1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * System Control and Management Interface (SCMI) System Power Protocol
4  *
5  * Copyright (C) 2020 ARM Ltd.
6  */
7 
8 #define pr_fmt(fmt) "SCMI Notifications SYSTEM - " fmt
9 
10 #include <linux/scmi_protocol.h>
11 
12 #include "common.h"
13 #include "notify.h"
14 
15 #define SCMI_SYSTEM_NUM_SOURCES		1
16 
17 enum scmi_system_protocol_cmd {
18 	SYSTEM_POWER_STATE_NOTIFY = 0x5,
19 };
20 
21 struct scmi_system_power_state_notify {
22 	__le32 notify_enable;
23 };
24 
25 struct scmi_system_power_state_notifier_payld {
26 	__le32 agent_id;
27 	__le32 flags;
28 	__le32 system_state;
29 };
30 
31 struct scmi_system_info {
32 	u32 version;
33 };
34 
35 static int scmi_system_request_notify(const struct scmi_handle *handle,
36 				      bool enable)
37 {
38 	int ret;
39 	struct scmi_xfer *t;
40 	struct scmi_system_power_state_notify *notify;
41 
42 	ret = scmi_xfer_get_init(handle, SYSTEM_POWER_STATE_NOTIFY,
43 				 SCMI_PROTOCOL_SYSTEM, sizeof(*notify), 0, &t);
44 	if (ret)
45 		return ret;
46 
47 	notify = t->tx.buf;
48 	notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
49 
50 	ret = scmi_do_xfer(handle, t);
51 
52 	scmi_xfer_put(handle, t);
53 	return ret;
54 }
55 
56 static int scmi_system_set_notify_enabled(const struct scmi_handle *handle,
57 					  u8 evt_id, u32 src_id, bool enable)
58 {
59 	int ret;
60 
61 	ret = scmi_system_request_notify(handle, enable);
62 	if (ret)
63 		pr_debug("FAIL_ENABLE - evt[%X] - ret:%d\n", evt_id, ret);
64 
65 	return ret;
66 }
67 
68 static void *scmi_system_fill_custom_report(const struct scmi_handle *handle,
69 					    u8 evt_id, ktime_t timestamp,
70 					    const void *payld, size_t payld_sz,
71 					    void *report, u32 *src_id)
72 {
73 	const struct scmi_system_power_state_notifier_payld *p = payld;
74 	struct scmi_system_power_state_notifier_report *r = report;
75 
76 	if (evt_id != SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER ||
77 	    sizeof(*p) != payld_sz)
78 		return NULL;
79 
80 	r->timestamp = timestamp;
81 	r->agent_id = le32_to_cpu(p->agent_id);
82 	r->flags = le32_to_cpu(p->flags);
83 	r->system_state = le32_to_cpu(p->system_state);
84 	*src_id = 0;
85 
86 	return r;
87 }
88 
89 static const struct scmi_event system_events[] = {
90 	{
91 		.id = SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER,
92 		.max_payld_sz =
93 			sizeof(struct scmi_system_power_state_notifier_payld),
94 		.max_report_sz =
95 			sizeof(struct scmi_system_power_state_notifier_report),
96 	},
97 };
98 
99 static const struct scmi_event_ops system_event_ops = {
100 	.set_notify_enabled = scmi_system_set_notify_enabled,
101 	.fill_custom_report = scmi_system_fill_custom_report,
102 };
103 
104 static int scmi_system_protocol_init(struct scmi_handle *handle)
105 {
106 	u32 version;
107 	struct scmi_system_info *pinfo;
108 
109 	scmi_version_get(handle, SCMI_PROTOCOL_SYSTEM, &version);
110 
111 	dev_dbg(handle->dev, "System Power Version %d.%d\n",
112 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
113 
114 	pinfo = devm_kzalloc(handle->dev, sizeof(*pinfo), GFP_KERNEL);
115 	if (!pinfo)
116 		return -ENOMEM;
117 
118 	scmi_register_protocol_events(handle,
119 				      SCMI_PROTOCOL_SYSTEM, SCMI_PROTO_QUEUE_SZ,
120 				      &system_event_ops,
121 				      system_events,
122 				      ARRAY_SIZE(system_events),
123 				      SCMI_SYSTEM_NUM_SOURCES);
124 
125 	pinfo->version = version;
126 	handle->system_priv = pinfo;
127 
128 	return 0;
129 }
130 
131 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_SYSTEM, system)
132