HID: wiimote: convert BATTERY to module

This introduces a new sub-device module for the BATTERY handlers. It
moves the whole power_supply battery handling over to wiimote-modules.

This doesn't change any semantics or ABI but only converts the battery
handling into a sub-device module.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 98 insertions, 0 deletions

diff --git a/drivers/hid/hid-wiimote-modules.c b/drivers/hid/hid-wiimote-modules.c
index 616f24024f77..4cbbbe651ba5 100644
--- a/drivers/hid/hid-wiimote-modules.c
+++ b/drivers/hid/hid-wiimote-modules.c
@@ -171,9 +171,107 @@ static const struct wiimod_ops wiimod_rumble = {
         .remove = wiimod_rumble_remove,
 };
 
+/*
+ * Battery
+ * 1 byte of battery capacity information is sent along every protocol status
+ * report. The wiimote core caches it but we try to update it on every
+ * user-space request.
+ * This is supported by nearly every device so it's almost always enabled.
+ */
+
+static enum power_supply_property wiimod_battery_props[] = {
+        POWER_SUPPLY_PROP_CAPACITY,
+        POWER_SUPPLY_PROP_SCOPE,
+};
+
+static int wiimod_battery_get_property(struct power_supply *psy,
+                                       enum power_supply_property psp,
+                                       union power_supply_propval *val)
+{
+        struct wiimote_data *wdata = container_of(psy, struct wiimote_data,
+                                                  battery);
+        int ret = 0, state;
+        unsigned long flags;
+
+        if (psp == POWER_SUPPLY_PROP_SCOPE) {
+                val->intval = POWER_SUPPLY_SCOPE_DEVICE;
+                return 0;
+        } else if (psp != POWER_SUPPLY_PROP_CAPACITY) {
+                return -EINVAL;
+        }
+
+        ret = wiimote_cmd_acquire(wdata);
+        if (ret)
+                return ret;
+
+        spin_lock_irqsave(&wdata->state.lock, flags);
+        wiimote_cmd_set(wdata, WIIPROTO_REQ_SREQ, 0);
+        wiiproto_req_status(wdata);
+        spin_unlock_irqrestore(&wdata->state.lock, flags);
+
+        wiimote_cmd_wait(wdata);
+        wiimote_cmd_release(wdata);
+
+        spin_lock_irqsave(&wdata->state.lock, flags);
+        state = wdata->state.cmd_battery;
+        spin_unlock_irqrestore(&wdata->state.lock, flags);
+
+        val->intval = state * 100 / 255;
+        return ret;
+}
+
+static int wiimod_battery_probe(const struct wiimod_ops *ops,
+                                struct wiimote_data *wdata)
+{
+        int ret;
+
+        wdata->battery.properties = wiimod_battery_props;
+        wdata->battery.num_properties = ARRAY_SIZE(wiimod_battery_props);
+        wdata->battery.get_property = wiimod_battery_get_property;
+        wdata->battery.type = POWER_SUPPLY_TYPE_BATTERY;
+        wdata->battery.use_for_apm = 0;
+        wdata->battery.name = kasprintf(GFP_KERNEL, "wiimote_battery_%s",
+                                        wdata->hdev->uniq);
+        if (!wdata->battery.name)
+                return -ENOMEM;
+
+        ret = power_supply_register(&wdata->hdev->dev, &wdata->battery);
+        if (ret) {
+                hid_err(wdata->hdev, "cannot register battery device\n");
+                goto err_free;
+        }
+
+        power_supply_powers(&wdata->battery, &wdata->hdev->dev);
+        return 0;
+
+err_free:
+        kfree(wdata->battery.name);
+        wdata->battery.name = NULL;
+        return ret;
+}
+
+static void wiimod_battery_remove(const struct wiimod_ops *ops,
+                                  struct wiimote_data *wdata)
+{
+        if (!wdata->battery.name)
+                return;
+
+        power_supply_unregister(&wdata->battery);
+        kfree(wdata->battery.name);
+        wdata->battery.name = NULL;
+}
+
+static const struct wiimod_ops wiimod_battery = {
+        .flags = 0,
+        .arg = 0,
+        .probe = wiimod_battery_probe,
+        .remove = wiimod_battery_remove,
+};
+
 /* module table */
 
 const struct wiimod_ops *wiimod_table[WIIMOD_NUM] = {
         [WIIMOD_KEYS] = &wiimod_keys,
         [WIIMOD_RUMBLE] = &wiimod_rumble,
+        [WIIMOD_BATTERY] = &wiimod_battery,
 };