FilesExpand file tree

 master

/

buffer_impl.h

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

168 lines (135 loc) · 5.57 KB

 master

/

buffer_impl.h

Copy path

Top

File metadata and controls

• Code
• Blame

168 lines (135 loc) · 5.57 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _IIO_BUFFER_GENERIC_IMPL_H_

#define _IIO_BUFFER_GENERIC_IMPL_H_

#include <linux/sysfs.h>

#include <linux/kref.h>

#ifdef CONFIG_IIO_BUFFER

#include <uapi/linux/iio/buffer.h>

#include <linux/iio/buffer.h>

struct iio_dev;

struct iio_buffer;

/**

* INDIO_BUFFER_FLAG_FIXED_WATERMARK - Watermark level of the buffer can not be

* configured. It has a fixed value which will be buffer specific.

*/

#define INDIO_BUFFER_FLAG_FIXED_WATERMARK BIT(0)

/**

* struct iio_buffer_access_funcs - access functions for buffers.

* @store_to: actually store stuff to the buffer

* @read: try to get a specified number of bytes (must exist)

* @data_available: indicates how much data is available for reading from

* the buffer.

* @remove_from: remove scan from buffer. Drivers should calls this to

* remove a scan from a buffer.

* @write: try to write a number of bytes

* @space_available: returns the amount of bytes available in a buffer

* @request_update: if a parameter change has been marked, update underlying

* storage.

* @set_bytes_per_datum:set number of bytes per datum

* @set_length: set number of datums in buffer

* @enable: called if the buffer is attached to a device and the

* device starts sampling. Calls are balanced with

* @disable.

* @disable: called if the buffer is attached to a device and the

* device stops sampling. Calles are balanced with @enable.

* @release: called when the last reference to the buffer is dropped,

* should free all resources allocated by the buffer.

* @modes: Supported operating modes by this buffer type

* @flags: A bitmask combination of INDIO_BUFFER_FLAG_*

*

* The purpose of this structure is to make the buffer element

* modular as event for a given driver, different usecases may require

* different buffer designs (space efficiency vs speed for example).

*

* It is worth noting that a given buffer implementation may only support a

* small proportion of these functions. The core code 'should' cope fine with

* any of them not existing.

**/

struct iio_buffer_access_funcs {

int (*store_to)(struct iio_buffer *buffer, const void *data);

int (*read)(struct iio_buffer *buffer, size_t n, char __user *buf);

size_t (*data_available)(struct iio_buffer *buffer);

int (*remove_from)(struct iio_buffer *buffer, void *data);

int (*write)(struct iio_buffer *buffer, size_t n, const char __user *buf);

size_t (*space_available)(struct iio_buffer *buffer);

int (*request_update)(struct iio_buffer *buffer);

int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd);

int (*set_length)(struct iio_buffer *buffer, unsigned int length);

int (*enable)(struct iio_buffer *buffer, struct iio_dev *indio_dev);

int (*disable)(struct iio_buffer *buffer, struct iio_dev *indio_dev);

void (*release)(struct iio_buffer *buffer);

unsigned int modes;

unsigned int flags;

};

/**

* struct iio_buffer - general buffer structure

*

* Note that the internals of this structure should only be of interest to

* those writing new buffer implementations.

*/

struct iio_buffer {

/** @length: Number of datums in buffer. */

unsigned int length;

/** @flags: File ops flags including busy flag. */

unsigned long flags;

/** @bytes_per_datum: Size of individual datum including timestamp. */

size_t bytes_per_datum;

/* @direction: Direction of the data stream (in/out). */

enum iio_buffer_direction direction;

/**

* @access: Buffer access functions associated with the

* implementation.

*/

const struct iio_buffer_access_funcs *access;

/** @scan_mask: Bitmask used in masking scan mode elements. */

long *scan_mask;

/** @demux_list: List of operations required to demux the scan. */

struct list_head demux_list;

/** @pollq: Wait queue to allow for polling on the buffer. */

wait_queue_head_t pollq;

/** @watermark: Number of datums to wait for poll/read. */

unsigned int watermark;

/* private: */

/* @scan_timestamp: Does the scan mode include a timestamp. */

bool scan_timestamp;

/* @buffer_attr_list: List of buffer attributes. */

struct list_head buffer_attr_list;

/*

* @buffer_group: Attributes of the new buffer group.

* Includes scan elements attributes.

*/

struct attribute_group buffer_group;

/* @attrs: Standard attributes of the buffer. */

const struct attribute **attrs;

/* @demux_bounce: Buffer for doing gather from incoming scan. */

void *demux_bounce;

/* @attached_entry: Entry in the devices list of buffers attached by the driver. */

struct list_head attached_entry;

/* @buffer_list: Entry in the devices list of current buffers. */

struct list_head buffer_list;

/* @ref: Reference count of the buffer. */

struct kref ref;

};

/**

* iio_update_buffers() - add or remove buffer from active list

* @indio_dev: device to add buffer to

* @insert_buffer: buffer to insert

* @remove_buffer: buffer_to_remove

*

* Note this will tear down the all buffering and build it up again

*/

int iio_update_buffers(struct iio_dev *indio_dev,

struct iio_buffer *insert_buffer,

struct iio_buffer *remove_buffer);

/**

* iio_buffer_init() - Initialize the buffer structure

* @buffer: buffer to be initialized

**/

void iio_buffer_init(struct iio_buffer *buffer);

struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer);

void iio_buffer_put(struct iio_buffer *buffer);

#else /* CONFIG_IIO_BUFFER */

static inline void iio_buffer_get(struct iio_buffer *buffer) {}

static inline void iio_buffer_put(struct iio_buffer *buffer) {}

#endif /* CONFIG_IIO_BUFFER */

#endif /* _IIO_BUFFER_GENERIC_IMPL_H_ */