[PATCH v3 1/3] firmware: arm_scmi: Add System Power Protocol support

From: Cristian Marussi
Date: Mon Jun 22 2020 - 11:18:36 EST


Add bare protocol support for SCMI SystemPower 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 by this commit.

Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
---
V2 --> V3
- fixes related to SCMI Notifications core support V10
V1 --> V2
- use common event enums
---
drivers/firmware/arm_scmi/Makefile | 2 +-
drivers/firmware/arm_scmi/system.c | 136 +++++++++++++++++++++++++++++
include/linux/scmi_protocol.h | 18 ++++
3 files changed, 155 insertions(+), 1 deletion(-)
create mode 100644 drivers/firmware/arm_scmi/system.c

diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
index 11f1e07f603e..2bb446c3df67 100644
--- a/drivers/firmware/arm_scmi/Makefile
+++ b/drivers/firmware/arm_scmi/Makefile
@@ -5,5 +5,5 @@ scmi-driver-y = driver.o notify.o
scmi-transport-y = shmem.o
scmi-transport-$(CONFIG_MAILBOX) += mailbox.o
scmi-transport-$(CONFIG_ARM_PSCI_FW) += smc.o
-scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o
+scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o
obj-$(CONFIG_ARM_SCMI_POWER_DOMAIN) += scmi_pm_domain.o
diff --git a/drivers/firmware/arm_scmi/system.c b/drivers/firmware/arm_scmi/system.c
new file mode 100644
index 000000000000..e5d6dfa66009
--- /dev/null
+++ b/drivers/firmware/arm_scmi/system.c
@@ -0,0 +1,136 @@
+// 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 bool 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, u64 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);
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 46d98be92466..f59e5df1a61e 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -292,6 +292,7 @@ struct scmi_handle {
void *sensor_priv;
void *reset_priv;
void *notify_priv;
+ void *system_priv;
};

enum scmi_std_protocol {
@@ -304,6 +305,15 @@ enum scmi_std_protocol {
SCMI_PROTOCOL_RESET = 0x16,
};

+enum scmi_system_events {
+ SCMI_SYSTEM_SHUTDOWN,
+ SCMI_SYSTEM_COLDRESET,
+ SCMI_SYSTEM_WARMRESET,
+ SCMI_SYSTEM_POWERUP,
+ SCMI_SYSTEM_SUSPEND,
+ SCMI_SYSTEM_MAX
+};
+
struct scmi_device {
u32 id;
u8 protocol_id;
@@ -378,6 +388,7 @@ enum scmi_notification_events {
SCMI_EVENT_SENSOR_TRIP_POINT_EVENT = 0x0,
SCMI_EVENT_RESET_ISSUED = 0x0,
SCMI_EVENT_BASE_ERROR_EVENT = 0x0,
+ SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER = 0x0,
};

struct scmi_power_state_changed_report {
@@ -387,6 +398,13 @@ struct scmi_power_state_changed_report {
u32 power_state;
};

+struct scmi_system_power_state_notifier_report {
+ u64 timestamp;
+ u32 agent_id;
+ u32 flags;
+ u32 system_state;
+};
+
struct scmi_perf_limits_report {
u64 timestamp;
u32 agent_id;
--
2.17.1