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

From: Jon Hunter
Date: Thu Oct 22 2009 - 19:23:24 EST



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.

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.

Jon
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