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Input: uinput - switch to the new FF interface
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The userspace interface of the force feedback part is changed and
documentation in uinput.h is updated accordingly. MODULE_VERSION
is also incremented to reflect the revision.

Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
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Anssi Hannula authored and Dmitry Torokhov committed Jul 19, 2006
1 parent dc76c91 commit ff46255
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Showing 2 changed files with 74 additions and 28 deletions.
67 changes: 51 additions & 16 deletions drivers/input/misc/uinput.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,9 @@
* Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
*
* Changes/Revisions:
* 0.3 09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>)
* - updated ff support for the changes in kernel interface
* - added MODULE_VERSION
* 0.2 16/10/2004 (Micah Dowty <micah@navi.cx>)
* - added force feedback support
* - added UI_SET_PHYS
Expand Down Expand Up @@ -107,18 +110,31 @@ static int uinput_request_submit(struct input_dev *dev, struct uinput_request *r
return request->retval;
}

static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect)
static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
{
uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
}

static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
{
uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
}

static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
{
return uinput_dev_event(dev, EV_FF, effect_id, value);
}

static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect, struct ff_effect *old)
{
struct uinput_request request;
int retval;

if (!test_bit(EV_FF, dev->evbit))
return -ENOSYS;

request.id = -1;
init_completion(&request.done);
request.code = UI_FF_UPLOAD;
request.u.effect = effect;
request.u.upload.effect = effect;
request.u.upload.old = old;

retval = uinput_request_reserve_slot(dev->private, &request);
if (!retval)
Expand Down Expand Up @@ -168,22 +184,37 @@ static void uinput_destroy_device(struct uinput_device *udev)

static int uinput_create_device(struct uinput_device *udev)
{
struct input_dev *dev = udev->dev;
int error;

if (udev->state != UIST_SETUP_COMPLETE) {
printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
return -EINVAL;
}

error = input_register_device(udev->dev);
if (error) {
uinput_destroy_device(udev);
return error;
if (udev->ff_effects_max) {
error = input_ff_create(dev, udev->ff_effects_max);
if (error)
goto fail1;

dev->ff->upload = uinput_dev_upload_effect;
dev->ff->erase = uinput_dev_erase_effect;
dev->ff->playback = uinput_dev_playback;
dev->ff->set_gain = uinput_dev_set_gain;
dev->ff->set_autocenter = uinput_dev_set_autocenter;
}

error = input_register_device(udev->dev);
if (error)
goto fail2;

udev->state = UIST_CREATED;

return 0;

fail2: input_ff_destroy(dev);
fail1: uinput_destroy_device(udev);
return error;
}

static int uinput_open(struct inode *inode, struct file *file)
Expand Down Expand Up @@ -243,8 +274,6 @@ static int uinput_allocate_device(struct uinput_device *udev)
return -ENOMEM;

udev->dev->event = uinput_dev_event;
udev->dev->upload_effect = uinput_dev_upload_effect;
udev->dev->erase_effect = uinput_dev_erase_effect;
udev->dev->private = udev;

return 0;
Expand Down Expand Up @@ -278,6 +307,8 @@ static int uinput_setup_device(struct uinput_device *udev, const char __user *bu
goto exit;
}

udev->ff_effects_max = user_dev->ff_effects_max;

size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE) + 1;
if (!size) {
retval = -EINVAL;
Expand All @@ -296,7 +327,6 @@ static int uinput_setup_device(struct uinput_device *udev, const char __user *bu
dev->id.vendor = user_dev->id.vendor;
dev->id.product = user_dev->id.product;
dev->id.version = user_dev->id.version;
dev->ff_effects_max = user_dev->ff_effects_max;

size = sizeof(int) * (ABS_MAX + 1);
memcpy(dev->absmax, user_dev->absmax, size);
Expand Down Expand Up @@ -525,12 +555,17 @@ static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
break;
}
req = uinput_request_find(udev, ff_up.request_id);
if (!(req && req->code == UI_FF_UPLOAD && req->u.effect)) {
if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
retval = -EINVAL;
break;
}
ff_up.retval = 0;
memcpy(&ff_up.effect, req->u.effect, sizeof(struct ff_effect));
memcpy(&ff_up.effect, req->u.upload.effect, sizeof(struct ff_effect));
if (req->u.upload.old)
memcpy(&ff_up.old, req->u.upload.old, sizeof(struct ff_effect));
else
memset(&ff_up.old, 0, sizeof(struct ff_effect));

if (copy_to_user(p, &ff_up, sizeof(ff_up))) {
retval = -EFAULT;
break;
Expand Down Expand Up @@ -561,12 +596,11 @@ static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
break;
}
req = uinput_request_find(udev, ff_up.request_id);
if (!(req && req->code == UI_FF_UPLOAD && req->u.effect)) {
if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
retval = -EINVAL;
break;
}
req->retval = ff_up.retval;
memcpy(req->u.effect, &ff_up.effect, sizeof(struct ff_effect));
uinput_request_done(udev, req);
break;

Expand Down Expand Up @@ -622,6 +656,7 @@ static void __exit uinput_exit(void)
MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
MODULE_DESCRIPTION("User level driver support for input subsystem");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.3");

module_init(uinput_init);
module_exit(uinput_exit);
Expand Down
35 changes: 23 additions & 12 deletions include/linux/uinput.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -22,12 +22,18 @@
* Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
*
* Changes/Revisions:
* 0.3 24/05/2006 (Anssi Hannula <anssi.hannulagmail.com>)
* - update ff support for the changes in kernel interface
* - add UINPUT_VERSION
* 0.2 16/10/2004 (Micah Dowty <micah@navi.cx>)
* - added force feedback support
* - added UI_SET_PHYS
* 0.1 20/06/2002
* - first public version
*/

#define UINPUT_VERSION 3

#ifdef __KERNEL__
#define UINPUT_MINOR 223
#define UINPUT_NAME "uinput"
Expand All @@ -45,7 +51,10 @@ struct uinput_request {

union {
int effect_id;
struct ff_effect* effect;
struct {
struct ff_effect *effect;
struct ff_effect *old;
} upload;
} u;
};

Expand All @@ -58,6 +67,7 @@ struct uinput_device {
unsigned char head;
unsigned char tail;
struct input_event buff[UINPUT_BUFFER_SIZE];
int ff_effects_max;

struct uinput_request *requests[UINPUT_NUM_REQUESTS];
wait_queue_head_t requests_waitq;
Expand All @@ -69,6 +79,7 @@ struct uinput_ff_upload {
int request_id;
int retval;
struct ff_effect effect;
struct ff_effect old;
};

struct uinput_ff_erase {
Expand Down Expand Up @@ -98,33 +109,33 @@ struct uinput_ff_erase {
#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
/*
* 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.
* The described callback mechanism is only used if ff_effects_max
* is set.
*
* To implement upload_effect():
* 1. Wait for an event with type==EV_UINPUT and code==UI_FF_UPLOAD.
* 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.
* ff_effects passed to upload_effect().
* 4. Perform the effect upload, and place 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.
* 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.
Expand All @@ -133,13 +144,13 @@ struct uinput_ff_erase {
* 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.
/*
* 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
Expand Down

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