usb: misc: usb3503: get optional clock by devm_clk_get_optional()

When the driver tries to get optional clock, it ignores all errors except
-EPROBE_DEFER, but if only ignores -ENOENT, it will cover some real errors,
such as -ENOMEM, so use devm_clk_get_optional() to get optional clock.
And remove unnecessary stack variable clk.

Cc: Dongjin Kim <tobetter@gmail.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/misc/usb3503.c b/drivers/usb/misc/usb3503.c
index d5141aa79dd4045c9bdcd6a4c66a4bb3df4c736c..72f39a9751b583c8dbc890b4d7a0a065cd820898 100644 (file)
--- a/drivers/usb/misc/usb3503.c
+++ b/drivers/usb/misc/usb3503.c
@@ -172,7 +172,6 @@ static int usb3503_probe(struct usb3503 *hub)
                hub->gpio_reset         = pdata->gpio_reset;
                hub->mode               = pdata->initial_mode;
        } else if (np) {
-               struct clk *clk;
                u32 rate = 0;
                hub->port_off_mask = 0;
 
@@ -198,34 +197,29 @@ static int usb3503_probe(struct usb3503 *hub)
                        }
                }
 
-               clk = devm_clk_get(dev, "refclk");
-               if (IS_ERR(clk) && PTR_ERR(clk) != -ENOENT) {
+               hub->clk = devm_clk_get_optional(dev, "refclk");
+               if (IS_ERR(hub->clk)) {
                        dev_err(dev, "unable to request refclk (%ld)\n",
-                                       PTR_ERR(clk));
-                       return PTR_ERR(clk);
+                                       PTR_ERR(hub->clk));
+                       return PTR_ERR(hub->clk);
                }
 
-               if (!IS_ERR(clk)) {
-                       hub->clk = clk;
-
-                       if (rate != 0) {
-                               err = clk_set_rate(hub->clk, rate);
-                               if (err) {
-                                       dev_err(dev,
-                                               "unable to set reference clock rate to %d\n",
-                                               (int) rate);
-                                       return err;
-                               }
-                       }
-
-                       err = clk_prepare_enable(hub->clk);
+               if (rate != 0) {
+                       err = clk_set_rate(hub->clk, rate);
                        if (err) {
                                dev_err(dev,
-                                       "unable to enable reference clock\n");
+                                       "unable to set reference clock rate to %d\n",
+                                       (int)rate);
                                return err;
                        }
                }
 
+               err = clk_prepare_enable(hub->clk);
+               if (err) {
+                       dev_err(dev, "unable to enable reference clock\n");
+                       return err;
+               }
+
                property = of_get_property(np, "disabled-ports", &len);
                if (property && (len / sizeof(u32)) > 0) {
                        int i;
@@ -324,8 +318,7 @@ static int usb3503_i2c_remove(struct i2c_client *i2c)
        struct usb3503 *hub;
 
        hub = i2c_get_clientdata(i2c);
-       if (hub->clk)
-               clk_disable_unprepare(hub->clk);
+       clk_disable_unprepare(hub->clk);
 
        return 0;
 }
@@ -348,8 +341,7 @@ static int usb3503_platform_remove(struct platform_device *pdev)
        struct usb3503 *hub;
 
        hub = platform_get_drvdata(pdev);
-       if (hub->clk)
-               clk_disable_unprepare(hub->clk);
+       clk_disable_unprepare(hub->clk);
 
        return 0;
 }
@@ -358,18 +350,14 @@ static int usb3503_platform_remove(struct platform_device *pdev)
 static int usb3503_suspend(struct usb3503 *hub)
 {
        usb3503_switch_mode(hub, USB3503_MODE_STANDBY);
-
-       if (hub->clk)
-               clk_disable_unprepare(hub->clk);
+       clk_disable_unprepare(hub->clk);
 
        return 0;
 }
 
 static int usb3503_resume(struct usb3503 *hub)
 {
-       if (hub->clk)
-               clk_prepare_enable(hub->clk);
-
+       clk_prepare_enable(hub->clk);
        usb3503_switch_mode(hub, hub->mode);
 
        return 0;