[Letux-kernel] [PATCH v2 00/10] iio mount matrix - revitalize missing bindings documentation and provide code for bmc150, bmg160, bma180, itg3200, hmc584x

[H. Nikolaus Schaller]

Hi Andreas,

> Am 25.02.2019 um 18:56 schrieb Andreas Kemnade <andreas at kemnade.info>:
> 
> Hi,
> 
> On Thu, 21 Feb 2019 18:02:45 +0100
> "H. Nikolaus Schaller" <hns at goldelico.com> wrote:
> 
>> Fixes V2:
>> * make get_mount_matrix() functions more readable (use temp variable)
>>  (suggested by Jonathan and Andy)
>> * add these readability improvements also for ak8975 and mpu6050
>>  (suggested by Jonathan and Andy)
>> * squash bindings documentation into single commit for better discussion
>>  (suggested by Linus)
>> * FOR DISCUSSION: add some more clarifications to the bindings documentation
>>  and an attempt to define the magnetometer orientation
>> * add "iio: Allow to read mount matrix from ACPI" to the beginning of
>>  the series to make it compile
>>  (suggested by Andy)
>> * replace of_iio_read_mount_matrix() by iio_read_mount_matrix()
>>  (required by "iio: Allow to read mount matrix from ACPI")
>> * drop patch to convert bma180 to devm (potential race)
>>  (suggested by Jonathan)
>> 
>> PATCH V1 2019-02-20 15:01:02:
>> This patch series adds the mount-matrix to several iio sensor drivers
>> used in handheld devices.
>> 
>> The mount-matrix translates the quite arbitrary orientation of the sensor
>> on some printed circuit board to user-tangible orientation in handheld
>> devices that relates to typical screen orientation.
>> 
>> There was a bindings documentation by Linus Walleij but the patch
>> did not make it into mainline. Therefore I resend it here.
>> 
>> Next I have added some clarifications (at least I hope it clarifies)
>> in a second patch.
>> 
>> Finally, the patch set implements the hooks for the mount matrix
>> in several iio drivers: bmc150, bma180, bmg160, itg3200, hmc5843.
>> This includes also one patch for the bma180 to convert it to devm API.
>> 
>> We use them in different variants of the omap3-gta04 so a separate
>> patch set will provide device tree additions for them.
>> 
>> 
>> Andy Shevchenko (1):
>>  iio: Allow to read mount matrix from ACPI
>> 
>> H. Nikolaus Schaller (8):
>>  iio: accel: bmc150: add mount matrix support
>>  iio: accel: bma180: add mount matrix support
>>  iio: gyro: bmg160: add mount matrix support
>>  iio: gyro: itg3200: add mount matrix support
>>  iio: magnetometer: bmc150: add mount matrix support
>>  iio: magnetometer: hmc5843: add mount matrix support
>>  iio: mpu6050: improve code readability
>>  iio: ak8975: improve code readability
>> 
> Hmm, you are missing the most important device with iio interface...
> tsc2007 is missing. Would be interesting to know how it is oriented
> towards the screen. (not CC'd yet to LKML and other stuff yet by
> intention)

Well, there is already a different mechanism implemented for this purpose.
There are common touchscreen bindings: touchscreen-inverted-x/y,
touchscreen-swapped-x-y. This allows to define +/-1 for the x/y parts
of a matrix... 

BTW: having iio on this device is not the primary interface...
But feel free to propose it :)

BR,
Nikolaus