197 строки
6.4 KiB
C
197 строки
6.4 KiB
C
/* The industrial I/O core - generic buffer interfaces.
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*
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* Copyright (c) 2008 Jonathan Cameron
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#ifndef _IIO_BUFFER_GENERIC_H_
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#define _IIO_BUFFER_GENERIC_H_
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#include <linux/sysfs.h>
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#include <linux/iio/iio.h>
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#ifdef CONFIG_IIO_BUFFER
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struct iio_buffer;
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/**
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* struct iio_buffer_access_funcs - access functions for buffers.
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* @store_to: actually store stuff to the buffer
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* @read_first_n: try to get a specified number of bytes (must exist)
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* @request_update: if a parameter change has been marked, update underlying
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* storage.
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* @get_bytes_per_datum:get current bytes per datum
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* @set_bytes_per_datum:set number of bytes per datum
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* @get_length: get number of datums in buffer
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* @set_length: set number of datums in buffer
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*
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* The purpose of this structure is to make the buffer element
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* modular as event for a given driver, different usecases may require
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* different buffer designs (space efficiency vs speed for example).
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*
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* It is worth noting that a given buffer implementation may only support a
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* small proportion of these functions. The core code 'should' cope fine with
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* any of them not existing.
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**/
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struct iio_buffer_access_funcs {
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int (*store_to)(struct iio_buffer *buffer, u8 *data);
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int (*read_first_n)(struct iio_buffer *buffer,
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size_t n,
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char __user *buf);
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int (*request_update)(struct iio_buffer *buffer);
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int (*get_bytes_per_datum)(struct iio_buffer *buffer);
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int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd);
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int (*get_length)(struct iio_buffer *buffer);
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int (*set_length)(struct iio_buffer *buffer, int length);
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};
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/**
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* struct iio_buffer - general buffer structure
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* @length: [DEVICE] number of datums in buffer
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* @bytes_per_datum: [DEVICE] size of individual datum including timestamp
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* @scan_el_attrs: [DRIVER] control of scan elements if that scan mode
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* control method is used
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* @scan_mask: [INTERN] bitmask used in masking scan mode elements
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* @scan_timestamp: [INTERN] does the scan mode include a timestamp
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* @access: [DRIVER] buffer access functions associated with the
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* implementation.
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* @scan_el_dev_attr_list:[INTERN] list of scan element related attributes.
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* @scan_el_group: [DRIVER] attribute group for those attributes not
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* created from the iio_chan_info array.
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* @pollq: [INTERN] wait queue to allow for polling on the buffer.
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* @stufftoread: [INTERN] flag to indicate new data.
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* @demux_list: [INTERN] list of operations required to demux the scan.
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* @demux_bounce: [INTERN] buffer for doing gather from incoming scan.
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* @buffer_list: [INTERN] entry in the devices list of current buffers.
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*/
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struct iio_buffer {
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int length;
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int bytes_per_datum;
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struct attribute_group *scan_el_attrs;
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long *scan_mask;
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bool scan_timestamp;
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const struct iio_buffer_access_funcs *access;
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struct list_head scan_el_dev_attr_list;
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struct attribute_group scan_el_group;
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wait_queue_head_t pollq;
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bool stufftoread;
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const struct attribute_group *attrs;
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struct list_head demux_list;
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unsigned char *demux_bounce;
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struct list_head buffer_list;
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};
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/**
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* iio_update_buffers() - add or remove buffer from active list
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* @indio_dev: device to add buffer to
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* @insert_buffer: buffer to insert
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* @remove_buffer: buffer_to_remove
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*
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* Note this will tear down the all buffering and build it up again
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*/
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int iio_update_buffers(struct iio_dev *indio_dev,
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struct iio_buffer *insert_buffer,
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struct iio_buffer *remove_buffer);
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/**
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* iio_buffer_init() - Initialize the buffer structure
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* @buffer: buffer to be initialized
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**/
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void iio_buffer_init(struct iio_buffer *buffer);
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int iio_scan_mask_query(struct iio_dev *indio_dev,
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struct iio_buffer *buffer, int bit);
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/**
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* iio_scan_mask_set() - set particular bit in the scan mask
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* @indio_dev IIO device structure
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* @buffer: the buffer whose scan mask we are interested in
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* @bit: the bit to be set.
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**/
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int iio_scan_mask_set(struct iio_dev *indio_dev,
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struct iio_buffer *buffer, int bit);
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/**
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* iio_push_to_buffers() - push to a registered buffer.
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* @indio_dev: iio_dev structure for device.
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* @data: Full scan.
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*/
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int iio_push_to_buffers(struct iio_dev *indio_dev, unsigned char *data);
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int iio_update_demux(struct iio_dev *indio_dev);
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/**
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* iio_buffer_register() - register the buffer with IIO core
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* @indio_dev: device with the buffer to be registered
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* @channels: the channel descriptions used to construct buffer
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* @num_channels: the number of channels
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**/
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int iio_buffer_register(struct iio_dev *indio_dev,
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const struct iio_chan_spec *channels,
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int num_channels);
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/**
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* iio_buffer_unregister() - unregister the buffer from IIO core
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* @indio_dev: the device with the buffer to be unregistered
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**/
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void iio_buffer_unregister(struct iio_dev *indio_dev);
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/**
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* iio_buffer_read_length() - attr func to get number of datums in the buffer
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**/
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ssize_t iio_buffer_read_length(struct device *dev,
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struct device_attribute *attr,
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char *buf);
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/**
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* iio_buffer_write_length() - attr func to set number of datums in the buffer
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**/
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ssize_t iio_buffer_write_length(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t len);
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/**
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* iio_buffer_store_enable() - attr to turn the buffer on
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**/
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ssize_t iio_buffer_store_enable(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t len);
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/**
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* iio_buffer_show_enable() - attr to see if the buffer is on
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**/
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ssize_t iio_buffer_show_enable(struct device *dev,
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struct device_attribute *attr,
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char *buf);
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#define IIO_BUFFER_LENGTH_ATTR DEVICE_ATTR(length, S_IRUGO | S_IWUSR, \
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iio_buffer_read_length, \
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iio_buffer_write_length)
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#define IIO_BUFFER_ENABLE_ATTR DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, \
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iio_buffer_show_enable, \
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iio_buffer_store_enable)
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int iio_sw_buffer_preenable(struct iio_dev *indio_dev);
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bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
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const unsigned long *mask);
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#else /* CONFIG_IIO_BUFFER */
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static inline int iio_buffer_register(struct iio_dev *indio_dev,
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const struct iio_chan_spec *channels,
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int num_channels)
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{
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return 0;
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}
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static inline void iio_buffer_unregister(struct iio_dev *indio_dev)
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{}
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#endif /* CONFIG_IIO_BUFFER */
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#endif /* _IIO_BUFFER_GENERIC_H_ */
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