Force feedback support for uinput

@@ -22,6 +22,9 @@
  * Author: Aristeu Sergio Rozanski Filho <[email protected]>
  * 
  * Changes/Revisions:
+ *	0.2	16/10/2004 (Micah Dowty <[email protected]>)
+ *		- added force feedback support
+ *             - added UI_SET_PHYS
  *	0.1	20/06/2002
  *		- first public version
  */

@@ -29,10 +32,25 @@
 #define UINPUT_MINOR		223
 #define UINPUT_NAME		"uinput"
 #define UINPUT_BUFFER_SIZE	16
+#define UINPUT_NUM_REQUESTS	16
 
 /* state flags => bit index for {set|clear|test}_bit ops */
 #define UIST_CREATED		0
 
+struct uinput_request {
+	int			id;
+	int			code;	/* UI_FF_UPLOAD, UI_FF_ERASE */
+
+	int			retval;
+	wait_queue_head_t	waitq;
+	int			completed;
+
+	union {
+		int		effect_id;
+		struct ff_effect* effect;
+	} u;
+};
+
 struct uinput_device {
 	struct input_dev	*dev;
 	unsigned long		state;

@@ -41,13 +59,30 @@
 				head,
 				tail;
 	struct input_event	buff[UINPUT_BUFFER_SIZE];
+
+	struct uinput_request	*requests[UINPUT_NUM_REQUESTS];
+	wait_queue_head_t	requests_waitq;
+	struct semaphore	requests_sem;
 };
 #endif	/* __KERNEL__ */
 
+struct uinput_ff_upload {
+	int			request_id;
+	int			retval;
+	struct ff_effect	effect;
+};
+
+struct uinput_ff_erase {
+	int			request_id;
+	int			retval;
+	int			effect_id;
+};
+
 /* ioctl */
 #define UINPUT_IOCTL_BASE	'U'
 #define UI_DEV_CREATE		_IO(UINPUT_IOCTL_BASE, 1)
 #define UI_DEV_DESTROY		_IO(UINPUT_IOCTL_BASE, 2)
+
 #define UI_SET_EVBIT		_IOW(UINPUT_IOCTL_BASE, 100, int)
 #define UI_SET_KEYBIT		_IOW(UINPUT_IOCTL_BASE, 101, int)
 #define UI_SET_RELBIT		_IOW(UINPUT_IOCTL_BASE, 102, int)

@@ -56,6 +91,63 @@
 #define UI_SET_LEDBIT		_IOW(UINPUT_IOCTL_BASE, 105, int)
 #define UI_SET_SNDBIT		_IOW(UINPUT_IOCTL_BASE, 106, int)
 #define UI_SET_FFBIT		_IOW(UINPUT_IOCTL_BASE, 107, int)
+#define UI_SET_PHYS		_IOW(UINPUT_IOCTL_BASE, 108, char*)
+
+#define UI_BEGIN_FF_UPLOAD	_IOWR(UINPUT_IOCTL_BASE, 200, struct uinput_ff_upload)
+#define UI_END_FF_UPLOAD	_IOW(UINPUT_IOCTL_BASE, 201, struct uinput_ff_upload)
+#define UI_BEGIN_FF_ERASE	_IOWR(UINPUT_IOCTL_BASE, 202, struct uinput_ff_erase)
+#define UI_END_FF_ERASE		_IOW(UINPUT_IOCTL_BASE, 203, struct uinput_ff_erase)
+
+/* To write a force-feedback-capable driver, the upload_effect
+ * and erase_effect callbacks in input_dev must be implemented.
+ * The uinput driver will generate a fake input event when one of
+ * these callbacks are invoked. The userspace code then uses
+ * ioctls to retrieve additional parameters and send the return code.
+ * The callback blocks until this return code is sent.
+ *
+ * The described callback mechanism is only used if EV_FF is set.
+ * Otherwise, default implementations of upload_effect and erase_effect
+ * are used.
+ *
+ * To implement upload_effect():
+ *   1. Wait for an event with type==EV_UINPUT and code==UI_FF_UPLOAD.
+ *      A request ID will be given in 'value'.
+ *   2. Allocate a uinput_ff_upload struct, fill in request_id with
+ *      the 'value' from the EV_UINPUT event.
+ *   3. Issue a UI_BEGIN_FF_UPLOAD ioctl, giving it the
+ *      uinput_ff_upload struct. It will be filled in with the
+ *      ff_effect passed to upload_effect().
+ *   4. Perform the effect upload, and place the modified ff_effect
+ *      and a return code back into the uinput_ff_upload struct.
+ *   5. Issue a UI_END_FF_UPLOAD ioctl, also giving it the
+ *      uinput_ff_upload_effect struct. This will complete execution
+ *      of our upload_effect() handler.
+ *
+ * To implement erase_effect():
+ *   1. Wait for an event with type==EV_UINPUT and code==UI_FF_ERASE.
+ *      A request ID will be given in 'value'.
+ *   2. Allocate a uinput_ff_erase struct, fill in request_id with
+ *      the 'value' from the EV_UINPUT event.
+ *   3. Issue a UI_BEGIN_FF_ERASE ioctl, giving it the
+ *      uinput_ff_erase struct. It will be filled in with the
+ *      effect ID passed to erase_effect().
+ *   4. Perform the effect erasure, and place a return code back
+ *      into the uinput_ff_erase struct.
+ *      and a return code back into the uinput_ff_erase struct.
+ *   5. Issue a UI_END_FF_ERASE ioctl, also giving it the
+ *      uinput_ff_erase_effect struct. This will complete execution
+ *      of our erase_effect() handler.
+ */
+
+/* This is the new event type, used only by uinput.
+ * 'code' is UI_FF_UPLOAD or UI_FF_ERASE, and 'value'
+ * is the unique request ID. This number was picked
+ * arbitrarily, above EV_MAX (since the input system
+ * never sees it) but in the range of a 16-bit int.
+ */
+#define EV_UINPUT		0x0101
+#define UI_FF_UPLOAD		1
+#define UI_FF_ERASE		2
 
 #ifndef NBITS
 #define NBITS(x) ((((x)-1)/(sizeof(long)*8))+1)

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diff -puNr linux-2.6.10-rc2-bk5/include/linux/input.h linux-uinput-ff/include/linux/input.h
@@ -94,6 +94,8 @@ struct input_absinfo {
 #define EV_FF_STATUS		0x17
 #define EV_MAX			0x1f
 
+#define EV_UINPUT		0x0101     /* Used only between /dev/uinput and applications */
+
 /*
  * Synchronization events.
  */

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