[PATCH 3/3] ARM: OMAP3: fix dpll4_m3_ck and dpll4_m4_ck dividers

Tero Kristo t-kristo at ti.com
Wed Oct 9 09:43:29 EDT 2013


On 10/09/2013 04:33 PM, Tomi Valkeinen wrote:
> On 09/10/13 16:22, Tero Kristo wrote:
>> On 10/09/2013 04:12 PM, Tomi Valkeinen wrote:
>>> dpll4_m3_ck and dpll4_m4_ck have divider bit fields which are 6 bits
>>> wide. However, only values from 1 to 32 are allowed. This means we have
>>> to add a divider tables and list the dividers explicitly.
>>>
>>> I believe the same issue is there for other dpll4_mx_ck clocks, but as
>>> I'm not familiar with them, I didn't touch them.
>>
>> I think you can limit the max value with a mask only, no need to define
>> new tables.
>
> The bit field is 6 bits wide, so the mask is correct. It's just that the
> biggest allowed value is 32, which takes 6 bits, not 63.
>
> Changing the mask to 5 bits would limit the divider to 31, wouldn't it?

Oh true. Sucks with legacy clocks then.

For dt clocks, you should be able to declare max / min divider values 
for ti,divider-clock type which would take care of this case. Just 
change the ti,max-div = <63>; field to ... = <32>;

-Tero




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