2009-08-18 17:06:24 +00:00
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/* The industrial I/O core - generic ring 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_RING_GENERIC_H_
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#define _IIO_RING_GENERIC_H_
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#include "iio.h"
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2010-07-11 15:39:14 +00:00
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#ifdef CONFIG_IIO_RING_BUFFER
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2009-08-18 17:06:24 +00:00
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struct iio_ring_buffer;
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/**
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* struct iio_ring_access_funcs - access functions for ring buffers.
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* @mark_in_use: reference counting, typically to prevent module removal
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* @unmark_in_use: reduce reference count when no longer using ring buffer
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* @store_to: actually store stuff to the ring buffer
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* @read_last: get the last element stored
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2011-04-15 17:55:55 +00:00
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* @read_first_n: try to get a specified number of elements (must exist)
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2009-08-18 17:06:24 +00:00
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* @mark_param_change: notify ring that some relevant parameter has changed
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* Often this means the underlying storage may need to
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* change.
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* @request_update: if a parameter change has been marked, update underlying
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* storage.
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2010-09-04 16:54:45 +00:00
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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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2009-08-18 17:06:24 +00:00
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* @get_length: get number of datums in ring
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* @set_length: set number of datums in ring
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* @is_enabled: query if ring is currently being used
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* @enable: enable the ring
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*
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* The purpose of this structure is to make the ring buffer element
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* modular as event for a given driver, different usecases may require
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2009-10-05 02:34:02 +00:00
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* different ring designs (space efficiency vs speed for example).
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2009-08-18 17:06:24 +00:00
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*
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* It is worth noting that a given ring implementation may only support a small
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* proportion of these functions. The core code 'should' cope fine with any of
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* them not existing.
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**/
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struct iio_ring_access_funcs {
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void (*mark_in_use)(struct iio_ring_buffer *ring);
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void (*unmark_in_use)(struct iio_ring_buffer *ring);
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int (*store_to)(struct iio_ring_buffer *ring, u8 *data, s64 timestamp);
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int (*read_last)(struct iio_ring_buffer *ring, u8 *data);
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2011-04-15 17:55:55 +00:00
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int (*read_first_n)(struct iio_ring_buffer *ring,
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size_t n,
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2011-05-18 13:41:02 +00:00
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char __user *buf);
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2009-08-18 17:06:24 +00:00
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int (*mark_param_change)(struct iio_ring_buffer *ring);
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int (*request_update)(struct iio_ring_buffer *ring);
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2010-08-31 09:32:50 +00:00
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int (*get_bytes_per_datum)(struct iio_ring_buffer *ring);
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int (*set_bytes_per_datum)(struct iio_ring_buffer *ring, size_t bpd);
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2009-08-18 17:06:24 +00:00
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int (*get_length)(struct iio_ring_buffer *ring);
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int (*set_length)(struct iio_ring_buffer *ring, int length);
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int (*is_enabled)(struct iio_ring_buffer *ring);
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int (*enable)(struct iio_ring_buffer *ring);
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};
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2011-05-18 13:42:24 +00:00
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struct iio_ring_setup_ops {
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int (*preenable)(struct iio_dev *);
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int (*postenable)(struct iio_dev *);
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int (*predisable)(struct iio_dev *);
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int (*postdisable)(struct iio_dev *);
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};
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2009-08-18 17:06:24 +00:00
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/**
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* struct iio_ring_buffer - general ring buffer structure
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2009-10-05 02:34:02 +00:00
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* @dev: ring buffer device struct
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* @indio_dev: industrial I/O device structure
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* @owner: module that owns the ring buffer (for ref counting)
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* @length: [DEVICE] number of datums in ring
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2010-09-04 16:54:45 +00:00
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* @bytes_per_datum: [DEVICE] size of individual datum including timestamp
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2010-07-11 15:39:16 +00:00
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* @bpe: [DEVICE] size of individual channel value
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2010-08-31 09:32:52 +00:00
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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_count: [INTERN] the number of elements in the current scan mode
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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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2009-10-05 02:34:02 +00:00
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* @access_handler: [INTERN] chrdev access handling
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* @access: [DRIVER] ring access functions associated with the
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2009-08-18 17:06:24 +00:00
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* implementation.
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2009-10-05 02:34:02 +00:00
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* @preenable: [DRIVER] function to run prior to marking ring enabled
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* @postenable: [DRIVER] function to run after marking ring enabled
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* @predisable: [DRIVER] function to run prior to marking ring disabled
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* @postdisable: [DRIVER] function to run after marking ring disabled
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2011-05-18 13:42:34 +00:00
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**/
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2009-08-18 17:06:24 +00:00
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struct iio_ring_buffer {
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2011-05-18 13:42:34 +00:00
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struct device dev;
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struct iio_dev *indio_dev;
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struct module *owner;
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int length;
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int bytes_per_datum;
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int bpe;
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struct attribute_group *scan_el_attrs;
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int scan_count;
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unsigned long scan_mask;
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bool scan_timestamp;
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struct iio_handler access_handler;
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2011-05-18 13:42:24 +00:00
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const struct iio_ring_access_funcs *access;
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2011-05-18 13:42:34 +00:00
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const struct iio_ring_setup_ops *setup_ops;
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struct list_head scan_el_dev_attr_list;
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2011-05-18 13:40:55 +00:00
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2011-05-18 13:42:34 +00:00
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wait_queue_head_t pollq;
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bool stufftoread;
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2009-08-18 17:06:24 +00:00
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};
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2010-09-04 16:54:45 +00:00
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/**
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* iio_ring_buffer_init() - Initialize the buffer structure
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* @ring: buffer to be initialized
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* @dev_info: the iio device the buffer is assocated with
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**/
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2009-08-18 17:06:24 +00:00
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void iio_ring_buffer_init(struct iio_ring_buffer *ring,
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struct iio_dev *dev_info);
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/**
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2010-03-02 13:35:35 +00:00
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* __iio_update_ring_buffer() - update common elements of ring buffers
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2009-10-05 02:34:02 +00:00
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* @ring: ring buffer that is the event source
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* @bytes_per_datum: size of individual datum including timestamp
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* @length: number of datums in ring
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2009-08-18 17:06:24 +00:00
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**/
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2010-03-02 13:35:35 +00:00
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static inline void __iio_update_ring_buffer(struct iio_ring_buffer *ring,
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int bytes_per_datum, int length)
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2009-08-18 17:06:24 +00:00
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{
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2010-08-31 09:32:50 +00:00
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ring->bytes_per_datum = bytes_per_datum;
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2009-08-18 17:06:24 +00:00
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ring->length = length;
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}
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2010-08-31 09:32:52 +00:00
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/*
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* These are mainly provided to allow for a change of implementation if a device
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* has a large number of scan elements
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*/
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#define IIO_MAX_SCAN_LENGTH 31
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/* note 0 used as error indicator as it doesn't make sense. */
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static inline u32 iio_scan_mask_match(u32 *av_masks, u32 mask)
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{
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while (*av_masks) {
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if (!(~*av_masks & mask))
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return *av_masks;
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av_masks++;
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}
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return 0;
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}
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static inline int iio_scan_mask_query(struct iio_ring_buffer *ring, int bit)
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{
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struct iio_dev *dev_info = ring->indio_dev;
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u32 mask;
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if (bit > IIO_MAX_SCAN_LENGTH)
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return -EINVAL;
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if (!ring->scan_mask)
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return 0;
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if (dev_info->available_scan_masks)
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mask = iio_scan_mask_match(dev_info->available_scan_masks,
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ring->scan_mask);
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else
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mask = ring->scan_mask;
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if (!mask)
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return -EINVAL;
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return !!(mask & (1 << bit));
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};
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2010-09-04 16:54:45 +00:00
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/**
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* iio_scan_mask_set() - set particular bit in the scan mask
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* @ring: the ring 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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2010-08-31 09:32:52 +00:00
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static inline int iio_scan_mask_set(struct iio_ring_buffer *ring, int bit)
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{
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struct iio_dev *dev_info = ring->indio_dev;
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u32 mask;
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u32 trialmask = ring->scan_mask | (1 << bit);
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if (bit > IIO_MAX_SCAN_LENGTH)
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return -EINVAL;
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if (dev_info->available_scan_masks) {
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mask = iio_scan_mask_match(dev_info->available_scan_masks,
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trialmask);
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if (!mask)
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return -EINVAL;
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}
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ring->scan_mask = trialmask;
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ring->scan_count++;
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return 0;
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};
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2010-09-04 16:54:45 +00:00
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/**
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* iio_put_ring_buffer() - notify done with buffer
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* @ring: the buffer we are done with.
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**/
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2009-08-18 17:06:24 +00:00
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static inline void iio_put_ring_buffer(struct iio_ring_buffer *ring)
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{
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put_device(&ring->dev);
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};
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2011-05-18 13:42:34 +00:00
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#define to_iio_ring_buffer(d) \
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2009-08-18 17:06:24 +00:00
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container_of(d, struct iio_ring_buffer, dev)
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2010-09-04 16:54:45 +00:00
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/**
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2011-05-18 13:42:34 +00:00
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* iio_ring_buffer_register_ex() - register the buffer with IIO core
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2011-05-18 13:40:51 +00:00
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* @ring: the buffer to be registered
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* @id: the id of the buffer (typically 0)
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**/
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int iio_ring_buffer_register_ex(struct iio_ring_buffer *ring, int id,
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const struct iio_chan_spec *channels,
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int num_channels);
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2011-05-18 13:40:57 +00:00
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void iio_ring_access_release(struct device *dev);
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2010-09-04 16:54:45 +00:00
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/**
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* iio_ring_buffer_unregister() - unregister the buffer from IIO core
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* @ring: the buffer to be unregistered
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**/
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2009-08-18 17:06:24 +00:00
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void iio_ring_buffer_unregister(struct iio_ring_buffer *ring);
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2010-09-04 16:54:45 +00:00
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/**
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* iio_read_ring_length() - attr func to get number of datums in the buffer
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**/
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2009-08-18 17:06:24 +00:00
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ssize_t iio_read_ring_length(struct device *dev,
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struct device_attribute *attr,
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char *buf);
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2010-09-04 16:54:45 +00:00
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/**
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* iio_write_ring_length() - attr func to set number of datums in the buffer
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**/
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2009-08-18 17:06:24 +00:00
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ssize_t iio_write_ring_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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2010-09-04 16:54:45 +00:00
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/**
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* iio_read_ring_bytes_per_datum() - attr for number of bytes in whole datum
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**/
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2010-08-31 09:32:50 +00:00
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ssize_t iio_read_ring_bytes_per_datum(struct device *dev,
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2009-08-18 17:06:24 +00:00
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struct device_attribute *attr,
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char *buf);
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2010-09-04 16:54:45 +00:00
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/**
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* iio_store_ring_enable() - attr to turn the buffer on
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**/
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2009-08-18 17:06:24 +00:00
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ssize_t iio_store_ring_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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2010-09-04 16:54:45 +00:00
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/**
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* iio_show_ring_enable() - attr to see if the buffer is on
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**/
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2009-08-18 17:06:24 +00:00
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ssize_t iio_show_ring_enable(struct device *dev,
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struct device_attribute *attr,
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char *buf);
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#define IIO_RING_LENGTH_ATTR DEVICE_ATTR(length, S_IRUGO | S_IWUSR, \
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iio_read_ring_length, \
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iio_write_ring_length)
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2010-08-31 09:32:50 +00:00
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#define IIO_RING_BYTES_PER_DATUM_ATTR DEVICE_ATTR(bytes_per_datum, S_IRUGO | S_IWUSR, \
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iio_read_ring_bytes_per_datum, NULL)
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#define IIO_RING_ENABLE_ATTR DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, \
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2009-08-18 17:06:24 +00:00
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iio_show_ring_enable, \
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iio_store_ring_enable)
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2011-05-18 13:42:24 +00:00
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int iio_sw_ring_preenable(struct iio_dev *indio_dev);
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2010-07-11 15:39:14 +00:00
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#else /* CONFIG_IIO_RING_BUFFER */
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2011-05-18 13:40:51 +00:00
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static inline int iio_ring_buffer_register_ex(struct iio_ring_buffer *ring,
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int id,
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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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2010-07-11 15:39:14 +00:00
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static inline void iio_ring_buffer_unregister(struct iio_ring_buffer *ring)
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{};
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#endif /* CONFIG_IIO_RING_BUFFER */
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2009-08-18 17:06:24 +00:00
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#endif /* _IIO_RING_GENERIC_H_ */
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