[PATCH v1 1/3] drm/tegra: dc: Enable plane scaling filters

From: Dmitry Osipenko
Date: Thu May 03 2018 - 20:11:04 EST


Currently resized plane produces a "pixelated" image which doesn't look
nice, especially in a case of a video overlay. Enable scaling filters that
significantly improve image quality of a scaled overlay.

Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
drivers/gpu/drm/tegra/dc.c | 51 ++++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/tegra/dc.h | 7 ++++++
2 files changed, 58 insertions(+)

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 9f83a65b5ea9..2e81142281c3 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -361,6 +361,47 @@ static void tegra_dc_setup_window(struct tegra_plane *plane,
if (window->bottom_up)
value |= V_DIRECTION;

+ if (!(dc->soc->has_win_a_without_filter && plane->index == 0) &&
+ !(window->src.w == window->dst.w)) {
+ /*
+ * Enable horizontal 6-tap filter and set filtering
+ * coefficients to the default values defined in TRM.
+ */
+ tegra_plane_writel(plane, 0x00008000, DC_WIN_H_FILTER_P(0));
+ tegra_plane_writel(plane, 0x3e087ce1, DC_WIN_H_FILTER_P(1));
+ tegra_plane_writel(plane, 0x3b117ac1, DC_WIN_H_FILTER_P(2));
+ tegra_plane_writel(plane, 0x591b73aa, DC_WIN_H_FILTER_P(3));
+ tegra_plane_writel(plane, 0x57256d9a, DC_WIN_H_FILTER_P(4));
+ tegra_plane_writel(plane, 0x552f668b, DC_WIN_H_FILTER_P(5));
+ tegra_plane_writel(plane, 0x73385e8b, DC_WIN_H_FILTER_P(6));
+ tegra_plane_writel(plane, 0x72435583, DC_WIN_H_FILTER_P(7));
+ tegra_plane_writel(plane, 0x714c4c8b, DC_WIN_H_FILTER_P(8));
+ tegra_plane_writel(plane, 0x70554393, DC_WIN_H_FILTER_P(9));
+ tegra_plane_writel(plane, 0x715e389b, DC_WIN_H_FILTER_P(10));
+ tegra_plane_writel(plane, 0x71662faa, DC_WIN_H_FILTER_P(11));
+ tegra_plane_writel(plane, 0x536d25ba, DC_WIN_H_FILTER_P(12));
+ tegra_plane_writel(plane, 0x55731bca, DC_WIN_H_FILTER_P(13));
+ tegra_plane_writel(plane, 0x387a11d9, DC_WIN_H_FILTER_P(14));
+ tegra_plane_writel(plane, 0x3c7c08f1, DC_WIN_H_FILTER_P(15));
+
+ value |= H_FILTER;
+ }
+
+ if (!(dc->soc->has_win_a_without_filter && plane->index == 0) &&
+ !(dc->soc->has_win_c_without_vert_filter && plane->index == 2) &&
+ !(window->src.h == window->dst.h)) {
+ unsigned int i, k;
+
+ /*
+ * Enable vertical 2-tap filter and set filtering
+ * coefficients to the default values defined in TRM.
+ */
+ for (i = 0, k = 128; i < 16; i++, k -= 8)
+ tegra_plane_writel(plane, k, DC_WIN_V_FILTER_P(i));
+
+ value |= V_FILTER;
+ }
+
tegra_plane_writel(plane, value, DC_WIN_WIN_OPTIONS);

if (dc->soc->supports_blending)
@@ -1978,6 +2019,8 @@ static const struct tegra_dc_soc_info tegra20_dc_soc_info = {
.num_overlay_formats = ARRAY_SIZE(tegra20_overlay_formats),
.overlay_formats = tegra20_overlay_formats,
.modifiers = tegra20_modifiers,
+ .has_win_a_without_filter = true,
+ .has_win_c_without_vert_filter = true,
};

static const struct tegra_dc_soc_info tegra30_dc_soc_info = {
@@ -1995,6 +2038,8 @@ static const struct tegra_dc_soc_info tegra30_dc_soc_info = {
.num_overlay_formats = ARRAY_SIZE(tegra20_overlay_formats),
.overlay_formats = tegra20_overlay_formats,
.modifiers = tegra20_modifiers,
+ .has_win_a_without_filter = false,
+ .has_win_c_without_vert_filter = false,
};

static const struct tegra_dc_soc_info tegra114_dc_soc_info = {
@@ -2012,6 +2057,8 @@ static const struct tegra_dc_soc_info tegra114_dc_soc_info = {
.num_overlay_formats = ARRAY_SIZE(tegra114_overlay_formats),
.overlay_formats = tegra114_overlay_formats,
.modifiers = tegra20_modifiers,
+ .has_win_a_without_filter = false,
+ .has_win_c_without_vert_filter = false,
};

static const struct tegra_dc_soc_info tegra124_dc_soc_info = {
@@ -2029,6 +2076,8 @@ static const struct tegra_dc_soc_info tegra124_dc_soc_info = {
.num_overlay_formats = ARRAY_SIZE(tegra124_overlay_formats),
.overlay_formats = tegra124_overlay_formats,
.modifiers = tegra124_modifiers,
+ .has_win_a_without_filter = false,
+ .has_win_c_without_vert_filter = false,
};

static const struct tegra_dc_soc_info tegra210_dc_soc_info = {
@@ -2046,6 +2095,8 @@ static const struct tegra_dc_soc_info tegra210_dc_soc_info = {
.num_overlay_formats = ARRAY_SIZE(tegra114_overlay_formats),
.overlay_formats = tegra114_overlay_formats,
.modifiers = tegra124_modifiers,
+ .has_win_a_without_filter = false,
+ .has_win_c_without_vert_filter = false,
};

static const struct tegra_windowgroup_soc tegra186_dc_wgrps[] = {
diff --git a/drivers/gpu/drm/tegra/dc.h b/drivers/gpu/drm/tegra/dc.h
index d2b50d32de4d..5c3d1d6faa3b 100644
--- a/drivers/gpu/drm/tegra/dc.h
+++ b/drivers/gpu/drm/tegra/dc.h
@@ -67,6 +67,8 @@ struct tegra_dc_soc_info {
const u32 *overlay_formats;
unsigned int num_overlay_formats;
const u64 *modifiers;
+ bool has_win_a_without_filter;
+ bool has_win_c_without_vert_filter;
};

struct tegra_dc {
@@ -553,6 +555,9 @@ int tegra_dc_rgb_exit(struct tegra_dc *dc);
#define THREAD_NUM(x) (((x) & 0x1f) << 1)
#define THREAD_GROUP_ENABLE (1 << 0)

+#define DC_WIN_H_FILTER_P(p) (0x601 + p)
+#define DC_WIN_V_FILTER_P(p) (0x619 + p)
+
#define DC_WIN_CSC_YOF 0x611
#define DC_WIN_CSC_KYRGB 0x612
#define DC_WIN_CSC_KUR 0x613
@@ -566,6 +571,8 @@ int tegra_dc_rgb_exit(struct tegra_dc *dc);
#define H_DIRECTION (1 << 0)
#define V_DIRECTION (1 << 2)
#define COLOR_EXPAND (1 << 6)
+#define H_FILTER (1 << 8)
+#define V_FILTER (1 << 10)
#define CSC_ENABLE (1 << 18)
#define WIN_ENABLE (1 << 30)

--
2.17.0