diff mbox series

[v6,03/10] rpmsg: Move the rpmsg control device from rpmsg_char to rpmsg_ctrl

Message ID 20211022125426.2579-4-arnaud.pouliquen@foss.st.com (mailing list archive)
State Superseded
Headers show
Series Restructure the rpmsg_char driver and introduce rpmsg_ctrl driver. | expand

Commit Message

Arnaud POULIQUEN Oct. 22, 2021, 12:54 p.m. UTC
Create the rpmsg_ctrl.c module and move the code related to the
rpmsg_ctrldev device in this new module.

Add the dependency between rpmsg_char and rpmsg_ctrl in the
kconfig file.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

---
update vs previous version:
- set the ctrl device class with new rpmsg_get_class API for legacy support
---
 drivers/rpmsg/Kconfig      |   9 ++
 drivers/rpmsg/Makefile     |   1 +
 drivers/rpmsg/rpmsg_char.c | 169 +----------------------------
 drivers/rpmsg/rpmsg_char.h |   2 +
 drivers/rpmsg/rpmsg_ctrl.c | 216 +++++++++++++++++++++++++++++++++++++
 5 files changed, 230 insertions(+), 167 deletions(-)
 create mode 100644 drivers/rpmsg/rpmsg_ctrl.c

Comments

Bjorn Andersson Nov. 1, 2021, 5:07 p.m. UTC | #1
On Fri 22 Oct 07:54 CDT 2021, Arnaud Pouliquen wrote:

> Create the rpmsg_ctrl.c module and move the code related to the
> rpmsg_ctrldev device in this new module.
> 
> Add the dependency between rpmsg_char and rpmsg_ctrl in the
> kconfig file.
> 
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> 
> ---
> update vs previous version:
> - set the ctrl device class with new rpmsg_get_class API for legacy support
> ---
>  drivers/rpmsg/Kconfig      |   9 ++
>  drivers/rpmsg/Makefile     |   1 +
>  drivers/rpmsg/rpmsg_char.c | 169 +----------------------------
>  drivers/rpmsg/rpmsg_char.h |   2 +
>  drivers/rpmsg/rpmsg_ctrl.c | 216 +++++++++++++++++++++++++++++++++++++
>  5 files changed, 230 insertions(+), 167 deletions(-)
>  create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
> 
> diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
> index 0b4407abdf13..d822ec9ec692 100644
> --- a/drivers/rpmsg/Kconfig
> +++ b/drivers/rpmsg/Kconfig
> @@ -10,11 +10,20 @@ config RPMSG_CHAR
>  	tristate "RPMSG device interface"
>  	depends on RPMSG
>  	depends on NET
> +	select RPMSG_CTRL

We don't want select of user selectable config options.

>  	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_CTRL

I still don't like the introduction of more Kconfig options - search the
list for the number of patches that has corrected Kconfig dependency
issues.

That said, if you get it right...

> +	tristate "RPMSG control interface"
> +	depends on RPMSG
> +	help
> +	  Say Y here to enable the support of the /dev/rpmsg_ctrlX API. This API
> +	  allows user-space programs to create endpoints with specific service name,
> +	  source and destination addresses.
> +
>  config RPMSG_NS
>  	tristate "RPMSG name service announcement"
>  	depends on RPMSG
[..]
> diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
[..]
> diff --git a/drivers/rpmsg/rpmsg_char.h b/drivers/rpmsg/rpmsg_char.h
> index 109c2c43005f..ff1acc42628a 100644
> --- a/drivers/rpmsg/rpmsg_char.h
> +++ b/drivers/rpmsg/rpmsg_char.h
> @@ -12,6 +12,8 @@
>   * In such case a kernel warning is printed to help develloper to fix the issue.
>   */
>  
> +#define RPMSG_DEV_MAX	(MINORMASK + 1)

This was used to define the minors of the rpmsg chdev, now you're
splitting that range in one for the ctrl and one for the char.

Moving this define to a common place gives an impression that there's a
relationship between the two, but I don't see any. So I think you should
duplicate this in the two files - just like the other stuff.

> +
>  #if IS_REACHABLE(CONFIG_RPMSG_CHAR)
>  /**
>   * rpmsg_chrdev_eptdev_create() - register char device based on an endpoint
> diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
> new file mode 100644
> index 000000000000..1d3c12e5cdcf
> --- /dev/null
> +++ b/drivers/rpmsg/rpmsg_ctrl.c
> @@ -0,0 +1,216 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021, STMicroelectronics

Did you actually change anything that warrant the explicit copyright
claim?

> + * 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.
> + */
[..]
> +static int rpmsg_ctrldev_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_get_class();

Thank you.

Regards,
Bjorn
Arnaud POULIQUEN Nov. 2, 2021, 3:42 p.m. UTC | #2
On 11/1/21 6:07 PM, Bjorn Andersson wrote:
> On Fri 22 Oct 07:54 CDT 2021, Arnaud Pouliquen wrote:
> 
>> Create the rpmsg_ctrl.c module and move the code related to the
>> rpmsg_ctrldev device in this new module.
>>
>> Add the dependency between rpmsg_char and rpmsg_ctrl in the
>> kconfig file.
>>
>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
>> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
>>
>> ---
>> update vs previous version:
>> - set the ctrl device class with new rpmsg_get_class API for legacy support
>> ---
>>  drivers/rpmsg/Kconfig      |   9 ++
>>  drivers/rpmsg/Makefile     |   1 +
>>  drivers/rpmsg/rpmsg_char.c | 169 +----------------------------
>>  drivers/rpmsg/rpmsg_char.h |   2 +
>>  drivers/rpmsg/rpmsg_ctrl.c | 216 +++++++++++++++++++++++++++++++++++++
>>  5 files changed, 230 insertions(+), 167 deletions(-)
>>  create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
>>
>> diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
>> index 0b4407abdf13..d822ec9ec692 100644
>> --- a/drivers/rpmsg/Kconfig
>> +++ b/drivers/rpmsg/Kconfig
>> @@ -10,11 +10,20 @@ config RPMSG_CHAR
>>  	tristate "RPMSG device interface"
>>  	depends on RPMSG
>>  	depends on NET
>> +	select RPMSG_CTRL
> 
> We don't want select of user selectable config options.
> 
>>  	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_CTRL
> 
> I still don't like the introduction of more Kconfig options - search the
> list for the number of patches that has corrected Kconfig dependency
> issues.
> 
> That said, if you get it right...
> 
>> +	tristate "RPMSG control interface"
>> +	depends on RPMSG
>> +	help
>> +	  Say Y here to enable the support of the /dev/rpmsg_ctrlX API. This API
>> +	  allows user-space programs to create endpoints with specific service name,
>> +	  source and destination addresses.
>> +
>>  config RPMSG_NS
>>  	tristate "RPMSG name service announcement"
>>  	depends on RPMSG
> [..]
>> diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
> [..]
>> diff --git a/drivers/rpmsg/rpmsg_char.h b/drivers/rpmsg/rpmsg_char.h
>> index 109c2c43005f..ff1acc42628a 100644
>> --- a/drivers/rpmsg/rpmsg_char.h
>> +++ b/drivers/rpmsg/rpmsg_char.h
>> @@ -12,6 +12,8 @@
>>   * In such case a kernel warning is printed to help develloper to fix the issue.
>>   */
>>  
>> +#define RPMSG_DEV_MAX	(MINORMASK + 1)
> 
> This was used to define the minors of the rpmsg chdev, now you're
> splitting that range in one for the ctrl and one for the char.
> 
> Moving this define to a common place gives an impression that there's a
> relationship between the two, but I don't see any. So I think you should
> duplicate this in the two files - just like the other stuff.

That's true, I will fix this

> 
>> +
>>  #if IS_REACHABLE(CONFIG_RPMSG_CHAR)
>>  /**
>>   * rpmsg_chrdev_eptdev_create() - register char device based on an endpoint
>> diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
>> new file mode 100644
>> index 000000000000..1d3c12e5cdcf
>> --- /dev/null
>> +++ b/drivers/rpmsg/rpmsg_ctrl.c
>> @@ -0,0 +1,216 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (C) 2021, STMicroelectronics
> 
> Did you actually change anything that warrant the explicit copyright
> claim?
> 

Mainly because i created a new file here, but right it is a copy-past, so
I will remove it.

Thanks,
Arnaud

>> + * 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.
>> + */
> [..]
>> +static int rpmsg_ctrldev_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_get_class();
> 
> Thank you.
> 
> Regards,
> Bjorn
>
diff mbox series

Patch

diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
index 0b4407abdf13..d822ec9ec692 100644
--- a/drivers/rpmsg/Kconfig
+++ b/drivers/rpmsg/Kconfig
@@ -10,11 +10,20 @@  config RPMSG_CHAR
 	tristate "RPMSG device interface"
 	depends on RPMSG
 	depends on NET
+	select RPMSG_CTRL
 	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_CTRL
+	tristate "RPMSG control interface"
+	depends on RPMSG
+	help
+	  Say Y here to enable the support of the /dev/rpmsg_ctrlX API. This API
+	  allows user-space programs to create endpoints with specific service name,
+	  source and destination addresses.
+
 config RPMSG_NS
 	tristate "RPMSG name service announcement"
 	depends on RPMSG
diff --git a/drivers/rpmsg/Makefile b/drivers/rpmsg/Makefile
index 8d452656f0ee..58e3b382e316 100644
--- a/drivers/rpmsg/Makefile
+++ b/drivers/rpmsg/Makefile
@@ -1,6 +1,7 @@ 
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_RPMSG)		+= rpmsg_core.o
 obj-$(CONFIG_RPMSG_CHAR)	+= rpmsg_char.o
+obj-$(CONFIG_RPMSG_CTRL)	+= rpmsg_ctrl.o
 obj-$(CONFIG_RPMSG_NS)		+= rpmsg_ns.o
 obj-$(CONFIG_RPMSG_MTK_SCP)	+= mtk_rpmsg.o
 qcom_glink-objs			:= qcom_glink_native.o qcom_glink_ssr.o
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 327ed739a3a7..3607865d7be7 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -25,32 +25,14 @@ 
 
 #include "rpmsg_char.h"
 
-#define RPMSG_DEV_MAX	(MINORMASK + 1)
-
 static dev_t rpmsg_major;
 
-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
@@ -407,169 +389,22 @@  int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent
 }
 EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create);
 
-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_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, 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,
-	.compat_ioctl = compat_ptr_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_get_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_add 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_chrdev_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_chrdev_init(void)
 {
 	int ret;
 
-	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg");
+	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_char");
 	if (ret < 0) {
 		pr_err("rpmsg: failed to allocate char dev region\n");
 		return ret;
 	}
 
-	ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
-	if (ret < 0) {
-		pr_err("rpmsgchr: failed to register rpmsg driver\n");
-		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
-	}
-
-	return ret;
+	return 0;
 }
 postcore_initcall(rpmsg_chrdev_init);
 
 static void rpmsg_chrdev_exit(void)
 {
-	unregister_rpmsg_driver(&rpmsg_chrdev_driver);
 	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
 }
 module_exit(rpmsg_chrdev_exit);
diff --git a/drivers/rpmsg/rpmsg_char.h b/drivers/rpmsg/rpmsg_char.h
index 109c2c43005f..ff1acc42628a 100644
--- a/drivers/rpmsg/rpmsg_char.h
+++ b/drivers/rpmsg/rpmsg_char.h
@@ -12,6 +12,8 @@ 
  * In such case a kernel warning is printed to help develloper to fix the issue.
  */
 
+#define RPMSG_DEV_MAX	(MINORMASK + 1)
+
 #if IS_REACHABLE(CONFIG_RPMSG_CHAR)
 /**
  * rpmsg_chrdev_eptdev_create() - register char device based on an endpoint
diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
new file mode 100644
index 000000000000..1d3c12e5cdcf
--- /dev/null
+++ b/drivers/rpmsg/rpmsg_ctrl.c
@@ -0,0 +1,216 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021, STMicroelectronics
+ * 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.
+ */
+#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/rpmsg.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <uapi/linux/rpmsg.h>
+
+#include "rpmsg_char.h"
+
+static dev_t rpmsg_major;
+
+static DEFINE_IDA(rpmsg_ctrl_ida);
+static DEFINE_IDA(rpmsg_minor_ida);
+
+#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;
+};
+
+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_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, 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,
+	.compat_ioctl = compat_ptr_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_ctrldev_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_get_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_add 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_ctrldev_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_chrdev_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_ctrldev_driver = {
+	.probe = rpmsg_ctrldev_probe,
+	.remove = rpmsg_ctrldev_remove,
+	.drv = {
+		.name = "rpmsg_chrdev",
+	},
+};
+
+static int rpmsg_ctrldev_init(void)
+{
+	int ret;
+
+	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
+	if (ret < 0) {
+		pr_err("rpmsg: failed to allocate char dev region\n");
+		return ret;
+	}
+
+	ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
+	if (ret < 0) {
+		pr_err("rpmsg ctrl: failed to register rpmsg driver\n");
+		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+	}
+
+	return ret;
+}
+postcore_initcall(rpmsg_ctrldev_init);
+
+static void rpmsg_ctrldev_exit(void)
+{
+	unregister_rpmsg_driver(&rpmsg_ctrldev_driver);
+	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+}
+module_exit(rpmsg_ctrldev_exit);
+
+MODULE_DESCRIPTION("rpmsg control interface");
+MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
+MODULE_LICENSE("GPL v2");