[RFC/PATCH] net/libertas: remove GPIO-CS handling in SPI interface code
andrey at cozybit.com
Wed Jun 3 15:09:05 EDT 2009
On Tue, Jun 2, 2009 at 10:47 PM, Mike Rapoport <mike at compulab.co.il> wrote:
> Andrey Yurovsky wrote:
>> On Mon, Jun 1, 2009 at 12:41 PM, Sebastian Andrzej Siewior
>> <bigeasy at linutronix.de> wrote:
>>> * Mike Rapoport | 2009-05-31 10:58:09 [+0300]:
>>>> Sebastian Andrzej Siewior wrote:
>>>>> This removes the dependency on GPIO framework and lets the SPI host
>>>>> driver handle the chip select. The SPI host driver is required to keep
>>>>> the CS active for the entire message unless cs_change says otherwise.
>>>>> This patch collects the two/three single SPI transfers into a message.
>>>>> Also the delay in read path in case use_dummy_writes are not used is
>>>>> moved into the SPI host driver.
>>>>> Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
>>>> For PXA270 platform
>>>> Tested-by: Mike Rapoport <mike at compulab.co.il>
>>> That's good to hear. Thanks for that.
>>> Once Andrey is happy with that I would Cc: wireless if there are no
>> It's working for me with dummy_writes disabled (that is, we use a
>> fixed delay when reading) but it's not working with dummy_writes
>> enabled (we clock dummy bytes when reading).
>> Mike and Sebastian -- have you tested with both dummy_writes enabled
>> and disabled? If not, which option did you choose? Ideally, we will
>> have both working or, if we get rid of one, it should be
>> dummy_writes=0 (I'd prefer that we clock in dummy bytes rather than
>> specifying a fixed delay).
> I've tested with both dummy_writes enabled and disabled. Seems to be Ok in both
Thanks Mike. In that case, it may be an issue with my SPI host
controller (on the Blackfin BF527 SoC) but I've at least been able to
confirm with dummy_writes=0 so that's a great start. I'll probably be
able to work out the dummy_writes issue in the near future.
Sebastian -- would you like to go ahead and send the patch (rebased if
needed) to wireless-testing? Please CC Dan Williams as well. You can
add a "Tested-by: Andrey Yurovsky <andrey at cozybit.com>" (and one for
Mike as well, I suppose?). I'll update the wireless Wiki about the
Chip Select and dummy_wires after the patch is merged. Thanks!
>> Looks good to me otherwise, thanks!
> Sincerely yours,
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