Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 847 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/skl_scaler.c b/drivers/gpu/drm/i915/display/skl_scaler.c
new file mode 100644
index 000000000..0b74f91e8
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/skl_scaler.c
@@ -0,0 +1,847 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+#include "intel_de.h"
+#include "intel_display_types.h"
+#include "intel_fb.h"
+#include "skl_scaler.h"
+#include "skl_universal_plane.h"
+
+/*
+ * The hardware phase 0.0 refers to the center of the pixel.
+ * We want to start from the top/left edge which is phase
+ * -0.5. That matches how the hardware calculates the scaling
+ * factors (from top-left of the first pixel to bottom-right
+ * of the last pixel, as opposed to the pixel centers).
+ *
+ * For 4:2:0 subsampled chroma planes we obviously have to
+ * adjust that so that the chroma sample position lands in
+ * the right spot.
+ *
+ * Note that for packed YCbCr 4:2:2 formats there is no way to
+ * control chroma siting. The hardware simply replicates the
+ * chroma samples for both of the luma samples, and thus we don't
+ * actually get the expected MPEG2 chroma siting convention :(
+ * The same behaviour is observed on pre-SKL platforms as well.
+ *
+ * Theory behind the formula (note that we ignore sub-pixel
+ * source coordinates):
+ * s = source sample position
+ * d = destination sample position
+ *
+ * Downscaling 4:1:
+ * -0.5
+ * | 0.0
+ * | |     1.5 (initial phase)
+ * | |     |
+ * v v     v
+ * | s | s | s | s |
+ * |       d       |
+ *
+ * Upscaling 1:4:
+ * -0.5
+ * | -0.375 (initial phase)
+ * | |     0.0
+ * | |     |
+ * v v     v
+ * |       s       |
+ * | d | d | d | d |
+ */
+static u16 skl_scaler_calc_phase(int sub, int scale, bool chroma_cosited)
+{
+	int phase = -0x8000;
+	u16 trip = 0;
+
+	if (chroma_cosited)
+		phase += (sub - 1) * 0x8000 / sub;
+
+	phase += scale / (2 * sub);
+
+	/*
+	 * Hardware initial phase limited to [-0.5:1.5].
+	 * Since the max hardware scale factor is 3.0, we
+	 * should never actually excdeed 1.0 here.
+	 */
+	WARN_ON(phase < -0x8000 || phase > 0x18000);
+
+	if (phase < 0)
+		phase = 0x10000 + phase;
+	else
+		trip = PS_PHASE_TRIP;
+
+	return ((phase >> 2) & PS_PHASE_MASK) | trip;
+}
+
+#define SKL_MIN_SRC_W 8
+#define SKL_MAX_SRC_W 4096
+#define SKL_MIN_SRC_H 8
+#define SKL_MAX_SRC_H 4096
+#define SKL_MIN_DST_W 8
+#define SKL_MAX_DST_W 4096
+#define SKL_MIN_DST_H 8
+#define SKL_MAX_DST_H 4096
+#define ICL_MAX_SRC_W 5120
+#define ICL_MAX_SRC_H 4096
+#define ICL_MAX_DST_W 5120
+#define ICL_MAX_DST_H 4096
+#define MTL_MAX_SRC_W 4096
+#define MTL_MAX_SRC_H 8192
+#define MTL_MAX_DST_W 8192
+#define MTL_MAX_DST_H 8192
+#define SKL_MIN_YUV_420_SRC_W 16
+#define SKL_MIN_YUV_420_SRC_H 16
+
+static int
+skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
+		  unsigned int scaler_user, int *scaler_id,
+		  int src_w, int src_h, int dst_w, int dst_h,
+		  const struct drm_format_info *format,
+		  u64 modifier, bool need_scaler)
+{
+	struct intel_crtc_scaler_state *scaler_state =
+		&crtc_state->scaler_state;
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	const struct drm_display_mode *adjusted_mode =
+		&crtc_state->hw.adjusted_mode;
+	int pipe_src_w = drm_rect_width(&crtc_state->pipe_src);
+	int pipe_src_h = drm_rect_height(&crtc_state->pipe_src);
+	int min_src_w, min_src_h, min_dst_w, min_dst_h;
+	int max_src_w, max_src_h, max_dst_w, max_dst_h;
+
+	/*
+	 * Src coordinates are already rotated by 270 degrees for
+	 * the 90/270 degree plane rotation cases (to match the
+	 * GTT mapping), hence no need to account for rotation here.
+	 */
+	if (src_w != dst_w || src_h != dst_h)
+		need_scaler = true;
+
+	/*
+	 * Scaling/fitting not supported in IF-ID mode in GEN9+
+	 * TODO: Interlace fetch mode doesn't support YUV420 planar formats.
+	 * Once NV12 is enabled, handle it here while allocating scaler
+	 * for NV12.
+	 */
+	if (DISPLAY_VER(dev_priv) >= 9 && crtc_state->hw.enable &&
+	    need_scaler && adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "Pipe/Plane scaling not supported with IF-ID mode\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * if plane is being disabled or scaler is no more required or force detach
+	 *  - free scaler binded to this plane/crtc
+	 *  - in order to do this, update crtc->scaler_usage
+	 *
+	 * Here scaler state in crtc_state is set free so that
+	 * scaler can be assigned to other user. Actual register
+	 * update to free the scaler is done in plane/panel-fit programming.
+	 * For this purpose crtc/plane_state->scaler_id isn't reset here.
+	 */
+	if (force_detach || !need_scaler) {
+		if (*scaler_id >= 0) {
+			scaler_state->scaler_users &= ~(1 << scaler_user);
+			scaler_state->scalers[*scaler_id].in_use = 0;
+
+			drm_dbg_kms(&dev_priv->drm,
+				    "scaler_user index %u.%u: "
+				    "Staged freeing scaler id %d scaler_users = 0x%x\n",
+				    crtc->pipe, scaler_user, *scaler_id,
+				    scaler_state->scaler_users);
+			*scaler_id = -1;
+		}
+		return 0;
+	}
+
+	if (format && intel_format_info_is_yuv_semiplanar(format, modifier) &&
+	    (src_h < SKL_MIN_YUV_420_SRC_H || src_w < SKL_MIN_YUV_420_SRC_W)) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "Planar YUV: src dimensions not met\n");
+		return -EINVAL;
+	}
+
+	min_src_w = SKL_MIN_SRC_W;
+	min_src_h = SKL_MIN_SRC_H;
+	min_dst_w = SKL_MIN_DST_W;
+	min_dst_h = SKL_MIN_DST_H;
+
+	if (DISPLAY_VER(dev_priv) < 11) {
+		max_src_w = SKL_MAX_SRC_W;
+		max_src_h = SKL_MAX_SRC_H;
+		max_dst_w = SKL_MAX_DST_W;
+		max_dst_h = SKL_MAX_DST_H;
+	} else if (DISPLAY_VER(dev_priv) < 14) {
+		max_src_w = ICL_MAX_SRC_W;
+		max_src_h = ICL_MAX_SRC_H;
+		max_dst_w = ICL_MAX_DST_W;
+		max_dst_h = ICL_MAX_DST_H;
+	} else {
+		max_src_w = MTL_MAX_SRC_W;
+		max_src_h = MTL_MAX_SRC_H;
+		max_dst_w = MTL_MAX_DST_W;
+		max_dst_h = MTL_MAX_DST_H;
+	}
+
+	/* range checks */
+	if (src_w < min_src_w || src_h < min_src_h ||
+	    dst_w < min_dst_w || dst_h < min_dst_h ||
+	    src_w > max_src_w || src_h > max_src_h ||
+	    dst_w > max_dst_w || dst_h > max_dst_h) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "scaler_user index %u.%u: src %ux%u dst %ux%u "
+			    "size is out of scaler range\n",
+			    crtc->pipe, scaler_user, src_w, src_h,
+			    dst_w, dst_h);
+		return -EINVAL;
+	}
+
+	/*
+	 * The pipe scaler does not use all the bits of PIPESRC, at least
+	 * on the earlier platforms. So even when we're scaling a plane
+	 * the *pipe* source size must not be too large. For simplicity
+	 * we assume the limits match the scaler source size limits. Might
+	 * not be 100% accurate on all platforms, but good enough for now.
+	 */
+	if (pipe_src_w > max_src_w || pipe_src_h > max_src_h) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "scaler_user index %u.%u: pipe src size %ux%u "
+			    "is out of scaler range\n",
+			    crtc->pipe, scaler_user, pipe_src_w, pipe_src_h);
+		return -EINVAL;
+	}
+
+	/* mark this plane as a scaler user in crtc_state */
+	scaler_state->scaler_users |= (1 << scaler_user);
+	drm_dbg_kms(&dev_priv->drm, "scaler_user index %u.%u: "
+		    "staged scaling request for %ux%u->%ux%u scaler_users = 0x%x\n",
+		    crtc->pipe, scaler_user, src_w, src_h, dst_w, dst_h,
+		    scaler_state->scaler_users);
+
+	return 0;
+}
+
+int skl_update_scaler_crtc(struct intel_crtc_state *crtc_state)
+{
+	const struct drm_display_mode *pipe_mode = &crtc_state->hw.pipe_mode;
+	int width, height;
+
+	if (crtc_state->pch_pfit.enabled) {
+		width = drm_rect_width(&crtc_state->pch_pfit.dst);
+		height = drm_rect_height(&crtc_state->pch_pfit.dst);
+	} else {
+		width = pipe_mode->crtc_hdisplay;
+		height = pipe_mode->crtc_vdisplay;
+	}
+	return skl_update_scaler(crtc_state, !crtc_state->hw.active,
+				 SKL_CRTC_INDEX,
+				 &crtc_state->scaler_state.scaler_id,
+				 drm_rect_width(&crtc_state->pipe_src),
+				 drm_rect_height(&crtc_state->pipe_src),
+				 width, height, NULL, 0,
+				 crtc_state->pch_pfit.enabled);
+}
+
+/**
+ * skl_update_scaler_plane - Stages update to scaler state for a given plane.
+ * @crtc_state: crtc's scaler state
+ * @plane_state: atomic plane state to update
+ *
+ * Return
+ *     0 - scaler_usage updated successfully
+ *    error - requested scaling cannot be supported or other error condition
+ */
+int skl_update_scaler_plane(struct intel_crtc_state *crtc_state,
+			    struct intel_plane_state *plane_state)
+{
+	struct intel_plane *intel_plane =
+		to_intel_plane(plane_state->uapi.plane);
+	struct drm_i915_private *dev_priv = to_i915(intel_plane->base.dev);
+	struct drm_framebuffer *fb = plane_state->hw.fb;
+	int ret;
+	bool force_detach = !fb || !plane_state->uapi.visible;
+	bool need_scaler = false;
+
+	/* Pre-gen11 and SDR planes always need a scaler for planar formats. */
+	if (!icl_is_hdr_plane(dev_priv, intel_plane->id) &&
+	    fb && intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier))
+		need_scaler = true;
+
+	ret = skl_update_scaler(crtc_state, force_detach,
+				drm_plane_index(&intel_plane->base),
+				&plane_state->scaler_id,
+				drm_rect_width(&plane_state->uapi.src) >> 16,
+				drm_rect_height(&plane_state->uapi.src) >> 16,
+				drm_rect_width(&plane_state->uapi.dst),
+				drm_rect_height(&plane_state->uapi.dst),
+				fb ? fb->format : NULL,
+				fb ? fb->modifier : 0,
+				need_scaler);
+
+	if (ret || plane_state->scaler_id < 0)
+		return ret;
+
+	/* check colorkey */
+	if (plane_state->ckey.flags) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "[PLANE:%d:%s] scaling with color key not allowed",
+			    intel_plane->base.base.id,
+			    intel_plane->base.name);
+		return -EINVAL;
+	}
+
+	/* Check src format */
+	switch (fb->format->format) {
+	case DRM_FORMAT_RGB565:
+	case DRM_FORMAT_XBGR8888:
+	case DRM_FORMAT_XRGB8888:
+	case DRM_FORMAT_ABGR8888:
+	case DRM_FORMAT_ARGB8888:
+	case DRM_FORMAT_XRGB2101010:
+	case DRM_FORMAT_XBGR2101010:
+	case DRM_FORMAT_ARGB2101010:
+	case DRM_FORMAT_ABGR2101010:
+	case DRM_FORMAT_YUYV:
+	case DRM_FORMAT_YVYU:
+	case DRM_FORMAT_UYVY:
+	case DRM_FORMAT_VYUY:
+	case DRM_FORMAT_NV12:
+	case DRM_FORMAT_XYUV8888:
+	case DRM_FORMAT_P010:
+	case DRM_FORMAT_P012:
+	case DRM_FORMAT_P016:
+	case DRM_FORMAT_Y210:
+	case DRM_FORMAT_Y212:
+	case DRM_FORMAT_Y216:
+	case DRM_FORMAT_XVYU2101010:
+	case DRM_FORMAT_XVYU12_16161616:
+	case DRM_FORMAT_XVYU16161616:
+		break;
+	case DRM_FORMAT_XBGR16161616F:
+	case DRM_FORMAT_ABGR16161616F:
+	case DRM_FORMAT_XRGB16161616F:
+	case DRM_FORMAT_ARGB16161616F:
+		if (DISPLAY_VER(dev_priv) >= 11)
+			break;
+		fallthrough;
+	default:
+		drm_dbg_kms(&dev_priv->drm,
+			    "[PLANE:%d:%s] FB:%d unsupported scaling format 0x%x\n",
+			    intel_plane->base.base.id, intel_plane->base.name,
+			    fb->base.id, fb->format->format);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int intel_atomic_setup_scaler(struct intel_crtc_scaler_state *scaler_state,
+				     int num_scalers_need, struct intel_crtc *intel_crtc,
+				     const char *name, int idx,
+				     struct intel_plane_state *plane_state,
+				     int *scaler_id)
+{
+	struct drm_i915_private *dev_priv = to_i915(intel_crtc->base.dev);
+	int j;
+	u32 mode;
+
+	if (*scaler_id < 0) {
+		/* find a free scaler */
+		for (j = 0; j < intel_crtc->num_scalers; j++) {
+			if (scaler_state->scalers[j].in_use)
+				continue;
+
+			*scaler_id = j;
+			scaler_state->scalers[*scaler_id].in_use = 1;
+			break;
+		}
+	}
+
+	if (drm_WARN(&dev_priv->drm, *scaler_id < 0,
+		     "Cannot find scaler for %s:%d\n", name, idx))
+		return -EINVAL;
+
+	/* set scaler mode */
+	if (plane_state && plane_state->hw.fb &&
+	    plane_state->hw.fb->format->is_yuv &&
+	    plane_state->hw.fb->format->num_planes > 1) {
+		struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
+
+		if (DISPLAY_VER(dev_priv) == 9) {
+			mode = SKL_PS_SCALER_MODE_NV12;
+		} else if (icl_is_hdr_plane(dev_priv, plane->id)) {
+			/*
+			 * On gen11+'s HDR planes we only use the scaler for
+			 * scaling. They have a dedicated chroma upsampler, so
+			 * we don't need the scaler to upsample the UV plane.
+			 */
+			mode = PS_SCALER_MODE_NORMAL;
+		} else {
+			struct intel_plane *linked =
+				plane_state->planar_linked_plane;
+
+			mode = PS_SCALER_MODE_PLANAR;
+
+			if (linked)
+				mode |= PS_PLANE_Y_SEL(linked->id);
+		}
+	} else if (DISPLAY_VER(dev_priv) >= 10) {
+		mode = PS_SCALER_MODE_NORMAL;
+	} else if (num_scalers_need == 1 && intel_crtc->num_scalers > 1) {
+		/*
+		 * when only 1 scaler is in use on a pipe with 2 scalers
+		 * scaler 0 operates in high quality (HQ) mode.
+		 * In this case use scaler 0 to take advantage of HQ mode
+		 */
+		scaler_state->scalers[*scaler_id].in_use = 0;
+		*scaler_id = 0;
+		scaler_state->scalers[0].in_use = 1;
+		mode = SKL_PS_SCALER_MODE_HQ;
+	} else {
+		mode = SKL_PS_SCALER_MODE_DYN;
+	}
+
+	/*
+	 * FIXME: we should also check the scaler factors for pfit, so
+	 * this shouldn't be tied directly to planes.
+	 */
+	if (plane_state && plane_state->hw.fb) {
+		const struct drm_framebuffer *fb = plane_state->hw.fb;
+		const struct drm_rect *src = &plane_state->uapi.src;
+		const struct drm_rect *dst = &plane_state->uapi.dst;
+		int hscale, vscale, max_vscale, max_hscale;
+
+		/*
+		 * FIXME: When two scalers are needed, but only one of
+		 * them needs to downscale, we should make sure that
+		 * the one that needs downscaling support is assigned
+		 * as the first scaler, so we don't reject downscaling
+		 * unnecessarily.
+		 */
+
+		if (DISPLAY_VER(dev_priv) >= 14) {
+			/*
+			 * On versions 14 and up, only the first
+			 * scaler supports a vertical scaling factor
+			 * of more than 1.0, while a horizontal
+			 * scaling factor of 3.0 is supported.
+			 */
+			max_hscale = 0x30000 - 1;
+			if (*scaler_id == 0)
+				max_vscale = 0x30000 - 1;
+			else
+				max_vscale = 0x10000;
+
+		} else if (DISPLAY_VER(dev_priv) >= 10 ||
+			   !intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier)) {
+			max_hscale = 0x30000 - 1;
+			max_vscale = 0x30000 - 1;
+		} else {
+			max_hscale = 0x20000 - 1;
+			max_vscale = 0x20000 - 1;
+		}
+
+		/*
+		 * FIXME: We should change the if-else block above to
+		 * support HQ vs dynamic scaler properly.
+		 */
+
+		/* Check if required scaling is within limits */
+		hscale = drm_rect_calc_hscale(src, dst, 1, max_hscale);
+		vscale = drm_rect_calc_vscale(src, dst, 1, max_vscale);
+
+		if (hscale < 0 || vscale < 0) {
+			drm_dbg_kms(&dev_priv->drm,
+				    "Scaler %d doesn't support required plane scaling\n",
+				    *scaler_id);
+			drm_rect_debug_print("src: ", src, true);
+			drm_rect_debug_print("dst: ", dst, false);
+
+			return -EINVAL;
+		}
+	}
+
+	drm_dbg_kms(&dev_priv->drm, "Attached scaler id %u.%u to %s:%d\n",
+		    intel_crtc->pipe, *scaler_id, name, idx);
+	scaler_state->scalers[*scaler_id].mode = mode;
+
+	return 0;
+}
+
+/**
+ * intel_atomic_setup_scalers() - setup scalers for crtc per staged requests
+ * @dev_priv: i915 device
+ * @intel_crtc: intel crtc
+ * @crtc_state: incoming crtc_state to validate and setup scalers
+ *
+ * This function sets up scalers based on staged scaling requests for
+ * a @crtc and its planes. It is called from crtc level check path. If request
+ * is a supportable request, it attaches scalers to requested planes and crtc.
+ *
+ * This function takes into account the current scaler(s) in use by any planes
+ * not being part of this atomic state
+ *
+ *  Returns:
+ *         0 - scalers were setup successfully
+ *         error code - otherwise
+ */
+int intel_atomic_setup_scalers(struct drm_i915_private *dev_priv,
+			       struct intel_crtc *intel_crtc,
+			       struct intel_crtc_state *crtc_state)
+{
+	struct drm_plane *plane = NULL;
+	struct intel_plane *intel_plane;
+	struct intel_crtc_scaler_state *scaler_state =
+		&crtc_state->scaler_state;
+	struct drm_atomic_state *drm_state = crtc_state->uapi.state;
+	struct intel_atomic_state *intel_state = to_intel_atomic_state(drm_state);
+	int num_scalers_need;
+	int i;
+
+	num_scalers_need = hweight32(scaler_state->scaler_users);
+
+	/*
+	 * High level flow:
+	 * - staged scaler requests are already in scaler_state->scaler_users
+	 * - check whether staged scaling requests can be supported
+	 * - add planes using scalers that aren't in current transaction
+	 * - assign scalers to requested users
+	 * - as part of plane commit, scalers will be committed
+	 *   (i.e., either attached or detached) to respective planes in hw
+	 * - as part of crtc_commit, scaler will be either attached or detached
+	 *   to crtc in hw
+	 */
+
+	/* fail if required scalers > available scalers */
+	if (num_scalers_need > intel_crtc->num_scalers) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "Too many scaling requests %d > %d\n",
+			    num_scalers_need, intel_crtc->num_scalers);
+		return -EINVAL;
+	}
+
+	/* walkthrough scaler_users bits and start assigning scalers */
+	for (i = 0; i < sizeof(scaler_state->scaler_users) * 8; i++) {
+		struct intel_plane_state *plane_state = NULL;
+		int *scaler_id;
+		const char *name;
+		int idx, ret;
+
+		/* skip if scaler not required */
+		if (!(scaler_state->scaler_users & (1 << i)))
+			continue;
+
+		if (i == SKL_CRTC_INDEX) {
+			name = "CRTC";
+			idx = intel_crtc->base.base.id;
+
+			/* panel fitter case: assign as a crtc scaler */
+			scaler_id = &scaler_state->scaler_id;
+		} else {
+			name = "PLANE";
+
+			/* plane scaler case: assign as a plane scaler */
+			/* find the plane that set the bit as scaler_user */
+			plane = drm_state->planes[i].ptr;
+
+			/*
+			 * to enable/disable hq mode, add planes that are using scaler
+			 * into this transaction
+			 */
+			if (!plane) {
+				struct drm_plane_state *state;
+
+				/*
+				 * GLK+ scalers don't have a HQ mode so it
+				 * isn't necessary to change between HQ and dyn mode
+				 * on those platforms.
+				 */
+				if (DISPLAY_VER(dev_priv) >= 10)
+					continue;
+
+				plane = drm_plane_from_index(&dev_priv->drm, i);
+				state = drm_atomic_get_plane_state(drm_state, plane);
+				if (IS_ERR(state)) {
+					drm_dbg_kms(&dev_priv->drm,
+						    "Failed to add [PLANE:%d] to drm_state\n",
+						    plane->base.id);
+					return PTR_ERR(state);
+				}
+			}
+
+			intel_plane = to_intel_plane(plane);
+			idx = plane->base.id;
+
+			/* plane on different crtc cannot be a scaler user of this crtc */
+			if (drm_WARN_ON(&dev_priv->drm,
+					intel_plane->pipe != intel_crtc->pipe))
+				continue;
+
+			plane_state = intel_atomic_get_new_plane_state(intel_state,
+								       intel_plane);
+			scaler_id = &plane_state->scaler_id;
+		}
+
+		ret = intel_atomic_setup_scaler(scaler_state, num_scalers_need,
+						intel_crtc, name, idx,
+						plane_state, scaler_id);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int glk_coef_tap(int i)
+{
+	return i % 7;
+}
+
+static u16 glk_nearest_filter_coef(int t)
+{
+	return t == 3 ? 0x0800 : 0x3000;
+}
+
+/*
+ *  Theory behind setting nearest-neighbor integer scaling:
+ *
+ *  17 phase of 7 taps requires 119 coefficients in 60 dwords per set.
+ *  The letter represents the filter tap (D is the center tap) and the number
+ *  represents the coefficient set for a phase (0-16).
+ *
+ *         +------------+------------------------+------------------------+
+ *         |Index value | Data value coeffient 1 | Data value coeffient 2 |
+ *         +------------+------------------------+------------------------+
+ *         |   00h      |          B0            |          A0            |
+ *         +------------+------------------------+------------------------+
+ *         |   01h      |          D0            |          C0            |
+ *         +------------+------------------------+------------------------+
+ *         |   02h      |          F0            |          E0            |
+ *         +------------+------------------------+------------------------+
+ *         |   03h      |          A1            |          G0            |
+ *         +------------+------------------------+------------------------+
+ *         |   04h      |          C1            |          B1            |
+ *         +------------+------------------------+------------------------+
+ *         |   ...      |          ...           |          ...           |
+ *         +------------+------------------------+------------------------+
+ *         |   38h      |          B16           |          A16           |
+ *         +------------+------------------------+------------------------+
+ *         |   39h      |          D16           |          C16           |
+ *         +------------+------------------------+------------------------+
+ *         |   3Ah      |          F16           |          C16           |
+ *         +------------+------------------------+------------------------+
+ *         |   3Bh      |        Reserved        |          G16           |
+ *         +------------+------------------------+------------------------+
+ *
+ *  To enable nearest-neighbor scaling:  program scaler coefficents with
+ *  the center tap (Dxx) values set to 1 and all other values set to 0 as per
+ *  SCALER_COEFFICIENT_FORMAT
+ *
+ */
+
+static void glk_program_nearest_filter_coefs(struct drm_i915_private *dev_priv,
+					     enum pipe pipe, int id, int set)
+{
+	int i;
+
+	intel_de_write_fw(dev_priv, GLK_PS_COEF_INDEX_SET(pipe, id, set),
+			  PS_COEE_INDEX_AUTO_INC);
+
+	for (i = 0; i < 17 * 7; i += 2) {
+		u32 tmp;
+		int t;
+
+		t = glk_coef_tap(i);
+		tmp = glk_nearest_filter_coef(t);
+
+		t = glk_coef_tap(i + 1);
+		tmp |= glk_nearest_filter_coef(t) << 16;
+
+		intel_de_write_fw(dev_priv, GLK_PS_COEF_DATA_SET(pipe, id, set),
+				  tmp);
+	}
+
+	intel_de_write_fw(dev_priv, GLK_PS_COEF_INDEX_SET(pipe, id, set), 0);
+}
+
+static u32 skl_scaler_get_filter_select(enum drm_scaling_filter filter, int set)
+{
+	if (filter == DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
+		return (PS_FILTER_PROGRAMMED |
+			PS_Y_VERT_FILTER_SELECT(set) |
+			PS_Y_HORZ_FILTER_SELECT(set) |
+			PS_UV_VERT_FILTER_SELECT(set) |
+			PS_UV_HORZ_FILTER_SELECT(set));
+	}
+
+	return PS_FILTER_MEDIUM;
+}
+
+static void skl_scaler_setup_filter(struct drm_i915_private *dev_priv, enum pipe pipe,
+				    int id, int set, enum drm_scaling_filter filter)
+{
+	switch (filter) {
+	case DRM_SCALING_FILTER_DEFAULT:
+		break;
+	case DRM_SCALING_FILTER_NEAREST_NEIGHBOR:
+		glk_program_nearest_filter_coefs(dev_priv, pipe, id, set);
+		break;
+	default:
+		MISSING_CASE(filter);
+	}
+}
+
+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);
+	const struct intel_crtc_scaler_state *scaler_state =
+		&crtc_state->scaler_state;
+	const struct drm_rect *dst = &crtc_state->pch_pfit.dst;
+	u16 uv_rgb_hphase, uv_rgb_vphase;
+	enum pipe pipe = crtc->pipe;
+	int width = drm_rect_width(dst);
+	int height = drm_rect_height(dst);
+	int x = dst->x1;
+	int y = dst->y1;
+	int hscale, vscale;
+	struct drm_rect src;
+	int id;
+	u32 ps_ctrl;
+
+	if (!crtc_state->pch_pfit.enabled)
+		return;
+
+	if (drm_WARN_ON(&dev_priv->drm,
+			crtc_state->scaler_state.scaler_id < 0))
+		return;
+
+	drm_rect_init(&src, 0, 0,
+		      drm_rect_width(&crtc_state->pipe_src) << 16,
+		      drm_rect_height(&crtc_state->pipe_src) << 16);
+
+	hscale = drm_rect_calc_hscale(&src, dst, 0, INT_MAX);
+	vscale = drm_rect_calc_vscale(&src, dst, 0, INT_MAX);
+
+	uv_rgb_hphase = skl_scaler_calc_phase(1, hscale, false);
+	uv_rgb_vphase = skl_scaler_calc_phase(1, vscale, false);
+
+	id = scaler_state->scaler_id;
+
+	ps_ctrl = skl_scaler_get_filter_select(crtc_state->hw.scaling_filter, 0);
+	ps_ctrl |=  PS_SCALER_EN | scaler_state->scalers[id].mode;
+
+	skl_scaler_setup_filter(dev_priv, pipe, id, 0,
+				crtc_state->hw.scaling_filter);
+
+	intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id), ps_ctrl);
+
+	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),
+			  PS_Y_PHASE(0) | PS_UV_RGB_PHASE(uv_rgb_hphase));
+	intel_de_write_fw(dev_priv, SKL_PS_WIN_POS(pipe, id),
+			  x << 16 | y);
+	intel_de_write_fw(dev_priv, SKL_PS_WIN_SZ(pipe, id),
+			  width << 16 | height);
+}
+
+void
+skl_program_plane_scaler(struct intel_plane *plane,
+			 const struct intel_crtc_state *crtc_state,
+			 const struct intel_plane_state *plane_state)
+{
+	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
+	const struct drm_framebuffer *fb = plane_state->hw.fb;
+	enum pipe pipe = plane->pipe;
+	int scaler_id = plane_state->scaler_id;
+	const struct intel_scaler *scaler =
+		&crtc_state->scaler_state.scalers[scaler_id];
+	int crtc_x = plane_state->uapi.dst.x1;
+	int crtc_y = plane_state->uapi.dst.y1;
+	u32 crtc_w = drm_rect_width(&plane_state->uapi.dst);
+	u32 crtc_h = drm_rect_height(&plane_state->uapi.dst);
+	u16 y_hphase, uv_rgb_hphase;
+	u16 y_vphase, uv_rgb_vphase;
+	int hscale, vscale;
+	u32 ps_ctrl;
+
+	hscale = drm_rect_calc_hscale(&plane_state->uapi.src,
+				      &plane_state->uapi.dst,
+				      0, INT_MAX);
+	vscale = drm_rect_calc_vscale(&plane_state->uapi.src,
+				      &plane_state->uapi.dst,
+				      0, INT_MAX);
+
+	/* TODO: handle sub-pixel coordinates */
+	if (intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier) &&
+	    !icl_is_hdr_plane(dev_priv, plane->id)) {
+		y_hphase = skl_scaler_calc_phase(1, hscale, false);
+		y_vphase = skl_scaler_calc_phase(1, vscale, false);
+
+		/* MPEG2 chroma siting convention */
+		uv_rgb_hphase = skl_scaler_calc_phase(2, hscale, true);
+		uv_rgb_vphase = skl_scaler_calc_phase(2, vscale, false);
+	} else {
+		/* not used */
+		y_hphase = 0;
+		y_vphase = 0;
+
+		uv_rgb_hphase = skl_scaler_calc_phase(1, hscale, false);
+		uv_rgb_vphase = skl_scaler_calc_phase(1, vscale, false);
+	}
+
+	ps_ctrl = skl_scaler_get_filter_select(plane_state->hw.scaling_filter, 0);
+	ps_ctrl |= PS_SCALER_EN | PS_PLANE_SEL(plane->id) | scaler->mode;
+
+	skl_scaler_setup_filter(dev_priv, pipe, scaler_id, 0,
+				plane_state->hw.scaling_filter);
+
+	intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, scaler_id), ps_ctrl);
+	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),
+			  PS_Y_PHASE(y_hphase) | PS_UV_RGB_PHASE(uv_rgb_hphase));
+	intel_de_write_fw(dev_priv, SKL_PS_WIN_POS(pipe, scaler_id),
+			  (crtc_x << 16) | crtc_y);
+	intel_de_write_fw(dev_priv, SKL_PS_WIN_SZ(pipe, scaler_id),
+			  (crtc_w << 16) | crtc_h);
+}
+
+static void skl_detach_scaler(struct intel_crtc *crtc, int id)
+{
+	struct drm_device *dev = crtc->base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+
+	intel_de_write_fw(dev_priv, SKL_PS_CTRL(crtc->pipe, id), 0);
+	intel_de_write_fw(dev_priv, SKL_PS_WIN_POS(crtc->pipe, id), 0);
+	intel_de_write_fw(dev_priv, SKL_PS_WIN_SZ(crtc->pipe, id), 0);
+}
+
+/*
+ * This function detaches (aka. unbinds) unused scalers in hardware
+ */
+void skl_detach_scalers(const struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+	const struct intel_crtc_scaler_state *scaler_state =
+		&crtc_state->scaler_state;
+	int i;
+
+	/* loop through and disable scalers that aren't in use */
+	for (i = 0; i < crtc->num_scalers; i++) {
+		if (!scaler_state->scalers[i].in_use)
+			skl_detach_scaler(crtc, i);
+	}
+}
+
+void skl_scaler_disable(const struct intel_crtc_state *old_crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(old_crtc_state->uapi.crtc);
+	int i;
+
+	for (i = 0; i < crtc->num_scalers; i++)
+		skl_detach_scaler(crtc, i);
+}