[PATCH] USB: S3C2410: use clk_enable() to ensure 48MHz to OHCI core

Get the "usb-bus" clock and ensure it is enabled
when the OHCI core is in use.

It seems that a few bootloaders do not enable the
UPLL at startup, which stops the OHCI core having
a 48MHz bus clock. The improvements to the clock
framework for the s3c24xx now allow the USB PLL
to be started and stopped when being used.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 24 insertions, 8 deletions

diff --git a/drivers/usb/host/ohci-s3c2410.c b/drivers/usb/host/ohci-s3c2410.c
index b27669fe9f0f..1da5de573a6f 100644
--- a/drivers/usb/host/ohci-s3c2410.c
+++ b/drivers/usb/host/ohci-s3c2410.c
@@ -30,6 +30,7 @@
 /* clock device associated with the hcd */
 
 static struct clk *clk;
+static struct clk *usb_clk;
 
 /* forward definitions */
 
@@ -47,6 +48,10 @@ static void s3c2410_start_hc(struct platform_device *dev, struct usb_hcd *hcd)
         struct s3c2410_hcd_info *info = dev->dev.platform_data;
 
         dev_dbg(&dev->dev, "s3c2410_start_hc:\n");
+
+        clk_enable(usb_clk);
+        mdelay(2);                      /* let the bus clock stabilise */
+
         clk_enable(clk);
 
         if (info != NULL) {
@@ -75,6 +80,7 @@ static void s3c2410_stop_hc(struct platform_device *dev)
         }
 
         clk_disable(clk);
+        clk_disable(usb_clk);
 }
 
 /* ohci_s3c2410_hub_status_data
@@ -354,14 +360,21 @@ static int usb_hcd_s3c2410_probe (const struct hc_driver *driver,
         if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
                 dev_err(&dev->dev, "request_mem_region failed");
                 retval = -EBUSY;
-                goto err0;
+                goto err_put;
         }
 
-        clk = clk_get(NULL, "usb-host");
+        clk = clk_get(&dev->dev, "usb-host");
         if (IS_ERR(clk)) {
                 dev_err(&dev->dev, "cannot get usb-host clock\n");
                 retval = -ENOENT;
-                goto err1;
+                goto err_mem;
+        }
+
+        usb_clk = clk_get(&dev->dev, "upll");
+        if (IS_ERR(usb_clk)) {
+                dev_err(&dev->dev, "cannot get usb-host clock\n");
+                retval = -ENOENT;
+                goto err_clk;
         }
 
         s3c2410_start_hc(dev, hcd);
@@ -370,26 +383,29 @@ static int usb_hcd_s3c2410_probe (const struct hc_driver *driver,
         if (!hcd->regs) {
                 dev_err(&dev->dev, "ioremap failed\n");
                 retval = -ENOMEM;
-                goto err2;
+                goto err_ioremap;
         }
 
         ohci_hcd_init(hcd_to_ohci(hcd));
 
         retval = usb_add_hcd(hcd, dev->resource[1].start, SA_INTERRUPT);
         if (retval != 0)
-                goto err2;
+                goto err_ioremap;
 
         return 0;
 
- err2:
+ err_ioremap:
         s3c2410_stop_hc(dev);
         iounmap(hcd->regs);
+        clk_put(usb_clk);
+
+ err_clk:
         clk_put(clk);
 
- err1:
+ err_mem:
         release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
 
- err0:
+ err_put:
         usb_put_hcd(hcd);
         return retval;
 }