[PATCH v5 12/12] powercap: arm_scmi: Synthetic zone enable/disable

Philip Radford
2026-04-28T09:10:08Z

Add functionality to disable and enable the synthetic zone which
also affects the immediate children of the synthetic zone by applying
the same command to them.

Signed-off-by: Philip Radford <philip.radford@arm.com>
---
drivers/powercap/arm_scmi_powercap.c | 81 ++++++++++++++++++++++++++++
1 file changed, 81 insertions(+)

diff --git a/drivers/powercap/arm_scmi_powercap.c b/drivers/powercap/arm_scmi_powercap.c
index 81b5214acda4..1ed2949b06cb 100644
--- a/drivers/powercap/arm_scmi_powercap.c
+++ b/drivers/powercap/arm_scmi_powercap.c
@@ -270,6 +270,85 @@ static int instance_root_release(struct powercap_zone *pz)
return 0;
}

+static int instance_root_set_enable_state(struct powercap_zone *pz, bool enable)
+{
+ struct scmi_powercap_zone *root;
+ struct scmi_powercap_root *pr;
+ struct scmi_powercap_zone *child;
+ int ret, first_err = 0;
+
+ if (!pz)
+ return -EINVAL;
+
+ root = to_scmi_powercap_zone(pz);
+ pr = container_of(root, struct scmi_powercap_root, instance_root);
+
+ list_for_each_entry(child, &pr->registered_zones[0], node) {
+ if (child == &pr->instance_root)
+ continue;
+
+ if (child->info->parent_id != SCMI_POWERCAP_ROOT_ZONE_ID)
+ continue;
+
+ if (!child->info->cpli[0].cap_config)
+ continue;
+
+ ret = powercap_ops->cap_enable_set(child->ph, child->info->id, enable);
+
+ if (ret && !first_err) {
+ first_err = ret;
+ dev_err(child->dev, "failed to %s zone %s: %d\n",
+ enable ? "enable" : "disable",
+ child->info->name, ret);
+ }
+ }
+
+ return first_err;
+}
+
+static int instance_root_set_enable(struct powercap_zone *pz, bool mode)
+{
+ return instance_root_set_enable_state(pz, mode);
+}
+
+static int instance_root_get_enable(struct powercap_zone *pz, bool *mode)
+{
+ struct scmi_powercap_zone *root;
+ struct scmi_powercap_root *pr;
+ struct scmi_powercap_zone *child;
+ bool enabled;
+ int ret;
+
+ if (!pz || !mode)
+ return -EINVAL;
+
+ root = to_scmi_powercap_zone(pz);
+ pr = container_of(root, struct scmi_powercap_root, instance_root);
+
+ *mode = true;
+
+ list_for_each_entry(child, &pr->registered_zones[0], node) {
+ if (child == &pr->instance_root)
+ continue;
+ if (child->info->parent_id != SCMI_POWERCAP_ROOT_ZONE_ID)
+ continue;
+ if (!child->info->cpli[0].cap_config)
+ continue;
+
+ ret = powercap_ops->cap_enable_get(child->ph, child->info->id, &enabled);
+
+ if (ret)
+ return ret;
+
+ if (!enabled) {
+ *mode = false;
+ return 0;
+ }
+ }
+
+ return 0;
+}
+
static int instance_root_get_power_uw(struct powercap_zone *pz, u64 *power_uw)
{
struct scmi_powercap_zone *root = to_scmi_powercap_zone(pz);
@@ -315,6 +394,8 @@ static const struct powercap_zone_ops instance_root_ops = {
.get_max_power_range_uw = scmi_powercap_get_max_power_range_uw,
.get_power_uw = instance_root_get_power_uw,
.release = instance_root_release,
+ .set_enable = instance_root_set_enable,
+ .get_enable = instance_root_get_enable,
};

static const struct powercap_zone_constraint_ops instance_root_const_ops = {
--
2.47.3