platform/chrome: cros_ec_dev - utilize new cdev_device_add helper function

Replace the open coded registration of the cdev and dev with the
new device_add_cdev() helper. The helper replaces a common pattern by
taking the proper reference against the parent device and adding both
the cdev and the device.

At the same time we cleanup the error path through device_probe
function: we use put_device instead of kfree directly as recommended
by the device_initialize documentation.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
index 6f09da4dadb8877e2eec9d705e60e8f46c93116e..6aa120cd0574d89ba63db30bc0e473255fe7c161 100644 (file)
--- a/drivers/platform/chrome/cros_ec_dev.c
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -391,7 +391,6 @@ static int ec_device_probe(struct platform_device *pdev)
        int retval = -ENOMEM;
        struct device *dev = &pdev->dev;
        struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
-       dev_t devno = MKDEV(ec_major, pdev->id);
        struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
 
        if (!ec)
@@ -406,24 +405,12 @@ static int ec_device_probe(struct platform_device *pdev)
        device_initialize(&ec->class_dev);
        cdev_init(&ec->cdev, &fops);
 
-       /*
-        * Add the character device
-        * Link cdev to the class device to be sure device is not used
-        * before unbinding it.
-        */
-       ec->cdev.kobj.parent = &ec->class_dev.kobj;
-       retval = cdev_add(&ec->cdev, devno, 1);
-       if (retval) {
-               dev_err(dev, ": failed to add character device\n");
-               goto cdev_add_failed;
-       }
-
        /*
         * Add the class device
         * Link to the character device for creating the /dev entry
         * in devtmpfs.
         */
-       ec->class_dev.devt = ec->cdev.dev;
+       ec->class_dev.devt = MKDEV(ec_major, pdev->id);
        ec->class_dev.class = &cros_class;
        ec->class_dev.parent = dev;
        ec->class_dev.release = __remove;
@@ -431,13 +418,13 @@ static int ec_device_probe(struct platform_device *pdev)
        retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
        if (retval) {
                dev_err(dev, "dev_set_name failed => %d\n", retval);
-               goto set_named_failed;
+               goto failed;
        }
 
-       retval = device_add(&ec->class_dev);
+       retval = cdev_device_add(&ec->cdev, &ec->class_dev);
        if (retval) {
-               dev_err(dev, "device_register failed => %d\n", retval);
-               goto dev_reg_failed;
+               dev_err(dev, "cdev_device_add failed => %d\n", retval);
+               goto failed;
        }
 
        /* check whether this EC is a sensor hub. */
@@ -446,12 +433,8 @@ static int ec_device_probe(struct platform_device *pdev)
 
        return 0;
 
-dev_reg_failed:
-set_named_failed:
-       dev_set_drvdata(dev, NULL);
-       cdev_del(&ec->cdev);
-cdev_add_failed:
-       kfree(ec);
+failed:
+       put_device(&ec->class_dev);
        return retval;
 }