Re: [PATCH v11 05/10] drm/mediatek: Add MT8195 Embedded DisplayPort driver

Hi, Bo-Chen:

On Fri, 2022-06-10 at 18:55 +0800, Bo-Chen Chen wrote:

From: Markus Schneider-Pargmann msp@baylibre.com

This patch adds a embedded 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 Jitao shi jitao.shi@mediatek.com

Signed-off-by: Markus Schneider-Pargmann msp@baylibre.com Signed-off-by: Guillaume Ranquet granquet@baylibre.com [Bo-Chen: Cleanup the drivers and modify comments from reviewers] Signed-off-by: Bo-Chen Chen rex-bc.chen@mediatek.com

---

[snip]

+static int mtk_dp_probe(struct platform_device *pdev) +{

• struct mtk_dp *mtk_dp;
• struct device *dev = &pdev->dev;
• int ret;
• int irq_num = 0;
• mtk_dp = devm_kzalloc(dev, sizeof(*mtk_dp), GFP_KERNEL);
• if (!mtk_dp)

• return -ENOMEM;
  

• mtk_dp->dev = dev;
• irq_num = platform_get_irq(pdev, 0);
• if (irq_num < 0)

• return dev_err_probe(dev, irq_num,
  

• 		     "failed to request dp irq
  

resource\n");

• mtk_dp->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node,

1, 0);

• if (IS_ERR(mtk_dp->next_bridge))

• return dev_err_probe(dev, PTR_ERR(mtk_dp->next_bridge),
  

• 		     "Failed to get bridge\n");
  

• ret = mtk_dp_dt_parse(mtk_dp, pdev);
• if (ret)

• return dev_err_probe(dev, ret, "Failed to parse dt\n");
  

• drm_dp_aux_init(&mtk_dp->aux);
• mtk_dp->aux.name = "aux_mtk_dp";
• mtk_dp->aux.transfer = mtk_dp_aux_transfer;

In the comment of drm_dp_aux_init(), drm_dp_aux_init() is used before drm_dp_aux_register(). So I think we still need to call drm_dp_aux_register().

Regards, CK

• ret = devm_request_threaded_irq(dev, irq_num, mtk_dp_hpd_event,

• 			mtk_dp_hpd_event_thread,
  

• 			IRQ_TYPE_LEVEL_HIGH,
  

dev_name(dev),

• 			mtk_dp);
  

• if (ret)

• return dev_err_probe(dev, -EPROBE_DEFER,
  

• 		     "failed to request mediatek dptx
  

irq\n");

• mutex_init(&mtk_dp->dp_lock);
• platform_set_drvdata(pdev, mtk_dp);
• mtk_dp->phy_dev = platform_device_register_data(dev, "mediatek-

dp-phy",

• 					PLATFORM_DEVID_
  

AUTO,

• 					&mtk_dp->regs,
  

• 					sizeof(struct
  

regmap *));

• if (IS_ERR(mtk_dp->phy_dev))

• return dev_err_probe(dev, PTR_ERR(mtk_dp->phy_dev),
  

• 		     "Failed to create device mediatek-
  

dp-phy\n");

• mtk_dp_get_calibration_data(mtk_dp);
• mtk_dp->phy = devm_phy_get(&mtk_dp->phy_dev->dev, "dp");
• if (IS_ERR(mtk_dp->phy)) {

• platform_device_unregister(mtk_dp->phy_dev);
  

• return dev_err_probe(dev, PTR_ERR(mtk_dp->phy),
  

• 		     "Failed to get phy\n");
  

• }
• mtk_dp->bridge.funcs = &mtk_dp_bridge_funcs;
• mtk_dp->bridge.of_node = dev->of_node;
• mtk_dp->bridge.ops =

• DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID |
  

DRM_BRIDGE_OP_HPD;

• mtk_dp->bridge.type = DRM_MODE_CONNECTOR_eDP;
• drm_bridge_add(&mtk_dp->bridge);
• pm_runtime_enable(dev);
• pm_runtime_get_sync(dev);
• return 0;

+}