[U-Boot] [PATCH 6/7 v2] OMAP3: Add OMAP3 core changes for MUSB

Nishanth Menon menon.nishanth at gmail.com
Mon Feb 23 13:30:40 CET 2009


Grazvydas Ignotas said the following on 02/23/2009 02:13 PM:
>>>> +#ifdef CONFIG_MUSB
>>>> +    /* Enable the MUSB interface clock */
>>>> +    sr32(&prcm_base->iclken1_core, 4, 1, 0x1);
>>>> +#endif
>>>>         
>>> the design of u-boot is to enagle the IP only when he use it
>>> so please do not enable the clock every time just when you want to use
>>> (in the USB driver init)
>>>       
>> This is already answered in
>>
>> http://lists.denx.de/pipermail/u-boot/2009-February/047452.html
>>     
>
> He probably wants to say that clocks should be enabled only when "usb
> start" is issued, as you might have u-boot compiled with USB defines
> set, but never actually use USB.
>   
Comparing having all clock initialization at a central point (clock.c) -
which seems simple vs having get-put kind of clock apis in U-boot : I
might go for the simple solution of all clocks in a single place..
u-boot is supposed to "keep it simple", enable/disable clocks on a need
basis is elegant, though could end up getting extended to i2c and other
peripherals too(if I were to stretch is pretty hard ;) ).. makes more
sense in kernel(which is already there) than here - my 2 cents..

Regards,
Nishanth Menon


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