[PATCH v3 05/13] firmware: scmi: install base protocol to SCMI agent

Etienne CARRIERE etienne.carriere at st.com
Fri Sep 8 16:02:22 CEST 2023


Hello Akashi-san,

Some minor comments.

> From: AKASHI Takahiro <takahiro.akashi at linaro.org>
> Sent: Friday, September 8, 2023 04:51
> 
> SCMI base protocol is mandatory, and once SCMI node is found in a device
> tree, the protocol handle (udevice) is unconditionally installed to
> the agent. Then basic information will be retrieved from SCMI server via
> the protocol and saved into the agent instance's local storage.
> 
> 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
> * typo fix: add '@' for argument name in function description
> * eliminate dev_get_uclass_plat()'s repeated in inline
> * modify the code for dynamically allocated sub-vendor/agent names
> v2
> * use helper functions, removing direct uses of ops
> ---
>  drivers/firmware/scmi/scmi_agent-uclass.c | 116 ++++++++++++++++++++++
>  include/scmi_agent-uclass.h               |  66 ++++++++++++
>  2 files changed, 182 insertions(+)
> 
> diff --git a/drivers/firmware/scmi/scmi_agent-uclass.c b/drivers/firmware/scmi/scmi_agent-uclass.c
> index e823d105a3eb..87a667d60124 100644
> --- a/drivers/firmware/scmi/scmi_agent-uclass.c
> +++ b/drivers/firmware/scmi/scmi_agent-uclass.c
> @@ -57,6 +57,9 @@ struct udevice *scmi_get_protocol(struct udevice *dev,
>          }
>  
>          switch (id) {
> +       case SCMI_PROTOCOL_ID_BASE:
> +               proto = priv->base_dev;
> +               break;
>          case SCMI_PROTOCOL_ID_CLOCK:
>                  proto = priv->clock_dev;
>                  break;
> @@ -101,6 +104,9 @@ static int scmi_add_protocol(struct udevice *dev,
>          }
>  
>          switch (proto_id) {
> +       case SCMI_PROTOCOL_ID_BASE:
> +               priv->base_dev = proto;
> +               break;
>          case SCMI_PROTOCOL_ID_CLOCK:
>                  priv->clock_dev = proto;
>                  break;
> @@ -237,6 +243,83 @@ int devm_scmi_process_msg(struct udevice *dev, struct scmi_msg *msg)
>          return scmi_process_msg(protocol->parent, priv->channel, msg);
>  }
>  
> +/**
> + * scmi_fill_base_info - get base information about SCMI server
> + * @agent:     SCMI agent device
> + * @dev:       SCMI protocol device
> + *
> + * By using Base protocol commands, collect the base information
> + * about SCMI server.
> + *
> + * Return: 0 on success, error code otherwise
> + */
> +static int scmi_fill_base_info(struct udevice *agent, struct udevice *dev)
> +{
> +       struct scmi_agent_priv *priv = dev_get_uclass_plat(agent);
> +       int ret;
> +
> +       ret = scmi_base_protocol_version(dev, &priv->version);
> +       if (ret) {
> +               dev_err(dev, "protocol_version() failed (%d)\n", ret);
> +               return ret;
> +       }
> +       /* check for required version */
> +       if (priv->version < SCMI_BASE_PROTOCOL_VERSION) {
> +               dev_err(dev, "base protocol version (%d) lower than expected\n",
> +                       priv->version);
> +               return -EPROTO;
> +       }
> +
> +       ret = scmi_base_protocol_attrs(dev, &priv->num_agents,
> +                                      &priv->num_protocols);
> +       if (ret) {
> +               dev_err(dev, "protocol_attrs() failed (%d)\n", ret);
> +               return ret;
> +       }
> +       ret = scmi_base_discover_vendor(dev, &priv->vendor);
> +       if (ret) {
> +               dev_err(dev, "base_discover_vendor() failed (%d)\n", ret);
> +               return ret;
> +       }
> +       ret = scmi_base_discover_sub_vendor(dev, &priv->sub_vendor);
> +       if (ret) {
> +               if (ret != -EOPNOTSUPP) {
> +                       dev_err(dev, "base_discover_sub_vendor() failed (%d)\n",
> +                               ret);
> +                       return ret;
> +               }
> +               priv->sub_vendor = "NA";
> +       }
> +       ret = scmi_base_discover_impl_version(dev, &priv->impl_version);
> +       if (ret) {
> +               dev_err(dev, "base_discover_impl_version() failed (%d)\n",
> +                       ret);
> +               return ret;
> +       }
> +
> +       priv->agent_id = 0xffffffff; /* to avoid false claim */

I think this line should move in below instruction block, next to
priv->agent_name = "NA", for consistency,

> +       ret = scmi_base_discover_agent(dev, 0xffffffff,
> +                                      &priv->agent_id, &priv->agent_name);
> +       if (ret) {
> +               if (ret != -EOPNOTSUPP) {
> +                       dev_err(dev,
> +                               "base_discover_agent() failed for myself (%d)\n",
> +                               ret);
> +                       return ret;
> +               }
> +               priv->agent_name = "NA";
> +       }
> +
> +       ret = scmi_base_discover_list_protocols(dev, &priv->protocols);
> +       if (ret != priv->num_protocols) {
> +               dev_err(dev, "base_discover_list_protocols() failed (%d)\n",
> +                       ret);
> +               return ret;

Value of ret here is not really relevant. I suggest to force to -EPROTO.

> +       }
> +
> +       return 0;
> +}
> +
>  /*
>   * SCMI agent devices binds devices of various uclasses depeding on
>   * the FDT description. scmi_bind_protocol() is a generic bind sequence
> @@ -251,6 +334,39 @@ static int scmi_bind_protocols(struct udevice *dev)
>          struct driver *drv;
>          struct udevice *proto;
>  
> +       if (!uclass_get_device(UCLASS_SCMI_AGENT, 1, &agent)) {
> +               /* This is a second SCMI agent */
> +               dev_err(dev, "Cannot have more than one SCMI agent\n");
> +               return -EEXIST;
> +       }
> +
> +       /* initialize the device from device tree */
> +       drv = DM_DRIVER_GET(scmi_base_drv);
> +       name = "scmi-base.0";
> +       ret = device_bind(dev, drv, name, NULL, ofnode_null(), &proto);
> +       if (ret) {
> +               dev_err(dev, "failed to bind base protocol\n");
> +               return ret;
> +       }
> +       ret = scmi_add_protocol(dev, SCMI_PROTOCOL_ID_BASE, proto);
> +       if (ret) {
> +               dev_err(dev, "failed to add protocol: %s, ret: %d\n",
> +                       proto->name, ret);
> +               return ret;
> +       }
> +
> +       ret = device_probe(proto);
> +       if (ret) {
> +               dev_err(dev, "failed to probe base protocol\n");
> +               return ret;
> +       }
> +
> +       ret = scmi_fill_base_info(dev, proto);
> +       if (ret) {
> +               dev_err(dev, "failed to get base information\n");
> +               return ret;
> +       }
> +
>          dev_for_each_subnode(node, dev) {
>                  u32 protocol_id;
>  
> diff --git a/include/scmi_agent-uclass.h b/include/scmi_agent-uclass.h
> index 3358c2b2d804..6fd6d54d6a5a 100644
> --- a/include/scmi_agent-uclass.h
> +++ b/include/scmi_agent-uclass.h
> @@ -5,6 +5,7 @@
>  #ifndef _SCMI_AGENT_UCLASS_H
>  #define _SCMI_AGENT_UCLASS_H
>  
> +#include <scmi_protocols.h>
>  #include <dm/device.h>
>  
>  struct scmi_msg;
> @@ -12,16 +13,81 @@ struct scmi_channel;
>  
>  /**
>   * struct scmi_agent_priv - private data maintained by agent instance
> + * @version:           Version
> + * @num_agents:                Number of agents
> + * @num_protocols:     Number of protocols
> + * @impl_version:      Implementation version
> + * @protocols:         Array of protocol IDs
> + * @vendor:            Vendor name
> + * @sub_vendor:                Sub-vendor name
> + * @agent_name:                Agent name
> + * agent_id:           Identifier of agent

nitpicking: s/agent_id/@agent_id/

> + * @base_dev:          SCMI base protocol device
>   * @clock_dev:         SCMI clock protocol device
>   * @resetdom_dev:      SCMI reset domain protocol device
>   * @voltagedom_dev:    SCMI voltage domain protocol device
>   */
>  struct scmi_agent_priv {
> +       u32 version;
> +       u32 num_agents;
> +       u32 num_protocols;
> +       u32 impl_version;
> +       u8 *protocols;
> +       u8 *vendor;
> +       u8 *sub_vendor;
> +       u8 *agent_name;
> +       u32 agent_id;
> +       struct udevice *base_dev;
>          struct udevice *clock_dev;
>          struct udevice *resetdom_dev;
>          struct udevice *voltagedom_dev;
>  };
>  
> +static inline u32 scmi_version(struct udevice *dev)
> +{
> +       return ((struct scmi_agent_priv *)dev_get_uclass_plat(dev))->version;
> +}
> +
> +static inline u32 scmi_num_agents(struct udevice *dev)
> +{
> +       return ((struct scmi_agent_priv *)dev_get_uclass_plat(dev))->num_agents;
> +}
> +
> +static inline u32 scmi_num_protocols(struct udevice *dev)
> +{
> +       return ((struct scmi_agent_priv *)dev_get_uclass_plat(dev))->num_protocols;
> +}
> +
> +static inline u32 scmi_impl_version(struct udevice *dev)
> +{
> +       return ((struct scmi_agent_priv *)dev_get_uclass_plat(dev))->impl_version;
> +}
> +
> +static inline u8 *scmi_protocols(struct udevice *dev)
> +{
> +       return ((struct scmi_agent_priv *)dev_get_uclass_plat(dev))->protocols;
> +}
> +
> +static inline u8 *scmi_vendor(struct udevice *dev)
> +{
> +       return ((struct scmi_agent_priv *)dev_get_uclass_plat(dev))->vendor;
> +}
> +
> +static inline u8 *scmi_sub_vendor(struct udevice *dev)
> +{
> +       return ((struct scmi_agent_priv *)dev_get_uclass_plat(dev))->sub_vendor;
> +}
> +
> +static inline u8 *scmi_agent_name(struct udevice *dev)
> +{
> +       return ((struct scmi_agent_priv *)dev_get_uclass_plat(dev))->agent_name;
> +}
> +
> +static inline u32 scmi_agent_id(struct udevice *dev)
> +{
> +       return ((struct scmi_agent_priv *)dev_get_uclass_plat(dev))->agent_id;
> +}
> +
>  /**
>   * struct scmi_transport_ops - The functions that a SCMI transport layer must implement.
>   */
> -- 
> 2.34.1
> 


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