The "clock-frequency" DT property is listed as optional, However,
the current code stores the return value of of_property_read_u32 in
the return code of mv64xxx_of_config, but then forgets to clear it
after setting the default value of "clock-frequency". It is then
passed out to the main probe function, resulting in a probe failure
when "clock-frequency" is missing.

This patch checks and then throws away the return value of
of_property_read_u32, instead of storing it and having to clear it
afterwards.

This issue was discovered after the property was removed from all
sunxi DTs.

Fixes: 4c730a06 ("i2c: mv64xxx: Set bus frequency to 100kHz if clock-frequency is not provided")
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Cc: stable@vger.kernel.org
Acked-by: NAndrew Lunn <andrew@lunn.ch>
Acked-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
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>

The Allwinner A10 compatibles were following a slightly different compatible
patterns than the rest of the SoCs for historical reasons. Move to the other
pattern for consistency across all Allwinner Socs.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
[wsa: dropped binding OK as per
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-February/229438.html]
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>

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 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>

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: NMaxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: NWolfram 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: NMaxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Because the offload mechanism can fall back to a standard transfer,
having two seperate initialization states is unfortunate. Let's just
have one state which does things consistently. This fixes a bug where
some preparation was missing when the fallback happened. And it makes
the code much easier to follow. To implement this, we put the check
if offload is possible at the top of the offload setup function.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Cc: stable@vger.kernel.org # v3.12+
Fixes: 930ab3d4 (i2c: mv64xxx: Add I2C Transaction Generator support)

The first variants of Armada XP SoCs (A0 stepping) have issues related
to the i2c controller which prevent to use the offload mechanism and
lead to a kernel hang during boot.

The commit introduces a new the compatible string
marvell,mv78230-a0-i2c for the i2c controller. When this compatible
string is used the driver disables the offload mechanism and the
kernel no more hangs on these SoCs.
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Reported-by: NAndrew Lunn <andrew@lunn.ch>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org # v3.12+: af8d1c63: ARM: mvebu: Add support to get the ID and the revision of a SoC
Cc: stable@vger.kernel.org # v3.12+: 85e618a1: ARM: mvebu: Add quirk for i2c for the OpenBlocks AX3-4 board
Cc: stable@vger.kernel.org # v3.12+
Fixes: 930ab3d4 (i2c: mv64xxx: Add I2C Transaction Generator support)
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

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>

The driver is used on PowerPC which don't provide writel_relaxed(). This
breaks the c2k and prpmc2800 default configurations. To fix the build,
turn the calls to writel_relaxed() into writel(). The impacts for ARM
should be minimal.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Some functions and variables are only used if the configuration selects
HAVE_CLK. Protect them with a corresponding #ifdef CONFIG_HAVE_CLK block
to avoid compiler warnings.
Signed-off-by: NThierry Reding <treding@nvidia.com>
[wsa: added marker to #endif]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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>

All the Armada XP (mv78230, mv78260 and mv78460) have a silicon issue
in the I2C controller which violate the i2c repeated start
timing. The I2C standard requires a minimum of 4.7us for the repeated
start condition whereas the I2C controller of the Armada XP this time
is 2.9us.

So this patch adds a 5us delay for the start case only if the
the compatible i2c-mv78230 is set.

Based on the initals patches from Zbigniew Bodek
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: NZbigniew Bodek <zbb@semihalf.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The I2C Transaction Generator offloads CPU from managing I2C
transfer step by step.

This feature is currently only available on Armada XP, so usage of
this mechanism is activated through device tree.

Based on the work of Piotr Ziecik and rewrote to use the new way of
handling multiples i2c messages.
Signed-off-by: NPiotr Ziecik <kosmo@semihalf.com>
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
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 commit adds checking whether clock-frequency property acquisition
has succeeded. If not, the frequency is set to 100kHz by default.

The Device Tree binding documentation is updated accordingly.

Based on the intials patches from Zbigniew Bodek
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: NZbigniew Bodek <zbb@semihalf.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The driver returns -ENODEV as error code if it did not get an ACK
from the device. Per Documentation/i2c/fault-codes, it should
return -ENXIO.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add the compatible string for the Allwinner A10 i2c controller and the
associated register layout.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The Allwinner i2c controller uses the same logic as the Marvell one, but
with slightly different register offsets.

Introduce a structure that will be passed by either the pdata or
associated to the compatible strings, and that holds the various
registers that might be needed.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

These macros make it more comprehensive to access to useful masked and
shifted area of the various registers used.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Asking for a multi-part message to be handled by this driver is racy; it
has been observed that the following sequence is possible with this
driver:

	- send start
	- send address + write
	- send data
	- send (repeated) start
	- send address + write
	- send (repeated) start
	- send address + read
	- unrecoverable bus hang (except by system reset)

The problem is that the interrupt handling sees the next event after the
first repeated start is sent - the IFLG bit is set in the register even
though INTEN is disabled.

Let's fix this by moving all of the message processing into interrupt
context, rather than having it partly in IRQ and partly in process
context.  This allows us to move immediately to the next message in the
interrupt handler and get on with the transfer, rather than incuring a
couple of scheduling switches to get the next message.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Move mv64xxx_i2c_prepare_for_io() higher up in the driver to avoid a
future forward declaration for this function.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

As this driver does not advertise protocol mangling support
(I2C_FUNC_PROTOCOL_MANGLING is not set), having code to act on
I2C_M_NOSTART is illogical, and in any case isn't supportable on
anything but the first message - which makes no sense.  Remove
the I2C_M_NOSTART code.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Propagate the error code from request_irq() rather than ignoring it
entirely.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

As we're changing to using devm_* APIs to fix various problems
in this driver, lets also do devm_kzalloc() while we're here too.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This driver forgets to use clk_put().  Rather than adding clk_put(),
lets instead use devm_clk_get() to obtain this clock so that it's
automatically handled on cleanup.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Eliminate reg_base_p and reg_size, mv64xxx_i2c_unmap_regs() and an
unchecked ioremap() return from this driver by using the devm_*
API for requesting and ioremapping resources.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

mv64xxx_i2c_map_regs() already returns an error code, so lets
propagate that to mv64xxx_i2c_probe()'s caller.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Do not use interruptible waits in an I2C driver; if a process uses
signals (eg, Xorg uses SIGALRM and SIGPIPE) then these signals can
cause the I2C driver to abort a transaction in progress by another
driver, which can cause that driver to fail.  I2C drivers are not
expected to abort transactions on signals.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

i2c_del_adapter() always returns 0. So all checks testing whether it will be
non zero will always evaluate to false and the conditional code is dead code.
This patch updates all callers of i2c_del_mux_adapter() to ignore the return
value and assume that it will always succeed (which it will). In a subsequent
patch the return type of i2c_del_adapter() will be made void.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NBen Hutchings <bhutchings@solarflare.com>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

CONFIG_HOTPLUG is going away as an option.  As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> (for ocores and mux-gpio)
Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com> (for i2c-gpio)
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> (for puf3)
Acked-by: Barry Song <baohua.song@csr.com> (for sirf)
Reviewed-by: NJean Delvare <khali@linux-fr.org>
[wsa: Fixed "foo* bar" flaws while we are here]
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Extends the driver to get properties from device tree. Rather than
pass the N & M factors in DT, use the more standard clock-frequency
property. Calculate N & M at run time. In order to do this, we need to
know tclk. So the driver uses clk_get() etc in order to get the clock
and clk_get_rate() to determine the tclk rate. Not all platforms
however have CLK, so some #ifdefery is needed to ensure the driver
still compiles when CLK is not available.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>

[wsa: converted some ints to u32 to match signedness]
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The driver currently checks the platform device id and rejects platform
device id different from 0. This prevents the registration of a second
i2c controller on systems where a second one might be available (such as
Kirkwood 88F6282).

CC: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: NNicolas Schichan <nschichan@freebox.fr>
Signed-off-by: NFlorian Fainelli <ffainelli@freebox.fr>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Convert the drivers in drivers/i2c/busses/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Cc: Ben Dooks <ben-linux@fluff.org>
Acked-by: NJochen Friedrich <jochen@scram.de>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Cc: Manuel Lauss <manuel.lauss@googlemail.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Yong Zhang <yong.zhang0@gmail.com>
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

As stated into file include/linux/i2c.h we must send a repeated START
between messages in the same xfer groupset:

 * Except when I2C "protocol mangling" is used, all I2C adapters implement
 * the standard rules for I2C transactions.  Each transaction begins with a
 * START.  That is followed by the slave address, and a bit encoding read
 * versus write.  Then follow all the data bytes, possibly including a byte
 * with SMBus PEC.  The transfer terminates with a NAK, or when all those
 * bytes have been transferred and ACKed.  If this is the last message in a
 * group, it is followed by a STOP.  Otherwise it is followed by the next
 * @i2c_msg transaction segment, beginning with a (repeated) START.
Signed-off-by: NRodolfo Giometti <giometti@linux.it>
Signed-off-by: NMauro Barella <mbarella@vds-it.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

As warned by checkpatch.pl, <linux/io.h> should be used instead of
<asm/io.h>.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>