^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Userspace driver for the LED subsystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2016 David Lechner <david@lechnology.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Based on uinput.c: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/leds.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/miscdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/poll.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <uapi/linux/uleds.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #define ULEDS_NAME "uleds"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) enum uleds_state {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) ULEDS_STATE_UNKNOWN,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) ULEDS_STATE_REGISTERED,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) struct uleds_device {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) struct uleds_user_dev user_dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) struct led_classdev led_cdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) struct mutex mutex;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) enum uleds_state state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) wait_queue_head_t waitq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) int brightness;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) bool new_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static struct miscdevice uleds_misc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) static void uleds_brightness_set(struct led_classdev *led_cdev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) enum led_brightness brightness)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) struct uleds_device *udev = container_of(led_cdev, struct uleds_device,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) led_cdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) if (udev->brightness != brightness) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) udev->brightness = brightness;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) udev->new_data = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) wake_up_interruptible(&udev->waitq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) static int uleds_open(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) struct uleds_device *udev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) udev = kzalloc(sizeof(*udev), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) if (!udev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) udev->led_cdev.name = udev->user_dev.name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) udev->led_cdev.brightness_set = uleds_brightness_set;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) mutex_init(&udev->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) init_waitqueue_head(&udev->waitq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) udev->state = ULEDS_STATE_UNKNOWN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) file->private_data = udev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) stream_open(inode, file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) static ssize_t uleds_write(struct file *file, const char __user *buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) size_t count, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) struct uleds_device *udev = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) const char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (count == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) ret = mutex_lock_interruptible(&udev->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) if (udev->state == ULEDS_STATE_REGISTERED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) ret = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) if (count != sizeof(struct uleds_user_dev)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) if (copy_from_user(&udev->user_dev, buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) sizeof(struct uleds_user_dev))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) ret = -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) name = udev->user_dev.name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) if (!name[0] || !strcmp(name, ".") || !strcmp(name, "..") ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) strchr(name, '/')) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) if (udev->user_dev.max_brightness <= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) udev->led_cdev.max_brightness = udev->user_dev.max_brightness;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) ret = devm_led_classdev_register(uleds_misc.this_device,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) &udev->led_cdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) udev->new_data = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) udev->state = ULEDS_STATE_REGISTERED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) ret = count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) mutex_unlock(&udev->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static ssize_t uleds_read(struct file *file, char __user *buffer, size_t count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) struct uleds_device *udev = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) ssize_t retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) if (count < sizeof(udev->brightness))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) retval = mutex_lock_interruptible(&udev->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) if (retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) if (udev->state != ULEDS_STATE_REGISTERED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) retval = -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) } else if (!udev->new_data && (file->f_flags & O_NONBLOCK)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) retval = -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) } else if (udev->new_data) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) retval = copy_to_user(buffer, &udev->brightness,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) sizeof(udev->brightness));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) udev->new_data = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) retval = sizeof(udev->brightness);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) mutex_unlock(&udev->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) if (retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) if (!(file->f_flags & O_NONBLOCK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) retval = wait_event_interruptible(udev->waitq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) udev->new_data ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) udev->state != ULEDS_STATE_REGISTERED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) } while (retval == 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) static __poll_t uleds_poll(struct file *file, poll_table *wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) struct uleds_device *udev = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) poll_wait(file, &udev->waitq, wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) if (udev->new_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) return EPOLLIN | EPOLLRDNORM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) static int uleds_release(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) struct uleds_device *udev = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) if (udev->state == ULEDS_STATE_REGISTERED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) udev->state = ULEDS_STATE_UNKNOWN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) devm_led_classdev_unregister(uleds_misc.this_device,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) &udev->led_cdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) kfree(udev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) static const struct file_operations uleds_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) .owner = THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) .open = uleds_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) .release = uleds_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) .read = uleds_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) .write = uleds_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) .poll = uleds_poll,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) .llseek = no_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) static struct miscdevice uleds_misc = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) .fops = &uleds_fops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) .minor = MISC_DYNAMIC_MINOR,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) .name = ULEDS_NAME,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) static int __init uleds_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) return misc_register(&uleds_misc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) module_init(uleds_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) static void __exit uleds_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) misc_deregister(&uleds_misc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) module_exit(uleds_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) MODULE_AUTHOR("David Lechner <david@lechnology.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) MODULE_DESCRIPTION("Userspace driver for the LED subsystem");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) MODULE_LICENSE("GPL");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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