Re: [PATCH v3 14/17] drm/mediatek: add OUTPROC support for MT8196

["CK Hu (胡俊光)" <ck.hu@mediatek.com>]

On Thu, 2025-05-15 at 17:34 +0800, paul-pl.chen wrote:
> From: Nancy Lin <nancy.lin@mediatek.com>
> 
> OUTPROC handles the post-stage of pixel processing in
> the overlapping procedure.OUTPROC manages pixels for
> gamma correction and ensures that pixel values are
> within the correct range.
> 
> Signed-off-by: Nancy Lin <nancy.lin@mediatek.com>
> Signed-off-by: Paul-pl Chen <paul-pl.chen@mediatek.com>
> ---

[snip]

> +void mtk_disp_outproc_config(struct device *dev, unsigned int w,
> +			     unsigned int h, unsigned int vrefresh,
> +			     unsigned int bpc, struct cmdq_pkt *cmdq_pkt)
> +{
> +	struct mtk_disp_outproc *priv = dev_get_drvdata(dev);
> +	u32 tmp;
> +
> +	dev_dbg(dev, "%s-w:%d, h:%d\n", __func__, w, h);
> +
> +	writel((h << 16) | w, priv->regs + DISP_REG_OVL_OUTPROC_ROI_SIZE);
> +
> +	tmp = readl(priv->regs + DISP_REG_OVL_OUTPROC_DATAPATH_CON);
> +	tmp = (tmp & ~OVL_OUTPROC_DATAPATH_CON_OUTPUT_CLAMP) |
> +		  (OVL_OUTPROC_DATAPATH_CON_OUTPUT_CLAMP & OVL_OUTPROC_DATAPATH_CON_OUTPUT_CLAMP);

This would simplified as

tmp |= OVL_OUTPROC_DATAPATH_CON_OUTPUT_CLAMP;

> +	writel(tmp, priv->regs + DISP_REG_OVL_OUTPROC_DATAPATH_CON);
> +}
> +
> +void mtk_disp_outproc_start(struct device *dev)
> +{
> +	struct mtk_disp_outproc *priv = dev_get_drvdata(dev);
> +	unsigned int tmp;
> +
> +	tmp = readl(priv->regs + DISP_REG_OVL_OUTPROC_SHADOW_CTRL);
> +	tmp = tmp | OVL_OUTPROC_BYPASS_SHADOW;

tmp |= OVL_OUTPROC_BYPASS_SHADOW;

> +	writel(tmp, priv->regs + DISP_REG_OVL_OUTPROC_SHADOW_CTRL);
> +
> +	writel(0, priv->regs + DISP_REG_OVL_OUTPROC_INTSTA);

To align OVL driver, clear interrupt status in enable_vblank() function.

> +
> +	tmp = readl(priv->regs + DISP_REG_OVL_OUTPROC_EN);
> +	tmp = (tmp & ~OVL_OUTPROC_OVL_EN) | (OVL_OUTPROC_OVL_EN & OVL_OUTPROC_OVL_EN);

This would be simplified as

tmp |= OVL_OUTPROC_OVL_EN;

One question. In mtk_disp_outproc_stop(), you overwrite the whole register of  DISP_REG_OVL_OUTPROC_EN.
Why here not overwrite the whole register?

Regards,
CK

> +	writel(tmp, priv->regs + DISP_REG_OVL_OUTPROC_EN);
> +}
> +
> +void mtk_disp_outproc_stop(struct device *dev)
> +{
> +	struct mtk_disp_outproc *priv = dev_get_drvdata(dev);
> +
> +	writel(0, priv->regs + DISP_REG_OVL_OUTPROC_EN);
> +	writel(OVL_OUTPROC_RST, priv->regs + DISP_REG_OVL_OUTPROC_RST);
> +	writel(0, priv->regs + DISP_REG_OVL_OUTPROC_RST);
> +}
> +