Quoting Laurent Pinchart (2022-09-28 11:05:33)
> Hi Kieran,
>
> On Wed, Sep 28, 2022 at 10:59:36AM +0100, Kieran Bingham wrote:
> > Quoting Laurent Pinchart (2022-09-28 01:58:12)
> > > From: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>
> >
> > It looks like this has progressed a bit since it left my computer ;-)
>
> I wish the same would be universally true for all patches :-)
>
> > > 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@xxxxxxxxxxxxxxxx>
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > > ---
> > > Changes since v1:
> > >
> > > - Support all YCbCr encodings and quantization ranges
> > > - Drop incorrect comment
> > > ---
> > > drivers/gpu/drm/mxsfb/lcdif_kms.c | 183 +++++++++++++++++++++++++----
> > > drivers/gpu/drm/mxsfb/lcdif_regs.h | 5 +-
> > > 2 files changed, 164 insertions(+), 24 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/mxsfb/lcdif_kms.c b/drivers/gpu/drm/mxsfb/lcdif_kms.c
> > > index c3622be0c587..b469a90fd50f 100644
> > > --- a/drivers/gpu/drm/mxsfb/lcdif_kms.c
> > > +++ b/drivers/gpu/drm/mxsfb/lcdif_kms.c
> > > @@ -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_framebuffer.h>
> > > @@ -32,13 +33,77 @@
> > > /* -----------------------------------------------------------------------------
> > > * CRTC
> > > */
> > > +
> > > +/*
> > > + * Despite the reference manual stating the opposite, the D1, D2 and D3 offset
> > > + * values are added to Y, U and V, not subtracted. They must thus be programmed
> > > + * with negative values.
> > > + */
> > > +static const u32 lcdif_yuv2rgb_coeffs[3][2][6] = {
> >
> > Ick ... I sort of dislike this. It's fine here at the moment, and I like
> > the table ... but here we're definining the size of the table based on
> > external enum values. (Are those ABI stable, perhaps they are already?)
> >
> > If someone were to put
> >
> > enum drm_color_encoding {
> > + DRM_COLOR_LEGACY,
> > DRM_COLOR_YCBCR_BT601,
> > DRM_COLOR_YCBCR_BT709,
> > DRM_COLOR_YCBCR_BT2020,
> > DRM_COLOR_ENCODING_MAX,
> > };
> >
> > enum drm_color_range {
> > DRM_COLOR_YCBCR_LIMITED_RANGE,
> > + DRM_COLOR_YCBCR_MID_RANGE,
> > DRM_COLOR_YCBCR_FULL_RANGE,
> > DRM_COLOR_RANGE_MAX,
> > };
> >
> > Then this table allocation would be wrong.
> >
> > Perhaps swapping for
> >
> > > +static const u32 lcdif_yuv2rgb_coeffs[DRM_COLOR_ENCODING_MAX][DRM_COLOR_RANGE_MAX][6] = {
> >
> > Would be safer ... but longer :-( ?
> >
> > Anyway, I think the rest of it looks fine, and perhaps these enums are
> > in the UAPI which would make them stable anyway:
>
> The enums themselves are not exposed in UAPI headers, but userspace
> depends on the values, which thus have to remain stable.
And I saw you had to redefine them to use them in libcamera. Perhaps
they should be in a UAPI header then...
--
Kieran
>
> > Reviewed-by: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>
> >
> > > + [DRM_COLOR_YCBCR_BT601] = {
> > > + [DRM_COLOR_YCBCR_LIMITED_RANGE] = {
> > > + CSC0_COEF0_A1(0x012a) | CSC0_COEF0_A2(0x0000),
> > > + CSC0_COEF1_A3(0x01a2) | CSC0_COEF1_B1(0x0123),
> > > + CSC0_COEF2_B2(0x079c) | CSC0_COEF2_B3(0x0730),
> > > + CSC0_COEF3_C1(0x0124) | CSC0_COEF3_C2(0x0204),
> > > + CSC0_COEF4_C3(0x0000) | CSC0_COEF4_D1(0x01f0),
> > > + CSC0_COEF5_D2(0x0180) | CSC0_COEF5_D3(0x0180),
> > > + },
> > > + [DRM_COLOR_YCBCR_FULL_RANGE] = {
> > > + CSC0_COEF0_A1(0x0100) | CSC0_COEF0_A2(0x0000),
> > > + CSC0_COEF1_A3(0x0167) | CSC0_COEF1_B1(0x0100),
> > > + CSC0_COEF2_B2(0x07a8) | CSC0_COEF2_B3(0x0749),
> > > + CSC0_COEF3_C1(0x0100) | CSC0_COEF3_C2(0x01c6),
> > > + CSC0_COEF4_C3(0x0000) | CSC0_COEF4_D1(0x0000),
> > > + CSC0_COEF5_D2(0x0180) | CSC0_COEF5_D3(0x0180),
> > > + },
> > > + },
> > > + [DRM_COLOR_YCBCR_BT709] = {
> > > + [DRM_COLOR_YCBCR_LIMITED_RANGE] = {
> > > + CSC0_COEF0_A1(0x012a) | CSC0_COEF0_A2(0x0000),
> > > + CSC0_COEF1_A3(0x01d6) | CSC0_COEF1_B1(0x0123),
> > > + CSC0_COEF2_B2(0x07c9) | CSC0_COEF2_B3(0x0778),
> > > + CSC0_COEF3_C1(0x0123) | CSC0_COEF3_C2(0x021d),
> > > + CSC0_COEF4_C3(0x0000) | CSC0_COEF4_D1(0x01f0),
> > > + CSC0_COEF5_D2(0x0180) | CSC0_COEF5_D3(0x0180),
> > > + },
> > > + [DRM_COLOR_YCBCR_FULL_RANGE] = {
> > > + CSC0_COEF0_A1(0x0100) | CSC0_COEF0_A2(0x0000),
> > > + CSC0_COEF1_A3(0x0193) | CSC0_COEF1_B1(0x0100),
> > > + CSC0_COEF2_B2(0x07d0) | CSC0_COEF2_B3(0x0788),
> > > + CSC0_COEF3_C1(0x0100) | CSC0_COEF3_C2(0x01db),
> > > + CSC0_COEF4_C3(0x0000) | CSC0_COEF4_D1(0x0000),
> > > + CSC0_COEF5_D2(0x0180) | CSC0_COEF5_D3(0x0180),
> > > + },
> > > + },
> > > + [DRM_COLOR_YCBCR_BT2020] = {
> > > + [DRM_COLOR_YCBCR_LIMITED_RANGE] = {
> > > + CSC0_COEF0_A1(0x012a) | CSC0_COEF0_A2(0x0000),
> > > + CSC0_COEF1_A3(0x01b8) | CSC0_COEF1_B1(0x0123),
> > > + CSC0_COEF2_B2(0x07d0) | CSC0_COEF2_B3(0x075a),
> > > + CSC0_COEF3_C1(0x0124) | CSC0_COEF3_C2(0x0224),
> > > + CSC0_COEF4_C3(0x0000) | CSC0_COEF4_D1(0x01f0),
> > > + CSC0_COEF5_D2(0x0180) | CSC0_COEF5_D3(0x0180),
> > > + },
> > > + [DRM_COLOR_YCBCR_FULL_RANGE] = {
> > > + CSC0_COEF0_A1(0x0100) | CSC0_COEF0_A2(0x0000),
> > > + CSC0_COEF1_A3(0x0179) | CSC0_COEF1_B1(0x0100),
> > > + CSC0_COEF2_B2(0x07d6) | CSC0_COEF2_B3(0x076e),
> > > + CSC0_COEF3_C1(0x0100) | CSC0_COEF3_C2(0x01e2),
> > > + CSC0_COEF4_C3(0x0000) | CSC0_COEF4_D1(0x0000),
> > > + CSC0_COEF5_D2(0x0180) | CSC0_COEF5_D3(0x0180),
> > > + },
> > > + },
> > > +};
> > > +
> > > 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:
> > > @@ -52,24 +117,7 @@ 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. */
> > > - 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);
> > > @@ -77,6 +125,7 @@ static void lcdif_set_formats(struct lcdif_drm_private *lcdif,
> > > }
> > >
> > > switch (format) {
> > > + /* RGB Formats */
> > > case DRM_FORMAT_RGB565:
> > > writel(CTRLDESCL0_5_BPP_16_RGB565,
> > > lcdif->base + LCDC_V8_CTRLDESCL0_5);
> > > @@ -101,10 +150,78 @@ static void lcdif_set_formats(struct lcdif_drm_private *lcdif,
> > > writel(CTRLDESCL0_5_BPP_32_ARGB8888,
> > > lcdif->base + LCDC_V8_CTRLDESCL0_5);
> > > break;
> > > +
> > > + /* YUYV 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. */
> > > + 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)
> > > @@ -201,6 +318,7 @@ 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)
> > > {
> > > @@ -223,7 +341,7 @@ 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);
> > > }
> > > @@ -306,7 +424,7 @@ 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_cma_get_gem_addr(new_pstate->fb, new_pstate, 0);
> > > @@ -456,6 +574,12 @@ static const u32 lcdif_primary_plane_formats[] = {
> > > 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[] = {
> > > @@ -469,6 +593,11 @@ 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;
> > > @@ -484,6 +613,14 @@ 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,
> > > diff --git a/drivers/gpu/drm/mxsfb/lcdif_regs.h b/drivers/gpu/drm/mxsfb/lcdif_regs.h
> > > index 0d5d9bedd94a..fb74eb5ccbf1 100644
> > > --- a/drivers/gpu/drm/mxsfb/lcdif_regs.h
> > > +++ b/drivers/gpu/drm/mxsfb/lcdif_regs.h
> > > @@ -216,7 +216,10 @@
> > > #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)
> > >
>
> --
> Regards,
>
> Laurent Pinchart
