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@xxxxxxxxxxxx>
---
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
