ASR_BASE

Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/package/system/gator-daemon/src/libsensors/sysfs.c b/package/system/gator-daemon/src/libsensors/sysfs.c
new file mode 100755
index 0000000..2b494c9
--- /dev/null
+++ b/package/system/gator-daemon/src/libsensors/sysfs.c
@@ -0,0 +1,926 @@
+/*
+    sysfs.c - Part of libsensors, a library for reading Linux sensor data
+    Copyright (c) 2005 Mark M. Hoffman <mhoffman@lightlink.com>
+    Copyright (C) 2007-2010 Jean Delvare <khali@linux-fr.org>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library 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 Lesser General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+    MA 02110-1301 USA.
+*/
+
+/*** This file modified by ARM on Jan 23, 2013 to improve performance by substituting calls to fread() with calls to read() and to read non-scaled values. ***/
+
+/* this define needed for strndup() */
+#define _GNU_SOURCE
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/vfs.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <errno.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include "data.h"
+#include "error.h"
+#include "access.h"
+#include "general.h"
+#include "sysfs.h"
+
+
+/****************************************************************************/
+
+#define ATTR_MAX	128
+#define SYSFS_MAGIC	0x62656572
+
+int sensors_sysfs_no_scaling;
+
+/*
+ * Read an attribute from sysfs
+ * Returns a pointer to a freshly allocated string; free it yourself.
+ * If the file doesn't exist or can't be read, NULL is returned.
+ */
+static char *sysfs_read_attr(const char *device, const char *attr)
+{
+	char path[NAME_MAX];
+	char buf[ATTR_MAX], *p;
+	FILE *f;
+
+	snprintf(path, NAME_MAX, "%s/%s", device, attr);
+
+	if (!(f = fopen(path, "r")))
+		return NULL;
+	p = fgets(buf, ATTR_MAX, f);
+	fclose(f);
+	if (!p)
+		return NULL;
+
+	/* Last byte is a '\n'; chop that off */
+	p = strndup(buf, strlen(buf) - 1);
+	if (!p)
+		sensors_fatal_error(__func__, "Out of memory");
+	return p;
+}
+
+/*
+ * Call an arbitrary function for each class device of the given class
+ * Returns 0 on success (all calls returned 0), a positive errno for
+ * local errors, or a negative error value if any call fails.
+ */
+static int sysfs_foreach_classdev(const char *class_name,
+				   int (*func)(const char *, const char *))
+{
+	char path[NAME_MAX];
+	int path_off, ret;
+	DIR *dir;
+	struct dirent *ent;
+
+	path_off = snprintf(path, NAME_MAX, "%s/class/%s",
+			    sensors_sysfs_mount, class_name);
+	if (!(dir = opendir(path)))
+		return errno;
+
+	ret = 0;
+	while (!ret && (ent = readdir(dir))) {
+		if (ent->d_name[0] == '.')	/* skip hidden entries */
+			continue;
+
+		snprintf(path + path_off, NAME_MAX - path_off, "/%s",
+			 ent->d_name);
+		ret = func(path, ent->d_name);
+	}
+
+	closedir(dir);
+	return ret;
+}
+
+/*
+ * Call an arbitrary function for each device of the given bus type
+ * Returns 0 on success (all calls returned 0), a positive errno for
+ * local errors, or a negative error value if any call fails.
+ */
+static int sysfs_foreach_busdev(const char *bus_type,
+				 int (*func)(const char *, const char *))
+{
+	char path[NAME_MAX];
+	int path_off, ret;
+	DIR *dir;
+	struct dirent *ent;
+
+	path_off = snprintf(path, NAME_MAX, "%s/bus/%s/devices",
+			    sensors_sysfs_mount, bus_type);
+	if (!(dir = opendir(path)))
+		return errno;
+
+	ret = 0;
+	while (!ret && (ent = readdir(dir))) {
+		if (ent->d_name[0] == '.')	/* skip hidden entries */
+			continue;
+
+		snprintf(path + path_off, NAME_MAX - path_off, "/%s",
+			 ent->d_name);
+		ret = func(path, ent->d_name);
+	}
+
+	closedir(dir);
+	return ret;
+}
+
+/****************************************************************************/
+
+char sensors_sysfs_mount[NAME_MAX];
+
+#define MAX_MAIN_SENSOR_TYPES	(SENSORS_FEATURE_MAX_MAIN - SENSORS_FEATURE_IN)
+#define MAX_OTHER_SENSOR_TYPES	(SENSORS_FEATURE_MAX_OTHER - SENSORS_FEATURE_VID)
+#define MAX_SENSORS_PER_TYPE	24
+/* max_subfeatures is now computed dynamically */
+#define FEATURE_SIZE		(max_subfeatures * 2)
+#define FEATURE_TYPE_SIZE	(MAX_SENSORS_PER_TYPE * FEATURE_SIZE)
+
+/*
+ * Room for all 7 main types (in, fan, temp, power, energy, current, humidity)
+ * and 2 other types (VID, intrusion) with all their subfeatures + misc features
+ */
+#define SUB_OFFSET_OTHER	(MAX_MAIN_SENSOR_TYPES * FEATURE_TYPE_SIZE)
+#define SUB_OFFSET_MISC		(SUB_OFFSET_OTHER + \
+				 MAX_OTHER_SENSOR_TYPES * FEATURE_TYPE_SIZE)
+#define ALL_POSSIBLE_SUBFEATURES	(SUB_OFFSET_MISC + 1)
+
+static
+int get_type_scaling(sensors_subfeature_type type)
+{
+	/* Multipliers for subfeatures */
+	switch (type & 0xFF80) {
+	case SENSORS_SUBFEATURE_IN_INPUT:
+	case SENSORS_SUBFEATURE_TEMP_INPUT:
+	case SENSORS_SUBFEATURE_CURR_INPUT:
+	case SENSORS_SUBFEATURE_HUMIDITY_INPUT:
+		return 1000;
+	case SENSORS_SUBFEATURE_FAN_INPUT:
+		return 1;
+	case SENSORS_SUBFEATURE_POWER_AVERAGE:
+	case SENSORS_SUBFEATURE_ENERGY_INPUT:
+		return 1000000;
+	}
+
+	/* Multipliers for second class subfeatures
+	   that need their own multiplier */
+	switch (type) {
+	case SENSORS_SUBFEATURE_POWER_AVERAGE_INTERVAL:
+	case SENSORS_SUBFEATURE_VID:
+	case SENSORS_SUBFEATURE_TEMP_OFFSET:
+		return 1000;
+	default:
+		return 1;
+	}
+}
+
+static
+char *get_feature_name(sensors_feature_type ftype, char *sfname)
+{
+	char *name, *underscore;
+
+	switch (ftype) {
+	case SENSORS_FEATURE_IN:
+	case SENSORS_FEATURE_FAN:
+	case SENSORS_FEATURE_TEMP:
+	case SENSORS_FEATURE_POWER:
+	case SENSORS_FEATURE_ENERGY:
+	case SENSORS_FEATURE_CURR:
+	case SENSORS_FEATURE_HUMIDITY:
+	case SENSORS_FEATURE_INTRUSION:
+		underscore = strchr(sfname, '_');
+		name = strndup(sfname, underscore - sfname);
+		if (!name)
+			sensors_fatal_error(__func__, "Out of memory");
+
+		break;
+	default:
+		name = strdup(sfname);
+		if (!name)
+			sensors_fatal_error(__func__, "Out of memory");
+	}
+
+	return name;
+}
+
+/* Static mappings for use by sensors_subfeature_get_type() */
+struct subfeature_type_match
+{
+	const char *name;
+	sensors_subfeature_type type;
+};
+
+struct feature_type_match
+{
+	const char *name;
+	const struct subfeature_type_match *submatches;
+};
+
+static const struct subfeature_type_match temp_matches[] = {
+	{ "input", SENSORS_SUBFEATURE_TEMP_INPUT },
+	{ "max", SENSORS_SUBFEATURE_TEMP_MAX },
+	{ "max_hyst", SENSORS_SUBFEATURE_TEMP_MAX_HYST },
+	{ "min", SENSORS_SUBFEATURE_TEMP_MIN },
+	{ "crit", SENSORS_SUBFEATURE_TEMP_CRIT },
+	{ "crit_hyst", SENSORS_SUBFEATURE_TEMP_CRIT_HYST },
+	{ "lcrit", SENSORS_SUBFEATURE_TEMP_LCRIT },
+	{ "emergency", SENSORS_SUBFEATURE_TEMP_EMERGENCY },
+	{ "emergency_hyst", SENSORS_SUBFEATURE_TEMP_EMERGENCY_HYST },
+	{ "lowest", SENSORS_SUBFEATURE_TEMP_LOWEST },
+	{ "highest", SENSORS_SUBFEATURE_TEMP_HIGHEST },
+	{ "alarm", SENSORS_SUBFEATURE_TEMP_ALARM },
+	{ "min_alarm", SENSORS_SUBFEATURE_TEMP_MIN_ALARM },
+	{ "max_alarm", SENSORS_SUBFEATURE_TEMP_MAX_ALARM },
+	{ "crit_alarm", SENSORS_SUBFEATURE_TEMP_CRIT_ALARM },
+	{ "emergency_alarm", SENSORS_SUBFEATURE_TEMP_EMERGENCY_ALARM },
+	{ "lcrit_alarm", SENSORS_SUBFEATURE_TEMP_LCRIT_ALARM },
+	{ "fault", SENSORS_SUBFEATURE_TEMP_FAULT },
+	{ "type", SENSORS_SUBFEATURE_TEMP_TYPE },
+	{ "offset", SENSORS_SUBFEATURE_TEMP_OFFSET },
+	{ "beep", SENSORS_SUBFEATURE_TEMP_BEEP },
+	{ NULL, 0 }
+};
+
+static const struct subfeature_type_match in_matches[] = {
+	{ "input", SENSORS_SUBFEATURE_IN_INPUT },
+	{ "min", SENSORS_SUBFEATURE_IN_MIN },
+	{ "max", SENSORS_SUBFEATURE_IN_MAX },
+	{ "lcrit", SENSORS_SUBFEATURE_IN_LCRIT },
+	{ "crit", SENSORS_SUBFEATURE_IN_CRIT },
+	{ "average", SENSORS_SUBFEATURE_IN_AVERAGE },
+	{ "lowest", SENSORS_SUBFEATURE_IN_LOWEST },
+	{ "highest", SENSORS_SUBFEATURE_IN_HIGHEST },
+	{ "alarm", SENSORS_SUBFEATURE_IN_ALARM },
+	{ "min_alarm", SENSORS_SUBFEATURE_IN_MIN_ALARM },
+	{ "max_alarm", SENSORS_SUBFEATURE_IN_MAX_ALARM },
+	{ "lcrit_alarm", SENSORS_SUBFEATURE_IN_LCRIT_ALARM },
+	{ "crit_alarm", SENSORS_SUBFEATURE_IN_CRIT_ALARM },
+	{ "beep", SENSORS_SUBFEATURE_IN_BEEP },
+	{ NULL, 0 }
+};
+
+static const struct subfeature_type_match fan_matches[] = {
+	{ "input", SENSORS_SUBFEATURE_FAN_INPUT },
+	{ "min", SENSORS_SUBFEATURE_FAN_MIN },
+	{ "max", SENSORS_SUBFEATURE_FAN_MAX },
+	{ "div", SENSORS_SUBFEATURE_FAN_DIV },
+	{ "pulses", SENSORS_SUBFEATURE_FAN_PULSES },
+	{ "alarm", SENSORS_SUBFEATURE_FAN_ALARM },
+	{ "min_alarm", SENSORS_SUBFEATURE_FAN_MIN_ALARM },
+	{ "max_alarm", SENSORS_SUBFEATURE_FAN_MAX_ALARM },
+	{ "fault", SENSORS_SUBFEATURE_FAN_FAULT },
+	{ "beep", SENSORS_SUBFEATURE_FAN_BEEP },
+	{ NULL, 0 }
+};
+
+static const struct subfeature_type_match power_matches[] = {
+	{ "average", SENSORS_SUBFEATURE_POWER_AVERAGE },
+	{ "average_highest", SENSORS_SUBFEATURE_POWER_AVERAGE_HIGHEST },
+	{ "average_lowest", SENSORS_SUBFEATURE_POWER_AVERAGE_LOWEST },
+	{ "input", SENSORS_SUBFEATURE_POWER_INPUT },
+	{ "input_highest", SENSORS_SUBFEATURE_POWER_INPUT_HIGHEST },
+	{ "input_lowest", SENSORS_SUBFEATURE_POWER_INPUT_LOWEST },
+	{ "cap", SENSORS_SUBFEATURE_POWER_CAP },
+	{ "cap_hyst", SENSORS_SUBFEATURE_POWER_CAP_HYST },
+	{ "cap_alarm", SENSORS_SUBFEATURE_POWER_CAP_ALARM },
+	{ "alarm", SENSORS_SUBFEATURE_POWER_ALARM },
+	{ "max", SENSORS_SUBFEATURE_POWER_MAX },
+	{ "max_alarm", SENSORS_SUBFEATURE_POWER_MAX_ALARM },
+	{ "crit", SENSORS_SUBFEATURE_POWER_CRIT },
+	{ "crit_alarm", SENSORS_SUBFEATURE_POWER_CRIT_ALARM },
+	{ "average_interval", SENSORS_SUBFEATURE_POWER_AVERAGE_INTERVAL },
+	{ NULL, 0 }
+};
+
+static const struct subfeature_type_match energy_matches[] = {
+	{ "input", SENSORS_SUBFEATURE_ENERGY_INPUT },
+	{ NULL, 0 }
+};
+
+static const struct subfeature_type_match curr_matches[] = {
+	{ "input", SENSORS_SUBFEATURE_CURR_INPUT },
+	{ "min", SENSORS_SUBFEATURE_CURR_MIN },
+	{ "max", SENSORS_SUBFEATURE_CURR_MAX },
+	{ "lcrit", SENSORS_SUBFEATURE_CURR_LCRIT },
+	{ "crit", SENSORS_SUBFEATURE_CURR_CRIT },
+	{ "average", SENSORS_SUBFEATURE_CURR_AVERAGE },
+	{ "lowest", SENSORS_SUBFEATURE_CURR_LOWEST },
+	{ "highest", SENSORS_SUBFEATURE_CURR_HIGHEST },
+	{ "alarm", SENSORS_SUBFEATURE_CURR_ALARM },
+	{ "min_alarm", SENSORS_SUBFEATURE_CURR_MIN_ALARM },
+	{ "max_alarm", SENSORS_SUBFEATURE_CURR_MAX_ALARM },
+	{ "lcrit_alarm", SENSORS_SUBFEATURE_CURR_LCRIT_ALARM },
+	{ "crit_alarm", SENSORS_SUBFEATURE_CURR_CRIT_ALARM },
+	{ "beep", SENSORS_SUBFEATURE_CURR_BEEP },
+	{ NULL, 0 }
+};
+
+static const struct subfeature_type_match humidity_matches[] = {
+	{ "input", SENSORS_SUBFEATURE_HUMIDITY_INPUT },
+	{ NULL, 0 }
+};
+
+static const struct subfeature_type_match cpu_matches[] = {
+	{ "vid", SENSORS_SUBFEATURE_VID },
+	{ NULL, 0 }
+};
+
+static const struct subfeature_type_match intrusion_matches[] = {
+	{ "alarm", SENSORS_SUBFEATURE_INTRUSION_ALARM },
+	{ "beep", SENSORS_SUBFEATURE_INTRUSION_BEEP },
+	{ NULL, 0 }
+};
+static struct feature_type_match matches[] = {
+	{ "temp%d%c", temp_matches },
+	{ "in%d%c", in_matches },
+	{ "fan%d%c", fan_matches },
+	{ "cpu%d%c", cpu_matches },
+	{ "power%d%c", power_matches },
+	{ "curr%d%c", curr_matches },
+	{ "energy%d%c", energy_matches },
+	{ "intrusion%d%c", intrusion_matches },
+	{ "humidity%d%c", humidity_matches },
+};
+
+/* Return the subfeature type and channel number based on the subfeature
+   name */
+static
+sensors_subfeature_type sensors_subfeature_get_type(const char *name, int *nr)
+{
+	char c;
+	int i, count;
+	const struct subfeature_type_match *submatches;
+
+	/* Special case */
+	if (!strcmp(name, "beep_enable")) {
+		*nr = 0;
+		return SENSORS_SUBFEATURE_BEEP_ENABLE;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(matches); i++)
+		if ((count = sscanf(name, matches[i].name, nr, &c)))
+			break;
+
+	if (i == ARRAY_SIZE(matches) || count != 2 || c != '_')
+		return SENSORS_SUBFEATURE_UNKNOWN;  /* no match */
+
+	submatches = matches[i].submatches;
+	name = strchr(name + 3, '_') + 1;
+	for (i = 0; submatches[i].name != NULL; i++)
+		if (!strcmp(name, submatches[i].name))
+			return submatches[i].type;
+
+	return SENSORS_SUBFEATURE_UNKNOWN;
+}
+
+static int sensors_compute_max(void)
+{
+	int i, j, max, offset;
+	const struct subfeature_type_match *submatches;
+	sensors_feature_type ftype;
+
+	max = 0;
+	for (i = 0; i < ARRAY_SIZE(matches); i++) {
+		submatches = matches[i].submatches;
+		for (j = 0; submatches[j].name != NULL; j++) {
+			ftype = submatches[j].type >> 8;
+
+			if (ftype < SENSORS_FEATURE_VID) {
+				offset = submatches[j].type & 0x7F;
+				if (offset >= max)
+					max = offset + 1;
+			} else {
+				offset = submatches[j].type & 0xFF;
+				if (offset >= max * 2)
+					max = ((offset + 1) + 1) / 2;
+			}
+		}
+	}
+
+	return max;
+}
+
+static int sensors_get_attr_mode(const char *device, const char *attr)
+{
+	char path[NAME_MAX];
+	struct stat st;
+	int mode = 0;
+
+	snprintf(path, NAME_MAX, "%s/%s", device, attr);
+	if (!stat(path, &st)) {
+		if (st.st_mode & S_IRUSR)
+			mode |= SENSORS_MODE_R;
+		if (st.st_mode & S_IWUSR)
+			mode |= SENSORS_MODE_W;
+	}
+	return mode;
+}
+
+static int sensors_read_dynamic_chip(sensors_chip_features *chip,
+				     const char *dev_path)
+{
+	int i, fnum = 0, sfnum = 0, prev_slot;
+	static int max_subfeatures;
+	DIR *dir;
+	struct dirent *ent;
+	sensors_subfeature *all_subfeatures;
+	sensors_subfeature *dyn_subfeatures;
+	sensors_feature *dyn_features;
+	sensors_feature_type ftype;
+	sensors_subfeature_type sftype;
+
+	if (!(dir = opendir(dev_path)))
+		return -errno;
+
+	/* Dynamically figure out the max number of subfeatures */
+	if (!max_subfeatures)
+		max_subfeatures = sensors_compute_max();
+
+	/* We use a large sparse table at first to store all found
+	   subfeatures, so that we can store them sorted at type and index
+	   and then later create a dense sorted table. */
+	all_subfeatures = calloc(ALL_POSSIBLE_SUBFEATURES,
+				 sizeof(sensors_subfeature));
+	if (!all_subfeatures)
+		sensors_fatal_error(__func__, "Out of memory");
+
+	while ((ent = readdir(dir))) {
+		char *name;
+		int nr;
+
+		/* Skip directories and symlinks */
+		if (ent->d_type != DT_REG)
+			continue;
+
+		name = ent->d_name;
+
+		sftype = sensors_subfeature_get_type(name, &nr);
+		if (sftype == SENSORS_SUBFEATURE_UNKNOWN)
+			continue;
+		ftype = sftype >> 8;
+
+		/* Adjust the channel number */
+		switch (ftype) {
+		case SENSORS_FEATURE_FAN:
+		case SENSORS_FEATURE_TEMP:
+		case SENSORS_FEATURE_POWER:
+		case SENSORS_FEATURE_ENERGY:
+		case SENSORS_FEATURE_CURR:
+		case SENSORS_FEATURE_HUMIDITY:
+			nr--;
+			break;
+		default:
+			break;
+		}
+
+		if (nr < 0 || nr >= MAX_SENSORS_PER_TYPE) {
+			/* More sensors of one type than MAX_SENSORS_PER_TYPE,
+			   we have to ignore it */
+#ifdef DEBUG
+			sensors_fatal_error(__func__,
+					    "Increase MAX_SENSORS_PER_TYPE!");
+#endif
+			continue;
+		}
+
+		/* "calculate" a place to store the subfeature in our sparse,
+		   sorted table */
+		switch (ftype) {
+		case SENSORS_FEATURE_VID:
+		case SENSORS_FEATURE_INTRUSION:
+			i = SUB_OFFSET_OTHER +
+			    (ftype - SENSORS_FEATURE_VID) * FEATURE_TYPE_SIZE +
+			    nr * FEATURE_SIZE + (sftype & 0xFF);
+			break;
+		case SENSORS_FEATURE_BEEP_ENABLE:
+			i = SUB_OFFSET_MISC +
+			    (ftype - SENSORS_FEATURE_BEEP_ENABLE);
+			break;
+		default:
+			i = ftype * FEATURE_TYPE_SIZE +
+			    nr * FEATURE_SIZE +
+			    ((sftype & 0x80) >> 7) * max_subfeatures +
+			    (sftype & 0x7F);
+		}
+
+		if (all_subfeatures[i].name) {
+#ifdef DEBUG
+			sensors_fatal_error(__func__, "Duplicate subfeature");
+#endif
+			continue;
+		}
+
+		/* fill in the subfeature members */
+		all_subfeatures[i].type = sftype;
+		all_subfeatures[i].name = strdup(name);
+		if (!all_subfeatures[i].name)
+			sensors_fatal_error(__func__, "Out of memory");
+
+		/* Other and misc subfeatures are never scaled */
+		if (sftype < SENSORS_SUBFEATURE_VID && !(sftype & 0x80))
+			all_subfeatures[i].flags |= SENSORS_COMPUTE_MAPPING;
+		all_subfeatures[i].flags |= sensors_get_attr_mode(dev_path, name);
+
+		sfnum++;
+	}
+	closedir(dir);
+
+	if (!sfnum) { /* No subfeature */
+		chip->subfeature = NULL;
+		goto exit_free;
+	}
+
+	/* How many main features? */
+	prev_slot = -1;
+	for (i = 0; i < ALL_POSSIBLE_SUBFEATURES; i++) {
+		if (!all_subfeatures[i].name)
+			continue;
+
+		if (i >= SUB_OFFSET_MISC || i / FEATURE_SIZE != prev_slot) {
+			fnum++;
+			prev_slot = i / FEATURE_SIZE;
+		}
+	}
+
+	dyn_subfeatures = calloc(sfnum, sizeof(sensors_subfeature));
+	dyn_features = calloc(fnum, sizeof(sensors_feature));
+	if (!dyn_subfeatures || !dyn_features)
+		sensors_fatal_error(__func__, "Out of memory");
+
+	/* Copy from the sparse array to the compact array */
+	sfnum = 0;
+	fnum = -1;
+	prev_slot = -1;
+	for (i = 0; i < ALL_POSSIBLE_SUBFEATURES; i++) {
+		if (!all_subfeatures[i].name)
+			continue;
+
+		/* New main feature? */
+		if (i >= SUB_OFFSET_MISC || i / FEATURE_SIZE != prev_slot) {
+			ftype = all_subfeatures[i].type >> 8;
+			fnum++;
+			prev_slot = i / FEATURE_SIZE;
+
+			dyn_features[fnum].name = get_feature_name(ftype,
+						all_subfeatures[i].name);
+			dyn_features[fnum].number = fnum;
+			dyn_features[fnum].first_subfeature = sfnum;
+			dyn_features[fnum].type = ftype;
+		}
+
+		dyn_subfeatures[sfnum] = all_subfeatures[i];
+		dyn_subfeatures[sfnum].number = sfnum;
+		/* Back to the feature */
+		dyn_subfeatures[sfnum].mapping = fnum;
+
+		sfnum++;
+	}
+
+	chip->subfeature = dyn_subfeatures;
+	chip->subfeature_count = sfnum;
+	chip->feature = dyn_features;
+	chip->feature_count = ++fnum;
+
+exit_free:
+	free(all_subfeatures);
+	return 0;
+}
+
+/* returns !0 if sysfs filesystem was found, 0 otherwise */
+int sensors_init_sysfs(void)
+{
+	struct statfs statfsbuf;
+
+	snprintf(sensors_sysfs_mount, NAME_MAX, "%s", "/sys");
+	if (statfs(sensors_sysfs_mount, &statfsbuf) < 0
+	 || statfsbuf.f_type != SYSFS_MAGIC)
+		return 0;
+
+	return 1;
+}
+
+/* returns: number of devices added (0 or 1) if successful, <0 otherwise */
+static int sensors_read_one_sysfs_chip(const char *dev_path,
+				       const char *dev_name,
+				       const char *hwmon_path)
+{
+	int domain, bus, slot, fn, vendor, product, id;
+	int err = -SENSORS_ERR_KERNEL;
+	char *bus_attr;
+	char bus_path[NAME_MAX];
+	char linkpath[NAME_MAX];
+	char subsys_path[NAME_MAX], *subsys;
+	int sub_len;
+	sensors_chip_features entry;
+
+	/* ignore any device without name attribute */
+	if (!(entry.chip.prefix = sysfs_read_attr(hwmon_path, "name")))
+		return 0;
+
+	entry.chip.path = strdup(hwmon_path);
+	if (!entry.chip.path)
+		sensors_fatal_error(__func__, "Out of memory");
+
+	if (dev_path == NULL) {
+		/* Virtual device */
+		entry.chip.bus.type = SENSORS_BUS_TYPE_VIRTUAL;
+		entry.chip.bus.nr = 0;
+		/* For now we assume that virtual devices are unique */
+		entry.chip.addr = 0;
+		goto done;
+	}
+
+	/* Find bus type */
+	snprintf(linkpath, NAME_MAX, "%s/subsystem", dev_path);
+	sub_len = readlink(linkpath, subsys_path, NAME_MAX - 1);
+	if (sub_len < 0 && errno == ENOENT) {
+		/* Fallback to "bus" link for kernels <= 2.6.17 */
+		snprintf(linkpath, NAME_MAX, "%s/bus", dev_path);
+		sub_len = readlink(linkpath, subsys_path, NAME_MAX - 1);
+	}
+	if (sub_len < 0) {
+		/* Older kernels (<= 2.6.11) have neither the subsystem
+		   symlink nor the bus symlink */
+		if (errno == ENOENT)
+			subsys = NULL;
+		else
+			goto exit_free;
+	} else {
+		subsys_path[sub_len] = '\0';
+		subsys = strrchr(subsys_path, '/') + 1;
+	}
+
+	if ((!subsys || !strcmp(subsys, "i2c")) &&
+	    sscanf(dev_name, "%hd-%x", &entry.chip.bus.nr,
+		   &entry.chip.addr) == 2) {
+		/* find out if legacy ISA or not */
+		if (entry.chip.bus.nr == 9191) {
+			entry.chip.bus.type = SENSORS_BUS_TYPE_ISA;
+			entry.chip.bus.nr = 0;
+		} else {
+			entry.chip.bus.type = SENSORS_BUS_TYPE_I2C;
+			snprintf(bus_path, sizeof(bus_path),
+				"%s/class/i2c-adapter/i2c-%d/device",
+				sensors_sysfs_mount, entry.chip.bus.nr);
+
+			if ((bus_attr = sysfs_read_attr(bus_path, "name"))) {
+				if (!strncmp(bus_attr, "ISA ", 4)) {
+					entry.chip.bus.type = SENSORS_BUS_TYPE_ISA;
+					entry.chip.bus.nr = 0;
+				}
+
+				free(bus_attr);
+			}
+		}
+	} else
+	if ((!subsys || !strcmp(subsys, "spi")) &&
+	    sscanf(dev_name, "spi%hd.%d", &entry.chip.bus.nr,
+		   &entry.chip.addr) == 2) {
+		/* SPI */
+		entry.chip.bus.type = SENSORS_BUS_TYPE_SPI;
+	} else
+	if ((!subsys || !strcmp(subsys, "pci")) &&
+	    sscanf(dev_name, "%x:%x:%x.%x", &domain, &bus, &slot, &fn) == 4) {
+		/* PCI */
+		entry.chip.addr = (domain << 16) + (bus << 8) + (slot << 3) + fn;
+		entry.chip.bus.type = SENSORS_BUS_TYPE_PCI;
+		entry.chip.bus.nr = 0;
+	} else
+	if ((!subsys || !strcmp(subsys, "platform") ||
+			!strcmp(subsys, "of_platform"))) {
+		/* must be new ISA (platform driver) */
+		if (sscanf(dev_name, "%*[a-z0-9_].%d", &entry.chip.addr) != 1)
+			entry.chip.addr = 0;
+		entry.chip.bus.type = SENSORS_BUS_TYPE_ISA;
+		entry.chip.bus.nr = 0;
+	} else if (subsys && !strcmp(subsys, "acpi")) {
+		entry.chip.bus.type = SENSORS_BUS_TYPE_ACPI;
+		/* For now we assume that acpi devices are unique */
+		entry.chip.bus.nr = 0;
+		entry.chip.addr = 0;
+	} else
+	if (subsys && !strcmp(subsys, "hid") &&
+	    sscanf(dev_name, "%x:%x:%x.%x", &bus, &vendor, &product, &id) == 4) {
+		entry.chip.bus.type = SENSORS_BUS_TYPE_HID;
+		/* As of kernel 2.6.32, the hid device names don't look good */
+		entry.chip.bus.nr = bus;
+		entry.chip.addr = id;
+	} else {
+		/* Ignore unknown device */
+		err = 0;
+		goto exit_free;
+	}
+
+done:
+	if (sensors_read_dynamic_chip(&entry, hwmon_path) < 0)
+		goto exit_free;
+	if (!entry.subfeature) { /* No subfeature, discard chip */
+		err = 0;
+		goto exit_free;
+	}
+	sensors_add_proc_chips(&entry);
+
+	return 1;
+
+exit_free:
+	free(entry.chip.prefix);
+	free(entry.chip.path);
+	return err;
+}
+
+static int sensors_add_hwmon_device_compat(const char *path,
+					   const char *dev_name)
+{
+	int err;
+
+	err = sensors_read_one_sysfs_chip(path, dev_name, path);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+/* returns 0 if successful, !0 otherwise */
+static int sensors_read_sysfs_chips_compat(void)
+{
+	int ret;
+
+	ret = sysfs_foreach_busdev("i2c", sensors_add_hwmon_device_compat);
+	if (ret && ret != ENOENT)
+		return -SENSORS_ERR_KERNEL;
+
+	return 0;
+}
+
+static int sensors_add_hwmon_device(const char *path, const char *classdev)
+{
+	char linkpath[NAME_MAX];
+	char device[NAME_MAX], *device_p;
+	int dev_len, err;
+	(void)classdev; /* hide warning */
+
+	snprintf(linkpath, NAME_MAX, "%s/device", path);
+	dev_len = readlink(linkpath, device, NAME_MAX - 1);
+	if (dev_len < 0) {
+		/* No device link? Treat as virtual */
+		err = sensors_read_one_sysfs_chip(NULL, NULL, path);
+	} else {
+		device[dev_len] = '\0';
+		device_p = strrchr(device, '/') + 1;
+
+		/* The attributes we want might be those of the hwmon class
+		   device, or those of the device itself. */
+		err = sensors_read_one_sysfs_chip(linkpath, device_p, path);
+		if (err == 0)
+			err = sensors_read_one_sysfs_chip(linkpath, device_p,
+							  linkpath);
+	}
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+/* returns 0 if successful, !0 otherwise */
+int sensors_read_sysfs_chips(void)
+{
+	int ret;
+
+	ret = sysfs_foreach_classdev("hwmon", sensors_add_hwmon_device);
+	if (ret == ENOENT) {
+		/* compatibility function for kernel 2.6.n where n <= 13 */
+		return sensors_read_sysfs_chips_compat();
+	}
+
+	if (ret > 0)
+		ret = -SENSORS_ERR_KERNEL;
+	return ret;
+}
+
+/* returns 0 if successful, !0 otherwise */
+static int sensors_add_i2c_bus(const char *path, const char *classdev)
+{
+	sensors_bus entry;
+
+	if (sscanf(classdev, "i2c-%hd", &entry.bus.nr) != 1 ||
+	    entry.bus.nr == 9191) /* legacy ISA */
+		return 0;
+	entry.bus.type = SENSORS_BUS_TYPE_I2C;
+
+	/* Get the adapter name from the classdev "name" attribute
+	 * (Linux 2.6.20 and later). If it fails, fall back to
+	 * the device "name" attribute (for older kernels). */
+	entry.adapter = sysfs_read_attr(path, "name");
+	if (!entry.adapter)
+		entry.adapter = sysfs_read_attr(path, "device/name");
+	if (entry.adapter)
+		sensors_add_proc_bus(&entry);
+
+	return 0;
+}
+
+/* returns 0 if successful, !0 otherwise */
+int sensors_read_sysfs_bus(void)
+{
+	int ret;
+
+	ret = sysfs_foreach_classdev("i2c-adapter", sensors_add_i2c_bus);
+	if (ret == ENOENT)
+		ret = sysfs_foreach_busdev("i2c", sensors_add_i2c_bus);
+	if (ret && ret != ENOENT)
+		return -SENSORS_ERR_KERNEL;
+
+	return 0;
+}
+
+int sensors_read_sysfs_attr(const sensors_chip_name *name,
+			    const sensors_subfeature *subfeature,
+			    double *value)
+{
+	char n[NAME_MAX];
+	int f;
+
+	snprintf(n, NAME_MAX, "%s/%s", name->path, subfeature->name);
+	if ((f = open(n, O_RDONLY)) != -1) {
+		int res, err = 0;
+		char buf[512];
+		int count;
+
+		errno = 0;
+		if ((count = read(f, buf, sizeof(buf) - 1)) == -1) {
+			if (errno == EIO)
+				err = -SENSORS_ERR_IO;
+			else 
+				err = -SENSORS_ERR_ACCESS_R;
+		} else {
+			buf[count] = '\0';
+			errno = 0;
+			res = sscanf(buf, "%lf", value);
+			if (res == EOF && errno == EIO)
+				err = -SENSORS_ERR_IO;
+			else if (res != 1)
+				err = -SENSORS_ERR_ACCESS_R;
+		}
+		res = close(f);
+		if (err)
+			return err;
+
+		if (res != 0) {
+			if (errno == EIO)
+				return -SENSORS_ERR_IO;
+			else 
+				return -SENSORS_ERR_ACCESS_R;
+		}
+		if (!sensors_sysfs_no_scaling)
+			*value /= get_type_scaling(subfeature->type);
+	} else
+		return -SENSORS_ERR_KERNEL;
+
+	return 0;
+}
+
+int sensors_write_sysfs_attr(const sensors_chip_name *name,
+			     const sensors_subfeature *subfeature,
+			     double value)
+{
+	char n[NAME_MAX];
+	FILE *f;
+
+	snprintf(n, NAME_MAX, "%s/%s", name->path, subfeature->name);
+	if ((f = fopen(n, "w"))) {
+		int res, err = 0;
+
+		if (!sensors_sysfs_no_scaling)
+			value *= get_type_scaling(subfeature->type);
+		res = fprintf(f, "%d", (int) value);
+		if (res == -EIO)
+			err = -SENSORS_ERR_IO;
+		else if (res < 0)
+			err = -SENSORS_ERR_ACCESS_W;
+		res = fclose(f);
+		if (err)
+			return err;
+
+		if (res == EOF) {
+			if (errno == EIO)
+				return -SENSORS_ERR_IO;
+			else 
+				return -SENSORS_ERR_ACCESS_W;
+		}
+	} else
+		return -SENSORS_ERR_KERNEL;
+
+	return 0;
+}