Re: [PATCH v10 18/21] drm/mediatek: Add mt8195 Embedded DisplayPort driver

On Tue, 2022-06-07 at 17:04 +0800, CK Hu wrote:

Hi, Rex:

On Mon, 2022-05-23 at 12:47 +0200, Guillaume Ranquet wrote:

...

From: Markus Schneider-Pargmann msp@baylibre.com

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@mediatek.com.

Signed-off-by: Markus Schneider-Pargmann msp@baylibre.com Signed-off-by: Guillaume Ranquet granquet@baylibre.com

---

[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

Hello CK,

ok, I move them to dp patch.

BRs, Bo-Chen

...

• 	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;

+}