Merge tag 'rpmsg-v4.11' of git://github.com/andersson/remoteproc

Pull rpmsg updates from Bjorn Andersson:
 "This introduces an interface for user space to directly communicate on
  rpmsg endpoints without the implementation of specific kernel drivers,
  which is useful for e.g. debug channels:

* tag 'rpmsg-v4.11' of git://github.com/andersson/remoteproc:
  rpmsg: rpmsg_create_ept() returns NULL on error
  rpmsg: qcom: smd: Return positively when not enabled
  rpmsg: unlock on error in rpmsg_eptdev_read()
  rpmsg: char: add CONFIG_NET dependency
  rpmsg: smd: Register rpmsg user space interface for edges
  rpmsg: Driver for user space endpoint interface
  rpmsg: qcom_smd: Implement endpoint "poll"
  rpmsg: Introduce "poll" to endpoint ops
  rpmsg: qcom_smd: Add support for "label" property

Documentation/ioctl/ioctl-number.txt

@@ -321,6 +321,7 @@ Code  Seq#(hex)	Include File		Comments
 0xB1	00-1F	PPPoX			<mailto:mostrows@styx.uwaterloo.ca>
 0xB3	00	linux/mmc/ioctl.h
 0xB4	00-0F	linux/gpio.h		<mailto:linux-gpio@vger.kernel.org>
+0xB5	00-0F	uapi/linux/rpmsg.h	<mailto:linux-remoteproc@vger.kernel.org>
 0xC0	00-0F	linux/usb/iowarrior.h
 0xCA	00-0F	uapi/misc/cxl.h
 0xCA	80-8F	uapi/scsi/cxlflash_ioctl.h

drivers/rpmsg/Kconfig

@@ -4,6 +4,15 @@ menu "Rpmsg drivers"
 config RPMSG
 	tristate
 
+config RPMSG_CHAR
+	tristate "RPMSG device interface"
+	depends on RPMSG
+	depends on NET
+	help
+	  Say Y here to export rpmsg endpoints as device files, usually found
+	  in /dev. They make it possible for user-space programs to send and
+	  receive rpmsg packets.
+
 config RPMSG_QCOM_SMD
 	tristate "Qualcomm Shared Memory Driver (SMD)"
 	depends on QCOM_SMEM

drivers/rpmsg/Makefile

 obj-$(CONFIG_RPMSG)		+= rpmsg_core.o
+obj-$(CONFIG_RPMSG_CHAR)	+= rpmsg_char.o
 obj-$(CONFIG_RPMSG_QCOM_SMD)	+= qcom_smd.o
 obj-$(CONFIG_RPMSG_VIRTIO)	+= virtio_rpmsg_bus.o

drivers/rpmsg/qcom_smd.c

@@ -117,6 +117,8 @@ static const struct {
 struct qcom_smd_edge {
 	struct device dev;
 
+	const char *name;
+
 	struct device_node *of_node;
 	unsigned edge_id;
 	unsigned remote_pid;
@@ -917,6 +919,21 @@ static int qcom_smd_trysend(struct rpmsg_endpoint *ept, void *data, int len)
 	return __qcom_smd_send(qsept->qsch, data, len, false);
 }
 
+static unsigned int qcom_smd_poll(struct rpmsg_endpoint *ept,
+				  struct file *filp, poll_table *wait)
+{
+	struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
+	struct qcom_smd_channel *channel = qsept->qsch;
+	unsigned int mask = 0;
+
+	poll_wait(filp, &channel->fblockread_event, wait);
+
+	if (qcom_smd_get_tx_avail(channel) > 20)
+		mask |= POLLOUT | POLLWRNORM;
+
+	return mask;
+}
+
 /*
  * Finds the device_node for the smd child interested in this channel.
  */
@@ -949,6 +966,7 @@ static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = {
 	.destroy_ept = qcom_smd_destroy_ept,
 	.send = qcom_smd_send,
 	.trysend = qcom_smd_trysend,
+	.poll = qcom_smd_poll,
 };
 
 /*
@@ -984,6 +1002,20 @@ static int qcom_smd_create_device(struct qcom_smd_channel *channel)
 	return rpmsg_register_device(rpdev);
 }
 
+static int qcom_smd_create_chrdev(struct qcom_smd_edge *edge)
+{
+	struct qcom_smd_device *qsdev;
+
+	qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
+	if (!qsdev)
+		return -ENOMEM;
+
+	qsdev->edge = edge;
+	qsdev->rpdev.ops = &qcom_smd_device_ops;
+	qsdev->rpdev.dev.parent = &edge->dev;
+	return rpmsg_chrdev_register_device(&qsdev->rpdev);
+}
+
 /*
  * Allocate the qcom_smd_channel object for a newly found smd channel,
  * retrieving and validating the smem items involved.
@@ -1248,6 +1280,10 @@ static int qcom_smd_parse_edge(struct device *dev,
 		return -EINVAL;
 	}
 
+	ret = of_property_read_string(node, "label", &edge->name);
+	if (ret < 0)
+		edge->name = node->name;
+
 	irq = irq_of_parse_and_map(node, 0);
 	if (irq < 0) {
 		dev_err(dev, "required smd interrupt missing\n");
@@ -1285,6 +1321,21 @@ static void qcom_smd_edge_release(struct device *dev)
 	kfree(edge);
 }
 
+static ssize_t rpmsg_name_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct qcom_smd_edge *edge = to_smd_edge(dev);
+
+	return sprintf(buf, "%s\n", edge->name);
+}
+static DEVICE_ATTR_RO(rpmsg_name);
+
+static struct attribute *qcom_smd_edge_attrs[] = {
+	&dev_attr_rpmsg_name.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(qcom_smd_edge);
+
 /**
  * qcom_smd_register_edge() - register an edge based on an device_node
  * @parent:    parent device for the edge
@@ -1306,6 +1357,7 @@ struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
 
 	edge->dev.parent = parent;
 	edge->dev.release = qcom_smd_edge_release;
+	edge->dev.groups = qcom_smd_edge_groups;
 	dev_set_name(&edge->dev, "%s:%s", dev_name(parent), node->name);
 	ret = device_register(&edge->dev);
 	if (ret) {
@@ -1319,6 +1371,12 @@ struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
 		goto unregister_dev;
 	}
 
+	ret = qcom_smd_create_chrdev(edge);
+	if (ret) {
+		dev_err(&edge->dev, "failed to register chrdev for edge\n");
+		goto unregister_dev;
+	}
+
 	schedule_work(&edge->scan_work);
 
 	return edge;

drivers/rpmsg/rpmsg_char.c

+/*
+ * Copyright (c) 2016, Linaro Ltd.
+ * Copyright (c) 2012, Michal Simek <monstr@monstr.eu>
+ * Copyright (c) 2012, PetaLogix
+ * Copyright (c) 2011, Texas Instruments, Inc.
+ * Copyright (c) 2011, Google, Inc.
+ *
+ * Based on rpmsg performance statistics driver by Michal Simek, which in turn
+ * was based on TI & Google OMX rpmsg driver.
+ *
+ * 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/cdev.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/poll.h>
+#include <linux/rpmsg.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <uapi/linux/rpmsg.h>
+
+#include "rpmsg_internal.h"
+
+#define RPMSG_DEV_MAX	(MINORMASK + 1)
+
+static dev_t rpmsg_major;
+static struct class *rpmsg_class;
+
+static DEFINE_IDA(rpmsg_ctrl_ida);
+static DEFINE_IDA(rpmsg_ept_ida);
+static DEFINE_IDA(rpmsg_minor_ida);
+
+#define dev_to_eptdev(dev) container_of(dev, struct rpmsg_eptdev, dev)
+#define cdev_to_eptdev(i_cdev) container_of(i_cdev, struct rpmsg_eptdev, cdev)
+
+#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev)
+#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev)
+
+/**
+ * struct rpmsg_ctrldev - control device for instantiating endpoint devices
+ * @rpdev:	underlaying rpmsg device
+ * @cdev:	cdev for the ctrl device
+ * @dev:	device for the ctrl device
+ */
+struct rpmsg_ctrldev {
+	struct rpmsg_device *rpdev;
+	struct cdev cdev;
+	struct device dev;
+};
+
+/**
+ * struct rpmsg_eptdev - endpoint device context
+ * @dev:	endpoint device
+ * @cdev:	cdev for the endpoint device
+ * @rpdev:	underlaying rpmsg device
+ * @chinfo:	info used to open the endpoint
+ * @ept_lock:	synchronization of @ept modifications
+ * @ept:	rpmsg endpoint reference, when open
+ * @queue_lock:	synchronization of @queue operations
+ * @queue:	incoming message queue
+ * @readq:	wait object for incoming queue
+ */
+struct rpmsg_eptdev {
+	struct device dev;
+	struct cdev cdev;
+
+	struct rpmsg_device *rpdev;
+	struct rpmsg_channel_info chinfo;
+
+	struct mutex ept_lock;
+	struct rpmsg_endpoint *ept;
+
+	spinlock_t queue_lock;
+	struct sk_buff_head queue;
+	wait_queue_head_t readq;
+};
+
+static int rpmsg_eptdev_destroy(struct device *dev, void *data)
+{
+	struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
+
+	mutex_lock(&eptdev->ept_lock);
+	if (eptdev->ept) {
+		rpmsg_destroy_ept(eptdev->ept);
+		eptdev->ept = NULL;
+	}
+	mutex_unlock(&eptdev->ept_lock);
+
+	/* wake up any blocked readers */
+	wake_up_interruptible(&eptdev->readq);
+
+	device_del(&eptdev->dev);
+	put_device(&eptdev->dev);
+
+	return 0;
+}
+
+static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len,
+			void *priv, u32 addr)
+{
+	struct rpmsg_eptdev *eptdev = priv;
+	struct sk_buff *skb;
+
+	skb = alloc_skb(len, GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
+
+	memcpy(skb_put(skb, len), buf, len);
+
+	spin_lock(&eptdev->queue_lock);
+	skb_queue_tail(&eptdev->queue, skb);
+	spin_unlock(&eptdev->queue_lock);
+
+	/* wake up any blocking processes, waiting for new data */
+	wake_up_interruptible(&eptdev->readq);
+
+	return 0;
+}
+
+static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
+{
+	struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
+	struct rpmsg_endpoint *ept;
+	struct rpmsg_device *rpdev = eptdev->rpdev;
+	struct device *dev = &eptdev->dev;
+
+	get_device(dev);
+
+	ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);
+	if (!ept) {
+		dev_err(dev, "failed to open %s\n", eptdev->chinfo.name);
+		put_device(dev);
+		return -EINVAL;
+	}
+
+	eptdev->ept = ept;
+	filp->private_data = eptdev;
+
+	return 0;
+}
+
+static int rpmsg_eptdev_release(struct inode *inode, struct file *filp)
+{
+	struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
+	struct device *dev = &eptdev->dev;
+	struct sk_buff *skb;
+
+	/* Close the endpoint, if it's not already destroyed by the parent */
+	mutex_lock(&eptdev->ept_lock);
+	if (eptdev->ept) {
+		rpmsg_destroy_ept(eptdev->ept);
+		eptdev->ept = NULL;
+	}
+	mutex_unlock(&eptdev->ept_lock);
+
+	/* Discard all SKBs */
+	while (!skb_queue_empty(&eptdev->queue)) {
+		skb = skb_dequeue(&eptdev->queue);
+		kfree_skb(skb);
+	}
+
+	put_device(dev);
+
+	return 0;
+}
+
+static ssize_t rpmsg_eptdev_read(struct file *filp, char __user *buf,
+				 size_t len, loff_t *f_pos)
+{
+	struct rpmsg_eptdev *eptdev = filp->private_data;
+	unsigned long flags;
+	struct sk_buff *skb;
+	int use;
+
+	if (!eptdev->ept)
+		return -EPIPE;
+
+	spin_lock_irqsave(&eptdev->queue_lock, flags);
+
+	/* Wait for data in the queue */
+	if (skb_queue_empty(&eptdev->queue)) {
+		spin_unlock_irqrestore(&eptdev->queue_lock, flags);
+
+		if (filp->f_flags & O_NONBLOCK)
+			return -EAGAIN;
+
+		/* Wait until we get data or the endpoint goes away */
+		if (wait_event_interruptible(eptdev->readq,
+					     !skb_queue_empty(&eptdev->queue) ||
+					     !eptdev->ept))
+			return -ERESTARTSYS;
+
+		/* We lost the endpoint while waiting */
+		if (!eptdev->ept)
+			return -EPIPE;
+
+		spin_lock_irqsave(&eptdev->queue_lock, flags);
+	}
+
+	skb = skb_dequeue(&eptdev->queue);
+	spin_unlock_irqrestore(&eptdev->queue_lock, flags);
+	if (!skb)
+		return -EFAULT;
+
+	use = min_t(size_t, len, skb->len);
+	if (copy_to_user(buf, skb->data, use))
+		use = -EFAULT;
+
+	kfree_skb(skb);
+
+	return use;
+}
+
+static ssize_t rpmsg_eptdev_write(struct file *filp, const char __user *buf,
+				  size_t len, loff_t *f_pos)
+{
+	struct rpmsg_eptdev *eptdev = filp->private_data;
+	void *kbuf;
+	int ret;
+
+	kbuf = memdup_user(buf, len);
+	if (IS_ERR(kbuf))
+		return PTR_ERR(kbuf);
+
+	if (mutex_lock_interruptible(&eptdev->ept_lock)) {
+		ret = -ERESTARTSYS;
+		goto free_kbuf;
+	}
+
+	if (!eptdev->ept) {
+		ret = -EPIPE;
+		goto unlock_eptdev;
+	}
+
+	if (filp->f_flags & O_NONBLOCK)
+		ret = rpmsg_trysend(eptdev->ept, kbuf, len);
+	else
+		ret = rpmsg_send(eptdev->ept, kbuf, len);
+
+unlock_eptdev:
+	mutex_unlock(&eptdev->ept_lock);
+
+free_kbuf:
+	kfree(kbuf);
+	return ret < 0 ? ret : len;
+}
+
+static unsigned int rpmsg_eptdev_poll(struct file *filp, poll_table *wait)
+{
+	struct rpmsg_eptdev *eptdev = filp->private_data;
+	unsigned int mask = 0;
+
+	if (!eptdev->ept)
+		return POLLERR;
+
+	poll_wait(filp, &eptdev->readq, wait);
+
+	if (!skb_queue_empty(&eptdev->queue))
+		mask |= POLLIN | POLLRDNORM;
+
+	mask |= rpmsg_poll(eptdev->ept, filp, wait);
+
+	return mask;
+}
+
+static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
+			       unsigned long arg)
+{
+	struct rpmsg_eptdev *eptdev = fp->private_data;
+
+	if (cmd != RPMSG_DESTROY_EPT_IOCTL)
+		return -EINVAL;
+
+	return rpmsg_eptdev_destroy(&eptdev->dev, NULL);
+}
+
+static const struct file_operations rpmsg_eptdev_fops = {
+	.owner = THIS_MODULE,
+	.open = rpmsg_eptdev_open,
+	.release = rpmsg_eptdev_release,
+	.read = rpmsg_eptdev_read,
+	.write = rpmsg_eptdev_write,
+	.poll = rpmsg_eptdev_poll,
+	.unlocked_ioctl = rpmsg_eptdev_ioctl,
+};
+
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%s\n", eptdev->chinfo.name);
+}
+static DEVICE_ATTR_RO(name);
+
+static ssize_t src_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", eptdev->chinfo.src);
+}
+static DEVICE_ATTR_RO(src);
+
+static ssize_t dst_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", eptdev->chinfo.dst);
+}
+static DEVICE_ATTR_RO(dst);
+
+static struct attribute *rpmsg_eptdev_attrs[] = {
+	&dev_attr_name.attr,
+	&dev_attr_src.attr,
+	&dev_attr_dst.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(rpmsg_eptdev);
+
+static void rpmsg_eptdev_release_device(struct device *dev)
+{
+	struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
+
+	ida_simple_remove(&rpmsg_ept_ida, dev->id);
+	ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt));
+	cdev_del(&eptdev->cdev);
+	kfree(eptdev);
+}
+
+static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev,
+			       struct rpmsg_channel_info chinfo)
+{
+	struct rpmsg_device *rpdev = ctrldev->rpdev;
+	struct rpmsg_eptdev *eptdev;
+	struct device *dev;
+	int ret;
+
+	eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL);
+	if (!eptdev)
+		return -ENOMEM;
+
+	dev = &eptdev->dev;
+	eptdev->rpdev = rpdev;
+	eptdev->chinfo = chinfo;
+
+	mutex_init(&eptdev->ept_lock);
+	spin_lock_init(&eptdev->queue_lock);
+	skb_queue_head_init(&eptdev->queue);
+	init_waitqueue_head(&eptdev->readq);
+
+	device_initialize(dev);
+	dev->class = rpmsg_class;
+	dev->parent = &ctrldev->dev;
+	dev->groups = rpmsg_eptdev_groups;
+	dev_set_drvdata(dev, eptdev);
+
+	cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops);
+	eptdev->cdev.owner = THIS_MODULE;
+
+	ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
+	if (ret < 0)
+		goto free_eptdev;
+	dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
+
+	ret = ida_simple_get(&rpmsg_ept_ida, 0, 0, GFP_KERNEL);
+	if (ret < 0)
+		goto free_minor_ida;
+	dev->id = ret;
+	dev_set_name(dev, "rpmsg%d", ret);
+
+	ret = cdev_add(&eptdev->cdev, dev->devt, 1);
+	if (ret)
+		goto free_ept_ida;
+
+	/* We can now rely on the release function for cleanup */
+	dev->release = rpmsg_eptdev_release_device;
+
+	ret = device_add(dev);
+	if (ret) {
+		dev_err(dev, "device_register failed: %d\n", ret);
+		put_device(dev);
+	}
+
+	return ret;
+
+free_ept_ida:
+	ida_simple_remove(&rpmsg_ept_ida, dev->id);
+free_minor_ida:
+	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
+free_eptdev:
+	put_device(dev);
+	kfree(eptdev);
+
+	return ret;
+}
+
+static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp)
+{
+	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
+
+	get_device(&ctrldev->dev);
+	filp->private_data = ctrldev;
+
+	return 0;
+}
+
+static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp)
+{
+	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
+
+	put_device(&ctrldev->dev);
+
+	return 0;
+}
+
+static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd,
+				unsigned long arg)
+{
+	struct rpmsg_ctrldev *ctrldev = fp->private_data;
+	void __user *argp = (void __user *)arg;
+	struct rpmsg_endpoint_info eptinfo;
+	struct rpmsg_channel_info chinfo;
+
+	if (cmd != RPMSG_CREATE_EPT_IOCTL)
+		return -EINVAL;
+
+	if (copy_from_user(&eptinfo, argp, sizeof(eptinfo)))
+		return -EFAULT;
+
+	memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE);
+	chinfo.name[RPMSG_NAME_SIZE-1] = '\0';
+	chinfo.src = eptinfo.src;
+	chinfo.dst = eptinfo.dst;
+
+	return rpmsg_eptdev_create(ctrldev, chinfo);
+};
+
+static const struct file_operations rpmsg_ctrldev_fops = {
+	.owner = THIS_MODULE,
+	.open = rpmsg_ctrldev_open,
+	.release = rpmsg_ctrldev_release,
+	.unlocked_ioctl = rpmsg_ctrldev_ioctl,
+};
+
+static void rpmsg_ctrldev_release_device(struct device *dev)
+{
+	struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);
+
+	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
+	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
+	cdev_del(&ctrldev->cdev);
+	kfree(ctrldev);
+}
+
+static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
+{
+	struct rpmsg_ctrldev *ctrldev;
+	struct device *dev;
+	int ret;
+
+	ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL);
+	if (!ctrldev)
+		return -ENOMEM;
+
+	ctrldev->rpdev = rpdev;
+
+	dev = &ctrldev->dev;
+	device_initialize(dev);
+	dev->parent = &rpdev->dev;
+	dev->class = rpmsg_class;
+
+	cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
+	ctrldev->cdev.owner = THIS_MODULE;
+
+	ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
+	if (ret < 0)
+		goto free_ctrldev;
+	dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
+
+	ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL);
+	if (ret < 0)
+		goto free_minor_ida;
+	dev->id = ret;
+	dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);
+
+	ret = cdev_add(&ctrldev->cdev, dev->devt, 1);
+	if (ret)
+		goto free_ctrl_ida;
+
+	/* We can now rely on the release function for cleanup */
+	dev->release = rpmsg_ctrldev_release_device;
+
+	ret = device_add(dev);
+	if (ret) {
+		dev_err(&rpdev->dev, "device_register failed: %d\n", ret);
+		put_device(dev);
+	}
+
+	dev_set_drvdata(&rpdev->dev, ctrldev);
+
+	return ret;
+
+free_ctrl_ida:
+	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
+free_minor_ida:
+	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
+free_ctrldev:
+	put_device(dev);
+	kfree(ctrldev);
+
+	return ret;
+}
+
+static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
+{
+	struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
+	int ret;
+
+	/* Destroy all endpoints */
+	ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_eptdev_destroy);
+	if (ret)
+		dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
+
+	device_del(&ctrldev->dev);
+	put_device(&ctrldev->dev);
+}
+
+static struct rpmsg_driver rpmsg_chrdev_driver = {
+	.probe = rpmsg_chrdev_probe,
+	.remove = rpmsg_chrdev_remove,
+	.drv = {
+		.name = "rpmsg_chrdev",
+	},
+};
+
+static int rpmsg_char_init(void)
+{
+	int ret;
+
+	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg");
+	if (ret < 0) {
+		pr_err("rpmsg: failed to allocate char dev region\n");
+		return ret;
+	}
+
+	rpmsg_class = class_create(THIS_MODULE, "rpmsg");
+	if (IS_ERR(rpmsg_class)) {
+		pr_err("failed to create rpmsg class\n");
+		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+		return PTR_ERR(rpmsg_class);
+	}
+
+	ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
+	if (ret < 0) {
+		pr_err("rpmsgchr: failed to register rpmsg driver\n");
+		class_destroy(rpmsg_class);
+		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+	}
+
+	return ret;
+}
+postcore_initcall(rpmsg_char_init);
+
+static void rpmsg_chrdev_exit(void)
+{
+	unregister_rpmsg_driver(&rpmsg_chrdev_driver);
+	class_destroy(rpmsg_class);
+	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+}
+module_exit(rpmsg_chrdev_exit);
+MODULE_LICENSE("GPL v2");

drivers/rpmsg/rpmsg_core.c

@@ -72,7 +72,7 @@ struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev,
 					struct rpmsg_channel_info chinfo)
 {
 	if (WARN_ON(!rpdev))
-		return ERR_PTR(-EINVAL);
+		return NULL;
 
 	return rpdev->ops->create_ept(rpdev, cb, priv, chinfo);
 }
@@ -239,6 +239,26 @@ int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
 }
 EXPORT_SYMBOL(rpmsg_trysendto);
 
+/**
+ * rpmsg_poll() - poll the endpoint's send buffers
+ * @ept:	the rpmsg endpoint
+ * @filp:	file for poll_wait()
+ * @wait:	poll_table for poll_wait()
+ *
+ * Returns mask representing the current state of the endpoint's send buffers
+ */
+unsigned int rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
+			poll_table *wait)
+{
+	if (WARN_ON(!ept))
+		return 0;
+	if (!ept->ops->poll)
+		return 0;
+
+	return ept->ops->poll(ept, filp, wait);
+}
+EXPORT_SYMBOL(rpmsg_poll);
+
 /**
  * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
  * @ept: the rpmsg endpoint

drivers/rpmsg/rpmsg_internal.h

@@ -21,6 +21,7 @@
 #define __RPMSG_INTERNAL_H__
 
 #include <linux/rpmsg.h>
+#include <linux/poll.h>
 
 #define to_rpmsg_device(d) container_of(d, struct rpmsg_device, dev)
 #define to_rpmsg_driver(d) container_of(d, struct rpmsg_driver, drv)
@@ -70,6 +71,8 @@ struct rpmsg_endpoint_ops {
 	int (*trysendto)(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
 	int (*trysend_offchannel)(struct rpmsg_endpoint *ept, u32 src, u32 dst,
 			     void *data, int len);
+	unsigned int (*poll)(struct rpmsg_endpoint *ept, struct file *filp,
+			     poll_table *wait);
 };
 
 int rpmsg_register_device(struct rpmsg_device *rpdev);
@@ -79,4 +82,19 @@ int rpmsg_unregister_device(struct device *parent,
 struct device *rpmsg_find_device(struct device *parent,
 				 struct rpmsg_channel_info *chinfo);
 
+/**
+ * rpmsg_chrdev_register_device() - register chrdev device based on rpdev
+ * @rpdev:	prepared rpdev to be used for creating endpoints
+ *
+ * This function wraps rpmsg_register_device() preparing the rpdev for use as
+ * basis for the rpmsg chrdev.
+ */
+static inline int rpmsg_chrdev_register_device(struct rpmsg_device *rpdev)
+{
+	strcpy(rpdev->id.name, "rpmsg_chrdev");
+	rpdev->driver_override = "rpmsg_chrdev";
+
+	return rpmsg_register_device(rpdev);
+}
+
 #endif

include/linux/rpmsg.h

@@ -41,6 +41,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/kref.h>
 #include <linux/mutex.h>
+#include <linux/poll.h>
 
 #define RPMSG_ADDR_ANY		0xFFFFFFFF
 
@@ -156,6 +157,9 @@ int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
 int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
 			     void *data, int len);
 
+unsigned int rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
+			poll_table *wait);
+
 #else
 
 static inline int register_rpmsg_device(struct rpmsg_device *dev)
@@ -254,6 +258,15 @@ static inline int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
 	return -ENXIO;
 }
 
+static inline unsigned int rpmsg_poll(struct rpmsg_endpoint *ept,
+				      struct file *filp, poll_table *wait)
+{
+	/* This shouldn't be possible */
+	WARN_ON(1);
+
+	return 0;
+}
+
 #endif /* IS_ENABLED(CONFIG_RPMSG) */
 
 /* use a macro to avoid include chaining to get THIS_MODULE */

include/linux/rpmsg/qcom_smd.h

@@ -18,14 +18,12 @@ static inline struct qcom_smd_edge *
 qcom_smd_register_edge(struct device *parent,
 		       struct device_node *node)
 {
-	return ERR_PTR(-ENXIO);
+	return NULL;
 }
 
 static inline int qcom_smd_unregister_edge(struct qcom_smd_edge *edge)
 {
-	/* This shouldn't be possible */
-	WARN_ON(1);
-	return -ENXIO;
+	return 0;
 }
 
 #endif

include/uapi/linux/rpmsg.h

+/*
+ * Copyright (c) 2016, Linaro Ltd.
+ *
+ * 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.
+ */
+
+#ifndef _UAPI_RPMSG_H_
+#define _UAPI_RPMSG_H_
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/**
+ * struct rpmsg_endpoint_info - endpoint info representation
+ * @name: name of service
+ * @src: local address
+ * @dst: destination address
+ */
+struct rpmsg_endpoint_info {
+	char name[32];
+	__u32 src;
+	__u32 dst;
+};
+
+#define RPMSG_CREATE_EPT_IOCTL	_IOW(0xb5, 0x1, struct rpmsg_endpoint_info)
+#define RPMSG_DESTROY_EPT_IOCTL	_IO(0xb5, 0x2)
+
+#endif