drm/tegra: dc: Implement hardware cursor on Tegra186 and later

The hardware cursor on Tegra186 differs slightly from the implementation
on older SoC generations. In particular the new implementation relies on
software for clipping the cursor against the screen. Fortunately, atomic
KMS already computes clipped coordinates for (cursor) planes, so this is
trivial to implement.

The format supported by the hardware cursor is also slightly different.

v2: use more drm_rect helpers (Dmitry)

Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/dc.c

@@ -832,10 +832,14 @@ static struct drm_plane *tegra_primary_plane_create(struct drm_device *drm,
 	return &plane->base;
 }
 
-static const u32 tegra_cursor_plane_formats[] = {
+static const u32 tegra_legacy_cursor_plane_formats[] = {
 	DRM_FORMAT_RGBA8888,
 };
 
+static const u32 tegra_cursor_plane_formats[] = {
+	DRM_FORMAT_ARGB8888,
+};
+
 static int tegra_cursor_atomic_check(struct drm_plane *plane,
 				     struct drm_atomic_state *state)
 {
@@ -875,12 +879,24 @@ static void tegra_cursor_atomic_update(struct drm_plane *plane,
 									   plane);
 	struct tegra_plane_state *tegra_plane_state = to_tegra_plane_state(new_state);
 	struct tegra_dc *dc = to_tegra_dc(new_state->crtc);
-	u32 value = CURSOR_CLIP_DISPLAY;
+	struct tegra_drm *tegra = plane->dev->dev_private;
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+	u64 dma_mask = *dc->dev->dma_mask;
+#endif
+	unsigned int x, y;
+	u32 value = 0;
 
 	/* rien ne va plus */
 	if (!new_state->crtc || !new_state->fb)
 		return;
 
+	/*
+	 * Legacy display supports hardware clipping of the cursor, but
+	 * nvdisplay relies on software to clip the cursor to the screen.
+	 */
+	if (!dc->soc->has_nvdisplay)
+		value |= CURSOR_CLIP_DISPLAY;
+
 	switch (new_state->crtc_w) {
 	case 32:
 		value |= CURSOR_SIZE_32x32;
@@ -908,7 +924,7 @@ static void tegra_cursor_atomic_update(struct drm_plane *plane,
 	tegra_dc_writel(dc, value, DC_DISP_CURSOR_START_ADDR);
 
 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
-	value = (tegra_plane_state->iova[0] >> 32) & 0x3;
+	value = (tegra_plane_state->iova[0] >> 32) & (dma_mask >> 32);
 	tegra_dc_writel(dc, value, DC_DISP_CURSOR_START_ADDR_HI);
 #endif
 
@@ -920,15 +936,39 @@ static void tegra_cursor_atomic_update(struct drm_plane *plane,
 	value = tegra_dc_readl(dc, DC_DISP_BLEND_CURSOR_CONTROL);
 	value &= ~CURSOR_DST_BLEND_MASK;
 	value &= ~CURSOR_SRC_BLEND_MASK;
+
+	if (dc->soc->has_nvdisplay)
+		value &= ~CURSOR_COMPOSITION_MODE_XOR;
+	else
 		value |= CURSOR_MODE_NORMAL;
+
 	value |= CURSOR_DST_BLEND_NEG_K1_TIMES_SRC;
 	value |= CURSOR_SRC_BLEND_K1_TIMES_SRC;
 	value |= CURSOR_ALPHA;
 	tegra_dc_writel(dc, value, DC_DISP_BLEND_CURSOR_CONTROL);
 
+	/* nvdisplay relies on software for clipping */
+	if (dc->soc->has_nvdisplay) {
+		struct drm_rect src;
+
+		x = new_state->dst.x1;
+		y = new_state->dst.y1;
+
+		drm_rect_fp_to_int(&src, &new_state->src);
+
+		value = (src.y1 & tegra->vmask) << 16 | (src.x1 & tegra->hmask);
+		tegra_dc_writel(dc, value, DC_DISP_PCALC_HEAD_SET_CROPPED_POINT_IN_CURSOR);
+
+		value = (drm_rect_height(&src) & tegra->vmask) << 16 |
+			(drm_rect_width(&src) & tegra->hmask);
+		tegra_dc_writel(dc, value, DC_DISP_PCALC_HEAD_SET_CROPPED_SIZE_IN_CURSOR);
+	} else {
+		x = new_state->crtc_x;
+		y = new_state->crtc_y;
+	}
+
 	/* position the cursor */
-	value = (new_state->crtc_y & 0x3fff) << 16 |
+	value = ((y & tegra->vmask) << 16) | (x & tegra->hmask);
-		(new_state->crtc_x & 0x3fff);
 	tegra_dc_writel(dc, value, DC_DISP_CURSOR_POSITION);
 }
 
@@ -982,8 +1022,13 @@ static struct drm_plane *tegra_dc_cursor_plane_create(struct drm_device *drm,
 	plane->index = 6;
 	plane->dc = dc;
 
+	if (!dc->soc->has_nvdisplay) {
+		num_formats = ARRAY_SIZE(tegra_legacy_cursor_plane_formats);
+		formats = tegra_legacy_cursor_plane_formats;
+	} else {
 		num_formats = ARRAY_SIZE(tegra_cursor_plane_formats);
 		formats = tegra_cursor_plane_formats;
+	}
 
 	err = drm_universal_plane_init(drm, &plane->base, possible_crtcs,
 				       &tegra_plane_funcs, formats,

drivers/gpu/drm/tegra/dc.h

@@ -511,6 +511,8 @@ int tegra_dc_rgb_exit(struct tegra_dc *dc);
 
 #define DC_DISP_CURSOR_START_ADDR_HI		0x4ec
 #define DC_DISP_BLEND_CURSOR_CONTROL		0x4f1
+#define CURSOR_COMPOSITION_MODE_BLEND		(0 << 25)
+#define CURSOR_COMPOSITION_MODE_XOR		(1 << 25)
 #define CURSOR_MODE_LEGACY			(0 << 24)
 #define CURSOR_MODE_NORMAL			(1 << 24)
 #define CURSOR_DST_BLEND_ZERO			(0 << 16)
@@ -705,6 +707,9 @@ int tegra_dc_rgb_exit(struct tegra_dc *dc);
 #define PROTOCOL_MASK (0xf << 8)
 #define PROTOCOL_SINGLE_TMDS_A (0x1 << 8)
 
+#define DC_DISP_PCALC_HEAD_SET_CROPPED_POINT_IN_CURSOR	0x442
+#define DC_DISP_PCALC_HEAD_SET_CROPPED_SIZE_IN_CURSOR	0x446
+
 #define DC_WIN_CORE_WINDOWGROUP_SET_CONTROL	0x702
 #define OWNER_MASK (0xf << 0)
 #define OWNER(x) (((x) & 0xf) << 0)