[linux-2.6-block.git] / drivers / staging / iio / ring_generic.h

/* The industrial I/O core - generic ring buffer interfaces.
 *
 * Copyright (c) 2008 Jonathan Cameron
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#ifndef _IIO_RING_GENERIC_H_
#define _IIO_RING_GENERIC_H_
#include "iio.h"

#ifdef CONFIG_IIO_RING_BUFFER

struct iio_ring_buffer;

/**
 * struct iio_ring_access_funcs - access functions for ring buffers.
 * @mark_in_use:	reference counting, typically to prevent module removal
 * @unmark_in_use:	reduce reference count when no longer using ring buffer
 * @store_to:		actually store stuff to the ring buffer
 * @read_last:		get the last element stored
 * @read_first_n:	try to get a specified number of elements (must exist)
 * @mark_param_change:	notify ring that some relevant parameter has changed
 *			Often this means the underlying storage may need to
 *			change.
 * @request_update:	if a parameter change has been marked, update underlying
 *			storage.
 * @get_bytes_per_datum:get current bytes per datum
 * @set_bytes_per_datum:set number of bytes per datum
 * @get_length:		get number of datums in ring
 * @set_length:		set number of datums in ring
 * @is_enabled:		query if ring is currently being used
 * @enable:		enable the ring
 *
 * The purpose of this structure is to make the ring buffer element
 * modular as event for a given driver, different usecases may require
 * different ring designs (space efficiency vs speed for example).
 *
 * It is worth noting that a given ring implementation may only support a small
 * proportion of these functions.  The core code 'should' cope fine with any of
 * them not existing.
 **/
struct iio_ring_access_funcs {
	void (*mark_in_use)(struct iio_ring_buffer *ring);
	void (*unmark_in_use)(struct iio_ring_buffer *ring);

	int (*store_to)(struct iio_ring_buffer *ring, u8 *data, s64 timestamp);
	int (*read_last)(struct iio_ring_buffer *ring, u8 *data);
	int (*read_first_n)(struct iio_ring_buffer *ring,
			    size_t n,
			    char __user *buf);

	int (*mark_param_change)(struct iio_ring_buffer *ring);
	int (*request_update)(struct iio_ring_buffer *ring);

	int (*get_bytes_per_datum)(struct iio_ring_buffer *ring);
	int (*set_bytes_per_datum)(struct iio_ring_buffer *ring, size_t bpd);
	int (*get_length)(struct iio_ring_buffer *ring);
	int (*set_length)(struct iio_ring_buffer *ring, int length);

	int (*is_enabled)(struct iio_ring_buffer *ring);
	int (*enable)(struct iio_ring_buffer *ring);
};

struct iio_ring_setup_ops {
	int				(*preenable)(struct iio_dev *);
	int				(*postenable)(struct iio_dev *);
	int				(*predisable)(struct iio_dev *);
	int				(*postdisable)(struct iio_dev *);
};

/**
 * struct iio_ring_buffer - general ring buffer structure
 * @dev:		ring buffer device struct
 * @indio_dev:		industrial I/O device structure
 * @owner:		module that owns the ring buffer (for ref counting)
 * @id:			unique id number
 * @length:		[DEVICE] number of datums in ring
 * @bytes_per_datum:	[DEVICE] size of individual datum including timestamp
 * @bpe:		[DEVICE] size of individual channel value
 * @loopcount:		[INTERN] number of times the ring has looped
 * @scan_el_attrs:	[DRIVER] control of scan elements if that scan mode
 *			control method is used
 * @scan_count:	[INTERN] the number of elements in the current scan mode
 * @scan_mask:		[INTERN] bitmask used in masking scan mode elements
 * @scan_timestamp:	[INTERN] does the scan mode include a timestamp
 * @access_handler:	[INTERN] chrdev access handling
 * @access:		[DRIVER] ring access functions associated with the
 *			implementation.
 * @preenable:		[DRIVER] function to run prior to marking ring enabled
 * @postenable:		[DRIVER] function to run after marking ring enabled
 * @predisable:		[DRIVER] function to run prior to marking ring disabled
 * @postdisable:	[DRIVER] function to run after marking ring disabled
  **/
struct iio_ring_buffer {
	struct device dev;
	struct iio_dev *indio_dev;
	struct module *owner;
	int				id;
	int				length;
	int				bytes_per_datum;
	int				bpe;
	int				loopcount;
	struct attribute_group		*scan_el_attrs;
	int				scan_count;
	u32				scan_mask;
	bool				scan_timestamp;
	struct iio_handler		access_handler;
	const struct iio_ring_access_funcs	*access;
	const struct iio_ring_setup_ops	*setup_ops;
	struct list_head scan_el_dev_attr_list;

	wait_queue_head_t pollq;
	bool stufftoread;
};

/**
 * iio_ring_buffer_init() - Initialize the buffer structure
 * @ring: buffer to be initialized
 * @dev_info: the iio device the buffer is assocated with
 **/
void iio_ring_buffer_init(struct iio_ring_buffer *ring,
			  struct iio_dev *dev_info);

/**
 * __iio_update_ring_buffer() - update common elements of ring buffers
 * @ring:		ring buffer that is the event source
 * @bytes_per_datum:	size of individual datum including timestamp
 * @length:		number of datums in ring
 **/
static inline void __iio_update_ring_buffer(struct iio_ring_buffer *ring,
					    int bytes_per_datum, int length)
{
	ring->bytes_per_datum = bytes_per_datum;
	ring->length = length;
	ring->loopcount = 0;
}

/**
 * iio_scan_el_store() - sysfs scan element selection interface
 * @dev: the target device
 * @attr: the device attribute that is being processed
 * @buf: input from userspace
 * @len: length of input
 *
 * A generic function used to enable various scan elements.  In some
 * devices explicit read commands for each channel mean this is merely
 * a software switch.  In others this must actively disable the channel.
 * Complexities occur when this interacts with data ready type triggers
 * which may not reset unless every channel that is enabled is explicitly
 * read.
 **/
ssize_t iio_scan_el_store(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t len);
/**
 * iio_scan_el_show() -	sysfs interface to query whether a scan element
 *			is enabled or not
 * @dev: the target device
 * @attr: the device attribute that is being processed
 * @buf: output buffer
 **/
ssize_t iio_scan_el_show(struct device *dev, struct device_attribute *attr,
			 char *buf);

/**
 * iio_scan_el_ts_store() - sysfs interface to set whether a timestamp is included
 *			    in the scan.
 **/
ssize_t iio_scan_el_ts_store(struct device *dev, struct device_attribute *attr,
			     const char *buf, size_t len);
/**
 * iio_scan_el_ts_show() - sysfs interface to query if a timestamp is included
 *			   in the scan.
 **/
ssize_t iio_scan_el_ts_show(struct device *dev, struct device_attribute *attr,
			    char *buf);

/*
 * These are mainly provided to allow for a change of implementation if a device
 * has a large number of scan elements
 */
#define IIO_MAX_SCAN_LENGTH 31

/* note 0 used as error indicator as it doesn't make sense. */
static inline u32 iio_scan_mask_match(u32 *av_masks, u32 mask)
{
	while (*av_masks) {
		if (!(~*av_masks & mask))
			return *av_masks;
		av_masks++;
	}
	return 0;
}

static inline int iio_scan_mask_query(struct iio_ring_buffer *ring, int bit)
{
	struct iio_dev *dev_info = ring->indio_dev;
	u32 mask;

	if (bit > IIO_MAX_SCAN_LENGTH)
		return -EINVAL;

	if (!ring->scan_mask)
		return 0;

	if (dev_info->available_scan_masks)
		mask = iio_scan_mask_match(dev_info->available_scan_masks,
					ring->scan_mask);
	else
		mask = ring->scan_mask;

	if (!mask)
		return -EINVAL;

	return !!(mask & (1 << bit));
};

/**
 * iio_scan_mask_set() - set particular bit in the scan mask
 * @ring: the ring buffer whose scan mask we are interested in
 * @bit: the bit to be set.
 **/
static inline int iio_scan_mask_set(struct iio_ring_buffer *ring, int bit)
{
	struct iio_dev *dev_info = ring->indio_dev;
	u32 mask;
	u32 trialmask = ring->scan_mask | (1 << bit);

	if (bit > IIO_MAX_SCAN_LENGTH)
		return -EINVAL;
	if (dev_info->available_scan_masks) {
		mask = iio_scan_mask_match(dev_info->available_scan_masks,
					trialmask);
		if (!mask)
			return -EINVAL;
	}
	ring->scan_mask = trialmask;
	ring->scan_count++;

	return 0;
};

/**
 * iio_scan_mask_clear() - clear a particular element from the scan mask
 * @ring: the ring buffer whose scan mask we are interested in
 * @bit: the bit to clear
 **/
static inline int iio_scan_mask_clear(struct iio_ring_buffer *ring, int bit)
{
	if (bit > IIO_MAX_SCAN_LENGTH)
		return -EINVAL;
	ring->scan_mask &= ~(1 << bit);
	ring->scan_count--;
	return 0;
};

/**
 * iio_scan_mask_count_to_right() - how many scan elements occur before here
 * @ring: the ring buffer whose scan mask we interested in
 * @bit: which number scan element is this
 **/
static inline int iio_scan_mask_count_to_right(struct iio_ring_buffer *ring,
						int bit)
{
	int count = 0;
	int mask = (1 << bit);
	if (bit > IIO_MAX_SCAN_LENGTH)
		return -EINVAL;
	while (mask) {
		mask >>= 1;
		if (mask & ring->scan_mask)
			count++;
	}

	return count;
}

/**
 * iio_put_ring_buffer() - notify done with buffer
 * @ring: the buffer we are done with.
 **/
static inline void iio_put_ring_buffer(struct iio_ring_buffer *ring)
{
	put_device(&ring->dev);
};

#define to_iio_ring_buffer(d)			\
	container_of(d, struct iio_ring_buffer, dev)

/**
 * iio_ring_buffer_register() - register the buffer with IIO core
 * @ring: the buffer to be registered
 * @id: the id of the buffer (typically 0)
 **/
int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id);

/** iio_ring_buffer_register_ex() - register the buffer with IIO core
 * @ring: the buffer to be registered
 * @id: the id of the buffer (typically 0)
 **/
int iio_ring_buffer_register_ex(struct iio_ring_buffer *ring, int id,
				const struct iio_chan_spec *channels,
				int num_channels);

void iio_ring_access_release(struct device *dev);

/**
 * iio_ring_buffer_unregister() - unregister the buffer from IIO core
 * @ring: the buffer to be unregistered
 **/
void iio_ring_buffer_unregister(struct iio_ring_buffer *ring);

/**
 * iio_read_ring_length() - attr func to get number of datums in the buffer
 **/
ssize_t iio_read_ring_length(struct device *dev,
			     struct device_attribute *attr,
			     char *buf);
/**
 * iio_write_ring_length() - attr func to set number of datums in the buffer
 **/
ssize_t iio_write_ring_length(struct device *dev,
			      struct device_attribute *attr,
			      const char *buf,
			      size_t len);
/**
 * iio_read_ring_bytes_per_datum() - attr for number of bytes in whole datum
 **/
ssize_t iio_read_ring_bytes_per_datum(struct device *dev,
			  struct device_attribute *attr,
			  char *buf);
/**
 * iio_store_ring_enable() - attr to turn the buffer on
 **/
ssize_t iio_store_ring_enable(struct device *dev,
			      struct device_attribute *attr,
			      const char *buf,
			      size_t len);
/**
 * iio_show_ring_enable() - attr to see if the buffer is on
 **/
ssize_t iio_show_ring_enable(struct device *dev,
			     struct device_attribute *attr,
			     char *buf);
#define IIO_RING_LENGTH_ATTR DEVICE_ATTR(length, S_IRUGO | S_IWUSR,	\
					 iio_read_ring_length,		\
					 iio_write_ring_length)
#define IIO_RING_BYTES_PER_DATUM_ATTR DEVICE_ATTR(bytes_per_datum, S_IRUGO | S_IWUSR,	\
				      iio_read_ring_bytes_per_datum, NULL)
#define IIO_RING_ENABLE_ATTR DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, \
					 iio_show_ring_enable,		\
					 iio_store_ring_enable)

int iio_sw_ring_preenable(struct iio_dev *indio_dev);

#else /* CONFIG_IIO_RING_BUFFER */
static inline int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id)
{
	return 0;
};

static inline int iio_ring_buffer_register_ex(struct iio_ring_buffer *ring,
					      int id,
					      struct iio_chan_spec *channels,
					      int num_channels)
{
	return 0;
}

static inline void iio_ring_buffer_unregister(struct iio_ring_buffer *ring)
{};

#endif /* CONFIG_IIO_RING_BUFFER */

#endif /* _IIO_RING_GENERIC_H_ */
Commit	Line	Data
7026ea4b JC	1	/* The industrial I/O core - generic ring buffer interfaces.
	2	*
	3	* Copyright (c) 2008 Jonathan Cameron
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License version 2 as published by
	7	* the Free Software Foundation.
	8	*/
	9
	10	#ifndef _IIO_RING_GENERIC_H_
	11	#define _IIO_RING_GENERIC_H_
	12	#include "iio.h"
	13
2662051e JC	14	#ifdef CONFIG_IIO_RING_BUFFER
2662051e JC	15
7026ea4b	16	struct iio_ring_buffer;
7026ea4b	17
7026ea4b JC	18	/**
7026ea4b JC	19	* struct iio_ring_access_funcs - access functions for ring buffers.
7026ea4b JC	20	* @mark_in_use: reference counting, typically to prevent module removal
	21	* @unmark_in_use: reduce reference count when no longer using ring buffer
	22	* @store_to: actually store stuff to the ring buffer
	23	* @read_last: get the last element stored
b4281733	24	* @read_first_n: try to get a specified number of elements (must exist)
7026ea4b JC	25	* @mark_param_change: notify ring that some relevant parameter has changed
	26	* Often this means the underlying storage may need to
	27	* change.
	28	* @request_update: if a parameter change has been marked, update underlying
	29	* storage.
c3e5d410 JC	30	* @get_bytes_per_datum:get current bytes per datum
c3e5d410 JC	31	* @set_bytes_per_datum:set number of bytes per datum
7026ea4b JC	32	* @get_length: get number of datums in ring
	33	* @set_length: set number of datums in ring
	34	* @is_enabled: query if ring is currently being used
	35	* @enable: enable the ring
	36	*
	37	* The purpose of this structure is to make the ring buffer element
	38	* modular as event for a given driver, different usecases may require
4c572605	39	* different ring designs (space efficiency vs speed for example).
7026ea4b JC	40	*
	41	* It is worth noting that a given ring implementation may only support a small
	42	* proportion of these functions. The core code 'should' cope fine with any of
	43	* them not existing.
	44	**/
	45	struct iio_ring_access_funcs {
	46	void (mark_in_use)(struct iio_ring_buffer ring);
	47	void (unmark_in_use)(struct iio_ring_buffer ring);
	48
	49	int (store_to)(struct iio_ring_buffer ring, u8 *data, s64 timestamp);
	50	int (read_last)(struct iio_ring_buffer ring, u8 *data);
b4281733 JC	51	int (read_first_n)(struct iio_ring_buffer ring,
b4281733 JC	52	size_t n,
b26a2188	53	char __user *buf);
7026ea4b JC	54
	55	int (mark_param_change)(struct iio_ring_buffer ring);
	56	int (request_update)(struct iio_ring_buffer ring);
	57
ffcab07a MS	58	int (get_bytes_per_datum)(struct iio_ring_buffer ring);
ffcab07a MS	59	int (set_bytes_per_datum)(struct iio_ring_buffer ring, size_t bpd);
7026ea4b JC	60	int (get_length)(struct iio_ring_buffer ring);
	61	int (set_length)(struct iio_ring_buffer ring, int length);
	62
	63	int (is_enabled)(struct iio_ring_buffer ring);
	64	int (enable)(struct iio_ring_buffer ring);
	65	};
	66
5565a450 JC	67	struct iio_ring_setup_ops {
	68	int (preenable)(struct iio_dev );
	69	int (postenable)(struct iio_dev );
	70	int (predisable)(struct iio_dev );
	71	int (postdisable)(struct iio_dev );
	72	};
	73
7026ea4b JC	74	/**
7026ea4b JC	75	* struct iio_ring_buffer - general ring buffer structure
4c572605	76	* @dev: ring buffer device struct
4c572605 RD	77	* @indio_dev: industrial I/O device structure
	78	* @owner: module that owns the ring buffer (for ref counting)
	79	* @id: unique id number
4c572605	80	* @length: [DEVICE] number of datums in ring
c3e5d410	81	* @bytes_per_datum: [DEVICE] size of individual datum including timestamp
ad577f8d	82	* @bpe: [DEVICE] size of individual channel value
4c572605	83	* @loopcount: [INTERN] number of times the ring has looped
bf32963c MS	84	* @scan_el_attrs: [DRIVER] control of scan elements if that scan mode
	85	* control method is used
	86	* @scan_count: [INTERN] the number of elements in the current scan mode
	87	* @scan_mask: [INTERN] bitmask used in masking scan mode elements
	88	* @scan_timestamp: [INTERN] does the scan mode include a timestamp
4c572605	89	* @access_handler: [INTERN] chrdev access handling
4c572605	90	* @access: [DRIVER] ring access functions associated with the
7026ea4b	91	* implementation.
4c572605 RD	92	* @preenable: [DRIVER] function to run prior to marking ring enabled
	93	* @postenable: [DRIVER] function to run after marking ring enabled
	94	* @predisable: [DRIVER] function to run prior to marking ring disabled
	95	* @postdisable: [DRIVER] function to run after marking ring disabled
7026ea4b JC	96	**/
	97	struct iio_ring_buffer {
	98	struct device dev;
7026ea4b JC	99	struct iio_dev *indio_dev;
	100	struct module *owner;
	101	int id;
7026ea4b	102	int length;
ffcab07a	103	int bytes_per_datum;
ad577f8d	104	int bpe;
7026ea4b	105	int loopcount;
bf32963c MS	106	struct attribute_group *scan_el_attrs;
	107	int scan_count;
	108	u32 scan_mask;
	109	bool scan_timestamp;
7026ea4b	110	struct iio_handler access_handler;
5565a450 JC	111	const struct iio_ring_access_funcs *access;
5565a450 JC	112	const struct iio_ring_setup_ops *setup_ops;
1d892719	113	struct list_head scan_el_dev_attr_list;
a7348347 JC	114
	115	wait_queue_head_t pollq;
	116	bool stufftoread;
7026ea4b	117	};
c3e5d410 JC	118
	119	/**
	120	* iio_ring_buffer_init() - Initialize the buffer structure
	121	* @ring: buffer to be initialized
	122	* @dev_info: the iio device the buffer is assocated with
	123	**/
7026ea4b JC	124	void iio_ring_buffer_init(struct iio_ring_buffer *ring,
	125	struct iio_dev *dev_info);
	126
	127	/**
6f2dfb31	128	* __iio_update_ring_buffer() - update common elements of ring buffers
4c572605 RD	129	* @ring: ring buffer that is the event source
	130	* @bytes_per_datum: size of individual datum including timestamp
	131	* @length: number of datums in ring
7026ea4b	132	**/
6f2dfb31 JC	133	static inline void __iio_update_ring_buffer(struct iio_ring_buffer *ring,
6f2dfb31 JC	134	int bytes_per_datum, int length)
7026ea4b	135	{
ffcab07a	136	ring->bytes_per_datum = bytes_per_datum;
7026ea4b JC	137	ring->length = length;
7026ea4b JC	138	ring->loopcount = 0;
7026ea4b JC	139	}
7026ea4b JC	140
7026ea4b	141	/**
4c572605 RD	142	* iio_scan_el_store() - sysfs scan element selection interface
	143	* @dev: the target device
	144	* @attr: the device attribute that is being processed
	145	* @buf: input from userspace
	146	* @len: length of input
7026ea4b JC	147	*
	148	* A generic function used to enable various scan elements. In some
	149	* devices explicit read commands for each channel mean this is merely
	150	* a software switch. In others this must actively disable the channel.
	151	* Complexities occur when this interacts with data ready type triggers
	152	* which may not reset unless every channel that is enabled is explicitly
	153	* read.
	154	**/
	155	ssize_t iio_scan_el_store(struct device dev, struct device_attribute attr,
	156	const char *buf, size_t len);
	157	/**
c3e5d410	158	* iio_scan_el_show() - sysfs interface to query whether a scan element
4c572605 RD	159	* is enabled or not
	160	* @dev: the target device
	161	* @attr: the device attribute that is being processed
	162	* @buf: output buffer
7026ea4b JC	163	**/
	164	ssize_t iio_scan_el_show(struct device dev, struct device_attribute attr,
	165	char *buf);
7026ea4b	166
c3e5d410 JC	167	/**
	168	* iio_scan_el_ts_store() - sysfs interface to set whether a timestamp is included
	169	* in the scan.
	170	**/
7026ea4b JC	171	ssize_t iio_scan_el_ts_store(struct device dev, struct device_attribute attr,
7026ea4b JC	172	const char *buf, size_t len);
c3e5d410 JC	173	/**
	174	* iio_scan_el_ts_show() - sysfs interface to query if a timestamp is included
	175	* in the scan.
	176	**/
7026ea4b JC	177	ssize_t iio_scan_el_ts_show(struct device dev, struct device_attribute attr,
7026ea4b JC	178	char *buf);
e968d095	179
bf32963c MS	180	/*
	181	* These are mainly provided to allow for a change of implementation if a device
	182	* has a large number of scan elements
	183	*/
	184	#define IIO_MAX_SCAN_LENGTH 31
	185
	186	/* note 0 used as error indicator as it doesn't make sense. */
	187	static inline u32 iio_scan_mask_match(u32 *av_masks, u32 mask)
	188	{
	189	while (*av_masks) {
	190	if (!(~*av_masks & mask))
	191	return *av_masks;
	192	av_masks++;
	193	}
	194	return 0;
	195	}
	196
	197	static inline int iio_scan_mask_query(struct iio_ring_buffer *ring, int bit)
	198	{
	199	struct iio_dev *dev_info = ring->indio_dev;
	200	u32 mask;
	201
	202	if (bit > IIO_MAX_SCAN_LENGTH)
	203	return -EINVAL;
	204
	205	if (!ring->scan_mask)
	206	return 0;
	207
	208	if (dev_info->available_scan_masks)
	209	mask = iio_scan_mask_match(dev_info->available_scan_masks,
	210	ring->scan_mask);
	211	else
	212	mask = ring->scan_mask;
	213
	214	if (!mask)
	215	return -EINVAL;
	216
	217	return !!(mask & (1 << bit));
	218	};
	219
c3e5d410 JC	220	/**
	221	* iio_scan_mask_set() - set particular bit in the scan mask
	222	* @ring: the ring buffer whose scan mask we are interested in
	223	* @bit: the bit to be set.
	224	**/
bf32963c MS	225	static inline int iio_scan_mask_set(struct iio_ring_buffer *ring, int bit)
	226	{
	227	struct iio_dev *dev_info = ring->indio_dev;
	228	u32 mask;
	229	u32 trialmask = ring->scan_mask \| (1 << bit);
	230
	231	if (bit > IIO_MAX_SCAN_LENGTH)
	232	return -EINVAL;
	233	if (dev_info->available_scan_masks) {
	234	mask = iio_scan_mask_match(dev_info->available_scan_masks,
	235	trialmask);
	236	if (!mask)
	237	return -EINVAL;
	238	}
	239	ring->scan_mask = trialmask;
	240	ring->scan_count++;
	241
	242	return 0;
	243	};
	244
c3e5d410 JC	245	/**
	246	* iio_scan_mask_clear() - clear a particular element from the scan mask
	247	* @ring: the ring buffer whose scan mask we are interested in
	248	* @bit: the bit to clear
	249	**/
bf32963c MS	250	static inline int iio_scan_mask_clear(struct iio_ring_buffer *ring, int bit)
	251	{
	252	if (bit > IIO_MAX_SCAN_LENGTH)
	253	return -EINVAL;
	254	ring->scan_mask &= ~(1 << bit);
	255	ring->scan_count--;
	256	return 0;
	257	};
	258
	259	/**
	260	* iio_scan_mask_count_to_right() - how many scan elements occur before here
c3e5d410	261	* @ring: the ring buffer whose scan mask we interested in
bf32963c MS	262	* @bit: which number scan element is this
	263	**/
	264	static inline int iio_scan_mask_count_to_right(struct iio_ring_buffer *ring,
	265	int bit)
	266	{
	267	int count = 0;
	268	int mask = (1 << bit);
	269	if (bit > IIO_MAX_SCAN_LENGTH)
	270	return -EINVAL;
	271	while (mask) {
	272	mask >>= 1;
	273	if (mask & ring->scan_mask)
	274	count++;
	275	}
	276
	277	return count;
	278	}
	279
c3e5d410 JC	280	/**
	281	* iio_put_ring_buffer() - notify done with buffer
	282	* @ring: the buffer we are done with.
	283	**/
7026ea4b JC	284	static inline void iio_put_ring_buffer(struct iio_ring_buffer *ring)
	285	{
	286	put_device(&ring->dev);
	287	};
	288
	289	#define to_iio_ring_buffer(d) \
	290	container_of(d, struct iio_ring_buffer, dev)
c3e5d410 JC	291
	292	/**
	293	* iio_ring_buffer_register() - register the buffer with IIO core
	294	* @ring: the buffer to be registered
	295	* @id: the id of the buffer (typically 0)
	296	**/
758d988c	297	int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id);
c3e5d410	298
1d892719 JC	299	/** iio_ring_buffer_register_ex() - register the buffer with IIO core
	300	* @ring: the buffer to be registered
	301	* @id: the id of the buffer (typically 0)
	302	**/
	303	int iio_ring_buffer_register_ex(struct iio_ring_buffer *ring, int id,
	304	const struct iio_chan_spec *channels,
	305	int num_channels);
	306
3feb0797 JC	307	void iio_ring_access_release(struct device *dev);
3feb0797 JC	308
c3e5d410 JC	309	/**
	310	* iio_ring_buffer_unregister() - unregister the buffer from IIO core
	311	* @ring: the buffer to be unregistered
	312	**/
7026ea4b JC	313	void iio_ring_buffer_unregister(struct iio_ring_buffer *ring);
7026ea4b JC	314
c3e5d410 JC	315	/**
	316	* iio_read_ring_length() - attr func to get number of datums in the buffer
	317	**/
7026ea4b JC	318	ssize_t iio_read_ring_length(struct device *dev,
	319	struct device_attribute *attr,
	320	char *buf);
c3e5d410 JC	321	/**
	322	* iio_write_ring_length() - attr func to set number of datums in the buffer
	323	**/
7026ea4b JC	324	ssize_t iio_write_ring_length(struct device *dev,
	325	struct device_attribute *attr,
	326	const char *buf,
	327	size_t len);
c3e5d410 JC	328	/**
	329	* iio_read_ring_bytes_per_datum() - attr for number of bytes in whole datum
	330	**/
ffcab07a	331	ssize_t iio_read_ring_bytes_per_datum(struct device *dev,
7026ea4b JC	332	struct device_attribute *attr,
7026ea4b JC	333	char *buf);
c3e5d410 JC	334	/**
	335	* iio_store_ring_enable() - attr to turn the buffer on
	336	**/
7026ea4b JC	337	ssize_t iio_store_ring_enable(struct device *dev,
	338	struct device_attribute *attr,
	339	const char *buf,
	340	size_t len);
c3e5d410 JC	341	/**
	342	* iio_show_ring_enable() - attr to see if the buffer is on
	343	**/
7026ea4b JC	344	ssize_t iio_show_ring_enable(struct device *dev,
	345	struct device_attribute *attr,
	346	char *buf);
	347	#define IIO_RING_LENGTH_ATTR DEVICE_ATTR(length, S_IRUGO \| S_IWUSR, \
	348	iio_read_ring_length, \
	349	iio_write_ring_length)
ffcab07a MS	350	#define IIO_RING_BYTES_PER_DATUM_ATTR DEVICE_ATTR(bytes_per_datum, S_IRUGO \| S_IWUSR, \
	351	iio_read_ring_bytes_per_datum, NULL)
	352	#define IIO_RING_ENABLE_ATTR DEVICE_ATTR(enable, S_IRUGO \| S_IWUSR, \
7026ea4b JC	353	iio_show_ring_enable, \
7026ea4b JC	354	iio_store_ring_enable)
5565a450 JC	355
	356	int iio_sw_ring_preenable(struct iio_dev *indio_dev);
	357
2662051e JC	358	#else /* CONFIG_IIO_RING_BUFFER */
	359	static inline int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id)
	360	{
	361	return 0;
	362	};
1d892719 JC	363
	364	static inline int iio_ring_buffer_register_ex(struct iio_ring_buffer *ring,
	365	int id,
	366	struct iio_chan_spec *channels,
	367	int num_channels)
	368	{
	369	return 0;
	370	}
	371
2662051e JC	372	static inline void iio_ring_buffer_unregister(struct iio_ring_buffer *ring)
	373	{};
	374
	375	#endif /* CONFIG_IIO_RING_BUFFER */
7026ea4b JC	376
7026ea4b JC	377	#endif /* _IIO_RING_GENERIC_H_ */