This morning, I asked myself why I needed 10 seconds to configure the camera. After looking with the logic analyzer, I saw that the SCCB communication used a 250 Hz frequency.
Flo explained to me that chThdWaitMicroseconds doesn’t work in ChibiOS. Thus, the minimum wait time is 1 ms. Charles had the same problem yesterday. In order to wait a smaller time, he used GPT.
I changed the driver to wait a smaller time with GPT. Now, the time to configure the camera is reasonable.
Here the file : https://gist.github.com/Morikko/523c4e8a5bc85ceef224
chThdSleepMicroseconds works just fine in ChibiOS. The problem is with your system frequency, configurable in chconf.h.