drm/i915/gmbus: Add Wa_16025573575 for PTL/WCL for bit-bashing

As per Wa_16025573575 for PTL/WCL, set the GPIO masks bit before starting
bit-bashing and maintain value through the bit-bashing sequence. After the
bit-bashing sequence is done, clear the GPIO masks bits.

v2:
-Use new helper for display workarounds. (Jani)
-Use a separate if-block for the workaround. (Gustavo)

v3:
-Document the workaround details in intel_display_wa.c
-Extend the workaround to WCL too. (Gustavo)

v4:
-Fix the platform check. (Gustavo)
-Avoid read when preserve bits are 0. (Gustavo)

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://lore.kernel.org/r/20250715142211.3145299-1-ankit.k.nautiyal@intel.com

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_display_wa.h b/drivers/gpu/drm/i915/display/intel_display_wa.h
index 8319e16eb460..aedea4cfa3ce 100644
--- a/drivers/gpu/drm/i915/display/intel_display_wa.h
+++ b/drivers/gpu/drm/i915/display/intel_display_wa.h
@@ -23,6 +23,7 @@ bool intel_display_needs_wa_16023588340(struct intel_display *display);
 
 enum intel_display_wa {
 	INTEL_DISPLAY_WA_16023588340,
+	INTEL_DISPLAY_WA_16025573575,
 };
 
 bool __intel_display_wa(struct intel_display *display, enum intel_display_wa wa, const char *name);