[BATTERY] Universal power supply class (was: battery class)
Anton Vorontsov [Thu, 3 May 2007 20:27:45 +0000 (00:27 +0400)]
This class is result of "external power" and "battery" classes merge,
as suggested by David Woodhouse. He also implemented uevent support.

Here how userspace seeing it now:

     # ls /sys/class/power\ supply/
     ac  main-battery  usb

     # cat /sys/class/power\ supply/ac/type
     AC

     # cat /sys/class/power\ supply/usb/type
     USB

     # cat /sys/class/power\ supply/main-battery/type
     Battery

     # cat /sys/class/power\ supply/ac/online
     1

     # cat /sys/class/power\ supply/usb/online
     0

     # cat /sys/class/power\ supply/main-battery/status
     Charging

     # cat /sys/class/leds/h5400\:red-left/trigger
     none h5400-radio timer hwtimer ac-online usb-online
     main-battery-charging-or-full [main-battery-charging]
     main-battery-full

Signed-off-by: Anton Vorontsov <cbou@mail.ru>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Documentation/power_supply_class.txt [new file with mode: 0644]
drivers/Kconfig
drivers/Makefile
drivers/power/Kconfig [new file with mode: 0644]
drivers/power/Makefile [new file with mode: 0644]
drivers/power/power_supply.h [new file with mode: 0644]
drivers/power/power_supply_core.c [new file with mode: 0644]
drivers/power/power_supply_leds.c [new file with mode: 0644]
drivers/power/power_supply_sysfs.c [new file with mode: 0644]
include/linux/power_supply.h [new file with mode: 0644]

diff --git a/Documentation/power_supply_class.txt b/Documentation/power_supply_class.txt
new file mode 100644 (file)
index 0000000..9758cf4
--- /dev/null
@@ -0,0 +1,167 @@
+Linux power supply class
+========================
+
+Synopsis
+~~~~~~~~
+Power supply class used to represent battery, UPS, AC or DC power supply
+properties to user-space.
+
+It defines core set of attributes, which should be applicable to (almost)
+every power supply out there. Attributes are available via sysfs and uevent
+interfaces.
+
+Each attribute has well defined meaning, up to unit of measure used. While
+the attributes provided are believed to be universally applicable to any
+power supply, specific monitoring hardware may not be able to provide them
+all, so any of them may be skipped.
+
+Power supply class is extensible, and allows to define drivers own attributes.
+The core attribute set is subject to the standard Linux evolution (i.e.
+if it will be found that some attribute is applicable to many power supply
+types or their drivers, it can be added to the core set).
+
+It also integrates with LED framework, for the purpose of providing
+typically expected feedback of battery charging/fully charged status and
+AC/USB power supply online status. (Note that specific details of the
+indication (including whether to use it at all) are fully controllable by
+user and/or specific machine defaults, per design principles of LED
+framework).
+
+
+Attributes/properties
+~~~~~~~~~~~~~~~~~~~~~
+Power supply class has predefined set of attributes, this eliminates code
+duplication across drivers. Power supply class insist on reusing its
+predefined attributes *and* their units.
+
+So, userspace gets predictable set of attributes and their units for any
+kind of power supply, and can process/present them to a user in consistent
+manner. Results for different power supplies and machines are also directly
+comparable.
+
+See drivers/power/ds2760_battery.c and drivers/power/pda_power.c for the
+example how to declare and handle attributes.
+
+
+Units
+~~~~~
+Quoting include/linux/power_supply.h:
+
+  All voltages, currents, charges, energies, time and temperatures in µV,
+  µA, µAh, µWh, seconds and tenths of degree Celsius unless otherwise
+  stated. It's driver's job to convert its raw values to units in which
+  this class operates.
+
+
+Attributes/properties detailed
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+~ ~ ~ ~ ~ ~ ~  Charge/Energy/Capacity - how to not confuse  ~ ~ ~ ~ ~ ~ ~
+~                                                                       ~
+~ Because both "charge" (µAh) and "energy" (µWh) represents "capacity"  ~
+~ of battery, this class distinguish these terms. Don't mix them!       ~
+~                                                                       ~
+~ CHARGE_* attributes represents capacity in µAh only.                  ~
+~ ENERGY_* attributes represents capacity in µWh only.                  ~
+~ CAPACITY attribute represents capacity in *percents*, from 0 to 100.  ~
+~                                                                       ~
+~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
+
+Postfixes:
+_AVG - *hardware* averaged value, use it if your hardware is really able to
+report averaged values.
+_NOW - momentary/instantaneous values.
+
+STATUS - this attribute represents operating status (charging, full,
+discharging (i.e. powering a load), etc.). This corresponds to
+BATTERY_STATUS_* values, as defined in battery.h.
+
+HEALTH - represents health of the battery, values corresponds to
+POWER_SUPPLY_HEALTH_*, defined in battery.h.
+
+VOLTAGE_MAX_DESIGN, VOLTAGE_MIN_DESIGN - design values for maximal and
+minimal power supply voltages. Maximal/minimal means values of voltages
+when battery considered "full"/"empty" at normal conditions. Yes, there is
+no direct relation between voltage and battery capacity, but some dumb
+batteries use voltage for very approximated calculation of capacity.
+Battery driver also can use this attribute just to inform userspace
+about maximal and minimal voltage thresholds of a given battery.
+
+CHARGE_FULL_DESIGN, CHARGE_EMPTY_DESIGN - design charge values, when
+battery considered full/empty.
+
+ENERGY_FULL_DESIGN, ENERGY_EMPTY_DESIGN - same as above but for energy.
+
+CHARGE_FULL, CHARGE_EMPTY - These attributes means "last remembered value
+of charge when battery became full/empty". It also could mean "value of
+charge when battery considered full/empty at given conditions (temperature,
+age)". I.e. these attributes represents real thresholds, not design values.
+
+ENERGY_FULL, ENERGY_EMPTY - same as above but for energy.
+
+CAPACITY - capacity in percents.
+CAPACITY_LEVEL - capacity level. This corresponds to
+POWER_SUPPLY_CAPACITY_LEVEL_*.
+
+TEMP - temperature of the power supply.
+TEMP_AMBIENT - ambient temperature.
+
+TIME_TO_EMPTY - seconds left for battery to be considered empty (i.e.
+while battery powers a load)
+TIME_TO_FULL - seconds left for battery to be considered full (i.e.
+while battery is charging)
+
+
+Battery <-> external power supply interaction
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Often power supplies are acting as supplies and supplicants at the same
+time. Batteries are good example. So, batteries usually care if they're
+externally powered or not.
+
+For that case, power supply class implements notification mechanism for
+batteries.
+
+External power supply (AC) lists supplicants (batteries) names in
+"supplied_to" struct member, and each power_supply_changed() call
+issued by external power supply will notify supplicants via
+external_power_changed callback.
+
+
+QA
+~~
+Q: Where is POWER_SUPPLY_PROP_XYZ attribute?
+A: If you cannot find attribute suitable for your driver needs, feel free
+   to add it and send patch along with your driver.
+
+   The attributes available currently are the ones currently provided by the
+   drivers written.
+
+   Good candidates to add in future: model/part#, cycle_time, manufacturer,
+   etc.
+
+
+Q: I have some very specific attribute (e.g. battery color), should I add
+   this attribute to standard ones?
+A: Most likely, no. Such attribute can be placed in the driver itself, if
+   it is useful. Of course, if the attribute in question applicable to
+   large set of batteries, provided by many drivers, and/or comes from
+   some general battery specification/standard, it may be a candidate to
+   be added to the core attribute set.
+
+
+Q: Suppose, my battery monitoring chip/firmware does not provides capacity
+   in percents, but provides charge_{now,full,empty}. Should I calculate
+   percentage capacity manually, inside the driver, and register CAPACITY
+   attribute? The same question about time_to_empty/time_to_full.
+A: Most likely, no. This class is designed to export properties which are
+   directly measurable by the specific hardware available.
+
+   Inferring not available properties using some heuristics or mathematical
+   model is not subject of work for a battery driver. Such functionality
+   should be factored out, and in fact, apm_power, the driver to serve
+   legacy APM API on top of power supply class, uses a simple heuristic of
+   approximating remaining battery capacity based on its charge, current,
+   voltage and so on. But full-fledged battery model is likely not subject
+   for kernel at all, as it would require floating point calculation to deal
+   with things like differential equations and Kalman filters. This is
+   better be handled by batteryd/libbattery, yet to be written.
index 050323f..c546de3 100644 (file)
@@ -54,6 +54,8 @@ source "drivers/spi/Kconfig"
 
 source "drivers/w1/Kconfig"
 
+source "drivers/power/Kconfig"
+
 source "drivers/hwmon/Kconfig"
 
 source "drivers/mfd/Kconfig"
index adad2f3..503d825 100644 (file)
@@ -61,6 +61,7 @@ obj-$(CONFIG_I2O)             += message/
 obj-$(CONFIG_RTC_LIB)          += rtc/
 obj-y                          += i2c/
 obj-$(CONFIG_W1)               += w1/
+obj-$(CONFIG_POWER_SUPPLY)     += power/
 obj-$(CONFIG_HWMON)            += hwmon/
 obj-$(CONFIG_PHONE)            += telephony/
 obj-$(CONFIG_MD)               += md/
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
new file mode 100644 (file)
index 0000000..7811fa6
--- /dev/null
@@ -0,0 +1,17 @@
+menuconfig POWER_SUPPLY
+       tristate "Power supply class support"
+       help
+         Say Y here to enable power supply class support. This allows
+         power supply (batteries, AC, USB) monitoring by userspace
+         via sysfs and uevent (if available) and/or APM kernel interface
+         (if selected below).
+
+if POWER_SUPPLY
+
+config POWER_SUPPLY_DEBUG
+       bool "Power supply debug"
+       help
+         Say Y here to enable debugging messages for power supply class
+         and drivers.
+
+endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
new file mode 100644 (file)
index 0000000..3c88148
--- /dev/null
@@ -0,0 +1,15 @@
+power_supply-objs := power_supply_core.o
+
+ifeq ($(CONFIG_SYSFS),y)
+power_supply-objs += power_supply_sysfs.o
+endif
+
+ifeq ($(CONFIG_LEDS_TRIGGERS),y)
+power_supply-objs += power_supply_leds.o
+endif
+
+ifeq ($(CONFIG_POWER_SUPPLY_DEBUG),y)
+EXTRA_CFLAGS += -DDEBUG
+endif
+
+obj-$(CONFIG_POWER_SUPPLY)     += power_supply.o
diff --git a/drivers/power/power_supply.h b/drivers/power/power_supply.h
new file mode 100644 (file)
index 0000000..a9880d4
--- /dev/null
@@ -0,0 +1,42 @@
+/*
+ *  Functions private to power supply class
+ *
+ *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
+ *  Copyright © 2004  Szabolcs Gyurko
+ *  Copyright © 2003  Ian Molton <spyro@f2s.com>
+ *
+ *  Modified: 2004, Oct     Szabolcs Gyurko
+ *
+ *  You may use this code as per GPL version 2
+ */
+
+#ifdef CONFIG_SYSFS
+
+extern int power_supply_create_attrs(struct power_supply *psy);
+extern void power_supply_remove_attrs(struct power_supply *psy);
+extern int power_supply_uevent(struct device *dev, char **envp, int num_envp,
+                              char *buffer, int buffer_size);
+
+#else
+
+static inline int power_supply_create_attrs(struct power_supply *psy)
+{ return 0; }
+static inline void power_supply_remove_attrs(struct power_supply *psy) {}
+#define power_supply_uevent NULL
+
+#endif /* CONFIG_SYSFS */
+
+#ifdef CONFIG_LEDS_TRIGGERS
+
+extern void power_supply_update_leds(struct power_supply *psy);
+extern int power_supply_create_triggers(struct power_supply *psy);
+extern void power_supply_remove_triggers(struct power_supply *psy);
+
+#else
+
+static inline void power_supply_update_leds(struct power_supply *psy) {}
+static inline int power_supply_create_triggers(struct power_supply *psy)
+{ return 0; }
+static inline void power_supply_remove_triggers(struct power_supply *psy) {}
+
+#endif /* CONFIG_LEDS_TRIGGERS */
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
new file mode 100644 (file)
index 0000000..e87ea51
--- /dev/null
@@ -0,0 +1,168 @@
+/*
+ *  Universal power supply monitor class
+ *
+ *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
+ *  Copyright © 2004  Szabolcs Gyurko
+ *  Copyright © 2003  Ian Molton <spyro@f2s.com>
+ *
+ *  Modified: 2004, Oct     Szabolcs Gyurko
+ *
+ *  You may use this code as per GPL version 2
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/power_supply.h>
+#include "power_supply.h"
+
+struct class *power_supply_class;
+
+static void power_supply_changed_work(struct work_struct *work)
+{
+       struct power_supply *psy = container_of(work, struct power_supply,
+                                               changed_work);
+       int i;
+
+       dev_dbg(psy->dev, "%s\n", __FUNCTION__);
+
+       for (i = 0; i < psy->num_supplicants; i++) {
+               struct device *dev;
+
+               down(&power_supply_class->sem);
+               list_for_each_entry(dev, &power_supply_class->devices, node) {
+                       struct power_supply *pst = dev_get_drvdata(dev);
+
+                       if (!strcmp(psy->supplied_to[i], pst->name)) {
+                               if (pst->external_power_changed)
+                                       pst->external_power_changed(pst);
+                       }
+               }
+               up(&power_supply_class->sem);
+       }
+
+       power_supply_update_leds(psy);
+
+       kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
+
+       return;
+}
+
+void power_supply_changed(struct power_supply *psy)
+{
+       dev_dbg(psy->dev, "%s\n", __FUNCTION__);
+
+       schedule_work(&psy->changed_work);
+
+       return;
+}
+
+int power_supply_am_i_supplied(struct power_supply *psy)
+{
+       union power_supply_propval ret = {0,};
+       struct device *dev;
+
+       down(&power_supply_class->sem);
+       list_for_each_entry(dev, &power_supply_class->devices, node) {
+               struct power_supply *epsy = dev_get_drvdata(dev);
+               int i;
+
+               for (i = 0; i < epsy->num_supplicants; i++) {
+                       if (!strcmp(epsy->supplied_to[i], psy->name)) {
+                               if (epsy->get_property(epsy,
+                                         POWER_SUPPLY_PROP_ONLINE, &ret))
+                                       continue;
+                               if (ret.intval)
+                                       goto out;
+                       }
+               }
+       }
+out:
+       up(&power_supply_class->sem);
+
+       dev_dbg(psy->dev, "%s %d\n", __FUNCTION__, ret.intval);
+
+       return ret.intval;
+}
+
+int power_supply_register(struct device *parent, struct power_supply *psy)
+{
+       int rc = 0;
+
+       psy->dev = device_create(power_supply_class, parent, 0,
+                                "%s", psy->name);
+       if (IS_ERR(psy->dev)) {
+               rc = PTR_ERR(psy->dev);
+               goto dev_create_failed;
+       }
+
+       dev_set_drvdata(psy->dev, psy);
+
+       INIT_WORK(&psy->changed_work, power_supply_changed_work);
+
+       rc = power_supply_create_attrs(psy);
+       if (rc)
+               goto create_attrs_failed;
+
+       rc = power_supply_create_triggers(psy);
+       if (rc)
+               goto create_triggers_failed;
+
+       power_supply_changed(psy);
+
+       goto success;
+
+create_triggers_failed:
+       power_supply_remove_attrs(psy);
+create_attrs_failed:
+       device_unregister(psy->dev);
+dev_create_failed:
+success:
+       return rc;
+}
+
+void power_supply_unregister(struct power_supply *psy)
+{
+       flush_scheduled_work();
+       power_supply_remove_triggers(psy);
+       power_supply_remove_attrs(psy);
+       device_unregister(psy->dev);
+       return;
+}
+
+static int __init power_supply_class_init(void)
+{
+       power_supply_class = class_create(THIS_MODULE, "power_supply");
+
+       if (IS_ERR(power_supply_class))
+               return PTR_ERR(power_supply_class);
+
+       power_supply_class->dev_uevent = power_supply_uevent;
+
+       return 0;
+}
+
+static void __exit power_supply_class_exit(void)
+{
+       class_destroy(power_supply_class);
+       return;
+}
+
+EXPORT_SYMBOL_GPL(power_supply_changed);
+EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
+EXPORT_SYMBOL_GPL(power_supply_register);
+EXPORT_SYMBOL_GPL(power_supply_unregister);
+
+/* exported for the APM Power driver, APM emulation */
+EXPORT_SYMBOL_GPL(power_supply_class);
+
+subsys_initcall(power_supply_class_init);
+module_exit(power_supply_class_exit);
+
+MODULE_DESCRIPTION("Universal power supply monitor class");
+MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
+             "Szabolcs Gyurko, "
+             "Anton Vorontsov <cbou@mail.ru>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/power/power_supply_leds.c b/drivers/power/power_supply_leds.c
new file mode 100644 (file)
index 0000000..7232490
--- /dev/null
@@ -0,0 +1,176 @@
+/*
+ *  LEDs triggers for power supply class
+ *
+ *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
+ *  Copyright © 2004  Szabolcs Gyurko
+ *  Copyright © 2003  Ian Molton <spyro@f2s.com>
+ *
+ *  Modified: 2004, Oct     Szabolcs Gyurko
+ *
+ *  You may use this code as per GPL version 2
+ */
+
+#include <linux/power_supply.h>
+
+/* Battery specific LEDs triggers. */
+
+static void power_supply_update_bat_leds(struct power_supply *psy)
+{
+       union power_supply_propval status;
+
+       if (psy->get_property(psy, POWER_SUPPLY_PROP_STATUS, &status))
+               return;
+
+       dev_dbg(psy->dev, "%s %d\n", __FUNCTION__, status.intval);
+
+       switch (status.intval) {
+       case POWER_SUPPLY_STATUS_FULL:
+               led_trigger_event(psy->charging_full_trig, LED_FULL);
+               led_trigger_event(psy->charging_trig, LED_OFF);
+               led_trigger_event(psy->full_trig, LED_FULL);
+               break;
+       case POWER_SUPPLY_STATUS_CHARGING:
+               led_trigger_event(psy->charging_full_trig, LED_FULL);
+               led_trigger_event(psy->charging_trig, LED_FULL);
+               led_trigger_event(psy->full_trig, LED_OFF);
+               break;
+       default:
+               led_trigger_event(psy->charging_full_trig, LED_OFF);
+               led_trigger_event(psy->charging_trig, LED_OFF);
+               led_trigger_event(psy->full_trig, LED_OFF);
+               break;
+       }
+
+       return;
+}
+
+static int power_supply_create_bat_triggers(struct power_supply *psy)
+{
+       int rc = 0;
+
+       psy->charging_full_trig_name = kmalloc(strlen(psy->name) +
+                                 sizeof("-charging-or-full"), GFP_KERNEL);
+       if (!psy->charging_full_trig_name)
+               goto charging_full_failed;
+
+       psy->charging_trig_name = kmalloc(strlen(psy->name) +
+                                         sizeof("-charging"), GFP_KERNEL);
+       if (!psy->charging_trig_name)
+               goto charging_failed;
+
+       psy->full_trig_name = kmalloc(strlen(psy->name) +
+                                     sizeof("-full"), GFP_KERNEL);
+       if (!psy->full_trig_name)
+               goto full_failed;
+
+       strcpy(psy->charging_full_trig_name, psy->name);
+       strcat(psy->charging_full_trig_name, "-charging-or-full");
+       strcpy(psy->charging_trig_name, psy->name);
+       strcat(psy->charging_trig_name, "-charging");
+       strcpy(psy->full_trig_name, psy->name);
+       strcat(psy->full_trig_name, "-full");
+
+       led_trigger_register_simple(psy->charging_full_trig_name,
+                                   &psy->charging_full_trig);
+       led_trigger_register_simple(psy->charging_trig_name,
+                                   &psy->charging_trig);
+       led_trigger_register_simple(psy->full_trig_name,
+                                   &psy->full_trig);
+
+       goto success;
+
+full_failed:
+       kfree(psy->charging_trig_name);
+charging_failed:
+       kfree(psy->charging_full_trig_name);
+charging_full_failed:
+       rc = -ENOMEM;
+success:
+       return rc;
+}
+
+static void power_supply_remove_bat_triggers(struct power_supply *psy)
+{
+       led_trigger_unregister_simple(psy->charging_full_trig);
+       led_trigger_unregister_simple(psy->charging_trig);
+       led_trigger_unregister_simple(psy->full_trig);
+       kfree(psy->full_trig_name);
+       kfree(psy->charging_trig_name);
+       kfree(psy->charging_full_trig_name);
+       return;
+}
+
+/* Generated power specific LEDs triggers. */
+
+static void power_supply_update_gen_leds(struct power_supply *psy)
+{
+       union power_supply_propval online;
+
+       if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &online))
+               return;
+
+       dev_dbg(psy->dev, "%s %d\n", __FUNCTION__, online.intval);
+
+       if (online.intval)
+               led_trigger_event(psy->online_trig, LED_FULL);
+       else
+               led_trigger_event(psy->online_trig, LED_OFF);
+
+       return;
+}
+
+static int power_supply_create_gen_triggers(struct power_supply *psy)
+{
+       int rc = 0;
+
+       psy->online_trig_name = kmalloc(strlen(psy->name) + sizeof("-online"),
+                                       GFP_KERNEL);
+       if (!psy->online_trig_name)
+               goto online_failed;
+
+       strcpy(psy->online_trig_name, psy->name);
+       strcat(psy->online_trig_name, "-online");
+
+       led_trigger_register_simple(psy->online_trig_name, &psy->online_trig);
+
+       goto success;
+
+online_failed:
+       rc = -ENOMEM;
+success:
+       return rc;
+}
+
+static void power_supply_remove_gen_triggers(struct power_supply *psy)
+{
+       led_trigger_unregister_simple(psy->online_trig);
+       kfree(psy->online_trig_name);
+       return;
+}
+
+/* Choice what triggers to create&update. */
+
+void power_supply_update_leds(struct power_supply *psy)
+{
+       if (psy->type == POWER_SUPPLY_TYPE_BATTERY)
+               power_supply_update_bat_leds(psy);
+       else
+               power_supply_update_gen_leds(psy);
+       return;
+}
+
+int power_supply_create_triggers(struct power_supply *psy)
+{
+       if (psy->type == POWER_SUPPLY_TYPE_BATTERY)
+               return power_supply_create_bat_triggers(psy);
+       return power_supply_create_gen_triggers(psy);
+}
+
+void power_supply_remove_triggers(struct power_supply *psy)
+{
+       if (psy->type == POWER_SUPPLY_TYPE_BATTERY)
+               power_supply_remove_bat_triggers(psy);
+       else
+               power_supply_remove_gen_triggers(psy);
+       return;
+}
diff --git a/drivers/power/power_supply_sysfs.c b/drivers/power/power_supply_sysfs.c
new file mode 100644 (file)
index 0000000..c07d425
--- /dev/null
@@ -0,0 +1,299 @@
+/*
+ *  Sysfs interface for the universal power supply monitor class
+ *
+ *  Copyright © 2007  David Woodhouse <dwmw2@infradead.org>
+ *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
+ *  Copyright © 2004  Szabolcs Gyurko
+ *  Copyright © 2003  Ian Molton <spyro@f2s.com>
+ *
+ *  Modified: 2004, Oct     Szabolcs Gyurko
+ *
+ *  You may use this code as per GPL version 2
+ */
+
+#include <linux/ctype.h>
+#include <linux/power_supply.h>
+
+/*
+ * This is because the name "current" breaks the device attr macro.
+ * The "current" word resolves to "(get_current())" so instead of
+ * "current" "(get_current())" appears in the sysfs.
+ *
+ * The source of this definition is the device.h which calls __ATTR
+ * macro in sysfs.h which calls the __stringify macro.
+ *
+ * Only modification that the name is not tried to be resolved
+ * (as a macro let's say).
+ */
+
+#define POWER_SUPPLY_ATTR(_name)                                       \
+{                                                                      \
+       .attr = { .name = #_name, .mode = 0444, .owner = THIS_MODULE }, \
+       .show = power_supply_show_property,                             \
+       .store = NULL,                                                  \
+}
+
+static struct device_attribute power_supply_attrs[];
+
+static ssize_t power_supply_show_property(struct device *dev,
+                                         struct device_attribute *attr,
+                                         char *buf) {
+       static char *status_text[] = {
+               "Unknown", "Charging", "Discharging", "Not charging", "Full"
+       };
+       static char *health_text[] = {
+               "Unknown", "Good", "Overheat", "Dead", "Over voltage",
+               "Unspecified failure"
+       };
+       static char *technology_text[] = {
+               "Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd"
+       };
+       static char *capacity_level_text[] = {
+               "Unknown", "Critical", "Low", "Normal", "High", "Full"
+       };
+       ssize_t ret;
+       struct power_supply *psy = dev_get_drvdata(dev);
+       const ptrdiff_t off = attr - power_supply_attrs;
+       union power_supply_propval value;
+
+       ret = psy->get_property(psy, off, &value);
+
+       if (ret < 0) {
+               if (ret != -ENODEV)
+                       dev_err(dev, "driver failed to report `%s' property\n",
+                               attr->attr.name);
+               return ret;
+       }
+
+       if (off == POWER_SUPPLY_PROP_STATUS)
+               return sprintf(buf, "%s\n", status_text[value.intval]);
+       else if (off == POWER_SUPPLY_PROP_HEALTH)
+               return sprintf(buf, "%s\n", health_text[value.intval]);
+       else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
+               return sprintf(buf, "%s\n", technology_text[value.intval]);
+       else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
+               return sprintf(buf, "%s\n",
+                              capacity_level_text[value.intval]);
+       else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
+               return sprintf(buf, "%s\n", value.strval);
+
+       return sprintf(buf, "%d\n", value.intval);
+}
+
+/* Must be in the same order as POWER_SUPPLY_PROP_* */
+static struct device_attribute power_supply_attrs[] = {
+       /* Properties of type `int' */
+       POWER_SUPPLY_ATTR(status),
+       POWER_SUPPLY_ATTR(health),
+       POWER_SUPPLY_ATTR(present),
+       POWER_SUPPLY_ATTR(online),
+       POWER_SUPPLY_ATTR(technology),
+       POWER_SUPPLY_ATTR(voltage_max_design),
+       POWER_SUPPLY_ATTR(voltage_min_design),
+       POWER_SUPPLY_ATTR(voltage_now),
+       POWER_SUPPLY_ATTR(voltage_avg),
+       POWER_SUPPLY_ATTR(current_now),
+       POWER_SUPPLY_ATTR(current_avg),
+       POWER_SUPPLY_ATTR(charge_full_design),
+       POWER_SUPPLY_ATTR(charge_empty_design),
+       POWER_SUPPLY_ATTR(charge_full),
+       POWER_SUPPLY_ATTR(charge_empty),
+       POWER_SUPPLY_ATTR(charge_now),
+       POWER_SUPPLY_ATTR(charge_avg),
+       POWER_SUPPLY_ATTR(energy_full_design),
+       POWER_SUPPLY_ATTR(energy_empty_design),
+       POWER_SUPPLY_ATTR(energy_full),
+       POWER_SUPPLY_ATTR(energy_empty),
+       POWER_SUPPLY_ATTR(energy_now),
+       POWER_SUPPLY_ATTR(energy_avg),
+       POWER_SUPPLY_ATTR(capacity),
+       POWER_SUPPLY_ATTR(capacity_level),
+       POWER_SUPPLY_ATTR(temp),
+       POWER_SUPPLY_ATTR(temp_ambient),
+       POWER_SUPPLY_ATTR(time_to_empty_now),
+       POWER_SUPPLY_ATTR(time_to_empty_avg),
+       POWER_SUPPLY_ATTR(time_to_full_now),
+       POWER_SUPPLY_ATTR(time_to_full_avg),
+       /* Properties of type `const char *' */
+       POWER_SUPPLY_ATTR(model_name),
+       POWER_SUPPLY_ATTR(manufacturer),
+};
+
+static ssize_t power_supply_show_static_attrs(struct device *dev,
+                                             struct device_attribute *attr,
+                                             char *buf) {
+       static char *type_text[] = { "Battery", "UPS", "Mains", "USB" };
+       struct power_supply *psy = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%s\n", type_text[psy->type]);
+}
+
+static struct device_attribute power_supply_static_attrs[] = {
+       __ATTR(type, 0444, power_supply_show_static_attrs, NULL),
+};
+
+int power_supply_create_attrs(struct power_supply *psy)
+{
+       int rc = 0;
+       int i, j;
+
+       for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++) {
+               rc = device_create_file(psy->dev,
+                           &power_supply_static_attrs[i]);
+               if (rc)
+                       goto statics_failed;
+       }
+
+       for (j = 0; j < psy->num_properties; j++) {
+               rc = device_create_file(psy->dev,
+                           &power_supply_attrs[psy->properties[j]]);
+               if (rc)
+                       goto dynamics_failed;
+       }
+
+       goto succeed;
+
+dynamics_failed:
+       while (j--)
+               device_remove_file(psy->dev,
+                          &power_supply_attrs[psy->properties[j]]);
+statics_failed:
+       while (i--)
+               device_remove_file(psy->dev,
+                          &power_supply_static_attrs[psy->properties[i]]);
+succeed:
+       return rc;
+}
+
+void power_supply_remove_attrs(struct power_supply *psy)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++)
+               device_remove_file(psy->dev,
+                           &power_supply_static_attrs[i]);
+
+       for (i = 0; i < psy->num_properties; i++)
+               device_remove_file(psy->dev,
+                           &power_supply_attrs[psy->properties[i]]);
+
+       return;
+}
+
+static char *kstruprdup(const char *str, gfp_t gfp)
+{
+       char *ret, *ustr;
+
+       ustr = ret = kmalloc(strlen(str) + 1, gfp);
+
+       if (!ret)
+               return NULL;
+
+       while (*str)
+               *ustr++ = toupper(*str++);
+
+       *ustr = 0;
+
+       return ret;
+}
+
+int power_supply_uevent(struct device *dev, char **envp, int num_envp,
+                       char *buffer, int buffer_size)
+{
+       struct power_supply *psy = dev_get_drvdata(dev);
+       int i = 0, length = 0, ret = 0, j;
+       char *prop_buf;
+       char *attrname;
+
+       dev_dbg(dev, "uevent\n");
+
+       if (!psy) {
+               dev_dbg(dev, "No power supply yet\n");
+               return ret;
+       }
+
+       dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
+
+       ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
+                            &length, "POWER_SUPPLY_NAME=%s", psy->name);
+       if (ret)
+               return ret;
+
+       prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
+       if (!prop_buf)
+               return -ENOMEM;
+
+       for (j = 0; j < ARRAY_SIZE(power_supply_static_attrs); j++) {
+               struct device_attribute *attr;
+               char *line;
+
+               attr = &power_supply_static_attrs[j];
+
+               ret = power_supply_show_static_attrs(dev, attr, prop_buf);
+               if (ret < 0)
+                       goto out;
+
+               line = strchr(prop_buf, '\n');
+               if (line)
+                       *line = 0;
+
+               attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
+               if (!attrname) {
+                       ret = -ENOMEM;
+                       goto out;
+               }
+
+               dev_dbg(dev, "Static prop %s=%s\n", attrname, prop_buf);
+
+               ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
+                                    &length, "POWER_SUPPLY_%s=%s",
+                                    attrname, prop_buf);
+               kfree(attrname);
+               if (ret)
+                       goto out;
+       }
+
+       dev_dbg(dev, "%zd dynamic props\n", psy->num_properties);
+
+       for (j = 0; j < psy->num_properties; j++) {
+               struct device_attribute *attr;
+               char *line;
+
+               attr = &power_supply_attrs[psy->properties[j]];
+
+               ret = power_supply_show_property(dev, attr, prop_buf);
+               if (ret == -ENODEV) {
+                       /* When a battery is absent, we expect -ENODEV. Don't abort;
+                          send the uevent with at least the the PRESENT=0 property */
+                       ret = 0;
+                       continue;
+               }
+
+               if (ret < 0)
+                       goto out;
+
+               line = strchr(prop_buf, '\n');
+               if (line)
+                       *line = 0;
+
+               attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
+               if (!attrname) {
+                       ret = -ENOMEM;
+                       goto out;
+               }
+
+               dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
+
+               ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
+                                    &length, "POWER_SUPPLY_%s=%s",
+                                    attrname, prop_buf);
+               kfree(attrname);
+               if (ret)
+                       goto out;
+       }
+
+out:
+       free_page((unsigned long)prop_buf);
+
+       return ret;
+}
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
new file mode 100644 (file)
index 0000000..606c095
--- /dev/null
@@ -0,0 +1,180 @@
+/*
+ *  Universal power supply monitor class
+ *
+ *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
+ *  Copyright © 2004  Szabolcs Gyurko
+ *  Copyright © 2003  Ian Molton <spyro@f2s.com>
+ *
+ *  Modified: 2004, Oct     Szabolcs Gyurko
+ *
+ *  You may use this code as per GPL version 2
+ */
+
+#ifndef __LINUX_POWER_SUPPLY_H__
+#define __LINUX_POWER_SUPPLY_H__
+
+#include <linux/device.h>
+#include <linux/workqueue.h>
+#include <linux/leds.h>
+
+/*
+ * All voltages, currents, charges, energies, time and temperatures in uV,
+ * µA, µAh, µWh, seconds and tenths of degree Celsius unless otherwise
+ * stated. It's driver's job to convert its raw values to units in which
+ * this class operates.
+ */
+
+/*
+ * For systems where the charger determines the maximum battery capacity
+ * the min and max fields should be used to present these values to user
+ * space. Unused/unknown fields will not appear in sysfs.
+ */
+
+enum {
+       POWER_SUPPLY_STATUS_UNKNOWN = 0,
+       POWER_SUPPLY_STATUS_CHARGING,
+       POWER_SUPPLY_STATUS_DISCHARGING,
+       POWER_SUPPLY_STATUS_NOT_CHARGING,
+       POWER_SUPPLY_STATUS_FULL,
+};
+
+enum {
+       POWER_SUPPLY_HEALTH_UNKNOWN = 0,
+       POWER_SUPPLY_HEALTH_GOOD,
+       POWER_SUPPLY_HEALTH_OVERHEAT,
+       POWER_SUPPLY_HEALTH_DEAD,
+       POWER_SUPPLY_HEALTH_OVERVOLTAGE,
+       POWER_SUPPLY_HEALTH_UNSPEC_FAILURE,
+};
+
+enum {
+       POWER_SUPPLY_TECHNOLOGY_UNKNOWN = 0,
+       POWER_SUPPLY_TECHNOLOGY_NiMH,
+       POWER_SUPPLY_TECHNOLOGY_LION,
+       POWER_SUPPLY_TECHNOLOGY_LIPO,
+       POWER_SUPPLY_TECHNOLOGY_LiFe,
+       POWER_SUPPLY_TECHNOLOGY_NiCd,
+};
+
+enum {
+       POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN = 0,
+       POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL,
+       POWER_SUPPLY_CAPACITY_LEVEL_LOW,
+       POWER_SUPPLY_CAPACITY_LEVEL_NORMAL,
+       POWER_SUPPLY_CAPACITY_LEVEL_HIGH,
+       POWER_SUPPLY_CAPACITY_LEVEL_FULL,
+};
+
+enum power_supply_property {
+       /* Properties of type `int' */
+       POWER_SUPPLY_PROP_STATUS = 0,
+       POWER_SUPPLY_PROP_HEALTH,
+       POWER_SUPPLY_PROP_PRESENT,
+       POWER_SUPPLY_PROP_ONLINE,
+       POWER_SUPPLY_PROP_TECHNOLOGY,
+       POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+       POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+       POWER_SUPPLY_PROP_VOLTAGE_NOW,
+       POWER_SUPPLY_PROP_VOLTAGE_AVG,
+       POWER_SUPPLY_PROP_CURRENT_NOW,
+       POWER_SUPPLY_PROP_CURRENT_AVG,
+       POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+       POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN,
+       POWER_SUPPLY_PROP_CHARGE_FULL,
+       POWER_SUPPLY_PROP_CHARGE_EMPTY,
+       POWER_SUPPLY_PROP_CHARGE_NOW,
+       POWER_SUPPLY_PROP_CHARGE_AVG,
+       POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
+       POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN,
+       POWER_SUPPLY_PROP_ENERGY_FULL,
+       POWER_SUPPLY_PROP_ENERGY_EMPTY,
+       POWER_SUPPLY_PROP_ENERGY_NOW,
+       POWER_SUPPLY_PROP_ENERGY_AVG,
+       POWER_SUPPLY_PROP_CAPACITY, /* in percents! */
+       POWER_SUPPLY_PROP_CAPACITY_LEVEL,
+       POWER_SUPPLY_PROP_TEMP,
+       POWER_SUPPLY_PROP_TEMP_AMBIENT,
+       POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
+       POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
+       POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
+       POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
+       /* Properties of type `const char *' */
+       POWER_SUPPLY_PROP_MODEL_NAME,
+       POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+enum power_supply_type {
+       POWER_SUPPLY_TYPE_BATTERY = 0,
+       POWER_SUPPLY_TYPE_UPS,
+       POWER_SUPPLY_TYPE_MAINS,
+       POWER_SUPPLY_TYPE_USB,
+};
+
+union power_supply_propval {
+       int intval;
+       const char *strval;
+};
+
+struct power_supply {
+       const char *name;
+       enum power_supply_type type;
+       enum power_supply_property *properties;
+       size_t num_properties;
+
+       char **supplied_to;
+       size_t num_supplicants;
+
+       int (*get_property)(struct power_supply *psy,
+                           enum power_supply_property psp,
+                           union power_supply_propval *val);
+       void (*external_power_changed)(struct power_supply *psy);
+
+       /* For APM emulation, think legacy userspace. */
+       int use_for_apm;
+
+       /* private */
+       struct device *dev;
+       struct work_struct changed_work;
+
+#ifdef CONFIG_LEDS_TRIGGERS
+       struct led_trigger *charging_full_trig;
+       char *charging_full_trig_name;
+       struct led_trigger *charging_trig;
+       char *charging_trig_name;
+       struct led_trigger *full_trig;
+       char *full_trig_name;
+       struct led_trigger *online_trig;
+       char *online_trig_name;
+#endif
+};
+
+/*
+ * This is recommended structure to specify static power supply parameters.
+ * Generic one, parametrizable for different power supplies. Power supply
+ * class itself does not use it, but that's what implementing most platform
+ * drivers, should try reuse for consistency.
+ */
+
+struct power_supply_info {
+       const char *name;
+       int technology;
+       int voltage_max_design;
+       int voltage_min_design;
+       int charge_full_design;
+       int charge_empty_design;
+       int energy_full_design;
+       int energy_empty_design;
+       int use_for_apm;
+};
+
+extern void power_supply_changed(struct power_supply *psy);
+extern int power_supply_am_i_supplied(struct power_supply *psy);
+
+extern int power_supply_register(struct device *parent,
+                                struct power_supply *psy);
+extern void power_supply_unregister(struct power_supply *psy);
+
+/* For APM emulation, think legacy userspace. */
+extern struct class *power_supply_class;
+
+#endif /* __LINUX_POWER_SUPPLY_H__ */