phy: ti: gmii-sel: Add support for CPSW5G GMII SEL in J7200

JIRA: https://issues.redhat.com/browse/RHEL-44742

commit af96579
Author: Siddharth Vadapalli <s-vadapalli@ti.com>
Date:   Mon Sep 12 14:26:50 2022 +0530

    phy: ti: gmii-sel: Add support for CPSW5G GMII SEL in J7200

    Each of the CPSW5G ports in J7200 support additional modes like QSGMII.
    Add a new compatible for J7200 to support the additional modes.

    In TI's J7200, each of the CPSW5G ethernet interfaces can act as a
    QSGMII or QSGMII-SUB port. The QSGMII interface is responsible for
    performing auto-negotiation between the MAC and the PHY while the rest of
    the interfaces are designated as QSGMII-SUB interfaces, indicating that
    they will not be taking part in the auto-negotiation process.

    To indicate the interface which will serve as the main QSGMII interface,
    add a property "ti,qsgmii-main-ports", whose value indicates the
    port number of the interface which shall serve as the main QSGMII
    interface. The rest of the interfaces are then assigned QSGMII-SUB mode by
    default. The property "ti,qsgmii-main-ports" is used to configure the
    CTRLMMR_ENETx_CTRL register.

    Depending on the device, it is possible for more than one QSGMII main port
    to exist. Thus, the property "ti,qsgmii-main-ports" is defined as an array
    of values in order to reuse the property for other devices.

    Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
    Link: https://lore.kernel.org/r/20220912085650.83263-4-s-vadapalli@ti.com
    Signed-off-by: Vinod Koul <vkoul@kernel.org>

Signed-off-by: Andrew Halaney <ahalaney@redhat.com>

Author: ahalaney

drivers/phy/ti/phy-gmii-sel.c

@@ -22,6 +22,12 @@
 #define AM33XX_GMII_SEL_MODE_RMII	1
 #define AM33XX_GMII_SEL_MODE_RGMII	2
 
+/* J72xx SoC specific definitions for the CONTROL port */
+#define J72XX_GMII_SEL_MODE_QSGMII	4
+#define J72XX_GMII_SEL_MODE_QSGMII_SUB	6
+
+#define PHY_GMII_PORT(n)	BIT((n) - 1)
+
 enum {
 	PHY_GMII_SEL_PORT_MODE = 0,
 	PHY_GMII_SEL_RGMII_ID_MODE,
@@ -43,6 +49,7 @@ struct phy_gmii_sel_soc_data {
 	u32 features;
 	const struct reg_field (*regfields)[PHY_GMII_SEL_LAST];
 	bool use_of_data;
+	u64 extra_modes;
 };
 
 struct phy_gmii_sel_priv {
@@ -53,6 +60,7 @@ struct phy_gmii_sel_priv {
 	struct phy_gmii_sel_phy_priv *if_phys;
 	u32 num_ports;
 	u32 reg_offset;
+	u32 qsgmii_main_ports;
 };
 
 static int phy_gmii_sel_mode(struct phy *phy, enum phy_mode mode, int submode)
@@ -88,10 +96,17 @@ static int phy_gmii_sel_mode(struct phy *phy, enum phy_mode mode, int submode)
 		gmii_sel_mode = AM33XX_GMII_SEL_MODE_MII;
 		break;
 
+	case PHY_INTERFACE_MODE_QSGMII:
+		if (!(soc_data->extra_modes & BIT(PHY_INTERFACE_MODE_QSGMII)))
+			goto unsupported;
+		if (if_phy->priv->qsgmii_main_ports & BIT(if_phy->id - 1))
+			gmii_sel_mode = J72XX_GMII_SEL_MODE_QSGMII;
+		else
+			gmii_sel_mode = J72XX_GMII_SEL_MODE_QSGMII_SUB;
+		break;
+
 	default:
-		dev_warn(dev, "port%u: unsupported mode: \"%s\"\n",
-			 if_phy->id, phy_modes(submode));
-		return -EINVAL;
+		goto unsupported;
 	}
 
 	if_phy->phy_if_mode = submode;
@@ -123,6 +138,11 @@ static int phy_gmii_sel_mode(struct phy *phy, enum phy_mode mode, int submode)
 	}
 
 	return 0;
+
+unsupported:
+	dev_warn(dev, "port%u: unsupported mode: \"%s\"\n",
+		 if_phy->id, phy_modes(submode));
+	return -EINVAL;
 }
 
 static const
@@ -188,6 +208,13 @@ struct phy_gmii_sel_soc_data phy_gmii_sel_soc_am654 = {
 	.regfields = phy_gmii_sel_fields_am654,
 };
 
+static const
+struct phy_gmii_sel_soc_data phy_gmii_sel_cpsw5g_soc_j7200 = {
+	.use_of_data = true,
+	.regfields = phy_gmii_sel_fields_am654,
+	.extra_modes = BIT(PHY_INTERFACE_MODE_QSGMII),
+};
+
 static const struct of_device_id phy_gmii_sel_id_table[] = {
 	{
 		.compatible	= "ti,am3352-phy-gmii-sel",
@@ -209,6 +236,10 @@ static const struct of_device_id phy_gmii_sel_id_table[] = {
 		.compatible	= "ti,am654-phy-gmii-sel",
 		.data		= &phy_gmii_sel_soc_am654,
 	},
+	{
+		.compatible	= "ti,j7200-cpsw5g-phy-gmii-sel",
+		.data		= &phy_gmii_sel_cpsw5g_soc_j7200,
+	},
 	{}
 };
 MODULE_DEVICE_TABLE(of, phy_gmii_sel_id_table);
@@ -350,6 +381,7 @@ static int phy_gmii_sel_probe(struct platform_device *pdev)
 	struct device_node *node = dev->of_node;
 	const struct of_device_id *of_id;
 	struct phy_gmii_sel_priv *priv;
+	u32 main_ports = 1;
 	int ret;
 
 	of_id = of_match_node(phy_gmii_sel_id_table, pdev->dev.of_node);
@@ -363,6 +395,15 @@ static int phy_gmii_sel_probe(struct platform_device *pdev)
 	priv->dev = &pdev->dev;
 	priv->soc_data = of_id->data;
 	priv->num_ports = priv->soc_data->num_ports;
+	of_property_read_u32(node, "ti,qsgmii-main-ports", &main_ports);
+	/*
+	 * Ensure that main_ports is within bounds. If the property
+	 * ti,qsgmii-main-ports is not mentioned, or the value mentioned
+	 * is out of bounds, default to 1.
+	 */
+	if (main_ports < 1 || main_ports > 4)
+		main_ports = 1;
+	priv->qsgmii_main_ports = PHY_GMII_PORT(main_ports);
 
 	priv->regmap = syscon_node_to_regmap(node->parent);
 	if (IS_ERR(priv->regmap)) {