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staging: vchiq: convert to use a miscdevice

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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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Greg Kroah-Hartman 2021-09-07 13:50:45 +02:00
parent b561d2f0dc
commit dfd1a05a38
1 changed files with 11 additions and 60 deletions
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71
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c
View File

@ -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_miscdev.parent = parent;
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));
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 @@ error_exit:
*/
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);
}