From 326ed382256475aa4b8b7eae8a2f60689fd25e78 Mon Sep 17 00:00:00 2001
From: "lionel.debieve@st.com" <lionel.debieve@st.com>
Date: Thu, 15 Feb 2018 14:03:08 +0100
Subject: [PATCH] hwrng: stm32 - add reset during probe
Git-commit: 326ed382256475aa4b8b7eae8a2f60689fd25e78
Patch-mainline: v4.17-rc1
References: bsc#1051510
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/char/hw_random/stm32-rng.c | 9 +++++++++
1 file changed, 9 insertions(+)
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),
--
2.18.0