[PATCH v3 9/9] firmware: arm_scmi: add Powercap MAI get/set support
From: Philip Radford <hidden>
Date: 2026-02-26 14:19:08
Also in:
arm-scmi, linux-pm, lkml
Subsystem:
system control & power/management interface (scpi/scmi) message protocol drivers, the rest · Maintainers:
Sudeep Holla, Linus Torvalds
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 <redacted> --- drivers/firmware/arm_scmi/powercap.c | 120 +++++++++++++++++++++++++++ include/linux/scmi_protocol.h | 8 ++ 2 files changed, 128 insertions(+)
diff --git a/drivers/firmware/arm_scmi/powercap.c b/drivers/firmware/arm_scmi/powercap.c
index 1087d59ac873..7dc6d3001637 100644
--- a/drivers/firmware/arm_scmi/powercap.c
+++ b/drivers/firmware/arm_scmi/powercap.c@@ -401,6 +401,34 @@ 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 problem 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 =
@@ -1082,6 +1110,96 @@ 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,
@@ -1094,6 +1212,8 @@ 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..73d66281dcc3 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h@@ -675,6 +675,10 @@ 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;
@@ -758,6 +762,10 @@ 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 {
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2.47.3