5 files changed, 64 insertions, 2 deletions

diff --git a/drivers/input/tablet/Kconfig b/drivers/input/tablet/Kconfig
index 58a87755b936..0edeb949109b 100644
--- a/drivers/input/tablet/Kconfig
+++ b/drivers/input/tablet/Kconfig
@@ -76,6 +76,7 @@ config TABLET_USB_KBTAB
 config TABLET_USB_WACOM
         tristate "Wacom Intuos/Graphire tablet support (USB)"
         depends on USB_ARCH_HAS_HCD
+        select POWER_SUPPLY
         select USB
         help
           Say Y here if you want to use the USB version of the Wacom Intuos
diff --git a/drivers/input/tablet/wacom.h b/drivers/input/tablet/wacom.h
index febbfd9f3a84..b4842d0e61dd 100644
--- a/drivers/input/tablet/wacom.h
+++ b/drivers/input/tablet/wacom.h
@@ -88,6 +88,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/init.h>
 #include <linux/usb/input.h>
+#include <linux/power_supply.h>
 #include <asm/unaligned.h>
 
 /*
@@ -121,6 +122,7 @@ struct wacom {
                 u8 hlv;       /* status led brightness button pressed (1..127) */
                 u8 img_lum;   /* OLED matrix display brightness */
         } led;
+        struct power_supply battery;
 };
 
 static inline void wacom_schedule_work(struct wacom_wac *wacom_wac)
diff --git a/drivers/input/tablet/wacom_sys.c b/drivers/input/tablet/wacom_sys.c
index 2fc77053960f..19ba58640dc2 100644
--- a/drivers/input/tablet/wacom_sys.c
+++ b/drivers/input/tablet/wacom_sys.c
@@ -843,6 +843,55 @@ static void wacom_destroy_leds(struct wacom *wacom)
         }
 }
 
+static enum power_supply_property wacom_battery_props[] = {
+        POWER_SUPPLY_PROP_CAPACITY
+};
+
+static int wacom_battery_get_property(struct power_supply *psy,
+                                      enum power_supply_property psp,
+                                      union power_supply_propval *val)
+{
+        struct wacom *wacom = container_of(psy, struct wacom, battery);
+        int ret = 0;
+
+        switch (psp) {
+                case POWER_SUPPLY_PROP_CAPACITY:
+                        val->intval =
+                                wacom->wacom_wac.battery_capacity * 100 / 31;
+                        break;
+                default:
+                        ret = -EINVAL;
+                        break;
+        }
+
+        return ret;
+}
+
+static int wacom_initialize_battery(struct wacom *wacom)
+{
+        int error = 0;
+
+        if (wacom->wacom_wac.features.quirks & WACOM_QUIRK_MONITOR) {
+                wacom->battery.properties = wacom_battery_props;
+                wacom->battery.num_properties = ARRAY_SIZE(wacom_battery_props);
+                wacom->battery.get_property = wacom_battery_get_property;
+                wacom->battery.name = "wacom_battery";
+                wacom->battery.type = POWER_SUPPLY_TYPE_BATTERY;
+                wacom->battery.use_for_apm = 0;
+
+                error = power_supply_register(&wacom->usbdev->dev,
+                                              &wacom->battery);
+        }
+
+        return error;
+}
+
+static void wacom_destroy_battery(struct wacom *wacom)
+{
+        if (wacom->wacom_wac.features.quirks & WACOM_QUIRK_MONITOR)
+                power_supply_unregister(&wacom->battery);
+}
+
 static int wacom_register_input(struct wacom *wacom)
 {
         struct input_dev *input_dev;
@@ -1016,10 +1065,14 @@ static int wacom_probe(struct usb_interface *intf, const struct usb_device_id *i
         if (error)
                 goto fail4;
 
+        error = wacom_initialize_battery(wacom);
+        if (error)
+                goto fail5;
+
         if (!(features->quirks & WACOM_QUIRK_NO_INPUT)) {
                 error = wacom_register_input(wacom);
                 if (error)
-                        goto fail5;
+                        goto fail6;
         }
 
         /* Note that if query fails it is not a hard failure */
@@ -1034,6 +1087,7 @@ static int wacom_probe(struct usb_interface *intf, const struct usb_device_id *i
 
         return 0;
 
+ fail6: wacom_destroy_battery(wacom);
  fail5: wacom_destroy_leds(wacom);
  fail4: wacom_remove_shared_data(wacom_wac);
  fail3: usb_free_urb(wacom->irq);
@@ -1052,6 +1106,7 @@ static void wacom_disconnect(struct usb_interface *intf)
         cancel_work_sync(&wacom->work);
         if (wacom->wacom_wac.input)
                 input_unregister_device(wacom->wacom_wac.input);
+        wacom_destroy_battery(wacom);
         wacom_destroy_leds(wacom);
         usb_free_urb(wacom->irq);
         usb_free_coherent(interface_to_usbdev(intf), WACOM_PKGLEN_MAX,
diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c
index fce7a09fb5db..99fb6fed2bf3 100644
--- a/drivers/input/tablet/wacom_wac.c
+++ b/drivers/input/tablet/wacom_wac.c
@@ -1054,17 +1054,20 @@ static int wacom_wireless_irq(struct wacom_wac *wacom, size_t len)
 
         connected = data[1] & 0x01;
         if (connected) {
-                int pid;
+                int pid, battery;
 
                 pid = get_unaligned_be16(&data[6]);
+                battery = data[5] & 0x3f;
                 if (wacom->pid != pid) {
                         wacom->pid = pid;
                         wacom_schedule_work(wacom);
                 }
+                wacom->battery_capacity = battery;
         } else if (wacom->pid != 0) {
                 /* disconnected while previously connected */
                 wacom->pid = 0;
                 wacom_schedule_work(wacom);
+                wacom->battery_capacity = 0;
         }
 
         return 0;
diff --git a/drivers/input/tablet/wacom_wac.h b/drivers/input/tablet/wacom_wac.h
index cffaf6b7e6e9..ba5a334e54d6 100644
--- a/drivers/input/tablet/wacom_wac.h
+++ b/drivers/input/tablet/wacom_wac.h
@@ -112,6 +112,7 @@ struct wacom_wac {
         struct wacom_shared *shared;
         struct input_dev *input;
         int pid;
+        int battery_capacity;
 };
 
 #endif