On ARM Chromebooks we have a few devices that are accessed by both the
AP (the main "Application Processor") and the EC (the Embedded
Controller).  These are:
* The battery (sbs-battery).
* The power management unit tps65090.

On the original Samsung ARM Chromebook these devices were on an I2C
bus that was shared between the AP and the EC and arbitrated using
some extranal GPIOs (see i2c-arb-gpio-challenge).

The original arbitration scheme worked well enough but had some
downsides:
* It was nonstandard (not using standard I2C multimaster)
* It only worked if the EC-AP communication was I2C
* It was relatively hard to debug problems (hard to tell if i2c issues
  were caused by the EC, the AP, or some device on the bus).

On the HP Chromebook 11 the design was changed to:
* The AP/EC comms were still i2c, but the battery/tps65090 were no
  longer on the bus used for AP/EC communication.  The battery was
  exposed to the AP through a limited i2c tunnel and tps65090 was
  exposed to the AP through a custom Linux driver.

On the Samsung ARM Chromebook 2 the scheme is changed yet again, now:
* The AP/EC comms are now using SPI for faster speeds.
* The EC's i2c bus is exposed to the AP through a full i2c tunnel.

The upstream "tegra124-venice2" uses the same scheme as the Samsung
ARM Chromebook 2, though it has a different set of components on the
other side of the bus.

This driver supports the scheme used by the Samsung ARM Chromebook 2.
Future patches to this driver could add support for the battery tunnel
on the HP Chromebook 11 (and perhaps could even be used to access
tps65090 on the HP Chromebook 11 instead of using a special driver,
but I haven't researched that enough).
Signed-off-by: NVincent Palatin <vpalatin@chromium.org>
Signed-off-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

This hardware does not support zero length transfers. Instead, the
driver does one (random) byte transfers currently with undefined results
for the slaves. We now bail out.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

This patch corrects the error check on the call to pm_runtime_get_sync.
Signed-off-by: NAndy Gross <agross@codeaurora.org>
Reviewed-by: NIvan T. Ivanov <iivanov@mm-sol.com>
Acked-by: NBjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Don't unmark the device as suspended until after it's been re-setup.

The main race would be w.r.t. an i2c driver that gets resumed at the same
time (asyncronously), that is allowed to do a transfer since suspended
is set to 0 before reinit, but really should have seen the -EIO return
instead.
Signed-off-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

devm_ioremap() returns NULL on error, not an error.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

There have been "i2c_designware 80860F41:00: controller timed out" errors
on a number of Baytrail platforms. The issue is caused by incorrect value in
Interrupt Mask Register (DW_IC_INTR_MASK)  when i2c core is being enabled.
This causes call to __i2c_dw_enable() to immediately start the transfer which
leads to timeout. There are 3 failure modes observed:

1. Failure in S0 to S3 resume path

The default value after reset for DW_IC_INTR_MASK is 0x8ff. When we start
the first transaction after resuming from system sleep, TX_EMPTY interrupt
is already unmasked because of the hardware default.

2. Failure in normal operational path

This failure happens rarely and is hard to reproduce. Debug trace showed that
DW_IC_INTR_MASK had value of 0x254 when failure occurred, which meant
TX_EMPTY was unmasked.

3. Failure in S3 to S0 suspend path

This failure also happens rarely and is hard to reproduce. Adding debug trace
that read DW_IC_INTR_MASK made this failure not reproducible. But from ISR
call trace we could conclude TX_EMPTY was unmasked when problem occurred.

The patch masks all interrupts before the controller is enabled to resolve the
faulty DW_IC_INTR_MASK conditions.
Signed-off-by: NWenkai Du <wenkai.du@intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
[wsa: improved the comment and removed typo in commit msg]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

If the renamed symbol is defined lib/iomap.c implements ioport_map and
ioport_unmap and currently (nearly) all platforms define the port
accessor functions outb/inb and friend unconditionally.  So
HAS_IOPORT_MAP is the better name for this.

Consequently NO_IOPORT is renamed to NO_IOPORT_MAP.

The motivation for this change is to reintroduce a symbol HAS_IOPORT
that signals if outb/int et al are available.  I will address that at
least one merge window later though to keep surprises to a minimum and
catch new introductions of (HAS|NO)_IOPORT.

The changes in this commit were done using:

	$ git grep -l -E '(NO|HAS)_IOPORT' | xargs perl -p -i -e 's/\b((?:CONFIG_)?(?:NO|HAS)_IOPORT)\b/$1_MAP/'
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

During development, the driver first really needed to depend on
COMMON_CLK only. Later, it was switched to writel_relaxed, but it was
forgotten to update the dependencies, so build errors occured:

config: make ARCH=i386 allyesconfig

All error/warnings:

   drivers/i2c/busses/i2c-cadence.c: In function 'cdns_i2c_clear_bus_hold':
>> drivers/i2c/busses/i2c-cadence.c:168:3: error: implicit declaration
>> of function 'writel_relaxed' [-Werror=implicit-function-declaration]

Use a very safe dependency for now.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add a driver for the Cadence I2C controller. This controller is for
example found in Xilinx Zynq.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: NMichal Simek <michal.simek@xilinx.com>
Reviewed-by: NHarini Katakam <harinik@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

It is used with of_property_read_u32(), so it should be u32.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NBjorn Andersson <bjorn.andersson@sonymobile.com>
Fixes: 10c5a842 ('i2c: qup: New bus driver for the Qualcomm QUP I2C controller')

These should ">= ARRAY_SIZE()" instead of "> ARRAY_SIZE()".

Fixes: 10c5a842 ('i2c: qup: New bus driver for the Qualcomm QUP I2C controller')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This bus driver supports the QUP i2c hardware controller in the Qualcomm SOCs.
The Qualcomm Universal Peripheral Engine (QUP) is a general purpose data path
engine with input/output FIFOs and an embedded i2c mini-core. The driver
supports FIFO mode (for low bandwidth applications) and block mode (interrupt
generated for each block-size data transfer).
Signed-off-by: NIvan T. Ivanov <iivanov@mm-sol.com>
Signed-off-by: NBjorn Andersson <bjorn.andersson@sonymobile.com>
Reviewed-by: NAndy Gross <agross@codeaurora.org>
Tested-by: NPhilip Elcan <pelcan@codeaurora.org>
[wsa: removed needless IS_ERR_VALUE]
Signed-off-by: NWolfram 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: NWolfram 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: NWolfram Sang <wsa@the-dreams.de>
Cc: Barry Song <baohua@kernel.org>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: NWolfram 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: NWolfram 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: NWolfram Sang <wsa@the-dreams.de>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>

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

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: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NWolfram 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: NNishanth Menon <nm@ti.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram 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: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Fixes a build break due to the undeclared use of irq_of_parse_and_map()
and of_iomap().  This build break was apparently introduced while the
driver was unbuildable due to the bug fixed by
62c19c9d ("i2c: Remove usage of
orphaned symbol OF_I2C").  When 62c19c was added in v3.14-rc7,
the driver was enabled again, breaking the powerpc mpc85xx_defconfig
and mpc85xx_smp_defconfig.

62c19c is marked for stable, so this should go there as well.
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

The symbol is an orphan, don't depend on it anymore.
Signed-off-by: NRichard Weinberger <richard@nod.at>
[wsa: enhanced commit message]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Fixes: 687b81d0 (i2c: move OF helpers into the core)
Cc: stable@kernel.org

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: NJingoo Han <jg1.han@samsung.com>
Reviewed-by: NNaveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: NWolfram 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: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NWolfram 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: NBen Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Don't use DEFINE_PCI_DEVICE_TABLE macro, because this macro
is not preferred.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NWolfram 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: NSimon Glass <sjg@chromium.org>
Signed-off-by: NNaveen Krishna Chatradhi <ch.naveen@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NWolfram 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: NWolfram 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: NMarek Roszko <mark.roszko@gmail.com>
Signed-off-by: NWolfram 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: NChew, Chiau Ee <chiau.ee.chew@intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram 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: NMaxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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

For start and restart, we are doing the same thing. Let's consolidate
that.
Tested-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NWolfram 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: NChew, Chiau Ee <chiau.ee.chew@intel.com>
Signed-off-by: NOng, Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: NWolfram 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: NJingoo Han <jg1.han@samsung.com>
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram 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: NJingoo Han <jg1.han@samsung.com>
Acked-by: NStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add Device ID of Intel BayTrail SMBus Controller.
Signed-off-by: NChew, Kean ho <kean.ho.chew@intel.com>
Signed-off-by: NChew, Chiau Ee <chiau.ee.chew@intel.com>
Reviewed-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NWolfram 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: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>