Input: add force feedback driver for PID devices

This replaces the older PID driver which was never completed.

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

1 files changed, 1330 insertions, 0 deletions

diff --git a/drivers/usb/input/hid-pidff.c b/drivers/usb/input/hid-pidff.c
new file mode 100644
index 00000000000..5420c13eb8e
--- /dev/null
+++ b/drivers/usb/input/hid-pidff.c
@@ -0,0 +1,1330 @@
+/*
+ *  Force feedback driver for USB HID PID compliant devices
+ *
+ *  Copyright (c) 2005, 2006 Anssi Hannula <anssi.hannula@gmail.com>
+ */
+
+/*
+ * 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("hid-pidff: " format "\n" , ## arg)
+
+#include <linux/sched.h>
+#include <linux/input.h>
+#include <linux/usb.h>
+
+#include "hid.h"
+
+#define	PID_EFFECTS_MAX		64
+
+/* Report usage table used to put reports into an array */
+
+#define PID_SET_EFFECT		0
+#define PID_EFFECT_OPERATION	1
+#define PID_DEVICE_GAIN		2
+#define PID_POOL		3
+#define PID_BLOCK_LOAD		4
+#define PID_BLOCK_FREE		5
+#define PID_DEVICE_CONTROL	6
+#define PID_CREATE_NEW_EFFECT	7
+
+#define PID_REQUIRED_REPORTS	7
+
+#define PID_SET_ENVELOPE	8
+#define PID_SET_CONDITION	9
+#define PID_SET_PERIODIC	10
+#define PID_SET_CONSTANT	11
+#define PID_SET_RAMP		12
+static const u8 pidff_reports[] = {
+	0x21, 0x77, 0x7d, 0x7f, 0x89, 0x90, 0x96, 0xab,
+	0x5a, 0x5f, 0x6e, 0x73, 0x74
+};
+
+/* device_control is really 0x95, but 0x96 specified as it is the usage of
+the only field in that report */
+
+/* Value usage tables used to put fields and values into arrays */
+
+#define PID_EFFECT_BLOCK_INDEX	0
+
+#define PID_DURATION		1
+#define PID_GAIN		2
+#define PID_TRIGGER_BUTTON	3
+#define PID_TRIGGER_REPEAT_INT	4
+#define PID_DIRECTION_ENABLE	5
+#define PID_START_DELAY		6
+static const u8 pidff_set_effect[] = {
+	0x22, 0x50, 0x52, 0x53, 0x54, 0x56, 0xa7
+};
+
+#define PID_ATTACK_LEVEL	1
+#define PID_ATTACK_TIME		2
+#define PID_FADE_LEVEL		3
+#define PID_FADE_TIME		4
+static const u8 pidff_set_envelope[] = { 0x22, 0x5b, 0x5c, 0x5d, 0x5e };
+
+#define PID_PARAM_BLOCK_OFFSET	1
+#define PID_CP_OFFSET		2
+#define PID_POS_COEFFICIENT	3
+#define PID_NEG_COEFFICIENT	4
+#define PID_POS_SATURATION	5
+#define PID_NEG_SATURATION	6
+#define PID_DEAD_BAND		7
+static const u8 pidff_set_condition[] = {
+	0x22, 0x23, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65
+};
+
+#define PID_MAGNITUDE		1
+#define PID_OFFSET		2
+#define PID_PHASE		3
+#define PID_PERIOD		4
+static const u8 pidff_set_periodic[] = { 0x22, 0x70, 0x6f, 0x71, 0x72 };
+static const u8 pidff_set_constant[] = { 0x22, 0x70 };
+
+#define PID_RAMP_START		1
+#define PID_RAMP_END		2
+static const u8 pidff_set_ramp[] = { 0x22, 0x75, 0x76 };
+
+#define PID_RAM_POOL_AVAILABLE	1
+static const u8 pidff_block_load[] = { 0x22, 0xac };
+
+#define PID_LOOP_COUNT		1
+static const u8 pidff_effect_operation[] = { 0x22, 0x7c };
+
+static const u8 pidff_block_free[] = { 0x22 };
+
+#define PID_DEVICE_GAIN_FIELD	0
+static const u8 pidff_device_gain[] = { 0x7e };
+
+#define PID_RAM_POOL_SIZE	0
+#define PID_SIMULTANEOUS_MAX	1
+#define PID_DEVICE_MANAGED_POOL	2
+static const u8 pidff_pool[] = { 0x80, 0x83, 0xa9 };
+
+/* Special field key tables used to put special field keys into arrays */
+
+#define PID_ENABLE_ACTUATORS	0
+#define PID_RESET		1
+static const u8 pidff_device_control[] = { 0x97, 0x9a };
+
+#define PID_CONSTANT	0
+#define PID_RAMP	1
+#define PID_SQUARE	2
+#define PID_SINE	3
+#define PID_TRIANGLE	4
+#define PID_SAW_UP	5
+#define PID_SAW_DOWN	6
+#define PID_SPRING	7
+#define PID_DAMPER	8
+#define PID_INERTIA	9
+#define PID_FRICTION	10
+static const u8 pidff_effect_types[] = {
+	0x26, 0x27, 0x30, 0x31, 0x32, 0x33, 0x34,
+	0x40, 0x41, 0x42, 0x43
+};
+
+#define PID_BLOCK_LOAD_SUCCESS	0
+#define PID_BLOCK_LOAD_FULL	1
+static const u8 pidff_block_load_status[] = { 0x8c, 0x8d };
+
+#define PID_EFFECT_START	0
+#define PID_EFFECT_STOP		1
+static const u8 pidff_effect_operation_status[] = { 0x79, 0x7b };
+
+struct pidff_usage {
+	struct hid_field *field;
+	s32 *value;
+};
+
+struct pidff_device {
+	struct hid_device *hid;
+
+	struct hid_report *reports[sizeof(pidff_reports)];
+
+	struct pidff_usage set_effect[sizeof(pidff_set_effect)];
+	struct pidff_usage set_envelope[sizeof(pidff_set_envelope)];
+	struct pidff_usage set_condition[sizeof(pidff_set_condition)];
+	struct pidff_usage set_periodic[sizeof(pidff_set_periodic)];
+	struct pidff_usage set_constant[sizeof(pidff_set_constant)];
+	struct pidff_usage set_ramp[sizeof(pidff_set_ramp)];
+
+	struct pidff_usage device_gain[sizeof(pidff_device_gain)];
+	struct pidff_usage block_load[sizeof(pidff_block_load)];
+	struct pidff_usage pool[sizeof(pidff_pool)];
+	struct pidff_usage effect_operation[sizeof(pidff_effect_operation)];
+	struct pidff_usage block_free[sizeof(pidff_block_free)];
+
+	/* Special field is a field that is not composed of
+	   usage<->value pairs that pidff_usage values are */
+
+	/* Special field in create_new_effect */
+	struct hid_field *create_new_effect_type;
+
+	/* Special fields in set_effect */
+	struct hid_field *set_effect_type;
+	struct hid_field *effect_direction;
+
+	/* Special field in device_control */
+	struct hid_field *device_control;
+
+	/* Special field in block_load */
+	struct hid_field *block_load_status;
+
+	/* Special field in effect_operation */
+	struct hid_field *effect_operation_status;
+
+	int control_id[sizeof(pidff_device_control)];
+	int type_id[sizeof(pidff_effect_types)];
+	int status_id[sizeof(pidff_block_load_status)];
+	int operation_id[sizeof(pidff_effect_operation_status)];
+
+	int pid_id[PID_EFFECTS_MAX];
+};
+
+/*
+ * Scale an unsigned value with range 0..max for the given field
+ */
+static int pidff_rescale(int i, int max, struct hid_field *field)
+{
+	return i * (field->logical_maximum - field->logical_minimum) / max +
+	    field->logical_minimum;
+}
+
+/*
+ * Scale a signed value in range -0x8000..0x7fff for the given field
+ */
+static int pidff_rescale_signed(int i, struct hid_field *field)
+{
+	return i == 0 ? 0 : i >
+	    0 ? i * field->logical_maximum / 0x7fff : i *
+	    field->logical_minimum / -0x8000;
+}
+
+static void pidff_set(struct pidff_usage *usage, u16 value)
+{
+	usage->value[0] = pidff_rescale(value, 0xffff, usage->field);
+	debug("calculated from %d to %d", value, usage->value[0]);
+}
+
+static void pidff_set_signed(struct pidff_usage *usage, s16 value)
+{
+	if (usage->field->logical_minimum < 0)
+		usage->value[0] = pidff_rescale_signed(value, usage->field);
+	else {
+		if (value < 0)
+			usage->value[0] =
+			    pidff_rescale(-value, 0x8000, usage->field);
+		else
+			usage->value[0] =
+			    pidff_rescale(value, 0x7fff, usage->field);
+	}
+	debug("calculated from %d to %d", value, usage->value[0]);
+}
+
+/*
+ * Send envelope report to the device
+ */
+static void pidff_set_envelope_report(struct pidff_device *pidff,
+				      struct ff_envelope *envelope)
+{
+	pidff->set_envelope[PID_EFFECT_BLOCK_INDEX].value[0] =
+	    pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
+
+	pidff->set_envelope[PID_ATTACK_LEVEL].value[0] =
+	    pidff_rescale(envelope->attack_level >
+			  0x7fff ? 0x7fff : envelope->attack_level, 0x7fff,
+			  pidff->set_envelope[PID_ATTACK_LEVEL].field);
+	pidff->set_envelope[PID_FADE_LEVEL].value[0] =
+	    pidff_rescale(envelope->fade_level >
+			  0x7fff ? 0x7fff : envelope->fade_level, 0x7fff,
+			  pidff->set_envelope[PID_FADE_LEVEL].field);
+
+	pidff->set_envelope[PID_ATTACK_TIME].value[0] = envelope->attack_length;
+	pidff->set_envelope[PID_FADE_TIME].value[0] = envelope->fade_length;
+
+	debug("attack %u => %d", envelope->attack_level,
+	      pidff->set_envelope[PID_ATTACK_LEVEL].value[0]);
+
+	hid_submit_report(pidff->hid, pidff->reports[PID_SET_ENVELOPE],
+			  USB_DIR_OUT);
+}
+
+/*
+ * Test if the new envelope differs from old one
+ */
+static int pidff_needs_set_envelope(struct ff_envelope *envelope,
+				    struct ff_envelope *old)
+{
+	return envelope->attack_level != old->attack_level ||
+	       envelope->fade_level != old->fade_level ||
+	       envelope->attack_length != old->attack_length ||
+	       envelope->fade_length != old->fade_length;
+}
+
+/*
+ * Send constant force report to the device
+ */
+static void pidff_set_constant_force_report(struct pidff_device *pidff,
+					    struct ff_effect *effect)
+{
+	pidff->set_constant[PID_EFFECT_BLOCK_INDEX].value[0] =
+		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
+	pidff_set_signed(&pidff->set_constant[PID_MAGNITUDE],
+			 effect->u.constant.level);
+
+	hid_submit_report(pidff->hid, pidff->reports[PID_SET_CONSTANT],
+			  USB_DIR_OUT);
+}
+
+/*
+ * Test if the constant parameters have changed between effects
+ */
+static int pidff_needs_set_constant(struct ff_effect *effect,
+				    struct ff_effect *old)
+{
+	return effect->u.constant.level != old->u.constant.level;
+}
+
+/*
+ * Send set effect report to the device
+ */
+static void pidff_set_effect_report(struct pidff_device *pidff,
+				    struct ff_effect *effect)
+{
+	pidff->set_effect[PID_EFFECT_BLOCK_INDEX].value[0] =
+		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
+	pidff->set_effect_type->value[0] =
+		pidff->create_new_effect_type->value[0];
+	pidff->set_effect[PID_DURATION].value[0] = effect->replay.length;
+	pidff->set_effect[PID_TRIGGER_BUTTON].value[0] = effect->trigger.button;
+	pidff->set_effect[PID_TRIGGER_REPEAT_INT].value[0] =
+		effect->trigger.interval;
+	pidff->set_effect[PID_GAIN].value[0] =
+		pidff->set_effect[PID_GAIN].field->logical_maximum;
+	pidff->set_effect[PID_DIRECTION_ENABLE].value[0] = 1;
+	pidff->effect_direction->value[0] =
+		pidff_rescale(effect->direction, 0xffff,
+				pidff->effect_direction);
+	pidff->set_effect[PID_START_DELAY].value[0] = effect->replay.delay;
+
+	hid_submit_report(pidff->hid, pidff->reports[PID_SET_EFFECT],
+			  USB_DIR_OUT);
+}
+
+/*
+ * Test if the values used in set_effect have changed
+ */
+static int pidff_needs_set_effect(struct ff_effect *effect,
+				  struct ff_effect *old)
+{
+	return effect->replay.length != old->replay.length ||
+	       effect->trigger.interval != old->trigger.interval ||
+	       effect->trigger.button != old->trigger.button ||
+	       effect->direction != old->direction ||
+	       effect->replay.delay != old->replay.delay;
+}
+
+/*
+ * Send periodic effect report to the device
+ */
+static void pidff_set_periodic_report(struct pidff_device *pidff,
+				      struct ff_effect *effect)
+{
+	pidff->set_periodic[PID_EFFECT_BLOCK_INDEX].value[0] =
+		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
+	pidff_set_signed(&pidff->set_periodic[PID_MAGNITUDE],
+			 effect->u.periodic.magnitude);
+	pidff_set_signed(&pidff->set_periodic[PID_OFFSET],
+			 effect->u.periodic.offset);
+	pidff_set(&pidff->set_periodic[PID_PHASE], effect->u.periodic.phase);
+	pidff->set_periodic[PID_PERIOD].value[0] = effect->u.periodic.period;
+
+	hid_submit_report(pidff->hid, pidff->reports[PID_SET_PERIODIC],
+			  USB_DIR_OUT);
+
+}
+
+/*
+ * Test if periodic effect parameters have changed
+ */
+static int pidff_needs_set_periodic(struct ff_effect *effect,
+				    struct ff_effect *old)
+{
+	return effect->u.periodic.magnitude != old->u.periodic.magnitude ||
+	       effect->u.periodic.offset != old->u.periodic.offset ||
+	       effect->u.periodic.phase != old->u.periodic.phase ||
+	       effect->u.periodic.period != old->u.periodic.period;
+}
+
+/*
+ * Send condition effect reports to the device
+ */
+static void pidff_set_condition_report(struct pidff_device *pidff,
+				       struct ff_effect *effect)
+{
+	int i;
+
+	pidff->set_condition[PID_EFFECT_BLOCK_INDEX].value[0] =
+		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
+
+	for (i = 0; i < 2; i++) {
+		pidff->set_condition[PID_PARAM_BLOCK_OFFSET].value[0] = i;
+		pidff_set_signed(&pidff->set_condition[PID_CP_OFFSET],
+				 effect->u.condition[i].center);
+		pidff_set_signed(&pidff->set_condition[PID_POS_COEFFICIENT],
+				 effect->u.condition[i].right_coeff);
+		pidff_set_signed(&pidff->set_condition[PID_NEG_COEFFICIENT],
+				 effect->u.condition[i].left_coeff);
+		pidff_set(&pidff->set_condition[PID_POS_SATURATION],
+			  effect->u.condition[i].right_saturation);
+		pidff_set(&pidff->set_condition[PID_NEG_SATURATION],
+			  effect->u.condition[i].left_saturation);
+		pidff_set(&pidff->set_condition[PID_DEAD_BAND],
+			  effect->u.condition[i].deadband);
+		hid_wait_io(pidff->hid);
+		hid_submit_report(pidff->hid, pidff->reports[PID_SET_CONDITION],
+				  USB_DIR_OUT);
+	}
+}
+
+/*
+ * Test if condition effect parameters have changed
+ */
+static int pidff_needs_set_condition(struct ff_effect *effect,
+				     struct ff_effect *old)
+{
+	int i;
+	int ret = 0;
+
+	for (i = 0; i < 2; i++) {
+		struct ff_condition_effect *cond = &effect->u.condition[i];
+		struct ff_condition_effect *old_cond = &old->u.condition[i];
+
+		ret |= cond->center != old_cond->center ||
+		       cond->right_coeff != old_cond->right_coeff ||
+		       cond->left_coeff != old_cond->left_coeff ||
+		       cond->right_saturation != old_cond->right_saturation ||
+		       cond->left_saturation != old_cond->left_saturation ||
+		       cond->deadband != old_cond->deadband;
+	}
+
+	return ret;
+}
+
+/*
+ * Send ramp force report to the device
+ */
+static void pidff_set_ramp_force_report(struct pidff_device *pidff,
+					struct ff_effect *effect)
+{
+	pidff->set_ramp[PID_EFFECT_BLOCK_INDEX].value[0] =
+		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
+	pidff_set_signed(&pidff->set_ramp[PID_RAMP_START],
+			 effect->u.ramp.start_level);
+	pidff_set_signed(&pidff->set_ramp[PID_RAMP_END],
+			 effect->u.ramp.end_level);
+	hid_submit_report(pidff->hid, pidff->reports[PID_SET_RAMP],
+			  USB_DIR_OUT);
+}
+
+/*
+ * Test if ramp force parameters have changed
+ */
+static int pidff_needs_set_ramp(struct ff_effect *effect, struct ff_effect *old)
+{
+	return effect->u.ramp.start_level != old->u.ramp.start_level ||
+	       effect->u.ramp.end_level != old->u.ramp.end_level;
+}
+
+/*
+ * Send a request for effect upload to the device
+ *
+ * Returns 0 if device reported success, -ENOSPC if the device reported memory
+ * is full. Upon unknown response the function will retry for 60 times, if
+ * still unsuccessful -EIO is returned.
+ */
+static int pidff_request_effect_upload(struct pidff_device *pidff, int efnum)
+{
+	int j;
+
+	pidff->create_new_effect_type->value[0] = efnum;
+	hid_submit_report(pidff->hid, pidff->reports[PID_CREATE_NEW_EFFECT],
+			  USB_DIR_OUT);
+	debug("create_new_effect sent, type: %d", efnum);
+
+	pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0] = 0;
+	pidff->block_load_status->value[0] = 0;
+	hid_wait_io(pidff->hid);
+
+	for (j = 0; j < 60; j++) {
+		debug("pid_block_load requested");
+		hid_submit_report(pidff->hid, pidff->reports[PID_BLOCK_LOAD],
+				  USB_DIR_IN);
+		hid_wait_io(pidff->hid);
+		if (pidff->block_load_status->value[0] ==
+		    pidff->status_id[PID_BLOCK_LOAD_SUCCESS]) {
+			debug("device reported free memory: %d bytes",
+			      pidff->block_load[PID_RAM_POOL_AVAILABLE].value ?
+				pidff->block_load[PID_RAM_POOL_AVAILABLE].value[0] : -1);
+			return 0;
+		}
+		if (pidff->block_load_status->value[0] ==
+		    pidff->status_id[PID_BLOCK_LOAD_FULL]) {
+			debug("not enough memory free: %d bytes",
+			      pidff->block_load[PID_RAM_POOL_AVAILABLE].value ?
+				pidff->block_load[PID_RAM_POOL_AVAILABLE].value[0] : -1);
+			return -ENOSPC;
+		}
+	}
+	printk(KERN_ERR "hid-pidff: pid_block_load failed 60 times\n");
+	return -EIO;
+}
+
+/*
+ * Play the effect with PID id n times
+ */
+static void pidff_playback_pid(struct pidff_device *pidff, int pid_id, int n)
+{
+	pidff->effect_operation[PID_EFFECT_BLOCK_INDEX].value[0] = pid_id;
+
+	if (n == 0) {
+		pidff->effect_operation_status->value[0] =
+			pidff->operation_id[PID_EFFECT_STOP];
+	} else {
+		pidff->effect_operation_status->value[0] =
+			pidff->operation_id[PID_EFFECT_START];
+		pidff->effect_operation[PID_LOOP_COUNT].value[0] = n;
+	}
+
+	hid_wait_io(pidff->hid);
+	hid_submit_report(pidff->hid, pidff->reports[PID_EFFECT_OPERATION],
+			  USB_DIR_OUT);
+}
+
+/**
+ * Play the effect with effect id @effect_id for @value times
+ */
+static int pidff_playback(struct input_dev *dev, int effect_id, int value)
+{
+	struct pidff_device *pidff = dev->ff->private;
+
+	pidff_playback_pid(pidff, pidff->pid_id[effect_id], value);
+
+	return 0;
+}
+
+/*
+ * Erase effect with PID id
+ */
+static void pidff_erase_pid(struct pidff_device *pidff, int pid_id)
+{
+	pidff->block_free[PID_EFFECT_BLOCK_INDEX].value[0] = pid_id;
+	hid_submit_report(pidff->hid, pidff->reports[PID_BLOCK_FREE],
+			  USB_DIR_OUT);
+}
+
+/*
+ * Stop and erase effect with effect_id
+ */
+static int pidff_erase_effect(struct input_dev *dev, int effect_id)
+{
+	struct pidff_device *pidff = dev->ff->private;
+	int pid_id = pidff->pid_id[effect_id];
+
+	debug("starting to erase %d/%d", effect_id, pidff->pid_id[effect_id]);
+	pidff_playback_pid(pidff, pid_id, 0);
+	pidff_erase_pid(pidff, pid_id);
+
+	return 0;
+}
+
+/*
+ * Effect upload handler
+ */
+static int pidff_upload_effect(struct input_dev *dev, struct ff_effect *effect,
+			       struct ff_effect *old)
+{
+	struct pidff_device *pidff = dev->ff->private;
+	int type_id;
+	int error;
+
+	switch (effect->type) {
+	case FF_CONSTANT:
+		if (!old) {
+			error = pidff_request_effect_upload(pidff,
+					pidff->type_id[PID_CONSTANT]);
+			if (error)
+				return error;
+		}
+		if (!old || pidff_needs_set_effect(effect, old))
+			pidff_set_effect_report(pidff, effect);
+		if (!old || pidff_needs_set_constant(effect, old))
+			pidff_set_constant_force_report(pidff, effect);
+		if (!old ||
+		    pidff_needs_set_envelope(&effect->u.constant.envelope,
+					&old->u.constant.envelope))
+			pidff_set_envelope_report(pidff,
+					&effect->u.constant.envelope);
+		break;
+
+	case FF_PERIODIC:
+		if (!old) {
+			switch (effect->u.periodic.waveform) {
+			case FF_SQUARE:
+				type_id = PID_SQUARE;
+				break;
+			case FF_TRIANGLE:
+				type_id = PID_TRIANGLE;
+				break;
+			case FF_SINE:
+				type_id = PID_SINE;
+				break;
+			case FF_SAW_UP:
+				type_id = PID_SAW_UP;
+				break;
+			case FF_SAW_DOWN:
+				type_id = PID_SAW_DOWN;
+				break;
+			default:
+				printk(KERN_ERR
+				       "hid-pidff: invalid waveform\n");
+				return -EINVAL;
+			}
+
+			error = pidff_request_effect_upload(pidff,
+					pidff->type_id[type_id]);
+			if (error)
+				return error;
+		}
+		if (!old || pidff_needs_set_effect(effect, old))
+			pidff_set_effect_report(pidff, effect);
+		if (!old || pidff_needs_set_periodic(effect, old))
+			pidff_set_periodic_report(pidff, effect);
+		if (!old ||
+		    pidff_needs_set_envelope(&effect->u.periodic.envelope,
+					&old->u.periodic.envelope))
+			pidff_set_envelope_report(pidff,
+					&effect->u.periodic.envelope);
+		break;
+
+	case FF_RAMP:
+		if (!old) {
+			error = pidff_request_effect_upload(pidff,
+					pidff->type_id[PID_RAMP]);
+			if (error)
+				return error;
+		}
+		if (!old || pidff_needs_set_effect(effect, old))
+			pidff_set_effect_report(pidff, effect);
+		if (!old || pidff_needs_set_ramp(effect, old))
+			pidff_set_ramp_force_report(pidff, effect);
+		if (!old ||
+		    pidff_needs_set_envelope(&effect->u.ramp.envelope,
+					&old->u.ramp.envelope))
+			pidff_set_envelope_report(pidff,
+					&effect->u.ramp.envelope);
+		break;
+
+	case FF_SPRING:
+		if (!old) {
+			error = pidff_request_effect_upload(pidff,
+					pidff->type_id[PID_SPRING]);
+			if (error)
+				return error;
+		}
+		if (!old || pidff_needs_set_effect(effect, old))
+			pidff_set_effect_report(pidff, effect);
+		if (!old || pidff_needs_set_condition(effect, old))
+			pidff_set_condition_report(pidff, effect);
+		break;
+
+	case FF_FRICTION:
+		if (!old) {
+			error = pidff_request_effect_upload(pidff,
+					pidff->type_id[PID_FRICTION]);
+			if (error)
+				return error;
+		}
+		if (!old || pidff_needs_set_effect(effect, old))
+			pidff_set_effect_report(pidff, effect);
+		if (!old || pidff_needs_set_condition(effect, old))
+			pidff_set_condition_report(pidff, effect);
+		break;
+
+	case FF_DAMPER:
+		if (!old) {
+			error = pidff_request_effect_upload(pidff,
+					pidff->type_id[PID_DAMPER]);
+			if (error)
+				return error;
+		}
+		if (!old || pidff_needs_set_effect(effect, old))
+			pidff_set_effect_report(pidff, effect);
+		if (!old || pidff_needs_set_condition(effect, old))
+			pidff_set_condition_report(pidff, effect);
+		break;
+
+	case FF_INERTIA:
+		if (!old) {
+			error = pidff_request_effect_upload(pidff,
+					pidff->type_id[PID_INERTIA]);
+			if (error)
+				return error;
+		}
+		if (!old || pidff_needs_set_effect(effect, old))
+			pidff_set_effect_report(pidff, effect);
+		if (!old || pidff_needs_set_condition(effect, old))
+			pidff_set_condition_report(pidff, effect);
+		break;
+
+	default:
+		printk(KERN_ERR "hid-pidff: invalid type\n");
+		return -EINVAL;
+	}
+
+	if (!old)
+		pidff->pid_id[effect->id] =
+		    pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
+
+	debug("uploaded");
+
+	return 0;
+}
+
+/*
+ * set_gain() handler
+ */
+static void pidff_set_gain(struct input_dev *dev, u16 gain)
+{
+	struct pidff_device *pidff = dev->ff->private;
+
+	pidff_set(&pidff->device_gain[PID_DEVICE_GAIN_FIELD], gain);
+	hid_submit_report(pidff->hid, pidff->reports[PID_DEVICE_GAIN],
+			  USB_DIR_OUT);
+}
+
+static void pidff_autocenter(struct pidff_device *pidff, u16 magnitude)
+{
+	struct hid_field *field =
+		pidff->block_load[PID_EFFECT_BLOCK_INDEX].field;
+
+	if (!magnitude) {
+		pidff_playback_pid(pidff, field->logical_minimum, 0);
+		return;
+	}
+
+	pidff_playback_pid(pidff, field->logical_minimum, 1);
+
+	pidff->set_effect[PID_EFFECT_BLOCK_INDEX].value[0] =
+		pidff->block_load[PID_EFFECT_BLOCK_INDEX].field->logical_minimum;
+	pidff->set_effect_type->value[0] = pidff->type_id[PID_SPRING];
+	pidff->set_effect[PID_DURATION].value[0] = 0;
+	pidff->set_effect[PID_TRIGGER_BUTTON].value[0] = 0;
+	pidff->set_effect[PID_TRIGGER_REPEAT_INT].value[0] = 0;
+	pidff_set(&pidff->set_effect[PID_GAIN], magnitude);
+	pidff->set_effect[PID_START_DELAY].value[0] = 0;
+
+	hid_submit_report(pidff->hid, pidff->reports[PID_SET_EFFECT],
+			  USB_DIR_OUT);
+}
+
+/*
+ * pidff_set_autocenter() handler
+ */
+static void pidff_set_autocenter(struct input_dev *dev, u16 magnitude)
+{
+	struct pidff_device *pidff = dev->ff->private;
+
+	pidff_autocenter(pidff, magnitude);
+}
+
+/*
+ * Find fields from a report and fill a pidff_usage
+ */
+static int pidff_find_fields(struct pidff_usage *usage, const u8 *table,
+			     struct hid_report *report, int count, int strict)
+{
+	int i, j, k, found;
+
+	for (k = 0; k < count; k++) {
+		found = 0;
+		for (i = 0; i < report->maxfield; i++) {
+			if (report->field[i]->maxusage !=
+			    report->field[i]->report_count) {
+				debug("maxusage and report_count do not match, "
+				      "skipping");
+				continue;
+			}
+			for (j = 0; j < report->field[i]->maxusage; j++) {
+				if (report->field[i]->usage[j].hid ==
+				    (HID_UP_PID | table[k])) {
+					debug("found %d at %d->%d", k, i, j);
+					usage[k].field = report->field[i];
+					usage[k].value =
+						&report->field[i]->value[j];
+					found = 1;
+					break;
+				}
+			}
+			if (found)
+				break;
+		}
+		if (!found && strict) {
+			debug("failed to locate %d", k);
+			return -1;
+		}
+	}
+	return 0;
+}
+
+/*
+ * Return index into pidff_reports for the given usage
+ */
+static int pidff_check_usage(int usage)
+{
+	int i;
+
+	for (i = 0; i < sizeof(pidff_reports); i++)
+		if (usage == (HID_UP_PID | pidff_reports[i]))
+			return i;
+
+	return -1;
+}
+
+/*
+ * Find the reports and fill pidff->reports[]
+ * report_type specifies either OUTPUT or FEATURE reports
+ */
+static void pidff_find_reports(struct hid_device *hid, int report_type,
+			       struct pidff_device *pidff)
+{
+	struct hid_report *report;
+	int i, ret;
+
+	list_for_each_entry(report,
+			    &hid->report_enum[report_type].report_list, list) {
+		if (report->maxfield < 1)
+			continue;
+		ret = pidff_check_usage(report->field[0]->logical);
+		if (ret != -1) {
+			debug("found usage 0x%02x from field->logical",
+			      pidff_reports[ret]);
+			pidff->reports[ret] = report;
+			continue;
+		}
+
+		/*
+		 * Sometimes logical collections are stacked to indicate
+		 * different usages for the report and the field, in which
+		 * case we want the usage of the parent. However, Linux HID
+		 * implementation hides this fact, so we have to dig it up
+		 * ourselves
+		 */
+		i = report->field[0]->usage[0].collection_index;
+		if (i <= 0 ||
+		    hid->collection[i - 1].type != HID_COLLECTION_LOGICAL)
+			continue;
+		ret = pidff_check_usage(hid->collection[i - 1].usage);
+		if (ret != -1 && !pidff->reports[ret]) {
+			debug("found usage 0x%02x from collection array",
+			      pidff_reports[ret]);
+			pidff->reports[ret] = report;
+		}
+	}
+}
+
+/*
+ * Test if the required reports have been found
+ */
+static int pidff_reports_ok(struct pidff_device *pidff)
+{
+	int i;
+
+	for (i = 0; i <= PID_REQUIRED_REPORTS; i++) {
+		if (!pidff->reports[i]) {
+			debug("%d missing", i);
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+/*
+ * Find a field with a specific usage within a report
+ */
+static struct hid_field *pidff_find_special_field(struct hid_report *report,
+						  int usage, int enforce_min)
+{
+	int i;
+
+	for (i = 0; i < report->maxfield; i++) {
+		if (report->field[i]->logical == (HID_UP_PID | usage) &&
+		    report->field[i]->report_count > 0) {
+			if (!enforce_min ||
+			    report->field[i]->logical_minimum == 1)
+				return report->field[i];
+			else {
+				printk(KERN_ERR "hid-pidff: logical_minimum "
+					"is not 1 as it should be\n");
+				return NULL;
+			}
+		}
+	}
+	return NULL;
+}
+
+/*
+ * Fill a pidff->*_id struct table
+ */
+static int pidff_find_special_keys(int *keys, struct hid_field *fld,
+				   const u8 *usagetable, int count)
+{
+
+	int i, j;
+	int found = 0;
+
+	for (i = 0; i < count; i++) {
+		for (j = 0; j < fld->maxusage; j++) {
+			if (fld->usage[j].hid == (HID_UP_PID | usagetable[i])) {
+				keys[i] = j + 1;
+				found++;
+				break;
+			}
+		}
+	}
+	return found;
+}
+
+#define PIDFF_FIND_SPECIAL_KEYS(keys, field, name) \
+	pidff_find_special_keys(pidff->keys, pidff->field, pidff_ ## name, \
+		sizeof(pidff_ ## name))
+
+/*
+ * Find and check the special fields
+ */
+static int pidff_find_special_fields(struct pidff_device *pidff)
+{
+	debug("finding special fields");
+
+	pidff->create_new_effect_type =
+		pidff_find_special_field(pidff->reports[PID_CREATE_NEW_EFFECT],
+					 0x25, 1);
+	pidff->set_effect_type =
+		pidff_find_special_field(pidff->reports[PID_SET_EFFECT],
+					 0x25, 1);
+	pidff->effect_direction =
+		pidff_find_special_field(pidff->reports[PID_SET_EFFECT],
+					 0x57, 0);
+	pidff->device_control =
+		pidff_find_special_field(pidff->reports[PID_DEVICE_CONTROL],
+					 0x96, 1);
+	pidff->block_load_status =
+		pidff_find_special_field(pidff->reports[PID_BLOCK_LOAD],
+					 0x8b, 1);
+	pidff->effect_operation_status =
+		pidff_find_special_field(pidff->reports[PID_EFFECT_OPERATION],
+					 0x78, 1);
+
+	debug("search done");
+
+	if (!pidff->create_new_effect_type || !pidff->set_effect_type) {
+		printk(KERN_ERR "hid-pidff: effect lists not found\n");
+		return -1;
+	}
+
+	if (!pidff->effect_direction) {
+		printk(KERN_ERR "hid-pidff: direction field not found\n");
+		return -1;
+	}
+
+	if (!pidff->device_control) {
+		printk(KERN_ERR "hid-pidff: device control field not found\n");
+		return -1;
+	}
+
+	if (!pidff->block_load_status) {
+		printk(KERN_ERR
+		       "hid-pidff: block load status field not found\n");
+		return -1;
+	}
+
+	if (!pidff->effect_operation_status) {
+		printk(KERN_ERR
+		       "hid-pidff: effect operation field not found\n");
+		return -1;
+	}
+
+	pidff_find_special_keys(pidff->control_id, pidff->device_control,
+				pidff_device_control,
+				sizeof(pidff_device_control));
+
+	PIDFF_FIND_SPECIAL_KEYS(control_id, device_control, device_control);
+
+	if (!PIDFF_FIND_SPECIAL_KEYS(type_id, create_new_effect_type,
+				     effect_types)) {
+		printk(KERN_ERR "hid-pidff: no effect types found\n");
+		return -1;
+	}
+
+	if (PIDFF_FIND_SPECIAL_KEYS(status_id, block_load_status,
+				    block_load_status) !=
+			sizeof(pidff_block_load_status)) {
+		printk(KERN_ERR
+		       "hidpidff: block load status identifiers not found\n");
+		return -1;
+	}
+
+	if (PIDFF_FIND_SPECIAL_KEYS(operation_id, effect_operation_status,
+				    effect_operation_status) !=
+			sizeof(pidff_effect_operation_status)) {
+		printk(KERN_ERR
+		       "hidpidff: effect operation identifiers not found\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+/**
+ * Find the implemented effect types
+ */
+static int pidff_find_effects(struct pidff_device *pidff,
+			      struct input_dev *dev)
+{
+	int i;
+
+	for (i = 0; i < sizeof(pidff_effect_types); i++) {
+		int pidff_type = pidff->type_id[i];
+		if (pidff->set_effect_type->usage[pidff_type].hid !=
+		    pidff->create_new_effect_type->usage[pidff_type].hid) {
+			printk(KERN_ERR "hid-pidff: "
+			       "effect type number %d is invalid\n", i);
+			return -1;
+		}
+	}
+
+	if (pidff->type_id[PID_CONSTANT])
+		set_bit(FF_CONSTANT, dev->ffbit);
+	if (pidff->type_id[PID_RAMP])
+		set_bit(FF_RAMP, dev->ffbit);
+	if (pidff->type_id[PID_SQUARE]) {
+		set_bit(FF_SQUARE, dev->ffbit);
+		set_bit(FF_PERIODIC, dev->ffbit);
+	}
+	if (pidff->type_id[PID_SINE]) {
+		set_bit(FF_SINE, dev->ffbit);
+		set_bit(FF_PERIODIC, dev->ffbit);
+	}
+	if (pidff->type_id[PID_TRIANGLE]) {
+		set_bit(FF_TRIANGLE, dev->ffbit);
+		set_bit(FF_PERIODIC, dev->ffbit);
+	}
+	if (pidff->type_id[PID_SAW_UP]) {
+		set_bit(FF_SAW_UP, dev->ffbit);
+		set_bit(FF_PERIODIC, dev->ffbit);
+	}
+	if (pidff->type_id[PID_SAW_DOWN]) {
+		set_bit(FF_SAW_DOWN, dev->ffbit);
+		set_bit(FF_PERIODIC, dev->ffbit);
+	}
+	if (pidff->type_id[PID_SPRING])
+		set_bit(FF_SPRING, dev->ffbit);
+	if (pidff->type_id[PID_DAMPER])
+		set_bit(FF_DAMPER, dev->ffbit);
+	if (pidff->type_id[PID_INERTIA])
+		set_bit(FF_INERTIA, dev->ffbit);
+	if (pidff->type_id[PID_FRICTION])
+		set_bit(FF_FRICTION, dev->ffbit);
+
+	return 0;
+
+}
+
+#define PIDFF_FIND_FIELDS(name, report, strict) \
+	pidff_find_fields(pidff->name, pidff_ ## name, \
+		pidff->reports[report], \
+		sizeof(pidff_ ## name), strict)
+
+/*
+ * Fill and check the pidff_usages
+ */
+static int pidff_init_fields(struct pidff_device *pidff, struct input_dev *dev)
+{
+	int envelope_ok = 0;
+
+	if (PIDFF_FIND_FIELDS(set_effect, PID_SET_EFFECT, 1)) {
+		printk(KERN_ERR
+		       "hid-pidff: unknown set_effect report layout\n");
+		return -ENODEV;
+	}
+
+	PIDFF_FIND_FIELDS(block_load, PID_BLOCK_LOAD, 0);
+	if (!pidff->block_load[PID_EFFECT_BLOCK_INDEX].value) {
+		printk(KERN_ERR
+		       "hid-pidff: unknown pid_block_load report layout\n");
+		return -ENODEV;
+	}
+
+	if (PIDFF_FIND_FIELDS(effect_operation, PID_EFFECT_OPERATION, 1)) {
+		printk(KERN_ERR
+		       "hid-pidff: unknown effect_operation report layout\n");
+		return -ENODEV;
+	}
+
+	if (PIDFF_FIND_FIELDS(block_free, PID_BLOCK_FREE, 1)) {
+		printk(KERN_ERR
+		       "hid-pidff: unknown pid_block_free report layout\n");
+		return -ENODEV;
+	}
+
+	if (!PIDFF_FIND_FIELDS(set_envelope, PID_SET_ENVELOPE, 1))
+		envelope_ok = 1;
+
+	if (pidff_find_special_fields(pidff) || pidff_find_effects(pidff, dev))
+		return -ENODEV;
+
+	if (!envelope_ok) {
+		if (test_and_clear_bit(FF_CONSTANT, dev->ffbit))
+			printk(KERN_WARNING "hid-pidff: "
+			       "has constant effect but no envelope\n");
+		if (test_and_clear_bit(FF_RAMP, dev->ffbit))
+			printk(KERN_WARNING "hid-pidff: "
+				"has ramp effect but no envelope\n");
+
+		if (test_and_clear_bit(FF_PERIODIC, dev->ffbit))
+			printk(KERN_WARNING "hid-pidff: "
+				"has periodic effect but no envelope\n");
+	}
+
+	if (test_bit(FF_CONSTANT, dev->ffbit) &&
+	    PIDFF_FIND_FIELDS(set_constant, PID_SET_CONSTANT, 1)) {
+		printk(KERN_WARNING
+		       "hid-pidff: unknown constant effect layout\n");
+		clear_bit(FF_CONSTANT, dev->ffbit);
+	}
+
+	if (test_bit(FF_RAMP, dev->ffbit) &&
+	    PIDFF_FIND_FIELDS(set_ramp, PID_SET_RAMP, 1)) {
+		printk(KERN_WARNING "hid-pidff: unknown ramp effect layout\n");
+		clear_bit(FF_RAMP, dev->ffbit);
+	}
+
+	if ((test_bit(FF_SPRING, dev->ffbit) ||
+	     test_bit(FF_DAMPER, dev->ffbit) ||
+	     test_bit(FF_FRICTION, dev->ffbit) ||
+	     test_bit(FF_INERTIA, dev->ffbit)) &&
+	    PIDFF_FIND_FIELDS(set_condition, PID_SET_CONDITION, 1)) {
+		printk(KERN_WARNING
+		       "hid-pidff: unknown condition effect layout\n");
+		clear_bit(FF_SPRING, dev->ffbit);
+		clear_bit(FF_DAMPER, dev->ffbit);
+		clear_bit(FF_FRICTION, dev->ffbit);
+		clear_bit(FF_INERTIA, dev->ffbit);
+	}
+
+	if (test_bit(FF_PERIODIC, dev->ffbit) &&
+	    PIDFF_FIND_FIELDS(set_periodic, PID_SET_PERIODIC, 1)) {
+		printk(KERN_WARNING
+		       "hid-pidff: unknown periodic effect layout\n");
+		clear_bit(FF_PERIODIC, dev->ffbit);
+	}
+
+	PIDFF_FIND_FIELDS(pool, PID_POOL, 0);
+
+	if (!PIDFF_FIND_FIELDS(device_gain, PID_DEVICE_GAIN, 1))
+		set_bit(FF_GAIN, dev->ffbit);
+
+	return 0;
+}
+
+/*
+ * Reset the device
+ */
+static void pidff_reset(struct pidff_device *pidff)
+{
+	struct hid_device *hid = pidff->hid;
+	int i = 0;
+
+	pidff->device_control->value[0] = pidff->control_id[PID_RESET];
+	/* We reset twice as sometimes hid_wait_io isn't waiting long enough */
+	hid_submit_report(hid, pidff->reports[PID_DEVICE_CONTROL], USB_DIR_OUT);
+	hid_wait_io(hid);
+	hid_submit_report(hid, pidff->reports[PID_DEVICE_CONTROL], USB_DIR_OUT);
+	hid_wait_io(hid);
+
+	pidff->device_control->value[0] =
+		pidff->control_id[PID_ENABLE_ACTUATORS];
+	hid_submit_report(hid, pidff->reports[PID_DEVICE_CONTROL], USB_DIR_OUT);
+	hid_wait_io(hid);
+
+	/* pool report is sometimes messed up, refetch it */
+	hid_submit_report(hid, pidff->reports[PID_POOL], USB_DIR_IN);
+	hid_wait_io(hid);
+
+	if (pidff->pool[PID_SIMULTANEOUS_MAX].value) {
+		int sim_effects = pidff->pool[PID_SIMULTANEOUS_MAX].value[0];
+		while (sim_effects < 2) {
+			if (i++ > 20) {
+				printk(KERN_WARNING "hid-pidff: device reports "
+				       "%d simultaneous effects\n",
+				       sim_effects);
+				break;
+			}
+			debug("pid_pool requested again");
+			hid_submit_report(hid, pidff->reports[PID_POOL],
+					  USB_DIR_IN);
+			hid_wait_io(hid);
+		}
+	}
+}
+
+/*
+ * Test if autocenter modification is using the supported method
+ */
+static int pidff_check_autocenter(struct pidff_device *pidff,
+				  struct input_dev *dev)
+{
+	int error;
+
+	/*
+	 * Let's find out if autocenter modification is supported
+	 * Specification doesn't specify anything, so we request an
+	 * effect upload and cancel it immediately. If the approved
+	 * effect id was one above the minimum, then we assume the first
+	 * effect id is a built-in spring type effect used for autocenter
+	 */
+
+	error = pidff_request_effect_upload(pidff, 1);
+	if (error) {
+		printk(KERN_ERR "hid-pidff: upload request failed\n");
+		return error;
+	}
+
+	if (pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0] ==
+	    pidff->block_load[PID_EFFECT_BLOCK_INDEX].field->logical_minimum + 1) {
+		pidff_autocenter(pidff, 0xffff);
+		set_bit(FF_AUTOCENTER, dev->ffbit);
+	} else {
+		printk(KERN_NOTICE "hid-pidff: "
+		       "device has unknown autocenter control method\n");
+	}
+
+	pidff_erase_pid(pidff,
+			pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0]);
+
+	return 0;
+
+}
+
+/*
+ * Check if the device is PID and initialize it
+ */
+int hid_pidff_init(struct hid_device *hid)
+{
+	struct pidff_device *pidff;
+	struct hid_input *hidinput = list_entry(hid->inputs.next,
+						struct hid_input, list);
+	struct input_dev *dev = hidinput->input;
+	struct ff_device *ff;
+	int max_effects;
+	int error;
+
+	debug("starting pid init");
+
+	if (list_empty(&hid->report_enum[HID_OUTPUT_REPORT].report_list)) {
+		debug("not a PID device, no output report");
+		return -ENODEV;
+	}
+
+	pidff = kzalloc(sizeof(*pidff), GFP_KERNEL);
+	if (!pidff)
+		return -ENOMEM;
+
+	pidff->hid = hid;
+
+	pidff_find_reports(hid, HID_OUTPUT_REPORT, pidff);
+	pidff_find_reports(hid, HID_FEATURE_REPORT, pidff);
+
+	if (!pidff_reports_ok(pidff)) {
+		debug("reports not ok, aborting");
+		error = -ENODEV;
+		goto fail;
+	}
+
+	error = pidff_init_fields(pidff, dev);
+	if (error)
+		goto fail;
+
+	pidff_reset(pidff);
+
+	if (test_bit(FF_GAIN, dev->ffbit)) {
+		pidff_set(&pidff->device_gain[PID_DEVICE_GAIN_FIELD], 0xffff);
+		hid_submit_report(pidff->hid, pidff->reports[PID_DEVICE_GAIN],
+				  USB_DIR_OUT);
+	}
+
+	error = pidff_check_autocenter(pidff, dev);
+	if (error)
+		goto fail;
+
+	max_effects =
+	    pidff->block_load[PID_EFFECT_BLOCK_INDEX].field->logical_maximum -
+	    pidff->block_load[PID_EFFECT_BLOCK_INDEX].field->logical_minimum +
+	    1;
+	debug("max effects is %d", max_effects);
+
+	if (max_effects > PID_EFFECTS_MAX)
+		max_effects = PID_EFFECTS_MAX;
+
+	if (pidff->pool[PID_SIMULTANEOUS_MAX].value)
+		debug("max simultaneous effects is %d",
+		      pidff->pool[PID_SIMULTANEOUS_MAX].value[0]);
+
+	if (pidff->pool[PID_RAM_POOL_SIZE].value)
+		debug("device memory size is %d bytes",
+		      pidff->pool[PID_RAM_POOL_SIZE].value[0]);
+
+	if (pidff->pool[PID_DEVICE_MANAGED_POOL].value &&
+	    pidff->pool[PID_DEVICE_MANAGED_POOL].value[0] == 0) {
+		printk(KERN_NOTICE "hid-pidff: "
+		       "device does not support device managed pool\n");
+		goto fail;
+	}
+
+	error = input_ff_create(dev, max_effects);
+	if (error)
+		goto fail;
+
+	ff = dev->ff;
+	ff->private = pidff;
+	ff->upload = pidff_upload_effect;
+	ff->erase = pidff_erase_effect;
+	ff->set_gain = pidff_set_gain;
+	ff->set_autocenter = pidff_set_autocenter;
+	ff->playback = pidff_playback;
+
+	printk(KERN_INFO "Force feedback for USB HID PID devices by "
+	       "Anssi Hannula <anssi.hannula@gmail.com>\n");
+
+	return 0;
+
+ fail:
+	kfree(pidff);
+	return error;
+}