From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Simek Subject: Re: [PATCH 1/3] dt: xilinx: zynqmp: Add bindings for PM firmware Date: Mon, 14 Aug 2017 15:47:15 +0200 Message-ID: <5d2e3a5e-6060-ff13-a065-c4b6be37e4c9@xilinx.com> References: <8c27b7eec6cc00d37dfe9b3998212ce9c9c27a31.1501854302.git.michal.simek@xilinx.com> <20170810191056.ur5b3zdrcgmb6sim@rob-hp-laptop> <4e5d9f8c-9e87-bdcd-388a-aab3c32415e8@xilinx.com> <20170811135453.GU12347@toto> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170811135453.GU12347@toto> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: "Edgar E. Iglesias" , Michal Simek Cc: Rob Herring , Edgar Iglesias , linux-arm-kernel@lists.infradead.org, Soren Brinkmann , devicetree@vger.kernel.org, monstr@monstr.eu, linux-kernel@vger.kernel.org, Mark Rutland List-Id: devicetree@vger.kernel.org On 11.8.2017 15:54, Edgar E. Iglesias wrote: > On Fri, Aug 11, 2017 at 02:58:03PM +0200, Michal Simek wrote: >> Hi Rob, +Edgar, >> >> On 10.8.2017 21:10, Rob Herring wrote: >>> On Fri, Aug 04, 2017 at 03:45:30PM +0200, Michal Simek wrote: >>>> From: Soren Brinkmann >>>> >>>> Document the DT bindings for the Zynq UltraScale+ PM Firmware. >>>> >>>> Signed-off-by: Soren Brinkmann >>>> Signed-off-by: Michal Simek >>>> --- >>>> >>>> .../devicetree/bindings/soc/xilinx/xlnx,zynqmp-pm.txt | 19 +++++++++++++++++++ >>> >>> bindings/firmware/ >> >> will move. >> >>> >>>> 1 file changed, 19 insertions(+) >>>> create mode 100644 Documentation/devicetree/bindings/soc/xilinx/xlnx,zynqmp-pm.txt >>>> >>>> diff --git a/Documentation/devicetree/bindings/soc/xilinx/xlnx,zynqmp-pm.txt b/Documentation/devicetree/bindings/soc/xilinx/xlnx,zynqmp-pm.txt >>>> new file mode 100644 >>>> index 000000000000..222a18ce07fc >>>> --- /dev/null >>>> +++ b/Documentation/devicetree/bindings/soc/xilinx/xlnx,zynqmp-pm.txt >>>> @@ -0,0 +1,19 @@ >>>> +Xilinx Zynq MPSoC Firmware Device Tree Bindings >>>> + >>>> +The zynqmp-pm node describes the interface to platform firmware. >>> >>> Please define this should be under /firmware node. >>> >>>> +Required properties: >>>> + - compatible: Must contain: "xlnx,zynqmp-pm" >>>> + - method: The method of calling the PM-API firmware layer. >>>> + Permitted values are: >>>> + - "smc" : To be used in configurations without a hypervisor >>>> + - "hvc" : To be used when hypervisor is present >>> >>> Do you really use both? >>> >> >> SMCs definitely yes. >> >> Interface was designed in that way and I don't know if people are using >> it or not. >> >> Not sure if Xen is blocking SMCs. I know we have discussed it but not >> sure if this is enabled by default or only for certain configurations. >> Also not sure if xen contains handler for hvc. >> Edgar: Do you know? > > We have patches for Xen that implement a power-management mediator. > That implementation handles PM calls over both SMC and HVC insns. > Patches are on the Xen mailing list. > > Other hypervisors may work differently. > > I think we should support both but I don't have a strong opinion on it. Rob: Are you ok with having it there? Thanks, Michal