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 000000000000..5420c13eb8eb
--- /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;
+}