Re: [Qemu-devel] [PATCH v4 1/2] ARM: exynos4210: CMU support

[Maksim Kozlov <m.kozlov@samsung.com>]

17.07.2012 01:05, Peter Maydell пишет:
> On 4 July 2012 17:27, Maksim Kozlov<m.kozlov@samsung.com>  wrote:
>> Add exynos4210 Clock Management Units emulation
>
> General comment, which I suspect you're not going to like...
>
> Underlying the exynos-specific code here, there's a general
> mechanism of "I'm a device, I have a clock input, I want to be
> able to find out when that clock is reprogrammed so I can
> adjust my behaviour, and I want to do things like ask what
> its rate is", and there's a provider of clock signals which
> has some kind of clock tree, possibly rearrangable at runtime
> by reprogramming the clock management unit. This is basically
> the same thing the OMAP clock code in hw/omap_clk.c also provides
> (though again the commonality is obscured under a heap of OMAP
> specific stuff).
>
> I think we need a generic interface for providing clocks
> and plumbing them together, which can then be used by both
> OMAP and Exynos and whatever later platforms come along
> with clock trees. I'd also really like to see this use QOM
> links rather than being a set of ad-hoc C functions for
> register/get rate/etc.
>
> You're platform number two, which I'm afraid means you get
> the pain of writing a generic mechanism...
>
> (There is a conceptual parallel with the kernel efforts to
> move to a common struct_clk infrastructure, I think; I'd
> much rather we did this while we have two clock tree models
> rather than waiting until we have half a dozen.)
>
> I've added some specific code review comments below, but
> this is the biggie.
>
Ok, I will think what I can do in this direction.
Thanks