release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/staging/iio/Documentation/iio_utils.h

   1 /* IIO - useful set of util functionality
   2  *
   3  * Copyright (c) 2008 Jonathan Cameron
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  */
   9
  10 /* Made up value to limit allocation sizes */
  11 #include <string.h>
  12 #include <stdlib.h>
  13
  14 #define IIO_MAX_NAME_LENGTH 30
  15
  16 #define IIO_EVENT_CODE_RING_50_FULL 200
  17 #define IIO_EVENT_CODE_RING_75_FULL 201
  18 #define IIO_EVENT_CODE_RING_100_FULL 202
  19
  20 const char *iio_dir = "/sys/bus/iio/devices/";
  21
  22 struct iio_event_data {
  23         int id;
  24         __s64 timestamp;
  25 };
  26
  27 /**
  28  * find_type_by_name() - function to match top level types by name
  29  * @name: top level type instance name
  30  * @type: the type of top level instance being sort
  31  *
  32  * Typical types this is used for are device and trigger.
  33  **/
  34 inline int find_type_by_name(const char *name, const char *type)
  35 {
  36         const struct dirent *ent;
  37         int number, numstrlen;
  38
  39         FILE *nameFile;
  40         DIR *dp;
  41         char thisname[IIO_MAX_NAME_LENGTH];
  42         char *filename;
  43         struct stat Stat;
  44
  45         dp = opendir(iio_dir);
  46         if (dp == NULL) {
  47                 printf("No industrialio devices available");
  48                 return -ENODEV;
  49         }
  50
  51         while (ent = readdir(dp), ent != NULL) {
  52                 if (strcmp(ent->d_name, ".") != 0 &&
  53                         strcmp(ent->d_name, "..") != 0 &&
  54                         strlen(ent->d_name) > strlen(type) &&
  55                         strncmp(ent->d_name, type, strlen(type)) == 0) {
  56                         numstrlen = sscanf(ent->d_name + strlen(type),
  57                                            "%d",
  58                                            &number);
  59                         /* verify the next character is not a colon */
  60                         if (strncmp(ent->d_name + strlen(type) + numstrlen,
  61                                         ":",
  62                                         1) != 0) {
  63                                 filename = malloc(strlen(iio_dir)
  64                                                 + strlen(type)
  65                                                 + numstrlen
  66                                                 + 6);
  67                                 if (filename == NULL)
  68                                         return -ENOMEM;
  69                                 sprintf(filename, "%s%s%d/name",
  70                                         iio_dir,
  71                                         type,
  72                                         number);
  73                                 nameFile = fopen(filename, "r");
  74                                 if (!nameFile)
  75                                         continue;
  76                                 free(filename);
  77                                 fscanf(nameFile, "%s", thisname);
  78                                 if (strcmp(name, thisname) == 0)
  79                                         return number;
  80                                 fclose(nameFile);
  81                         }
  82                 }
  83         }
  84         return -ENODEV;
  85 }
  86
  87 inline int _write_sysfs_int(char *filename, char *basedir, int val, int verify)
  88 {
  89         int ret;
  90         FILE *sysfsfp;
  91         int test;
  92         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
  93         if (temp == NULL)
  94                 return -ENOMEM;
  95         sprintf(temp, "%s/%s", basedir, filename);
  96         sysfsfp = fopen(temp, "w");
  97         if (sysfsfp == NULL) {
  98                 printf("failed to open %s\n", temp);
  99                 ret = -errno;
 100                 goto error_free;
 101         }
 102         fprintf(sysfsfp, "%d", val);
 103         fclose(sysfsfp);
 104         if (verify) {
 105                 sysfsfp = fopen(temp, "r");
 106                 if (sysfsfp == NULL) {
 107                         printf("failed to open %s\n", temp);
 108                         ret = -errno;
 109                         goto error_free;
 110                 }
 111                 fscanf(sysfsfp, "%d", &test);
 112                 if (test != val) {
 113                         printf("Possible failure in int write %d to %s%s\n",
 114                                 val,
 115                                 basedir,
 116                                 filename);
 117                         ret = -1;
 118                 }
 119         }
 120 error_free:
 121         free(temp);
 122         return ret;
 123 }
 124
 125 int write_sysfs_int(char *filename, char *basedir, int val)
 126 {
 127         return _write_sysfs_int(filename, basedir, val, 0);
 128 }
 129
 130 int write_sysfs_int_and_verify(char *filename, char *basedir, int val)
 131 {
 132         return _write_sysfs_int(filename, basedir, val, 1);
 133 }
 134
 135 int _write_sysfs_string(char *filename, char *basedir, char *val, int verify)
 136 {
 137         int ret;
 138         FILE  *sysfsfp;
 139         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 140         if (temp == NULL) {
 141                 printf("Memory allocation failed\n");
 142                 return -ENOMEM;
 143         }
 144         sprintf(temp, "%s/%s", basedir, filename);
 145         sysfsfp = fopen(temp, "w");
 146         if (sysfsfp == NULL) {
 147                 printf("Could not open %s\n", temp);
 148                 ret = -errno;
 149                 goto error_free;
 150         }
 151         fprintf(sysfsfp, "%s", val);
 152         fclose(sysfsfp);
 153         if (verify) {
 154                 sysfsfp = fopen(temp, "r");
 155                 if (sysfsfp == NULL) {
 156                         ret = -errno;
 157                         goto error_free;
 158                 }
 159                 fscanf(sysfsfp, "%s", temp);
 160                 if (strcmp(temp, val) != 0) {
 161                         printf("Possible failure in string write of %s "
 162                                 "Should be %s "
 163                                 "writen to %s\%s\n",
 164                                 temp,
 165                                 val,
 166                                 basedir,
 167                                 filename);
 168                         ret = -1;
 169                 }
 170         }
 171 error_free:
 172         free(temp);
 173
 174         return ret;
 175 }
 176 /**
 177  * write_sysfs_string_and_verify() - string write, readback and verify
 178  * @filename: name of file to write to
 179  * @basedir: the sysfs directory in which the file is to be found
 180  * @val: the string to write
 181  **/
 182 int write_sysfs_string_and_verify(char *filename, char *basedir, char *val)
 183 {
 184         return _write_sysfs_string(filename, basedir, val, 1);
 185 }
 186
 187 int write_sysfs_string(char *filename, char *basedir, char *val)
 188 {
 189         return _write_sysfs_string(filename, basedir, val, 0);
 190 }
 191
 192 int read_sysfs_posint(char *filename, char *basedir)
 193 {
 194         int ret;
 195         FILE  *sysfsfp;
 196         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 197         if (temp == NULL) {
 198                 printf("Memory allocation failed");
 199                 return -ENOMEM;
 200         }
 201         sprintf(temp, "%s/%s", basedir, filename);
 202         sysfsfp = fopen(temp, "r");
 203         if (sysfsfp == NULL) {
 204                 ret = -errno;
 205                 goto error_free;
 206         }
 207         fscanf(sysfsfp, "%d\n", &ret);
 208         fclose(sysfsfp);
 209 error_free:
 210         free(temp);
 211         return ret;
 212 }
 213
 214 int read_sysfs_float(char *filename, char *basedir, float *val)
 215 {
 216         float ret = 0;
 217         FILE  *sysfsfp;
 218         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 219         if (temp == NULL) {
 220                 printf("Memory allocation failed");
 221                 return -ENOMEM;
 222         }
 223         sprintf(temp, "%s/%s", basedir, filename);
 224         sysfsfp = fopen(temp, "r");
 225         if (sysfsfp == NULL) {
 226                 ret = -errno;
 227                 goto error_free;
 228         }
 229         fscanf(sysfsfp, "%f\n", val);
 230         fclose(sysfsfp);
 231 error_free:
 232         free(temp);
 233         return ret;
 234 }