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Subject[PATCH v6 6/6] iio: core: use new common ioctl() mechanism
Date
This change makes use of the new centralized ioctl() mechanism. The event
interface registers it's ioctl() handler to IIO device.
Both the buffer & event interface call 'iio_device_ioctl()', which should
take care of all of indio_dev's ioctl() calls.

Later, we may add per-buffer ioctl() calls, and since each buffer will get
it's own chardev, the buffer ioctl() handler will need a bit of tweaking
for the first/legacy buffer (i.e. indio_dev->buffer).
Also, those per-buffer ioctl() calls will not be registered with this
mechanism.

The move of the comment in this patch is intentional to show that [with
this patch], the 'indio_dev->info' NULL check is still around, but it just
got moved.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
drivers/iio/iio_core.h | 3 ---
drivers/iio/industrialio-buffer.c | 2 +-
drivers/iio/industrialio-core.c | 5 +++++
drivers/iio/industrialio-event.c | 19 ++++++++-----------
4 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h
index 34c3e19229d8..f68de4af2738 100644
--- a/drivers/iio/iio_core.h
+++ b/drivers/iio/iio_core.h
@@ -54,9 +54,6 @@ ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals);
#ifdef CONFIG_IIO_BUFFER
struct poll_table_struct;

-long iio_device_event_ioctl(struct iio_dev *indio_dev, struct file *filp,
- unsigned int cmd, unsigned long arg);
-
void iio_device_buffer_attach_chrdev(struct iio_dev *indio_dev);

int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev);
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 0689c100b041..c5c5b7537e28 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -1179,7 +1179,7 @@ static long iio_buffer_ioctl(struct file *filep, unsigned int cmd,
if (!buffer || !buffer->access)
return -ENODEV;

- return iio_device_event_ioctl(buffer->indio_dev, filep, cmd, arg);
+ return iio_device_ioctl(buffer->indio_dev, filep, cmd, arg);
}

static ssize_t iio_buffer_store_enable(struct device *dev,
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 94e7f9541e81..24c294e45502 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1600,6 +1600,11 @@ long iio_device_ioctl(struct iio_dev *indio_dev, struct file *filp,

mutex_lock(&indio_dev->info_exist_lock);

+ /**
+ * The NULL check here is required to prevent crashing when a device
+ * is being removed while userspace would still have open file handles
+ * to try to access this device.
+ */
if (!indio_dev->info)
goto out_unlock;

diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c
index d532a689c2eb..429f1d5f3c1d 100644
--- a/drivers/iio/industrialio-event.c
+++ b/drivers/iio/industrialio-event.c
@@ -32,6 +32,7 @@
* @read_lock: lock to protect kfifo read operations
* @chrdev: associated chardev for this event
* @indio_dev: IIO device to which this event interface belongs to
+ * @ioctl_handler: handler for event ioctl() calls
*/
struct iio_event_interface {
wait_queue_head_t wait;
@@ -44,6 +45,7 @@ struct iio_event_interface {

struct cdev chrdev;
struct iio_dev *indio_dev;
+ struct iio_ioctl_handler ioctl_handler;
};

bool iio_event_enabled(const struct iio_event_interface *ev_int)
@@ -261,20 +263,12 @@ static int iio_chrdev_release(struct inode *inode, struct file *filp)
return 0;
}

-long iio_device_event_ioctl(struct iio_dev *indio_dev, struct file *filp,
+static long iio_event_ioctl(struct iio_dev *indio_dev, struct file *filp,
unsigned int cmd, unsigned long arg)
{
int __user *ip = (int __user *)arg;
int fd;

- /**
- * The NULL check here is required to prevent crashing when a device
- * is being removed while userspace would still have open file handles
- * to try to access this device.
- */
- if (!indio_dev->info)
- return -ENODEV;
-
if (cmd == IIO_GET_EVENT_FD_IOCTL) {
fd = iio_event_getfd(indio_dev);
if (fd < 0)
@@ -283,7 +277,7 @@ long iio_device_event_ioctl(struct iio_dev *indio_dev, struct file *filp,
return -EFAULT;
return 0;
}
- return -EINVAL;
+ return IIO_IOCTL_UNHANDLED;
}

static long iio_event_ioctl_wrapper(struct file *filp, unsigned int cmd,
@@ -291,7 +285,7 @@ static long iio_event_ioctl_wrapper(struct file *filp, unsigned int cmd,
{
struct iio_event_interface *ev = filp->private_data;

- return iio_device_event_ioctl(ev->indio_dev, filp, cmd, arg);
+ return iio_device_ioctl(ev->indio_dev, filp, cmd, arg);
}

static const struct file_operations iio_event_fileops = {
@@ -313,7 +307,10 @@ void iio_device_event_attach_chrdev(struct iio_dev *indio_dev)
cdev_init(&ev->chrdev, &iio_event_fileops);

ev->indio_dev = indio_dev;
+ ev->ioctl_handler.ioctl = iio_event_ioctl;
indio_dev->chrdev = &ev->chrdev;
+
+ iio_device_ioctl_handler_register(indio_dev, &ev->ioctl_handler);
}

static const char * const iio_ev_type_text[] = {
--
2.17.1
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