[PATCH v3 04/13] firmware: scmi: framework for installing additional protocols

[Etienne CARRIERE]

> From: AKASHI Takahiro <takahiro.akashi at linaro.org>
> Sent: Friday, September 8, 2023 04:51
>  
> This framework allows SCMI protocols to be installed and bound to the agent
> so that the agent can manage and utilize them later.
> 
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> Reviewed-by: Etienne Carriere <etienne.carriere at foss.st.com>
> ---
> v3
> * move "per_device_plat_auto" from a earlier patch
> * fix comments in "scmi_agent_priv"
> * modify an order of include files in scmi_agent.h
> v2
> * check for availability of protocols
> ---
>  drivers/firmware/scmi/scmi_agent-uclass.c | 101 +++++++++++++++++++++-
>  include/scmi_agent-uclass.h               |  15 +++-
>  include/scmi_agent.h                      |  14 +++
>  3 files changed, 126 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/firmware/scmi/scmi_agent-uclass.c b/drivers/firmware/scmi/scmi_agent-uclass.c
> index 94e54eeb066b..e823d105a3eb 100644
> --- a/drivers/firmware/scmi/scmi_agent-uclass.c
> +++ b/drivers/firmware/scmi/scmi_agent-uclass.c
> @@ -38,6 +38,86 @@ static const struct error_code scmi_linux_errmap[] = {
>          { .scmi = SCMI_PROTOCOL_ERROR, .errno = -EPROTO, },
>  };
>  
> +/*
> + * NOTE: The only one instance should exist according to
> + * the current specification and device tree bindings.
> + */
> +struct udevice *scmi_agent;
> +
> +struct udevice *scmi_get_protocol(struct udevice *dev,
> +                                 enum scmi_std_protocol id)
> +{
> +       struct scmi_agent_priv *priv;
> +       struct udevice *proto;
> +
> +       priv = dev_get_uclass_plat(dev);
> +       if (!priv) {
> +               dev_err(dev, "No priv data found\n");
> +               return NULL;
> +       }
> +
> +       switch (id) {
> +       case SCMI_PROTOCOL_ID_CLOCK:
> +               proto = priv->clock_dev;
> +               break;
> +       case SCMI_PROTOCOL_ID_RESET_DOMAIN:
> +               proto = priv->resetdom_dev;
> +               break;
> +       case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
> +               proto = priv->voltagedom_dev;
> +               break;
> +       default:
> +               dev_err(dev, "Protocol not supported\n");
> +               proto = NULL;
> +               break;
> +       }
> +       if (proto && device_probe(proto))
> +               dev_err(dev, "Probe failed\n");
> +
> +       return proto;
> +}
> +
> +/**
> + * scmi_add_protocol - add protocol to agent
> + * @dev:       SCMI agent device
> + * @proto_id:  SCMI protocol ID
> + * @proto:     SCMI protocol device
> + *
> + * Associate the protocol instance, @proto, to the agent, @dev,
> + * for later use.
> + *
> + * Return:     0 on success, error code otherwise
> + */
> +static int scmi_add_protocol(struct udevice *dev,
> +                            enum scmi_std_protocol proto_id,
> +                            struct udevice *proto)
> +{
> +       struct scmi_agent_priv *priv;
> +
> +       priv = dev_get_uclass_plat(dev);
> +       if (!priv) {
> +               dev_err(dev, "No priv data found\n");
> +               return -ENODEV;
> +       }
> +
> +       switch (proto_id) {
> +       case SCMI_PROTOCOL_ID_CLOCK:
> +               priv->clock_dev = proto;
> +               break;
> +       case SCMI_PROTOCOL_ID_RESET_DOMAIN:
> +               priv->resetdom_dev = proto;
> +               break;
> +       case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
> +               priv->voltagedom_dev = proto;
> +               break;
> +       default:
> +               dev_err(dev, "Protocol not supported\n");
> +               return -EPROTO;
> +       }
> +
> +       return 0;
> +}
> +
>  int scmi_to_linux_errno(s32 scmi_code)
>  {
>          int n;
> @@ -164,12 +244,14 @@ int devm_scmi_process_msg(struct udevice *dev, struct scmi_msg *msg)
>   */
>  static int scmi_bind_protocols(struct udevice *dev)
>  {
> +       struct udevice *agent;

nit: my build reported 'agent' here is not used in the scope of this patch.
Strictly speaking, it should be brought by patch v3 05/13.
("firmware: scmi: install base protocol to SCMI agent")

BR,
etienne

> (snip)