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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
26#define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
27
28#include <linux/input.h>
29#include <linux/module.h>
30#include <linux/mutex.h>
31#include <linux/sched.h>
32#include <linux/slab.h>
33
34/*
35 * Check that the effect_id is a valid effect and whether the user
36 * is the owner
37 */
38static 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 */
54static 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 */
65static 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 */
106int 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)) {
119 pr_debug("invalid or not supported effect type in upload\n");
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))) {
127 pr_debug("invalid or not supported wave form in upload\n");
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++)
141 if (!ff->effect_owners[id])
142 break;
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
171 spin_lock_irq(&dev->event_lock);
172 ff->effects[id] = *effect;
173 ff->effect_owners[id] = file;
174 spin_unlock_irq(&dev->event_lock);
175
176 out:
177 mutex_unlock(&ff->mutex);
178 return ret;
179}
180EXPORT_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 */
186static 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
196 spin_lock_irq(&dev->event_lock);
197 ff->playback(dev, effect_id, 0);
198 ff->effect_owners[effect_id] = NULL;
199 spin_unlock_irq(&dev->event_lock);
200
201 if (ff->erase) {
202 error = ff->erase(dev, effect_id);
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
208 return error;
209 }
210 }
211
212 return 0;
213}
214
215/**
216 * input_ff_erase - erase a force-feedback effect from device
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 */
225int 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}
239EXPORT_SYMBOL_GPL(input_ff_erase);
240
241/*
242 * flush_effects - erase all effects owned by a file handle
243 */
244static int flush_effects(struct input_dev *dev, struct file *file)
245{
246 struct ff_device *ff = dev->ff;
247 int i;
248
249 pr_debug("flushing now\n");
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 */
268int 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
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:
292 if (check_effect_access(ff, code, NULL) == 0)
293 ff->playback(dev, code, value);
294 break;
295 }
296
297 return 0;
298}
299EXPORT_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 */
312int input_ff_create(struct input_dev *dev, int max_effects)
313{
314 struct ff_device *ff;
315 int i;
316
317 if (!max_effects) {
318 pr_err("cannot allocate device without any effects\n");
319 return -EINVAL;
320 }
321
322 ff = kzalloc(sizeof(struct ff_device) +
323 max_effects * sizeof(struct file *), 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 = flush_effects;
339 dev->event = input_ff_event;
340 __set_bit(EV_FF, dev->evbit);
341
342 /* Copy "true" bits into ff device bitmap */
343 for (i = 0; i <= FF_MAX; i++)
344 if (test_bit(i, dev->ffbit))
345 __set_bit(i, ff->ffbit);
346
347 /* we can emulate RUMBLE with periodic effects */
348 if (test_bit(FF_PERIODIC, ff->ffbit))
349 __set_bit(FF_RUMBLE, dev->ffbit);
350
351 return 0;
352}
353EXPORT_SYMBOL_GPL(input_ff_create);
354
355/**
356 * input_ff_destroy() - frees force feedback portion of input device
357 * @dev: input device supporting force feedback
358 *
359 * This function is only needed in error path as input core will
360 * automatically free force feedback structures when device is
361 * destroyed.
362 */
363void input_ff_destroy(struct input_dev *dev)
364{
365 struct ff_device *ff = dev->ff;
366
367 __clear_bit(EV_FF, dev->evbit);
368 if (ff) {
369 if (ff->destroy)
370 ff->destroy(ff);
371 kfree(ff->private);
372 kfree(ff->effects);
373 kfree(ff);
374 dev->ff = NULL;
375 }
376}
377EXPORT_SYMBOL_GPL(input_ff_destroy);
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
26#include <linux/input.h>
27#include <linux/module.h>
28#include <linux/mutex.h>
29#include <linux/sched.h>
30#include <linux/slab.h>
31
32/*
33 * Check that the effect_id is a valid effect and whether the user
34 * is the owner
35 */
36static int check_effect_access(struct ff_device *ff, int effect_id,
37 struct file *file)
38{
39 if (effect_id < 0 || effect_id >= ff->max_effects ||
40 !ff->effect_owners[effect_id])
41 return -EINVAL;
42
43 if (file && ff->effect_owners[effect_id] != file)
44 return -EACCES;
45
46 return 0;
47}
48
49/*
50 * Checks whether 2 effects can be combined together
51 */
52static inline int check_effects_compatible(struct ff_effect *e1,
53 struct ff_effect *e2)
54{
55 return e1->type == e2->type &&
56 (e1->type != FF_PERIODIC ||
57 e1->u.periodic.waveform == e2->u.periodic.waveform);
58}
59
60/*
61 * Convert an effect into compatible one
62 */
63static int compat_effect(struct ff_device *ff, struct ff_effect *effect)
64{
65 int magnitude;
66
67 switch (effect->type) {
68 case FF_RUMBLE:
69 if (!test_bit(FF_PERIODIC, ff->ffbit))
70 return -EINVAL;
71
72 /*
73 * calculate magnitude of sine wave as average of rumble's
74 * 2/3 of strong magnitude and 1/3 of weak magnitude
75 */
76 magnitude = effect->u.rumble.strong_magnitude / 3 +
77 effect->u.rumble.weak_magnitude / 6;
78
79 effect->type = FF_PERIODIC;
80 effect->u.periodic.waveform = FF_SINE;
81 effect->u.periodic.period = 50;
82 effect->u.periodic.magnitude = max(magnitude, 0x7fff);
83 effect->u.periodic.offset = 0;
84 effect->u.periodic.phase = 0;
85 effect->u.periodic.envelope.attack_length = 0;
86 effect->u.periodic.envelope.attack_level = 0;
87 effect->u.periodic.envelope.fade_length = 0;
88 effect->u.periodic.envelope.fade_level = 0;
89
90 return 0;
91
92 default:
93 /* Let driver handle conversion */
94 return 0;
95 }
96}
97
98/**
99 * input_ff_upload() - upload effect into force-feedback device
100 * @dev: input device
101 * @effect: effect to be uploaded
102 * @file: owner of the effect
103 */
104int input_ff_upload(struct input_dev *dev, struct ff_effect *effect,
105 struct file *file)
106{
107 struct ff_device *ff = dev->ff;
108 struct ff_effect *old;
109 int ret = 0;
110 int id;
111
112 if (!test_bit(EV_FF, dev->evbit))
113 return -ENOSYS;
114
115 if (effect->type < FF_EFFECT_MIN || effect->type > FF_EFFECT_MAX ||
116 !test_bit(effect->type, dev->ffbit)) {
117 dev_dbg(&dev->dev, "invalid or not supported effect type in upload\n");
118 return -EINVAL;
119 }
120
121 if (effect->type == FF_PERIODIC &&
122 (effect->u.periodic.waveform < FF_WAVEFORM_MIN ||
123 effect->u.periodic.waveform > FF_WAVEFORM_MAX ||
124 !test_bit(effect->u.periodic.waveform, dev->ffbit))) {
125 dev_dbg(&dev->dev, "invalid or not supported wave form in upload\n");
126 return -EINVAL;
127 }
128
129 if (!test_bit(effect->type, ff->ffbit)) {
130 ret = compat_effect(ff, effect);
131 if (ret)
132 return ret;
133 }
134
135 mutex_lock(&ff->mutex);
136
137 if (effect->id == -1) {
138 for (id = 0; id < ff->max_effects; id++)
139 if (!ff->effect_owners[id])
140 break;
141
142 if (id >= ff->max_effects) {
143 ret = -ENOSPC;
144 goto out;
145 }
146
147 effect->id = id;
148 old = NULL;
149
150 } else {
151 id = effect->id;
152
153 ret = check_effect_access(ff, id, file);
154 if (ret)
155 goto out;
156
157 old = &ff->effects[id];
158
159 if (!check_effects_compatible(effect, old)) {
160 ret = -EINVAL;
161 goto out;
162 }
163 }
164
165 ret = ff->upload(dev, effect, old);
166 if (ret)
167 goto out;
168
169 spin_lock_irq(&dev->event_lock);
170 ff->effects[id] = *effect;
171 ff->effect_owners[id] = file;
172 spin_unlock_irq(&dev->event_lock);
173
174 out:
175 mutex_unlock(&ff->mutex);
176 return ret;
177}
178EXPORT_SYMBOL_GPL(input_ff_upload);
179
180/*
181 * Erases the effect if the requester is also the effect owner. The mutex
182 * should already be locked before calling this function.
183 */
184static int erase_effect(struct input_dev *dev, int effect_id,
185 struct file *file)
186{
187 struct ff_device *ff = dev->ff;
188 int error;
189
190 error = check_effect_access(ff, effect_id, file);
191 if (error)
192 return error;
193
194 spin_lock_irq(&dev->event_lock);
195 ff->playback(dev, effect_id, 0);
196 ff->effect_owners[effect_id] = NULL;
197 spin_unlock_irq(&dev->event_lock);
198
199 if (ff->erase) {
200 error = ff->erase(dev, effect_id);
201 if (error) {
202 spin_lock_irq(&dev->event_lock);
203 ff->effect_owners[effect_id] = file;
204 spin_unlock_irq(&dev->event_lock);
205
206 return error;
207 }
208 }
209
210 return 0;
211}
212
213/**
214 * input_ff_erase - erase a force-feedback effect from device
215 * @dev: input device to erase effect from
216 * @effect_id: id of the effect to be erased
217 * @file: purported owner of the request
218 *
219 * This function erases a force-feedback effect from specified device.
220 * The effect will only be erased if it was uploaded through the same
221 * file handle that is requesting erase.
222 */
223int input_ff_erase(struct input_dev *dev, int effect_id, struct file *file)
224{
225 struct ff_device *ff = dev->ff;
226 int ret;
227
228 if (!test_bit(EV_FF, dev->evbit))
229 return -ENOSYS;
230
231 mutex_lock(&ff->mutex);
232 ret = erase_effect(dev, effect_id, file);
233 mutex_unlock(&ff->mutex);
234
235 return ret;
236}
237EXPORT_SYMBOL_GPL(input_ff_erase);
238
239/*
240 * flush_effects - erase all effects owned by a file handle
241 */
242static int flush_effects(struct input_dev *dev, struct file *file)
243{
244 struct ff_device *ff = dev->ff;
245 int i;
246
247 dev_dbg(&dev->dev, "flushing now\n");
248
249 mutex_lock(&ff->mutex);
250
251 for (i = 0; i < ff->max_effects; i++)
252 erase_effect(dev, i, file);
253
254 mutex_unlock(&ff->mutex);
255
256 return 0;
257}
258
259/**
260 * input_ff_event() - generic handler for force-feedback events
261 * @dev: input device to send the effect to
262 * @type: event type (anything but EV_FF is ignored)
263 * @code: event code
264 * @value: event value
265 */
266int input_ff_event(struct input_dev *dev, unsigned int type,
267 unsigned int code, int value)
268{
269 struct ff_device *ff = dev->ff;
270
271 if (type != EV_FF)
272 return 0;
273
274 switch (code) {
275 case FF_GAIN:
276 if (!test_bit(FF_GAIN, dev->ffbit) || value > 0xffffU)
277 break;
278
279 ff->set_gain(dev, value);
280 break;
281
282 case FF_AUTOCENTER:
283 if (!test_bit(FF_AUTOCENTER, dev->ffbit) || value > 0xffffU)
284 break;
285
286 ff->set_autocenter(dev, value);
287 break;
288
289 default:
290 if (check_effect_access(ff, code, NULL) == 0)
291 ff->playback(dev, code, value);
292 break;
293 }
294
295 return 0;
296}
297EXPORT_SYMBOL_GPL(input_ff_event);
298
299/**
300 * input_ff_create() - create force-feedback device
301 * @dev: input device supporting force-feedback
302 * @max_effects: maximum number of effects supported by the device
303 *
304 * This function allocates all necessary memory for a force feedback
305 * portion of an input device and installs all default handlers.
306 * @dev->ffbit should be already set up before calling this function.
307 * Once ff device is created you need to setup its upload, erase,
308 * playback and other handlers before registering input device
309 */
310int input_ff_create(struct input_dev *dev, unsigned int max_effects)
311{
312 struct ff_device *ff;
313 size_t ff_dev_size;
314 int i;
315
316 if (!max_effects) {
317 dev_err(&dev->dev, "cannot allocate device without any effects\n");
318 return -EINVAL;
319 }
320
321 if (max_effects > FF_MAX_EFFECTS) {
322 dev_err(&dev->dev, "cannot allocate more than FF_MAX_EFFECTS effects\n");
323 return -EINVAL;
324 }
325
326 ff_dev_size = sizeof(struct ff_device) +
327 max_effects * sizeof(struct file *);
328 if (ff_dev_size < max_effects) /* overflow */
329 return -EINVAL;
330
331 ff = kzalloc(ff_dev_size, GFP_KERNEL);
332 if (!ff)
333 return -ENOMEM;
334
335 ff->effects = kcalloc(max_effects, sizeof(struct ff_effect),
336 GFP_KERNEL);
337 if (!ff->effects) {
338 kfree(ff);
339 return -ENOMEM;
340 }
341
342 ff->max_effects = max_effects;
343 mutex_init(&ff->mutex);
344
345 dev->ff = ff;
346 dev->flush = flush_effects;
347 dev->event = input_ff_event;
348 __set_bit(EV_FF, dev->evbit);
349
350 /* Copy "true" bits into ff device bitmap */
351 for_each_set_bit(i, dev->ffbit, FF_CNT)
352 __set_bit(i, ff->ffbit);
353
354 /* we can emulate RUMBLE with periodic effects */
355 if (test_bit(FF_PERIODIC, ff->ffbit))
356 __set_bit(FF_RUMBLE, dev->ffbit);
357
358 return 0;
359}
360EXPORT_SYMBOL_GPL(input_ff_create);
361
362/**
363 * input_ff_destroy() - frees force feedback portion of input device
364 * @dev: input device supporting force feedback
365 *
366 * This function is only needed in error path as input core will
367 * automatically free force feedback structures when device is
368 * destroyed.
369 */
370void input_ff_destroy(struct input_dev *dev)
371{
372 struct ff_device *ff = dev->ff;
373
374 __clear_bit(EV_FF, dev->evbit);
375 if (ff) {
376 if (ff->destroy)
377 ff->destroy(ff);
378 kfree(ff->private);
379 kfree(ff->effects);
380 kfree(ff);
381 dev->ff = NULL;
382 }
383}
384EXPORT_SYMBOL_GPL(input_ff_destroy);