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? > Regards, > > Hans
