From a1b03e7ade409125712313c04a97242e18aae88e Mon Sep 17 00:00:00 2001 From: Gatien Chevallier Date: Thu, 21 Sep 2023 10:02:59 +0200 Subject: [PATCH] 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 Signed-off-by: Herbert Xu --- drivers/char/hw_random/stm32-rng.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c index 819f062f454d..4a602d666dad 100644 --- a/drivers/char/hw_random/stm32-rng.c +++ b/drivers/char/hw_random/stm32-rng.c @@ -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)