Re: [PATCH v4 6/8] drm/mediatek: add matrix bits private data for ccorr

Hi, Hsin-Yi:

On Fri, 2021-01-29 at 15:34 +0800, Hsin-Yi Wang wrote:

From: Yongqiang Niu yongqiang.niu@mediatek.com

matrix bits of mt8183 is 12 matrix bits of mt8192 is 13

Signed-off-by: Yongqiang Niu yongqiang.niu@mediatek.com Signed-off-by: Hsin-Yi Wang hsinyi@chromium.org

---

drivers/gpu/drm/mediatek/mtk_disp_ccorr.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ccorr.c b/drivers/gpu/drm/mediatek/mtk_disp_ccorr.c index 0c68090eb1e92..1c7163a12f3b1 100644 --- a/drivers/gpu/drm/mediatek/mtk_disp_ccorr.c +++ b/drivers/gpu/drm/mediatek/mtk_disp_ccorr.c @@ -31,8 +31,10 @@ #define DISP_CCORR_COEF_3 0x008C #define DISP_CCORR_COEF_4 0x0090

+#define CCORR_MATRIX_BITS 12

struct mtk_disp_ccorr_data {

• u32 reserved;

• u32 matrix_bits;

};

/** @@ -116,6 +118,7 @@ void mtk_ccorr_ctm_set(struct device *dev, struct drm_crtc_state *state) uint16_t coeffs[9] = { 0 }; int i; struct cmdq_pkt *cmdq_pkt = NULL;

• u32 matrix_bits;

  if (!blob) return;

@@ -123,8 +126,16 @@ void mtk_ccorr_ctm_set(struct device *dev, struct drm_crtc_state *state) ctm = (struct drm_color_ctm *)blob->data; input = ctm->matrix;

• for (i = 0; i < ARRAY_SIZE(coeffs); i++)

• if (ccorr->data)

• matrix_bits = ccorr->data->matrix_bits;
  

• else

• matrix_bits = CCORR_MATRIX_BITS;
  

• for (i = 0; i < ARRAY_SIZE(coeffs); i++) { coeffs[i] = mtk_ctm_s31_32_to_s1_10(input[i]);

• if (matrix_bits > CCORR_MATRIX_BITS)
  

• 	coeffs[i] <<= (matrix_bits - CCORR_MATRIX_BITS);
  

I think format of MT8192 ccorr coeffs is s1.11, after mtk_ctm_s31_32_to_s1_10(), you lose one bit precision. So modify mtk_ctm_s31_32_to_s1_10() to get maximum precision.

Regards, CK

• }

  mtk_ddp_write(cmdq_pkt, coeffs[0] << 16 | coeffs[1], &ccorr->cmdq_reg, ccorr->regs, DISP_CCORR_COEF_0);

@@ -205,8 +216,13 @@ static int mtk_disp_ccorr_remove(struct platform_device *pdev) return 0; }

+static const struct mtk_disp_ccorr_data mt8183_ccorr_driver_data = {

• .matrix_bits = CCORR_MATRIX_BITS,

+};

static const struct of_device_id mtk_disp_ccorr_driver_dt_match[] = {

• { .compatible = "mediatek,mt8183-disp-ccorr"},

• { .compatible = "mediatek,mt8183-disp-ccorr",

•  .data = &mt8183_ccorr_driver_data},
  

  {},

}; MODULE_DEVICE_TABLE(of, mtk_disp_ccorr_driver_dt_match);