On Mon, Aug 01, 2011 at 12:52:37PM +0900, daeinki wrote: > Hi, Sascha Hauer. > thank you for your comments and below is my answer. > > Sascha Hauer wrote: > >Hi, > > > >On Fri, Jul 29, 2011 at 04:24:35PM +0900, Inki Dae wrote: > >>This patch is a DRM Driver(only including FIMD Driver yet) > >>for Samsung SoC Exynos4210. and as RFC, I am sending only DRM driver part. > >> > >>this patch is based on git repository below: > >>git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6.git, > >>branch: drm-next > >>commit-id: 5a96a899bbdee86024ab9ea6d02b9e242faacbed > >> > >>We tried to re-use lowlevel codes of the FIMD driver(s3c-fb.c > >>based on Linux framebuffer) but couldn't so because lowlevel codes > >>of s3c-fb.c are included internally and so this driver shares only > >>platform device. > >> > >>Sub drivers such as fimd or hdmi have indenpendent platform device and > >>Platform driver and when driver's probe is called, the driver object > >>including callbacks(for hardware control) would be registered to > >>Samsung drm driver. and then when samsung drm driver is probed, > >>each probe callback of the driver object registered is called so that > >>additional callbacks for drm framework would be set at this time. > >> > >>We used GEM framework for buffer management and this driver supports > >>only physically continuous memory yet(non-iommu). and for buffer allocation, > >>we used DMA APIs(dma_alloc_writecombine) but we will change it to CMA > >>instead > >>of DMA APIs later. > >> > >>Refer to this link for CMA(Continuous Memory Allocator): > >>http://lkml.org/lkml/2011/7/20/45 > >> > >>Future works: > >>- HDMI support. > >>- drm plane feature support. > >> refer to this link for drm plane feature: > >> http://www.spinics.net/lists/dri-devel/msg11778.html > >>- change the allocator to CMA. > >>- iommu support.(for non-continuous physical memory usage) > >>- fimd driver update. > >>- add exception codes and code clean. > >> > >>to support all features above, we need long time and hard work. > >>so we wish that only some features(fimd and non-iommu) are applied to > >>mainline first. > >> > >>We would be pleased you to give us your comments. > > > >So far I only had a quick look over the driver. You might know that > >I wrote a Freescale i.MX drm driver which I posted to the list some time > >ago. > > > >My driver lacks GEM support which your driver has, so I specifically > >looked at this part. It seems we could reuse the GEM code on i.MX and > >probably on most other ARMs aswell. Can you split out this code > >and remove the samsung_ namespace? > > > By any chance, you mean drm_gem_free_mmap_offset()? > this patch had already been posted by Rob Clark, Omap TI as RFC. > > you can refer to this link for it. > http://www.spinics.net/lists/dri-devel/msg13018.html > > if so, I am aware of it but his patch isn't applied to drm-next yet > and so my drm driver doesn't include his patch. of course I will > reuse it and remove the samsung_ namespace as you pointed out if the > patch is applied to drm-next.
Not only. I meant the full content of samsaung_drm_gem.c, samsung_drm_buf.c and maybe even samsung_drm_fb.c. Except for the samsung namespace these functions could look the same on i.MX and other dumb framebuffer drm drivers. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
