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

Dirk Behme
2009-02-23T19:31:52Z

Nishanth Menon wrote:
> 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..

Yes, I agree. Let us keep it simple. If CONFIG_MUSB is enabled by
additional patch, this clock will be necessary.

Thanks

Dirk