@@ -137,6 +137,24 @@ static int sort_i2c_busses(const void *a, const void *b)
return adap1->nr - adap2->nr;
}
+static int dir_has_entries(const char* path)
+{
+ struct dirent *de;
+ DIR *dir;
+ if((dir = opendir(path))) {
+ while ((de = readdir(dir)) != NULL) {
+ if (!strcmp(de->d_name, "."))
+ continue;
+ if (!strcmp(de->d_name, ".."))
+ continue;
+ closedir(dir);
+ return 1;
+ }
+ closedir(dir);
+ }
+ return 0;
+}
+
struct i2c_adap *gather_i2c_busses(void)
{
char s[120];
@@ -144,6 +162,7 @@ struct i2c_adap *gather_i2c_busses(void)
DIR *dir, *ddir;
FILE *f;
char fstype[NAME_MAX], sysfs[NAME_MAX], n[NAME_MAX];
+ size_t sysfs_end = 0;
int foundsysfs = 0;
int len, count = 0;
struct i2c_adap *adapters;
@@ -199,6 +218,13 @@ struct i2c_adap *gather_i2c_busses(void)
/* look in sysfs */
/* First figure out where sysfs was mounted */
if ((f = fopen("/proc/mounts", "r")) == NULL) {
+ fprintf(stderr, "Error: Could not open /proc/mounts: "
+ "%s\n", strerror(errno));
+ if (errno == ENOENT) {
+ fprintf(stderr, "Please mount procfs: "
+ "%smount -t procfs proc /proc\n",
+ getenv("SUDO_COMMAND") ? "sudo " : "");
+ }
goto done;
}
while (fgets(n, NAME_MAX, f)) {
@@ -210,15 +236,43 @@ struct i2c_adap *gather_i2c_busses(void)
}
fclose(f);
if (! foundsysfs) {
+ fprintf(stderr, "Error: Could not find sysfs mount\n");
+ fprintf(stderr, "Please mount sysfs: "
+ "%smount -t sysfs sysfs /sys\n",
+ getenv("SUDO_COMMAND") ? "sudo " : "");
goto done;
}
/* Bus numbers in i2c-adapter don't necessarily match those in
i2c-dev and what we really care about are the i2c-dev numbers.
Unfortunately the names are harder to get in i2c-dev */
+ sysfs_end = strlen(sysfs);
strcat(sysfs, "/class/i2c-dev");
- if(!(dir = opendir(sysfs)))
+ if(!(dir = opendir(sysfs))) {
+ if (errno == ENOENT) {
+ /* Check if there are i2c bus devices in other dirs
+ as when there are none the error isn't useful
+ as loading i2c-dev also won't find devices */
+ int devices_present = 0;
+ strcpy(sysfs + sysfs_end, "/bus/i2c/devices");
+ devices_present = dir_has_entries(sysfs);
+ if (!devices_present) {
+ strcpy(sysfs + sysfs_end, "/class/i2c-adapter");
+ devices_present = dir_has_entries(sysfs);
+ }
+ if (devices_present) {
+ fprintf(stderr, "Error: Could not find dir "
+ "`%s`\n", sysfs);
+ fprintf(stderr, "Please load i2c-dev: "
+ "%smodprobe i2c-dev\n",
+ getenv("SUDO_COMMAND") ? "sudo " : "");
+ }
+ } else {
+ fprintf(stderr, "Error: Could not open dir "
+ "`%s': %s\n", sysfs, strerror(errno));
+ }
goto done;
+ }
/* go through the busses */
while ((de = readdir(dir)) != NULL) {
if (!strcmp(de->d_name, "."))