[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/limits.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/overflow.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 = magnitude;
		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 error;
	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)) {
		error = compat_effect(ff, effect);
		if (error)
			return error;
	}

	guard(mutex)(&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)
			return -ENOSPC;

		effect->id = id;
		old = NULL;

	} else {
		id = effect->id;

		error = check_effect_access(ff, id, file);
		if (error)
			return error;

		old = &ff->effects[id];

		if (!check_effects_compatible(effect, old))
			return -EINVAL;
	}

	error = ff->upload(dev, effect, old);
	if (error)
		return error;

	scoped_guard(spinlock_irq, &dev->event_lock) {
		ff->effects[id] = *effect;
		ff->effect_owners[id] = file;
	}

	return 0;
}
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;

	scoped_guard(spinlock_irq, &dev->event_lock) {
		ff->playback(dev, effect_id, 0);
		ff->effect_owners[effect_id] = NULL;
	}

	if (ff->erase) {
		error = ff->erase(dev, effect_id);
		if (error) {
			scoped_guard(spinlock_irq, &dev->event_lock)
				ff->effect_owners[effect_id] = file;

			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;

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

	guard(mutex)(&ff->mutex);
	return erase_effect(dev, effect_id, file);
}
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");

	guard(mutex)(&ff->mutex);

	for (i = 0; i < ff->max_effects; i++)
		erase_effect(dev, i, file);

	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)
{
	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;
	}

	struct ff_device *ff __free(kfree) =
		kzalloc(struct_size(ff, effect_owners, max_effects),
			GFP_KERNEL);
	if (!ff)
		return -ENOMEM;

	ff->effects = kcalloc(max_effects, sizeof(*ff->effects), GFP_KERNEL);
	if (!ff->effects)
		return -ENOMEM;

	ff->max_effects = max_effects;
	mutex_init(&ff->mutex);

	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);

	dev->ff = no_free_ptr(ff);

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