Le samedi 15 juillet 2017 à 12:42 +0300, Laurent Pinchart a écrit : > Hi Jacob, > > Thank you for the patch. > > On Saturday 15 Jul 2017 14:58:36 Jacob Chen wrote: > > Rockchip RGA is a separate 2D raster graphic acceleration unit. It > > accelerates 2D graphics operations, such as point/line drawing, image > > scaling, rotation, BitBLT, alpha blending and image blur/sharpness. > > > > The drvier is mostly based on s5p-g2d v4l2 m2m driver. > > And supports various operations from the rendering pipeline. > > - copy > > - fast solid color fill > > - rotation > > - flip > > - alpha blending > > I notice that you don't support the drawing operations. How do you plan to > support them later through the V4L2 M2M API ? I hate stating the obvious, but > wouldn't the DRM API be better fit for a graphic accelerator ? It could fit, maybe, but it really lacks some framework. Also, DRM is not really meant for M2M operation, and it's also not great for multi- process. Until recently, there was competing drivers for Exynos, both implemented in V4L2 and DRM, for similar rational, all DRM ones are being deprecated/removed. I think 2D blitters in V4L2 are fine, but they terribly lack something to differentiate them from converters/scalers when looking up the HW list. Could be as simple as a capability flag, if I can suggest. For the reference, the 2D blitter on IMX6 has been used to implement a live video mixer in GStreamer. https://bugzilla.gnome.org/show_bug.cgi?id=772766 > > Additionally, V4L2 M2M has one source and one destination. How do you > implement alpha blending in that case, which by definition requires at least > two sources ? This type of HW only do in-place blits. When using such a node, the buffer queued on the V4L2_CAPTURE contains the destination image, and the buffer queued on the V4L2_OUTPUT is the source image. > > > The code in rga-hw.c is used to configure regs accroding to operations. > > > > The code in rga-buf.c is used to create private mmu table for RGA. > > The tables is stored in a list, and be removed when buffer is cleanup. > > Looking at the implementation it seems to be a scatter-gather list, not an > MMU. Is that right ? Does the hardware documentation refer to it as an MMU ? > > > Signed-off-by: Jacob Chen <jacob-chen@xxxxxxxxxx> > > --- > > drivers/media/platform/Kconfig | 11 + > > drivers/media/platform/Makefile | 2 + > > drivers/media/platform/rockchip-rga/Makefile | 3 + > > drivers/media/platform/rockchip-rga/rga-buf.c | 122 ++++ > > drivers/media/platform/rockchip-rga/rga-hw.c | 652 ++++++++++++++++++ > > drivers/media/platform/rockchip-rga/rga-hw.h | 437 ++++++++++++ > > drivers/media/platform/rockchip-rga/rga.c | 958 +++++++++++++++++++++++ > > drivers/media/platform/rockchip-rga/rga.h | 111 +++ > > 8 files changed, 2296 insertions(+) > > create mode 100644 drivers/media/platform/rockchip-rga/Makefile > > create mode 100644 drivers/media/platform/rockchip-rga/rga-buf.c > > create mode 100644 drivers/media/platform/rockchip-rga/rga-hw.c > > create mode 100644 drivers/media/platform/rockchip-rga/rga-hw.h > > create mode 100644 drivers/media/platform/rockchip-rga/rga.c > > create mode 100644 drivers/media/platform/rockchip-rga/rga.h > >
