selftests/bpf: Reject graph kptr use after RCU unlockgrafted

Add a sleepable verifier test that loads a graph-node local kptr in an
explicit RCU read-side critical section, then passes its node to
bpf_rbtree_remove() after the section ends.

Before the verifier fix, the stale NON_OWN_REF flag makes the node look like
a live borrowed reference and the program is accepted. After the fix, the
pointer is demoted without NON_OWN_REF and the graph kfunc argument is
rejected.

Also exercise a graph kptr loaded while a spin lock provides implicit RCU
protection. The pointer must be invalidated when the lock is released, which
guards the required ordering between non-owning-reference invalidation and
RCU demotion.

Update the existing fault-protected load test state description. The
post-unlock pointer no longer carries NON_OWN_REF, but remains readable
because the load is rewritten to use BPF_PROBE_MEM.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 1653 insertions, 0 deletions

diff --git a/drivers/hid/usbhid/hid-pidff.c b/drivers/hid/usbhid/hid-pidff.c
new file mode 100644
index 000000000..22951b7ec
--- /dev/null
+++ b/drivers/hid/usbhid/hid-pidff.c
@@ -0,0 +1,1653 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Force feedback driver for USB HID PID compliant devices
+ *
+ *  Copyright (c) 2005, 2006 Anssi Hannula <anssi.hannula@gmail.com>
+ *  Upgraded 2025 by Oleg Makarenko and Tomasz Pakuła
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include "hid-pidff.h"
+#include <linux/hid.h>
+#include <linux/input.h>
+#include <linux/math64.h>
+#include <linux/minmax.h>
+#include <linux/slab.h>
+#include <linux/stringify.h>
+#include <linux/usb.h>
+
+#define	PID_EFFECTS_MAX		64
+#define	PID_INFINITE		U16_MAX
+
+/* Linux Force Feedback API uses miliseconds as time unit */
+#define FF_TIME_EXPONENT	-3
+#define FF_INFINITE		0
+
+/* 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	8
+
+#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.
+ */
+
+/* PID special fields */
+#define PID_EFFECT_TYPE			0x25
+#define PID_AXES_ENABLE			0x55
+#define PID_DIRECTION			0x57
+#define PID_EFFECT_OPERATION_ARRAY	0x78
+#define PID_BLOCK_LOAD_STATUS		0x8b
+#define PID_DEVICE_CONTROL_ARRAY	0x96
+
+/* 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_DEADBAND		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_DISABLE_ACTUATORS	1
+#define PID_STOP_ALL_EFFECTS	2
+#define PID_RESET		3
+#define PID_PAUSE		4
+#define PID_CONTINUE		5
+static const u8 pidff_device_control[] = { 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c };
+
+#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
+#define PID_BLOCK_LOAD_ERROR	2
+static const u8 pidff_block_load_status[] = { 0x8c, 0x8d, 0x8e };
+
+#define PID_EFFECT_START	0
+#define PID_EFFECT_STOP		1
+static const u8 pidff_effect_operation_status[] = { 0x79, 0x7b };
+
+#define PID_DIRECTION_NORTH	0x0000
+#define PID_DIRECTION_EAST	0x4000
+#define PID_DIRECTION_SOUTH	0x8000
+#define PID_DIRECTION_WEST	0xc000
+
+#define PIDFF_FIXED_WHEEL_DIRECTION	PID_DIRECTION_EAST
+
+/* AXES_ENABLE and DIRECTION axes */
+enum pid_axes {
+	PID_AXIS_X,
+	PID_AXIS_Y,
+	PID_AXIS_Z,
+	PID_AXIS_RX,
+	PID_AXIS_RY,
+	PID_AXIS_RZ,
+	PID_AXIS_SLIDER,
+	PID_AXIS_DIAL,
+	PID_AXIS_WHEEL,
+	PID_AXES_COUNT,
+};
+static const u8 pidff_direction_axis[] = {
+	HID_USAGE & HID_GD_X,
+	HID_USAGE & HID_GD_Y,
+	HID_USAGE & HID_GD_Z,
+	HID_USAGE & HID_GD_RX,
+	HID_USAGE & HID_GD_RY,
+	HID_USAGE & HID_GD_RZ,
+	HID_USAGE & HID_GD_SLIDER,
+	HID_USAGE & HID_GD_DIAL,
+	HID_USAGE & HID_GD_WHEEL,
+};
+
+struct pidff_usage {
+	struct hid_field *field;
+	s32 *value;
+};
+
+struct pidff_effect {
+	int pid_id;
+	int is_infinite;
+	unsigned int loop_count;
+};
+
+struct pidff_device {
+	struct hid_device *hid;
+
+	struct hid_report *reports[ARRAY_SIZE(pidff_reports)];
+
+	struct pidff_usage set_effect[ARRAY_SIZE(pidff_set_effect)];
+	struct pidff_usage set_envelope[ARRAY_SIZE(pidff_set_envelope)];
+	struct pidff_usage set_condition[ARRAY_SIZE(pidff_set_condition)];
+	struct pidff_usage set_periodic[ARRAY_SIZE(pidff_set_periodic)];
+	struct pidff_usage set_constant[ARRAY_SIZE(pidff_set_constant)];
+	struct pidff_usage set_ramp[ARRAY_SIZE(pidff_set_ramp)];
+
+	struct pidff_usage device_gain[ARRAY_SIZE(pidff_device_gain)];
+	struct pidff_usage block_load[ARRAY_SIZE(pidff_block_load)];
+	struct pidff_usage pool[ARRAY_SIZE(pidff_pool)];
+	struct pidff_usage effect_operation[ARRAY_SIZE(pidff_effect_operation)];
+	struct pidff_usage block_free[ARRAY_SIZE(pidff_block_free)];
+
+	struct pidff_effect effect[PID_EFFECTS_MAX];
+
+	/*
+	 * 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;
+	struct hid_field *axes_enable;
+
+	/* 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[ARRAY_SIZE(pidff_device_control)];
+	int type_id[ARRAY_SIZE(pidff_effect_types)];
+	int status_id[ARRAY_SIZE(pidff_block_load_status)];
+	int operation_id[ARRAY_SIZE(pidff_effect_operation_status)];
+	int direction_axis_id[ARRAY_SIZE(pidff_direction_axis)];
+
+	u32 quirks;
+	u8 effect_count;
+	u8 axis_count;
+};
+
+static int pidff_is_effect_conditional(struct ff_effect *effect)
+{
+	return effect->type == FF_SPRING  ||
+	       effect->type == FF_DAMPER  ||
+	       effect->type == FF_INERTIA ||
+	       effect->type == FF_FRICTION;
+}
+
+static int pidff_is_duration_infinite(u16 duration)
+{
+	return duration == FF_INFINITE || duration == PID_INFINITE;
+}
+
+/*
+ * Get PID effect index from FF effect type.
+ * Return 0 if invalid.
+ */
+static int pidff_effect_ff_to_pid(struct ff_effect *effect)
+{
+	switch (effect->type) {
+	case FF_CONSTANT:
+		return PID_CONSTANT;
+	case FF_RAMP:
+		return PID_RAMP;
+	case FF_SPRING:
+		return PID_SPRING;
+	case FF_DAMPER:
+		return PID_DAMPER;
+	case FF_INERTIA:
+		return PID_INERTIA;
+	case FF_FRICTION:
+		return PID_FRICTION;
+	case FF_PERIODIC:
+		switch (effect->u.periodic.waveform) {
+		case FF_SQUARE:
+			return PID_SQUARE;
+		case FF_TRIANGLE:
+			return PID_TRIANGLE;
+		case FF_SINE:
+			return PID_SINE;
+		case FF_SAW_UP:
+			return PID_SAW_UP;
+		case FF_SAW_DOWN:
+			return PID_SAW_DOWN;
+		}
+	}
+	pr_err("invalid effect type\n");
+	return -EINVAL;
+}
+
+/*
+ * Get effect id in the device descriptor.
+ * Return 0 if invalid.
+ */
+static int pidff_get_effect_type_id(struct pidff_device *pidff,
+				    struct ff_effect *effect)
+{
+	int id = pidff_effect_ff_to_pid(effect);
+
+	if (id < 0)
+		return 0;
+
+	if (effect->type == FF_PERIODIC &&
+	    pidff->quirks & HID_PIDFF_QUIRK_PERIODIC_SINE_ONLY)
+		id = PID_SINE;
+
+	return pidff->type_id[id];
+}
+
+/*
+ * Clamp value for a given field
+ */
+static s32 pidff_clamp(s32 i, struct hid_field *field)
+{
+	return (s32)clamp(i, field->logical_minimum, field->logical_maximum);
+}
+
+/*
+ * Scale an unsigned value with range 0..max for the given field
+ */
+static int pidff_rescale(int i, int max, struct hid_field *field)
+{
+	/* 64 bits needed for big values during rescale */
+	s64 result = field->logical_maximum - field->logical_minimum;
+
+	return div_s64(result * i, max) + field->logical_minimum;
+}
+
+/*
+ * Scale a signed value in range S16_MIN..S16_MAX for the given field
+ */
+static int pidff_rescale_signed(int i, struct hid_field *field)
+{
+	if (i > 0)
+		return i * field->logical_maximum / S16_MAX;
+	if (i < 0)
+		return i * field->logical_minimum / S16_MIN;
+	return 0;
+}
+
+/*
+ * Scale time value from Linux default (ms) to field units
+ */
+static u32 pidff_rescale_time(u16 time, struct hid_field *field)
+{
+	u32 scaled_time = time;
+	int exponent = field->unit_exponent;
+
+	pr_debug("time field exponent: %d\n", exponent);
+	for (; exponent < FF_TIME_EXPONENT; exponent++)
+		scaled_time *= 10;
+	for (; exponent > FF_TIME_EXPONENT; exponent--)
+		scaled_time /= 10;
+
+	pr_debug("time calculated from %d to %d\n", time, scaled_time);
+	return scaled_time;
+}
+
+static void pidff_set(struct pidff_usage *usage, u16 value)
+{
+	usage->value[0] = pidff_rescale(value, U16_MAX, usage->field);
+	pr_debug("calculated from %d to %d\n", 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, -S16_MIN, usage->field);
+		else
+			usage->value[0] =
+				pidff_rescale(value, S16_MAX, usage->field);
+	}
+	pr_debug("calculated from %d to %d\n", value, usage->value[0]);
+}
+
+static void pidff_set_time(struct pidff_usage *usage, u16 time)
+{
+	usage->value[0] = pidff_clamp(pidff_rescale_time(time, usage->field),
+				      usage->field);
+}
+
+static void pidff_set_duration(struct pidff_usage *usage, u16 duration)
+{
+	/* PID defines INFINITE as the max possible value for duration field */
+	if (pidff_is_duration_infinite(duration)) {
+		usage->value[0] = (1U << usage->field->report_size) - 1;
+		return;
+	}
+
+	pidff_set_time(usage, duration);
+}
+
+static void pidff_set_effect_direction(struct pidff_device *pidff,
+				       struct ff_effect *effect)
+{
+	u16 direction = effect->direction;
+	int direction_enable = 1;
+
+	/* Use fixed direction if needed */
+	if (pidff->quirks & HID_PIDFF_QUIRK_FIX_CONDITIONAL_DIRECTION &&
+	    pidff_is_effect_conditional(effect))
+		direction = PIDFF_FIXED_WHEEL_DIRECTION;
+
+	pidff->set_effect[PID_DIRECTION_ENABLE].value[0] = direction_enable;
+	pidff->effect_direction->value[0] =
+		pidff_rescale(direction, U16_MAX, pidff->effect_direction);
+
+	if (direction_enable)
+		return;
+
+	/*
+	 * For use with improved FFB API
+	 * We want to read the selected axes and their direction from the effect
+	 * struct and only enable those. For now, enable all axes.
+	 *
+	 */
+	for (int i = 0; i < PID_AXES_COUNT; i++) {
+		/* HID index starts with 1 */
+		int index = pidff->direction_axis_id[i] - 1;
+
+		if (index < 0)
+			continue;
+
+		pidff->axes_enable->value[index] = 1;
+		pidff->effect_direction->value[index] = pidff_rescale(
+			direction, U16_MAX, pidff->effect_direction);
+	}
+}
+
+/*
+ * 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 >
+			S16_MAX ? S16_MAX : envelope->attack_level, S16_MAX,
+			pidff->set_envelope[PID_ATTACK_LEVEL].field);
+	pidff->set_envelope[PID_FADE_LEVEL].value[0] =
+		pidff_rescale(envelope->fade_level >
+			S16_MAX ? S16_MAX : envelope->fade_level, S16_MAX,
+			pidff->set_envelope[PID_FADE_LEVEL].field);
+
+	pidff_set_time(&pidff->set_envelope[PID_ATTACK_TIME],
+		       envelope->attack_length);
+	pidff_set_time(&pidff->set_envelope[PID_FADE_TIME],
+		       envelope->fade_length);
+
+	hid_hw_request(pidff->hid, pidff->reports[PID_SET_ENVELOPE],
+		       HID_REQ_SET_REPORT);
+}
+
+/*
+ * Test if the new envelope differs from old one
+ */
+static int pidff_needs_set_envelope(struct ff_envelope *envelope,
+				    struct ff_envelope *old)
+{
+	int needs_new_envelope;
+
+	needs_new_envelope = envelope->attack_level  != 0 ||
+			     envelope->fade_level    != 0 ||
+			     envelope->attack_length != 0 ||
+			     envelope->fade_length   != 0;
+
+	if (!needs_new_envelope)
+		return 0;
+	if (!old)
+		return needs_new_envelope;
+
+	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_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_hw_request(pidff->hid, pidff->reports[PID_SET_CONSTANT],
+		       HID_REQ_SET_REPORT);
+}
+
+/*
+ * 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_get_effect_type_id(pidff, effect);
+
+	pidff_set_duration(&pidff->set_effect[PID_DURATION],
+			   effect->replay.length);
+
+	/* Some games set this to random values that can be out of range */
+	s32 trigger_button_max =
+		pidff->set_effect[PID_TRIGGER_BUTTON].field->logical_maximum;
+	if (effect->trigger.button <= trigger_button_max) {
+		pidff->set_effect[PID_TRIGGER_BUTTON].value[0] =
+			effect->trigger.button;
+		pidff_set_time(&pidff->set_effect[PID_TRIGGER_REPEAT_INT],
+			       effect->trigger.interval);
+	} else {
+		pidff->set_effect[PID_TRIGGER_BUTTON].value[0] = 0;
+		pidff->set_effect[PID_TRIGGER_REPEAT_INT].value[0] = 0;
+	}
+
+	pidff->set_effect[PID_GAIN].value[0] =
+		pidff->set_effect[PID_GAIN].field->logical_maximum;
+
+	pidff_set_effect_direction(pidff, effect);
+
+	/* Omit setting delay field if it's missing */
+	if (!(pidff->quirks & HID_PIDFF_QUIRK_MISSING_DELAY))
+		pidff_set_time(&pidff->set_effect[PID_START_DELAY],
+			       effect->replay.delay);
+
+	hid_hw_request(pidff->hid, pidff->reports[PID_SET_EFFECT],
+		       HID_REQ_SET_REPORT);
+}
+
+/*
+ * 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_time(&pidff->set_periodic[PID_PERIOD],
+		       effect->u.periodic.period);
+
+	hid_hw_request(pidff->hid, pidff->reports[PID_SET_PERIODIC],
+		       HID_REQ_SET_REPORT);
+}
+
+/*
+ * 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, max_axis;
+
+	/* Devices missing Parameter Block Offset can only have one axis */
+	max_axis = pidff->quirks & HID_PIDFF_QUIRK_MISSING_PBO ? 1 : 2;
+
+	pidff->set_condition[PID_EFFECT_BLOCK_INDEX].value[0] =
+		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
+
+	for (i = 0; i < max_axis; i++) {
+		/* Omit Parameter Block Offset if missing */
+		if (!(pidff->quirks & HID_PIDFF_QUIRK_MISSING_PBO))
+			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(&pidff->set_condition[PID_POS_SATURATION],
+			  effect->u.condition[i].right_saturation);
+
+		/* Omit Negative Coefficient if missing */
+		if (!(pidff->quirks & HID_PIDFF_QUIRK_MISSING_NEG_COEFFICIENT))
+			pidff_set_signed(&pidff->set_condition[PID_NEG_COEFFICIENT],
+					effect->u.condition[i].left_coeff);
+
+		/* Omit Negative Saturation if missing */
+		if (!(pidff->quirks & HID_PIDFF_QUIRK_MISSING_NEG_SATURATION))
+			pidff_set_signed(&pidff->set_condition[PID_NEG_SATURATION],
+					effect->u.condition[i].left_saturation);
+
+		/* Omit Deadband field if missing */
+		if (!(pidff->quirks & HID_PIDFF_QUIRK_MISSING_DEADBAND))
+			pidff_set(&pidff->set_condition[PID_DEADBAND],
+				effect->u.condition[i].deadband);
+
+		hid_hw_request(pidff->hid, pidff->reports[PID_SET_CONDITION],
+			       HID_REQ_SET_REPORT);
+	}
+}
+
+/*
+ * 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_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_hw_request(pidff->hid, pidff->reports[PID_SET_RAMP],
+		       HID_REQ_SET_REPORT);
+}
+
+/*
+ * 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;
+}
+
+/*
+ * Set device gain
+ */
+static void pidff_set_gain_report(struct pidff_device *pidff, u16 gain)
+{
+	if (!pidff->device_gain[PID_DEVICE_GAIN_FIELD].field)
+		return;
+
+	pidff_set(&pidff->device_gain[PID_DEVICE_GAIN_FIELD], gain);
+	hid_hw_request(pidff->hid, pidff->reports[PID_DEVICE_GAIN],
+		       HID_REQ_SET_REPORT);
+}
+
+/*
+ * Send device control report to the device
+ */
+static void pidff_set_device_control(struct pidff_device *pidff, int field)
+{
+	const int field_index = pidff->control_id[field];
+
+	if (field_index < 1)
+		return;
+
+	/* Detect if the field is a bitmask variable or an array */
+	if (pidff->device_control->flags & HID_MAIN_ITEM_VARIABLE) {
+		hid_dbg(pidff->hid, "DEVICE_CONTROL is a bitmask\n");
+
+		/* Clear current bitmask */
+		for (int i = 0; i < ARRAY_SIZE(pidff_device_control); i++) {
+			int index = pidff->control_id[i];
+
+			if (index < 1)
+				continue;
+
+			pidff->device_control->value[index - 1] = 0;
+		}
+
+		pidff->device_control->value[field_index - 1] = 1;
+	} else {
+		hid_dbg(pidff->hid, "DEVICE_CONTROL is an array\n");
+		pidff->device_control->value[0] = field_index;
+	}
+
+	hid_hw_request(pidff->hid, pidff->reports[PID_DEVICE_CONTROL], HID_REQ_SET_REPORT);
+	hid_hw_wait(pidff->hid);
+	hid_dbg(pidff->hid, "Device control command 0x%02x sent",
+		pidff_device_control[field]);
+}
+
+/*
+ * Reset the device, stop all effects, enable actuators
+ */
+static void pidff_reset(struct pidff_device *pidff)
+{
+	/* We reset twice as sometimes hid_wait_io isn't waiting long enough */
+	pidff_set_device_control(pidff, PID_RESET);
+	pidff_set_device_control(pidff, PID_RESET);
+	pidff->effect_count = 0;
+
+	pidff_set_device_control(pidff, PID_STOP_ALL_EFFECTS);
+	pidff_set_device_control(pidff, PID_ENABLE_ACTUATORS);
+}
+
+/*
+ * Fetch pool report
+ */
+static void pidff_fetch_pool(struct pidff_device *pidff)
+{
+	int i;
+	struct hid_device *hid = pidff->hid;
+
+	/* Repeat if PID_SIMULTANEOUS_MAX < 2 to make sure it's correct */
+	for (i = 0; i < 20; i++) {
+		hid_hw_request(hid, pidff->reports[PID_POOL], HID_REQ_GET_REPORT);
+		hid_hw_wait(hid);
+
+		if (!pidff->pool[PID_SIMULTANEOUS_MAX].value)
+			return;
+		if (pidff->pool[PID_SIMULTANEOUS_MAX].value[0] >= 2)
+			return;
+	}
+	hid_warn(hid, "device reports %d simultaneous effects\n",
+		 pidff->pool[PID_SIMULTANEOUS_MAX].value[0]);
+}
+
+/*
+ * Send a request for effect upload to the device
+ *
+ * Reset and enable actuators if no effects were present on 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)
+{
+	pidff->create_new_effect_type->value[0] = efnum;
+	hid_hw_request(pidff->hid, pidff->reports[PID_CREATE_NEW_EFFECT],
+		       HID_REQ_SET_REPORT);
+	hid_dbg(pidff->hid, "create_new_effect sent, type: %d\n", efnum);
+
+	pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0] = 0;
+	pidff->block_load_status->value[0] = 0;
+	hid_hw_wait(pidff->hid);
+
+	for (int i = 0; i < 60; i++) {
+		hid_dbg(pidff->hid, "pid_block_load requested\n");
+		hid_hw_request(pidff->hid, pidff->reports[PID_BLOCK_LOAD],
+			       HID_REQ_GET_REPORT);
+		hid_hw_wait(pidff->hid);
+		if (pidff->block_load_status->value[0] ==
+		    pidff->status_id[PID_BLOCK_LOAD_SUCCESS]) {
+			hid_dbg(pidff->hid, "device reported free memory: %d bytes\n",
+				 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]) {
+			hid_dbg(pidff->hid, "not enough memory free: %d bytes\n",
+				pidff->block_load[PID_RAM_POOL_AVAILABLE].value ?
+				pidff->block_load[PID_RAM_POOL_AVAILABLE].value[0] : -1);
+			return -ENOSPC;
+		}
+		if (pidff->block_load_status->value[0] ==
+		    pidff->status_id[PID_BLOCK_LOAD_ERROR]) {
+			hid_dbg(pidff->hid, "device error during effect creation\n");
+			return -EREMOTEIO;
+		}
+	}
+	hid_err(pidff->hid, "pid_block_load failed 60 times\n");
+	return -EIO;
+}
+
+static int pidff_needs_playback(struct pidff_device *pidff, int effect_id, int n)
+{
+	return !pidff->effect[effect_id].is_infinite ||
+		pidff->effect[effect_id].loop_count != n;
+}
+
+/*
+ * 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;
+
+	hid_dbg(pidff->hid, "%s PID effect %d", n == 0 ? "stopping" : "playing",
+		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] =
+			pidff_clamp(n, pidff->effect_operation[PID_LOOP_COUNT].field);
+	}
+
+	hid_hw_request(pidff->hid, pidff->reports[PID_EFFECT_OPERATION],
+		       HID_REQ_SET_REPORT);
+}
+
+/*
+ * 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;
+
+	if (!pidff_needs_playback(pidff, effect_id, value))
+		return 0;
+
+	hid_dbg(pidff->hid, "requesting %s on FF effect %d",
+		value == 0 ? "stop" : "playback", effect_id);
+
+	pidff->effect[effect_id].loop_count = value;
+	pidff_playback_pid(pidff, pidff->effect[effect_id].pid_id, value);
+	return 0;
+}
+
+/*
+ * Erase effect with PID id
+ * Decrease the device effect counter
+ */
+static void pidff_erase_pid(struct pidff_device *pidff, int pid_id)
+{
+	pidff->block_free[PID_EFFECT_BLOCK_INDEX].value[0] = pid_id;
+	hid_hw_request(pidff->hid, pidff->reports[PID_BLOCK_FREE],
+		       HID_REQ_SET_REPORT);
+}
+
+/*
+ * 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->effect[effect_id].pid_id;
+
+	hid_dbg(pidff->hid, "starting to erase %d/%d\n", effect_id, pid_id);
+
+	/*
+	 * Wait for the queue to clear. We do not want
+	 * a full fifo to prevent the effect removal.
+	 */
+	hid_hw_wait(pidff->hid);
+	pidff_playback_pid(pidff, pid_id, 0);
+	pidff_erase_pid(pidff, pid_id);
+
+	if (pidff->effect_count > 0)
+		pidff->effect_count--;
+
+	hid_dbg(pidff->hid, "current effect count: %d", pidff->effect_count);
+	return 0;
+}
+
+#define PIDFF_SET_REPORT_IF_NEEDED(type, effect, old) \
+	({ if (!old || pidff_needs_set_## type(effect, old)) \
+		pidff_set_ ##type## _report(pidff, effect); })
+
+#define PIDFF_SET_ENVELOPE_IF_NEEDED(type, effect, old) \
+	({ if (pidff_needs_set_envelope(&effect->u.type.envelope, \
+	       old ? &old->u.type.envelope : NULL)) \
+		pidff_set_envelope_report(pidff, &effect->u.type.envelope); })
+
+/*
+ * Effect upload handler
+ */
+static int pidff_upload_effect(struct input_dev *dev, struct ff_effect *new,
+			       struct ff_effect *old)
+{
+	struct pidff_device *pidff = dev->ff->private;
+	const int type_id = pidff_get_effect_type_id(pidff, new);
+
+	if (!type_id) {
+		hid_err(pidff->hid, "effect type not supported\n");
+		return -EINVAL;
+	}
+
+	if (!pidff->effect_count)
+		pidff_reset(pidff);
+
+	if (!old) {
+		int error = pidff_request_effect_upload(pidff, type_id);
+
+		if (error)
+			return error;
+
+		pidff->effect_count++;
+		hid_dbg(pidff->hid, "current effect count: %d", pidff->effect_count);
+		pidff->effect[new->id].loop_count = 0;
+		pidff->effect[new->id].pid_id =
+			pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
+	}
+
+	pidff->effect[new->id].is_infinite =
+		pidff_is_duration_infinite(new->replay.length);
+
+	pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0] =
+		pidff->effect[new->id].pid_id;
+
+	PIDFF_SET_REPORT_IF_NEEDED(effect, new, old);
+	switch (new->type) {
+	case FF_CONSTANT:
+		PIDFF_SET_REPORT_IF_NEEDED(constant, new, old);
+		PIDFF_SET_ENVELOPE_IF_NEEDED(constant, new, old);
+		break;
+
+	case FF_PERIODIC:
+		PIDFF_SET_REPORT_IF_NEEDED(periodic, new, old);
+		PIDFF_SET_ENVELOPE_IF_NEEDED(periodic, new, old);
+		break;
+
+	case FF_RAMP:
+		PIDFF_SET_REPORT_IF_NEEDED(ramp, new, old);
+		PIDFF_SET_ENVELOPE_IF_NEEDED(ramp, new, old);
+		break;
+
+	case FF_SPRING:
+	case FF_DAMPER:
+	case FF_INERTIA:
+	case FF_FRICTION:
+		PIDFF_SET_REPORT_IF_NEEDED(condition, new, old);
+		break;
+	}
+	hid_dbg(pidff->hid, "uploaded\n");
+	return 0;
+}
+
+/*
+ * set_gain() handler
+ */
+static void pidff_set_gain(struct input_dev *dev, u16 gain)
+{
+	pidff_set_gain_report(dev->ff->private, gain);
+}
+
+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_DIRECTION_ENABLE].value[0] = 1;
+
+	/* Omit setting delay field if it's missing */
+	if (!(pidff->quirks & HID_PIDFF_QUIRK_MISSING_DELAY))
+		pidff->set_effect[PID_START_DELAY].value[0] = 0;
+
+	hid_hw_request(pidff->hid, pidff->reports[PID_SET_EFFECT],
+		       HID_REQ_SET_REPORT);
+}
+
+/*
+ * pidff_set_autocenter() handler
+ */
+static void pidff_set_autocenter(struct input_dev *dev, u16 magnitude)
+{
+	pidff_autocenter(dev->ff->private, magnitude);
+}
+
+/*
+ * Find specific usage in a given hid_field
+ */
+static int pidff_find_usage(struct hid_field *fld, unsigned int usage_code)
+{
+	for (int i = 0; i < fld->maxusage; i++) {
+		if (fld->usage[i].hid == usage_code)
+			return i;
+	}
+	return -1;
+}
+
+/*
+ * Find hid_field with a specific usage. Return the usage index as well
+ */
+static int pidff_find_field_with_usage(int *usage_index,
+				       struct hid_report *report,
+				       unsigned int usage_code)
+{
+	for (int i = 0; i < report->maxfield; i++) {
+		struct hid_field *fld = report->field[i];
+
+		if (fld->maxusage != fld->report_count) {
+			pr_debug("maxusage and report_count do not match, skipping\n");
+			continue;
+		}
+
+		int index = pidff_find_usage(fld, usage_code);
+
+		if (index >= 0) {
+			*usage_index = index;
+			return i;
+		}
+	}
+	return -1;
+}
+
+#define PIDFF_MISSING_FIELD(name, quirks) \
+	({ pr_debug("%s field not found, but that's OK\n", __stringify(name)); \
+	   pr_debug("Setting MISSING_%s quirk\n", __stringify(name)); \
+	   *quirks |= HID_PIDFF_QUIRK_MISSING_ ## name; })
+
+/*
+ * 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,
+			     u32 *quirks)
+{
+	if (!report) {
+		pr_debug("%s, null report\n", __func__);
+		return -1;
+	}
+
+	for (int i = 0; i < count; i++) {
+		int index;
+		int found = pidff_find_field_with_usage(&index, report,
+							HID_UP_PID | table[i]);
+
+		if (found >= 0) {
+			pr_debug("found %d at %d->%d\n", i, found, index);
+			usage[i].field = report->field[found];
+			usage[i].value = &report->field[found]->value[index];
+			continue;
+		}
+
+		/* Field quirks auto-detection */
+		if (table[i] == pidff_set_effect[PID_START_DELAY])
+			PIDFF_MISSING_FIELD(DELAY, quirks);
+
+		else if (table[i] == pidff_set_condition[PID_PARAM_BLOCK_OFFSET])
+			PIDFF_MISSING_FIELD(PBO, quirks);
+
+		else if (table[i] == pidff_set_condition[PID_NEG_COEFFICIENT])
+			PIDFF_MISSING_FIELD(NEG_COEFFICIENT, quirks);
+
+		else if (table[i] == pidff_set_condition[PID_NEG_SATURATION])
+			PIDFF_MISSING_FIELD(NEG_SATURATION, quirks);
+
+		else if (table[i] == pidff_set_condition[PID_DEADBAND])
+			PIDFF_MISSING_FIELD(DEADBAND, quirks);
+
+		else if (strict) {
+			pr_debug("failed to locate %d\n", i);
+			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 < ARRAY_SIZE(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) {
+			hid_dbg(hid, "found usage 0x%02x from field->logical\n",
+				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]) {
+			hid_dbg(hid,
+				"found usage 0x%02x from collection array\n",
+				pidff_reports[ret]);
+			pidff->reports[ret] = report;
+		}
+	}
+}
+
+/*
+ * Test if the required reports have been found
+ */
+static int pidff_reports_ok(struct pidff_device *pidff)
+{
+	for (int i = 0; i < PID_REQUIRED_REPORTS; i++) {
+		if (!pidff->reports[i]) {
+			hid_dbg(pidff->hid, "%d missing\n", 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)
+{
+	if (!report) {
+		pr_debug("%s, null report\n", __func__);
+		return NULL;
+	}
+
+	for (int 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];
+
+			pr_err("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,
+				   unsigned int usage_page)
+{
+	int found = 0;
+
+	if (!fld)
+		return 0;
+
+	for (int i = 0; i < count; i++) {
+		keys[i] = pidff_find_usage(fld, usage_page | usagetable[i]) + 1;
+		if (keys[i])
+			found++;
+	}
+	return found;
+}
+
+#define PIDFF_FIND_SPECIAL_KEYS(keys, field, name) \
+	pidff_find_special_keys(pidff->keys, pidff->field, pidff_ ## name, \
+		ARRAY_SIZE(pidff_ ## name), HID_UP_PID)
+
+#define PIDFF_FIND_GENERAL_DESKTOP(keys, field, name) \
+	pidff_find_special_keys(pidff->keys, pidff->field, pidff_ ## name, \
+		ARRAY_SIZE(pidff_ ## name), HID_UP_GENDESK)
+
+/*
+ * Find and check the special fields
+ */
+static int pidff_find_special_fields(struct pidff_device *pidff)
+{
+	hid_dbg(pidff->hid, "finding special fields\n");
+
+	pidff->create_new_effect_type =
+		pidff_find_special_field(pidff->reports[PID_CREATE_NEW_EFFECT],
+					 PID_EFFECT_TYPE, 1);
+	pidff->set_effect_type =
+		pidff_find_special_field(pidff->reports[PID_SET_EFFECT],
+					 PID_EFFECT_TYPE, 1);
+	pidff->axes_enable =
+		pidff_find_special_field(pidff->reports[PID_SET_EFFECT],
+					 PID_AXES_ENABLE, 0);
+	pidff->effect_direction =
+		pidff_find_special_field(pidff->reports[PID_SET_EFFECT],
+					 PID_DIRECTION, 0);
+	pidff->device_control =
+		pidff_find_special_field(pidff->reports[PID_DEVICE_CONTROL],
+			PID_DEVICE_CONTROL_ARRAY, 1);
+
+	/* Detect and set permissive control quirk */
+	if (!pidff->device_control) {
+		pr_debug("Setting PERMISSIVE_CONTROL quirk\n");
+		pidff->quirks |= HID_PIDFF_QUIRK_PERMISSIVE_CONTROL;
+		pidff->device_control = pidff_find_special_field(
+			pidff->reports[PID_DEVICE_CONTROL],
+			PID_DEVICE_CONTROL_ARRAY, 0);
+	}
+
+	pidff->block_load_status =
+		pidff_find_special_field(pidff->reports[PID_BLOCK_LOAD],
+					 PID_BLOCK_LOAD_STATUS, 1);
+	pidff->effect_operation_status =
+		pidff_find_special_field(pidff->reports[PID_EFFECT_OPERATION],
+					 PID_EFFECT_OPERATION_ARRAY, 1);
+
+	hid_dbg(pidff->hid, "search done\n");
+
+	if (!pidff->create_new_effect_type || !pidff->set_effect_type) {
+		hid_err(pidff->hid, "effect lists not found\n");
+		return -1;
+	}
+
+	if (!pidff->effect_direction) {
+		hid_err(pidff->hid, "direction field not found\n");
+		return -1;
+	}
+
+	if (!pidff->device_control) {
+		hid_err(pidff->hid, "device control field not found\n");
+		return -1;
+	}
+
+	if (!pidff->block_load_status) {
+		hid_err(pidff->hid, "block load status field not found\n");
+		return -1;
+	}
+
+	if (!pidff->effect_operation_status) {
+		hid_err(pidff->hid, "effect operation field not found\n");
+		return -1;
+	}
+
+	PIDFF_FIND_SPECIAL_KEYS(control_id, device_control, device_control);
+
+	if (!PIDFF_FIND_SPECIAL_KEYS(type_id, create_new_effect_type,
+				     effect_types)) {
+		hid_err(pidff->hid, "no effect types found\n");
+		return -1;
+	}
+
+	if (PIDFF_FIND_SPECIAL_KEYS(status_id, block_load_status,
+				    block_load_status) !=
+	    ARRAY_SIZE(pidff_block_load_status)) {
+		hid_err(pidff->hid,
+			"block load status identifiers not found\n");
+		return -1;
+	}
+
+	if (PIDFF_FIND_SPECIAL_KEYS(operation_id, effect_operation_status,
+				    effect_operation_status) !=
+	    ARRAY_SIZE(pidff_effect_operation_status)) {
+		hid_err(pidff->hid, "effect operation identifiers not found\n");
+		return -1;
+	}
+
+	if (!pidff->axes_enable) {
+		hid_info(pidff->hid, "axes enable field not found!\n");
+		return 0;
+	}
+
+	hid_dbg(pidff->hid, "axes enable report count: %u\n",
+		pidff->axes_enable->report_count);
+
+	uint found = PIDFF_FIND_GENERAL_DESKTOP(direction_axis_id, axes_enable,
+						direction_axis);
+
+	pidff->axis_count = found;
+	hid_dbg(pidff->hid, "found direction axes: %u", found);
+
+	for (int i = 0; i < ARRAY_SIZE(pidff_direction_axis); i++) {
+		if (!pidff->direction_axis_id[i])
+			continue;
+
+		hid_dbg(pidff->hid, "axis %d, usage: 0x%04x, index: %d", i + 1,
+			pidff_direction_axis[i], pidff->direction_axis_id[i]);
+	}
+
+	if (pidff->axes_enable && found != pidff->axes_enable->report_count)
+		hid_warn(pidff->hid, "axes_enable: %u != direction axes: %u",
+			 pidff->axes_enable->report_count, found);
+
+	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 < ARRAY_SIZE(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) {
+			hid_err(pidff->hid,
+				"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], \
+		ARRAY_SIZE(pidff_ ## name), strict, &pidff->quirks)
+
+/*
+ * Fill and check the pidff_usages
+ */
+static int pidff_init_fields(struct pidff_device *pidff, struct input_dev *dev)
+{
+	if (PIDFF_FIND_FIELDS(set_effect, PID_SET_EFFECT, 1)) {
+		hid_err(pidff->hid, "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) {
+		hid_err(pidff->hid, "unknown pid_block_load report layout\n");
+		return -ENODEV;
+	}
+
+	if (PIDFF_FIND_FIELDS(effect_operation, PID_EFFECT_OPERATION, 1)) {
+		hid_err(pidff->hid, "unknown effect_operation report layout\n");
+		return -ENODEV;
+	}
+
+	if (PIDFF_FIND_FIELDS(block_free, PID_BLOCK_FREE, 1)) {
+		hid_err(pidff->hid, "unknown pid_block_free report layout\n");
+		return -ENODEV;
+	}
+
+	if (pidff_find_special_fields(pidff) || pidff_find_effects(pidff, dev))
+		return -ENODEV;
+
+	if (PIDFF_FIND_FIELDS(set_envelope, PID_SET_ENVELOPE, 1)) {
+		if (test_and_clear_bit(FF_CONSTANT, dev->ffbit))
+			hid_warn(pidff->hid,
+				 "has constant effect but no envelope\n");
+		if (test_and_clear_bit(FF_RAMP, dev->ffbit))
+			hid_warn(pidff->hid,
+				 "has ramp effect but no envelope\n");
+
+		if (test_and_clear_bit(FF_PERIODIC, dev->ffbit))
+			hid_warn(pidff->hid,
+				 "has periodic effect but no envelope\n");
+	}
+
+	if (PIDFF_FIND_FIELDS(set_constant, PID_SET_CONSTANT, 1) &&
+	    test_and_clear_bit(FF_CONSTANT, dev->ffbit))
+		hid_warn(pidff->hid, "unknown constant effect layout\n");
+
+	if (PIDFF_FIND_FIELDS(set_ramp, PID_SET_RAMP, 1) &&
+	    test_and_clear_bit(FF_RAMP, dev->ffbit))
+		hid_warn(pidff->hid, "unknown ramp effect layout\n");
+
+	if (PIDFF_FIND_FIELDS(set_condition, PID_SET_CONDITION, 1)) {
+		bool test = false;
+
+		test |= test_and_clear_bit(FF_SPRING, dev->ffbit);
+		test |= test_and_clear_bit(FF_DAMPER, dev->ffbit);
+		test |= test_and_clear_bit(FF_FRICTION, dev->ffbit);
+		test |= test_and_clear_bit(FF_INERTIA, dev->ffbit);
+		if (test)
+			hid_warn(pidff->hid, "unknown condition effect layout\n");
+	}
+
+	if (PIDFF_FIND_FIELDS(set_periodic, PID_SET_PERIODIC, 1) &&
+	    test_and_clear_bit(FF_PERIODIC, dev->ffbit))
+		hid_warn(pidff->hid, "unknown periodic effect layout\n");
+
+	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;
+}
+
+/*
+ * 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) {
+		hid_err(pidff->hid, "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, U16_MAX);
+		set_bit(FF_AUTOCENTER, dev->ffbit);
+	} else {
+		hid_notice(pidff->hid,
+			   "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
+ * Set initial quirks
+ */
+int hid_pidff_init_with_quirks(struct hid_device *hid, u32 initial_quirks)
+{
+	struct pidff_device *pidff;
+	struct hid_input *hidinput;
+	struct input_dev *dev;
+	struct ff_device *ff;
+	int max_effects;
+	int error;
+
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+
+	hidinput = list_first_entry(&hid->inputs, struct hid_input, list);
+	dev = hidinput->input;
+
+	hid_dbg(hid, "starting pid init\n");
+
+	if (list_empty(&hid->report_enum[HID_OUTPUT_REPORT].report_list)) {
+		hid_dbg(hid, "not a PID device, no output report\n");
+		return -ENODEV;
+	}
+
+	pidff = kzalloc_obj(*pidff);
+	if (!pidff)
+		return -ENOMEM;
+
+	pidff->hid = hid;
+	pidff->quirks = initial_quirks;
+	pidff->effect_count = 0;
+
+	hid_device_io_start(hid);
+
+	pidff_find_reports(hid, HID_OUTPUT_REPORT, pidff);
+	pidff_find_reports(hid, HID_FEATURE_REPORT, pidff);
+
+	if (!pidff_reports_ok(pidff)) {
+		hid_dbg(hid, "reports not ok, aborting\n");
+		error = -ENODEV;
+		goto fail;
+	}
+
+	error = pidff_init_fields(pidff, dev);
+	if (error)
+		goto fail;
+
+	/* pool report is sometimes messed up, refetch it */
+	pidff_fetch_pool(pidff);
+	pidff_set_gain_report(pidff, U16_MAX);
+	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;
+	hid_dbg(hid, "max effects is %d\n", max_effects);
+
+	if (max_effects > PID_EFFECTS_MAX)
+		max_effects = PID_EFFECTS_MAX;
+
+	if (pidff->pool[PID_SIMULTANEOUS_MAX].value)
+		hid_dbg(hid, "max simultaneous effects is %d\n",
+			pidff->pool[PID_SIMULTANEOUS_MAX].value[0]);
+
+	if (pidff->pool[PID_RAM_POOL_SIZE].value)
+		hid_dbg(hid, "device memory size is %d bytes\n",
+			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) {
+		error = -EPERM;
+		hid_notice(hid,
+			   "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;
+
+	hid_info(dev, "Force feedback for USB HID PID devices by Anssi Hannula\n");
+	hid_dbg(dev, "Active quirks mask: 0x%08x\n", pidff->quirks);
+
+	hid_device_io_stop(hid);
+
+	return 0;
+
+fail:
+	hid_device_io_stop(hid);
+
+	kfree(pidff);
+	return error;
+}
+EXPORT_SYMBOL_GPL(hid_pidff_init_with_quirks);
+
+/*
+ * Check if the device is PID and initialize it
+ * Wrapper made to keep the compatibility with old
+ * init function
+ */
+int hid_pidff_init(struct hid_device *hid)
+{
+	return hid_pidff_init_with_quirks(hid, 0);
+}