diff options
Diffstat (limited to 'samples/mic/mpssd/sysfs.c')
-rw-r--r-- | samples/mic/mpssd/sysfs.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/samples/mic/mpssd/sysfs.c b/samples/mic/mpssd/sysfs.c new file mode 100644 index 000000000..8dd326936 --- /dev/null +++ b/samples/mic/mpssd/sysfs.c @@ -0,0 +1,102 @@ +/* + * Intel MIC Platform Software Stack (MPSS) + * + * Copyright(c) 2013 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * The full GNU General Public License is included in this distribution in + * the file called "COPYING". + * + * Intel MIC User Space Tools. + */ + +#include "mpssd.h" + +#define PAGE_SIZE 4096 + +char * +readsysfs(char *dir, char *entry) +{ + char filename[PATH_MAX]; + char value[PAGE_SIZE]; + char *string = NULL; + int fd; + int len; + + if (dir == NULL) + snprintf(filename, PATH_MAX, "%s/%s", MICSYSFSDIR, entry); + else + snprintf(filename, PATH_MAX, + "%s/%s/%s", MICSYSFSDIR, dir, entry); + + fd = open(filename, O_RDONLY); + if (fd < 0) { + mpsslog("Failed to open sysfs entry '%s': %s\n", + filename, strerror(errno)); + return NULL; + } + + len = read(fd, value, sizeof(value)); + if (len < 0) { + mpsslog("Failed to read sysfs entry '%s': %s\n", + filename, strerror(errno)); + goto readsys_ret; + } + if (len == 0) + goto readsys_ret; + + value[len - 1] = '\0'; + + string = malloc(strlen(value) + 1); + if (string) + strcpy(string, value); + +readsys_ret: + close(fd); + return string; +} + +int +setsysfs(char *dir, char *entry, char *value) +{ + char filename[PATH_MAX]; + char *oldvalue; + int fd, ret = 0; + + if (dir == NULL) + snprintf(filename, PATH_MAX, "%s/%s", MICSYSFSDIR, entry); + else + snprintf(filename, PATH_MAX, "%s/%s/%s", + MICSYSFSDIR, dir, entry); + + oldvalue = readsysfs(dir, entry); + + fd = open(filename, O_RDWR); + if (fd < 0) { + ret = errno; + mpsslog("Failed to open sysfs entry '%s': %s\n", + filename, strerror(errno)); + goto done; + } + + if (!oldvalue || strcmp(value, oldvalue)) { + if (write(fd, value, strlen(value)) < 0) { + ret = errno; + mpsslog("Failed to write new sysfs entry '%s': %s\n", + filename, strerror(errno)); + } + } + close(fd); +done: + if (oldvalue) + free(oldvalue); + return ret; +} |