Re: [RFC,PATCH 2/3] clk: Generic support for fixed-rate clocks

[Jeremy Kerr]

Hi Saravana,

> >> A fixed clock may still have other operations such as enable/disable.
> > 
> > Then it's not a fixed clock; I'd prefer this to be a separate type, as
> > it's now hardware dependent.
> 
> I'm confused. If a clock's rate can't be changed and it can't be enabled
> or disabled, then what's the point of representing that clock
> signal/line as a clock in the driver.

Because the drivers using this clock don't know that it's a fixed clock.

For example, a uart needs to know the rate of its clock source, so that it can 
set its internal divisors to get a valid baud rate. The uart driver will query  
the input rate using clk_get_rate(). The driver still needs to call 
clk_enable/clk_prepare/etc, because on some systems it may have a switchable 
clock.

Cheers,


Jeremy

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