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-rw-r--r--tools/iio/iio_utils.c988
1 files changed, 988 insertions, 0 deletions
diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c
new file mode 100644
index 0000000000..6a00a6eeca
--- /dev/null
+++ b/tools/iio/iio_utils.c
@@ -0,0 +1,988 @@
+// 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
+ * @buffer_idx: the IIO buffer index
+ * @name: the channel name
+ * @generic_name: the channel type name
+ *
+ * Returns a value >= 0 on success, otherwise a negative error code.
+ **/
+static int iioutils_get_type(unsigned int *is_signed, unsigned int *bytes,
+ unsigned int *bits_used, unsigned int *shift,
+ uint64_t *mask, unsigned int *be,
+ const char *device_dir, int buffer_idx,
+ 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, buffer_idx);
+ 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;
+
+ fclose(sysfsfp);
+ 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
+ * @buffer_idx: the IIO buffer for this channel array
+ * @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, int buffer_idx,
+ 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, buffer_idx);
+ 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");
+ free(filename);
+ if (!sysfsfp) {
+ ret = -errno;
+ 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");
+
+ goto error_close_dir;
+ }
+ if (ret == 1)
+ (*counter)++;
+
+ if (fclose(sysfsfp)) {
+ ret = -errno;
+ goto error_close_dir;
+ }
+
+ }
+
+ *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");
+ free(filename);
+ if (!sysfsfp) {
+ ret = -errno;
+ count--;
+ goto error_cleanup_array;
+ }
+
+ errno = 0;
+ if (fscanf(sysfsfp, "%i", &current_enabled) != 1) {
+ ret = errno ? -errno : -ENODATA;
+ count--;
+ goto error_cleanup_array;
+ }
+
+ if (fclose(sysfsfp)) {
+ ret = -errno;
+ count--;
+ goto error_cleanup_array;
+ }
+
+ if (!current_enabled) {
+ count--;
+ continue;
+ }
+
+ current->scale = 1.0;
+ current->offset = 0;
+ current->name = strndup(ent->d_name,
+ strlen(ent->d_name) -
+ strlen("_en"));
+ if (!current->name) {
+ ret = -ENOMEM;
+ count--;
+ goto error_cleanup_array;
+ }
+
+ /* Get the generic and specific name elements */
+ ret = iioutils_break_up_name(current->name,
+ &current->generic_name);
+ if (ret) {
+ free(current->name);
+ count--;
+ goto error_cleanup_array;
+ }
+
+ ret = asprintf(&filename,
+ "%s/%s_index",
+ scan_el_dir,
+ current->name);
+ if (ret < 0) {
+ ret = -ENOMEM;
+ goto error_cleanup_array;
+ }
+
+ sysfsfp = fopen(filename, "r");
+ free(filename);
+ if (!sysfsfp) {
+ ret = -errno;
+ fprintf(stderr, "failed to open %s/%s_index\n",
+ scan_el_dir, current->name);
+ goto error_cleanup_array;
+ }
+
+ errno = 0;
+ if (fscanf(sysfsfp, "%u", &current->index) != 1) {
+ ret = errno ? -errno : -ENODATA;
+ if (fclose(sysfsfp))
+ perror("build_channel_array(): Failed to close file");
+
+ goto error_cleanup_array;
+ }
+
+ if (fclose(sysfsfp)) {
+ ret = -errno;
+ goto error_cleanup_array;
+ }
+
+ /* Find the scale */
+ ret = iioutils_get_param_float(&current->scale,
+ "scale",
+ device_dir,
+ current->name,
+ current->generic_name);
+ if ((ret < 0) && (ret != -ENOENT))
+ goto error_cleanup_array;
+
+ ret = iioutils_get_param_float(&current->offset,
+ "offset",
+ device_dir,
+ current->name,
+ current->generic_name);
+ if ((ret < 0) && (ret != -ENOENT))
+ goto error_cleanup_array;
+
+ ret = iioutils_get_type(&current->is_signed,
+ &current->bytes,
+ &current->bits_used,
+ &current->shift,
+ &current->mask,
+ &current->be,
+ device_dir,
+ buffer_idx,
+ 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;
+
+ /* It takes a digit to represent zero */
+ if (!num)
+ return 1;
+
+ 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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 23:06:09 +0000