git.ozlabs.org Git - petitboot/blob - discover/dt.c

   1 #include <asm/byteorder.h>
   2 #include <dirent.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <sys/types.h>
   6
   7 #include <talloc/talloc.h>
   8 #include <file/file.h>
   9
  10 #include "dt.h"
  11
  12 static int filter_sensors(const struct dirent *ent)
  13 {
  14         /* Check for prefix "sensor@" */
  15         return strncmp(ent->d_name, "sensor@", strlen("sensor@")) == 0;
  16 }
  17
  18 int get_ipmi_sensor(void *t, enum ipmi_sensor_ids sensor_id)
  19 {
  20         int rc, len, n;
  21         struct dirent **namelist;
  22         char *buf, *filename;
  23         const char sensor_dir[] = "/proc/device-tree/bmc/sensors/";
  24
  25         n = scandir(sensor_dir, &namelist, filter_sensors, alphasort);
  26         if (n <= 0)
  27                 return -1;
  28
  29         while (n--) {
  30                 filename = talloc_asprintf(t, "%s%s/ipmi-sensor-type",
  31                                            sensor_dir, namelist[n]->d_name);
  32                 rc = read_file(t, filename, &buf, &len);
  33                 if (rc == 0 && len == 4 &&
  34                     __be32_to_cpu(*(uint32_t *)buf) == sensor_id)
  35                                 break;
  36                 free(namelist[n]);
  37         }
  38         if (n < 0) {
  39                 rc = -1;
  40                 goto out;
  41         }
  42
  43         filename = talloc_asprintf(t, "%s%s/reg", sensor_dir,
  44                                    namelist[n]->d_name);
  45         /* Free the rest of the scandir strings, if there are any */
  46         do {
  47                 free(namelist[n]);
  48         } while (n-- > 0);
  49
  50         rc = read_file(t, filename, &buf, &len);
  51         if (rc != 0 || len != 4) {
  52                 rc = -1;
  53                 goto out;
  54         }
  55
  56         rc = __be32_to_cpu(*(uint32_t *)buf);
  57
  58 out:
  59         talloc_free(buf);
  60         free(namelist);
  61         return rc;
  62 }