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path: root/drivers/char/hw_random/omap-rng.c
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Diffstat (limited to 'drivers/char/hw_random/omap-rng.c')
-rw-r--r--drivers/char/hw_random/omap-rng.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c
index b27f39688b5e..0ed07d16ec8e 100644
--- a/drivers/char/hw_random/omap-rng.c
+++ b/drivers/char/hw_random/omap-rng.c
@@ -66,6 +66,13 @@
#define OMAP4_RNG_OUTPUT_SIZE 0x8
#define EIP76_RNG_OUTPUT_SIZE 0x10
+/*
+ * EIP76 RNG takes approx. 700us to produce 16 bytes of output data
+ * as per testing results. And to account for the lack of udelay()'s
+ * reliability, we keep the timeout as 1000us.
+ */
+#define RNG_DATA_FILL_TIMEOUT 100
+
enum {
RNG_OUTPUT_0_REG = 0,
RNG_OUTPUT_1_REG,
@@ -176,7 +183,7 @@ static int omap_rng_do_read(struct hwrng *rng, void *data, size_t max,
if (max < priv->pdata->data_size)
return 0;
- for (i = 0; i < 20; i++) {
+ for (i = 0; i < RNG_DATA_FILL_TIMEOUT; i++) {
present = priv->pdata->data_present(priv);
if (present || !wait)
break;
@@ -432,7 +439,6 @@ static int get_omap_rng_device_details(struct omap_rng_dev *omap_rng)
static int omap_rng_probe(struct platform_device *pdev)
{
struct omap_rng_dev *priv;
- struct resource *res;
struct device *dev = &pdev->dev;
int ret;
@@ -449,8 +455,7 @@ static int omap_rng_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, priv);
priv->dev = dev;
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- priv->base = devm_ioremap_resource(dev, res);
+ priv->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->base)) {
ret = PTR_ERR(priv->base);
goto err_ioremap;