On Tue 30 Sep 06:49 PDT 2014, Kumar Gala wrote: > > On Sep 29, 2014, at 7:34 PM, Bjorn Andersson <Bjorn.Andersson@xxxxxxxxxxxxxx> wrote: > > > All Qualcomm platforms implements a shared heap among the processors in the > > SoC, used for sharing data with other parts of the system. > > > > One consumer of items from this heap is the "Shared Memory Driver", a ring > > buffer based point-to-point communication mechanism used to send either stream > > or packet based data to remote processors. > > > > Starting with 8x74 this system is used to talk to the Resource Power Manager > > (RPM), a power efficient "coprocessor" with responsibility of aggregate votes > > from the various systems in the SoC related to regulators, clocks and bus > > frequencies. > > > > The PMIC regulators and root clocks in these platforms are only accessible via > > the RPM, so to get access to these we need the full chain of smem, smd, rpm and > > a regulator driver implemented. And that is exactly what this series provides. > > > > > > A key outstanding question is where in the tree we should put the > > implementation, for now I dropped them in drivers/soc/qcom but that's only > > because I don't know where to put it otherwise. I have not found any equivalent > > of the SMEM driver, SMD resembles mailbox and rpmsg - but comments in that > > patch on why it's neither. > > > > RPM is a mfd and regulator is a regulator :) > > I still don’t see why RPM support for either A-family or B-family should > exist in MFD vis drivers/soc/qcom. What benefit is there in putting this in > MFD? > > I think both A and B-family support should be in drivers/soc/qcom for the > current time being until we determine there is some framework that makes more > sense in the future. I almost see RPM more like a bus controller than > anything else. Something like an I2C bus controller that than has some set > of devices off of that bus. > When you look at what functionality the RPM exposes it has very much in common with a PMIC. So after looking at this back and forth for months I think MFD is a nice fit. As with all the other pmics we could create a new subsystem (drivers/pmic?) for this kind of devices that exposes variable size registers for children to read and write. But if you can convince the maintainers about that then we have a whole bunch of stuff in mfd etc that we should move out, so let's not put this in qcom-staging just for the sake of it. Regards, Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
