From: Luca Coelho <luciano.coelho@intel.com>
Date: Tue, 24 Mar 2026 08:04:25 +0000 (+0200)
Subject: drm/i915/display: move clock-gating init for IBX to display
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c80c68e777587330e5d89b4c294a32fe7365879c;p=thirdparty%2Flinux.git

drm/i915/display: move clock-gating init for IBX to display

Add a new function in the display code to help initialize clock-gating
without reading display PCH registers directly from non-display code.

This adds a mini-framework to deal with display-specific PCH registers
and uses it for IBX as a start.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patch.msgid.link/20260324080441.154609-2-luciano.coelho@intel.com
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
---

diff --git a/drivers/gpu/drm/i915/display/intel_pch.c b/drivers/gpu/drm/i915/display/intel_pch.c
index 65359a36df483..65812b720bda1 100644
--- a/drivers/gpu/drm/i915/display/intel_pch.c
+++ b/drivers/gpu/drm/i915/display/intel_pch.c
@@ -5,6 +5,8 @@
 
 #include <drm/drm_print.h>
 
+#include "intel_de.h"
+#include "intel_display_regs.h"
 #include "intel_display_core.h"
 #include "intel_display_utils.h"
 #include "intel_pch.h"
@@ -214,6 +216,28 @@ intel_pch_type(const struct intel_display *display, unsigned short id)
 	}
 }
 
+static void intel_pch_ibx_init_clock_gating(struct intel_display *display)
+{
+	/*
+	 * On Ibex Peak and Cougar Point, we need to disable clock
+	 * gating for the panel power sequencer or it will fail to
+	 * start up when no ports are active.
+	 */
+	intel_de_write(display, SOUTH_DSPCLK_GATE_D,
+		       PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
+}
+
+void intel_pch_init_clock_gating(struct intel_display *display)
+{
+	switch (INTEL_PCH_TYPE(display)) {
+	case PCH_IBX:
+		intel_pch_ibx_init_clock_gating(display);
+		break;
+	default:
+		break;
+	}
+}
+
 static bool intel_is_virt_pch(unsigned short id,
 			      unsigned short svendor, unsigned short sdevice)
 {
diff --git a/drivers/gpu/drm/i915/display/intel_pch.h b/drivers/gpu/drm/i915/display/intel_pch.h
index 19cac7412d0af..aa971fa141e76 100644
--- a/drivers/gpu/drm/i915/display/intel_pch.h
+++ b/drivers/gpu/drm/i915/display/intel_pch.h
@@ -52,5 +52,6 @@ enum intel_pch {
 #define HAS_PCH_SPLIT(display)			(INTEL_PCH_TYPE(display) != PCH_NONE)
 
 void intel_pch_detect(struct intel_display *display);
+void intel_pch_init_clock_gating(struct intel_display *display);
 
 #endif /* __INTEL_PCH__ */
diff --git a/drivers/gpu/drm/i915/intel_clock_gating.c b/drivers/gpu/drm/i915/intel_clock_gating.c
index 68a6f94f2a376..c0382607224dd 100644
--- a/drivers/gpu/drm/i915/intel_clock_gating.c
+++ b/drivers/gpu/drm/i915/intel_clock_gating.c
@@ -33,6 +33,7 @@
 #include "display/intel_display.h"
 #include "display/intel_display_core.h"
 #include "display/intel_display_regs.h"
+#include "display/intel_pch.h"
 #include "gt/intel_engine_regs.h"
 #include "gt/intel_gt.h"
 #include "gt/intel_gt_mcr.h"
@@ -124,16 +125,6 @@ static void glk_init_clock_gating(struct drm_i915_private *i915)
 			   PWM1_GATING_DIS | PWM2_GATING_DIS);
 }
 
-static void ibx_init_clock_gating(struct drm_i915_private *i915)
-{
-	/*
-	 * On Ibex Peak and Cougar Point, we need to disable clock
-	 * gating for the panel power sequencer or it will fail to
-	 * start up when no ports are active.
-	 */
-	intel_uncore_write(&i915->uncore, SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
-}
-
 static void g4x_disable_trickle_feed(struct drm_i915_private *dev_priv)
 {
 	struct intel_display *display = dev_priv->display;
@@ -202,7 +193,7 @@ static void ilk_init_clock_gating(struct drm_i915_private *i915)
 
 	g4x_disable_trickle_feed(i915);
 
-	ibx_init_clock_gating(i915);
+	intel_pch_init_clock_gating(i915->display);
 }
 
 static void cpt_init_clock_gating(struct drm_i915_private *i915)