Commit Graph

3780 Commits

Author SHA1 Message Date
Mike Looijmans a2f8445d4c i2c: mux: pca954x: force reset on probe if available
Instead of just hogging the reset GPIO into deactivated state, activate and
then de-activate the reset. This allows for better recovery if the CPU was
reset halfway through an I2C transaction for example.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Peter Rosin <peda@axentia.se>
2018-05-19 23:54:47 +02:00
Wolfram Sang fca700d6d2 i2c: mux: demux-pinctrl: disable PM user interface
The demux device is only a logical device with no children. So, no
RuntimePM is needed, let's disable the sysfs interface for it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
2018-05-19 23:54:36 +02:00
Peter Rosin f56f316dcf i2c: mux: ltc4306: switch to using .probe_new
Use the new probe style for i2c drivers.

Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
2018-05-19 23:54:30 +02:00
Wolfram Sang 3d8b7a4ea3 Merge branch 'i2c/platform_data-immutable' into i2c/for-4.18 2018-05-17 16:29:19 +02:00
Wolfram Sang caaccda136 i2c: pnx: move header into the driver
There are no platform_data users anymore. Move the structs into the
driver.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
2018-05-17 16:27:59 +02:00
Wolfram Sang 7072b75c15 i2c: xiic: move header to platform_data
This header only contains platform_data. Move it to the proper directory.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
2018-05-17 16:27:59 +02:00
Wolfram Sang e5c7137793 i2c: pca-platform: move header to platform_data
This header only contains platform_data. Move it to the proper directory.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-17 16:27:58 +02:00
Wolfram Sang 79fc540fd5 i2c: omap: move header to platform_data
This header only contains platform_data. Move it to the proper directory.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Tony Lindgren <tony@atomide.com>
2018-05-17 16:27:58 +02:00
Wolfram Sang 985ecf0037 i2c: ocores: move header to platform_data
This header only contains platform_data. Move it to the proper directory.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
2018-05-17 16:27:57 +02:00
Wolfram Sang 62ea22c495 i2c: mux: gpio: move header to platform_data
This header only contains platform_data. Move it to the proper directory.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com>
2018-05-17 16:27:52 +02:00
Wolfram Sang 1e9d42194e i2c: gpio: move header to platform_data
This header only contains platform_data. Move it to the proper directory.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: James Hogan <jhogan@kernel.org>
Acked-by: Greg Ungerer <gerg@uclinux.org>
2018-05-17 16:27:09 +02:00
Pierre-Yves MORDRET c599eb4ff6 i2c: stm32f7: fix documentation typo
Some data structure members were either misspelled or missing.

Fixes: aeb068c572 ("i2c: i2c-stm32f7: add driver")
Fixes: 380b8a85e7 ("i2c: i2c-stm32f7: Add initial SMBus protocols support")
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-17 15:59:02 +02:00
Anders Roxell 4b2f9bd5e3 i2c: i801: fix unused-function warning
With CONFIG_PM, we get a harmless build warning:
drivers/i2c/busses/i2c-i801.c:1723:12: warning: ‘i801_resume’ defined but not used [-Wunused-function]
 static int i801_resume(struct device *dev)
            ^~~~~~~~~~~
drivers/i2c/busses/i2c-i801.c:1714:12: warning: ‘i801_suspend’ defined but not used [-Wunused-function]
 static int i801_suspend(struct device *dev)
            ^~~~~~~~~~~~

Follow design pattern from other drivers like i2c-brcmstb, i2c-mpc,
i2c-ocores, i2c-pnx, i2c-puv3, i2c-st, i2c-stu300 and i2c-mux-pca954x
and changing the ifdef CONFIG_PM to CONFIG_PM_SLEEP.

Fixes: a9c8088c79 ("i2c: i801: Don't restore config registers on runtime PM")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-17 15:54:12 +02:00
Colin Ian King 1ee7cdbfcd i2c: xiic: fix spelling mistake: "unexpexted" -> "unexpected"
Trivial fix to spelling mistakes in dev_dbg messages

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-17 15:51:59 +02:00
Peter Rosin 5e87270bec i2c: synquacer: fix fence-post error in retry loop
There is a difference between attempts and retries.

Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-17 15:40:33 +02:00
Wenwen Wang 8e03477cb7 i2c: core: smbus: fix a potential missing-check bug
In i2c_smbus_xfer_emulated(), the function i2c_transfer() is invoked to
transfer i2c messages. The number of actual transferred messages is
returned and saved to 'status'. If 'status' is negative, that means an
error occurred during the transfer process. In that case, the value of
'status' is an error code to indicate the reason of the transfer failure.
In most cases, i2c_transfer() can transfer 'num' messages with no error.
And so 'status' == 'num'. However, due to unexpected errors, it is probable
that only partial messages are transferred by i2c_transfer(). As a result,
'status' != 'num'. This special case is not checked after the invocation of
i2c_transfer() and can potentially lead to unexpected issues in the
following execution since it is expected that 'status' == 'num'.

This patch checks the return value of i2c_transfer() and returns an error
code -EIO if the number of actual transferred messages 'status' is not
equal to 'num'.

Signed-off-by: Wenwen Wang <wang6495@umn.edu>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-17 15:40:12 +02:00
Peter Rosin a5dab8698c i2c: hix5hd2: remove some dead code
The else branch cannot be taken as i will always equal num.
Get rid of the whole construct.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-15 10:43:38 +02:00
Andrzej Hajda 043056270b i2c: exynos5: simplify transfer function
exynos5_i2c_xfer contains lots of dead code, let's remove it and simplify
the rest. The patch should not introduce functional changes.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Suggested-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Andi Shyti <andi@etezian.org>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-15 10:43:38 +02:00
Boris Brezillon 4fad8868af i2c: Get rid of i2c_board_info->archdata
The only user of i2c_board_info->archdata is the OF parsing code and it
just pass a zero-initialized object which has the same effect as leaving
->archdata to NULL since the client object is allocated with kzalloc().

Get rid of this useless field.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-15 10:42:20 +02:00
Alexander Monakov 9f4659ba38 i2c: designware: refactor low-level enable/disable
Low-level controller enable function __i2c_dw_enable is overloaded to
also handle disabling. What's worse, even though the documentation
requires polling the IC_ENABLE_STATUS register when disabling, this
is not done: polling needs to be requested specifically by calling
__i2c_dw_enable_and_wait, which can also poll on enabling, but that
doesn't work if the IC_ENABLE_STATUS register is not implemented.
This is quite confusing if not in fact backwards.

Especially since the documentation says that disabling should be
followed by polling, the driver should be using a separate function
where it does one-shot disables to make the optimization stand out.

This refactors the two functions so that requested status is given
in the name rather than in a boolean argument. Specifically:

 - __i2c_dw_enable: enable without polling (in accordance with docs)
 - __i2c_dw_disable: disable and do poll (also as suggested by docs)
 - __i2c_dw_disable_nowait: disable without polling (Linux-specific)

No functional change.

Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
[wsa: fixed blank lines in header file]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-15 10:42:19 +02:00
Wolfram Sang e6218bf390 Merge branch 'i2c/for-current-fixed' into i2c/for-4.18 2018-05-15 10:41:01 +02:00
Peter Rosin 35cd67a0ca i2c: viperboard: return message count on master_xfer success
Returning zero is wrong in this case.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 174a13aa86 ("i2c: Add viperboard i2c master driver")
2018-05-15 09:31:26 +02:00
Peter Rosin 12d9bbc5a7 i2c: pmcmsp: fix error return from master_xfer
Returning -1 (-EPERM) is not appropriate here, go with -EIO.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 1b144df1d7 ("i2c: New PMC MSP71xx TWI bus driver")
2018-05-15 09:31:19 +02:00
Peter Rosin de9a8634f1 i2c: pmcmsp: return message count on master_xfer success
Returning zero is wrong in this case.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 1b144df1d7 ("i2c: New PMC MSP71xx TWI bus driver")
2018-05-15 09:30:34 +02:00
Ulf Hansson e6a20b6cd2 i2c: Respect all error codes from dev_pm_domain_attach()
The limitation of being able to check only for -EPROBE_DEFER from
dev_pm_domain_attach() has been removed. Hence let's respect all error
codes and bail out accordingly.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-14 22:58:45 +02:00
Alexander Monakov 06cb616b1b i2c: designware: fix poll-after-enable regression
Not all revisions of DW I2C controller implement the enable status register.
On platforms where that's the case (e.g. BG2CD and SPEAr ARM SoCs), waiting
for enable will time out as reading the unimplemented register yields zero.

It was observed that reading the IC_ENABLE_STATUS register once suffices to
avoid getting it stuck on Bay Trail hardware, so replace polling with one
dummy read of the register.

Fixes: fba4adbbf6 ("i2c: designware: must wait for enable")
Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Tested-by: Ben Gardner <gardner.ben@gmail.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2018-05-10 12:30:20 +02:00
Wolfram Sang 77bade677c i2c: busses: remove superfluous ignoring of children for RPM
These days, the I2C core ensures that the embedded adapter device
ignores the PM states of its children already. Because the adapter
device is an opaque logical device, there is no need for drivers to
repeat that again.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-08 23:19:02 +02:00
Tobias Jordan e6faa71034 i2c: axxia: enable clock before calling clk_get_rate()
axxia_i2c_init() uses clk_get_rate() for idev->i2c_clk. clk_get_rate()
should only be called if the clock is enabled, so ensure that by moving
the clk_prepare_enable() call before the call to axxia_i2c_init().

Found by Linux Driver Verification project (linuxtesting.org).

Fixes: 08678b850c ("i2c: axxia: Add I2C driver for AXM55xx")
Signed-off-by: Tobias Jordan <Tobias.Jordan@elektrobit.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-08 23:13:19 +02:00
Wolfram Sang b1437dcb97 i2c: rcar: enhance comment to avoid regressions
Give a clear testcase for people wishing to change this code. It is also
a reminder for me if people ask about it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 11:14:35 +02:00
Hans de Goede 7781edaed6 i2c: core: ACPI: Log device not acking errors at dbg loglevel
Unfortunately some DSDTs issue bogus i2c reads to non existing devices
resulting in -EREMOTEIO errors because the non existing device of course
does not ack.

This happens e.g. from the The Asus T100TA's _BIX method, the DSDT on
the T100TA defines 2 resources on the I2C1 bus:

        Name (EHID, ResourceTemplate ()
        {
            I2cSerialBusV2 (0x005B, ControllerInitiated, 0x00061A80,
                AddressingMode7Bit, "\\_SB.I2C1",
                0x00, ResourceConsumer, , Exclusive,
                )
        })
        OperationRegion (EHOR, GenericSerialBus, Zero, 0x0100)
        Field (EHOR, BufferAcc, NoLock, Preserve)
        {
            Connection (EHID),
            Offset (0x01),
            AccessAs (BufferAcc, AttribBytes (0x10)),
            ABCD,   8
        }

        Name (UMPC, ResourceTemplate ()
        {
            I2cSerialBusV2 (0x0066, ControllerInitiated, 0x00061A80,
                AddressingMode7Bit, "\\_SB.I2C1",
                0x00, ResourceConsumer, , Exclusive,
                )
        })

The _BIX method does a single read (on each BIX() call) from the EHID
device through the ABCD Field, only to completely ignore the result.
This read always fails as there is no i2c client at address 0x5b.

The _BIX method also does several reads from the UMPC device and actually
uses the results of those to provide battery information.

IIRC I've also seen some DSTDs which do an i2c read to detect if a device
is present, also leading to false positive errors being logged.

Esp. the _BIX use is problematic as the _BIX method gets called
periodically to monitor battery status.

This commit stops the logs from filling up with errors like these:

[   57.327858] i2c i2c-0: i2c read 16 bytes from client@0x5b starting at
               reg 0x1 failed, error: -121

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:53:31 +02:00
Hans de Goede c8016fa215 i2c: core: ACPI: Improve OpRegion read errors
When we get an error doing an ACPI SerialBus I2C OpRegion read log some
useful details, like the client address and which register is being
read.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:53:26 +02:00
Michael Shych ae4aa68dd3 i2c: mlxcpld: Allow configurable adapter id for mlxcpld
It allows mlxcpld driver to be connected to pre-defined adapter number
equal or greater than one, in order to avoid current limitation, assuming
usage of id number one only.

Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:29 +02:00
Michael Shych 845f2a6d00 i2c: mlxcpld: Fix adapter functionality support callback
It fixes report about supported functionality.
Functionality can be different up to CPLD capability.

Fixes: 6bec23bff9 (i2c: mlxcpld: add master driver for mellanox systems)
Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:28 +02:00
Michael Shych c9bfdc7c16 i2c: mlxcpld: Add support for smbus block read transaction
It adds support for smbus block read transaction. CPLD smbus block read bit
of capability register is verified during driver initialization, and driver
data is updated if such capability is available. In case an upper layer
requests a read transaction of length one and expects that length will be
the first received byte, driver will notify CPLD about SMBus block read
transaction flavor, so CPLD will know to execute such kind of transaction.

Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:28 +02:00
Michael Shych 313ce648b5 i2c: mlxcpld: Add support for extended transaction length for i2c-mlxcpld
It adds support for extended length of read and write transactions.
New CPLD logic allows double size of the read and write transactions
length. This feature is verified through capability register, which is
renamed from unclear LPF_REG to CPBLTY_REG. Two bits 5 and 6 of these
register are used for length capability detection, while only 01
combination indicates support of extended transaction length.
Others mean lack of such support.

Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:28 +02:00
Ryder Lee 6e29577fc2 i2c: mediatek: use of_device_get_match_data()
The usage of of_device_get_match_data() reduce the code size a bit.

Also, the only way to call mtk_i2c_probe() is to match an entry in
mtk_i2c_of_match[], so of_id cannot be NULL.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:28 +02:00
Krzysztof Kozlowski 952cfd1581 i2c: s3c2410: Remove support for Exynos5440
The Exynos5440 is not actively developed, there are no development
boards available and probably there are no real products with it.
Remove wide-tree support for Exynos5440.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:28 +02:00
Jean Delvare a9c8088c79 i2c: i801: Don't restore config registers on runtime PM
Restoring configuration registers is only needed when we hand control
to the firmware. This is never the case with runtime power
management. The device will autosuspend whenever not used, so avoid
useless register writes by defining suspend/resume only, and not
runtime_suspend/runtime_resume.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:28 +02:00
David Engraf e8f39e9fc0 i2c: at91: Read all available bytes at once
With FIFO enabled it is possible to read multiple bytes
at once in the interrupt handler as long as RXRDY is
set. This may also reduce the number of interrupts.

This patch polls RXRDY and reads all available bytes at
once.

Signed-off-by: David Engraf <david.engraf@sysgo.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
[wsa: reformatted comment]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:28 +02:00
Pierre-Yves MORDRET 562de4ff4c i2c: i2c-stm32f7: Implement I2C release mechanism
Feature prevents I2C lock-ups. Mechanism resets I2C state machine
and releases SCL/SDA signals but preserves I2C registers.

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:28 +02:00
Pierre-Yves MORDRET 7ecc8cfde5 i2c: i2c-stm32f7: Add DMA support
This patch adds DMA support for i2c-stm32f7 driver

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:28 +02:00
Pierre-Yves MORDRET bb8822cbbc i2c: i2c-stm32: Add generic DMA API
This patch adds a generic DMA API to implement DMA support for i2c-stm32fx
drivers

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:27 +02:00
Pierre-Yves MORDRET 9e48155f6b i2c: i2c-stm32f7: Add initial SMBus protocols support
This patch adds SMBus support for I2C controller embedded in STM32F7 Soc.
All SMBus protocols are implemented except SMBus-specific protocols like
SMBus Host Notification and SMBus Alert protocols.

Implemented: SMBus Quick command, Send byte, Receive byte, Write byte/word,
read byte/word, Process call, Block write/read and Block write-block read
process call.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:27 +02:00
Pierre-Yves MORDRET 60d609f30d i2c: i2c-stm32f7: Add slave support
This patch adds slave support for I2C controller embedded in STM32F7 SoC

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:27 +02:00
Pierre-Yves MORDRET 8c7ecc9953 i2c: i2c-stm32f7: Add 10-bit address support
This patch adds support for 10-bit device address for STM32F7 I2C

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:39:27 +02:00
Baolin Wang 2a01046120 i2c: sprd: Fix the i2c count issue
We found the I2C controller count register is unreliable sometimes,
that will cause I2C to lose data. Thus we can read the data count
from 'i2c_dev->count' instead of the I2C controller count register.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-27 14:12:43 +02:00
Baolin Wang da33aa03fa i2c: sprd: Prevent i2c accesses after suspend is called
Add one flag to indicate if the i2c controller has been in suspend state,
which can prevent i2c accesses after i2c controller is suspended following
system suspend.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-27 14:12:17 +02:00
Alexander Popov 23a27722b5 i2c: dev: prevent ZERO_SIZE_PTR deref in i2cdev_ioctl_rdwr()
i2cdev_ioctl_rdwr() allocates i2c_msg.buf using memdup_user(), which
returns ZERO_SIZE_PTR if i2c_msg.len is zero.

Currently i2cdev_ioctl_rdwr() always dereferences the buf pointer in case
of I2C_M_RD | I2C_M_RECV_LEN transfer. That causes a kernel oops in
case of zero len.

Let's check the len against zero before dereferencing buf pointer.

This issue was triggered by syzkaller.

Signed-off-by: Alexander Popov <alex.popov@linux.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[wsa: use '< 1' instead of '!' for easier readability]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-27 14:04:10 +02:00
Geert Uytterhoeven 14a8f0d88c i2c: Remove depends on HAS_DMA in case of platform dependency
Remove dependencies on HAS_DMA where a Kconfig symbol depends on another
symbol that implies HAS_DMA, and, optionally, on "|| COMPILE_TEST".
In most cases this other symbol is an architecture or platform specific
symbol, or PCI.

Generic symbols and drivers without platform dependencies keep their
dependencies on HAS_DMA, to prevent compiling subsystems or drivers that
cannot work anyway.

This simplifies the dependencies, and allows to improve compile-testing.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-18 10:07:24 +02:00
Ard Biesheuvel 1eace8344c i2c: add param sanity check to i2c_transfer()
The API docs describe i2c_transfer() as taking a pointer to an array
of i2c_msg containing at least 1 entry, but leaves it to the individual
drivers to sanity check the msgs and num parameters. Let's do this in
core code instead.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[wsa: changed '<= 0' to '< 1']
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-11 23:33:46 +02:00
Jean Delvare f7f6d915a1 i2c: i801: Restore configuration at shutdown
On some systems, the BIOS expects certain SMBus register values to
match the hardware defaults. Restore these configuration registers at
shutdown time to avoid confusing the BIOS. This avoids hard-locking
such systems upon reboot.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org
2018-04-11 23:08:13 +02:00
Jean Delvare a086bb8317 i2c: i801: Save register SMBSLVCMD value only once
Saving the original value of register SMBSLVCMD in
i801_enable_host_notify() doesn't work, because this function is
called not only at probe time but also at resume time. Do it in
i801_probe() instead, so that the saved value is not overwritten at
resume time.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 22e94bd677 ("i2c: i801: store and restore the SLVCMD register at load and unload")
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org	# v4.10+
2018-04-11 23:07:14 +02:00
Linus Torvalds 0d5b1bd332 Merge branch 'i2c/for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:

 -I2C core now reports proper OF style module alias. I'd like to repeat
  the note from the commit msg here (Thanks, Javier!):

      NOTE: This patch may break out-of-tree drivers that were relying
            on this behavior, and only had an I2C device ID table even
            when the device was registered via OF.

            There are no remaining drivers in mainline that do this, but
            out-of-tree drivers have to be fixed and define a proper OF
            device ID table to have module auto-loading working.

 - new driver for the SynQuacer I2C controller

 - major refactoring of the QUP driver

 - the piix4 driver now uses request_muxed_region which should fix a
   long standing resource conflict with the sp5100_tco watchdog

 - a bunch of small core & driver improvements

* 'i2c/for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (53 commits)
  i2c: add support for Socionext SynQuacer I2C controller
  dt-bindings: i2c: add binding for Socionext SynQuacer I2C
  i2c: Update i2c_trace_msg static key to modern api
  i2c: fix parameter of trace_i2c_result
  i2c: imx: avoid taking clk_prepare mutex in PM callbacks
  i2c: imx: use clk notifier for rate changes
  i2c: make i2c_check_addr_validity() static
  i2c: rcar: fix mask value of prohibited bit
  dt-bindings: i2c: document R8A77965 bindings
  i2c: pca-platform: drop gpio from platform data
  i2c: pca-platform: use device_property_read_u32
  i2c: pca-platform: unconditionally use devm_gpiod_get_optional
  sh: sh7785lcr: add GPIO lookup table for i2c controller reset
  i2c: qup: reorganization of driver code to remove polling for qup v2
  i2c: qup: reorganization of driver code to remove polling for qup v1
  i2c: qup: send NACK for last read sub transfers
  i2c: qup: fix buffer overflow for multiple msg of maximum xfer len
  i2c: qup: change completion timeout according to transfer length
  i2c: qup: use the complete transfer length to choose DMA mode
  i2c: qup: proper error handling for i2c error in BAM mode
  ...
2018-04-07 12:36:18 -07:00
Ard Biesheuvel 0d676a6c43 i2c: add support for Socionext SynQuacer I2C controller
This is a cleaned up version of the I2C controller driver for
the Fujitsu F_I2C IP, which was never supported upstream, and
has now been incorporated into the Socionext SynQuacer SoC.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
[wsa: updated MAINTAINERS entry and removed two empty lines]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-04 20:33:03 +02:00
Davidlohr Bueso 50888b015d i2c: Update i2c_trace_msg static key to modern api
No changes in refcount semantics -- key init is false; replace

static_key_slow_inc|dec   with   static_branch_inc|dec
static_key_false          with   static_branch_unlikely

Added a '_key' suffix to i2c_trace_msg, for better self
documentation.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-03 19:20:26 +02:00
Ahbong Chang 4a3f7691e2 i2c: fix parameter of trace_i2c_result
According to the event i2c_result defined in include/trace/events/i2c.h,
the second parameter should be the number of messages instead of the
ended loop index. The value of ended loop index is the same as ret.

Signed-off-by: Ahbong Chang <cwahbong@google.com>
Reviewed-by: Todd Poynor <toddpoynor@google.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-03 16:37:45 +02:00
Lucas Stach d9a22d713a i2c: imx: avoid taking clk_prepare mutex in PM callbacks
This is unsafe, as the runtime PM callbacks are called from the PM
workqueue, so this may deadlock when handling an i2c attached clock,
which may already hold the clk_prepare mutex from another context.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-03 15:29:28 +02:00
Lucas Stach 90ad2cbe88 i2c: imx: use clk notifier for rate changes
Instead of repeatedly calling clk_get_rate for each transfer, register
a clock notifier to update the cached divider value each time the clock
rate actually changes.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-03 15:28:53 +02:00
Linus Torvalds f5a8eb632b arch: remove obsolete architecture ports
This removes the entire architecture code for blackfin, cris, frv, m32r,
 metag, mn10300, score, and tile, including the associated device drivers.
 
 I have been working with the (former) maintainers for each one to ensure
 that my interpretation was right and the code is definitely unused in
 mainline kernels. Many had fond memories of working on the respective
 ports to start with and getting them included in upstream, but also saw
 no point in keeping the port alive without any users.
 
 In the end, it seems that while the eight architectures are extremely
 different, they all suffered the same fate: There was one company
 in charge of an SoC line, a CPU microarchitecture and a software
 ecosystem, which was more costly than licensing newer off-the-shelf
 CPU cores from a third party (typically ARM, MIPS, or RISC-V). It seems
 that all the SoC product lines are still around, but have not used the
 custom CPU architectures for several years at this point. In contrast,
 CPU instruction sets that remain popular and have actively maintained
 kernel ports tend to all be used across multiple licensees.
 
 The removal came out of a discussion that is now documented at
 https://lwn.net/Articles/748074/. Unlike the original plans, I'm not
 marking any ports as deprecated but remove them all at once after I made
 sure that they are all unused. Some architectures (notably tile, mn10300,
 and blackfin) are still being shipped in products with old kernels,
 but those products will never be updated to newer kernel releases.
 
 After this series, we still have a few architectures without mainline
 gcc support:
 
 - unicore32 and hexagon both have very outdated gcc releases, but the
   maintainers promised to work on providing something newer. At least
   in case of hexagon, this will only be llvm, not gcc.
 
 - openrisc, risc-v and nds32 are still in the process of finishing their
   support or getting it added to mainline gcc in the first place.
   They all have patched gcc-7.3 ports that work to some degree, but
   complete upstream support won't happen before gcc-8.1. Csky posted
   their first kernel patch set last week, their situation will be similar.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJawdL2AAoJEGCrR//JCVInuH0P/RJAZh1nTD+TR34ZhJq2TBoo
 PgygwDU7Z2+tQVU+EZ453Gywz9/NMRFk1RWAZqrLix4ZtyIMvC6A1qfT2yH1Y7Fb
 Qh6tccQeLe4ezq5u4S/46R/fQXu3Txr92yVwzJJUuPyU0arF9rv5MmI8e6p7L1en
 yb74kSEaCe+/eMlsEj1Cc1dgthDNXGKIURHkRsILoweysCpesjiTg4qDcL+yTibV
 FP2wjVbniKESMKS6qL71tiT5sexvLsLwMNcGiHPj94qCIQuI7DLhLdBVsL5Su6gI
 sbtgv0dsq4auRYAbQdMaH1hFvu6WptsuttIbOMnz2Yegi2z28H8uVXkbk2WVLbqG
 ZESUwutGh8MzOL2RJ4jyyQq5sfo++CRGlfKjr6ImZRv03dv0pe/W85062cK5cKNs
 cgDDJjGRorOXW7dyU6jG2gRqODOQBObIv3w5efdq5OgzOWlbI4EC+Y5u1Z0JF/76
 pSwtGXA6YhwC+9LLAlnVTHG+yOwuLmAICgoKcTbzTVDKA2YQZG/cYuQfI5S1wD8e
 X6urPx3Md2GCwLXQ9mzKBzKZUpu/Tuhx0NvwF4qVxy6x1PELjn68zuP7abDHr46r
 57/09ooVN+iXXnEGMtQVS/OPvYHSa2NgTSZz6Y86lCRbZmUOOlK31RDNlMvYNA+s
 3iIVHovno/JuJnTOE8LY
 =fQ8z
 -----END PGP SIGNATURE-----

Merge tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pul removal of obsolete architecture ports from Arnd Bergmann:
 "This removes the entire architecture code for blackfin, cris, frv,
  m32r, metag, mn10300, score, and tile, including the associated device
  drivers.

  I have been working with the (former) maintainers for each one to
  ensure that my interpretation was right and the code is definitely
  unused in mainline kernels. Many had fond memories of working on the
  respective ports to start with and getting them included in upstream,
  but also saw no point in keeping the port alive without any users.

  In the end, it seems that while the eight architectures are extremely
  different, they all suffered the same fate: There was one company in
  charge of an SoC line, a CPU microarchitecture and a software
  ecosystem, which was more costly than licensing newer off-the-shelf
  CPU cores from a third party (typically ARM, MIPS, or RISC-V). It
  seems that all the SoC product lines are still around, but have not
  used the custom CPU architectures for several years at this point. In
  contrast, CPU instruction sets that remain popular and have actively
  maintained kernel ports tend to all be used across multiple licensees.

  [ See the new nds32 port merged in the previous commit for the next
    generation of "one company in charge of an SoC line, a CPU
    microarchitecture and a software ecosystem"   - Linus ]

  The removal came out of a discussion that is now documented at
  https://lwn.net/Articles/748074/. Unlike the original plans, I'm not
  marking any ports as deprecated but remove them all at once after I
  made sure that they are all unused. Some architectures (notably tile,
  mn10300, and blackfin) are still being shipped in products with old
  kernels, but those products will never be updated to newer kernel
  releases.

  After this series, we still have a few architectures without mainline
  gcc support:

   - unicore32 and hexagon both have very outdated gcc releases, but the
     maintainers promised to work on providing something newer. At least
     in case of hexagon, this will only be llvm, not gcc.

   - openrisc, risc-v and nds32 are still in the process of finishing
     their support or getting it added to mainline gcc in the first
     place. They all have patched gcc-7.3 ports that work to some
     degree, but complete upstream support won't happen before gcc-8.1.
     Csky posted their first kernel patch set last week, their situation
     will be similar

  [ Palmer Dabbelt points out that RISC-V support is in mainline gcc
    since gcc-7, although gcc-7.3.0 is the recommended minimum  - Linus ]"

This really says it all:

 2498 files changed, 95 insertions(+), 467668 deletions(-)

* tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (74 commits)
  MAINTAINERS: UNICORE32: Change email account
  staging: iio: remove iio-trig-bfin-timer driver
  tty: hvc: remove tile driver
  tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers
  serial: remove tile uart driver
  serial: remove m32r_sio driver
  serial: remove blackfin drivers
  serial: remove cris/etrax uart drivers
  usb: Remove Blackfin references in USB support
  usb: isp1362: remove blackfin arch glue
  usb: musb: remove blackfin port
  usb: host: remove tilegx platform glue
  pwm: remove pwm-bfin driver
  i2c: remove bfin-twi driver
  spi: remove blackfin related host drivers
  watchdog: remove bfin_wdt driver
  can: remove bfin_can driver
  mmc: remove bfin_sdh driver
  input: misc: remove blackfin rotary driver
  input: keyboard: remove bf54x driver
  ...
2018-04-02 20:20:12 -07:00
Arnd Bergmann e58af24ccd i2c: remove bfin-twi driver
The blackfin architecture is getting removed, so the
twi driver can also be removed.

Acked-by: Aaron Wu <aaron.wu@analog.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-26 15:57:07 +02:00
Wolfram Sang 398432edde i2c: make i2c_check_addr_validity() static
After previous refactoring, there is only one user in the same file
left. Make the function static now.

[wsa: added 'int' to bare 'unsigned']
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 14:07:23 +01:00
Hiromitsu Yamasaki a1de3253a8 i2c: rcar: fix mask value of prohibited bit
According to documentation, Bit 7 of ICMSR is unused and 0 should be
written to it. Fix the mask accordingly.

Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
[wsa: edited commit message]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 14:04:38 +01:00
Wolfram Sang 0b884c22c5 - three new special cases for device tree compatible strings
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEFp3rbAvDxGAT0sefEacuoBRx13IFAlqyYdkACgkQEacuoBRx
 13LnHA/8CFMaR7o5ZYlDaDNizlg0Wu7oT/zEKK/erF+/3LYoYHl5FaCuFgZ6R9e3
 hEwqBkyJ1QjwhQhS4IIZn1Z34zSpXgUTXzb6+U+zWhdQNj8j+QqG81u+eLjNgcsa
 5DxOcwyEpqUTXQI2MMYxK60NHVWfJaq2VmxzKDTqZkJHiOzQsoR4H1O7tPOCDvHE
 R8uDgSamz4lRRANuxu5jONbgD04p4c+No42LLsYLo/DKUJN5rS6IbFyzURjWHaA3
 +8WA2y6bG3v6YVdIvRXfw7NCi+U/pWCbSD3OqzIQkUKnWfDLnbqCw1wRrWVPLhnE
 edpkmyHLhaXHG0vb1J4Hwq9mV4UXSb/XyH4DZp5v4EZKT4ImnI64GnDU3O+JEqXe
 upb2r0WQ7z6bA1A99GqNc0em7BI/8nXIY4LZCJXTgAkBLQq6+b3EYQGElMSiI0X6
 k638GcY87t0AaJgR2laOIx0ADgdxoabyb07v8oh2o9C1o/Ujb4AhCg5TouPHNMtS
 CZmohAY6rmPMZ9jT6GzAsGfF7+hXQ6OtSXowQ713Eez8haq8dC9wNo3DUiCCyMMv
 KssF1uPwa6pnSF3mtAFAq8wI2AqPfVcnzI14OkaxHVHrm8iWpT2+FD2kJcMAvJX0
 OGljH0WN/WTw/v8BUeyqsvOyEurglOR3dyns8IWNLnoV9R6Gzvg=
 =rCow
 -----END PGP SIGNATURE-----

Merge tag 'at24-4.17-updates-for-wolfram' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux into i2c/for-4.17

"three new special cases for device tree compatible strings"
2018-03-24 13:39:18 +01:00
Pierre-Yves MORDRET 771b7bf053 i2c: i2c-stm32f7: fix no check on returned setup
Before assigning returned setup structure check if not null

Fixes: 463a9215f3 ("i2c: stm32f7: fix setup structure")
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2018-03-24 13:37:41 +01:00
Chris Packham 7562dee282 i2c: pca-platform: use device_property_read_u32
Use device_property_read_u32 instead of of_property_read_u32_index to
lookup the "clock-frequency" property.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:26:04 +01:00
Chris Packham 0678326175 i2c: pca-platform: unconditionally use devm_gpiod_get_optional
Allow for the reset-gpios property to be defined in the device tree
or via a GPIO lookup table.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:26:00 +01:00
Abhishek Sahu 7545c7dba1 i2c: qup: reorganization of driver code to remove polling for qup v2
Following are the major issues in current driver code

1. The current driver simply assumes the transfer completion
   whenever its gets any non-error interrupts and then simply do the
   polling of available/free bytes in FIFO.
2. The block mode is not working properly since no handling in
   being done for OUT_BLOCK_WRITE_REQ and IN_BLOCK_READ_READ.
3. An i2c transfer can contain multiple message and QUP v2
   supports reconfiguration during run in which the mode should be same
   for all the sub transfer. Currently the mode is being programmed
   before every sub transfer which is functionally wrong. If one message
   is less than FIFO length and other message is greater than FIFO
   length, then transfers will fail.

Because of above, i2c v2 transfers of size greater than 64 are failing
with following error message

	i2c_qup 78b6000.i2c: timeout for fifo out full

To make block mode working properly and move to use the interrupts
instead of polling, major code reorganization is required. Following
are the major changes done in this patch

1. Remove the polling of TX FIFO free space and RX FIFO available
   bytes and move to interrupts completely. QUP has QUP_MX_OUTPUT_DONE,
   QUP_MX_INPUT_DONE, OUT_BLOCK_WRITE_REQ and IN_BLOCK_READ_REQ
   interrupts to handle FIFO’s properly so check all these interrupts.
2. Determine the mode for transfer before starting by checking
   all the tx/rx data length in each message. The complete message can be
   transferred either in DMA mode or Programmed IO by FIFO/Block mode.
   in DMA mode, both tx and rx uses same mode but in PIO mode, the TX and
   RX can be in different mode.
3. During write, For FIFO mode, TX FIFO can be directly written
   without checking for FIFO space. For block mode, the QUP will generate
   OUT_BLOCK_WRITE_REQ interrupt whenever it has block size of available
   space.
4. During read, both TX and RX FIFO will be used. TX will be used
   for writing tags and RX will be used for receiving the data. In QUP,
   TX and RX can operate in separate mode so configure modes accordingly.
5. For read FIFO mode, wait for QUP_MX_INPUT_DONE interrupt which
   will be generated after all the bytes have been copied in RX FIFO. For
   read Block mode, QUP will generate IN_BLOCK_READ_REQ interrupts
   whenever it has block size of available data.
6. Split the transfer in chunk of one QUP block size(256 bytes)
   and schedule each block separately. QUP v2 supports reconfiguration
   during run in which QUP can transfer multiple blocks without issuing a
   stop events.
7. Port the SMBus block read support for new code changes.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:21:02 +01:00
Abhishek Sahu fbfab1ab06 i2c: qup: reorganization of driver code to remove polling for qup v1
Following are the major issues in current driver code

1. The current driver simply assumes the transfer completion
   whenever its gets any non-error interrupts and then simply do the
   polling of available/free bytes in FIFO.
2. The block mode is not working properly since no handling in
   being done for OUT_BLOCK_WRITE_REQ and IN_BLOCK_READ_REQ.

Because of above, i2c v1 transfers of size greater than 32 are failing
with following error message

	i2c_qup 78b6000.i2c: timeout for fifo out full

To make block mode working properly and move to use the interrupts
instead of polling, major code reorganization is required. Following
are the major changes done in this patch

1. Remove the polling of TX FIFO free space and RX FIFO available
   bytes and move to interrupts completely. QUP has QUP_MX_OUTPUT_DONE,
   QUP_MX_INPUT_DONE, OUT_BLOCK_WRITE_REQ and IN_BLOCK_READ_REQ
   interrupts to handle FIFO’s properly so check all these interrupts.
2. During write, For FIFO mode, TX FIFO can be directly written
   without checking for FIFO space. For block mode, the QUP will generate
   OUT_BLOCK_WRITE_REQ interrupt whenever it has block size of available
   space.
3. During read, both TX and RX FIFO will be used. TX will be used
   for writing tags and RX will be used for receiving the data. In QUP,
   TX and RX can operate in separate mode so configure modes accordingly.
4. For read FIFO mode, wait for QUP_MX_INPUT_DONE interrupt which
   will be generated after all the bytes have been copied in RX FIFO. For
   read Block mode, QUP will generate IN_BLOCK_READ_REQ interrupts
   whenever it has block size of available data.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:20:51 +01:00
Abhishek Sahu f7714b4e45 i2c: qup: send NACK for last read sub transfers
According to I2c specification, “If a master-receiver sends a
repeated START condition, it sends a not-acknowledge (A) just
before the repeated START condition”. QUP v2 supports sending
of NACK without stop with QUP_TAG_V2_DATARD_NACK so added the
same.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:20:41 +01:00
Abhishek Sahu 6f2f0f6465 i2c: qup: fix buffer overflow for multiple msg of maximum xfer len
The BAM mode requires buffer for start tag data and tx, rx SG
list. Currently, this is being taken for maximum transfer length
(65K). But an I2C transfer can have multiple messages and each
message can be of this maximum length so the buffer overflow will
happen in this case. Since increasing buffer length won’t be
feasible since an I2C transfer can contain any number of messages
so this patch does following changes to make i2c transfers working
for multiple messages case.

1. Calculate the required buffers for 2 maximum length messages
   (65K * 2).
2. Split the descriptor formation and descriptor scheduling.
   The idea is to fit as many messages in one DMA transfers for 65K
   threshold value (max_xfer_sg_len). Whenever the sg_cnt is
   crossing this, then schedule the BAM transfer and subsequent
   transfer will again start from zero.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:20:30 +01:00
Abhishek Sahu ecb6e1e5f4 i2c: qup: change completion timeout according to transfer length
Currently the completion timeout is being taken according to
maximum transfer length which is too high if SCL is operating in
high frequency. This patch calculates timeout on the basis of
one-byte transfer time and uses the same for completion timeout.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:20:20 +01:00
Abhishek Sahu 08f15963bc i2c: qup: use the complete transfer length to choose DMA mode
Currently each message length in complete transfer is being
checked for determining DMA mode and if any of the message length
is less than FIFO length then non DMA mode is being used which
will increase overhead. DMA can be used for any length and it
should be determined with complete transfer length. Now, this
patch selects DMA mode if the total length is greater than FIFO
length.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:20:09 +01:00
Abhishek Sahu 3f450d3eea i2c: qup: proper error handling for i2c error in BAM mode
Currently the i2c error handling in BAM mode is not working
properly in stress condition.

1. After an error, the FIFO are being written with FLUSH and
   EOT tags which should not be required since already these tags
   have been written in BAM descriptor itself.

2. QUP state is being moved to RESET in IRQ handler in case
   of error. When QUP HW encounters an error in BAM mode then it
   moves the QUP STATE to PAUSE state. In this case, I2C_FLUSH
   command needs to be executed while moving to RUN_STATE by writing
   to the QUP_STATE register with the I2C_FLUSH bit set to 1.

3. In Error case, sometimes, QUP generates more than one
   interrupt which will trigger the complete again. After an error,
   the flush operation will be scheduled after doing
   reinit_completion which should be triggered by BAM IRQ callback.
   If the second QUP IRQ comes during this time then it will call
   the complete and the transfer function will assume the all the
   BAM HW descriptors have been completed.

4. The release DMA is being called after each error which
   will free the DMA tx and rx channels. The error like NACK is very
   common in I2C transfer and every time this will be overhead. Now,
   since the error handling is proper so this release channel can be
   completely avoided.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:19:59 +01:00
Abhishek Sahu 7e6c35fe60 i2c: qup: fix the transfer length for BAM RX EOT FLUSH tags
In case of FLUSH operation, BAM copies INPUT EOT FLUSH (0x94)
instead of normal EOT (0x93) tag in input data stream when an
input EOT tag is received during flush operation. So only one tag
will be written instead of 2 separate tags.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:19:48 +01:00
Abhishek Sahu c5adc0fa63 i2c: qup: schedule EOT and FLUSH tags at the end of transfer
The role of FLUSH and EOT tag is to flush already scheduled
descriptors in BAM HW in case of error. EOT is required only
when descriptors are scheduled in RX FIFO. If all the messages
are WRITE, then only FLUSH tag will be used.

A single BAM transfer can have multiple read and write messages.
The EOT and FLUSH tags should be scheduled at the end of BAM HW
descriptors. Since the READ and WRITE can be present in any order
so for some of the cases, these tags are not being written
correctly.

Following is one of the example

   READ, READ, READ, READ

Currently EOT and FLUSH tags are being written after each READ.
If QUP gets NACK for first READ itself, then flush will be
triggered. It will look for first FLUSH tag in TX FIFO and will
stop there so only descriptors for first READ descriptors be
flushed. All the scheduled descriptors should be cleared to
generate BAM DMA completion.

Now this patch is scheduling FLUSH and EOT only once after all the
descriptors. So, flush will clear all the scheduled descriptors and
BAM will generate the completion interrupt.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:19:38 +01:00
Abhishek Sahu 6d5f37f166 i2c: qup: remove redundant variables for BAM SG count
The rx_nents and tx_nents are redundant. rx_buf and tx_buf can
be used for total number of SG entries. Since rx_buf and tx_buf
give the impression that it is buffer instead of count so rename
it to tx_cnt and rx_cnt for giving it more meaningful variable
name.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:19:28 +01:00
Abhishek Sahu eb422b539c i2c: qup: minor code reorganization for use_dma
1. Assigns use_dma in qup_dev structure itself which will
   help in subsequent patches to determine the mode in IRQ handler.
2. Does minor code reorganization for loops to reduce the
   unnecessary comparison and assignment.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:19:17 +01:00
Abhishek Sahu 7239872fb3 i2c: qup: fixed releasing dma without flush operation completion
The QUP BSLP BAM generates the following error sometimes if the
current I2C DMA transfer fails and the flush operation has been
scheduled

    “bam-dma-engine 7884000.dma: Cannot free busy channel”

If any I2C error comes during BAM DMA transfer, then the QUP I2C
interrupt will be generated and the flush operation will be
carried out to make I2C consume all scheduled DMA transfer.
Currently, the same completion structure is being used for BAM
transfer which has already completed without reinit. It will make
flush operation wait_for_completion_timeout completed immediately
and will proceed for freeing the DMA resources where the
descriptors are still in process.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Acked-by: Sricharan R <sricharan@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:19:07 +01:00
Abhishek Sahu 0668bc44a4 i2c: qup: fix copyrights and update to SPDX identifier
The file has been updated from 2016 to 2018 so fixed the
copyright years.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 13:18:56 +01:00
George Cherian e349d7d08e i2c: xlp9xx: Handle NACK on DATA properly
In case we receive NACK on DATA we shouldn't be resetting the controller,
rather we should issue STOP command. This will terminate the current
transaction and -EIO is returned.

While at that handle the SMBus Quick Command properly.
We shouldn't be setting the XLP9XX_I2C_CMD_READ/WRITE for such
transactions.

Signed-off-by: George Cherian <george.cherian@cavium.com>
Reviewed-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-17 21:57:44 +01:00
George Cherian d3898a7852 i2c: xlp9xx: Check for Bus state before every transfer
I2C bus enters the STOP condition after the DATA_DONE interrupt is raised.
Essentially the driver should be checking the bus state before sending
any transaction. In case a transaction is initiated while the
bus is busy, the prior transaction's stop condition is not achieved.
Add the check to make sure the bus is not busy before every transaction.

Signed-off-by: George Cherian <george.cherian@cavium.com>
Reviewed-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-17 21:56:35 +01:00
Alexander Monakov 7a20e707aa i2c: designware: suppress unneeded SDA hold time warnings
The hardware may not support SDA hold time configuration, but if it is
not set in the Device Tree either, there is no need to print a warning.

Reported-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-17 21:53:01 +01:00
Gregory CLEMENT 31184d8c6e i2c: mv64xxx: Apply errata delay only in standard mode
The errata FE-8471889 description has been updated. There is still a
timing violation for repeated start. But the errata now states that it
was only the case for the Standard mode (100 kHz), in Fast mode (400 kHz)
there is no issue.

This patch limit the errata fix to the Standard mode.

It has been tesed successfully on the clearfog (Aramda 388 based board).

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-17 21:20:04 +01:00
Moritz Fischer 74d23319fd i2c: xiic: Make suspend function names consistent
Suspend functions seem to have been copied from i2c-cadence driver.
Rename the functions to match the rest of the driver.

Signed-off-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-17 21:15:12 +01:00
Wolfram Sang 8efb11adee Merge branch 'i2c-mux/for-next' of https://github.com/peda-r/i2c-mux into i2c/for-4.17
"These patches verify the device id of the PCA984x mux chips using
standardized (but rarely implemented) i2c device identification."
2018-03-17 21:11:23 +01:00
Arnd Bergmann b67aea2bba Remove metag architecture
These patches remove the metag architecture and tightly dependent
 drivers from the kernel. With the 4.16 kernel the ancient gcc 4.2.4
 based metag toolchain we have been using is hitting compiler bugs, so
 now seems a good time to drop it altogether.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEd80NauSabkiESfLYbAtpk944dnoFAlqdcgQACgkQbAtpk944
 dno/1BAAvaiRcKcNxMrYkxG+Wn4r68odu7+E1dy99AaUnvPFT42R5XLMOv4BCu/Y
 bhMQ14lMJ9ZBKdYg9E97ulTV0YFhCBHuEWDyDnk/G3CVAEvdPuAQ6ktHDZxRQBFK
 JoTUKky53OZbWU9KhLeWpFg4F4E64FBm1kyAkqhs8pPM/LwmrxwIG2sxdTTqkhkc
 b+6ABf2NKtmQwHXWmKWCB8rmXMzulYth2ePC/r9MVj92xGKxADsiFArZk4kmoIUb
 H5eZ8FkemtUEfZp600dsGR/ffaTBwZJ3SULSkAklUnrcvdIRM+Fu8osG8O8yQKTd
 H7xnmtTJ2kCnhhuUMxt6v8WrDbKB8JdFxFOpXW93YKpKAkiGMvoUEZjlwPYIqWxL
 xtnDb9Rv+uZ4RpqZf9AtE4Td8lHTH7OZ78RDs9eMo6n1ZIr5CwcLaM2k5skAeyPr
 yt1lXePhXFqSS+OpOV6hn95ROqlkuZgvPfkcdNpCJPfM4SpfRLlUjIVqiVK0LDRk
 FAkk0VIfzjjNuyV9yr2XXuw90DerhFUgUl6ZYggkgf6umOHhZQdDTFr8gsfvaLm1
 1k1banUEF1tpDcUeShylDvqNmVSZZC6siTQMA7T0zjbjYJD25hJWLpFEcPkx/Anp
 4oGQNNoe4WgJIrJAoTJTiBVwC/xLDeZV6b5t2pOXBlH+v2eKgMg=
 =zDIl
 -----END PGP SIGNATURE-----

Merge tag 'metag_remove_2' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jhogan/metag into asm-generic

Remove metag architecture

These patches remove the metag architecture and tightly dependent
drivers from the kernel. With the 4.16 kernel the ancient gcc 4.2.4
based metag toolchain we have been using is hitting compiler bugs, so
now seems a good time to drop it altogether.

* tag 'metag_remove_2' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
  i2c: img-scb: Drop METAG dependency
  media: img-ir: Drop METAG dependency
  watchdog: imgpdc: Drop METAG dependency
  MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE
  tty: Remove metag DA TTY and console driver
  clocksource: Remove metag generic timer driver
  irqchip: Remove metag irqchip drivers
  Drop a bunch of metag references
  docs: Remove remaining references to metag
  docs: Remove metag docs
  metag: Remove arch/metag/

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-07 22:18:39 +01:00
Peter Rosin 2d74187d5b i2c: mux: pca954x: verify the device id of the pca984x chips
Make sure to not disallow the chips on adapters that are not capable
of reading the device id, but also make sure to check the device id
before writing to the chip.

Tested-by: Adrian Fiergolski <adrian.fiergolski@cern.ch>
Signed-off-by: Peter Rosin <peda@axentia.se>
2018-03-06 10:57:59 +01:00
Peter Rosin dde67eb1be i2c: add i2c_get_device_id() to get the standard i2c device id
Can be used during probe to double check that the probed device is
what is expected.

Loosely based on code from Adrian Fiergolski <adrian.fiergolski@cern.ch>.

Tested-by: Adrian Fiergolski <adrian.fiergolski@cern.ch>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Peter Rosin <peda@axentia.se>
2018-03-06 10:57:59 +01:00
James Hogan 8d06c33026
i2c: img-scb: Drop METAG dependency
Now that arch/metag/ has been removed, remove the METAG dependency from
the IMG SCB I2C device driver. The hardware is also present on MIPS SoCs
so the driver still has value.

Signed-off-by: James Hogan <jhogan@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-i2c@vger.kernel.org
Cc: linux-metag@vger.kernel.org
2018-03-05 16:34:26 +00:00
Javier Martinez Canillas af503716ac i2c: core: report OF style module alias for devices registered via OF
The buses should honor the firmware interface used to register the device,
but the I2C core reports a MODALIAS of the form i2c:<device> even for I2C
devices registered via OF.

This means that user-space will never get an OF stype uevent MODALIAS even
when the drivers modules contain aliases exported from both the I2C and OF
device ID tables. For example, an Atmel maXTouch Touchscreen registered by
a DT node with compatible "atmel,maxtouch" has the following module alias:

$ cat /sys/class/i2c-adapter/i2c-8/8-004b/modalias
i2c:maxtouch

So udev won't be able to auto-load a module for an OF-only device driver.
Many OF-only drivers duplicate the OF device ID table entries in an I2C ID
table only has a workaround for how the I2C core reports the module alias.

This patch changes the I2C core to report an OF related MODALIAS uevent if
the device was registered via OF. So for the previous example, after this
patch, the reported MODALIAS for the Atmel maXTouch will be the following:

$ cat /sys/class/i2c-adapter/i2c-8/8-004b/modalias
of:NtrackpadT<NULL>Catmel,maxtouch

NOTE: This patch may break out-of-tree drivers that were relying on this
      behavior, and only had an I2C device ID table even when the device
      was registered via OF. There are no remaining drivers in mainline
      that do this, but out-of-tree drivers have to be fixed and define
      a proper OF device ID table to have module auto-loading working.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Dmitry Mastykin <mastichi@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-05 16:25:32 +01:00
Jean Delvare e9d09d97af i2c: scmi: Use standard device message logging functions
ACPI_ERROR and ACPI_DEBUG_PRINT are not intended to be used by device
drivers. Use acpi_handle message logging functions instead.

As a nice side effect, it removes the following compiler warnings
which were printed when ACPI debug is disabled:

drivers/i2c/busses/i2c-scmi.c: In function "acpi_smbus_cmi_add_cap":
drivers/i2c/busses/i2c-scmi.c:328:39: warning: suggest braces around empty body in an "else" statement [-Wempty-body]
drivers/i2c/busses/i2c-scmi.c:338:12: warning: suggest braces around empty body in an "else" statement [-Wempty-body]

Suggested-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-02 11:18:55 +01:00
Guenter Roeck 04b6fcaba3 i2c: piix4: Use request_muxed_region
Accesses to SB800_PIIX4_SMB_IDX can occur from multiple drivers.
One example for another driver is the sp5100_tco driver.

Use request_muxed_region() to ensure synchronization.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-02 11:17:23 +01:00
Guenter Roeck 0e89b2fec7 i2c: piix4: Use usleep_range()
The piix4 i2c driver is extremely slow. Replacing msleep()
with usleep_range() increases its speed substantially.
Use sleep ranges similar to those used in the i2c-801 driver
to keep things simple.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-02 11:16:52 +01:00
Jan Glauber 7c4246797b i2c: octeon: Prevent error message on bus error
The error message:

[Fri Feb 16 13:42:13 2018] i2c-thunderx 0000:01:09.4: unhandled state: 0

is mis-leading as state 0 (bus error) is not an unknown state.

Return -EIO as before but avoid printing the message. Also rename
STAT_ERROR to STATE_BUS_ERROR.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-02 11:11:15 +01:00
Wolfram Sang be5b928038 i2c: reformat comments around i2c_smbus_xfer_emulated()
Use Kernel coding style for better readability.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Peter Rosin <peda@axentia.se>
2018-02-27 13:54:05 +01:00
Colin Ian King bead21687f i2c-stm32f4: remove redundant initialization of pointer reg
The pointer reg is assigned a value that is never read, it is later
overwritten with a new value, hence the redundant initialization can
be removed.

Cleans up clang warning:
drivers/i2c/busses/i2c-stm32f4.c:352:16: warning: Value stored to 'reg'
during its initialization is never read

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-02-27 13:51:05 +01:00
Andrzej Hajda 939c5a46e5 i2c: exynos5: rework HSI2C_MASTER_ST_LOSE state handling
HSI2C_MASTER_ST_LOSE state is not documented properly, extensive tests
show that hardware is usually able to recover from this state without
interrupting the transfer. Moreover documentation says that
such state can be caused by slave clock stretching, and should not be
treated as an error during transaction. The only place it indicates
an error is just before starting transaction. In such case bus recovery
procedure should be performed - master should pulse SCL line nine times
and then send STOP condition, it can be repeated until SDA goes high.
The procedure can be performed using manual commands HSI2C_CMD_READ_DATA
and HSI2C_CMD_SEND_STOP.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-02-27 13:47:28 +01:00
George Cherian 41b1d4de96 i2c: xlp9xx: Handle transactions with I2C_M_RECV_LEN properly
In case of transaction with I2C_M_RECV_LEN set, make sure the driver reads
the first byte and then updates the RX fifo with the expected length. Set
threshold to 1 byte so that driver gets an interrupt on receiving the first byte.
After which the transfer length is updated depending on the received length.
Also report SMBus block read functionality.

Signed-off-by: George Cherian <george.cherian@cavium.com>
Tested-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-02-26 21:16:11 +01:00
Dmitry Bazhenov c2a3b3cce8 i2c: xlp9xx: return ENXIO on slave address NACK
Fix the driver violation of the common practice to return
ENXIO error on a slave address NACK.

Signed-off-by: Dmitry Bazhenov <dmitry.bazhenov@auriga.com>
Signed-off-by: George Cherian <george.cherian@cavium.com>
Tested-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-02-26 21:14:09 +01:00
Wolfram Sang a1671af286 i2c: of: simplify reading the "reg" property
of_get_property() is a bit cumbersome to use. Replace it with the newer
of_property_read_u32() for more readable code.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-02-26 20:40:46 +01:00