diff --git a/drivers/common/cnxk/roc_bphy_cgx.c b/drivers/common/cnxk/roc_bphy_cgx.c
index 029d4102e..8549145a1 100644
--- a/drivers/common/cnxk/roc_bphy_cgx.c
+++ b/drivers/common/cnxk/roc_bphy_cgx.c
@@ -2,8 +2,13 @@
  * Copyright(C) 2021 Marvell.
  */
 
+#include <pthread.h>
+
 #include "roc_api.h"
+#include "roc_priv.h"
 
+#define CGX_CMRX_INT		       0x40
+#define CGX_CMRX_INT_OVERFLW	       BIT_ULL(1)
 /*
  * CN10K stores number of lmacs in 4 bit filed
  * in contraty to CN9K which uses only 3 bits.
@@ -15,6 +20,8 @@
  */
 #define CGX_CMRX_RX_LMACS	0x128
 #define CGX_CMRX_RX_LMACS_LMACS GENMASK_ULL(3, 0)
+#define CGX_CMRX_SCRATCH0	0x1050
+#define CGX_CMRX_SCRATCH1	0x1058
 
 static uint64_t
 roc_bphy_cgx_read(struct roc_bphy_cgx *roc_cgx, uint64_t lmac, uint64_t offset)
@@ -25,6 +32,137 @@ roc_bphy_cgx_read(struct roc_bphy_cgx *roc_cgx, uint64_t lmac, uint64_t offset)
 	return plt_read64(base + (lmac << shift) + offset);
 }
 
+static void
+roc_bphy_cgx_write(struct roc_bphy_cgx *roc_cgx, uint64_t lmac, uint64_t offset,
+		   uint64_t value)
+{
+	int shift = roc_model_is_cn10k() ? 20 : 18;
+	uint64_t base = (uint64_t)roc_cgx->bar0_va;
+
+	plt_write64(value, base + (lmac << shift) + offset);
+}
+
+static void
+roc_bphy_cgx_ack(struct roc_bphy_cgx *roc_cgx, unsigned int lmac,
+		 uint64_t *scr0)
+{
+	uint64_t val;
+
+	/* clear interrupt */
+	val = roc_bphy_cgx_read(roc_cgx, lmac, CGX_CMRX_INT);
+	val |= FIELD_PREP(CGX_CMRX_INT_OVERFLW, 1);
+	roc_bphy_cgx_write(roc_cgx, lmac, CGX_CMRX_INT, val);
+
+	/* ack fw response */
+	*scr0 &= ~SCR0_ETH_EVT_STS_S_ACK;
+	roc_bphy_cgx_write(roc_cgx, lmac, CGX_CMRX_SCRATCH0, *scr0);
+}
+
+static int
+roc_bphy_cgx_wait_for_ownership(struct roc_bphy_cgx *roc_cgx, unsigned int lmac,
+				uint64_t *scr0)
+{
+	int tries = 5000;
+	uint64_t scr1;
+
+	do {
+		*scr0 = roc_bphy_cgx_read(roc_cgx, lmac, CGX_CMRX_SCRATCH0);
+		scr1 = roc_bphy_cgx_read(roc_cgx, lmac, CGX_CMRX_SCRATCH1);
+
+		if (FIELD_GET(SCR1_OWN_STATUS, scr1) == ETH_OWN_NON_SECURE_SW &&
+		    FIELD_GET(SCR0_ETH_EVT_STS_S_ACK, *scr0) == 0)
+			break;
+
+		/* clear async events if any */
+		if (FIELD_GET(SCR0_ETH_EVT_STS_S_EVT_TYPE, *scr0) == ETH_EVT_ASYNC &&
+		    FIELD_GET(SCR0_ETH_EVT_STS_S_ACK, *scr0))
+			roc_bphy_cgx_ack(roc_cgx, lmac, scr0);
+
+		plt_delay_ms(1);
+	} while (--tries);
+
+	return tries ? 0 : -ETIMEDOUT;
+}
+
+static int
+roc_bphy_cgx_wait_for_ack(struct roc_bphy_cgx *roc_cgx, unsigned int lmac,
+			  uint64_t *scr0)
+{
+	int tries = 5000;
+	uint64_t scr1;
+
+	do {
+		*scr0 = roc_bphy_cgx_read(roc_cgx, lmac, CGX_CMRX_SCRATCH0);
+		scr1 = roc_bphy_cgx_read(roc_cgx, lmac, CGX_CMRX_SCRATCH1);
+
+		if (FIELD_GET(SCR1_OWN_STATUS, scr1) == ETH_OWN_NON_SECURE_SW &&
+		    FIELD_GET(SCR0_ETH_EVT_STS_S_ACK, *scr0))
+			break;
+
+		plt_delay_ms(1);
+	} while (--tries);
+
+	return tries ? 0 : -ETIMEDOUT;
+}
+
+static int __rte_unused
+roc_bphy_cgx_intf_req(struct roc_bphy_cgx *roc_cgx, unsigned int lmac,
+		      uint64_t scr1, uint64_t *scr0)
+{
+	uint8_t cmd_id = FIELD_GET(SCR1_ETH_CMD_ID, scr1);
+	int ret;
+
+	pthread_mutex_lock(&roc_cgx->lock);
+
+	/* wait for ownership */
+	ret = roc_bphy_cgx_wait_for_ownership(roc_cgx, lmac, scr0);
+	if (ret) {
+		plt_err("timed out waiting for ownership");
+		goto out;
+	}
+
+	/* write command */
+	scr1 |= FIELD_PREP(SCR1_OWN_STATUS, ETH_OWN_FIRMWARE);
+	roc_bphy_cgx_write(roc_cgx, lmac, CGX_CMRX_SCRATCH1, scr1);
+
+	/* wait for command ack */
+	ret = roc_bphy_cgx_wait_for_ack(roc_cgx, lmac, scr0);
+	if (ret) {
+		plt_err("timed out waiting for response");
+		goto out;
+	}
+
+	if (cmd_id == ETH_CMD_INTF_SHUTDOWN)
+		goto out;
+
+	if (FIELD_GET(SCR0_ETH_EVT_STS_S_EVT_TYPE, *scr0) != ETH_EVT_CMD_RESP) {
+		plt_err("received async event instead of cmd resp event");
+		ret = -EIO;
+		goto out;
+	}
+
+	if (FIELD_GET(SCR0_ETH_EVT_STS_S_ID, *scr0) != cmd_id) {
+		plt_err("received resp for cmd %d expected for cmd %d",
+			(int)FIELD_GET(SCR0_ETH_EVT_STS_S_ID, *scr0), cmd_id);
+		ret = -EIO;
+		goto out;
+	}
+
+	if (FIELD_GET(SCR0_ETH_EVT_STS_S_STAT, *scr0) != ETH_STAT_SUCCESS) {
+		plt_err("cmd %d failed on cgx%u lmac%u with errcode %d", cmd_id,
+			roc_cgx->id, lmac,
+			(int)FIELD_GET(SCR0_ETH_LNK_STS_S_ERR_TYPE, *scr0));
+		ret = -EIO;
+	}
+
+out:
+	roc_bphy_cgx_ack(roc_cgx, lmac, scr0);
+
+	pthread_mutex_unlock(&roc_cgx->lock);
+
+	return ret;
+}
+
 static unsigned int
 roc_bphy_cgx_dev_id(struct roc_bphy_cgx *roc_cgx)
 {
@@ -38,10 +176,15 @@ int
 roc_bphy_cgx_dev_init(struct roc_bphy_cgx *roc_cgx)
 {
 	uint64_t val;
+	int ret;
 
 	if (!roc_cgx || !roc_cgx->bar0_va || !roc_cgx->bar0_pa)
 		return -EINVAL;
 
+	ret = pthread_mutex_init(&roc_cgx->lock, NULL);
+	if (ret)
+		return ret;
+
 	val = roc_bphy_cgx_read(roc_cgx, 0, CGX_CMRX_RX_LMACS);
 	val = FIELD_GET(CGX_CMRX_RX_LMACS_LMACS, val);
 	if (roc_model_is_cn9k())
@@ -58,5 +201,7 @@ roc_bphy_cgx_dev_fini(struct roc_bphy_cgx *roc_cgx)
 	if (!roc_cgx)
 		return -EINVAL;
 
+	pthread_mutex_destroy(&roc_cgx->lock);
+
 	return 0;
 }
diff --git a/drivers/common/cnxk/roc_bphy_cgx.h b/drivers/common/cnxk/roc_bphy_cgx.h
index aac2c262c..37b5c2742 100644
--- a/drivers/common/cnxk/roc_bphy_cgx.h
+++ b/drivers/common/cnxk/roc_bphy_cgx.h
@@ -5,6 +5,8 @@
 #ifndef _ROC_BPHY_CGX_H_
 #define _ROC_BPHY_CGX_H_
 
+#include <pthread.h>
+
 #include "roc_api.h"
 
 struct roc_bphy_cgx {
@@ -12,6 +14,8 @@ struct roc_bphy_cgx {
 	void *bar0_va;
 	uint64_t lmac_bmap;
 	unsigned int id;
+	/* serialize access to the whole structure */
+	pthread_mutex_t lock;
 } __plt_cache_aligned;
 
 __roc_api int roc_bphy_cgx_dev_init(struct roc_bphy_cgx *roc_cgx);
diff --git a/drivers/common/cnxk/roc_bphy_cgx_priv.h b/drivers/common/cnxk/roc_bphy_cgx_priv.h
new file mode 100644
index 000000000..42d0bce7a
--- /dev/null
+++ b/drivers/common/cnxk/roc_bphy_cgx_priv.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(C) 2021 Marvell.
+ */
+
+#ifndef _ROC_BPHY_CGX_PRIV_H_
+#define _ROC_BPHY_CGX_PRIV_H_
+
+/* REQUEST ID types. Input to firmware */
+enum eth_cmd_id {
+	ETH_CMD_INTF_SHUTDOWN = 12,
+};
+
+/* event types - cause of interrupt */
+enum eth_evt_type {
+	ETH_EVT_ASYNC,
+	ETH_EVT_CMD_RESP,
+};
+
+enum eth_stat {
+	ETH_STAT_SUCCESS,
+	ETH_STAT_FAIL,
+};
+
+enum eth_cmd_own {
+	/* default ownership with kernel/uefi/u-boot */
+	ETH_OWN_NON_SECURE_SW,
+	/* set by kernel/uefi/u-boot after posting a new request to ATF */
+	ETH_OWN_FIRMWARE,
+};
+
+/* scratchx(0) CSR used for ATF->non-secure SW communication.
+ * This acts as the status register
+ * Provides details on command ack/status, link status, error details
+ */
+
+/* struct eth_evt_sts_s */
+#define SCR0_ETH_EVT_STS_S_ACK	    BIT_ULL(0)
+#define SCR0_ETH_EVT_STS_S_EVT_TYPE BIT_ULL(1)
+#define SCR0_ETH_EVT_STS_S_STAT	    BIT_ULL(2)
+#define SCR0_ETH_EVT_STS_S_ID	    GENMASK_ULL(8, 3)
+
+/* struct eth_lnk_sts_s */
+#define SCR0_ETH_LNK_STS_S_ERR_TYPE    GENMASK_ULL(24, 15)
+
+/* scratchx(1) CSR used for non-secure SW->ATF communication
+ * This CSR acts as a command register
+ */
+
+/* struct eth_cmd */
+#define SCR1_ETH_CMD_ID GENMASK_ULL(7, 2)
+
+#define SCR1_OWN_STATUS GENMASK_ULL(1, 0)
+
+#endif /* _ROC_BPHY_CGX_PRIV_H_ */
diff --git a/drivers/common/cnxk/roc_priv.h b/drivers/common/cnxk/roc_priv.h
index 5e7564ce5..feca732a9 100644
--- a/drivers/common/cnxk/roc_priv.h
+++ b/drivers/common/cnxk/roc_priv.h
@@ -32,4 +32,7 @@
 /* TIM */
 #include "roc_tim_priv.h"
 
+/* BPHY CGX */
+#include "roc_bphy_cgx_priv.h"
+
 #endif /* _ROC_PRIV_H_ */
