[PATCH 2/3] firmware: arm_scmi: Add perf_opp_xlate interface

[Sibi Sankar <quic_sibis@xxxxxxxxxxx>]

Add a new perf_opp_xlate interface to the existing perf_ops to translate
a given perf index to frequency.

This can be used by the cpufreq driver and framework to determine the
throttled frequency from a given perf index and apply HW pressure
accordingly.

Signed-off-by: Sibi Sankar <quic_sibis@xxxxxxxxxxx>
---
 drivers/firmware/arm_scmi/perf.c | 21 +++++++++++++++++++++
 include/linux/scmi_protocol.h    |  3 +++
 2 files changed, 24 insertions(+)

diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c
index c167bb5e3607..f26390924e1c 100644
--- a/drivers/firmware/arm_scmi/perf.c
+++ b/drivers/firmware/arm_scmi/perf.c
@@ -964,6 +964,26 @@ static int scmi_notify_support(const struct scmi_protocol_handle *ph, u32 domain
 	return 0;
 }
 
+static int scmi_perf_opp_xlate(const struct scmi_protocol_handle *ph, u32 domain,
+			       int idx, unsigned long *freq)
+{
+	struct perf_dom_info *dom;
+
+	dom = scmi_perf_domain_lookup(ph, domain);
+	if (IS_ERR(dom))
+		return PTR_ERR(dom);
+
+	if (idx >= dom->opp_count)
+		return -ERANGE;
+
+	if (!dom->level_indexing_mode)
+		*freq = dom->opp[idx].perf * dom->mult_factor;
+	else
+		*freq = dom->opp[idx].indicative_freq * dom->mult_factor;
+
+	return 0;
+}
+
 static const struct scmi_perf_proto_ops perf_proto_ops = {
 	.num_domains_get = scmi_perf_num_domains_get,
 	.info_get = scmi_perf_info_get,
@@ -979,6 +999,7 @@ static const struct scmi_perf_proto_ops perf_proto_ops = {
 	.fast_switch_possible = scmi_fast_switch_possible,
 	.power_scale_get = scmi_power_scale_get,
 	.perf_notify_support = scmi_notify_support,
+	.perf_opp_xlate = scmi_perf_opp_xlate,
 };
 
 static int scmi_perf_set_notify_enabled(const struct scmi_protocol_handle *ph,
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index b0947d004826..9c285ae89848 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -145,6 +145,7 @@ struct scmi_perf_notify_info {
  * @power_scale_mw_get: indicates if the power values provided are in milliWatts
  *	or in some other (abstract) scale
  * @perf_notify_support: indicates if limit and level change notification is supported
+ * @perf_opp_xlate: translates the given perf index to frequency in Hz
  */
 struct scmi_perf_proto_ops {
 	int (*num_domains_get)(const struct scmi_protocol_handle *ph);
@@ -173,6 +174,8 @@ struct scmi_perf_proto_ops {
 	enum scmi_power_scale (*power_scale_get)(const struct scmi_protocol_handle *ph);
 	int (*perf_notify_support)(const struct scmi_protocol_handle *ph, u32 domain,
 				   struct scmi_perf_notify_info *info);
+	int (*perf_opp_xlate)(const struct scmi_protocol_handle *ph, u32 domain,
+			      int idx, unsigned long *freq);
 };
 
 /**
-- 
2.17.1