Re: [PATCH v4 06/11] drm/mediatek: gamma: Use bitfield macros

[CK Hu (胡俊光)]

Hi, Angelo:

On Thu, 2023-05-18 at 12:48 +0200, AngeloGioacchino Del Regno wrote:
> External email : Please do not click links or open attachments until
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> 
> 
> 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@xxxxxxxxxxxxx>
> Reviewed-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
> ---
>  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 1592614b6de7..ed2aa1fb0171 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>
> @@ -22,9 +23,16 @@
>  #define GAMMA_LUT_EN                                   BIT(1)
>  #define
> GAMMA_DITHERING                                        BIT(2)
>  #define DISP_GAMMA_SIZE                                0x0030
> +#define DISP_GAMMA_SIZE_HSIZE                          GENMASK(28,
> 16)
> +#define DISP_GAMMA_SIZE_VSIZE                          GENMASK(12,
> 0)
>  #define DISP_GAMMA_LUT                         0x0700
> 
> +#define DISP_GAMMA_LUT_10BIT_R                 GENMASK(29, 20)
> +#define DISP_GAMMA_LUT_10BIT_G                 GENMASK(19, 10)
> +#define DISP_GAMMA_LUT_10BIT_B                 GENMASK(9, 0)
> +
>  #define LUT_10BIT_MASK                         0x03ff
> +#define LUT_BITS_DEFAULT                       10

This is used only for AAL after patch "drm/mediatek: gamma: Support
specifying number of bits per LUT component", so I would like move AAL
definition to AAL driver and pass it to gamma driver.

Regards,
CK

>  #define LUT_SIZE_DEFAULT                       512 /* for setting
> gamma lut from AAL */
> 
>  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);
> +               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);
> --
> 2.40.1
>