@@ -38,6 +38,17 @@ config INPUT_FF_MEMLESS
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
tristate "Polled input device skeleton"
help
@@ -8,6 +8,7 @@ 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-$(CONFIG_INPUT_SPARSEKMAP) += sparse-keymap.o
obj-$(CONFIG_INPUT_MATRIXKMAP) += matrix-keymap.o
new file mode 100644
@@ -0,0 +1,1036 @@
+/*
+ * Force feedback support for memoryless devices
+ *
+ * This module is based on "ff-memless" orignally written by Anssi Hannula.
+ * It is extended to support all force feedback effects currently supported
+ * by the Linux input stack.
+ * Logic of emulation of FF_RUMBLE through FF_PERIODIC provided by
+ * Elias Vanderstuyft <elias.vds@gmail.com>
+ *
+ * Copyright(c) 2014 Michal "MadCatX" Maly <madcatxster@devoid-pointer.net>
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/jiffies.h>
+#include <linux/fixp-arith.h>
+#include <linux/input/ff-memless-next.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Michal \"MadCatX\" Maly");
+MODULE_DESCRIPTION("Force feedback support for memoryless force feedback devices");
+
+#define FF_MAX_EFFECTS 16
+#define FF_MIN_EFFECT_LENGTH ((1000 / CONFIG_HZ) + 1)
+#define FF_EFFECT_STARTED 1
+#define FF_EFFECT_PLAYING 2
+#define FF_EFFECT_EMULATED 3
+
+enum mlnx_emulate {
+ EMUL_NOTHING, /* Do not emulate anything */
+ EMUL_RUMBLE, /* Emulate FF_RUMBLE with FF_PERIODIC */
+ EMUL_PERIODIC /* Emulate FF_PERIODIC with FF_RUMBLE */
+};
+
+struct mlnx_effect {
+ struct ff_effect effect;
+ unsigned long flags;
+ unsigned long begin_at;
+ unsigned long stop_at;
+ unsigned long updated_at;
+ unsigned long attack_stop;
+ unsigned long fade_begin;
+ int repeat;
+};
+
+struct mlnx_device {
+ u8 combinable_playing;
+ u8 rumble_playing;
+ unsigned long update_rate_jiffies;
+ void *private;
+ struct mlnx_effect effects[FF_MAX_EFFECTS];
+ u16 gain;
+ struct timer_list timer;
+ struct input_dev *dev;
+ enum mlnx_emulate emul;
+
+ int (*control_effect)(struct input_dev *, void *,
+ const struct mlnx_effect_command *);
+};
+
+static s32 mlnx_calculate_x_force(const s32 level,
+ const u16 direction)
+{
+ s32 new = (level * -fixp_sin(direction)) >> FRAC_N;
+ pr_debug("x force: %d\n", new);
+ return new;
+}
+
+static s32 mlnx_calculate_y_force(const s32 level,
+ const u16 direction)
+{
+ s32 new = (level * fixp_cos(direction)) >> FRAC_N;
+ pr_debug("y force: %d\n", new);
+ return new;
+}
+
+static bool mlnx_is_combinable(const struct ff_effect *effect)
+{
+ switch (effect->type) {
+ case FF_CONSTANT:
+ case FF_PERIODIC:
+ case FF_RAMP:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool mlnx_is_conditional(const struct ff_effect *effect)
+{
+ switch (effect->type) {
+ case FF_DAMPER:
+ case FF_FRICTION:
+ case FF_INERTIA:
+ case FF_SPRING:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static void mlnx_clr_emulated(struct mlnx_effect *mlnxeff)
+{
+ __clear_bit(FF_EFFECT_EMULATED, &mlnxeff->flags);
+}
+
+static void mlnx_clr_playing(struct mlnx_effect *mlnxeff)
+{
+ __clear_bit(FF_EFFECT_PLAYING, &mlnxeff->flags);
+}
+
+static void mlnx_clr_started(struct mlnx_effect *mlnxeff)
+{
+ __clear_bit(FF_EFFECT_STARTED, &mlnxeff->flags);
+}
+
+static bool mlnx_is_emulated(const struct mlnx_effect *mlnxeff)
+{
+ return test_bit(FF_EFFECT_EMULATED, &mlnxeff->flags);
+}
+
+static bool mlnx_is_rumble(const struct ff_effect *effect)
+{
+ return effect->type == FF_RUMBLE;
+}
+
+static bool mlnx_is_playing(const struct mlnx_effect *mlnxeff)
+{
+ return test_bit(FF_EFFECT_PLAYING, &mlnxeff->flags);
+}
+
+static bool mlnx_is_started(const struct mlnx_effect *mlnxeff)
+{
+ return test_bit(FF_EFFECT_STARTED, &mlnxeff->flags);
+}
+
+static bool mlnx_test_set_playing(struct mlnx_effect *mlnxeff)
+{
+ return test_and_set_bit(FF_EFFECT_PLAYING, &mlnxeff->flags);
+}
+
+static const struct ff_envelope *mlnx_get_envelope(const struct ff_effect *effect)
+{
+ static const struct ff_envelope empty;
+
+ switch (effect->type) {
+ case FF_CONSTANT:
+ return &effect->u.constant.envelope;
+ case FF_PERIODIC:
+ return &effect->u.periodic.envelope;
+ case FF_RAMP:
+ return &effect->u.ramp.envelope;
+ default:
+ return ∅
+ }
+}
+
+/* Some devices might have a limit on how many uncombinable effects
+ * can be played at once */
+static int mlnx_upload_conditional(struct mlnx_device *mlnxdev,
+ const struct ff_effect *effect)
+{
+ struct mlnx_effect_command ecmd = {
+ .cmd = MLNX_UPLOAD_UNCOMB,
+ .u.uncomb.id = effect->id,
+ .u.uncomb.effect = effect
+ };
+ return mlnxdev->control_effect(mlnxdev->dev, mlnxdev->private, &ecmd);
+}
+
+static int mlnx_erase_conditional(struct mlnx_device *mlnxdev,
+ const struct ff_effect *effect)
+{
+ struct mlnx_effect_command ecmd = {
+ .cmd = MLNX_ERASE_UNCOMB,
+ .u.uncomb.id = effect->id,
+ .u.uncomb.effect = effect
+ };
+ return mlnxdev->control_effect(mlnxdev->dev, mlnxdev->private, &ecmd);
+}
+
+static void mlnx_set_envelope_times(struct mlnx_effect *mlnxeff)
+{
+ const struct ff_effect *effect = &mlnxeff->effect;
+ const struct ff_envelope *envelope = mlnx_get_envelope(effect);
+
+ if (envelope->attack_length) {
+ unsigned long j = msecs_to_jiffies(envelope->attack_length);
+ mlnxeff->attack_stop = mlnxeff->begin_at + j;
+ }
+ if (effect->replay.length && envelope->fade_length) {
+ unsigned long j = msecs_to_jiffies(envelope->fade_length);
+ mlnxeff->fade_begin = mlnxeff->stop_at - j;
+ }
+}
+
+static void mlnx_set_trip_times(struct mlnx_effect *mlnxeff,
+ const unsigned long now)
+{
+ const struct ff_effect *effect = &mlnxeff->effect;
+ const u16 replay_delay = effect->replay.delay;
+ const u16 replay_length = effect->replay.length;
+
+ mlnxeff->begin_at = now + msecs_to_jiffies(replay_delay);
+ mlnxeff->stop_at = mlnxeff->begin_at + msecs_to_jiffies(replay_length);
+ mlnxeff->updated_at = mlnxeff->begin_at;
+}
+
+static void mlnx_start_effect(struct mlnx_effect *mlnxeff)
+{
+ const unsigned long now = jiffies;
+
+ mlnx_set_trip_times(mlnxeff, now);
+ mlnx_set_envelope_times(mlnxeff);
+ __set_bit(FF_EFFECT_STARTED, &mlnxeff->flags);
+}
+
+static void mlnx_stop_effect(struct mlnx_device *mlnxdev,
+ const struct mlnx_effect *mlnxeff)
+{
+ switch (mlnxeff->effect.type) {
+ case FF_PERIODIC:
+ if (mlnx_is_emulated(mlnxeff)) {
+ if (--mlnxdev->rumble_playing == 0) {
+ const struct mlnx_effect_command c = {
+ .cmd = MLNX_STOP_RUMBLE
+ };
+ mlnxdev->control_effect(mlnxdev->dev,
+ mlnxdev->private, &c);
+ }
+ return;
+ }
+ case FF_CONSTANT:
+ case FF_RAMP:
+ if (--mlnxdev->combinable_playing == 0) {
+ const struct mlnx_effect_command c = {
+ .cmd = MLNX_STOP_COMBINED
+ };
+ mlnxdev->control_effect(mlnxdev->dev, mlnxdev->private,
+ &c);
+ }
+ return;
+ case FF_RUMBLE:
+ if (mlnx_is_emulated(mlnxeff)) {
+ if (--mlnxdev->combinable_playing == 0) {
+ const struct mlnx_effect_command c = {
+ .cmd = MLNX_STOP_COMBINED
+ };
+ mlnxdev->control_effect(mlnxdev->dev,
+ mlnxdev->private, &c);
+ }
+ } else {
+ if (--mlnxdev->rumble_playing == 0) {
+ const struct mlnx_effect_command c = {
+ .cmd = MLNX_STOP_RUMBLE
+ };
+ mlnxdev->control_effect(mlnxdev->dev,
+ mlnxdev->private, &c);
+ }
+ }
+ return;
+ case FF_DAMPER:
+ case FF_FRICTION:
+ case FF_INERTIA:
+ case FF_SPRING:
+ {
+ const struct mlnx_effect_command c = {
+ .cmd = MLNX_STOP_UNCOMB,
+ .u.uncomb.id = mlnxeff->effect.id,
+ .u.uncomb.effect = &mlnxeff->effect
+ };
+ mlnxdev->control_effect(mlnxdev->dev, mlnxdev->private, &c);
+ return;
+ }
+ default:
+ return;
+ }
+}
+
+static int mlnx_restart_effect(struct mlnx_device *mlnxdev,
+ struct mlnx_effect *mlnxeff)
+{
+ const struct ff_effect *effect = &mlnxeff->effect;
+ const unsigned long now = jiffies;
+
+ if (mlnx_is_combinable(effect)) {
+ if (effect->replay.delay)
+ mlnx_stop_effect(mlnxdev, mlnxeff);
+ else {
+ if (mlnx_is_emulated(mlnxeff))
+ mlnxdev->rumble_playing--;
+ else
+ mlnxdev->combinable_playing--;
+ }
+ } else if (mlnx_is_rumble(effect)) {
+ if (effect->replay.delay)
+ mlnx_stop_effect(mlnxdev, mlnxeff);
+ else {
+ if (mlnx_is_emulated(mlnxeff))
+ mlnxdev->combinable_playing--;
+ else
+ mlnxdev->rumble_playing--;
+ }
+ } else if (mlnx_is_conditional(effect)) {
+ int ret;
+ if (effect->replay.delay)
+ mlnx_stop_effect(mlnxdev, mlnxeff);
+
+ ret = mlnx_upload_conditional(mlnxdev, &mlnxeff->effect);
+ if (ret)
+ return ret;
+ }
+
+ mlnx_set_trip_times(mlnxeff, now);
+ mlnx_set_envelope_times(mlnxeff);
+
+ return 0;
+}
+
+static s32 mlnx_apply_envelope(const struct mlnx_effect *mlnxeff,
+ const s32 level)
+{
+ const struct ff_effect *effect = &mlnxeff->effect;
+ const struct ff_envelope *envelope = mlnx_get_envelope(effect);
+ const unsigned long now = jiffies;
+ const s32 alevel = abs(level);
+
+ /* Effect has an envelope with nonzero attack time */
+ if (envelope->attack_length && time_before(now, mlnxeff->attack_stop)) {
+ const s32 clength = jiffies_to_msecs(now - mlnxeff->begin_at);
+ const s32 alength = envelope->attack_length;
+ const s32 dlevel = (alevel - envelope->attack_level)
+ * clength / alength;
+ return level < 0 ? -(dlevel + envelope->attack_level) :
+ (dlevel + envelope->attack_level);
+ } else if (envelope->fade_length && time_before_eq(mlnxeff->fade_begin, now)) {
+ const s32 clength = jiffies_to_msecs(now - mlnxeff->fade_begin);
+ const s32 flength = envelope->fade_length;
+ const s32 dlevel = (envelope->fade_level - alevel)
+ * clength / flength;
+ return level < 0 ? -(dlevel + alevel) : (dlevel + alevel);
+ }
+
+ return level;
+}
+
+static s32 mlnx_calculate_periodic(struct mlnx_effect *mlnxeff, const s32 level)
+{
+ const struct ff_effect *effect = &mlnxeff->effect;
+ const unsigned long now = jiffies;
+ const u16 period = effect->u.periodic.period;
+ const u16 phase = effect->u.periodic.phase;
+ const s16 offset = effect->u.periodic.offset;
+ s32 new = level;
+ u16 t = (jiffies_to_msecs(now - mlnxeff->begin_at) + phase) % period;
+
+ switch (effect->u.periodic.waveform) {
+ case FF_SINE:
+ {
+ u16 degrees = (360 * t) / period;
+ new = ((level * fixp_sin(degrees)) >> FRAC_N) + offset;
+ break;
+ }
+ case FF_SQUARE:
+ {
+ u16 degrees = (360 * t) / period;
+ new = level * (degrees < 180 ? 1 : -1) + offset;
+ break;
+ }
+ case FF_SAW_UP:
+ new = 2 * level * t / period - level + offset;
+ break;
+ case FF_SAW_DOWN:
+ new = level - 2 * level * t / period + offset;
+ break;
+ case FF_TRIANGLE:
+ {
+ new = (2 * abs(level - (2 * level * t) / period));
+ new = new - abs(level) + offset;
+ break;
+ }
+ case FF_CUSTOM:
+ pr_debug("Custom waveform is not handled by this driver\n");
+ return level;
+ default:
+ pr_err("Invalid waveform\n");
+ return level;
+ }
+
+ /* Ensure that the offset did not make the value exceed s16 range */
+ new = clamp(new, -0x7fff, 0x7fff);
+ pr_debug("level: %d, t: %u\n", new, t);
+ return new;
+}
+
+static s32 mlnx_calculate_ramp(const struct mlnx_effect *mlnxeff)
+{
+ const struct ff_effect *effect = &mlnxeff->effect;
+ const struct ff_envelope *envelope = mlnx_get_envelope(effect);
+ const unsigned long now = jiffies;
+ const u16 length = effect->replay.length;
+ const s16 mean = (effect->u.ramp.start_level + effect->u.ramp.end_level) / 2;
+ const u16 t = jiffies_to_msecs(now - mlnxeff->begin_at);
+ s32 start = effect->u.ramp.start_level;
+ s32 end = effect->u.ramp.end_level;
+ s32 new;
+
+ if (envelope->attack_length && time_before(now, mlnxeff->attack_stop)) {
+ const s32 clength = jiffies_to_msecs(now - mlnxeff->begin_at);
+ const s32 alength = envelope->attack_length;
+ s32 attack_level;
+ if (end > start)
+ attack_level = mean - envelope->attack_level;
+ else
+ attack_level = mean + envelope->attack_level;
+ start = (start - attack_level) * clength / alength
+ + attack_level;
+ } else if (envelope->fade_length && time_before_eq(mlnxeff->fade_begin, now)) {
+ const s32 clength = jiffies_to_msecs(now - mlnxeff->fade_begin);
+ const s32 flength = envelope->fade_length;
+ s32 fade_level;
+ if (end > start)
+ fade_level = mean + envelope->fade_level;
+ else
+ fade_level = mean - envelope->fade_level;
+ end = (fade_level - end) * clength / flength + end;
+ }
+
+ new = ((end - start) * t) / length + start;
+ new = clamp(new, -0x7fff, 0x7fff);
+ pr_debug("RAMP level: %d, t: %u\n", new, t);
+ return new;
+}
+
+static void mlnx_destroy(struct ff_device *dev)
+{
+ struct mlnx_device *mlnxdev = dev->private;
+ del_timer_sync(&mlnxdev->timer);
+
+ kfree(mlnxdev->private);
+}
+
+static unsigned long mlnx_get_envelope_update_time(const struct mlnx_effect *mlnxeff,
+ const unsigned long update_rate_jiffies)
+{
+ const struct ff_effect *effect = &mlnxeff->effect;
+ const struct ff_envelope *envelope = mlnx_get_envelope(effect);
+ const unsigned long now = jiffies;
+ unsigned long fade_next;
+
+ /* Effect has an envelope with nonzero attack time */
+ if (envelope->attack_length && time_before(now, mlnxeff->attack_stop)) {
+ if (time_before(mlnxeff->updated_at + update_rate_jiffies, mlnxeff->attack_stop))
+ return mlnxeff->updated_at + update_rate_jiffies;
+
+ return mlnxeff->attack_stop;
+ }
+
+ /* Effect has an envelope with nonzero fade time */
+ if (mlnxeff->effect.replay.length) {
+ if (!envelope->fade_length)
+ return mlnxeff->stop_at;
+
+ /* Schedule the next update when the fade begins */
+ if (time_before(mlnxeff->updated_at, mlnxeff->fade_begin))
+ return mlnxeff->fade_begin;
+
+ /* Already fading */
+ fade_next = mlnxeff->updated_at + update_rate_jiffies;
+
+ /* Schedule update when the effect stops */
+ if (time_after(fade_next, mlnxeff->stop_at))
+ return mlnxeff->stop_at;
+ /* Schedule update at the next checkpoint */
+ return fade_next;
+ }
+
+ /* There is no envelope */
+
+ /* Prevent the effect from being started twice */
+ if (mlnxeff->begin_at == now && mlnx_is_playing(mlnxeff))
+ return now - 1;
+
+ return mlnxeff->begin_at;
+}
+
+static unsigned long mlnx_get_update_time(struct mlnx_effect *mlnxeff,
+ const unsigned long update_rate_jiffies)
+{
+ const unsigned long now = jiffies;
+ unsigned long time, update_periodic;
+
+ switch (mlnxeff->effect.type) {
+ /* Constant effect does not change with time, but it can have
+ * an envelope and a duration */
+ case FF_CONSTANT:
+ return mlnx_get_envelope_update_time(mlnxeff,
+ update_rate_jiffies);
+ /* Periodic and ramp effects have to be periodically updated */
+ case FF_PERIODIC:
+ case FF_RAMP:
+ time = mlnx_get_envelope_update_time(mlnxeff,
+ update_rate_jiffies);
+ if (mlnx_is_emulated(mlnxeff))
+ update_periodic = mlnxeff->stop_at;
+ else
+ update_periodic = mlnxeff->updated_at +
+ update_rate_jiffies;
+
+ /* Periodic effect has to be updated earlier than envelope
+ * or envelope update time is in the past */
+ if (time_before(update_periodic, time) || time_before(time, now))
+ return update_periodic;
+ /* Envelope needs to be updated */
+ return time;
+ case FF_RUMBLE:
+ if (mlnx_is_emulated(mlnxeff))
+ return mlnxeff->updated_at + update_rate_jiffies;
+ case FF_DAMPER:
+ case FF_FRICTION:
+ case FF_INERTIA:
+ case FF_SPRING:
+ default:
+ if (time_after_eq(mlnxeff->begin_at, now))
+ return mlnxeff->begin_at;
+
+ return mlnxeff->stop_at;
+ }
+}
+
+static void mlnx_schedule_playback(struct mlnx_device *mlnxdev)
+{
+ struct mlnx_effect *mlnxeff;
+ const unsigned long now = jiffies;
+ int events = 0;
+ int i;
+ unsigned long earliest = 0;
+ unsigned long time;
+
+ /* Iterate over all effects and determine the earliest
+ * time when we have to attend to any */
+ for (i = 0; i < FF_MAX_EFFECTS; i++) {
+ mlnxeff = &mlnxdev->effects[i];
+
+ if (!mlnx_is_started(mlnxeff))
+ continue; /* Effect is not started, skip it */
+
+ if (mlnx_is_playing(mlnxeff))
+ time = mlnx_get_update_time(mlnxeff,
+ mlnxdev->update_rate_jiffies);
+ else
+ time = mlnxeff->begin_at;
+
+ pr_debug("Update time for effect %d: %lu\n", i, time);
+
+ /* Scheduled time is in the future and is either
+ * before the current earliest time or it is
+ * the first valid time value in this pass */
+ if (time_before_eq(now, time) &&
+ (++events == 1 || time_before(time, earliest)))
+ earliest = time;
+ }
+
+ if (events) {
+ pr_debug("Events: %d, earliest: %lu\n", events, earliest);
+ mod_timer(&mlnxdev->timer, earliest);
+ } else {
+ pr_debug("No events, deactivating timer\n");
+ del_timer(&mlnxdev->timer);
+ }
+}
+
+static u16 mlnx_calculate_rumble_direction(const u32 total_mag, const u16 total_dir,
+ const u32 new_mag, const u16 new_dir)
+{
+ if (!new_mag)
+ return total_dir;
+ if (!total_mag)
+ return new_dir;
+ return (((total_dir >> 1) * total_mag +
+ (new_dir >> 1) * new_mag) /
+ (total_mag + new_mag)) << 1;
+}
+
+static void mlnx_add_force(struct mlnx_effect *mlnxeff, s32 *cfx, s32 *cfy,
+ const u16 gain)
+{
+ const struct ff_effect *effect = &mlnxeff->effect;
+ u16 direction;
+ s32 level;
+
+ pr_debug("Processing effect type %d, ID %d\n",
+ mlnxeff->effect.type, mlnxeff->effect.id);
+
+ direction = mlnxeff->effect.direction * 360 / 0xffff;
+ pr_debug("Direction deg: %u\n", direction);
+
+ switch (mlnxeff->effect.type) {
+ case FF_CONSTANT:
+ level = mlnx_apply_envelope(mlnxeff, effect->u.constant.level);
+ break;
+ case FF_PERIODIC:
+ level = mlnx_apply_envelope(mlnxeff,
+ effect->u.periodic.magnitude);
+ level = mlnx_calculate_periodic(mlnxeff, level);
+ break;
+ case FF_RAMP:
+ level = mlnx_calculate_ramp(mlnxeff);
+ break;
+ default:
+ pr_err("Effect %d not handled by mlnx_add_force\n",
+ mlnxeff->effect.type);
+ return;
+ }
+
+ *cfx += mlnx_calculate_x_force(level, direction) * gain / 0xffff;
+ *cfy += mlnx_calculate_y_force(level, direction) * gain / 0xffff;
+}
+
+static void mlnx_add_rumble(const struct mlnx_effect *mlnxeff, u32 *strong_mag,
+ u32 *weak_mag, u16 *strong_dir,
+ u16 *weak_dir, const u16 gain)
+{
+ const struct ff_effect *eff = &mlnxeff->effect;
+ const struct ff_rumble_effect *reff = &mlnxeff->effect.u.rumble;
+ const u32 new_strong_mag = (u32)reff->strong_magnitude * gain / 0xffffU;
+ const u32 new_weak_mag = (u32)reff->weak_magnitude * gain / 0xffffU;
+
+ *strong_dir = mlnx_calculate_rumble_direction(*strong_mag, *strong_dir,
+ new_strong_mag,
+ eff->direction);
+ *weak_dir = mlnx_calculate_rumble_direction(*weak_mag, *weak_dir,
+ new_weak_mag,
+ eff->direction);
+ *strong_mag += new_strong_mag;
+ *weak_mag += new_weak_mag;
+}
+
+static void mlnx_add_emul_periodic(const struct mlnx_effect *mlnxeff,
+ u32 *strong_mag, u32 *weak_mag,
+ u16 *strong_dir, u16 *weak_dir,
+ const u16 gain)
+{
+ const struct ff_effect *eff = &mlnxeff->effect;
+ const u32 level = (u32)abs(mlnx_apply_envelope(mlnxeff,
+ eff->u.periodic.magnitude)) * gain / 0x7fffU;
+
+ *strong_dir = mlnx_calculate_rumble_direction(*strong_mag, *strong_dir,
+ level, eff->direction);
+ *weak_dir = mlnx_calculate_rumble_direction(*weak_mag, *weak_dir,
+ level, eff->direction);
+
+ *strong_mag += level;
+ *weak_mag += level;
+}
+
+static void mlnx_add_emul_rumble(const struct mlnx_effect *mlnxeff, s32 *cfx,
+ s32 *cfy, const u16 gain,
+ const unsigned long now,
+ const unsigned long update_rate_jiffies)
+{
+ const struct ff_effect *effect = &mlnxeff->effect;
+ const u16 strong = effect->u.rumble.strong_magnitude;
+ const u16 weak = effect->u.rumble.weak_magnitude;
+ /* To calculate 't', we pretend that mlnxeff->begin_at == 0, thus t == now. */
+ /* This will synchronise all simultaneously playing emul rumble effects, */
+ /* otherwise non-deterministic phase-inversions could occur depending on */
+ /* upload time, which could lead to undesired cancellation of these effects. */
+ const unsigned long t = now % (4UL * update_rate_jiffies);
+ s32 level = 0;
+ bool direction_up;
+ bool direction_left;
+
+ if (strong)
+ level += (strong / 4) * (t < 2UL * update_rate_jiffies ? 1 : -1);
+ if (weak)
+ level += (weak / 4) * (t < 2UL * update_rate_jiffies ?
+ (t < 1UL * update_rate_jiffies ? 1 : -1) :
+ (t < 3UL * update_rate_jiffies ? 1 : -1));
+ direction_up = (effect->direction > 0x3fffU && effect->direction <= 0xbfffU);
+ direction_left = (effect->direction <= 0x7fffU);
+
+ pr_debug("Emulated cf: %d, t: %lu, n: %lu, begin: %lu, diff: %lu j: %lu\n",
+ level, t, now, mlnxeff->begin_at, now - mlnxeff->begin_at,
+ update_rate_jiffies);
+ level = (level * gain) / 0xffff;
+ *cfx += direction_left ? -level : level;
+ *cfy += direction_up ? -level : level;
+}
+
+static void mlnx_play_effects(struct mlnx_device *mlnxdev)
+{
+ const u16 gain = mlnxdev->gain;
+ const unsigned long now = jiffies;
+ int i;
+ s32 cfx = 0;
+ s32 cfy = 0;
+ u32 strong_mag = 0;
+ u32 weak_mag = 0;
+ u16 strong_dir = 0;
+ u16 weak_dir = 0;
+
+ for (i = 0; i < FF_MAX_EFFECTS; i++) {
+ struct mlnx_effect *mlnxeff = &mlnxdev->effects[i];
+
+ if (!mlnx_is_started(mlnxeff)) {
+ pr_debug("Effect %hd/%d not started\n",
+ mlnxeff->effect.id, i);
+ continue;
+ }
+
+ if (time_before(now, mlnxeff->begin_at)) {
+ pr_debug("Effect %hd/%d begins at a later time\n",
+ mlnxeff->effect.id, i);
+ continue;
+ }
+
+ if (time_before_eq(mlnxeff->stop_at, now) && mlnxeff->effect.replay.length) {
+ pr_debug("Effect %hd/%d has to be stopped\n",
+ mlnxeff->effect.id, i);
+
+ mlnx_clr_playing(mlnxeff);
+ if (--mlnxeff->repeat > 0)
+ mlnx_restart_effect(mlnxdev, mlnxeff);
+ else {
+ mlnx_stop_effect(mlnxdev, mlnxeff);
+ mlnx_clr_started(mlnxeff);
+ mlnx_clr_emulated(mlnxeff);
+ if (mlnx_is_conditional(&mlnxeff->effect))
+ mlnx_erase_conditional(mlnxdev, &mlnxeff->effect);
+ }
+
+ continue;
+ }
+
+ switch (mlnxeff->effect.type) {
+ case FF_PERIODIC:
+ if (mlnxdev->emul == EMUL_PERIODIC) {
+ if (!mlnx_test_set_playing(mlnxeff)) {
+ mlnxdev->rumble_playing++;
+ pr_debug("Starting emul periodic, total rumble %u\n",
+ mlnxdev->rumble_playing);
+ }
+ __set_bit(FF_EFFECT_EMULATED, &mlnxeff->flags);
+ mlnx_add_emul_periodic(mlnxeff, &strong_mag, &weak_mag,
+ &strong_dir, &weak_dir, gain);
+ break;
+ }
+ case FF_CONSTANT:
+ case FF_RAMP:
+ if (!mlnx_test_set_playing(mlnxeff)) {
+ mlnxdev->combinable_playing++;
+ pr_debug("Starting combinable effect, total %u\n",
+ mlnxdev->combinable_playing);
+ }
+ mlnx_add_force(mlnxeff, &cfx, &cfy, gain);
+ break;
+ case FF_RUMBLE:
+ if (mlnxdev->emul == EMUL_RUMBLE) {
+ if (!mlnx_test_set_playing(mlnxeff)) {
+ mlnxdev->combinable_playing++;
+ pr_debug("Starting emul rumble, total comb %u\n",
+ mlnxdev->combinable_playing);
+ }
+ __set_bit(FF_EFFECT_EMULATED, &mlnxeff->flags);
+ mlnx_add_emul_rumble(mlnxeff, &cfx, &cfy, gain, now,
+ mlnxdev->update_rate_jiffies);
+ } else {
+ if (!mlnx_test_set_playing(mlnxeff)) {
+ mlnxdev->rumble_playing++;
+ pr_debug("Starting rumble effect, total %u\n",
+ mlnxdev->rumble_playing);
+ }
+ mlnx_add_rumble(mlnxeff, &strong_mag, &weak_mag,
+ &strong_dir, &weak_dir, gain);
+ }
+ break;
+ case FF_DAMPER:
+ case FF_FRICTION:
+ case FF_INERTIA:
+ case FF_SPRING:
+ if (!mlnx_test_set_playing(mlnxeff)) {
+ const struct mlnx_effect_command ecmd = {
+ .cmd = MLNX_START_UNCOMB,
+ .u.uncomb.id = i,
+ .u.uncomb.effect = &mlnxeff->effect
+ };
+ mlnxdev->control_effect(mlnxdev->dev,
+ mlnxdev->private, &ecmd);
+ }
+ break;
+ default:
+ pr_debug("Unhandled type of effect\n");
+ }
+ mlnxeff->updated_at = now;
+ }
+
+ if (mlnxdev->combinable_playing) {
+ const struct mlnx_effect_command ecmd = {
+ .cmd = MLNX_START_COMBINED,
+ .u.simple_force = {
+ .x = clamp(cfx, -0x7fff, 0x7fff),
+ .y = clamp(cfy, -0x7fff, 0x7fff)
+ }
+ };
+ mlnxdev->control_effect(mlnxdev->dev, mlnxdev->private, &ecmd);
+ }
+ if (mlnxdev->rumble_playing) {
+ const struct mlnx_effect_command ecmd = {
+ .cmd = MLNX_START_RUMBLE,
+ .u.rumble_force = {
+ .strong = clamp(strong_mag, (u32)0, (u32)0xffffU),
+ .weak = clamp(weak_mag, (u32)0, (u32)0xffffU),
+ .strong_dir = clamp(strong_dir, (u16)0, (u16)0xffffU),
+ .weak_dir = clamp(weak_dir, (u16)0, (u16)0xffffU)
+ }
+ };
+ mlnxdev->control_effect(mlnxdev->dev, mlnxdev->private, &ecmd);
+ }
+
+ mlnx_schedule_playback(mlnxdev);
+}
+
+static void mlnx_set_gain(struct input_dev *dev, u16 gain)
+{
+ struct mlnx_device *mlnxdev = dev->ff->private;
+ int i;
+
+ mlnxdev->gain = gain;
+
+ for (i = 0; i < FF_MAX_EFFECTS; i++) {
+ struct mlnx_effect *eff = &mlnxdev->effects[i];
+ if (eff == NULL)
+ continue;
+ if (mlnx_is_playing(eff)) {
+ if (mlnx_is_combinable(&eff->effect)) {
+ mlnx_clr_playing(eff);
+ if (mlnx_is_emulated(eff))
+ --mlnxdev->rumble_playing;
+ else
+ --mlnxdev->combinable_playing;
+ } else if (mlnx_is_rumble(&eff->effect)) {
+ mlnx_clr_playing(eff);
+ if (mlnx_is_emulated(eff))
+ --mlnxdev->combinable_playing;
+ else
+ --mlnxdev->rumble_playing;
+ }
+ }
+ }
+
+ mlnx_play_effects(mlnxdev);
+}
+
+static int mlnx_startstop(struct input_dev *dev, int effect_id, int repeat)
+{
+ struct mlnx_device *mlnxdev = dev->ff->private;
+ struct mlnx_effect *mlnxeff = &mlnxdev->effects[effect_id];
+ int ret;
+
+ if (repeat > 0) {
+ pr_debug("Starting effect ID %d\n", effect_id);
+ mlnxeff->repeat = repeat;
+
+ if (!mlnx_is_started(mlnxeff)) {
+ /* Check that device has a free effect slot */
+ if (mlnx_is_conditional(&mlnxeff->effect)) {
+ ret = mlnx_upload_conditional(mlnxdev, &mlnxeff->effect);
+ if (ret) {
+ /* Device effect slots are all occupied */
+ pr_debug("No free effect slot for EID %d\n", effect_id);
+ return ret;
+ }
+ }
+ mlnx_start_effect(mlnxeff);
+ }
+ } else {
+ pr_debug("Stopping effect ID %d\n", effect_id);
+ if (mlnx_is_started(mlnxeff)) {
+ if (mlnx_is_playing(mlnxeff)) {
+ mlnx_clr_playing(mlnxeff);
+ mlnx_stop_effect(mlnxdev, mlnxeff);
+ }
+ mlnx_clr_started(mlnxeff);
+ mlnx_clr_emulated(mlnxeff);
+
+ if (mlnx_is_conditional(&mlnxeff->effect))
+ return mlnx_erase_conditional(mlnxdev, &mlnxeff->effect);
+ } else {
+ pr_debug("Effect ID %d already stopped\n", effect_id);
+ return 0;
+ }
+ }
+ mlnx_play_effects(mlnxdev);
+
+ return 0;
+}
+
+static void mlnx_timer_fired(unsigned long data)
+{
+ struct input_dev *dev = (struct input_dev *)data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->event_lock, flags);
+ mlnx_play_effects(dev->ff->private);
+ spin_unlock_irqrestore(&dev->event_lock, flags);
+}
+
+static int mlnx_upload(struct input_dev *dev, struct ff_effect *effect,
+ struct ff_effect *old)
+{
+ struct mlnx_device *mlnxdev = dev->ff->private;
+ struct mlnx_effect *mlnxeff = &mlnxdev->effects[effect->id];
+ const u16 length = effect->replay.length;
+ const u16 delay = effect->replay.delay;
+ int ret, fade_from;
+
+ /* Effect's timing is below kernel timer resolution */
+ if (length && length < FF_MIN_EFFECT_LENGTH)
+ effect->replay.length = FF_MIN_EFFECT_LENGTH;
+ if (delay && delay < FF_MIN_EFFECT_LENGTH)
+ effect->replay.delay = FF_MIN_EFFECT_LENGTH;
+
+ /* Periodic effects must have a non-zero period */
+ if (effect->type == FF_PERIODIC) {
+ if (!effect->u.periodic.period)
+ return -EINVAL;
+ }
+ /* Ramp effects cannot be infinite */
+ if (effect->type == FF_RAMP && !length)
+ return -EINVAL;
+
+ if (mlnx_is_combinable(effect)) {
+ const struct ff_envelope *envelope = mlnx_get_envelope(effect);
+
+ /* Infinite effects cannot fade */
+ if (!length && envelope->fade_length > 0)
+ return -EINVAL;
+ /* Fade length cannot be greater than effect duration */
+ fade_from = (int)length - (int)envelope->fade_length;
+ if (fade_from < 0)
+ return -EINVAL;
+ /* Envelope cannot start fading before it finishes attacking */
+ if (fade_from < envelope->attack_length && fade_from > 0)
+ return -EINVAL;
+ }
+
+
+ spin_lock_irq(&dev->event_lock);
+ mlnxeff->effect = *effect; /* Keep internal copy of the effect */
+ /* Check if the effect being modified is playing */
+ if (mlnx_is_started(mlnxeff)) {
+ if (mlnx_is_playing(mlnxeff)) {
+ mlnx_clr_playing(mlnxeff);
+ ret = mlnx_restart_effect(mlnxdev, mlnxeff);
+
+ if (ret) {
+ /* Restore the original effect */
+ if (old)
+ mlnxeff->effect = *old;
+ spin_unlock_irq(&dev->event_lock);
+ return ret;
+ }
+ }
+
+ mlnx_schedule_playback(mlnxdev);
+ }
+
+ spin_unlock_irq(&dev->event_lock);
+
+ return 0;
+}
+
+int input_ff_create_mlnx(struct input_dev *dev, void *data,
+ int (*control_effect)(struct input_dev *, void *, const struct mlnx_effect_command *),
+ const u16 update_rate)
+{
+ struct mlnx_device *mlnxdev;
+ int ret;
+
+ mlnxdev = kzalloc(sizeof(*mlnxdev), GFP_KERNEL);
+ if (!mlnxdev)
+ return -ENOMEM;
+
+ mlnxdev->dev = dev;
+ mlnxdev->private = data;
+ mlnxdev->control_effect = control_effect;
+ mlnxdev->gain = 0xffff;
+ mlnxdev->update_rate_jiffies = update_rate < FF_MIN_EFFECT_LENGTH ?
+ FF_MIN_EFFECT_LENGTH : update_rate;
+ input_set_capability(dev, EV_FF, FF_GAIN);
+ setup_timer(&mlnxdev->timer, mlnx_timer_fired, (unsigned long)dev);
+
+ /* Set up effect emulation if needed */
+ if (test_bit(FF_PERIODIC, dev->ffbit) &&
+ !test_bit(FF_RUMBLE, dev->ffbit)) {
+ set_bit(FF_RUMBLE, dev->ffbit);
+ mlnxdev->emul = EMUL_RUMBLE;
+ pr_debug("Emulating RUMBLE with PERIODIC\n");
+ } else if (test_bit(FF_RUMBLE, dev->ffbit) &&
+ !test_bit(FF_PERIODIC, dev->ffbit)) {
+ set_bit(FF_PERIODIC, dev->ffbit);
+ set_bit(FF_SINE, dev->ffbit);
+ set_bit(FF_SQUARE, dev->ffbit);
+ set_bit(FF_TRIANGLE, dev->ffbit);
+ set_bit(FF_SAW_DOWN, dev->ffbit);
+ set_bit(FF_SAW_UP, dev->ffbit);
+ mlnxdev->emul = EMUL_PERIODIC;
+ pr_debug("Emulating PERIODIC with RUMBLE\n");
+ } else {
+ mlnxdev->emul = EMUL_NOTHING;
+ pr_debug("No effect emulation is necessary\n");
+ }
+
+ ret = input_ff_create(dev, FF_MAX_EFFECTS);
+ if (ret) {
+ kfree(mlnxdev);
+ return ret;
+ }
+
+
+ dev->ff->private = mlnxdev;
+ dev->ff->upload = mlnx_upload;
+ dev->ff->set_gain = mlnx_set_gain;
+ dev->ff->destroy = mlnx_destroy;
+ dev->ff->playback = mlnx_startstop;
+
+ pr_debug("Device successfully registered.\n");
+ return 0;
+}
+EXPORT_SYMBOL_GPL(input_ff_create_mlnx);
new file mode 100644
@@ -0,0 +1,149 @@
+#include <linux/input.h>
+
+/** DEFINITION OF TERMS
+ *
+ * Combined effect - An effect whose force is a superposition of forces
+ * generated by all effects that can be added together.
+ * Only one combined effect can be playing at a time.
+ * Effects that can be added together to create a combined
+ * effect are FF_CONSTANT, FF_PERIODIC and FF_RAMP.
+ * Uncombinable effect - An effect that cannot be combined with another effect.
+ * All conditional effects - FF_DAMPER, FF_FRICTION,
+ * FF_INERTIA and FF_SPRING are uncombinable.
+ * Number of uncombinable effects playing simultaneously
+ * depends on the capabilities of the hardware.
+ * Rumble effect - An effect generated by device's rumble motors instead of
+ * force feedback actuators.
+ *
+ *
+ * HANDLING OF UNCOMBINABLE EFFECTS
+ *
+ * Uncombinable effects cannot be combined together into just one effect, at
+ * least not in a clear and obvious manner. Therefore these effects have to
+ * be handled individually by ff-memless-next. Handling of these effects is
+ * left entirely to the hardware-specific driver, ff-memless-next merely
+ * passes these effects to the hardware-specific driver at appropriate time.
+ * ff-memless-next provides the UPLOAD command to notify the hardware-specific
+ * driver that the userspace is about to request playback of an uncombinable
+ * effect. The hardware-specific driver shall take all steps needed to make
+ * the device ready to play the effect when it receives the UPLOAD command.
+ * The actual playback shall commence when START_UNCOMB command is received.
+ * Opposite to the UPLOAD command is the ERASE command which tells
+ * the hardware-specific driver that the playback has finished and that
+ * the effect will not be restarted. STOP_UNCOMB command tells
+ * the hardware-specific driver that the playback shall stop but the device
+ * shall still be ready to resume the playback immediately.
+ *
+ * In case it is not possible to make the device ready to play an uncombinable
+ * effect (all hardware effect slots are occupied), the hardware-specific
+ * driver may return an error when it receives an UPLOAD command. If the
+ * hardware-specific driver returns 0, the upload is considered successful.
+ * START_UNCOMB and STOP_UNCOMB commands cannot fail and the device must always
+ * start the playback of the requested effect if the UPLOAD command of the
+ * respective effect has been successful. ff-memless-next will never send
+ * a START/STOP_UNCOMB command for an effect that has not been uploaded
+ * successfully, nor will it send an ERASE command for an effect that is
+ * playing (= has been started with START_UNCOMB command).
+ */
+
+enum mlnx_commands {
+ /* Start or update a combined effect. This command is sent whenever
+ * a FF_CONSTANT, FF_PERIODIC or FF_RAMP is started, stopped or
+ * updated by userspace, when the applied envelopes are recalculated
+ * or when periodic effects are recalculated. */
+ MLNX_START_COMBINED,
+ /* Stop combined effect. This command is sent when all combinable
+ * effects are stopped. */
+ MLNX_STOP_COMBINED,
+ /* Start or update a rumble effect. This command is sent whenever
+ * a FF_RUMBLE effect is started or when its magnitudes or directions
+ * change. */
+ MLNX_START_RUMBLE,
+ /* Stop a rumble effect. This command is sent when all FF_RUMBLE
+ * effects are stopped. */
+ MLNX_STOP_RUMBLE,
+ /* Start or update an uncombinable effect. This command is sent
+ * whenever an uncombinable effect is started or updated. */
+ MLNX_START_UNCOMB,
+ /* Stop uncombinable effect. This command is sent when an uncombinable
+ * effect is stopped. */
+ MLNX_STOP_UNCOMB,
+ /* Upload uncombinable effect to device. This command is sent when the
+ * effect is started from userspace. It is up to the hardware-specific
+ * driver to handle this situation.
+ */
+ MLNX_UPLOAD_UNCOMB,
+ /* Remove uncombinable effect from device, This command is sent when
+ * and uncombinable effect has finished playing and will not be
+ * restarted.
+ */
+ MLNX_ERASE_UNCOMB
+};
+
+/** struct mlnx_simple_force - holds constant forces along X and Y axis
+ * @x: Force along X axis. Negative value denotes force pulling to the left,
+ * positive value denotes force pulling to the right.
+ * @y: Force along Y axis. Negative value denotes force denotes force pulling
+ * away from the user, positive value denotes force pulling towards
+ * the user.
+ */
+struct mlnx_simple_force {
+ const s32 x;
+ const s32 y;
+};
+
+/** struct mlnx_rumble_force - holds information about rumble effect
+ * @strong: Magnitude of the strong vibration.
+ * @weak: Magnitude of the weak vibration.
+ * @strong_dir: Direction of the strong vibration expressed in the same way
+ * as the direction of force feedback effect in struct ff_effect.
+ * @weak_dir: Direction of the weak vibration, same as above applies.
+ */
+struct mlnx_rumble_force {
+ const u32 strong;
+ const u32 weak;
+ const u16 strong_dir;
+ const u16 weak_dir;
+};
+
+/** struct mlnx_uncomb_effect - holds information about uncombinable effect
+ * @id: Id of the effect assigned by ff-core.
+ * @effect: Pointer to the uncombinable effect stored in ff-memless-next module
+ * Hardware-specific driver must not alter this.
+ */
+struct mlnx_uncomb_effect {
+ const int id;
+ const struct ff_effect *effect;
+};
+
+/** struct mlnx_commands - describes what action shall the force feedback
+ * device perform
+ * @cmd: Type of the action.
+ * @u: Data associated with the action.
+ */
+struct mlnx_effect_command {
+ const enum mlnx_commands cmd;
+ union {
+ const struct mlnx_simple_force simple_force;
+ const struct mlnx_rumble_force rumble_force;
+ const struct mlnx_uncomb_effect uncomb;
+ } u;
+};
+
+/** input_ff_create_mlnx() - Register a device within ff-memless-next and
+ * the kernel force feedback system
+ * @dev: Pointer to the struct input_dev associated with the device.
+ * @data: Any device-specific data that shall be passed to the callback.
+ * function called by ff-memless-next when a force feedback action
+ * shall be performed.
+ * @control_effect: Pointer to the callback function.
+ * @update_date: Delay in milliseconds between two recalculations of periodic
+ * effects, ramp effects and envelopes. Note that this value will
+ * never be lower than (CONFIG_HZ / 1000) + 1 regardless of the
+ * value specified here. This is not a "hard" rate limiter.
+ * Userspace still can submit effects at a rate faster than
+ * this value.
+ */
+int input_ff_create_mlnx(struct input_dev *dev, void *data,
+ int (*control_effect)(struct input_dev *, void *, const struct mlnx_effect_command *),
+ const u16 update_rate);