^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * media-dev-allocator.c - Media Controller Device Allocator API
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (c) 2019 Shuah Khan <shuah@kernel.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Credits: Suggested by Laurent Pinchart <laurent.pinchart@ideasonboard.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * This file adds a global refcounted Media Controller Device Instance API.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * A system wide global media device list is managed and each media device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * includes a kref count. The last put on the media device releases the media
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * device instance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/kref.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/usb.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <media/media-device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <media/media-dev-allocator.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) static LIST_HEAD(media_device_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) static DEFINE_MUTEX(media_device_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) struct media_device_instance {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) struct media_device mdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) struct module *owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) struct list_head list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) struct kref refcount;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static inline struct media_device_instance *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) to_media_device_instance(struct media_device *mdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) return container_of(mdev, struct media_device_instance, mdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) static void media_device_instance_release(struct kref *kref)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) struct media_device_instance *mdi =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) container_of(kref, struct media_device_instance, refcount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) dev_dbg(mdi->mdev.dev, "%s: releasing Media Device\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) mutex_lock(&media_device_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) media_device_unregister(&mdi->mdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) media_device_cleanup(&mdi->mdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) list_del(&mdi->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) mutex_unlock(&media_device_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) kfree(mdi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) /* Callers should hold media_device_lock when calling this function */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) static struct media_device *__media_device_get(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) const char *module_name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) struct module *owner)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) struct media_device_instance *mdi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) list_for_each_entry(mdi, &media_device_list, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) if (mdi->mdev.dev != dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) kref_get(&mdi->refcount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) /* get module reference for the media_device owner */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) if (owner != mdi->owner && !try_module_get(mdi->owner))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) dev_err(dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) "%s: module %s get owner reference error\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) __func__, module_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) dev_dbg(dev, "%s: module %s got owner reference\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) __func__, module_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return &mdi->mdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) mdi = kzalloc(sizeof(*mdi), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) if (!mdi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) mdi->owner = owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) kref_init(&mdi->refcount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) list_add_tail(&mdi->list, &media_device_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) dev_dbg(dev, "%s: Allocated media device for owner %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) __func__, module_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) return &mdi->mdev;
^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) struct media_device *media_device_usb_allocate(struct usb_device *udev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) const char *module_name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) struct module *owner)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) struct media_device *mdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) mutex_lock(&media_device_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) mdev = __media_device_get(&udev->dev, module_name, owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) if (!mdev) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) mutex_unlock(&media_device_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) return ERR_PTR(-ENOMEM);
^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) /* check if media device is already initialized */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) if (!mdev->dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) __media_device_usb_init(mdev, udev, udev->product,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) module_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) mutex_unlock(&media_device_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return mdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) EXPORT_SYMBOL_GPL(media_device_usb_allocate);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) void media_device_delete(struct media_device *mdev, const char *module_name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) struct module *owner)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) struct media_device_instance *mdi = to_media_device_instance(mdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) mutex_lock(&media_device_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) /* put module reference for the media_device owner */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) if (mdi->owner != owner) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) module_put(mdi->owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) dev_dbg(mdi->mdev.dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) "%s: module %s put owner module reference\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) __func__, module_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) mutex_unlock(&media_device_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) kref_put(&mdi->refcount, media_device_instance_release);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) EXPORT_SYMBOL_GPL(media_device_delete);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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