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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 | |
7026ea4b | 20 | /** |
14555b14 | 21 | * struct iio_buffer_access_funcs - access functions for buffers. |
14555b14 | 22 | * @store_to: actually store stuff to the buffer |
8fe64955 | 23 | * @read_first_n: try to get a specified number of bytes (must exist) |
37d34556 JC |
24 | * @data_available: indicates how much data is available for reading from |
25 | * the buffer. | |
7026ea4b JC |
26 | * @request_update: if a parameter change has been marked, update underlying |
27 | * storage. | |
c3e5d410 | 28 | * @set_bytes_per_datum:set number of bytes per datum |
14555b14 | 29 | * @set_length: set number of datums in buffer |
9e69c935 LPC |
30 | * @release: called when the last reference to the buffer is dropped, |
31 | * should free all resources allocated by the buffer. | |
7026ea4b | 32 | * |
14555b14 | 33 | * The purpose of this structure is to make the buffer element |
7026ea4b | 34 | * modular as event for a given driver, different usecases may require |
14555b14 | 35 | * different buffer designs (space efficiency vs speed for example). |
7026ea4b | 36 | * |
14555b14 JC |
37 | * It is worth noting that a given buffer implementation may only support a |
38 | * small proportion of these functions. The core code 'should' cope fine with | |
39 | * any of them not existing. | |
7026ea4b | 40 | **/ |
14555b14 | 41 | struct iio_buffer_access_funcs { |
5d65d920 | 42 | int (*store_to)(struct iio_buffer *buffer, const void *data); |
14555b14 | 43 | int (*read_first_n)(struct iio_buffer *buffer, |
b4281733 | 44 | size_t n, |
b26a2188 | 45 | char __user *buf); |
37d34556 | 46 | size_t (*data_available)(struct iio_buffer *buffer); |
7026ea4b | 47 | |
14555b14 | 48 | int (*request_update)(struct iio_buffer *buffer); |
7026ea4b | 49 | |
14555b14 | 50 | int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd); |
14555b14 | 51 | int (*set_length)(struct iio_buffer *buffer, int length); |
9e69c935 LPC |
52 | |
53 | void (*release)(struct iio_buffer *buffer); | |
7026ea4b JC |
54 | }; |
55 | ||
56 | /** | |
14555b14 | 57 | * struct iio_buffer - general buffer structure |
14555b14 | 58 | * @length: [DEVICE] number of datums in buffer |
c3e5d410 | 59 | * @bytes_per_datum: [DEVICE] size of individual datum including timestamp |
bf32963c MS |
60 | * @scan_el_attrs: [DRIVER] control of scan elements if that scan mode |
61 | * control method is used | |
bf32963c MS |
62 | * @scan_mask: [INTERN] bitmask used in masking scan mode elements |
63 | * @scan_timestamp: [INTERN] does the scan mode include a timestamp | |
14555b14 | 64 | * @access: [DRIVER] buffer access functions associated with the |
7026ea4b | 65 | * implementation. |
5f070a36 JC |
66 | * @scan_el_dev_attr_list:[INTERN] list of scan element related attributes. |
67 | * @scan_el_group: [DRIVER] attribute group for those attributes not | |
68 | * created from the iio_chan_info array. | |
69 | * @pollq: [INTERN] wait queue to allow for polling on the buffer. | |
70 | * @stufftoread: [INTERN] flag to indicate new data. | |
5ada4ea9 JC |
71 | * @demux_list: [INTERN] list of operations required to demux the scan. |
72 | * @demux_bounce: [INTERN] buffer for doing gather from incoming scan. | |
84b36ce5 | 73 | * @buffer_list: [INTERN] entry in the devices list of current buffers. |
9e69c935 | 74 | * @ref: [INTERN] reference count of the buffer. |
37d34556 | 75 | * @watermark: [INTERN] number of datums to wait for poll/read. |
84b36ce5 | 76 | */ |
14555b14 | 77 | struct iio_buffer { |
8d213f24 JC |
78 | int length; |
79 | int bytes_per_datum; | |
8d213f24 | 80 | struct attribute_group *scan_el_attrs; |
32b5eeca | 81 | long *scan_mask; |
8d213f24 | 82 | bool scan_timestamp; |
14555b14 | 83 | const struct iio_buffer_access_funcs *access; |
8d213f24 | 84 | struct list_head scan_el_dev_attr_list; |
08e7e0ad | 85 | struct attribute_group buffer_group; |
26d25ae3 | 86 | struct attribute_group scan_el_group; |
8d213f24 JC |
87 | wait_queue_head_t pollq; |
88 | bool stufftoread; | |
08e7e0ad | 89 | const struct attribute **attrs; |
5ada4ea9 | 90 | struct list_head demux_list; |
5d65d920 | 91 | void *demux_bounce; |
84b36ce5 | 92 | struct list_head buffer_list; |
9e69c935 | 93 | struct kref ref; |
37d34556 | 94 | unsigned int watermark; |
7026ea4b | 95 | }; |
c3e5d410 | 96 | |
84b36ce5 JC |
97 | /** |
98 | * iio_update_buffers() - add or remove buffer from active list | |
99 | * @indio_dev: device to add buffer to | |
100 | * @insert_buffer: buffer to insert | |
101 | * @remove_buffer: buffer_to_remove | |
102 | * | |
103 | * Note this will tear down the all buffering and build it up again | |
104 | */ | |
105 | int iio_update_buffers(struct iio_dev *indio_dev, | |
106 | struct iio_buffer *insert_buffer, | |
107 | struct iio_buffer *remove_buffer); | |
108 | ||
c3e5d410 | 109 | /** |
14555b14 | 110 | * iio_buffer_init() - Initialize the buffer structure |
3bdff937 | 111 | * @buffer: buffer to be initialized |
c3e5d410 | 112 | **/ |
f79a9098 | 113 | void iio_buffer_init(struct iio_buffer *buffer); |
7026ea4b | 114 | |
f79a9098 JC |
115 | int iio_scan_mask_query(struct iio_dev *indio_dev, |
116 | struct iio_buffer *buffer, int bit); | |
bf32963c | 117 | |
5ada4ea9 | 118 | /** |
84b36ce5 JC |
119 | * iio_push_to_buffers() - push to a registered buffer. |
120 | * @indio_dev: iio_dev structure for device. | |
121 | * @data: Full scan. | |
5ada4ea9 | 122 | */ |
5d65d920 | 123 | int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data); |
5ada4ea9 | 124 | |
d2c3d072 LPC |
125 | /* |
126 | * iio_push_to_buffers_with_timestamp() - push data and timestamp to buffers | |
127 | * @indio_dev: iio_dev structure for device. | |
128 | * @data: sample data | |
129 | * @timestamp: timestamp for the sample data | |
130 | * | |
131 | * Pushes data to the IIO device's buffers. If timestamps are enabled for the | |
132 | * device the function will store the supplied timestamp as the last element in | |
133 | * the sample data buffer before pushing it to the device buffers. The sample | |
134 | * data buffer needs to be large enough to hold the additional timestamp | |
135 | * (usually the buffer should be indio->scan_bytes bytes large). | |
136 | * | |
137 | * Returns 0 on success, a negative error code otherwise. | |
138 | */ | |
139 | static inline int iio_push_to_buffers_with_timestamp(struct iio_dev *indio_dev, | |
140 | void *data, int64_t timestamp) | |
141 | { | |
142 | if (indio_dev->scan_timestamp) { | |
143 | size_t ts_offset = indio_dev->scan_bytes / sizeof(int64_t) - 1; | |
144 | ((int64_t *)data)[ts_offset] = timestamp; | |
145 | } | |
146 | ||
147 | return iio_push_to_buffers(indio_dev, data); | |
148 | } | |
149 | ||
5ada4ea9 JC |
150 | int iio_update_demux(struct iio_dev *indio_dev); |
151 | ||
81636632 LPC |
152 | bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, |
153 | const unsigned long *mask); | |
154 | ||
9e69c935 LPC |
155 | struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer); |
156 | void iio_buffer_put(struct iio_buffer *buffer); | |
157 | ||
158 | /** | |
159 | * iio_device_attach_buffer - Attach a buffer to a IIO device | |
160 | * @indio_dev: The device the buffer should be attached to | |
161 | * @buffer: The buffer to attach to the device | |
162 | * | |
163 | * This function attaches a buffer to a IIO device. The buffer stays attached to | |
164 | * the device until the device is freed. The function should only be called at | |
165 | * most once per device. | |
166 | */ | |
167 | static inline void iio_device_attach_buffer(struct iio_dev *indio_dev, | |
168 | struct iio_buffer *buffer) | |
169 | { | |
170 | indio_dev->buffer = iio_buffer_get(buffer); | |
171 | } | |
172 | ||
f2a96245 | 173 | #else /* CONFIG_IIO_BUFFER */ |
1d892719 | 174 | |
9e69c935 LPC |
175 | static inline void iio_buffer_get(struct iio_buffer *buffer) {} |
176 | static inline void iio_buffer_put(struct iio_buffer *buffer) {} | |
177 | ||
f2a96245 | 178 | #endif /* CONFIG_IIO_BUFFER */ |
7026ea4b | 179 | |
3811cd62 | 180 | #endif /* _IIO_BUFFER_GENERIC_H_ */ |