OrangePi_CM5/include/linux/iio/iio-opaque.h

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iio: core: wrap IIO device into an iio_dev_opaque object There are plenty of bad designs we want to discourage or not have to review manually usually about accessing private (marked as [INTERN]) fields of 'struct iio_dev'. Sometimes users copy drivers that are not always the best examples. A better idea is to hide those fields into the framework. For 'struct iio_dev' this is a 'struct iio_dev_opaque' which wraps a public 'struct iio_dev' object. In the next series, some fields will be moved to this new struct, each with it's own rework. This rework will not be complete-able for a while, as many fields need some drivers to be reworked in order to finalize them (e.g. 'indio_dev->mlock'). But some fields can already be moved, and in time, all of them may get there (in the 'struct iio_dev_opaque' object). Since a lot of drivers also call 'iio_priv()', in order to preserve fast-paths (where this matters), the public iio_dev object will have a 'priv' field that will have the pointer to the private information already computed. The reference returned by this field should be guaranteed to be cacheline aligned. The opaque parts will be moved into the 'include/linux/iio/iio-opaque.h' header. Should the hidden information be required for some debugging or some special needs, it can be made available via this header. Otherwise, only the IIO core files should include this file. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-06-30 12:57:03 +08:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _INDUSTRIAL_IO_OPAQUE_H_
#define _INDUSTRIAL_IO_OPAQUE_H_
/**
* struct iio_dev_opaque - industrial I/O device opaque information
* @indio_dev: public industrial I/O device information
* @event_interface: event chrdevs associated with interrupt lines
* @buffer_list: list of all buffers currently attached
* @channel_attr_list: keep track of automatically created channel
* attributes
* @chan_attr_group: group for all attrs in base directory
* @debugfs_dentry: device specific debugfs dentry
* @cached_reg_addr: cached register address for debugfs reads
* @read_buf: read buffer to be used for the initial reg read
* @read_buf_len: data length in @read_buf
iio: core: wrap IIO device into an iio_dev_opaque object There are plenty of bad designs we want to discourage or not have to review manually usually about accessing private (marked as [INTERN]) fields of 'struct iio_dev'. Sometimes users copy drivers that are not always the best examples. A better idea is to hide those fields into the framework. For 'struct iio_dev' this is a 'struct iio_dev_opaque' which wraps a public 'struct iio_dev' object. In the next series, some fields will be moved to this new struct, each with it's own rework. This rework will not be complete-able for a while, as many fields need some drivers to be reworked in order to finalize them (e.g. 'indio_dev->mlock'). But some fields can already be moved, and in time, all of them may get there (in the 'struct iio_dev_opaque' object). Since a lot of drivers also call 'iio_priv()', in order to preserve fast-paths (where this matters), the public iio_dev object will have a 'priv' field that will have the pointer to the private information already computed. The reference returned by this field should be guaranteed to be cacheline aligned. The opaque parts will be moved into the 'include/linux/iio/iio-opaque.h' header. Should the hidden information be required for some debugging or some special needs, it can be made available via this header. Otherwise, only the IIO core files should include this file. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-06-30 12:57:03 +08:00
*/
struct iio_dev_opaque {
struct iio_dev indio_dev;
struct iio_event_interface *event_interface;
struct list_head buffer_list;
struct list_head channel_attr_list;
struct attribute_group chan_attr_group;
#if defined(CONFIG_DEBUG_FS)
struct dentry *debugfs_dentry;
unsigned cached_reg_addr;
char read_buf[20];
unsigned int read_buf_len;
#endif
iio: core: wrap IIO device into an iio_dev_opaque object There are plenty of bad designs we want to discourage or not have to review manually usually about accessing private (marked as [INTERN]) fields of 'struct iio_dev'. Sometimes users copy drivers that are not always the best examples. A better idea is to hide those fields into the framework. For 'struct iio_dev' this is a 'struct iio_dev_opaque' which wraps a public 'struct iio_dev' object. In the next series, some fields will be moved to this new struct, each with it's own rework. This rework will not be complete-able for a while, as many fields need some drivers to be reworked in order to finalize them (e.g. 'indio_dev->mlock'). But some fields can already be moved, and in time, all of them may get there (in the 'struct iio_dev_opaque' object). Since a lot of drivers also call 'iio_priv()', in order to preserve fast-paths (where this matters), the public iio_dev object will have a 'priv' field that will have the pointer to the private information already computed. The reference returned by this field should be guaranteed to be cacheline aligned. The opaque parts will be moved into the 'include/linux/iio/iio-opaque.h' header. Should the hidden information be required for some debugging or some special needs, it can be made available via this header. Otherwise, only the IIO core files should include this file. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-06-30 12:57:03 +08:00
};
#define to_iio_dev_opaque(indio_dev) \
container_of(indio_dev, struct iio_dev_opaque, indio_dev)
#endif