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
scmi_system_request_notify(const struct scmi_protocol_handle * ph,bool enable)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
scmi_system_set_notify_enabled(const struct scmi_protocol_handle * ph,u8 evt_id,u32 src_id,bool enable)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 *
scmi_system_fill_custom_report(const struct scmi_protocol_handle * ph,u8 evt_id,ktime_t timestamp,const void * payld,size_t payld_sz,void * report,u32 * src_id)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
scmi_system_protocol_init(const struct scmi_protocol_handle * ph)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)
159