[thirdparty/linux.git] / drivers / input / ff-core.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Force feedback support for Linux input subsystem
 *
 *  Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com>
 *  Copyright (c) 2006 Dmitry Torokhov <dtor@mail.ru>
 */

/*
 */

/* #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);

/*
 * input_ff_flush - erase all effects owned by a file handle
 * @dev: input device to erase effect from
 * @file: purported owner of the effects
 *
 * This function erases all force-feedback effects associated with
 * the given owner from specified device. Note that @file may be %NULL,
 * in which case all effects will be erased.
 */
int input_ff_flush(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;
}
EXPORT_SYMBOL_GPL(input_ff_flush);

/**
 * 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 > 0xffffU)
			break;

		ff->set_gain(dev, value);
		break;

	case FF_AUTOCENTER:
		if (!test_bit(FF_AUTOCENTER, dev->ffbit) || value > 0xffffU)
			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;
	}

	if (max_effects > FF_MAX_EFFECTS) {
		dev_err(&dev->dev, "cannot allocate more than FF_MAX_EFFECTS 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 = input_ff_flush;
	dev->event = input_ff_event;
	__set_bit(EV_FF, dev->evbit);

	/* Copy "true" bits into ff device bitmap */
	for_each_set_bit(i, dev->ffbit, FF_CNT)
		__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
1a59d1b8	1	// SPDX-License-Identifier: GPL-2.0-or-later
509ca1a9 AH	2	/*
	3	* Force feedback support for Linux input subsystem
	4	*
	5	* Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com>
	6	* Copyright (c) 2006 Dmitry Torokhov <dtor@mail.ru>
	7	*/
	8
	9	/*
509ca1a9 AH	10	*/
	11
	12	/* #define DEBUG */
	13
509ca1a9 AH	14	#include <linux/input.h>
	15	#include <linux/module.h>
	16	#include <linux/mutex.h>
83680cdb	17	#include <linux/sched.h>
5a0e3ad6	18	#include <linux/slab.h>
509ca1a9 AH	19
	20	/*
	21	* Check that the effect_id is a valid effect and whether the user
	22	* is the owner
	23	*/
	24	static int check_effect_access(struct ff_device *ff, int effect_id,
	25	struct file *file)
	26	{
	27	if (effect_id < 0 \|\| effect_id >= ff->max_effects \|\|
	28	!ff->effect_owners[effect_id])
	29	return -EINVAL;
	30
	31	if (file && ff->effect_owners[effect_id] != file)
	32	return -EACCES;
	33
	34	return 0;
	35	}
	36
	37	/*
	38	* Checks whether 2 effects can be combined together
	39	*/
	40	static inline int check_effects_compatible(struct ff_effect *e1,
	41	struct ff_effect *e2)
	42	{
	43	return e1->type == e2->type &&
	44	(e1->type != FF_PERIODIC \|\|
	45	e1->u.periodic.waveform == e2->u.periodic.waveform);
	46	}
	47
	48	/*
	49	* Convert an effect into compatible one
	50	*/
	51	static int compat_effect(struct ff_device ff, struct ff_effect effect)
	52	{
	53	int magnitude;
	54
	55	switch (effect->type) {
	56	case FF_RUMBLE:
	57	if (!test_bit(FF_PERIODIC, ff->ffbit))
	58	return -EINVAL;
	59
	60	/*
8a4dda79	61	* calculate magnitude of sine wave as average of rumble's
509ca1a9 AH	62	* 2/3 of strong magnitude and 1/3 of weak magnitude
	63	*/
	64	magnitude = effect->u.rumble.strong_magnitude / 3 +
	65	effect->u.rumble.weak_magnitude / 6;
	66
	67	effect->type = FF_PERIODIC;
	68	effect->u.periodic.waveform = FF_SINE;
	69	effect->u.periodic.period = 50;
	70	effect->u.periodic.magnitude = max(magnitude, 0x7fff);
	71	effect->u.periodic.offset = 0;
	72	effect->u.periodic.phase = 0;
	73	effect->u.periodic.envelope.attack_length = 0;
	74	effect->u.periodic.envelope.attack_level = 0;
	75	effect->u.periodic.envelope.fade_length = 0;
	76	effect->u.periodic.envelope.fade_level = 0;
	77
	78	return 0;
	79
	80	default:
	81	/* Let driver handle conversion */
	82	return 0;
	83	}
	84	}
	85
	86	/**
	87	* input_ff_upload() - upload effect into force-feedback device
	88	* @dev: input device
	89	* @effect: effect to be uploaded
	90	* @file: owner of the effect
	91	*/
	92	int input_ff_upload(struct input_dev dev, struct ff_effect effect,
	93	struct file *file)
	94	{
	95	struct ff_device *ff = dev->ff;
	96	struct ff_effect *old;
	97	int ret = 0;
	98	int id;
	99
	100	if (!test_bit(EV_FF, dev->evbit))
	101	return -ENOSYS;
	102
	103	if (effect->type < FF_EFFECT_MIN \|\| effect->type > FF_EFFECT_MAX \|\|
	104	!test_bit(effect->type, dev->ffbit)) {
2afebafd	105	dev_dbg(&dev->dev, "invalid or not supported effect type in upload\n");
509ca1a9 AH	106	return -EINVAL;
	107	}
	108
	109	if (effect->type == FF_PERIODIC &&
	110	(effect->u.periodic.waveform < FF_WAVEFORM_MIN \|\|
	111	effect->u.periodic.waveform > FF_WAVEFORM_MAX \|\|
	112	!test_bit(effect->u.periodic.waveform, dev->ffbit))) {
2afebafd	113	dev_dbg(&dev->dev, "invalid or not supported wave form in upload\n");
509ca1a9 AH	114	return -EINVAL;
	115	}
	116
	117	if (!test_bit(effect->type, ff->ffbit)) {
	118	ret = compat_effect(ff, effect);
	119	if (ret)
	120	return ret;
	121	}
	122
	123	mutex_lock(&ff->mutex);
	124
	125	if (effect->id == -1) {
	126	for (id = 0; id < ff->max_effects; id++)
41091ad0 BC	127	if (!ff->effect_owners[id])
41091ad0 BC	128	break;
509ca1a9 AH	129
	130	if (id >= ff->max_effects) {
	131	ret = -ENOSPC;
	132	goto out;
	133	}
	134
	135	effect->id = id;
	136	old = NULL;
	137
	138	} else {
	139	id = effect->id;
	140
	141	ret = check_effect_access(ff, id, file);
	142	if (ret)
	143	goto out;
	144
	145	old = &ff->effects[id];
	146
	147	if (!check_effects_compatible(effect, old)) {
	148	ret = -EINVAL;
	149	goto out;
	150	}
	151	}
	152
	153	ret = ff->upload(dev, effect, old);
	154	if (ret)
	155	goto out;
	156
656acd2b	157	spin_lock_irq(&dev->event_lock);
509ca1a9 AH	158	ff->effects[id] = *effect;
509ca1a9 AH	159	ff->effect_owners[id] = file;
656acd2b	160	spin_unlock_irq(&dev->event_lock);
509ca1a9 AH	161
	162	out:
	163	mutex_unlock(&ff->mutex);
	164	return ret;
	165	}
	166	EXPORT_SYMBOL_GPL(input_ff_upload);
	167
	168	/*
	169	* Erases the effect if the requester is also the effect owner. The mutex
	170	* should already be locked before calling this function.
	171	*/
	172	static int erase_effect(struct input_dev *dev, int effect_id,
	173	struct file *file)
	174	{
	175	struct ff_device *ff = dev->ff;
	176	int error;
	177
	178	error = check_effect_access(ff, effect_id, file);
	179	if (error)
	180	return error;
	181
656acd2b	182	spin_lock_irq(&dev->event_lock);
509ca1a9	183	ff->playback(dev, effect_id, 0);
656acd2b DT	184	ff->effect_owners[effect_id] = NULL;
656acd2b DT	185	spin_unlock_irq(&dev->event_lock);
509ca1a9 AH	186
	187	if (ff->erase) {
	188	error = ff->erase(dev, effect_id);
656acd2b DT	189	if (error) {
	190	spin_lock_irq(&dev->event_lock);
	191	ff->effect_owners[effect_id] = file;
	192	spin_unlock_irq(&dev->event_lock);
	193
509ca1a9	194	return error;
656acd2b	195	}
509ca1a9 AH	196	}
509ca1a9 AH	197
509ca1a9 AH	198	return 0;
	199	}
	200
	201	/**
e4477d2d	202	* input_ff_erase - erase a force-feedback effect from device
509ca1a9	203	* @dev: input device to erase effect from
4e3e4629	204	* @effect_id: id of the effect to be erased
509ca1a9 AH	205	* @file: purported owner of the request
	206	*
	207	* This function erases a force-feedback effect from specified device.
	208	* The effect will only be erased if it was uploaded through the same
	209	* file handle that is requesting erase.
	210	*/
	211	int input_ff_erase(struct input_dev dev, int effect_id, struct file file)
	212	{
	213	struct ff_device *ff = dev->ff;
	214	int ret;
	215
	216	if (!test_bit(EV_FF, dev->evbit))
	217	return -ENOSYS;
	218
	219	mutex_lock(&ff->mutex);
	220	ret = erase_effect(dev, effect_id, file);
	221	mutex_unlock(&ff->mutex);
	222
	223	return ret;
	224	}
	225	EXPORT_SYMBOL_GPL(input_ff_erase);
	226
	227	/*
e8b95728 DT	228	* input_ff_flush - erase all effects owned by a file handle
	229	* @dev: input device to erase effect from
	230	* @file: purported owner of the effects
	231	*
	232	* This function erases all force-feedback effects associated with
	233	* the given owner from specified device. Note that @file may be %NULL,
	234	* in which case all effects will be erased.
509ca1a9	235	*/
e8b95728	236	int input_ff_flush(struct input_dev dev, struct file file)
509ca1a9 AH	237	{
	238	struct ff_device *ff = dev->ff;
	239	int i;
	240
2afebafd	241	dev_dbg(&dev->dev, "flushing now\n");
509ca1a9 AH	242
	243	mutex_lock(&ff->mutex);
	244
	245	for (i = 0; i < ff->max_effects; i++)
	246	erase_effect(dev, i, file);
	247
	248	mutex_unlock(&ff->mutex);
	249
	250	return 0;
	251	}
e8b95728	252	EXPORT_SYMBOL_GPL(input_ff_flush);
509ca1a9 AH	253
	254	/**
	255	* input_ff_event() - generic handler for force-feedback events
	256	* @dev: input device to send the effect to
	257	* @type: event type (anything but EV_FF is ignored)
	258	* @code: event code
	259	* @value: event value
	260	*/
	261	int input_ff_event(struct input_dev *dev, unsigned int type,
	262	unsigned int code, int value)
	263	{
	264	struct ff_device *ff = dev->ff;
	265
	266	if (type != EV_FF)
	267	return 0;
	268
509ca1a9 AH	269	switch (code) {
509ca1a9 AH	270	case FF_GAIN:
379d7cfa	271	if (!test_bit(FF_GAIN, dev->ffbit) \|\| value > 0xffffU)
509ca1a9 AH	272	break;
	273
	274	ff->set_gain(dev, value);
	275	break;
	276
	277	case FF_AUTOCENTER:
379d7cfa	278	if (!test_bit(FF_AUTOCENTER, dev->ffbit) \|\| value > 0xffffU)
509ca1a9 AH	279	break;
	280
	281	ff->set_autocenter(dev, value);
	282	break;
	283
	284	default:
dec3eb01 DT	285	if (check_effect_access(ff, code, NULL) == 0)
dec3eb01 DT	286	ff->playback(dev, code, value);
509ca1a9 AH	287	break;
	288	}
	289
509ca1a9 AH	290	return 0;
	291	}
	292	EXPORT_SYMBOL_GPL(input_ff_event);
	293
	294	/**
	295	* input_ff_create() - create force-feedback device
	296	* @dev: input device supporting force-feedback
	297	* @max_effects: maximum number of effects supported by the device
	298	*
	299	* This function allocates all necessary memory for a force feedback
	300	* portion of an input device and installs all default handlers.
	301	* @dev->ffbit should be already set up before calling this function.
	302	* Once ff device is created you need to setup its upload, erase,
	303	* playback and other handlers before registering input device
	304	*/
05be8b81	305	int input_ff_create(struct input_dev *dev, unsigned int max_effects)
509ca1a9 AH	306	{
509ca1a9 AH	307	struct ff_device *ff;
05be8b81	308	size_t ff_dev_size;
509ca1a9 AH	309	int i;
	310
	311	if (!max_effects) {
2afebafd	312	dev_err(&dev->dev, "cannot allocate device without any effects\n");
509ca1a9 AH	313	return -EINVAL;
	314	}
	315
33b96d93 EV	316	if (max_effects > FF_MAX_EFFECTS) {
	317	dev_err(&dev->dev, "cannot allocate more than FF_MAX_EFFECTS effects\n");
	318	return -EINVAL;
	319	}
	320
05be8b81 DC	321	ff_dev_size = sizeof(struct ff_device) +
	322	max_effects * sizeof(struct file *);
	323	if (ff_dev_size < max_effects) /* overflow */
	324	return -EINVAL;
	325
	326	ff = kzalloc(ff_dev_size, GFP_KERNEL);
509ca1a9 AH	327	if (!ff)
	328	return -ENOMEM;
	329
	330	ff->effects = kcalloc(max_effects, sizeof(struct ff_effect),
	331	GFP_KERNEL);
	332	if (!ff->effects) {
	333	kfree(ff);
	334	return -ENOMEM;
	335	}
	336
	337	ff->max_effects = max_effects;
	338	mutex_init(&ff->mutex);
	339
	340	dev->ff = ff;
e8b95728	341	dev->flush = input_ff_flush;
509ca1a9	342	dev->event = input_ff_event;
bf3204cb	343	__set_bit(EV_FF, dev->evbit);
509ca1a9 AH	344
509ca1a9 AH	345	/* Copy "true" bits into ff device bitmap */
948cea14 AG	346	for_each_set_bit(i, dev->ffbit, FF_CNT)
948cea14 AG	347	__set_bit(i, ff->ffbit);
509ca1a9 AH	348
	349	/* we can emulate RUMBLE with periodic effects */
	350	if (test_bit(FF_PERIODIC, ff->ffbit))
bf3204cb	351	__set_bit(FF_RUMBLE, dev->ffbit);
509ca1a9 AH	352
	353	return 0;
	354	}
	355	EXPORT_SYMBOL_GPL(input_ff_create);
	356
	357	/**
721a730e	358	* input_ff_destroy() - frees force feedback portion of input device
e4477d2d	359	* @dev: input device supporting force feedback
509ca1a9 AH	360	*
	361	* This function is only needed in error path as input core will
	362	* automatically free force feedback structures when device is
	363	* destroyed.
	364	*/
	365	void input_ff_destroy(struct input_dev *dev)
	366	{
bf3204cb DT	367	struct ff_device *ff = dev->ff;
	368
	369	__clear_bit(EV_FF, dev->evbit);
	370	if (ff) {
	371	if (ff->destroy)
	372	ff->destroy(ff);
	373	kfree(ff->private);
6a47081c	374	kfree(ff->effects);
bf3204cb	375	kfree(ff);
509ca1a9 AH	376	dev->ff = NULL;
	377	}
	378	}
	379	EXPORT_SYMBOL_GPL(input_ff_destroy);