[PATCH v5 04/16] pwm: Add table-based lookup for static mappings
Shawn Guo
shawn.guo at linaro.org
Sun Apr 1 11:20:46 EDT 2012
On Sat, Mar 31, 2012 at 04:30:21PM +0200, Thierry Reding wrote:
...
> The best solution that I could come up with is to not pass the index into the
> of_pwm_request() function but rather forward the consumer name as passed into
> pwm_get(). The of_pwm_request() could use the "pwm-names" property to do a
> reverse lookup of the index and request that. One good thing about that would
> be that I no longer need to export the of_pwm_request() function.
I never understand why of_pwm_request() needs to be exported anyway.
pwm_get() should be the only interface to pwm new/DT users, IMO.
> The "bad"
> thing is that it'll make the "pwm-names" property mandatory if more than a
> single PWM is requested.
>
You do not have to make it mandatory, but anyone requesting any pwm
other than the first on in "pwms" list should fail.
> Does that sound reasonable?
>
The above is exactly what clock DT does, so it sounds reasonable to me.
And I would expect the next version can just turn the second parameter
of pwm_get() into the one that will be used to identify the pwm device
rather than adding one more parameter. Then we have pwm API well
aligned with clk and regulator.
--
Regards,
Shawn
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