7 files changed, 704 insertions, 0 deletions

diff --git a/drivers/arm/css/scmi/scmi_ap_core_proto.c b/drivers/arm/css/scmi/scmi_ap_core_proto.c
new file mode 100644
index 0000000..5941b87
--- /dev/null
+++ b/drivers/arm/css/scmi/scmi_ap_core_proto.c
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <arch_helpers.h>
+#include <common/debug.h>
+#include <drivers/arm/css/scmi.h>
+
+#include "scmi_private.h"
+
+/*
+ * API to set the SCMI AP core reset address and attributes
+ */
+int scmi_ap_core_set_reset_addr(void *p, uint64_t reset_addr, uint32_t attr)
+{
+	mailbox_mem_t *mbx_mem;
+	unsigned int token = 0;
+	int ret;
+	scmi_channel_t *ch = (scmi_channel_t *)p;
+
+	validate_scmi_channel(ch);
+
+	scmi_get_channel(ch);
+
+	mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
+	mbx_mem->msg_header = SCMI_MSG_CREATE(SCMI_AP_CORE_PROTO_ID,
+			SCMI_AP_CORE_RESET_ADDR_SET_MSG, token);
+	mbx_mem->len = SCMI_AP_CORE_RESET_ADDR_SET_MSG_LEN;
+	mbx_mem->flags = SCMI_FLAG_RESP_POLL;
+	SCMI_PAYLOAD_ARG3(mbx_mem->payload, reset_addr & 0xffffffff,
+		reset_addr >> 32, attr);
+
+	scmi_send_sync_command(ch);
+
+	/* Get the return values */
+	SCMI_PAYLOAD_RET_VAL1(mbx_mem->payload, ret);
+	assert(mbx_mem->len == SCMI_AP_CORE_RESET_ADDR_SET_RESP_LEN);
+	assert(token == SCMI_MSG_GET_TOKEN(mbx_mem->msg_header));
+
+	scmi_put_channel(ch);
+
+	return ret;
+}
+
+/*
+ * API to get the SCMI AP core reset address and attributes
+ */
+int scmi_ap_core_get_reset_addr(void *p, uint64_t *reset_addr, uint32_t *attr)
+{
+	mailbox_mem_t *mbx_mem;
+	unsigned int token = 0;
+	int ret;
+	scmi_channel_t *ch = (scmi_channel_t *)p;
+	uint32_t lo_addr, hi_addr;
+
+	validate_scmi_channel(ch);
+
+	scmi_get_channel(ch);
+
+	mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
+	mbx_mem->msg_header = SCMI_MSG_CREATE(SCMI_AP_CORE_PROTO_ID,
+			SCMI_AP_CORE_RESET_ADDR_GET_MSG, token);
+	mbx_mem->len = SCMI_AP_CORE_RESET_ADDR_GET_MSG_LEN;
+	mbx_mem->flags = SCMI_FLAG_RESP_POLL;
+
+	scmi_send_sync_command(ch);
+
+	/* Get the return values */
+	SCMI_PAYLOAD_RET_VAL4(mbx_mem->payload, ret, lo_addr, hi_addr, *attr);
+	*reset_addr = lo_addr | (uint64_t)hi_addr << 32;
+	assert(mbx_mem->len == SCMI_AP_CORE_RESET_ADDR_GET_RESP_LEN);
+	assert(token == SCMI_MSG_GET_TOKEN(mbx_mem->msg_header));
+
+	scmi_put_channel(ch);
+
+	return ret;
+}
diff --git a/drivers/arm/css/scmi/scmi_common.c b/drivers/arm/css/scmi/scmi_common.c
new file mode 100644
index 0000000..ec749fb
--- /dev/null
+++ b/drivers/arm/css/scmi/scmi_common.c
@@ -0,0 +1,210 @@
+/*
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <arch_helpers.h>
+#include <common/debug.h>
+#include <drivers/arm/css/scmi.h>
+
+#include "scmi_private.h"
+
+#if HW_ASSISTED_COHERENCY
+#define scmi_lock_init(lock)
+#define scmi_lock_get(lock)		spin_lock(lock)
+#define scmi_lock_release(lock)		spin_unlock(lock)
+#else
+#define scmi_lock_init(lock)		bakery_lock_init(lock)
+#define scmi_lock_get(lock)		bakery_lock_get(lock)
+#define scmi_lock_release(lock)		bakery_lock_release(lock)
+#endif
+
+
+/*
+ * Private helper function to get exclusive access to SCMI channel.
+ */
+void scmi_get_channel(scmi_channel_t *ch)
+{
+	assert(ch->lock);
+	scmi_lock_get(ch->lock);
+
+	/* Make sure any previous command has finished */
+	assert(SCMI_IS_CHANNEL_FREE(
+			((mailbox_mem_t *)(ch->info->scmi_mbx_mem))->status));
+}
+
+/*
+ * Private helper function to transfer ownership of channel from AP to SCP.
+ */
+void scmi_send_sync_command(scmi_channel_t *ch)
+{
+	mailbox_mem_t *mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
+
+	SCMI_MARK_CHANNEL_BUSY(mbx_mem->status);
+
+	/*
+	 * Ensure that any write to the SCMI payload area is seen by SCP before
+	 * we write to the doorbell register. If these 2 writes were reordered
+	 * by the CPU then SCP would read stale payload data
+	 */
+	dmbst();
+
+	ch->info->ring_doorbell(ch->info);
+	/*
+	 * Ensure that the write to the doorbell register is ordered prior to
+	 * checking whether the channel is free.
+	 */
+	dmbsy();
+
+	/* Wait for channel to be free */
+	while (!SCMI_IS_CHANNEL_FREE(mbx_mem->status))
+		;
+
+	/*
+	 * Ensure that any read to the SCMI payload area is done after reading
+	 * mailbox status. If these 2 reads were reordered then the CPU would
+	 * read invalid payload data
+	 */
+	dmbld();
+}
+
+/*
+ * Private helper function to release exclusive access to SCMI channel.
+ */
+void scmi_put_channel(scmi_channel_t *ch)
+{
+	/* Make sure any previous command has finished */
+	assert(SCMI_IS_CHANNEL_FREE(
+			((mailbox_mem_t *)(ch->info->scmi_mbx_mem))->status));
+
+	assert(ch->lock);
+	scmi_lock_release(ch->lock);
+}
+
+/*
+ * API to query the SCMI protocol version.
+ */
+int scmi_proto_version(void *p, uint32_t proto_id, uint32_t *version)
+{
+	mailbox_mem_t *mbx_mem;
+	unsigned int token = 0;
+	int ret;
+	scmi_channel_t *ch = (scmi_channel_t *)p;
+
+	validate_scmi_channel(ch);
+
+	scmi_get_channel(ch);
+
+	mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
+	mbx_mem->msg_header = SCMI_MSG_CREATE(proto_id, SCMI_PROTO_VERSION_MSG,
+							token);
+	mbx_mem->len = SCMI_PROTO_VERSION_MSG_LEN;
+	mbx_mem->flags = SCMI_FLAG_RESP_POLL;
+
+	scmi_send_sync_command(ch);
+
+	/* Get the return values */
+	SCMI_PAYLOAD_RET_VAL2(mbx_mem->payload, ret, *version);
+	assert(mbx_mem->len == SCMI_PROTO_VERSION_RESP_LEN);
+	assert(token == SCMI_MSG_GET_TOKEN(mbx_mem->msg_header));
+
+	scmi_put_channel(ch);
+
+	return ret;
+}
+
+/*
+ * API to query the protocol message attributes for a SCMI protocol.
+ */
+int scmi_proto_msg_attr(void *p, uint32_t proto_id,
+		uint32_t command_id, uint32_t *attr)
+{
+	mailbox_mem_t *mbx_mem;
+	unsigned int token = 0;
+	int ret;
+	scmi_channel_t *ch = (scmi_channel_t *)p;
+
+	validate_scmi_channel(ch);
+
+	scmi_get_channel(ch);
+
+	mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
+	mbx_mem->msg_header = SCMI_MSG_CREATE(proto_id,
+				SCMI_PROTO_MSG_ATTR_MSG, token);
+	mbx_mem->len = SCMI_PROTO_MSG_ATTR_MSG_LEN;
+	mbx_mem->flags = SCMI_FLAG_RESP_POLL;
+	SCMI_PAYLOAD_ARG1(mbx_mem->payload, command_id);
+
+	scmi_send_sync_command(ch);
+
+	/* Get the return values */
+	SCMI_PAYLOAD_RET_VAL2(mbx_mem->payload, ret, *attr);
+	assert(mbx_mem->len == SCMI_PROTO_MSG_ATTR_RESP_LEN);
+	assert(token == SCMI_MSG_GET_TOKEN(mbx_mem->msg_header));
+
+	scmi_put_channel(ch);
+
+	return ret;
+}
+
+/*
+ * SCMI Driver initialization API. Returns initialized channel on success
+ * or NULL on error. The return type is an opaque void pointer.
+ */
+void *scmi_init(scmi_channel_t *ch)
+{
+	uint32_t version;
+	int ret;
+
+	assert(ch && ch->info);
+	assert(ch->info->db_reg_addr);
+	assert(ch->info->db_modify_mask);
+	assert(ch->info->db_preserve_mask);
+	assert(ch->info->ring_doorbell != NULL);
+
+	assert(ch->lock);
+
+	scmi_lock_init(ch->lock);
+
+	ch->is_initialized = 1;
+
+	ret = scmi_proto_version(ch, SCMI_PWR_DMN_PROTO_ID, &version);
+	if (ret != SCMI_E_SUCCESS) {
+		WARN("SCMI power domain protocol version message failed\n");
+		goto error;
+	}
+
+	if (!is_scmi_version_compatible(SCMI_PWR_DMN_PROTO_VER, version)) {
+		WARN("SCMI power domain protocol version 0x%x incompatible with driver version 0x%x\n",
+			version, SCMI_PWR_DMN_PROTO_VER);
+		goto error;
+	}
+
+	VERBOSE("SCMI power domain protocol version 0x%x detected\n", version);
+
+	ret = scmi_proto_version(ch, SCMI_SYS_PWR_PROTO_ID, &version);
+	if ((ret != SCMI_E_SUCCESS)) {
+		WARN("SCMI system power protocol version message failed\n");
+		goto error;
+	}
+
+	if (!is_scmi_version_compatible(SCMI_SYS_PWR_PROTO_VER, version)) {
+		WARN("SCMI system power management protocol version 0x%x incompatible with driver version 0x%x\n",
+			version, SCMI_SYS_PWR_PROTO_VER);
+		goto error;
+	}
+
+	VERBOSE("SCMI system power management protocol version 0x%x detected\n",
+						version);
+
+	INFO("SCMI driver initialized\n");
+
+	return (void *)ch;
+
+error:
+	ch->is_initialized = 0;
+	return NULL;
+}
diff --git a/drivers/arm/css/scmi/scmi_private.h b/drivers/arm/css/scmi/scmi_private.h
new file mode 100644
index 0000000..a684ca5
--- /dev/null
+++ b/drivers/arm/css/scmi/scmi_private.h
@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef SCMI_PRIVATE_H
+#define SCMI_PRIVATE_H
+
+#include <lib/mmio.h>
+
+/*
+ * SCMI power domain management protocol message and response lengths. It is
+ * calculated as sum of length in bytes of the message header (4) and payload
+ * area (the number of bytes of parameters or return values in the payload).
+ */
+#define SCMI_PROTO_VERSION_MSG_LEN		4
+#define SCMI_PROTO_VERSION_RESP_LEN		12
+
+#define SCMI_PROTO_MSG_ATTR_MSG_LEN		8
+#define SCMI_PROTO_MSG_ATTR_RESP_LEN		12
+
+#define SCMI_AP_CORE_RESET_ADDR_SET_MSG_LEN	16
+#define SCMI_AP_CORE_RESET_ADDR_SET_RESP_LEN	8
+
+#define SCMI_AP_CORE_RESET_ADDR_GET_MSG_LEN	4
+#define SCMI_AP_CORE_RESET_ADDR_GET_RESP_LEN	20
+
+#define SCMI_PWR_STATE_SET_MSG_LEN		16
+#define SCMI_PWR_STATE_SET_RESP_LEN		8
+
+#define SCMI_PWR_STATE_GET_MSG_LEN		8
+#define SCMI_PWR_STATE_GET_RESP_LEN		12
+
+#define SCMI_SYS_PWR_STATE_SET_MSG_LEN		12
+#define SCMI_SYS_PWR_STATE_SET_RESP_LEN		8
+
+#define SCMI_SYS_PWR_STATE_GET_MSG_LEN		4
+#define SCMI_SYS_PWR_STATE_GET_RESP_LEN		12
+
+/* SCMI message header format bit field */
+#define SCMI_MSG_ID_SHIFT		0
+#define SCMI_MSG_ID_WIDTH		8
+#define SCMI_MSG_ID_MASK		((1 << SCMI_MSG_ID_WIDTH) - 1)
+
+#define SCMI_MSG_TYPE_SHIFT		8
+#define SCMI_MSG_TYPE_WIDTH		2
+#define SCMI_MSG_TYPE_MASK		((1 << SCMI_MSG_TYPE_WIDTH) - 1)
+
+#define SCMI_MSG_PROTO_ID_SHIFT		10
+#define SCMI_MSG_PROTO_ID_WIDTH		8
+#define SCMI_MSG_PROTO_ID_MASK		((1 << SCMI_MSG_PROTO_ID_WIDTH) - 1)
+
+#define SCMI_MSG_TOKEN_SHIFT		18
+#define SCMI_MSG_TOKEN_WIDTH		10
+#define SCMI_MSG_TOKEN_MASK		((1 << SCMI_MSG_TOKEN_WIDTH) - 1)
+
+
+/* SCMI mailbox flags */
+#define SCMI_FLAG_RESP_POLL	0
+#define SCMI_FLAG_RESP_INT	1
+
+/* SCMI power domain protocol `POWER_STATE_SET` message flags */
+#define SCMI_PWR_STATE_SET_FLAG_SYNC	0
+#define SCMI_PWR_STATE_SET_FLAG_ASYNC	1
+
+/*
+ * Helper macro to create an SCMI message header given protocol, message id
+ * and token.
+ */
+#define SCMI_MSG_CREATE(_protocol, _msg_id, _token)				\
+	((((_protocol) & SCMI_MSG_PROTO_ID_MASK) << SCMI_MSG_PROTO_ID_SHIFT) |	\
+	(((_msg_id) & SCMI_MSG_ID_MASK) << SCMI_MSG_ID_SHIFT) |			\
+	(((_token) & SCMI_MSG_TOKEN_MASK) << SCMI_MSG_TOKEN_SHIFT))
+
+/* Helper macro to get the token from a SCMI message header */
+#define SCMI_MSG_GET_TOKEN(_msg)				\
+	(((_msg) >> SCMI_MSG_TOKEN_SHIFT) & SCMI_MSG_TOKEN_MASK)
+
+/* SCMI Channel Status bit fields */
+#define SCMI_CH_STATUS_RES0_MASK	0xFFFFFFFE
+#define SCMI_CH_STATUS_FREE_SHIFT	0
+#define SCMI_CH_STATUS_FREE_WIDTH	1
+#define SCMI_CH_STATUS_FREE_MASK	((1 << SCMI_CH_STATUS_FREE_WIDTH) - 1)
+
+/* Helper macros to check and write the channel status */
+#define SCMI_IS_CHANNEL_FREE(status)					\
+	(!!(((status) >> SCMI_CH_STATUS_FREE_SHIFT) & SCMI_CH_STATUS_FREE_MASK))
+
+#define SCMI_MARK_CHANNEL_BUSY(status)	do {				\
+		assert(SCMI_IS_CHANNEL_FREE(status));			\
+		(status) &= ~(SCMI_CH_STATUS_FREE_MASK <<		\
+				SCMI_CH_STATUS_FREE_SHIFT);		\
+	} while (0)
+
+/* Helper macros to copy arguments to the mailbox payload */
+#define SCMI_PAYLOAD_ARG1(payld_arr, arg1)				\
+		mmio_write_32((uintptr_t)&payld_arr[0], arg1)
+
+#define SCMI_PAYLOAD_ARG2(payld_arr, arg1, arg2)	do {		\
+		SCMI_PAYLOAD_ARG1(payld_arr, arg1);			\
+		mmio_write_32((uintptr_t)&payld_arr[1], arg2);		\
+	} while (0)
+
+#define SCMI_PAYLOAD_ARG3(payld_arr, arg1, arg2, arg3)	do {		\
+		SCMI_PAYLOAD_ARG2(payld_arr, arg1, arg2);		\
+		mmio_write_32((uintptr_t)&payld_arr[2], arg3);		\
+	} while (0)
+
+/* Helper macros to read return values from the mailbox payload */
+#define SCMI_PAYLOAD_RET_VAL1(payld_arr, val1)				\
+		(val1) = mmio_read_32((uintptr_t)&payld_arr[0])
+
+#define SCMI_PAYLOAD_RET_VAL2(payld_arr, val1, val2)	do {		\
+		SCMI_PAYLOAD_RET_VAL1(payld_arr, val1);			\
+		(val2) = mmio_read_32((uintptr_t)&payld_arr[1]);	\
+	} while (0)
+
+#define SCMI_PAYLOAD_RET_VAL3(payld_arr, val1, val2, val3)	do {	\
+		SCMI_PAYLOAD_RET_VAL2(payld_arr, val1, val2);		\
+		(val3) = mmio_read_32((uintptr_t)&payld_arr[2]);	\
+	} while (0)
+
+#define SCMI_PAYLOAD_RET_VAL4(payld_arr, val1, val2, val3, val4)	do {	\
+		SCMI_PAYLOAD_RET_VAL3(payld_arr, val1, val2, val3);		\
+		(val4) = mmio_read_32((uintptr_t)&payld_arr[3]);		\
+	} while (0)
+
+/*
+ * Private data structure for representing the mailbox memory layout. Refer
+ * the SCMI specification for more details.
+ */
+typedef struct mailbox_mem {
+	uint32_t res_a; /* Reserved */
+	volatile uint32_t status;
+	uint64_t res_b; /* Reserved */
+	uint32_t flags;
+	volatile uint32_t len;
+	volatile uint32_t msg_header;
+	uint32_t payload[];
+} mailbox_mem_t;
+
+
+/* Private APIs for use within SCMI driver */
+void scmi_get_channel(scmi_channel_t *ch);
+void scmi_send_sync_command(scmi_channel_t *ch);
+void scmi_put_channel(scmi_channel_t *ch);
+
+static inline void validate_scmi_channel(scmi_channel_t *ch)
+{
+	assert(ch && ch->is_initialized);
+	assert(ch->info && ch->info->scmi_mbx_mem);
+}
+
+/*
+ * SCMI vendor specific protocol
+ */
+#define SCMI_SYS_VENDOR_EXT_PROTO_ID		0x80
+
+#endif /* SCMI_PRIVATE_H */
diff --git a/drivers/arm/css/scmi/scmi_pwr_dmn_proto.c b/drivers/arm/css/scmi/scmi_pwr_dmn_proto.c
new file mode 100644
index 0000000..a342aa8
--- /dev/null
+++ b/drivers/arm/css/scmi/scmi_pwr_dmn_proto.c
@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <arch_helpers.h>
+#include <common/debug.h>
+#include <drivers/arm/css/scmi.h>
+
+#include "scmi_private.h"
+
+/*
+ * API to set the SCMI power domain power state.
+ */
+int scmi_pwr_state_set(void *p, uint32_t domain_id,
+					uint32_t scmi_pwr_state)
+{
+	mailbox_mem_t *mbx_mem;
+	unsigned int token = 0;
+	int ret;
+
+	/*
+	 * Only asynchronous mode of `set power state` command is allowed on
+	 * application processors.
+	 */
+	uint32_t pwr_state_set_msg_flag = SCMI_PWR_STATE_SET_FLAG_ASYNC;
+	scmi_channel_t *ch = (scmi_channel_t *)p;
+
+	validate_scmi_channel(ch);
+
+	scmi_get_channel(ch);
+
+	mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
+	mbx_mem->msg_header = SCMI_MSG_CREATE(SCMI_PWR_DMN_PROTO_ID,
+			SCMI_PWR_STATE_SET_MSG, token);
+	mbx_mem->len = SCMI_PWR_STATE_SET_MSG_LEN;
+	mbx_mem->flags = SCMI_FLAG_RESP_POLL;
+	SCMI_PAYLOAD_ARG3(mbx_mem->payload, pwr_state_set_msg_flag,
+						domain_id, scmi_pwr_state);
+
+	scmi_send_sync_command(ch);
+
+	/* Get the return values */
+	SCMI_PAYLOAD_RET_VAL1(mbx_mem->payload, ret);
+	assert(mbx_mem->len == SCMI_PWR_STATE_SET_RESP_LEN);
+	assert(token == SCMI_MSG_GET_TOKEN(mbx_mem->msg_header));
+
+	scmi_put_channel(ch);
+
+	return ret;
+}
+
+/*
+ * API to get the SCMI power domain power state.
+ */
+int scmi_pwr_state_get(void *p, uint32_t domain_id,
+					uint32_t *scmi_pwr_state)
+{
+	mailbox_mem_t *mbx_mem;
+	unsigned int token = 0;
+	int ret;
+	scmi_channel_t *ch = (scmi_channel_t *)p;
+
+	validate_scmi_channel(ch);
+
+	scmi_get_channel(ch);
+
+	mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
+	mbx_mem->msg_header = SCMI_MSG_CREATE(SCMI_PWR_DMN_PROTO_ID,
+			SCMI_PWR_STATE_GET_MSG, token);
+	mbx_mem->len = SCMI_PWR_STATE_GET_MSG_LEN;
+	mbx_mem->flags = SCMI_FLAG_RESP_POLL;
+	SCMI_PAYLOAD_ARG1(mbx_mem->payload, domain_id);
+
+	scmi_send_sync_command(ch);
+
+	/* Get the return values */
+	SCMI_PAYLOAD_RET_VAL2(mbx_mem->payload, ret, *scmi_pwr_state);
+	assert(mbx_mem->len == SCMI_PWR_STATE_GET_RESP_LEN);
+	assert(token == SCMI_MSG_GET_TOKEN(mbx_mem->msg_header));
+
+	scmi_put_channel(ch);
+
+	return ret;
+}
diff --git a/drivers/arm/css/scmi/scmi_sys_pwr_proto.c b/drivers/arm/css/scmi/scmi_sys_pwr_proto.c
new file mode 100644
index 0000000..c8e62d1
--- /dev/null
+++ b/drivers/arm/css/scmi/scmi_sys_pwr_proto.c
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <arch_helpers.h>
+#include <common/debug.h>
+#include <drivers/arm/css/scmi.h>
+
+#include "scmi_private.h"
+
+/*
+ * API to set the SCMI system power state
+ */
+int scmi_sys_pwr_state_set(void *p, uint32_t flags, uint32_t system_state)
+{
+	mailbox_mem_t *mbx_mem;
+	unsigned int token = 0;
+	int ret;
+	scmi_channel_t *ch = (scmi_channel_t *)p;
+
+	validate_scmi_channel(ch);
+
+	scmi_get_channel(ch);
+
+	mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
+	mbx_mem->msg_header = SCMI_MSG_CREATE(SCMI_SYS_PWR_PROTO_ID,
+			SCMI_SYS_PWR_STATE_SET_MSG, token);
+	mbx_mem->len = SCMI_SYS_PWR_STATE_SET_MSG_LEN;
+	mbx_mem->flags = SCMI_FLAG_RESP_POLL;
+	SCMI_PAYLOAD_ARG2(mbx_mem->payload, flags, system_state);
+
+	scmi_send_sync_command(ch);
+
+	/* Get the return values */
+	SCMI_PAYLOAD_RET_VAL1(mbx_mem->payload, ret);
+	assert(mbx_mem->len == SCMI_SYS_PWR_STATE_SET_RESP_LEN);
+	assert(token == SCMI_MSG_GET_TOKEN(mbx_mem->msg_header));
+
+	scmi_put_channel(ch);
+
+	return ret;
+}
+
+/*
+ * API to get the SCMI system power state
+ */
+int scmi_sys_pwr_state_get(void *p, uint32_t *system_state)
+{
+	mailbox_mem_t *mbx_mem;
+	unsigned int token = 0;
+	int ret;
+	scmi_channel_t *ch = (scmi_channel_t *)p;
+
+	validate_scmi_channel(ch);
+
+	scmi_get_channel(ch);
+
+	mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
+	mbx_mem->msg_header = SCMI_MSG_CREATE(SCMI_SYS_PWR_PROTO_ID,
+			SCMI_SYS_PWR_STATE_GET_MSG, token);
+	mbx_mem->len = SCMI_SYS_PWR_STATE_GET_MSG_LEN;
+	mbx_mem->flags = SCMI_FLAG_RESP_POLL;
+
+	scmi_send_sync_command(ch);
+
+	/* Get the return values */
+	SCMI_PAYLOAD_RET_VAL2(mbx_mem->payload, ret, *system_state);
+	assert(mbx_mem->len == SCMI_SYS_PWR_STATE_GET_RESP_LEN);
+	assert(token == SCMI_MSG_GET_TOKEN(mbx_mem->msg_header));
+
+	scmi_put_channel(ch);
+
+	return ret;
+}
diff --git a/drivers/arm/css/scmi/vendor/scmi_sq.c b/drivers/arm/css/scmi/vendor/scmi_sq.c
new file mode 100644
index 0000000..f185424
--- /dev/null
+++ b/drivers/arm/css/scmi/vendor/scmi_sq.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <arch_helpers.h>
+#include <common/debug.h>
+#include <drivers/arm/css/scmi.h>
+
+#include "scmi_private.h"
+#include "scmi_sq.h"
+
+#include <sq_common.h>
+
+/* SCMI messge ID to get the available DRAM region */
+#define SCMI_VENDOR_EXT_MEMINFO_GET_MSG		0x3
+
+#define SCMI_VENDOR_EXT_MEMINFO_GET_MSG_LEN	4
+
+/*
+ * API to get the available DRAM region
+ */
+int scmi_get_draminfo(void *p, struct draminfo *info)
+{
+	mailbox_mem_t *mbx_mem;
+	int token = 0, ret;
+	scmi_channel_t *ch = (scmi_channel_t *)p;
+	struct dram_info_resp response;
+
+	validate_scmi_channel(ch);
+
+	scmi_get_channel(ch);
+
+	mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
+	mbx_mem->msg_header = SCMI_MSG_CREATE(SCMI_SYS_VENDOR_EXT_PROTO_ID,
+			SCMI_VENDOR_EXT_MEMINFO_GET_MSG, token);
+	mbx_mem->len = SCMI_VENDOR_EXT_MEMINFO_GET_MSG_LEN;
+	mbx_mem->flags = SCMI_FLAG_RESP_POLL;
+
+	scmi_send_sync_command(ch);
+
+	/*
+	 * Ensure that any read to the SCPI payload area is done after reading
+	 * the MHU register. If these 2 reads were reordered then the CPU would
+	 * read invalid payload data
+	 */
+	dmbld();
+
+	/* Get the return values */
+	SCMI_PAYLOAD_RET_VAL1(mbx_mem->payload, ret);
+
+	memcpy(&response, (void *)mbx_mem->payload, sizeof(response));
+
+	scmi_put_channel(ch);
+
+	*info = response.info;
+
+	return ret;
+}
diff --git a/drivers/arm/css/scmi/vendor/scmi_sq.h b/drivers/arm/css/scmi/vendor/scmi_sq.h
new file mode 100644
index 0000000..aee1a3a
--- /dev/null
+++ b/drivers/arm/css/scmi/vendor/scmi_sq.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef SCMI_SQ_H
+#define SCMI_SQ_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <sq_common.h>
+
+/* Structure to represent available DRAM region */
+struct dram_info_resp {
+	int status;
+	int reserved;
+	struct draminfo info;
+};
+
+/* API to get the available DRAM region */
+int scmi_get_draminfo(void *p, struct draminfo *info);
+
+#endif /* SCMI_SQ_H */