Commit 692e1a08 authored by AngeloGioacchino Del Regno's avatar AngeloGioacchino Del Regno Committed by Chun-Kuang Hu
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drm/mediatek: gamma: Program gamma LUT type for descending or rising 



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.

Reviewed-by: default avatarJason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: default avatarAlexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: default avatarCK Hu <ck.hu@mediatek.com>
Signed-off-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20231012095736.100784-14-angelogioacchino.delregno@collabora.com/


Signed-off-by: default avatarChun-Kuang Hu <chunkuang.hu@kernel.org>
parent 921e902b

drivers/gpu/drm/mediatek/mtk_disp_gamma.c

+20 −0
Original line number Diff line number Diff line
@@ -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)
@@ -82,6 +83,17 @@ unsigned int mtk_gamma_get_lut_size(struct device *dev) 
	return 0;

}



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
@@ -173,6 +185,14 @@ void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state) 


	cfg_val = readl(gamma->regs + DISP_GAMMA_CFG);



	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);

		else

			cfg_val &= ~GAMMA_LUT_TYPE;

	}



	/* Enable the gamma table */

	cfg_val |= FIELD_PREP(GAMMA_LUT_EN, 1);