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>

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: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Use a mutex to protect access to idev->msg_len, idev->buf, etc. which
are modified by both altr_i2c_xfer_msg() and altr_i2c_isr().

This is the minimal fix for easy backporting. A cleanup to remove the
spinlock will be added later.
Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Acked-by: Thor Thayer <thor.thayer@linux.intel.com>
[wsa: updated commit message]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The 'pengutronix' address is defunct for years. Use the proper contact
address.
Signed-off-by: Wolfram Sang <wsa@kernel.org>

devm_gpiod_get() usually calls gpio_request_enable() for non-strict pinmux
drivers. These puts the pins in GPIO mode, whithout notifying the pinctrl
driver. At this point, the I2C bus no longer owns the pins. To mux the
pins back to the I2C bus, we use the pinctrl driver to change the state
of the pins to GPIO, before using devm_gpiod_get(). After the pins are
received as GPIOs, we switch theer pinctrl state back to the default
one,

Fixes: d3d3fdcc ("i2c: at91: implement i2c bus recovery")
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Allow slave mode for PCI enumerated devices by calling a common i2c_dw_probe()
instead of i2c_dw_probe_master().

While dropping dependency to platform driver in slave module, move its
configuration section above, closer to core.
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>

As a preparatory patch to support slave mode for PCI enumerated devices rename
i2c_dw_probe() to i2c_dw_probe_master() and split common i2c_dw_probe() as
inline helper.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Since we have available helper to configure master mode, let's use it
in the PCI driver instead of spread open-coded variant.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Move configuration routines to respective modules, i.e. master and slave.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Use devm_platform_ioremap_resource() instead of
platform_get_resource() + devm_ioremap_resource().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Tegra210 has an extra instance of the I2C controller that is in the
domain of host1x and usually used for camera use-cases. The programming
model for the VI variant of the controller is roughly the same as for
the other variants, except that the I2C registers start at an offset
and are spaced further apart. VI I2C also doesn't support slave mode.
Signed-off-by: Thierry Reding <treding@nvidia.com>

Using these macros helps increase readability of the code.
Signed-off-by: Thierry Reding <treding@nvidia.com>

Use master-abort to send the stop condition after an address cycle
rather than resetting the controller.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

If we timeout during a message transfer, the control register may
contain bits that cause an action to be set. Read-modify-writing the
register leaving these bits set may trigger the hardware to attempt
one of these actions unintentionally.

Always clear these bits when cleaning up after a message or after
a timeout.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Remove unnecessary show_state() in the loop inside
i2c_pxa_pio_set_master(), which can be unnecessarily verbose.

Remove the i2c_pxa_scream_blue_murder() in i2c_pxa_pio_xfer(), which
will trigger if we are probing the I2C bus and a slave does not
respond; this is a normal event, and not something to report.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Ensure that the various timeout messages can identify where in the code
they were produced from to aid debugging.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@kernel.org>