Drop the doubled word "be" in a comment.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

All in-tree users have been converted to the new i2c_new_client_device
function, so remove this deprecated one.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
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>

This reverts commit 6fe12cdb. Testing in
linux-next showed it needs some more time.
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>

The old email is still active, but for easier handling, I am going to
use my kernel.org address from now on. Also, add a mailmap for the now
defunct Pengutronix address.
Signed-off-by: NWolfram Sang <wsa@kernel.org>

All in-tree users have been converted to the new i2c_new_scanned_device
function, so remove this deprecated one.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There are few maximum bus frequencies being used in the I²C core code.
Provide generic definitions for bus frequencies and use them in the core.

The drivers may use predefined constants where it is appropriate.
Some of them are already using these under slightly different names.
We will convert them later to use newly introduced defines.

Note, the name of modes are chosen to follow well established naming
scheme [1].

These definitions will also help to avoid typos in the numbers that
may lead to subtle errors.

[1]: https://en.wikipedia.org/wiki/I%C2%B2C#Differences_between_modesAcked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Don't let non-letters inside a literal block without escaping it, as
the toolchain would mis-interpret it:

./include/linux/i2c.h:518: WARNING: Inline strong start-string without end-string.
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

According to coding-style.rst, extern should not be specified for
exported functions.
Signed-off-by: NLuca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

As a preparation for an API conversion, factor out something frequently
used in the media subsystem. As an improvement, it bails out on both,
NULL and ERRPTR to handle the old and new API.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Fix kernel-doc warning in <linux/i2c.h>.

../include/linux/i2c.h:337: warning: Function parameter or member 'init_irq' not described in 'i2c_client'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

All in-kernel users have been converted to
{devm_}i2c_new_dummy_device(). Remove the old API.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: NLuca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: NLuca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

In the general move to have i2c_new_*_device functions which return
ERR_PTR instead of NULL, this patch converts i2c_new_probed_device().

There are only few users, so this patch converts the I2C core and all
users in one go. The function gets renamed to i2c_new_scanned_device()
so out-of-tree users will get a build failure to understand they need to
adapt their error checking code.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NLuca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: NMax Staudt <max@enpas.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There are no in-tree users of these helpers anymore, and there
shouldn't. Most use cases went away once the driver model started to
refcount for us. There have been users like the media subsystem, but
they all switched to better refcounting methods meanwhile. Media did
this in 2008. Last user (IPMI) left 2018. Remove this cruft.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: NJean Delvare <jdelvare@suse.de>
Tested-by: NLuca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: NLuca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>

i2c-digital-filter-width-ns:
This optional timing property specifies the width of the spikes on the i2c
lines (in ns) that can be filtered out by built-in digital filters which are
embedded in some i2c controllers.
i2c-analog-filter-cutoff-frequency:
This optional timing property specifies the cutoff frequency of a low-pass
analog filter built-in i2c controllers. This low pass filter is used to filter
out high frequency noise on the i2c lines. Specified in Hz.
Include these properties in the timings structure and read them as integers.
Signed-off-by: NEugen Hristev <eugen.hristev@microchip.com>
Acked-by: NLudovic Desroches <ludovic.desroches@microchip.com>
Reviewed-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

In the general move to have i2c_new_*_device functions which return
ERR_PTR instead of NULL, this patch converts i2c_new_secondary_device().

There are only few users, so this patch converts the I2C core and all
users in one go. The function gets renamed to i2c_new_ancillary_device()
so out-of-tree users will get a build failure to understand they need to
adapt their error checking code.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> # adv748x
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> # adv7511 + adv7604
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # adv7604
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Convert each file at I2C subsystem, renaming them to .rst and
adding to the driver-api book.
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Nobody (including me) noticed that these functions were exported but not
added to the header :/

Fixes: 7159dbda ("i2c: core: improve return value handling of i2c_new_device and i2c_new_dummy")
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Let's stick to coding style.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Update kerneldoc for i2c client flags because they increased over time.
Also, move them to a position where they can be more easily found.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Much better to read and understand. Naming for i2c_adapter is not
consistent (yet), so use the name which is also used in core code.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

It is not a struct device, so 'dev' is confusing. Use 'adap', the most
common name.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This allows drivers to lookup i2c adapters on ACPI based systems similar to
of_get_i2c_adapter_by_node() with DT based systems.
Signed-off-by: NRuslan Babayev <ruslan@babayev.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This allows drivers to lookup i2c adapters on ACPI based systems similar to
of_get_i2c_adapter_by_node() with DT based systems.
Signed-off-by: NRuslan Babayev <ruslan@babayev.com>
Cc: xe-linux-external@cisco.com
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  51 franklin street fifth floor boston ma 02110 1301 usa

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option [no]_[pad]_[ctrl] any later version this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation inc 51 franklin street fifth floor boston ma
  02110 1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 176 file(s).
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NJilayne Lovejoy <opensource@jilayne.com>
Reviewed-by: NSteve Winslow <swinslow@gmail.com>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190519154040.652910950@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

i2c_new_dummy is typically called from the probe function of the
driver for the primary i2c client. It requires calls to
i2c_unregister_device in the error path of the probe function and
in the remove function.
This can be simplified by introducing a device-managed version.

Note the changed error case return value type: i2c_new_dummy returns
NULL whilst devm_i2c_new_dummy_device returns an ERR_PTR.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
[wsa: rename new functions and fix minor kdoc issues]
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NPeter Rosin <peda@axentia.se>
Reviewed-by: NKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There are two problems with WARN_ON() here. One: It is not ratelimited.
Two: We don't see which adapter was used when trying to transfer
something when already suspended. Implement a custom ratelimit once per
adapter and use dev_WARN there. This fixes both issues. Drawback is that
we don't see if multiple drivers are trying to transfer with the same
adapter while suspended. They need to be discovered one after the other
now. This is better than a high CPU load because a really broken driver
might try to resend endlessly.

Fixes: 9ac6cb5f ("i2c: add suspended flag and accessors for i2c adapters")
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org # v5.1+

We had the request to access devices very late when interrupts are not
available anymore multiple times now. Mostly to prepare shutdown or
reboot. Allow adapters to specify a specific callback for this case.
Note that we fall back to the generic {master|smbus}_xfer callback if
this new atomic one is not present. This is intentional to preserve the
previous behaviour and avoid regressions. Because there are drivers not
using interrupts or because it might have worked "accidently" before.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NStefan Lengfeld <contact@stefanchrist.eu>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NSimon Horman <horms+renesas@verge.net.au>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

A previous change allowed I2C client devices to discover new IRQs upon
reprobe by clearing the IRQ in i2c_device_remove. However, if an IRQ was
assigned in i2c_new_device, that information is lost.

For example, the touchscreen and trackpad devices on a Dell Inspiron laptop
are I2C devices whose IRQs are defined by ACPI extended IRQ types. The
client device structures are initialized during an ACPI walk. After
removing the i2c_hid device, modprobe fails.

This change caches the initial IRQ value in i2c_new_device and then resets
the client device IRQ to the initial value in i2c_device_remove.

Fixes: 6f108dd7 ("i2c: Clear client->irq in i2c_device_remove")
Signed-off-by: NJim Broadus <jbroadus@gmail.com>
Reviewed-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: NCharles Keepax <ckeepax@opensource.cirrus.com>
[wsa: this is an easy to backport fix for the regression. We will
refactor the code to handle irq assignments better in general.]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

As discussed previously the best location for certain bus related bits,
e.g. I2C, is its own realm of the headers.

In order to uncontaminate acpi.h move the I2C bits to i2c.h.

There is no functional change intended.

Link: https://lkml.org/lkml/2018/11/28/744Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

A few drivers open code the handling of suspended adapters. It could be
handled by the core, though, to ensure generic handling. This patch adds
the flag and accessor functions. The usage of these helpers is optional,
though. See the kerneldoc in this patch. Using the new flag, we now
reject further transfers if the adapter is already marked suspended.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

a) rename to 'put' instead of 'release' to match 'get' when obtaining
   the buffer
b) change the argument order to have the buffer as first argument
c) add a new argument telling the function if the message was
   transferred. This allows the function to be used also in cases
   where setting up DMA failed, so the buffer needs to be freed without
   syncing to the message buffer.

Also convert the only user.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There aren't any users left. Remove this callback from the 2.4 times.
Phew, finally, that took years to reach...
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There are two drivers already using the SDA hold time setting.
It might be more in the future, thus, make I2C core to parse the setting
for us if provided by firmware.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: NLudovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Some adapters do not support a message length of 0. Add this as a quirk
so drivers don't have to open code it.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Removes all locking from i2c_smbus_xfer and renames it to __i2c_smbus_xfer,
then adds a new i2c_smbus_xfer function that simply grabs the lock while
calling the unlocked variant.

This is not perfectly equivalent, since i2c_smbus_xfer was callable from
atomic/irq context if you happened to end up emulating SMBus with an I2C
transfer, and that is no longer the case with this patch. It is unknown
(to me) if anything depends on that quirk, but it seems fragile enough to
simply break those cases and require them to call i2c_transfer directly
instead.

While at it, for consistency rename the 2nd to last argument (size) of
the i2c_smbus_xfer declaration to protocol and remove the surplus extern
marker.
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Some IP cores have an internal 'bus free' logic which may be more
advanced than just checking if SDA is high. Add a separate callback to
get this status. Filling it is optional.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

For bus recovery, we either need to bail out early if we can read SDA or
we need to send STOP after every pulse. Otherwise recovery might be
misinterpreted as an unwanted write. So, require one of those SDA
handling functions to avoid this problem.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>