Extend detect_cvt/gtf API to indicate the format type (interlaced
or progressive). In case of interlaced, the vertical front and back
porch and vsync values for both (odd,even) fields are considered to
derive image height. Populated vsync, vertical front, back porch
values in bt timing structure for even and odd fields and updated
the flags appropriately.

Also modified the functions calling the detect_cvt/gtf(). As of now
these functions are calling detect_cvt/gtf() with interlaced flag
set to false.

Cc: Martin Bugge <marbugge@cisco.com>
Cc: Mats Randgaard <matrandg@cisco.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NPrashant Laddha <prladdha@cisco.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The v4l2_print_dv_timings() didn't log the interlaced format correctly. The timings
for the bottom field weren't logged and the fields per second value was half of what
it should have been.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Currently, in gtf hblank calculations, the rounding is used twice,
one at intermediate division and one at final state where hblank
is rounded to nearest multiple of twice cell granularity. This
error got introduced in 'commit d7ed5a3d ("[media]
v4l2-dv-timings: fix rounding in hblank and hsync calculation"),
where it missed combining the rounding step. Correcting the same
in this patch.
Signed-off-by: NPrashant Laddha <prladdha@cisco.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The intermediate calculation in the expression for hblank can exceed
32 bit signed range. This overflow can lead to negative values for
hblank. Typecasting intermediate variable to higher precision.

Cc: Martin Bugge <marbugge@cisco.com>
Signed-off-by: NPrashant Laddha <prladdha@cisco.com>
[hans.verkuil@cisco.com: made the denominator u32, since that's what div_u64 expects]
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

This change will not change timing calculation. In CVT generator
spreadsheet the nominal value of hsync (as a percentage of line)
is 8 percent.

Cc: Martin Bugge <marbugge@cisco.com>
Signed-off-by: NPrashant Laddha <prladdha@cisco.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Wrong values of hfreq and image height can lead to strange timings.
Avoid timing calculations for such values.

Suggested By: Martin Bugge <marbugge@cisco.com>

Cc: Martin Bugge <marbugge@cisco.com>
Signed-off-by: NPrashant Laddha <prladdha@cisco.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Changed the rounding calculation for hblank and hsync to match it
to equations in cvt and gtf standards.

In cvt calculation, hsync needs to be rounded down.

In gtf calculations, hblank needs to be rounded to nearest multiple
of twice the cell granularity and hsync needs to be rounded to the
nearest multiple of cell granularity.

Cc: Martin Bugge <marbugge@cisco.com>
Signed-off-by: NPrashant Laddha <prladdha@cisco.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Changed the rounding offsets used in vsync_bp calculation in cvt and
gtf timings. The results for vsync_bp should now match with results
from timing generator spreadsheets for cvt and gtf standards.

In the vsync_bp calculation for cvt, always round down the value of
(CVT_MIN_VSYNC_BP / h_period_est) and then add 1. It thus, reflects
the equation used in timing generator spreadsheet. Using 1999999 as
rounding offset, could pontentially lead to bumping up the vsync_bp
value by extra 1.

In the vsync_bp calculations for gtf, instead of round up or round
down, round the (CVT_MIN_VSYNC_BP / h_period_est) to the nearest
integer.

Thanks to Martin Bugge <marbugge@cisco.com> for validating with
standards and suggestions on equations.

Cc: Martin Bugge <marbugge@cisco.com>
Signed-off-by: NPrashant Laddha <prladdha@cisco.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add support for the new flag to v4l2_print_dv_timings().
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

If one or both of the timings being compared have the standards field
with value 0, then accept that. Only check for matching standards if
both timings have actually filled in that field.

Otherwise no match will ever be found since when timings are detected
the standards field will typically be set to 0 by the driver.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Wrong value used in same cases for the aspect ratio.
Signed-off-by: NRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Acked-by: NLad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: stable@vger.kernel.org      # for v3.12 and up
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

Add the new CEA-861-F and DMT 4K timings to the list of predefined
timings.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

I completely forgot to add them when I made this module. Loading this module
without it will taint the kernel, which is not intended.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Cc: stable@vger.kernel.org      # for v3.12 and up
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

The VESA standard added a version 2 of the reduced blanking formula.
Note in the comment that this is not yet supported by the v4l2_detect_cvt
function. Obviously this should be implemented eventually, but for now add
this as a reminder.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

Round off image width to nearest 8 (GTF_CELL_GRAN)

A source sending a GTF (Generalized Timing Formula) format have no means of
signalling image width. The assumed aspect ratio may result in an odd image
width but according to the standard image width should be in multiple of 8.

Cc: Mats Randgaard <matrandg@cisco.com>
Signed-off-by: NMartin Bugge <marbugge@cisco.com>
Reviewed-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

In most cases the v4l2_bt_timings_cap struct has all the information
necessary to determine valid timings, but occasionally there are exceptions.
Add a callback function to be able to test for those exceptions.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

All other functions follow the v4l2_<foo>_dv_timings pattern, do the same for
this function.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

Some drivers need to be able to access the full list of timings.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

The detect_cvt/gtf functions didn't fill in the type field.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

It's the only function in v4l2-dv-timings.c with the v4l prefix instead
of v4l2. Make it consistent with the other functions.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

Drivers often have to log the contents of a dv_timings struct. Adding
this helper will make it easier for drivers to do so.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

This patch fixes two errors that caused incorrect format detections:
The first bug is in the calculation of the vertical backporch: the combined
period of vsync and backporch must *exceed* a certain minimum value, and not
be equal to it.
The second bug is a rounding error in the reduced blanking calculation:
expand the ideal_duty_cylce to be in parts per ten thousand to avoid
rounding errors.
Signed-off-by: NMartin Bugge <marbugge@cisco.com>
Cc: Mats Randgaard <matrandg@cisco.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

v4l2-common.c contained a bunch of dv-timings related functions.
Move that to the new v4l2-dv-timings.c which is a more appropriate
place for them.
There aren't many drivers that do HDTV, so it is a good idea to separate
common code related to that into a module of its own.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NLad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

This module makes it easy to filter valid timings from the full list of
CEA and DMT timings based on the timings capabilities.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NLad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>