[RFC][PATCH 3/5] drm/i915: Enable scaling filter for plane and pipe

[Pankaj Bharadiya]

Attach scaling filter property for crtc and plane and program the
scaler control register for the selected filter type.

This is preparatory patch to enable Nearest-neighbor integer scaling.

Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@xxxxxxxxx>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
---
 drivers/gpu/drm/i915/display/intel_display.c | 17 +++++++++++++++--
 drivers/gpu/drm/i915/display/intel_sprite.c  | 12 +++++++++++-
 drivers/gpu/drm/i915/i915_reg.h              |  1 +
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 3031e64ee518..b5903ef3c5a0 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -6242,6 +6242,8 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	enum pipe pipe = crtc->pipe;
+	const struct drm_crtc_state *state = &crtc_state->uapi;
+	u32 scaling_filter = PS_FILTER_MEDIUM;
 	const struct intel_crtc_scaler_state *scaler_state =
 		&crtc_state->scaler_state;
 
@@ -6258,6 +6260,11 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
 		pfit_w = (crtc_state->pch_pfit.size >> 16) & 0xFFFF;
 		pfit_h = crtc_state->pch_pfit.size & 0xFFFF;
 
+		if (state->scaling_filter ==
+		    DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
+			scaling_filter = PS_FILTER_PROGRAMMED;
+		}
+
 		hscale = (crtc_state->pipe_src_w << 16) / pfit_w;
 		vscale = (crtc_state->pipe_src_h << 16) / pfit_h;
 
@@ -6268,8 +6275,10 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
 
 		spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
 
-		intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id), PS_SCALER_EN |
-				  PS_FILTER_MEDIUM | scaler_state->scalers[id].mode);
+		intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id),
+				  PS_SCALER_EN |
+				  scaling_filter |
+				  scaler_state->scalers[id].mode);
 		intel_de_write_fw(dev_priv, SKL_PS_VPHASE(pipe, id),
 				  PS_Y_PHASE(0) | PS_UV_RGB_PHASE(uv_rgb_vphase));
 		intel_de_write_fw(dev_priv, SKL_PS_HPHASE(pipe, id),
@@ -16695,6 +16704,10 @@ static int intel_crtc_init(struct drm_i915_private *dev_priv, enum pipe pipe)
 		dev_priv->plane_to_crtc_mapping[i9xx_plane] = crtc;
 	}
 
+
+	if (INTEL_GEN(dev_priv) >= 11)
+		drm_crtc_enable_scaling_filter(&crtc->base);
+
 	intel_color_init(crtc);
 
 	drm_WARN_ON(&dev_priv->drm, drm_crtc_index(&crtc->base) != crtc->pipe);
diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c
index 7abeefe8dce5..fd7b31a21723 100644
--- a/drivers/gpu/drm/i915/display/intel_sprite.c
+++ b/drivers/gpu/drm/i915/display/intel_sprite.c
@@ -414,6 +414,12 @@ skl_program_scaler(struct intel_plane *plane,
 	u16 y_hphase, uv_rgb_hphase;
 	u16 y_vphase, uv_rgb_vphase;
 	int hscale, vscale;
+	const struct drm_plane_state *state = &plane_state->uapi;
+	u32 scaling_filter = PS_FILTER_MEDIUM;
+
+	if (state->scaling_filter == DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
+		scaling_filter = PS_FILTER_PROGRAMMED;
+	}
 
 	hscale = drm_rect_calc_hscale(&plane_state->uapi.src,
 				      &plane_state->uapi.dst,
@@ -441,7 +447,8 @@ skl_program_scaler(struct intel_plane *plane,
 	}
 
 	intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, scaler_id),
-			  PS_SCALER_EN | PS_PLANE_SEL(plane->id) | scaler->mode);
+			  scaling_filter | PS_SCALER_EN |
+			  PS_PLANE_SEL(plane->id) | scaler->mode);
 	intel_de_write_fw(dev_priv, SKL_PS_VPHASE(pipe, scaler_id),
 			  PS_Y_PHASE(y_vphase) | PS_UV_RGB_PHASE(uv_rgb_vphase));
 	intel_de_write_fw(dev_priv, SKL_PS_HPHASE(pipe, scaler_id),
@@ -3104,6 +3111,9 @@ skl_universal_plane_create(struct drm_i915_private *dev_priv,
 
 	drm_plane_create_zpos_immutable_property(&plane->base, plane_id);
 
+	if (INTEL_GEN(dev_priv) >= 11)
+		drm_plane_enable_scaling_filter(&plane->base);
+
 	drm_plane_helper_add(&plane->base, &intel_plane_helper_funcs);
 
 	return plane;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f45b5e86ec63..34923b1c284c 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7212,6 +7212,7 @@ enum {
 #define PS_PLANE_SEL(plane) (((plane) + 1) << 25)
 #define PS_FILTER_MASK         (3 << 23)
 #define PS_FILTER_MEDIUM       (0 << 23)
+#define PS_FILTER_PROGRAMMED   (1 << 23)
 #define PS_FILTER_EDGE_ENHANCE (2 << 23)
 #define PS_FILTER_BILINEAR     (3 << 23)
 #define PS_VERT3TAP            (1 << 21)
-- 
2.23.0