I've seen i2c recovery reporting long loops of:

[ 1035.887818] i2c i2c-4: SCL is stuck low, exit recovery
[ 1037.999748] i2c i2c-4: SCL is stuck low, exit recovery
[ 1040.111694] i2c i2c-4: SCL is stuck low, exit recovery
...

Add a TWSI software reset which clears the status and
STA,STP,IFLG in SW_TWSI_EOP_TWSI_CTL.

With this the recovery works fine and above message is not seen.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch allows Cadence I2C controller to be selected in systems using Cadence Xtensa processors.
Signed-off-by: Jan Kotas <jank@cadence.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add per-Generation fallback bindings for R-Car SoCs.

This is in keeping with the compatibility string scheme is being adopted
for drivers for Renesas SoCs.

Also, improve readability by listing the rmobile fallback compatibility
string after the more-specific compatibility strings they provide a
fallback for.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

In the case of Renesas R-Car hardware we know that there are generations of
SoCs, e.g. Gen 2 and Gen 3. But beyond that it's not clear what the
relationship between IP blocks might be. For example, I believe that
r8a7790 is older than r8a7791 but that doesn't imply that the latter is a
descendant of the former or vice versa.

We can, however, by examining the documentation and behaviour of the
hardware at run-time observe that the current driver implementation appears
to be compatible with the IP blocks on SoCs within a given generation.

For the above reasons and convenience when enabling new SoCs a
per-generation fallback compatibility string scheme is being adopted for
drivers for Renesas SoCs.

Also:
* Deprecate renesas,i2c-rcar. It seems poorly named as it is only
  compatible with R-Car Gen 1. It also appears unused in mainline.
* Add some text to describe per-SoC bindings
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch adds lpi2c bus driver to support new i.MX products
which use lpi2c instead of the old imx i2c.

The lpi2c can continue operating in stop mode when an appropriate
clock is available. It is also designed for low CPU overhead with
DMA offloading of FIFO register accesses.
Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Reviewed-by: Fugang Duan <B38611@freescale.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add a binding document for lpi2c driver.
Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Both Merrifield TRM and Medfield TRM state:
"Both 7-bit and 10-bit addressing modes are supported."
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The Armada 3700 has two I2C controllers that is compliant with the I2C
Bus Specificiation 2.1, supports multi-master and different bus speed:
Standard mode (up to 100 KHz), Fast mode (up to 400 KHz),
High speed mode (up to 3.4 Mhz).

This IP block has a lot of similarity with the PXA, except some register
offsets and bitfield. This commits adds a basic support for this I2C
unit.
Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

So far, the bit masks for the fast and high speed mode were statically
defined. Some IP blocks might use different bits for these modes.

This commit introduces new fields in order to enable the definition of
different bit masks for these features. If these fields are undefined,
ICR_FM and ICR_HS are selected to preserve backward compatibility with
other IPs.
Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This commit documents the compatible string to have the compatibility for
the I2C unit found in the Armada 3700.
Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

I2C QUP driver relies on SMBus emulation support from the framework.
To handle SMBus block reads, the driver should check I2C_M_RECV_LEN
flag and should read the first byte received as the message length.

The driver configures the QUP hardware to read one byte. Once the
message length is known from this byte, the QUP hardware is configured
to read the rest.
Signed-off-by: Naveen Kaje <nkaje@codeaurora.org>
Signed-off-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add support to get the device parameters from ACPI. Assume
that the clocks are managed by firmware.
Signed-off-by: Naveen Kaje <nkaje@codeaurora.org>
Signed-off-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Use a common place for default functionality bits for both platform
and pci driver.
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

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>

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: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

On the platform tested, reading SMBNTFDDAT always returns 0 (using 1 read
of a word or 2 of 2 bytes). Given that we are not sure why and that we
don't need to rely on the data parameter in the current users of Host
Notify, remove this part of the code.

If someone wants to re-enable it, just revert this commit and data should
be available.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

no functional changes
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

i801 mixes hexadecimal and decimal values for defining bits. However,
we have a nice BIT() macro for this exact purpose.

No functional changes, cleanup only.
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

No functional changes, just typos and remove unused #define.
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Also do not override any other configuration in this register.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Device driver for Mellanox I2C controller logic, implemented in Lattice
CPLD device.
Device supports:
 - Master mode
 - One physical bus
 - Polling mode

The Kconfig currently controlling compilation of this code is:
drivers/i2c/busses/Kconfig:config I2C_MLXCPLD
Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The ACPI companion of the adapter has to be set for I2C controller
code to read and attach the slave devices described in the ACPI table
with the I2CSerialBus resource descriptor. Used ACPI_COMPANION_SET
macro to set this.
Signed-off-by: Tanmay Jagdale <tanmay.jagdale@broadcom.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Documentation/CodingStyle recommends to use label names which say
what the goto does or why the goto exists.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Documentation/CodingStyle recommends to use label names which say
what the goto does or why the goto exists.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Allow more flexibility to bus speed selection. Now if there are I2C
slave connections defined in ACPI the speed of slowest device on the bus
will define the bus speed. However if also "clock-frequency" device
property is defined we should use the slowest of these two.

This is targeted to maker boards where developer may want to connect
slower I2C slave devices to the bus than defined in existing ACPI I2C
slave connections.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Free and Open IPMI use SMBUS BLOCK Read/Write to support SSIF protocol.
However, I2C Designware Core Driver doesn't handle the case at the moment.
The below patch supports this feature.
Signed-off-by: Tin Huynh <tnhuynh@apm.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Check for i2c_adapter_quirks structures that are only stored in the
quirks field of an i2c_adapter structure.  This field is declared
const, so i2c_adapter_quirks structures that have this property can be
declared as const also.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Ray Jui <ray.jui@broadcom.com> # for bcm-iproc
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The Kconfig currently controlling compilation of this code is:

drivers/i2c/busses/Kconfig:config I2C_PXA_PCI
drivers/i2c/busses/Kconfig:     def_bool I2C_PXA && X86_32 && PCI && OF

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

We explicitly disallow a driver unbind, since that doesn't have a
sensible use case anyway, and it allows us to drop the ".remove"
code for non-modular drivers.

Since module_pci_driver() uses the same init level priority as
builtin_pci_driver() the init ordering remains unchanged with
this commit.

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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>

As part of an effort to rid the mostly unused second parameter for I2C
related .probe() functions and to conform to other existing frameworks
we're moving over to a temporary replacement .probe() call-back.
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram 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: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
[Kieran: fix rebase conflicts and adapt for dev_pm_domain_{attach,detach}]
Tested-by: Kieran Bingham <kieran@bingham.xyz>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Wolfram 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: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Tested-by: Kieran Bingham <kieran@bingham.xyz>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Wolfram 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: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Tested-by: Kieran Bingham <kieran@bingham.xyz>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Wolfram 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: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
[Kieran: Fix static inline usage on !CONFIG_OF]
Tested-by: Kieran Bingham <kieran@bingham.xyz>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Wolfram 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: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Wolfram 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: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Tested-by: Kieran Bingham <kieran@bingham.xyz>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Support a dynamic clock by reading the frequency and setting the
divisor in the transfer function instead of during probe.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Use i2c_adapter->timeout for the completion timeout value. The core
default is 1 second.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Documentation/i2c/i2c-protocol states that Combined transactions should
separate messages with a Start bit and end the whole transaction with a
Stop bit. This patch adds support for issuing only a Start between
messages instead of a Stop followed by a Start.

This implementation differs from downstream i2c-bcm2708 in 2 respects:
- it uses an interrupt to detect that the transfer is active instead
  of using polling. There is no interrupt for Transfer Active, but by
  not prefilling the FIFO it's possible to use the TXW interrupt.
- when resetting/disabling the controller between transfers it writes
  CLEAR to the control register instead of just zero.
  Using just zero gave many errors. This might be the reason why
  downstream had to disable this feature and make it available with a
  module parameter.

I have run thousands of transfers to a DS1307 (rtc), MMA8451 (accel)
and AT24C32 (eeprom) in parallel without problems.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>