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)
159