1 files changed, 56 insertions, 0 deletions

diff --git a/drivers/hid/hid-wiimote.c b/drivers/hid/hid-wiimote.c
index c811a7d14174..0a5e458820b2 100644
--- a/drivers/hid/hid-wiimote.c
+++ b/drivers/hid/hid-wiimote.c
@@ -10,11 +10,13 @@
  * any later version.
  */
 
+#include <linux/completion.h>
 #include <linux/device.h>
 #include <linux/hid.h>
 #include <linux/input.h>
 #include <linux/leds.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/spinlock.h>
 #include "hid-ids.h"
 
@@ -31,6 +33,12 @@ struct wiimote_state {
 	spinlock_t lock;
 	__u8 flags;
 	__u8 accel_split[2];
+
+	/* synchronous cmd requests */
+	struct mutex sync;
+	struct completion ready;
+	int cmd;
+	__u32 opt;
 };
 
 struct wiimote_data {
@@ -118,6 +126,52 @@ static __u16 wiiproto_keymap[] = {
 	BTN_MODE,	/* WIIPROTO_KEY_HOME */
 };
 
+/* requires the state.lock spinlock to be held */
+static inline bool wiimote_cmd_pending(struct wiimote_data *wdata, int cmd,
+								__u32 opt)
+{
+	return wdata->state.cmd == cmd && wdata->state.opt == opt;
+}
+
+/* requires the state.lock spinlock to be held */
+static inline void wiimote_cmd_complete(struct wiimote_data *wdata)
+{
+	wdata->state.cmd = WIIPROTO_REQ_NULL;
+	complete(&wdata->state.ready);
+}
+
+static inline int wiimote_cmd_acquire(struct wiimote_data *wdata)
+{
+	return mutex_lock_interruptible(&wdata->state.sync) ? -ERESTARTSYS : 0;
+}
+
+/* requires the state.lock spinlock to be held */
+static inline void wiimote_cmd_set(struct wiimote_data *wdata, int cmd,
+								__u32 opt)
+{
+	INIT_COMPLETION(wdata->state.ready);
+	wdata->state.cmd = cmd;
+	wdata->state.opt = opt;
+}
+
+static inline void wiimote_cmd_release(struct wiimote_data *wdata)
+{
+	mutex_unlock(&wdata->state.sync);
+}
+
+static inline int wiimote_cmd_wait(struct wiimote_data *wdata)
+{
+	int ret;
+
+	ret = wait_for_completion_interruptible_timeout(&wdata->state.ready, HZ);
+	if (ret < 0)
+		return -ERESTARTSYS;
+	else if (ret == 0)
+		return -EIO;
+	else
+		return 0;
+}
+
 static ssize_t wiimote_hid_send(struct hid_device *hdev, __u8 *buffer,
 								size_t count)
 {
@@ -875,6 +929,8 @@ static struct wiimote_data *wiimote_create(struct hid_device *hdev)
 	INIT_WORK(&wdata->worker, wiimote_worker);
 
 	spin_lock_init(&wdata->state.lock);
+	init_completion(&wdata->state.ready);
+	mutex_init(&wdata->state.sync);
 
 	return wdata;