if we allow compiler reorder our writes, we could
fall into a situation where dev->buf_len is reset
for no apparent reason.

This bug was found with a simple script which would
transfer data to an i2c client from 1 to 1024 bytes
(a simple for loop), when we got to transfer sizes
bigger than the fifo size, dev->buf_len was reset
to zero before we had an oportunity to handle XDR
Interrupt. Because dev->buf_len was zero, we entered
omap_i2c_transmit_data() to transfer zero bytes,
which would mean we would just silently exit
omap_i2c_transmit_data() without actually writing
anything to DATA register. That would cause XDR
IRQ to trigger forever and we would never transfer
the remaining bytes.

After adding the memory barrier, we also drop resetting
dev->buf_len to zero in omap_i2c_xfer_msg() because
both omap_i2c_transmit_data() and omap_i2c_receive_data()
will act until dev->buf_len reaches zero, rendering the
other write in omap_i2c_xfer_msg() redundant.

This patch has been tested with pandaboard for a few
iterations of the script mentioned above.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

This reverts commit 3db11fef
(ARM: OMAP: convert I2C driver to PM QoS for MPU latency constraints).
This commit causes I2C timeouts to appear on several OMAP3430/3530-based
boards:

  http://marc.info/?l=linux-arm-kernel&m=135071372426971&w=2
  http://marc.info/?l=linux-arm-kernel&m=135067558415214&w=2
  http://marc.info/?l=linux-arm-kernel&m=135216013608196&w=2

and appears to have been sent for merging before one of its prerequisites
was merged:

  http://marc.info/?l=linux-arm-kernel&m=135219411617621&w=2Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Acked-by: NJean Pihet <j-pihet@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The driver claims to support SMBus quick command but it was not the
case. This patch fixes this issue. Without it, i2cdetect finds imaginary
devices. And with some IP versions, trying to send 0 byte can cause
issue when writing data to an EEPROM.
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Acked-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

[wsa: improved the commit message]
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

When watching the irqs name of tegra i2c, all instances
irq name shows as tegra_i2c.

Passing the device name properly to have the irq names with
instance like tegra-i2c.0, tegra-i2c.1 etc.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Make sure to clk_prepare as well as clk_enable.
Signed-off-by: NPhilippe Begnic <philippe.begnic@stericsson.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

This I2C master can do DMA and PIOQUEUE (PIO with FIFO). Originally,
only PIOQUEUE was supported and it had issues, then DMA support was added
this cycle. The original intention was to keep PIOQUEUE since it has
less overhead what is nice for small transfers. However, runtime
switching between PIOQEUE and DMA depending on the transfer size never
worked despite a lot of trying. Since PIOQUEUE mode itself was flaky
(polling at places where interrupts failed to work) and the
implementation also imposed a size limit for transfers, it is best to
remove the support, so users don't fall over its limitations. It also
makes the driver a lot cleaner and more robust. If somebody really wants
less overhead, plain PIO mode could still be implemented with the
addidtional advantage that this mode is also available on MX23, too.
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Reviewed-by: NMarek Vasut <marex@denx.de>

Signed-off-by: NJean Delvare <khali@linux-fr.org>

Arbitrarily selecting GPIOLIB causes trouble on some architectures,
so don't do that. Instead, just make the optional multiplexing code
depend on CONFIG_I2C_MUX_GPIO instead of CONFIG_I2C_MUX for now. We
can revisit if the i2c-i801 driver ever supports other multiplexing
flavors.

Also make that optional code depend on DMI, as it won't do anything
without that.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>

Move the i2c-stub driver to drivers/i2c, to match the Kconfig entry.
This is less confusing that way.

I also fixed all checkpatch warnings and errors.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Peter Huewe <peterhuewe@gmx.de>

This patch implements DMA support into mxs-i2c. DMA transfers are now enabled
via DT. The DMA operation is enabled by default.
Signed-off-by: NMarek Vasut <marex@denx.de>
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>

[wsa: rebased to 3.6-rc7]
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

R-Car I2C is similar with SH7760 I2C.
But the SH7760 I2C driver had many workaround operations, since H/W had bugs.
Thus, it was pointless to keep compatible between SH7760 and R-Car I2C drivers.
This patch creates new Renesas R-Car I2C driver.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Convert clk_enable/clk_disable to clk_prepare_enable/clk_disable_unprepare
calls as required by common clock framework.
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Convert the driver from the outdated omap_pm_set_max_mpu_wakeup_lat
API to the new PM QoS API.
Since the constraint is on the MPU subsystem, use the PM_QOS_CPU_DMA_LATENCY
class of PM QoS. The resulting MPU constraints are used by cpuidle to
decide the next power state of the MPU subsystem.

The I2C device latency timing is derived from the FIFO size and the
clock speed and so is applicable to all OMAP SoCs.
Signed-off-by: NJean Pihet <j-pihet@ti.com>
Acked-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Here we apply the bindings required for successful Device Tree
probing of the i2c-nomadik driver.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The parameter passed to pca9665_reset is adap->data (which is bus driver
specific), not i2c_algp_pca_data *adap. pca9665_reset expects it to be
i2c_algp_pca_data *adap. All other wrappers from the algo call back to
the bus driver, which knows to handle its custom data. Only pca9665_reset
resides inside the algorithm code and does not know how to handle a custom
data structure. This can result in a kernel crash.

Fix by re-factoring pca_reset() from a macro to a function handling chip
specific code, and only call adap->reset_chip() if the chip is not PCA9665.
Signed-off-by: NThomas Kavanagh <tkavanagh@juniper.net>
Signed-off-by: NGuenter Roeck <groeck@juniper.net>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Fix build failure in Intel PIIX4 I2C driver.
Signed-off-by: NDaniel J Blueman <daniel@quora.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: stable@vger.kernel.org [v3.6]

Now that i2c-mux-gpio is able to find the GPIO chip by itself, we can
delegate this task. The great thing here is that i2c-mux-gpio can
defer device probing until the gpio chip is available, so we no longer
depend on the module loading order.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The code instantiating an i2c-mux-gpio platform device doesn't
necessarily know in advance the GPIO pin numbers it wants to use. If
pins are on a GPIO device which gets its base GPIO number assigned
dynamically at run-time, the values can't be hard-coded.

In that case, let the caller tell i2c-mux-gpio the name of the GPIO
chip and the (relative) GPIO pin numbers to use. At probe time, the
i2c-mux-gpio driver will look for the chip and apply the proper offset
to turn relative GPIO pin numbers to absolute GPIO pin numbers.

The same could be (and was so far) done on the caller's end, however
doing it in i2c-mux-gpio has two benefits:
* It avoids duplicating the code on every caller's side (about 30
  lines of code.)
* It allows for deferred probing for the muxed part of the I2C bus
  only. If finding the GPIO chip is the caller's responsibility, then
  deferred probing (if the GPIO chip isn't there yet) will not only
  affect the mux and the I2C bus segments behind it, but also the I2C
  bus trunk.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Peter Korsgaard <peter.korsgaard@barco.com>

Use the devm_kzalloc managed function to stripdown the error and remove
code.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Add support for SMBus multiplexing on Asus Z8 motherboard series. On
these boards, the memory slots are behind a GPIO-controlled I2C
multiplexer. Models with 6 or 12 memory slots have 2 segments behind
the multiplexer, while models with 18 memory slots have 3 such
segments.

On these boards, only the memory slots are behind the multiplexer,
so it is possible to keep the autodetection mechanism.

The code is generic enough so it could work on other boards as long as
the multiplexer is controlled by GPIO pins. For other forms of
multiplexing (for example using an I2C device) additional code will be
needed.

Thanks to Asus for providing a board to develop and test this feature,
as well as all the technical information required.

At the moment, the GPIO driver must be loaded before the i2c-i801
driver, but I hope to solve this soon, using deferred probing on
the i2c-mux-gpio side.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The SMBus controller in the VIA VX900 appears to be compatible with
the VIA VX855, so just add the device ID.

This closes kernel bug #43096.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

i2c_parport_irq is only called internally so it can be static.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

i2c_dw_xfer_msg is only called internally so it can be static. It
original was, before the driver split. No idea why it was changed at
that time.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NDirk Brandewie <dirk.brandewie@gmail.com>

Replace printks with pr_<level>s, add pr_fmt()s to replace NAMEs
Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Reviewed-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Remove the global dependency of the I2C subsystem on HAS_IOMEM and
move the dependency to the i2c/busses submenu, with an exception for
i2c-stub.

The generic I2C part does not need to have HAS_IOMEM set and thus now
becomes available in UML, so the I2C subsystem can now be used, e.g.
by the i2c-stub driver, for development of I2C device drivers.

[JD: Some adjustments.]

[Heiko Carstens: Keep I2C disabled on S390.]
Signed-off-by: NPeter Huewe <peterhuewe@gmx.de>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Convert the struct i2c_msg initialization to C99 format. This makes
maintaining and editing the code simpler. Also helps once other fields
like transferred are added in future.
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Converting kzalloc to devm_kzalloc simplifies the code and ensures that the
result, alert, is freed after the irq allocated by the subsequent
devm_request_irq.  This in turn ensures that when an interrupt can be
triggered, the alert structure is still available.

The problem of a free after a devm_request_irq was found using the
following semantic match (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression e1,e2,x,a,b,c,d;
identifier free;
position p1,p2;
@@

  devm_request_irq@p1(e1,e2,...,x)
  ... when any
      when != e2 = a
      when != x = b
  if (...) {
    ... when != e2 = c
        when != x = d
    free@p2(...,x,...);
    ...
    return ...;
  }
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Let I2C bus segments behind multiplexers have a class. This allows for
device auto-detection on these segments. As long as parent segments
don't share the same class, it should be fine.

I implemented support in drivers i2c-mux-gpio and i2c-mux-pca954x. I
left i2c-mux-pca9541 and i2c-mux-pinctrl alone for the moment as I
don't know if this feature makes sense for the use cases of these
drivers.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Peter Korsgaard <peter.korsgaard@barco.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Michael Lawnick <ml.lawnick@gmx.de>
Cc: Rodolfo Giometti <giometti@linux.it>

To avoid name conflicts:

  drivers/video/riva/fbdev.c:281:9: sparse: preprocessor token MAX_LEVEL redefined

While at it, also make the other names more consistent and add
parentheses.

[akpm@linux-foundation.org: repair fallout]
[sfr@canb.auug.org.au: IB/mlx4: fix for MAX_ID_MASK to MAX_IDR_MASK name change]
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: walter harms <wharms@bfs.de>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

Platform data for device drivers should be defined in
include/linux/platform_data/*.h, not in the architecture
and platform specific directories.

This moves such data out of the samsung include directories
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Wolfram Sang (embedded platforms)" <w.sang@pengutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Bryan Wu <bryan.wu@canonical.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Chris Ball <cjb@laptop.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: Liam Girdwood <lrg@ti.com>
Cc: linux-samsung-soc@vger.kernel.org

mpc_i2c_stop() only initiates STOP but does not wait for it to
hit the I2C bus. This is a problem when using I2C devices which
uses fairly long clock stretching just before STOP if you also
have an i2c-mux which may switch to another bus before STOP has
been processed.
Signed-off-by: NJoakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The code currently always selects turbo mode for PCA9665, no matter which
clock frequency is configured. This is because it compares the clock frequency
against constants reflecting (boundary / 100). Compare against real boundary
frequencies to fix the problem.
Signed-off-by: NThomas Kavanagh <tkavanagh@juniper.net>
Signed-off-by: NGuenter Roeck <groeck@juniper.net>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

As a first step towards migrating davinci platforms to use common clock
framework, replace all instances of clk_enable() with clk_prepare_enable()
and clk_disable() with clk_disable_unprepare(). Until the platform is
switched to use the CONFIG_HAVE_CLK_PREPARE Kconfig variable, this just
adds a might_sleep() call and would work without any issues.

This will make it easy later to switch to common clk based implementation
of clk driver from DaVinci specific driver.
Signed-off-by: NMurali Karicheri <m-karicheri2@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Platform data for device drivers should be defined in
include/linux/platform_data/*.h, not in the architecture
and platform specific directories.

This moves such data out of the w90x900 include directories
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NNicolas Pitre <nico@linaro.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: "Ben Dooks (embedded platforms)" <ben-linux@fluff.org>
Cc: "Wolfram Sang (embedded platforms)" <w.sang@pengutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

Platform data for device drivers should be defined in
include/linux/platform_data/*.h, not in the architecture
and platform specific directories.

This moves such data out of the imx include directories
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: NSascha Hauer <kernel@pengutronix.de>
Acked-by: NVinod Koul <vinod.koul@linux.intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Dan Williams <djbw@fb.com>
Cc: "Ben Dooks (embedded platforms)" <ben-linux@fluff.org>
Cc: "Wolfram Sang (embedded platforms)" <w.sang@pengutronix.de>
Cc: Chris Ball <cjb@laptop.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Liam Girdwood <lrg@ti.com>
Cc: Javier Martin <javier.martin@vista-silicon.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>

Platform data for device drivers should be defined in
include/linux/platform_data/*.h, not in the architecture
and platform specific directories.

This moves such data out of the davinci include directories
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: NFelipe Balbi <balbi@ti.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: "Ben Dooks" <ben-linux@fluff.org>
Cc: "Wolfram Sang" <w.sang@pengutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Chris Ball <cjb@laptop.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Liam Girdwood <lrg@ti.com>
Cc: davinci-linux-open-source@linux.davincidsp.com

Tegra I2C driver enables the fast clock during initialization
and does not disable till driver removed.
Enable this clock before transfer and disable after transfer done.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NStephen Warren <swarren@nvidia.com>

Tegra20 i2c controller does not support the continue transfer
which implements the I2C_M_NOSTART functionality of i2c
protocol mangling.
Removing the I2C_M_NOSTART functionality support for Tegra20.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NStephen Warren <swarren@nvidia.com>

Tegra's i2c controller require two clock sources named as
div_clk and fast_clk.
This change make sure that driver pass the correct clock's
name when it acquires clock handle. Also change the
variable name to reflect the correct clock handles.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NStephen Warren <swarren@nvidia.com>