drm/i915: Introduce lpt_pch_disable()

Let's add lpt_pch_disable() as the counterpart to
lpt_pch_enable().

Note that unlike the ilk+ code the fdi_link_train()
and fdi_disable() calls are still left directly in
intel_crt.c. If we wanted to move those we'd need to
add lpt_pch_pre_enable(). But the two fdi direct fdi
calls are pretry symmetric so it doesn't seem too bad
to just keep them as is.

v2: Make lpt_disable_pch_transcoder() static (lkp@intel.com)

Cc: Dave Airlie <airlied@redhat.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211015071625.593-10-ville.syrjala@linux.intel.comReviewed-by: Dave Airlie <airlied@redhat.com>

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

@@ -46,7 +46,6 @@
 #include "intel_gmbus.h"
 #include "intel_hotplug.h"
 #include "intel_pch_display.h"
-#include "intel_pch_refclk.h"
 
 /* Here's the desired hotplug mode */
 #define ADPA_HOTPLUG_BITS (ADPA_CRT_HOTPLUG_PERIOD_128 |		\
@@ -247,6 +246,7 @@ static void hsw_post_disable_crt(struct intel_atomic_state *state,
 				 const struct intel_crtc_state *old_crtc_state,
 				 const struct drm_connector_state *old_conn_state)
 {
+	struct intel_crtc *crtc = to_intel_crtc(old_crtc_state->uapi.crtc);
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 
 	intel_crtc_vblank_off(old_crtc_state);
@@ -261,8 +261,7 @@ static void hsw_post_disable_crt(struct intel_atomic_state *state,
 
 	pch_post_disable_crt(state, encoder, old_crtc_state, old_conn_state);
 
-	lpt_disable_pch_transcoder(dev_priv);
-	lpt_disable_iclkip(dev_priv);
+	lpt_pch_disable(state, crtc);
 
 	hsw_fdi_disable(encoder);
 

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

@@ -434,7 +434,7 @@ static void lpt_enable_pch_transcoder(struct drm_i915_private *dev_priv,
 		drm_err(&dev_priv->drm, "Failed to enable PCH transcoder\n");
 }
 
-void lpt_disable_pch_transcoder(struct drm_i915_private *dev_priv)
+static void lpt_disable_pch_transcoder(struct drm_i915_private *dev_priv)
 {
 	u32 val;
 
@@ -470,6 +470,16 @@ void lpt_pch_enable(struct intel_atomic_state *state,
 	lpt_enable_pch_transcoder(dev_priv, cpu_transcoder);
 }
 
+void lpt_pch_disable(struct intel_atomic_state *state,
+		     struct intel_crtc *crtc)
+{
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+
+	lpt_disable_pch_transcoder(dev_priv);
+
+	lpt_disable_iclkip(dev_priv);
+}
+
 void lpt_pch_get_config(struct intel_crtc_state *crtc_state)
 {
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);

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

@@ -6,7 +6,6 @@
 #ifndef _INTEL_PCH_DISPLAY_H_
 #define _INTEL_PCH_DISPLAY_H_
 
-struct drm_i915_private;
 struct intel_atomic_state;
 struct intel_crtc;
 struct intel_crtc_state;
@@ -19,9 +18,10 @@ void ilk_pch_post_disable(struct intel_atomic_state *state,
 			  struct intel_crtc *crtc);
 void ilk_pch_get_config(struct intel_crtc_state *crtc_state);
 
-void lpt_disable_pch_transcoder(struct drm_i915_private *dev_priv);
 void lpt_pch_enable(struct intel_atomic_state *state,
 		    struct intel_crtc *crtc);
+void lpt_pch_disable(struct intel_atomic_state *state,
+		     struct intel_crtc *crtc);
 void lpt_pch_get_config(struct intel_crtc_state *crtc_state);
 
 #endif