Message-Id: <1398524543-15012-25-git-send-email-madcatxster@devoid-pointer.net>
Date:	Sat, 26 Apr 2014 17:02:23 +0200
From:	Michal Malý <madcatxster@...oid-pointer.net>
To:	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:	dmitry.torokhov@...il.com, jkosina@...e.cz, elias.vds@...il.com,
	anssi.hannula@....fi, simon@...gewell.org,
	Michal Malý <madcatxster@...oid-pointer.net>
Subject: [PATCH v4 24/24] input: Replace ff-memless with ff-memless-next

Replace ff-memless with ff-memless-next

ff-memless-next is a module for handling force feedback devices that
have no FFB effect memory of their own. It is based on the ff-memless
module but it has been largerly extended. Notable changes include:
- Support for all force feedback effects currently defined by Microsoft
  DirectInput.
- Improved emulation of periodic and rumble effects in case either of
  those is not supported by a device.
- New kernel API to interface with HW-specific drivers.

Signed-off-by: Michal Malý <madcatxster@...oid-pointer.net>
---
 drivers/input/Kconfig      |  13 +-
 drivers/input/Makefile     |   1 -
 drivers/input/ff-memless.c | 547 ---------------------------------------------
 include/linux/input.h      |   3 -
 4 files changed, 1 insertion(+), 563 deletions(-)
 delete mode 100644 drivers/input/ff-memless.c

diff --git a/drivers/input/Kconfig b/drivers/input/Kconfig
index 3780962..061ae3c 100644
--- a/drivers/input/Kconfig
+++ b/drivers/input/Kconfig
@@ -25,7 +25,7 @@ config INPUT
 
 if INPUT
 
-config INPUT_FF_MEMLESS
+config INPUT_FF_MEMLESS_NEXT
 	tristate "Support for memoryless force-feedback devices"
 	help
 	  Say Y here if you have memoryless force-feedback input device
@@ -36,17 +36,6 @@ config INPUT_FF_MEMLESS
 	  If unsure, say N.
 
 	  To compile this driver as a module, choose M here: the
-	  module will be called ff-memless.
-
-config INPUT_FF_MEMLESS_NEXT
-	tristate "New version of support for memoryless force-feedback devices"
-	help
-	  Say Y here to enable a new version of support for memoryless force
-	  feedback devices.
-
-	  If unsure, say N.
-
-	  To compile this driver as a module, choose M here: the
 	  module will be called ff-memless-next.
 
 config INPUT_POLLDEV
diff --git a/drivers/input/Makefile b/drivers/input/Makefile
index b4f11f5..f7ae055 100644
--- a/drivers/input/Makefile
+++ b/drivers/input/Makefile
@@ -7,7 +7,6 @@
 obj-$(CONFIG_INPUT)		+= input-core.o
 input-core-y := input.o input-compat.o input-mt.o ff-core.o
 
-obj-$(CONFIG_INPUT_FF_MEMLESS)	+= ff-memless.o
 obj-$(CONFIG_INPUT_FF_MEMLESS_NEXT)	+= ff-memless-next.o
 obj-$(CONFIG_INPUT_POLLDEV)	+= input-polldev.o
 obj-$(CONFIG_INPUT_SPARSEKMAP)	+= sparse-keymap.o
diff --git a/drivers/input/ff-memless.c b/drivers/input/ff-memless.c
deleted file mode 100644
index 74c0d8c..0000000
--- a/drivers/input/ff-memless.c
+++ /dev/null
@@ -1,547 +0,0 @@
-/*
- *  Force feedback support for memoryless devices
- *
- *  Copyright (c) 2006 Anssi Hannula <anssi.hannula@...il.com>
- *  Copyright (c) 2006 Dmitry Torokhov <dtor@...l.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 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@...il.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;
-}
-
-/*
- * 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 = (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(unsigned long timer_data)
-{
-	struct input_dev *dev = (struct input_dev *)timer_data;
-	struct ml_device *ml = dev->ff->private;
-	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;
-
-	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;
-	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);
diff --git a/include/linux/input.h b/include/linux/input.h
index 82ce323..0c6c3f1 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -528,7 +528,4 @@ 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
-- 
1.9.2

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