diff --git a/drivers/firmware/arm_scpi.c b/drivers/firmware/arm_scpi.c
index 21542a32ad9f..2982bc7b8c33 100644
--- a/drivers/firmware/arm_scpi.c
+++ b/drivers/firmware/arm_scpi.c
@@ -50,13 +50,20 @@
 #define CMD_TOKEN_ID_MASK	0xff
 #define CMD_DATA_SIZE_SHIFT	16
 #define CMD_DATA_SIZE_MASK	0x1ff
+#define CMD_LEGACY_DATA_SIZE_SHIFT	20
+#define CMD_LEGACY_DATA_SIZE_MASK	0x1ff
 #define PACK_SCPI_CMD(cmd_id, tx_sz)			\
 	((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |	\
 	(((tx_sz) & CMD_DATA_SIZE_MASK) << CMD_DATA_SIZE_SHIFT))
 #define ADD_SCPI_TOKEN(cmd, token)			\
 	((cmd) |= (((token) & CMD_TOKEN_ID_MASK) << CMD_TOKEN_ID_SHIFT))
+#define PACK_LEGACY_SCPI_CMD(cmd_id, tx_sz)				\
+	((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |			       \
+	(((tx_sz) & CMD_LEGACY_DATA_SIZE_MASK) << CMD_LEGACY_DATA_SIZE_SHIFT))
 
 #define CMD_SIZE(cmd)	(((cmd) >> CMD_DATA_SIZE_SHIFT) & CMD_DATA_SIZE_MASK)
+#define CMD_LEGACY_SIZE(cmd)	(((cmd) >> CMD_LEGACY_DATA_SIZE_SHIFT) & \
+					CMD_LEGACY_DATA_SIZE_MASK)
 #define CMD_UNIQ_MASK	(CMD_TOKEN_ID_MASK << CMD_TOKEN_ID_SHIFT | CMD_ID_MASK)
 #define CMD_XTRACT_UNIQ(cmd)	((cmd) & CMD_UNIQ_MASK)
 
@@ -133,7 +140,62 @@ enum scpi_std_cmd {
 	SCPI_CMD_COUNT
 };
 
-/* List of all commands used by this driver, used as indices */
+/* SCPI Legacy Commands */
+enum legacy_scpi_std_cmd {
+	LEGACY_SCPI_CMD_INVALID			= 0x00,
+	LEGACY_SCPI_CMD_SCPI_READY		= 0x01,
+	LEGACY_SCPI_CMD_SCPI_CAPABILITIES	= 0x02,
+	LEGACY_SCPI_CMD_EVENT			= 0x03,
+	LEGACY_SCPI_CMD_SET_CSS_PWR_STATE	= 0x04,
+	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE	= 0x05,
+	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT	= 0x06,
+	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT	= 0x07,
+	LEGACY_SCPI_CMD_SYS_PWR_STATE		= 0x08,
+	LEGACY_SCPI_CMD_L2_READY		= 0x09,
+	LEGACY_SCPI_CMD_SET_AP_TIMER		= 0x0a,
+	LEGACY_SCPI_CMD_CANCEL_AP_TIME		= 0x0b,
+	LEGACY_SCPI_CMD_DVFS_CAPABILITIES	= 0x0c,
+	LEGACY_SCPI_CMD_GET_DVFS_INFO		= 0x0d,
+	LEGACY_SCPI_CMD_SET_DVFS		= 0x0e,
+	LEGACY_SCPI_CMD_GET_DVFS		= 0x0f,
+	LEGACY_SCPI_CMD_GET_DVFS_STAT		= 0x10,
+	LEGACY_SCPI_CMD_SET_RTC			= 0x11,
+	LEGACY_SCPI_CMD_GET_RTC			= 0x12,
+	LEGACY_SCPI_CMD_CLOCK_CAPABILITIES	= 0x13,
+	LEGACY_SCPI_CMD_SET_CLOCK_INDEX		= 0x14,
+	LEGACY_SCPI_CMD_SET_CLOCK_VALUE		= 0x15,
+	LEGACY_SCPI_CMD_GET_CLOCK_VALUE		= 0x16,
+	LEGACY_SCPI_CMD_PSU_CAPABILITIES	= 0x17,
+	LEGACY_SCPI_CMD_SET_PSU			= 0x18,
+	LEGACY_SCPI_CMD_GET_PSU			= 0x19,
+	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES	= 0x1a,
+	LEGACY_SCPI_CMD_SENSOR_INFO		= 0x1b,
+	LEGACY_SCPI_CMD_SENSOR_VALUE		= 0x1c,
+	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC	= 0x1d,
+	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS	= 0x1e,
+	LEGACY_SCPI_CMD_SENSOR_ASYNC_VALUE	= 0x1f,
+	LEGACY_SCPI_CMD_COUNT
+};
+
+/* List all commands that are required to go through the high priority link */
+static int legacy_hpriority_cmds[] = {
+	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE,
+	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT,
+	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT,
+	LEGACY_SCPI_CMD_SET_DVFS,
+	LEGACY_SCPI_CMD_GET_DVFS,
+	LEGACY_SCPI_CMD_SET_RTC,
+	LEGACY_SCPI_CMD_GET_RTC,
+	LEGACY_SCPI_CMD_SET_CLOCK_INDEX,
+	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
+	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
+	LEGACY_SCPI_CMD_SET_PSU,
+	LEGACY_SCPI_CMD_GET_PSU,
+	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC,
+	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS,
+};
+
+/* List all commands used by this driver, used as indexes */
 enum scpi_drv_cmds {
 	CMD_SCPI_CAPABILITIES = 0,
 	CMD_GET_CLOCK_INFO,
@@ -165,6 +227,21 @@ enum scpi_drv_cmds {
 	SCPI_CMD_GET_DEVICE_PWR_STATE,
 };
 
+static int scpi_legacy_commands[CMD_MAX_COUNT] = {
+	LEGACY_SCPI_CMD_SCPI_CAPABILITIES,
+	-1, /* GET_CLOCK_INFO */
+	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
+	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
+	LEGACY_SCPI_CMD_GET_DVFS,
+	LEGACY_SCPI_CMD_SET_DVFS,
+	LEGACY_SCPI_CMD_GET_DVFS_INFO,
+	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES,
+	LEGACY_SCPI_CMD_SENSOR_INFO,
+	LEGACY_SCPI_CMD_SENSOR_VALUE,
+	-1, /* SET_DEVICE_PWR_STATE */
+	-1, /* GET_DEVICE_PWR_STATE */
+};
+
 struct scpi_xfer {
 	u32 slot; /* has to be first element */
 	u32 cmd;
@@ -193,8 +270,10 @@ struct scpi_chan {
 struct scpi_drvinfo {
 	u32 protocol_version;
 	u32 firmware_version;
+	bool is_legacy;
 	int num_chans;
 	int *commands;
+	DECLARE_BITMAP(cmd_priority, LEGACY_SCPI_CMD_COUNT);
 	atomic_t next_chan;
 	struct scpi_ops *scpi_ops;
 	struct scpi_chan *channels;
@@ -211,6 +290,11 @@ struct scpi_shared_mem {
 	u8 payload[0];
 } __packed;
 
+struct legacy_scpi_shared_mem {
+	__le32 status;
+	u8 payload[0];
+} __packed;
+
 struct scp_capabilities {
 	__le32 protocol_version;
 	__le32 event_version;
@@ -236,6 +320,12 @@ struct clk_set_value {
 	__le32 rate;
 } __packed;
 
+struct legacy_clk_set_value {
+	__le32 rate;
+	__le16 id;
+	__le16 reserved;
+} __packed;
+
 struct dvfs_info {
 	__le32 header;
 	struct {
@@ -307,19 +397,43 @@ static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
 		return;
 	}
 
-	list_for_each_entry(t, &ch->rx_pending, node)
-		if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
-			list_del(&t->node);
-			match = t;
-			break;
-		}
+	/* Command type is not replied by the SCP Firmware in legacy Mode
+	 * We should consider that command is the head of pending RX commands
+	 * if the list is not empty. In TX only mode, the list would be empty.
+	 */
+	if (scpi_info->is_legacy) {
+		match = list_first_entry(&ch->rx_pending, struct scpi_xfer,
+					 node);
+		list_del(&match->node);
+	} else {
+		list_for_each_entry(t, &ch->rx_pending, node)
+			if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
+				list_del(&t->node);
+				match = t;
+				break;
+			}
+	}
 	/* check if wait_for_completion is in progress or timed-out */
 	if (match && !completion_done(&match->done)) {
-		struct scpi_shared_mem *mem = ch->rx_payload;
-		unsigned int len = min(match->rx_len, CMD_SIZE(cmd));
+		unsigned int len;
+
+		if (scpi_info->is_legacy) {
+			struct legacy_scpi_shared_mem *mem = ch->rx_payload;
+
+			/* RX Length is not replied by the legacy Firmware */
+			len = match->rx_len;
+
+			match->status = le32_to_cpu(mem->status);
+			memcpy_fromio(match->rx_buf, mem->payload, len);
+		} else {
+			struct scpi_shared_mem *mem = ch->rx_payload;
+
+			len = min(match->rx_len, CMD_SIZE(cmd));
+
+			match->status = le32_to_cpu(mem->status);
+			memcpy_fromio(match->rx_buf, mem->payload, len);
+		}
 
-		match->status = le32_to_cpu(mem->status);
-		memcpy_fromio(match->rx_buf, mem->payload, len);
 		if (match->rx_len > len)
 			memset(match->rx_buf + len, 0, match->rx_len - len);
 		complete(&match->done);
@@ -331,7 +445,10 @@ static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
 {
 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
 	struct scpi_shared_mem *mem = ch->rx_payload;
-	u32 cmd = le32_to_cpu(mem->command);
+	u32 cmd = 0;
+
+	if (!scpi_info->is_legacy)
+		cmd = le32_to_cpu(mem->command);
 
 	scpi_process_cmd(ch, cmd);
 }
@@ -343,8 +460,13 @@ static void scpi_tx_prepare(struct mbox_client *c, void *msg)
 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
 	struct scpi_shared_mem *mem = (struct scpi_shared_mem *)ch->tx_payload;
 
-	if (t->tx_buf)
-		memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
+	if (t->tx_buf) {
+		if (scpi_info->is_legacy)
+			memcpy_toio(ch->tx_payload, t->tx_buf, t->tx_len);
+		else
+			memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
+	}
+
 	if (t->rx_buf) {
 		if (!(++ch->token))
 			++ch->token;
@@ -353,7 +475,9 @@ static void scpi_tx_prepare(struct mbox_client *c, void *msg)
 		list_add_tail(&t->node, &ch->rx_pending);
 		spin_unlock_irqrestore(&ch->rx_lock, flags);
 	}
-	mem->command = cpu_to_le32(t->cmd);
+
+	if (!scpi_info->is_legacy)
+		mem->command = cpu_to_le32(t->cmd);
 }
 
 static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
@@ -392,15 +516,24 @@ static int scpi_send_message(u8 idx, void *tx_buf, unsigned int tx_len,
 
 	cmd = scpi_info->commands[idx];
 
-	chan = atomic_inc_return(&scpi_info->next_chan) % scpi_info->num_chans;
+	if (scpi_info->is_legacy)
+		chan = test_bit(cmd, scpi_info->cmd_priority) ? 1 : 0;
+	else
+		chan = atomic_inc_return(&scpi_info->next_chan) %
+			scpi_info->num_chans;
 	scpi_chan = scpi_info->channels + chan;
 
 	msg = get_scpi_xfer(scpi_chan);
 	if (!msg)
 		return -ENOMEM;
 
-	msg->slot = BIT(SCPI_SLOT);
-	msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
+	if (scpi_info->is_legacy) {
+		msg->cmd = PACK_LEGACY_SCPI_CMD(cmd, tx_len);
+		msg->slot = msg->cmd;
+	} else {
+		msg->slot = BIT(SCPI_SLOT);
+		msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
+	}
 	msg->tx_buf = tx_buf;
 	msg->tx_len = tx_len;
 	msg->rx_buf = rx_buf;
@@ -470,6 +603,18 @@ static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
 				 &stat, sizeof(stat));
 }
 
+static int legacy_scpi_clk_set_val(u16 clk_id, unsigned long rate)
+{
+	int stat;
+	struct legacy_clk_set_value clk = {
+		.id = cpu_to_le16(clk_id),
+		.rate = cpu_to_le32(rate)
+	};
+
+	return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
+				 &stat, sizeof(stat));
+}
+
 static int scpi_dvfs_get_idx(u8 domain)
 {
 	int ret;
@@ -800,6 +945,17 @@ static int scpi_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, scpi_info);
 
+	if (scpi_info->is_legacy) {
+		/* Replace with legacy variants */
+		scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
+		scpi_info->commands = scpi_legacy_commands;
+
+		/* Fill priority bitmap */
+		for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
+			set_bit(legacy_hpriority_cmds[idx],
+				scpi_info->cmd_priority);
+	}
+
 	ret = scpi_init_versions(scpi_info);
 	if (ret) {
 		dev_err(dev, "incorrect or no SCP firmware found\n");
