hwrng: mxc-rnga - Use devm_clk_get_enabled() helpers

The devm_clk_get_enabled() helpers:
    - call devm_clk_get()
    - call clk_prepare_enable() and register what is needed in order to
     call clk_disable_unprepare() when needed, as a managed resource.

This simplifies the code and avoids the calls to clk_disable_unprepare().
Signed-off-by: Huan Yang <link@vivo.com>
Reviewed-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/mxc-rnga.c

@@ -147,33 +147,25 @@ static int mxc_rnga_probe(struct platform_device *pdev)
 	mxc_rng->rng.data_present = mxc_rnga_data_present;
 	mxc_rng->rng.data_read = mxc_rnga_data_read;
 
-	mxc_rng->clk = devm_clk_get(&pdev->dev, NULL);
+	mxc_rng->clk = devm_clk_get_enabled(&pdev->dev, NULL);
 	if (IS_ERR(mxc_rng->clk)) {
 		dev_err(&pdev->dev, "Could not get rng_clk!\n");
 		return PTR_ERR(mxc_rng->clk);
 	}
 
-	err = clk_prepare_enable(mxc_rng->clk);
-	if (err)
-		return err;
-
 	mxc_rng->mem = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(mxc_rng->mem)) {
 		err = PTR_ERR(mxc_rng->mem);
-		goto err_ioremap;
+		return err;
 	}
 
 	err = hwrng_register(&mxc_rng->rng);
 	if (err) {
 		dev_err(&pdev->dev, "MXC RNGA registering failed (%d)\n", err);
-		goto err_ioremap;
+		return err;
 	}
 
 	return 0;
-
-err_ioremap:
-	clk_disable_unprepare(mxc_rng->clk);
-	return err;
 }
 
 static void mxc_rnga_remove(struct platform_device *pdev)
@@ -181,8 +173,6 @@ static void mxc_rnga_remove(struct platform_device *pdev)
 	struct mxc_rng *mxc_rng = platform_get_drvdata(pdev);
 
 	hwrng_unregister(&mxc_rng->rng);
-
-	clk_disable_unprepare(mxc_rng->clk);
 }
 
 static const struct of_device_id mxc_rnga_of_match[] = {