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![Peter Meerwald](/assets/img/avatar_default.png)
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
654 lines
15 KiB
C
654 lines
15 KiB
C
/* 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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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <string.h>
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#include <stdlib.h>
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#include <ctype.h>
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#include <stdio.h>
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#include <stdint.h>
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#include <dirent.h>
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#include <errno.h>
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/* Made up value to limit allocation sizes */
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#define IIO_MAX_NAME_LENGTH 30
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#define FORMAT_SCAN_ELEMENTS_DIR "%s/scan_elements"
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#define FORMAT_TYPE_FILE "%s_type"
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const char *iio_dir = "/sys/bus/iio/devices/";
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/**
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* iioutils_break_up_name() - extract generic name from full channel name
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* @full_name: the full channel name
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* @generic_name: the output generic channel name
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**/
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inline int iioutils_break_up_name(const char *full_name,
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char **generic_name)
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{
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char *current;
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char *w, *r;
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char *working;
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current = strdup(full_name);
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working = strtok(current, "_\0");
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w = working;
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r = working;
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while (*r != '\0') {
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if (!isdigit(*r)) {
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*w = *r;
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w++;
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}
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r++;
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}
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*w = '\0';
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*generic_name = strdup(working);
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free(current);
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return 0;
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}
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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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* @mask: a bit mask for the raw output
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* @is_signed: is the raw value stored signed
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* @enabled: is this channel enabled
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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 enabled;
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unsigned location;
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};
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/**
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* iioutils_get_type() - find and process _type attribute data
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* @is_signed: output whether channel is signed
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* @bytes: output how many bytes the channel storage occupies
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* @mask: output a bit mask for the raw data
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* @be: big endian
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* @device_dir: the iio device directory
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* @name: the channel name
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* @generic_name: the channel type name
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**/
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inline int iioutils_get_type(unsigned *is_signed,
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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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const char *device_dir,
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const char *name,
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const char *generic_name)
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{
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FILE *sysfsfp;
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int ret;
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DIR *dp;
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char *scan_el_dir, *builtname, *builtname_generic, *filename = 0;
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char signchar, endianchar;
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unsigned padint;
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const struct dirent *ent;
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ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir);
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if (ret < 0) {
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ret = -ENOMEM;
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goto error_ret;
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}
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ret = asprintf(&builtname, FORMAT_TYPE_FILE, name);
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if (ret < 0) {
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ret = -ENOMEM;
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goto error_free_scan_el_dir;
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}
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ret = asprintf(&builtname_generic, FORMAT_TYPE_FILE, generic_name);
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if (ret < 0) {
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ret = -ENOMEM;
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goto error_free_builtname;
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}
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dp = opendir(scan_el_dir);
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if (dp == NULL) {
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ret = -errno;
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goto error_free_builtname_generic;
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}
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while (ent = readdir(dp), ent != NULL)
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/*
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* Do we allow devices to override a generic name with
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* a specific one?
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*/
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if ((strcmp(builtname, ent->d_name) == 0) ||
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(strcmp(builtname_generic, ent->d_name) == 0)) {
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ret = asprintf(&filename,
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"%s/%s", scan_el_dir, ent->d_name);
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if (ret < 0) {
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ret = -ENOMEM;
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goto error_closedir;
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}
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sysfsfp = fopen(filename, "r");
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if (sysfsfp == NULL) {
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printf("failed to open %s\n", filename);
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ret = -errno;
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goto error_free_filename;
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}
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ret = fscanf(sysfsfp,
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"%ce:%c%u/%u>>%u",
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&endianchar,
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&signchar,
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bits_used,
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&padint, shift);
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if (ret < 0) {
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printf("failed to pass scan type description\n");
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ret = -errno;
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goto error_close_sysfsfp;
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}
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*be = (endianchar == 'b');
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*bytes = padint / 8;
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if (*bits_used == 64)
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*mask = ~0;
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else
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*mask = (1 << *bits_used) - 1;
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if (signchar == 's')
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*is_signed = 1;
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else
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*is_signed = 0;
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fclose(sysfsfp);
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free(filename);
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filename = 0;
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sysfsfp = 0;
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}
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error_close_sysfsfp:
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if (sysfsfp)
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fclose(sysfsfp);
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error_free_filename:
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if (filename)
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free(filename);
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error_closedir:
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closedir(dp);
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error_free_builtname_generic:
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free(builtname_generic);
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error_free_builtname:
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free(builtname);
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error_free_scan_el_dir:
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free(scan_el_dir);
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error_ret:
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return ret;
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}
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inline int iioutils_get_param_float(float *output,
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const char *param_name,
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const char *device_dir,
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const char *name,
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const char *generic_name)
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{
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FILE *sysfsfp;
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int ret;
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DIR *dp;
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char *builtname, *builtname_generic;
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char *filename = NULL;
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const struct dirent *ent;
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ret = asprintf(&builtname, "%s_%s", name, param_name);
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if (ret < 0) {
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ret = -ENOMEM;
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goto error_ret;
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}
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ret = asprintf(&builtname_generic,
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"%s_%s", generic_name, param_name);
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if (ret < 0) {
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ret = -ENOMEM;
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goto error_free_builtname;
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}
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dp = opendir(device_dir);
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if (dp == NULL) {
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ret = -errno;
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goto error_free_builtname_generic;
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}
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while (ent = readdir(dp), ent != NULL)
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if ((strcmp(builtname, ent->d_name) == 0) ||
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(strcmp(builtname_generic, ent->d_name) == 0)) {
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ret = asprintf(&filename,
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"%s/%s", device_dir, ent->d_name);
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if (ret < 0) {
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ret = -ENOMEM;
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goto error_closedir;
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}
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sysfsfp = fopen(filename, "r");
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if (!sysfsfp) {
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ret = -errno;
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goto error_free_filename;
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}
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fscanf(sysfsfp, "%f", output);
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break;
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}
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error_free_filename:
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if (filename)
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free(filename);
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error_closedir:
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closedir(dp);
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error_free_builtname_generic:
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free(builtname_generic);
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error_free_builtname:
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free(builtname);
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error_ret:
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return ret;
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}
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/**
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* bsort_channel_array_by_index() - reorder so that the array is in index order
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*
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**/
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inline void bsort_channel_array_by_index(struct iio_channel_info **ci_array,
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int cnt)
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{
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struct iio_channel_info temp;
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int x, y;
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for (x = 0; x < cnt; x++)
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for (y = 0; y < (cnt - 1); y++)
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if ((*ci_array)[y].index > (*ci_array)[y+1].index) {
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temp = (*ci_array)[y + 1];
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(*ci_array)[y + 1] = (*ci_array)[y];
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(*ci_array)[y] = temp;
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}
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}
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/**
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* build_channel_array() - function to figure out what channels are present
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* @device_dir: the IIO device directory in sysfs
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* @
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**/
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inline int build_channel_array(const char *device_dir,
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struct iio_channel_info **ci_array,
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int *counter)
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{
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DIR *dp;
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FILE *sysfsfp;
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int count, i;
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struct iio_channel_info *current;
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int ret;
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const struct dirent *ent;
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char *scan_el_dir;
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char *filename;
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*counter = 0;
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ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir);
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if (ret < 0) {
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ret = -ENOMEM;
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goto error_ret;
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}
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dp = opendir(scan_el_dir);
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if (dp == NULL) {
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ret = -errno;
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goto error_free_name;
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}
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while (ent = readdir(dp), ent != NULL)
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if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"),
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"_en") == 0) {
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ret = asprintf(&filename,
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"%s/%s", scan_el_dir, ent->d_name);
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if (ret < 0) {
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ret = -ENOMEM;
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goto error_close_dir;
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}
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sysfsfp = fopen(filename, "r");
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if (sysfsfp == NULL) {
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ret = -errno;
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free(filename);
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goto error_close_dir;
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}
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fscanf(sysfsfp, "%u", &ret);
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if (ret == 1)
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(*counter)++;
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fclose(sysfsfp);
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free(filename);
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}
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*ci_array = malloc(sizeof(**ci_array) * (*counter));
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if (*ci_array == NULL) {
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ret = -ENOMEM;
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goto error_close_dir;
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}
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seekdir(dp, 0);
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count = 0;
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while (ent = readdir(dp), ent != NULL) {
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if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"),
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"_en") == 0) {
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current = &(*ci_array)[count++];
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ret = asprintf(&filename,
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"%s/%s", scan_el_dir, ent->d_name);
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if (ret < 0) {
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ret = -ENOMEM;
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/* decrement count to avoid freeing name */
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count--;
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goto error_cleanup_array;
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}
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sysfsfp = fopen(filename, "r");
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if (sysfsfp == NULL) {
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free(filename);
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ret = -errno;
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goto error_cleanup_array;
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}
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fscanf(sysfsfp, "%u", ¤t->enabled);
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fclose(sysfsfp);
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if (!current->enabled) {
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free(filename);
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count--;
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continue;
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}
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current->scale = 1.0;
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current->offset = 0;
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current->name = strndup(ent->d_name,
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strlen(ent->d_name) -
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strlen("_en"));
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if (current->name == NULL) {
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free(filename);
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ret = -ENOMEM;
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goto error_cleanup_array;
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}
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/* Get the generic and specific name elements */
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ret = iioutils_break_up_name(current->name,
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¤t->generic_name);
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if (ret) {
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free(filename);
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goto error_cleanup_array;
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}
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ret = asprintf(&filename,
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"%s/%s_index",
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scan_el_dir,
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current->name);
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if (ret < 0) {
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free(filename);
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ret = -ENOMEM;
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goto error_cleanup_array;
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}
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sysfsfp = fopen(filename, "r");
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fscanf(sysfsfp, "%u", ¤t->index);
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fclose(sysfsfp);
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free(filename);
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/* Find the scale */
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ret = iioutils_get_param_float(¤t->scale,
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"scale",
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device_dir,
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current->name,
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current->generic_name);
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if (ret < 0)
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goto error_cleanup_array;
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ret = iioutils_get_param_float(¤t->offset,
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"offset",
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device_dir,
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current->name,
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current->generic_name);
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if (ret < 0)
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goto error_cleanup_array;
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ret = iioutils_get_type(¤t->is_signed,
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¤t->bytes,
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¤t->bits_used,
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¤t->shift,
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¤t->mask,
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¤t->be,
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device_dir,
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current->name,
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current->generic_name);
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}
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}
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closedir(dp);
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/* reorder so that the array is in index order */
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bsort_channel_array_by_index(ci_array, *counter);
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return 0;
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error_cleanup_array:
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for (i = count - 1; i >= 0; i--)
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free((*ci_array)[i].name);
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free(*ci_array);
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error_close_dir:
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closedir(dp);
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error_free_name:
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free(scan_el_dir);
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error_ret:
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return ret;
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}
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/**
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* find_type_by_name() - function to match top level types by name
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* @name: top level type instance name
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* @type: the type of top level instance being sort
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*
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* Typical types this is used for are device and trigger.
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**/
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inline int find_type_by_name(const char *name, const char *type)
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{
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const struct dirent *ent;
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int number, numstrlen;
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FILE *nameFile;
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DIR *dp;
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char thisname[IIO_MAX_NAME_LENGTH];
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char *filename;
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dp = opendir(iio_dir);
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if (dp == NULL) {
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printf("No industrialio devices available\n");
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return -ENODEV;
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}
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while (ent = readdir(dp), ent != NULL) {
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if (strcmp(ent->d_name, ".") != 0 &&
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strcmp(ent->d_name, "..") != 0 &&
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strlen(ent->d_name) > strlen(type) &&
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strncmp(ent->d_name, type, strlen(type)) == 0) {
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numstrlen = sscanf(ent->d_name + strlen(type),
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"%d",
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&number);
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/* verify the next character is not a colon */
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if (strncmp(ent->d_name + strlen(type) + numstrlen,
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":",
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1) != 0) {
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filename = malloc(strlen(iio_dir)
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+ strlen(type)
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+ numstrlen
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+ 6);
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if (filename == NULL) {
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closedir(dp);
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return -ENOMEM;
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}
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sprintf(filename, "%s%s%d/name",
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iio_dir,
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type,
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number);
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nameFile = fopen(filename, "r");
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if (!nameFile) {
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free(filename);
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continue;
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}
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free(filename);
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fscanf(nameFile, "%s", thisname);
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fclose(nameFile);
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if (strcmp(name, thisname) == 0) {
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closedir(dp);
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return number;
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}
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}
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}
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}
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closedir(dp);
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return -ENODEV;
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}
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inline int _write_sysfs_int(char *filename, char *basedir, int val, int verify)
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{
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int ret;
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FILE *sysfsfp;
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int test;
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char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
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if (temp == NULL)
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return -ENOMEM;
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sprintf(temp, "%s/%s", basedir, filename);
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sysfsfp = fopen(temp, "w");
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if (sysfsfp == NULL) {
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printf("failed to open %s\n", temp);
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ret = -errno;
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goto error_free;
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}
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fprintf(sysfsfp, "%d", val);
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fclose(sysfsfp);
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if (verify) {
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sysfsfp = fopen(temp, "r");
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if (sysfsfp == NULL) {
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printf("failed to open %s\n", temp);
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ret = -errno;
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goto error_free;
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}
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fscanf(sysfsfp, "%d", &test);
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fclose(sysfsfp);
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if (test != val) {
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printf("Possible failure in int write %d to %s%s\n",
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val,
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basedir,
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filename);
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ret = -1;
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}
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}
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error_free:
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free(temp);
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return ret;
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}
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int write_sysfs_int(char *filename, char *basedir, int val)
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{
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return _write_sysfs_int(filename, basedir, val, 0);
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}
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int write_sysfs_int_and_verify(char *filename, char *basedir, int val)
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{
|
|
return _write_sysfs_int(filename, basedir, val, 1);
|
|
}
|
|
|
|
int _write_sysfs_string(char *filename, char *basedir, char *val, int verify)
|
|
{
|
|
int ret = 0;
|
|
FILE *sysfsfp;
|
|
char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
|
|
if (temp == NULL) {
|
|
printf("Memory allocation failed\n");
|
|
return -ENOMEM;
|
|
}
|
|
sprintf(temp, "%s/%s", basedir, filename);
|
|
sysfsfp = fopen(temp, "w");
|
|
if (sysfsfp == NULL) {
|
|
printf("Could not open %s\n", temp);
|
|
ret = -errno;
|
|
goto error_free;
|
|
}
|
|
fprintf(sysfsfp, "%s", val);
|
|
fclose(sysfsfp);
|
|
if (verify) {
|
|
sysfsfp = fopen(temp, "r");
|
|
if (sysfsfp == NULL) {
|
|
printf("could not open file to verify\n");
|
|
ret = -errno;
|
|
goto error_free;
|
|
}
|
|
fscanf(sysfsfp, "%s", temp);
|
|
fclose(sysfsfp);
|
|
if (strcmp(temp, val) != 0) {
|
|
printf("Possible failure in string write of %s "
|
|
"Should be %s "
|
|
"written to %s\%s\n",
|
|
temp,
|
|
val,
|
|
basedir,
|
|
filename);
|
|
ret = -1;
|
|
}
|
|
}
|
|
error_free:
|
|
free(temp);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* write_sysfs_string_and_verify() - string write, readback and verify
|
|
* @filename: name of file to write to
|
|
* @basedir: the sysfs directory in which the file is to be found
|
|
* @val: the string to write
|
|
**/
|
|
int write_sysfs_string_and_verify(char *filename, char *basedir, char *val)
|
|
{
|
|
return _write_sysfs_string(filename, basedir, val, 1);
|
|
}
|
|
|
|
int write_sysfs_string(char *filename, char *basedir, char *val)
|
|
{
|
|
return _write_sysfs_string(filename, basedir, val, 0);
|
|
}
|
|
|
|
int read_sysfs_posint(char *filename, char *basedir)
|
|
{
|
|
int ret;
|
|
FILE *sysfsfp;
|
|
char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
|
|
if (temp == NULL) {
|
|
printf("Memory allocation failed");
|
|
return -ENOMEM;
|
|
}
|
|
sprintf(temp, "%s/%s", basedir, filename);
|
|
sysfsfp = fopen(temp, "r");
|
|
if (sysfsfp == NULL) {
|
|
ret = -errno;
|
|
goto error_free;
|
|
}
|
|
fscanf(sysfsfp, "%d\n", &ret);
|
|
fclose(sysfsfp);
|
|
error_free:
|
|
free(temp);
|
|
return ret;
|
|
}
|
|
|
|
int read_sysfs_float(char *filename, char *basedir, float *val)
|
|
{
|
|
float ret = 0;
|
|
FILE *sysfsfp;
|
|
char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
|
|
if (temp == NULL) {
|
|
printf("Memory allocation failed");
|
|
return -ENOMEM;
|
|
}
|
|
sprintf(temp, "%s/%s", basedir, filename);
|
|
sysfsfp = fopen(temp, "r");
|
|
if (sysfsfp == NULL) {
|
|
ret = -errno;
|
|
goto error_free;
|
|
}
|
|
fscanf(sysfsfp, "%f\n", val);
|
|
fclose(sysfsfp);
|
|
error_free:
|
|
free(temp);
|
|
return ret;
|
|
}
|