drivers/scmi-msg: support for clock protocol
Adds SCMI clock protocol support in the SCMI message drivers as
defined in SCMI specification v2.0 [1] for clock protocol messages.
Platform can provide one of the plat_scmi_clock_*() handler for the
supported operations set/get state/rate and others.
scmi_msg_get_clock_handler() sanitizes the message_id value
against any speculative use of clock ID as a index since by
SCMI specification, IDs are indices.
This implementation is based on the OP-TEE project implementation [2]
itself based on the SCP-firmware implementation [3] of the SCMI
protocol server side.
Link: [1] http://infocenter.arm.com/help/topic/com.arm.doc.den0056a/DEN0056A_System_Control_and_Management_Interface.pdf
Link: [2] https://github.com/OP-TEE/optee_os/commit/a7a9e3ba71dd908aafdc4c5ed9b29b15faa9692d
Link: [3] https://github.com/ARM-software/SCP-firmware.git
Change-Id: Ib56e096512042d4f7b9563d1e4181554eb8ed02c
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
diff --git a/drivers/st/scmi-msg/clock.c b/drivers/st/scmi-msg/clock.c
new file mode 100644
index 0000000..319557c
--- /dev/null
+++ b/drivers/st/scmi-msg/clock.c
@@ -0,0 +1,381 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2015-2020, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2019-2020, Linaro Limited
+ */
+#include <cdefs.h>
+#include <string.h>
+
+#include <drivers/st/scmi-msg.h>
+#include <drivers/st/scmi.h>
+#include <lib/utils_def.h>
+
+#include "common.h"
+
+#pragma weak plat_scmi_clock_count
+#pragma weak plat_scmi_clock_get_name
+#pragma weak plat_scmi_clock_rates_array
+#pragma weak plat_scmi_clock_rates_by_step
+#pragma weak plat_scmi_clock_get_rate
+#pragma weak plat_scmi_clock_set_rate
+#pragma weak plat_scmi_clock_get_state
+#pragma weak plat_scmi_clock_set_state
+
+static bool message_id_is_supported(unsigned int message_id);
+
+size_t plat_scmi_clock_count(unsigned int agent_id __unused)
+{
+ return 0U;
+}
+
+const char *plat_scmi_clock_get_name(unsigned int agent_id __unused,
+ unsigned int scmi_id __unused)
+{
+ return NULL;
+}
+
+int32_t plat_scmi_clock_rates_array(unsigned int agent_id __unused,
+ unsigned int scmi_id __unused,
+ unsigned long *rates __unused,
+ size_t *nb_elts __unused)
+{
+ return SCMI_NOT_SUPPORTED;
+}
+
+int32_t plat_scmi_clock_rates_by_step(unsigned int agent_id __unused,
+ unsigned int scmi_id __unused,
+ unsigned long *steps __unused)
+{
+ return SCMI_NOT_SUPPORTED;
+}
+
+unsigned long plat_scmi_clock_get_rate(unsigned int agent_id __unused,
+ unsigned int scmi_id __unused)
+{
+ return 0U;
+}
+
+int32_t plat_scmi_clock_set_rate(unsigned int agent_id __unused,
+ unsigned int scmi_id __unused,
+ unsigned long rate __unused)
+{
+ return SCMI_NOT_SUPPORTED;
+}
+
+int32_t plat_scmi_clock_get_state(unsigned int agent_id __unused,
+ unsigned int scmi_id __unused)
+{
+ return SCMI_NOT_SUPPORTED;
+}
+
+int32_t plat_scmi_clock_set_state(unsigned int agent_id __unused,
+ unsigned int scmi_id __unused,
+ bool enable_not_disable __unused)
+{
+ return SCMI_NOT_SUPPORTED;
+}
+
+static void report_version(struct scmi_msg *msg)
+{
+ struct scmi_protocol_version_p2a return_values = {
+ .status = SCMI_SUCCESS,
+ .version = SCMI_PROTOCOL_VERSION_CLOCK,
+ };
+
+ if (msg->in_size != 0) {
+ scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+ return;
+ }
+
+ scmi_write_response(msg, &return_values, sizeof(return_values));
+}
+
+static void report_attributes(struct scmi_msg *msg)
+{
+ size_t agent_count = plat_scmi_clock_count(msg->agent_id);
+ struct scmi_protocol_attributes_p2a return_values = {
+ .status = SCMI_SUCCESS,
+ .attributes = SCMI_CLOCK_PROTOCOL_ATTRIBUTES(1U, agent_count),
+ };
+
+ if (msg->in_size != 0) {
+ scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+ return;
+ }
+
+ scmi_write_response(msg, &return_values, sizeof(return_values));
+}
+
+static void report_message_attributes(struct scmi_msg *msg)
+{
+ struct scmi_protocol_message_attributes_a2p *in_args = (void *)msg->in;
+ struct scmi_protocol_message_attributes_p2a return_values = {
+ .status = SCMI_SUCCESS,
+ /* For this protocol, attributes shall be zero */
+ .attributes = 0U,
+ };
+
+ if (msg->in_size != sizeof(*in_args)) {
+ scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+ return;
+ }
+
+ if (!message_id_is_supported(in_args->message_id)) {
+ scmi_status_response(msg, SCMI_NOT_FOUND);
+ return;
+ }
+
+ scmi_write_response(msg, &return_values, sizeof(return_values));
+}
+
+static void scmi_clock_attributes(struct scmi_msg *msg)
+{
+ const struct scmi_clock_attributes_a2p *in_args = (void *)msg->in;
+ struct scmi_clock_attributes_p2a return_values = {
+ .status = SCMI_SUCCESS,
+ };
+ const char *name = NULL;
+ unsigned int clock_id = 0U;
+
+ if (msg->in_size != sizeof(*in_args)) {
+ scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+ return;
+ }
+
+ clock_id = SPECULATION_SAFE_VALUE(in_args->clock_id);
+
+ if (clock_id >= plat_scmi_clock_count(msg->agent_id)) {
+ scmi_status_response(msg, SCMI_INVALID_PARAMETERS);
+ return;
+ }
+
+
+ name = plat_scmi_clock_get_name(msg->agent_id, clock_id);
+ if (name == NULL) {
+ scmi_status_response(msg, SCMI_NOT_FOUND);
+ return;
+ }
+
+ COPY_NAME_IDENTIFIER(return_values.clock_name, name);
+
+ return_values.attributes = plat_scmi_clock_get_state(msg->agent_id,
+ clock_id);
+
+ scmi_write_response(msg, &return_values, sizeof(return_values));
+}
+
+static void scmi_clock_rate_get(struct scmi_msg *msg)
+{
+ const struct scmi_clock_rate_get_a2p *in_args = (void *)msg->in;
+ unsigned long rate = 0U;
+ struct scmi_clock_rate_get_p2a return_values = {
+ .status = SCMI_SUCCESS,
+ };
+ unsigned int clock_id = 0U;
+
+ if (msg->in_size != sizeof(*in_args)) {
+ scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+ return;
+ }
+
+ clock_id = SPECULATION_SAFE_VALUE(in_args->clock_id);
+
+ if (clock_id >= plat_scmi_clock_count(msg->agent_id)) {
+ scmi_status_response(msg, SCMI_INVALID_PARAMETERS);
+ return;
+ }
+
+ rate = plat_scmi_clock_get_rate(msg->agent_id, clock_id);
+
+ return_values.rate[0] = (uint32_t)rate;
+ return_values.rate[1] = (uint32_t)((uint64_t)rate >> 32);
+
+ scmi_write_response(msg, &return_values, sizeof(return_values));
+}
+
+static void scmi_clock_rate_set(struct scmi_msg *msg)
+{
+ const struct scmi_clock_rate_set_a2p *in_args = (void *)msg->in;
+ unsigned long rate = 0U;
+ int32_t status = 0;
+ unsigned int clock_id = 0U;
+
+ if (msg->in_size != sizeof(*in_args)) {
+ scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+ return;
+ }
+
+ clock_id = SPECULATION_SAFE_VALUE(in_args->clock_id);
+
+ if (clock_id >= plat_scmi_clock_count(msg->agent_id)) {
+ scmi_status_response(msg, SCMI_INVALID_PARAMETERS);
+ return;
+ }
+
+ rate = (unsigned long)(((uint64_t)in_args->rate[1] << 32) |
+ in_args->rate[0]);
+
+ status = plat_scmi_clock_set_rate(msg->agent_id, clock_id, rate);
+
+ scmi_status_response(msg, status);
+}
+
+static void scmi_clock_config_set(struct scmi_msg *msg)
+{
+ const struct scmi_clock_config_set_a2p *in_args = (void *)msg->in;
+ int32_t status = SCMI_GENERIC_ERROR;
+ bool enable = false;
+ unsigned int clock_id = 0U;
+
+ if (msg->in_size != sizeof(*in_args)) {
+ scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+ return;
+ }
+
+ clock_id = SPECULATION_SAFE_VALUE(in_args->clock_id);
+
+ if (clock_id >= plat_scmi_clock_count(msg->agent_id)) {
+ scmi_status_response(msg, SCMI_INVALID_PARAMETERS);
+ return;
+ }
+
+ enable = in_args->attributes & SCMI_CLOCK_CONFIG_SET_ENABLE_MASK;
+
+ status = plat_scmi_clock_set_state(msg->agent_id, clock_id, enable);
+
+ scmi_status_response(msg, status);
+}
+
+#define RATES_ARRAY_SIZE_MAX (SCMI_PLAYLOAD_MAX - \
+ sizeof(struct scmi_clock_describe_rates_p2a))
+
+#define SCMI_RATES_BY_ARRAY(_nb_rates, _rem_rates) \
+ SCMI_CLOCK_DESCRIBE_RATES_NUM_RATES_FLAGS((_nb_rates), \
+ SCMI_CLOCK_RATE_FORMAT_LIST, \
+ (_rem_rates))
+#define SCMI_RATES_BY_STEP \
+ SCMI_CLOCK_DESCRIBE_RATES_NUM_RATES_FLAGS(3U, \
+ SCMI_CLOCK_RATE_FORMAT_RANGE, \
+ 0U)
+
+#define RATE_DESC_SIZE sizeof(struct scmi_clock_rate)
+
+static void write_rate_desc_array_in_buffer(char *dest, unsigned long *rates,
+ size_t nb_elt)
+{
+ uint32_t *out = (uint32_t *)(uintptr_t)dest;
+ size_t n;
+
+ ASSERT_SYM_PTR_ALIGN(out);
+
+ for (n = 0U; n < nb_elt; n++) {
+ out[2 * n] = (uint32_t)rates[n];
+ out[2 * n + 1] = (uint32_t)((uint64_t)rates[n] >> 32);
+ }
+}
+
+static void scmi_clock_describe_rates(struct scmi_msg *msg)
+{
+ const struct scmi_clock_describe_rates_a2p *in_args = (void *)msg->in;
+ struct scmi_clock_describe_rates_p2a p2a = {
+ .status = SCMI_SUCCESS,
+ };
+ size_t nb_rates;
+ int32_t status;
+ unsigned int clock_id;
+
+ if (msg->in_size != sizeof(*in_args)) {
+ scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+ return;
+ }
+
+ clock_id = SPECULATION_SAFE_VALUE(in_args->clock_id);
+
+ if (clock_id >= plat_scmi_clock_count(msg->agent_id)) {
+ scmi_status_response(msg, SCMI_INVALID_PARAMETERS);
+ return;
+ }
+
+ /* Platform may support array rate description */
+ status = plat_scmi_clock_rates_array(msg->agent_id, clock_id, NULL,
+ &nb_rates);
+ if (status == SCMI_SUCCESS) {
+ /* Currently 12 cells mex, so it's affordable for the stack */
+ unsigned long plat_rates[RATES_ARRAY_SIZE_MAX / RATE_DESC_SIZE];
+ size_t max_nb = RATES_ARRAY_SIZE_MAX / RATE_DESC_SIZE;
+ size_t ret_nb = MIN(nb_rates - in_args->rate_index, max_nb);
+ size_t rem_nb = nb_rates - in_args->rate_index - ret_nb;
+
+ status = plat_scmi_clock_rates_array(msg->agent_id, clock_id,
+ plat_rates, &ret_nb);
+ if (status == SCMI_SUCCESS) {
+ write_rate_desc_array_in_buffer(msg->out + sizeof(p2a),
+ plat_rates, ret_nb);
+
+ p2a.num_rates_flags = SCMI_RATES_BY_ARRAY(ret_nb,
+ rem_nb);
+ p2a.status = SCMI_SUCCESS;
+
+ memcpy(msg->out, &p2a, sizeof(p2a));
+ msg->out_size_out = sizeof(p2a) +
+ ret_nb * RATE_DESC_SIZE;
+ }
+ } else if (status == SCMI_NOT_SUPPORTED) {
+ unsigned long triplet[3] = { 0U, 0U, 0U };
+
+ /* Platform may support min§max/step triplet description */
+ status = plat_scmi_clock_rates_by_step(msg->agent_id, clock_id,
+ triplet);
+ if (status == SCMI_SUCCESS) {
+ write_rate_desc_array_in_buffer(msg->out + sizeof(p2a),
+ triplet, 3U);
+
+ p2a.num_rates_flags = SCMI_RATES_BY_STEP;
+ p2a.status = SCMI_SUCCESS;
+
+ memcpy(msg->out, &p2a, sizeof(p2a));
+ msg->out_size_out = sizeof(p2a) + (3U * RATE_DESC_SIZE);
+ }
+ } else {
+ /* Fallthrough generic exit sequence below with error status */
+ }
+
+ if (status != SCMI_SUCCESS) {
+ scmi_status_response(msg, status);
+ } else {
+ /*
+ * Message payload is already writen to msg->out, and
+ * msg->out_size_out updated.
+ */
+ }
+}
+
+static const scmi_msg_handler_t scmi_clock_handler_table[] = {
+ [SCMI_PROTOCOL_VERSION] = report_version,
+ [SCMI_PROTOCOL_ATTRIBUTES] = report_attributes,
+ [SCMI_PROTOCOL_MESSAGE_ATTRIBUTES] = report_message_attributes,
+ [SCMI_CLOCK_ATTRIBUTES] = scmi_clock_attributes,
+ [SCMI_CLOCK_DESCRIBE_RATES] = scmi_clock_describe_rates,
+ [SCMI_CLOCK_RATE_SET] = scmi_clock_rate_set,
+ [SCMI_CLOCK_RATE_GET] = scmi_clock_rate_get,
+ [SCMI_CLOCK_CONFIG_SET] = scmi_clock_config_set,
+};
+
+static bool message_id_is_supported(size_t message_id)
+{
+ return (message_id < ARRAY_SIZE(scmi_clock_handler_table)) &&
+ (scmi_clock_handler_table[message_id] != NULL);
+}
+
+scmi_msg_handler_t scmi_msg_get_clock_handler(struct scmi_msg *msg)
+{
+ const size_t array_size = ARRAY_SIZE(scmi_clock_handler_table);
+ unsigned int message_id = SPECULATION_SAFE_VALUE(msg->message_id);
+
+ if (message_id >= array_size) {
+ VERBOSE("Clock handle not found %u", msg->message_id);
+ return NULL;
+ }
+
+ return scmi_clock_handler_table[message_id];
+}
diff --git a/drivers/st/scmi-msg/clock.h b/drivers/st/scmi-msg/clock.h
new file mode 100644
index 0000000..a637934
--- /dev/null
+++ b/drivers/st/scmi-msg/clock.h
@@ -0,0 +1,150 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#ifndef SCMI_MSG_CLOCK_H
+#define SCMI_MSG_CLOCK_H
+
+#include <stdint.h>
+
+#include <lib/utils_def.h>
+
+#define SCMI_PROTOCOL_VERSION_CLOCK 0x20000U
+
+/*
+ * Identifiers of the SCMI Clock Management Protocol commands
+ */
+enum scmi_clock_command_id {
+ SCMI_CLOCK_ATTRIBUTES = 0x003,
+ SCMI_CLOCK_DESCRIBE_RATES = 0x004,
+ SCMI_CLOCK_RATE_SET = 0x005,
+ SCMI_CLOCK_RATE_GET = 0x006,
+ SCMI_CLOCK_CONFIG_SET = 0x007,
+};
+
+/* Protocol attributes */
+#define SCMI_CLOCK_CLOCK_COUNT_MASK GENMASK(15, 0)
+#define SCMI_CLOCK_MAX_PENDING_TRANSITIONS_MASK GENMASK(23, 16)
+
+#define SCMI_CLOCK_PROTOCOL_ATTRIBUTES(_max_pending, _clk_count) \
+ ((((_max_pending) << 16) & SCMI_CLOCK_MAX_PENDING_TRANSITIONS_MASK) | \
+ (((_clk_count) & SCMI_CLOCK_CLOCK_COUNT_MASK)))
+
+struct scmi_clock_attributes_a2p {
+ uint32_t clock_id;
+};
+
+#define SCMI_CLOCK_NAME_LENGTH_MAX 16U
+
+struct scmi_clock_attributes_p2a {
+ int32_t status;
+ uint32_t attributes;
+ char clock_name[SCMI_CLOCK_NAME_LENGTH_MAX];
+};
+
+/*
+ * Clock Rate Get
+ */
+
+struct scmi_clock_rate_get_a2p {
+ uint32_t clock_id;
+};
+
+struct scmi_clock_rate_get_p2a {
+ int32_t status;
+ uint32_t rate[2];
+};
+
+/*
+ * Clock Rate Set
+ */
+
+/* If set, set the new clock rate asynchronously */
+#define SCMI_CLOCK_RATE_SET_ASYNC_POS 0
+/* If set, do not send a delayed asynchronous response */
+#define SCMI_CLOCK_RATE_SET_NO_DELAYED_RESPONSE_POS 1
+/* Round up, if set, otherwise round down */
+#define SCMI_CLOCK_RATE_SET_ROUND_UP_POS 2
+/* If set, the platform chooses the appropriate rounding mode */
+#define SCMI_CLOCK_RATE_SET_ROUND_AUTO_POS 3
+
+#define SCMI_CLOCK_RATE_SET_ASYNC_MASK \
+ BIT(SCMI_CLOCK_RATE_SET_ASYNC_POS)
+#define SCMI_CLOCK_RATE_SET_NO_DELAYED_RESPONSE_MASK \
+ BIT(SCMI_CLOCK_RATE_SET_NO_DELAYED_RESPONSE_POS)
+#define SCMI_CLOCK_RATE_SET_ROUND_UP_MASK \
+ BIT(SCMI_CLOCK_RATE_SET_ROUND_UP_POS)
+#define SCMI_CLOCK_RATE_SET_ROUND_AUTO_MASK \
+ BIT(SCMI_CLOCK_RATE_SET_ROUND_AUTO_POS)
+
+struct scmi_clock_rate_set_a2p {
+ uint32_t flags;
+ uint32_t clock_id;
+ uint32_t rate[2];
+};
+
+struct scmi_clock_rate_set_p2a {
+ int32_t status;
+};
+
+/*
+ * Clock Config Set
+ */
+
+#define SCMI_CLOCK_CONFIG_SET_ENABLE_POS 0
+
+#define SCMI_CLOCK_CONFIG_SET_ENABLE_MASK \
+ BIT(SCMI_CLOCK_CONFIG_SET_ENABLE_POS)
+
+struct scmi_clock_config_set_a2p {
+ uint32_t clock_id;
+ uint32_t attributes;
+};
+
+struct scmi_clock_config_set_p2a {
+ int32_t status;
+};
+
+/*
+ * Clock Describe Rates
+ */
+
+#define SCMI_CLOCK_RATE_FORMAT_RANGE 1U
+#define SCMI_CLOCK_RATE_FORMAT_LIST 0U
+
+#define SCMI_CLOCK_DESCRIBE_RATES_REMAINING_MASK GENMASK_32(31, 16)
+#define SCMI_CLOCK_DESCRIBE_RATES_REMAINING_POS 16
+
+#define SCMI_CLOCK_DESCRIBE_RATES_FORMAT_MASK BIT(12)
+#define SCMI_CLOCK_DESCRIBE_RATES_FORMAT_POS 12
+
+#define SCMI_CLOCK_DESCRIBE_RATES_COUNT_MASK GENMASK_32(11, 0)
+
+#define SCMI_CLOCK_DESCRIBE_RATES_NUM_RATES_FLAGS(_count, _fmt, _rem_rates) \
+ ( \
+ ((_count) & SCMI_CLOCK_DESCRIBE_RATES_COUNT_MASK) | \
+ (((_rem_rates) << SCMI_CLOCK_DESCRIBE_RATES_REMAINING_POS) & \
+ SCMI_CLOCK_DESCRIBE_RATES_REMAINING_MASK) | \
+ (((_fmt) << SCMI_CLOCK_DESCRIBE_RATES_FORMAT_POS) & \
+ SCMI_CLOCK_DESCRIBE_RATES_FORMAT_MASK) \
+ )
+
+struct scmi_clock_rate {
+ uint32_t low;
+ uint32_t high;
+};
+
+struct scmi_clock_describe_rates_a2p {
+ uint32_t clock_id;
+ uint32_t rate_index;
+};
+
+struct scmi_clock_describe_rates_p2a {
+ int32_t status;
+ uint32_t num_rates_flags;
+ struct scmi_clock_rate rates[];
+};
+
+#endif /* SCMI_MSG_CLOCK_H */
diff --git a/drivers/st/scmi-msg/common.h b/drivers/st/scmi-msg/common.h
index 4777dbe..63b92aa 100644
--- a/drivers/st/scmi-msg/common.h
+++ b/drivers/st/scmi-msg/common.h
@@ -12,6 +12,7 @@
#include <string.h>
#include "base.h"
+#include "clock.h"
#define SCMI_VERSION 0x20000U
#define SCMI_IMPL_VERSION 0U
@@ -95,6 +96,13 @@
scmi_msg_handler_t scmi_msg_get_base_handler(struct scmi_msg *msg);
/*
+ * scmi_msg_get_clock_handler - Return a handler for a clock message
+ * @msg - message to process
+ * Return a function handler for the message or NULL
+ */
+scmi_msg_handler_t scmi_msg_get_clock_handler(struct scmi_msg *msg);
+
+/*
* Process Read, process and write response for input SCMI message
*
* @msg: SCMI message context
diff --git a/drivers/st/scmi-msg/entry.c b/drivers/st/scmi-msg/entry.c
index cd62413..7b06f35 100644
--- a/drivers/st/scmi-msg/entry.c
+++ b/drivers/st/scmi-msg/entry.c
@@ -41,6 +41,9 @@
case SCMI_PROTOCOL_ID_BASE:
handler = scmi_msg_get_base_handler(msg);
break;
+ case SCMI_PROTOCOL_ID_CLOCK:
+ handler = scmi_msg_get_clock_handler(msg);
+ break;
default:
break;
}
diff --git a/include/drivers/st/scmi-msg.h b/include/drivers/st/scmi-msg.h
index af683e2..48fac16 100644
--- a/include/drivers/st/scmi-msg.h
+++ b/include/drivers/st/scmi-msg.h
@@ -62,4 +62,83 @@
/* Get the name of the SCMI sub-vendor for the platform */
const char *plat_scmi_sub_vendor_name(void);
+/* Handlers for SCMI Clock protocol services */
+
+/*
+ * Return number of clock controllers for an agent
+ * @agent_id: SCMI agent ID
+ * Return number of clock controllers
+ */
+size_t plat_scmi_clock_count(unsigned int agent_id);
+
+/*
+ * Get clock controller string ID (aka name)
+ * @agent_id: SCMI agent ID
+ * @scmi_id: SCMI clock ID
+ * Return pointer to name or NULL
+ */
+const char *plat_scmi_clock_get_name(unsigned int agent_id,
+ unsigned int scmi_id);
+
+/*
+ * Get clock possible rate as an array of frequencies in Hertz.
+ *
+ * @agent_id: SCMI agent ID
+ * @scmi_id: SCMI clock ID
+ * @rates: If NULL, function returns, else output rates array
+ * @nb_elts: Array size of @rates.
+ * Return an SCMI compliant error code
+ */
+int32_t plat_scmi_clock_rates_array(unsigned int agent_id, unsigned int scmi_id,
+ unsigned long *rates, size_t *nb_elts);
+
+/*
+ * Get clock possible rate as range with regular steps in Hertz
+ *
+ * @agent_id: SCMI agent ID
+ * @scmi_id: SCMI clock ID
+ * @min_max_step: 3 cell array for min, max and step rate data
+ * Return an SCMI compliant error code
+ */
+int32_t plat_scmi_clock_rates_by_step(unsigned int agent_id,
+ unsigned int scmi_id,
+ unsigned long *min_max_step);
+
+/*
+ * Get clock rate in Hertz
+ * @agent_id: SCMI agent ID
+ * @scmi_id: SCMI clock ID
+ * Return clock rate or 0 if not supported
+ */
+unsigned long plat_scmi_clock_get_rate(unsigned int agent_id,
+ unsigned int scmi_id);
+
+/*
+ * Set clock rate in Hertz
+ * @agent_id: SCMI agent ID
+ * @scmi_id: SCMI clock ID
+ * @rate: Target clock frequency in Hertz
+ * Return a compliant SCMI error code
+ */
+int32_t plat_scmi_clock_set_rate(unsigned int agent_id, unsigned int scmi_id,
+ unsigned long rate);
+
+/*
+ * Get clock state (enabled or disabled)
+ * @agent_id: SCMI agent ID
+ * @scmi_id: SCMI clock ID
+ * Return 1 if clock is enabled, 0 if disables, or a negative SCMI error code
+ */
+int32_t plat_scmi_clock_get_state(unsigned int agent_id, unsigned int scmi_id);
+
+/*
+ * Get clock state (enabled or disabled)
+ * @agent_id: SCMI agent ID
+ * @scmi_id: SCMI clock ID
+ * @enable_not_disable: Enable clock if true, disable clock otherwise
+ * Return a compliant SCMI error code
+ */
+int32_t plat_scmi_clock_set_state(unsigned int agent_id, unsigned int scmi_id,
+ bool enable_not_disable);
+
#endif /* SCMI_MSG_H */