| Message ID | 20200427131100.50845-4-alexandru.ardelean@analog.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: core,buffer: re-organize chardev creation | expand |
On Mon, 27 Apr 2020 16:10:57 +0300 Alexandru Ardelean <alexandru.ardelean@analog.com> wrote: > The final intent is to localize all buffer ops into the > industrialio-buffer.c file, to be able to add support for multiple buffers > per IIO device. > > We only need a chardev if we need to support buffers and/or events. > > With this change, a chardev will be created only if an IIO buffer is > attached OR an event_interface is configured. > > Otherwise, no chardev will be created, and the IIO device will get > registered with the 'device_add()' call. > > Quite a lot of IIO devices don't really need a chardev, so this is a minor > improvement to the IIO core, as the IIO device will take up (slightly) > fewer resources. > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> > --- > drivers/iio/industrialio-core.c | 25 ++++++++++++++++++++++--- > 1 file changed, 22 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c > index 32c489139cd2..51e279c60793 100644 > --- a/drivers/iio/industrialio-core.c > +++ b/drivers/iio/industrialio-core.c > @@ -1682,6 +1682,15 @@ static int iio_check_unique_scan_index(struct iio_dev *indio_dev) > > static const struct iio_buffer_setup_ops noop_ring_setup_ops; > > +static const struct file_operations iio_event_fileops = { > + .owner = THIS_MODULE, > + .llseek = noop_llseek, > + .unlocked_ioctl = iio_event_ioctl_wrapper, Unfortunately this doesn't exist until the next patch... > + .compat_ioctl = compat_ptr_ioctl, > + .open = iio_chrdev_open, > + .release = iio_chrdev_release, > +}; > + > int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod) > { > int ret; > @@ -1732,11 +1741,18 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod) > indio_dev->setup_ops == NULL) > indio_dev->setup_ops = &noop_ring_setup_ops; > > - cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); > + if (indio_dev->buffer) > + cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); > + else if (indio_dev->event_interface) > + cdev_init(&indio_dev->chrdev, &iio_event_fileops); > > indio_dev->chrdev.owner = this_mod; > > - ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev); > + if (indio_dev->buffer || indio_dev->event_interface) > + ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev); > + else > + ret = device_add(&indio_dev->dev); > + > if (ret < 0) > goto error_unreg_eventset; > > @@ -1760,7 +1776,10 @@ EXPORT_SYMBOL(__iio_device_register); > **/ > void iio_device_unregister(struct iio_dev *indio_dev) > { > - cdev_device_del(&indio_dev->chrdev, &indio_dev->dev); > + if (indio_dev->buffer || indio_dev->event_interface) > + cdev_device_del(&indio_dev->chrdev, &indio_dev->dev); > + else > + device_del(&indio_dev->dev); > > mutex_lock(&indio_dev->info_exist_lock); >
On Sun, 2020-05-03 at 16:39 +0100, Jonathan Cameron wrote: > [External] > > On Mon, 27 Apr 2020 16:10:57 +0300 > Alexandru Ardelean <alexandru.ardelean@analog.com> wrote: > > > The final intent is to localize all buffer ops into the > > industrialio-buffer.c file, to be able to add support for multiple buffers > > per IIO device. > > > > We only need a chardev if we need to support buffers and/or events. > > > > With this change, a chardev will be created only if an IIO buffer is > > attached OR an event_interface is configured. > > > > Otherwise, no chardev will be created, and the IIO device will get > > registered with the 'device_add()' call. > > > > Quite a lot of IIO devices don't really need a chardev, so this is a minor > > improvement to the IIO core, as the IIO device will take up (slightly) > > fewer resources. > > > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> > > --- > > drivers/iio/industrialio-core.c | 25 ++++++++++++++++++++++--- > > 1 file changed, 22 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio- > > core.c > > index 32c489139cd2..51e279c60793 100644 > > --- a/drivers/iio/industrialio-core.c > > +++ b/drivers/iio/industrialio-core.c > > @@ -1682,6 +1682,15 @@ static int iio_check_unique_scan_index(struct iio_dev > > *indio_dev) > > > > static const struct iio_buffer_setup_ops noop_ring_setup_ops; > > > > +static const struct file_operations iio_event_fileops = { > > + .owner = THIS_MODULE, > > + .llseek = noop_llseek, > > + .unlocked_ioctl = iio_event_ioctl_wrapper, > > Unfortunately this doesn't exist until the next patch... crap; i copied this from the wrong place when i re-ordered this, and forgot to run a build on each patchset will fix > > > + .compat_ioctl = compat_ptr_ioctl, > > + .open = iio_chrdev_open, > > + .release = iio_chrdev_release, > > +}; > > + > > int __iio_device_register(struct iio_dev *indio_dev, struct module > > *this_mod) > > { > > int ret; > > @@ -1732,11 +1741,18 @@ int __iio_device_register(struct iio_dev *indio_dev, > > struct module *this_mod) > > indio_dev->setup_ops == NULL) > > indio_dev->setup_ops = &noop_ring_setup_ops; > > > > - cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); > > + if (indio_dev->buffer) > > + cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); > > + else if (indio_dev->event_interface) > > + cdev_init(&indio_dev->chrdev, &iio_event_fileops); > > > > indio_dev->chrdev.owner = this_mod; > > > > - ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev); > > + if (indio_dev->buffer || indio_dev->event_interface) > > + ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev); > > + else > > + ret = device_add(&indio_dev->dev); > > + > > if (ret < 0) > > goto error_unreg_eventset; > > > > @@ -1760,7 +1776,10 @@ EXPORT_SYMBOL(__iio_device_register); > > **/ > > void iio_device_unregister(struct iio_dev *indio_dev) > > { > > - cdev_device_del(&indio_dev->chrdev, &indio_dev->dev); > > + if (indio_dev->buffer || indio_dev->event_interface) > > + cdev_device_del(&indio_dev->chrdev, &indio_dev->dev); > > + else > > + device_del(&indio_dev->dev); > > > > mutex_lock(&indio_dev->info_exist_lock); > >
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index 32c489139cd2..51e279c60793 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -1682,6 +1682,15 @@ static int iio_check_unique_scan_index(struct iio_dev *indio_dev) static const struct iio_buffer_setup_ops noop_ring_setup_ops; +static const struct file_operations iio_event_fileops = { + .owner = THIS_MODULE, + .llseek = noop_llseek, + .unlocked_ioctl = iio_event_ioctl_wrapper, + .compat_ioctl = compat_ptr_ioctl, + .open = iio_chrdev_open, + .release = iio_chrdev_release, +}; + int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod) { int ret; @@ -1732,11 +1741,18 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod) indio_dev->setup_ops == NULL) indio_dev->setup_ops = &noop_ring_setup_ops; - cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); + if (indio_dev->buffer) + cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); + else if (indio_dev->event_interface) + cdev_init(&indio_dev->chrdev, &iio_event_fileops); indio_dev->chrdev.owner = this_mod; - ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev); + if (indio_dev->buffer || indio_dev->event_interface) + ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev); + else + ret = device_add(&indio_dev->dev); + if (ret < 0) goto error_unreg_eventset; @@ -1760,7 +1776,10 @@ EXPORT_SYMBOL(__iio_device_register); **/ void iio_device_unregister(struct iio_dev *indio_dev) { - cdev_device_del(&indio_dev->chrdev, &indio_dev->dev); + if (indio_dev->buffer || indio_dev->event_interface) + cdev_device_del(&indio_dev->chrdev, &indio_dev->dev); + else + device_del(&indio_dev->dev); mutex_lock(&indio_dev->info_exist_lock);
The final intent is to localize all buffer ops into the industrialio-buffer.c file, to be able to add support for multiple buffers per IIO device. We only need a chardev if we need to support buffers and/or events. With this change, a chardev will be created only if an IIO buffer is attached OR an event_interface is configured. Otherwise, no chardev will be created, and the IIO device will get registered with the 'device_add()' call. Quite a lot of IIO devices don't really need a chardev, so this is a minor improvement to the IIO core, as the IIO device will take up (slightly) fewer resources. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> --- drivers/iio/industrialio-core.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-)