iio: imu: inv_mpu6050: move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: imu: inv_mpu6050: Check ACPI companion directly

Instead of checking for ACPI handle followed by extracting a companion
device, do the latter first and use it for checks.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220203155920.18586-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: imu: inv_mpu6050: Drop double check for ACPI companion device

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: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: imu: inv_mpu6050: convert to use i2c_new_client_device()

Move away from the deprecated API and return the shiny new ERRPTR where
useful.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope 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

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 263 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: inv_mpu6050: Use i2c_acpi_get_i2c_resource() helper

ACPI provides a generic helper to get I2C Serial Bus resources.
Use it instead of open coded variant.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: imu: inv_mpu6050: Remove duplicate NULL check

Since i2c_unregister_device() became NULL-aware we may remove duplicate
NULL check.

Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: linux-iio@vger.kernel.org
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: inv_mpu6050: Fix use-after-free in ACPI code

In some cases this can result in incorrectly returning a negative value
from asus_acpi_get_sensor_info and the AK8963 magnetometer failing to
show up.

Note cpm is an alias for buffer.pointer which isn't apparent in this
patch on it's own.

Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Acked-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: imu: inv_mpu6050: convert to use an explicit i2c mux core

Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.

Acked-by: Jonathan Cameron <jic23@kernel.org>
Tested-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

iio: imu: inv_mpu6050: Remove unnecessary parentheses

Fixes the following checkpatch warning:
CHECK: Unnecessary parentheses around cpm->package.elements[i]

Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: imu: inv_mpu6050: Fix newlines to make code easier to read

This fixes the following checkpatch.pl warnings:
* WARNING: Missing a blank line after declarations
* CHECK: Blank lines aren't necessary before a close brace '}'

Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: imu: inv_mpu6050: Separate driver into core and i2c functionality.

Separate this driver into core and i2c functionality.
This is in preparation for adding spi support.

Signed-off-by: Adriana Reus <adriana.reus@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: imu: inv_mpu6050: Create mux clients for ACPI

This is a follow up patches after adding i2c mux adapter for bypass
mode. Potentially many different types of sensor can be attached to
INVMPU6XXX device, which can be connected to main cpu i2c bus in
bypass mode.
Why do we need this?
The system ACPI table entry will consist of only one device for
INV6XXX, assuming that this driver will handle all connected sensors.
That is not true for the Linux driver. There are bunch of IIO drivers
for each sensors, hence we created a mux on this device. So to load
these additional drivers, we need to create i2c devices for them
in this driver using this mux adapter.

There are multiple options:
1. Use the auto detect feature, this needs a new i2c class for the
adapter as the existing HWMON class is not acceptable. Also the
autodetect has overhead of executing detect method for each
matching class of adapters.
This is a simple implementation. This option was previously submitted
with not a happy feedback.

2. Option is use ACPI magic and parse the configuration data. What
we need to create a i2c device at a minimum is address and a name.
Address can be obtained for secondary device in more or less in a
standard way from using _CRS element. But there is no name. To get
name we need to process proprietary vendor data. Not having name is
not fun, as you have to create device using the device name of
INVN6XXXX, respecting driver duplicate name space restriction.
Also each client driver needs to have this name in the id table.
Since multiple driver can be loaded, the driver should be able to
detect its presence and gracefully exit for the other client driver
to take it over.
So we use two step process:
- Use DMI to id platform and parse propritery data. This is not uncommon
for many x86 platform specific driver. We will get both name and address.
The change created necessary infrastructure to add more properitery vendor
data parsing.
- If DMI match fails, then create device on INV6XXX-client (we can't
create with same name as INV6XXX as it will cause duplicate name and driver
model will reject.) With this each client sensor driver which needs to get
attached via INV6XXXX, need this name in the id table and detect the
physical presence of sensor in probe and exit if not found.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>