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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/input/ff-memless.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/input/ff-memless.c')
-rw-r--r-- | drivers/input/ff-memless.c | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/drivers/input/ff-memless.c b/drivers/input/ff-memless.c new file mode 100644 index 000000000..c321cdabd --- /dev/null +++ b/drivers/input/ff-memless.c @@ -0,0 +1,553 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Force feedback support for memoryless devices + * + * Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com> + * Copyright (c) 2006 Dmitry Torokhov <dtor@mail.ru> + */ + +/* #define DEBUG */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/slab.h> +#include <linux/input.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/spinlock.h> +#include <linux/jiffies.h> +#include <linux/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; + 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; + + pr_debug("calculating next timer\n"); + + 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) { + pr_debug("no actions\n"); + del_timer(&ml->timer); + } else { + pr_debug("timer set\n"); + 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))) { + pr_debug("value = 0x%x, attack_level = 0x%x\n", + value, envelope->attack_level); + time_from_level = jiffies_to_msecs(now - state->play_at); + time_of_envelope = envelope->attack_length; + envelope_level = min_t(u16, 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(u16, envelope->fade_level, 0x7fff); + } else + return value; + + difference = abs(value) - envelope_level; + + pr_debug("difference = %d\n", difference); + pr_debug("time_from_level = 0x%x\n", time_from_level); + pr_debug("time_of_envelope = 0x%x\n", time_of_envelope); + + difference = difference * time_from_level / time_of_envelope; + + pr_debug("difference = %d\n", 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; + + pr_err("invalid type in get_compatible_type()\n"); + + return 0; +} + +/* + * Only left/right direction should be used (under/over 0x8000) for + * forward/reverse motor direction (to keep calculation fast & simple). + */ +static u16 ml_calculate_direction(u16 direction, u16 force, + u16 new_direction, u16 new_force) +{ + if (!force) + return new_direction; + if (!new_force) + return direction; + return (((u32)(direction >> 1) * force + + (new_direction >> 1) * new_force) / + (force + new_force)) << 1; +} + +#define FRAC_N 8 +static inline s16 fixp_new16(s16 a) +{ + return ((s32)a) >> (16 - FRAC_N); +} + +static inline s16 fixp_mult(s16 a, s16 b) +{ + a = ((s32)a * 0x100) / 0x7fff; + return ((s32)(a * b)) >> FRAC_N; +} + +/* + * 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; + s16 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_sin16(i), level) * gain / 0xffff; + y = fixp_mult(-fixp_cos16(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 = (u32)new->u.rumble.strong_magnitude * gain / 0xffff; + weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff; + + if (effect->u.rumble.strong_magnitude + strong) + effect->direction = ml_calculate_direction( + effect->direction, + effect->u.rumble.strong_magnitude, + new->direction, strong); + else if (effect->u.rumble.weak_magnitude + weak) + effect->direction = ml_calculate_direction( + effect->direction, + effect->u.rumble.weak_magnitude, + new->direction, weak); + else + effect->direction = 0; + 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; + + if (effect->u.rumble.strong_magnitude + i) + effect->direction = ml_calculate_direction( + effect->direction, + effect->u.rumble.strong_magnitude, + new->direction, i); + else + effect->direction = 0; + 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: + pr_err("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(struct timer_list *t) +{ + struct ml_device *ml = from_timer(ml, t, timer); + struct input_dev *dev = ml->dev; + unsigned long flags; + + pr_debug("timer: updating effects\n"); + + spin_lock_irqsave(&dev->event_lock, flags); + ml_play_effects(ml); + spin_unlock_irqrestore(&dev->event_lock, flags); +} + +/* + * Sets requested gain for FF effects. Called with dev->event_lock held. + */ +static void ml_ff_set_gain(struct input_dev *dev, u16 gain) +{ + struct ml_device *ml = dev->ff->private; + int i; + + ml->gain = gain; + + for (i = 0; i < FF_MEMLESS_EFFECTS; i++) + __clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags); + + ml_play_effects(ml); +} + +/* + * Start/stop specified FF effect. Called with dev->event_lock held. + */ +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]; + + if (value > 0) { + pr_debug("initiated play\n"); + + __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; + + } else { + pr_debug("initiated stop\n"); + + 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); + + 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_irq(&dev->event_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_irq(&dev->event_lock); + + return 0; +} + +static void ml_ff_destroy(struct ff_device *ff) +{ + struct ml_device *ml = ff->private; + + /* + * Even though we stop all playing effects when tearing down + * an input device (via input_device_flush() that calls into + * input_ff_flush() that stops and erases all effects), we + * do not actually stop the timer, and therefore we should + * do it here. + */ + del_timer_sync(&ml->timer); + + 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; + timer_setup(&ml->timer, ml_effect_timer, 0); + + 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); |