phy: meson-g12a-usb3-pcie: Add support for PCIe mode

This adds extended PCIe PHY functions for the Amlogic G12A
USB3+PCIE Combo PHY to support reset, power_on and power_off for
PCIe exclusively.

With these callbacks, we can handle all the needed operations of the
Amlogic PCIe controller driver.

Signed-off-by: Neil Armstrong <[email protected]>
Signed-off-by: Lorenzo Pieralisi <[email protected]>
Reviewed-by: Andrew Murray <[email protected]>

drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c

@@ -50,6 +50,8 @@
 	#define PHY_R5_PHY_CR_ACK				BIT(16)
 	#define PHY_R5_PHY_BS_OUT				BIT(17)
 
+#define PCIE_RESET_DELAY					500
+
 struct phy_g12a_usb3_pcie_priv {
 	struct regmap		*regmap;
 	struct regmap		*regmap_cr;
@@ -196,6 +198,10 @@ static int phy_g12a_usb3_init(struct phy *phy)
 	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
 	int data, ret;
 
+	ret = reset_control_reset(priv->reset);
+	if (ret)
+		return ret;
+
 	/* Switch PHY to USB3 */
 	/* TODO figure out how to handle when PCIe was set in the bootloader */
 	regmap_update_bits(priv->regmap, PHY_R0,
@@ -272,32 +278,75 @@ static int phy_g12a_usb3_init(struct phy *phy)
 	return 0;
 }
 
-static int phy_g12a_usb3_pcie_init(struct phy *phy)
+static int phy_g12a_usb3_pcie_power_on(struct phy *phy)
+{
+	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
+
+	if (priv->mode == PHY_TYPE_USB3)
+		return 0;
+
+	regmap_update_bits(priv->regmap, PHY_R0,
+			   PHY_R0_PCIE_POWER_STATE,
+			   FIELD_PREP(PHY_R0_PCIE_POWER_STATE, 0x1c));
+
+	return 0;
+}
+
+static int phy_g12a_usb3_pcie_power_off(struct phy *phy)
+{
+	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
+
+	if (priv->mode == PHY_TYPE_USB3)
+		return 0;
+
+	regmap_update_bits(priv->regmap, PHY_R0,
+			   PHY_R0_PCIE_POWER_STATE,
+			   FIELD_PREP(PHY_R0_PCIE_POWER_STATE, 0x1d));
+
+	return 0;
+}
+
+static int phy_g12a_usb3_pcie_reset(struct phy *phy)
 {
 	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
 	int ret;
 
-	ret = reset_control_reset(priv->reset);
+	if (priv->mode == PHY_TYPE_USB3)
+		return 0;
+
+	ret = reset_control_assert(priv->reset);
 	if (ret)
 		return ret;
 
+	udelay(PCIE_RESET_DELAY);
+
+	ret = reset_control_deassert(priv->reset);
+	if (ret)
+		return ret;
+
+	udelay(PCIE_RESET_DELAY);
+
+	return 0;
+}
+
+static int phy_g12a_usb3_pcie_init(struct phy *phy)
+{
+	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
+
 	if (priv->mode == PHY_TYPE_USB3)
 		return phy_g12a_usb3_init(phy);
 
-	/* Power UP PCIE */
-	/* TODO figure out when the bootloader has set USB3 mode before */
-	regmap_update_bits(priv->regmap, PHY_R0,
-			   PHY_R0_PCIE_POWER_STATE,
-			   FIELD_PREP(PHY_R0_PCIE_POWER_STATE, 0x1c));
-
 	return 0;
 }
 
 static int phy_g12a_usb3_pcie_exit(struct phy *phy)
 {
 	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
 
-	return reset_control_reset(priv->reset);
+	if (priv->mode == PHY_TYPE_USB3)
+		return reset_control_reset(priv->reset);
+
+	return 0;
 }
 
 static struct phy *phy_g12a_usb3_pcie_xlate(struct device *dev,
@@ -326,6 +375,9 @@ static struct phy *phy_g12a_usb3_pcie_xlate(struct device *dev,
 static const struct phy_ops phy_g12a_usb3_pcie_ops = {
 	.init		= phy_g12a_usb3_pcie_init,
 	.exit		= phy_g12a_usb3_pcie_exit,
+	.power_on	= phy_g12a_usb3_pcie_power_on,
+	.power_off	= phy_g12a_usb3_pcie_power_off,
+	.reset		= phy_g12a_usb3_pcie_reset,
 	.owner		= THIS_MODULE,
 };