phy: allwinner: phy-sun6i-mipi-dphy: Make RX support optional

While all variants of the DPHY likely support RX mode, the new variant
in the A100 is not used in this direction by the BSP, and it has some
analog register changes, so its RX power-on sequence is unknown. To be
safe, limit RX support to variants where the power-on sequence is known.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20221114022113.31694-6-samuel@sholland.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/allwinner/phy-sun6i-mipi-dphy.c

@@ -114,6 +114,10 @@ enum sun6i_dphy_direction {
 	SUN6I_DPHY_DIRECTION_RX,
 };
 
+struct sun6i_dphy_variant {
+	bool	rx_supported;
+};
+
 struct sun6i_dphy {
 	struct clk				*bus_clk;
 	struct clk				*mod_clk;
@@ -123,6 +127,7 @@ struct sun6i_dphy {
 	struct phy				*phy;
 	struct phy_configure_opts_mipi_dphy	config;
 
+	const struct sun6i_dphy_variant		*variant;
 	enum sun6i_dphy_direction		direction;
 };
 
@@ -409,6 +414,10 @@ static int sun6i_dphy_probe(struct platform_device *pdev)
 	if (!dphy)
 		return -ENOMEM;
 
+	dphy->variant = device_get_match_data(&pdev->dev);
+	if (!dphy->variant)
+		return -EINVAL;
+
 	regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(regs)) {
 		dev_err(&pdev->dev, "Couldn't map the DPHY encoder registers\n");
@@ -445,8 +454,14 @@ static int sun6i_dphy_probe(struct platform_device *pdev)
 	ret = of_property_read_string(pdev->dev.of_node, "allwinner,direction",
 				      &direction);
 
-	if (!ret && !strncmp(direction, "rx", 2))
+	if (!ret && !strncmp(direction, "rx", 2)) {
+		if (!dphy->variant->rx_supported) {
+			dev_err(&pdev->dev, "RX not supported on this variant\n");
+			return -EOPNOTSUPP;
+		}
+
 		dphy->direction = SUN6I_DPHY_DIRECTION_RX;
+	}
 
 	phy_set_drvdata(dphy->phy, dphy);
 	phy_provider = devm_of_phy_provider_register(&pdev->dev, of_phy_simple_xlate);
@@ -454,8 +469,15 @@ static int sun6i_dphy_probe(struct platform_device *pdev)
 	return PTR_ERR_OR_ZERO(phy_provider);
 }
 
+static const struct sun6i_dphy_variant sun6i_a31_mipi_dphy_variant = {
+	.rx_supported	= true,
+};
+
 static const struct of_device_id sun6i_dphy_of_table[] = {
-	{ .compatible = "allwinner,sun6i-a31-mipi-dphy" },
+	{
+		.compatible	= "allwinner,sun6i-a31-mipi-dphy",
+		.data		= &sun6i_a31_mipi_dphy_variant,
+	},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sun6i_dphy_of_table);