cregit-Linux how code gets into the kernel

Release 4.14 drivers/input/ff-core.c

Directory: drivers/input
/*
 *  Force feedback support for Linux input subsystem
 *
 *  Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com>
 *  Copyright (c) 2006 Dmitry Torokhov <dtor@mail.ru>
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/* #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; }

Contributors

PersonTokensPropCommitsCommitProp
Anssi Hannula63100.00%1100.00%
Total63100.00%1100.00%

/* * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Anssi Hannula50100.00%1100.00%
Total50100.00%1100.00%

/* * 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; } }

Contributors

PersonTokensPropCommitsCommitProp
Anssi Hannula18599.46%150.00%
Dan Murphy10.54%150.00%
Total186100.00%2100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Anssi Hannula36292.35%125.00%
Dmitry Torokhov164.08%125.00%
Oliver Neukum123.06%125.00%
Joe Perches20.51%125.00%
Total392100.00%4100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Anssi Hannula9365.96%150.00%
Dmitry Torokhov4834.04%150.00%
Total141100.00%2100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Anssi Hannula76100.00%1100.00%
Total76100.00%1100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Anssi Hannula7290.00%125.00%
Oliver Neukum67.50%125.00%
Joe Perches11.25%125.00%
Dmitry Torokhov11.25%125.00%
Total80100.00%4100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Anssi Hannula11988.81%133.33%
Dmitry Torokhov139.70%133.33%
Dan Carpenter21.49%133.33%
Total134100.00%3100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Anssi Hannula17274.14%112.50%
Elias Vanderstuyft229.48%112.50%
Dan Carpenter229.48%112.50%
Oliver Neukum62.59%112.50%
Anshul Garg52.16%112.50%
Dmitry Torokhov41.72%225.00%
Joe Perches10.43%112.50%
Total232100.00%8100.00%

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; } }

Contributors

PersonTokensPropCommitsCommitProp
Anssi Hannula5576.39%133.33%
Dmitry Torokhov1013.89%133.33%
Jari Vanhala79.72%133.33%
Total72100.00%3100.00%

EXPORT_SYMBOL_GPL(input_ff_destroy);

Overall Contributors

PersonTokensPropCommitsCommitProp
Anssi Hannula129186.99%15.88%
Dmitry Torokhov986.60%423.53%
Dan Carpenter241.62%211.76%
Oliver Neukum241.62%15.88%
Elias Vanderstuyft221.48%15.88%
Jari Vanhala70.47%15.88%
Anshul Garg50.34%15.88%
Joe Perches40.27%15.88%
Geert Uytterhoeven30.20%15.88%
Tejun Heo30.20%15.88%
Roger Quadros10.07%15.88%
Shailendra Verma10.07%15.88%
Dan Murphy10.07%15.88%
Total1484100.00%17100.00%
Directory: drivers/input
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