Hi Marek, > -----Original Message----- > From: linux-kernel-ow...@vger.kernel.org [mailto:linux-kernel- > ow...@vger.kernel.org] On Behalf Of Jolly Shah > Sent: Thursday, March 15, 2018 10:47 AM > To: Marek Szyprowski <m.szyprow...@samsung.com>; Geert Uytterhoeven > <ge...@linux-m68k.org>; Rob Herring <r...@kernel.org> > Cc: Matthias Brugger <matthias....@gmail.com>; Andy Gross > <andy.gr...@linaro.org>; Shawn Guo <shawn...@kernel.org>; Geert > Uytterhoeven <geert+rene...@glider.be>; Björn Andersson > <bjorn.anders...@linaro.org>; sean.w...@mediatek.com; Michal Simek > <michal.si...@xilinx.com>; Mark Rutland <mark.rutl...@arm.com>; Rajan > Vaja <raj...@xilinx.com>; open list:OPEN FIRMWARE AND FLATTENED > DEVICE TREE BINDINGS <devicet...@vger.kernel.org>; Linux ARM <linux-arm- > ker...@lists.infradead.org>; Linux Kernel Mailing List <linux- > ker...@vger.kernel.org> > Subject: RE: [PATCH 1/2] dt-bindings: power: Add ZynqMP power domain > bindings > > [This sender failed our fraud detection checks and may not be who they appear > to be. Learn about spoofing at http://aka.ms/LearnAboutSpoofing] > > Hi Rob, Geert, Marek, > > > -----Original Message----- > > From: Marek Szyprowski [mailto:m.szyprow...@samsung.com] > > Sent: Tuesday, March 06, 2018 12:06 AM > > To: Geert Uytterhoeven <ge...@linux-m68k.org>; Rob Herring > > <r...@kernel.org> > > Cc: Jolly Shah <jol...@xilinx.com>; Matthias Brugger > > <matthias....@gmail.com>; Andy Gross <andy.gr...@linaro.org>; Shawn > > Guo <shawn...@kernel.org>; Geert Uytterhoeven > > <geert+rene...@glider.be>; Björn Andersson > > <bjorn.anders...@linaro.org>; sean.w...@mediatek.com; Michal Simek > > <michal.si...@xilinx.com>; Mark Rutland <mark.rutl...@arm.com>; Rajan > > Vaja <raj...@xilinx.com>; open list:OPEN FIRMWARE AND FLATTENED > DEVICE > > TREE BINDINGS <devicet...@vger.kernel.org>; Linux ARM <linux-arm- > > ker...@lists.infradead.org>; Linux Kernel Mailing List <linux- > > ker...@vger.kernel.org>; Jolly Shah <jol...@xilinx.com> > > Subject: Re: [PATCH 1/2] dt-bindings: power: Add ZynqMP power domain > > bindings > > > > Hi All, > > > > On 2018-03-06 08:59, Geert Uytterhoeven wrote: > > > Hi Rob, Jolly, > > > > > > On Mon, Mar 5, 2018 at 11:39 PM, Rob Herring <r...@kernel.org> wrote: > > >> On Tue, Feb 27, 2018 at 03:55:49PM -0800, Jolly Shah wrote: > > >>> Add documentation to describe ZynqMP power domain bindings. > > >>> > > >>> Signed-off-by: Jolly Shah <jol...@xilinx.com> > > >>> Signed-off-by: Rajan Vaja <raj...@xilinx.com> > > >>> --- > > >>> .../devicetree/bindings/power/zynqmp-genpd.txt | 46 > > ++++++++++++++++++++++ > > >>> 1 file changed, 46 insertions(+) > > >>> create mode 100644 > > >>> Documentation/devicetree/bindings/power/zynqmp-genpd.txt > > >>> > > >>> diff --git > > >>> a/Documentation/devicetree/bindings/power/zynqmp-genpd.txt > > >>> b/Documentation/devicetree/bindings/power/zynqmp-genpd.txt > > >>> new file mode 100644 > > >>> index 0000000..25f9711 > > >>> --- /dev/null > > >>> +++ b/Documentation/devicetree/bindings/power/zynqmp-genpd.txt > > >>> +This node contains a number of subnodes, each representing a > > >>> +single PM domain that PM domain consumer devices reference. > > >>> + > > >>> +== PM Domain Nodes == > > >>> + > > >>> +Required properties: > > >>> + - #power-domain-cells: Number of cells in a PM domain specifier. > > >>> +Must be > > 0. > > >>> + - pd-id: List of domain identifiers of as defined by platform > > >>> firmware. > > These > > >>> + identifiers are passed to the PM firmware. > > >>> + > > >>> +Example: > > >>> + zynqmp-genpd { > > >>> + compatible = "xlnx,zynqmp-genpd"; > > >> What's the control interface for controlling the domains? > > >>> + > > >>> + pd_usb0: pd-usb0 { > > >>> + pd-id = <22>; > > >>> + #power-domain-cells = <0>; > > >> There's no need for all these sub nodes. Make #power-domain-cells 1 > > >> and put the id in the cell value. > > > That was my first reaction, too... > > >>> + }; > > >>> + > > >>> + pd_sata: pd-sata { > > >>> + pd-id = <28>; > > >>> + #power-domain-cells = <0>; > > >>> + }; > > >>> + > > >>> + pd_gpu: pd-gpu { > > >>> + pd-id = <58 20 21>; > > > ... until I saw the above. > > > Controlling the GPU power area requires controlling 3 physical areas? > > > > > > However, doing it this way may bite you in the future, if a need > > > arises to control a subset. And what about power up/down order? > > > > What about defining 3 separate domains and arranging them in > > parent-child relationship? generic power domains already supports that > > and this allows to nicely define the power on/off order. > > > > >>> + #power-domain-cells = <0x0>; > > >>> + }; > > >>> + }; > > > > I agree it should be arranged in as parent child order to control subset or > control > order. Will incorporate those changes in next version. > > > Best regards > > -- > > Marek Szyprowski, PhD > > Samsung R&D Institute Poland
As suggested, I tried out parent, child approach. However what I found is Genpd core takes care of parent child dependencies for power on off routines only. In our case, We need them in attach-detach routines too. In that case, we need to handle dependencies manually for those routines. Please suggest better approach, if any. Thanks, Jolly Shah
