Re: [PATCH 05/10] omap1: Fix DSP public peripherals support forams-delta

From: Tony Lindgren
Date: Fri Oct 23 2009 - 15:19:51 EST


* Jon Hunter <jon-hunter@xxxxxx> [091022 16:22]:
>
> Tony Lindgren wrote:
>> From: Janusz Krzysztofik <jkrzyszt@xxxxxxxxxxxx>
>>
>> DSP public peripherals used to work on OMAP1510 based (or all OMAP1 class?)
>> machines as long as old dspgateway code were present in the l-o tree. For
>> several months it is no longer included, breaking support for McBSP1 based
>> audio on Amstrad Delta, for example.
>>
>> This patch, derived from the old dspgateway code, corrects the problem for the
>> board by simply taking the DSP out of reset state, I guess. That way, things
>> should not break when a new dsp code is added to the tree, and the change can
>> be reverted then.
>
> A minor comment/correction here. Although this bit is called "DSP_RST"
> this does not actually release the DSP from reset. This bit actually
> releases the reset for the "priority registers (TIPB module), EMIF
> configuration registers, and the MPUI control logic (partially) in the
> DSP", thus allowing you to access the DSP peripherals via the MPUI. Bit
> 1 of the same register, called "DSP_EN", actually releases the DSP reset.

Thanks for clarifying that.

>> If there are any reports on McBSP1 or other DSP public peripherals not working
>> for other OMAP1 machines (I've not heard of any for now), I can prepare a more
>> general patch providing an extra include file with a helper function defined.
>
> This would be necessary for all OMAP15xx based devices that use McBSP1
> (or McBSP3 for that matter). However, I am not sure if it is common for
> other boards to use McBSP1 for audio.

Yeah, I guess currently only board-ams-delta.c needs this for audio.
But that could of course change once there are more 15xx boards using ASoC.

Regards,

Tony
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