drivers/input/ff-core.c - kernel/skids - Git at Google

 /*
  *  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 */

 #define debug(format, arg...) pr_debug("ff-core: " format "\n", ## arg)

 #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 manginude 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)) {
 		debug("invalid or not supported effect type in upload");
 		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))) {
 		debug("invalid or not supported wave form in upload");
 		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 ffect 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;

 	debug("flushing now");

 	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, int max_effects)
 {
 	struct ff_device *ff;
 	int i;

 	if (!max_effects) {
 		printk(KERN_ERR
 		       "ff-core: cannot allocate device without any effects\n");
 		return -EINVAL;
 	}

 	ff = kzalloc(sizeof(struct ff_device) +
 		     max_effects * sizeof(struct file *), 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 */

	#define debug(format, arg...) pr_debug("ff-core: " format "\n", ## arg)

	#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 manginude 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)) {
	debug("invalid or not supported effect type in upload");
	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))) {
	debug("invalid or not supported wave form in upload");
	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 ffect 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;

	debug("flushing now");

	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, int max_effects)
	{
	struct ff_device *ff;
	int i;

	if (!max_effects) {
	printk(KERN_ERR
	"ff-core: cannot allocate device without any effects\n");
	return -EINVAL;
	}

	ff = kzalloc(sizeof(struct ff_device) +
	max_effects * sizeof(struct file *), 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);