Hi Neil,

On 2016/8/9 18:29, Neil Armstrong wrote:

This patchset aims to support the legacy SCPI firmware implementation that
was
delivered as early technology preview for the JUNO platform.

Finally a stable, maintained and public implementation for the SCPI protocol
has been upstreamed part of the JUNO support and it is the recommended way
of implementing SCP communication on ARMv8 platforms.

The Amlogic GXBB platform is using this legacy protocol, as the RK3368 &
RK3399
platforms. Only the GXBB example is provided here, but it's unclear if other
Amlogic ARMv8 based SoCs uses this legacy procotol.

In order to support the legacy protocol :
  - Move the scpi_get_ops to a thin registry layer
  - Change the arm_scpi.c to use the registry layer
  - Add a separate config option to build the registry layer
  - Add the legacy SCPI driver based on the new implementation
  - For example, add the Amlogic GXBB MHU and SCPI DT cpufreq & sensors nodes

Changes since RFC v2 at https://lkml.org/lkml/2016/6/21/324 :
  - Moved MHU to a separate patchset posted at
http://lkml.kernel.org/r/1470732737-18391-1-git-send-email-narmstrong at baylib
re.com
  - Added a vendor send_message callback into scpi_ops to implement vendor
commands
  - Implement EXT commands on arm scpi as vendor send_command
  - Added Rockchip variant mailbox handling

Two questions,

1. For legacy_scpi, I saw you have implemented .vendor_send_message api, 
however, it seems that does not distinguish standard and extended 
command, so it may be misleading if the vendor send out a non-standard 
command from their own driver module.

2. For arm_scpi, it have already distinguished standard and extended 
command, but unfortunately, there was no rockchip_scpi_xfer structure 
something like in legacy_scpi driver, so if some vendor (just like 
Rockchip :-)) wanna switch the driver from legacy_scpi to arm_scpi, 
maybe this is a bit problem, how do you think?


BR.
Frank

Initial RFC discution tread can be found at
https://lkml.org/lkml/2016/5/26/111

@Sudeep: I know you wished I merged the legacy into the arm_scpi, but can
you take a look at the vendor extension and how I implemented the rockchip
mailbox handling ?

Neil Armstrong (8):
   firmware: Add a SCPI registry to handle multiple implementations
   firmware: scpi: Switch arm_scpi to use new registry
   scpi: Add vendor_send_message to enable access to vendor commands
   firmware: arm_scpi: Enable vendor_send_message as ext commands
   firmware: Add legacy SCPI protocol driver
   dt-bindings: arm: Update arm,scpi bindings with Meson GXBB SCPI
   ARM64: dts: meson-gxbb: Add SRAM node
   ARM64: dts: meson-gxbb: Add SCPI with cpufreq & sensors Nodes

  Documentation/devicetree/bindings/arm/arm,scpi.txt |   8 +-
  arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi        |  45 ++
  drivers/firmware/Kconfig                           |  24 +
  drivers/firmware/Makefile                          |   2 +
  drivers/firmware/arm_scpi.c                        |  40 +-
  drivers/firmware/legacy_scpi.c                     | 710
+++++++++++++++++++++
  drivers/firmware/scpi.c                            |  94 +++
  include/linux/scpi_protocol.h                      |  20 +-
  8 files changed, 928 insertions(+), 15 deletions(-)
  create mode 100644 drivers/firmware/legacy_scpi.c
  create mode 100644 drivers/firmware/scpi.c