root/drivers/firmware/arm_scmi/power.c
// SPDX-License-Identifier: GPL-2.0
/*
 * System Control and Management Interface (SCMI) Power Protocol
 *
 * Copyright (C) 2018-2022 ARM Ltd.
 */

#define pr_fmt(fmt) "SCMI Notifications POWER - " fmt

#include <linux/module.h>
#include <linux/scmi_protocol.h>

#include "protocols.h"
#include "notify.h"

/* Updated only after ALL the mandatory features for that version are merged */
#define SCMI_PROTOCOL_SUPPORTED_VERSION         0x30001

enum scmi_power_protocol_cmd {
        POWER_DOMAIN_ATTRIBUTES = 0x3,
        POWER_STATE_SET = 0x4,
        POWER_STATE_GET = 0x5,
        POWER_STATE_NOTIFY = 0x6,
        POWER_DOMAIN_NAME_GET = 0x8,
};

struct scmi_msg_resp_power_attributes {
        __le16 num_domains;
        __le16 reserved;
        __le32 stats_addr_low;
        __le32 stats_addr_high;
        __le32 stats_size;
};

struct scmi_msg_resp_power_domain_attributes {
        __le32 flags;
#define SUPPORTS_STATE_SET_NOTIFY(x)    ((x) & BIT(31))
#define SUPPORTS_STATE_SET_ASYNC(x)     ((x) & BIT(30))
#define SUPPORTS_STATE_SET_SYNC(x)      ((x) & BIT(29))
#define SUPPORTS_EXTENDED_NAMES(x)      ((x) & BIT(27))
            u8 name[SCMI_SHORT_NAME_MAX_SIZE];
};

struct scmi_power_set_state {
        __le32 flags;
#define STATE_SET_ASYNC         BIT(0)
        __le32 domain;
        __le32 state;
};

struct scmi_power_state_notify {
        __le32 domain;
        __le32 notify_enable;
};

struct scmi_power_state_notify_payld {
        __le32 agent_id;
        __le32 domain_id;
        __le32 power_state;
};

struct power_dom_info {
        bool state_set_sync;
        bool state_set_async;
        bool state_set_notify;
        char name[SCMI_MAX_STR_SIZE];
};

struct scmi_power_info {
        bool notify_state_change_cmd;
        int num_domains;
        u64 stats_addr;
        u32 stats_size;
        struct power_dom_info *dom_info;
};

static int scmi_power_attributes_get(const struct scmi_protocol_handle *ph,
                                     struct scmi_power_info *pi)
{
        int ret;
        struct scmi_xfer *t;
        struct scmi_msg_resp_power_attributes *attr;

        ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
                                      0, sizeof(*attr), &t);
        if (ret)
                return ret;

        attr = t->rx.buf;

        ret = ph->xops->do_xfer(ph, t);
        if (!ret) {
                pi->num_domains = le16_to_cpu(attr->num_domains);
                pi->stats_addr = le32_to_cpu(attr->stats_addr_low) |
                                (u64)le32_to_cpu(attr->stats_addr_high) << 32;
                pi->stats_size = le32_to_cpu(attr->stats_size);
        }

        ph->xops->xfer_put(ph, t);

        if (!ret)
                if (!ph->hops->protocol_msg_check(ph, POWER_STATE_NOTIFY, NULL))
                        pi->notify_state_change_cmd = true;

        return ret;
}

static int
scmi_power_domain_attributes_get(const struct scmi_protocol_handle *ph,
                                 u32 domain, struct power_dom_info *dom_info,
                                 bool notify_state_change_cmd)
{
        int ret;
        u32 flags;
        struct scmi_xfer *t;
        struct scmi_msg_resp_power_domain_attributes *attr;

        ret = ph->xops->xfer_get_init(ph, POWER_DOMAIN_ATTRIBUTES,
                                      sizeof(domain), sizeof(*attr), &t);
        if (ret)
                return ret;

        put_unaligned_le32(domain, t->tx.buf);
        attr = t->rx.buf;

        ret = ph->xops->do_xfer(ph, t);
        if (!ret) {
                flags = le32_to_cpu(attr->flags);

                if (notify_state_change_cmd)
                        dom_info->state_set_notify =
                                SUPPORTS_STATE_SET_NOTIFY(flags);
                dom_info->state_set_async = SUPPORTS_STATE_SET_ASYNC(flags);
                dom_info->state_set_sync = SUPPORTS_STATE_SET_SYNC(flags);
                strscpy(dom_info->name, attr->name, SCMI_SHORT_NAME_MAX_SIZE);
        }
        ph->xops->xfer_put(ph, t);

        /*
         * If supported overwrite short name with the extended one;
         * on error just carry on and use already provided short name.
         */
        if (!ret && PROTOCOL_REV_MAJOR(ph->version) >= 0x3 &&
            SUPPORTS_EXTENDED_NAMES(flags)) {
                ph->hops->extended_name_get(ph, POWER_DOMAIN_NAME_GET,
                                            domain, NULL, dom_info->name,
                                            SCMI_MAX_STR_SIZE);
        }

        return ret;
}

static int scmi_power_state_set(const struct scmi_protocol_handle *ph,
                                u32 domain, u32 state)
{
        int ret;
        struct scmi_xfer *t;
        struct scmi_power_set_state *st;

        ret = ph->xops->xfer_get_init(ph, POWER_STATE_SET, sizeof(*st), 0, &t);
        if (ret)
                return ret;

        st = t->tx.buf;
        st->flags = cpu_to_le32(0);
        st->domain = cpu_to_le32(domain);
        st->state = cpu_to_le32(state);

        ret = ph->xops->do_xfer(ph, t);

        ph->xops->xfer_put(ph, t);
        return ret;
}

static int scmi_power_state_get(const struct scmi_protocol_handle *ph,
                                u32 domain, u32 *state)
{
        int ret;
        struct scmi_xfer *t;

        ret = ph->xops->xfer_get_init(ph, POWER_STATE_GET, sizeof(u32), sizeof(u32), &t);
        if (ret)
                return ret;

        put_unaligned_le32(domain, t->tx.buf);

        ret = ph->xops->do_xfer(ph, t);
        if (!ret)
                *state = get_unaligned_le32(t->rx.buf);

        ph->xops->xfer_put(ph, t);
        return ret;
}

static int scmi_power_num_domains_get(const struct scmi_protocol_handle *ph)
{
        struct scmi_power_info *pi = ph->get_priv(ph);

        return pi->num_domains;
}

static const char *
scmi_power_name_get(const struct scmi_protocol_handle *ph,
                    u32 domain)
{
        struct scmi_power_info *pi = ph->get_priv(ph);
        struct power_dom_info *dom = pi->dom_info + domain;

        return dom->name;
}

static const struct scmi_power_proto_ops power_proto_ops = {
        .num_domains_get = scmi_power_num_domains_get,
        .name_get = scmi_power_name_get,
        .state_set = scmi_power_state_set,
        .state_get = scmi_power_state_get,
};

static int scmi_power_request_notify(const struct scmi_protocol_handle *ph,
                                     u32 domain, bool enable)
{
        int ret;
        struct scmi_xfer *t;
        struct scmi_power_state_notify *notify;

        ret = ph->xops->xfer_get_init(ph, POWER_STATE_NOTIFY,
                                      sizeof(*notify), 0, &t);
        if (ret)
                return ret;

        notify = t->tx.buf;
        notify->domain = cpu_to_le32(domain);
        notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;

        ret = ph->xops->do_xfer(ph, t);

        ph->xops->xfer_put(ph, t);
        return ret;
}

static bool scmi_power_notify_supported(const struct scmi_protocol_handle *ph,
                                        u8 evt_id, u32 src_id)
{
        struct power_dom_info *dom;
        struct scmi_power_info *pinfo = ph->get_priv(ph);

        if (evt_id != SCMI_EVENT_POWER_STATE_CHANGED ||
            src_id >= pinfo->num_domains)
                return false;

        dom = pinfo->dom_info + src_id;
        return dom->state_set_notify;
}

static int scmi_power_set_notify_enabled(const struct scmi_protocol_handle *ph,
                                         u8 evt_id, u32 src_id, bool enable)
{
        int ret;

        ret = scmi_power_request_notify(ph, src_id, enable);
        if (ret)
                pr_debug("FAIL_ENABLE - evt[%X] dom[%d] - ret:%d\n",
                         evt_id, src_id, ret);

        return ret;
}

static void *
scmi_power_fill_custom_report(const struct scmi_protocol_handle *ph,
                              u8 evt_id, ktime_t timestamp,
                              const void *payld, size_t payld_sz,
                              void *report, u32 *src_id)
{
        const struct scmi_power_state_notify_payld *p = payld;
        struct scmi_power_state_changed_report *r = report;

        if (evt_id != SCMI_EVENT_POWER_STATE_CHANGED || sizeof(*p) != payld_sz)
                return NULL;

        r->timestamp = timestamp;
        r->agent_id = le32_to_cpu(p->agent_id);
        r->domain_id = le32_to_cpu(p->domain_id);
        r->power_state = le32_to_cpu(p->power_state);
        *src_id = r->domain_id;

        return r;
}

static int scmi_power_get_num_sources(const struct scmi_protocol_handle *ph)
{
        struct scmi_power_info *pinfo = ph->get_priv(ph);

        if (!pinfo)
                return -EINVAL;

        return pinfo->num_domains;
}

static const struct scmi_event power_events[] = {
        {
                .id = SCMI_EVENT_POWER_STATE_CHANGED,
                .max_payld_sz = sizeof(struct scmi_power_state_notify_payld),
                .max_report_sz =
                        sizeof(struct scmi_power_state_changed_report),
        },
};

static const struct scmi_event_ops power_event_ops = {
        .is_notify_supported = scmi_power_notify_supported,
        .get_num_sources = scmi_power_get_num_sources,
        .set_notify_enabled = scmi_power_set_notify_enabled,
        .fill_custom_report = scmi_power_fill_custom_report,
};

static const struct scmi_protocol_events power_protocol_events = {
        .queue_sz = SCMI_PROTO_QUEUE_SZ,
        .ops = &power_event_ops,
        .evts = power_events,
        .num_events = ARRAY_SIZE(power_events),
};

static int scmi_power_protocol_init(const struct scmi_protocol_handle *ph)
{
        int domain, ret;
        struct scmi_power_info *pinfo;

        dev_dbg(ph->dev, "Power Version %d.%d\n",
                PROTOCOL_REV_MAJOR(ph->version), PROTOCOL_REV_MINOR(ph->version));

        pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
        if (!pinfo)
                return -ENOMEM;

        ret = scmi_power_attributes_get(ph, pinfo);
        if (ret)
                return ret;

        pinfo->dom_info = devm_kcalloc(ph->dev, pinfo->num_domains,
                                       sizeof(*pinfo->dom_info), GFP_KERNEL);
        if (!pinfo->dom_info)
                return -ENOMEM;

        for (domain = 0; domain < pinfo->num_domains; domain++) {
                struct power_dom_info *dom = pinfo->dom_info + domain;

                scmi_power_domain_attributes_get(ph, domain, dom,
                                                 pinfo->notify_state_change_cmd);
        }

        return ph->set_priv(ph, pinfo);
}

static const struct scmi_protocol scmi_power = {
        .id = SCMI_PROTOCOL_POWER,
        .owner = THIS_MODULE,
        .instance_init = &scmi_power_protocol_init,
        .ops = &power_proto_ops,
        .events = &power_protocol_events,
        .supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
};

DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(power, scmi_power)