From acd19633751f14607ccd76f9dfde5bde7935766c Mon Sep 17 00:00:00 2001
From: Linus Walleij <linus.walleij@linaro.org>
Date: Fri, 21 Apr 2017 20:46:12 +0200
Subject: [PATCH 29/31] usb: host: fotg2: add silicon clock handling

When used in a system with software-controller silicon clocks,
the FOTG210 needs to grab, prepare and enable the clock.
This is needed on for example the Cortina Gemini, where the
platform will by default gate off the clock unless the
peripheral (in this case the USB driver) grabs and enables
the clock.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/usb/host/fotg210-hcd.c | 26 ++++++++++++++++++++++----
 drivers/usb/host/fotg210.h     |  3 +++
 2 files changed, 25 insertions(+), 4 deletions(-)

--- a/drivers/usb/host/fotg210-hcd.c
+++ b/drivers/usb/host/fotg210-hcd.c
@@ -45,6 +45,7 @@
 #include <linux/uaccess.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
+#include <linux/clk.h>
 
 #include <asm/byteorder.h>
 #include <asm/irq.h>
@@ -5636,7 +5637,7 @@ static int fotg210_hcd_probe(struct plat
 	hcd->regs = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(hcd->regs)) {
 		retval = PTR_ERR(hcd->regs);
-		goto failed;
+		goto failed_put_hcd;
 	}
 
 	hcd->rsrc_start = res->start;
@@ -5646,22 +5647,35 @@ static int fotg210_hcd_probe(struct plat
 
 	fotg210->caps = hcd->regs;
 
+	/* It's OK not to supply this clock */
+	fotg210->pclk = clk_get(dev, "PCLK");
+	if (!IS_ERR(fotg210->pclk)) {
+		retval = clk_prepare_enable(fotg210->pclk);
+		if (retval) {
+			dev_err(dev, "failed to enable PCLK\n");
+			goto failed_dis_clk;
+		}
+	}
+
 	retval = fotg210_setup(hcd);
 	if (retval)
-		goto failed;
+		goto failed_dis_clk;
 
 	fotg210_init(fotg210);
 
 	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 	if (retval) {
 		dev_err(dev, "failed to add hcd with err %d\n", retval);
-		goto failed;
+		goto failed_dis_clk;
 	}
 	device_wakeup_enable(hcd->self.controller);
 
 	return retval;
 
-failed:
+failed_dis_clk:
+	if (!IS_ERR(fotg210->pclk))
+		clk_disable_unprepare(fotg210->pclk);
+failed_put_hcd:
 	usb_put_hcd(hcd);
 fail_create_hcd:
 	dev_err(dev, "init %s fail, %d\n", dev_name(dev), retval);
@@ -5677,6 +5691,10 @@ static int fotg210_hcd_remove(struct pla
 {
 	struct device *dev = &pdev->dev;
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+
+	if (!IS_ERR(fotg210->pclk))
+		clk_disable_unprepare(fotg210->pclk);
 
 	if (!hcd)
 		return 0;
--- a/drivers/usb/host/fotg210.h
+++ b/drivers/usb/host/fotg210.h
@@ -182,6 +182,9 @@ struct fotg210_hcd {			/* one per contro
 #	define COUNT(x)
 #endif
 
+	/* silicon clock */
+	struct clk		*pclk;
+
 	/* debug files */
 	struct dentry		*debug_dir;
 };