diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index dd3b43885e..61acd8d79f 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -361,6 +361,11 @@
 			compatible = "sandbox,scmi-agent";
 			#address-cells = <1>;
 			#size-cells = <0>;
+
+			clk_scmi0: protocol@14 {
+				reg = <0x14>;
+				#clock-cells = <1>;
+			};
 		};
 
 		sandbox-scmi-agent@1 {
@@ -368,6 +373,11 @@
 			#address-cells = <1>;
 			#size-cells = <0>;
 
+			clk_scmi1: protocol@14 {
+				reg = <0x14>;
+				#clock-cells = <1>;
+			};
+
 			protocol@10 {
 				reg = <0x10>;
 			};
@@ -1052,6 +1062,11 @@
 		compatible = "sandbox,virtio2";
 	};
 
+	sandbox_scmi {
+		compatible = "sandbox,scmi-devices";
+		clocks = <&clk_scmi0 7>, <&clk_scmi0 3>, <&clk_scmi1 1>;
+	};
+
 	pinctrl {
 		compatible = "sandbox,pinctrl";
 
diff --git a/arch/sandbox/include/asm/scmi_test.h b/arch/sandbox/include/asm/scmi_test.h
index a811fe19c3..4e09957bc7 100644
--- a/arch/sandbox/include/asm/scmi_test.h
+++ b/arch/sandbox/include/asm/scmi_test.h
@@ -10,12 +10,28 @@ struct udevice;
 struct sandbox_scmi_agent;
 struct sandbox_scmi_service;
 
+/**
+ * struct sandbox_scmi_clk - Simulated clock exposed by SCMI
+ * @id:		Identifier of the clock used in the SCMI protocol
+ * @enabled:	Clock state: true if enabled, false if disabled
+ * @rate:	Clock rate in Hertz
+ */
+struct sandbox_scmi_clk {
+	uint id;
+	bool enabled;
+	ulong rate;
+};
+
 /**
  * struct sandbox_scmi_agent - Simulated SCMI service seen by SCMI agent
  * @idx:	Identifier for the SCMI agent, its index
+ * @clk:	Simulated clocks
+ * @clk_count:	Simulated clocks array size
  */
 struct sandbox_scmi_agent {
 	uint idx;
+	struct sandbox_scmi_clk *clk;
+	size_t clk_count;
 };
 
 /**
@@ -28,16 +44,37 @@ struct sandbox_scmi_service {
 	size_t agent_count;
 };
 
+/**
+ * struct sandbox_scmi_devices - Reference to devices probed through SCMI
+ * @clk:		Array the clock devices
+ * @clk_count:		Number of clock devices probed
+ */
+struct sandbox_scmi_devices {
+	struct clk *clk;
+	size_t clk_count;
+};
+
 #ifdef CONFIG_SCMI_FIRMWARE
 /**
  * sandbox_scmi_service_context - Get the simulated SCMI services context
  * @return:	Reference to backend simulated resources state
  */
 struct sandbox_scmi_service *sandbox_scmi_service_ctx(void);
+
+/**
+ * sandbox_scmi_devices_get_ref - Get references to devices accessed through SCMI
+ * @return:	Reference to the devices probed by the SCMI test
+ */
+struct sandbox_scmi_devices *sandbox_scmi_devices_ctx(void);
 #else
 static inline struct sandbox_scmi_service *sandbox_scmi_service_ctx(void)
 {
 	return NULL;
 }
+
+static inline struct sandbox_scmi_devices *sandbox_scmi_devices_ctx(void)
+{
+	return NULL;
+}
 #endif /* CONFIG_SCMI_FIRMWARE */
 #endif /* __SANDBOX_SCMI_TEST_H */
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index 2c130c01f0..7d71c805dc 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -122,6 +122,7 @@ CONFIG_BUTTON=y
 CONFIG_BUTTON_GPIO=y
 CONFIG_CLK=y
 CONFIG_CLK_COMPOSITE_CCF=y
+CONFIG_CLK_SCMI=y
 CONFIG_SANDBOX_CLK_CCF=y
 CONFIG_CPU=y
 CONFIG_DM_DEMO=y
diff --git a/drivers/firmware/scmi/Makefile b/drivers/firmware/scmi/Makefile
index 2f782bbd55..e1e0224066 100644
--- a/drivers/firmware/scmi/Makefile
+++ b/drivers/firmware/scmi/Makefile
@@ -2,4 +2,4 @@ obj-y	+= scmi_agent-uclass.o
 obj-y	+= smt.o
 obj-$(CONFIG_ARM_SMCCC) 	+= smccc_agent.o
 obj-$(CONFIG_DM_MAILBOX)	+= mailbox_agent.o
-obj-$(CONFIG_SANDBOX)		+= sandbox-scmi_agent.o
+obj-$(CONFIG_SANDBOX)		+= sandbox-scmi_agent.o sandbox-scmi_devices.o
diff --git a/drivers/firmware/scmi/sandbox-scmi_agent.c b/drivers/firmware/scmi/sandbox-scmi_agent.c
index ce0d49c951..262efbd12c 100644
--- a/drivers/firmware/scmi/sandbox-scmi_agent.c
+++ b/drivers/firmware/scmi/sandbox-scmi_agent.c
@@ -16,18 +16,34 @@
 /*
  * The sandbox SCMI agent driver simulates to some extend a SCMI message
  * processing. It simulates few of the SCMI services for some of the
- * SCMI protocols embedded in U-Boot. Currently none.
+ * SCMI protocols embedded in U-Boot. Currently:
+ * - SCMI clock protocol: emulate 2 agents each exposing few clocks
  *
- * This driver simulates 2 SCMI agents for test purpose.
+ * Agent #0 simulates 2 clocks.
+ * See IDs in scmi0_clk[] and "sandbox-scmi-agent@0" in test.dts.
+ *
+ * Agent #1 simulates 1 clock.
+ * See IDs in scmi1_clk[] and "sandbox-scmi-agent@1" in test.dts.
+ *
+ * All clocks are default disabled.
  *
  * This Driver exports sandbox_scmi_service_ct() for the test sequence to
  * get the state of the simulated services (clock state, rate, ...) and
  * check back-end device state reflects the request send through the
- * various uclass devices, currently nothing.
+ * various uclass devices, currently only clock controllers.
  */
 
 #define SANDBOX_SCMI_AGENT_COUNT	2
 
+static struct sandbox_scmi_clk scmi0_clk[] = {
+	{ .id = 7, .rate = 1000 },
+	{ .id = 3, .rate = 333 },
+};
+
+static struct sandbox_scmi_clk scmi1_clk[] = {
+	{ .id = 1, .rate = 44 },
+};
+
 /* The list saves to simulted end devices references for test purpose */
 struct sandbox_scmi_agent *sandbox_scmi_agent_list[SANDBOX_SCMI_AGENT_COUNT];
 
@@ -51,17 +67,158 @@ static void debug_print_agent_state(struct udevice *dev, char *str)
 	struct sandbox_scmi_agent *agent = dev2agent(dev);
 
 	dev_dbg(dev, "Dump sandbox_scmi_agent %u: %s\n", agent->idx, str);
+	dev_dbg(dev, " scmi%u_clk   (%zu): %d/%ld, %d/%ld, %d/%ld, ...\n",
+		agent->idx,
+		agent->clk_count,
+		agent->clk_count ? agent->clk[0].enabled : -1,
+		agent->clk_count ? agent->clk[0].rate : -1,
+		agent->clk_count > 1 ? agent->clk[1].enabled : -1,
+		agent->clk_count > 1 ? agent->clk[1].rate : -1,
+		agent->clk_count > 2 ? agent->clk[2].enabled : -1,
+		agent->clk_count > 2 ? agent->clk[2].rate : -1);
 };
 
+static struct sandbox_scmi_clk *get_scmi_clk_state(uint agent_id, uint clock_id)
+{
+	struct sandbox_scmi_clk *target = NULL;
+	size_t target_count = 0;
+	size_t n;
+
+	switch (agent_id) {
+	case 0:
+		target = scmi0_clk;
+		target_count = ARRAY_SIZE(scmi0_clk);
+		break;
+	case 1:
+		target = scmi1_clk;
+		target_count = ARRAY_SIZE(scmi1_clk);
+		break;
+	default:
+		return NULL;
+	}
+
+	for (n = 0; n < target_count; n++)
+		if (target[n].id == clock_id)
+			return target + n;
+
+	return NULL;
+}
+
+/*
+ * Sandbox SCMI agent ops
+ */
+
+static int sandbox_scmi_clock_rate_set(struct udevice *dev,
+				       struct scmi_msg *msg)
+{
+	struct sandbox_scmi_agent *agent = dev2agent(dev);
+	struct scmi_clk_rate_set_in *in = NULL;
+	struct scmi_clk_rate_set_out *out = NULL;
+	struct sandbox_scmi_clk *clk_state = NULL;
+
+	if (!msg->in_msg || msg->in_msg_sz < sizeof(*in) ||
+	    !msg->out_msg || msg->out_msg_sz < sizeof(*out))
+		return -EINVAL;
+
+	in = (struct scmi_clk_rate_set_in *)msg->in_msg;
+	out = (struct scmi_clk_rate_set_out *)msg->out_msg;
+
+	clk_state = get_scmi_clk_state(agent->idx, in->clock_id);
+	if (!clk_state) {
+		dev_err(dev, "Unexpected clock ID %u\n", in->clock_id);
+
+		out->status = SCMI_NOT_FOUND;
+	} else {
+		u64 rate = ((u64)in->rate_msb << 32) + in->rate_lsb;
+
+		clk_state->rate = (ulong)rate;
+
+		out->status = SCMI_SUCCESS;
+	}
+
+	return 0;
+}
+
+static int sandbox_scmi_clock_rate_get(struct udevice *dev,
+				       struct scmi_msg *msg)
+{
+	struct sandbox_scmi_agent *agent = dev2agent(dev);
+	struct scmi_clk_rate_get_in *in = NULL;
+	struct scmi_clk_rate_get_out *out = NULL;
+	struct sandbox_scmi_clk *clk_state = NULL;
+
+	if (!msg->in_msg || msg->in_msg_sz < sizeof(*in) ||
+	    !msg->out_msg || msg->out_msg_sz < sizeof(*out))
+		return -EINVAL;
+
+	in = (struct scmi_clk_rate_get_in *)msg->in_msg;
+	out = (struct scmi_clk_rate_get_out *)msg->out_msg;
+
+	clk_state = get_scmi_clk_state(agent->idx, in->clock_id);
+	if (!clk_state) {
+		dev_err(dev, "Unexpected clock ID %u\n", in->clock_id);
+
+		out->status = SCMI_NOT_FOUND;
+	} else {
+		out->rate_msb = (u32)((u64)clk_state->rate >> 32);
+		out->rate_lsb = (u32)clk_state->rate;
+
+		out->status = SCMI_SUCCESS;
+	}
+
+	return 0;
+}
+
+static int sandbox_scmi_clock_gate(struct udevice *dev, struct scmi_msg *msg)
+{
+	struct sandbox_scmi_agent *agent = dev2agent(dev);
+	struct scmi_clk_state_in *in = NULL;
+	struct scmi_clk_state_out *out = NULL;
+	struct sandbox_scmi_clk *clk_state = NULL;
+
+	if (!msg->in_msg || msg->in_msg_sz < sizeof(*in) ||
+	    !msg->out_msg || msg->out_msg_sz < sizeof(*out))
+		return -EINVAL;
+
+	in = (struct scmi_clk_state_in *)msg->in_msg;
+	out = (struct scmi_clk_state_out *)msg->out_msg;
+
+	clk_state = get_scmi_clk_state(agent->idx, in->clock_id);
+	if (!clk_state) {
+		dev_err(dev, "Unexpected clock ID %u\n", in->clock_id);
+
+		out->status = SCMI_NOT_FOUND;
+	} else if (in->attributes > 1) {
+		out->status = SCMI_PROTOCOL_ERROR;
+	} else {
+		clk_state->enabled = in->attributes;
+
+		out->status = SCMI_SUCCESS;
+	}
+
+	return 0;
+}
+
 static int sandbox_scmi_test_process_msg(struct udevice *dev,
 					 struct scmi_msg *msg)
 {
 	switch (msg->protocol_id) {
+	case SCMI_PROTOCOL_ID_CLOCK:
+		switch (msg->message_id) {
+		case SCMI_CLOCK_RATE_SET:
+			return sandbox_scmi_clock_rate_set(dev, msg);
+		case SCMI_CLOCK_RATE_GET:
+			return sandbox_scmi_clock_rate_get(dev, msg);
+		case SCMI_CLOCK_CONFIG_SET:
+			return sandbox_scmi_clock_gate(dev, msg);
+		default:
+			break;
+		}
+		break;
 	case SCMI_PROTOCOL_ID_BASE:
 	case SCMI_PROTOCOL_ID_POWER_DOMAIN:
 	case SCMI_PROTOCOL_ID_SYSTEM:
 	case SCMI_PROTOCOL_ID_PERF:
-	case SCMI_PROTOCOL_ID_CLOCK:
 	case SCMI_PROTOCOL_ID_SENSOR:
 	case SCMI_PROTOCOL_ID_RESET_DOMAIN:
 		*(u32 *)msg->out_msg = SCMI_NOT_SUPPORTED;
@@ -106,11 +263,15 @@ static int sandbox_scmi_test_probe(struct udevice *dev)
 	case '0':
 		*agent = (struct sandbox_scmi_agent){
 			.idx = 0,
+			.clk = scmi0_clk,
+			.clk_count = ARRAY_SIZE(scmi0_clk),
 		};
 		break;
 	case '1':
 		*agent = (struct sandbox_scmi_agent){
 			.idx = 1,
+			.clk = scmi1_clk,
+			.clk_count = ARRAY_SIZE(scmi1_clk),
 		};
 		break;
 	default:
diff --git a/drivers/firmware/scmi/sandbox-scmi_devices.c b/drivers/firmware/scmi/sandbox-scmi_devices.c
new file mode 100644
index 0000000000..2ce8e664df
--- /dev/null
+++ b/drivers/firmware/scmi/sandbox-scmi_devices.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020, Linaro Limited
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/scmi_test.h>
+#include <dm/device_compat.h>
+
+/*
+ * Simulate to some extend a SCMI exhange.
+ * This drivers gets SCMI resources and offers API function to the
+ * SCMI test sequence manipulate the resources.
+ */
+
+#define SCMI_TEST_DEVICES_CLK_COUNT		3
+
+/*
+ * These tables store de handles used in the various uclasses device function
+ * that are instancied when probed through the SCMI agent. Use a static
+ * memory allocation to ease sharing with test sequence implementation.
+ */
+static struct clk sandbox_scmi_clk_device[SCMI_TEST_DEVICES_CLK_COUNT];
+static struct sandbox_scmi_devices sandbox_scmi_devhld;
+
+struct sandbox_scmi_devices *sandbox_scmi_devices_ctx(void)
+{
+	return &sandbox_scmi_devhld;
+}
+
+static void dereference_device_handles(struct sandbox_scmi_devices *devices)
+{
+	devices->clk = NULL;
+	devices->clk_count = 0;
+}
+
+static int sandbox_scmi_devices_remove(struct udevice *dev)
+{
+	struct sandbox_scmi_devices *devices = sandbox_scmi_devices_ctx();
+
+	dereference_device_handles(devices);
+
+	return 0;
+}
+
+static int sandbox_scmi_devices_probe(struct udevice *dev)
+{
+	struct sandbox_scmi_devices *devices = sandbox_scmi_devices_ctx();
+	int rc;
+	size_t n;
+
+	devices->clk = sandbox_scmi_clk_device;
+	devices->clk_count = SCMI_TEST_DEVICES_CLK_COUNT;
+
+	for (n = 0; n < SCMI_TEST_DEVICES_CLK_COUNT; n++) {
+		rc = clk_get_by_index(dev, n, devices->clk + n);
+		if (rc) {
+			dev_err(dev, "%s: Failed on clk %zu\n", __func__, n);
+			goto err_clk;
+		}
+	}
+
+	return 0;
+
+err_clk:
+	dereference_device_handles(devices);
+
+	return rc;
+}
+
+static const struct udevice_id sandbox_scmi_devices_ids[] = {
+	{ .compatible = "sandbox,scmi-devices" },
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_scmi_devices) = {
+	.name = "sandbox-scmi_devices",
+	.id = UCLASS_MISC,
+	.of_match = sandbox_scmi_devices_ids,
+	.remove = sandbox_scmi_devices_remove,
+	.probe = sandbox_scmi_devices_probe,
+};
diff --git a/test/dm/scmi.c b/test/dm/scmi.c
index d8c1e71f12..e652dbf52b 100644
--- a/test/dm/scmi.c
+++ b/test/dm/scmi.c
@@ -13,26 +13,153 @@
  */
 
 #include <common.h>
+#include <clk.h>
 #include <dm.h>
 #include <asm/scmi_test.h>
 #include <dm/device-internal.h>
 #include <dm/test.h>
+#include <linux/kconfig.h>
 #include <test/ut.h>
 
+static int ut_assert_scmi_state_preprobe(struct unit_test_state *uts)
+{
+	struct sandbox_scmi_devices *scmi_devices = sandbox_scmi_devices_ctx();
+	struct sandbox_scmi_service *scmi_ctx = sandbox_scmi_service_ctx();
+
+	ut_assertnonnull(scmi_ctx);
+
+	if (scmi_ctx->agent_count)
+		ut_asserteq(2, scmi_ctx->agent_count);
+
+	ut_assertnonnull(scmi_devices);
+
+	if (scmi_devices->clk_count)
+		ut_asserteq(3, scmi_devices->clk_count);
+
+	return 0;
+}
+
+static int ut_assert_scmi_state_postprobe(struct unit_test_state *uts)
+{
+	struct sandbox_scmi_devices *scmi_devices = sandbox_scmi_devices_ctx();
+	struct sandbox_scmi_service *scmi_ctx = sandbox_scmi_service_ctx();
+
+	/* Device references to check context against test sequence */
+	ut_assertnonnull(scmi_devices);
+	if (IS_ENABLED(CONFIG_CLK_SCMI))
+		ut_asserteq(3, scmi_devices->clk_count);
+
+	/* State of the simulated SCMI server exposed */
+	ut_asserteq(2, scmi_ctx->agent_count);
+
+	ut_assertnonnull(scmi_ctx->agent[0]);
+	ut_asserteq(2, scmi_ctx->agent[0]->clk_count);
+	ut_assertnonnull(scmi_ctx->agent[0]->clk);
+
+	ut_assertnonnull(scmi_ctx->agent[1]);
+	ut_assertnonnull(scmi_ctx->agent[1]->clk);
+	ut_asserteq(1, scmi_ctx->agent[1]->clk_count);
+
+	return 0;
+}
+
+static int load_sandbox_scmi_test_devices(struct unit_test_state *uts,
+					  struct udevice **dev)
+{
+	int rc;
+
+	rc = ut_assert_scmi_state_preprobe(uts);
+	if (rc)
+		return rc;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_MISC, "sandbox_scmi",
+					      dev));
+
+	return ut_assert_scmi_state_postprobe(uts);
+}
+
+static int release_sandbox_scmi_test_devices(struct unit_test_state *uts,
+					     struct udevice *dev)
+{
+	ut_assertok(device_remove(dev, DM_REMOVE_NORMAL));
+
+	/* Not sure test devices are fully removed, agent may not be visible */
+	return 0;
+}
+
 /*
  * Test SCMI states when loading and releasing resources
  * related to SCMI drivers.
  */
 static int dm_test_scmi_sandbox_agent(struct unit_test_state *uts)
 {
-	struct sandbox_scmi_service *scmi_ctx = sandbox_scmi_service_ctx();
+	struct udevice *dev = NULL;
+	int rc;
 
-	ut_assertnonnull(scmi_ctx);
-	ut_asserteq(2, scmi_ctx->agent_count);
-	ut_assertnull(scmi_ctx->agent[0]);
-	ut_assertnull(scmi_ctx->agent[1]);
+	rc = load_sandbox_scmi_test_devices(uts, &dev);
+	if (!rc)
+		rc = release_sandbox_scmi_test_devices(uts, dev);
 
-	return 0;
+	return rc;
 }
 
 DM_TEST(dm_test_scmi_sandbox_agent, UT_TESTF_SCAN_FDT);
+
+static int dm_test_scmi_clocks(struct unit_test_state *uts)
+{
+	struct sandbox_scmi_devices *scmi_devices = sandbox_scmi_devices_ctx();
+	struct sandbox_scmi_service *scmi_ctx = sandbox_scmi_service_ctx();
+	struct udevice *dev = NULL;
+	int rc_dev;
+	int rc;
+
+	if (!IS_ENABLED(CONFIG_CLK_SCMI))
+		return 0;
+
+	rc = load_sandbox_scmi_test_devices(uts, &dev);
+	if (rc)
+		return rc;
+
+	/* Test SCMI clocks rate manipulation */
+	ut_asserteq(1000, clk_get_rate(&scmi_devices->clk[0]));
+	ut_asserteq(333, clk_get_rate(&scmi_devices->clk[1]));
+	ut_asserteq(44, clk_get_rate(&scmi_devices->clk[2]));
+
+	rc_dev = clk_set_rate(&scmi_devices->clk[1], 1088);
+	ut_assert(!rc_dev || rc_dev == 1088);
+
+	ut_asserteq(1000, scmi_ctx->agent[0]->clk[0].rate);
+	ut_asserteq(1088, scmi_ctx->agent[0]->clk[1].rate);
+	ut_asserteq(44, scmi_ctx->agent[1]->clk[0].rate);
+
+	ut_asserteq(1000, clk_get_rate(&scmi_devices->clk[0]));
+	ut_asserteq(1088, clk_get_rate(&scmi_devices->clk[1]));
+	ut_asserteq(44, clk_get_rate(&scmi_devices->clk[2]));
+
+	/* restore original rate for further tests */
+	rc_dev = clk_set_rate(&scmi_devices->clk[1], 333);
+	ut_assert(!rc_dev || rc_dev == 333);
+
+	/* Test SCMI clocks gating manipulation */
+	ut_assert(!scmi_ctx->agent[0]->clk[0].enabled);
+	ut_assert(!scmi_ctx->agent[0]->clk[1].enabled);
+	ut_assert(!scmi_ctx->agent[1]->clk[0].enabled);
+
+	ut_asserteq(0, clk_enable(&scmi_devices->clk[1]));
+	ut_asserteq(0, clk_enable(&scmi_devices->clk[2]));
+
+	ut_assert(!scmi_ctx->agent[0]->clk[0].enabled);
+	ut_assert(scmi_ctx->agent[0]->clk[1].enabled);
+	ut_assert(scmi_ctx->agent[1]->clk[0].enabled);
+
+	ut_assertok(clk_disable(&scmi_devices->clk[1]));
+	ut_assertok(clk_disable(&scmi_devices->clk[2]));
+
+	ut_assert(!scmi_ctx->agent[0]->clk[0].enabled);
+	ut_assert(!scmi_ctx->agent[0]->clk[1].enabled);
+	ut_assert(!scmi_ctx->agent[1]->clk[0].enabled);
+
+	return release_sandbox_scmi_test_devices(uts, dev);
+}
+
+DM_TEST(dm_test_scmi_clocks, UT_TESTF_SCAN_FDT);
