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: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
[wsa: fix type of 'rx_valid' and remove outdated kdoc var description]
Signed-off-by: NWolfram 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: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram 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: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram 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: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram 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: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram 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: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWolfram 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: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWolfram 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: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWolfram 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: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: minor updates to commit message]
Signed-off-by: NWolfram 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: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NWolfram 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: NJean Delvare <jdelvare@suse.de>
[wsa: minor change for new API]
Signed-off-by: NWolfram 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: NWolfram 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: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

We have a kzalloced struct, no need to init to 0.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram 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: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram 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: NAishwarya Ramakrishnan <aishwaryarj100@gmail.com>
Reviewed-by: NAjay Gupta <ajayg@nvidia.com>
Signed-off-by: NWolfram 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: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram 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: NShengju Zhang <zhangshengju@cmss.chinamobile.com>
Signed-off-by: NTang Bin <tangbin@cmss.chinamobile.com>
Signed-off-by: NWolfram 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: NShengju Zhang <zhangshengju@cmss.chinamobile.com>
Signed-off-by: NTang Bin <tangbin@cmss.chinamobile.com>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

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

This reverts commit 6fe12cdb. Testing in
linux-next showed it needs some more time.
Signed-off-by: NWolfram 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: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram 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: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

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

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

Implement generic GPIO-based I2C bus recovery for the PXA I2C driver.
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NWolfram 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: NAtsushi Nemoto <atsushi.nemoto@sord.co.jp>
Reviewed-by: NThor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: NWolfram 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: NBibby Hsieh <bibby.hsieh@mediatek.com>
Reviewed-by: NTomasz Figa <tfiga@chromium.org>
Signed-off-by: NWolfram 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: NBibby Hsieh <bibby.hsieh@mediatek.com>
Acked-by: NRob Herring <robh@kernel.org>
[wsa: rebased to i2c/for-next]
Signed-off-by: NWolfram 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: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram 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: NPatrick Williams <patrick@stwcx.xyz>
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NPatrick Williams <patrick@stwcx.xyz>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

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

Add Qii Wang as maintainer for mediatek i2c controller driver.
Signed-off-by: NQii Wang <qii.wang@mediatek.com>
Signed-off-by: NWolfram 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: NGustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

A call to 'i2c_demux_deactivate_master()' is missing in the error handling
path, as already done in the remove function.

Fixes: 50a5ba87 ("i2c: mux: demux-pinctrl: add driver")
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: NWolfram Sang <wsa@kernel.org>