ata: ahci_platform: add support for PHY controller regulator

The SoC R40 AHCI controller need a PHY regulator to work.
But since the PHY is embedded in the controller, we cannot do a DT node for it,
since phy-supply works only in node with a PHY compatible.
So this patch adds a way to add an optional phy-supply regulator on AHCI controller node.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/ata/ahci.h

@@ -353,6 +353,7 @@ struct ahci_host_priv {
 	struct reset_control	*rsts;		/* Optional */
 	struct regulator	**target_pwrs;	/* Optional */
 	struct regulator	*ahci_regulator;/* Optional */
+	struct regulator	*phy_regulator;/* Optional */
 	/*
 	 * If platform uses PHYs. There is a 1:1 relation between the port number and
 	 * the PHY position in this array.

drivers/ata/libahci_platform.c

@@ -157,6 +157,12 @@ int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv)
 			return rc;
 	}
 
+	if (hpriv->phy_regulator) {
+		rc = regulator_enable(hpriv->phy_regulator);
+		if (rc)
+			goto disable_ahci_pwrs;
+	}
+
 	for (i = 0; i < hpriv->nports; i++) {
 		if (!hpriv->target_pwrs[i])
 			continue;
@@ -173,6 +179,9 @@ int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv)
 		if (hpriv->target_pwrs[i])
 			regulator_disable(hpriv->target_pwrs[i]);
 
+	if (hpriv->phy_regulator)
+		regulator_disable(hpriv->phy_regulator);
+disable_ahci_pwrs:
 	if (hpriv->ahci_regulator)
 		regulator_disable(hpriv->ahci_regulator);
 	return rc;
@@ -198,6 +207,8 @@ void ahci_platform_disable_regulators(struct ahci_host_priv *hpriv)
 
 	if (hpriv->ahci_regulator)
 		regulator_disable(hpriv->ahci_regulator);
+	if (hpriv->phy_regulator)
+		regulator_disable(hpriv->phy_regulator);
 }
 EXPORT_SYMBOL_GPL(ahci_platform_disable_regulators);
 /**
@@ -430,6 +441,15 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev,
 		hpriv->ahci_regulator = NULL;
 	}
 
+	hpriv->phy_regulator = devm_regulator_get_optional(dev, "phy");
+	if (IS_ERR(hpriv->phy_regulator)) {
+		rc = PTR_ERR(hpriv->phy_regulator);
+		if (rc == -EPROBE_DEFER)
+			goto err_out;
+		rc = 0;
+		hpriv->phy_regulator = NULL;
+	}
+
 	if (flags & AHCI_PLATFORM_GET_RESETS) {
 		hpriv->rsts = devm_reset_control_array_get_optional_shared(dev);
 		if (IS_ERR(hpriv->rsts)) {