drm/msm/mdp: Add Software Pixel Extension support

In order to produce an image, the scalar needs to be fed extra
pixels. These top/bottom/left/right values depend on a various of
factors, including resolution, scaling type, phase step and
initial phase.

Pixel Extension are programmed by hardware in most targets - and
can be overwritten by software. For some targets (e.g.: msm8996),
software *must* program those registers.

In order to ease this computation, let's always use bilinear
filters, which are easier to program from kernel. Eventually,
all of these values will come down from user space for better
quality.

Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c

@@ -548,40 +548,120 @@ static int calc_scaley_steps(struct drm_plane *plane,
 	return 0;
 }
 
-static uint32_t get_scale_config(enum mdp_chroma_samp_type chroma_sample,
-		uint32_t src, uint32_t dest, bool hor)
+static uint32_t get_scale_config(const struct mdp_format *format,
+		uint32_t src, uint32_t dst, bool horz)
 {
-	uint32_t y_filter =   (src <= dest) ? SCALE_FILTER_CA  : SCALE_FILTER_PCMN;
-	uint32_t y_a_filter = (src <= dest) ? SCALE_FILTER_BIL : SCALE_FILTER_PCMN;
-	uint32_t uv_filter = ((src / 2) <= dest) ? /* 2x upsample */
-			SCALE_FILTER_BIL : SCALE_FILTER_PCMN;
-	uint32_t value = 0;
-
-	if (chroma_sample == CHROMA_420 || chroma_sample == CHROMA_H2V1) {
-		if (hor)
-			value = MDP5_PIPE_SCALE_CONFIG_SCALEX_EN |
-				MDP5_PIPE_SCALE_CONFIG_SCALEX_FILTER_COMP_0(y_filter) |
-				MDP5_PIPE_SCALE_CONFIG_SCALEX_FILTER_COMP_3(y_a_filter) |
-				MDP5_PIPE_SCALE_CONFIG_SCALEX_FILTER_COMP_1_2(uv_filter);
-		else
-			value = MDP5_PIPE_SCALE_CONFIG_SCALEY_EN |
-				MDP5_PIPE_SCALE_CONFIG_SCALEY_FILTER_COMP_0(y_filter) |
-				MDP5_PIPE_SCALE_CONFIG_SCALEY_FILTER_COMP_3(y_a_filter) |
-				MDP5_PIPE_SCALE_CONFIG_SCALEY_FILTER_COMP_1_2(uv_filter);
-	} else if (src != dest) {
-		if (hor)
-			value = MDP5_PIPE_SCALE_CONFIG_SCALEX_EN |
-				MDP5_PIPE_SCALE_CONFIG_SCALEX_FILTER_COMP_0(y_a_filter) |
-				MDP5_PIPE_SCALE_CONFIG_SCALEX_FILTER_COMP_3(y_a_filter);
-		else
-			value = MDP5_PIPE_SCALE_CONFIG_SCALEY_EN |
-				MDP5_PIPE_SCALE_CONFIG_SCALEY_FILTER_COMP_0(y_a_filter) |
-				MDP5_PIPE_SCALE_CONFIG_SCALEY_FILTER_COMP_3(y_a_filter);
+	bool scaling = format->is_yuv ? true : (src != dst);
+	uint32_t sub, pix_fmt = format->base.pixel_format;
+	uint32_t ya_filter, uv_filter;
+	bool yuv = format->is_yuv;
+
+	if (!scaling)
+		return 0;
+
+	if (yuv) {
+		sub = horz ? drm_format_horz_chroma_subsampling(pix_fmt) :
+			     drm_format_vert_chroma_subsampling(pix_fmt);
+		uv_filter = ((src / sub) <= dst) ?
+				   SCALE_FILTER_BIL : SCALE_FILTER_PCMN;
+	}
+	ya_filter = (src <= dst) ? SCALE_FILTER_BIL : SCALE_FILTER_PCMN;
+
+	if (horz)
+		return  MDP5_PIPE_SCALE_CONFIG_SCALEX_EN |
+			MDP5_PIPE_SCALE_CONFIG_SCALEX_FILTER_COMP_0(ya_filter) |
+			MDP5_PIPE_SCALE_CONFIG_SCALEX_FILTER_COMP_3(ya_filter) |
+			COND(yuv, MDP5_PIPE_SCALE_CONFIG_SCALEX_FILTER_COMP_1_2(uv_filter));
+	else
+		return  MDP5_PIPE_SCALE_CONFIG_SCALEY_EN |
+			MDP5_PIPE_SCALE_CONFIG_SCALEY_FILTER_COMP_0(ya_filter) |
+			MDP5_PIPE_SCALE_CONFIG_SCALEY_FILTER_COMP_3(ya_filter) |
+			COND(yuv, MDP5_PIPE_SCALE_CONFIG_SCALEY_FILTER_COMP_1_2(uv_filter));
+}
+
+static void calc_pixel_ext(const struct mdp_format *format,
+		uint32_t src, uint32_t dst, uint32_t phase_step[2],
+		int pix_ext_edge1[COMP_MAX], int pix_ext_edge2[COMP_MAX],
+		bool horz)
+{
+	bool scaling = format->is_yuv ? true : (src != dst);
+	int i;
+
+	/*
+	 * Note:
+	 * We assume here that:
+	 *     1. PCMN filter is used for downscale
+	 *     2. bilinear filter is used for upscale
+	 *     3. we are in a single pipe configuration
+	 */
+
+	for (i = 0; i < COMP_MAX; i++) {
+		pix_ext_edge1[i] = 0;
+		pix_ext_edge2[i] = scaling ? 1 : 0;
 	}
+}
 
-	return value;
+static void mdp5_write_pixel_ext(struct mdp5_kms *mdp5_kms, enum mdp5_pipe pipe,
+	const struct mdp_format *format,
+	uint32_t src_w, int pe_left[COMP_MAX], int pe_right[COMP_MAX],
+	uint32_t src_h, int pe_top[COMP_MAX], int pe_bottom[COMP_MAX])
+{
+	uint32_t pix_fmt = format->base.pixel_format;
+	uint32_t lr, tb, req;
+	int i;
+
+	for (i = 0; i < COMP_MAX; i++) {
+		uint32_t roi_w = src_w;
+		uint32_t roi_h = src_h;
+
+		if (format->is_yuv && i == COMP_1_2) {
+			roi_w /= drm_format_horz_chroma_subsampling(pix_fmt);
+			roi_h /= drm_format_vert_chroma_subsampling(pix_fmt);
+		}
+
+		lr  = (pe_left[i] >= 0) ?
+			MDP5_PIPE_SW_PIX_EXT_LR_LEFT_RPT(pe_left[i]) :
+			MDP5_PIPE_SW_PIX_EXT_LR_LEFT_OVF(pe_left[i]);
+
+		lr |= (pe_right[i] >= 0) ?
+			MDP5_PIPE_SW_PIX_EXT_LR_RIGHT_RPT(pe_right[i]) :
+			MDP5_PIPE_SW_PIX_EXT_LR_RIGHT_OVF(pe_right[i]);
+
+		tb  = (pe_top[i] >= 0) ?
+			MDP5_PIPE_SW_PIX_EXT_TB_TOP_RPT(pe_top[i]) :
+			MDP5_PIPE_SW_PIX_EXT_TB_TOP_OVF(pe_top[i]);
+
+		tb |= (pe_bottom[i] >= 0) ?
+			MDP5_PIPE_SW_PIX_EXT_TB_BOTTOM_RPT(pe_bottom[i]) :
+			MDP5_PIPE_SW_PIX_EXT_TB_BOTTOM_OVF(pe_bottom[i]);
+
+		req  = MDP5_PIPE_SW_PIX_EXT_REQ_PIXELS_LEFT_RIGHT(roi_w +
+				pe_left[i] + pe_right[i]);
+
+		req |= MDP5_PIPE_SW_PIX_EXT_REQ_PIXELS_TOP_BOTTOM(roi_h +
+				pe_top[i] + pe_bottom[i]);
+
+		mdp5_write(mdp5_kms, REG_MDP5_PIPE_SW_PIX_EXT_LR(pipe, i), lr);
+		mdp5_write(mdp5_kms, REG_MDP5_PIPE_SW_PIX_EXT_TB(pipe, i), tb);
+		mdp5_write(mdp5_kms, REG_MDP5_PIPE_SW_PIX_EXT_REQ_PIXELS(pipe, i), req);
+
+		DBG("comp-%d (L/R): rpt=%d/%d, ovf=%d/%d, req=%d", i,
+			FIELD(lr,  MDP5_PIPE_SW_PIX_EXT_LR_LEFT_RPT),
+			FIELD(lr,  MDP5_PIPE_SW_PIX_EXT_LR_RIGHT_RPT),
+			FIELD(lr,  MDP5_PIPE_SW_PIX_EXT_LR_LEFT_OVF),
+			FIELD(lr,  MDP5_PIPE_SW_PIX_EXT_LR_RIGHT_OVF),
+			FIELD(req, MDP5_PIPE_SW_PIX_EXT_REQ_PIXELS_LEFT_RIGHT));
+
+		DBG("comp-%d (T/B): rpt=%d/%d, ovf=%d/%d, req=%d", i,
+			FIELD(tb,  MDP5_PIPE_SW_PIX_EXT_TB_TOP_RPT),
+			FIELD(tb,  MDP5_PIPE_SW_PIX_EXT_TB_BOTTOM_RPT),
+			FIELD(tb,  MDP5_PIPE_SW_PIX_EXT_TB_TOP_OVF),
+			FIELD(tb,  MDP5_PIPE_SW_PIX_EXT_TB_BOTTOM_OVF),
+			FIELD(req, MDP5_PIPE_SW_PIX_EXT_REQ_PIXELS_TOP_BOTTOM));
+	}
 }
 
+
 static int mdp5_plane_mode_set(struct drm_plane *plane,
 		struct drm_crtc *crtc, struct drm_framebuffer *fb,
 		int crtc_x, int crtc_y,
@@ -596,6 +676,9 @@ static int mdp5_plane_mode_set(struct drm_plane *plane,
 	const struct mdp_format *format;
 	uint32_t nplanes, config = 0;
 	uint32_t phasex_step[COMP_MAX] = {0,}, phasey_step[COMP_MAX] = {0,};
+	bool pe = mdp5_plane->caps & MDP_PIPE_CAP_SW_PIX_EXT;
+	int pe_left[COMP_MAX], pe_right[COMP_MAX];
+	int pe_top[COMP_MAX], pe_bottom[COMP_MAX];
 	uint32_t hdecm = 0, vdecm = 0;
 	uint32_t pix_format;
 	bool vflip, hflip;
@@ -643,11 +726,18 @@ static int mdp5_plane_mode_set(struct drm_plane *plane,
 	if (ret)
 		return ret;
 
+	if (mdp5_plane->caps & MDP_PIPE_CAP_SW_PIX_EXT) {
+		calc_pixel_ext(format, src_w, crtc_w, phasex_step,
+					 pe_left, pe_right, true);
+		calc_pixel_ext(format, src_h, crtc_h, phasey_step,
+					pe_top, pe_bottom, false);
+	}
+
 	/* TODO calc hdecm, vdecm */
 
 	/* SCALE is used to both scale and up-sample chroma components */
-	config |= get_scale_config(format->chroma_sample, src_w, crtc_w, true);
-	config |= get_scale_config(format->chroma_sample, src_h, crtc_h, false);
+	config |= get_scale_config(format, src_w, crtc_w, true);
+	config |= get_scale_config(format, src_h, crtc_h, false);
 	DBG("scale config = %x", config);
 
 	hflip = !!(pstate->rotation & BIT(DRM_REFLECT_X));
@@ -696,11 +786,17 @@ static int mdp5_plane_mode_set(struct drm_plane *plane,
 	mdp5_write(mdp5_kms, REG_MDP5_PIPE_SRC_OP_MODE(pipe),
 			(hflip ? MDP5_PIPE_SRC_OP_MODE_FLIP_LR : 0) |
 			(vflip ? MDP5_PIPE_SRC_OP_MODE_FLIP_UD : 0) |
+			COND(pe, MDP5_PIPE_SRC_OP_MODE_SW_PIX_EXT_OVERRIDE) |
 			MDP5_PIPE_SRC_OP_MODE_BWC(BWC_LOSSLESS));
 
 	/* not using secure mode: */
 	mdp5_write(mdp5_kms, REG_MDP5_PIPE_SRC_ADDR_SW_STATUS(pipe), 0);
 
+	if (mdp5_plane->caps & MDP_PIPE_CAP_SW_PIX_EXT)
+		mdp5_write_pixel_ext(mdp5_kms, pipe, format,
+				src_w, pe_left, pe_right,
+				src_h, pe_top, pe_bottom);
+
 	if (mdp5_plane->caps & MDP_PIPE_CAP_SCALE) {
 		mdp5_write(mdp5_kms, REG_MDP5_PIPE_SCALE_PHASE_STEP_X(pipe),
 				phasex_step[COMP_0]);

drivers/gpu/drm/msm/mdp/mdp_kms.h

@@ -106,6 +106,7 @@ const struct msm_format *mdp_get_format(struct msm_kms *kms, uint32_t format);
 #define MDP_PIPE_CAP_SCALE			BIT(2)
 #define MDP_PIPE_CAP_CSC			BIT(3)
 #define MDP_PIPE_CAP_DECIMATION			BIT(4)
+#define MDP_PIPE_CAP_SW_PIX_EXT			BIT(5)
 
 static inline bool pipe_supports_yuv(uint32_t pipe_caps)
 {