In order to keep backwards compatibility with the current chardev
mechanism, and in order to add support for multiple buffers per IIO device,
we need to pass both the IIO device & IIO buffer to the chardev.
This is particularly needed for the iio_buffer_read_outer() function, where
we need to pass another buffer object than 'indio_dev->buffer'.
Since we'll also open some chardevs via anon inodes, we can pass extra
buffers in that function by assigning another object to the
iio_dev_buffer_pair object.
Signed-off-by: Alexandru Ardelean <[email protected]>
---
drivers/iio/iio_core.h | 6 ++++++
drivers/iio/industrialio-buffer.c | 10 ++++++----
drivers/iio/industrialio-core.c | 18 ++++++++++++++++--
3 files changed, 28 insertions(+), 6 deletions(-)
diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h
index 43d44ec92781..ad6716fe1a93 100644
--- a/drivers/iio/iio_core.h
+++ b/drivers/iio/iio_core.h
@@ -12,11 +12,17 @@
#include <linux/kernel.h>
#include <linux/device.h>
+struct iio_buffer;
struct iio_chan_spec;
struct iio_dev;
extern struct device_type iio_device_type;
+struct iio_dev_buffer_pair {
+ struct iio_dev *indio_dev;
+ struct iio_buffer *buffer;
+};
+
#define IIO_IOCTL_UNHANDLED 1
struct iio_ioctl_handler {
struct list_head entry;
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 887c71272e9c..62cb90385246 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -112,8 +112,9 @@ static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf,
ssize_t iio_buffer_read_outer(struct file *filp, char __user *buf,
size_t n, loff_t *f_ps)
{
- struct iio_dev *indio_dev = filp->private_data;
- struct iio_buffer *rb = indio_dev->buffer;
+ struct iio_dev_buffer_pair *ib = filp->private_data;
+ struct iio_buffer *rb = ib->buffer;
+ struct iio_dev *indio_dev = ib->indio_dev;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
size_t datum_size;
size_t to_wait;
@@ -178,8 +179,9 @@ ssize_t iio_buffer_read_outer(struct file *filp, char __user *buf,
__poll_t iio_buffer_poll(struct file *filp,
struct poll_table_struct *wait)
{
- struct iio_dev *indio_dev = filp->private_data;
- struct iio_buffer *rb = indio_dev->buffer;
+ struct iio_dev_buffer_pair *ib = filp->private_data;
+ struct iio_buffer *rb = ib->buffer;
+ struct iio_dev *indio_dev = ib->indio_dev;
if (!indio_dev->info || rb == NULL)
return 0;
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 088e59042226..0d1880837776 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1666,13 +1666,24 @@ static int iio_chrdev_open(struct inode *inode, struct file *filp)
{
struct iio_dev *indio_dev = container_of(inode->i_cdev,
struct iio_dev, chrdev);
+ struct iio_dev_buffer_pair *ib;
if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
return -EBUSY;
iio_device_get(indio_dev);
- filp->private_data = indio_dev;
+ ib = kmalloc(sizeof(*ib), GFP_KERNEL);
+ if (!ib) {
+ iio_device_put(indio_dev);
+ clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
+ return -ENOMEM;
+ }
+
+ ib->indio_dev = indio_dev;
+ ib->buffer = indio_dev->buffer;
+
+ filp->private_data = ib;
return 0;
}
@@ -1686,10 +1697,12 @@ static int iio_chrdev_open(struct inode *inode, struct file *filp)
*/
static int iio_chrdev_release(struct inode *inode, struct file *filp)
{
+ struct iio_dev_buffer_pair *ib = filp->private_data;
struct iio_dev *indio_dev = container_of(inode->i_cdev,
struct iio_dev, chrdev);
clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
iio_device_put(indio_dev);
+ kfree(ib);
return 0;
}
@@ -1709,7 +1722,8 @@ void iio_device_ioctl_handler_unregister(struct iio_ioctl_handler *h)
static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
- struct iio_dev *indio_dev = filp->private_data;
+ struct iio_dev_buffer_pair *ib = filp->private_data;
+ struct iio_dev *indio_dev = ib->indio_dev;
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_ioctl_handler *h;
int ret = -ENODEV;
--
2.17.1