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Commit 791af4f4 authored by Florian Fainelli's avatar Florian Fainelli Committed by Herbert Xu
Browse files

hwrng: bcm2835 - Manage an optional clock 



One of the last steps before bcm63xx-rng can be eliminated is to manage
a clock during hwrng::init and hwrng::cleanup, so fetch it in the probe
function, and manage it during these two steps when valid.

Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: default avatarEric Anholt <eric@anholt.net>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 04b154fa

drivers/char/hw_random/bcm2835-rng.c

+16 −1
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/of_platform.h>

#include <linux/platform_device.h>

#include <linux/printk.h>

#include <linux/clk.h>



#define RNG_CTRL	0x0

#define RNG_STATUS	0x4
@@ -33,6 +34,7 @@ struct bcm2835_rng_priv { 
	struct hwrng rng;

	void __iomem *base;

	bool mask_interrupts;

	struct clk *clk;

};



static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng)
@@ -66,8 +68,15 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max, 
static int bcm2835_rng_init(struct hwrng *rng)

{

	struct bcm2835_rng_priv *priv = to_rng_priv(rng);

	int ret = 0;

	u32 val;



	if (!IS_ERR(priv->clk)) {

		ret = clk_prepare_enable(priv->clk);

		if (ret)

			return ret;

	}



	if (priv->mask_interrupts) {

		/* mask the interrupt */

		val = readl(priv->base + RNG_INT_MASK);
@@ -79,7 +88,7 @@ static int bcm2835_rng_init(struct hwrng *rng) 
	__raw_writel(RNG_WARMUP_COUNT, priv->base + RNG_STATUS);

	__raw_writel(RNG_RBGEN, priv->base + RNG_CTRL);



	return 0;

	return ret;

}



static void bcm2835_rng_cleanup(struct hwrng *rng)
@@ -88,6 +97,9 @@ static void bcm2835_rng_cleanup(struct hwrng *rng) 


	/* disable rng hardware */

	__raw_writel(0, priv->base + RNG_CTRL);



	if (!IS_ERR(priv->clk))

		clk_disable_unprepare(priv->clk);

}



struct bcm2835_rng_of_data {
@@ -130,6 +142,9 @@ static int bcm2835_rng_probe(struct platform_device *pdev) 
		return PTR_ERR(priv->base);

	}



	/* Clock is optional on most platforms */

	priv->clk = devm_clk_get(dev, NULL);



	priv->rng.name = "bcm2835-rng";

	priv->rng.init = bcm2835_rng_init;

	priv->rng.read = bcm2835_rng_read;