There are devices that need to handle block transactions
regardless of the capabilities exported by the adapter.
For performance reasons, they need to use i2c read blocks
if available, otherwise emulate the block transaction with word
or byte transactions.

Add support for a helper function that would read a data block
using the best transfer available: I2C_FUNC_SMBUS_READ_I2C_BLOCK,
I2C_FUNC_SMBUS_READ_WORD_DATA or I2C_FUNC_SMBUS_READ_BYTE_DATA.
Signed-off-by: NIrina Tirdea <irina.tirdea@intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

And update indentation with one more tab, sigh...
Tested-by: NAndrey Danin <danindrey@mail.ru>
Acked-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

of_find_i2c_adapter_by_node() call requires quite often missing
put_device(), and i2c_put_adapter() releases a device locked by
i2c_get_adapter() only. In general module_put(adapter->owner) and
put_device(dev) are not interchangeable.

This is a common error reproduction scenario as a result of the
misusage described above (for clearness this is run on iMX6 platform
with HDMI and I2C bus drivers compiled as kernel modules):

    root@mx6q:~# lsmod | grep i2c
    i2c_imx                10213  0
    root@mx6q:~# lsmod | grep dw_hdmi_imx
    dw_hdmi_imx             3631  0
    dw_hdmi                11846  1 dw_hdmi_imx
    imxdrm                  8674  3 dw_hdmi_imx,imx_ipuv3_crtc,imx_ldb
    drm_kms_helper        113765  5 dw_hdmi,imxdrm,imx_ipuv3_crtc,imx_ldb
    root@mx6q:~# rmmod dw_hdmi_imx
    root@mx6q:~# lsmod | grep i2c
    i2c_imx                10213  -1

                                 ^^^^^

    root@mx6q:~# rmmod i2c_imx
    rmmod: ERROR: Module i2c_imx is in use

To fix existing users of these interfaces and to avoid any further
confusion and misusage in future, add one more interface
of_get_i2c_adapter_by_node(), it is similar to i2c_get_adapter() in
sense that an I2C bus device driver found and locked by user can be
correctly unlocked by i2c_put_adapter().
Signed-off-by: NVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This patch changes type of input parameter for
prepare/unprepare_recovery() callbacks from struct i2c_bus_recovery_info
* to struct i2c_adapter *. This allows to simplify implementation of
these callbacks and avoid type conversations from i2c_bus_recovery_info
to i2c_adapter. The i2c_bus_recovery_info can be simply retrieved from
struct i2c_adapter which contains pointer on it. There are no users
currently, so this is safe to do.
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

After more discussion, brave users, and additional datasheet evaluation,
some API updates for the new I2C slave framework became imminent. The
slave events now get some easier to understand naming. Also, the event
handling has been simplified to only need a single call to the slave
callback when an action by the backend is required.
Reported-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Now that we have struct fwnode_handle, we can use that to point to
ACPI companions from struct device objects instead of pointing to
struct acpi_device directly.

There are two benefits from that.  First, the somewhat ugly and
hackish struct acpi_dev_node can be dropped and, second, the same
struct fwnode_handle pointer can be used in the future to point
to other (non-ACPI) firmware device node types.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NGrant Likely <grant.likely@linaro.org>

The number of I2C adapters which are not fully I2C compatible is rising,
sadly. Drivers usually do handle the flaws, still the user receives only
some errno for a transfer which normally can be expected to work. This
patch introduces a formal description of flaws. One advantage is that
the core can check before the actual transfer if the messages could be
transferred at all. This is done in the next patch. Another advantage is
that we can pass this information to the user so the restrictions are
exactly known and further actions can be based on that. This will be
done later after some stabilization period for this description.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NRay Jui <rjui@broadcom.com>
Tested-by: NIvan T. Ivanov <iivanov@mm-sol.com>
Tested-by: NNeelesh Gupta <neelegup@linux.vnet.ibm.com>
Tested-By: NLudovic Desroches <ludovic.desroches@atmel.com>

Make the slave support depend on CONFIG_I2C_SLAVE. Otherwise it gets
included unconditionally, even when it is not needed.

I2C bus drivers which implement slave support must select
I2C_SLAVE.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There haven't been any I2C driver that use the legacy suspend/resume
callbacks for a while now and new drivers are supposed to use PM ops. So
remove support for legacy suspend/resume for I2C drivers.

Since there aren't any special bus specific things to do during
suspend/resume and since the PM core will automatically fallback directly to
using the device's PM ops if no bus PM ops are specified there is no need to
have any I2C bus PM ops.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Finally(!), make Linux support being an I2C slave. Most of the existing
infrastructure is reused. We mainly add i2c_slave_register/unregister()
calls which tells i2c bus drivers to activate the slave mode. Then, they
also get a callback to report slave events to.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This patch fix speeling typo found in html files within
Documentation/DocBook/device-drivers.
It is because html files are generated from comments in source,
so I have to fix comments in the source.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Commit 5d98e61d ("I2C/ACPI: Add i2c ACPI operation region support")
renamed the i2c-core module. This may cause regressions for
distributions, so put the ACPI code back into the core.
Reported-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NLan Tianyu <tianyu.lan@intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Commit da3c6647(I2C/ACPI: Clean up I2C ACPI code and Add CONFIG_I2C_ACPI
config) adds a new kernel config I2C_ACPI and make I2C core built in
when the config is selected. This is wrong because distributions
etc generally compile I2C as a module and the commit broken that.
This patch is to rename I2C_ACPI to ACPI_I2C_OPREGION. New config
only controls ACPI I2C operation region code and depends on I2C=y.
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
[wsa: removed unrelated change for Kconfig]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Clean up ACPI related code in the i2c core and add CONFIG_I2C_ACPI
to enable I2C ACPI code.

Current there is a race between removing I2C ACPI operation region
and ACPI AML code accessing. So make i2c core built-in if CONFIG_I2C_ACPI
is set.
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

ACPI 5.0 spec(5.5.2.4.5) defines GenericSerialBus(i2c, spi, uart) operation region.
It allows ACPI aml code able to access such kind of devices to implement
some ACPI standard method.

ACPI Spec defines some access attribute to associate with i2c protocol.
AttribQuick 	       	       		Read/Write Quick Protocol
AttribSendReceive			Send/Receive Byte Protocol
AttribByte 			 	Read/Write Byte Protocol
AttribWord				Read/Write Word Protocol
AttribBlock				Read/Write Block Protocol
AttribBytes				Read/Write N-Bytes Protocol
AttribProcessCall			Process Call Protocol
AttribBlockProcessCall			Write Block-Read Block Process Call Protocol
AttribRawBytes 				Raw Read/Write N-BytesProtocol
AttribRawProcessBytes			Raw Process Call Protocol

On the Asus T100TA, Bios use GenericSerialBus operation region to access
i2c device to get battery info.

Sample code From Asus T100TA

    Scope (_SB.I2C1)
    {
        Name (UMPC, ResourceTemplate ()
        {
            I2cSerialBus (0x0066, ControllerInitiated, 0x00061A80,
                AddressingMode7Bit, "\\_SB.I2C1",
                0x00, ResourceConsumer, ,
                )
        })

	...

        OperationRegion (DVUM, GenericSerialBus, Zero, 0x0100)
        Field (DVUM, BufferAcc, NoLock, Preserve)
        {
            Connection (UMPC),
            Offset (0x81),
            AccessAs (BufferAcc, AttribBytes (0x3E)),
            FGC0,   8
        }
	...
     }

     Device (BATC)
     {
         Name (_HID, EisaId ("PNP0C0A"))  // _HID: Hardware ID
         Name (_UID, One)  // _UID: Unique ID
	 ...

            Method (_BST, 0, NotSerialized)  // _BST: Battery Status
            {
                If (LEqual (AVBL, One))
                {
                    Store (FGC0, BFFG)
                    If (LNotEqual (STAT, One))
                    {
                        ShiftRight (CHST, 0x04, Local0)
                        And (Local0, 0x03, Local0)
                        If (LOr (LEqual (Local0, One), LEqual (Local0, 0x02)))
                        {
                            Store (0x02, Local1)
                        }
	...

    }

The i2c operation region is defined under I2C1 scope. _BST method under
battery device BATC read battery status from the field "FCG0". The request
would be sent to i2c operation region handler.

This patch is to add i2c ACPI operation region support. Due to there are
only "Byte" and "Bytes" protocol access on the Asus T100TA, other protocols
have not been tested.

About RawBytes and RawProcessBytes protocol, they needs specific drivers to interpret
reference data from AML code according ACPI 5.0 SPEC(5.5.2.4.5.3.9 and 5.5.2.4.5.3.10).
So far, not found such case and will add when find real case.
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram 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: NWolfram Sang <wsa@the-dreams.de>

Add some kerneldoc style documentaton to the i2c_algorithm
structure, and point the master_xfer return codes at the
right place in Documentation/i2c/fault_codes
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The body of i2c_parent_is_i2c_adapter() is currently guarded by
I2C_MUX. It should be CONFIG_I2C_MUX instead.

Among potentially other problems, this resulted in i2c_lock_adapter()
only locking I2C mux child adapters, and not the parent adapter. In
turn, this could allow inter-mingling of mux child selection and I2C
transactions, which could result in I2C transactions being directed to
the wrong I2C bus, and possibly even switching between busses in the
middle of a transaction.

One concrete issue caused by this bug was corrupted HDMI EDID reads
during boot on the NVIDIA Tegra Seaboard system, although this only
became apparent in recent linux-next, when the boot timing was changed
just enough to trigger the race condition.

Fixes: 3923172b ("i2c: reduce parent checking to a NOOP in non-I2C_MUX case")
Cc: Phil Carmody <phil.carmody@partner.samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The 'driver' field of the i2c_client struct is redundant. The same data can be
accessed through to_i2c_driver(client->dev.driver). The generated code for both
approaches in more or less the same.

E.g. on ARM the expression client->driver->command(...) generates

		...
		ldr     r3, [r0, #28]
		ldr     r3, [r3, #32]
		blx     r3
		...

and the expression to_i2c_driver(client->dev.driver)->command(...) generates

		...
		ldr     r3, [r0, #160]
    	ldr     r3, [r3, #-4]
    	blx     r3
		...

Other architectures will generate similar code.

All users of the 'driver' field outside of the I2C core have already been
converted. So this only leaves the core itself. This patch converts the
remaining few users in the I2C core and then removes the 'driver' field from the
i2c_client struct.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This follows what has already been done for the DeviceTree helpers. Move
the ACPI helpers from drivers/acpi/acpi_i2c.c to the I2C core and update
documentation accordingly.

This also solves a problem reported by Jerry Snitselaar that we can't build
the ACPI I2C helpers as a module.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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>

In 0826374b - i2c: Multiplexed I2C bus core support
core i2c code increased in size and complexity even when I2C_MUX
wasn't selected.

Turning this check into a constant NULL in the n case lets the
client functions in be simplified too, not needing to include
never-called calls to the mux-specific helpers.
Signed-off-by: NPhil Carmody <phil.carmody@partner.samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

i2c_del_adapter() is usually called from a drivers remove callback. The Linux
device driver model does not allow the remove callback to fail and all resources
allocated in the probe callback need to be freed, as well as all resources which
have been provided to the rest of the kernel(for example a I2C adapter) need to
be revoked. So any function revoking such resources isn't allowed to fail
either. i2c_del_adapter() adheres to this requirement and will never fail. But
i2c_del_adapter()'s return type is int, which may cause driver authors to think
that it can fail. This led to code constructs like:

	ret = i2c_del_adapter(...);
	BUG_ON(ret);

Since i2c_del_adapter() always returns 0 the BUG_ON is never hit and essentially
becomes dead code, which means it can be removed. Making the return type of
i2c_del_adapter() void makes it explicit that the function will never fail and
should prevent constructs like the above from re-appearing in the kernel code.

All callers of i2c_del_adapter() have already been updated in a previous patch
to ignore the return value, so the conversion of the return type from int to
void can be done without causing any build failures.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The detach_adapter callback has been deprecated for quite some time and has no
user left. Keeping it alive blocks other cleanups, so remove it.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add i2c bus recovery infrastructure to i2c adapters as specified in the i2c
protocol Rev. 03 section 3.1.16 titled "Bus clear".

http://www.nxp.com/documents/user_manual/UM10204.pdf

Sometimes during operation i2c bus hangs and we need to give dummy clocks to
slave device to start the transfer again. Now we may have capability in the bus
controller to generate these clocks or platform may have gpio pins which can be
toggled to generate dummy clocks. This patch supports both.

This patch also adds in generic bus recovery routines gpio or scl line based
which can be used by bus controller. In addition controller driver may provide
its own version of the bus recovery routine.

This doesn't support multi-master recovery for now.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
[wsa: changed gpio type to int and minor reformatting]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

ACPI 5 introduced I2cSerialBus resource that makes it possible to enumerate
and configure the I2C slave devices behind the I2C controller. This patch
adds helper functions to support I2C slave enumeration.

An ACPI enabled I2C controller driver only needs to call acpi_i2c_register_devices()
in order to get its slave devices enumerated, created and bound to the
corresponding ACPI handle.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NDave Jones <davej@redhat.com>

s/address_data/address_list/ in addition to c3813d6a.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

SCCB is a serial communication bus developed by Omnivision. Its 2-wire
mode is very similar to SMBus byte data transactions, but requires the
controller to ignore the ACK bit and to insert a stop condition after
each message.

Add a device SCCB flag and a message stop flag to be passed to
controller drivers.

[JD: Kill rogue definition in go7007 driver.]
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Some drivers (in particular for TV cards) need exclusive access to
their I2C buses for specific operations. Export an unlocked flavor
of i2c_transfer to give them full control.

The unlocked flavor has the following limitations:
* Obviously, caller must hold the i2c adapter lock.
* No debug messages are logged. We don't want to log messages while
  holding a rt_mutex.
* No check is done on the existence of adap->algo->master_xfer. It
  is thus the caller's responsibility to ensure that the function is
  OK to call.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Since there are uses for I2C_M_NOSTART which are much more sensible and
standard than most of the protocol mangling functionality (the main one
being gather writes to devices where something like a register address
needs to be inserted before a block of data) create a new I2C_FUNC_NOSTART
for this feature and update all the users to use it.

Also strengthen the disrecommendation of the protocol mangling while we're
at it.

In the case of regmap-i2c we remove the requirement for mangling as
I2C_M_NOSTART is the only mangling feature which is being used.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This converts a struct device * to a struct i2c_adapter * while verifying
that the device really is an I2C adapter. Just like i2c_verify_client.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

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

Last piece of code using ANY_I2C_BUS was deleted almost 2 years ago,
so ANY_I2C_BUS can go away as well.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

This patch introduces the module_i2c_driver macro which is a convenience macro
for I2C driver modules similar to module_platform_driver. It is intended to be
used by drivers which init/exit section does nothing but register/unregister
the I2C driver. By using this macro it is possible to eliminate a few lines of
boilerplate code per I2C driver.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NJonathan Cameron <jic23@cam.ac.uk>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The <linux/module.h> pretty much brings in the kitchen sink along
with it, so it should be avoided wherever reasonably possible in
terms of being included from other commonly used <linux/something.h>
files, as it results in a measureable increase on compile times.

The worst culprit was probably device.h since it is used everywhere.
This file also had an implicit dependency/usage of mutex.h which was
masked by module.h, and is also fixed here at the same time.

There are over a dozen other headers that simply declare the
struct instead of pulling in the whole file, so follow their lead
and simply make it a few more.

Most of the implicit dependencies on module.h being present by
these headers pulling it in have been now weeded out, so we can
finally make this change with hopefully minimal breakage.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

The original implementations reference THIS_MODULE in an inline.
We could include <linux/export.h>, but it is better to avoid chaining.

Fortunately someone else already thought of this, and made a similar
inline into a #define in <linux/device.h> for device_schedule_callback(),
[see commit 523ded71] so follow that precedent here.

Also bubble up any __must_check that were used on the prev. wrapper inline
functions up one to the real __register functions, to preserve any prev.
sanity checks that were used in those instances.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Reimplemented at least 17 times discounting error mangling cases
where it could be used.
Signed-off-by: NJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

While the JC42-compatible chips are temperature sensors, I2C_CLASS_SPD
makes more sense because these chips always live on memory modules.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>

There is no user left of i2c_adapter.id, so we can get rid of it.
Finally! :)
Signed-off-by: NJean Delvare <khali@linux-fr.org>