[PATCH net-next v2 2/5] net: phy: mxl-gpy: add MxL86211C VDDP supply

[Robert Marko]

Read the VDDP supply voltage and configure the MxL86211C MDIO, MDC,
and MDINT pads for the matching 1.8 V or 3.3 V level.

Keep the shared GPY driver buildable without regulator support; only
the MxL86211C probe requires the supply.

Signed-off-by: Robert Marko <robert.marko@xxxxxxxxxx>
---
Changes in v2:
- Replace the MDIO regulator provider with a VDDP supply consumer.
- Set the pad voltage from the supply's reported voltage.
- Keep the shared driver buildable with CONFIG_REGULATOR=n.

 drivers/net/phy/mxl-gpy.c | 63 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 62 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/mxl-gpy.c b/drivers/net/phy/mxl-gpy.c
index 089a1a9e5bc61..fbac7c49b4759 100644
--- a/drivers/net/phy/mxl-gpy.c
+++ b/drivers/net/phy/mxl-gpy.c
@@ -14,6 +14,7 @@
 #include <linux/polynomial.h>
 #include <linux/property.h>
 #include <linux/netdevice.h>
+#include <linux/regulator/consumer.h>
 
 /* PHY ID */
 #define PHY_ID_GPYx15B_MASK	0xFFFFFFFC
@@ -110,6 +111,10 @@
 #define VSPEC1_SGMII_ANEN_ANRS	(VSPEC1_SGMII_CTRL_ANEN | \
 				 VSPEC1_SGMII_CTRL_ANRS)
 
+/* Packet Manager Control */
+#define VSPEC1_PM_CTRL		0x0c
+#define VSPEC1_PM_CTRL_MDIO_VOL	BIT(14)
+
 /* Temperature sensor */
 #define VSPEC1_TEMP_STA	0x0E
 #define VSPEC1_TEMP_STA_DATA	GENMASK(9, 0)
@@ -140,6 +145,7 @@ struct gpy_priv {
 	u8 fw_minor;
 	u32 wolopts;
 	u64 rx_errors;
+	struct regulator *vddp;
 
 	/* It takes 3 seconds to fully switch out of loopback mode before
 	 * it can safely re-enter loopback mode. Record the time when
@@ -390,6 +396,61 @@ static int gpy_probe(struct phy_device *phydev)
 	return 0;
 }
 
+static int mxl86211c_configure_mdio_voltage(struct phy_device *phydev,
+					    struct regulator *vddp)
+{
+	int voltage;
+	int val;
+
+	voltage = regulator_get_voltage(vddp);
+	if (voltage < 0)
+		return voltage;
+
+	switch (voltage) {
+	case 1800000:
+		val = VSPEC1_PM_CTRL_MDIO_VOL;
+		break;
+	case 3300000:
+		val = 0;
+		break;
+	default:
+		phydev_err(phydev, "unsupported VDDP voltage: %d\n", voltage);
+		return -EINVAL;
+	}
+
+	return phy_modify_mmd(phydev, MDIO_MMD_VEND1, VSPEC1_PM_CTRL,
+			      VSPEC1_PM_CTRL_MDIO_VOL, val);
+}
+
+static int mxl86211c_probe(struct phy_device *phydev)
+{
+	struct device *dev = &phydev->mdio.dev;
+	struct gpy_priv *priv;
+	struct regulator *vddp;
+	int ret;
+
+	vddp = devm_regulator_get(dev, "vddp");
+	if (IS_ERR(vddp))
+		return dev_err_probe(dev, PTR_ERR(vddp),
+				     "failed to get VDDP supply\n");
+	if (!vddp)
+		return dev_err_probe(dev, -EOPNOTSUPP,
+				     "VDDP supply requires regulator support\n");
+
+	ret = mxl86211c_configure_mdio_voltage(phydev, vddp);
+	if (ret)
+		return ret;
+
+	ret = gpy_probe(phydev);
+	if (ret)
+		return ret;
+
+	priv = phydev->priv;
+	priv->vddp = vddp;
+
+	return 0;
+}
+
 static bool gpy_sgmii_need_reaneg(struct phy_device *phydev)
 {
 	struct gpy_priv *priv = phydev->priv;
@@ -1406,7 +1467,7 @@ static struct phy_driver gpy_drivers[] = {
 		.name		= "Maxlinear Ethernet MxL86211C",
 		.get_features	= genphy_c45_pma_read_abilities,
 		.config_init	= gpy21x_config_init,
-		.probe		= gpy_probe,
+		.probe		= mxl86211c_probe,
 		.inband_caps	= gpy_inband_caps,
 		.config_inband	= gpy_config_inband,
 		.suspend	= genphy_suspend,
-- 
2.56.0