Florian Fainelli <f.fainelli@xxxxxxxxx> writes:
> 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: Florian Fainelli <f.fainelli@xxxxxxxxx>
> ---
> drivers/char/hw_random/bcm2835-rng.c | 17 ++++++++++++++++-
> 1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
> index ed20e0b6b7ae..99b56fd5482c 100644
> --- a/drivers/char/hw_random/bcm2835-rng.c
> +++ b/drivers/char/hw_random/bcm2835-rng.c
> @@ -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;
> + }
clk_prepare_enable() is protected by IS_ERR_OR_NULL() checks and will
return 0.
> +
> 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);
Same. With those conditionals dropped,
Reviewed-by: Eric Anholt <eric@xxxxxxxxxx>
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