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path: root/drivers/char/hw_random/imx-rngc.c
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Diffstat (limited to 'drivers/char/hw_random/imx-rngc.c')
-rw-r--r--drivers/char/hw_random/imx-rngc.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c
index 0576801944fd..903894518c8d 100644
--- a/drivers/char/hw_random/imx-rngc.c
+++ b/drivers/char/hw_random/imx-rngc.c
@@ -31,6 +31,7 @@
#define RNGC_CTRL_MASK_ERROR 0x00000040
#define RNGC_CTRL_MASK_DONE 0x00000020
+#define RNGC_CTRL_AUTO_SEED 0x00000010
#define RNGC_STATUS_ERROR 0x00010000
#define RNGC_STATUS_FIFO_LEVEL_MASK 0x00000f00
@@ -167,7 +168,7 @@ static irqreturn_t imx_rngc_irq(int irq, void *priv)
static int imx_rngc_init(struct hwrng *rng)
{
struct imx_rngc *rngc = container_of(rng, struct imx_rngc, rng);
- u32 cmd;
+ u32 cmd, ctrl;
int ret;
/* clear error */
@@ -192,7 +193,18 @@ static int imx_rngc_init(struct hwrng *rng)
} while (rngc->err_reg == RNGC_ERROR_STATUS_STAT_ERR);
- return rngc->err_reg ? -EIO : 0;
+ if (rngc->err_reg)
+ return -EIO;
+
+ /*
+ * enable automatic seeding, the rngc creates a new seed automatically
+ * after serving 2^20 random 160-bit words
+ */
+ ctrl = readl(rngc->base + RNGC_CONTROL);
+ ctrl |= RNGC_CTRL_AUTO_SEED;
+ writel(ctrl, rngc->base + RNGC_CONTROL);
+
+ return 0;
}
static int imx_rngc_probe(struct platform_device *pdev)