hwrng: stm32 - support RNG configuration locking mechanism

If "st,rng-lock-conf" DT binding property is set for a stm32-rng node,
the RNG configuration will be locked until next hardware block reset
or platform reset.

Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Gatien Chevallier 2023-09-21 10:02:59 +02:00 committed by Herbert Xu
parent 28d13f3fdb
commit a1b03e7ade

View file

@ -62,6 +62,7 @@ struct stm32_rng_private {
struct reset_control *rst;
const struct stm32_rng_data *data;
bool ced;
bool lock_conf;
};
/*
@ -301,6 +302,9 @@ static int stm32_rng_init(struct hwrng *rng)
reg &= ~RNG_CR_CONDRST;
reg |= RNG_CR_RNGEN;
if (priv->lock_conf)
reg |= RNG_CR_CONFLOCK;
writel_relaxed(reg, priv->base + RNG_CR);
err = readl_relaxed_poll_timeout_atomic(priv->base + RNG_CR, reg,
@ -439,6 +443,7 @@ static int stm32_rng_probe(struct platform_device *ofdev)
}
priv->ced = of_property_read_bool(np, "clock-error-detect");
priv->lock_conf = of_property_read_bool(np, "st,rng-lock-conf");
priv->data = of_device_get_match_data(dev);
if (!priv->data)