On 06/15/17 14:29, Dave Stevenson wrote: > On 15 June 2017 at 08:17, Hans Verkuil <hverkuil@xxxxxxxxx> wrote: >> On 06/14/2017 11:03 PM, Dave Stevenson wrote: >>> >>> On 14 June 2017 at 18:38, Hans Verkuil <hverkuil@xxxxxxxxx> wrote: >>>> >>>> On 06/14/2017 06:29 PM, Dave Stevenson wrote: >>>>> >>>>> >>>>> Hi Hans. >>>>> >>>>> On 14 June 2017 at 16:42, Hans Verkuil <hverkuil@xxxxxxxxx> wrote: >>>>>> >>>>>> >>>>>> Hi Dave, >>>>>> >>>>>> How does this driver relate to this staging driver: >>>>>> >>>>>> drivers/staging/vc04_services/bcm2835-camera/ >>>>>> >>>>>> It's not obvious to me. >>>>> >>>>> >>>>> >>>>> drivers/staging/vc04_services/bcm2835-camera/ is using the VideoCore >>>>> firmware to control Unicam, ISP, and all the tuner algorithms. The ARM >>>>> gets delivered fully processed buffers from the VideoCore side. The >>>>> firmware only has drivers for the Omnivision OV5647 and Sony IMX219 >>>>> (and an unsupported one for the Toshiba TC358743). >>>>> >>>>> This driver is solely the Unicam block, reading the data in over >>>>> CSI2/CCP2 from the sensor and writing it to memory. No ISP or control >>>>> loops. >>>>> Other than power management, this driver is running solely on the ARM >>>>> with no involvement from the VideoCore firmware. >>>>> The sensor driver is whatever suitable V4L2 subdevice driver you fancy >>>>> attaching (as long as it supports CSI2, or eventually CCP2). >>>> >>>> >>>> >>>> What is the interaction between these two drivers? Can they co-exist? >>>> I would expect them to be mutually exclusive. >>> >>> >>> Mutually exclusive for the same Unicam instance, yes. >>> >>> There are two Unicam instances on all BCM283x chips and both are >>> brought out on the Compute Modules. You could run bcm2835-unicam on >>> one and bcm2835-camera on the other if you so wished. >>> The firmware checks whether the csi nodes in the device tree are >>> active, and won't touch them if they are. >> >> >> It would be good if this explanation is mentioned both in the driver code >> and (I think) in the bindings document of *both* drivers. This setup is >> unusual, so some extra documentation isn't amiss. > > OK, will add it to this driver for V2. > The other driver cleanups are on my to-do list. Would you object > horrendously if I deferred adding the explanation to that driver to > when I'm doing those cleanups? That's OK. Just mention in the cover letter of the v2 patch series that you are planning to do this. Hans
