[PATCH v9 1/3] gpio: bcm281xx: Add GPIO driver

Christian Daudt csd at broadcom.com
Tue Sep 10 17:14:24 EDT 2013


Hi Stephen,
On 13-09-10 01:02 PM, Stephen Warren wrote:
> On 09/10/2013 12:07 PM, Markus Mayer wrote:
>> From: Markus Mayer <mmayer at broadcom.com>
>>
>> Add the GPIO driver for the Broadcom bcm281xx family of mobile SoCs.
>> These GPIO controllers may contain up to 8 banks where each bank
>> includes 32 pins that can be driven high or low and act as an edge
>> sensitive interrupt.
> The binding,
> Reviewed-by: Stephen Warren <swarren at nvidia.com>
>
> although ...
>
>> diff --git a/Documentation/devicetree/bindings/gpio/gpio-bcm-kona.txt b/Documentation/devicetree/bindings/gpio/gpio-bcm-kona.txt
>> +This GPIO driver is used in the following Broadcom SoCs:
>> +  BCM11130, BCM11140, BCM11351, BCM28145, BCM28155
> Given that, I would expect the documentation of the compatible property
> to enumerate the compatible values for all of those different chips,
> although the driver could choose to only bind to e.g. brcm,bcm11351-gpio
> or brcm,kona-gpio, since they're all compatible with it.
>
How would this help ? All of these chips are part of the same family and 
thus quite similar (the primary difference being on the memory 
controller and packaging), and we can't know a priori on which 
variations bugs will happen, if any. So listing out a number of 
theoretical compatible properties in the documentation that most likely 
will never get used anyone doesn't seem to serve a purpose. If we were 
to need a workaround triggered on compatible, it would more likely be 
over a specific rev of the chip instead of the model within this family 
(as we have already done for rev a2 in cache-l2x0.c)

  Thanks,
    csd





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