Commit dfd1a05a authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

staging: vchiq: convert to use a miscdevice 

Using a struct class, a cdev, and another device just for a single minor
device is total overkill.  Just use a dynamic misc device instead,
saving lots of logic and memory.

Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Ojaswin Mujoo <ojaswin98@gmail.com>
Cc: Phil Elwell <phil@raspberrypi.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: linux-rpi-kernel@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20210907115045.2206083-1-gregkh@linuxfoundation.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b561d2f0

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c

+11 −60
Original line number Diff line number Diff line
@@ -9,18 +9,13 @@ 
#include <linux/device.h>

#include <linux/slab.h>

#include <linux/compat.h>

#include <linux/miscdevice.h>



#include "vchiq_core.h"

#include "vchiq_ioctl.h"

#include "vchiq_arm.h"

#include "vchiq_debugfs.h"



#define DEVICE_NAME "vchiq"



static struct cdev    vchiq_cdev;

static dev_t          vchiq_devid;

static struct class  *vchiq_class;



static const char *const ioctl_names[] = {

	"CONNECT",

	"SHUTDOWN",
@@ -1364,6 +1359,13 @@ vchiq_fops = { 
	.read = vchiq_read

};



static struct miscdevice vchiq_miscdev = {

	.fops = &vchiq_fops,

	.minor = MISC_DYNAMIC_MINOR,

	.name = "vchiq",



};



/**

 *	vchiq_register_chrdev - Register the char driver for vchiq

 *				and create the necessary class and
@@ -1374,57 +1376,9 @@ vchiq_fops = { 
 */

int vchiq_register_chrdev(struct device *parent)

{

	struct device *vchiq_dev;

	int ret;



	vchiq_class = class_create(THIS_MODULE, DEVICE_NAME);

	if (IS_ERR(vchiq_class)) {

		pr_err("Failed to create vchiq class\n");

		ret = PTR_ERR(vchiq_class);

		goto error_exit;

	}



	ret = alloc_chrdev_region(&vchiq_devid, 0, 1, DEVICE_NAME);

	if (ret) {

		pr_err("vchiq: Failed to allocate vchiq's chrdev region\n");

		goto alloc_region_error;

	}



	cdev_init(&vchiq_cdev, &vchiq_fops);

	vchiq_cdev.owner = THIS_MODULE;

	ret = cdev_add(&vchiq_cdev, vchiq_devid, 1);

	if (ret) {

		vchiq_log_error(vchiq_arm_log_level,

				"Unable to register vchiq char device");

		goto cdev_add_error;

	}



	vchiq_dev = device_create(vchiq_class, parent, vchiq_devid, NULL,

				  DEVICE_NAME);

	if (IS_ERR(vchiq_dev)) {

		vchiq_log_error(vchiq_arm_log_level,

				"Failed to create vchiq char device node");

		ret = PTR_ERR(vchiq_dev);

		goto device_create_error;

	}



	vchiq_log_info(vchiq_arm_log_level,

		       "vchiq char dev initialised successfully - device %d.%d",

			MAJOR(vchiq_devid), MINOR(vchiq_devid));

	vchiq_miscdev.parent = parent;



	return 0;



device_create_error:

	cdev_del(&vchiq_cdev);



cdev_add_error:

	unregister_chrdev_region(vchiq_devid, 1);



alloc_region_error:

	class_destroy(vchiq_class);



error_exit:

	return ret;

	return misc_register(&vchiq_miscdev);

}



/**
@@ -1433,8 +1387,5 @@ int vchiq_register_chrdev(struct device *parent) 
 */

void vchiq_deregister_chrdev(void)

{

	device_destroy(vchiq_class, vchiq_devid);

	cdev_del(&vchiq_cdev);

	unregister_chrdev_region(vchiq_devid, 1);

	class_destroy(vchiq_class);

	misc_deregister(&vchiq_miscdev);

}