/* * Force feedback support for Linux input subsystem * * Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com> * Copyright (c) 2006 Dmitry Torokhov <dtor@mail.ru> */ /* * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* #define DEBUG */ #include <linux/input.h>#include <linux/module.h>#include <linux/mutex.h>#include <linux/sched.h>#include <linux/slab.h> /* * Check that the effect_id is a valid effect and whether the user * is the owner */static int check_effect_access(struct ff_device *ff, int effect_id, struct file *file){ if (effect_id < 0 || effect_id >= ff->max_effects || !ff->effect_owners[effect_id]) return -EINVAL; if (file && ff->effect_owners[effect_id] != file) return -EACCES; return 0;} /* * Checks whether 2 effects can be combined together */static inline int check_effects_compatible(struct ff_effect *e1, struct ff_effect *e2){ return e1->type == e2->type && (e1->type != FF_PERIODIC || e1->u.periodic.waveform == e2->u.periodic.waveform);} /* * Convert an effect into compatible one */static int compat_effect(struct ff_device *ff, struct ff_effect *effect){ int magnitude; switch (effect->type) { case FF_RUMBLE: if (!test_bit(FF_PERIODIC, ff->ffbit)) return -EINVAL; /* * calculate magnitude of sine wave as average of rumble's * 2/3 of strong magnitude and 1/3 of weak magnitude */ magnitude = effect->u.rumble.strong_magnitude / 3 + effect->u.rumble.weak_magnitude / 6; effect->type = FF_PERIODIC; effect->u.periodic.waveform = FF_SINE; effect->u.periodic.period = 50; effect->u.periodic.magnitude = max(magnitude, 0x7fff); effect->u.periodic.offset = 0; effect->u.periodic.phase = 0; effect->u.periodic.envelope.attack_length = 0; effect->u.periodic.envelope.attack_level = 0; effect->u.periodic.envelope.fade_length = 0; effect->u.periodic.envelope.fade_level = 0; return 0; default: /* Let driver handle conversion */ return 0; }} /** * input_ff_upload() - upload effect into force-feedback device * @dev: input device * @effect: effect to be uploaded * @file: owner of the effect */int input_ff_upload(struct input_dev *dev, struct ff_effect *effect, struct file *file){ struct ff_device *ff = dev->ff; struct ff_effect *old; int ret = 0; int id; if (!test_bit(EV_FF, dev->evbit)) return -ENOSYS; if (effect->type < FF_EFFECT_MIN || effect->type > FF_EFFECT_MAX || !test_bit(effect->type, dev->ffbit)) { dev_dbg(&dev->dev, "invalid or not supported effect type in upload\n"); return -EINVAL; } if (effect->type == FF_PERIODIC && (effect->u.periodic.waveform < FF_WAVEFORM_MIN || effect->u.periodic.waveform > FF_WAVEFORM_MAX || !test_bit(effect->u.periodic.waveform, dev->ffbit))) { dev_dbg(&dev->dev, "invalid or not supported wave form in upload\n"); return -EINVAL; } if (!test_bit(effect->type, ff->ffbit)) { ret = compat_effect(ff, effect); if (ret) return ret; } mutex_lock(&ff->mutex); if (effect->id == -1) { for (id = 0; id < ff->max_effects; id++) if (!ff->effect_owners[id]) break; if (id >= ff->max_effects) { ret = -ENOSPC; goto out; } effect->id = id; old = NULL; } else { id = effect->id; ret = check_effect_access(ff, id, file); if (ret) goto out; old = &ff->effects[id]; if (!check_effects_compatible(effect, old)) { ret = -EINVAL; goto out; } } ret = ff->upload(dev, effect, old); if (ret) goto out; spin_lock_irq(&dev->event_lock); ff->effects[id] = *effect; ff->effect_owners[id] = file; spin_unlock_irq(&dev->event_lock); out: mutex_unlock(&ff->mutex); return ret;}EXPORT_SYMBOL_GPL(input_ff_upload); /* * Erases the effect if the requester is also the effect owner. The mutex * should already be locked before calling this function. */static int erase_effect(struct input_dev *dev, int effect_id, struct file *file){ struct ff_device *ff = dev->ff; int error; error = check_effect_access(ff, effect_id, file); if (error) return error; spin_lock_irq(&dev->event_lock); ff->playback(dev, effect_id, 0); ff->effect_owners[effect_id] = NULL; spin_unlock_irq(&dev->event_lock); if (ff->erase) { error = ff->erase(dev, effect_id); if (error) { spin_lock_irq(&dev->event_lock); ff->effect_owners[effect_id] = file; spin_unlock_irq(&dev->event_lock); return error; } } return 0;} /** * input_ff_erase - erase a force-feedback effect from device * @dev: input device to erase effect from * @effect_id: id of the effect to be erased * @file: purported owner of the request * * This function erases a force-feedback effect from specified device. * The effect will only be erased if it was uploaded through the same * file handle that is requesting erase. */int input_ff_erase(struct input_dev *dev, int effect_id, struct file *file){ struct ff_device *ff = dev->ff; int ret; if (!test_bit(EV_FF, dev->evbit)) return -ENOSYS; mutex_lock(&ff->mutex); ret = erase_effect(dev, effect_id, file); mutex_unlock(&ff->mutex); return ret;}EXPORT_SYMBOL_GPL(input_ff_erase); /* * flush_effects - erase all effects owned by a file handle */static int flush_effects(struct input_dev *dev, struct file *file){ struct ff_device *ff = dev->ff; int i; dev_dbg(&dev->dev, "flushing now\n"); mutex_lock(&ff->mutex); for (i = 0; i < ff->max_effects; i++) erase_effect(dev, i, file); mutex_unlock(&ff->mutex); return 0;} /** * input_ff_event() - generic handler for force-feedback events * @dev: input device to send the effect to * @type: event type (anything but EV_FF is ignored) * @code: event code * @value: event value */int input_ff_event(struct input_dev *dev, unsigned int type, unsigned int code, int value){ struct ff_device *ff = dev->ff; if (type != EV_FF) return 0; switch (code) { case FF_GAIN: if (!test_bit(FF_GAIN, dev->ffbit) || value > 0xffff) break; ff->set_gain(dev, value); break; case FF_AUTOCENTER: if (!test_bit(FF_AUTOCENTER, dev->ffbit) || value > 0xffff) break; ff->set_autocenter(dev, value); break; default: if (check_effect_access(ff, code, NULL) == 0) ff->playback(dev, code, value); break; } return 0;}EXPORT_SYMBOL_GPL(input_ff_event); /** * input_ff_create() - create force-feedback device * @dev: input device supporting force-feedback * @max_effects: maximum number of effects supported by the device * * This function allocates all necessary memory for a force feedback * portion of an input device and installs all default handlers. * @dev->ffbit should be already set up before calling this function. * Once ff device is created you need to setup its upload, erase, * playback and other handlers before registering input device */int input_ff_create(struct input_dev *dev, unsigned int max_effects){ struct ff_device *ff; size_t ff_dev_size; int i; if (!max_effects) { dev_err(&dev->dev, "cannot allocate device without any effects\n"); return -EINVAL; } ff_dev_size = sizeof(struct ff_device) + max_effects * sizeof(struct file *); if (ff_dev_size < max_effects) /* overflow */ return -EINVAL; ff = kzalloc(ff_dev_size, GFP_KERNEL); if (!ff) return -ENOMEM; ff->effects = kcalloc(max_effects, sizeof(struct ff_effect), GFP_KERNEL); if (!ff->effects) { kfree(ff); return -ENOMEM; } ff->max_effects = max_effects; mutex_init(&ff->mutex); dev->ff = ff; dev->flush = flush_effects; dev->event = input_ff_event; __set_bit(EV_FF, dev->evbit); /* Copy "true" bits into ff device bitmap */ for (i = 0; i <= FF_MAX; i++) if (test_bit(i, dev->ffbit)) __set_bit(i, ff->ffbit); /* we can emulate RUMBLE with periodic effects */ if (test_bit(FF_PERIODIC, ff->ffbit)) __set_bit(FF_RUMBLE, dev->ffbit); return 0;}EXPORT_SYMBOL_GPL(input_ff_create); /** * input_ff_destroy() - frees force feedback portion of input device * @dev: input device supporting force feedback * * This function is only needed in error path as input core will * automatically free force feedback structures when device is * destroyed. */void input_ff_destroy(struct input_dev *dev){ struct ff_device *ff = dev->ff; __clear_bit(EV_FF, dev->evbit); if (ff) { if (ff->destroy) ff->destroy(ff); kfree(ff->private); kfree(ff->effects); kfree(ff); dev->ff = NULL; }}EXPORT_SYMBOL_GPL(input_ff_destroy);
/*
* Force feedback support for Linux input subsystem
*
* Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com>
* Copyright (c) 2006 Dmitry Torokhov <dtor@mail.ru>
*/
/*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* #define DEBUG */
#include <linux/input.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/slab.h>
/*
* Check that the effect_id is a valid effect and whether the user
* is the owner
*/
static int check_effect_access(struct ff_device *ff, int effect_id,
struct file *file)
{
if (effect_id < 0 || effect_id >= ff->max_effects ||
!ff->effect_owners[effect_id])
return -EINVAL;
if (file && ff->effect_owners[effect_id] != file)
return -EACCES;
return 0;
}
/*
* Checks whether 2 effects can be combined together
*/
static inline int check_effects_compatible(struct ff_effect *e1,
struct ff_effect *e2)
{
return e1->type == e2->type &&
(e1->type != FF_PERIODIC ||
e1->u.periodic.waveform == e2->u.periodic.waveform);
}
/*
* Convert an effect into compatible one
*/
static int compat_effect(struct ff_device *ff, struct ff_effect *effect)
{
int magnitude;
switch (effect->type) {
case FF_RUMBLE:
if (!test_bit(FF_PERIODIC, ff->ffbit))
return -EINVAL;
/*
* calculate magnitude of sine wave as average of rumble's
* 2/3 of strong magnitude and 1/3 of weak magnitude
*/
magnitude = effect->u.rumble.strong_magnitude / 3 +
effect->u.rumble.weak_magnitude / 6;
effect->type = FF_PERIODIC;
effect->u.periodic.waveform = FF_SINE;
effect->u.periodic.period = 50;
effect->u.periodic.magnitude = max(magnitude, 0x7fff);
effect->u.periodic.offset = 0;
effect->u.periodic.phase = 0;
effect->u.periodic.envelope.attack_length = 0;
effect->u.periodic.envelope.attack_level = 0;
effect->u.periodic.envelope.fade_length = 0;
effect->u.periodic.envelope.fade_level = 0;
return 0;
default:
/* Let driver handle conversion */
return 0;
}
}
/**
* input_ff_upload() - upload effect into force-feedback device
* @dev: input device
* @effect: effect to be uploaded
* @file: owner of the effect
*/
int input_ff_upload(struct input_dev *dev, struct ff_effect *effect,
struct file *file)
{
struct ff_device *ff = dev->ff;
struct ff_effect *old;
int ret = 0;
int id;
if (!test_bit(EV_FF, dev->evbit))
return -ENOSYS;
if (effect->type < FF_EFFECT_MIN || effect->type > FF_EFFECT_MAX ||
!test_bit(effect->type, dev->ffbit)) {
dev_dbg(&dev->dev, "invalid or not supported effect type in upload\n");
return -EINVAL;
}
if (effect->type == FF_PERIODIC &&
(effect->u.periodic.waveform < FF_WAVEFORM_MIN ||
effect->u.periodic.waveform > FF_WAVEFORM_MAX ||
!test_bit(effect->u.periodic.waveform, dev->ffbit))) {
dev_dbg(&dev->dev, "invalid or not supported wave form in upload\n");
return -EINVAL;
}
if (!test_bit(effect->type, ff->ffbit)) {
ret = compat_effect(ff, effect);
if (ret)
return ret;
}
mutex_lock(&ff->mutex);
if (effect->id == -1) {
for (id = 0; id < ff->max_effects; id++)
if (!ff->effect_owners[id])
break;
if (id >= ff->max_effects) {
ret = -ENOSPC;
goto out;
}
effect->id = id;
old = NULL;
} else {
id = effect->id;
ret = check_effect_access(ff, id, file);
if (ret)
goto out;
old = &ff->effects[id];
if (!check_effects_compatible(effect, old)) {
ret = -EINVAL;
goto out;
}
}
ret = ff->upload(dev, effect, old);
if (ret)
goto out;
spin_lock_irq(&dev->event_lock);
ff->effects[id] = *effect;
ff->effect_owners[id] = file;
spin_unlock_irq(&dev->event_lock);
out:
mutex_unlock(&ff->mutex);
return ret;
}
EXPORT_SYMBOL_GPL(input_ff_upload);
/*
* Erases the effect if the requester is also the effect owner. The mutex
* should already be locked before calling this function.
*/
static int erase_effect(struct input_dev *dev, int effect_id,
struct file *file)
{
struct ff_device *ff = dev->ff;
int error;
error = check_effect_access(ff, effect_id, file);
if (error)
return error;
spin_lock_irq(&dev->event_lock);
ff->playback(dev, effect_id, 0);
ff->effect_owners[effect_id] = NULL;
spin_unlock_irq(&dev->event_lock);
if (ff->erase) {
error = ff->erase(dev, effect_id);
if (error) {
spin_lock_irq(&dev->event_lock);
ff->effect_owners[effect_id] = file;
spin_unlock_irq(&dev->event_lock);
return error;
}
}
return 0;
}
/**
* input_ff_erase - erase a force-feedback effect from device
* @dev: input device to erase effect from
* @effect_id: id of the effect to be erased
* @file: purported owner of the request
*
* This function erases a force-feedback effect from specified device.
* The effect will only be erased if it was uploaded through the same
* file handle that is requesting erase.
*/
int input_ff_erase(struct input_dev *dev, int effect_id, struct file *file)
{
struct ff_device *ff = dev->ff;
int ret;
if (!test_bit(EV_FF, dev->evbit))
return -ENOSYS;
mutex_lock(&ff->mutex);
ret = erase_effect(dev, effect_id, file);
mutex_unlock(&ff->mutex);
return ret;
}
EXPORT_SYMBOL_GPL(input_ff_erase);
/*
* flush_effects - erase all effects owned by a file handle
*/
static int flush_effects(struct input_dev *dev, struct file *file)
{
struct ff_device *ff = dev->ff;
int i;
dev_dbg(&dev->dev, "flushing now\n");
mutex_lock(&ff->mutex);
for (i = 0; i < ff->max_effects; i++)
erase_effect(dev, i, file);
mutex_unlock(&ff->mutex);
return 0;
}
/**
* input_ff_event() - generic handler for force-feedback events
* @dev: input device to send the effect to
* @type: event type (anything but EV_FF is ignored)
* @code: event code
* @value: event value
*/
int input_ff_event(struct input_dev *dev, unsigned int type,
unsigned int code, int value)
{
struct ff_device *ff = dev->ff;
if (type != EV_FF)
return 0;
switch (code) {
case FF_GAIN:
if (!test_bit(FF_GAIN, dev->ffbit) || value > 0xffff)
break;
ff->set_gain(dev, value);
break;
case FF_AUTOCENTER:
if (!test_bit(FF_AUTOCENTER, dev->ffbit) || value > 0xffff)
break;
ff->set_autocenter(dev, value);
break;
default:
if (check_effect_access(ff, code, NULL) == 0)
ff->playback(dev, code, value);
break;
}
return 0;
}
EXPORT_SYMBOL_GPL(input_ff_event);
/**
* input_ff_create() - create force-feedback device
* @dev: input device supporting force-feedback
* @max_effects: maximum number of effects supported by the device
*
* This function allocates all necessary memory for a force feedback
* portion of an input device and installs all default handlers.
* @dev->ffbit should be already set up before calling this function.
* Once ff device is created you need to setup its upload, erase,
* playback and other handlers before registering input device
*/
int input_ff_create(struct input_dev *dev, unsigned int max_effects)
{
struct ff_device *ff;
size_t ff_dev_size;
int i;
if (!max_effects) {
dev_err(&dev->dev, "cannot allocate device without any effects\n");
return -EINVAL;
}
ff_dev_size = sizeof(struct ff_device) +
max_effects * sizeof(struct file *);
if (ff_dev_size < max_effects) /* overflow */
return -EINVAL;
ff = kzalloc(ff_dev_size, GFP_KERNEL);
if (!ff)
return -ENOMEM;
ff->effects = kcalloc(max_effects, sizeof(struct ff_effect),
GFP_KERNEL);
if (!ff->effects) {
kfree(ff);
return -ENOMEM;
}
ff->max_effects = max_effects;
mutex_init(&ff->mutex);
dev->ff = ff;
dev->flush = flush_effects;
dev->event = input_ff_event;
__set_bit(EV_FF, dev->evbit);
/* Copy "true" bits into ff device bitmap */
for (i = 0; i <= FF_MAX; i++)
if (test_bit(i, dev->ffbit))
__set_bit(i, ff->ffbit);
/* we can emulate RUMBLE with periodic effects */
if (test_bit(FF_PERIODIC, ff->ffbit))
__set_bit(FF_RUMBLE, dev->ffbit);
return 0;
}
EXPORT_SYMBOL_GPL(input_ff_create);
/**
* input_ff_destroy() - frees force feedback portion of input device
* @dev: input device supporting force feedback
*
* This function is only needed in error path as input core will
* automatically free force feedback structures when device is
* destroyed.
*/
void input_ff_destroy(struct input_dev *dev)
{
struct ff_device *ff = dev->ff;
__clear_bit(EV_FF, dev->evbit);
if (ff) {
if (ff->destroy)
ff->destroy(ff);
kfree(ff->private);
kfree(ff->effects);
kfree(ff);
dev->ff = NULL;
}
}
EXPORT_SYMBOL_GPL(input_ff_destroy);