[PATCH v6 09/12] firmware: arm_scmi: add Powercap MAI get/set support
Philip Radford
philip.radford at arm.com
Mon May 18 06:52:31 PDT 2026
Add support for Power Measurement Averaging Interval (MAI) get and set
operations to the SCMI powercap protocol driver. Extends scmi_powercap_info
to store MAI configuration and implement MAI get/set via xfer and optional
fast-channel support.
Signed-off-by: Philip Radford <philip.radford at arm.com>
---
V5->V6
- Fixed comment length
- Changed warning message wording
- Fixed line lengths and alignment
- Updated docs for new fields
---
drivers/firmware/arm_scmi/powercap.c | 127 +++++++++++++++++++++++++++
include/linux/scmi_protocol.h | 18 ++++
2 files changed, 145 insertions(+)
diff --git a/drivers/firmware/arm_scmi/powercap.c b/drivers/firmware/arm_scmi/powercap.c
index 09152bb8642c..dfec09fd687f 100644
--- a/drivers/firmware/arm_scmi/powercap.c
+++ b/drivers/firmware/arm_scmi/powercap.c
@@ -403,6 +403,34 @@ scmi_powercap_domain_attrs_process(const struct scmi_protocol_handle *ph,
dom_info->notify_powercap_measurement_change =
SUPPORTS_POWERCAP_MEASUREMENTS_CHANGE_NOTIFY(flags);
+ if (PROTOCOL_REV_MAJOR(ph->version) >= 0x3) {
+ struct scmi_msg_resp_powercap_domain_attributes_v3 *resp_v3 = r;
+
+ flags = le32_to_cpu(resp_v3->attributes);
+ if (pinfo->notify_measurements_cmd)
+ dom_info->notify_powercap_measurement_change =
+ SUPPORTS_POWERCAP_MEASUREMENTS_CHANGE_NOTIFY(flags);
+
+ dom_info->mai_config = SUPPORTS_POWERCAP_MAI_CONFIGURATION(flags);
+ dom_info->min_mai = le32_to_cpu(resp_v3->min_mai);
+ dom_info->max_mai = le32_to_cpu(resp_v3->max_mai);
+ dom_info->mai_step = le32_to_cpu(resp_v3->mai_step);
+
+ if (dom_info->mai_config) {
+ ret = scmi_powercap_validate(dom_info->min_mai,
+ dom_info->max_mai,
+ dom_info->mai_step,
+ dom_info->mai_config);
+
+ if (ret) {
+ dev_warn(ph->dev, "Platform reported invalid MAI config for domain %d - %s\n",
+ dom_info->id, dom_info->name);
+
+ return ret;
+ }
+ }
+ }
+
dom_info->extended_names = SUPPORTS_EXTENDED_NAMES(flags);
dom_info->async_powercap_cap_set =
@@ -1084,6 +1112,103 @@ static int scmi_powercap_cap_enable_get(const struct scmi_protocol_handle *ph,
return 0;
}
+static int scmi_powercap_xfer_mai_get(const struct scmi_protocol_handle *ph,
+ u32 domain_id, u32 *mai)
+{
+ int ret;
+ struct scmi_xfer *t;
+
+ ret = ph->xops->xfer_get_init(ph, POWERCAP_MAI_GET, sizeof(u32),
+ sizeof(u32), &t);
+
+ if (ret)
+ return ret;
+
+ put_unaligned_le32(domain_id, t->tx.buf);
+
+ ret = ph->xops->do_xfer(ph, t);
+ if (!ret)
+ *mai = get_unaligned_le32(t->rx.buf);
+
+ ph->xops->xfer_put(ph, t);
+ return ret;
+}
+
+static int scmi_powercap_xfer_mai_set(const struct scmi_protocol_handle *ph,
+ u32 domain_id, u32 mai)
+{
+ int ret;
+ struct scmi_xfer *t;
+ struct scmi_msg_powercap_cap_or_pai_set *msg;
+
+ ret = ph->xops->xfer_get_init(ph, POWERCAP_MAI_SET, sizeof(*msg),
+ 0, &t);
+ if (ret)
+ return ret;
+
+ msg = t->tx.buf;
+ msg->domain_id = cpu_to_le32(domain_id);
+ msg->flags = cpu_to_le32(0);
+ msg->value = cpu_to_le32(mai);
+
+ ret = ph->xops->do_xfer(ph, t);
+
+ ph->xops->xfer_put(ph, t);
+ return ret;
+}
+
+static int
+scmi_powercap_measurements_interval_get(const struct scmi_protocol_handle *ph,
+ u32 domain_id,
+ u32 *val)
+{
+ const struct scmi_powercap_info *pc;
+ struct scmi_fc_info *fci;
+
+ if (!val)
+ return -EINVAL;
+
+ pc = scmi_powercap_dom_info_get(ph, domain_id);
+ if (!pc)
+ return -EINVAL;
+
+ fci = pc->cpli[CPL0].fc_info;
+ if (fci && fci[POWERCAP_FC_MAI].get_addr) {
+ *val = ioread32(fci[POWERCAP_FC_MAI].get_addr);
+ trace_scmi_fc_call(SCMI_PROTOCOL_POWERCAP, POWERCAP_MAI_GET,
+ domain_id, 0, *val, 0);
+ return 0;
+ }
+
+ return scmi_powercap_xfer_mai_get(ph, domain_id, val);
+}
+
+static int
+scmi_powercap_measurements_interval_set(const struct scmi_protocol_handle *ph,
+ u32 domain_id,
+ u32 val)
+{
+ const struct scmi_powercap_info *pc;
+ struct scmi_fc_info *fci;
+
+ pc = scmi_powercap_dom_info_get(ph, domain_id);
+ if (!pc)
+ return -EINVAL;
+
+ if (!pc->mai_config || !val || val < pc->min_mai || val > pc->max_mai)
+ return -EINVAL;
+
+ fci = pc->cpli[CPL0].fc_info;
+ if (fci && fci[POWERCAP_FC_MAI].set_addr) {
+ iowrite32(val, fci[POWERCAP_FC_MAI].set_addr);
+ ph->hops->fastchannel_db_ring(fci[POWERCAP_FC_MAI].set_db);
+ trace_scmi_fc_call(SCMI_PROTOCOL_POWERCAP, POWERCAP_MAI_SET, domain_id, 0, val, 0);
+ return 0;
+ }
+
+ return scmi_powercap_xfer_mai_set(ph, domain_id, val);
+}
+
static const struct scmi_powercap_proto_ops powercap_proto_ops = {
.num_domains_get = scmi_powercap_num_domains_get,
.info_get = scmi_powercap_dom_info_get,
@@ -1096,6 +1221,8 @@ static const struct scmi_powercap_proto_ops powercap_proto_ops = {
.measurements_get = scmi_powercap_measurements_get,
.measurements_threshold_set = scmi_powercap_measurements_threshold_set,
.measurements_threshold_get = scmi_powercap_measurements_threshold_get,
+ .measurements_interval_get = scmi_powercap_measurements_interval_get,
+ .measurements_interval_set = scmi_powercap_measurements_interval_set,
};
static void scmi_powercap_domain_init_fc(const struct scmi_protocol_handle *ph,
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index d0f6c0102559..90615611be4a 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -654,6 +654,12 @@ struct scmi_powercap_cpl_info {
* reports power data on an abstract linear scale.
* @extended_names: Support for long names.
* @fastchannels: Support for at least one fastchannel,
+ * @mai_config: MAI configuration support.
+ * @min_mai: Minimum supported Power Measurement Averaging Interval in
+ * microseconds.
+ * @max_mai: Maximum supporte Power Measurement Averaging Interval in
+ microseconds.
+ * @mai_step: Step size between supported MAI values in microseconds.
* @name: name assigned to the Powercap Domain by platform.
* @sustainable_power: Maximum sustainable power consumption for this domain
* under normal conditions.
@@ -675,6 +681,10 @@ struct scmi_powercap_info {
bool powercap_scale_uw;
bool extended_names;
bool fastchannels;
+ bool mai_config;
+ u32 min_mai;
+ u32 max_mai;
+ u32 mai_step;
char name[SCMI_MAX_STR_SIZE];
unsigned int sustainable_power;
unsigned int accuracy;
@@ -733,6 +743,10 @@ struct scmi_powercap_info {
* @measurements_threshold_get: get the currently configured low and high power
* thresholds used when registering callbacks for
* notification POWERCAP_MEASUREMENTS_NOTIFY.
+ * @measurements_interval_get: get the current Power Measurement Averaging
+ * Interval (MAI) value for the specified domain.
+ * @measurements_interval_set: set the Power Measurement Averaging Interval
+ * (MAI) value for the specified domain.
*/
struct scmi_powercap_proto_ops {
int (*num_domains_get)(const struct scmi_protocol_handle *ph);
@@ -758,6 +772,10 @@ struct scmi_powercap_proto_ops {
int (*measurements_threshold_get)(const struct scmi_protocol_handle *ph,
u32 domain_id, u32 *power_thresh_low,
u32 *power_thresh_high);
+ int (*measurements_interval_get)(const struct scmi_protocol_handle *ph,
+ u32 domain_id, u32 *val);
+ int (*measurements_interval_set)(const struct scmi_protocol_handle *ph,
+ u32 domain_id, u32 val);
};
enum scmi_pinctrl_selector_type {
--
2.47.3
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