Some platforms might need to activate the driver quirks at a very early
probe stage. For instance, Baikal-T1 System I2C doesn't need to map the
registers space as ones belong to the system controller. Instead it will
request the syscon regmap from the parental DT node. In order to be able
to do so let's retrieve the model flags right after the DW I2C private
data is created. While at it replace the or-assignment with just
assignment operator since or-ing is redundant at this stage.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Seeing the DW I2C driver is using flags-based accessors with two
conditional clauses it would be better to replace them with the regmap
API IO methods and to initialize the regmap object with read/write
callbacks specific to the controller registers map implementation. This
will be also handy for the drivers with non-standard registers mapping
(like an embedded into the Baikal-T1 System Controller DW I2C block, which
glue-driver is a part of this series).

As before the driver tries to detect the mapping setup at probe stage and
creates a regmap object accordingly, which will be used by the rest of the
code to correctly access the controller registers. In two places it was
appropriate to convert the hand-written read-modify-write and
read-poll-loop design patterns to the corresponding regmap API
ready-to-use methods.

Note the regmap IO methods return value is checked only at the probe
stage. The rest of the code won't do this because basically we have
MMIO-based regmap so non of the read/write methods can fail (this also
won't be needed for the Baikal-T1-specific I2C controller).
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[wsa: fix type of 'rx_valid' and remove outdated kdoc var description]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

A PM workaround activated by the flag MODEL_CHERRYTRAIL has been removed
since commit 9cbeeca0 ("i2c: designware: Remove Cherry Trail PMIC I2C
bus pm_disabled workaround"), but the flag most likely by mistake has been
left in the Dw I2C drivers. Let's remove it. Since MODEL_MSCC_OCELOT is
the only model-flag left, redefine it to be 0x100 so setting a very first
bit in the MODEL_MASK bits range.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Currently Intel Baytrail I2C semaphore is a feature of the DW APB I2C
platform driver. It's a bit confusing to see it's config in the menu at
some separated place with no reference to the platform code. Let's move the
config definition to be below the I2C_DESIGNWARE_PLATFORM config and mark
it with "depends on I2C_DESIGNWARE_PLATFORM" statement. By doing so the
config menu will display the feature right below the DW I2C platform
driver item and will indent it to the right so signifying its belonging.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

DW APB I2C slave code in fact depends on the DW I2C driver core, but not
on the platform code as it used to be before commit 90bc1ee6de9f ("i2c:
designware: Allow slave mode for PCI enumerated devices"). Yes, the I2C
slave interface is currently supported by both the platform and PCI
versions of the IP core, but it still depends on the DW I2C core
functionality and must be available only if the last one is enabled.
So make sure the DW APB I2C slave config is only available if the
I2C_DESIGNWARE_CORE config is enabled.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Since commit 4f827280 ("Documentation: update kbuild loadable modules
goals & examples") `-objs` is fitted for building host programs, lets
change DW I2C core, platform and PCI driver kbuild directives to using
`-y`, which more straightforward for device drivers. By doing so we can
discard the ifeq construction in favor to the more natural and less bulky
`<module>-$(CONFIG_X) += x.o`
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Add the "baikal,bt1-sys-i2c" compatible string to the DW I2C binding. Even
though the corresponding node is supposed to be a child of the Baikal-T1
System Controller, its reg property is left required for compatibility.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

dtc currently doesn't support I2C_OWN_SLAVE_ADDRESS flag set in the
i2c "reg" property. If dtc finds an i2c-slave sub-node having an address
higher than ten-bits wide it'll print an ugly warning:

Warning (i2c_bus_reg): /example-2/i2c@1120000/eeprom@64: I2C bus unit address format error, expected "40000064"
Warning (i2c_bus_reg): /example-2/i2c@1120000/eeprom@64:reg: I2C address must be less than 10-bits, got "0x40000064"

In order to silence dtc up let's replace the corresponding DT binding
example with a normal DW I2C master mode-based one. It's done by clearing
the I2C_OWN_SLAVE_ADDRESS bit in the reg property and converting the
sub-node to be compatible with normal EEPROM like "atmel,24c02".

Just revert this commit when dtc is fixed.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Modern device tree bindings are supposed to be created as YAML-files
in accordance with dt-schema. This commit replaces Synopsys DW I2C
legacy bare text bindings with YAML file. As before the bindings file
states that the corresponding dts node is supposed to be compatible
either with generic DW I2C controller or with Microsemi Ocelot SoC I2C
one, to have registers, interrupts and clocks properties. In addition
the node may have clock-frequency, i2c-sda-hold-time-ns,
i2c-scl-falling-time-ns and i2c-sda-falling-time-ns optional properties.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

This currently generates a warning:

drivers/i2c/busses/i2c-sh_mobile.c: In function 'sh_mobile_i2c_isr':
drivers/i2c/busses/i2c-sh_mobile.c:399:26: warning: 'data' may be used uninitialized in this function [-Wmaybe-uninitialized]

Though the code looks okay and shouldn't ever use the variable
uninitialized. Fix the warning by moving the code around and getting rid
of 'data'.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: minor updates to commit message]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Call the function to instantiate SPD EEPROMs automatically on the
main SMBus controller.

Multiplexed SMBus systems are excluded for now as they are more
complex to handle.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

In simple cases we can instantiate SPD EEPROMs on the SMBus
automatically. Start with just DDR2, DDR3 and DDR4 on x86 for now,
and only for systems with no more than 4 memory slots. These
limitations may be lifted later.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
[wsa: minor change for new API]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c_client pointers are usually named 'client'. Use it here to get rid
of the ambiguity of 'dev->dev'.
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Support for 16-bit addresses has been added, so remove it from the todo
list. Also, in the introductory sentence, may clear we talk about "slave
IP cores" to make reading easier.

Fixes: 82d51481 ("i2c-eeprom_slave: Add support for more eeprom models")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

We have a kzalloced struct, no need to init to 0.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

acpi_dev_get_resources() does perform the NULL pointer check against
ACPI companion device which is given as function parameter. Thus,
there is no need to duplicate this check in the caller.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

PTR_ERR_OR_ZERO contains if(IS_ERR(...)) + PTR_ERR.

Generated by: scripts/coccinelle/api/ptr_ret.cocci
Signed-off-by: Aishwarya Ramakrishnan <aishwaryarj100@gmail.com>
Reviewed-by: Ajay Gupta <ajayg@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

No need to populate a variable if it is used only in debug output which
may get compiled away anyhow.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The function efm32_i2c_probe() is only called with an
openfirmware platform device.Therefore there is no need
to check that it has an openfirmware node.
Signed-off-by: Shengju Zhang <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

In the function efm32_i2c_probe(),when get irq failed,the function
platform_get_irq() logs an error message,so remove redundant message
here.
Signed-off-by: Shengju Zhang <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

This reverts commit 6aab46bc. Testing in
linux-next showed it needs some more time.
Signed-off-by: Wolfram Sang <wsa@kernel.org>

This reverts commit 6fe12cdb. Testing in
linux-next showed it needs some more time.
Signed-off-by: Wolfram Sang <wsa@kernel.org>

It's not clear why the commit fe20ff5c
  ("i2c-designware: Add support for Designware core behind PCI devices.")
followed by commit b61b1415
  ("i2c-designware: add support for Intel Lynxpoint")
chose to hard code FIFO depth size. The FIFO depth on all hardware,
I have tested on, can be nicely detected automatically.

Thus, we may safely drop hard coded FIFO sizes from the driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

PCI devices may have been backed with ACPI handle which supplies
an additional information to the drivers, such as counters.

Call for ACPI configuration from PCI driver in order to utilize counters
provided by ACPI.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

For possible code reuse in the future, move ACPI parts into common module.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

We may bailout directly from the loop instead of breaking it and
testing a loop counter. This also gives advantages such as decreased
indentation level along with dropped unneeded condition.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

In order to export array supported speed for wider use, move it
to a header along with i2c_dw_validate_speed() helper moved to
a common code.

No functional changes intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

This header is a user of some generic ones, include them respectively.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Do not spread PCI specifics over common code. It seems to be a layering
violation which can be easily avoided. Refactor PCI driver and drop
PCI specifics from common code.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Implement generic GPIO-based I2C bus recovery for the PXA I2C driver.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Merge tag 'for-5.8-i2c' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into i2c/for-5.8

i2c: tegra: Changes for v5.8-rc1

This includes a few improvements to make the Tegra I2C controller behave
properly on suspend/resume, does a bit of cleanup and adds support for
the VI-variant of the I2C controller that is used primarily for video
capture purposes.

Protect altr_i2c_int_enable() by the mutex and remove unneeded spinlock.
Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Reviewed-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Although in the most platforms, the bus power of i2c
are alway on, some platforms disable the i2c bus power
in order to meet low power request.

We get and enable bulk regulator in i2c adapter device.
Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

In some platforms, they disable the power-supply of i2c due
to power consumption reduction. This patch add bus-supply property.
Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
[wsa: rebased to i2c/for-next]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Atomic transfers are not only about sending messages like the original
wording suggested. Speak of 'accessing' now like in i2c.h.
Reported-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

I don't plan to support every EEPROM type, but the 24c512 ones need a
tiny code update, so let's have that upstream.
Reported-by: Patrick Williams <patrick@stwcx.xyz>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Patrick Williams <patrick@stwcx.xyz>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

This patch adds a algorithm to calculate some ac-timing parameters
which can fully meet I2C Spec.
Signed-off-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Add Qii Wang as maintainer for mediatek i2c controller driver.
Signed-off-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>