of_clk_get() / devm_clk_get()

[swarren@wwwdotorg.org (Stephen Warren)]

On 02/13/2013 11:42 PM, Tony Prisk wrote:
> On Wed, 2013-02-13 at 21:40 -0700, Stephen Warren wrote:
>> On 02/13/2013 09:17 PM, Tony Prisk wrote:
>>> Currently we have devm_clk_get() which gives a managed-resource clk (by
>>> name), or of_clk_get() which gives an unmanaged resource clk (by id).
>>>
>>> I just wanted to sound out everyone as to whether there is a need for a
>>> managed version of the of_clk_get.
>>>
>>> My personal concern about devm_clk_get is that it requires (if I
>>> understand correctly) that the DT node have the clock-names property
>>> (which is optional). If the optional name is not supplied, it fails.
>>> This basically makes it 'not optional' when a driver uses devm_clk_get.
>>> (Please correct me if I'm wrong about this).
>>
>> I thought supplying NULL for the name/ID simply gave you the first clock
>> in the list (clocks property)? I'm sure I've seen plenty of Tegra
>> drivers that end up doing that.
>>
> 
> I think someone else told me that once before so it is probably correct
> - but it doesn't solve the problem of requesting a second clock without
> a clock-names property.
> 
> That leaves us in the situation of only being able to use managed clocks
> when there is only one, or forcing dts files to include the 'optional'
> property.

True. Writing a devm_ wrapper around of_clk_get() should be pretty
trivial though.