Sebastian Reichel

Motorola Droid 4 - Automated Tests

I would like being able to test patches on the Droid 4 without having to carry a development phone around all the time. Testing on my day-to-day phone is not a good idea, since that means being offline during the tests. A simple solution would be to do the testing remotely, which should also allow doing automated tests for KernelCI. Unfortunatley doing this on a phone is a bit harder than on an average development board due to the hardware design. Read more →

Motorola Droid 4 - Camera Info

Multiple people asked camera related questions during my talk as FOSDEM (and after it). I did some basic reverse engineering, so let me share what I know. The Droid 4 works with a OMAP4430, which has a imaging subsystem (ISS). It is documented quite well in the datasheet and there is a Linux kernel driver available in staging (omap4iss), which was written by Laurent Pinchart (thanks!). This module provides two MIPI CSI-2 interfaces to connect camera sensors. Read more →


I gave a talk at FOSDEM about the current mainline kernel support for the Droid 4 and its open issues. If you follow this blog you probably already know the information I presented and I’m not a good presenter (sorry!). If you are interested anyways, you can find the recording and my slides on the following here: Slides Video Recording (mp4) Video Recording (WebM/VP9) Video Recording (Youtube) – Sebastian Read more →

Collabora & Linux Kernel 4.13

Linux kernel v4.13 was released and - like in the v4.12 release - 12 Collabora developers contributed a total of 72 patches. In addition Collabora developers provided 25 Reviewed-by tags and 10 Tested-by tags. Furthermore 83 patches received a Signed-off-by tag from Collabora peoples. Again, general information about the merge window is available by in form of the following articles: part 1 and part 2. Now here is a look at the specific changes made by Collaborans. Read more →

Motorola Droid 4 - August Update

It has been some time since my last post about the Droid 4. 4.13 will most likely be released next week, so let’s have a look at newly added features related to the Droid 4: crypto acceleration for AES and 3DES support for ISL29030 (proximity and ambient light sensor) USB phy support battery monitoring support bluetooth Unfortunately the list for 4.14 will be a lot shorter (or even empty), since most other submissions are still in review (or need work). Read more →

Motorola Droid 4 - Update

The 4.12 merge window will most likely close on Sunday, so its a good time to check the Droid 4 status matrix. This merge window lots of changes were queued: New drivers: real time clock (RTC), power button, analogue digital converter (ADC), battery charger, LEDs (RGB, capslock status, android buttons) DTS additions: LCD (no driver yet), HDMI, Keyboard/LCD backlight (no driver yet), Touchscreen, Temperature sensor, Accelerometer, Compass, Regulators, RTC, Power button, ADC, USB PHY (no driver yet), Battery charger, LEDs, Keyboard, Poweroff, USB configuration for modems Read more →