// SPDX-License-Identifier: GPL-2.0
/*
 * System Control and Management Interface (SCMI) Power Protocol
 *
 * Copyright (C) 2018-2022 ARM Ltd.
 */

#define pr_fmt(fmt) "SCMI Notifications POWER - " fmt

#include <linux/module.h>
#include <linux/scmi_protocol.h>

#include "protocols.h"
#include "notify.h"

/* Updated only after ALL the mandatory features for that version are merged */
#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x30001

enum scmi_power_protocol_cmd {
	POWER_DOMAIN_ATTRIBUTES = 0x3,
	POWER_STATE_SET = 0x4,
	POWER_STATE_GET = 0x5,
	POWER_STATE_NOTIFY = 0x6,
	POWER_DOMAIN_NAME_GET = 0x8,
};

struct scmi_msg_resp_power_attributes {
	__le16 num_domains;
	__le16 reserved;
	__le32 stats_addr_low;
	__le32 stats_addr_high;
	__le32 stats_size;
};

struct scmi_msg_resp_power_domain_attributes {
	__le32 flags;
#define SUPPORTS_STATE_SET_NOTIFY(x)	((x) & BIT(31))
#define SUPPORTS_STATE_SET_ASYNC(x)	((x) & BIT(30))
#define SUPPORTS_STATE_SET_SYNC(x)	((x) & BIT(29))
#define SUPPORTS_EXTENDED_NAMES(x)	((x) & BIT(27))
	    u8 name[SCMI_SHORT_NAME_MAX_SIZE];
};

struct scmi_power_set_state {
	__le32 flags;
#define STATE_SET_ASYNC		BIT(0)
	__le32 domain;
	__le32 state;
};

struct scmi_power_state_notify {
	__le32 domain;
	__le32 notify_enable;
};

struct scmi_power_state_notify_payld {
	__le32 agent_id;
	__le32 domain_id;
	__le32 power_state;
};

struct power_dom_info {
	bool state_set_sync;
	bool state_set_async;
	bool state_set_notify;
	char name[SCMI_MAX_STR_SIZE];
};

struct scmi_power_info {
	u32 version;
	bool notify_state_change_cmd;
	int num_domains;
	u64 stats_addr;
	u32 stats_size;
	struct power_dom_info *dom_info;
};

static int scmi_power_attributes_get(const struct scmi_protocol_handle *ph,
				     struct scmi_power_info *pi)
{
	int ret;
	struct scmi_xfer *t;
	struct scmi_msg_resp_power_attributes *attr;

	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
				      0, sizeof(*attr), &t);
	if (ret)
		return ret;

	attr = t->rx.buf;

	ret = ph->xops->do_xfer(ph, t);
	if (!ret) {
		pi->num_domains = le16_to_cpu(attr->num_domains);
		pi->stats_addr = le32_to_cpu(attr->stats_addr_low) |
				(u64)le32_to_cpu(attr->stats_addr_high) << 32;
		pi->stats_size = le32_to_cpu(attr->stats_size);
	}

	ph->xops->xfer_put(ph, t);

	if (!ret)
		if (!ph->hops->protocol_msg_check(ph, POWER_STATE_NOTIFY, NULL))
			pi->notify_state_change_cmd = true;

	return ret;
}

static int
scmi_power_domain_attributes_get(const struct scmi_protocol_handle *ph,
				 u32 domain, struct power_dom_info *dom_info,
				 u32 version, bool notify_state_change_cmd)
{
	int ret;
	u32 flags;
	struct scmi_xfer *t;
	struct scmi_msg_resp_power_domain_attributes *attr;

	ret = ph->xops->xfer_get_init(ph, POWER_DOMAIN_ATTRIBUTES,
				      sizeof(domain), sizeof(*attr), &t);
	if (ret)
		return ret;

	put_unaligned_le32(domain, t->tx.buf);
	attr = t->rx.buf;

	ret = ph->xops->do_xfer(ph, t);
	if (!ret) {
		flags = le32_to_cpu(attr->flags);

		if (notify_state_change_cmd)
			dom_info->state_set_notify =
				SUPPORTS_STATE_SET_NOTIFY(flags);
		dom_info->state_set_async = SUPPORTS_STATE_SET_ASYNC(flags);
		dom_info->state_set_sync = SUPPORTS_STATE_SET_SYNC(flags);
		strscpy(dom_info->name, attr->name, SCMI_SHORT_NAME_MAX_SIZE);
	}
	ph->xops->xfer_put(ph, t);

	/*
	 * If supported overwrite short name with the extended one;
	 * on error just carry on and use already provided short name.
	 */
	if (!ret && PROTOCOL_REV_MAJOR(version) >= 0x3 &&
	    SUPPORTS_EXTENDED_NAMES(flags)) {
		ph->hops->extended_name_get(ph, POWER_DOMAIN_NAME_GET,
					    domain, NULL, dom_info->name,
					    SCMI_MAX_STR_SIZE);
	}

	return ret;
}

static int scmi_power_state_set(const struct scmi_protocol_handle *ph,
				u32 domain, u32 state)
{
	int ret;
	struct scmi_xfer *t;
	struct scmi_power_set_state *st;

	ret = ph->xops->xfer_get_init(ph, POWER_STATE_SET, sizeof(*st), 0, &t);
	if (ret)
		return ret;

	st = t->tx.buf;
	st->flags = cpu_to_le32(0);
	st->domain = cpu_to_le32(domain);
	st->state = cpu_to_le32(state);

	ret = ph->xops->do_xfer(ph, t);

	ph->xops->xfer_put(ph, t);
	return ret;
}

static int scmi_power_state_get(const struct scmi_protocol_handle *ph,
				u32 domain, u32 *state)
{
	int ret;
	struct scmi_xfer *t;

	ret = ph->xops->xfer_get_init(ph, POWER_STATE_GET, sizeof(u32), sizeof(u32), &t);
	if (ret)
		return ret;

	put_unaligned_le32(domain, t->tx.buf);

	ret = ph->xops->do_xfer(ph, t);
	if (!ret)
		*state = get_unaligned_le32(t->rx.buf);

	ph->xops->xfer_put(ph, t);
	return ret;
}

static int scmi_power_num_domains_get(const struct scmi_protocol_handle *ph)
{
	struct scmi_power_info *pi = ph->get_priv(ph);

	return pi->num_domains;
}

static const char *
scmi_power_name_get(const struct scmi_protocol_handle *ph,
		    u32 domain)
{
	struct scmi_power_info *pi = ph->get_priv(ph);
	struct power_dom_info *dom = pi->dom_info + domain;

	return dom->name;
}

static const struct scmi_power_proto_ops power_proto_ops = {
	.num_domains_get = scmi_power_num_domains_get,
	.name_get = scmi_power_name_get,
	.state_set = scmi_power_state_set,
	.state_get = scmi_power_state_get,
};

static int scmi_power_request_notify(const struct scmi_protocol_handle *ph,
				     u32 domain, bool enable)
{
	int ret;
	struct scmi_xfer *t;
	struct scmi_power_state_notify *notify;

	ret = ph->xops->xfer_get_init(ph, POWER_STATE_NOTIFY,
				      sizeof(*notify), 0, &t);
	if (ret)
		return ret;

	notify = t->tx.buf;
	notify->domain = cpu_to_le32(domain);
	notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;

	ret = ph->xops->do_xfer(ph, t);

	ph->xops->xfer_put(ph, t);
	return ret;
}

static bool scmi_power_notify_supported(const struct scmi_protocol_handle *ph,
					u8 evt_id, u32 src_id)
{
	struct power_dom_info *dom;
	struct scmi_power_info *pinfo = ph->get_priv(ph);

	if (evt_id != SCMI_EVENT_POWER_STATE_CHANGED ||
	    src_id >= pinfo->num_domains)
		return false;

	dom = pinfo->dom_info + src_id;
	return dom->state_set_notify;
}

static int scmi_power_set_notify_enabled(const struct scmi_protocol_handle *ph,
					 u8 evt_id, u32 src_id, bool enable)
{
	int ret;

	ret = scmi_power_request_notify(ph, src_id, enable);
	if (ret)
		pr_debug("FAIL_ENABLE - evt[%X] dom[%d] - ret:%d\n",
			 evt_id, src_id, ret);

	return ret;
}

static void *
scmi_power_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)
{
	const struct scmi_power_state_notify_payld *p = payld;
	struct scmi_power_state_changed_report *r = report;

	if (evt_id != SCMI_EVENT_POWER_STATE_CHANGED || sizeof(*p) != payld_sz)
		return NULL;

	r->timestamp = timestamp;
	r->agent_id = le32_to_cpu(p->agent_id);
	r->domain_id = le32_to_cpu(p->domain_id);
	r->power_state = le32_to_cpu(p->power_state);
	*src_id = r->domain_id;

	return r;
}

static int scmi_power_get_num_sources(const struct scmi_protocol_handle *ph)
{
	struct scmi_power_info *pinfo = ph->get_priv(ph);

	if (!pinfo)
		return -EINVAL;

	return pinfo->num_domains;
}

static const struct scmi_event power_events[] = {
	{
		.id = SCMI_EVENT_POWER_STATE_CHANGED,
		.max_payld_sz = sizeof(struct scmi_power_state_notify_payld),
		.max_report_sz =
			sizeof(struct scmi_power_state_changed_report),
	},
};

static const struct scmi_event_ops power_event_ops = {
	.is_notify_supported = scmi_power_notify_supported,
	.get_num_sources = scmi_power_get_num_sources,
	.set_notify_enabled = scmi_power_set_notify_enabled,
	.fill_custom_report = scmi_power_fill_custom_report,
};

static const struct scmi_protocol_events power_protocol_events = {
	.queue_sz = SCMI_PROTO_QUEUE_SZ,
	.ops = &power_event_ops,
	.evts = power_events,
	.num_events = ARRAY_SIZE(power_events),
};

static int scmi_power_protocol_init(const struct scmi_protocol_handle *ph)
{
	int domain, ret;
	u32 version;
	struct scmi_power_info *pinfo;

	ret = ph->xops->version_get(ph, &version);
	if (ret)
		return ret;

	dev_dbg(ph->dev, "Power Version %d.%d\n",
		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));

	pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
	if (!pinfo)
		return -ENOMEM;

	ret = scmi_power_attributes_get(ph, pinfo);
	if (ret)
		return ret;

	pinfo->dom_info = devm_kcalloc(ph->dev, pinfo->num_domains,
				       sizeof(*pinfo->dom_info), GFP_KERNEL);
	if (!pinfo->dom_info)
		return -ENOMEM;

	for (domain = 0; domain < pinfo->num_domains; domain++) {
		struct power_dom_info *dom = pinfo->dom_info + domain;

		scmi_power_domain_attributes_get(ph, domain, dom, version,
						 pinfo->notify_state_change_cmd);
	}

	pinfo->version = version;

	return ph->set_priv(ph, pinfo, version);
}

static const struct scmi_protocol scmi_power = {
	.id = SCMI_PROTOCOL_POWER,
	.owner = THIS_MODULE,
	.instance_init = &scmi_power_protocol_init,
	.ops = &power_proto_ops,
	.events = &power_protocol_events,
	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
};

DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(power, scmi_power)