diff --git a/drivers/net/wwan/Kconfig b/drivers/net/wwan/Kconfig
index 7ad1920120bcb..ec0b194a373c8 100644
--- a/drivers/net/wwan/Kconfig
+++ b/drivers/net/wwan/Kconfig
@@ -20,6 +20,16 @@ config WWAN_CORE
 	  To compile this driver as a module, choose M here: the module will be
 	  called wwan.
 
+config WWAN_HWSIM
+	tristate "Simulated WWAN device"
+	depends on WWAN_CORE
+	help
+	  This driver is a developer testing tool that can be used to test WWAN
+	  framework.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called wwan_hwsim.  If unsure, say N.
+
 config MHI_WWAN_CTRL
 	tristate "MHI WWAN control driver for QCOM-based PCIe modems"
 	select WWAN_CORE
diff --git a/drivers/net/wwan/Makefile b/drivers/net/wwan/Makefile
index 556cd90958cae..f33f77ca10218 100644
--- a/drivers/net/wwan/Makefile
+++ b/drivers/net/wwan/Makefile
@@ -6,4 +6,6 @@
 obj-$(CONFIG_WWAN_CORE) += wwan.o
 wwan-objs += wwan_core.o
 
+obj-$(CONFIG_WWAN_HWSIM) += wwan_hwsim.o
+
 obj-$(CONFIG_MHI_WWAN_CTRL) += mhi_wwan_ctrl.o
diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c
index 6e8f19c71a9ef..45a41aee8958f 100644
--- a/drivers/net/wwan/wwan_core.c
+++ b/drivers/net/wwan/wwan_core.c
@@ -12,9 +12,11 @@
 #include <linux/skbuff.h>
 #include <linux/slab.h>
 #include <linux/types.h>
+#include <linux/termios.h>
 #include <linux/wwan.h>
 
-#define WWAN_MAX_MINORS 256 /* 256 minors allowed with register_chrdev() */
+/* Maximum number of minors in use */
+#define WWAN_MAX_MINORS		(1 << MINORBITS)
 
 static DEFINE_MUTEX(wwan_register_lock); /* WWAN device create|remove lock */
 static DEFINE_IDA(minors); /* minors for WWAN port chardevs */
@@ -33,12 +35,10 @@ static int wwan_major;
  *
  * @id: WWAN device unique ID.
  * @dev: Underlying device.
- * @port_id: Current available port ID to pick.
  */
 struct wwan_device {
 	unsigned int id;
 	struct device dev;
-	atomic_t port_id;
 };
 
 /**
@@ -51,6 +51,8 @@ struct wwan_device {
  * @dev: Underlying device
  * @rxq: Buffer inbound queue
  * @waitqueue: The waitqueue for port fops (read/write/poll)
+ * @data_lock: Port specific data access serialization
+ * @at_data: AT port specific data
  */
 struct wwan_port {
 	enum wwan_port_type type;
@@ -61,6 +63,13 @@ struct wwan_port {
 	struct device dev;
 	struct sk_buff_head rxq;
 	wait_queue_head_t waitqueue;
+	struct mutex data_lock;	/* Port specific data access serialization */
+	union {
+		struct {
+			struct ktermios termios;
+			int mdmbits;
+		} at_data;
+	};
 };
 
 static ssize_t index_show(struct device *dev, struct device_attribute *attr, char *buf)
@@ -184,13 +193,30 @@ static void wwan_remove_dev(struct wwan_device *wwandev)
 
 /* ------- WWAN port management ------- */
 
-/* Keep aligned with wwan_port_type enum */
-static const char * const wwan_port_type_str[] = {
-	"AT",
-	"MBIM",
-	"QMI",
-	"QCDM",
-	"FIREHOSE"
+static const struct {
+	const char * const name;	/* Port type name */
+	const char * const devsuf;	/* Port devce name suffix */
+} wwan_port_types[WWAN_PORT_MAX + 1] = {
+	[WWAN_PORT_AT] = {
+		.name = "AT",
+		.devsuf = "at",
+	},
+	[WWAN_PORT_MBIM] = {
+		.name = "MBIM",
+		.devsuf = "mbim",
+	},
+	[WWAN_PORT_QMI] = {
+		.name = "QMI",
+		.devsuf = "qmi",
+	},
+	[WWAN_PORT_QCDM] = {
+		.name = "QCDM",
+		.devsuf = "qcdm",
+	},
+	[WWAN_PORT_FIREHOSE] = {
+		.name = "FIREHOSE",
+		.devsuf = "firehose",
+	},
 };
 
 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
@@ -198,7 +224,7 @@ static ssize_t type_show(struct device *dev, struct device_attribute *attr,
 {
 	struct wwan_port *port = to_wwan_port(dev);
 
-	return sprintf(buf, "%s\n", wwan_port_type_str[port->type]);
+	return sprintf(buf, "%s\n", wwan_port_types[port->type].name);
 }
 static DEVICE_ATTR_RO(type);
 
@@ -213,7 +239,7 @@ static void wwan_port_destroy(struct device *dev)
 	struct wwan_port *port = to_wwan_port(dev);
 
 	ida_free(&minors, MINOR(port->dev.devt));
-	skb_queue_purge(&port->rxq);
+	mutex_destroy(&port->data_lock);
 	mutex_destroy(&port->ops_lock);
 	kfree(port);
 }
@@ -241,6 +267,56 @@ static struct wwan_port *wwan_port_get_by_minor(unsigned int minor)
 	return to_wwan_port(dev);
 }
 
+/* Allocate and set unique name based on passed format
+ *
+ * Name allocation approach is highly inspired by the __dev_alloc_name()
+ * function.
+ *
+ * To avoid names collision, the caller must prevent the new port device
+ * registration as well as concurrent invocation of this function.
+ */
+static int __wwan_port_dev_assign_name(struct wwan_port *port, const char *fmt)
+{
+	struct wwan_device *wwandev = to_wwan_dev(port->dev.parent);
+	const unsigned int max_ports = PAGE_SIZE * 8;
+	struct class_dev_iter iter;
+	unsigned long *idmap;
+	struct device *dev;
+	char buf[0x20];
+	int id;
+
+	idmap = (unsigned long *)get_zeroed_page(GFP_KERNEL);
+	if (!idmap)
+		return -ENOMEM;
+
+	/* Collect ids of same name format ports */
+	class_dev_iter_init(&iter, wwan_class, NULL, &wwan_port_dev_type);
+	while ((dev = class_dev_iter_next(&iter))) {
+		if (dev->parent != &wwandev->dev)
+			continue;
+		if (sscanf(dev_name(dev), fmt, &id) != 1)
+			continue;
+		if (id < 0 || id >= max_ports)
+			continue;
+		set_bit(id, idmap);
+	}
+	class_dev_iter_exit(&iter);
+
+	/* Allocate unique id */
+	id = find_first_zero_bit(idmap, max_ports);
+	free_page((unsigned long)idmap);
+
+	snprintf(buf, sizeof(buf), fmt, id);	/* Name generation */
+
+	dev = device_find_child_by_name(&wwandev->dev, buf);
+	if (dev) {
+		put_device(dev);
+		return -ENFILE;
+	}
+
+	return dev_set_name(&port->dev, buf);
+}
+
 struct wwan_port *wwan_create_port(struct device *parent,
 				   enum wwan_port_type type,
 				   const struct wwan_port_ops *ops,
@@ -249,8 +325,9 @@ struct wwan_port *wwan_create_port(struct device *parent,
 	struct wwan_device *wwandev;
 	struct wwan_port *port;
 	int minor, err = -ENOMEM;
+	char namefmt[0x20];
 
-	if (type >= WWAN_PORT_MAX || !ops)
+	if (type > WWAN_PORT_MAX || !ops)
 		return ERR_PTR(-EINVAL);
 
 	/* A port is always a child of a WWAN device, retrieve (allocate or
@@ -276,6 +353,7 @@ struct wwan_port *wwan_create_port(struct device *parent,
 	mutex_init(&port->ops_lock);
 	skb_queue_head_init(&port->rxq);
 	init_waitqueue_head(&port->waitqueue);
+	mutex_init(&port->data_lock);
 
 	port->dev.parent = &wwandev->dev;
 	port->dev.class = wwan_class;
@@ -283,12 +361,18 @@ struct wwan_port *wwan_create_port(struct device *parent,
 	port->dev.devt = MKDEV(wwan_major, minor);
 	dev_set_drvdata(&port->dev, drvdata);
 
-	/* create unique name based on wwan device id, port index and type */
-	dev_set_name(&port->dev, "wwan%up%u%s", wwandev->id,
-		     atomic_inc_return(&wwandev->port_id),
-		     wwan_port_type_str[port->type]);
+	/* allocate unique name based on wwan device id, port type and number */
+	snprintf(namefmt, sizeof(namefmt), "wwan%u%s%%d", wwandev->id,
+		 wwan_port_types[port->type].devsuf);
 
+	/* Serialize ports registration */
+	mutex_lock(&wwan_register_lock);
+
+	__wwan_port_dev_assign_name(port, namefmt);
 	err = device_register(&port->dev);
+
+	mutex_unlock(&wwan_register_lock);
+
 	if (err)
 		goto error_put_device;
 
@@ -377,8 +461,11 @@ static void wwan_port_op_stop(struct wwan_port *port)
 {
 	mutex_lock(&port->ops_lock);
 	port->start_count--;
-	if (port->ops && !port->start_count)
-		port->ops->stop(port);
+	if (!port->start_count) {
+		if (port->ops)
+			port->ops->stop(port);
+		skb_queue_purge(&port->rxq);
+	}
 	mutex_unlock(&port->ops_lock);
 }
 
@@ -545,6 +632,110 @@ static __poll_t wwan_port_fops_poll(struct file *filp, poll_table *wait)
 	return mask;
 }
 
+/* Implements minimalistic stub terminal IOCTLs support */
+static long wwan_port_fops_at_ioctl(struct wwan_port *port, unsigned int cmd,
+				    unsigned long arg)
+{
+	int ret = 0;
+
+	mutex_lock(&port->data_lock);
+
+	switch (cmd) {
+	case TCFLSH:
+		break;
+
+	case TCGETS:
+		if (copy_to_user((void __user *)arg, &port->at_data.termios,
+				 sizeof(struct termios)))
+			ret = -EFAULT;
+		break;
+
+	case TCSETS:
+	case TCSETSW:
+	case TCSETSF:
+		if (copy_from_user(&port->at_data.termios, (void __user *)arg,
+				   sizeof(struct termios)))
+			ret = -EFAULT;
+		break;
+
+#ifdef TCGETS2
+	case TCGETS2:
+		if (copy_to_user((void __user *)arg, &port->at_data.termios,
+				 sizeof(struct termios2)))
+			ret = -EFAULT;
+		break;
+
+	case TCSETS2:
+	case TCSETSW2:
+	case TCSETSF2:
+		if (copy_from_user(&port->at_data.termios, (void __user *)arg,
+				   sizeof(struct termios2)))
+			ret = -EFAULT;
+		break;
+#endif
+
+	case TIOCMGET:
+		ret = put_user(port->at_data.mdmbits, (int __user *)arg);
+		break;
+
+	case TIOCMSET:
+	case TIOCMBIC:
+	case TIOCMBIS: {
+		int mdmbits;
+
+		if (copy_from_user(&mdmbits, (int __user *)arg, sizeof(int))) {
+			ret = -EFAULT;
+			break;
+		}
+		if (cmd == TIOCMBIC)
+			port->at_data.mdmbits &= ~mdmbits;
+		else if (cmd == TIOCMBIS)
+			port->at_data.mdmbits |= mdmbits;
+		else
+			port->at_data.mdmbits = mdmbits;
+		break;
+	}
+
+	default:
+		ret = -ENOIOCTLCMD;
+	}
+
+	mutex_unlock(&port->data_lock);
+
+	return ret;
+}
+
+static long wwan_port_fops_ioctl(struct file *filp, unsigned int cmd,
+				 unsigned long arg)
+{
+	struct wwan_port *port = filp->private_data;
+	int res;
+
+	if (port->type == WWAN_PORT_AT) {	/* AT port specific IOCTLs */
+		res = wwan_port_fops_at_ioctl(port, cmd, arg);
+		if (res != -ENOIOCTLCMD)
+			return res;
+	}
+
+	switch (cmd) {
+	case TIOCINQ: {	/* aka SIOCINQ aka FIONREAD */
+		unsigned long flags;
+		struct sk_buff *skb;
+		int amount = 0;
+
+		spin_lock_irqsave(&port->rxq.lock, flags);
+		skb_queue_walk(&port->rxq, skb)
+			amount += skb->len;
+		spin_unlock_irqrestore(&port->rxq.lock, flags);
+
+		return put_user(amount, (int __user *)arg);
+	}
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
 static const struct file_operations wwan_port_fops = {
 	.owner = THIS_MODULE,
 	.open = wwan_port_fops_open,
@@ -552,6 +743,10 @@ static const struct file_operations wwan_port_fops = {
 	.read = wwan_port_fops_read,
 	.write = wwan_port_fops_write,
 	.poll = wwan_port_fops_poll,
+	.unlocked_ioctl = wwan_port_fops_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = compat_ptr_ioctl,
+#endif
 	.llseek = noop_llseek,
 };
 
@@ -562,7 +757,8 @@ static int __init wwan_init(void)
 		return PTR_ERR(wwan_class);
 
 	/* chrdev used for wwan ports */
-	wwan_major = register_chrdev(0, "wwan_port", &wwan_port_fops);
+	wwan_major = __register_chrdev(0, 0, WWAN_MAX_MINORS, "wwan_port",
+				       &wwan_port_fops);
 	if (wwan_major < 0) {
 		class_destroy(wwan_class);
 		return wwan_major;
@@ -573,7 +769,7 @@ static int __init wwan_init(void)
 
 static void __exit wwan_exit(void)
 {
-	unregister_chrdev(wwan_major, "wwan_port");
+	__unregister_chrdev(wwan_major, 0, WWAN_MAX_MINORS, "wwan_port");
 	class_destroy(wwan_class);
 }
 
diff --git a/drivers/net/wwan/wwan_hwsim.c b/drivers/net/wwan/wwan_hwsim.c
new file mode 100644
index 0000000000000..472cae544a2bd
--- /dev/null
+++ b/drivers/net/wwan/wwan_hwsim.c
@@ -0,0 +1,500 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * WWAN device simulator for WWAN framework testing.
+ *
+ * Copyright (c) 2021, Sergey Ryazanov <ryazanov.s.a@gmail.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/skbuff.h>
+#include <linux/wwan.h>
+#include <linux/debugfs.h>
+#include <linux/workqueue.h>
+
+static int wwan_hwsim_devsnum = 2;
+module_param_named(devices, wwan_hwsim_devsnum, int, 0444);
+MODULE_PARM_DESC(devices, "Number of simulated devices");
+
+static struct class *wwan_hwsim_class;
+
+static struct dentry *wwan_hwsim_debugfs_topdir;
+static struct dentry *wwan_hwsim_debugfs_devcreate;
+
+static DEFINE_SPINLOCK(wwan_hwsim_devs_lock);
+static LIST_HEAD(wwan_hwsim_devs);
+static unsigned int wwan_hwsim_dev_idx;
+
+struct wwan_hwsim_dev {
+	struct list_head list;
+	unsigned int id;
+	struct device dev;
+	struct work_struct del_work;
+	struct dentry *debugfs_topdir;
+	struct dentry *debugfs_portcreate;
+	spinlock_t ports_lock;	/* Serialize ports creation/deletion */
+	unsigned int port_idx;
+	struct list_head ports;
+};
+
+struct wwan_hwsim_port {
+	struct list_head list;
+	unsigned int id;
+	struct wwan_hwsim_dev *dev;
+	struct wwan_port *wwan;
+	struct work_struct del_work;
+	struct dentry *debugfs_topdir;
+	enum {			/* AT command parser state */
+		AT_PARSER_WAIT_A,
+		AT_PARSER_WAIT_T,
+		AT_PARSER_WAIT_TERM,
+		AT_PARSER_SKIP_LINE,
+	} pstate;
+};
+
+static const struct file_operations wwan_hwsim_debugfs_portdestroy_fops;
+static const struct file_operations wwan_hwsim_debugfs_portcreate_fops;
+static const struct file_operations wwan_hwsim_debugfs_devdestroy_fops;
+static void wwan_hwsim_port_del_work(struct work_struct *work);
+static void wwan_hwsim_dev_del_work(struct work_struct *work);
+
+static int wwan_hwsim_port_start(struct wwan_port *wport)
+{
+	struct wwan_hwsim_port *port = wwan_port_get_drvdata(wport);
+
+	port->pstate = AT_PARSER_WAIT_A;
+
+	return 0;
+}
+
+static void wwan_hwsim_port_stop(struct wwan_port *wport)
+{
+}
+
+/* Implements a minimalistic AT commands parser that echo input back and
+ * reply with 'OK' to each input command. See AT command protocol details in the
+ * ITU-T V.250 recomendations document.
+ *
+ * Be aware that this processor is not fully V.250 compliant.
+ */
+static int wwan_hwsim_port_tx(struct wwan_port *wport, struct sk_buff *in)
+{
+	struct wwan_hwsim_port *port = wwan_port_get_drvdata(wport);
+	struct sk_buff *out;
+	int i, n, s;
+
+	/* Estimate a max possible number of commands by counting the number of
+	 * termination chars (S3 param, CR by default). And then allocate the
+	 * output buffer that will be enough to fit the echo and result codes of
+	 * all commands.
+	 */
+	for (i = 0, n = 0; i < in->len; ++i)
+		if (in->data[i] == '\r')
+			n++;
+	n = in->len + n * (2 + 2 + 2);	/* Output buffer size */
+	out = alloc_skb(n, GFP_KERNEL);
+	if (!out)
+		return -ENOMEM;
+
+	for (i = 0, s = 0; i < in->len; ++i) {
+		char c = in->data[i];
+
+		if (port->pstate == AT_PARSER_WAIT_A) {
+			if (c == 'A' || c == 'a')
+				port->pstate = AT_PARSER_WAIT_T;
+			else if (c != '\n')	/* Ignore formating char */
+				port->pstate = AT_PARSER_SKIP_LINE;
+		} else if (port->pstate == AT_PARSER_WAIT_T) {
+			if (c == 'T' || c == 't')
+				port->pstate = AT_PARSER_WAIT_TERM;
+			else
+				port->pstate = AT_PARSER_SKIP_LINE;
+		} else if (port->pstate == AT_PARSER_WAIT_TERM) {
+			if (c != '\r')
+				continue;
+			/* Consume the trailing formatting char as well */
+			if ((i + 1) < in->len && in->data[i + 1] == '\n')
+				i++;
+			n = i - s + 1;
+			memcpy(skb_put(out, n), &in->data[s], n);/* Echo */
+			memcpy(skb_put(out, 6), "\r\nOK\r\n", 6);
+			s = i + 1;
+			port->pstate = AT_PARSER_WAIT_A;
+		} else if (port->pstate == AT_PARSER_SKIP_LINE) {
+			if (c != '\r')
+				continue;
+			port->pstate = AT_PARSER_WAIT_A;
+		}
+	}
+
+	if (i > s) {
+		/* Echo the processed portion of a not yet completed command */
+		n = i - s;
+		memcpy(skb_put(out, n), &in->data[s], n);
+	}
+
+	consume_skb(in);
+
+	wwan_port_rx(wport, out);
+
+	return 0;
+}
+
+static const struct wwan_port_ops wwan_hwsim_port_ops = {
+	.start = wwan_hwsim_port_start,
+	.stop = wwan_hwsim_port_stop,
+	.tx = wwan_hwsim_port_tx,
+};
+
+static struct wwan_hwsim_port *wwan_hwsim_port_new(struct wwan_hwsim_dev *dev)
+{
+	struct wwan_hwsim_port *port;
+	char name[0x10];
+	int err;
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return ERR_PTR(-ENOMEM);
+
+	port->dev = dev;
+
+	spin_lock(&dev->ports_lock);
+	port->id = dev->port_idx++;
+	spin_unlock(&dev->ports_lock);
+
+	port->wwan = wwan_create_port(&dev->dev, WWAN_PORT_AT,
+				      &wwan_hwsim_port_ops,
+				      port);
+	if (IS_ERR(port->wwan)) {
+		err = PTR_ERR(port->wwan);
+		goto err_free_port;
+	}
+
+	INIT_WORK(&port->del_work, wwan_hwsim_port_del_work);
+
+	snprintf(name, sizeof(name), "port%u", port->id);
+	port->debugfs_topdir = debugfs_create_dir(name, dev->debugfs_topdir);
+	debugfs_create_file("destroy", 0200, port->debugfs_topdir, port,
+			    &wwan_hwsim_debugfs_portdestroy_fops);
+
+	return port;
+
+err_free_port:
+	kfree(port);
+
+	return ERR_PTR(err);
+}
+
+static void wwan_hwsim_port_del(struct wwan_hwsim_port *port)
+{
+	debugfs_remove(port->debugfs_topdir);
+
+	/* Make sure that there is no pending deletion work */
+	if (current_work() != &port->del_work)
+		cancel_work_sync(&port->del_work);
+
+	wwan_remove_port(port->wwan);
+	kfree(port);
+}
+
+static void wwan_hwsim_port_del_work(struct work_struct *work)
+{
+	struct wwan_hwsim_port *port =
+				container_of(work, typeof(*port), del_work);
+	struct wwan_hwsim_dev *dev = port->dev;
+
+	spin_lock(&dev->ports_lock);
+	if (list_empty(&port->list)) {
+		/* Someone else deleting port at the moment */
+		spin_unlock(&dev->ports_lock);
+		return;
+	}
+	list_del_init(&port->list);
+	spin_unlock(&dev->ports_lock);
+
+	wwan_hwsim_port_del(port);
+}
+
+static void wwan_hwsim_dev_release(struct device *sysdev)
+{
+	struct wwan_hwsim_dev *dev = container_of(sysdev, typeof(*dev), dev);
+
+	kfree(dev);
+}
+
+static struct wwan_hwsim_dev *wwan_hwsim_dev_new(void)
+{
+	struct wwan_hwsim_dev *dev;
+	int err;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	spin_lock(&wwan_hwsim_devs_lock);
+	dev->id = wwan_hwsim_dev_idx++;
+	spin_unlock(&wwan_hwsim_devs_lock);
+
+	dev->dev.release = wwan_hwsim_dev_release;
+	dev->dev.class = wwan_hwsim_class;
+	dev_set_name(&dev->dev, "hwsim%u", dev->id);
+
+	spin_lock_init(&dev->ports_lock);
+	INIT_LIST_HEAD(&dev->ports);
+
+	err = device_register(&dev->dev);
+	if (err)
+		goto err_free_dev;
+
+	INIT_WORK(&dev->del_work, wwan_hwsim_dev_del_work);
+
+	dev->debugfs_topdir = debugfs_create_dir(dev_name(&dev->dev),
+						 wwan_hwsim_debugfs_topdir);
+	debugfs_create_file("destroy", 0200, dev->debugfs_topdir, dev,
+			    &wwan_hwsim_debugfs_devdestroy_fops);
+	dev->debugfs_portcreate =
+		debugfs_create_file("portcreate", 0200,
+				    dev->debugfs_topdir, dev,
+				    &wwan_hwsim_debugfs_portcreate_fops);
+
+	return dev;
+
+err_free_dev:
+	kfree(dev);
+
+	return ERR_PTR(err);
+}
+
+static void wwan_hwsim_dev_del(struct wwan_hwsim_dev *dev)
+{
+	debugfs_remove(dev->debugfs_portcreate);	/* Avoid new ports */
+
+	spin_lock(&dev->ports_lock);
+	while (!list_empty(&dev->ports)) {
+		struct wwan_hwsim_port *port;
+
+		port = list_first_entry(&dev->ports, struct wwan_hwsim_port,
+					list);
+		list_del_init(&port->list);
+		spin_unlock(&dev->ports_lock);
+		wwan_hwsim_port_del(port);
+		spin_lock(&dev->ports_lock);
+	}
+	spin_unlock(&dev->ports_lock);
+
+	debugfs_remove(dev->debugfs_topdir);
+
+	/* Make sure that there is no pending deletion work */
+	if (current_work() != &dev->del_work)
+		cancel_work_sync(&dev->del_work);
+
+	device_unregister(&dev->dev);
+	/* Memory will be freed in the device release callback */
+}
+
+static void wwan_hwsim_dev_del_work(struct work_struct *work)
+{
+	struct wwan_hwsim_dev *dev = container_of(work, typeof(*dev), del_work);
+
+	spin_lock(&wwan_hwsim_devs_lock);
+	if (list_empty(&dev->list)) {
+		/* Someone else deleting device at the moment */
+		spin_unlock(&wwan_hwsim_devs_lock);
+		return;
+	}
+	list_del_init(&dev->list);
+	spin_unlock(&wwan_hwsim_devs_lock);
+
+	wwan_hwsim_dev_del(dev);
+}
+
+static ssize_t wwan_hwsim_debugfs_portdestroy_write(struct file *file,
+						    const char __user *usrbuf,
+						    size_t count, loff_t *ppos)
+{
+	struct wwan_hwsim_port *port = file->private_data;
+
+	/* We can not delete port here since it will cause a deadlock due to
+	 * waiting this callback to finish in the debugfs_remove() call. So,
+	 * use workqueue.
+	 */
+	schedule_work(&port->del_work);
+
+	return count;
+}
+
+static const struct file_operations wwan_hwsim_debugfs_portdestroy_fops = {
+	.write = wwan_hwsim_debugfs_portdestroy_write,
+	.open = simple_open,
+	.llseek = noop_llseek,
+};
+
+static ssize_t wwan_hwsim_debugfs_portcreate_write(struct file *file,
+						   const char __user *usrbuf,
+						   size_t count, loff_t *ppos)
+{
+	struct wwan_hwsim_dev *dev = file->private_data;
+	struct wwan_hwsim_port *port;
+
+	port = wwan_hwsim_port_new(dev);
+	if (IS_ERR(port))
+		return PTR_ERR(port);
+
+	spin_lock(&dev->ports_lock);
+	list_add_tail(&port->list, &dev->ports);
+	spin_unlock(&dev->ports_lock);
+
+	return count;
+}
+
+static const struct file_operations wwan_hwsim_debugfs_portcreate_fops = {
+	.write = wwan_hwsim_debugfs_portcreate_write,
+	.open = simple_open,
+	.llseek = noop_llseek,
+};
+
+static ssize_t wwan_hwsim_debugfs_devdestroy_write(struct file *file,
+						   const char __user *usrbuf,
+						   size_t count, loff_t *ppos)
+{
+	struct wwan_hwsim_dev *dev = file->private_data;
+
+	/* We can not delete device here since it will cause a deadlock due to
+	 * waiting this callback to finish in the debugfs_remove() call. So,
+	 * use workqueue.
+	 */
+	schedule_work(&dev->del_work);
+
+	return count;
+}
+
+static const struct file_operations wwan_hwsim_debugfs_devdestroy_fops = {
+	.write = wwan_hwsim_debugfs_devdestroy_write,
+	.open = simple_open,
+	.llseek = noop_llseek,
+};
+
+static ssize_t wwan_hwsim_debugfs_devcreate_write(struct file *file,
+						  const char __user *usrbuf,
+						  size_t count, loff_t *ppos)
+{
+	struct wwan_hwsim_dev *dev;
+
+	dev = wwan_hwsim_dev_new();
+	if (IS_ERR(dev))
+		return PTR_ERR(dev);
+
+	spin_lock(&wwan_hwsim_devs_lock);
+	list_add_tail(&dev->list, &wwan_hwsim_devs);
+	spin_unlock(&wwan_hwsim_devs_lock);
+
+	return count;
+}
+
+static const struct file_operations wwan_hwsim_debugfs_devcreate_fops = {
+	.write = wwan_hwsim_debugfs_devcreate_write,
+	.open = simple_open,
+	.llseek = noop_llseek,
+};
+
+static int __init wwan_hwsim_init_devs(void)
+{
+	struct wwan_hwsim_dev *dev;
+	int i, j;
+
+	for (i = 0; i < wwan_hwsim_devsnum; ++i) {
+		dev = wwan_hwsim_dev_new();
+		if (IS_ERR(dev))
+			return PTR_ERR(dev);
+
+		spin_lock(&wwan_hwsim_devs_lock);
+		list_add_tail(&dev->list, &wwan_hwsim_devs);
+		spin_unlock(&wwan_hwsim_devs_lock);
+
+		/* Create a couple of ports per each device to accelerate
+		 * the simulator readiness time.
+		 */
+		for (j = 0; j < 2; ++j) {
+			struct wwan_hwsim_port *port;
+
+			port = wwan_hwsim_port_new(dev);
+			if (IS_ERR(port))
+				return PTR_ERR(port);
+
+			spin_lock(&dev->ports_lock);
+			list_add_tail(&port->list, &dev->ports);
+			spin_unlock(&dev->ports_lock);
+		}
+	}
+
+	return 0;
+}
+
+static void wwan_hwsim_free_devs(void)
+{
+	struct wwan_hwsim_dev *dev;
+
+	spin_lock(&wwan_hwsim_devs_lock);
+	while (!list_empty(&wwan_hwsim_devs)) {
+		dev = list_first_entry(&wwan_hwsim_devs, struct wwan_hwsim_dev,
+				       list);
+		list_del_init(&dev->list);
+		spin_unlock(&wwan_hwsim_devs_lock);
+		wwan_hwsim_dev_del(dev);
+		spin_lock(&wwan_hwsim_devs_lock);
+	}
+	spin_unlock(&wwan_hwsim_devs_lock);
+}
+
+static int __init wwan_hwsim_init(void)
+{
+	int err;
+
+	if (wwan_hwsim_devsnum < 0 || wwan_hwsim_devsnum > 128)
+		return -EINVAL;
+
+	wwan_hwsim_class = class_create(THIS_MODULE, "wwan_hwsim");
+	if (IS_ERR(wwan_hwsim_class))
+		return PTR_ERR(wwan_hwsim_class);
+
+	wwan_hwsim_debugfs_topdir = debugfs_create_dir("wwan_hwsim", NULL);
+	wwan_hwsim_debugfs_devcreate =
+			debugfs_create_file("devcreate", 0200,
+					    wwan_hwsim_debugfs_topdir, NULL,
+					    &wwan_hwsim_debugfs_devcreate_fops);
+
+	err = wwan_hwsim_init_devs();
+	if (err)
+		goto err_clean_devs;
+
+	return 0;
+
+err_clean_devs:
+	wwan_hwsim_free_devs();
+	debugfs_remove(wwan_hwsim_debugfs_topdir);
+	class_destroy(wwan_hwsim_class);
+
+	return err;
+}
+
+static void __exit wwan_hwsim_exit(void)
+{
+	debugfs_remove(wwan_hwsim_debugfs_devcreate);	/* Avoid new devs */
+	wwan_hwsim_free_devs();
+	flush_scheduled_work();		/* Wait deletion works completion */
+	debugfs_remove(wwan_hwsim_debugfs_topdir);
+	class_destroy(wwan_hwsim_class);
+}
+
+module_init(wwan_hwsim_init);
+module_exit(wwan_hwsim_exit);
+
+MODULE_AUTHOR("Sergey Ryazanov");
+MODULE_DESCRIPTION("Device simulator for WWAN framework");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/wwan.h b/include/linux/wwan.h
index 7216c114d7582..fa33cc16d931a 100644
--- a/include/linux/wwan.h
+++ b/include/linux/wwan.h
@@ -15,8 +15,10 @@
  * @WWAN_PORT_QMI: Qcom modem/MSM interface for modem control
  * @WWAN_PORT_QCDM: Qcom Modem diagnostic interface
  * @WWAN_PORT_FIREHOSE: XML based command protocol
- * @WWAN_PORT_UNKNOWN: Unknown port type
- * @WWAN_PORT_MAX: Number of supported port types
+ *
+ * @WWAN_PORT_MAX: Highest supported port types
+ * @WWAN_PORT_UNKNOWN: Special value to indicate an unknown port type
+ * @__WWAN_PORT_MAX: Internal use
  */
 enum wwan_port_type {
 	WWAN_PORT_AT,
@@ -24,8 +26,12 @@ enum wwan_port_type {
 	WWAN_PORT_QMI,
 	WWAN_PORT_QCDM,
 	WWAN_PORT_FIREHOSE,
+
+	/* Add new port types above this line */
+
+	__WWAN_PORT_MAX,
+	WWAN_PORT_MAX = __WWAN_PORT_MAX - 1,
 	WWAN_PORT_UNKNOWN,
-	WWAN_PORT_MAX = WWAN_PORT_UNKNOWN,
 };
 
 struct wwan_port;