drivers/firmware/arm_scmi/system.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * System Control and Management Interface (SCMI) System Power Protocol
   4  *
   5  * Copyright (C) 2020-2022 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 "protocols.h"
  14 #include "notify.h"
  15
  16 #define SCMI_SYSTEM_NUM_SOURCES         1
  17
  18 enum scmi_system_protocol_cmd {
  19         SYSTEM_POWER_STATE_NOTIFY = 0x5,
  20 };
  21
  22 struct scmi_system_power_state_notify {
  23         __le32 notify_enable;
  24 };
  25
  26 struct scmi_system_power_state_notifier_payld {
  27         __le32 agent_id;
  28         __le32 flags;
  29         __le32 system_state;
  30 };
  31
  32 struct scmi_system_info {
  33         u32 version;
  34 };
  35
  36 static 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
  57 static 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
  69 static void *
  70 scmi_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
  91 static 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
 101 static 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
 106 static 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
 114 static int scmi_system_protocol_init(const struct scmi_protocol_handle *ph)
 115 {
 116         int ret;
 117         u32 version;
 118         struct scmi_system_info *pinfo;
 119
 120         ret = ph->xops->version_get(ph, &version);
 121         if (ret)
 122                 return ret;
 123
 124         dev_dbg(ph->dev, "System Power Version %d.%d\n",
 125                 PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 126
 127         pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
 128         if (!pinfo)
 129                 return -ENOMEM;
 130
 131         pinfo->version = version;
 132         return ph->set_priv(ph, pinfo);
 133 }
 134
 135 static const struct scmi_protocol scmi_system = {
 136         .id = SCMI_PROTOCOL_SYSTEM,
 137         .owner = THIS_MODULE,
 138         .instance_init = &scmi_system_protocol_init,
 139         .ops = NULL,
 140         .events = &system_protocol_events,
 141 };
 142
 143 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(system, scmi_system)