[BATTERY] Universal power supply class (was: battery class)

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>

1 files changed, 168 insertions, 0 deletions

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
new file mode 100644
index 000000000000..e87ea5156755
--- /dev/null
+++ b/drivers/power/power_supply_core.c
@@ -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");