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 /* Updated only after ALL the mandatory features for that version are merged */
  17 #define SCMI_PROTOCOL_SUPPORTED_VERSION         0x20000
  18
  19 #define SCMI_SYSTEM_NUM_SOURCES         1
  20
  21 enum scmi_system_protocol_cmd {
  22         SYSTEM_POWER_STATE_NOTIFY = 0x5,
  23 };
  24
  25 struct scmi_system_power_state_notify {
  26         __le32 notify_enable;
  27 };
  28
  29 struct scmi_system_power_state_notifier_payld {
  30         __le32 agent_id;
  31         __le32 flags;
  32         __le32 system_state;
  33         __le32 timeout;
  34 };
  35
  36 struct scmi_system_info {
  37         u32 version;
  38         bool graceful_timeout_supported;
  39 };
  40
  41 static int scmi_system_request_notify(const struct scmi_protocol_handle *ph,
  42                                       bool enable)
  43 {
  44         int ret;
  45         struct scmi_xfer *t;
  46         struct scmi_system_power_state_notify *notify;
  47
  48         ret = ph->xops->xfer_get_init(ph, SYSTEM_POWER_STATE_NOTIFY,
  49                                       sizeof(*notify), 0, &t);
  50         if (ret)
  51                 return ret;
  52
  53         notify = t->tx.buf;
  54         notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
  55
  56         ret = ph->xops->do_xfer(ph, t);
  57
  58         ph->xops->xfer_put(ph, t);
  59         return ret;
  60 }
  61
  62 static int scmi_system_set_notify_enabled(const struct scmi_protocol_handle *ph,
  63                                           u8 evt_id, u32 src_id, bool enable)
  64 {
  65         int ret;
  66
  67         ret = scmi_system_request_notify(ph, enable);
  68         if (ret)
  69                 pr_debug("FAIL_ENABLE - evt[%X] - ret:%d\n", evt_id, ret);
  70
  71         return ret;
  72 }
  73
  74 static void *
  75 scmi_system_fill_custom_report(const struct scmi_protocol_handle *ph,
  76                                u8 evt_id, ktime_t timestamp,
  77                                const void *payld, size_t payld_sz,
  78                                void *report, u32 *src_id)
  79 {
  80         size_t expected_sz;
  81         const struct scmi_system_power_state_notifier_payld *p = payld;
  82         struct scmi_system_power_state_notifier_report *r = report;
  83         struct scmi_system_info *pinfo = ph->get_priv(ph);
  84
  85         expected_sz = pinfo->graceful_timeout_supported ?
  86                         sizeof(*p) : sizeof(*p) - sizeof(__le32);
  87         if (evt_id != SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER ||
  88             payld_sz != expected_sz)
  89                 return NULL;
  90
  91         r->timestamp = timestamp;
  92         r->agent_id = le32_to_cpu(p->agent_id);
  93         r->flags = le32_to_cpu(p->flags);
  94         r->system_state = le32_to_cpu(p->system_state);
  95         if (pinfo->graceful_timeout_supported &&
  96             r->system_state == SCMI_SYSTEM_SHUTDOWN &&
  97             SCMI_SYSPOWER_IS_REQUEST_GRACEFUL(r->flags))
  98                 r->timeout = le32_to_cpu(p->timeout);
  99         else
 100                 r->timeout = 0x00;
 101         *src_id = 0;
 102
 103         return r;
 104 }
 105
 106 static const struct scmi_event system_events[] = {
 107         {
 108                 .id = SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER,
 109                 .max_payld_sz =
 110                         sizeof(struct scmi_system_power_state_notifier_payld),
 111                 .max_report_sz =
 112                         sizeof(struct scmi_system_power_state_notifier_report),
 113         },
 114 };
 115
 116 static const struct scmi_event_ops system_event_ops = {
 117         .set_notify_enabled = scmi_system_set_notify_enabled,
 118         .fill_custom_report = scmi_system_fill_custom_report,
 119 };
 120
 121 static const struct scmi_protocol_events system_protocol_events = {
 122         .queue_sz = SCMI_PROTO_QUEUE_SZ,
 123         .ops = &system_event_ops,
 124         .evts = system_events,
 125         .num_events = ARRAY_SIZE(system_events),
 126         .num_sources = SCMI_SYSTEM_NUM_SOURCES,
 127 };
 128
 129 static int scmi_system_protocol_init(const struct scmi_protocol_handle *ph)
 130 {
 131         int ret;
 132         u32 version;
 133         struct scmi_system_info *pinfo;
 134
 135         ret = ph->xops->version_get(ph, &version);
 136         if (ret)
 137                 return ret;
 138
 139         dev_dbg(ph->dev, "System Power Version %d.%d\n",
 140                 PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 141
 142         pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
 143         if (!pinfo)
 144                 return -ENOMEM;
 145
 146         pinfo->version = version;
 147         if (PROTOCOL_REV_MAJOR(pinfo->version) >= 0x2)
 148                 pinfo->graceful_timeout_supported = true;
 149
 150         return ph->set_priv(ph, pinfo, version);
 151 }
 152
 153 static const struct scmi_protocol scmi_system = {
 154         .id = SCMI_PROTOCOL_SYSTEM,
 155         .owner = THIS_MODULE,
 156         .instance_init = &scmi_system_protocol_init,
 157         .ops = NULL,
 158         .events = &system_protocol_events,
 159         .supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
 160 };
 161
 162 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(system, scmi_system)