drm/i915/hti: abstract hti handling

The HTI or HDPORT handling is sprinkled around. Centralize to one place.

Add a note about how subtle the mapping from HDPORT_STATE register to
dpll mask actually is.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221109144209.3624739-1-jani.nikula@intel.com

drivers/gpu/drm/i915/Makefile

@@ -247,6 +247,7 @@ i915-y += \
 	display/intel_global_state.o \
 	display/intel_hdcp.o \
 	display/intel_hotplug.o \
+	display/intel_hti.o \
 	display/intel_lpe_audio.o \
 	display/intel_modeset_verify.o \
 	display/intel_modeset_setup.o \

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -57,6 +57,7 @@
 #include "intel_hdcp.h"
 #include "intel_hdmi.h"
 #include "intel_hotplug.h"
+#include "intel_hti.h"
 #include "intel_lspcon.h"
 #include "intel_mg_phy_regs.h"
 #include "intel_pps.h"
@@ -4114,12 +4115,6 @@ intel_ddi_max_lanes(struct intel_digital_port *dig_port)
 	return max_lanes;
 }
 
-static bool hti_uses_phy(struct drm_i915_private *i915, enum phy phy)
-{
-	return i915->hti_state & HDPORT_ENABLED &&
-	       i915->hti_state & HDPORT_DDI_USED(phy);
-}
-
 static enum hpd_pin xelpd_hpd_pin(struct drm_i915_private *dev_priv,
 				  enum port port)
 {
@@ -4248,7 +4243,7 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 	 * driver.  In that case we should skip initializing the corresponding
 	 * outputs.
 	 */
-	if (hti_uses_phy(dev_priv, phy)) {
+	if (intel_hti_uses_phy(dev_priv, phy)) {
 		drm_dbg_kms(&dev_priv->drm, "PORT %c / PHY %c reserved by HTI\n",
 			    port_name(port), phy_name(phy));
 		return;

drivers/gpu/drm/i915/display/intel_display.c

@@ -101,6 +101,7 @@
 #include "intel_frontbuffer.h"
 #include "intel_hdcp.h"
 #include "intel_hotplug.h"
+#include "intel_hti.h"
 #include "intel_modeset_verify.h"
 #include "intel_modeset_setup.h"
 #include "intel_overlay.h"
@@ -8736,12 +8737,7 @@ int intel_modeset_init_nogem(struct drm_i915_private *i915)
 	if (i915->display.cdclk.max_cdclk_freq == 0)
 		intel_update_max_cdclk(i915);
 
-	/*
-	 * If the platform has HTI, we need to find out whether it has reserved
-	 * any display resources before we create our display outputs.
-	 */
-	if (INTEL_INFO(i915)->display.has_hti)
-		i915->hti_state = intel_de_read(i915, HDPORT_STATE);
+	intel_hti_init(i915);
 
 	/* Just disable it once at startup */
 	intel_vga_disable(i915);

drivers/gpu/drm/i915/display/intel_dpll_mgr.c

@@ -31,6 +31,7 @@
 #include "intel_dpio_phy.h"
 #include "intel_dpll.h"
 #include "intel_dpll_mgr.h"
+#include "intel_hti.h"
 #include "intel_mg_phy_regs.h"
 #include "intel_pch_refclk.h"
 #include "intel_tc.h"
@@ -3164,14 +3165,6 @@ static void icl_update_active_dpll(struct intel_atomic_state *state,
 	icl_set_active_port_dpll(crtc_state, port_dpll_id);
 }
 
-static u32 intel_get_hti_plls(struct drm_i915_private *i915)
-{
-	if (!(i915->hti_state & HDPORT_ENABLED))
-		return 0;
-
-	return REG_FIELD_GET(HDPORT_DPLL_USED_MASK, i915->hti_state);
-}
-
 static int icl_compute_combo_phy_dpll(struct intel_atomic_state *state,
 				      struct intel_crtc *crtc)
 {
@@ -3246,7 +3239,7 @@ static int icl_get_combo_phy_dpll(struct intel_atomic_state *state,
 	}
 
 	/* Eliminate DPLLs from consideration if reserved by HTI */
-	dpll_mask &= ~intel_get_hti_plls(dev_priv);
+	dpll_mask &= ~intel_hti_dpll_mask(dev_priv);
 
 	port_dpll->pll = intel_find_shared_dpll(state, crtc,
 						&port_dpll->hw_state,

drivers/gpu/drm/i915/display/intel_hti.c

@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include "i915_drv.h"
+#include "intel_de.h"
+#include "intel_display.h"
+#include "intel_hti.h"
+#include "intel_hti_regs.h"
+
+void intel_hti_init(struct drm_i915_private *i915)
+{
+	/*
+	 * If the platform has HTI, we need to find out whether it has reserved
+	 * any display resources before we create our display outputs.
+	 */
+	if (INTEL_INFO(i915)->display.has_hti)
+		i915->hti_state = intel_de_read(i915, HDPORT_STATE);
+}
+
+bool intel_hti_uses_phy(struct drm_i915_private *i915, enum phy phy)
+{
+	return i915->hti_state & HDPORT_ENABLED &&
+		i915->hti_state & HDPORT_DDI_USED(phy);
+}
+
+u32 intel_hti_dpll_mask(struct drm_i915_private *i915)
+{
+	if (!(i915->hti_state & HDPORT_ENABLED))
+		return 0;
+
+	/*
+	 * Note: This is subtle. The values must coincide with what's defined
+	 * for the platform.
+	 */
+	return REG_FIELD_GET(HDPORT_DPLL_USED_MASK, i915->hti_state);
+}

drivers/gpu/drm/i915/display/intel_hti.h

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#ifndef __INTEL_HTI_H__
+#define __INTEL_HTI_H__
+
+#include <linux/types.h>
+
+struct drm_i915_private;
+enum phy;
+
+void intel_hti_init(struct drm_i915_private *i915);
+bool intel_hti_uses_phy(struct drm_i915_private *i915, enum phy phy);
+u32 intel_hti_dpll_mask(struct drm_i915_private *i915);
+
+#endif /* __INTEL_HTI_H__ */

drivers/gpu/drm/i915/display/intel_hti_regs.h

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#ifndef __INTEL_HTI_REGS_H__
+#define __INTEL_HTI_REGS_H__
+
+#include "i915_reg_defs.h"
+
+#define HDPORT_STATE			_MMIO(0x45050)
+#define   HDPORT_DPLL_USED_MASK		REG_GENMASK(15, 12)
+#define   HDPORT_DDI_USED(phy)		REG_BIT(2 * (phy) + 1)
+#define   HDPORT_ENABLED		REG_BIT(0)
+
+#endif /* __INTEL_HTI_REGS_H__ */

drivers/gpu/drm/i915/i915_reg.h

@@ -1079,11 +1079,6 @@
 #define MBUS_JOIN_PIPE_SELECT(pipe)	REG_FIELD_PREP(MBUS_JOIN_PIPE_SELECT_MASK, pipe)
 #define MBUS_JOIN_PIPE_SELECT_NONE	MBUS_JOIN_PIPE_SELECT(7)
 
-#define HDPORT_STATE			_MMIO(0x45050)
-#define   HDPORT_DPLL_USED_MASK		REG_GENMASK(15, 12)
-#define   HDPORT_DDI_USED(phy)		REG_BIT(2 * (phy) + 1)
-#define   HDPORT_ENABLED		REG_BIT(0)
-
 /* Make render/texture TLB fetches lower priorty than associated data
  *   fetches. This is not turned on by default
  */