/* * Force feedback support for memoryless devices * * 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 */ #define debug(format, arg...) pr_debug("ff-memless: " format "\n", ## arg) #include <linux/input.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/spinlock.h> #include <linux/jiffies.h> #include "fixp-arith.h" MODULE_LICENSE("GPL"); MODULE_AUTHOR("Anssi Hannula <anssi.hannula@gmail.com>"); MODULE_DESCRIPTION("Force feedback support for memoryless devices"); /* Number of effects handled with memoryless devices */ #define FF_MEMLESS_EFFECTS 16 /* Envelope update interval in ms */ #define FF_ENVELOPE_INTERVAL 50 #define FF_EFFECT_STARTED 0 #define FF_EFFECT_PLAYING 1 #define FF_EFFECT_ABORTING 2 struct ml_effect_state { struct ff_effect *effect; unsigned long flags; /* effect state (STARTED, PLAYING, etc) */ int count; /* loop count of the effect */ unsigned long play_at; /* start time */ unsigned long stop_at; /* stop time */ unsigned long adj_at; /* last time the effect was sent */ }; struct ml_device { void *private; struct ml_effect_state states[FF_MEMLESS_EFFECTS]; int gain; struct timer_list timer; spinlock_t timer_lock; struct input_dev *dev; int (*play_effect)(struct input_dev *dev, void *data, struct ff_effect *effect); }; static const struct ff_envelope *get_envelope(const struct ff_effect *effect) { static const struct ff_envelope empty_envelope; switch (effect->type) { case FF_PERIODIC: return &effect->u.periodic.envelope; case FF_CONSTANT: return &effect->u.constant.envelope; default: return &empty_envelope; } } /* * Check for the next time envelope requires an update on memoryless devices */ static unsigned long calculate_next_time(struct ml_effect_state *state) { const struct ff_envelope *envelope = get_envelope(state->effect); unsigned long attack_stop, fade_start, next_fade; if (envelope->attack_length) { attack_stop = state->play_at + msecs_to_jiffies(envelope->attack_length); if (time_before(state->adj_at, attack_stop)) return state->adj_at + msecs_to_jiffies(FF_ENVELOPE_INTERVAL); } if (state->effect->replay.length) { if (envelope->fade_length) { /* check when fading should start */ fade_start = state->stop_at - msecs_to_jiffies(envelope->fade_length); if (time_before(state->adj_at, fade_start)) return fade_start; /* already fading, advance to next checkpoint */ next_fade = state->adj_at + msecs_to_jiffies(FF_ENVELOPE_INTERVAL); if (time_before(next_fade, state->stop_at)) return next_fade; } return state->stop_at; } return state->play_at; } static void ml_schedule_timer(struct ml_device *ml) { struct ml_effect_state *state; unsigned long now = jiffies; unsigned long earliest = 0; unsigned long next_at; int events = 0; int i; debug("calculating next timer"); for (i = 0; i < FF_MEMLESS_EFFECTS; i++) { state = &ml->states[i]; if (!test_bit(FF_EFFECT_STARTED, &state->flags)) continue; if (test_bit(FF_EFFECT_PLAYING, &state->flags)) next_at = calculate_next_time(state); else next_at = state->play_at; if (time_before_eq(now, next_at) && (++events == 1 || time_before(next_at, earliest))) earliest = next_at; } if (!events) { debug("no actions"); del_timer(&ml->timer); } else { debug("timer set"); mod_timer(&ml->timer, earliest); } } /* * Apply an envelope to a value */ static int apply_envelope(struct ml_effect_state *state, int value, struct ff_envelope *envelope) { struct ff_effect *effect = state->effect; unsigned long now = jiffies; int time_from_level; int time_of_envelope; int envelope_level; int difference; if (envelope->attack_length && time_before(now, state->play_at + msecs_to_jiffies(envelope->attack_length))) { debug("value = 0x%x, attack_level = 0x%x", value, envelope->attack_level); time_from_level = jiffies_to_msecs(now - state->play_at); time_of_envelope = envelope->attack_length; envelope_level = min_t(__s16, envelope->attack_level, 0x7fff); } else if (envelope->fade_length && effect->replay.length && time_after(now, state->stop_at - msecs_to_jiffies(envelope->fade_length)) && time_before(now, state->stop_at)) { time_from_level = jiffies_to_msecs(state->stop_at - now); time_of_envelope = envelope->fade_length; envelope_level = min_t(__s16, envelope->fade_level, 0x7fff); } else return value; difference = abs(value) - envelope_level; debug("difference = %d", difference); debug("time_from_level = 0x%x", time_from_level); debug("time_of_envelope = 0x%x", time_of_envelope); difference = difference * time_from_level / time_of_envelope; debug("difference = %d", difference); return value < 0 ? -(difference + envelope_level) : (difference + envelope_level); } /* * Return the type the effect has to be converted into (memless devices) */ static int get_compatible_type(struct ff_device *ff, int effect_type) { if (test_bit(effect_type, ff->ffbit)) return effect_type; if (effect_type == FF_PERIODIC && test_bit(FF_RUMBLE, ff->ffbit)) return FF_RUMBLE; printk(KERN_ERR "ff-memless: invalid type in get_compatible_type()\n"); return 0; } /* * Combine two effects and apply gain. */ static void ml_combine_effects(struct ff_effect *effect, struct ml_effect_state *state, int gain) { struct ff_effect *new = state->effect; unsigned int strong, weak, i; int x, y; fixp_t level; switch (new->type) { case FF_CONSTANT: i = new->direction * 360 / 0xffff; level = fixp_new16(apply_envelope(state, new->u.constant.level, &new->u.constant.envelope)); x = fixp_mult(fixp_sin(i), level) * gain / 0xffff; y = fixp_mult(-fixp_cos(i), level) * gain / 0xffff; /* * here we abuse ff_ramp to hold x and y of constant force * If in future any driver wants something else than x and y * in s8, this should be changed to something more generic */ effect->u.ramp.start_level = clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f); effect->u.ramp.end_level = clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f); break; case FF_RUMBLE: strong = new->u.rumble.strong_magnitude * gain / 0xffff; weak = new->u.rumble.weak_magnitude * gain / 0xffff; effect->u.rumble.strong_magnitude = min(strong + effect->u.rumble.strong_magnitude, 0xffffU); effect->u.rumble.weak_magnitude = min(weak + effect->u.rumble.weak_magnitude, 0xffffU); break; case FF_PERIODIC: i = apply_envelope(state, abs(new->u.periodic.magnitude), &new->u.periodic.envelope); /* here we also scale it 0x7fff => 0xffff */ i = i * gain / 0x7fff; effect->u.rumble.strong_magnitude = min(i + effect->u.rumble.strong_magnitude, 0xffffU); effect->u.rumble.weak_magnitude = min(i + effect->u.rumble.weak_magnitude, 0xffffU); break; default: printk(KERN_ERR "ff-memless: invalid type in ml_combine_effects()\n"); break; } } /* * Because memoryless devices have only one effect per effect type active * at one time we have to combine multiple effects into one */ static int ml_get_combo_effect(struct ml_device *ml, unsigned long *effect_handled, struct ff_effect *combo_effect) { struct ff_effect *effect; struct ml_effect_state *state; int effect_type; int i; memset(combo_effect, 0, sizeof(struct ff_effect)); for (i = 0; i < FF_MEMLESS_EFFECTS; i++) { if (__test_and_set_bit(i, effect_handled)) continue; state = &ml->states[i]; effect = state->effect; if (!test_bit(FF_EFFECT_STARTED, &state->flags)) continue; if (time_before(jiffies, state->play_at)) continue; /* * here we have started effects that are either * currently playing (and may need be aborted) * or need to start playing. */ effect_type = get_compatible_type(ml->dev->ff, effect->type); if (combo_effect->type != effect_type) { if (combo_effect->type != 0) { __clear_bit(i, effect_handled); continue; } combo_effect->type = effect_type; } if (__test_and_clear_bit(FF_EFFECT_ABORTING, &state->flags)) { __clear_bit(FF_EFFECT_PLAYING, &state->flags); __clear_bit(FF_EFFECT_STARTED, &state->flags); } else if (effect->replay.length && time_after_eq(jiffies, state->stop_at)) { __clear_bit(FF_EFFECT_PLAYING, &state->flags); if (--state->count <= 0) { __clear_bit(FF_EFFECT_STARTED, &state->flags); } else { state->play_at = jiffies + msecs_to_jiffies(effect->replay.delay); state->stop_at = state->play_at + msecs_to_jiffies(effect->replay.length); } } else { __set_bit(FF_EFFECT_PLAYING, &state->flags); state->adj_at = jiffies; ml_combine_effects(combo_effect, state, ml->gain); } } return combo_effect->type != 0; } static void ml_play_effects(struct ml_device *ml) { struct ff_effect effect; DECLARE_BITMAP(handled_bm, FF_MEMLESS_EFFECTS); memset(handled_bm, 0, sizeof(handled_bm)); while (ml_get_combo_effect(ml, handled_bm, &effect)) ml->play_effect(ml->dev, ml->private, &effect); ml_schedule_timer(ml); } static void ml_effect_timer(unsigned long timer_data) { struct input_dev *dev = (struct input_dev *)timer_data; struct ml_device *ml = dev->ff->private; debug("timer: updating effects"); spin_lock(&ml->timer_lock); ml_play_effects(ml); spin_unlock(&ml->timer_lock); } static void ml_ff_set_gain(struct input_dev *dev, u16 gain) { struct ml_device *ml = dev->ff->private; int i; spin_lock_bh(&ml->timer_lock); ml->gain = gain; for (i = 0; i < FF_MEMLESS_EFFECTS; i++) __clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags); ml_play_effects(ml); spin_unlock_bh(&ml->timer_lock); } static int ml_ff_playback(struct input_dev *dev, int effect_id, int value) { struct ml_device *ml = dev->ff->private; struct ml_effect_state *state = &ml->states[effect_id]; unsigned long flags; spin_lock_irqsave(&ml->timer_lock, flags); if (value > 0) { debug("initiated play"); __set_bit(FF_EFFECT_STARTED, &state->flags); state->count = value; state->play_at = jiffies + msecs_to_jiffies(state->effect->replay.delay); state->stop_at = state->play_at + msecs_to_jiffies(state->effect->replay.length); state->adj_at = state->play_at; ml_schedule_timer(ml); } else { debug("initiated stop"); if (test_bit(FF_EFFECT_PLAYING, &state->flags)) __set_bit(FF_EFFECT_ABORTING, &state->flags); else __clear_bit(FF_EFFECT_STARTED, &state->flags); ml_play_effects(ml); } spin_unlock_irqrestore(&ml->timer_lock, flags); return 0; } static int ml_ff_upload(struct input_dev *dev, struct ff_effect *effect, struct ff_effect *old) { struct ml_device *ml = dev->ff->private; struct ml_effect_state *state = &ml->states[effect->id]; spin_lock_bh(&ml->timer_lock); if (test_bit(FF_EFFECT_STARTED, &state->flags)) { __clear_bit(FF_EFFECT_PLAYING, &state->flags); state->play_at = jiffies + msecs_to_jiffies(state->effect->replay.delay); state->stop_at = state->play_at + msecs_to_jiffies(state->effect->replay.length); state->adj_at = state->play_at; ml_schedule_timer(ml); } spin_unlock_bh(&ml->timer_lock); return 0; } static void ml_ff_destroy(struct ff_device *ff) { struct ml_device *ml = ff->private; kfree(ml->private); } /** * input_ff_create_memless() - create memoryless force-feedback device * @dev: input device supporting force-feedback * @data: driver-specific data to be passed into @play_effect * @play_effect: driver-specific method for playing FF effect */ int input_ff_create_memless(struct input_dev *dev, void *data, int (*play_effect)(struct input_dev *, void *, struct ff_effect *)) { struct ml_device *ml; struct ff_device *ff; int error; int i; ml = kzalloc(sizeof(struct ml_device), GFP_KERNEL); if (!ml) return -ENOMEM; ml->dev = dev; ml->private = data; ml->play_effect = play_effect; ml->gain = 0xffff; spin_lock_init(&ml->timer_lock); setup_timer(&ml->timer, ml_effect_timer, (unsigned long)dev); set_bit(FF_GAIN, dev->ffbit); error = input_ff_create(dev, FF_MEMLESS_EFFECTS); if (error) { kfree(ml); return error; } ff = dev->ff; ff->private = ml; ff->upload = ml_ff_upload; ff->playback = ml_ff_playback; ff->set_gain = ml_ff_set_gain; ff->destroy = ml_ff_destroy; /* we can emulate periodic effects with RUMBLE */ if (test_bit(FF_RUMBLE, ff->ffbit)) { set_bit(FF_PERIODIC, dev->ffbit); set_bit(FF_SINE, dev->ffbit); set_bit(FF_TRIANGLE, dev->ffbit); set_bit(FF_SQUARE, dev->ffbit); } for (i = 0; i < FF_MEMLESS_EFFECTS; i++) ml->states[i].effect = &ff->effects[i]; return 0; } EXPORT_SYMBOL_GPL(input_ff_create_memless);