Re: Info on LDM, domain system and SOCs

Francesco VIRLINZI
2007-09-24T11:14:26Z

Amit Kucheria ha scritto:
> On 9/10/07, Francesco VIRLINZI <francesco.virlinzi@st.com> wrote:
>
>> If you mean the <include/linux/clk.h>, I already saw it.
>> I think it's good but it isn't enough.
>> I want track also the devices on a clock to be able to notify (for each
>> device) if a clock changes.
>>
>
> You should propose these changes to the clock framework. Designing a
> new framework is unlikely to be accepted in the kernel easily since a
> lot of platforms are using the clock framework already.
>
Hi
I'm sorry but this is really what I don't want to do.
I think the problem is really this.

In the kernel there are a several clock struct... one for each
architecture...

A lot of them have no relation with the linux driver model... and they
aren't showed under /sys/...
This means there is a physical clock network not aware by the kernel.

For this reason I don't want "write-a-new" or "extend-an-existent" clock
framework..

I'm working on a domain framework arch independent (a kind of ancestor
of all the clock framework)
able to track the domain relationship and also the device-on-domain
relationship.
This framework should go under <root>/drivers/base/...
The basic idea is to create a base code for all the architectures to
simplify (I hope)
the clocks managements in the SOCs.

For example in my platform I can do something like:

# ls /sys/domains/pll1_clk/comms_clk/devices/
# ssc-0 ssc-1 ssc-2

This means in my platform there are
- a parent clock pll1_clk
- a child clock comms_clk
- three devices (ssc-0 ssc-1 ssc-2) under comms_clk

And this information are available in user space (I think this information
could help a power manager in user space)

Francesco
> /Amit
> --
> Amit Kucheria, Linux developer
>