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static void gpiochip_setup_devs(void){ struct gpio_device *gdev; int err;  list_for_each_entry(gdev, &gpio_devices, list) {  err = gpiochip_setup_dev(gdev);  if (err)   pr_err("%s: Failed to initialize gpio device (%d)\n",          dev_name(&gdev->dev), err); }}

static const struct file_operations gpio_fileops = { .release = gpio_chrdev_release, .open = gpio_chrdev_open, .owner = THIS_MODULE, .llseek = noop_llseek, .unlocked_ioctl = gpio_ioctl,#ifdef CONFIG_COMPAT .compat_ioctl = gpio_ioctl_compat,#endif};

static int gpiochip_setup_dev(struct gpio_device *gdev){ int status;  cdev_init(&gdev->chrdev, &gpio_fileops); gdev->chrdev.owner = THIS_MODULE; gdev->chrdev.kobj.parent = &gdev->dev.kobj; gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id); status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1); if (status < 0)  chip_warn(gdev->chip, "failed to add char device %d:%d\n",     MAJOR(gpio_devt), gdev->id); else  chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",    MAJOR(gpio_devt), gdev->id); status = device_add(&gdev->dev); if (status)  goto err_remove_chardev;  status = gpiochip_sysfs_register(gdev); if (status)  goto err_remove_device;  /* From this point, the .release() function cleans up gpio_device */ gdev->dev.release = gpiodevice_release; pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",   __func__, gdev->base, gdev->base + gdev->ngpio - 1,   dev_name(&gdev->dev), gdev->chip->label ? : "generic");  return 0; err_remove_device: device_del(&gdev->dev);err_remove_chardev: cdev_del(&gdev->chrdev); return status;}

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