linux/drivers/firmware/arm_scmi/system.c
Cristian Marussi a880305512 firmware: arm_scmi: Add system power protocol support
Add bare protocol support for SCMI system power protocol as needed by
an OSPM agent: basic initialization and SYSTEM_POWER_STATE_NOTIFIER
core notification support.

No event-handling logic is attached to such notification..

Link: https://lore.kernel.org/r/20200907174657.32466-2-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-09-08 16:00:55 +01:00

137 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* System Control and Management Interface (SCMI) System Power Protocol
*
* Copyright (C) 2020 ARM Ltd.
*/
#define pr_fmt(fmt) "SCMI Notifications SYSTEM - " fmt
#include <linux/scmi_protocol.h>
#include "common.h"
#include "notify.h"
#define SCMI_SYSTEM_NUM_SOURCES 1
enum scmi_system_protocol_cmd {
SYSTEM_POWER_STATE_NOTIFY = 0x5,
};
struct scmi_system_power_state_notify {
__le32 notify_enable;
};
struct scmi_system_power_state_notifier_payld {
__le32 agent_id;
__le32 flags;
__le32 system_state;
};
struct scmi_system_info {
u32 version;
};
static int scmi_system_request_notify(const struct scmi_handle *handle,
bool enable)
{
int ret;
struct scmi_xfer *t;
struct scmi_system_power_state_notify *notify;
ret = scmi_xfer_get_init(handle, SYSTEM_POWER_STATE_NOTIFY,
SCMI_PROTOCOL_SYSTEM, sizeof(*notify), 0, &t);
if (ret)
return ret;
notify = t->tx.buf;
notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
ret = scmi_do_xfer(handle, t);
scmi_xfer_put(handle, t);
return ret;
}
static int scmi_system_set_notify_enabled(const struct scmi_handle *handle,
u8 evt_id, u32 src_id, bool enable)
{
int ret;
ret = scmi_system_request_notify(handle, enable);
if (ret)
pr_debug("FAIL_ENABLE - evt[%X] - ret:%d\n", evt_id, ret);
return ret;
}
static void *scmi_system_fill_custom_report(const struct scmi_handle *handle,
u8 evt_id, ktime_t timestamp,
const void *payld, size_t payld_sz,
void *report, u32 *src_id)
{
const struct scmi_system_power_state_notifier_payld *p = payld;
struct scmi_system_power_state_notifier_report *r = report;
if (evt_id != SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER ||
sizeof(*p) != payld_sz)
return NULL;
r->timestamp = timestamp;
r->agent_id = le32_to_cpu(p->agent_id);
r->flags = le32_to_cpu(p->flags);
r->system_state = le32_to_cpu(p->system_state);
*src_id = 0;
return r;
}
static const struct scmi_event system_events[] = {
{
.id = SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER,
.max_payld_sz =
sizeof(struct scmi_system_power_state_notifier_payld),
.max_report_sz =
sizeof(struct scmi_system_power_state_notifier_report),
},
};
static const struct scmi_event_ops system_event_ops = {
.set_notify_enabled = scmi_system_set_notify_enabled,
.fill_custom_report = scmi_system_fill_custom_report,
};
static int scmi_system_protocol_init(struct scmi_handle *handle)
{
u32 version;
struct scmi_system_info *pinfo;
scmi_version_get(handle, SCMI_PROTOCOL_SYSTEM, &version);
dev_dbg(handle->dev, "System Power Version %d.%d\n",
PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
pinfo = devm_kzalloc(handle->dev, sizeof(*pinfo), GFP_KERNEL);
if (!pinfo)
return -ENOMEM;
scmi_register_protocol_events(handle,
SCMI_PROTOCOL_SYSTEM, SCMI_PROTO_QUEUE_SZ,
&system_event_ops,
system_events,
ARRAY_SIZE(system_events),
SCMI_SYSTEM_NUM_SOURCES);
pinfo->version = version;
handle->system_priv = pinfo;
return 0;
}
static int __init scmi_system_init(void)
{
return scmi_protocol_register(SCMI_PROTOCOL_SYSTEM,
&scmi_system_protocol_init);
}
subsys_initcall(scmi_system_init);