Hey Martin, so sorry for forgetting about this. On Thu, Apr 18, 2019 at 9:50 PM Martin Blumenstingl <[email protected]> wrote: > > Hi Maxime, > > On Sat, Apr 13, 2019 at 8:54 PM Maxime Jourdan <[email protected]> > wrote: > > > > Hi Martin, > > On Sat, Apr 13, 2019 at 7:15 PM Martin Blumenstingl > > <[email protected]> wrote: > > > > > > This adds the canvas module on Meson8, Meson8b and Meson8m2. The canvas > > > IP is used by the video decoder hardware as well as the VPU (video > > > output) hardware. > > > > > > Neither the VPU nor the video decoder driver support the 32-bit SoCs > > > yet. However, we can still add the canvas module to have it available > > > once these drivers gain support for the older SoCs. > > > > > > I have tested this on my Meson8m2 board by hacking the VPU driver to > > > not re-initialize the VPU (and to use the configuration set by u-boot). > > > With that hack I could get some image out of the CVBS connector. No > > > changes to the canvas driver were required. > > > > > > Due to lack of hardware I could not test Meson8, but I'm following (as > > > always) what the Amlogic 3.10 vendor kernel uses. > > > Meson8b is also not tested because u-boot of my EC-100 doesn't have > > > video output enabled (so I couldn't use the same hack I used on my > > > Meson8m2 board). > > > > > > This series meant to be applied on top of "Meson8b: add support for the > > > RTC on EC-100 and Odroid-C1" from [0] > > > > > > > > > > The series looks good to me, however I wonder if we should maybe add a > > new compatible ? > > > > The canvas IP before the GX* generation does not handle what Amlogic > > calls "endianness", the field that allows doing some byte-switching to > > get proper NV12/NV21. So the following defines are unusable: > > > > #define MESON_CANVAS_ENDIAN_SWAP16 0x1 > > #define MESON_CANVAS_ENDIAN_SWAP32 0x3 > > #define MESON_CANVAS_ENDIAN_SWAP64 0x7 > > #define MESON_CANVAS_ENDIAN_SWAP128 0xf > I didn't know about this - thank you for pointing this out. > > your suggestions to add new compatible strings is a good idea for that case. > Amlogic uses different defines for Meson8 and Meson8m2 in their vendor > kernel and they keep Meson8b different. > I will add three new compatibles, one for each SoC (Meson8, Meson8b, > Meson8m2) just to be on the safe side if we discover differences in > the canvas IP on these SoCs. > > what do you think? >
Sure thing. Keep an eye out for any hints regarding the amount of canvases as well, I *think* I remember some old SoCs having only 192 but I haven't been able to find it again. > > It wouldn't change much functionally, but we could have e.g a warning > > if a m8 canvas user tries to set endianness even though it does > > nothing. > this is a good idea, that will make it easier to spot why something > doesn't work. > we can also return -EINVAL, like you already do for the case where the > canvas ID is already used. > Yes, returning an error is a good idea. Maxime > > Martin
