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linux/drivers/iio/buffer_cb.c

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staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/iio/buffer.h>
#include <linux/iio/consumer.h>
struct iio_cb_buffer {
struct iio_buffer buffer;
iio: iio_push_to_buffers(): Change type of 'data' to const void * Change the type of the 'data' parameter for iio_push_to_buffers() from 'u8 *' to 'const void *'. Drivers typically use the correct type (e.g. __be16 *) for their data buffer. When passing the buffer to iio_push_to_buffers() it needs to be cast to 'u8 *' for the compiler to not complain (and also having to add __force if we want to keep sparse happy as well). Since the buffer implementation should not care about the data layout (except the size of one sample) using a void pointer is the correct thing to do. Also make it const as the buffer implementations are not supposed to modify it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-09-15 20:50:00 +04:00
int (*cb)(const void *data, void *private);
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
void *private;
struct iio_channel *channels;
};
iio: Add reference counting for buffers Since the buffer is accessed by userspace we can not just free the buffers memory once we are done with it in kernel space. There might still be open file descriptors and userspace still might be accessing the buffer. This patch adds support for reference counting to the IIO buffers. When a buffer is created and initialized its initial reference count is set to 1. Instead of freeing the memory of the buffer the buffer's _free() function will drop that reference again. But only after the last reference to the buffer has been dropped the buffer the buffer's memory will be freed. The IIO device will take a reference to its primary buffer. The patch adds a small helper function for this called iio_device_attach_buffer() which will get a reference to the buffer and assign the buffer to the IIO device. This function must be used instead of assigning the buffer to the device by hand. The reference is only dropped once the IIO device is freed and we can be sure that there are no more open file handles. A reference to a buffer will also be taken whenever the buffer is active to avoid the buffer being freed while data is still being send to it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-10-04 15:06:00 +04:00
static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
{
iio: Add reference counting for buffers Since the buffer is accessed by userspace we can not just free the buffers memory once we are done with it in kernel space. There might still be open file descriptors and userspace still might be accessing the buffer. This patch adds support for reference counting to the IIO buffers. When a buffer is created and initialized its initial reference count is set to 1. Instead of freeing the memory of the buffer the buffer's _free() function will drop that reference again. But only after the last reference to the buffer has been dropped the buffer the buffer's memory will be freed. The IIO device will take a reference to its primary buffer. The patch adds a small helper function for this called iio_device_attach_buffer() which will get a reference to the buffer and assign the buffer to the IIO device. This function must be used instead of assigning the buffer to the device by hand. The reference is only dropped once the IIO device is freed and we can be sure that there are no more open file handles. A reference to a buffer will also be taken whenever the buffer is active to avoid the buffer being freed while data is still being send to it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-10-04 15:06:00 +04:00
return container_of(buffer, struct iio_cb_buffer, buffer);
}
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
iio: Add reference counting for buffers Since the buffer is accessed by userspace we can not just free the buffers memory once we are done with it in kernel space. There might still be open file descriptors and userspace still might be accessing the buffer. This patch adds support for reference counting to the IIO buffers. When a buffer is created and initialized its initial reference count is set to 1. Instead of freeing the memory of the buffer the buffer's _free() function will drop that reference again. But only after the last reference to the buffer has been dropped the buffer the buffer's memory will be freed. The IIO device will take a reference to its primary buffer. The patch adds a small helper function for this called iio_device_attach_buffer() which will get a reference to the buffer and assign the buffer to the IIO device. This function must be used instead of assigning the buffer to the device by hand. The reference is only dropped once the IIO device is freed and we can be sure that there are no more open file handles. A reference to a buffer will also be taken whenever the buffer is active to avoid the buffer being freed while data is still being send to it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-10-04 15:06:00 +04:00
static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
{
struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
return cb_buff->cb(data, cb_buff->private);
}
iio: Add reference counting for buffers Since the buffer is accessed by userspace we can not just free the buffers memory once we are done with it in kernel space. There might still be open file descriptors and userspace still might be accessing the buffer. This patch adds support for reference counting to the IIO buffers. When a buffer is created and initialized its initial reference count is set to 1. Instead of freeing the memory of the buffer the buffer's _free() function will drop that reference again. But only after the last reference to the buffer has been dropped the buffer the buffer's memory will be freed. The IIO device will take a reference to its primary buffer. The patch adds a small helper function for this called iio_device_attach_buffer() which will get a reference to the buffer and assign the buffer to the IIO device. This function must be used instead of assigning the buffer to the device by hand. The reference is only dropped once the IIO device is freed and we can be sure that there are no more open file handles. A reference to a buffer will also be taken whenever the buffer is active to avoid the buffer being freed while data is still being send to it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-10-04 15:06:00 +04:00
static void iio_buffer_cb_release(struct iio_buffer *buffer)
{
struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
kfree(cb_buff->buffer.scan_mask);
kfree(cb_buff);
}
iio:buffer_cb: Constify iio_cb_access The iio_cb_access struct is never modified so we can mark it as const. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-09-15 20:09:00 +04:00
static const struct iio_buffer_access_funcs iio_cb_access = {
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
.store_to = &iio_buffer_cb_store_to,
iio: Add reference counting for buffers Since the buffer is accessed by userspace we can not just free the buffers memory once we are done with it in kernel space. There might still be open file descriptors and userspace still might be accessing the buffer. This patch adds support for reference counting to the IIO buffers. When a buffer is created and initialized its initial reference count is set to 1. Instead of freeing the memory of the buffer the buffer's _free() function will drop that reference again. But only after the last reference to the buffer has been dropped the buffer the buffer's memory will be freed. The IIO device will take a reference to its primary buffer. The patch adds a small helper function for this called iio_device_attach_buffer() which will get a reference to the buffer and assign the buffer to the IIO device. This function must be used instead of assigning the buffer to the device by hand. The reference is only dropped once the IIO device is freed and we can be sure that there are no more open file handles. A reference to a buffer will also be taken whenever the buffer is active to avoid the buffer being freed while data is still being send to it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-10-04 15:06:00 +04:00
.release = &iio_buffer_cb_release,
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
};
iio: Update iio_channel_get_all and iio_channel_get_all_cb API Pass device pointer instead of device name as parameter to iio_channel_get_all and iio_channel_get_all_cb. This will enable us to use OF information to retrieve consumer channel information. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-02-01 01:43:00 +04:00
struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
iio: iio_push_to_buffers(): Change type of 'data' to const void * Change the type of the 'data' parameter for iio_push_to_buffers() from 'u8 *' to 'const void *'. Drivers typically use the correct type (e.g. __be16 *) for their data buffer. When passing the buffer to iio_push_to_buffers() it needs to be cast to 'u8 *' for the compiler to not complain (and also having to add __force if we want to keep sparse happy as well). Since the buffer implementation should not care about the data layout (except the size of one sample) using a void pointer is the correct thing to do. Also make it const as the buffer implementations are not supposed to modify it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-09-15 20:50:00 +04:00
int (*cb)(const void *data,
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
void *private),
void *private)
{
int ret;
struct iio_cb_buffer *cb_buff;
struct iio_dev *indio_dev;
struct iio_channel *chan;
cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
if (cb_buff == NULL) {
ret = -ENOMEM;
goto error_ret;
}
iio:buffer_cb: Add missing iio_buffer_init() Make sure to properly initialize the IIO buffer data structure. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-09-19 00:02:00 +04:00
iio_buffer_init(&cb_buff->buffer);
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
cb_buff->private = private;
cb_buff->cb = cb;
cb_buff->buffer.access = &iio_cb_access;
INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
iio: Update iio_channel_get_all and iio_channel_get_all_cb API Pass device pointer instead of device name as parameter to iio_channel_get_all and iio_channel_get_all_cb. This will enable us to use OF information to retrieve consumer channel information. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-02-01 01:43:00 +04:00
cb_buff->channels = iio_channel_get_all(dev);
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
if (IS_ERR(cb_buff->channels)) {
ret = PTR_ERR(cb_buff->channels);
goto error_free_cb_buff;
}
indio_dev = cb_buff->channels[0].indio_dev;
cb_buff->buffer.scan_mask
= kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long),
GFP_KERNEL);
if (cb_buff->buffer.scan_mask == NULL) {
ret = -ENOMEM;
goto error_release_channels;
}
chan = &cb_buff->channels[0];
while (chan->indio_dev) {
if (chan->indio_dev != indio_dev) {
ret = -EINVAL;
iio:callback buffer: free the scan_mask Reported-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-05-23 01:41:00 +04:00
goto error_free_scan_mask;
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
}
set_bit(chan->channel->scan_index,
cb_buff->buffer.scan_mask);
chan++;
}
return cb_buff;
iio:callback buffer: free the scan_mask Reported-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-05-23 01:41:00 +04:00
error_free_scan_mask:
kfree(cb_buff->buffer.scan_mask);
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
error_release_channels:
iio_channel_release_all(cb_buff->channels);
error_free_cb_buff:
kfree(cb_buff);
error_ret:
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
{
return iio_update_buffers(cb_buff->channels[0].indio_dev,
&cb_buff->buffer,
NULL);
}
EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
{
iio_update_buffers(cb_buff->channels[0].indio_dev,
NULL,
&cb_buff->buffer);
}
EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
{
iio_channel_release_all(cb_buff->channels);
iio: Add reference counting for buffers Since the buffer is accessed by userspace we can not just free the buffers memory once we are done with it in kernel space. There might still be open file descriptors and userspace still might be accessing the buffer. This patch adds support for reference counting to the IIO buffers. When a buffer is created and initialized its initial reference count is set to 1. Instead of freeing the memory of the buffer the buffer's _free() function will drop that reference again. But only after the last reference to the buffer has been dropped the buffer the buffer's memory will be freed. The IIO device will take a reference to its primary buffer. The patch adds a small helper function for this called iio_device_attach_buffer() which will get a reference to the buffer and assign the buffer to the IIO device. This function must be used instead of assigning the buffer to the device by hand. The reference is only dropped once the IIO device is freed and we can be sure that there are no more open file handles. A reference to a buffer will also be taken whenever the buffer is active to avoid the buffer being freed while data is still being send to it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-10-04 15:06:00 +04:00
iio_buffer_put(&cb_buff->buffer);
staging:iio: add a callback buffer for in kernel push interface This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-30 23:06:00 +04:00
}
EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
struct iio_channel
*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
{
return cb_buffer->channels;
}
EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
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