[PATCH v6 7/9] phy: rockchip-samsung-dcphy: Support the new phy-type and direction binding

[Jason Yang]

The binding now selects the PHY with the cell and the mode of the block
with the phy-type property of the provider. Read phy-type in probe,
D-PHY by default.

of_xlate() returns the transmitter for PHY_DIRECTION_TX. The deprecated
PHY_TYPE_DPHY and PHY_TYPE_CPHY select the transmitter as today, so
existing DTs are unaffected.

A phy-type other than D-PHY or C-PHY fails probe. A deprecated cell
value that does not match phy-type gets a warning, and the transmitter
then refuses to power on, as in C-PHY mode today.

Signed-off-by: Jason Yang <jason98166 at gmail.com>
---
 drivers/phy/rockchip/phy-rockchip-samsung-dcphy.c | 32 ++++++++++++++++++-----
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-samsung-dcphy.c b/drivers/phy/rockchip/phy-rockchip-samsung-dcphy.c
index c40c84791eca..e8e229fc4856 100644
--- a/drivers/phy/rockchip/phy-rockchip-samsung-dcphy.c
+++ b/drivers/phy/rockchip/phy-rockchip-samsung-dcphy.c
@@ -297,6 +297,7 @@ struct samsung_mipi_dcphy {
 	struct reset_control *grf_apb_rst;
 	struct samsung_mipi_phy tx;
 	u8 type;
+	bool legacy_mismatch;
 
 	const struct samsung_mipi_dcphy_plat_data *pdata;
 	struct {
@@ -1376,6 +1377,9 @@ static int samsung_mipi_dcphy_tx_power_on(struct phy *phy)
 {
 	struct samsung_mipi_dcphy *samsung = phy_get_drvdata(phy);
 
+	if (samsung->legacy_mismatch)
+		return -EOPNOTSUPP;
+
 	switch (samsung->type) {
 	case PHY_TYPE_DPHY:
 		return samsung_mipi_dphy_tx_power_on(samsung);
@@ -1549,13 +1553,21 @@ static struct phy *samsung_mipi_dcphy_xlate(struct device *dev,
 		return ERR_PTR(-EINVAL);
 	}
 
-	if (samsung->type != PHY_NONE && samsung->type != args->args[0])
-		dev_warn(dev, "phy type select %d overwriting type %d\n",
-			 args->args[0], samsung->type);
-
-	samsung->type = args->args[0];
-
-	return samsung->tx.phy;
+	switch (args->args[0]) {
+	case PHY_DIRECTION_TX:
+		return samsung->tx.phy;
+	case PHY_TYPE_DPHY:
+	case PHY_TYPE_CPHY:
+		if (args->args[0] != samsung->type) {
+			dev_warn(dev, "unsupported phy cell %u with phy-type %u\n",
+				 args->args[0], samsung->type);
+			samsung->legacy_mismatch = true;
+		}
+		return samsung->tx.phy;
+	default:
+		dev_err(dev, "invalid phy cell %u\n", args->args[0]);
+		return ERR_PTR(-EINVAL);
+	}
 }
 
 static int samsung_mipi_dcphy_probe(struct platform_device *pdev)
@@ -1566,6 +1578,7 @@ static int samsung_mipi_dcphy_probe(struct platform_device *pdev)
 	struct phy_provider *phy_provider;
 	struct resource *res;
 	void __iomem *regs;
+	u32 type = PHY_TYPE_DPHY;
 	int ret;
 
 	samsung = devm_kzalloc(dev, sizeof(*samsung), GFP_KERNEL);
@@ -1620,6 +1633,11 @@ static int samsung_mipi_dcphy_probe(struct platform_device *pdev)
 		return dev_err_probe(dev, PTR_ERR(samsung->grf_apb_rst),
 				     "Failed to get system grf_apb_rst control\n");
 
+	of_property_read_u32(np, "phy-type", &type);
+	if (type != PHY_TYPE_DPHY && type != PHY_TYPE_CPHY)
+		return dev_err_probe(dev, -EINVAL, "unsupported phy-type %u\n", type);
+	samsung->type = type;
+
 	ret = devm_pm_runtime_enable(dev);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to enable runtime PM\n");

-- 
2.43.0