drm/amd/display: Validate hw_points_num before using it

[WHAT]
hw_points_num is 0 before ogam LUT is programmed; however, function
"dwb3_program_ogam_pwl" assumes hw_points_num is always greater than 0,
i.e. substracting it by 1 as an array index.

[HOW]
Check hw_points_num is not equal to 0 before using it.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Revert "drm/amd/display: Validate hw_points_num before using it"

This reverts commit 58c3b3341cea4f75dc8c003b89f8a6dd8ec55e50.

[WHY & HOW]
The writeback series cause a regression in thunderbolt display.

Signed-off-by: Alex Hung <alex.hung@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Validate hw_points_num before using it

[WHAT]
hw_points_num is 0 before ogam LUT is programmed; however, function
"dwb3_program_ogam_pwl" assumes hw_points_num is always greater than 0,
i.e. substracting it by 1 as an array index.

[HOW]
Check hw_points_num is not equal to 0 before using it.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Fix the delta clamping for shaper LUT

The shaper LUT requires a 10-bit value of the delta between segments. We
were using dc_fixpt_clamp_u0d10() to do that but it doesn't do what we
want it to do. It will preserve 10-bit precision after the decimal
point, but that's not quite what we want. We want 14-bit precision and
discard the 4 most-significant bytes.

To do that we'll do dc_fixpt_clamp_u0d14() & 0x3ff instead.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Krunoslav Kovac <krunoslav.kovac@amd.com>
Acked-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: fix incorrect CM/TF programming sequence in dwb

[How]
the programming sequeune was for old asic.
the correct programming sequeunce should be similar to the one
used in mpc. the fix is copied from the mpc programming sequeunce.

Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Signed-off-by: Roy Chan <roy.chan@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Remove unnecessary conversion to bool

Fix the following coccicheck warnings:

./drivers/gpu/drm/amd/display/dc/dcn30/dcn30_dwb_cm.c:220:65-70:
WARNING: conversion to bool not needed here.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Add DCN3 DWB

Add support to program the DCN3 DWB (Display Writeback)

HW Blocks:

+--------++------+ +----------+
| HUBBUB || HUBP | <-- | MMHUBBUB |
+--------++------+ +----------+
| ^
v |
+--------+ +--------+
| DPP | | DWB |
+--------+ +--------+
|
v ^
+--------+ |
| MPC | |
+--------+ |
| |
v |
+-------+ |
| OPP | |
+-------+ |
| |
v |
+--------+ /
| OPTC | --------------
+--------+
|
v
+--------+ +--------+
| DIO | | DCCG |
+--------+ +--------+

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>