Input: unified force feedback support for memoryless devices
Anssi Hannula [Wed, 19 Jul 2006 05:40:30 +0000 (01:40 -0400)]
Consolidate core implementing memoryless devices in one module; added
support for gain and envelopes and periodic => rumble conversion.

Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/Kconfig
drivers/input/Makefile
drivers/input/ff-memless.c [new file with mode: 0644]
include/linux/input.h

index 58223b5..9623231 100644 (file)
@@ -24,6 +24,20 @@ config INPUT
 
 if INPUT
 
+config INPUT_FF_MEMLESS
+       tristate "Support for memoryless force-feedback devices"
+       default n
+       ---help---
+         Say Y here if you have memoryless force-feedback input device
+         such as Logitech WingMan Force 3D, ThrustMaster FireStorm Dual
+         Power 2, or similar. You will also need to enable hardware-specific
+         driver.
+
+         If unsure, say N.
+
+         To compile this driver as a module, choose M here: the
+         module will be called ff-memless.
+
 comment "Userland interfaces"
 
 config INPUT_MOUSEDEV
index abdc9d4..a005b1d 100644 (file)
@@ -7,6 +7,8 @@
 obj-$(CONFIG_INPUT)            += input-core.o
 input-core-objs := input.o ff-core.o
 
+obj-$(CONFIG_INPUT_FF_MEMLESS) += ff-memless.o
+
 obj-$(CONFIG_INPUT_MOUSEDEV)   += mousedev.o
 obj-$(CONFIG_INPUT_JOYDEV)     += joydev.o
 obj-$(CONFIG_INPUT_EVDEV)      += evdev.o
diff --git a/drivers/input/ff-memless.c b/drivers/input/ff-memless.c
new file mode 100644 (file)
index 0000000..cd8b729
--- /dev/null
@@ -0,0 +1,515 @@
+/*
+ *  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/sched.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 =
+                       max(min(effect->u.ramp.start_level + x, 0x7f), -0x80);
+               effect->u.ramp.end_level =
+                       max(min(effect->u.ramp.end_level + y, 0x7f), -0x80);
+               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];
+
+       spin_lock_bh(&ml->timer_lock);
+
+       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_bh(&ml->timer_lock);
+
+       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 FF 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);
index 81c6ea5..d8b0c56 100644 (file)
@@ -1169,5 +1169,8 @@ int input_ff_event(struct input_dev *dev, unsigned int type, unsigned int code,
 int input_ff_upload(struct input_dev *dev, struct ff_effect *effect, struct file *file);
 int input_ff_erase(struct input_dev *dev, int effect_id, struct file *file);
 
+int input_ff_create_memless(struct input_dev *dev, void *data,
+               int (*play_effect)(struct input_dev *, void *, struct ff_effect *));
+
 #endif
 #endif