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path: root/drivers/char/hw_random/atmel-rng.c
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Diffstat (limited to 'drivers/char/hw_random/atmel-rng.c')
-rw-r--r--drivers/char/hw_random/atmel-rng.c38
1 files changed, 16 insertions, 22 deletions
diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c
index f518b99f53f..851bc7e20ad 100644
--- a/drivers/char/hw_random/atmel-rng.c
+++ b/drivers/char/hw_random/atmel-rng.c
@@ -34,8 +34,15 @@ static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max,
u32 *data = buf;
/* data ready? */
- if (readl(trng->base + TRNG_ODATA) & 1) {
+ if (readl(trng->base + TRNG_ISR) & 1) {
*data = readl(trng->base + TRNG_ODATA);
+ /*
+ ensure data ready is only set again AFTER the next data
+ word is ready in case it got set between checking ISR
+ and reading ODATA, so we don't risk re-reading the
+ same word
+ */
+ readl(trng->base + TRNG_ISR);
return 4;
} else
return 0;
@@ -47,29 +54,22 @@ static int atmel_trng_probe(struct platform_device *pdev)
struct resource *res;
int ret;
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res)
- return -EINVAL;
-
trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
if (!trng)
return -ENOMEM;
- if (!devm_request_mem_region(&pdev->dev, res->start,
- resource_size(res), pdev->name))
- return -EBUSY;
-
- trng->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
- if (!trng->base)
- return -EBUSY;
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ trng->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(trng->base))
+ return PTR_ERR(trng->base);
- trng->clk = clk_get(&pdev->dev, NULL);
+ trng->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(trng->clk))
return PTR_ERR(trng->clk);
ret = clk_enable(trng->clk);
if (ret)
- goto err_enable;
+ return ret;
writel(TRNG_KEY | 1, trng->base + TRNG_CR);
trng->rng.name = pdev->name;
@@ -85,13 +85,10 @@ static int atmel_trng_probe(struct platform_device *pdev)
err_register:
clk_disable(trng->clk);
-err_enable:
- clk_put(trng->clk);
-
return ret;
}
-static int __devexit atmel_trng_remove(struct platform_device *pdev)
+static int atmel_trng_remove(struct platform_device *pdev)
{
struct atmel_trng *trng = platform_get_drvdata(pdev);
@@ -99,9 +96,6 @@ static int __devexit atmel_trng_remove(struct platform_device *pdev)
writel(TRNG_KEY, trng->base + TRNG_CR);
clk_disable(trng->clk);
- clk_put(trng->clk);
-
- platform_set_drvdata(pdev, NULL);
return 0;
}
@@ -131,7 +125,7 @@ static const struct dev_pm_ops atmel_trng_pm_ops = {
static struct platform_driver atmel_trng_driver = {
.probe = atmel_trng_probe,
- .remove = __devexit_p(atmel_trng_remove),
+ .remove = atmel_trng_remove,
.driver = {
.name = "atmel-trng",
.owner = THIS_MODULE,