HID: wiimote: Add debugfs support stubs

Add initializer and deinitializer for debugfs support. This will later allow raw
eeprom access and direct DRM modifications to debug wiimote behaviour and
further protocol reverse-engineerings.

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

4 files changed, 73 insertions, 0 deletions

diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 5fab4e632eab..15c1a84537eb 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -29,6 +29,9 @@ hid-wiimote-y		:= hid-wiimote-core.o
 ifdef CONFIG_HID_WIIMOTE_EXT
         hid-wiimote-y   += hid-wiimote-ext.o
 endif
+ifdef CONFIG_DEBUG_FS
+        hid-wiimote-y   += hid-wiimote-debug.o
+endif
 
 obj-$(CONFIG_HID_A4TECH)        += hid-a4tech.o
 obj-$(CONFIG_HID_ACRUX)         += hid-axff.o
diff --git a/drivers/hid/hid-wiimote-core.c b/drivers/hid/hid-wiimote-core.c
index d8ed1ec58e9f..919abbaba840 100644
--- a/drivers/hid/hid-wiimote-core.c
+++ b/drivers/hid/hid-wiimote-core.c
@@ -1161,6 +1161,7 @@ err:
 
 static void wiimote_destroy(struct wiimote_data *wdata)
 {
+        wiidebug_deinit(wdata);
         wiiext_deinit(wdata);
         wiimote_leds_destroy(wdata);
 
@@ -1237,6 +1238,10 @@ static int wiimote_hid_probe(struct hid_device *hdev,
         if (ret)
                 goto err_free;
 
+        ret = wiidebug_init(wdata);
+        if (ret)
+                goto err_free;
+
         hid_info(hdev, "New device registered\n");
 
         /* by default set led1 after device initialization */
diff --git a/drivers/hid/hid-wiimote-debug.c b/drivers/hid/hid-wiimote-debug.c
new file mode 100644
index 000000000000..6282e3c1a362
--- /dev/null
+++ b/drivers/hid/hid-wiimote-debug.c
@@ -0,0 +1,52 @@
+/*
+ * Debug support for HID Nintendo Wiimote devices
+ * Copyright (c) 2011 David Herrmann
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include "hid-wiimote.h"
+
+struct wiimote_debug {
+        struct wiimote_data *wdata;
+};
+
+int wiidebug_init(struct wiimote_data *wdata)
+{
+        struct wiimote_debug *dbg;
+        unsigned long flags;
+
+        dbg = kzalloc(sizeof(*dbg), GFP_KERNEL);
+        if (!dbg)
+                return -ENOMEM;
+
+        dbg->wdata = wdata;
+
+        spin_lock_irqsave(&wdata->state.lock, flags);
+        wdata->debug = dbg;
+        spin_unlock_irqrestore(&wdata->state.lock, flags);
+
+        return 0;
+}
+
+void wiidebug_deinit(struct wiimote_data *wdata)
+{
+        struct wiimote_debug *dbg = wdata->debug;
+        unsigned long flags;
+
+        if (!dbg)
+                return;
+
+        spin_lock_irqsave(&wdata->state.lock, flags);
+        wdata->debug = NULL;
+        spin_unlock_irqrestore(&wdata->state.lock, flags);
+
+        kfree(dbg);
+}
diff --git a/drivers/hid/hid-wiimote.h b/drivers/hid/hid-wiimote.h
index 1f3e53a3a148..89b8851dbf1f 100644
--- a/drivers/hid/hid-wiimote.h
+++ b/drivers/hid/hid-wiimote.h
@@ -74,6 +74,7 @@ struct wiimote_data {
         struct input_dev *ir;
         struct power_supply battery;
         struct wiimote_ext *ext;
+        struct wiimote_debug *debug;
 
         spinlock_t qlock;
         __u8 head;
@@ -137,6 +138,18 @@ static inline void wiiext_handle(void *u, const __u8 *p) { }
 
 #endif
 
+#ifdef CONFIG_DEBUG_FS
+
+extern int wiidebug_init(struct wiimote_data *wdata);
+extern void wiidebug_deinit(struct wiimote_data *wdata);
+
+#else
+
+static inline int wiidebug_init(void *u) { return 0; }
+static inline void wiidebug_deinit(void *u) { }
+
+#endif
+
 /* requires the state.lock spinlock to be held */
 static inline bool wiimote_cmd_pending(struct wiimote_data *wdata, int cmd,
                                                                 __u32 opt)