hwrng: bcm63xx - make use of devm_hwrng_register

This change converts bcm63xx-rng to use devm* API for managing all
resources, which allows us to dispense with the rest of error handling
path and remove() function. Also we combine hwern and driver-private
data into a single allocation, use clk_prepare_enable() instead
of "naked" clk_enable() and move clock enabling/disabling into hwrnd
inti(0 and cleanup() methods so the clock stays off until rng is
used.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/char/hw_random/bcm63xx-rng.c b/drivers/char/hw_random/bcm63xx-rng.c
index 27da00f68c8f4c34bc6c0b3437b3dee4678e972a..d1494ecd9e116490dd5c5875387be7e6a2a92fde 100644 (file)
--- a/drivers/char/hw_random/bcm63xx-rng.c
+++ b/drivers/char/hw_random/bcm63xx-rng.c
@@ -24,16 +24,22 @@
 #define RNG_MASK                       0x10
 
 struct bcm63xx_rng_priv {
+       struct hwrng rng;
        struct clk *clk;
        void __iomem *regs;
 };
 
-#define to_rng_priv(rng)       ((struct bcm63xx_rng_priv *)rng->priv)
+#define to_rng_priv(rng)       container_of(rng, struct bcm63xx_rng_priv, rng)
 
 static int bcm63xx_rng_init(struct hwrng *rng)
 {
        struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
        u32 val;
+       int error;
+
+       error = clk_prepare_enable(priv->clk);
+       if (error)
+               return error;
 
        val = __raw_readl(priv->regs + RNG_CTRL);
        val |= RNG_EN;
@@ -50,6 +56,8 @@ static void bcm63xx_rng_cleanup(struct hwrng *rng)
        val = __raw_readl(priv->regs + RNG_CTRL);
        val &= ~RNG_EN;
        __raw_writel(val, priv->regs + RNG_CTRL);
+
+       clk_didsable_unprepare(prov->clk);
 }
 
 static int bcm63xx_rng_data_present(struct hwrng *rng, int wait)
@@ -79,86 +87,53 @@ static int bcm63xx_rng_probe(struct platform_device *pdev)
        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!r) {
                dev_err(&pdev->dev, "no iomem resource\n");
-               ret = -ENXIO;
-               goto out;
+               return -ENXIO;
        }
 
        priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
-       if (!priv) {
-               ret = -ENOMEM;
-               goto out;
-       }
-
-       rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
-       if (!rng) {
-               ret = -ENOMEM;
-               goto out;
+       if (!priv)
+               return -ENOMEM;
+
+       priv->rng.name = pdev->name;
+       priv->rng.init = bcm63xx_rng_init;
+       priv->rng.cleanup = bcm63xx_rng_cleanup;
+       prov->rng.data_present = bcm63xx_rng_data_present;
+       priv->rng.data_read = bcm63xx_rng_data_read;
+
+       priv->clk = devm_clk_get(&pdev->dev, "ipsec");
+       if (IS_ERR(priv->clk)) {
+               error = PTR_ERR(priv->clk);
+               dev_err(&pdev->dev, "no clock for device: %d\n", error);
+               return error;
        }
 
-       platform_set_drvdata(pdev, rng);
-       rng->priv = (unsigned long)priv;
-       rng->name = pdev->name;
-       rng->init = bcm63xx_rng_init;
-       rng->cleanup = bcm63xx_rng_cleanup;
-       rng->data_present = bcm63xx_rng_data_present;
-       rng->data_read = bcm63xx_rng_data_read;
-
-       clk = clk_get(&pdev->dev, "ipsec");
-       if (IS_ERR(clk)) {
-               dev_err(&pdev->dev, "no clock for device\n");
-               ret = PTR_ERR(clk);
-               goto out;
-       }
-
-       priv->clk = clk;
-
        if (!devm_request_mem_region(&pdev->dev, r->start,
                                        resource_size(r), pdev->name)) {
                dev_err(&pdev->dev, "request mem failed");
-               ret = -ENOMEM;
-               goto out;
+               return -EBUSY;
        }
 
        priv->regs = devm_ioremap_nocache(&pdev->dev, r->start,
                                        resource_size(r));
        if (!priv->regs) {
                dev_err(&pdev->dev, "ioremap failed");
-               ret = -ENOMEM;
-               goto out;
+               return -ENOMEM;
        }
 
-       clk_enable(clk);
-
-       ret = hwrng_register(rng);
-       if (ret) {
-               dev_err(&pdev->dev, "failed to register rng device\n");
-               goto out_clk_disable;
+       error = devm_hwrng_register(&pdev->dev, &priv->rng);
+       if (error) {
+               dev_err(&pdev->dev, "failed to register rng device: %d\n",
+                       error);
+               return error;
        }
 
        dev_info(&pdev->dev, "registered RNG driver\n");
 
-       return 0;
-
-out_clk_disable:
-       clk_disable(clk);
-out:
-       return ret;
-}
-
-static int bcm63xx_rng_remove(struct platform_device *pdev)
-{
-       struct hwrng *rng = platform_get_drvdata(pdev);
-       struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
-
-       hwrng_unregister(rng);
-       clk_disable(priv->clk);
-
        return 0;
 }
 
 static struct platform_driver bcm63xx_rng_driver = {
        .probe          = bcm63xx_rng_probe,
-       .remove         = bcm63xx_rng_remove,
        .driver         = {
                .name   = "bcm63xx-rng",
        },