i2c_davinci_cpufreq_transition() is implemented in a way that will
block if it ever gets called while no transfer is in progress.

Not only that, but reinit_completion() is never called for xfr_complete.

Use the fact that cpufreq uses an srcu_notifier (running in process
context) for transitions and that the bus_lock is taken during the call
to master_xfer() and simplify the code by removing the transfer
completion entirely and protecting i2c_davinci_cpufreq_transition()
with i2c_lock/unlock_adapter().
Reported-by: NDavid Lechner <david@lechnology.com>
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NSekhar Nori <nsekhar@ti.com>
Tested-by: NDavid Lechner <david@lechnology.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Alter the DaVinci GPIO recovery fetch to use descriptors
all the way down into the board files.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NSekhar Nori <nsekhar@ti.com>
Tested-by: NSekhar Nori <nsekhar@ti.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Change the driver to use the gpio descriptors for the bus recovery
information instead of the deprecated integer interface.
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Reviewed-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Fixes this warning (found by build testing with 64bit):

format ‘%i’ expects argument of type ‘int’, but argument 3 has type
‘size_t {aka long unsigned int}’ [-Wformat=]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NSekhar Nori <nsekhar@ti.com>

66AK2G has I2C instances that are not apart of the ALWAYS_ON power domain
unlike other Keystone 2 SoCs and OMAPL138. Therefore, pm_runtime
is required to insure the power domain used by the specific I2C instance is
properly turned on along with its functional clock.
Signed-off-by: NFranklin S Cooper Jr <fcooper@ti.com>
Acked-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The i2c driver can run into driver dependency issues if its loaded
before a clock driver it depends on. Therefore, EPROBE_DEFER may be
returned by devm_clk_get and should be returned in probe to allow the
kernel to reprobe the driver at a later time. This patch allows the error
value returned by devm_clk_get to be passed through and not overwritten.
Signed-off-by: NFranklin S Cooper Jr <fcooper@ti.com>
Reviewed-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Check for i2c_algorithm and i2c_adapter_quirks structures that are only
stored in the algo and quirks fields of an i2c_adapter structure
correspondingly. These fields are declared const, so i2c_algorithm and
i2c_adapter_quirks structures that have this property can be declared
as const also.
Signed-off-by: NGustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> (for designware)
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Several drivers call to_platform_device() to get platform_device
and pass it to platform_get_drvdata().  In platform_get_drvdata(),
the platform_device is converted back to struct device again.

Use dev_get_drvdata() to avoid platform_device/device dance.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> (for DesignWare only)
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The core will do this for us now.
Signed-off-by: NWolfram Sang <wsa-dev@sang-engineering.com>
Reviewed-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NPeter Korsgaard <peter@korsgaard.com>
Acked-by: NHeiko Stuebner <heiko@sntech.de>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Acked-by: NThierry Reding <treding@nvidia.com>
Acked-by: NRay Jui <ray.jui@broadcom.com>
Acked-by: NVladimir Zapolskiy <vz@mleia.com>
Acked-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Acked-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

I2C controller used in Keystone SoC has an undocumented peculiarity which
results in SDA-SCL margins being dependent on module clock. Driving high
capacity bus near its limits can result in STOP condition sometimes being
understood as REPEATED-START by slaves (or NACK instead of ACK, etc...).
Driving the module with higher clocks increases the margin between SDA and SCL
transitions, making the operations with higher bus rates more robust. Therefore,
target the module clock to 12MHz instead of 7MHz, still staying within
the specification limits.

Before the change STOP timing looked like this on 400kHz:

SDA   ----------+          +----
                 \        /
                  \      /
                   +----+
                       (1)
SCL   --+          +------------
         \        /
          \      /
           +----+
               (2)

While only point (1) signals STOP, point (2) could be incorrectly recognized as
repeated-START (almost no margin between SDA and SCL transitions).

After the change there is at least 600ns margin measured between SCL fall and
SDA fall during STOP generation:

SDA   ------+          +----
             \        /
              \      /
               +----+

SCL   --+          +--------
         \        /
          \      /
           +----+
           ->|    |<- 600ns
                ->|   |<- tSUSTO

So called tSUSTO (setup time for STOP condition) is still slightly higher than
600ns, so no problem here.
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

According to "KeyStone Architecture Inter-IC Control Bus User Guide", fixed
additive part of frequency divisors (referred as "d" in the code and datasheet)
always equals to 6, independent of module clock prescaler.

                         module clock frequency
master clock frequency = ----------------------
                         (ICCL + 6) + (ICCH + 6)

It was not the case with original Davinci IP. Introduce new compatible property
"ti,keystone-i2c", which triggers special handling in the driver.

Without this change Keystone-based systems (having 204.8MHz input clock) choose
prescaler 29 (PSC=28). Using d=5 in this case leads to bus bitrate ~353kHz
instead of requested 400kHz. After correction, assuming d=6 bus rate is ~392kHz.
This gives ~11% transfer rate increase.
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Reviewed-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NHemanth Guruva Reddy <hemanth.guruva_reddy@nokia.com>
Tested-by: NLukasz Gemborowski <lukasz.gemborowski@nokia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There are several cases where current clock configuration algorithm produces
not optimal results:
- truncation in "clk" calculation leads to the fact that actual BUS frequency
  will be always higher than spec except two exact module frequences 8MHz and
  12MHz in the whole 7-12MHz range of permitted frequences
- driver configures SCL HIGH to LOW ratio always 1 to 1 and this doesn't work
  well in 400kHz case, namely minimum time of LOW state (according to I2C Spec
  2.1) 1.3us will not be fulfilled. HIGH to LOW ratio 1 to 2 would be more
  approriate here.
Signed-off-by: NMichael Lawnick <michael.lawnick@nokia.com>
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Sending a message to own address locks the controller up in very bizarre state,
it behaves as slave even if MDR register clearly states master. The controller
remains in this state until reset. To avoid unnecessary timeouts simply avoid
sending to own address. The controller cannot do this any way. Also, do not
enable AAS IRQ, as the slave mode is not supported by the driver and the only
possibility to trigger this IRQ is to send to own address.
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There are several problems in the function:
- "to_cnt" variable does nothing
- schedule_timeout() call without setting current state does nothing
- "allow_sleep" parameter is not really used

Refactor the function so that it really tries to wait. In case of timeout try
to recover the bus.
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Having a board where the I2C bus locks up occasionally made it clear
that the bus recovery in the i2c-davinci driver will only work on
some boards, because on regular boards, this will only toggle GPIO
lines that aren't muxed to the actual pins.

The I2C controller on SoCs like da850 (and da830), Keystone 2 has the
built-in capability to bit-bang its lines by using the ICPFUNC registers
of the i2c controller.
Implement the suggested procedure by toggling SCL and checking SDA using
the ICPFUNC registers of the I2C controller when present. Allow platforms
to indicate the presence of the ICPFUNC registers with a has_pfunc platform
data flag and add optional DT property "ti,has-pfunc" to indicate
the same in DT.
Reviewed-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: NMichael Lawnick <michael.lawnick@nokia.com>
Signed-off-by: NBen Gardiner <bengardiner@nanometrics.ca>
Signed-off-by: NMike Looijmans <milo-software@users.sourceforge.net>
[grygorii.strashko@ti.com: combined patches from Ben Gardiner and
Mike Looijmans and reimplemented ICPFUNC bus recovery using I2C
bus recovery infrastructure]
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This patch converts Davinci I2C driver to use I2C bus recovery
infrastructure, introduced by commit 5f9296ba ("i2c: Add
bus recovery infrastructure").

The i2c_bus_recovery_info is configured for Davinci I2C adapter
only in case scl_pin is provided in platform data.

As the controller must be held in reset while doing so, the
recovery routine must re-init the controller. Since this was already
being done after each call to i2c_recover_bus, move those calls into
the recovery_prepare/unprepare routines and as well.
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

wait_for_completion_timeout return 0 (timeout) or >=1 (completion) so the check
for >= 0 is always true and can be dropped implying that r==-EREMOTEIO and thus
the return of -EREMOTEIO can be done in the   if (dev->buf_len)  branch.
As wait_for_completion_timeout returns unsigned long not int, and   int r   is
exclusively used for wait_for_completion_timeout it is renamed and the type
changed to unsigned long.
Signed-off-by: NNicholas Mc Guire <hofrat@osadl.org>
Acked-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

According to I2C specification the NACK should be handled as follows:
"When SDA remains HIGH during this ninth clock pulse, this is defined as the Not
Acknowledge signal. The master can then generate either a STOP condition to
abort the transfer, or a repeated START condition to start a new transfer."
[I2C spec Rev. 6, 3.1.6: http://www.nxp.com/documents/user_manual/UM10204.pdf]

Currently the Davinci i2c driver interrupts the transfer on receipt of a
NACK but fails to send a STOP in some situations and so makes the bus
stuck until next I2C IP reset (idle/enable).

For example, the issue will happen during SMBus read transfer which
consists from two i2c messages write command/address and read data:

S Slave Address Wr A Command Code A Sr Slave Address Rd A D1..Dn A P
<--- write -----------------------> <--- read --------------------->

The I2C client device will send NACK if it can't recognize "Command Code"
and it's expected from I2C master to generate STP in this case.
But now, Davinci i2C driver will just exit with -EREMOTEIO and STP will
not be generated.

Hence, fix it by generating Stop condition (STP) always when NACK is received.

This patch fixes Davinci I2C in the same way it was done for OMAP I2C
commit cda2109a ("i2c: omap: query STP always when NACK is received").
Reviewed-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reported-by: NHein Tibosch <hein_tibosch@yahoo.es>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

Switch Davinci I2C driver to use platform_get_irq(), because
it is not recommened to use platform_get_resource(pdev, IORESOURCE_IRQ, ..)
for requesting IRQ resources any more, as they can be not ready yet
in case of DT-boot.
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

When a signal is caught while the i2c-davinci bus driver is
transferring, the driver just "abandons" the transfer and leaves the
controller to fend for itself. The next I2C transaction will find the
controller in an undefined state and often results in a stream of
"initiating i2c bus recovery" messages until the controller arrives in a
defined state. This behaviour also sends out "half" or possibly even
mixed messages to I2C client devices which may put them in an undesired
state as well. So, let's get simply uninterruptible.
Signed-off-by: NMike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

We have a central copy of the GPL for that. Some addresses were already
outdated.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This driver has been flagged to drop class based instantiation. The removal
improves boot-up time and is unneeded for embedded controllers. Users have been
warned to switch for some time now, so we can actually do the removal. Keep the
DEPRECATED flag, so the core can inform users that the behaviour finally
changed now. After another transition period, this flag can go, too.
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>

I2C IP block expect LE data, but CPU may operate in BE mode.
Need to use endian neutral functions to read/write h/w registers.
I.e instead of __raw_read[lw] and __raw_write[lw] functions code
need to use read[lw]_relaxed and write[lw]_relaxed functions.
If the first simply reads/writes register, the second will byteswap
it if host operates in BE mode.

Changes are trivial sed like replacement of __raw_xxx functions
with xxx_relaxed variant.
Signed-off-by: NTaras Kondratiuk <taras.kondratiuk@linaro.org>
Reviewed-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Use this new function to make code more comprehensible, since we are
reinitialzing the completion, not initializing.

[akpm@linux-foundation.org: linux-next resyncs]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The data structure of_match_ptr() protects is always compiled in.
Hence of_match_ptr() is not needed.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

commit 6d4028c6 (i2c: use dev_get_platdata()) did a bad conversion
of this one case:

  drivers/i2c/busses/i2c-davinci.c: In function 'davinci_i2c_probe':
  drivers/i2c/busses/i2c-davinci.c:665:2: warning: passing argument 1 of
	'dev_get_platdata' from incompatible pointer type [enabled by default]
Reviewed-by: NJingoo Han <jg1.han@samsung.com>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NOlof Johansson <olof@lixom.net>

I2C of helpers used to live in of_i2c.c but experience (from SPI) shows
that it is much cleaner to have this in the core. This also removes a
circular dependency between the helpers and the core, and so we can
finally register child nodes in the core instead of doing this manually
in each driver. So, fix the drivers and documentation, too.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This driver no longer uses definitions from mach/hardware.h.
On the other hand, including this header breaks this driver
on non-davinci platforms which don't have such a header.
Acked-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Driver core already takes care of refcounting, no need to do this on
driver level again.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NSekhar Nori <nsekhar@ti.com>

Update the code to use devm_* API so that driver core will manage
resources.
Signed-off-by: NVishwanathrao Badarkhe, Manish <manishv.b@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Since we have generic i2c bus recover routines now, these custom ones
need to be renamed to fix the namespace clash. Proper conversion needs
to be done by someone who has access to the hardware.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There is simply no reason to be manually setting the private driver
data to NULL in the remove/fail to probe cases.  This is just extra
cruft code that can be removed.

A few notes:
* Nothing relies on drvdata being set to NULL.
* The __device_release_driver() function eventually calls
  dev_set_drvdata(dev, NULL) anyway, so there's no need to do it
  twice.
* I verified that there were no cases where xxx_get_drvdata() was
  being called in these drivers and checking for / relying on the NULL
  return value.

This could be cleaned up kernel-wide but for now just take the baby
step and remove from the i2c subsystem.
Reported-by: NWolfram Sang <wsa@the-dreams.de>
Reported-by: NStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <wolfram@the-dreams.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 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

add of support for the davinci i2c driver.
Signed-off-by: NHeiko Schocher <hs@denx.de>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>

[wsa: fix indentation in the binding description]
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The freed IRQ is not necessary the one requested in probe.
Even if it was, with two or more i2c-controllers it will fails anyway.
Signed-off-by: NMarcus Folkesson <marcus.folkesson@gmail.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Cc: stable@kernel.org