lib/igt_amd: add helpers to check PSR capibility

[why]
For AMDGPU devices, the debugfs interface to check sink PSR cap
is a bit different from that of i915, i.e. the interface is located
in the path
<debugfs_root>/dri/0/eDP-X/psr_capability
where 'X' is eDP connector index.

We need such debugfs interface to check if the sink device and the
x86 driver supports PSR or PSR-SU capabilities.

[how]
define and add the helpers to read from connector debugfs interface

For sink device PSR cap check:
- for PSR1 device, the psr version DPCD be 0x1
- for PSR-SU device, the psr version DPCD be either 0x3 or 0x4.

For amdgpu x86 driver PSR support check:
- for PSR1, expect to contain sub-string "yes"
- for PSR-SU, expect to contain sub-string "yes [0x1]"

changes in v2
-------------------
* fix the typo in string comp within the helper to read from
  psr cap debugfs interface

Cc: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Cc: Wayne Lin <wayne.lin@amd.com>

Signed-off-by: David Zhang <dingchen.zhang@amd.com>
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>

0 files changed, 0 insertions, 0 deletions