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		0x20001
 18
 19#define SCMI_SYSTEM_NUM_SOURCES		1
 20
 21enum scmi_system_protocol_cmd {
 22	SYSTEM_POWER_STATE_NOTIFY = 0x5,
 23};
 24
 25struct scmi_system_power_state_notify {
 26	__le32 notify_enable;
 27};
 28
 29struct scmi_system_power_state_notifier_payld {
 30	__le32 agent_id;
 31	__le32 flags;
 32	__le32 system_state;
 33	__le32 timeout;
 34};
 35
 36struct scmi_system_info {
 37	u32 version;
 38	bool graceful_timeout_supported;
 39	bool power_state_notify_cmd;
 40};
 41
 42static 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
 53static 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
 74static 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
 86static void *
 87scmi_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
118static 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
128static 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
134static 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
142static 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
169static 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
178DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(system, scmi_system)