Re: [PATCH 3/3] ARM: dts: bcm2711: Enable HWRNG support

From: Stephen Brennan
Date: Tue Nov 19 2019 - 00:58:22 EST


Hello Stefan & Nicolas,

On Mon Nov 18, 2019 at 8:44 PM, Stefan Wahren wrote:
> Hi,
>
>
> Am 18.11.19 um 12:44 schrieb Nicolas Saenz Julienne:
> > Hi Stephen,
> >
> > On Sun, 2019-11-17 at 23:58 -0800, Stephen Brennan wrote:
> >> From: Stefan Wahren <wahrenst@xxxxxxx>
> >>
> >> This enables hardware random number generator support for the BCM2711
> >> on the Raspberry Pi 4 board.
> >>
> >> Signed-off-by: Stefan Wahren <wahrenst@xxxxxxx>
> >> Signed-off-by: Stephen Brennan <stephen@xxxxxxxxxx>
> >> ---
> >> arch/arm/boot/dts/bcm2711.dtsi | 5 ++---
> >> 1 file changed, 2 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
> >> index ac83dac2e6ba..2c19e5de284a 100644
> >> --- a/arch/arm/boot/dts/bcm2711.dtsi
> >> +++ b/arch/arm/boot/dts/bcm2711.dtsi
> >> @@ -92,10 +92,9 @@ pm: watchdog@7e100000 {
> >> };
> >>
> >> rng@7e104000 {
> >> + compatible = "brcm,bcm2711-rng200";
> >> interrupts = <GIC_SPI 125 IRQ_TYPE_LEVEL_HIGH>;
> >> -
> >> - /* RNG is incompatible with brcm,bcm2835-rng */
> >> - status = "disabled";
> >> + status = "okay";
> >> };
> >>
> >> uart2: serial@7e201400 {
> > We inherit the reg property from bcm283x.dtsi, on which we only define a size
> > of 0x10 bytes. I gather from the driver that iproc-rng200's register space is
> > at least 0x28 bytes big. We should also update the 'reg' property to:
> >
> > reg = <0x7e104000 0x28>;
>
>
> Thanks for sending and noticing. A proper solution would be to move the
> whole rng node from bcm283x.dtsi to bcm283x-common.dtsi and define a
> completely new rng node in bcm2711.dtsi.

Thanks both for your time and consideration. I'm not terribly familiar with
device tree source but I think I understand what you'd like here. I'll send
a v2 that does this!

Regards,
Stephen

>
>
> Regards
> Stefan
>
>
> >
> > Regards,
> > Nicolas
> >
> >
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>
>
>
>