Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We want the fixes in here as well as this resolves an iio driver merge
issue.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Adopt the SPDX license identifier headers to ease license compliance
management. Also fix MODULE_LICENSE for cros_ec_accel_legacy to match
the SPDX and boiler plate license.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Document cros_ec_sensors_read_lpc, adding an additional note to explain
that this is the safe function for reading the EC data.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The cros_ec sensors drivers do not call any sysfs functions
or use any sysfs defines, and thus do not need to include
linux/sysfs.h. Also, some cros_ec drivers include linux/delay.h
and is not used.

Signed-off-by: Guenter Roeck <groeck@chromium.org>
[remove linux/delay.h]
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Formatting of Kconfig files doesn't look so pretty, so just
take damp cloth and clean it up.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

When building with -Wsometimes-uninitialized, Clang warns:

drivers/iio/common/ssp_sensors/ssp_iio.c:95:6: warning: variable
'calculated_time' is used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]

While it isn't wrong, this will never be a problem because
iio_push_to_buffers_with_timestamp only uses calculated_time
on the same condition that it is assigned (when scan_timestamp
is not zero). While iio_push_to_buffers_with_timestamp is marked
as inline, Clang does inlining in the optimization stage, which
happens after the semantic analysis phase (plus inline is merely
a hint to the compiler).

Fix this by just zero initializing calculated_time.

Link: https://github.com/ClangBuiltLinux/linux/issues/394
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Calculation did not use IIO_DEGREE_TO_RAD and implemented a variant to
avoid precision loss as we aim a nano value. The offset added to avoid
rounding error, though, doesn't give us a close result to the expected
value. E.g.

For 1000dps, the result should be:

    (1000 * pi ) / 180 >> 15 ~= 0.000532632218

But with current calculation we get

    $ cat scale
    0.000547890

Fix the calculation by just doing the maths involved for a nano value

   val * pi * 10e12 / (180 * 2^15)

so we get a closer result.

    $ cat scale
    0.000532632

Fixes: c14dca07a31d ("iio: cros_ec_sensors: add ChromeOS EC Contiguous Sensors driver")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The statement is indented too much by one level, fix this by
removing the extraneous tab.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Miscellaneous cleanup to fix minor consistency, grammar, and spelling
issues.

Signed-off-by: Martin Kelly <martin@martingkelly.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>