Messages in this thread | | | Date | Fri, 11 Feb 2011 12:23:56 +1300 | From | Ryan Mallon <> | Subject | Re: [RFC,PATCH 2/3] clk: Generic support for fixed-rate clocks |
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On 02/09/2011 07:41 PM, Jeremy Kerr wrote: > Since most platforms will need a fixed-rate clock, add one. This will > also serve as a basic example of an implementation of struct clk. > > Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com> > > --- > drivers/clk/clk.c | 14 ++++++++++++++ > include/linux/clk.h | 16 ++++++++++++++++ > 2 files changed, 30 insertions(+) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index c35478a..bbbdb0d 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -124,3 +124,17 @@ void __clk_put(struct clk *clk) > if (clk->ops->put) > clk->ops->put(clk); > } > + > +/* clk_fixed support */ > + > +#define to_clk_fixed(clk) (container_of(clk, struct clk_fixed, clk)) > + > +static unsigned long clk_fixed_get_rate(struct clk *clk) > +{ > + return to_clk_fixed(clk)->rate; > +} > + > +struct clk_ops clk_fixed_ops = { > + .get_rate = clk_fixed_get_rate, > +}; > +EXPORT_SYMBOL_GPL(clk_fixed_ops); > diff --git a/include/linux/clk.h b/include/linux/clk.h > index fe806b7..e67fdb0 100644 > --- a/include/linux/clk.h > +++ b/include/linux/clk.h > @@ -185,6 +185,22 @@ static inline void clk_common_init(struct clk *clk) > mutex_init(&clk->prepare_lock); > } > > +/* Simple fixed-rate clock */ > +struct clk_fixed { > + struct clk clk; > + unsigned long rate; > +}; > + > +extern struct clk_ops clk_fixed_ops; > + > +#define INIT_CLK_FIXED(name, r) { \ > + .clk = INIT_CLK(name.clk, clk_fixed_ops), \ > + .rate = (r) \ > +}
A fixed clock may still have other operations such as enable/disable. Maybe do something like this instead:
#define INIT_CLK_FIXED(name, ops, r) { \ .clk = INIT_CLK(name.clk, ops, rate), \ .clk.ops.get_rate = clk_fixed_get_rate, \ .rate = (r), \ }
That's untested though. I'm not sure if you can reliably assign something twice in a struct initialiser?
~Ryan
-- Bluewater Systems Ltd - ARM Technology Solution Centre
Ryan Mallon 5 Amuri Park, 404 Barbadoes St ryan@bluewatersys.com PO Box 13 889, Christchurch 8013 http://www.bluewatersys.com New Zealand Phone: +64 3 3779127 Freecall: Australia 1800 148 751 Fax: +64 3 3779135 USA 1800 261 2934
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