usb: host: xhci-tegra: Reuse stored register base address

The base address of the XUSB controller's registers is already stored in
the HCD. Move assignment to the HCD fields to an earlier point so that
they can be reused in the tegra_xusb_config() function. This avoids the
need to pass the base address as an extra parameter, which in turn comes
in handy in subsequent patches that need to call this function from the
suspend/resume paths where these values are no longer readily available.

Based on work by JC Kuo <jckuo@nvidia.com>.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20191206140653.2085561-7-thierry.reding@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-tegra.c

@@ -626,9 +626,9 @@ static irqreturn_t tegra_xusb_mbox_thread(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static void tegra_xusb_config(struct tegra_xusb *tegra,
-			      struct resource *regs)
+static void tegra_xusb_config(struct tegra_xusb *tegra)
 {
+	u32 regs = tegra->hcd->rsrc_start;
 	u32 value;
 
 	if (tegra->soc->has_ipfs) {
@@ -642,7 +642,7 @@ static void tegra_xusb_config(struct tegra_xusb *tegra,
 	/* Program BAR0 space */
 	value = fpci_readl(tegra, XUSB_CFG_4);
 	value &= ~(XUSB_BASE_ADDR_MASK << XUSB_BASE_ADDR_SHIFT);
-	value |= regs->start & (XUSB_BASE_ADDR_MASK << XUSB_BASE_ADDR_SHIFT);
+	value |= regs & (XUSB_BASE_ADDR_MASK << XUSB_BASE_ADDR_SHIFT);
 	fpci_writel(tegra, value, XUSB_CFG_4);
 
 	usleep_range(100, 200);
@@ -1226,6 +1226,10 @@ static int tegra_xusb_probe(struct platform_device *pdev)
 		goto put_powerdomains;
 	}
 
+	tegra->hcd->regs = tegra->regs;
+	tegra->hcd->rsrc_start = regs->start;
+	tegra->hcd->rsrc_len = resource_size(regs);
+
 	/*
 	 * This must happen after usb_create_hcd(), because usb_create_hcd()
 	 * will overwrite the drvdata of the device with the hcd it creates.
@@ -1249,7 +1253,7 @@ static int tegra_xusb_probe(struct platform_device *pdev)
 		goto disable_phy;
 	}
 
-	tegra_xusb_config(tegra, regs);
+	tegra_xusb_config(tegra);
 
 	/*
 	 * The XUSB Falcon microcontroller can only address 40 bits, so set
@@ -1273,10 +1277,6 @@ static int tegra_xusb_probe(struct platform_device *pdev)
 		goto free_firmware;
 	}
 
-	tegra->hcd->regs = tegra->regs;
-	tegra->hcd->rsrc_start = regs->start;
-	tegra->hcd->rsrc_len = resource_size(regs);
-
 	err = usb_add_hcd(tegra->hcd, tegra->xhci_irq, IRQF_SHARED);
 	if (err < 0) {
 		dev_err(&pdev->dev, "failed to add USB HCD: %d\n", err);