The reset framework recently gained optional stubs when CONFIG_RESET_CONTROLLER
is not selected. It also introduced a function reset_get_optional, that is also
dummy-defined whenever the framework isn't enabled, for drivers that needs an
optional reset controller.

Switch to this function, since the mv64xxx driver is in this case. This also
fixes a compilation breakage whenever the reset framework wasn't selected:

drivers/i2c/busses/i2c-mv64xxx.c:771:2: error: implicit declaration of function 'devm_reset_control_get'

While we're at it, remove the redundant test on dev.of_node surrounding the
calls to reset framework functions, since it will either be a valid pointer, an
error pointer in the case where we called reset_get_optional without an of_node
pointer or if it failed, or NULL if we're not loaded through DT.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

we use IS_ERR_VALUE to check for error values of pm_runtime_get_sync,
when the value can only be < 0 in the case of err. Replace the
check with a simpler < 0 check.

This fixes the coccicheck warnings:
linux-2.6/drivers/i2c/busses/i2c-omap.c:1157:5-24:
pm_runtime_get_sync returns < 0 as error. Unecessary IS_ERR_VALUE at
line 1158
linux-2.6/drivers/i2c/busses/i2c-omap.c:1278:7-26:
pm_runtime_get_sync returns < 0 as error. Unecessary IS_ERR_VALUE at
line 1279
drivers/i2c/busses/i2c-omap.c:638:5-24:
pm_runtime_get_sync returns < 0 as error. Unecessary IS_ERR_VALUE at
line 639
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This was tested on a EFM32GG-DK3750 devboard that has a temperature
sensor and an eeprom on its i2c bus.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Remove unnecessary cast of void pointer, because 'algo_data' of
'struct i2c_adapter' is a void pointer. Casting the void pointer
is redundant. The conversion from void pointer to any other
pointer type is guaranteed by the C programming language.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Reviewed-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Add CONFIG_PM_SLEEP to suspend/resume functions to fix the following
build warning when CONFIG_PM_SLEEP is not selected. This is because
sleep PM callbacks defined by SIMPLE_DEV_PM_OPS are only used when
the CONFIG_PM_SLEEP is enabled.

  warning: 'exynos5_i2c_suspend_noirq' defined but not used [-Wunused-function]
  warning: 'exynos5_i2c_resume_noirq' defined but not used [-Wunused-function]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

When using device-tree and the i2c-gpio driver is called before the
GPIO node has been probed then it needs to correctly defer the probe
instead of returning a permanent error that the gpio numbers are not
valid.

This fixes the following error:
	/i2c@2: invalid GPIO pins, sda=-517/scl=-517
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The SMBUS tracepoints 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:

         ... smbus_read: i2c-0 a=051 f=0000 c=fa BYTE_DATA
         ... smbus_reply: i2c-0 a=051 f=0000 c=fa BYTE_DATA l=1 [39]
         ... smbus_result: i2c-0 a=051 f=0000 c=fa BYTE_DATA rd res=0

formatted as:

	i2c-<adapter-nr>
	a=<addr>
	f=<flags>
	c=<command>
	<protocol-name>
	<rd|wr>
	res=<result>
	l=<data-len>
	[<data-block>]

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

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

Note that this shares the same filter and enablement as i2c.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

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>