[PATCH v4 10/12] drm/mediatek: mtk_dp: Add support for HotPlug Detection in DP AUX

[CK Hu (胡俊光)]

On Thu, 2026-07-09 at 13:31 +0200, AngeloGioacchino Del Regno wrote:
> Newer MediaTek DisplayPort IPs can finally use the AUX to perform
> hotplug detection (HPD) without having to power up the entire eDP
> or DP IP (transmitter, encoder, etc).
> 
> Enable support for configuring and performing HPD in AUX and check
> the correct HPD strategy with a new platform data variable.
> This is done in preparation for adding support for the embedded
> DisplayPort (eDP) IP found in the MT8196 SoC.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
> ---

[snip]

>  static void mtk_dp_hwirq_enable(struct mtk_dp *mtk_dp, bool enable)
>  {
> +	u32 mask, val;
> +
> +	/* On SoCs with working AUX HPD, the transmitter HPD register is ignored by HW */
> +	if (enable) {
> +		mask = HPD_CONNECT_EVENT | HPD_INTERRUPT_EVENT | HPD_DISCONNECT_EVENT;
> +		val = 0;
> +	} else {
> +		mask = DP_TX_AUX_INT_MASK;
> +		val = DP_TX_AUX_INT_MASK;
> +	}
> +	mtk_dp_update_bits(mtk_dp, MTK_DP_TX_AUX_INT_MASKING, val, mask);

Why not refer to below coding?

Regards,
CK

> +
>  	mtk_dp_update_bits(mtk_dp, MTK_DP_TRANS_P0_3418,
>  			   enable ? 0 :
>  			   IRQ_MASK_DP_TRANS_P0_DISC_IRQ |
> @@ -1089,9 +1133,34 @@ static void mtk_dp_initialize_settings(struct mtk_dp *mtk_dp)
>  			   IRQ_MASK_AUX_TOP_IRQ, IRQ_MASK_AUX_TOP_IRQ);
>  }
>  

>