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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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/* #define DEBUG */
#include <linux/export.h>#include <linux/input.h>#include <linux/limits.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_flex(*ff, effect_owners, max_effects); if (!ff) return -ENOMEM;
ff->effects = kzalloc_objs(*ff->effects, max_effects); 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);