iio: accel: bmc150: Make bmc150_accel_core_remove() return void

Up to now bmc150_accel_core_remove() returns zero unconditionally. Make
it return void instead which makes it easier to see in the callers that
there is no error to handle.

Also the return value of i2c and spi remove callbacks is ignored anyway.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20211013203223.2694577-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: bmc150: Add support for BMC156

BMC156 is another accelerometer that works just fine with the bmc150-accel
driver. It's very similar to BMC150 (also a accelerometer + magnetometer
combo) but with only one accelerometer interrupt pin. It would make sense
if only INT1 was exposed but someone at Bosch decided to only have an
INT2 pin.

Try to deal with this by making use of the INT2 support introduced
in the previous commit and force using INT2 for BMC156. To detect
that we need to bring up a simplified version of the previous type IDs.

Note that unlike the type IDs removed in commit c06a6aba6835
("iio: accel: bmc150: Drop misleading/duplicate chip identifiers")
here I only add one for the special case of BMC156. Everything else
still happens by reading the CHIP_ID register since the chip type
information often is not accurate in ACPI tables.

Tested-by: Nikita Travkin <nikita@trvn.ru> # BMC156
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20210802155657.102766-5-stephan@gerhold.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: bmc150: Drop misleading/duplicate chip identifiers

Commit 0ad4bf370176 ("iio:accel:bmc150-accel: Use the chip ID to detect
sensor variant") stopped using the I2C/ACPI match data to look up the
bmc150_accel_chip_info. However, the bmc150_accel_chip_info_tbl remained
as-is, with multiple entries with the same chip_id (e.g. 0xFA for
BMC150/BMI055/BMA255). This is redundant now because actually the driver
will always select the first entry with a matching chip_id.

So even if a device probes e.g. with BMA0255 it will end up using the
chip_info for BMC150. And in general that's fine for now, the entries
for BMC150/BMI055/BMA255 were exactly the same anyway (except for the
name, which is replaced with the more accurate one later).

But in this case it's misleading because it suggests that one should
add even more entries with the same chip_id when adding support for
new variants. Let's make that more clear by removing the enum with
the chip identifiers entirely and instead have only one entry per
chip_id.

Note that we may need to bring back some mechanism to differentiate
between different chips with the same chip_id in the future.
For example, BMA250 (currently supported by the bma180 driver) has the
same chip_id = 0x03 as BMA222 even though they have different channel
sizes (8 bits vs 10 bits). But in any case, that mechanism would
need to look quite different from what we have right now.

Cc: Bastien Nocera <hadess@hadess.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20210611080903.14384-4-stephan@gerhold.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: bmc150: Add support for DUAL250E ACPI DSM for setting the hinge angle

Some 360 degree hinges (yoga) style 2-in-1 devices use 2 bmc150 accels
to allow the OS to determine the angle between the display and the base
of the device, so that the OS can determine if the 2-in-1 is in laptop
or in tablet-mode.

On Windows both accelerometers are read (polled) by a special service
and this service calls the DSM (Device Specific Method), which in turn
translates the angles to one of laptop/tablet/tent/stand mode and then
notifies the EC about the new mode and the EC then enables or disables
the builtin keyboard and touchpad based in the mode.

When the 2-in-1 is powered-on or resumed folded in tablet mode the
EC senses this independent of the DSM by using a HALL effect sensor
which senses that the keyboard has been folded away behind the display.

At power-on or resume the EC disables the keyboard based on this and
the only way to get the keyboard to work after this is to call the
DSM to re-enable it.

Call the DSM on probe() and resume() to fix the keyboard not working
when powered-on / resumed in tablet-mode.

This patch was developed and tested on a Lenovo Yoga 300-IBR.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210523170103.176958-8-hdegoede@redhat.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: bmc150: Remove bmc150_set/get_second_device() accessor functions

Now that the definition of the bmc150_accel_data struct is no longer
private to bmc150-accel-core.c, bmc150-accel-i2c.c can simply directly
access the second_dev member and the accessor functions are no longer
necessary.

Note if the i2c_acpi_new_device() for the second-client now fails,
an ERR_PTR gets stored in data->second_dev this is fine since it is only
ever passed to i2c_unregister_device() which has an IS_ERR_OR_NULL() check.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210523170103.176958-7-hdegoede@redhat.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: bmc150: Move struct bmc150_accel_data definition to bmc150-accel.h

Further patches to bmc150-accel-i2c.c need to store some extra info
(on top of the second_dev pointer) in the bmc150_accel_data struct,
rather then adding yet more accessor functions for this lets just
move the struct bmc150_accel_data definition to bmc150-accel.h.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210523170103.176958-6-hdegoede@redhat.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: bmc150: Don't make the remove function of the second accelerometer unregister itself

On machines with dual accelerometers described in a single ACPI fwnode,
the bmc150_accel_probe() instantiates a second i2c-client for the second
accelerometer.

A pointer to this manually instantiated second i2c-client is stored
inside the iio_dev's private-data through bmc150_set_second_device(),
so that the i2c-client can be unregistered from bmc150_accel_remove().

Before this commit bmc150_set_second_device() took only 1 argument so it
would store the pointer in private-data of the iio_dev belonging to the
manually instantiated i2c-client, leading to the bmc150_accel_remove()
call for the second_dev trying to unregister *itself* while it was
being removed, leading to a deadlock and rmmod hanging.

Change bmc150_set_second_device() to take 2 arguments: 1. The i2c-client
which is instantiating the second i2c-client for the 2nd accelerometer and
2. The second-device pointer itself (which also is an i2c-client).

This will store the second_device pointer in the private data of the
iio_dev belonging to the (ACPI instantiated) i2c-client for the first
accelerometer and will make bmc150_accel_remove() unregister the
second_device i2c-client when called for the first client,
avoiding the deadlock.

Fixes: 5bfb3a4bd8f6 ("iio: accel: bmc150: Check for a second ACPI device for BOSC0200")
Cc: Jeremy Cline <jeremy@jcline.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: bmc150: Check for a second ACPI device for BOSC0200

Some BOSC0200 acpi_device-s describe two accelerometers in a single ACPI
device. Normally we would handle this by letting the special
drivers/platform/x86/i2c-multi-instantiate.c driver handle the BOSC0200
ACPI id and let it instantiate 2 bmc150_accel type i2c_client-s for us.

But doing so changes the modalias for the first accelerometer
(which is already supported and used on many devices) from
acpi:BOSC0200 to i2c:bmc150_accel. The modalias is not only used
to load the driver, but is also used by hwdb matches in
/lib/udev/hwdb.d/60-sensor.hwdb which provide a mountmatrix to
userspace by setting the ACCEL_MOUNT_MATRIX udev property.

Switching the handling of the BOSC0200 over to i2c-multi-instantiate.c
will break the hwdb matches causing the ACCEL_MOUNT_MATRIX udev prop
to no longer be set. So switching over to i2c-multi-instantiate.c is
not an option.

Changes by Hans de Goede:
-Add explanation to the commit message why i2c-multi-instantiate.c
cannot be used
-Also set the dev_name, fwnode and irq i2c_board_info struct members
for the 2nd client

Signed-off-by: Jeremy Cline <jeremy@jcline.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20201130141954.339805-2-hdegoede@redhat.com
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=198671
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: bmc150-accel: Add support for BMA222

This adds support for the BMA222 version of this sensor,
found in for example the Samsung GT-I9070 mobile phone.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201115205745.618455-2-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: accel: bmc150: use common definition for regmap conf

bmc150_i2c_regmap_conf is defined three times (in bmc150-accel-core.c,
bmc150-accel-i2c.c and and bmc150-accel-spi.c), although the
definition is the same.

Use one common definition for bmc150_i2c_regmap_conf in all
included files.

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: bmc150: Split the driver into core and i2c

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Tested-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>