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8827faab2c
This change makes use of the new IIO buffer API to read data from an IIO
buffer.
It doesn't read the /sys/bus/iio/devices/iio:deviceX/scan_elements dir
anymore, it reads /sys/bus/iio/devices/iio:deviceX/bufferY, where all the
scan_elements have been merged together with the old/classical buffer
attributes.
And it makes use of the new IIO_BUFFER_GET_FD_IOCTL ioctl to get an FD for
the IIO buffer for which to read data from.
It also does a quick sanity check to see that -EBUSY is returned if reading
the chardev after the ioctl() has succeeded.
This was tested with the following cases:
1. Tested buffer0 works with ioctl()
2. Tested that buffer0 can't be opened via /dev/iio:deviceX after ioctl()
This check should be omitted under normal operation; it's being done
here to check that the driver change is sane
3. Moved valid buffer0 to be buffer1, and tested that data comes from it
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-25-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
78 lines
2.6 KiB
C
78 lines
2.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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#ifndef _IIO_UTILS_H_
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#define _IIO_UTILS_H_
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/* IIO - useful set of util functionality
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*
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* Copyright (c) 2008 Jonathan Cameron
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*/
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#include <stdint.h>
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/* Made up value to limit allocation sizes */
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#define IIO_MAX_NAME_LENGTH 64
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#define FORMAT_SCAN_ELEMENTS_DIR "%s/buffer%d"
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#define FORMAT_TYPE_FILE "%s_type"
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#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
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extern const char *iio_dir;
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/**
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* struct iio_channel_info - information about a given channel
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* @name: channel name
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* @generic_name: general name for channel type
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* @scale: scale factor to be applied for conversion to si units
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* @offset: offset to be applied for conversion to si units
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* @index: the channel index in the buffer output
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* @bytes: number of bytes occupied in buffer output
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* @bits_used: number of valid bits of data
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* @shift: amount of bits to shift right data before applying bit mask
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* @mask: a bit mask for the raw output
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* @be: flag if data is big endian
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* @is_signed: is the raw value stored signed
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* @location: data offset for this channel inside the buffer (in bytes)
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**/
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struct iio_channel_info {
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char *name;
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char *generic_name;
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float scale;
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float offset;
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unsigned index;
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unsigned bytes;
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unsigned bits_used;
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unsigned shift;
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uint64_t mask;
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unsigned be;
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unsigned is_signed;
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unsigned location;
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};
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static inline int iioutils_check_suffix(const char *str, const char *suffix)
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{
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return strlen(str) >= strlen(suffix) &&
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strncmp(str+strlen(str)-strlen(suffix),
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suffix, strlen(suffix)) == 0;
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}
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int iioutils_break_up_name(const char *full_name, char **generic_name);
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int iioutils_get_param_float(float *output, const char *param_name,
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const char *device_dir, const char *name,
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const char *generic_name);
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void bsort_channel_array_by_index(struct iio_channel_info *ci_array, int cnt);
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int build_channel_array(const char *device_dir, int buffer_idx,
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struct iio_channel_info **ci_array, int *counter);
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int find_type_by_name(const char *name, const char *type);
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int write_sysfs_int(const char *filename, const char *basedir, int val);
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int write_sysfs_int_and_verify(const char *filename, const char *basedir,
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int val);
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int write_sysfs_string_and_verify(const char *filename, const char *basedir,
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const char *val);
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int write_sysfs_string(const char *filename, const char *basedir,
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const char *val);
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int read_sysfs_posint(const char *filename, const char *basedir);
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int read_sysfs_float(const char *filename, const char *basedir, float *val);
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int read_sysfs_string(const char *filename, const char *basedir, char *str);
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#endif /* _IIO_UTILS_H_ */
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