From: Konstantin Kozhevnikov <Konstantin.Kozhevnikov@xxxxxxxxxxxxxxxxxx>
The image renderer, or the distortion correction engine, is a drawing
processor with a simple instruction system capable of referencing video
capture data or data in an external memory as the 2D texture data and
performing texture mapping and drawing with respect to any shape that is
split into triangular objects.
This V4L2 memory-to-memory device driver only supports image renderer light
extended 4 (IMR-LX4) found in the R-Car gen3 SoCs; the R-Car gen2 support
can be added later...
[Sergei: merged 2 original patches, added the patch description, removed
unrelated parts, added the binding document and the UAPI documentation,
ported the driver to the modern kernel, renamed the UAPI header file and
the guard macros to match the driver name, extended the copyrights, fixed
up Kconfig prompt/depends/help, made use of the BIT/GENMASK() macros,
sorted #include's, replaced 'imr_ctx::crop' array with the 'imr_ctx::rect'
structure, replaced imr_{g|s}_crop() with imr_{g|s}_selection(), completely
rewrote imr_queue_setup(), removed 'imr_format_info::name', moved the
applicable code from imr_buf_queue() to imr_buf_prepare() and moved the
rest of imr_buf_queue() after imr_buf_finish(), assigned 'src_vq->dev' and
'dst_vq->dev' in imr_queue_init(), removed imr_start_streaming(), assigned
'src_vq->dev' and 'dst_vq->dev' in imr_queue_init(), clarified the math in
imt_tri_type_{a|b|c}_length(), clarified the pointer math and avoided casts
to 'void *' in imr_tri_set_type_{a|b|c}(), replaced imr_{reqbufs|querybuf|
dqbuf|expbuf|streamon|streamoff}() with the generic helpers, implemented
vidioc_{create_bufs|prepare_buf}() methods, used ALIGN() macro and merged
the matrix size checks and replaced kmalloc()/copy_from_user() calls with
memdup_user() call in imr_ioctl_map(), moved setting device capabilities
from imr_querycap() to imr_probe(), set the valid default queue format in
imr_probe(), removed leading dots and fixed grammar in the comments, fixed
up the indentation to use tabs where possible, renamed DLSR, CMRCR.
DY1{0|2}, and ICR bits to match the manual, changed the prefixes of the
CMRCR[2]/TRI{M|C}R bits/fields to match the manual, removed non-existent
TRIMR.D{Y|U}D{X|V}M bits, added/used the IMR/{UV|CP}DPOR/SUSR bits/fields/
shifts, separated the register offset/bit #define's, sorted instruction
macros by opcode, removed unsupported LINE instruction, masked the register
address in WTL[2]/WTS instruction macros, moved the display list #define's
after the register #define's, removing the redundant comment, avoided
setting reserved bits when writing CMRCCR[2]/TRIMCR, used the SR bits
instead of a bare number, removed *inline* from .c file, fixed lines over
80 columns, removed useless spaces, comments, parens, operators, casts,
braces, variables, #include's, statements, and even 1 function, added
useful local variable, uppercased and spelled out the abbreviations,
made comment wording more consistent/correct, fixed the comment typos,
reformatted some multiline comments, inserted empty line after declaration,
removed extra empty lines, reordered some local variable desclarations,
removed calls to 4l2_err() on kmalloc() failure, replaced '*' with 'x'
in some format strings for v4l2_dbg(), fixed the error returned by
imr_default(), avoided code duplication in the IRQ handler, used '__packed'
for the UAPI structures, declared 'imr_map_desc::data' as '__u64' instead
of 'void *', switched to '__u{16|32}' in the UAPI header, enclosed the
macro parameters in parens, exchanged the values of IMR_MAP_AUTO{S|D}G
macros.]
