drm/i915/dmc: Create debugfs entry for dc6 counter

Starting from MTL we don't have a platform agnostic way to validate
DC6 state due to dc6 counter has been removed to validate DC state.

The goal is to validate that the display HW can reach the DC6 power
state. There is no HW DC6 residency counter (and there wasn't such
a counter earlier either), so an alternative way is required. According
to the HW team the display driver has programmed everything correctly in
order to allow the DC6 power state if the DC5 power state is reached
(indicated by the HW DC5 residency counter incrementing) and DC6 is
enabled by the driver.

Driver could take a snapshot of the DC5 residency counter right
after it enables DC6 (dc5_residency_start) and increment the SW
DC6 residency counter right before it disables DC6 or when user space
reads the DC6 counter. So the driver would update the counter at these
two points in the following way:
dc6_residency_counter += dc5_current_count - dc5_start_count

v2: Update the discription. (Imre)
    Read dc5 count during dc6 enable and disable then and update
    dc6 residency counter. (Imre)
    Remove variable from dmc structure. (Jani)
    Updated the subject title.
v3: Add i915_power_domains lock to updated dc6 count in debugfs. (Imre)
    Use flags to check dc6 enable/disable states. (Imre)
    Move the display version check and counter read/update to
    a helper. (Imre)
    Resize the variable length. (Rodrigo)
    Use old dc6 debugfs entry for every platform. (Rodrigo)
v4: Remove superfluous whitespace. (Jani)
    Read DMC registers in intel_dmc.c (Jani)
    Rename dc6_en_dis to dc6_enabled and change its type to bool. (Jani)
    Rename update_dc6_count and move it to intel_dmc.c (Jani)
    Rename dc6_en_dis to start_tracking. (Imre)
    Have lock for dc6 state read aswelll. (Imre)
    Keep the existing way print 'DC5 -> DC6 count' along with
    new 'DC6 Allowed Count' print. (Imre)
    Add counters in intel_dmc struct. (Imre)
    Have interface to return dc6 allowed count. (Imre)
    Rename dc6_count to dc6_allowed_count. (Rodrigo)
v5: Rename counters and move in to dc6_allowed structure. (Imre)
    Order declaration lines in decreasing line length. (Imre)
    Update start_tacking logic. (Imre)
    Move get couner inside lock and DISPLAY_VER code to helper. (Imre)
v6: Change intel_dmc_get_dc6_allowed_count return type to bool. (Imre)
    Update debugfs print to better allien with old print. (Imre)
    Remove braces at if/else for signle line statements. (Imre)
v7: Remove in line variable declaration. (Imre)
v8: Rebase the changes.

Signed-off-by: Mohammed Thasleem <mohammed.thasleem@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250321123707.287745-1-mohammed.thasleem@intel.com

0 files changed, 0 insertions, 0 deletions