[PATCH 07/11] drm/mediatek: mtk_dp: Add support for PHY from devicetree

[AngeloGioacchino Del Regno]

Add support for specifying `phys` in devicetree to pass handle
to the DisplayPort PHY.

In order to retain compatibility with older devicetrees, check if
`phys` was specified: if not, initialize the regmap_mmio with the
legacy configuration and register the mediatek-dp-phy platform
device from this driver, and get the PHY calibration data.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
---
 drivers/gpu/drm/mediatek/mtk_dp.c | 50 ++++++++++++++++++++++++++-----
 1 file changed, 43 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index 3b5348ab487d..bf3a4b15f3ec 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -426,6 +426,15 @@ static const struct regmap_config mtk_dp_regmap_legacy_config = {
 	.name = "mtk-dp-registers",
 };
 
+static const struct regmap_config mtk_dp_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = SEC_OFFSET + 0x90,
+	.name = "mtk-dp-registers",
+};
+
+
 static struct mtk_dp *mtk_dp_from_bridge(struct drm_bridge *b)
 {
 	return container_of(b, struct mtk_dp, bridge);
@@ -1298,7 +1307,13 @@ static int mtk_dp_phy_configure(struct mtk_dp *mtk_dp,
 	if (ret)
 		return ret;
 
-	mtk_dp_set_calibration_data(mtk_dp);
+	/*
+	 * For legacy, deprecated strategy, set partial PHY calibration here.
+	 * New-style will set all PHY calibrations with phy ops instead.
+	 */
+	if (mtk_dp->phy_dev)
+		mtk_dp_set_calibration_data(mtk_dp);
+
 	mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
 			   DP_PWR_STATE_BANDGAP_TPLL_LANE, DP_PWR_STATE_MASK);
 
@@ -2132,8 +2147,9 @@ static int mtk_dp_wait_hpd_asserted(struct drm_dp_aux *mtk_aux, unsigned long wa
 static int mtk_dp_dt_parse(struct mtk_dp *mtk_dp,
 			   struct platform_device *pdev)
 {
-	struct device_node *endpoint;
+	const struct regmap_config *regmap_cfg;
 	struct device *dev = &pdev->dev;
+	struct device_node *endpoint;
 	int ret;
 	void __iomem *base;
 	u32 linkrate;
@@ -2143,7 +2159,12 @@ static int mtk_dp_dt_parse(struct mtk_dp *mtk_dp,
 	if (IS_ERR(base))
 		return PTR_ERR(base);
 
-	mtk_dp->regs = devm_regmap_init_mmio(dev, base, &mtk_dp_regmap_legacy_config);
+	if (!mtk_dp->legacy_regoff)
+		regmap_cfg = &mtk_dp_regmap_config;
+	else
+		regmap_cfg = &mtk_dp_regmap_legacy_config;
+
+	mtk_dp->regs = devm_regmap_init_mmio(dev, base, regmap_cfg);
 	if (IS_ERR(mtk_dp->regs))
 		return PTR_ERR(mtk_dp->regs);
 
@@ -2769,6 +2790,7 @@ static int mtk_dp_register_phy(struct mtk_dp *mtk_dp)
 				     "Failed to add phy unregister devm action");
 	}
 
+	/* PHY calibration data is in mtk_dp only for legacy devicetree */
 	mtk_dp_get_calibration_data(mtk_dp);
 
 	mtk_dp->phy = devm_phy_get(&mtk_dp->phy_dev->dev, "dp");
@@ -2821,7 +2843,12 @@ static int mtk_dp_probe(struct platform_device *pdev)
 
 	mtk_dp->dev = dev;
 	mtk_dp->data = (struct mtk_dp_data *)of_device_get_match_data(dev);
-	mtk_dp->legacy_regoff = MTK_DP_TOP_OFFSET_LEGACY;
+
+	/* Prefer PHY from devicetree - if not found, this is legacy */
+	if (of_property_present(dev->of_node, "phys"))
+		mtk_dp->legacy_regoff = 0;
+	else
+		mtk_dp->legacy_regoff = MTK_DP_TOP_OFFSET_LEGACY;
 
 	ret = mtk_dp_dt_parse(mtk_dp, pdev);
 	if (ret)
@@ -2872,9 +2899,18 @@ static int mtk_dp_probe(struct platform_device *pdev)
 					     "Failed to register audio driver\n");
 	}
 
-	ret = mtk_dp_register_phy(mtk_dp);
-	if (ret)
-		return ret;
+	if (!mtk_dp->legacy_regoff) {
+		mtk_dp->phy = devm_phy_get(dev, NULL);
+		if (IS_ERR(mtk_dp->phy))
+			return dev_err_probe(dev, PTR_ERR(mtk_dp->phy),
+					     "Failed to get phy\n");
+
+		mtk_dp->phy_dev = NULL;
+	} else {
+		ret = mtk_dp_register_phy(mtk_dp);
+		if (ret)
+			return ret;
+	}
 
 	mtk_dp->bridge.of_node = dev->of_node;
 	mtk_dp->bridge.type = mtk_dp->data->bridge_type;
-- 
2.54.0