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14555b14 | 1 | /* The industrial I/O core - generic buffer interfaces. |
7026ea4b JC |
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 | ||
3811cd62 JC |
10 | #ifndef _IIO_BUFFER_GENERIC_H_ |
11 | #define _IIO_BUFFER_GENERIC_H_ | |
26d25ae3 | 12 | #include <linux/sysfs.h> |
06458e27 | 13 | #include <linux/iio/iio.h> |
9e69c935 | 14 | #include <linux/kref.h> |
7026ea4b | 15 | |
f2a96245 | 16 | #ifdef CONFIG_IIO_BUFFER |
2662051e | 17 | |
14555b14 | 18 | struct iio_buffer; |
7026ea4b | 19 | |
9f466777 JC |
20 | void iio_buffer_set_attrs(struct iio_buffer *buffer, |
21 | const struct attribute **attrs); | |
b440655b LPC |
22 | /** |
23 | * INDIO_BUFFER_FLAG_FIXED_WATERMARK - Watermark level of the buffer can not be | |
24 | * configured. It has a fixed value which will be buffer specific. | |
25 | */ | |
26 | #define INDIO_BUFFER_FLAG_FIXED_WATERMARK BIT(0) | |
27 | ||
7026ea4b | 28 | /** |
14555b14 | 29 | * struct iio_buffer_access_funcs - access functions for buffers. |
14555b14 | 30 | * @store_to: actually store stuff to the buffer |
8fe64955 | 31 | * @read_first_n: try to get a specified number of bytes (must exist) |
37d34556 JC |
32 | * @data_available: indicates how much data is available for reading from |
33 | * the buffer. | |
7026ea4b JC |
34 | * @request_update: if a parameter change has been marked, update underlying |
35 | * storage. | |
c3e5d410 | 36 | * @set_bytes_per_datum:set number of bytes per datum |
14555b14 | 37 | * @set_length: set number of datums in buffer |
e18a2ad4 LPC |
38 | * @enable: called if the buffer is attached to a device and the |
39 | * device starts sampling. Calls are balanced with | |
40 | * @disable. | |
41 | * @disable: called if the buffer is attached to a device and the | |
42 | * device stops sampling. Calles are balanced with @enable. | |
9e69c935 LPC |
43 | * @release: called when the last reference to the buffer is dropped, |
44 | * should free all resources allocated by the buffer. | |
225d59ad | 45 | * @modes: Supported operating modes by this buffer type |
b440655b | 46 | * @flags: A bitmask combination of INDIO_BUFFER_FLAG_* |
7026ea4b | 47 | * |
14555b14 | 48 | * The purpose of this structure is to make the buffer element |
7026ea4b | 49 | * modular as event for a given driver, different usecases may require |
14555b14 | 50 | * different buffer designs (space efficiency vs speed for example). |
7026ea4b | 51 | * |
14555b14 JC |
52 | * It is worth noting that a given buffer implementation may only support a |
53 | * small proportion of these functions. The core code 'should' cope fine with | |
54 | * any of them not existing. | |
7026ea4b | 55 | **/ |
14555b14 | 56 | struct iio_buffer_access_funcs { |
5d65d920 | 57 | int (*store_to)(struct iio_buffer *buffer, const void *data); |
14555b14 | 58 | int (*read_first_n)(struct iio_buffer *buffer, |
b4281733 | 59 | size_t n, |
b26a2188 | 60 | char __user *buf); |
37d34556 | 61 | size_t (*data_available)(struct iio_buffer *buffer); |
7026ea4b | 62 | |
14555b14 | 63 | int (*request_update)(struct iio_buffer *buffer); |
7026ea4b | 64 | |
14555b14 | 65 | int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd); |
14555b14 | 66 | int (*set_length)(struct iio_buffer *buffer, int length); |
9e69c935 | 67 | |
e18a2ad4 LPC |
68 | int (*enable)(struct iio_buffer *buffer, struct iio_dev *indio_dev); |
69 | int (*disable)(struct iio_buffer *buffer, struct iio_dev *indio_dev); | |
70 | ||
9e69c935 | 71 | void (*release)(struct iio_buffer *buffer); |
225d59ad LPC |
72 | |
73 | unsigned int modes; | |
b440655b | 74 | unsigned int flags; |
7026ea4b JC |
75 | }; |
76 | ||
77 | /** | |
14555b14 | 78 | * struct iio_buffer - general buffer structure |
263cf5e6 JC |
79 | * |
80 | * Note that the internals of this structure should only be of interest to | |
81 | * those writing new buffer implementations. | |
84b36ce5 | 82 | */ |
14555b14 | 83 | struct iio_buffer { |
263cf5e6 JC |
84 | /** @length: Number of datums in buffer. */ |
85 | int length; | |
86 | ||
87 | /** @bytes_per_datum: Size of individual datum including timestamp. */ | |
88 | int bytes_per_datum; | |
89 | ||
90 | /** | |
91 | * @access: Buffer access functions associated with the | |
92 | * implementation. | |
93 | */ | |
94 | const struct iio_buffer_access_funcs *access; | |
95 | ||
96 | /** @scan_mask: Bitmask used in masking scan mode elements. */ | |
97 | long *scan_mask; | |
98 | ||
99 | /** @demux_list: List of operations required to demux the scan. */ | |
100 | struct list_head demux_list; | |
101 | ||
102 | /** @pollq: Wait queue to allow for polling on the buffer. */ | |
103 | wait_queue_head_t pollq; | |
104 | ||
105 | /** @watermark: Number of datums to wait for poll/read. */ | |
106 | unsigned int watermark; | |
107 | ||
108 | /* private: */ | |
109 | /* | |
110 | * @scan_el_attrs: Control of scan elements if that scan mode | |
111 | * control method is used. | |
112 | */ | |
113 | struct attribute_group *scan_el_attrs; | |
114 | ||
115 | /* @scan_timestamp: Does the scan mode include a timestamp. */ | |
116 | bool scan_timestamp; | |
117 | ||
118 | /* @scan_el_dev_attr_list: List of scan element related attributes. */ | |
119 | struct list_head scan_el_dev_attr_list; | |
120 | ||
121 | /* @buffer_group: Attributes of the buffer group. */ | |
122 | struct attribute_group buffer_group; | |
123 | ||
124 | /* | |
125 | * @scan_el_group: Attribute group for those attributes not | |
126 | * created from the iio_chan_info array. | |
127 | */ | |
128 | struct attribute_group scan_el_group; | |
129 | ||
130 | /* @stufftoread: Flag to indicate new data. */ | |
131 | bool stufftoread; | |
132 | ||
133 | /* @attrs: Standard attributes of the buffer. */ | |
134 | const struct attribute **attrs; | |
135 | ||
136 | /* @demux_bounce: Buffer for doing gather from incoming scan. */ | |
137 | void *demux_bounce; | |
138 | ||
139 | /* @buffer_list: Entry in the devices list of current buffers. */ | |
140 | struct list_head buffer_list; | |
141 | ||
142 | /* @ref: Reference count of the buffer. */ | |
143 | struct kref ref; | |
7026ea4b | 144 | }; |
c3e5d410 | 145 | |
84b36ce5 JC |
146 | /** |
147 | * iio_update_buffers() - add or remove buffer from active list | |
148 | * @indio_dev: device to add buffer to | |
149 | * @insert_buffer: buffer to insert | |
150 | * @remove_buffer: buffer_to_remove | |
151 | * | |
152 | * Note this will tear down the all buffering and build it up again | |
153 | */ | |
154 | int iio_update_buffers(struct iio_dev *indio_dev, | |
155 | struct iio_buffer *insert_buffer, | |
156 | struct iio_buffer *remove_buffer); | |
157 | ||
c3e5d410 | 158 | /** |
14555b14 | 159 | * iio_buffer_init() - Initialize the buffer structure |
3bdff937 | 160 | * @buffer: buffer to be initialized |
c3e5d410 | 161 | **/ |
f79a9098 | 162 | void iio_buffer_init(struct iio_buffer *buffer); |
7026ea4b | 163 | |
5d65d920 | 164 | int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data); |
5ada4ea9 | 165 | |
d4ad4f4b | 166 | /** |
d2c3d072 LPC |
167 | * iio_push_to_buffers_with_timestamp() - push data and timestamp to buffers |
168 | * @indio_dev: iio_dev structure for device. | |
169 | * @data: sample data | |
170 | * @timestamp: timestamp for the sample data | |
171 | * | |
172 | * Pushes data to the IIO device's buffers. If timestamps are enabled for the | |
173 | * device the function will store the supplied timestamp as the last element in | |
174 | * the sample data buffer before pushing it to the device buffers. The sample | |
175 | * data buffer needs to be large enough to hold the additional timestamp | |
176 | * (usually the buffer should be indio->scan_bytes bytes large). | |
177 | * | |
178 | * Returns 0 on success, a negative error code otherwise. | |
179 | */ | |
180 | static inline int iio_push_to_buffers_with_timestamp(struct iio_dev *indio_dev, | |
181 | void *data, int64_t timestamp) | |
182 | { | |
183 | if (indio_dev->scan_timestamp) { | |
184 | size_t ts_offset = indio_dev->scan_bytes / sizeof(int64_t) - 1; | |
185 | ((int64_t *)data)[ts_offset] = timestamp; | |
186 | } | |
187 | ||
188 | return iio_push_to_buffers(indio_dev, data); | |
189 | } | |
190 | ||
81636632 LPC |
191 | bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, |
192 | const unsigned long *mask); | |
193 | ||
9e69c935 LPC |
194 | struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer); |
195 | void iio_buffer_put(struct iio_buffer *buffer); | |
196 | ||
2b827ad5 JC |
197 | void iio_device_attach_buffer(struct iio_dev *indio_dev, |
198 | struct iio_buffer *buffer); | |
9e69c935 | 199 | |
f2a96245 | 200 | #else /* CONFIG_IIO_BUFFER */ |
1d892719 | 201 | |
9e69c935 LPC |
202 | static inline void iio_buffer_get(struct iio_buffer *buffer) {} |
203 | static inline void iio_buffer_put(struct iio_buffer *buffer) {} | |
204 | ||
f2a96245 | 205 | #endif /* CONFIG_IIO_BUFFER */ |
7026ea4b | 206 | |
3811cd62 | 207 | #endif /* _IIO_BUFFER_GENERIC_H_ */ |