Re: [Qemu-devel] [PATCH v1 5/8] xilinx_zynq: add USB controllers

[Peter Crosthwaite <peter.crosthwaite@xilinx.com>]

On Thu, Oct 25, 2012 at 11:14 PM, Gerd Hoffmann <kraxel@redhat.com> wrote:
> On 10/25/12 14:56, Peter Crosthwaite wrote:
>> On Thu, Oct 25, 2012 at 10:16 PM, Peter Maydell
>> <peter.maydell@linaro.org> wrote:
>>> On 25 October 2012 13:12, Gerd Hoffmann <kraxel@redhat.com> wrote:
>>>>> +static inline void zynq_init_usb(uint32_t base_addr, qemu_irq irq)
>>>>> +{
>>>>> +    DeviceState *dev = qdev_create(NULL, "ehci-sysbus");
>>>>
>>>> I'd suggest to have a "ehci-sysbus-zynq" device instead which sets
>>>> capsbase & opregbase in ->init() ...
>>>>
>>>>> +    qdev_prop_set_uint16(dev, "capabase", 0x100);
>>>>> +    qdev_prop_set_uint32(dev, "opregbase", 0x140);
>>>>
>>>> ... then drop these lines.
>>>
>>> That sounds weird to me -- properties are exactly the mechanism
>>> for having a device which is configurable. Why have two differently
>>> named devices which only differ in the value of a configurable
>>> property?
>
>> Yes I agree. Creating a now QOM definition for every variant of a
>> device is tedious. EHCI provides a nice abstraction which should not
>> have awareness of its particular implementations.
>
> Maybe "zynq" is the wrong abstraction and this should be named by the
> actual ehci chip implementation (which could be the same for a bunch of
> sysbus boards).
>
> But, yes, different chips should have different QOM definitions.  Like
> we have a bunch of different uhci variants with a QOM definition for
> each of them.
>

Can we at least take a data driven approach to this? Get the device
names and their varying parameters into a big table up top and they
just create N device defs from it? hw/m25p80 is one example of a
device that does something similar although the variation is selected
using a single qdev prop rather than the QOM names.

> cheers,
>   Gerd
>
>