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