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 /* 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         bool power_state_notify_cmd;
  40 };
  41
  42 static bool scmi_system_notify_supported(const struct scmi_protocol_handle *ph,
  43                                          u8 evt_id, u32 src_id)
  44 {
  45         struct scmi_system_info *pinfo = ph->get_priv(ph);
  46
  47         if (evt_id != SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER)
  48                 return false;
  49
  50         return pinfo->power_state_notify_cmd;
  51 }
  52
  53 static int scmi_system_request_notify(const struct scmi_protocol_handle *ph,
  54                                       bool enable)
  55 {
  56         int ret;
  57         struct scmi_xfer *t;
  58         struct scmi_system_power_state_notify *notify;
  59
  60         ret = ph->xops->xfer_get_init(ph, SYSTEM_POWER_STATE_NOTIFY,
  61                                       sizeof(*notify), 0, &t);
  62         if (ret)
  63                 return ret;
  64
  65         notify = t->tx.buf;
  66         notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
  67
  68         ret = ph->xops->do_xfer(ph, t);
  69
  70         ph->xops->xfer_put(ph, t);
  71         return ret;
  72 }
  73
  74 static int scmi_system_set_notify_enabled(const struct scmi_protocol_handle *ph,
  75                                           u8 evt_id, u32 src_id, bool enable)
  76 {
  77         int ret;
  78
  79         ret = scmi_system_request_notify(ph, enable);
  80         if (ret)
  81                 pr_debug("FAIL_ENABLE - evt[%X] - ret:%d\n", evt_id, ret);
  82
  83         return ret;
  84 }
  85
  86 static void *
  87 scmi_system_fill_custom_report(const struct scmi_protocol_handle *ph,
  88                                u8 evt_id, ktime_t timestamp,
  89                                const void *payld, size_t payld_sz,
  90                                void *report, u32 *src_id)
  91 {
  92         size_t expected_sz;
  93         const struct scmi_system_power_state_notifier_payld *p = payld;
  94         struct scmi_system_power_state_notifier_report *r = report;
  95         struct scmi_system_info *pinfo = ph->get_priv(ph);
  96
  97         expected_sz = pinfo->graceful_timeout_supported ?
  98                         sizeof(*p) : sizeof(*p) - sizeof(__le32);
  99         if (evt_id != SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER ||
 100             payld_sz != expected_sz)
 101                 return NULL;
 102
 103         r->timestamp = timestamp;
 104         r->agent_id = le32_to_cpu(p->agent_id);
 105         r->flags = le32_to_cpu(p->flags);
 106         r->system_state = le32_to_cpu(p->system_state);
 107         if (pinfo->graceful_timeout_supported &&
 108             r->system_state == SCMI_SYSTEM_SHUTDOWN &&
 109             SCMI_SYSPOWER_IS_REQUEST_GRACEFUL(r->flags))
 110                 r->timeout = le32_to_cpu(p->timeout);
 111         else
 112                 r->timeout = 0x00;
 113         *src_id = 0;
 114
 115         return r;
 116 }
 117
 118 static const struct scmi_event system_events[] = {
 119         {
 120                 .id = SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER,
 121                 .max_payld_sz =
 122                         sizeof(struct scmi_system_power_state_notifier_payld),
 123                 .max_report_sz =
 124                         sizeof(struct scmi_system_power_state_notifier_report),
 125         },
 126 };
 127
 128 static const struct scmi_event_ops system_event_ops = {
 129         .is_notify_supported = scmi_system_notify_supported,
 130         .set_notify_enabled = scmi_system_set_notify_enabled,
 131         .fill_custom_report = scmi_system_fill_custom_report,
 132 };
 133
 134 static const struct scmi_protocol_events system_protocol_events = {
 135         .queue_sz = SCMI_PROTO_QUEUE_SZ,
 136         .ops = &system_event_ops,
 137         .evts = system_events,
 138         .num_events = ARRAY_SIZE(system_events),
 139         .num_sources = SCMI_SYSTEM_NUM_SOURCES,
 140 };
 141
 142 static int scmi_system_protocol_init(const struct scmi_protocol_handle *ph)
 143 {
 144         int ret;
 145         u32 version;
 146         struct scmi_system_info *pinfo;
 147
 148         ret = ph->xops->version_get(ph, &version);
 149         if (ret)
 150                 return ret;
 151
 152         dev_dbg(ph->dev, "System Power Version %d.%d\n",
 153                 PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 154
 155         pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
 156         if (!pinfo)
 157                 return -ENOMEM;
 158
 159         pinfo->version = version;
 160         if (PROTOCOL_REV_MAJOR(pinfo->version) >= 0x2)
 161                 pinfo->graceful_timeout_supported = true;
 162
 163         if (!ph->hops->protocol_msg_check(ph, SYSTEM_POWER_STATE_NOTIFY, NULL))
 164                 pinfo->power_state_notify_cmd = true;
 165
 166         return ph->set_priv(ph, pinfo, version);
 167 }
 168
 169 static const struct scmi_protocol scmi_system = {
 170         .id = SCMI_PROTOCOL_SYSTEM,
 171         .owner = THIS_MODULE,
 172         .instance_init = &scmi_system_protocol_init,
 173         .ops = NULL,
 174         .events = &system_protocol_events,
 175         .supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
 176 };
 177
 178 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(system, scmi_system)