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