[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / input / ff-core.c

/*
 *  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 pr_fmt(fmt) KBUILD_BASENAME ": " fmt

#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)) {
		pr_debug("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))) {
		pr_debug("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 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;

	pr_debug("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) {
		pr_err("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);
Commit	Line	Data
509ca1a9 AH	1	/*
	2	* Force feedback support for Linux input subsystem
	3	*
	4	* Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com>
	5	* Copyright (c) 2006 Dmitry Torokhov <dtor@mail.ru>
	6	*/
	7
	8	/*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2 of the License, or
	12	* (at your option) any later version.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
	20	* along with this program; if not, write to the Free Software
	21	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	22	*/
	23
	24	/* #define DEBUG */
	25
da0c4901	26	#define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
509ca1a9 AH	27
	28	#include <linux/input.h>
	29	#include <linux/module.h>
	30	#include <linux/mutex.h>
83680cdb	31	#include <linux/sched.h>
5a0e3ad6	32	#include <linux/slab.h>
509ca1a9 AH	33
	34	/*
	35	* Check that the effect_id is a valid effect and whether the user
	36	* is the owner
	37	*/
	38	static int check_effect_access(struct ff_device *ff, int effect_id,
	39	struct file *file)
	40	{
	41	if (effect_id < 0 \|\| effect_id >= ff->max_effects \|\|
	42	!ff->effect_owners[effect_id])
	43	return -EINVAL;
	44
	45	if (file && ff->effect_owners[effect_id] != file)
	46	return -EACCES;
	47
	48	return 0;
	49	}
	50
	51	/*
	52	* Checks whether 2 effects can be combined together
	53	*/
	54	static inline int check_effects_compatible(struct ff_effect *e1,
	55	struct ff_effect *e2)
	56	{
	57	return e1->type == e2->type &&
	58	(e1->type != FF_PERIODIC \|\|
	59	e1->u.periodic.waveform == e2->u.periodic.waveform);
	60	}
	61
	62	/*
	63	* Convert an effect into compatible one
	64	*/
	65	static int compat_effect(struct ff_device ff, struct ff_effect effect)
	66	{
	67	int magnitude;
	68
	69	switch (effect->type) {
	70	case FF_RUMBLE:
	71	if (!test_bit(FF_PERIODIC, ff->ffbit))
	72	return -EINVAL;
	73
	74	/*
	75	* calculate manginude of sine wave as average of rumble's
	76	* 2/3 of strong magnitude and 1/3 of weak magnitude
	77	*/
	78	magnitude = effect->u.rumble.strong_magnitude / 3 +
	79	effect->u.rumble.weak_magnitude / 6;
	80
	81	effect->type = FF_PERIODIC;
	82	effect->u.periodic.waveform = FF_SINE;
	83	effect->u.periodic.period = 50;
	84	effect->u.periodic.magnitude = max(magnitude, 0x7fff);
	85	effect->u.periodic.offset = 0;
	86	effect->u.periodic.phase = 0;
	87	effect->u.periodic.envelope.attack_length = 0;
	88	effect->u.periodic.envelope.attack_level = 0;
	89	effect->u.periodic.envelope.fade_length = 0;
	90	effect->u.periodic.envelope.fade_level = 0;
	91
	92	return 0;
	93
	94	default:
	95	/* Let driver handle conversion */
	96	return 0;
97	}
98	}
99
100	/**
101	* input_ff_upload() - upload effect into force-feedback device
102	* @dev: input device
103	* @effect: effect to be uploaded
104	* @file: owner of the effect
105	*/
106	int input_ff_upload(struct input_dev dev, struct ff_effect effect,
107	struct file *file)
108	{
109	struct ff_device *ff = dev->ff;
110	struct ff_effect *old;
111	int ret = 0;
112	int id;
113
114	if (!test_bit(EV_FF, dev->evbit))
115	return -ENOSYS;
116
117	if (effect->type < FF_EFFECT_MIN \|\| effect->type > FF_EFFECT_MAX \|\|
118	!test_bit(effect->type, dev->ffbit)) {
da0c4901	119	pr_debug("invalid or not supported effect type in upload\n");
509ca1a9 AH	120	return -EINVAL;
	121	}
	122
	123	if (effect->type == FF_PERIODIC &&
	124	(effect->u.periodic.waveform < FF_WAVEFORM_MIN \|\|
	125	effect->u.periodic.waveform > FF_WAVEFORM_MAX \|\|
	126	!test_bit(effect->u.periodic.waveform, dev->ffbit))) {
da0c4901	127	pr_debug("invalid or not supported wave form in upload\n");
509ca1a9 AH	128	return -EINVAL;
	129	}
	130
	131	if (!test_bit(effect->type, ff->ffbit)) {
	132	ret = compat_effect(ff, effect);
	133	if (ret)
	134	return ret;
	135	}
	136
	137	mutex_lock(&ff->mutex);
	138
	139	if (effect->id == -1) {
	140	for (id = 0; id < ff->max_effects; id++)
41091ad0 BC	141	if (!ff->effect_owners[id])
41091ad0 BC	142	break;
509ca1a9 AH	143
	144	if (id >= ff->max_effects) {
	145	ret = -ENOSPC;
	146	goto out;
	147	}
	148
	149	effect->id = id;
	150	old = NULL;
	151
	152	} else {
	153	id = effect->id;
	154
	155	ret = check_effect_access(ff, id, file);
	156	if (ret)
	157	goto out;
	158
	159	old = &ff->effects[id];
	160
	161	if (!check_effects_compatible(effect, old)) {
	162	ret = -EINVAL;
	163	goto out;
	164	}
	165	}
	166
	167	ret = ff->upload(dev, effect, old);
	168	if (ret)
	169	goto out;
	170
656acd2b	171	spin_lock_irq(&dev->event_lock);
509ca1a9 AH	172	ff->effects[id] = *effect;
509ca1a9 AH	173	ff->effect_owners[id] = file;
656acd2b	174	spin_unlock_irq(&dev->event_lock);
509ca1a9 AH	175
	176	out:
	177	mutex_unlock(&ff->mutex);
	178	return ret;
	179	}
	180	EXPORT_SYMBOL_GPL(input_ff_upload);
	181
	182	/*
	183	* Erases the effect if the requester is also the effect owner. The mutex
	184	* should already be locked before calling this function.
	185	*/
	186	static int erase_effect(struct input_dev *dev, int effect_id,
	187	struct file *file)
	188	{
	189	struct ff_device *ff = dev->ff;
	190	int error;
	191
	192	error = check_effect_access(ff, effect_id, file);
	193	if (error)
	194	return error;
	195
656acd2b	196	spin_lock_irq(&dev->event_lock);
509ca1a9	197	ff->playback(dev, effect_id, 0);
656acd2b DT	198	ff->effect_owners[effect_id] = NULL;
656acd2b DT	199	spin_unlock_irq(&dev->event_lock);
509ca1a9 AH	200
	201	if (ff->erase) {
	202	error = ff->erase(dev, effect_id);
656acd2b DT	203	if (error) {
	204	spin_lock_irq(&dev->event_lock);
	205	ff->effect_owners[effect_id] = file;
	206	spin_unlock_irq(&dev->event_lock);
	207
509ca1a9	208	return error;
656acd2b	209	}
509ca1a9 AH	210	}
509ca1a9 AH	211
509ca1a9 AH	212	return 0;
	213	}
	214
	215	/**
e4477d2d	216	* input_ff_erase - erase a force-feedback effect from device
509ca1a9 AH	217	* @dev: input device to erase effect from
	218	* @effect_id: id of the ffect to be erased
	219	* @file: purported owner of the request
	220	*
	221	* This function erases a force-feedback effect from specified device.
	222	* The effect will only be erased if it was uploaded through the same
	223	* file handle that is requesting erase.
	224	*/
	225	int input_ff_erase(struct input_dev dev, int effect_id, struct file file)
	226	{
	227	struct ff_device *ff = dev->ff;
	228	int ret;
	229
	230	if (!test_bit(EV_FF, dev->evbit))
	231	return -ENOSYS;
	232
	233	mutex_lock(&ff->mutex);
	234	ret = erase_effect(dev, effect_id, file);
	235	mutex_unlock(&ff->mutex);
	236
	237	return ret;
	238	}
	239	EXPORT_SYMBOL_GPL(input_ff_erase);
	240
	241	/*
	242	* flush_effects - erase all effects owned by a file handle
	243	*/
	244	static int flush_effects(struct input_dev dev, struct file file)
	245	{
	246	struct ff_device *ff = dev->ff;
	247	int i;
	248
da0c4901	249	pr_debug("flushing now\n");
509ca1a9 AH	250
	251	mutex_lock(&ff->mutex);
	252
	253	for (i = 0; i < ff->max_effects; i++)
	254	erase_effect(dev, i, file);
	255
	256	mutex_unlock(&ff->mutex);
	257
	258	return 0;
	259	}
	260
	261	/**
	262	* input_ff_event() - generic handler for force-feedback events
	263	* @dev: input device to send the effect to
	264	* @type: event type (anything but EV_FF is ignored)
	265	* @code: event code
	266	* @value: event value
	267	*/
	268	int input_ff_event(struct input_dev *dev, unsigned int type,
	269	unsigned int code, int value)
	270	{
	271	struct ff_device *ff = dev->ff;
	272
	273	if (type != EV_FF)
	274	return 0;
	275
509ca1a9 AH	276	switch (code) {
	277	case FF_GAIN:
	278	if (!test_bit(FF_GAIN, dev->ffbit) \|\| value > 0xffff)
	279	break;
	280
	281	ff->set_gain(dev, value);
	282	break;
	283
	284	case FF_AUTOCENTER:
	285	if (!test_bit(FF_AUTOCENTER, dev->ffbit) \|\| value > 0xffff)
	286	break;
	287
	288	ff->set_autocenter(dev, value);
	289	break;
	290
	291	default:
dec3eb01 DT	292	if (check_effect_access(ff, code, NULL) == 0)
dec3eb01 DT	293	ff->playback(dev, code, value);
509ca1a9 AH	294	break;
	295	}
	296
509ca1a9 AH	297	return 0;
	298	}
	299	EXPORT_SYMBOL_GPL(input_ff_event);
	300
	301	/**
	302	* input_ff_create() - create force-feedback device
	303	* @dev: input device supporting force-feedback
	304	* @max_effects: maximum number of effects supported by the device
	305	*
	306	* This function allocates all necessary memory for a force feedback
	307	* portion of an input device and installs all default handlers.
	308	* @dev->ffbit should be already set up before calling this function.
	309	* Once ff device is created you need to setup its upload, erase,
	310	* playback and other handlers before registering input device
	311	*/
05be8b81	312	int input_ff_create(struct input_dev *dev, unsigned int max_effects)
509ca1a9 AH	313	{
509ca1a9 AH	314	struct ff_device *ff;
05be8b81	315	size_t ff_dev_size;
509ca1a9 AH	316	int i;
	317
	318	if (!max_effects) {
da0c4901	319	pr_err("cannot allocate device without any effects\n");
509ca1a9 AH	320	return -EINVAL;
	321	}
	322
05be8b81 DC	323	ff_dev_size = sizeof(struct ff_device) +
	324	max_effects * sizeof(struct file *);
	325	if (ff_dev_size < max_effects) /* overflow */
	326	return -EINVAL;
	327
	328	ff = kzalloc(ff_dev_size, GFP_KERNEL);
509ca1a9 AH	329	if (!ff)
	330	return -ENOMEM;
	331
	332	ff->effects = kcalloc(max_effects, sizeof(struct ff_effect),
	333	GFP_KERNEL);
	334	if (!ff->effects) {
	335	kfree(ff);
	336	return -ENOMEM;
	337	}
	338
	339	ff->max_effects = max_effects;
	340	mutex_init(&ff->mutex);
	341
	342	dev->ff = ff;
	343	dev->flush = flush_effects;
	344	dev->event = input_ff_event;
bf3204cb	345	__set_bit(EV_FF, dev->evbit);
509ca1a9 AH	346
	347	/* Copy "true" bits into ff device bitmap */
	348	for (i = 0; i <= FF_MAX; i++)
	349	if (test_bit(i, dev->ffbit))
bf3204cb	350	__set_bit(i, ff->ffbit);
509ca1a9 AH	351
	352	/* we can emulate RUMBLE with periodic effects */
	353	if (test_bit(FF_PERIODIC, ff->ffbit))
bf3204cb	354	__set_bit(FF_RUMBLE, dev->ffbit);
509ca1a9 AH	355
	356	return 0;
	357	}
	358	EXPORT_SYMBOL_GPL(input_ff_create);
	359
	360	/**
721a730e	361	* input_ff_destroy() - frees force feedback portion of input device
e4477d2d	362	* @dev: input device supporting force feedback
509ca1a9 AH	363	*
	364	* This function is only needed in error path as input core will
	365	* automatically free force feedback structures when device is
	366	* destroyed.
	367	*/
	368	void input_ff_destroy(struct input_dev *dev)
	369	{
bf3204cb DT	370	struct ff_device *ff = dev->ff;
	371
	372	__clear_bit(EV_FF, dev->evbit);
	373	if (ff) {
	374	if (ff->destroy)
	375	ff->destroy(ff);
	376	kfree(ff->private);
6a47081c	377	kfree(ff->effects);
bf3204cb	378	kfree(ff);
509ca1a9 AH	379	dev->ff = NULL;
	380	}
	381	}
	382	EXPORT_SYMBOL_GPL(input_ff_destroy);