From dfd1a05a38763683fe121169e0998638913188c2 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 7 Sep 2021 13:50:45 +0200 Subject: [PATCH] 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 Cc: Stefan Wahren Cc: Arnd Bergmann Cc: Dan Carpenter Cc: Ojaswin Mujoo Cc: Phil Elwell 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 --- .../vc04_services/interface/vchiq_arm/vchiq_dev.c | 71 ++++------------------ 1 file changed, 11 insertions(+), 60 deletions(-) diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c index bf1a88c..788fa5a 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c @@ -9,18 +9,13 @@ #include #include #include +#include #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 @@ 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); } -- 2.7.4