Re: [RFC PATCH 6/7] dt-bindings: arm: Add virtio transport for SCMI
From: Peter Hilber <hidden>
Date: 2020-10-02 08:18:30
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On 23.09.20 22:54, Rob Herring wrote:
On Fri, Sep 18, 2020 at 06:55:58PM +0200, Peter Hilber wrote:quoted
From: Igor Skalkin <redacted> Document the properties for arm,scmi-virtio compatible nodes. The backing virtio SCMI device is described in patch [1]. [1] https://lists.oasis-open.org/archives/virtio-comment/202005/msg00096.html Co-developed-by: Peter Hilber <redacted> Signed-off-by: Peter Hilber <redacted> Signed-off-by: Igor Skalkin <redacted> --- .../devicetree/bindings/arm/arm,scmi.txt | 38 ++++++++++++++++++- 1 file changed, 36 insertions(+), 2 deletions(-)diff --git a/Documentation/devicetree/bindings/arm/arm,scmi.txt b/Documentation/devicetree/bindings/arm/arm,scmi.txt index 55deb68230eb..844ff3c40a49 100644 --- a/Documentation/devicetree/bindings/arm/arm,scmi.txt +++ b/Documentation/devicetree/bindings/arm/arm,scmi.txt@@ -13,6 +13,9 @@ the device tree. Required properties: The scmi node with the following properties shall be under the /firmware/ node. +Some properties are specific to a transport type. + +shmem-based transports (mailbox, smc/hvc): - compatible : shall be "arm,scmi" or "arm,scmi-smc" for smc/hvc transports - mboxes: List of phandle and mailbox channel specifiers. It should contain@@ -21,6 +24,17 @@ The scmi node with the following properties shall be under the /firmware/ node. supported. - shmem : List of phandle pointing to the shared memory(SHM) area as per generic mailbox client binding. + +Virtio transport: + +- compatible : shall be "arm,scmi-virtio". +- virtio_transport : phandle of the virtio device. This device must support one + virtqueue for transmitting commands ("tx", cmdq), and, + optionally, one more virtqueue for receiving notifications + and delayed responses ("rx", eventq).Isn't what the virtio device provides discoverable? We don't have virtio protocols in DT for anything else. Why is SCMI special? Rob
Does your comment refer to the presence of the `virtio_transport' phandle, or to the entire "arm,scmi-virtio" node? The protocol child nodes of "arm,scmi-virtio" can be clock providers, power domain providers, etc. The author and me are currently looking into how to replace the `virtio_transport' phandle. Best regards, Peter _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel