Dear all, This is an updated proposal for extending EXYNOS DRM API with generic support for hardware modules, which can be used for processing image data from the one memory buffer to another. Typical memory-to-memory operations are: rotation, scaling, colour space conversion or mix of them. This is a follow-up of my previous proposal "[RFC 0/2] New feature: Framebuffer processors", which has been rejected as "not really needed in the DRM core": http://www.mail-archive.com/dri-devel@xxxxxxxxxxxxxxxxxxxxx/msg146286.html In this proposal I moved all the code to Exynos DRM driver, so now this will be specific only to Exynos DRM. I've also changed the name from framebuffer processor (fbproc) to picture processor (pp) to avoid confusion with fbdev API. Here is a bit more information what picture processors are: Embedded SoCs are known to have a number of hardware blocks, which perform such operations. They can be used in paralel to the main GPU module to offload CPU from processing grapics or video data. One of example use of such modules is implementing video overlay, which usually requires color space conversion from NV12 (or similar) to RGB32 color space and scaling to target window size. The proposed API is heavily inspired by atomic KMS approach - it is also based on DRM objects and their properties. A new DRM object is introduced: picture processor (called pp for convenience). Such objects have a set of standard DRM properties, which describes the operation to be performed by respective hardware module. In typical case those properties are a source fb id and rectangle (x, y, width, height) and destination fb id and rectangle. Optionally a rotation property can be also specified if supported by the given hardware. To perform an operation on image data, userspace provides a set of properties and their values for given fbproc object in a similar way as object and properties are provided for performing atomic page flip / mode setting. The proposed API consists of the 3 new ioctls: - DRM_IOCTL_EXYNOS_PP_GET_RESOURCES: to enumerate all available picture processors, - DRM_IOCTL_EXYNOS_PP_GET: to query capabilities of given picture processor, - DRM_IOCTL_EXYNOS_PP_COMMIT: to perform operation described by given property set. The proposed API is extensible. Drivers can attach their own, custom properties to add support for more advanced picture processing (for example blending). This proposal aims to replace Exynos DRM IPP (Image Post Processing) subsystem. IPP API is over-engineered in general, but not really extensible on the other side. It is also buggy, with significant design flaws - the biggest issue is the fact that the API covers memory-2-memory picture operations together with CRTC writeback and duplicating features, which belongs to video plane. Comparing with IPP subsystem, the PP framework is smaller (1807 vs 778 lines) and allows driver simplification (Exynos rotator driver smaller by over 200 lines). Open questions: - How to expose pp capabilities and supported formats? Currently this is done with a drm_exynos_pp_get structure and DRM_IOCTL_EXYNOS_PP_GET ioctl. However one can try to use IMMUTABLE properties for capabilities and src/dst format set. Rationale: recently Rob Clark proposed to create a DRM property with supported pixelformats and modifiers: http://www.spinics.net/lists/dri-devel/msg137380.html - Is it okay to use DRM objects and properties API (DRM_IOCTL_MODE_GETPROPERTY and DRM_IOCTL_MODE_OBJ_GETPROPERTIES ioctls) for this purpose? TODO: - convert remaining Exynos DRM IPP drivers (FIMC, GScaller) - remove Exynos DRM IPP subsystem - (optional) provide virtual V4L2 mem2mem device on top of Exynos PP framework Patches were tested on Exynos 4412-based Odroid U3 board, on top of Linux next-20170420 kernel. Best regards Marek Szyprowski Samsung R&D Institute Poland Changelog: v1: - moved this feature from DRM core to Exynos DRM driver - changed name from framebuffer processor to picture processor - simplified code to cover only things needed by Exynos drivers - implemented simple fifo task scheduler - cleaned up rotator driver conversion (removed IPP remainings) v0: http://www.mail-archive.com/dri-devel@xxxxxxxxxxxxxxxxxxxxx/msg146286.html - initial post of "[RFC 0/2] New feature: Framebuffer processors" - generic approach implemented in DRM core, rejected Patch summary: Marek Szyprowski (4): drm: Export functions to create custom DRM objects drm: Add support for vendor specific DRM objects with custom properties drm/exynos: Add Picture Processor framework drm/exynos: Convert Exynos Rotator driver to Picture Processor interface drivers/gpu/drm/drm_crtc_internal.h | 4 - drivers/gpu/drm/drm_mode_object.c | 11 +- drivers/gpu/drm/drm_property.c | 2 +- drivers/gpu/drm/exynos/Kconfig | 1 - drivers/gpu/drm/exynos/Makefile | 3 +- drivers/gpu/drm/exynos/exynos_drm_drv.c | 9 + drivers/gpu/drm/exynos/exynos_drm_drv.h | 15 + drivers/gpu/drm/exynos/exynos_drm_pp.c | 775 ++++++++++++++++++++++++++++ drivers/gpu/drm/exynos/exynos_drm_pp.h | 155 ++++++ drivers/gpu/drm/exynos/exynos_drm_rotator.c | 513 +++++------------- drivers/gpu/drm/exynos/exynos_drm_rotator.h | 19 - include/drm/drm_mode_object.h | 6 + include/drm/drm_property.h | 7 + include/uapi/drm/drm_mode.h | 1 + include/uapi/drm/exynos_drm.h | 62 +++ 15 files changed, 1166 insertions(+), 417 deletions(-) create mode 100644 drivers/gpu/drm/exynos/exynos_drm_pp.c create mode 100644 drivers/gpu/drm/exynos/exynos_drm_pp.h delete mode 100644 drivers/gpu/drm/exynos/exynos_drm_rotator.h -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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