Re: [PATCH 2/2] clk: Move init fields from clk to clk_hw

[Sascha Hauer <s.hauer@pengutronix.de>]

On Tue, Mar 20, 2012 at 12:54:55AM -0700, Saravana Kannan wrote:
> 
> On Tue, March 20, 2012 12:20 am, Shawn Guo wrote:
> > On Mon, Mar 19, 2012 at 08:38:26PM -0700, Saravana Kannan wrote:
> >> This has a couple of advantages:
> >> * Completely hides struct clk from many clock platform drivers and
> >> static
> >>   clock initialization code.
> >> * Simplifies the generic clk_register() function and allows adding
> >> optional
> >>   fields in the future without modifying the function signature.
> >> * Allows for simpler static initialization of clocks on all platforms by
> >>   removing the need for forward delcarations.
> >> * Halves the number of symbols added for each static clock
> >> initialization.
> >>
> >> Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
> >
> > I agree this is a reasonable move.  But while you simplify the interface
> > of clk_register(), why not making a further step to simplify the
> > following interfaces simple too?
> >
> > struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
> >                 const char *parent_name, unsigned long flags,
> >                 unsigned long fixed_rate);
> > struct clk *clk_register_gate(struct device *dev, const char *name,
> >                 const char *parent_name, unsigned long flags,
> >                 void __iomem *reg, u8 bit_idx,
> >                 u8 clk_gate_flags, spinlock_t *lock);
> > struct clk *clk_register_divider(struct device *dev, const char *name,
> >                 const char *parent_name, unsigned long flags,
> >                 void __iomem *reg, u8 shift, u8 width,
> >                 u8 clk_divider_flags, spinlock_t *lock);
> > struct clk *clk_register_mux(struct device *dev, const char *name,
> >                 char **parent_names, u8 num_parents, unsigned long flags,
> >                 void __iomem *reg, u8 shift, u8 width,
> >                 u8 clk_mux_flags, spinlock_t *lock);
> 
> If you simplify those functions further. They would just become
> clk_register(). I'm not sure I see a value in them in at that point or
> even in their current form. But if others see (I'm guessing since they
> acked or didn't nack it), I'm not going to ask to remove them. If everyone
> agrees that we should just remove them, I would be glad to.
> 
> It's arguable that these functions for the common hardware types saves the
> need to deal with the kalloc in every platform driver. But it's not clear
> to me where they would get these parameters in the first place. Most
> likely form some sort of static array. At which point, it might as well be
> a static array of pointers to clk_gated.hw, clk_fixed_rate.hw, etc instead
> of a platform specific  struct to hold these initializers.

I am using these functions and don't need a static array, I just call
the functions with the desired parameters.

Overall the clock framework was written in a way that we have to expose
as little information about the internally used structs as necessary. It
seems your patches are pulling in the opposite direction now.

Sascha


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