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drm: lcdif: Add support for YUV planes
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The LCDIF includes a color space converter that supports YUV input. Use
it to support YUV planes, either through the converter if the output
format is RGB, or in conversion bypass mode otherwise.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Liu Ying <victor.liu@nxp.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220930083955.31580-5-laurent.pinchart@ideasonboard.com
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kbingham authored and Marek Vasut committed Oct 15, 2022
1 parent ec39dee commit 6cba31e
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Showing 2 changed files with 220 additions and 30 deletions.
245 changes: 216 additions & 29 deletions drivers/gpu/drm/mxsfb/lcdif_kms.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_color_mgmt.h>
#include <drm/drm_crtc.h>
#include <drm/drm_encoder.h>
#include <drm/drm_fb_dma_helper.h>
Expand All @@ -31,13 +32,126 @@
/* -----------------------------------------------------------------------------
* CRTC
*/

/*
* For conversion from YCbCr to RGB, the CSC operates as follows:
*
* |R| |A1 A2 A3| |Y + D1|
* |G| = |B1 B2 B3| * |Cb + D2|
* |B| |C1 C2 C3| |Cr + D3|
*
* The A, B and C coefficients are expressed as Q2.8 fixed point values, and
* the D coefficients as Q0.8. Despite the reference manual stating the
* opposite, the D1, D2 and D3 offset values are added to Y, Cb and Cr, not
* subtracted. They must thus be programmed with negative values.
*/
static const u32 lcdif_yuv2rgb_coeffs[3][2][6] = {
[DRM_COLOR_YCBCR_BT601] = {
[DRM_COLOR_YCBCR_LIMITED_RANGE] = {
/*
* BT.601 limited range:
*
* |R| |1.1644 0.0000 1.5960| |Y - 16 |
* |G| = |1.1644 -0.3917 -0.8129| * |Cb - 128|
* |B| |1.1644 2.0172 0.0000| |Cr - 128|
*/
CSC0_COEF0_A1(0x12a) | CSC0_COEF0_A2(0x000),
CSC0_COEF1_A3(0x199) | CSC0_COEF1_B1(0x12a),
CSC0_COEF2_B2(0x79c) | CSC0_COEF2_B3(0x730),
CSC0_COEF3_C1(0x12a) | CSC0_COEF3_C2(0x204),
CSC0_COEF4_C3(0x000) | CSC0_COEF4_D1(0x1f0),
CSC0_COEF5_D2(0x180) | CSC0_COEF5_D3(0x180),
},
[DRM_COLOR_YCBCR_FULL_RANGE] = {
/*
* BT.601 full range:
*
* |R| |1.0000 0.0000 1.4020| |Y - 0 |
* |G| = |1.0000 -0.3441 -0.7141| * |Cb - 128|
* |B| |1.0000 1.7720 0.0000| |Cr - 128|
*/
CSC0_COEF0_A1(0x100) | CSC0_COEF0_A2(0x000),
CSC0_COEF1_A3(0x167) | CSC0_COEF1_B1(0x100),
CSC0_COEF2_B2(0x7a8) | CSC0_COEF2_B3(0x749),
CSC0_COEF3_C1(0x100) | CSC0_COEF3_C2(0x1c6),
CSC0_COEF4_C3(0x000) | CSC0_COEF4_D1(0x000),
CSC0_COEF5_D2(0x180) | CSC0_COEF5_D3(0x180),
},
},
[DRM_COLOR_YCBCR_BT709] = {
[DRM_COLOR_YCBCR_LIMITED_RANGE] = {
/*
* Rec.709 limited range:
*
* |R| |1.1644 0.0000 1.7927| |Y - 16 |
* |G| = |1.1644 -0.2132 -0.5329| * |Cb - 128|
* |B| |1.1644 2.1124 0.0000| |Cr - 128|
*/
CSC0_COEF0_A1(0x12a) | CSC0_COEF0_A2(0x000),
CSC0_COEF1_A3(0x1cb) | CSC0_COEF1_B1(0x12a),
CSC0_COEF2_B2(0x7c9) | CSC0_COEF2_B3(0x778),
CSC0_COEF3_C1(0x12a) | CSC0_COEF3_C2(0x21d),
CSC0_COEF4_C3(0x000) | CSC0_COEF4_D1(0x1f0),
CSC0_COEF5_D2(0x180) | CSC0_COEF5_D3(0x180),
},
[DRM_COLOR_YCBCR_FULL_RANGE] = {
/*
* Rec.709 full range:
*
* |R| |1.0000 0.0000 1.5748| |Y - 0 |
* |G| = |1.0000 -0.1873 -0.4681| * |Cb - 128|
* |B| |1.0000 1.8556 0.0000| |Cr - 128|
*/
CSC0_COEF0_A1(0x100) | CSC0_COEF0_A2(0x000),
CSC0_COEF1_A3(0x193) | CSC0_COEF1_B1(0x100),
CSC0_COEF2_B2(0x7d0) | CSC0_COEF2_B3(0x788),
CSC0_COEF3_C1(0x100) | CSC0_COEF3_C2(0x1db),
CSC0_COEF4_C3(0x000) | CSC0_COEF4_D1(0x000),
CSC0_COEF5_D2(0x180) | CSC0_COEF5_D3(0x180),
},
},
[DRM_COLOR_YCBCR_BT2020] = {
[DRM_COLOR_YCBCR_LIMITED_RANGE] = {
/*
* BT.2020 limited range:
*
* |R| |1.1644 0.0000 1.6787| |Y - 16 |
* |G| = |1.1644 -0.1874 -0.6505| * |Cb - 128|
* |B| |1.1644 2.1418 0.0000| |Cr - 128|
*/
CSC0_COEF0_A1(0x12a) | CSC0_COEF0_A2(0x000),
CSC0_COEF1_A3(0x1ae) | CSC0_COEF1_B1(0x12a),
CSC0_COEF2_B2(0x7d0) | CSC0_COEF2_B3(0x759),
CSC0_COEF3_C1(0x12a) | CSC0_COEF3_C2(0x224),
CSC0_COEF4_C3(0x000) | CSC0_COEF4_D1(0x1f0),
CSC0_COEF5_D2(0x180) | CSC0_COEF5_D3(0x180),
},
[DRM_COLOR_YCBCR_FULL_RANGE] = {
/*
* BT.2020 full range:
*
* |R| |1.0000 0.0000 1.4746| |Y - 0 |
* |G| = |1.0000 -0.1646 -0.5714| * |Cb - 128|
* |B| |1.0000 1.8814 0.0000| |Cr - 128|
*/
CSC0_COEF0_A1(0x100) | CSC0_COEF0_A2(0x000),
CSC0_COEF1_A3(0x179) | CSC0_COEF1_B1(0x100),
CSC0_COEF2_B2(0x7d6) | CSC0_COEF2_B3(0x76e),
CSC0_COEF3_C1(0x100) | CSC0_COEF3_C2(0x1e2),
CSC0_COEF4_C3(0x000) | CSC0_COEF4_D1(0x000),
CSC0_COEF5_D2(0x180) | CSC0_COEF5_D3(0x180),
},
},
};

static void lcdif_set_formats(struct lcdif_drm_private *lcdif,
struct drm_plane_state *plane_state,
const u32 bus_format)
{
struct drm_device *drm = lcdif->drm;
const u32 format = lcdif->crtc.primary->state->fb->format->format;

writel(CSC0_CTRL_BYPASS, lcdif->base + LCDC_V8_CSC0_CTRL);
const u32 format = plane_state->fb->format->format;
bool in_yuv = false;
bool out_yuv = false;

switch (bus_format) {
case MEDIA_BUS_FMT_RGB565_1X16:
Expand All @@ -51,37 +165,15 @@ static void lcdif_set_formats(struct lcdif_drm_private *lcdif,
case MEDIA_BUS_FMT_UYVY8_1X16:
writel(DISP_PARA_LINE_PATTERN_UYVY_H,
lcdif->base + LCDC_V8_DISP_PARA);

/*
* CSC: BT.601 Limited Range RGB to YCbCr coefficients.
*
* |Y | | 0.2568 0.5041 0.0979| |R| |16 |
* |Cb| = |-0.1482 -0.2910 0.4392| * |G| + |128|
* |Cr| | 0.4392 0.4392 -0.3678| |B| |128|
*/
writel(CSC0_COEF0_A2(0x081) | CSC0_COEF0_A1(0x041),
lcdif->base + LCDC_V8_CSC0_COEF0);
writel(CSC0_COEF1_B1(0x7db) | CSC0_COEF1_A3(0x019),
lcdif->base + LCDC_V8_CSC0_COEF1);
writel(CSC0_COEF2_B3(0x070) | CSC0_COEF2_B2(0x7b6),
lcdif->base + LCDC_V8_CSC0_COEF2);
writel(CSC0_COEF3_C2(0x7a2) | CSC0_COEF3_C1(0x070),
lcdif->base + LCDC_V8_CSC0_COEF3);
writel(CSC0_COEF4_D1(0x010) | CSC0_COEF4_C3(0x7ee),
lcdif->base + LCDC_V8_CSC0_COEF4);
writel(CSC0_COEF5_D3(0x080) | CSC0_COEF5_D2(0x080),
lcdif->base + LCDC_V8_CSC0_COEF5);

writel(CSC0_CTRL_CSC_MODE_RGB2YCbCr,
lcdif->base + LCDC_V8_CSC0_CTRL);

out_yuv = true;
break;
default:
dev_err(drm->dev, "Unknown media bus format 0x%x\n", bus_format);
break;
}

switch (format) {
/* RGB Formats */
case DRM_FORMAT_RGB565:
writel(CTRLDESCL0_5_BPP_16_RGB565,
lcdif->base + LCDC_V8_CTRLDESCL0_5);
Expand All @@ -106,10 +198,84 @@ static void lcdif_set_formats(struct lcdif_drm_private *lcdif,
writel(CTRLDESCL0_5_BPP_32_ARGB8888,
lcdif->base + LCDC_V8_CTRLDESCL0_5);
break;

/* YUV Formats */
case DRM_FORMAT_YUYV:
writel(CTRLDESCL0_5_BPP_YCbCr422 | CTRLDESCL0_5_YUV_FORMAT_VY2UY1,
lcdif->base + LCDC_V8_CTRLDESCL0_5);
in_yuv = true;
break;
case DRM_FORMAT_YVYU:
writel(CTRLDESCL0_5_BPP_YCbCr422 | CTRLDESCL0_5_YUV_FORMAT_UY2VY1,
lcdif->base + LCDC_V8_CTRLDESCL0_5);
in_yuv = true;
break;
case DRM_FORMAT_UYVY:
writel(CTRLDESCL0_5_BPP_YCbCr422 | CTRLDESCL0_5_YUV_FORMAT_Y2VY1U,
lcdif->base + LCDC_V8_CTRLDESCL0_5);
in_yuv = true;
break;
case DRM_FORMAT_VYUY:
writel(CTRLDESCL0_5_BPP_YCbCr422 | CTRLDESCL0_5_YUV_FORMAT_Y2UY1V,
lcdif->base + LCDC_V8_CTRLDESCL0_5);
in_yuv = true;
break;

default:
dev_err(drm->dev, "Unknown pixel format 0x%x\n", format);
break;
}

/*
* The CSC differentiates between "YCbCr" and "YUV", but the reference
* manual doesn't detail how they differ. Experiments showed that the
* luminance value is unaffected, only the calculations involving chroma
* values differ. The YCbCr mode behaves as expected, with chroma values
* being offset by 128. The YUV mode isn't fully understood.
*/
if (!in_yuv && out_yuv) {
/* RGB -> YCbCr */
writel(CSC0_CTRL_CSC_MODE_RGB2YCbCr,
lcdif->base + LCDC_V8_CSC0_CTRL);

/*
* CSC: BT.601 Limited Range RGB to YCbCr coefficients.
*
* |Y | | 0.2568 0.5041 0.0979| |R| |16 |
* |Cb| = |-0.1482 -0.2910 0.4392| * |G| + |128|
* |Cr| | 0.4392 0.4392 -0.3678| |B| |128|
*/
writel(CSC0_COEF0_A2(0x081) | CSC0_COEF0_A1(0x041),
lcdif->base + LCDC_V8_CSC0_COEF0);
writel(CSC0_COEF1_B1(0x7db) | CSC0_COEF1_A3(0x019),
lcdif->base + LCDC_V8_CSC0_COEF1);
writel(CSC0_COEF2_B3(0x070) | CSC0_COEF2_B2(0x7b6),
lcdif->base + LCDC_V8_CSC0_COEF2);
writel(CSC0_COEF3_C2(0x7a2) | CSC0_COEF3_C1(0x070),
lcdif->base + LCDC_V8_CSC0_COEF3);
writel(CSC0_COEF4_D1(0x010) | CSC0_COEF4_C3(0x7ee),
lcdif->base + LCDC_V8_CSC0_COEF4);
writel(CSC0_COEF5_D3(0x080) | CSC0_COEF5_D2(0x080),
lcdif->base + LCDC_V8_CSC0_COEF5);
} else if (in_yuv && !out_yuv) {
/* YCbCr -> RGB */
const u32 *coeffs =
lcdif_yuv2rgb_coeffs[plane_state->color_encoding]
[plane_state->color_range];

writel(CSC0_CTRL_CSC_MODE_YCbCr2RGB,
lcdif->base + LCDC_V8_CSC0_CTRL);

writel(coeffs[0], lcdif->base + LCDC_V8_CSC0_COEF0);
writel(coeffs[1], lcdif->base + LCDC_V8_CSC0_COEF1);
writel(coeffs[2], lcdif->base + LCDC_V8_CSC0_COEF2);
writel(coeffs[3], lcdif->base + LCDC_V8_CSC0_COEF3);
writel(coeffs[4], lcdif->base + LCDC_V8_CSC0_COEF4);
writel(coeffs[5], lcdif->base + LCDC_V8_CSC0_COEF5);
} else {
/* RGB -> RGB, YCbCr -> YCbCr: bypass colorspace converter. */
writel(CSC0_CTRL_BYPASS, lcdif->base + LCDC_V8_CSC0_CTRL);
}
}

static void lcdif_set_mode(struct lcdif_drm_private *lcdif, u32 bus_flags)
Expand Down Expand Up @@ -194,6 +360,7 @@ static void lcdif_reset_block(struct lcdif_drm_private *lcdif)
}

static void lcdif_crtc_mode_set_nofb(struct lcdif_drm_private *lcdif,
struct drm_plane_state *plane_state,
struct drm_bridge_state *bridge_state,
const u32 bus_format)
{
Expand All @@ -216,7 +383,7 @@ static void lcdif_crtc_mode_set_nofb(struct lcdif_drm_private *lcdif,
/* Mandatory eLCDIF reset as per the Reference Manual */
lcdif_reset_block(lcdif);

lcdif_set_formats(lcdif, bus_format);
lcdif_set_formats(lcdif, plane_state, bus_format);

lcdif_set_mode(lcdif, bus_flags);
}
Expand Down Expand Up @@ -299,7 +466,7 @@ static void lcdif_crtc_atomic_enable(struct drm_crtc *crtc,

pm_runtime_get_sync(drm->dev);

lcdif_crtc_mode_set_nofb(lcdif, bridge_state, bus_format);
lcdif_crtc_mode_set_nofb(lcdif, new_pstate, bridge_state, bus_format);

/* Write cur_buf as well to avoid an initial corrupt frame */
paddr = drm_fb_dma_get_gem_addr(new_pstate->fb, new_pstate, 0);
Expand Down Expand Up @@ -443,12 +610,19 @@ static const struct drm_plane_funcs lcdif_plane_funcs = {
};

static const u32 lcdif_primary_plane_formats[] = {
/* RGB */
DRM_FORMAT_RGB565,
DRM_FORMAT_RGB888,
DRM_FORMAT_XBGR8888,
DRM_FORMAT_XRGB1555,
DRM_FORMAT_XRGB4444,
DRM_FORMAT_XRGB8888,

/* Packed YCbCr */
DRM_FORMAT_YUYV,
DRM_FORMAT_YVYU,
DRM_FORMAT_UYVY,
DRM_FORMAT_VYUY,
};

static const u64 lcdif_modifiers[] = {
Expand All @@ -462,6 +636,11 @@ static const u64 lcdif_modifiers[] = {

int lcdif_kms_init(struct lcdif_drm_private *lcdif)
{
const u32 supported_encodings = BIT(DRM_COLOR_YCBCR_BT601) |
BIT(DRM_COLOR_YCBCR_BT709) |
BIT(DRM_COLOR_YCBCR_BT2020);
const u32 supported_ranges = BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) |
BIT(DRM_COLOR_YCBCR_FULL_RANGE);
struct drm_encoder *encoder = &lcdif->encoder;
struct drm_crtc *crtc = &lcdif->crtc;
int ret;
Expand All @@ -477,6 +656,14 @@ int lcdif_kms_init(struct lcdif_drm_private *lcdif)
if (ret)
return ret;

ret = drm_plane_create_color_properties(&lcdif->planes.primary,
supported_encodings,
supported_ranges,
DRM_COLOR_YCBCR_BT601,
DRM_COLOR_YCBCR_LIMITED_RANGE);
if (ret)
return ret;

drm_crtc_helper_add(crtc, &lcdif_crtc_helper_funcs);
ret = drm_crtc_init_with_planes(lcdif->drm, crtc,
&lcdif->planes.primary, NULL,
Expand Down
5 changes: 4 additions & 1 deletion drivers/gpu/drm/mxsfb/lcdif_regs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -212,7 +212,10 @@
#define CTRLDESCL0_5_YUV_FORMAT_UY2VY1 (0x3 << 14)
#define CTRLDESCL0_5_YUV_FORMAT_MASK GENMASK(15, 14)

#define CSC0_CTRL_CSC_MODE_RGB2YCbCr GENMASK(2, 1)
#define CSC0_CTRL_CSC_MODE_YUV2RGB (0x0 << 1)
#define CSC0_CTRL_CSC_MODE_YCbCr2RGB (0x1 << 1)
#define CSC0_CTRL_CSC_MODE_RGB2YUV (0x2 << 1)
#define CSC0_CTRL_CSC_MODE_RGB2YCbCr (0x3 << 1)
#define CSC0_CTRL_CSC_MODE_MASK GENMASK(2, 1)
#define CSC0_CTRL_BYPASS BIT(0)

Expand Down

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