remove pxa ssp driver???

Chao Xie xiechao.mail at
Wed Aug 21 23:13:03 EDT 2013

On Wed, Aug 21, 2013 at 5:00 PM, Daniel Mack <zonque at> wrote:
> Hi Chao,
> On 21.08.2013 05:19, Chao Xie wrote:
>> In arch/arm/plat-pxa, there is a ssp driver named ssp.c.
>> The ssp driver will probe all the ssp devices one by one, and linked
>> them into a list.
>> The driver also provides two APIs pxa_request_pxa() and pxa_ssp_free().
>> So why we will have ssp.c driver? The only thing the driver will do is
>> linked all the ssp devices into a list, and then provides APIs to
>> others to allocate and free the ssp ports.
>> The ssp connection is defined by board, and it is fixed. So for a
>> single board, i do not think the port will be allocated or freed
>> dynamically. Is there any case that will two drivers will share same
>> port?
> It's really just to simplify the ssp port users, so they don't have to
> duplicate the resource allocation logic in their probe() implementation.
> However, that code is quite old, and with new ideas like devres
> allocation, probe functions can very small, so I agree with the idea of
> getting rid of that extra layer.
> However, I prepared some patches to provide device-tree functions to the
> ssp driver, and they are queued by Mark in the for-next branch of his
> ASoC tree:
> The approach there is now different, and the asoc ssp driver references
> the 'upstream' ssp port by phandle. But that API can't yet be fully used
> before the pxa-DMA bits go in, we can still change it I'd say.
>> If the two APIs are not needed. Then we can remove the driver, and
>> lets other drivers, for example, spi-pxa.c and sound/soc/pxa/pxa-ssp.c
>> to directly handle the ssp resources(get irq number, iomap the
>> register and etc.)
> Yes, I agree, but I'd like to schedule that for after the 3.12 merge
> window has settled. Is that ok for you?
That is fine.
You have submited the patches for removing the old pxa DMA driver, what is the
status for that?

> Thanks,
> Daniel

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