firmware: arm_scmi: Extend perf protocol ops to get information of a domain

Similar to other protocol ops, it's useful for an scmi module driver to get
some generic information of a performance domain. Therefore, let's add a
new callback to provide this information. The information is currently
limited to the name of the performance domain and whether the set-level
operation is supported, although this can easily be extended if we find the
need for it.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20230825112633.236607-3-ulf.hansson@linaro.orgSigned-off-by: Sudeep Holla <sudeep.holla@arm.com>

drivers/firmware/arm_scmi/perf.c

@@ -145,7 +145,6 @@ struct scmi_msg_resp_perf_describe_levels_v4 {
 struct perf_dom_info {
 	u32 id;
 	bool set_limits;
-	bool set_perf;
 	bool perf_limit_notify;
 	bool perf_level_notify;
 	bool perf_fastchannels;
@@ -154,7 +153,7 @@ struct perf_dom_info {
 	u32 sustained_freq_khz;
 	u32 sustained_perf_level;
 	u32 mult_factor;
-	char name[SCMI_MAX_STR_SIZE];
+	struct scmi_perf_domain_info info;
 	struct scmi_opp opp[MAX_OPPS];
 	struct scmi_fc_info *fc_info;
 	struct xarray opps_by_idx;
@@ -257,7 +256,7 @@ scmi_perf_domain_attributes_get(const struct scmi_protocol_handle *ph,
 		flags = le32_to_cpu(attr->flags);
 
 		dom_info->set_limits = SUPPORTS_SET_LIMITS(flags);
-		dom_info->set_perf = SUPPORTS_SET_PERF_LVL(flags);
+		dom_info->info.set_perf = SUPPORTS_SET_PERF_LVL(flags);
 		dom_info->perf_limit_notify = SUPPORTS_PERF_LIMIT_NOTIFY(flags);
 		dom_info->perf_level_notify = SUPPORTS_PERF_LEVEL_NOTIFY(flags);
 		dom_info->perf_fastchannels = SUPPORTS_PERF_FASTCHANNELS(flags);
@@ -276,7 +275,8 @@ scmi_perf_domain_attributes_get(const struct scmi_protocol_handle *ph,
 			dom_info->mult_factor =
 					(dom_info->sustained_freq_khz * 1000) /
 					dom_info->sustained_perf_level;
-		strscpy(dom_info->name, attr->name, SCMI_SHORT_NAME_MAX_SIZE);
+		strscpy(dom_info->info.name, attr->name,
+			SCMI_SHORT_NAME_MAX_SIZE);
 	}
 
 	ph->xops->xfer_put(ph, t);
@@ -288,7 +288,7 @@ scmi_perf_domain_attributes_get(const struct scmi_protocol_handle *ph,
 	if (!ret && PROTOCOL_REV_MAJOR(version) >= 0x3 &&
 	    SUPPORTS_EXTENDED_NAMES(flags))
 		ph->hops->extended_name_get(ph, PERF_DOMAIN_NAME_GET,
-					    dom_info->id, dom_info->name,
+					    dom_info->id, dom_info->info.name,
 					    SCMI_MAX_STR_SIZE);
 
 	if (dom_info->level_indexing_mode) {
@@ -430,6 +430,29 @@ static int scmi_perf_num_domains_get(const struct scmi_protocol_handle *ph)
 	return pi->num_domains;
 }
 
+static inline struct perf_dom_info *
+scmi_perf_domain_lookup(const struct scmi_protocol_handle *ph, u32 domain)
+{
+	struct scmi_perf_info *pi = ph->get_priv(ph);
+
+	if (domain >= pi->num_domains)
+		return ERR_PTR(-EINVAL);
+
+	return pi->dom_info + domain;
+}
+
+static const struct scmi_perf_domain_info *
+scmi_perf_info_get(const struct scmi_protocol_handle *ph, u32 domain)
+{
+	struct perf_dom_info *dom;
+
+	dom = scmi_perf_domain_lookup(ph, domain);
+	if (IS_ERR(dom))
+		return ERR_PTR(-EINVAL);
+
+	return &dom->info;
+}
+
 static int scmi_perf_msg_limits_set(const struct scmi_protocol_handle *ph,
 				    u32 domain, u32 max_perf, u32 min_perf)
 {
@@ -453,17 +476,6 @@ static int scmi_perf_msg_limits_set(const struct scmi_protocol_handle *ph,
 	return ret;
 }
 
-static inline struct perf_dom_info *
-scmi_perf_domain_lookup(const struct scmi_protocol_handle *ph, u32 domain)
-{
-	struct scmi_perf_info *pi = ph->get_priv(ph);
-
-	if (domain >= pi->num_domains)
-		return ERR_PTR(-EINVAL);
-
-	return pi->dom_info + domain;
-}
-
 static int __scmi_perf_limits_set(const struct scmi_protocol_handle *ph,
 				  struct perf_dom_info *dom, u32 max_perf,
 				  u32 min_perf)
@@ -819,7 +831,7 @@ static int scmi_dvfs_device_opps_add(const struct scmi_protocol_handle *ph,
 		}
 
 		dev_dbg(dev, "[%d][%s]:: Registered OPP[%d] %lu\n",
-			domain, dom->name, idx, freq);
+			domain, dom->info.name, idx, freq);
 	}
 	return 0;
 }
@@ -956,6 +968,7 @@ scmi_power_scale_get(const struct scmi_protocol_handle *ph)
 
 static const struct scmi_perf_proto_ops perf_proto_ops = {
 	.num_domains_get = scmi_perf_num_domains_get,
+	.info_get = scmi_perf_info_get,
 	.limits_set = scmi_perf_limits_set,
 	.limits_get = scmi_perf_limits_get,
 	.level_set = scmi_perf_level_set,

include/linux/scmi_protocol.h

@@ -106,11 +106,17 @@ struct scmi_clk_proto_ops {
 			      u8 oem_type, u32 oem_val, bool atomic);
 };
 
+struct scmi_perf_domain_info {
+	char name[SCMI_MAX_STR_SIZE];
+	bool set_perf;
+};
+
 /**
  * struct scmi_perf_proto_ops - represents the various operations provided
  *	by SCMI Performance Protocol
  *
  * @num_domains_get: gets the number of supported performance domains
+ * @info_get: get the information of a performance domain
  * @limits_set: sets limits on the performance level of a domain
  * @limits_get: gets limits on the performance level of a domain
  * @level_set: sets the performance level of a domain
@@ -131,6 +137,8 @@ struct scmi_clk_proto_ops {
  */
 struct scmi_perf_proto_ops {
 	int (*num_domains_get)(const struct scmi_protocol_handle *ph);
+	const struct scmi_perf_domain_info __must_check *(*info_get)
+		(const struct scmi_protocol_handle *ph, u32 domain);
 	int (*limits_set)(const struct scmi_protocol_handle *ph, u32 domain,
 			  u32 max_perf, u32 min_perf);
 	int (*limits_get)(const struct scmi_protocol_handle *ph, u32 domain,