USB: s3c-hsotg: add support for clock gating

This patch adds support for clock gating of the HS/OTG block. On S5PV210
otg gating clock is initally disabled so the driver needs to get and
enable it before it can access its registers.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 17 insertions, 3 deletions

diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index 258ca01ac679..521ebed0118d 100644
--- a/drivers/usb/gadget/s3c-hsotg.c
+++ b/drivers/usb/gadget/s3c-hsotg.c
@@ -152,6 +152,7 @@ struct s3c_hsotg {
         void __iomem            *regs;
         struct resource         *regs_res;
         int                     irq;
+        struct clk              *clk;
 
         unsigned int            dedicated_fifos:1;
 
@@ -3258,13 +3259,20 @@ static int __devinit s3c_hsotg_probe(struct platform_device *pdev)
         hsotg->dev = dev;
         hsotg->plat = plat;
 
+        hsotg->clk = clk_get(&pdev->dev, "otg");
+        if (IS_ERR(hsotg->clk)) {
+                dev_err(dev, "cannot get otg clock\n");
+                ret = -EINVAL;
+                goto err_mem;
+        }
+
         platform_set_drvdata(pdev, hsotg);
 
         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         if (!res) {
                 dev_err(dev, "cannot find register resource 0\n");
                 ret = -EINVAL;
-                goto err_mem;
+                goto err_clk;
         }
 
         hsotg->regs_res = request_mem_region(res->start, resource_size(res),
@@ -3272,7 +3280,7 @@ static int __devinit s3c_hsotg_probe(struct platform_device *pdev)
         if (!hsotg->regs_res) {
                 dev_err(dev, "cannot reserve registers\n");
                 ret = -ENOENT;
-                goto err_mem;
+                goto err_clk;
         }
 
         hsotg->regs = ioremap(res->start, resource_size(res));
@@ -3325,6 +3333,8 @@ static int __devinit s3c_hsotg_probe(struct platform_device *pdev)
 
         /* reset the system */
 
+        clk_enable(hsotg->clk);
+
         s3c_hsotg_gate(pdev, true);
 
         s3c_hsotg_otgreset(hsotg);
@@ -3348,7 +3358,8 @@ err_regs:
 err_regs_res:
         release_resource(hsotg->regs_res);
         kfree(hsotg->regs_res);
-
+err_clk:
+        clk_put(hsotg->clk);
 err_mem:
         kfree(hsotg);
         return ret;
@@ -3370,6 +3381,9 @@ static int __devexit s3c_hsotg_remove(struct platform_device *pdev)
 
         s3c_hsotg_gate(pdev, false);
 
+        clk_disable(hsotg->clk);
+        clk_put(hsotg->clk);
+
         kfree(hsotg);
         return 0;
 }