Messages in this thread | | | From | Arnd Bergmann <> | Date | Sat, 23 May 2020 21:40:17 +0200 | Subject | Re: [PATCH 2/2] firmware: smccc: Add ARCH_SOC_ID support |
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On Sat, May 23, 2020 at 7:27 PM Sudeep Holla <sudeep.holla@arm.com> wrote: > On Fri, May 22, 2020 at 08:41:59PM +0200, Arnd Bergmann wrote: > > On Fri, May 22, 2020 at 6:54 PM Sudeep Holla <sudeep.holla@arm.com> wrote: > > > jep106:5678 (the IMP_DEF_SOC_ID field in my example) would > > probably be sufficient to not conflict with a another soc_device > > driver, but is quite likely to clash with an ID used by another > > manufacturer. > > > > IIUC, you are fine with "jep106:1234:5678" where 1234 is jep106 manufacture > id code and 5678 is soc_id as it may avoid all the conflicts across > the manufacture namespaces.
I think either jep106:5678 or jep106:1234:5678 (or some variation with different field separators if you prefer) would be fine here.
> > jep106:1234 (the manufacturer ID) in turn seems too broad from > > the soc_id field, as that would include every chip made by one > > company. > > > > I understand, and IIUC you prefer this to be embedded with soc_id > especially to avoid namespace conflicts which makes sense. > > Thanks for all the discussion and valuable inputs. I am now bit nervous > to add SoC info from SMCCC ARCH_SOC_ID to sysfs yet as we need more info > especially "machine" and "serial_number" for elsewhere(OEM firmware mostly > from DT or ACPI).
I probably wouldn't mix those in with the same driver. If machine and serial_number have no smccc interface, then they should be left out, but there could be a separate soc_device that gets that information by other means, usually using one of the existing hardware id register drivers.
> TBH, the mix might be bit of a mess as there are soc drivers that rely > on DT completely today. Anyways, this SOC_ID can be added as library that > can be used by a *generic* soc driver once we define a standard way to > fetch other information("machine" and "serial_number"). I am happy to > get suggestions on that front especially from you and Francois as you > have got some context already.
Well, I suppose we could have the entire data from the smccc interface in a central place somewhere, such as (to stay with my example) "1234:5678:9abcdef0" in an attribute of any soc_device driver that adds a call to a library function for the jep106 ID, or possibly in /sys/firmware or even a field added to /proc/cpuinfo.
Arnd
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