<pre>
Hi, Angelo:

On Fri, 2023-08-04 at 09:28 +0200, AngeloGioacchino Del Regno wrote:
> Make the code more robust and improve readability by using bitfield
> macros instead of open coding bit operations.
> While at it, also add a definition for LUT_BITS_DEFAULT.
>
> 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 | 41 ++++++++++++++-------
> --
> 1 file changed, 26 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> index 18b102bef370..ea91d3619716 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> @@ -3,6 +3,7 @@
> * Copyright (c) 2021 MediaTek Inc.
> */
>
> +#include <linux/bitfield.h>
> #include <linux/clk.h>
> #include <linux/component.h>
> #include <linux/module.h>
> @@ -21,9 +22,16 @@
> #define GAMMA_LUT_ENBIT(1)
> #define GAMMA_DITHERINGBIT(2)
> #define DISP_GAMMA_SIZE0x0030
> +#define DISP_GAMMA_SIZE_HSIZEGENMASK
> (28, 16)
> +#define DISP_GAMMA_SIZE_VSIZEGENMASK
> (12, 0)
> #define DISP_GAMMA_LUT0x0700
>
> +#define DISP_GAMMA_LUT_10BIT_RGENMASK(29, 20)
> +#define DISP_GAMMA_LUT_10BIT_GGENMASK(19, 10)
> +#define DISP_GAMMA_LUT_10BIT_BGENMASK(9, 0)
> +
> #define LUT_10BIT_MASK0x03ff
> +#define LUT_BITS_DEFAULT10
> #define LUT_SIZE_DEFAULT512
>
> struct mtk_disp_gamma_data {
> @@ -96,33 +104,33 @@ void mtk_gamma_set_common(struct device *dev,
> void __iomem *regs, struct drm_crt
> for (i = 0; i < lut_size; i++) {
> struct drm_color_lut diff, hwlut;
>
> -hwlut.red = drm_color_lut_extract(lut[i].red, 10);
> -hwlut.green = drm_color_lut_extract(lut[i].green, 10);
> -hwlut.blue = drm_color_lut_extract(lut[i].blue, 10);
> +hwlut.red = drm_color_lut_extract(lut[i].red,
> LUT_BITS_DEFAULT);

You finally drop LUT_BITS_DEFAULT, so it's not necessary to introduce
it in this patch. Let this patch only use bitfield macros.

Regards,
CK

> +hwlut.green = drm_color_lut_extract(lut[i].green,
> LUT_BITS_DEFAULT);
> +hwlut.blue = drm_color_lut_extract(lut[i].blue,
> LUT_BITS_DEFAULT);
>
> if (!lut_diff || (i % 2 == 0)) {
> -word = hwlut.red << 20 +
> - hwlut.green << 10 +
> - hwlut.red;
> +word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R,
> hwlut.red);
> +word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G,
> hwlut.green);
> +word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B,
> hwlut.blue);
> } else {
> diff.red = lut[i].red - lut[i - 1].red;
> -diff.red = drm_color_lut_extract(diff.red, 10);
> +diff.red = drm_color_lut_extract(diff.red,
> LUT_BITS_DEFAULT);
>
> diff.green = lut[i].green - lut[i - 1].green;
> -diff.green = drm_color_lut_extract(diff.green,
> 10);
> +diff.green = drm_color_lut_extract(diff.green,
> LUT_BITS_DEFAULT);
>
> diff.blue = lut[i].blue - lut[i - 1].blue;
> -diff.blue = drm_color_lut_extract(diff.blue,
> 10);
> +diff.blue = drm_color_lut_extract(diff.blue,
> LUT_BITS_DEFAULT);
>
> -word = diff.blue << 20 +
> - diff.green << 10 +
> - diff.red;
> +word = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R,
> diff.red);
> +word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G,
> diff.green);
> +word |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B,
> diff.blue);
> }
> writel(word, (lut_base + i * 4));
> }
>
> /* Enable the gamma table */
> -cfg_val = cfg_val | GAMMA_LUT_EN;
> +cfg_val |= FIELD_PREP(GAMMA_LUT_EN, 1);
>
> writel(cfg_val, regs + DISP_GAMMA_CFG);
> }
> @@ -139,9 +147,12 @@ void mtk_gamma_config(struct device *dev,
> unsigned int w,
> unsigned int bpc, struct cmdq_pkt *cmdq_pkt)
> {
> struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
> +u32 sz;
> +
> +sz = FIELD_PREP(DISP_GAMMA_SIZE_HSIZE, w);
> +sz |= FIELD_PREP(DISP_GAMMA_SIZE_VSIZE, h);
>
> -mtk_ddp_write(cmdq_pkt, h << 16 | w, &gamma->cmdq_reg, gamma-
> >regs,
> - DISP_GAMMA_SIZE);
> +mtk_ddp_write(cmdq_pkt, sz, &gamma->cmdq_reg, gamma->regs,
> DISP_GAMMA_SIZE);
> if (gamma->data && gamma->data->has_dither)
> mtk_dither_set_common(gamma->regs, &gamma->cmdq_reg,
> bpc,
> DISP_GAMMA_CFG, GAMMA_DITHERING,
> cmdq_pkt);

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