diff options
Diffstat (limited to 'kernel/tools/iio/iio_utils.c')
| -rw-r--r-- | kernel/tools/iio/iio_utils.c | 688 |
1 files changed, 505 insertions, 183 deletions
diff --git a/kernel/tools/iio/iio_utils.c b/kernel/tools/iio/iio_utils.c index 6f6452167..5eb6793f3 100644 --- a/kernel/tools/iio/iio_utils.c +++ b/kernel/tools/iio/iio_utils.c @@ -6,9 +6,6 @@ * 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 <string.h> #include <stdlib.h> #include <stdio.h> @@ -29,16 +26,17 @@ static char * const iio_direction[] = { * 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) +int iioutils_break_up_name(const char *full_name, char **generic_name) { char *current; char *w, *r; char *working, *prefix = ""; - int i; + int i, ret; - for (i = 0; i < sizeof(iio_direction) / sizeof(iio_direction[0]); i++) + for (i = 0; i < ARRAY_SIZE(iio_direction); i++) if (!strncmp(full_name, iio_direction[i], strlen(iio_direction[i]))) { prefix = iio_direction[i]; @@ -46,7 +44,14 @@ int iioutils_break_up_name(const char *full_name, } 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; @@ -56,34 +61,34 @@ int iioutils_break_up_name(const char *full_name, *w = *r; w++; } + r++; } *w = '\0'; - asprintf(generic_name, "%s_%s", prefix, working); + ret = asprintf(generic_name, "%s_%s", prefix, working); free(current); - return 0; + 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: big endian - * @device_dir: the iio device directory + * @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) +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; @@ -94,10 +99,9 @@ int iioutils_get_type(unsigned *is_signed, const struct dirent *ent; ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir); - if (ret < 0) { - ret = -ENOMEM; - goto error_ret; - } + if (ret < 0) + return -ENOMEM; + ret = asprintf(&builtname, FORMAT_TYPE_FILE, name); if (ret < 0) { ret = -ENOMEM; @@ -110,11 +114,13 @@ int iioutils_get_type(unsigned *is_signed, } dp = opendir(scan_el_dir); - if (dp == NULL) { + if (!dp) { ret = -errno; goto error_free_builtname_generic; } - while (ent = readdir(dp), ent != NULL) + + ret = -ENOENT; + while (ent = readdir(dp), ent) /* * Do we allow devices to override a generic name with * a specific one? @@ -127,10 +133,12 @@ int iioutils_get_type(unsigned *is_signed, ret = -ENOMEM; goto error_closedir; } + sysfsfp = fopen(filename, "r"); - if (sysfsfp == NULL) { - printf("failed to open %s\n", filename); + if (!sysfsfp) { ret = -errno; + fprintf(stderr, "failed to open %s\n", + filename); goto error_free_filename; } @@ -141,49 +149,73 @@ int iioutils_get_type(unsigned *is_signed, bits_used, &padint, shift); if (ret < 0) { - printf("failed to pass scan type description\n"); 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 = ~0; else - *mask = (1 << *bits_used) - 1; - if (signchar == 's') - *is_signed = 1; - else - *is_signed = 0; - fclose(sysfsfp); - free(filename); + *mask = (1ULL << *bits_used) - 1; + + *is_signed = (signchar == 's'); + if (fclose(sysfsfp)) { + ret = -errno; + fprintf(stderr, "Failed to close %s\n", + filename); + goto error_free_filename; + } - filename = 0; sysfsfp = 0; + free(filename); + filename = 0; } + error_close_sysfsfp: if (sysfsfp) - fclose(sysfsfp); + if (fclose(sysfsfp)) + perror("iioutils_get_type(): Failed to close file"); + error_free_filename: if (filename) free(filename); + error_closedir: - closedir(dp); + 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); -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) +/** + * 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; @@ -193,22 +225,24 @@ int iioutils_get_param_float(float *output, const struct dirent *ent; ret = asprintf(&builtname, "%s_%s", name, param_name); - if (ret < 0) { - ret = -ENOMEM; - goto error_ret; - } + 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 == NULL) { + if (!dp) { ret = -errno; goto error_free_builtname_generic; } - while (ent = readdir(dp), ent != NULL) + + ret = -ENOENT; + while (ent = readdir(dp), ent) if ((strcmp(builtname, ent->d_name) == 0) || (strcmp(builtname_generic, ent->d_name) == 0)) { ret = asprintf(&filename, @@ -217,60 +251,69 @@ int iioutils_get_param_float(float *output, ret = -ENOMEM; goto error_closedir; } + sysfsfp = fopen(filename, "r"); if (!sysfsfp) { ret = -errno; goto error_free_filename; } - fscanf(sysfsfp, "%f", output); + + errno = 0; + if (fscanf(sysfsfp, "%f", output) != 1) + ret = errno ? -errno : -ENODATA; + break; } error_free_filename: if (filename) free(filename); + error_closedir: - closedir(dp); + 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); -error_ret: + return ret; } /** - * bsort_channel_array_by_index() - reorder so that the array is in index order - * + * 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) +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; + 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) + struct iio_channel_info **ci_array, int *counter) { DIR *dp; FILE *sysfsfp; - int count, i; + int count = 0, i; struct iio_channel_info *current; int ret; const struct dirent *ent; @@ -279,16 +322,16 @@ int build_channel_array(const char *device_dir, *counter = 0; ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir); - if (ret < 0) { - ret = -ENOMEM; - goto error_ret; - } + if (ret < 0) + return -ENOMEM; + dp = opendir(scan_el_dir); - if (dp == NULL) { + if (!dp) { ret = -errno; goto error_free_name; } - while (ent = readdir(dp), ent != NULL) + + while (ent = readdir(dp), ent) if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"), "_en") == 0) { ret = asprintf(&filename, @@ -297,26 +340,43 @@ int build_channel_array(const char *device_dir, ret = -ENOMEM; goto error_close_dir; } + sysfsfp = fopen(filename, "r"); - if (sysfsfp == NULL) { + if (!sysfsfp) { ret = -errno; free(filename); goto error_close_dir; } - fscanf(sysfsfp, "%i", &ret); + + 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)++; - fclose(sysfsfp); + + if (fclose(sysfsfp)) { + ret = -errno; + free(filename); + goto error_close_dir; + } + free(filename); } + *ci_array = malloc(sizeof(**ci_array) * (*counter)); - if (*ci_array == NULL) { + if (!*ci_array) { ret = -ENOMEM; goto error_close_dir; } + seekdir(dp, 0); - count = 0; - while (ent = readdir(dp), ent != NULL) { + while (ent = readdir(dp), ent) { if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"), "_en") == 0) { int current_enabled = 0; @@ -330,14 +390,29 @@ int build_channel_array(const char *device_dir, count--; goto error_cleanup_array; } + sysfsfp = fopen(filename, "r"); - if (sysfsfp == NULL) { + 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; } - fscanf(sysfsfp, "%i", ¤t_enabled); - fclose(sysfsfp); if (!current_enabled) { free(filename); @@ -350,18 +425,23 @@ int build_channel_array(const char *device_dir, current->name = strndup(ent->d_name, strlen(ent->d_name) - strlen("_en")); - if (current->name == NULL) { + 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, @@ -371,9 +451,32 @@ int build_channel_array(const char *device_dir, ret = -ENOMEM; goto error_cleanup_array; } + sysfsfp = fopen(filename, "r"); - fscanf(sysfsfp, "%u", ¤t->index); - fclose(sysfsfp); + 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, @@ -381,15 +484,17 @@ int build_channel_array(const char *device_dir, device_dir, current->name, current->generic_name); - if (ret < 0) + 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) + if ((ret < 0) && (ret != -ENOENT)) goto error_cleanup_array; + ret = iioutils_get_type(¤t->is_signed, ¤t->bytes, ¤t->bits_used, @@ -399,182 +504,317 @@ int build_channel_array(const char *device_dir, device_dir, current->name, current->generic_name); + if (ret < 0) + goto error_cleanup_array; } } - closedir(dp); + 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); + bsort_channel_array_by_index(*ci_array, *counter); return 0; error_cleanup_array: - for (i = count - 1; i >= 0; i--) + 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: - closedir(dp); + if (dp) + if (closedir(dp) == -1) + perror("build_channel_array(): Failed to close dir"); + error_free_name: free(scan_el_dir); -error_ret: + 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 sort + * @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; + int number, numstrlen, ret; - FILE *nameFile; + FILE *namefp; DIR *dp; char thisname[IIO_MAX_NAME_LENGTH]; char *filename; dp = opendir(iio_dir); - if (dp == NULL) { - printf("No industrialio devices available\n"); + if (!dp) { + fprintf(stderr, "No industrialio devices available\n"); return -ENODEV; } - while (ent = readdir(dp), ent != NULL) { + 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) { - numstrlen = sscanf(ent->d_name + strlen(type), - "%d", - &number); + 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 == NULL) { - closedir(dp); - return -ENOMEM; + ":", 1) != 0) { + filename = malloc(strlen(iio_dir) + strlen(type) + + numstrlen + 6); + if (!filename) { + ret = -ENOMEM; + goto error_close_dir; } - sprintf(filename, "%s%s%d/name", - iio_dir, - type, - number); - nameFile = fopen(filename, "r"); - if (!nameFile) { + + 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); - fscanf(nameFile, "%s", thisname); - fclose(nameFile); + 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) { - closedir(dp); + if (closedir(dp) == -1) + return -errno; + return number; } } } } - closedir(dp); + 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; } -int _write_sysfs_int(char *filename, char *basedir, int val, int verify) +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 == NULL) + if (!temp) return -ENOMEM; - sprintf(temp, "%s/%s", basedir, filename); + + ret = sprintf(temp, "%s/%s", basedir, filename); + if (ret < 0) + goto error_free; + sysfsfp = fopen(temp, "w"); - if (sysfsfp == NULL) { - printf("failed to open %s\n", temp); + 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; } - fprintf(sysfsfp, "%d", val); - fclose(sysfsfp); + + if (fclose(sysfsfp)) { + ret = -errno; + goto error_free; + } + if (verify) { sysfsfp = fopen(temp, "r"); - if (sysfsfp == NULL) { - printf("failed to open %s\n", temp); + 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; } - fscanf(sysfsfp, "%d", &test); - fclose(sysfsfp); + if (test != val) { - printf("Possible failure in int write %d to %s%s\n", - val, - basedir, - filename); + fprintf(stderr, + "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) +/** + * 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); } -int write_sysfs_int_and_verify(char *filename, char *basedir, int val) +/** + * 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); } -int _write_sysfs_string(char *filename, char *basedir, char *val, int verify) +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 == NULL) { - printf("Memory allocation failed\n"); + if (!temp) { + fprintf(stderr, "Memory allocation failed\n"); return -ENOMEM; } - sprintf(temp, "%s/%s", basedir, filename); + + ret = sprintf(temp, "%s/%s", basedir, filename); + if (ret < 0) + goto error_free; + sysfsfp = fopen(temp, "w"); - if (sysfsfp == NULL) { - printf("Could not open %s\n", temp); + 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; } - fprintf(sysfsfp, "%s", val); - fclose(sysfsfp); + if (verify) { sysfsfp = fopen(temp, "r"); - if (sysfsfp == NULL) { - printf("could not open file to verify\n"); + if (!sysfsfp) { ret = -errno; + fprintf(stderr, "Could not open file to verify\n"); goto error_free; } - fscanf(sysfsfp, "%s", temp); - fclose(sysfsfp); + + 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) { - printf("Possible failure in string write of %s " - "Should be %s " - "written to %s\%s\n", - temp, - val, - basedir, - filename); + 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); @@ -586,84 +826,166 @@ error_free: * @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(char *filename, char *basedir, char *val) +int write_sysfs_string_and_verify(const char *filename, const char *basedir, + const char *val) { return _write_sysfs_string(filename, basedir, val, 1); } -int write_sysfs_string(char *filename, char *basedir, char *val) +/** + * 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); } -int read_sysfs_posint(char *filename, char *basedir) +/** + * 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 == NULL) { - printf("Memory allocation failed"); + if (!temp) { + fprintf(stderr, "Memory allocation failed"); return -ENOMEM; } - sprintf(temp, "%s/%s", basedir, filename); + + ret = sprintf(temp, "%s/%s", basedir, filename); + if (ret < 0) + goto error_free; + sysfsfp = fopen(temp, "r"); - if (sysfsfp == NULL) { + if (!sysfsfp) { ret = -errno; goto error_free; } - fscanf(sysfsfp, "%d\n", &ret); - fclose(sysfsfp); + + 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; } -int read_sysfs_float(char *filename, char *basedir, float *val) +/** + * 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 == NULL) { - printf("Memory allocation failed"); + if (!temp) { + fprintf(stderr, "Memory allocation failed"); return -ENOMEM; } - sprintf(temp, "%s/%s", basedir, filename); + + ret = sprintf(temp, "%s/%s", basedir, filename); + if (ret < 0) + goto error_free; + sysfsfp = fopen(temp, "r"); - if (sysfsfp == NULL) { + if (!sysfsfp) { ret = -errno; goto error_free; } - fscanf(sysfsfp, "%f\n", val); - fclose(sysfsfp); + + 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 == NULL) { - printf("Memory allocation failed"); + if (!temp) { + fprintf(stderr, "Memory allocation failed"); return -ENOMEM; } - sprintf(temp, "%s/%s", basedir, filename); + + ret = sprintf(temp, "%s/%s", basedir, filename); + if (ret < 0) + goto error_free; + sysfsfp = fopen(temp, "r"); - if (sysfsfp == NULL) { + if (!sysfsfp) { ret = -errno; goto error_free; } - fscanf(sysfsfp, "%s\n", str); - fclose(sysfsfp); + + 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; } - -#endif /* _IIO_UTILS_H */ |