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Date:   Wed, 11 Oct 2023 12:05:19 -0400
From:   =?utf-8?B?TsOtY29sYXMgRi4gUi4gQS4=?= Prado 
        <nfraprado@collabora.com>
To:     AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
Cc:     chunkuang.hu@kernel.org, p.zabel@pengutronix.de, airlied@gmail.com,
        daniel@ffwll.ch, matthias.bgg@gmail.com,
        dri-devel@lists.freedesktop.org,
        linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, wenst@chromium.org,
        kernel@collabora.com, ehristev@collabora.com
Subject: Re: [PATCH v10 08/16] drm/mediatek: De-commonize disp_aal/disp_gamma
 gamma_set functions
Message-ID: <8cf3d18a-fe99-49c5-8d0c-eb5deaef79d6@notapiano>
References: <20230804072850.89365-1-angelogioacchino.delregno@collabora.com>
 <20230804072850.89365-9-angelogioacchino.delregno@collabora.com>
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In-Reply-To: <20230804072850.89365-9-angelogioacchino.delregno@collabora.com>
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On Fri, Aug 04, 2023 at 09:28:42AM +0200, AngeloGioacchino Del Regno wrote:
> In preparation for adding a 12-bits gamma support for the DISP_GAMMA
> IP, remove the mtk_gamma_set_common() function and move the relevant
> bits in mtk_gamma_set() for DISP_GAMMA and mtk_aal_gamma_set() for
> DISP_AAL: since the latter has no more support for gamma manipulation
> (being moved to a different IP) in newer revisions, those functions
> are about to diverge and it makes no sense to keep a common one (with
> all the complications of passing common data and making exclusions
> for device driver data) for just a few bits.
> 
> This commit brings no functional changes.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_aal.c   | 39 +++++++++++++++++++++--
>  drivers/gpu/drm/mediatek/mtk_disp_drv.h   |  1 -
>  drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 34 ++++----------------
>  3 files changed, 44 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_aal.c b/drivers/gpu/drm/mediatek/mtk_disp_aal.c
> index bec035780db0..21b25470e9b7 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_aal.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_aal.c
> @@ -17,10 +17,18 @@
>  
>  #define DISP_AAL_EN				0x0000
>  #define AAL_EN						BIT(0)
> +#define DISP_AAL_CFG				0x0020
> +#define AAL_RELAY_MODE					BIT(0)
> +#define AAL_GAMMA_LUT_EN				BIT(1)
>  #define DISP_AAL_SIZE				0x0030
>  #define DISP_AAL_SIZE_HSIZE				GENMASK(28, 16)
>  #define DISP_AAL_SIZE_VSIZE				GENMASK(12, 0)
>  #define DISP_AAL_OUTPUT_SIZE			0x04d8
> +#define DISP_AAL_GAMMA_LUT			0x0700
> +#define DISP_AAL_GAMMA_LUT_R				GENMASK(29, 20)
> +#define DISP_AAL_GAMMA_LUT_G				GENMASK(19, 10)
> +#define DISP_AAL_GAMMA_LUT_B				GENMASK(9, 0)
> +#define DISP_AAL_LUT_BITS			10
>  #define DISP_AAL_LUT_SIZE			512
>  
>  struct mtk_disp_aal_data {
> @@ -85,9 +93,36 @@ unsigned int mtk_aal_gamma_get_lut_size(struct device *dev)
>  void mtk_aal_gamma_set(struct device *dev, struct drm_crtc_state *state)
>  {
>  	struct mtk_disp_aal *aal = dev_get_drvdata(dev);
> +	struct drm_color_lut *lut;
> +	unsigned int i;
> +	u32 cfg_val;
> +
> +	/* If gamma is not supported in AAL, go out immediately */
> +	if (!(aal->data && aal->data->has_gamma))
> +		return;
> +
> +	/* Also, if there's no gamma lut there's nothing to do here. */
> +	if (!state->gamma_lut)
> +		return;
> +
> +	cfg_val = readl(aal->regs + DISP_AAL_CFG);
> +	lut = (struct drm_color_lut *)state->gamma_lut->data;
> +
> +	for (i = 0; i < DISP_AAL_LUT_SIZE; i++) {
> +		struct drm_color_lut hwlut = {
> +			.red = drm_color_lut_extract(lut[i].red, DISP_AAL_LUT_BITS),
> +			.green = drm_color_lut_extract(lut[i].green, DISP_AAL_LUT_BITS),
> +			.blue = drm_color_lut_extract(lut[i].blue, DISP_AAL_LUT_BITS)
> +		};
> +		u32 word;
> +
> +		word = FIELD_PREP(DISP_AAL_GAMMA_LUT_R, hwlut.red);
> +		word |= FIELD_PREP(DISP_AAL_GAMMA_LUT_G, hwlut.green);
> +		word |= FIELD_PREP(DISP_AAL_GAMMA_LUT_B, hwlut.blue);
> +		writel(word, (aal->regs + DISP_AAL_GAMMA_LUT) + (i * 4));
> +	}

Hi Angelo,

it looks like you're missing a

  	cfg_val |= FIELD_PREP(AAL_GAMMA_LUT_EN, 1);

to actually enable the AAL gamma table here, like was done in the common
function.

Thanks,
N?colas

>  
> -	if (aal->data && aal->data->has_gamma)
> -		mtk_gamma_set_common(NULL, aal->regs, state);
> +	writel(cfg_val, aal->regs + DISP_AAL_CFG);
>  }
[..]