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authorlionel.debieve@st.com <lionel.debieve@st.com>2018-02-15 14:03:08 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-30 07:50:48 +0200
commit086a52f1db8847dc0ab4acc5c9af3dd9cc4cf4e8 (patch)
tree7c305013797f25f81f6cb26ed2baee0d219c5075 /drivers/char
parent92ff7ff0318f3c38394d36629084a19ea0e61a23 (diff)
hwrng: stm32 - add reset during probe
[ Upstream commit 326ed382256475aa4b8b7eae8a2f60689fd25e78 ] Avoid issue when probing the RNG without reset if bad status has been detected previously Signed-off-by: Lionel Debieve <lionel.debieve@st.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/hw_random/stm32-rng.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c
index 63d84e6f1891..83c695938a2d 100644
--- a/drivers/char/hw_random/stm32-rng.c
+++ b/drivers/char/hw_random/stm32-rng.c
@@ -21,6 +21,7 @@
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
#include <linux/slab.h>
#define RNG_CR 0x00
@@ -46,6 +47,7 @@ struct stm32_rng_private {
struct hwrng rng;
void __iomem *base;
struct clk *clk;
+ struct reset_control *rst;
};
static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
@@ -140,6 +142,13 @@ static int stm32_rng_probe(struct platform_device *ofdev)
if (IS_ERR(priv->clk))
return PTR_ERR(priv->clk);
+ priv->rst = devm_reset_control_get(&ofdev->dev, NULL);
+ if (!IS_ERR(priv->rst)) {
+ reset_control_assert(priv->rst);
+ udelay(2);
+ reset_control_deassert(priv->rst);
+ }
+
dev_set_drvdata(dev, priv);
priv->rng.name = dev_driver_string(dev),