Commit Graph

2 Commits

Author SHA1 Message Date
Greg Kroah-Hartman
b24413180f 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>
2017-11-02 11:10:55 +01:00
Linus Walleij
3904b28efb iio: gyro: Add driver for the MPU-3050 gyroscope
This adds a new driver for the Invensense MPU-3050 gyroscope.
This driver is based on information from the rough input driver
in drivers/input/misc/mpu3050.c and the scratch misc driver
posted by Nathan Royer in 2011. Some years have passed but this
is finally a fully-fledged driver for this gyroscope. It was
developed and tested on the Qualcomm APQ8060 Dragonboard.

The driver supports both raw and buffered input. It also
supports the internal trigger mechanism by registering a trigger
that can fire in response to the internal sample engine of the
component. In addition to reading out the gyroscope sensor
values, the driver also supports reading the temperature from
the sensor.

The driver currently only supports I2C but the MPU-3050 can
also be used from SPI, so the I2C portions are split in their
own file and we just use regmap to access all registers, so
it will be trivial to plug in SPI support if/when someone has
a system requiring this.

To conserve power, the driver utilizes the runtime PM
framework and will put the sensor in off mode and disable the
regulators when unused, after a timeout of 10 seconds.

The fullscale can be set for the sensor to 250, 500, 1000 or
2000 deg/s. This corresponds to scale values of rougly 0.000122,
0.000275, 0.000512 or 0.001068. By writing such values (or close
to these) into "in_anglevel_scale", the corresponding fullscale
can be chosen. It will default to 2000 deg/s (~35 rad/s).

The gyro component can have DC offsets on all axes. These can be
compensated using the standard sysfs ABI property
"in_anglevel_[xyz]_calibbias". This is in positive/negative
values of the raw values, so a suitable calibration bias can be
determined by userspace by reading the "in_anglevel_[xyz]_raw"
for a few iterations while holding the sensor still, create an
average integer, and writing the negative inverse of that into
"in_anglevel_[xyz]_calibbias". After this the hardware will
automatically subtract the bias, also when using buffered
readings.

Since the MPU-3050 has an outgoing I2C port it needs to act as
an I2C mux. This means that the device is switching I2C traffic
to devices beyond it. On my system this is the only way to reach
the accelerometer. The "sensor fusion" ability of the MPU-3050
to directly talk to the device on the outgoing I2C port is
currently not used by the driver, but it has code to allow I2C
traffic to pass through so that the Linux kernel can reach the
device on the other side with a kernel driver.

Example usage with the native trigger:

$ generic_buffer -a -c10 -n mpu3050
iio device number being used is 0
iio trigger number being used is 0
No channels are enabled, enabling all channels
Enabling: in_anglvel_z_en
Enabling: in_timestamp_en
Enabling: in_anglvel_y_en
Enabling: in_temp_en
Enabling: in_anglvel_x_en
/sys/bus/iio/devices/iio:device0 mpu3050-dev0
29607.142578 -0.117493 0.074768 0.012817 180788797150
29639.285156 -0.117493 0.076904 0.013885 180888982335
29696.427734 -0.116425 0.076904 0.012817 180989178039
29742.857422 -0.117493 0.076904 0.012817 181089377742
29764.285156 -0.116425 0.077972 0.012817 181189574187
29860.714844 -0.115356 0.076904 0.012817 181289772705
29864.285156 -0.117493 0.076904 0.012817 181389971520
29910.714844 -0.115356 0.076904 0.013885 181490170483
29917.857422 -0.116425 0.076904 0.011749 181590369742
29975.000000 -0.116425 0.076904 0.012817 181690567075
Disabling: in_anglvel_z_en
Disabling: in_timestamp_en
Disabling: in_anglvel_y_en
Disabling: in_temp_en
Disabling: in_anglvel_x_en

The first column is the temperature in millidegrees, then the x,y,z
axes in succession followed by the timestamp. Also tested successfully
using the HRTimer trigger.

Cc: Nick Vaccaro <nvaccaro@google.com>
Cc: Ge Gao <ggao@invensense.com>
Cc: Anna Si <asi@invensense.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Crestez Dan Leonard <leonard.crestez@intel.com>
Cc: Daniel Baluta <daniel.baluta@intel.com>
Cc: Gregor Boirie <gregor.boirie@parrot.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-10-25 17:24:05 +01:00