drm/mediatek: dp: Add MT8195 External DisplayPort support

Add External DisplayPort support to the MT8195 eDP driver.
Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220901044149.16782-9-rex-bc.chen@mediatek.com

drivers/gpu/drm/mediatek/mtk_dp.c

@@ -35,6 +35,7 @@
 
 #define MTK_DP_SIP_CONTROL_AARCH32	MTK_SIP_SMC_CMD(0x523)
 #define MTK_DP_SIP_ATF_EDP_VIDEO_UNMUTE	(BIT(0) | BIT(5))
+#define MTK_DP_SIP_ATF_VIDEO_UNMUTE	BIT(5)
 
 #define MTK_DP_THREAD_CABLE_STATE_CHG	BIT(0)
 #define MTK_DP_THREAD_HPD_EVENT		BIT(1)
@@ -199,6 +200,89 @@ static const struct mtk_dp_efuse_fmt mt8195_edp_efuse_fmt[MTK_DP_CAL_MAX] = {
 	},
 };
 
+static const struct mtk_dp_efuse_fmt mt8195_dp_efuse_fmt[MTK_DP_CAL_MAX] = {
+	[MTK_DP_CAL_GLB_BIAS_TRIM] = {
+		.idx = 0,
+		.shift = 27,
+		.mask = 0x1f,
+		.min_val = 1,
+		.max_val = 0x1e,
+		.default_val = 0xf,
+	},
+	[MTK_DP_CAL_CLKTX_IMPSE] = {
+		.idx = 0,
+		.shift = 13,
+		.mask = 0xf,
+		.min_val = 1,
+		.max_val = 0xe,
+		.default_val = 0x8,
+	},
+	[MTK_DP_CAL_LN_TX_IMPSEL_PMOS_0] = {
+		.idx = 1,
+		.shift = 28,
+		.mask = 0xf,
+		.min_val = 1,
+		.max_val = 0xe,
+		.default_val = 0x8,
+	},
+	[MTK_DP_CAL_LN_TX_IMPSEL_PMOS_1] = {
+		.idx = 1,
+		.shift = 20,
+		.mask = 0xf,
+		.min_val = 1,
+		.max_val = 0xe,
+		.default_val = 0x8,
+	},
+	[MTK_DP_CAL_LN_TX_IMPSEL_PMOS_2] = {
+		.idx = 1,
+		.shift = 12,
+		.mask = 0xf,
+		.min_val = 1,
+		.max_val = 0xe,
+		.default_val = 0x8,
+	},
+	[MTK_DP_CAL_LN_TX_IMPSEL_PMOS_3] = {
+		.idx = 1,
+		.shift = 4,
+		.mask = 0xf,
+		.min_val = 1,
+		.max_val = 0xe,
+		.default_val = 0x8,
+	},
+	[MTK_DP_CAL_LN_TX_IMPSEL_NMOS_0] = {
+		.idx = 1,
+		.shift = 24,
+		.mask = 0xf,
+		.min_val = 1,
+		.max_val = 0xe,
+		.default_val = 0x8,
+	},
+	[MTK_DP_CAL_LN_TX_IMPSEL_NMOS_1] = {
+		.idx = 1,
+		.shift = 16,
+		.mask = 0xf,
+		.min_val = 1,
+		.max_val = 0xe,
+		.default_val = 0x8,
+	},
+	[MTK_DP_CAL_LN_TX_IMPSEL_NMOS_2] = {
+		.idx = 1,
+		.shift = 8,
+		.mask = 0xf,
+		.min_val = 1,
+		.max_val = 0xe,
+		.default_val = 0x8,
+	},
+	[MTK_DP_CAL_LN_TX_IMPSEL_NMOS_3] = {
+		.idx = 1,
+		.shift = 0,
+		.mask = 0xf,
+		.min_val = 1,
+		.max_val = 0xe,
+		.default_val = 0x8,
+	},
+};
+
 static struct regmap_config mtk_dp_regmap_config = {
 	.reg_bits = 32,
 	.val_bits = 32,
@@ -1479,6 +1563,50 @@ static int mtk_dp_dt_parse(struct mtk_dp *mtk_dp,
 	return 0;
 }
 
+static enum drm_connector_status mtk_dp_bdg_detect(struct drm_bridge *bridge)
+{
+	struct mtk_dp *mtk_dp = mtk_dp_from_bridge(bridge);
+	enum drm_connector_status ret = connector_status_disconnected;
+	bool enabled = mtk_dp->enabled;
+	u8 sink_count = 0;
+
+	if (mtk_dp->train_info.cable_plugged_in) {
+		if (!enabled) {
+			/* power on aux */
+			mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
+					   DP_PWR_STATE_BANDGAP_TPLL_LANE,
+					   DP_PWR_STATE_MASK);
+
+			/* power on panel */
+			drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER, DP_SET_POWER_D0);
+			usleep_range(2000, 5000);
+		}
+		/*
+		 * Some dongles still source HPD when they do not connect to any
+		 * sink device. To avoid this, we need to read the sink count
+		 * to make sure we do connect to sink devices. After this detect
+		 * function, we just need to check the HPD connection to check
+		 * whether we connect to a sink device.
+		 */
+		drm_dp_dpcd_readb(&mtk_dp->aux, DP_SINK_COUNT, &sink_count);
+		if (DP_GET_SINK_COUNT(sink_count))
+			ret = connector_status_connected;
+
+		if (!enabled) {
+			/* power off panel */
+			drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER, DP_SET_POWER_D3);
+			usleep_range(2000, 3000);
+
+			/* power off aux */
+			mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
+					   DP_PWR_STATE_BANDGAP_TPLL,
+					   DP_PWR_STATE_MASK);
+		}
+	}
+
+	return ret;
+}
+
 static struct edid *mtk_dp_get_edid(struct drm_bridge *bridge,
 				    struct drm_connector *connector)
 {
@@ -1865,6 +1993,7 @@ static const struct drm_bridge_funcs mtk_dp_bridge_funcs = {
 	.atomic_disable = mtk_dp_bridge_atomic_disable,
 	.mode_valid = mtk_dp_bridge_mode_valid,
 	.get_edid = mtk_dp_get_edid,
+	.detect = mtk_dp_bdg_detect,
 };
 
 static int mtk_dp_probe(struct platform_device *pdev)
@@ -1991,11 +2120,21 @@ static const struct mtk_dp_data mt8195_edp_data = {
 	.efuse_fmt = mt8195_edp_efuse_fmt,
 };
 
+static const struct mtk_dp_data mt8195_dp_data = {
+	.bridge_type = DRM_MODE_CONNECTOR_DisplayPort,
+	.smc_cmd = MTK_DP_SIP_ATF_VIDEO_UNMUTE,
+	.efuse_fmt = mt8195_dp_efuse_fmt,
+};
+
 static const struct of_device_id mtk_dp_of_match[] = {
 	{
 		.compatible = "mediatek,mt8195-edp-tx",
 		.data = &mt8195_edp_data,
 	},
+	{
+		.compatible = "mediatek,mt8195-dp-tx",
+		.data = &mt8195_dp_data,
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, mtk_dp_of_match);