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Diffstat (limited to 'drivers/staging/iio/buffer_generic.h')
| -rw-r--r-- | drivers/staging/iio/buffer_generic.h | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/drivers/staging/iio/buffer_generic.h b/drivers/staging/iio/buffer_generic.h new file mode 100644 index 00000000000..a1256c152cf --- /dev/null +++ b/drivers/staging/iio/buffer_generic.h @@ -0,0 +1,226 @@ +/* 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_BUFFER_GENERIC_H_ +#define _IIO_BUFFER_GENERIC_H_ +#include <linux/sysfs.h> +#include "iio.h" +#include "chrdev.h" + +#ifdef CONFIG_IIO_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 - buffer setup related callbacks + * @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_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) + * @length: [DEVICE] number of datums in ring + * @bytes_per_datum: [DEVICE] size of individual datum including timestamp + * @bpe: [DEVICE] size of individual channel value + * @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: [DRIVER] ring access functions associated with the + * implementation. + * @flags: [INTERN] file ops related flags including busy flag. + **/ +struct iio_ring_buffer { + struct iio_dev *indio_dev; + struct module *owner; + int length; + int bytes_per_datum; + int bpe; + struct attribute_group *scan_el_attrs; + int scan_count; + long *scan_mask; + bool scan_timestamp; + const struct iio_ring_access_funcs *access; + const struct iio_ring_setup_ops *setup_ops; + struct list_head scan_el_dev_attr_list; + struct attribute_group scan_el_group; + wait_queue_head_t pollq; + bool stufftoread; + unsigned long flags; + const struct attribute_group *attrs; +}; + +/** + * 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); + +void iio_ring_buffer_deinit(struct iio_ring_buffer *ring); + +/** + * __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; +} + +int iio_scan_mask_query(struct iio_ring_buffer *ring, int 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. + **/ +int iio_scan_mask_set(struct iio_ring_buffer *ring, int bit); + +#define to_iio_ring_buffer(d) \ + container_of(d, struct iio_ring_buffer, dev) + +/** + * iio_ring_buffer_register() - register the buffer with IIO core + * @indio_dev: device with the buffer to be registered + **/ +int iio_ring_buffer_register(struct iio_dev *indio_dev, + const struct iio_chan_spec *channels, + int num_channels); + +/** + * iio_ring_buffer_unregister() - unregister the buffer from IIO core + * @indio_dev: the device with the buffer to be unregistered + **/ +void iio_ring_buffer_unregister(struct iio_dev *indio_dev); + +/** + * 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_BUFFER */ + +static inline int iio_ring_buffer_register(struct iio_dev *indio_dev, + struct iio_chan_spec *channels, + int num_channels) +{ + return 0; +} + +static inline void iio_ring_buffer_unregister(struct iio_dev *indio_dev) +{}; + +#endif /* CONFIG_IIO_BUFFER */ + +#endif /* _IIO_BUFFER_GENERIC_H_ */ |