[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 cc70644db947..791fa0cc45fe 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 1ff4b6806381..7779cebcb3ae 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 000000000000..042bd950d036
--- /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");