diff --git a/Documentation/devicetree/bindings/drm/msm/sde-dp-sim.txt b/Documentation/devicetree/bindings/drm/msm/sde-dp-sim.txt
new file mode 100644
index 0000000000..f24aadeec6
--- /dev/null
+++ b/Documentation/devicetree/bindings/drm/msm/sde-dp-sim.txt
@@ -0,0 +1,58 @@
+QTI Snapdragon Display Engine (SDE) DP-MST sideband message emulation driver
+
+Required properties:
+- compatible:		"qcom,dp-mst-sim"
+
+Each child node represents a port at root branch, with properties:
+- qcom,mode-h-active:      A u32 property defines the horizontal active size.
+- qcom,mode-h-front-porch: A u32 property defines the horizontal front porch.
+- qcom,mode-h-pulse-width: A u32 property defines the horizontal pulse.
+- qcom,mode-h-back-porch:  A u32 property defines the horizontal back porch.
+- qcom,mode-h-active-high: A boolean property if horizontal polarity is high.
+- qcom,mode-v-active:      A u32 property defines the vertical active size.
+- qcom,mode-v-front-porch: A u32 property defines the vertical front portch.
+- qcom,mode-v-pulse-width: A u32 property defines the vertical pulse width.
+- qcom,mode-v-back-porch:  A u32 property defines the vertical back porch.
+- qcom,mode-v-active-high: A boolean property if vertical polarity is high.
+- qcom,mode-refresh-rate:  A u32 property defines vertial refresh rate.
+- qcom,mode-clock-in-khz:  A u32 property defines clock in kHz.
+
+Example:
+
+/ {
+	...
+
+	sde_dp_mst_sim: qcom,dp-mst-sim {
+		compatible = "qcom,dp-mst-sim";
+
+		port@0 {
+			qcom,mode-h-active = <1920>;
+			qcom,mode-h-front-porch = <88>;
+			qcom,mode-h-pulse-width = <44>;
+			qcom,mode-h-back-porch = <148>;
+			qcom,mode-h-active-high;
+			qcom,mode-v-active = <1080>;
+			qcom,mode-v-front-porch = <4>;
+			qcom,mode-v-pulse-width = <5>;
+			qcom,mode-v-back-porch = <36>;
+			qcom,mode-v-active-high;
+			qcom,mode-refresh-rate = <60>;
+			qcom,mode-clock-in-khz = <148500>;
+		};
+
+		port@1 {
+			qcom,mode-h-active = <1920>;
+			qcom,mode-h-front-porch = <88>;
+			qcom,mode-h-pulse-width = <44>;
+			qcom,mode-h-back-porch = <148>;
+			qcom,mode-h-active-high;
+			qcom,mode-v-active = <1080>;
+			qcom,mode-v-front-porch = <4>;
+			qcom,mode-v-pulse-width = <5>;
+			qcom,mode-v-back-porch = <36>;
+			qcom,mode-v-active-high;
+			qcom,mode-refresh-rate = <60>;
+			qcom,mode-clock-in-khz = <148500>;
+		};
+	};
+};
diff --git a/msm/Kbuild b/msm/Kbuild
index b2bf8bc1de..af948f24df 100644
--- a/msm/Kbuild
+++ b/msm/Kbuild
@@ -97,6 +97,7 @@ msm_drm-$(CONFIG_DRM_MSM_DP) += dp/dp_altmode.o \
 				dp/dp_hpd.o \
 				dp/dp_aux_bridge.o \
 				dp/dp_bridge_hpd.o \
+				dp/dp_mst_sim.o \
 				dp/dp_mst_sim_helper.o \
 				dp/dp_gpio_hpd.o \
 				dp/dp_lphw_hpd.o \
diff --git a/msm/dp/dp_mst_sim.c b/msm/dp/dp_mst_sim.c
new file mode 100644
index 0000000000..d032be2391
--- /dev/null
+++ b/msm/dp/dp_mst_sim.c
@@ -0,0 +1,363 @@
+/*
+ * Copyright (c) 2019-2021, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/debugfs.h>
+#include <linux/platform_device.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_modes.h>
+#include "dp_aux_bridge.h"
+#include "dp_debug.h"
+#include "dp_mst_sim_helper.h"
+
+struct dp_sim_device {
+	struct dp_aux_bridge bridge;
+	void *host_dev;
+	int (*hpd_cb)(void *, bool, bool);
+};
+
+#define to_dp_sim_dev(x) container_of((x), struct dp_sim_device, bridge)
+
+static const struct dp_mst_sim_port output_port = {
+	false, false, true, 3, false, 0x12,
+	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+	0, 0, 2520, 2520, NULL, 0
+};
+
+static int dp_sim_register_hpd(struct dp_aux_bridge *bridge,
+	int (*hpd_cb)(void *, bool, bool), void *dev)
+{
+	struct dp_sim_device *sim_dev = to_dp_sim_dev(bridge);
+
+	sim_dev->host_dev = dev;
+	sim_dev->hpd_cb = hpd_cb;
+
+	return 0;
+}
+
+static ssize_t dp_sim_transfer(struct dp_aux_bridge *bridge,
+	struct drm_dp_aux *drm_aux,
+	struct drm_dp_aux_msg *msg)
+{
+	struct dp_sim_device *sim_dev = to_dp_sim_dev(bridge);
+	int ret;
+
+	ret = dp_mst_sim_transfer(sim_dev->bridge.mst_ctx, msg);
+	if (ret < 0)
+		ret = drm_aux->transfer(drm_aux, msg);
+	else
+		ret = msg->size;
+
+	return ret;
+}
+
+static void dp_sim_host_hpd_irq(void *host_dev)
+{
+	struct dp_sim_device *sim_dev = host_dev;
+
+	if (sim_dev->hpd_cb)
+		sim_dev->hpd_cb(sim_dev->host_dev, false, true);
+}
+
+static void dp_sim_update_dtd(struct edid *edid,
+		struct drm_display_mode *mode)
+{
+	struct detailed_timing *dtd = &edid->detailed_timings[0];
+	struct detailed_pixel_timing *pd = &dtd->data.pixel_data;
+	u32 h_blank = mode->htotal - mode->hdisplay;
+	u32 v_blank = mode->vtotal - mode->vdisplay;
+	u32 h_img = 0, v_img = 0;
+
+	dtd->pixel_clock = cpu_to_le16(mode->clock / 10);
+
+	pd->hactive_lo = mode->hdisplay & 0xFF;
+	pd->hblank_lo = h_blank & 0xFF;
+	pd->hactive_hblank_hi = ((h_blank >> 8) & 0xF) |
+			((mode->hdisplay >> 8) & 0xF) << 4;
+
+	pd->vactive_lo = mode->vdisplay & 0xFF;
+	pd->vblank_lo = v_blank & 0xFF;
+	pd->vactive_vblank_hi = ((v_blank >> 8) & 0xF) |
+			((mode->vdisplay >> 8) & 0xF) << 4;
+
+	pd->hsync_offset_lo =
+		(mode->hsync_start - mode->hdisplay) & 0xFF;
+	pd->hsync_pulse_width_lo =
+		(mode->hsync_end - mode->hsync_start) & 0xFF;
+	pd->vsync_offset_pulse_width_lo =
+		(((mode->vsync_start - mode->vdisplay) & 0xF) << 4) |
+		((mode->vsync_end - mode->vsync_start) & 0xF);
+
+	pd->hsync_vsync_offset_pulse_width_hi =
+		((((mode->hsync_start - mode->hdisplay) >> 8) & 0x3) << 6) |
+		((((mode->hsync_end - mode->hsync_start) >> 8) & 0x3) << 4) |
+		((((mode->vsync_start - mode->vdisplay) >> 4) & 0x3) << 2) |
+		((((mode->vsync_end - mode->vsync_start) >> 4) & 0x3) << 0);
+
+	pd->width_mm_lo = h_img & 0xFF;
+	pd->height_mm_lo = v_img & 0xFF;
+	pd->width_height_mm_hi = (((h_img >> 8) & 0xF) << 4) |
+		((v_img >> 8) & 0xF);
+
+	pd->hborder = 0;
+	pd->vborder = 0;
+	pd->misc = 0;
+}
+
+static void dp_sim_update_checksum(struct edid *edid)
+{
+	u8 *data = (u8 *)edid;
+	u32 i, sum = 0;
+
+	for (i = 0; i < EDID_LENGTH - 1; i++)
+		sum += data[i];
+
+	edid->checksum = 0x100 - (sum & 0xFF);
+}
+
+static int dp_sim_parse(struct dp_sim_device *sim_dev)
+{
+	struct device_node *of_node = sim_dev->bridge.of_node;
+	struct device_node *node;
+	struct dp_mst_sim_port *ports;
+	struct drm_display_mode mode_buf, *mode = &mode_buf;
+	u16 h_front_porch, h_pulse_width, h_back_porch;
+	u16 v_front_porch, v_pulse_width, v_back_porch;
+	bool h_active_high, v_active_high;
+	u32 flags = 0;
+	int rc, port_num, i;
+	struct edid *edid;
+
+	const u8 edid_buf[EDID_LENGTH] = {
+		0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x44, 0x6D,
+		0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x1B, 0x10, 0x01, 0x03,
+		0x80, 0x50, 0x2D, 0x78, 0x0A, 0x0D, 0xC9, 0xA0, 0x57, 0x47,
+		0x98, 0x27, 0x12, 0x48, 0x4C, 0x00, 0x00, 0x00, 0x01, 0x01,
+		0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+		0x01, 0x01, 0x01, 0x01,
+	};
+
+	port_num = of_get_child_count(of_node);
+
+	if (!port_num)
+		return 0;
+
+	if (port_num >= 15)
+		return -EINVAL;
+
+	ports = kcalloc(port_num, sizeof(*ports), GFP_KERNEL);
+	if (!ports)
+		return -ENOMEM;
+
+	i = 0;
+	for_each_child_of_node(of_node, node) {
+		rc = of_property_read_u16(node, "qcom,mode-h-active",
+						&mode->hdisplay);
+		if (rc) {
+			DP_ERR("failed to read h-active, rc=%d\n", rc);
+			goto fail;
+		}
+
+		rc = of_property_read_u16(node, "qcom,mode-h-front-porch",
+						&h_front_porch);
+		if (rc) {
+			DP_ERR("failed to read h-front-porch, rc=%d\n", rc);
+			goto fail;
+		}
+
+		rc = of_property_read_u16(node, "qcom,mode-h-pulse-width",
+						&h_pulse_width);
+		if (rc) {
+			DP_ERR("failed to read h-pulse-width, rc=%d\n", rc);
+			goto fail;
+		}
+
+		rc = of_property_read_u16(node, "qcom,mode-h-back-porch",
+						&h_back_porch);
+		if (rc) {
+			DP_ERR("failed to read h-back-porch, rc=%d\n", rc);
+			goto fail;
+		}
+
+		h_active_high = of_property_read_bool(node,
+						"qcom,mode-h-active-high");
+
+		rc = of_property_read_u16(node, "qcom,mode-v-active",
+						&mode->vdisplay);
+		if (rc) {
+			DP_ERR("failed to read v-active, rc=%d\n", rc);
+			goto fail;
+		}
+
+		rc = of_property_read_u16(node, "qcom,mode-v-front-porch",
+						&v_front_porch);
+		if (rc) {
+			DP_ERR("failed to read v-front-porch, rc=%d\n", rc);
+			goto fail;
+		}
+
+		rc = of_property_read_u16(node, "qcom,mode-v-pulse-width",
+						&v_pulse_width);
+		if (rc) {
+			DP_ERR("failed to read v-pulse-width, rc=%d\n", rc);
+			goto fail;
+		}
+
+		rc = of_property_read_u16(node, "qcom,mode-v-back-porch",
+						&v_back_porch);
+		if (rc) {
+			DP_ERR("failed to read v-back-porch, rc=%d\n", rc);
+			goto fail;
+		}
+
+		v_active_high = of_property_read_bool(node,
+						"qcom,mode-v-active-high");
+
+		rc = of_property_read_u32(node, "qcom,mode-clock-in-khz",
+						&mode->clock);
+		if (rc) {
+			DP_ERR("failed to read clock, rc=%d\n", rc);
+			goto fail;
+		}
+
+		mode->hsync_start = mode->hdisplay + h_front_porch;
+		mode->hsync_end = mode->hsync_start + h_pulse_width;
+		mode->htotal = mode->hsync_end + h_back_porch;
+		mode->vsync_start = mode->vdisplay + v_front_porch;
+		mode->vsync_end = mode->vsync_start + v_pulse_width;
+		mode->vtotal = mode->vsync_end + v_back_porch;
+		if (h_active_high)
+			flags |= DRM_MODE_FLAG_PHSYNC;
+		else
+			flags |= DRM_MODE_FLAG_NHSYNC;
+		if (v_active_high)
+			flags |= DRM_MODE_FLAG_PVSYNC;
+		else
+			flags |= DRM_MODE_FLAG_NVSYNC;
+		mode->flags = flags;
+
+		edid = kzalloc(sizeof(*edid), GFP_KERNEL);
+		if (!edid) {
+			rc = -ENOMEM;
+			goto fail;
+		}
+
+		memcpy(edid, edid_buf, sizeof(edid_buf));
+		dp_sim_update_dtd(edid, mode);
+		dp_sim_update_checksum(edid);
+
+		memcpy(&ports[i], &output_port, sizeof(*ports));
+		ports[i].peer_guid[0] = i;
+		ports[i].edid = (u8 *)edid;
+		ports[i].edid_size = sizeof(*edid);
+		i++;
+	}
+
+	rc = dp_mst_sim_update(sim_dev->bridge.mst_ctx, port_num, ports);
+
+fail:
+	for (i = 0; i < port_num; i++)
+		kfree(ports[i].edid);
+	kfree(ports);
+
+	return rc;
+}
+
+int dp_sim_probe(struct platform_device *pdev)
+{
+	struct dp_sim_device *dp_sim_dev;
+	struct dp_mst_sim_cfg cfg;
+	int ret;
+
+	dp_sim_dev = devm_kzalloc(&pdev->dev, sizeof(*dp_sim_dev), GFP_KERNEL);
+	if (!dp_sim_dev)
+		return -ENOMEM;
+
+	dp_sim_dev->bridge.of_node = pdev->dev.of_node;
+	dp_sim_dev->bridge.register_hpd = dp_sim_register_hpd;
+	dp_sim_dev->bridge.transfer = dp_sim_transfer;
+	dp_sim_dev->bridge.dev_priv = dp_sim_dev;
+	dp_sim_dev->bridge.flag = DP_AUX_BRIDGE_MST;
+
+	memset(&cfg, 0, sizeof(cfg));
+	cfg.host_dev = dp_sim_dev;
+	cfg.host_hpd_irq = dp_sim_host_hpd_irq;
+
+	ret = dp_mst_sim_create(&cfg, &dp_sim_dev->bridge.mst_ctx);
+	if (ret)
+		return ret;
+
+	ret = dp_sim_parse(dp_sim_dev);
+	if (ret)
+		goto fail;
+
+	ret = dp_aux_add_bridge(&dp_sim_dev->bridge);
+	if (ret)
+		goto fail;
+
+	platform_set_drvdata(pdev, dp_sim_dev);
+
+	return 0;
+
+fail:
+	dp_mst_sim_destroy(dp_sim_dev->bridge.mst_ctx);
+	return ret;
+}
+
+int dp_sim_remove(struct platform_device *pdev)
+{
+	struct dp_sim_device *dp_sim_dev;
+
+	dp_sim_dev = platform_get_drvdata(pdev);
+	if (!dp_sim_dev)
+		return 0;
+
+	dp_mst_sim_destroy(dp_sim_dev->bridge.mst_ctx);
+
+	return 0;
+}
+
+#if 0
+static const struct of_device_id dt_match[] = {
+	{ .compatible = "qcom,dp-mst-sim"},
+	{},
+};
+
+static struct platform_driver dp_sim_driver = {
+	.probe = dp_sim_probe,
+	.remove = dp_sim_remove,
+	.driver = {
+		.name = "dp_sim",
+		.of_match_table = dt_match,
+		.suppress_bind_attrs = true,
+	},
+};
+
+static int __init dp_sim_register(void)
+{
+	return platform_driver_register(&dp_sim_driver);
+}
+
+static void __exit dp_sim_unregister(void)
+{
+	platform_driver_unregister(&dp_sim_driver);
+}
+
+module_init(dp_sim_register);
+module_exit(dp_sim_unregister);
+
+#endif
\ No newline at end of file