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author | Joel Stanley <joel@jms.id.au> | 2018-03-22 06:37:35 +0100 |
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committer | Joel Stanley <joel@jms.id.au> | 2018-04-30 06:51:29 +0200 |
commit | 5daa8212c08ecaf4f79b4e9426bb50c193d3370a (patch) | |
tree | 02421406ecabed567a0ff383ada77dbbd66fe86f | |
parent | Linux 4.17-rc2 (diff) | |
download | linux-5daa8212c08ecaf4f79b4e9426bb50c193d3370a.tar.xz linux-5daa8212c08ecaf4f79b4e9426bb50c193d3370a.zip |
ARM: dts: aspeed: Describe random number device
There is a random number generator that updates a register in the SCU
every second. This is compatible with the timeriomem rng driver in the
kernel.
From the timeriomem_rng bindings:
quality: estimated number of bits of true entropy per 1024 bits read
from the rng. Defaults to zero which causes the kernel's default
quality to be used instead. Note that the default quality is usually
zero which disables using this rng to automatically fill the kernel's
entropy pool.
As to the recommended value for us to use:
Rick Altherr <raltherr@google.com> wrote:
> Quality is #bit of entropy per 1000 bits read. 100 is a
> conservative value that was suggested by those in the know.
Signed-off-by: Joel Stanley <joel@jms.id.au>
-rw-r--r-- | arch/arm/boot/dts/aspeed-g4.dtsi | 8 | ||||
-rw-r--r-- | arch/arm/boot/dts/aspeed-g5.dtsi | 7 |
2 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm/boot/dts/aspeed-g4.dtsi b/arch/arm/boot/dts/aspeed-g4.dtsi index 518d2bc7c7fc..8d7303ad5273 100644 --- a/arch/arm/boot/dts/aspeed-g4.dtsi +++ b/arch/arm/boot/dts/aspeed-g4.dtsi @@ -125,6 +125,14 @@ pinctrl: pinctrl { compatible = "aspeed,g4-pinctrl"; }; + + }; + + rng: hwrng@78 { + compatible = "timeriomem_rng"; + reg = <0x78 0x4>; + period = <1>; + quality = <100>; }; adc: adc@1e6e9000 { diff --git a/arch/arm/boot/dts/aspeed-g5.dtsi b/arch/arm/boot/dts/aspeed-g5.dtsi index f9917717dd08..c4a20d590e47 100644 --- a/arch/arm/boot/dts/aspeed-g5.dtsi +++ b/arch/arm/boot/dts/aspeed-g5.dtsi @@ -164,6 +164,13 @@ }; }; + rng: hwrng@78 { + compatible = "timeriomem_rng"; + reg = <0x78 0x4>; + period = <1>; + quality = <100>; + }; + gfx: display@1e6e6000 { compatible = "aspeed,ast2500-gfx", "syscon"; reg = <0x1e6e6000 0x1000>; |