hw_random: timeriomem_rng: Allow setting RNG quality from platform data

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 <[email protected]> Signed-off-by: Herbert Xu <[email protected]>
opendata26 · Jun 1, 2017 · 284e763 · 284e763
1 parent b14c534
commit 284e763
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diff --git 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
@@ -13,4 +13,7 @@ struct timeriomem_rng_data {
 
 	/* measures in usecs */
 	unsigned int		period;
+
+	/* bits of entropy per 1024 bits read */
+	unsigned int		quality;
 };