[BATTERY] APM emulation driver for class batteries

Signed-off-by: Eugeny Boger <eugenyboger@dgap.mipt.ru>
Signed-off-by: Anton Vorontsov <cbou@mail.ru>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

3 files changed, 251 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index cc70644..791fa0c 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -21,4 +21,11 @@ config PDA_POWER
 	  one or two external power supplies (AC/USB) connected to main and
 	  backup batteries, and optional builtin charger.
 
+config APM_POWER
+	tristate "APM emulation for class batteries"
+	depends on APM_EMULATION
+	help
+	  Say Y here to enable support APM status emulation using
+	  battery class devices.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 1ff4b68..7779ceb 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -15,3 +15,4 @@ endif
 obj-$(CONFIG_POWER_SUPPLY)	+= power_supply.o
 
 obj-$(CONFIG_PDA_POWER)		+= pda_power.o
+obj-$(CONFIG_APM_POWER)		+= apm_power.o
diff --git a/drivers/power/apm_power.c b/drivers/power/apm_power.c
new file mode 100644
index 0000000..042bd95
--- /dev/null
+++ b/drivers/power/apm_power.c
@@ -0,0 +1,243 @@
+/*
+ * Copyright © 2007 Anton Vorontsov <cbou@mail.ru>
+ * Copyright © 2007 Eugeny Boger <eugenyboger@dgap.mipt.ru>
+ *
+ * Author: Eugeny Boger <eugenyboger@dgap.mipt.ru>
+ *
+ * Use consistent with the GNU GPL is permitted,
+ * provided that this copyright notice is
+ * preserved in its entirety in all copies and derived works.
+ */
+
+#include <linux/module.h>
+#include <linux/power_supply.h>
+#include <linux/apm-emulation.h>
+
+#define PSY_PROP(psy, prop, val) psy->get_property(psy, \
+			 POWER_SUPPLY_PROP_##prop, val)
+
+#define _MPSY_PROP(prop, val) main_battery->get_property(main_battery, \
+							 prop, val)
+
+#define MPSY_PROP(prop, val) _MPSY_PROP(POWER_SUPPLY_PROP_##prop, val)
+
+static struct power_supply *main_battery;
+
+static void find_main_battery(void)
+{
+	struct device *dev;
+	struct power_supply *bat, *batm;
+	union power_supply_propval full;
+	int max_charge = 0;
+
+	main_battery = NULL;
+	batm = NULL;
+	list_for_each_entry(dev, &power_supply_class->devices, node) {
+		bat = dev_get_drvdata(dev);
+		/* If none of battery devices cantains 'use_for_apm' flag,
+		   choice one with maximum design charge */
+		if (!PSY_PROP(bat, CHARGE_FULL_DESIGN, &full)) {
+			if (full.intval > max_charge) {
+				batm = bat;
+				max_charge = full.intval;
+			}
+		}
+
+		if (bat->use_for_apm)
+			main_battery = bat;
+	}
+	if (!main_battery)
+		main_battery = batm;
+
+	return;
+}
+
+static int calculate_time(int status)
+{
+	union power_supply_propval charge_full, charge_empty;
+	union power_supply_propval charge, I;
+
+	if (MPSY_PROP(CHARGE_FULL, &charge_full)) {
+		/* if battery can't report this property, use design value */
+		if (MPSY_PROP(CHARGE_FULL_DESIGN, &charge_full))
+			return -1;
+	}
+
+	if (MPSY_PROP(CHARGE_EMPTY, &charge_empty)) {
+		/* if battery can't report this property, use design value */
+		if (MPSY_PROP(CHARGE_EMPTY_DESIGN, &charge_empty))
+			charge_empty.intval = 0;
+	}
+
+	if (MPSY_PROP(CHARGE_AVG, &charge)) {
+		/* if battery can't report average value, use momentary */
+		if (MPSY_PROP(CHARGE_NOW, &charge))
+			return -1;
+	}
+
+	if (MPSY_PROP(CURRENT_AVG, &I)) {
+		/* if battery can't report average value, use momentary */
+		if (MPSY_PROP(CURRENT_NOW, &I))
+			return -1;
+	}
+
+	if (status == POWER_SUPPLY_STATUS_CHARGING)
+		return ((charge.intval - charge_full.intval) * 60L) /
+		       I.intval;
+	else
+		return -((charge.intval - charge_empty.intval) * 60L) /
+			I.intval;
+}
+
+static int calculate_capacity(int using_charge)
+{
+	enum power_supply_property full_prop, empty_prop;
+	enum power_supply_property full_design_prop, empty_design_prop;
+	enum power_supply_property now_prop, avg_prop;
+	union power_supply_propval empty, full, cur;
+	int ret;
+
+	if (using_charge) {
+		full_prop = POWER_SUPPLY_PROP_CHARGE_FULL;
+		empty_prop = POWER_SUPPLY_PROP_CHARGE_EMPTY;
+		full_design_prop = POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN;
+		empty_design_prop = POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN;
+		now_prop = POWER_SUPPLY_PROP_CHARGE_NOW;
+		avg_prop = POWER_SUPPLY_PROP_CHARGE_AVG;
+	} else {
+		full_prop = POWER_SUPPLY_PROP_ENERGY_FULL;
+		empty_prop = POWER_SUPPLY_PROP_ENERGY_EMPTY;
+		full_design_prop = POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN;
+		empty_design_prop = POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN;
+		now_prop = POWER_SUPPLY_PROP_ENERGY_NOW;
+		avg_prop = POWER_SUPPLY_PROP_ENERGY_AVG;
+	}
+
+	if (_MPSY_PROP(full_prop, &full)) {
+		/* if battery can't report this property, use design value */
+		if (_MPSY_PROP(full_design_prop, &full))
+			return -1;
+	}
+
+	if (_MPSY_PROP(avg_prop, &cur)) {
+		/* if battery can't report average value, use momentary */
+		if (_MPSY_PROP(now_prop, &cur))
+			return -1;
+	}
+
+	if (_MPSY_PROP(empty_prop, &empty)) {
+		/* if battery can't report this property, use design value */
+		if (_MPSY_PROP(empty_design_prop, &empty))
+			empty.intval = 0;
+	}
+
+	if (full.intval - empty.intval)
+		ret =  ((cur.intval - empty.intval) * 100L) /
+		       (full.intval - empty.intval);
+	else
+		return -1;
+
+	if (ret > 100)
+		return 100;
+	else if (ret < 0)
+		return 0;
+
+	return ret;
+}
+
+static void apm_battery_apm_get_power_status(struct apm_power_info *info)
+{
+	union power_supply_propval status;
+	union power_supply_propval capacity, time_to_full, time_to_empty;
+
+	down(&power_supply_class->sem);
+	find_main_battery();
+	if (!main_battery) {
+		up(&power_supply_class->sem);
+		return;
+	}
+
+	/* status */
+
+	if (MPSY_PROP(STATUS, &status))
+		status.intval = POWER_SUPPLY_STATUS_UNKNOWN;
+
+	/* ac line status */
+
+	if ((status.intval == POWER_SUPPLY_STATUS_CHARGING) ||
+	    (status.intval == POWER_SUPPLY_STATUS_NOT_CHARGING) ||
+	    (status.intval == POWER_SUPPLY_STATUS_FULL))
+		info->ac_line_status = APM_AC_ONLINE;
+	else
+		info->ac_line_status = APM_AC_OFFLINE;
+
+	/* battery life (i.e. capacity, in percents) */
+
+	if (MPSY_PROP(CAPACITY, &capacity) == 0) {
+		info->battery_life = capacity.intval;
+	} else {
+		/* try calculate using energy */
+		info->battery_life = calculate_capacity(0);
+		/* if failed try calculate using charge instead */
+		if (info->battery_life == -1)
+			info->battery_life = calculate_capacity(1);
+	}
+
+	/* charging status */
+
+	if (status.intval == POWER_SUPPLY_STATUS_CHARGING) {
+		info->battery_status = APM_BATTERY_STATUS_CHARGING;
+	} else {
+		if (info->battery_life > 50)
+			info->battery_status = APM_BATTERY_STATUS_HIGH;
+		else if (info->battery_life > 5)
+			info->battery_status = APM_BATTERY_STATUS_LOW;
+		else
+			info->battery_status = APM_BATTERY_STATUS_CRITICAL;
+	}
+	info->battery_flag = info->battery_status;
+
+	/* time */
+
+	info->units = APM_UNITS_MINS;
+
+	if (status.intval == POWER_SUPPLY_STATUS_CHARGING) {
+		if (MPSY_PROP(TIME_TO_FULL_AVG, &time_to_full)) {
+			if (MPSY_PROP(TIME_TO_FULL_NOW, &time_to_full))
+				info->time = calculate_time(status.intval);
+			else
+				info->time = time_to_full.intval / 60;
+		}
+	} else {
+		if (MPSY_PROP(TIME_TO_EMPTY_AVG, &time_to_empty)) {
+			if (MPSY_PROP(TIME_TO_EMPTY_NOW, &time_to_empty))
+				info->time = calculate_time(status.intval);
+			else
+				info->time = time_to_empty.intval / 60;
+		}
+	}
+
+	up(&power_supply_class->sem);
+	return;
+}
+
+static int __init apm_battery_init(void)
+{
+	printk(KERN_INFO "APM Battery Driver\n");
+
+	apm_get_power_status = apm_battery_apm_get_power_status;
+	return 0;
+}
+
+static void __exit apm_battery_exit(void)
+{
+	apm_get_power_status = NULL;
+	return;
+}
+
+module_init(apm_battery_init);
+module_exit(apm_battery_exit);
+
+MODULE_AUTHOR("Eugeny Boger <eugenyboger@dgap.mipt.ru>");
+MODULE_DESCRIPTION("APM emulation driver for battery monitoring class");
+MODULE_LICENSE("GPL");