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From: yendapally.reddy@broadcom.com (Yendapally Reddy Dhananjaya Reddy)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 4/4] hwrng: bcm2835: Read as much data as available
Date: Mon, 23 May 2016 12:20:51 -0400	[thread overview]
Message-ID: <1464020451-16520-5-git-send-email-yendapally.reddy@broadcom.com> (raw)
In-Reply-To: <1464020451-16520-1-git-send-email-yendapally.reddy@broadcom.com>

Read the requested number of data from the fifo

Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>
---
 drivers/char/hw_random/bcm2835-rng.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
index b1e8b78..9bbdc07 100644
--- a/drivers/char/hw_random/bcm2835-rng.c
+++ b/drivers/char/hw_random/bcm2835-rng.c
@@ -43,6 +43,8 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
 			       bool wait)
 {
 	void __iomem *rng_base = (void __iomem *)rng->priv;
+	u32 max_words = max/sizeof(u32);
+	u32 num_words, count;
 
 	while ((__raw_readl(rng_base + RNG_STATUS) >> 24) == 0) {
 		if (!wait)
@@ -50,8 +52,14 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
 		cpu_relax();
 	}
 
-	*(u32 *)buf = __raw_readl(rng_base + RNG_DATA);
-	return sizeof(u32);
+	num_words = (readl(rng_base + RNG_STATUS) >> 24);
+	if (num_words > max_words)
+		num_words = max_words;
+
+	for (count = 0; count < num_words; count++)
+		((u32 *)buf)[count] = readl(rng_base + RNG_DATA);
+
+	return (num_words * sizeof(u32));
 }
 
 static struct hwrng bcm2835_rng_ops = {
-- 
2.1.0

  parent reply	other threads:[~2016-05-23 16:20 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-23 16:20 [PATCH 0/4] hw rng support for NSP SoC Yendapally Reddy Dhananjaya Reddy
2016-05-23 16:20 ` [PATCH 1/4] dt-bindings: rng: Northstar Plus SoC rng bindings Yendapally Reddy Dhananjaya Reddy
2016-05-23 21:39   ` Rob Herring
2016-05-24  2:22   ` Eric Anholt
2016-05-23 16:20 ` [PATCH 2/4] hwrng: bcm2835: Support Broadcom NSP SoC rng Yendapally Reddy Dhananjaya Reddy
2016-05-24  2:14   ` Eric Anholt
2016-05-23 16:20 ` [PATCH 3/4] ARM: dts: nsp: Add rng device tree entry Yendapally Reddy Dhananjaya Reddy
2016-05-23 16:20 ` Yendapally Reddy Dhananjaya Reddy [this message]
2016-05-24  2:21   ` [PATCH 4/4] hwrng: bcm2835: Read as much data as available Eric Anholt

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