[U-Boot] [PATCH 0/7] [RFC] Driver model, take 1

[Graeme Russ]

Hi Marek,

On Tue, Sep 4, 2012 at 4:44 PM, Marek Vasut <marek.vasut at gmail.com> wrote:
> Dear Graeme Russ,
>
>> Hi DM Team,
>>
>> On Thu, Aug 23, 2012 at 4:28 AM, Marek Vasut <marek.vasut at gmail.com> wrote:
>> > Dear Marek Vasut,
>> >
>> >> I'm submitting hereby the initial code for the driver model. This is a
>> >> RFC patch, please give it a spin and scream :-)
>>
>> I haven't had a really deep play with this yet, but a couple of things
>> do come to mind...
>>
>> I've been thinking of a scenario of a simple LED module with both a
>> Serial (RS-232) and USB interface (or maybe an I2C connection). I can
>> think of two options:
>>  a) Write a separate driver for each interface
>>  b) Write a single driver that can handle all supported interfaces
>
> c) Write a muxing driver, basically you'd have two drivers -- "led-module-uart"
> and "led-module-usb" -- which would share common logic. The upcall towards the
> bus can also be pretty much covered by some local wrappers.

Adds a little overhead, but sounds sound. But also, you should give
the downstream driver the ability to check that it is being attached
to a valid upstream driver - Attaching a USB ethernet dongle to PCI
isn't going to cut it. This will be critical if we allow
modularisation of the driver sub-system (i.e. dynamically load a
driver module and bind it from the command line)

Regards,

Graeme