Re: [PATCH v10 18/21] drm/mediatek: Add mt8195 Embedded DisplayPort driver
From: CK Hu
Date: Tue Jun 07 2022 - 05:04:29 EST
Hi, Rex:
On Mon, 2022-05-23 at 12:47 +0200, Guillaume Ranquet wrote:
> From: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx>
>
> This patch adds a DisplayPort driver for the Mediatek mt8195 SoC.
>
> It supports the mt8195, the embedded DisplayPort units. It offers
> DisplayPort 1.4 with up to 4 lanes.
>
> The driver creates a child device for the phy. The child device will
> never exist without the parent being active. As they are sharing a
> register range, the parent passes a regmap pointer to the child so
> that
> both can work with the same register range. The phy driver sets
> device
> data that is read by the parent to get the phy device that can be
> used
> to control the phy properties.
>
> This driver is based on an initial version by
> Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>.
>
> Signed-off-by: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx>
> Signed-off-by: Guillaume Ranquet <granquet@xxxxxxxxxxxx>
> ---
[snip]
> +
> +static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev)
> +{
> + struct mtk_dp *mtk_dp = dev;
> + int event;
> + u8 buf[DP_RECEIVER_CAP_SIZE] = {};
> +
> + event = mtk_dp_plug_state(mtk_dp) ? connector_status_connected
> :
> + connector_status_disc
> onnected;
> +
> + if (event < 0)
> + return IRQ_HANDLED;
> +
> + if (mtk_dp->drm_dev) {
> + dev_info(mtk_dp->dev, "drm_helper_hpd_irq_event\n");
> + drm_helper_hpd_irq_event(mtk_dp->bridge.dev);
> + }
> +
> + if (mtk_dp->train_info.cable_state_change) {
> + mtk_dp->train_info.cable_state_change = false;
> +
> + mtk_dp->train_state = MTK_DP_TRAIN_STATE_STARTUP;
> +
> + if (!mtk_dp->train_info.cable_plugged_in ||
> + !mtk_dp_plug_state(mtk_dp)) {
> + mtk_dp_video_mute(mtk_dp, true);
For eDP, when does 'unplug' happen? Explain this or move unplug
processing to DP patch.
Regards,
CK
> +
> + mtk_dp_initialize_priv_data(mtk_dp);
> + mtk_dp_set_idle_pattern(mtk_dp, true);
> + if (mtk_dp->has_fec)
> + mtk_dp_fec_enable(mtk_dp, false);
> +
> + mtk_dp_update_bits(mtk_dp,
> MTK_DP_TOP_PWR_STATE,
> + DP_PWR_STATE_BANDGAP_TPLL,
> + DP_PWR_STATE_MASK);
> + } else {
> + mtk_dp_update_bits(mtk_dp,
> MTK_DP_TOP_PWR_STATE,
> + DP_PWR_STATE_BANDGAP_TPLL_LA
> NE,
> + DP_PWR_STATE_MASK);
> + drm_dp_read_dpcd_caps(&mtk_dp->aux, buf);
> + mtk_dp->train_info.link_rate =
> + min_t(int, mtk_dp->max_linkrate,
> + buf[mtk_dp->max_linkrate]);
> + mtk_dp->train_info.lane_count =
> + min_t(int, mtk_dp->max_lanes,
> + drm_dp_max_lane_count(buf));
> + }
> + }
> +
> + if (mtk_dp->train_info.irq_status & MTK_DP_HPD_INTERRUPT) {
> + dev_dbg(mtk_dp->dev, "MTK_DP_HPD_INTERRUPT\n");
> + mtk_dp->train_info.irq_status &= ~MTK_DP_HPD_INTERRUPT;
> + mtk_dp_hpd_sink_event(mtk_dp);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +