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
 18enum scmi_system_protocol_cmd {
 19	SYSTEM_POWER_STATE_NOTIFY = 0x5,
 20};
 21
 22struct scmi_system_power_state_notify {
 23	__le32 notify_enable;
 24};
 25
 26struct scmi_system_power_state_notifier_payld {
 27	__le32 agent_id;
 28	__le32 flags;
 29	__le32 system_state;
 30	__le32 timeout;
 31};
 32
 33struct scmi_system_info {
 34	u32 version;
 35	bool graceful_timeout_supported;
 36};
 37
 38static 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
 59static 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
 71static void *
 72scmi_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
103static 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
113static 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
118static 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
126static 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
150static 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
158DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(system, scmi_system)