uytterhoeven 7e5cd69a91 i2c: Allow compile test of GPIO consumers if !GPIOLIB
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>
2015-05-12 15:22:52 +02:00
Ioan Nicu 623e4ecb86 i2c: i2c-mux-gpio: remove error messages for probe deferrals
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>
2015-04-03 22:00:14 +02:00
Uwe Kleine-König 58b59e0f24 i2c: pca954x: improve usage of gpiod API
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>
2015-03-09 10:51:59 +01:00
Alexander Sverdlin 72f0271576 of: i2c: Add i2c-mux-idle-disconnect DT property to PCA954x mux driver
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>
2015-01-23 17:12:56 +01:00
Wolfram Sang 37e5dc1c27 i2c: muxes: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:20:38 +02:00
Linus Torvalds f7dbaef505 Merge branch 'i2c/for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "Highlights:

   - class based instantiation finally dropped for most embedded drivers
     bringing boot up performance gains
   - removed two drivers (one outdated, one a duplicate)
   - ACPI has now operation region support (thanks to Lan Tianyu)
   - the i2c-stub driver got overhauled and gained new features to
     become more useful when writing i2c client drivers (thanks to
     Guenter Roeck and Jean Delvare)

  The rest is driver bugfixes, added bindings/ids, cleanups..."

* 'i2c/for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (43 commits)
  i2c: mpc: delete unneeded test before of_node_put
  i2c: rk3x: fix interrupt handling issue
  i2c: imx: Fix format warning for dev_dbg
  i2c: qup: disable clks and return instead of just returning error
  i2c: exynos5: always enable HSI2C
  i2c: designware: add new bindings
  i2c: gpio: Drop dead code in i2c_gpio_remove
  i2c: pca954x: put the mux to disconnected state after resume
  i2c: st: Update i2c timings
  drivers/i2c/busses: use correct type for dma_map/unmap
  i2c: i2c-st: Use %pa to print 'resource_size_t' type
  i2c: s3c2410: resume the I2C controller earlier
  i2c: stub: Avoid an array overrun on I2C block transfers
  i2c: i801: Add device ID for Intel Wildcat Point PCH
  i2c: i801: Fix the alignment of the device table
  i2c: stub: Add support for banked register ranges
  i2c: stub: Remember the number of emulated chips
  i2c: stub: Add support for SMBus block commands
  i2c: efm32: correct namespacing of location property
  i2c: exynos5: remove extra line and fix an assignment
  ...
2014-08-09 09:15:07 -07:00
Jisheng Zhang f5e596cd9f i2c: pca954x: put the mux to disconnected state after resume
pca954x may be power lost during suspend, so after resume we also suffer
the issue fixed by commit cd823db8b1,

 "pca954x power-on default is channel 0 connected. If multiple pca954x
 muxes are connected to the same physical I2C bus, the parent bus will
 see channel 0 devices behind both muxes by default."

What's more, when resume bootloader may also operate the mux, so the
the channel connected after that may not be the one driver thought.

We fix this problem by putting the mux to disconnected state and
clearing last_chan in the resume hook.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-08-01 19:54:59 +02:00