[PATCHv2 0/3] Intel FPGA VIP Frame Buffer II DRM Driver

[Ong, Hean Loong]

On Thu, 2017-05-04 at 10:11 -0700, Eric Anholt wrote:
> "Ong, Hean Loong" <hean.loong.ong at intel.com> writes:
> 
> > 
> > On Wed, 2017-05-03 at 13:28 -0700, Eric Anholt wrote:
> > > 
> > > hean.loong.ong at intel.com writes:
> > > 
> > > > 
> > > > 
> > > > From: Ong Hean Loong <hean.loong.ong at intel.com>
> > > > 
> > > > Hi,
> > > > 
> > > > The new Intel Arria10 SOC FPGA devkit has a Display Port IP
> > > > component 
> > > > which requires a new driver. This is a virtual driver in which
> > > > the
> > > > FGPA hardware would enable the Display Port based on the
> > > > information
> > > > and data provided from the DRM frame buffer from the OS.
> > > > Basically
> > > > all
> > > > all information with reagrds to resolution and bits per pixel
> > > > are
> > > > pre-configured on the FPGA design and these information are fed
> > > > to
> > > > the driver via the device tree information as part of the
> > > > hardware 
> > > > information.
> > > I started reviewing the code, but I want to make sure I
> > > understand
> > > what's going on:
> > > 
> > > This IP core isn't displaying contents from system memory on some
> > > sort
> > > of actual physical display, right?  It's a core that takes some
> > > input
> > > video stream (not described in the DT or in this driver) and
> > > stores
> > > it
> > > to memory?
> > If the IP Core you are referring to is some form of GPU then in
> > this
> > case we are using the Intel FPGA Display Port Framebuffer IP. It
> > does
> > display contents streamed from the ARM/Linux system to the Display
> > Port
> > of the physical Monitor.
> > 
> > Below a simple illustration of the system:
> > 
> > ARM/Linux --DMA-->Intel FPGA Display Port Framebuffer IP
> > 				|
> > 				|
> > 			Physical Connection
> > 			Display Port
> The "DMA" in this diagram is the frame reader IP, right?  The frame
> reader, as described in the spec, sounds approximately like a DRM
> plane,
> so if you have that in your system then that needs to be part of this
> DRM driver (otherwise you won't be putting the right things on the
> screen!).

Would the drm_simple_display_pipe_init be able to handle this ? It
seems to be displaying the proper images on screen, based on my current
changes. There were recommendations to use the
drm_simple_display_pipe_init instead of creating the CRTC and planes
myself