Add tracepoints into the I2C message transfer function to retrieve the message
sent or received.  The following config options must be turned on to make use
of the facility:

	CONFIG_FTRACE
	CONFIG_ENABLE_DEFAULT_TRACERS

The I2C tracepoint can be enabled thusly:

	echo 1 >/sys/kernel/debug/tracing/events/i2c/enable

and will dump messages that can be viewed in /sys/kernel/debug/tracing/trace
that look like:

	... i2c_write: i2c-5 #0 a=044 f=0000 l=2 [02-14]
	... i2c_read: i2c-5 #1 a=044 f=0001 l=4
	... i2c_reply: i2c-5 #1 a=044 f=0001 l=4 [33-00-00-00]
	... i2c_result: i2c-5 n=2 ret=2

formatted as:

	i2c-<adapter-nr>
	#<message-array-index>
	a=<addr>
	f=<flags>
	l=<datalen>
	n=<message-array-size>
	ret=<result>
	[<data>]

The operation is done between the i2c_write/i2c_read lines and the i2c_reply
and i2c_result lines so that if the hardware hangs, the trace buffer can be
consulted to determine the problematic operation.

The adapters to be traced can be selected by something like:

	echo adapter_nr==1 >/sys/kernel/debug/tracing/events/i2c/filter

These changes are based on code from Steven Rostedt.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
[wsa: adapted path for 'enable' in the commit msg]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Don't use DEFINE_PCI_DEVICE_TABLE macro, because this macro
is not preferred.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

There is a rather odd feature of the exynos i2c controller that if it
is left enabled, it can lock itself up with the clk line held low.
This makes the bus unusable.

Unfortunately, the s3c24xx_i2c_set_master() function does not notice
this, and reports a timeout. From then on the bus cannot be used until
the AP is rebooted.

The problem happens when any sort of interrupt occurs (e.g. due to a
bus transition) when we are not in the middle of a transaction. We
have seen many instances of this when U-Boot leaves the bus apparently
happy, but Linux cannot access it.

The current code is therefore pretty fragile.

This fixes things by leaving the bus disabled unless we are actually
in a transaction. We enable the bus at the start of the transaction and
disable it at the end. That way we won't get interrupts and will not
lock up the bus.

It might be possible to clear pending interrupts on start-up, but this
seems to be a more robust solution. We can't service interrupts when
we are not in a transaction, and anyway would rather not lock up the
bus while we try.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>

This adds the ability to set "clock-frequency" in the device tree for the at91
i2cbus following the naming of other i2c bus implementations. If the property
is not set,the clock frequency will default to the previously used define
of 100KHz.
Signed-off-by: Marek Roszko <mark.roszko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

On Intel BayTrail, there was case whereby the resulting fast mode
bus speed becomes slower (~20% slower compared to expected speed)
if using the HCNT/LCNT calculated in the core layer. Thus, this
patch is added to allow pci glue layer to pass in optimal
HCNT/LCNT/SDA hold time values to core layer since the core
layer supports cofigurable HCNT/LCNT/SDA hold time values now.
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch fixes the error returned to the i2c_transfer function
to -EAGAIN in case of arbitratin lost, so that the retry mechanism
can be used.
Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Commit 436d42c6 ("ARM: samsung: move platform_data definitions")
moved the files to the current location but forgot to remove the pointer
to its previous location. Clean it up. While at it also change the header
file protection macros appropriately.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

We now have a central place to put this code to.
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Calling the state machine with a definite state which is only used in
this context is superfluous. Do it directly.
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

For start and restart, we are doing the same thing. Let's consolidate
that.
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

All the I2C controllers on Intel BayTrail LPSS subsystem able
to support 10-bit addressing mode functionality.
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Signed-off-by: Ong, Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Use devm_ioremap_resource() in order to make the code simpler,
and remove redundant return value check of platform_get_resource()
because the value is checked by devm_ioremap_resource().
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Use devm_ioremap_resource() in order to make the code simpler,
and remove redundant return value check of platform_get_resource()
because the value is checked by devm_ioremap_resource().
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add Device ID of Intel BayTrail SMBus Controller.
Signed-off-by: Chew, Kean ho <kean.ho.chew@intel.com>
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Intel Baytrail I2C controllers can be enumerated from PCI as well as from
ACPI. In order to support this add the Baytrail PCI IDs to the driver.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The PCI part of the DesignWare I2C driver does a lot of things that are not
required anymore. For example drivers aren't supposed to handle PCI state
transitions themselves. This is all provided by the PCI bus core already.

In addition to that there is no point scheduling RPM suspend on driver's
idle hook but instead we can use RPM autosuspend for this (which is enabled
in the driver already).

As a bonus, this patch also fixes following compile warning which is
emitted when the driver was compiled without CONFIG_PM_RUNTIME set:

drivers/i2c/busses/i2c-designware-pcidrv.c:245:12: warning: ‘i2c_dw_pci_runtime_idle’ defined but not used [-Wunused-function]
Reported-by: xinhui.pan <xinhuix.pan@intel.com>
Reported-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This patch allows to set independantly SCL and SDA falling times.
The tLOW period is computed by taking into account the SCL falling time.
The tHIGH period is computed by taking into account the SDA falling time.

For instance in case the margin on tLOW is considered too small, it can
be increased by increasing the SCL falling time which is by default set
at 300ns.

The same applies for tHIGH period with the help of SDA falling time.
Signed-off-by: Romain Baeriswyl <romainba@abilis.com>
Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com>
Acked-by: Shinya Kuribayashi <skuribay@pobox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Put necessary SSYNC code into blackfin twi arch header. The generic TWI
driver should not contain any architecture specific code.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The ADI TWI peripheral is not binding to the Blackfin processor only.
The bits macros and structs should be put in the generic include header.
And update head file path in drivers accordingly.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Commit 370136bc ("i2c: mv64xxx: Add reset deassert call")
introduced:

drivers/video/Kconfig:42:error: recursive dependency detected!

ARCH_SUNXI selects RESET_CONTROLLER anyhow.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The Allwinner A31 I2C controller is almost identical to the one used in the
other Allwinner SoCs, except for the fact that it needs to clear the interrupt
by setting the INT_FLAGS bit in the control register, instead of clearing it.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The Allwinner A31 SoC using that IP has a reset controller maintaining
it reset unless told otherwise.

Add some optional reset support to the driver.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Stephen Warren <swarren@nvidia.com>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Sonic Zhang <sonic.zhang@analog.com>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Class based instantiation can cause noticeable delays when booting. This
mechanism is used when it is not possible to describe slaves on I2C
busses. As we do have other mechanisms, most embedded I2C will not need
classes and for embedded it is explicitly not recommended to use them. Add
a deprecation warning for drivers which want to disable class based
instantiation in the near future to gain boot-up time, so users relying
on this technique can switch to something better. They really should.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

We should never be busy performing transfers at suspend late, thus
there are no reason to check for it.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

At system suspend_late, runtime PM has been disabled by the PM core
which means we can safely operate on these resources. Consequentially
we no longer have to wait until the noirq phase of the system suspend.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Since the runtime PM state is expected to be active according to the
amba bus, we must align our behaviour while probing to it.

Moreover, this is needed to be able to have the driver fully functional
without depending on CONFIG_RUNTIME_PM.

Since the device is active while a successful probe has been completed,
the reference counting for the clock will be screwed up and never reach
zero. We resolve this by implementing runtime PM callbacks and let them
handle the resources accordingly, including the clock.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[wsa: s/#if/#ifdef/]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The amba bus are responsible for pm_runtime_enable|disable, remove the
redundant pm_runtime_disable at driver removal.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Use devm_* functions to simplify code and error handling.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Move the former platform data struct nmk_i2c_controller into the
per-device state container struct i2c_nmk_client, and remove all
the platform data probe path hacks.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[wsa: use 100kHz as default]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

While we are here, also brush up the devicetree binding documentation.
The example was an inappropriate copy from the sh_mobile driver.
Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>