Re: [PATCH 2/2] als: add unique device-ids to the als device class

[Jonathan Cameron <jic23@cam.ac.uk>]

Greg KH wrote:
> On Thu, Nov 26, 2009 at 05:19:13PM +0000, Jonathan Cameron wrote:
>>> That being said... If we want user-space to know what device is there,
>>> we may want to still let drivers pass a name string to
>>> als_device_register() and let the ALS core create a "name" sysfs
>>> attribute returning the string in question. This would be much lighter
>>> (for individual drivers) than the previous situation, as the string in
>>> question would be a constant (e.g. "TSL2550".) Opinions?
>>>
>> Makes sense given we want all drivers to support some form of identification.
>> We could do it by stating they will all have that attribute, but given it's constant
>> will save repetition to put it in the driver. Conversely it might complicate the handling
>> of subsequent attribute_groups so I'd probably favour adding relevant documentation lines
>> and leaving it up to the drivers to implement this attribute.
>>
>> Thus we'd require (within reason) all drivers to have illuminance0 and name.
> 
> Why have a name attribute when you can just use the name of the device
> itself instead?  Isn't that what it is there for?
Could do, though I'm not entirely sure all bus types are implementing a name
attribute (I may be wrong, but I don't think spi does for example though it might
have gone in with the recent device table stuff).  We could just specify that it
should be present for the device.

Jonathan