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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) |
647cc7b9 LPC |
24 | * @data_available: indicates whether data for reading from the buffer is |
25 | * available. | |
7026ea4b JC |
26 | * @request_update: if a parameter change has been marked, update underlying |
27 | * storage. | |
c3e5d410 JC |
28 | * @get_bytes_per_datum:get current bytes per datum |
29 | * @set_bytes_per_datum:set number of bytes per datum | |
14555b14 JC |
30 | * @get_length: get number of datums in buffer |
31 | * @set_length: set number of datums in buffer | |
9e69c935 LPC |
32 | * @release: called when the last reference to the buffer is dropped, |
33 | * should free all resources allocated by the buffer. | |
7026ea4b | 34 | * |
14555b14 | 35 | * The purpose of this structure is to make the buffer element |
7026ea4b | 36 | * modular as event for a given driver, different usecases may require |
14555b14 | 37 | * different buffer designs (space efficiency vs speed for example). |
7026ea4b | 38 | * |
14555b14 JC |
39 | * It is worth noting that a given buffer implementation may only support a |
40 | * small proportion of these functions. The core code 'should' cope fine with | |
41 | * any of them not existing. | |
7026ea4b | 42 | **/ |
14555b14 | 43 | struct iio_buffer_access_funcs { |
5d65d920 | 44 | int (*store_to)(struct iio_buffer *buffer, const void *data); |
14555b14 | 45 | int (*read_first_n)(struct iio_buffer *buffer, |
b4281733 | 46 | size_t n, |
b26a2188 | 47 | char __user *buf); |
647cc7b9 | 48 | bool (*data_available)(struct iio_buffer *buffer); |
7026ea4b | 49 | |
14555b14 | 50 | int (*request_update)(struct iio_buffer *buffer); |
7026ea4b | 51 | |
14555b14 JC |
52 | int (*get_bytes_per_datum)(struct iio_buffer *buffer); |
53 | int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd); | |
54 | int (*get_length)(struct iio_buffer *buffer); | |
55 | int (*set_length)(struct iio_buffer *buffer, int length); | |
9e69c935 LPC |
56 | |
57 | void (*release)(struct iio_buffer *buffer); | |
7026ea4b JC |
58 | }; |
59 | ||
60 | /** | |
14555b14 | 61 | * struct iio_buffer - general buffer structure |
14555b14 | 62 | * @length: [DEVICE] number of datums in buffer |
c3e5d410 | 63 | * @bytes_per_datum: [DEVICE] size of individual datum including timestamp |
bf32963c MS |
64 | * @scan_el_attrs: [DRIVER] control of scan elements if that scan mode |
65 | * control method is used | |
bf32963c MS |
66 | * @scan_mask: [INTERN] bitmask used in masking scan mode elements |
67 | * @scan_timestamp: [INTERN] does the scan mode include a timestamp | |
14555b14 | 68 | * @access: [DRIVER] buffer access functions associated with the |
7026ea4b | 69 | * implementation. |
5f070a36 JC |
70 | * @scan_el_dev_attr_list:[INTERN] list of scan element related attributes. |
71 | * @scan_el_group: [DRIVER] attribute group for those attributes not | |
72 | * created from the iio_chan_info array. | |
73 | * @pollq: [INTERN] wait queue to allow for polling on the buffer. | |
74 | * @stufftoread: [INTERN] flag to indicate new data. | |
5ada4ea9 JC |
75 | * @demux_list: [INTERN] list of operations required to demux the scan. |
76 | * @demux_bounce: [INTERN] buffer for doing gather from incoming scan. | |
84b36ce5 | 77 | * @buffer_list: [INTERN] entry in the devices list of current buffers. |
9e69c935 | 78 | * @ref: [INTERN] reference count of the buffer. |
84b36ce5 | 79 | */ |
14555b14 | 80 | struct iio_buffer { |
8d213f24 JC |
81 | int length; |
82 | int bytes_per_datum; | |
8d213f24 | 83 | struct attribute_group *scan_el_attrs; |
32b5eeca | 84 | long *scan_mask; |
8d213f24 | 85 | bool scan_timestamp; |
14555b14 | 86 | const struct iio_buffer_access_funcs *access; |
8d213f24 | 87 | struct list_head scan_el_dev_attr_list; |
26d25ae3 | 88 | struct attribute_group scan_el_group; |
8d213f24 JC |
89 | wait_queue_head_t pollq; |
90 | bool stufftoread; | |
1aa04278 | 91 | const struct attribute_group *attrs; |
5ada4ea9 | 92 | struct list_head demux_list; |
5d65d920 | 93 | void *demux_bounce; |
84b36ce5 | 94 | struct list_head buffer_list; |
9e69c935 | 95 | struct kref ref; |
7026ea4b | 96 | }; |
c3e5d410 | 97 | |
84b36ce5 JC |
98 | /** |
99 | * iio_update_buffers() - add or remove buffer from active list | |
100 | * @indio_dev: device to add buffer to | |
101 | * @insert_buffer: buffer to insert | |
102 | * @remove_buffer: buffer_to_remove | |
103 | * | |
104 | * Note this will tear down the all buffering and build it up again | |
105 | */ | |
106 | int iio_update_buffers(struct iio_dev *indio_dev, | |
107 | struct iio_buffer *insert_buffer, | |
108 | struct iio_buffer *remove_buffer); | |
109 | ||
c3e5d410 | 110 | /** |
14555b14 | 111 | * iio_buffer_init() - Initialize the buffer structure |
3bdff937 | 112 | * @buffer: buffer to be initialized |
c3e5d410 | 113 | **/ |
f79a9098 | 114 | void iio_buffer_init(struct iio_buffer *buffer); |
7026ea4b | 115 | |
f79a9098 JC |
116 | int iio_scan_mask_query(struct iio_dev *indio_dev, |
117 | struct iio_buffer *buffer, int bit); | |
bf32963c | 118 | |
c3e5d410 JC |
119 | /** |
120 | * iio_scan_mask_set() - set particular bit in the scan mask | |
3bdff937 PM |
121 | * @indio_dev IIO device structure |
122 | * @buffer: the buffer whose scan mask we are interested in | |
123 | * @bit: the bit to be set. | |
c3e5d410 | 124 | **/ |
f79a9098 JC |
125 | int iio_scan_mask_set(struct iio_dev *indio_dev, |
126 | struct iio_buffer *buffer, int bit); | |
bf32963c | 127 | |
5ada4ea9 | 128 | /** |
84b36ce5 JC |
129 | * iio_push_to_buffers() - push to a registered buffer. |
130 | * @indio_dev: iio_dev structure for device. | |
131 | * @data: Full scan. | |
5ada4ea9 | 132 | */ |
5d65d920 | 133 | int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data); |
5ada4ea9 | 134 | |
d2c3d072 LPC |
135 | /* |
136 | * iio_push_to_buffers_with_timestamp() - push data and timestamp to buffers | |
137 | * @indio_dev: iio_dev structure for device. | |
138 | * @data: sample data | |
139 | * @timestamp: timestamp for the sample data | |
140 | * | |
141 | * Pushes data to the IIO device's buffers. If timestamps are enabled for the | |
142 | * device the function will store the supplied timestamp as the last element in | |
143 | * the sample data buffer before pushing it to the device buffers. The sample | |
144 | * data buffer needs to be large enough to hold the additional timestamp | |
145 | * (usually the buffer should be indio->scan_bytes bytes large). | |
146 | * | |
147 | * Returns 0 on success, a negative error code otherwise. | |
148 | */ | |
149 | static inline int iio_push_to_buffers_with_timestamp(struct iio_dev *indio_dev, | |
150 | void *data, int64_t timestamp) | |
151 | { | |
152 | if (indio_dev->scan_timestamp) { | |
153 | size_t ts_offset = indio_dev->scan_bytes / sizeof(int64_t) - 1; | |
154 | ((int64_t *)data)[ts_offset] = timestamp; | |
155 | } | |
156 | ||
157 | return iio_push_to_buffers(indio_dev, data); | |
158 | } | |
159 | ||
5ada4ea9 JC |
160 | int iio_update_demux(struct iio_dev *indio_dev); |
161 | ||
c3e5d410 | 162 | /** |
14555b14 | 163 | * iio_buffer_register() - register the buffer with IIO core |
3bdff937 PM |
164 | * @indio_dev: device with the buffer to be registered |
165 | * @channels: the channel descriptions used to construct buffer | |
166 | * @num_channels: the number of channels | |
1d892719 | 167 | **/ |
14555b14 JC |
168 | int iio_buffer_register(struct iio_dev *indio_dev, |
169 | const struct iio_chan_spec *channels, | |
170 | int num_channels); | |
1d892719 | 171 | |
c3e5d410 | 172 | /** |
14555b14 | 173 | * iio_buffer_unregister() - unregister the buffer from IIO core |
3bdff937 | 174 | * @indio_dev: the device with the buffer to be unregistered |
c3e5d410 | 175 | **/ |
14555b14 | 176 | void iio_buffer_unregister(struct iio_dev *indio_dev); |
7026ea4b | 177 | |
c3e5d410 | 178 | /** |
14555b14 | 179 | * iio_buffer_read_length() - attr func to get number of datums in the buffer |
c3e5d410 | 180 | **/ |
14555b14 JC |
181 | ssize_t iio_buffer_read_length(struct device *dev, |
182 | struct device_attribute *attr, | |
183 | char *buf); | |
c3e5d410 | 184 | /** |
14555b14 | 185 | * iio_buffer_write_length() - attr func to set number of datums in the buffer |
c3e5d410 | 186 | **/ |
14555b14 | 187 | ssize_t iio_buffer_write_length(struct device *dev, |
7026ea4b JC |
188 | struct device_attribute *attr, |
189 | const char *buf, | |
190 | size_t len); | |
c3e5d410 | 191 | /** |
14555b14 | 192 | * iio_buffer_store_enable() - attr to turn the buffer on |
c3e5d410 | 193 | **/ |
14555b14 JC |
194 | ssize_t iio_buffer_store_enable(struct device *dev, |
195 | struct device_attribute *attr, | |
196 | const char *buf, | |
197 | size_t len); | |
c3e5d410 | 198 | /** |
14555b14 | 199 | * iio_buffer_show_enable() - attr to see if the buffer is on |
c3e5d410 | 200 | **/ |
14555b14 JC |
201 | ssize_t iio_buffer_show_enable(struct device *dev, |
202 | struct device_attribute *attr, | |
203 | char *buf); | |
204 | #define IIO_BUFFER_LENGTH_ATTR DEVICE_ATTR(length, S_IRUGO | S_IWUSR, \ | |
205 | iio_buffer_read_length, \ | |
206 | iio_buffer_write_length) | |
14555b14 JC |
207 | |
208 | #define IIO_BUFFER_ENABLE_ATTR DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, \ | |
209 | iio_buffer_show_enable, \ | |
210 | iio_buffer_store_enable) | |
211 | ||
81636632 LPC |
212 | bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, |
213 | const unsigned long *mask); | |
214 | ||
9e69c935 LPC |
215 | struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer); |
216 | void iio_buffer_put(struct iio_buffer *buffer); | |
217 | ||
218 | /** | |
219 | * iio_device_attach_buffer - Attach a buffer to a IIO device | |
220 | * @indio_dev: The device the buffer should be attached to | |
221 | * @buffer: The buffer to attach to the device | |
222 | * | |
223 | * This function attaches a buffer to a IIO device. The buffer stays attached to | |
224 | * the device until the device is freed. The function should only be called at | |
225 | * most once per device. | |
226 | */ | |
227 | static inline void iio_device_attach_buffer(struct iio_dev *indio_dev, | |
228 | struct iio_buffer *buffer) | |
229 | { | |
230 | indio_dev->buffer = iio_buffer_get(buffer); | |
231 | } | |
232 | ||
f2a96245 | 233 | #else /* CONFIG_IIO_BUFFER */ |
1d892719 | 234 | |
14555b14 | 235 | static inline int iio_buffer_register(struct iio_dev *indio_dev, |
50d69b51 | 236 | const struct iio_chan_spec *channels, |
c009f7e4 | 237 | int num_channels) |
1d892719 JC |
238 | { |
239 | return 0; | |
240 | } | |
241 | ||
14555b14 | 242 | static inline void iio_buffer_unregister(struct iio_dev *indio_dev) |
19ea4752 | 243 | {} |
2662051e | 244 | |
9e69c935 LPC |
245 | static inline void iio_buffer_get(struct iio_buffer *buffer) {} |
246 | static inline void iio_buffer_put(struct iio_buffer *buffer) {} | |
247 | ||
f2a96245 | 248 | #endif /* CONFIG_IIO_BUFFER */ |
7026ea4b | 249 | |
3811cd62 | 250 | #endif /* _IIO_BUFFER_GENERIC_H_ */ |