meta-egvirt/recipes-kernel/linux/linux-yocto/virtio-scmi/0009-dt-bindings-arm-Add-virtio-transport-for-SCMI.patch

   1 From 592064dd36739ad5f3d885b9880ee1bc2d66e2df Mon Sep 17 00:00:00 2001
   2 From: Igor Skalkin <igor.skalkin@opensynergy.com>
   3 Date: Thu, 5 Nov 2020 22:21:15 +0100
   4 Subject: [PATCH] dt-bindings: arm: Add virtio transport for SCMI
   5
   6 Document the properties for arm,scmi-virtio compatible nodes. The
   7 backing virtio SCMI device is described in patch [1].
   8
   9 [1] https://lists.oasis-open.org/archives/virtio-comment/202005/msg00096.html
  10
  11 Co-developed-by: Peter Hilber <peter.hilber@opensynergy.com>
  12 Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
  13 Signed-off-by: Igor Skalkin <igor.skalkin@opensynergy.com>
  14 Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
  15 ---
  16  .../devicetree/bindings/arm/arm,scmi.txt      | 35 +++++++++++++++++--
  17  1 file changed, 33 insertions(+), 2 deletions(-)
  18
  19 diff --git a/Documentation/devicetree/bindings/arm/arm,scmi.txt b/Documentation/devicetree/bindings/arm/arm,scmi.txt
  20 index 55deb68230eb..6ded49d82773 100644
  21 --- a/Documentation/devicetree/bindings/arm/arm,scmi.txt
  22 +++ b/Documentation/devicetree/bindings/arm/arm,scmi.txt
  23 @@ -13,6 +13,9 @@ the device tree.
  24  Required properties:
  25
  26  The scmi node with the following properties shall be under the /firmware/ node.
  27 +Some properties are specific to a transport type.
  28 +
  29 +shmem-based transports (mailbox, smc/hvc):
  30
  31  - compatible : shall be "arm,scmi" or "arm,scmi-smc" for smc/hvc transports
  32  - mboxes: List of phandle and mailbox channel specifiers. It should contain
  33 @@ -21,6 +24,15 @@ The scmi node with the following properties shall be under the /firmware/ node.
  34           supported.
  35  - shmem : List of phandle pointing to the shared memory(SHM) area as per
  36           generic mailbox client binding.
  37 +
  38 +Virtio transport:
  39 +
  40 +- compatible : shall be "arm,scmi-virtio".
  41 +
  42 +The virtio transport only supports a single device.
  43 +
  44 +Additional required properties:
  45 +
  46  - #address-cells : should be '1' if the device has sub-nodes, maps to
  47           protocol identifier for a given sub-node.
  48  - #size-cells : should be '0' as 'reg' property doesn't have any size
  49 @@ -42,7 +54,8 @@ Each protocol supported shall have a sub-node with corresponding compatible
  50  as described in the following sections. If the platform supports dedicated
  51  communication channel for a particular protocol, the 3 properties namely:
  52  mboxes, mbox-names and shmem shall be present in the sub-node corresponding
  53 -to that protocol.
  54 +to that protocol. The virtio transport does not support dedicated communication
  55 +channels.
  56
  57  Clock/Performance bindings for the clocks/OPPs based on SCMI Message Protocol
  58  ------------------------------------------------------------
  59 @@ -106,7 +119,8 @@ Required sub-node properties:
  60  [4] Documentation/devicetree/bindings/sram/sram.yaml
  61  [5] Documentation/devicetree/bindings/reset/reset.txt
  62
  63 -Example:
  64 +Example (mailbox transport):
  65 +----------------------------
  66
  67  sram@50000000 {
  68         compatible = "mmio-sram";
  69 @@ -195,3 +209,20 @@ thermal-zones {
  70                 ...
  71         };
  72  };
  73 +
  74 +Example (virtio transport):
  75 +---------------------------
  76 +
  77 +virtio_mmio@4b001000 {
  78 +       compatible = "virtio,mmio";
  79 +       ...
  80 +};
  81 +
  82 +firmware {
  83 +       ...
  84 +       scmi {
  85 +               compatible = "arm,scmi-virtio";
  86 +               ...
  87 +
  88 +The rest is similar to the mailbox transport example, when omitting the
  89 +mailbox/shmem-specific properties.