/* IIO - useful set of util functionality * * 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_UTILS_H #define _IIO_UTILS_H #include #include #include #include #include #include #include #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 **/ 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 < sizeof(iio_direction) / sizeof(iio_direction[0]); 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"); 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 * @mask: output a bit mask for the raw data * @be: big endian * @device_dir: the iio device directory * @name: the channel name * @generic_name: the channel type name **/ 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) { ret = -ENOMEM; goto error_ret; } 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 == NULL) { ret = -errno; goto error_free_builtname_generic; } while (ent = readdir(dp), ent != NULL) /* * Do we allow devices to override a generic name with * a specific one? */ 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 == NULL) { ret = -errno; printf("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; printf("failed to pass scan type description\n"); goto error_close_sysfsfp; } else if (ret != 5) { ret = -EIO; printf("scan type description didn't match\n"); goto error_close_sysfsfp; } *be = (endianchar == 'b'); *bytes = padint / 8; if (*bits_used == 64) *mask = ~0; else *mask = (1 << *bits_used) - 1; if (signchar == 's') *is_signed = 1; else *is_signed = 0; fclose(sysfsfp); free(filename); filename = 0; sysfsfp = 0; } error_close_sysfsfp: if (sysfsfp) fclose(sysfsfp); error_free_filename: if (filename) free(filename); error_closedir: closedir(dp); error_free_builtname_generic: free(builtname_generic); error_free_builtname: free(builtname); error_free_scan_el_dir: free(scan_el_dir); error_ret: return ret; } 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) { ret = -ENOMEM; goto error_ret; } 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 == NULL) { ret = -errno; goto error_free_builtname_generic; } while (ent = readdir(dp), ent != NULL) 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; } fscanf(sysfsfp, "%f", output); break; } error_free_filename: if (filename) free(filename); error_closedir: closedir(dp); error_free_builtname_generic: free(builtname_generic); error_free_builtname: free(builtname); error_ret: return ret; } /** * bsort_channel_array_by_index() - reorder so that the array is in index order * **/ 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 * @ **/ int build_channel_array(const char *device_dir, struct iio_channel_info **ci_array, int *counter) { DIR *dp; FILE *sysfsfp; int count, 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) { ret = -ENOMEM; goto error_ret; } dp = opendir(scan_el_dir); if (dp == NULL) { ret = -errno; goto error_free_name; } while (ent = readdir(dp), ent != NULL) 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 == NULL) { ret = -errno; free(filename); goto error_close_dir; } fscanf(sysfsfp, "%i", &ret); if (ret == 1) (*counter)++; fclose(sysfsfp); free(filename); } *ci_array = malloc(sizeof(**ci_array) * (*counter)); if (*ci_array == NULL) { ret = -ENOMEM; goto error_close_dir; } seekdir(dp, 0); count = 0; while (ent = readdir(dp), ent != NULL) { 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 == NULL) { ret = -errno; free(filename); count--; goto error_cleanup_array; } fscanf(sysfsfp, "%i", ¤t_enabled); fclose(sysfsfp); 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 == NULL) { 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"); fscanf(sysfsfp, "%u", ¤t->index); fclose(sysfsfp); free(filename); /* Find the scale */ ret = iioutils_get_param_float(¤t->scale, "scale", device_dir, current->name, current->generic_name); if (ret < 0) goto error_cleanup_array; ret = iioutils_get_param_float(¤t->offset, "offset", device_dir, current->name, current->generic_name); if (ret < 0) 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); } } closedir(dp); 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); error_close_dir: closedir(dp); error_free_name: free(scan_el_dir); error_ret: return ret; } 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 sort * * 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 *nameFile; DIR *dp; char thisname[IIO_MAX_NAME_LENGTH]; char *filename; dp = opendir(iio_dir); if (dp == NULL) { printf("No industrialio devices available\n"); return -ENODEV; } while (ent = readdir(dp), ent != NULL) { 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; printf("failed to read element number\n"); goto error_close_dir; } else if (ret != 1) { ret = -EIO; printf("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 == NULL) { closedir(dp); return -ENOMEM; } sprintf(filename, "%s%s%d/name", iio_dir, type, number); nameFile = fopen(filename, "r"); if (!nameFile) { free(filename); continue; } free(filename); fscanf(nameFile, "%s", thisname); fclose(nameFile); if (strcmp(name, thisname) == 0) { closedir(dp); return number; } } } } closedir(dp); 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(char *filename, char *basedir, int val, int verify) { int ret = 0; FILE *sysfsfp; int test; char *temp = malloc(strlen(basedir) + strlen(filename) + 2); if (temp == NULL) return -ENOMEM; sprintf(temp, "%s/%s", basedir, filename); sysfsfp = fopen(temp, "w"); if (sysfsfp == NULL) { ret = -errno; printf("failed to open %s\n", temp); goto error_free; } fprintf(sysfsfp, "%d", val); fclose(sysfsfp); if (verify) { sysfsfp = fopen(temp, "r"); if (sysfsfp == NULL) { ret = -errno; printf("failed to open %s\n", temp); goto error_free; } fscanf(sysfsfp, "%d", &test); fclose(sysfsfp); if (test != val) { printf("Possible failure in int write %d to %s%s\n", val, basedir, filename); ret = -1; } } error_free: free(temp); return ret; } int write_sysfs_int(char *filename, char *basedir, int val) { return _write_sysfs_int(filename, basedir, val, 0); } int write_sysfs_int_and_verify(char *filename, char *basedir, int val) { return _write_sysfs_int(filename, basedir, val, 1); } static 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) { ret = -errno; printf("Could not open %s\n", temp); goto error_free; } fprintf(sysfsfp, "%s", val); fclose(sysfsfp); if (verify) { sysfsfp = fopen(temp, "r"); if (sysfsfp == NULL) { ret = -errno; printf("could not open file to verify\n"); 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) { int 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; } 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 == 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, "%s\n", str); fclose(sysfsfp); error_free: free(temp); return ret; } #endif /* _IIO_UTILS_H */