Thread (31 messages) 31 messages, 6 authors, 2017-11-07

[PATCH 08/12] hwrng: bcm2835-rng: Abstract I/O accessors

From: Eric Anholt <hidden>
Date: 2017-11-03 20:19:34
Also in: linux-crypto, linux-devicetree, lkml

Florian Fainelli [off-list ref] writes:
quoted hunk ↗ jump to hunk
In preparation for allowing BCM63xx to use this driver, we abstract I/O
accessors such that we can easily change those later on.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/char/hw_random/bcm2835-rng.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)
diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
index 35928efb52e7..500275d55044 100644
--- a/drivers/char/hw_random/bcm2835-rng.c
+++ b/drivers/char/hw_random/bcm2835-rng.c
@@ -42,6 +42,17 @@ static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng)
 	return container_of(rng, struct bcm2835_rng_priv, rng);
 }
 
+static inline u32 rng_readl(struct bcm2835_rng_priv *priv, u32 offset)
+{
+	return readl(priv->base + offset);
+}
+
+static inline void rng_writel(struct bcm2835_rng_priv *priv, u32 val,
+			      u32 offset)
+{
+	writel(val, priv->base + offset);
+}
+
 static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
 			       bool wait)
 {
@@ -49,18 +60,18 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
 	u32 max_words = max / sizeof(u32);
 	u32 num_words, count;
 
-	while ((__raw_readl(priv->base + RNG_STATUS) >> 24) == 0) {
+	while ((rng_readl(priv, RNG_STATUS) >> 24) == 0) {
 		if (!wait)
 			return 0;
 		cpu_relax();
 	}
What was the difference between the __raw_readl and readl that's now
being done in the new call?  Is it important?
 	/* set warm-up count & enable */
-	__raw_writel(RNG_WARMUP_COUNT, priv->base + RNG_STATUS);
-	__raw_writel(RNG_RBGEN, priv->base + RNG_CTRL);
+	rng_writel(priv, RNG_WARMUP_COUNT, RNG_STATUS);
+	rng_writel(priv, RNG_RBGEN, RNG_CTRL);
Similar question.
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