xref: /openbmc/linux/drivers/hid/usbhid/hid-pidff.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Force feedback driver for USB HID PID compliant devices
4  *
5  *  Copyright (c) 2005, 2006 Anssi Hannula <anssi.hannula@gmail.com>
6  */
7 
8 /*
9  */
10 
11 /* #define DEBUG */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/input.h>
16 #include <linux/slab.h>
17 #include <linux/usb.h>
18 
19 #include <linux/hid.h>
20 
21 #include "usbhid.h"
22 
23 #define	PID_EFFECTS_MAX		64
24 
25 /* Report usage table used to put reports into an array */
26 
27 #define PID_SET_EFFECT		0
28 #define PID_EFFECT_OPERATION	1
29 #define PID_DEVICE_GAIN		2
30 #define PID_POOL		3
31 #define PID_BLOCK_LOAD		4
32 #define PID_BLOCK_FREE		5
33 #define PID_DEVICE_CONTROL	6
34 #define PID_CREATE_NEW_EFFECT	7
35 
36 #define PID_REQUIRED_REPORTS	7
37 
38 #define PID_SET_ENVELOPE	8
39 #define PID_SET_CONDITION	9
40 #define PID_SET_PERIODIC	10
41 #define PID_SET_CONSTANT	11
42 #define PID_SET_RAMP		12
43 static const u8 pidff_reports[] = {
44 	0x21, 0x77, 0x7d, 0x7f, 0x89, 0x90, 0x96, 0xab,
45 	0x5a, 0x5f, 0x6e, 0x73, 0x74
46 };
47 
48 /* device_control is really 0x95, but 0x96 specified as it is the usage of
49 the only field in that report */
50 
51 /* Value usage tables used to put fields and values into arrays */
52 
53 #define PID_EFFECT_BLOCK_INDEX	0
54 
55 #define PID_DURATION		1
56 #define PID_GAIN		2
57 #define PID_TRIGGER_BUTTON	3
58 #define PID_TRIGGER_REPEAT_INT	4
59 #define PID_DIRECTION_ENABLE	5
60 #define PID_START_DELAY		6
61 static const u8 pidff_set_effect[] = {
62 	0x22, 0x50, 0x52, 0x53, 0x54, 0x56, 0xa7
63 };
64 
65 #define PID_ATTACK_LEVEL	1
66 #define PID_ATTACK_TIME		2
67 #define PID_FADE_LEVEL		3
68 #define PID_FADE_TIME		4
69 static const u8 pidff_set_envelope[] = { 0x22, 0x5b, 0x5c, 0x5d, 0x5e };
70 
71 #define PID_PARAM_BLOCK_OFFSET	1
72 #define PID_CP_OFFSET		2
73 #define PID_POS_COEFFICIENT	3
74 #define PID_NEG_COEFFICIENT	4
75 #define PID_POS_SATURATION	5
76 #define PID_NEG_SATURATION	6
77 #define PID_DEAD_BAND		7
78 static const u8 pidff_set_condition[] = {
79 	0x22, 0x23, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65
80 };
81 
82 #define PID_MAGNITUDE		1
83 #define PID_OFFSET		2
84 #define PID_PHASE		3
85 #define PID_PERIOD		4
86 static const u8 pidff_set_periodic[] = { 0x22, 0x70, 0x6f, 0x71, 0x72 };
87 static const u8 pidff_set_constant[] = { 0x22, 0x70 };
88 
89 #define PID_RAMP_START		1
90 #define PID_RAMP_END		2
91 static const u8 pidff_set_ramp[] = { 0x22, 0x75, 0x76 };
92 
93 #define PID_RAM_POOL_AVAILABLE	1
94 static const u8 pidff_block_load[] = { 0x22, 0xac };
95 
96 #define PID_LOOP_COUNT		1
97 static const u8 pidff_effect_operation[] = { 0x22, 0x7c };
98 
99 static const u8 pidff_block_free[] = { 0x22 };
100 
101 #define PID_DEVICE_GAIN_FIELD	0
102 static const u8 pidff_device_gain[] = { 0x7e };
103 
104 #define PID_RAM_POOL_SIZE	0
105 #define PID_SIMULTANEOUS_MAX	1
106 #define PID_DEVICE_MANAGED_POOL	2
107 static const u8 pidff_pool[] = { 0x80, 0x83, 0xa9 };
108 
109 /* Special field key tables used to put special field keys into arrays */
110 
111 #define PID_ENABLE_ACTUATORS	0
112 #define PID_RESET		1
113 static const u8 pidff_device_control[] = { 0x97, 0x9a };
114 
115 #define PID_CONSTANT	0
116 #define PID_RAMP	1
117 #define PID_SQUARE	2
118 #define PID_SINE	3
119 #define PID_TRIANGLE	4
120 #define PID_SAW_UP	5
121 #define PID_SAW_DOWN	6
122 #define PID_SPRING	7
123 #define PID_DAMPER	8
124 #define PID_INERTIA	9
125 #define PID_FRICTION	10
126 static const u8 pidff_effect_types[] = {
127 	0x26, 0x27, 0x30, 0x31, 0x32, 0x33, 0x34,
128 	0x40, 0x41, 0x42, 0x43
129 };
130 
131 #define PID_BLOCK_LOAD_SUCCESS	0
132 #define PID_BLOCK_LOAD_FULL	1
133 static const u8 pidff_block_load_status[] = { 0x8c, 0x8d };
134 
135 #define PID_EFFECT_START	0
136 #define PID_EFFECT_STOP		1
137 static const u8 pidff_effect_operation_status[] = { 0x79, 0x7b };
138 
139 struct pidff_usage {
140 	struct hid_field *field;
141 	s32 *value;
142 };
143 
144 struct pidff_device {
145 	struct hid_device *hid;
146 
147 	struct hid_report *reports[sizeof(pidff_reports)];
148 
149 	struct pidff_usage set_effect[sizeof(pidff_set_effect)];
150 	struct pidff_usage set_envelope[sizeof(pidff_set_envelope)];
151 	struct pidff_usage set_condition[sizeof(pidff_set_condition)];
152 	struct pidff_usage set_periodic[sizeof(pidff_set_periodic)];
153 	struct pidff_usage set_constant[sizeof(pidff_set_constant)];
154 	struct pidff_usage set_ramp[sizeof(pidff_set_ramp)];
155 
156 	struct pidff_usage device_gain[sizeof(pidff_device_gain)];
157 	struct pidff_usage block_load[sizeof(pidff_block_load)];
158 	struct pidff_usage pool[sizeof(pidff_pool)];
159 	struct pidff_usage effect_operation[sizeof(pidff_effect_operation)];
160 	struct pidff_usage block_free[sizeof(pidff_block_free)];
161 
162 	/* Special field is a field that is not composed of
163 	   usage<->value pairs that pidff_usage values are */
164 
165 	/* Special field in create_new_effect */
166 	struct hid_field *create_new_effect_type;
167 
168 	/* Special fields in set_effect */
169 	struct hid_field *set_effect_type;
170 	struct hid_field *effect_direction;
171 
172 	/* Special field in device_control */
173 	struct hid_field *device_control;
174 
175 	/* Special field in block_load */
176 	struct hid_field *block_load_status;
177 
178 	/* Special field in effect_operation */
179 	struct hid_field *effect_operation_status;
180 
181 	int control_id[sizeof(pidff_device_control)];
182 	int type_id[sizeof(pidff_effect_types)];
183 	int status_id[sizeof(pidff_block_load_status)];
184 	int operation_id[sizeof(pidff_effect_operation_status)];
185 
186 	int pid_id[PID_EFFECTS_MAX];
187 };
188 
189 /*
190  * Scale an unsigned value with range 0..max for the given field
191  */
192 static int pidff_rescale(int i, int max, struct hid_field *field)
193 {
194 	return i * (field->logical_maximum - field->logical_minimum) / max +
195 	    field->logical_minimum;
196 }
197 
198 /*
199  * Scale a signed value in range -0x8000..0x7fff for the given field
200  */
201 static int pidff_rescale_signed(int i, struct hid_field *field)
202 {
203 	return i == 0 ? 0 : i >
204 	    0 ? i * field->logical_maximum / 0x7fff : i *
205 	    field->logical_minimum / -0x8000;
206 }
207 
208 static void pidff_set(struct pidff_usage *usage, u16 value)
209 {
210 	usage->value[0] = pidff_rescale(value, 0xffff, usage->field);
211 	pr_debug("calculated from %d to %d\n", value, usage->value[0]);
212 }
213 
214 static void pidff_set_signed(struct pidff_usage *usage, s16 value)
215 {
216 	if (usage->field->logical_minimum < 0)
217 		usage->value[0] = pidff_rescale_signed(value, usage->field);
218 	else {
219 		if (value < 0)
220 			usage->value[0] =
221 			    pidff_rescale(-value, 0x8000, usage->field);
222 		else
223 			usage->value[0] =
224 			    pidff_rescale(value, 0x7fff, usage->field);
225 	}
226 	pr_debug("calculated from %d to %d\n", value, usage->value[0]);
227 }
228 
229 /*
230  * Send envelope report to the device
231  */
232 static void pidff_set_envelope_report(struct pidff_device *pidff,
233 				      struct ff_envelope *envelope)
234 {
235 	pidff->set_envelope[PID_EFFECT_BLOCK_INDEX].value[0] =
236 	    pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
237 
238 	pidff->set_envelope[PID_ATTACK_LEVEL].value[0] =
239 	    pidff_rescale(envelope->attack_level >
240 			  0x7fff ? 0x7fff : envelope->attack_level, 0x7fff,
241 			  pidff->set_envelope[PID_ATTACK_LEVEL].field);
242 	pidff->set_envelope[PID_FADE_LEVEL].value[0] =
243 	    pidff_rescale(envelope->fade_level >
244 			  0x7fff ? 0x7fff : envelope->fade_level, 0x7fff,
245 			  pidff->set_envelope[PID_FADE_LEVEL].field);
246 
247 	pidff->set_envelope[PID_ATTACK_TIME].value[0] = envelope->attack_length;
248 	pidff->set_envelope[PID_FADE_TIME].value[0] = envelope->fade_length;
249 
250 	hid_dbg(pidff->hid, "attack %u => %d\n",
251 		envelope->attack_level,
252 		pidff->set_envelope[PID_ATTACK_LEVEL].value[0]);
253 
254 	hid_hw_request(pidff->hid, pidff->reports[PID_SET_ENVELOPE],
255 			HID_REQ_SET_REPORT);
256 }
257 
258 /*
259  * Test if the new envelope differs from old one
260  */
261 static int pidff_needs_set_envelope(struct ff_envelope *envelope,
262 				    struct ff_envelope *old)
263 {
264 	return envelope->attack_level != old->attack_level ||
265 	       envelope->fade_level != old->fade_level ||
266 	       envelope->attack_length != old->attack_length ||
267 	       envelope->fade_length != old->fade_length;
268 }
269 
270 /*
271  * Send constant force report to the device
272  */
273 static void pidff_set_constant_force_report(struct pidff_device *pidff,
274 					    struct ff_effect *effect)
275 {
276 	pidff->set_constant[PID_EFFECT_BLOCK_INDEX].value[0] =
277 		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
278 	pidff_set_signed(&pidff->set_constant[PID_MAGNITUDE],
279 			 effect->u.constant.level);
280 
281 	hid_hw_request(pidff->hid, pidff->reports[PID_SET_CONSTANT],
282 			HID_REQ_SET_REPORT);
283 }
284 
285 /*
286  * Test if the constant parameters have changed between effects
287  */
288 static int pidff_needs_set_constant(struct ff_effect *effect,
289 				    struct ff_effect *old)
290 {
291 	return effect->u.constant.level != old->u.constant.level;
292 }
293 
294 /*
295  * Send set effect report to the device
296  */
297 static void pidff_set_effect_report(struct pidff_device *pidff,
298 				    struct ff_effect *effect)
299 {
300 	pidff->set_effect[PID_EFFECT_BLOCK_INDEX].value[0] =
301 		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
302 	pidff->set_effect_type->value[0] =
303 		pidff->create_new_effect_type->value[0];
304 	pidff->set_effect[PID_DURATION].value[0] = effect->replay.length;
305 	pidff->set_effect[PID_TRIGGER_BUTTON].value[0] = effect->trigger.button;
306 	pidff->set_effect[PID_TRIGGER_REPEAT_INT].value[0] =
307 		effect->trigger.interval;
308 	pidff->set_effect[PID_GAIN].value[0] =
309 		pidff->set_effect[PID_GAIN].field->logical_maximum;
310 	pidff->set_effect[PID_DIRECTION_ENABLE].value[0] = 1;
311 	pidff->effect_direction->value[0] =
312 		pidff_rescale(effect->direction, 0xffff,
313 				pidff->effect_direction);
314 	pidff->set_effect[PID_START_DELAY].value[0] = effect->replay.delay;
315 
316 	hid_hw_request(pidff->hid, pidff->reports[PID_SET_EFFECT],
317 			HID_REQ_SET_REPORT);
318 }
319 
320 /*
321  * Test if the values used in set_effect have changed
322  */
323 static int pidff_needs_set_effect(struct ff_effect *effect,
324 				  struct ff_effect *old)
325 {
326 	return effect->replay.length != old->replay.length ||
327 	       effect->trigger.interval != old->trigger.interval ||
328 	       effect->trigger.button != old->trigger.button ||
329 	       effect->direction != old->direction ||
330 	       effect->replay.delay != old->replay.delay;
331 }
332 
333 /*
334  * Send periodic effect report to the device
335  */
336 static void pidff_set_periodic_report(struct pidff_device *pidff,
337 				      struct ff_effect *effect)
338 {
339 	pidff->set_periodic[PID_EFFECT_BLOCK_INDEX].value[0] =
340 		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
341 	pidff_set_signed(&pidff->set_periodic[PID_MAGNITUDE],
342 			 effect->u.periodic.magnitude);
343 	pidff_set_signed(&pidff->set_periodic[PID_OFFSET],
344 			 effect->u.periodic.offset);
345 	pidff_set(&pidff->set_periodic[PID_PHASE], effect->u.periodic.phase);
346 	pidff->set_periodic[PID_PERIOD].value[0] = effect->u.periodic.period;
347 
348 	hid_hw_request(pidff->hid, pidff->reports[PID_SET_PERIODIC],
349 			HID_REQ_SET_REPORT);
350 
351 }
352 
353 /*
354  * Test if periodic effect parameters have changed
355  */
356 static int pidff_needs_set_periodic(struct ff_effect *effect,
357 				    struct ff_effect *old)
358 {
359 	return effect->u.periodic.magnitude != old->u.periodic.magnitude ||
360 	       effect->u.periodic.offset != old->u.periodic.offset ||
361 	       effect->u.periodic.phase != old->u.periodic.phase ||
362 	       effect->u.periodic.period != old->u.periodic.period;
363 }
364 
365 /*
366  * Send condition effect reports to the device
367  */
368 static void pidff_set_condition_report(struct pidff_device *pidff,
369 				       struct ff_effect *effect)
370 {
371 	int i;
372 
373 	pidff->set_condition[PID_EFFECT_BLOCK_INDEX].value[0] =
374 		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
375 
376 	for (i = 0; i < 2; i++) {
377 		pidff->set_condition[PID_PARAM_BLOCK_OFFSET].value[0] = i;
378 		pidff_set_signed(&pidff->set_condition[PID_CP_OFFSET],
379 				 effect->u.condition[i].center);
380 		pidff_set_signed(&pidff->set_condition[PID_POS_COEFFICIENT],
381 				 effect->u.condition[i].right_coeff);
382 		pidff_set_signed(&pidff->set_condition[PID_NEG_COEFFICIENT],
383 				 effect->u.condition[i].left_coeff);
384 		pidff_set(&pidff->set_condition[PID_POS_SATURATION],
385 			  effect->u.condition[i].right_saturation);
386 		pidff_set(&pidff->set_condition[PID_NEG_SATURATION],
387 			  effect->u.condition[i].left_saturation);
388 		pidff_set(&pidff->set_condition[PID_DEAD_BAND],
389 			  effect->u.condition[i].deadband);
390 		hid_hw_request(pidff->hid, pidff->reports[PID_SET_CONDITION],
391 				HID_REQ_SET_REPORT);
392 	}
393 }
394 
395 /*
396  * Test if condition effect parameters have changed
397  */
398 static int pidff_needs_set_condition(struct ff_effect *effect,
399 				     struct ff_effect *old)
400 {
401 	int i;
402 	int ret = 0;
403 
404 	for (i = 0; i < 2; i++) {
405 		struct ff_condition_effect *cond = &effect->u.condition[i];
406 		struct ff_condition_effect *old_cond = &old->u.condition[i];
407 
408 		ret |= cond->center != old_cond->center ||
409 		       cond->right_coeff != old_cond->right_coeff ||
410 		       cond->left_coeff != old_cond->left_coeff ||
411 		       cond->right_saturation != old_cond->right_saturation ||
412 		       cond->left_saturation != old_cond->left_saturation ||
413 		       cond->deadband != old_cond->deadband;
414 	}
415 
416 	return ret;
417 }
418 
419 /*
420  * Send ramp force report to the device
421  */
422 static void pidff_set_ramp_force_report(struct pidff_device *pidff,
423 					struct ff_effect *effect)
424 {
425 	pidff->set_ramp[PID_EFFECT_BLOCK_INDEX].value[0] =
426 		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
427 	pidff_set_signed(&pidff->set_ramp[PID_RAMP_START],
428 			 effect->u.ramp.start_level);
429 	pidff_set_signed(&pidff->set_ramp[PID_RAMP_END],
430 			 effect->u.ramp.end_level);
431 	hid_hw_request(pidff->hid, pidff->reports[PID_SET_RAMP],
432 			HID_REQ_SET_REPORT);
433 }
434 
435 /*
436  * Test if ramp force parameters have changed
437  */
438 static int pidff_needs_set_ramp(struct ff_effect *effect, struct ff_effect *old)
439 {
440 	return effect->u.ramp.start_level != old->u.ramp.start_level ||
441 	       effect->u.ramp.end_level != old->u.ramp.end_level;
442 }
443 
444 /*
445  * Send a request for effect upload to the device
446  *
447  * Returns 0 if device reported success, -ENOSPC if the device reported memory
448  * is full. Upon unknown response the function will retry for 60 times, if
449  * still unsuccessful -EIO is returned.
450  */
451 static int pidff_request_effect_upload(struct pidff_device *pidff, int efnum)
452 {
453 	int j;
454 
455 	pidff->create_new_effect_type->value[0] = efnum;
456 	hid_hw_request(pidff->hid, pidff->reports[PID_CREATE_NEW_EFFECT],
457 			HID_REQ_SET_REPORT);
458 	hid_dbg(pidff->hid, "create_new_effect sent, type: %d\n", efnum);
459 
460 	pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0] = 0;
461 	pidff->block_load_status->value[0] = 0;
462 	hid_hw_wait(pidff->hid);
463 
464 	for (j = 0; j < 60; j++) {
465 		hid_dbg(pidff->hid, "pid_block_load requested\n");
466 		hid_hw_request(pidff->hid, pidff->reports[PID_BLOCK_LOAD],
467 				HID_REQ_GET_REPORT);
468 		hid_hw_wait(pidff->hid);
469 		if (pidff->block_load_status->value[0] ==
470 		    pidff->status_id[PID_BLOCK_LOAD_SUCCESS]) {
471 			hid_dbg(pidff->hid, "device reported free memory: %d bytes\n",
472 				 pidff->block_load[PID_RAM_POOL_AVAILABLE].value ?
473 				 pidff->block_load[PID_RAM_POOL_AVAILABLE].value[0] : -1);
474 			return 0;
475 		}
476 		if (pidff->block_load_status->value[0] ==
477 		    pidff->status_id[PID_BLOCK_LOAD_FULL]) {
478 			hid_dbg(pidff->hid, "not enough memory free: %d bytes\n",
479 				pidff->block_load[PID_RAM_POOL_AVAILABLE].value ?
480 				pidff->block_load[PID_RAM_POOL_AVAILABLE].value[0] : -1);
481 			return -ENOSPC;
482 		}
483 	}
484 	hid_err(pidff->hid, "pid_block_load failed 60 times\n");
485 	return -EIO;
486 }
487 
488 /*
489  * Play the effect with PID id n times
490  */
491 static void pidff_playback_pid(struct pidff_device *pidff, int pid_id, int n)
492 {
493 	pidff->effect_operation[PID_EFFECT_BLOCK_INDEX].value[0] = pid_id;
494 
495 	if (n == 0) {
496 		pidff->effect_operation_status->value[0] =
497 			pidff->operation_id[PID_EFFECT_STOP];
498 	} else {
499 		pidff->effect_operation_status->value[0] =
500 			pidff->operation_id[PID_EFFECT_START];
501 		pidff->effect_operation[PID_LOOP_COUNT].value[0] = n;
502 	}
503 
504 	hid_hw_request(pidff->hid, pidff->reports[PID_EFFECT_OPERATION],
505 			HID_REQ_SET_REPORT);
506 }
507 
508 /**
509  * Play the effect with effect id @effect_id for @value times
510  */
511 static int pidff_playback(struct input_dev *dev, int effect_id, int value)
512 {
513 	struct pidff_device *pidff = dev->ff->private;
514 
515 	pidff_playback_pid(pidff, pidff->pid_id[effect_id], value);
516 
517 	return 0;
518 }
519 
520 /*
521  * Erase effect with PID id
522  */
523 static void pidff_erase_pid(struct pidff_device *pidff, int pid_id)
524 {
525 	pidff->block_free[PID_EFFECT_BLOCK_INDEX].value[0] = pid_id;
526 	hid_hw_request(pidff->hid, pidff->reports[PID_BLOCK_FREE],
527 			HID_REQ_SET_REPORT);
528 }
529 
530 /*
531  * Stop and erase effect with effect_id
532  */
533 static int pidff_erase_effect(struct input_dev *dev, int effect_id)
534 {
535 	struct pidff_device *pidff = dev->ff->private;
536 	int pid_id = pidff->pid_id[effect_id];
537 
538 	hid_dbg(pidff->hid, "starting to erase %d/%d\n",
539 		effect_id, pidff->pid_id[effect_id]);
540 	/* Wait for the queue to clear. We do not want a full fifo to
541 	   prevent the effect removal. */
542 	hid_hw_wait(pidff->hid);
543 	pidff_playback_pid(pidff, pid_id, 0);
544 	pidff_erase_pid(pidff, pid_id);
545 
546 	return 0;
547 }
548 
549 /*
550  * Effect upload handler
551  */
552 static int pidff_upload_effect(struct input_dev *dev, struct ff_effect *effect,
553 			       struct ff_effect *old)
554 {
555 	struct pidff_device *pidff = dev->ff->private;
556 	int type_id;
557 	int error;
558 
559 	pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0] = 0;
560 	if (old) {
561 		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0] =
562 			pidff->pid_id[effect->id];
563 	}
564 
565 	switch (effect->type) {
566 	case FF_CONSTANT:
567 		if (!old) {
568 			error = pidff_request_effect_upload(pidff,
569 					pidff->type_id[PID_CONSTANT]);
570 			if (error)
571 				return error;
572 		}
573 		if (!old || pidff_needs_set_effect(effect, old))
574 			pidff_set_effect_report(pidff, effect);
575 		if (!old || pidff_needs_set_constant(effect, old))
576 			pidff_set_constant_force_report(pidff, effect);
577 		if (!old ||
578 		    pidff_needs_set_envelope(&effect->u.constant.envelope,
579 					&old->u.constant.envelope))
580 			pidff_set_envelope_report(pidff,
581 					&effect->u.constant.envelope);
582 		break;
583 
584 	case FF_PERIODIC:
585 		if (!old) {
586 			switch (effect->u.periodic.waveform) {
587 			case FF_SQUARE:
588 				type_id = PID_SQUARE;
589 				break;
590 			case FF_TRIANGLE:
591 				type_id = PID_TRIANGLE;
592 				break;
593 			case FF_SINE:
594 				type_id = PID_SINE;
595 				break;
596 			case FF_SAW_UP:
597 				type_id = PID_SAW_UP;
598 				break;
599 			case FF_SAW_DOWN:
600 				type_id = PID_SAW_DOWN;
601 				break;
602 			default:
603 				hid_err(pidff->hid, "invalid waveform\n");
604 				return -EINVAL;
605 			}
606 
607 			error = pidff_request_effect_upload(pidff,
608 					pidff->type_id[type_id]);
609 			if (error)
610 				return error;
611 		}
612 		if (!old || pidff_needs_set_effect(effect, old))
613 			pidff_set_effect_report(pidff, effect);
614 		if (!old || pidff_needs_set_periodic(effect, old))
615 			pidff_set_periodic_report(pidff, effect);
616 		if (!old ||
617 		    pidff_needs_set_envelope(&effect->u.periodic.envelope,
618 					&old->u.periodic.envelope))
619 			pidff_set_envelope_report(pidff,
620 					&effect->u.periodic.envelope);
621 		break;
622 
623 	case FF_RAMP:
624 		if (!old) {
625 			error = pidff_request_effect_upload(pidff,
626 					pidff->type_id[PID_RAMP]);
627 			if (error)
628 				return error;
629 		}
630 		if (!old || pidff_needs_set_effect(effect, old))
631 			pidff_set_effect_report(pidff, effect);
632 		if (!old || pidff_needs_set_ramp(effect, old))
633 			pidff_set_ramp_force_report(pidff, effect);
634 		if (!old ||
635 		    pidff_needs_set_envelope(&effect->u.ramp.envelope,
636 					&old->u.ramp.envelope))
637 			pidff_set_envelope_report(pidff,
638 					&effect->u.ramp.envelope);
639 		break;
640 
641 	case FF_SPRING:
642 		if (!old) {
643 			error = pidff_request_effect_upload(pidff,
644 					pidff->type_id[PID_SPRING]);
645 			if (error)
646 				return error;
647 		}
648 		if (!old || pidff_needs_set_effect(effect, old))
649 			pidff_set_effect_report(pidff, effect);
650 		if (!old || pidff_needs_set_condition(effect, old))
651 			pidff_set_condition_report(pidff, effect);
652 		break;
653 
654 	case FF_FRICTION:
655 		if (!old) {
656 			error = pidff_request_effect_upload(pidff,
657 					pidff->type_id[PID_FRICTION]);
658 			if (error)
659 				return error;
660 		}
661 		if (!old || pidff_needs_set_effect(effect, old))
662 			pidff_set_effect_report(pidff, effect);
663 		if (!old || pidff_needs_set_condition(effect, old))
664 			pidff_set_condition_report(pidff, effect);
665 		break;
666 
667 	case FF_DAMPER:
668 		if (!old) {
669 			error = pidff_request_effect_upload(pidff,
670 					pidff->type_id[PID_DAMPER]);
671 			if (error)
672 				return error;
673 		}
674 		if (!old || pidff_needs_set_effect(effect, old))
675 			pidff_set_effect_report(pidff, effect);
676 		if (!old || pidff_needs_set_condition(effect, old))
677 			pidff_set_condition_report(pidff, effect);
678 		break;
679 
680 	case FF_INERTIA:
681 		if (!old) {
682 			error = pidff_request_effect_upload(pidff,
683 					pidff->type_id[PID_INERTIA]);
684 			if (error)
685 				return error;
686 		}
687 		if (!old || pidff_needs_set_effect(effect, old))
688 			pidff_set_effect_report(pidff, effect);
689 		if (!old || pidff_needs_set_condition(effect, old))
690 			pidff_set_condition_report(pidff, effect);
691 		break;
692 
693 	default:
694 		hid_err(pidff->hid, "invalid type\n");
695 		return -EINVAL;
696 	}
697 
698 	if (!old)
699 		pidff->pid_id[effect->id] =
700 		    pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
701 
702 	hid_dbg(pidff->hid, "uploaded\n");
703 
704 	return 0;
705 }
706 
707 /*
708  * set_gain() handler
709  */
710 static void pidff_set_gain(struct input_dev *dev, u16 gain)
711 {
712 	struct pidff_device *pidff = dev->ff->private;
713 
714 	pidff_set(&pidff->device_gain[PID_DEVICE_GAIN_FIELD], gain);
715 	hid_hw_request(pidff->hid, pidff->reports[PID_DEVICE_GAIN],
716 			HID_REQ_SET_REPORT);
717 }
718 
719 static void pidff_autocenter(struct pidff_device *pidff, u16 magnitude)
720 {
721 	struct hid_field *field =
722 		pidff->block_load[PID_EFFECT_BLOCK_INDEX].field;
723 
724 	if (!magnitude) {
725 		pidff_playback_pid(pidff, field->logical_minimum, 0);
726 		return;
727 	}
728 
729 	pidff_playback_pid(pidff, field->logical_minimum, 1);
730 
731 	pidff->set_effect[PID_EFFECT_BLOCK_INDEX].value[0] =
732 		pidff->block_load[PID_EFFECT_BLOCK_INDEX].field->logical_minimum;
733 	pidff->set_effect_type->value[0] = pidff->type_id[PID_SPRING];
734 	pidff->set_effect[PID_DURATION].value[0] = 0;
735 	pidff->set_effect[PID_TRIGGER_BUTTON].value[0] = 0;
736 	pidff->set_effect[PID_TRIGGER_REPEAT_INT].value[0] = 0;
737 	pidff_set(&pidff->set_effect[PID_GAIN], magnitude);
738 	pidff->set_effect[PID_DIRECTION_ENABLE].value[0] = 1;
739 	pidff->set_effect[PID_START_DELAY].value[0] = 0;
740 
741 	hid_hw_request(pidff->hid, pidff->reports[PID_SET_EFFECT],
742 			HID_REQ_SET_REPORT);
743 }
744 
745 /*
746  * pidff_set_autocenter() handler
747  */
748 static void pidff_set_autocenter(struct input_dev *dev, u16 magnitude)
749 {
750 	struct pidff_device *pidff = dev->ff->private;
751 
752 	pidff_autocenter(pidff, magnitude);
753 }
754 
755 /*
756  * Find fields from a report and fill a pidff_usage
757  */
758 static int pidff_find_fields(struct pidff_usage *usage, const u8 *table,
759 			     struct hid_report *report, int count, int strict)
760 {
761 	int i, j, k, found;
762 
763 	for (k = 0; k < count; k++) {
764 		found = 0;
765 		for (i = 0; i < report->maxfield; i++) {
766 			if (report->field[i]->maxusage !=
767 			    report->field[i]->report_count) {
768 				pr_debug("maxusage and report_count do not match, skipping\n");
769 				continue;
770 			}
771 			for (j = 0; j < report->field[i]->maxusage; j++) {
772 				if (report->field[i]->usage[j].hid ==
773 				    (HID_UP_PID | table[k])) {
774 					pr_debug("found %d at %d->%d\n",
775 						 k, i, j);
776 					usage[k].field = report->field[i];
777 					usage[k].value =
778 						&report->field[i]->value[j];
779 					found = 1;
780 					break;
781 				}
782 			}
783 			if (found)
784 				break;
785 		}
786 		if (!found && strict) {
787 			pr_debug("failed to locate %d\n", k);
788 			return -1;
789 		}
790 	}
791 	return 0;
792 }
793 
794 /*
795  * Return index into pidff_reports for the given usage
796  */
797 static int pidff_check_usage(int usage)
798 {
799 	int i;
800 
801 	for (i = 0; i < sizeof(pidff_reports); i++)
802 		if (usage == (HID_UP_PID | pidff_reports[i]))
803 			return i;
804 
805 	return -1;
806 }
807 
808 /*
809  * Find the reports and fill pidff->reports[]
810  * report_type specifies either OUTPUT or FEATURE reports
811  */
812 static void pidff_find_reports(struct hid_device *hid, int report_type,
813 			       struct pidff_device *pidff)
814 {
815 	struct hid_report *report;
816 	int i, ret;
817 
818 	list_for_each_entry(report,
819 			    &hid->report_enum[report_type].report_list, list) {
820 		if (report->maxfield < 1)
821 			continue;
822 		ret = pidff_check_usage(report->field[0]->logical);
823 		if (ret != -1) {
824 			hid_dbg(hid, "found usage 0x%02x from field->logical\n",
825 				pidff_reports[ret]);
826 			pidff->reports[ret] = report;
827 			continue;
828 		}
829 
830 		/*
831 		 * Sometimes logical collections are stacked to indicate
832 		 * different usages for the report and the field, in which
833 		 * case we want the usage of the parent. However, Linux HID
834 		 * implementation hides this fact, so we have to dig it up
835 		 * ourselves
836 		 */
837 		i = report->field[0]->usage[0].collection_index;
838 		if (i <= 0 ||
839 		    hid->collection[i - 1].type != HID_COLLECTION_LOGICAL)
840 			continue;
841 		ret = pidff_check_usage(hid->collection[i - 1].usage);
842 		if (ret != -1 && !pidff->reports[ret]) {
843 			hid_dbg(hid,
844 				"found usage 0x%02x from collection array\n",
845 				pidff_reports[ret]);
846 			pidff->reports[ret] = report;
847 		}
848 	}
849 }
850 
851 /*
852  * Test if the required reports have been found
853  */
854 static int pidff_reports_ok(struct pidff_device *pidff)
855 {
856 	int i;
857 
858 	for (i = 0; i <= PID_REQUIRED_REPORTS; i++) {
859 		if (!pidff->reports[i]) {
860 			hid_dbg(pidff->hid, "%d missing\n", i);
861 			return 0;
862 		}
863 	}
864 
865 	return 1;
866 }
867 
868 /*
869  * Find a field with a specific usage within a report
870  */
871 static struct hid_field *pidff_find_special_field(struct hid_report *report,
872 						  int usage, int enforce_min)
873 {
874 	int i;
875 
876 	for (i = 0; i < report->maxfield; i++) {
877 		if (report->field[i]->logical == (HID_UP_PID | usage) &&
878 		    report->field[i]->report_count > 0) {
879 			if (!enforce_min ||
880 			    report->field[i]->logical_minimum == 1)
881 				return report->field[i];
882 			else {
883 				pr_err("logical_minimum is not 1 as it should be\n");
884 				return NULL;
885 			}
886 		}
887 	}
888 	return NULL;
889 }
890 
891 /*
892  * Fill a pidff->*_id struct table
893  */
894 static int pidff_find_special_keys(int *keys, struct hid_field *fld,
895 				   const u8 *usagetable, int count)
896 {
897 
898 	int i, j;
899 	int found = 0;
900 
901 	for (i = 0; i < count; i++) {
902 		for (j = 0; j < fld->maxusage; j++) {
903 			if (fld->usage[j].hid == (HID_UP_PID | usagetable[i])) {
904 				keys[i] = j + 1;
905 				found++;
906 				break;
907 			}
908 		}
909 	}
910 	return found;
911 }
912 
913 #define PIDFF_FIND_SPECIAL_KEYS(keys, field, name) \
914 	pidff_find_special_keys(pidff->keys, pidff->field, pidff_ ## name, \
915 		sizeof(pidff_ ## name))
916 
917 /*
918  * Find and check the special fields
919  */
920 static int pidff_find_special_fields(struct pidff_device *pidff)
921 {
922 	hid_dbg(pidff->hid, "finding special fields\n");
923 
924 	pidff->create_new_effect_type =
925 		pidff_find_special_field(pidff->reports[PID_CREATE_NEW_EFFECT],
926 					 0x25, 1);
927 	pidff->set_effect_type =
928 		pidff_find_special_field(pidff->reports[PID_SET_EFFECT],
929 					 0x25, 1);
930 	pidff->effect_direction =
931 		pidff_find_special_field(pidff->reports[PID_SET_EFFECT],
932 					 0x57, 0);
933 	pidff->device_control =
934 		pidff_find_special_field(pidff->reports[PID_DEVICE_CONTROL],
935 					 0x96, 1);
936 	pidff->block_load_status =
937 		pidff_find_special_field(pidff->reports[PID_BLOCK_LOAD],
938 					 0x8b, 1);
939 	pidff->effect_operation_status =
940 		pidff_find_special_field(pidff->reports[PID_EFFECT_OPERATION],
941 					 0x78, 1);
942 
943 	hid_dbg(pidff->hid, "search done\n");
944 
945 	if (!pidff->create_new_effect_type || !pidff->set_effect_type) {
946 		hid_err(pidff->hid, "effect lists not found\n");
947 		return -1;
948 	}
949 
950 	if (!pidff->effect_direction) {
951 		hid_err(pidff->hid, "direction field not found\n");
952 		return -1;
953 	}
954 
955 	if (!pidff->device_control) {
956 		hid_err(pidff->hid, "device control field not found\n");
957 		return -1;
958 	}
959 
960 	if (!pidff->block_load_status) {
961 		hid_err(pidff->hid, "block load status field not found\n");
962 		return -1;
963 	}
964 
965 	if (!pidff->effect_operation_status) {
966 		hid_err(pidff->hid, "effect operation field not found\n");
967 		return -1;
968 	}
969 
970 	pidff_find_special_keys(pidff->control_id, pidff->device_control,
971 				pidff_device_control,
972 				sizeof(pidff_device_control));
973 
974 	PIDFF_FIND_SPECIAL_KEYS(control_id, device_control, device_control);
975 
976 	if (!PIDFF_FIND_SPECIAL_KEYS(type_id, create_new_effect_type,
977 				     effect_types)) {
978 		hid_err(pidff->hid, "no effect types found\n");
979 		return -1;
980 	}
981 
982 	if (PIDFF_FIND_SPECIAL_KEYS(status_id, block_load_status,
983 				    block_load_status) !=
984 			sizeof(pidff_block_load_status)) {
985 		hid_err(pidff->hid,
986 			"block load status identifiers not found\n");
987 		return -1;
988 	}
989 
990 	if (PIDFF_FIND_SPECIAL_KEYS(operation_id, effect_operation_status,
991 				    effect_operation_status) !=
992 			sizeof(pidff_effect_operation_status)) {
993 		hid_err(pidff->hid, "effect operation identifiers not found\n");
994 		return -1;
995 	}
996 
997 	return 0;
998 }
999 
1000 /**
1001  * Find the implemented effect types
1002  */
1003 static int pidff_find_effects(struct pidff_device *pidff,
1004 			      struct input_dev *dev)
1005 {
1006 	int i;
1007 
1008 	for (i = 0; i < sizeof(pidff_effect_types); i++) {
1009 		int pidff_type = pidff->type_id[i];
1010 		if (pidff->set_effect_type->usage[pidff_type].hid !=
1011 		    pidff->create_new_effect_type->usage[pidff_type].hid) {
1012 			hid_err(pidff->hid,
1013 				"effect type number %d is invalid\n", i);
1014 			return -1;
1015 		}
1016 	}
1017 
1018 	if (pidff->type_id[PID_CONSTANT])
1019 		set_bit(FF_CONSTANT, dev->ffbit);
1020 	if (pidff->type_id[PID_RAMP])
1021 		set_bit(FF_RAMP, dev->ffbit);
1022 	if (pidff->type_id[PID_SQUARE]) {
1023 		set_bit(FF_SQUARE, dev->ffbit);
1024 		set_bit(FF_PERIODIC, dev->ffbit);
1025 	}
1026 	if (pidff->type_id[PID_SINE]) {
1027 		set_bit(FF_SINE, dev->ffbit);
1028 		set_bit(FF_PERIODIC, dev->ffbit);
1029 	}
1030 	if (pidff->type_id[PID_TRIANGLE]) {
1031 		set_bit(FF_TRIANGLE, dev->ffbit);
1032 		set_bit(FF_PERIODIC, dev->ffbit);
1033 	}
1034 	if (pidff->type_id[PID_SAW_UP]) {
1035 		set_bit(FF_SAW_UP, dev->ffbit);
1036 		set_bit(FF_PERIODIC, dev->ffbit);
1037 	}
1038 	if (pidff->type_id[PID_SAW_DOWN]) {
1039 		set_bit(FF_SAW_DOWN, dev->ffbit);
1040 		set_bit(FF_PERIODIC, dev->ffbit);
1041 	}
1042 	if (pidff->type_id[PID_SPRING])
1043 		set_bit(FF_SPRING, dev->ffbit);
1044 	if (pidff->type_id[PID_DAMPER])
1045 		set_bit(FF_DAMPER, dev->ffbit);
1046 	if (pidff->type_id[PID_INERTIA])
1047 		set_bit(FF_INERTIA, dev->ffbit);
1048 	if (pidff->type_id[PID_FRICTION])
1049 		set_bit(FF_FRICTION, dev->ffbit);
1050 
1051 	return 0;
1052 
1053 }
1054 
1055 #define PIDFF_FIND_FIELDS(name, report, strict) \
1056 	pidff_find_fields(pidff->name, pidff_ ## name, \
1057 		pidff->reports[report], \
1058 		sizeof(pidff_ ## name), strict)
1059 
1060 /*
1061  * Fill and check the pidff_usages
1062  */
1063 static int pidff_init_fields(struct pidff_device *pidff, struct input_dev *dev)
1064 {
1065 	int envelope_ok = 0;
1066 
1067 	if (PIDFF_FIND_FIELDS(set_effect, PID_SET_EFFECT, 1)) {
1068 		hid_err(pidff->hid, "unknown set_effect report layout\n");
1069 		return -ENODEV;
1070 	}
1071 
1072 	PIDFF_FIND_FIELDS(block_load, PID_BLOCK_LOAD, 0);
1073 	if (!pidff->block_load[PID_EFFECT_BLOCK_INDEX].value) {
1074 		hid_err(pidff->hid, "unknown pid_block_load report layout\n");
1075 		return -ENODEV;
1076 	}
1077 
1078 	if (PIDFF_FIND_FIELDS(effect_operation, PID_EFFECT_OPERATION, 1)) {
1079 		hid_err(pidff->hid, "unknown effect_operation report layout\n");
1080 		return -ENODEV;
1081 	}
1082 
1083 	if (PIDFF_FIND_FIELDS(block_free, PID_BLOCK_FREE, 1)) {
1084 		hid_err(pidff->hid, "unknown pid_block_free report layout\n");
1085 		return -ENODEV;
1086 	}
1087 
1088 	if (!PIDFF_FIND_FIELDS(set_envelope, PID_SET_ENVELOPE, 1))
1089 		envelope_ok = 1;
1090 
1091 	if (pidff_find_special_fields(pidff) || pidff_find_effects(pidff, dev))
1092 		return -ENODEV;
1093 
1094 	if (!envelope_ok) {
1095 		if (test_and_clear_bit(FF_CONSTANT, dev->ffbit))
1096 			hid_warn(pidff->hid,
1097 				 "has constant effect but no envelope\n");
1098 		if (test_and_clear_bit(FF_RAMP, dev->ffbit))
1099 			hid_warn(pidff->hid,
1100 				 "has ramp effect but no envelope\n");
1101 
1102 		if (test_and_clear_bit(FF_PERIODIC, dev->ffbit))
1103 			hid_warn(pidff->hid,
1104 				 "has periodic effect but no envelope\n");
1105 	}
1106 
1107 	if (test_bit(FF_CONSTANT, dev->ffbit) &&
1108 	    PIDFF_FIND_FIELDS(set_constant, PID_SET_CONSTANT, 1)) {
1109 		hid_warn(pidff->hid, "unknown constant effect layout\n");
1110 		clear_bit(FF_CONSTANT, dev->ffbit);
1111 	}
1112 
1113 	if (test_bit(FF_RAMP, dev->ffbit) &&
1114 	    PIDFF_FIND_FIELDS(set_ramp, PID_SET_RAMP, 1)) {
1115 		hid_warn(pidff->hid, "unknown ramp effect layout\n");
1116 		clear_bit(FF_RAMP, dev->ffbit);
1117 	}
1118 
1119 	if ((test_bit(FF_SPRING, dev->ffbit) ||
1120 	     test_bit(FF_DAMPER, dev->ffbit) ||
1121 	     test_bit(FF_FRICTION, dev->ffbit) ||
1122 	     test_bit(FF_INERTIA, dev->ffbit)) &&
1123 	    PIDFF_FIND_FIELDS(set_condition, PID_SET_CONDITION, 1)) {
1124 		hid_warn(pidff->hid, "unknown condition effect layout\n");
1125 		clear_bit(FF_SPRING, dev->ffbit);
1126 		clear_bit(FF_DAMPER, dev->ffbit);
1127 		clear_bit(FF_FRICTION, dev->ffbit);
1128 		clear_bit(FF_INERTIA, dev->ffbit);
1129 	}
1130 
1131 	if (test_bit(FF_PERIODIC, dev->ffbit) &&
1132 	    PIDFF_FIND_FIELDS(set_periodic, PID_SET_PERIODIC, 1)) {
1133 		hid_warn(pidff->hid, "unknown periodic effect layout\n");
1134 		clear_bit(FF_PERIODIC, dev->ffbit);
1135 	}
1136 
1137 	PIDFF_FIND_FIELDS(pool, PID_POOL, 0);
1138 
1139 	if (!PIDFF_FIND_FIELDS(device_gain, PID_DEVICE_GAIN, 1))
1140 		set_bit(FF_GAIN, dev->ffbit);
1141 
1142 	return 0;
1143 }
1144 
1145 /*
1146  * Reset the device
1147  */
1148 static void pidff_reset(struct pidff_device *pidff)
1149 {
1150 	struct hid_device *hid = pidff->hid;
1151 	int i = 0;
1152 
1153 	pidff->device_control->value[0] = pidff->control_id[PID_RESET];
1154 	/* We reset twice as sometimes hid_wait_io isn't waiting long enough */
1155 	hid_hw_request(hid, pidff->reports[PID_DEVICE_CONTROL], HID_REQ_SET_REPORT);
1156 	hid_hw_wait(hid);
1157 	hid_hw_request(hid, pidff->reports[PID_DEVICE_CONTROL], HID_REQ_SET_REPORT);
1158 	hid_hw_wait(hid);
1159 
1160 	pidff->device_control->value[0] =
1161 		pidff->control_id[PID_ENABLE_ACTUATORS];
1162 	hid_hw_request(hid, pidff->reports[PID_DEVICE_CONTROL], HID_REQ_SET_REPORT);
1163 	hid_hw_wait(hid);
1164 
1165 	/* pool report is sometimes messed up, refetch it */
1166 	hid_hw_request(hid, pidff->reports[PID_POOL], HID_REQ_GET_REPORT);
1167 	hid_hw_wait(hid);
1168 
1169 	if (pidff->pool[PID_SIMULTANEOUS_MAX].value) {
1170 		while (pidff->pool[PID_SIMULTANEOUS_MAX].value[0] < 2) {
1171 			if (i++ > 20) {
1172 				hid_warn(pidff->hid,
1173 					 "device reports %d simultaneous effects\n",
1174 					 pidff->pool[PID_SIMULTANEOUS_MAX].value[0]);
1175 				break;
1176 			}
1177 			hid_dbg(pidff->hid, "pid_pool requested again\n");
1178 			hid_hw_request(hid, pidff->reports[PID_POOL],
1179 					  HID_REQ_GET_REPORT);
1180 			hid_hw_wait(hid);
1181 		}
1182 	}
1183 }
1184 
1185 /*
1186  * Test if autocenter modification is using the supported method
1187  */
1188 static int pidff_check_autocenter(struct pidff_device *pidff,
1189 				  struct input_dev *dev)
1190 {
1191 	int error;
1192 
1193 	/*
1194 	 * Let's find out if autocenter modification is supported
1195 	 * Specification doesn't specify anything, so we request an
1196 	 * effect upload and cancel it immediately. If the approved
1197 	 * effect id was one above the minimum, then we assume the first
1198 	 * effect id is a built-in spring type effect used for autocenter
1199 	 */
1200 
1201 	error = pidff_request_effect_upload(pidff, 1);
1202 	if (error) {
1203 		hid_err(pidff->hid, "upload request failed\n");
1204 		return error;
1205 	}
1206 
1207 	if (pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0] ==
1208 	    pidff->block_load[PID_EFFECT_BLOCK_INDEX].field->logical_minimum + 1) {
1209 		pidff_autocenter(pidff, 0xffff);
1210 		set_bit(FF_AUTOCENTER, dev->ffbit);
1211 	} else {
1212 		hid_notice(pidff->hid,
1213 			   "device has unknown autocenter control method\n");
1214 	}
1215 
1216 	pidff_erase_pid(pidff,
1217 			pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0]);
1218 
1219 	return 0;
1220 
1221 }
1222 
1223 /*
1224  * Check if the device is PID and initialize it
1225  */
1226 int hid_pidff_init(struct hid_device *hid)
1227 {
1228 	struct pidff_device *pidff;
1229 	struct hid_input *hidinput = list_entry(hid->inputs.next,
1230 						struct hid_input, list);
1231 	struct input_dev *dev = hidinput->input;
1232 	struct ff_device *ff;
1233 	int max_effects;
1234 	int error;
1235 
1236 	hid_dbg(hid, "starting pid init\n");
1237 
1238 	if (list_empty(&hid->report_enum[HID_OUTPUT_REPORT].report_list)) {
1239 		hid_dbg(hid, "not a PID device, no output report\n");
1240 		return -ENODEV;
1241 	}
1242 
1243 	pidff = kzalloc(sizeof(*pidff), GFP_KERNEL);
1244 	if (!pidff)
1245 		return -ENOMEM;
1246 
1247 	pidff->hid = hid;
1248 
1249 	hid_device_io_start(hid);
1250 
1251 	pidff_find_reports(hid, HID_OUTPUT_REPORT, pidff);
1252 	pidff_find_reports(hid, HID_FEATURE_REPORT, pidff);
1253 
1254 	if (!pidff_reports_ok(pidff)) {
1255 		hid_dbg(hid, "reports not ok, aborting\n");
1256 		error = -ENODEV;
1257 		goto fail;
1258 	}
1259 
1260 	error = pidff_init_fields(pidff, dev);
1261 	if (error)
1262 		goto fail;
1263 
1264 	pidff_reset(pidff);
1265 
1266 	if (test_bit(FF_GAIN, dev->ffbit)) {
1267 		pidff_set(&pidff->device_gain[PID_DEVICE_GAIN_FIELD], 0xffff);
1268 		hid_hw_request(hid, pidff->reports[PID_DEVICE_GAIN],
1269 				     HID_REQ_SET_REPORT);
1270 	}
1271 
1272 	error = pidff_check_autocenter(pidff, dev);
1273 	if (error)
1274 		goto fail;
1275 
1276 	max_effects =
1277 	    pidff->block_load[PID_EFFECT_BLOCK_INDEX].field->logical_maximum -
1278 	    pidff->block_load[PID_EFFECT_BLOCK_INDEX].field->logical_minimum +
1279 	    1;
1280 	hid_dbg(hid, "max effects is %d\n", max_effects);
1281 
1282 	if (max_effects > PID_EFFECTS_MAX)
1283 		max_effects = PID_EFFECTS_MAX;
1284 
1285 	if (pidff->pool[PID_SIMULTANEOUS_MAX].value)
1286 		hid_dbg(hid, "max simultaneous effects is %d\n",
1287 			pidff->pool[PID_SIMULTANEOUS_MAX].value[0]);
1288 
1289 	if (pidff->pool[PID_RAM_POOL_SIZE].value)
1290 		hid_dbg(hid, "device memory size is %d bytes\n",
1291 			pidff->pool[PID_RAM_POOL_SIZE].value[0]);
1292 
1293 	if (pidff->pool[PID_DEVICE_MANAGED_POOL].value &&
1294 	    pidff->pool[PID_DEVICE_MANAGED_POOL].value[0] == 0) {
1295 		hid_notice(hid,
1296 			   "device does not support device managed pool\n");
1297 		goto fail;
1298 	}
1299 
1300 	error = input_ff_create(dev, max_effects);
1301 	if (error)
1302 		goto fail;
1303 
1304 	ff = dev->ff;
1305 	ff->private = pidff;
1306 	ff->upload = pidff_upload_effect;
1307 	ff->erase = pidff_erase_effect;
1308 	ff->set_gain = pidff_set_gain;
1309 	ff->set_autocenter = pidff_set_autocenter;
1310 	ff->playback = pidff_playback;
1311 
1312 	hid_info(dev, "Force feedback for USB HID PID devices by Anssi Hannula <anssi.hannula@gmail.com>\n");
1313 
1314 	hid_device_io_stop(hid);
1315 
1316 	return 0;
1317 
1318  fail:
1319 	hid_device_io_stop(hid);
1320 
1321 	kfree(pidff);
1322 	return error;
1323 }
1324