Re: [PATCH 04/13] OMAP2/3 clock: ensure each clock has a unique name

[Tony Lindgren <tony@atomide.com>]

* Paul Walmsley <paul@pwsan.com> [090817 13:06]:
> Hello Russell,
> 
> On Mon, 17 Aug 2009, Russell King - ARM Linux wrote:
> 
> > On Mon, Aug 17, 2009 at 03:14:45AM -0600, Paul Walmsley wrote:
> > > What it does remove is the need for internal core code to fake up a struct 
> > > device simply to access a clock.  It also allows us to harmonize the 
> > > clock names, used internally in core code, with the hardware reality, 
> > > which uses unique names to identify clocks.
> > 
> > That problem is already solved.  clk_get_sys()
> 
> That solves the first problem, but not the second.  Is there some reason 
> that OMAP core code (aside from the clkdev mapping structures in 
> mach-omap2/clock*.c) should know, or care, whether a platform device name 
> is bound to that clock?
> 
> On OMAP, we have uniquely-named clock lines in the technical 
> documentation.  It is possible that other platforms don't have this.  But 
> for us, I'd submit that it makes more sense for internal core code to 
> fetch a clock documented as "MMC1_FCLK" with:
> 
>     c = omap_clk_get_by_name("mmc1_fck");
> 
> rather than: 
> 
>     c = clk_get_sys("mmci-omap-hs.0", "ick");
> 
> (* ideally, of course, we'd use "mmc1_fclk" rather than "mmc1_fck", this 
> is a legacy issue that has been left for a future patch.)
> 
> As a side benefit, it also makes our clock debugfs setup easier, so a 
> clock can be identified in the path as simply 
> /debugfs/clock/.../mmc1_fck/, rather than something like 
> /debugfs/clock/.../mmci-omap-hs.0-mmc1_fck/ or 
> /debugfs/clock/.../mmci-omap-hs.0/mmc1_fck.
> 
> Thoughts?

I guess if we wanted to do this in a generic way, we could have
clkdev_get_hw_name() in arch/arm/common/clkdev.c. Then we could
have struct omap_clk contain the hardware clock name.

But then we're wasting memory and duplicating parts of the names,
so I don't think that it would be any better solution compared to
renaming the clocks like you're doing.

Tony