Freescale Semiconductor i.MX 6SoloLite Linux, Справочное руководство

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In automatic mode, updates are generated automatically by the driver by detecting pages
in frame buffer memory region that have been modified.
MXCFB_SET_UPDATE_SCHEME / mxc_epdc_fb_set_upd_scheme
Description:
Select a scheme that dictates how the flow of updates within the driver.
Parameters:
__u32 scheme
Select of the following updates schemes:
UPDATE_SCHEME_SNAPSHOT - In the Snapshot update scheme, the contents of the
framebuffer are immediately processed and stored in a driver-internal memory buffer. By
the time the call to MXCFB_SEND_UPDATE has completed, the framebuffer region is
free and can be modified without affecting the integrity of the last update. If the update
frame submission is delayed due to other pending updates, the original buffer contents
will be displayed when the update is finally submitted to the EPDC hardware. If the
update results in a collision, the original update contents will be resubmitted when the
collision has cleared.
UPDATE_SCHEME_QUEUE - The Queue update scheme uses a work queue to
aynchronously handle the processing and submission of all updates. When an update is
submitted via MXCFB_SEND_UPDATE, the update is added to the queue and then
processed in order as EPDC hardware resources become available. As a result, the
framebuffer contents processed and updated are not guaranteed to reflect what was
present in the framebuffer when the update was sent to the driver.
UPDATE_SCHEME_QUEUE_AND_MERGE - The Queue and Merge scheme uses the
queueing concept from the Queue scheme, but adds a merging step. This means that,
before an update is processed in the work queue, it is first compared with other pending
updates. If any update matches the mode and flags of the current update and also overlaps
the update region of the current update, then that update will be merged with the current
update. After attempting to merge all pending updates, the final merged update will be
processed and submitted.
MXCFB_SEND_UPDATE / mxc_epdc_fb_send_update
Description:
Request a region of the frame buffer be updated to the display.
Parameters:
mxcfb_update_data *upd_data
Chapter 5 Electrophoretic Display Controller (EPDC) Frame Buffer Driver
i.MX 6SoloLite Linux Reference Manual, Rev. L3.0.35_4.1.0, 09/2013
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