OMAPDSS: DISPC: Support rotation through TILER
TILER is a block in OMAP4's DMM which lets DSS fetch frames in a rotated manner. Physical memory can be mapped to a portion of OMAP's system address space called TILER address space. The TILER address space is split into 8 views. Each view represents a rotated or mirrored form of the mapped physical memory. When a DISPC overlay's base address is programmed to one of these views, the TILER fetches the pixels according to the orientation of the view. A view is further split into 4 containers, each container holds elements of a particular size. Rotation can be achieved at the granularity of elements in the container. For more information on TILER, refer to the Memory Subsytem section in OMAP4 TRM. Rotation type TILER has been added which is used to exploit the capabilities of these 8 views for performing various rotations. When fetching from addresses mapped to TILER space, the DISPC DMA can fetch pixels in either 1D or 2D bursts. The fetch depends on which TILER container we are accessing. Accessing 8, 16 and 32 bit sized containers requires 2D bursts, and page mode sized containers require 1D bursts. The DSS2 user is expected to provide the Tiler address of the view that it is interested in. This is passed to the paddr and p_uv_addr parameters in omap_overlay_info. It is also expected to provide the stride value based on the view's orientation and container type, this should be passed to the screen_width parameter of omap_overlay_info. In calc_tiler_rotation_offset screen_width is used to calculate the required row_inc for DISPC. x_predecim and y_predecim are also used to calculate row_inc and pix_inc thereby adding predecimation support for TILER. Signed-off-by: NChandrabhanu Mahapatra <cmahapatra@ti.com> Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Showing
想要评论请 注册 或 登录