When a hw_random device's quality is non-zero, it will automatically be
used to fill the kernel's entropy pool. Since timeriomem_rng is used by
many different devices, the quality needs to be provided by platform
data or device tree.
Signed-off-by: Rick Altherr <raltherr@xxxxxxxxxx>
---
drivers/char/hw_random/timeriomem-rng.c | 7 +++++++
include/linux/timeriomem-rng.h | 3 +++
2 files changed, 10 insertions(+)
diff --git a/drivers/char/hw_random/timeriomem-rng.c b/drivers/char/hw_random/timeriomem-rng.c
index a0faa5f05deb..03ff5483d865 100644
--- a/drivers/char/hw_random/timeriomem-rng.c
+++ b/drivers/char/hw_random/timeriomem-rng.c
@@ -151,8 +151,15 @@ static int timeriomem_rng_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "missing period\n");
return -EINVAL;
}
+
+ if (!of_property_read_u32(pdev->dev.of_node,
+ "quality", &i))
+ priv->rng_ops.quality = i;
+ else
+ priv->rng_ops.quality = 0;
} else {
period = pdata->period;
+ priv->rng_ops.quality = pdata->quality;
}
priv->period = ns_to_ktime(period * NSEC_PER_USEC);
diff --git a/include/linux/timeriomem-rng.h b/include/linux/timeriomem-rng.h
index 46eb27ddbfab..320f743bf06b 100644
--- a/include/linux/timeriomem-rng.h
+++ b/include/linux/timeriomem-rng.h
@@ -13,4 +13,7 @@ struct timeriomem_rng_data {
/* measures in usecs */
unsigned int period;
+
+ /* bits of entropy per 1000 bits read */
+ unsigned int quality;
};
--
2.13.0.303.g4ebf302169-goog
