usb: phy: tegra: don't call into tegra-ehci directly

Both phy-tegra-usb.c and ehci-tegra.c export symbols used by the other one,
which does not work if one of them or both are loadable modules, resulting
in an error like:

drivers/built-in.o: In function `utmi_phy_clk_disable':
drivers/usb/phy/phy-tegra-usb.c:302: undefined reference to `tegra_ehci_set_phcd'
drivers/built-in.o: In function `utmi_phy_clk_enable':
drivers/usb/phy/phy-tegra-usb.c:324: undefined reference to `tegra_ehci_set_phcd'
drivers/built-in.o: In function `utmi_phy_power_on':
drivers/usb/phy/phy-tegra-usb.c:447: undefined reference to `tegra_ehci_set_pts'

This turns the interface into a one-way dependency by letting the tegra ehci
driver pass two function pointers for callbacks that need to be called by
the phy driver.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Venu Byravarasu <vbyravarasu@nvidia.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/phy/phy-tegra-usb.c

@@ -299,7 +299,7 @@ static void utmi_phy_clk_disable(struct tegra_usb_phy *phy)
 		val &= ~USB_SUSP_SET;
 		writel(val, base + USB_SUSP_CTRL);
 	} else
-		tegra_ehci_set_phcd(&phy->u_phy, true);
+		phy->set_phcd(&phy->u_phy, true);
 
 	if (utmi_wait_register(base + USB_SUSP_CTRL, USB_PHY_CLK_VALID, 0) < 0)
 		pr_err("%s: timeout waiting for phy to stabilize\n", __func__);
@@ -321,7 +321,7 @@ static void utmi_phy_clk_enable(struct tegra_usb_phy *phy)
 		val &= ~USB_SUSP_CLR;
 		writel(val, base + USB_SUSP_CTRL);
 	} else
-		tegra_ehci_set_phcd(&phy->u_phy, false);
+		phy->set_phcd(&phy->u_phy, false);
 
 	if (utmi_wait_register(base + USB_SUSP_CTRL, USB_PHY_CLK_VALID,
 						     USB_PHY_CLK_VALID))
@@ -444,7 +444,7 @@ static int utmi_phy_power_on(struct tegra_usb_phy *phy)
 	utmi_phy_clk_enable(phy);
 
 	if (!phy->is_legacy_phy)
-		tegra_ehci_set_pts(&phy->u_phy, 0);
+		phy->set_pts(&phy->u_phy, 0);
 
 	return 0;
 }
@@ -688,7 +688,10 @@ static int	tegra_usb_phy_suspend(struct usb_phy *x, int suspend)
 }
 
 struct tegra_usb_phy *tegra_usb_phy_open(struct device *dev, int instance,
-	void __iomem *regs, void *config, enum tegra_usb_phy_mode phy_mode)
+	void __iomem *regs, void *config, enum tegra_usb_phy_mode phy_mode,
+	void (*set_pts)(struct usb_phy *x, u8 pts_val),
+	void (*set_phcd)(struct usb_phy *x, bool enable))
+
 {
 	struct tegra_usb_phy *phy;
 	unsigned long parent_rate;
@@ -707,6 +710,8 @@ struct tegra_usb_phy *tegra_usb_phy_open(struct device *dev, int instance,
 	phy->dev = dev;
 	phy->is_legacy_phy =
 		of_property_read_bool(np, "nvidia,has-legacy-mode");
+	phy->set_pts = set_pts;
+	phy->set_phcd = set_phcd;
 	err = of_property_match_string(np, "phy_type", "ulpi");
 	if (err < 0)
 		phy->is_ulpi_phy = false;