From mboxrd@z Thu Jan 1 00:00:00 1970 From: galak@codeaurora.org (Kumar Gala) Date: Tue, 30 Sep 2014 08:49:52 -0500 Subject: [RFC 0/7] Qualcomm SMEM, SMD, RPM and regulators In-Reply-To: <1412037291-16880-1-git-send-email-bjorn.andersson@sonymobile.com> References: <1412037291-16880-1-git-send-email-bjorn.andersson@sonymobile.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sep 29, 2014, at 7:34 PM, Bjorn Andersson 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. - k -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation