greybus: add battery module
diff --git a/drivers/staging/greybus/battery-gb.c b/drivers/staging/greybus/battery-gb.c
new file mode 100644
index 0000000..123b2af
--- /dev/null
+++ b/drivers/staging/greybus/battery-gb.c
@@ -0,0 +1,153 @@
+/*
+ * Battery driver for a Greybus module.
+ *
+ * Copyright 2014 Google Inc.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/power_supply.h>
+#include "greybus.h"
+
+struct gb_battery {
+ struct power_supply bat;
+ struct greybus_device *gdev;
+};
+#define to_gb_battery(x) container_of(x, struct gb_battery, bat)
+
+static const struct greybus_module_id id_table[] = {
+ { GREYBUS_DEVICE(0x42, 0x42) }, /* make shit up */
+ { }, /* terminating NULL entry */
+};
+
+static int get_status(struct gb_battery *gb)
+{
+ // FIXME!!!
+ return 0;
+}
+
+static int get_capacity(struct gb_battery *gb)
+{
+ // FIXME!!!
+ return 0;
+}
+
+static int get_temp(struct gb_battery *gb)
+{
+ // FIXME!!!
+ return 0;
+}
+
+static int get_voltage(struct gb_battery *gb)
+{
+ // FIXME!!!
+ return 0;
+}
+
+
+
+static int get_property(struct power_supply *b,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct gb_battery *gb = to_gb_battery(b);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_TECHNOLOGY:
+ // FIXME - guess!
+ val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
+ break;
+
+ case POWER_SUPPLY_PROP_STATUS:
+ val->intval = get_status(gb);
+ break;
+
+ case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+ val->intval = 4700000; // FIXME - guess???
+ break;
+
+ case POWER_SUPPLY_PROP_CAPACITY:
+ val->intval = get_capacity(gb);
+ break;
+
+ case POWER_SUPPLY_PROP_TEMP:
+ val->intval = get_temp(gb);
+ break;
+
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ val->intval = get_voltage(gb);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+
+// FIXME - verify this list, odds are some can be removed and others added.
+static enum power_supply_property battery_props[] = {
+ POWER_SUPPLY_PROP_TECHNOLOGY,
+ POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+ POWER_SUPPLY_PROP_CAPACITY,
+ POWER_SUPPLY_PROP_TEMP,
+ POWER_SUPPLY_PROP_VOLTAGE_NOW,
+};
+
+int gb_battery_probe(struct greybus_device *gdev,
+ const struct greybus_module_id *id)
+{
+ struct gb_battery *gb;
+ struct power_supply *b;
+ int retval;
+
+ gb = kzalloc(sizeof(*gb), GFP_KERNEL);
+ if (!gb)
+ return -ENOMEM;
+
+ b = &gb->bat;
+ // FIXME - get a better (i.e. unique) name
+ // FIXME - anything else needs to be set?
+ b->name = "gb_battery";
+ b->type = POWER_SUPPLY_TYPE_BATTERY,
+ b->properties = battery_props,
+ b->num_properties = ARRAY_SIZE(battery_props),
+ b->get_property = get_property,
+
+ retval = power_supply_register(&gdev->dev, b);
+ if (retval) {
+ kfree(gb);
+ return retval;
+ }
+ gdev->gb_battery = gb;
+
+ return 0;
+}
+
+void gb_battery_disconnect(struct greybus_device *gdev)
+{
+ struct gb_battery *gb;
+
+ gb = gdev->gb_battery;
+
+ power_supply_unregister(&gb->bat);
+
+ kfree(gb);
+}
+
+#if 0
+static struct greybus_driver battery_gb_driver = {
+ .probe = gb_battery_probe,
+ .disconnect = gb_battery_disconnect,
+ .id_table = id_table,
+};
+
+module_greybus_driver(battery_gb_driver);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
+#endif