[PATCH v2 11/16] media: utilize new cdev_device_add helper function

Logan Gunthorpe
2017-02-26T06:38:12Z

Replace the open coded registration of the cdev and dev with the
new device_add_cdev() helper. The helper replaces a common pattern by
taking the proper reference against the parent device and adding both
the cdev and the device.

Signed-off-by: Logan Gunthorpe <logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
---
drivers/media/cec/cec-core.c | 16 ++++------------
drivers/media/media-devnode.c | 20 +++++---------------
2 files changed, 9 insertions(+), 27 deletions(-)

diff --git a/drivers/media/cec/cec-core.c b/drivers/media/cec/cec-core.c
index aca3ab8..3e93c1a 100644
--- a/drivers/media/cec/cec-core.c
+++ b/drivers/media/cec/cec-core.c
@@ -137,24 +137,17 @@ static int __must_check cec_devnode_register(struct cec_devnode *devnode,

/* Part 2: Initialize and register the character device */
cdev_init(&devnode->cdev, &cec_devnode_fops);
- devnode->cdev.kobj.parent = &devnode->dev.kobj;
devnode->cdev.owner = owner;

- ret = cdev_add(&devnode->cdev, devnode->dev.devt, 1);
- if (ret < 0) {
- pr_err("%s: cdev_add failed\n", __func__);
+ ret = cdev_device_add(&devnode->cdev, &devnode->dev);
+ if (ret) {
+ pr_err("%s: cdev_device_add failed\n", __func__);
goto clr_bit;
}

- ret = device_add(&devnode->dev);
- if (ret)
- goto cdev_del;
-
devnode->registered = true;
return 0;

-cdev_del:
- cdev_del(&devnode->cdev);
clr_bit:
mutex_lock(&cec_devnode_lock);
clear_bit(devnode->minor, cec_devnode_nums);
@@ -190,8 +183,7 @@ static void cec_devnode_unregister(struct cec_devnode *devnode)
devnode->unregistered = true;
mutex_unlock(&devnode->lock);

- device_del(&devnode->dev);
- cdev_del(&devnode->cdev);
+ cdev_device_del(&devnode->cdev, &devnode->dev);
put_device(&devnode->dev);
}

diff --git a/drivers/media/media-devnode.c b/drivers/media/media-devnode.c
index f2772ba..fafe520 100644
--- a/drivers/media/media-devnode.c
+++ b/drivers/media/media-devnode.c
@@ -252,31 +252,22 @@ int __must_check media_devnode_register(struct media_device *mdev,
dev_set_name(&devnode->dev, "media%d", devnode->minor);
device_initialize(&devnode->dev);

- /* Part 2: Initialize and register the character device */
+ /* Part 2: Initialize the character device */
cdev_init(&devnode->cdev, &media_devnode_fops);
devnode->cdev.owner = owner;
- devnode->cdev.kobj.parent = &devnode->dev.kobj;

- ret = cdev_add(&devnode->cdev, MKDEV(MAJOR(media_dev_t), devnode->minor), 1);
+ /* Part 3: Add the media and char device */
+ ret = cdev_device_add(&devnode->cdev, &devnode->dev);
if (ret < 0) {
- pr_err("%s: cdev_add failed\n", __func__);
+ pr_err("%s: cdev_device_add failed\n", __func__);
goto cdev_add_error;
}

- /* Part 3: Add the media device */
- ret = device_add(&devnode->dev);
- if (ret < 0) {
- pr_err("%s: device_add failed\n", __func__);
- goto device_add_error;
- }
-
/* Part 4: Activate this minor. The char device can now be used. */
set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);

return 0;

-device_add_error:
- cdev_del(&devnode->cdev);
cdev_add_error:
mutex_lock(&media_devnode_lock);
clear_bit(devnode->minor, media_devnode_nums);
@@ -302,9 +293,8 @@ void media_devnode_unregister(struct media_devnode *devnode)
{
mutex_lock(&media_devnode_lock);
/* Delete the cdev on this minor as well */
- cdev_del(&devnode->cdev);
+ cdev_device_del(&devnode->cdev, &devnode->dev);
mutex_unlock(&media_devnode_lock);
- device_del(&devnode->dev);
devnode->media_dev = NULL;
put_device(&devnode->dev);
}
--
2.1.4