linux/drivers/firmware/arm_scmi/system.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * System Control and Management Interface (SCMI) System Power Protocol
   4 *
   5 * Copyright (C) 2020-2021 ARM Ltd.
   6 */
   7
   8#define pr_fmt(fmt) "SCMI Notifications SYSTEM - " fmt
   9
  10#include <linux/module.h>
  11#include <linux/scmi_protocol.h>
  12
  13#include "common.h"
  14#include "notify.h"
  15
  16#define SCMI_SYSTEM_NUM_SOURCES         1
  17
  18enum scmi_system_protocol_cmd {
  19        SYSTEM_POWER_STATE_NOTIFY = 0x5,
  20};
  21
  22struct scmi_system_power_state_notify {
  23        __le32 notify_enable;
  24};
  25
  26struct scmi_system_power_state_notifier_payld {
  27        __le32 agent_id;
  28        __le32 flags;
  29        __le32 system_state;
  30};
  31
  32struct scmi_system_info {
  33        u32 version;
  34};
  35
  36static int scmi_system_request_notify(const struct scmi_protocol_handle *ph,
  37                                      bool enable)
  38{
  39        int ret;
  40        struct scmi_xfer *t;
  41        struct scmi_system_power_state_notify *notify;
  42
  43        ret = ph->xops->xfer_get_init(ph, SYSTEM_POWER_STATE_NOTIFY,
  44                                      sizeof(*notify), 0, &t);
  45        if (ret)
  46                return ret;
  47
  48        notify = t->tx.buf;
  49        notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
  50
  51        ret = ph->xops->do_xfer(ph, t);
  52
  53        ph->xops->xfer_put(ph, t);
  54        return ret;
  55}
  56
  57static int scmi_system_set_notify_enabled(const struct scmi_protocol_handle *ph,
  58                                          u8 evt_id, u32 src_id, bool enable)
  59{
  60        int ret;
  61
  62        ret = scmi_system_request_notify(ph, enable);
  63        if (ret)
  64                pr_debug("FAIL_ENABLE - evt[%X] - ret:%d\n", evt_id, ret);
  65
  66        return ret;
  67}
  68
  69static void *
  70scmi_system_fill_custom_report(const struct scmi_protocol_handle *ph,
  71                               u8 evt_id, ktime_t timestamp,
  72                               const void *payld, size_t payld_sz,
  73                               void *report, u32 *src_id)
  74{
  75        const struct scmi_system_power_state_notifier_payld *p = payld;
  76        struct scmi_system_power_state_notifier_report *r = report;
  77
  78        if (evt_id != SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER ||
  79            sizeof(*p) != payld_sz)
  80                return NULL;
  81
  82        r->timestamp = timestamp;
  83        r->agent_id = le32_to_cpu(p->agent_id);
  84        r->flags = le32_to_cpu(p->flags);
  85        r->system_state = le32_to_cpu(p->system_state);
  86        *src_id = 0;
  87
  88        return r;
  89}
  90
  91static const struct scmi_event system_events[] = {
  92        {
  93                .id = SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER,
  94                .max_payld_sz =
  95                        sizeof(struct scmi_system_power_state_notifier_payld),
  96                .max_report_sz =
  97                        sizeof(struct scmi_system_power_state_notifier_report),
  98        },
  99};
 100
 101static const struct scmi_event_ops system_event_ops = {
 102        .set_notify_enabled = scmi_system_set_notify_enabled,
 103        .fill_custom_report = scmi_system_fill_custom_report,
 104};
 105
 106static const struct scmi_protocol_events system_protocol_events = {
 107        .queue_sz = SCMI_PROTO_QUEUE_SZ,
 108        .ops = &system_event_ops,
 109        .evts = system_events,
 110        .num_events = ARRAY_SIZE(system_events),
 111        .num_sources = SCMI_SYSTEM_NUM_SOURCES,
 112};
 113
 114static int scmi_system_protocol_init(const struct scmi_protocol_handle *ph)
 115{
 116        u32 version;
 117        struct scmi_system_info *pinfo;
 118
 119        ph->xops->version_get(ph, &version);
 120
 121        dev_dbg(ph->dev, "System Power Version %d.%d\n",
 122                PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 123
 124        pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
 125        if (!pinfo)
 126                return -ENOMEM;
 127
 128        pinfo->version = version;
 129        return ph->set_priv(ph, pinfo);
 130}
 131
 132static const struct scmi_protocol scmi_system = {
 133        .id = SCMI_PROTOCOL_SYSTEM,
 134        .owner = THIS_MODULE,
 135        .instance_init = &scmi_system_protocol_init,
 136        .ops = NULL,
 137        .events = &system_protocol_events,
 138};
 139
 140DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(system, scmi_system)
 141