[PATCH v2 05/12] firmware: scmi: install base protocol to SCMI agent
Etienne CARRIERE
etienne.carriere at st.com
Thu Aug 3 12:01:05 CEST 2023
> From: AKASHI Takahiro <takahiro.akashi at linaro.org>
> Sent: Thursday, July 27, 2023 03:07
>
> Hi Simon,
>
> Thank you for your extensive review.
>
> On Wed, Jul 26, 2023 at 06:50:23PM -0600, Simon Glass wrote:
> > Hi,
> >
> > On Wed, 26 Jul 2023 at 02:39, AKASHI Takahiro
> > <takahiro.akashi at linaro.org> wrote:
> > >
> > > 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>
> > > ---
> > > v2
> > > * use helper functions, removing direct uses of ops
> > > ---
> > > drivers/firmware/scmi/scmi_agent-uclass.c | 116 ++++++++++++++++++++++
> > > include/scmi_agent-uclass.h | 70 ++++++++++++-
> > > 2 files changed, 184 insertions(+), 2 deletions(-)
> > >
> >
> > Reviewed-by: Simon Glass <sjg at chromium.org>
Reviewed-by: Etienne Carriere <etienne.carriere at foss.st.com>
with below reported typo preferrably addressed.
> >
> > > diff --git a/drivers/firmware/scmi/scmi_agent-uclass.c b/drivers/firmware/scmi/scmi_agent-uclass.c
> > > index 2244fcf487e8..279c2c218913 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;
> > > @@ -229,6 +235,83 @@ int devm_scmi_process_msg(struct udevice *dev, struct scmi_msg *msg)
> > > return scmi_process_msg(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;
> > > + }
> > > + strcpy(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 */
> > > + 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[0] = '\0';
> > > + }
> > > +
> > > + 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;
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +
> > > /*
> > > * SCMI agent devices binds devices of various uclasses depeding on
> > > * the FDT description. scmi_bind_protocol() is a generic bind sequence
> > > @@ -243,6 +326,39 @@ 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);
> >
> > Why is this not in the devicetree too?
>
> I don't know the history of discussions, but it is
> because no binding for the base protocol is necessary, I guess,
> as it is a mandatory protocol without any customisable parameters.
> Please see kernel's Documentation/devicetree/bindings/firmware/arm,scmi.yaml.
>
> > > + 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 f9e7d3f51de1..0043a93c8d90 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
typo: s/agent_id/@agent_id/
> > > + * @base_dev: SCMI base protocol device
> > > * @clock_dev: SCMI clock protocol device
> > > - * @clock_dev: SCMI reset domain protocol device
> > > - * @clock_dev: SCMI voltage domain 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[SCMI_BASE_NAME_LENGTH_MAX];
> > > + u8 sub_vendor[SCMI_BASE_NAME_LENGTH_MAX];
> > > + u8 agent_name[SCMI_BASE_NAME_LENGTH_MAX];
> > > + 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;
> > > +}
> >
> > Why these helper functions? It seems better to avoid inlining access
> > to dev_get_uclass_plat(). Are you worried about exposing the priv
> > struct to clients?
>
> Well, simply wanted to avoid repeating
> "((struct scmi_agent_priv *)dev_get_uclass_plat(dev))->)" in the code.
>
> Thanks,
> -Takahiro Akashi
>
> > > +
> > > /**
> > > * struct scmi_transport_ops - The functions that a SCMI transport layer must implement.
> > > */
> > > --
> > > 2.41.0
> > >
> >
> > Regards,
> > Simon
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