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Thomas Gleixner1a59d1b82019-05-27 08:55:05 +02001// SPDX-License-Identifier: GPL-2.0-or-later
Anssi Hannula509ca1a2006-07-19 01:40:22 -04002/*
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/*
Anssi Hannula509ca1a2006-07-19 01:40:22 -040010 */
11
12/* #define DEBUG */
13
Anssi Hannula509ca1a2006-07-19 01:40:22 -040014#include <linux/input.h>
15#include <linux/module.h>
16#include <linux/mutex.h>
Geert Uytterhoeven83680cd2008-07-01 13:55:25 +020017#include <linux/sched.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090018#include <linux/slab.h>
Anssi Hannula509ca1a2006-07-19 01:40:22 -040019
20/*
21 * Check that the effect_id is a valid effect and whether the user
22 * is the owner
23 */
24static 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 */
40static 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 */
51static 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 /*
Dan Murphy8a4dda72015-05-08 16:01:39 -070061 * calculate magnitude of sine wave as average of rumble's
Anssi Hannula509ca1a2006-07-19 01:40:22 -040062 * 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;
Charles Keepax8c374ef2021-12-06 23:23:00 -080070 effect->u.periodic.magnitude = magnitude;
Anssi Hannula509ca1a2006-07-19 01:40:22 -040071 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 */
92int 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)) {
Oliver Neukum2afebaf2015-04-14 14:24:09 -0700105 dev_dbg(&dev->dev, "invalid or not supported effect type in upload\n");
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400106 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))) {
Oliver Neukum2afebaf2015-04-14 14:24:09 -0700113 dev_dbg(&dev->dev, "invalid or not supported wave form in upload\n");
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400114 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++)
Baodong Chen41091ad2012-07-29 22:33:03 -0700127 if (!ff->effect_owners[id])
128 break;
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400129
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
Dmitry Torokhov656acd22008-06-26 11:30:02 -0400157 spin_lock_irq(&dev->event_lock);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400158 ff->effects[id] = *effect;
159 ff->effect_owners[id] = file;
Dmitry Torokhov656acd22008-06-26 11:30:02 -0400160 spin_unlock_irq(&dev->event_lock);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400161
162 out:
163 mutex_unlock(&ff->mutex);
164 return ret;
165}
166EXPORT_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 */
172static 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
Dmitry Torokhov656acd22008-06-26 11:30:02 -0400182 spin_lock_irq(&dev->event_lock);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400183 ff->playback(dev, effect_id, 0);
Dmitry Torokhov656acd22008-06-26 11:30:02 -0400184 ff->effect_owners[effect_id] = NULL;
185 spin_unlock_irq(&dev->event_lock);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400186
187 if (ff->erase) {
188 error = ff->erase(dev, effect_id);
Dmitry Torokhov656acd22008-06-26 11:30:02 -0400189 if (error) {
190 spin_lock_irq(&dev->event_lock);
191 ff->effect_owners[effect_id] = file;
192 spin_unlock_irq(&dev->event_lock);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400193
Dmitry Torokhov656acd22008-06-26 11:30:02 -0400194 return error;
195 }
196 }
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400197
198 return 0;
199}
200
201/**
Randy Dunlape4477d22006-11-24 00:43:09 -0500202 * input_ff_erase - erase a force-feedback effect from device
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400203 * @dev: input device to erase effect from
Shailendra Verma4e3e4622015-05-18 10:45:58 -0700204 * @effect_id: id of the effect to be erased
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400205 * @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 */
211int 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}
225EXPORT_SYMBOL_GPL(input_ff_erase);
226
227/*
Dmitry Torokhove8b95722017-09-01 17:13:43 -0700228 * 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.
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400235 */
Dmitry Torokhove8b95722017-09-01 17:13:43 -0700236int input_ff_flush(struct input_dev *dev, struct file *file)
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400237{
238 struct ff_device *ff = dev->ff;
239 int i;
240
Oliver Neukum2afebaf2015-04-14 14:24:09 -0700241 dev_dbg(&dev->dev, "flushing now\n");
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400242
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}
Dmitry Torokhove8b95722017-09-01 17:13:43 -0700252EXPORT_SYMBOL_GPL(input_ff_flush);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400253
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 */
261int 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
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400269 switch (code) {
270 case FF_GAIN:
Dan Carpenter379d7cf2015-09-29 16:02:29 -0700271 if (!test_bit(FF_GAIN, dev->ffbit) || value > 0xffffU)
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400272 break;
273
274 ff->set_gain(dev, value);
275 break;
276
277 case FF_AUTOCENTER:
Dan Carpenter379d7cf2015-09-29 16:02:29 -0700278 if (!test_bit(FF_AUTOCENTER, dev->ffbit) || value > 0xffffU)
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400279 break;
280
281 ff->set_autocenter(dev, value);
282 break;
283
284 default:
Dmitry Torokhovdec3eb02007-05-03 00:51:10 -0400285 if (check_effect_access(ff, code, NULL) == 0)
286 ff->playback(dev, code, value);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400287 break;
288 }
289
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400290 return 0;
291}
292EXPORT_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 */
Dan Carpenter05be8b82011-10-12 21:05:53 -0700305int input_ff_create(struct input_dev *dev, unsigned int max_effects)
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400306{
307 struct ff_device *ff;
Dan Carpenter05be8b82011-10-12 21:05:53 -0700308 size_t ff_dev_size;
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400309 int i;
310
311 if (!max_effects) {
Oliver Neukum2afebaf2015-04-14 14:24:09 -0700312 dev_err(&dev->dev, "cannot allocate device without any effects\n");
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400313 return -EINVAL;
314 }
315
Elias Vanderstuyft33b96d92015-10-14 17:29:37 -0700316 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
Dan Carpenter05be8b82011-10-12 21:05:53 -0700321 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);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400327 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;
Dmitry Torokhove8b95722017-09-01 17:13:43 -0700341 dev->flush = input_ff_flush;
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400342 dev->event = input_ff_event;
Dmitry Torokhovbf3204c2009-11-06 21:39:07 -0800343 __set_bit(EV_FF, dev->evbit);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400344
345 /* Copy "true" bits into ff device bitmap */
Anshul Garg948cea12015-07-08 16:43:20 -0700346 for_each_set_bit(i, dev->ffbit, FF_CNT)
347 __set_bit(i, ff->ffbit);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400348
349 /* we can emulate RUMBLE with periodic effects */
350 if (test_bit(FF_PERIODIC, ff->ffbit))
Dmitry Torokhovbf3204c2009-11-06 21:39:07 -0800351 __set_bit(FF_RUMBLE, dev->ffbit);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400352
353 return 0;
354}
355EXPORT_SYMBOL_GPL(input_ff_create);
356
357/**
Roger Quadros721a7302009-11-23 08:30:18 -0800358 * input_ff_destroy() - frees force feedback portion of input device
Randy Dunlape4477d22006-11-24 00:43:09 -0500359 * @dev: input device supporting force feedback
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400360 *
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 */
365void input_ff_destroy(struct input_dev *dev)
366{
Dmitry Torokhovbf3204c2009-11-06 21:39:07 -0800367 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);
Jari Vanhala6a470812009-12-04 10:24:21 -0800374 kfree(ff->effects);
Dmitry Torokhovbf3204c2009-11-06 21:39:07 -0800375 kfree(ff);
Anssi Hannula509ca1a2006-07-19 01:40:22 -0400376 dev->ff = NULL;
377 }
378}
379EXPORT_SYMBOL_GPL(input_ff_destroy);