Messages in this thread | | | From | CK Hu (胡俊光) <> | Subject | Re: [PATCH v10 13/16] drm/mediatek: gamma: Program gamma LUT type for descending or rising | Date | Thu, 12 Oct 2023 01:40:44 +0000 |
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Hi, Angelo:
On Fri, 2023-08-04 at 09:28 +0200, AngeloGioacchino Del Regno wrote: > All of the SoCs that don't have dithering control in the gamma IP > have got a GAMMA_LUT_TYPE bit that tells to the IP if the LUT is > "descending" (bit set) or "rising" (bit cleared): make sure to set > it correctly after programming the LUT. > > Signed-off-by: AngeloGioacchino Del Regno < > angelogioacchino.delregno@collabora.com> > Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com> > Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com> > --- > drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c > b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c > index fbff9f97b737..d9a70238d524 100644 > --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c > +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c > @@ -22,6 +22,7 @@ > #define GAMMA_RELAY_MODE BIT(0) > #define GAMMA_LUT_EN BIT(1) > #define GAMMA_DITHERING BIT(2) > +#define GAMMA_LUT_TYPE BIT(2) > #define DISP_GAMMA_SIZE 0x0030 > #define DISP_GAMMA_SIZE_HSIZE GENMASK > (28, 16) > #define DISP_GAMMA_SIZE_VSIZE GENMASK > (12, 0) > @@ -86,6 +87,17 @@ unsigned int mtk_gamma_get_lut_size(struct device > *dev) > return LUT_SIZE_DEFAULT; > } > > +static bool mtk_gamma_lut_is_descending(struct drm_color_lut *lut, > u32 lut_size) > +{ > + u64 first, last; > + int last_entry = lut_size - 1; > + > + first = lut[0].red + lut[0].green + lut[0].blue; > + last = lut[last_entry].red + lut[last_entry].green + > lut[last_entry].blue; > + > + return !!(first > last); > +} > + > /* > * SoCs supporting 12-bits LUTs are using a new register layout that > does > * always support (by HW) both 12-bits and 10-bits LUT but, on > those, we > @@ -175,6 +187,14 @@ void mtk_gamma_set(struct device *dev, struct > drm_crtc_state *state) > } > } > > + if (!gamma->data->has_dither) { > + /* Descending or Rising LUT */ > + if (mtk_gamma_lut_is_descending(lut, gamma->data- > >lut_size - 1)) > + cfg_val |= FIELD_PREP(GAMMA_LUT_TYPE, 1);
Reviewed-by: CK Hu <ck.hu@mediatek.com>
But I'm not sure why not write it more simply as
cfg_val |= GAMMA_LUT_TYPE;
Regards, CK
> + else > + cfg_val &= ~GAMMA_LUT_TYPE; > + } > + > /* Enable the gamma table */ > cfg_val |= FIELD_PREP(GAMMA_LUT_EN, 1); >
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