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From:   Samuel Holland <samuel@sholland.org>
To:     Corentin Labbe <clabbe.montjoie@gmail.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S . Miller" <davem@davemloft.net>,
        Chen-Yu Tsai <wens@csie.org>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Rob Herring <robh+dt@kernel.org>
Cc:     Samuel Holland <samuel@sholland.org>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Conor Dooley <conor@kernel.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-riscv@lists.infradead.org, linux-sunxi@lists.linux.dev
Subject: [PATCH v2 2/3] crypto: sun8i-ce - Add TRNG clock to the D1 variant
Date:   Sat, 31 Dec 2022 16:01:44 -0600
Message-Id: <20221231220146.646-3-samuel@sholland.org>
In-Reply-To: <20221231220146.646-1-samuel@sholland.org>
References: <20221231220146.646-1-samuel@sholland.org>
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At least the D1 variant requires a separate clock for the TRNG.
Without this clock enabled, reading from /dev/hwrng reports:

   sun8i-ce 3040000.crypto: DMA timeout for TRNG (tm=96) on flow 3

Experimentation shows that the necessary clock is the SoC's internal
RC oscillator. This makes sense, as noise from the oscillator can be
used as a source of entropy.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

Changes in v2:
 - New patch for v2

 drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c | 1 +
 drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h      | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
index 9f6594699835..a6865ff4d400 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
@@ -118,6 +118,7 @@ static const struct ce_variant ce_d1_variant = {
 		{ "bus", 0, 200000000 },
 		{ "mod", 300000000, 0 },
 		{ "ram", 0, 400000000 },
+		{ "trng", 0, 0 },
 		},
 	.esr = ESR_D1,
 	.prng = CE_ALG_PRNG,
diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h
index 8177aaba4434..27029fb77e29 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h
@@ -105,7 +105,7 @@
 
 #define MAX_SG 8
 
-#define CE_MAX_CLOCKS 3
+#define CE_MAX_CLOCKS 4
 
 #define MAXFLOW 4
 
-- 
2.37.4