On Thu, Jul 29, 2021 at 01:36:31PM -0600, Rob Herring wrote: > On Mon, Jul 19, 2021 at 04:53:14PM +0200, Stephan Gerhold wrote: > > In some configurations, the BAM DMA controller is set up by a remote > > processor and the local processor can simply start making use of it > > without setting up the BAM. This is already supported using the > > "qcom,controlled-remotely" property. > > > > However, for some reason another possible configuration is that the > > remote processor is responsible for powering up the BAM, but we are > > still responsible for initializing it (e.g. resetting it etc). Add > > a "qcom,remote-power-collapse" property to describe that configuration. > > > > Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx> > > --- > > NOTE: This is *not* a compile-time requirement for the BAM-DMUX driver > > so this could also go through the dmaengine tree. > > > > Also note that there is an ongoing effort to convert these bindings > > to DT schema but sadly there were not any updates for a while. :/ > > https://lore.kernel.org/linux-arm-msm/20210519143700.27392-2-bhupesh.sharma@xxxxxxxxxx/ > > --- > > Documentation/devicetree/bindings/dma/qcom_bam_dma.txt | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt > > index cf5b9e44432c..362a4f0905a8 100644 > > --- a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt > > +++ b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt > > @@ -15,6 +15,8 @@ Required properties: > > the secure world. > > - qcom,controlled-remotely : optional, indicates that the bam is controlled by > > remote proccessor i.e. execution environment. > > +- qcom,remote-power-collapse : optional, indicates that the bam is powered up by > > + a remote processor but must be initialized by the local processor. > > Wouldn't 'qcom,remote-power' or 'qcom,remote-powered' be sufficient? I > don't understand what 'collapse' means here. Doesn't sound good though. > Yeah I can't think of any significant meaning of the "collapse" part for the bindings, I probably just picked it up somewhere while trying to find some information about how the BAM DMUX setup works. :) Just one question, would you prefer "qcom,remote-powered" or rather "qcom,powered-remotely" for consistency with the existing "qcom,controlled-remotely"? Both sounds fine to me. Thanks! Stephan
