1 files changed, 160 insertions, 0 deletions
diff --git a/src/measurement/sysfs.cpp b/src/measurement/sysfs.cpp
new file mode 100644
index 0000000..c5a7a12
--- /dev/null
+++ b/src/measurement/sysfs.cpp
@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 2011 Anssi Hannula
+ *
+ * This file is part of PowerTOP
+ *
+ * This program file is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; version 2 of the License.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program in a file named COPYING; if not, write to the
+ * Free Software Foundation, Inc,
+ * 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA
+ * or just google for it.
+ *
+ * Authors:
+ *	Anssi Hannula <anssi.hannula@iki.fi>
+ */
+#include "measurement.h"
+#include "sysfs.h"
+#include "../lib.h"
+#include <string.h>
+#include <stdio.h>
+#include <limits.h>
+
+sysfs_power_meter::sysfs_power_meter(const char *power_supply_name)
+{
+	rate = 0.0;
+	capacity = 0.0;
+	pt_strcpy(name, power_supply_name);
+}
+
+bool sysfs_power_meter::get_sysfs_attr(const char *attribute, int *value)
+{
+	char filename[PATH_MAX];
+	bool ok;
+
+	snprintf(filename, sizeof(filename), "/sys/class/power_supply/%s/%s", name, attribute);
+	*value = read_sysfs(filename, &ok);
+
+	return ok;
+}
+
+bool sysfs_power_meter::is_present()
+{
+	int present = 0;
+
+	if (!get_sysfs_attr("present", &present))
+		return true; /* assume always present */
+
+	return present;
+}
+
+double sysfs_power_meter::get_voltage()
+{
+	int voltage;
+
+	if (!get_sysfs_attr("voltage_now", &voltage))
+		return -1.0;
+
+	/* µV to V */
+	return voltage / 1000000.0;
+}
+
+bool sysfs_power_meter::set_rate_from_power()
+{
+	int power;
+
+	if (!get_sysfs_attr("power_now", &power))
+		return false;
+
+	/* µW to W */
+	rate = power / 1000000.0;
+	return true;
+}
+
+bool sysfs_power_meter::set_rate_from_current(double voltage)
+{
+	int current;
+
+	if (!get_sysfs_attr("current_now", &current))
+		return false;
+
+	/* current: µA
+	 * voltage: V
+	 * rate: W */
+	rate = (current / 1000000.0) * voltage;
+	return true;
+}
+
+bool sysfs_power_meter::set_capacity_from_energy()
+{
+	int energy;
+
+	if (!get_sysfs_attr("energy_now", &energy))
+		return false;
+
+	/* µWh to J */
+	capacity = energy / 1000000.0 * 3600.0;
+	return true;
+}
+
+bool sysfs_power_meter::set_capacity_from_charge(double voltage)
+{
+	int charge;
+
+	if (!get_sysfs_attr("charge_now", &charge))
+		return false;
+
+	/* charge: µAh
+	 * voltage: V
+	 * capacity: J */
+	capacity = (charge / 1000000.0) * voltage * 3600.0;
+	return true;
+}
+
+void sysfs_power_meter::measure()
+{
+	bool got_rate = false;
+	bool got_capacity = false;
+
+	rate = 0.0;
+	capacity = 0.0;
+	this->set_discharging(false);
+
+	if (!is_present())
+		return;
+	/** do not jump over. we may have discharging battery */
+	if (read_sysfs_string("/sys/class/power_supply/%s/status", name) == "Discharging")
+		this->set_discharging(true);
+
+	got_rate = set_rate_from_power();
+	got_capacity = set_capacity_from_energy();
+
+	if (!got_rate || !got_capacity) {
+		double voltage = get_voltage();
+		if (voltage < 0.0)
+			return;
+		if (!got_rate)
+			set_rate_from_current(voltage);
+		if (!got_capacity)
+			set_capacity_from_charge(voltage);
+	}
+}
+
+void sysfs_power_meter::end_measurement(void)
+{
+	measure();
+}
+
+void sysfs_power_meter::start_measurement(void)
+{
+	/* Battery state is generally a lagging indication, lets only measure at the end */
+}