Re: [linux-sunxi] Re: [PATCH v2 1/5] ARM: dts: sun8i: Add SID node

Maxime Ripard
2015-12-01T08:41:22Z

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Hi,

On Wed, Nov 25, 2015 at 09:22:56AM +0800, Shuge wrote:
> On Monday, November 23, 2015 at 17:32 UTC+8, Maxime Ripard wrote:
> > On Mon, Nov 23, 2015 at 10:51:15PM -0800, Sugar Wu wrote:
> >> On Monday, November 23, 2015 at 8:43:59 PM UTC+8, Maxime Ripard wrote:
> >>>
> >>> Hi,
> >>>
> >>> On Mon, Nov 23, 2015 at 09:02:48AM +0100, Josef Gajdusek wrote:
> >>>> Add a node describing the Security ID memory to the
> >>>> Allwinner H3 .dtsi file.
> >>>>
> >>>> Signed-off-by: Josef Gajdusek <a...@atx.name <javascript:>>
> >>>> ---
> >>>> arch/arm/boot/dts/sun8i-h3.dtsi | 7 +++++++
> >>>> 1 file changed, 7 insertions(+)
> >>>>
> >>>> diff --git a/arch/arm/boot/dts/sun8i-h3.dtsi
> >>> b/arch/arm/boot/dts/sun8i-h3.dtsi
> >>>> index 0faa38a..58de718 100644
> >>>> --- a/arch/arm/boot/dts/sun8i-h3.dtsi
> >>>> +++ b/arch/arm/boot/dts/sun8i-h3.dtsi
> >>>> @@ -359,6 +359,13 @@
> >>>> #size-cells = <0>;
> >>>> };
> >>>>
> >>>> + sid: eeprom@01c14000 {
> >>>> + compatible = "allwinner,sun4i-a10-sid";
> >>>> + reg = <0x01c14000 0x400>;
> >>>
> >>> The datasheet says it's 256 bytes wide, while the size here is of 1kB,
> >>> is it intentional?
> >>
> >> SID memory map is 0x01c14000 ~ 0x01c143FF, include 2048bits efuse space.
> >> H3 efuse space is SID_SRAM, its range is 0x01c14200 ~ +0x100.
> >
> > Interesting, what is below the 0x200 registers?
> >
> Some control register about SID.
> offset: 0x40 SID Program/Read Control Register
> offset: 0x50 SID Program Key Value Register
> offset: 0x60 SID Read Key Value Register
> offset: 0x70 \
> offset: 0x80 SJTAG Attribute 0 Register
> offset: 0x84 SJTAG Attribute 1 Register
> offset: 0x88 SJTAG Select Register
> offset: 0x90 SID Program Ctrol register for burned timing

Thanks!

I guess the layout changed a bit from the A10 and alikes then.

Anyway, we should expose only to the nvmem framework the actual eeprom
space, so from 0x200 to 0x300 from what you're saying (just like we
should only expose the first 4 bytes in the A10 / A20)

Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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