// SPDX-License-Identifier: GPL-2.0-only /* IIO - useful set of util functionality * * Copyright (c) 2008 Jonathan Cameron */ #include <string.h> #include <stdlib.h> #include <stdio.h> #include <stdint.h> #include <dirent.h> #include <errno.h> #include <ctype.h> #include "iio_utils.h" const char *iio_dir = "/sys/bus/iio/devices/"; static char * const iio_direction[] = { "in", "out", }; /** * iioutils_break_up_name() - extract generic name from full channel name * @full_name: the full channel name * @generic_name: the output generic channel name * * Returns 0 on success, or a negative error code if string extraction failed. **/ int iioutils_break_up_name(const char *full_name, char **generic_name) { char *current; char *w, *r; char *working, *prefix = ""; int i, ret; for (i = 0; i < ARRAY_SIZE(iio_direction); i++) if (!strncmp(full_name, iio_direction[i], strlen(iio_direction[i]))) { prefix = iio_direction[i]; break; } current = strdup(full_name + strlen(prefix) + 1); if (!current) return -ENOMEM; working = strtok(current, "_\0"); if (!working) { free(current); return -EINVAL; } w = working; r = working; while (*r != '\0') { if (!isdigit(*r)) { *w = *r; w++; } r++; } *w = '\0'; ret = asprintf(generic_name, "%s_%s", prefix, working); free(current); return (ret == -1) ? -ENOMEM : 0; } /** * iioutils_get_type() - find and process _type attribute data * @is_signed: output whether channel is signed * @bytes: output how many bytes the channel storage occupies * @bits_used: output number of valid bits of data * @shift: output amount of bits to shift right data before applying bit mask * @mask: output a bit mask for the raw data * @be: output if data in big endian * @device_dir: the IIO device directory * @name: the channel name * @generic_name: the channel type name * * Returns a value >= 0 on success, otherwise a negative error code. **/ int iioutils_get_type(unsigned *is_signed, unsigned *bytes, unsigned *bits_used, unsigned *shift, uint64_t *mask, unsigned *be, const char *device_dir, const char *name, const char *generic_name) { FILE *sysfsfp; int ret; DIR *dp; char *scan_el_dir, *builtname, *builtname_generic, *filename = 0; char signchar, endianchar; unsigned padint; const struct dirent *ent; ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir); if (ret < 0) return -ENOMEM; ret = asprintf(&builtname, FORMAT_TYPE_FILE, name); if (ret < 0) { ret = -ENOMEM; goto error_free_scan_el_dir; } ret = asprintf(&builtname_generic, FORMAT_TYPE_FILE, generic_name); if (ret < 0) { ret = -ENOMEM; goto error_free_builtname; } dp = opendir(scan_el_dir); if (!dp) { ret = -errno; goto error_free_builtname_generic; } ret = -ENOENT; while (ent = readdir(dp), ent) if ((strcmp(builtname, ent->d_name) == 0) || (strcmp(builtname_generic, ent->d_name) == 0)) { ret = asprintf(&filename, "%s/%s", scan_el_dir, ent->d_name); if (ret < 0) { ret = -ENOMEM; goto error_closedir; } sysfsfp = fopen(filename, "r"); if (!sysfsfp) { ret = -errno; fprintf(stderr, "failed to open %s\n", filename); goto error_free_filename; } ret = fscanf(sysfsfp, "%ce:%c%u/%u>>%u", &endianchar, &signchar, bits_used, &padint, shift); if (ret < 0) { ret = -errno; fprintf(stderr, "failed to pass scan type description\n"); goto error_close_sysfsfp; } else if (ret != 5) { ret = -EIO; fprintf(stderr, "scan type description didn't match\n"); goto error_close_sysfsfp; } *be = (endianchar == 'b'); *bytes = padint / 8; if (*bits_used == 64) *mask = ~(0ULL); else *mask = (1ULL << *bits_used) - 1ULL; *is_signed = (signchar == 's'); if (fclose(sysfsfp)) { ret = -errno; fprintf(stderr, "Failed to close %s\n", filename); goto error_free_filename; } sysfsfp = 0; free(filename); filename = 0; /* * Avoid having a more generic entry overwriting * the settings. */ if (strcmp(builtname, ent->d_name) == 0) break; } error_close_sysfsfp: if (sysfsfp) if (fclose(sysfsfp)) perror("iioutils_get_type(): Failed to close file"); error_free_filename: if (filename) free(filename); error_closedir: if (closedir(dp) == -1) perror("iioutils_get_type(): Failed to close directory"); error_free_builtname_generic: free(builtname_generic); error_free_builtname: free(builtname); error_free_scan_el_dir: free(scan_el_dir); return ret; } /** * iioutils_get_param_float() - read a float value from a channel parameter * @output: output the float value * @param_name: the parameter name to read * @device_dir: the IIO device directory in sysfs * @name: the channel name * @generic_name: the channel type name * * Returns a value >= 0 on success, otherwise a negative error code. **/ int iioutils_get_param_float(float *output, const char *param_name, const char *device_dir, const char *name, const char *generic_name) { FILE *sysfsfp; int ret; DIR *dp; char *builtname, *builtname_generic; char *filename = NULL; const struct dirent *ent; ret = asprintf(&builtname, "%s_%s", name, param_name); if (ret < 0) return -ENOMEM; ret = asprintf(&builtname_generic, "%s_%s", generic_name, param_name); if (ret < 0) { ret = -ENOMEM; goto error_free_builtname; } dp = opendir(device_dir); if (!dp) { ret = -errno; goto error_free_builtname_generic; } ret = -ENOENT; while (ent = readdir(dp), ent) if ((strcmp(builtname, ent->d_name) == 0) || (strcmp(builtname_generic, ent->d_name) == 0)) { ret = asprintf(&filename, "%s/%s", device_dir, ent->d_name); if (ret < 0) { ret = -ENOMEM; goto error_closedir; } sysfsfp = fopen(filename, "r"); if (!sysfsfp) { ret = -errno; goto error_free_filename; } errno = 0; if (fscanf(sysfsfp, "%f", output) != 1) ret = errno ? -errno : -ENODATA; break; } error_free_filename: if (filename) free(filename); error_closedir: if (closedir(dp) == -1) perror("iioutils_get_param_float(): Failed to close directory"); error_free_builtname_generic: free(builtname_generic); error_free_builtname: free(builtname); return ret; } /** * bsort_channel_array_by_index() - sort the array in index order * @ci_array: the iio_channel_info array to be sorted * @cnt: the amount of array elements **/ void bsort_channel_array_by_index(struct iio_channel_info *ci_array, int cnt) { struct iio_channel_info temp; int x, y; for (x = 0; x < cnt; x++) for (y = 0; y < (cnt - 1); y++) if (ci_array[y].index > ci_array[y + 1].index) { temp = ci_array[y + 1]; ci_array[y + 1] = ci_array[y]; ci_array[y] = temp; } } /** * build_channel_array() - function to figure out what channels are present * @device_dir: the IIO device directory in sysfs * @ci_array: output the resulting array of iio_channel_info * @counter: output the amount of array elements * * Returns 0 on success, otherwise a negative error code. **/ int build_channel_array(const char *device_dir, struct iio_channel_info **ci_array, int *counter) { DIR *dp; FILE *sysfsfp; int count = 0, i; struct iio_channel_info *current; int ret; const struct dirent *ent; char *scan_el_dir; char *filename; *counter = 0; ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir); if (ret < 0) return -ENOMEM; dp = opendir(scan_el_dir); if (!dp) { ret = -errno; goto error_free_name; } while (ent = readdir(dp), ent) if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"), "_en") == 0) { ret = asprintf(&filename, "%s/%s", scan_el_dir, ent->d_name); if (ret < 0) { ret = -ENOMEM; goto error_close_dir; } sysfsfp = fopen(filename, "r"); if (!sysfsfp) { ret = -errno; free(filename); goto error_close_dir; } errno = 0; if (fscanf(sysfsfp, "%i", &ret) != 1) { ret = errno ? -errno : -ENODATA; if (fclose(sysfsfp)) perror("build_channel_array(): Failed to close file"); free(filename); goto error_close_dir; } if (ret == 1) (*counter)++; if (fclose(sysfsfp)) { ret = -errno; free(filename); goto error_close_dir; } free(filename); } *ci_array = malloc(sizeof(**ci_array) * (*counter)); if (!*ci_array) { ret = -ENOMEM; goto error_close_dir; } seekdir(dp, 0); while (ent = readdir(dp), ent) { if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"), "_en") == 0) { int current_enabled = 0; current = &(*ci_array)[count++]; ret = asprintf(&filename, "%s/%s", scan_el_dir, ent->d_name); if (ret < 0) { ret = -ENOMEM; /* decrement count to avoid freeing name */ count--; goto error_cleanup_array; } sysfsfp = fopen(filename, "r"); if (!sysfsfp) { ret = -errno; free(filename); count--; goto error_cleanup_array; } errno = 0; if (fscanf(sysfsfp, "%i", ¤t_enabled) != 1) { ret = errno ? -errno : -ENODATA; free(filename); count--; goto error_cleanup_array; } if (fclose(sysfsfp)) { ret = -errno; free(filename); count--; goto error_cleanup_array; } if (!current_enabled) { free(filename); count--; continue; } current->scale = 1.0; current->offset = 0; current->name = strndup(ent->d_name, strlen(ent->d_name) - strlen("_en")); if (!current->name) { free(filename); ret = -ENOMEM; count--; goto error_cleanup_array; } /* Get the generic and specific name elements */ ret = iioutils_break_up_name(current->name, ¤t->generic_name); if (ret) { free(filename); free(current->name); count--; goto error_cleanup_array; } ret = asprintf(&filename, "%s/%s_index", scan_el_dir, current->name); if (ret < 0) { free(filename); ret = -ENOMEM; goto error_cleanup_array; } sysfsfp = fopen(filename, "r"); if (!sysfsfp) { ret = -errno; fprintf(stderr, "failed to open %s\n", filename); free(filename); goto error_cleanup_array; } errno = 0; if (fscanf(sysfsfp, "%u", ¤t->index) != 1) { ret = errno ? -errno : -ENODATA; if (fclose(sysfsfp)) perror("build_channel_array(): Failed to close file"); free(filename); goto error_cleanup_array; } if (fclose(sysfsfp)) { ret = -errno; free(filename); goto error_cleanup_array; } free(filename); /* Find the scale */ ret = iioutils_get_param_float(¤t->scale, "scale", device_dir, current->name, current->generic_name); if ((ret < 0) && (ret != -ENOENT)) goto error_cleanup_array; ret = iioutils_get_param_float(¤t->offset, "offset", device_dir, current->name, current->generic_name); if ((ret < 0) && (ret != -ENOENT)) goto error_cleanup_array; ret = iioutils_get_type(¤t->is_signed, ¤t->bytes, ¤t->bits_used, ¤t->shift, ¤t->mask, ¤t->be, device_dir, current->name, current->generic_name); if (ret < 0) goto error_cleanup_array; } } if (closedir(dp) == -1) { ret = -errno; goto error_cleanup_array; } free(scan_el_dir); /* reorder so that the array is in index order */ bsort_channel_array_by_index(*ci_array, *counter); return 0; error_cleanup_array: for (i = count - 1; i >= 0; i--) { free((*ci_array)[i].name); free((*ci_array)[i].generic_name); } free(*ci_array); *ci_array = NULL; *counter = 0; error_close_dir: if (dp) if (closedir(dp) == -1) perror("build_channel_array(): Failed to close dir"); error_free_name: free(scan_el_dir); return ret; } static int calc_digits(int num) { int count = 0; while (num != 0) { num /= 10; count++; } return count; } /** * find_type_by_name() - function to match top level types by name * @name: top level type instance name * @type: the type of top level instance being searched * * Returns the device number of a matched IIO device on success, otherwise a * negative error code. * Typical types this is used for are device and trigger. **/ int find_type_by_name(const char *name, const char *type) { const struct dirent *ent; int number, numstrlen, ret; FILE *namefp; DIR *dp; char thisname[IIO_MAX_NAME_LENGTH]; char *filename; dp = opendir(iio_dir); if (!dp) { fprintf(stderr, "No industrialio devices available\n"); return -ENODEV; } while (ent = readdir(dp), ent) { if (strcmp(ent->d_name, ".") != 0 && strcmp(ent->d_name, "..") != 0 && strlen(ent->d_name) > strlen(type) && strncmp(ent->d_name, type, strlen(type)) == 0) { errno = 0; ret = sscanf(ent->d_name + strlen(type), "%d", &number); if (ret < 0) { ret = -errno; fprintf(stderr, "failed to read element number\n"); goto error_close_dir; } else if (ret != 1) { ret = -EIO; fprintf(stderr, "failed to match element number\n"); goto error_close_dir; } numstrlen = calc_digits(number); /* verify the next character is not a colon */ if (strncmp(ent->d_name + strlen(type) + numstrlen, ":", 1) != 0) { filename = malloc(strlen(iio_dir) + strlen(type) + numstrlen + 6); if (!filename) { ret = -ENOMEM; goto error_close_dir; } ret = sprintf(filename, "%s%s%d/name", iio_dir, type, number); if (ret < 0) { free(filename); goto error_close_dir; } namefp = fopen(filename, "r"); if (!namefp) { free(filename); continue; } free(filename); errno = 0; if (fscanf(namefp, "%s", thisname) != 1) { ret = errno ? -errno : -ENODATA; goto error_close_dir; } if (fclose(namefp)) { ret = -errno; goto error_close_dir; } if (strcmp(name, thisname) == 0) { if (closedir(dp) == -1) return -errno; return number; } } } } if (closedir(dp) == -1) return -errno; return -ENODEV; error_close_dir: if (closedir(dp) == -1) perror("find_type_by_name(): Failed to close directory"); return ret; } static int _write_sysfs_int(const char *filename, const char *basedir, int val, int verify) { int ret = 0; FILE *sysfsfp; int test; char *temp = malloc(strlen(basedir) + strlen(filename) + 2); if (!temp) return -ENOMEM; ret = sprintf(temp, "%s/%s", basedir, filename); if (ret < 0) goto error_free; sysfsfp = fopen(temp, "w"); if (!sysfsfp) { ret = -errno; fprintf(stderr, "failed to open %s\n", temp); goto error_free; } ret = fprintf(sysfsfp, "%d", val); if (ret < 0) { if (fclose(sysfsfp)) perror("_write_sysfs_int(): Failed to close dir"); goto error_free; } if (fclose(sysfsfp)) { ret = -errno; goto error_free; } if (verify) { sysfsfp = fopen(temp, "r"); if (!sysfsfp) { ret = -errno; fprintf(stderr, "failed to open %s\n", temp); goto error_free; } if (fscanf(sysfsfp, "%d", &test) != 1) { ret = errno ? -errno : -ENODATA; if (fclose(sysfsfp)) perror("_write_sysfs_int(): Failed to close dir"); goto error_free; } if (fclose(sysfsfp)) { ret = -errno; goto error_free; } if (test != val) { fprintf(stderr, "Possible failure in int write %d to %s/%s\n", val, basedir, filename); ret = -1; } } error_free: free(temp); return ret; } /** * write_sysfs_int() - write an integer value to a sysfs file * @filename: name of the file to write to * @basedir: the sysfs directory in which the file is to be found * @val: integer value to write to file * * Returns a value >= 0 on success, otherwise a negative error code. **/ int write_sysfs_int(const char *filename, const char *basedir, int val) { return _write_sysfs_int(filename, basedir, val, 0); } /** * write_sysfs_int_and_verify() - write an integer value to a sysfs file * and verify * @filename: name of the file to write to * @basedir: the sysfs directory in which the file is to be found * @val: integer value to write to file * * Returns a value >= 0 on success, otherwise a negative error code. **/ int write_sysfs_int_and_verify(const char *filename, const char *basedir, int val) { return _write_sysfs_int(filename, basedir, val, 1); } static int _write_sysfs_string(const char *filename, const char *basedir, const char *val, int verify) { int ret = 0; FILE *sysfsfp; char *temp = malloc(strlen(basedir) + strlen(filename) + 2); if (!temp) { fprintf(stderr, "Memory allocation failed\n"); return -ENOMEM; } ret = sprintf(temp, "%s/%s", basedir, filename); if (ret < 0) goto error_free; sysfsfp = fopen(temp, "w"); if (!sysfsfp) { ret = -errno; fprintf(stderr, "Could not open %s\n", temp); goto error_free; } ret = fprintf(sysfsfp, "%s", val); if (ret < 0) { if (fclose(sysfsfp)) perror("_write_sysfs_string(): Failed to close dir"); goto error_free; } if (fclose(sysfsfp)) { ret = -errno; goto error_free; } if (verify) { sysfsfp = fopen(temp, "r"); if (!sysfsfp) { ret = -errno; fprintf(stderr, "Could not open file to verify\n"); goto error_free; } if (fscanf(sysfsfp, "%s", temp) != 1) { ret = errno ? -errno : -ENODATA; if (fclose(sysfsfp)) perror("_write_sysfs_string(): Failed to close dir"); goto error_free; } if (fclose(sysfsfp)) { ret = -errno; goto error_free; } if (strcmp(temp, val) != 0) { fprintf(stderr, "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 * * Returns a value >= 0 on success, otherwise a negative error code. **/ int write_sysfs_string_and_verify(const char *filename, const char *basedir, const char *val) { return _write_sysfs_string(filename, basedir, val, 1); } /** * write_sysfs_string() - write string to a sysfs file * @filename: name of file to write to * @basedir: the sysfs directory in which the file is to be found * @val: the string to write * * Returns a value >= 0 on success, otherwise a negative error code. **/ int write_sysfs_string(const char *filename, const char *basedir, const char *val) { return _write_sysfs_string(filename, basedir, val, 0); } /** * read_sysfs_posint() - read an integer value from file * @filename: name of file to read from * @basedir: the sysfs directory in which the file is to be found * * Returns the read integer value >= 0 on success, otherwise a negative error * code. **/ int read_sysfs_posint(const char *filename, const char *basedir) { int ret; FILE *sysfsfp; char *temp = malloc(strlen(basedir) + strlen(filename) + 2); if (!temp) { fprintf(stderr, "Memory allocation failed"); return -ENOMEM; } ret = sprintf(temp, "%s/%s", basedir, filename); if (ret < 0) goto error_free; sysfsfp = fopen(temp, "r"); if (!sysfsfp) { ret = -errno; goto error_free; } errno = 0; if (fscanf(sysfsfp, "%d\n", &ret) != 1) { ret = errno ? -errno : -ENODATA; if (fclose(sysfsfp)) perror("read_sysfs_posint(): Failed to close dir"); goto error_free; } if (fclose(sysfsfp)) ret = -errno; error_free: free(temp); return ret; } /** * read_sysfs_float() - read a float value from file * @filename: name of file to read from * @basedir: the sysfs directory in which the file is to be found * @val: output the read float value * * Returns a value >= 0 on success, otherwise a negative error code. **/ int read_sysfs_float(const char *filename, const char *basedir, float *val) { int ret = 0; FILE *sysfsfp; char *temp = malloc(strlen(basedir) + strlen(filename) + 2); if (!temp) { fprintf(stderr, "Memory allocation failed"); return -ENOMEM; } ret = sprintf(temp, "%s/%s", basedir, filename); if (ret < 0) goto error_free; sysfsfp = fopen(temp, "r"); if (!sysfsfp) { ret = -errno; goto error_free; } errno = 0; if (fscanf(sysfsfp, "%f\n", val) != 1) { ret = errno ? -errno : -ENODATA; if (fclose(sysfsfp)) perror("read_sysfs_float(): Failed to close dir"); goto error_free; } if (fclose(sysfsfp)) ret = -errno; error_free: free(temp); return ret; } /** * read_sysfs_string() - read a string from file * @filename: name of file to read from * @basedir: the sysfs directory in which the file is to be found * @str: output the read string * * Returns a value >= 0 on success, otherwise a negative error code. **/ int read_sysfs_string(const char *filename, const char *basedir, char *str) { int ret = 0; FILE *sysfsfp; char *temp = malloc(strlen(basedir) + strlen(filename) + 2); if (!temp) { fprintf(stderr, "Memory allocation failed"); return -ENOMEM; } ret = sprintf(temp, "%s/%s", basedir, filename); if (ret < 0) goto error_free; sysfsfp = fopen(temp, "r"); if (!sysfsfp) { ret = -errno; goto error_free; } errno = 0; if (fscanf(sysfsfp, "%s\n", str) != 1) { ret = errno ? -errno : -ENODATA; if (fclose(sysfsfp)) perror("read_sysfs_string(): Failed to close dir"); goto error_free; } if (fclose(sysfsfp)) ret = -errno; error_free: free(temp); return ret; }