xref: /openbmc/linux/drivers/hid/hid-steam.c (revision f9a82c48)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * HID driver for Valve Steam Controller
4  *
5  * Copyright (c) 2018 Rodrigo Rivas Costa <rodrigorivascosta@gmail.com>
6  *
7  * Supports both the wired and wireless interfaces.
8  *
9  * This controller has a builtin emulation of mouse and keyboard: the right pad
10  * can be used as a mouse, the shoulder buttons are mouse buttons, A and B
11  * buttons are ENTER and ESCAPE, and so on. This is implemented as additional
12  * HID interfaces.
13  *
14  * This is known as the "lizard mode", because apparently lizards like to use
15  * the computer from the coach, without a proper mouse and keyboard.
16  *
17  * This driver will disable the lizard mode when the input device is opened
18  * and re-enable it when the input device is closed, so as not to break user
19  * mode behaviour. The lizard_mode parameter can be used to change that.
20  *
21  * There are a few user space applications (notably Steam Client) that use
22  * the hidraw interface directly to create input devices (XTest, uinput...).
23  * In order to avoid breaking them this driver creates a layered hidraw device,
24  * so it can detect when the client is running and then:
25  *  - it will not send any command to the controller.
26  *  - this input device will be removed, to avoid double input of the same
27  *    user action.
28  * When the client is closed, this input device will be created again.
29  *
30  * For additional functions, such as changing the right-pad margin or switching
31  * the led, you can use the user-space tool at:
32  *
33  *   https://github.com/rodrigorc/steamctrl
34  */
35 
36 #include <linux/device.h>
37 #include <linux/input.h>
38 #include <linux/hid.h>
39 #include <linux/module.h>
40 #include <linux/workqueue.h>
41 #include <linux/mutex.h>
42 #include <linux/rcupdate.h>
43 #include <linux/delay.h>
44 #include <linux/power_supply.h>
45 #include "hid-ids.h"
46 
47 MODULE_LICENSE("GPL");
48 MODULE_AUTHOR("Rodrigo Rivas Costa <rodrigorivascosta@gmail.com>");
49 
50 static bool lizard_mode = true;
51 
52 static DEFINE_MUTEX(steam_devices_lock);
53 static LIST_HEAD(steam_devices);
54 
55 #define STEAM_QUIRK_WIRELESS		BIT(0)
56 
57 /* Touch pads are 40 mm in diameter and 65535 units */
58 #define STEAM_PAD_RESOLUTION 1638
59 /* Trigger runs are about 5 mm and 256 units */
60 #define STEAM_TRIGGER_RESOLUTION 51
61 /* Joystick runs are about 5 mm and 256 units */
62 #define STEAM_JOYSTICK_RESOLUTION 51
63 
64 #define STEAM_PAD_FUZZ 256
65 
66 /*
67  * Commands that can be sent in a feature report.
68  * Thanks to Valve for some valuable hints.
69  */
70 #define STEAM_CMD_SET_MAPPINGS		0x80
71 #define STEAM_CMD_CLEAR_MAPPINGS	0x81
72 #define STEAM_CMD_GET_MAPPINGS		0x82
73 #define STEAM_CMD_GET_ATTRIB		0x83
74 #define STEAM_CMD_GET_ATTRIB_LABEL	0x84
75 #define STEAM_CMD_DEFAULT_MAPPINGS	0x85
76 #define STEAM_CMD_FACTORY_RESET		0x86
77 #define STEAM_CMD_WRITE_REGISTER	0x87
78 #define STEAM_CMD_CLEAR_REGISTER	0x88
79 #define STEAM_CMD_READ_REGISTER		0x89
80 #define STEAM_CMD_GET_REGISTER_LABEL	0x8a
81 #define STEAM_CMD_GET_REGISTER_MAX	0x8b
82 #define STEAM_CMD_GET_REGISTER_DEFAULT	0x8c
83 #define STEAM_CMD_SET_MODE		0x8d
84 #define STEAM_CMD_DEFAULT_MOUSE		0x8e
85 #define STEAM_CMD_FORCEFEEDBAK		0x8f
86 #define STEAM_CMD_REQUEST_COMM_STATUS	0xb4
87 #define STEAM_CMD_GET_SERIAL		0xae
88 
89 /* Some useful register ids */
90 #define STEAM_REG_LPAD_MODE		0x07
91 #define STEAM_REG_RPAD_MODE		0x08
92 #define STEAM_REG_RPAD_MARGIN		0x18
93 #define STEAM_REG_LED			0x2d
94 #define STEAM_REG_GYRO_MODE		0x30
95 
96 /* Raw event identifiers */
97 #define STEAM_EV_INPUT_DATA		0x01
98 #define STEAM_EV_CONNECT		0x03
99 #define STEAM_EV_BATTERY		0x04
100 
101 /* Values for GYRO_MODE (bitmask) */
102 #define STEAM_GYRO_MODE_OFF		0x0000
103 #define STEAM_GYRO_MODE_STEERING	0x0001
104 #define STEAM_GYRO_MODE_TILT		0x0002
105 #define STEAM_GYRO_MODE_SEND_ORIENTATION	0x0004
106 #define STEAM_GYRO_MODE_SEND_RAW_ACCEL		0x0008
107 #define STEAM_GYRO_MODE_SEND_RAW_GYRO		0x0010
108 
109 /* Other random constants */
110 #define STEAM_SERIAL_LEN 10
111 
112 struct steam_device {
113 	struct list_head list;
114 	spinlock_t lock;
115 	struct hid_device *hdev, *client_hdev;
116 	struct mutex mutex;
117 	bool client_opened;
118 	struct input_dev __rcu *input;
119 	unsigned long quirks;
120 	struct work_struct work_connect;
121 	bool connected;
122 	char serial_no[STEAM_SERIAL_LEN + 1];
123 	struct power_supply_desc battery_desc;
124 	struct power_supply __rcu *battery;
125 	u8 battery_charge;
126 	u16 voltage;
127 };
128 
129 static int steam_recv_report(struct steam_device *steam,
130 		u8 *data, int size)
131 {
132 	struct hid_report *r;
133 	u8 *buf;
134 	int ret;
135 
136 	r = steam->hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0];
137 	if (hid_report_len(r) < 64)
138 		return -EINVAL;
139 
140 	buf = hid_alloc_report_buf(r, GFP_KERNEL);
141 	if (!buf)
142 		return -ENOMEM;
143 
144 	/*
145 	 * The report ID is always 0, so strip the first byte from the output.
146 	 * hid_report_len() is not counting the report ID, so +1 to the length
147 	 * or else we get a EOVERFLOW. We are safe from a buffer overflow
148 	 * because hid_alloc_report_buf() allocates +7 bytes.
149 	 */
150 	ret = hid_hw_raw_request(steam->hdev, 0x00,
151 			buf, hid_report_len(r) + 1,
152 			HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
153 	if (ret > 0)
154 		memcpy(data, buf + 1, min(size, ret - 1));
155 	kfree(buf);
156 	return ret;
157 }
158 
159 static int steam_send_report(struct steam_device *steam,
160 		u8 *cmd, int size)
161 {
162 	struct hid_report *r;
163 	u8 *buf;
164 	unsigned int retries = 50;
165 	int ret;
166 
167 	r = steam->hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0];
168 	if (hid_report_len(r) < 64)
169 		return -EINVAL;
170 
171 	buf = hid_alloc_report_buf(r, GFP_KERNEL);
172 	if (!buf)
173 		return -ENOMEM;
174 
175 	/* The report ID is always 0 */
176 	memcpy(buf + 1, cmd, size);
177 
178 	/*
179 	 * Sometimes the wireless controller fails with EPIPE
180 	 * when sending a feature report.
181 	 * Doing a HID_REQ_GET_REPORT and waiting for a while
182 	 * seems to fix that.
183 	 */
184 	do {
185 		ret = hid_hw_raw_request(steam->hdev, 0,
186 				buf, size + 1,
187 				HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
188 		if (ret != -EPIPE)
189 			break;
190 		msleep(20);
191 	} while (--retries);
192 
193 	kfree(buf);
194 	if (ret < 0)
195 		hid_err(steam->hdev, "%s: error %d (%*ph)\n", __func__,
196 				ret, size, cmd);
197 	return ret;
198 }
199 
200 static inline int steam_send_report_byte(struct steam_device *steam, u8 cmd)
201 {
202 	return steam_send_report(steam, &cmd, 1);
203 }
204 
205 static int steam_write_registers(struct steam_device *steam,
206 		/* u8 reg, u16 val */...)
207 {
208 	/* Send: 0x87 len (reg valLo valHi)* */
209 	u8 reg;
210 	u16 val;
211 	u8 cmd[64] = {STEAM_CMD_WRITE_REGISTER, 0x00};
212 	va_list args;
213 
214 	va_start(args, steam);
215 	for (;;) {
216 		reg = va_arg(args, int);
217 		if (reg == 0)
218 			break;
219 		val = va_arg(args, int);
220 		cmd[cmd[1] + 2] = reg;
221 		cmd[cmd[1] + 3] = val & 0xff;
222 		cmd[cmd[1] + 4] = val >> 8;
223 		cmd[1] += 3;
224 	}
225 	va_end(args);
226 
227 	return steam_send_report(steam, cmd, 2 + cmd[1]);
228 }
229 
230 static int steam_get_serial(struct steam_device *steam)
231 {
232 	/*
233 	 * Send: 0xae 0x15 0x01
234 	 * Recv: 0xae 0x15 0x01 serialnumber (10 chars)
235 	 */
236 	int ret;
237 	u8 cmd[] = {STEAM_CMD_GET_SERIAL, 0x15, 0x01};
238 	u8 reply[3 + STEAM_SERIAL_LEN + 1];
239 
240 	ret = steam_send_report(steam, cmd, sizeof(cmd));
241 	if (ret < 0)
242 		return ret;
243 	ret = steam_recv_report(steam, reply, sizeof(reply));
244 	if (ret < 0)
245 		return ret;
246 	if (reply[0] != 0xae || reply[1] != 0x15 || reply[2] != 0x01)
247 		return -EIO;
248 	reply[3 + STEAM_SERIAL_LEN] = 0;
249 	strlcpy(steam->serial_no, reply + 3, sizeof(steam->serial_no));
250 	return 0;
251 }
252 
253 /*
254  * This command requests the wireless adaptor to post an event
255  * with the connection status. Useful if this driver is loaded when
256  * the controller is already connected.
257  */
258 static inline int steam_request_conn_status(struct steam_device *steam)
259 {
260 	return steam_send_report_byte(steam, STEAM_CMD_REQUEST_COMM_STATUS);
261 }
262 
263 static void steam_set_lizard_mode(struct steam_device *steam, bool enable)
264 {
265 	if (enable) {
266 		/* enable esc, enter, cursors */
267 		steam_send_report_byte(steam, STEAM_CMD_DEFAULT_MAPPINGS);
268 		/* enable mouse */
269 		steam_send_report_byte(steam, STEAM_CMD_DEFAULT_MOUSE);
270 		steam_write_registers(steam,
271 			STEAM_REG_RPAD_MARGIN, 0x01, /* enable margin */
272 			0);
273 	} else {
274 		/* disable esc, enter, cursor */
275 		steam_send_report_byte(steam, STEAM_CMD_CLEAR_MAPPINGS);
276 		steam_write_registers(steam,
277 			STEAM_REG_RPAD_MODE, 0x07, /* disable mouse */
278 			STEAM_REG_RPAD_MARGIN, 0x00, /* disable margin */
279 			0);
280 	}
281 }
282 
283 static int steam_input_open(struct input_dev *dev)
284 {
285 	struct steam_device *steam = input_get_drvdata(dev);
286 
287 	mutex_lock(&steam->mutex);
288 	if (!steam->client_opened && lizard_mode)
289 		steam_set_lizard_mode(steam, false);
290 	mutex_unlock(&steam->mutex);
291 	return 0;
292 }
293 
294 static void steam_input_close(struct input_dev *dev)
295 {
296 	struct steam_device *steam = input_get_drvdata(dev);
297 
298 	mutex_lock(&steam->mutex);
299 	if (!steam->client_opened && lizard_mode)
300 		steam_set_lizard_mode(steam, true);
301 	mutex_unlock(&steam->mutex);
302 }
303 
304 static enum power_supply_property steam_battery_props[] = {
305 	POWER_SUPPLY_PROP_PRESENT,
306 	POWER_SUPPLY_PROP_SCOPE,
307 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
308 	POWER_SUPPLY_PROP_CAPACITY,
309 };
310 
311 static int steam_battery_get_property(struct power_supply *psy,
312 				enum power_supply_property psp,
313 				union power_supply_propval *val)
314 {
315 	struct steam_device *steam = power_supply_get_drvdata(psy);
316 	unsigned long flags;
317 	s16 volts;
318 	u8 batt;
319 	int ret = 0;
320 
321 	spin_lock_irqsave(&steam->lock, flags);
322 	volts = steam->voltage;
323 	batt = steam->battery_charge;
324 	spin_unlock_irqrestore(&steam->lock, flags);
325 
326 	switch (psp) {
327 	case POWER_SUPPLY_PROP_PRESENT:
328 		val->intval = 1;
329 		break;
330 	case POWER_SUPPLY_PROP_SCOPE:
331 		val->intval = POWER_SUPPLY_SCOPE_DEVICE;
332 		break;
333 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
334 		val->intval = volts * 1000; /* mV -> uV */
335 		break;
336 	case POWER_SUPPLY_PROP_CAPACITY:
337 		val->intval = batt;
338 		break;
339 	default:
340 		ret = -EINVAL;
341 		break;
342 	}
343 	return ret;
344 }
345 
346 static int steam_battery_register(struct steam_device *steam)
347 {
348 	struct power_supply *battery;
349 	struct power_supply_config battery_cfg = { .drv_data = steam, };
350 	unsigned long flags;
351 	int ret;
352 
353 	steam->battery_desc.type = POWER_SUPPLY_TYPE_BATTERY;
354 	steam->battery_desc.properties = steam_battery_props;
355 	steam->battery_desc.num_properties = ARRAY_SIZE(steam_battery_props);
356 	steam->battery_desc.get_property = steam_battery_get_property;
357 	steam->battery_desc.name = devm_kasprintf(&steam->hdev->dev,
358 			GFP_KERNEL, "steam-controller-%s-battery",
359 			steam->serial_no);
360 	if (!steam->battery_desc.name)
361 		return -ENOMEM;
362 
363 	/* avoid the warning of 0% battery while waiting for the first info */
364 	spin_lock_irqsave(&steam->lock, flags);
365 	steam->voltage = 3000;
366 	steam->battery_charge = 100;
367 	spin_unlock_irqrestore(&steam->lock, flags);
368 
369 	battery = power_supply_register(&steam->hdev->dev,
370 			&steam->battery_desc, &battery_cfg);
371 	if (IS_ERR(battery)) {
372 		ret = PTR_ERR(battery);
373 		hid_err(steam->hdev,
374 				"%s:power_supply_register failed with error %d\n",
375 				__func__, ret);
376 		return ret;
377 	}
378 	rcu_assign_pointer(steam->battery, battery);
379 	power_supply_powers(battery, &steam->hdev->dev);
380 	return 0;
381 }
382 
383 static int steam_input_register(struct steam_device *steam)
384 {
385 	struct hid_device *hdev = steam->hdev;
386 	struct input_dev *input;
387 	int ret;
388 
389 	rcu_read_lock();
390 	input = rcu_dereference(steam->input);
391 	rcu_read_unlock();
392 	if (input) {
393 		dbg_hid("%s: already connected\n", __func__);
394 		return 0;
395 	}
396 
397 	input = input_allocate_device();
398 	if (!input)
399 		return -ENOMEM;
400 
401 	input_set_drvdata(input, steam);
402 	input->dev.parent = &hdev->dev;
403 	input->open = steam_input_open;
404 	input->close = steam_input_close;
405 
406 	input->name = (steam->quirks & STEAM_QUIRK_WIRELESS) ?
407 		"Wireless Steam Controller" :
408 		"Steam Controller";
409 	input->phys = hdev->phys;
410 	input->uniq = steam->serial_no;
411 	input->id.bustype = hdev->bus;
412 	input->id.vendor = hdev->vendor;
413 	input->id.product = hdev->product;
414 	input->id.version = hdev->version;
415 
416 	input_set_capability(input, EV_KEY, BTN_TR2);
417 	input_set_capability(input, EV_KEY, BTN_TL2);
418 	input_set_capability(input, EV_KEY, BTN_TR);
419 	input_set_capability(input, EV_KEY, BTN_TL);
420 	input_set_capability(input, EV_KEY, BTN_Y);
421 	input_set_capability(input, EV_KEY, BTN_B);
422 	input_set_capability(input, EV_KEY, BTN_X);
423 	input_set_capability(input, EV_KEY, BTN_A);
424 	input_set_capability(input, EV_KEY, BTN_DPAD_UP);
425 	input_set_capability(input, EV_KEY, BTN_DPAD_RIGHT);
426 	input_set_capability(input, EV_KEY, BTN_DPAD_LEFT);
427 	input_set_capability(input, EV_KEY, BTN_DPAD_DOWN);
428 	input_set_capability(input, EV_KEY, BTN_SELECT);
429 	input_set_capability(input, EV_KEY, BTN_MODE);
430 	input_set_capability(input, EV_KEY, BTN_START);
431 	input_set_capability(input, EV_KEY, BTN_GEAR_DOWN);
432 	input_set_capability(input, EV_KEY, BTN_GEAR_UP);
433 	input_set_capability(input, EV_KEY, BTN_THUMBR);
434 	input_set_capability(input, EV_KEY, BTN_THUMBL);
435 	input_set_capability(input, EV_KEY, BTN_THUMB);
436 	input_set_capability(input, EV_KEY, BTN_THUMB2);
437 
438 	input_set_abs_params(input, ABS_HAT2Y, 0, 255, 0, 0);
439 	input_set_abs_params(input, ABS_HAT2X, 0, 255, 0, 0);
440 	input_set_abs_params(input, ABS_X, -32767, 32767, 0, 0);
441 	input_set_abs_params(input, ABS_Y, -32767, 32767, 0, 0);
442 	input_set_abs_params(input, ABS_RX, -32767, 32767,
443 			STEAM_PAD_FUZZ, 0);
444 	input_set_abs_params(input, ABS_RY, -32767, 32767,
445 			STEAM_PAD_FUZZ, 0);
446 	input_set_abs_params(input, ABS_HAT0X, -32767, 32767,
447 			STEAM_PAD_FUZZ, 0);
448 	input_set_abs_params(input, ABS_HAT0Y, -32767, 32767,
449 			STEAM_PAD_FUZZ, 0);
450 	input_abs_set_res(input, ABS_X, STEAM_JOYSTICK_RESOLUTION);
451 	input_abs_set_res(input, ABS_Y, STEAM_JOYSTICK_RESOLUTION);
452 	input_abs_set_res(input, ABS_RX, STEAM_PAD_RESOLUTION);
453 	input_abs_set_res(input, ABS_RY, STEAM_PAD_RESOLUTION);
454 	input_abs_set_res(input, ABS_HAT0X, STEAM_PAD_RESOLUTION);
455 	input_abs_set_res(input, ABS_HAT0Y, STEAM_PAD_RESOLUTION);
456 	input_abs_set_res(input, ABS_HAT2Y, STEAM_TRIGGER_RESOLUTION);
457 	input_abs_set_res(input, ABS_HAT2X, STEAM_TRIGGER_RESOLUTION);
458 
459 	ret = input_register_device(input);
460 	if (ret)
461 		goto input_register_fail;
462 
463 	rcu_assign_pointer(steam->input, input);
464 	return 0;
465 
466 input_register_fail:
467 	input_free_device(input);
468 	return ret;
469 }
470 
471 static void steam_input_unregister(struct steam_device *steam)
472 {
473 	struct input_dev *input;
474 	rcu_read_lock();
475 	input = rcu_dereference(steam->input);
476 	rcu_read_unlock();
477 	if (!input)
478 		return;
479 	RCU_INIT_POINTER(steam->input, NULL);
480 	synchronize_rcu();
481 	input_unregister_device(input);
482 }
483 
484 static void steam_battery_unregister(struct steam_device *steam)
485 {
486 	struct power_supply *battery;
487 
488 	rcu_read_lock();
489 	battery = rcu_dereference(steam->battery);
490 	rcu_read_unlock();
491 
492 	if (!battery)
493 		return;
494 	RCU_INIT_POINTER(steam->battery, NULL);
495 	synchronize_rcu();
496 	power_supply_unregister(battery);
497 }
498 
499 static int steam_register(struct steam_device *steam)
500 {
501 	int ret;
502 
503 	/*
504 	 * This function can be called several times in a row with the
505 	 * wireless adaptor, without steam_unregister() between them, because
506 	 * another client send a get_connection_status command, for example.
507 	 * The battery and serial number are set just once per device.
508 	 */
509 	if (!steam->serial_no[0]) {
510 		/*
511 		 * Unlikely, but getting the serial could fail, and it is not so
512 		 * important, so make up a serial number and go on.
513 		 */
514 		if (steam_get_serial(steam) < 0)
515 			strlcpy(steam->serial_no, "XXXXXXXXXX",
516 					sizeof(steam->serial_no));
517 
518 		hid_info(steam->hdev, "Steam Controller '%s' connected",
519 				steam->serial_no);
520 
521 		/* ignore battery errors, we can live without it */
522 		if (steam->quirks & STEAM_QUIRK_WIRELESS)
523 			steam_battery_register(steam);
524 
525 		mutex_lock(&steam_devices_lock);
526 		list_add(&steam->list, &steam_devices);
527 		mutex_unlock(&steam_devices_lock);
528 	}
529 
530 	mutex_lock(&steam->mutex);
531 	if (!steam->client_opened) {
532 		steam_set_lizard_mode(steam, lizard_mode);
533 		ret = steam_input_register(steam);
534 	} else {
535 		ret = 0;
536 	}
537 	mutex_unlock(&steam->mutex);
538 
539 	return ret;
540 }
541 
542 static void steam_unregister(struct steam_device *steam)
543 {
544 	steam_battery_unregister(steam);
545 	steam_input_unregister(steam);
546 	if (steam->serial_no[0]) {
547 		hid_info(steam->hdev, "Steam Controller '%s' disconnected",
548 				steam->serial_no);
549 		mutex_lock(&steam_devices_lock);
550 		list_del(&steam->list);
551 		mutex_unlock(&steam_devices_lock);
552 		steam->serial_no[0] = 0;
553 	}
554 }
555 
556 static void steam_work_connect_cb(struct work_struct *work)
557 {
558 	struct steam_device *steam = container_of(work, struct steam_device,
559 							work_connect);
560 	unsigned long flags;
561 	bool connected;
562 	int ret;
563 
564 	spin_lock_irqsave(&steam->lock, flags);
565 	connected = steam->connected;
566 	spin_unlock_irqrestore(&steam->lock, flags);
567 
568 	if (connected) {
569 		ret = steam_register(steam);
570 		if (ret) {
571 			hid_err(steam->hdev,
572 				"%s:steam_register failed with error %d\n",
573 				__func__, ret);
574 		}
575 	} else {
576 		steam_unregister(steam);
577 	}
578 }
579 
580 static bool steam_is_valve_interface(struct hid_device *hdev)
581 {
582 	struct hid_report_enum *rep_enum;
583 
584 	/*
585 	 * The wired device creates 3 interfaces:
586 	 *  0: emulated mouse.
587 	 *  1: emulated keyboard.
588 	 *  2: the real game pad.
589 	 * The wireless device creates 5 interfaces:
590 	 *  0: emulated keyboard.
591 	 *  1-4: slots where up to 4 real game pads will be connected to.
592 	 * We know which one is the real gamepad interface because they are the
593 	 * only ones with a feature report.
594 	 */
595 	rep_enum = &hdev->report_enum[HID_FEATURE_REPORT];
596 	return !list_empty(&rep_enum->report_list);
597 }
598 
599 static int steam_client_ll_parse(struct hid_device *hdev)
600 {
601 	struct steam_device *steam = hdev->driver_data;
602 
603 	return hid_parse_report(hdev, steam->hdev->dev_rdesc,
604 			steam->hdev->dev_rsize);
605 }
606 
607 static int steam_client_ll_start(struct hid_device *hdev)
608 {
609 	return 0;
610 }
611 
612 static void steam_client_ll_stop(struct hid_device *hdev)
613 {
614 }
615 
616 static int steam_client_ll_open(struct hid_device *hdev)
617 {
618 	struct steam_device *steam = hdev->driver_data;
619 
620 	mutex_lock(&steam->mutex);
621 	steam->client_opened = true;
622 	mutex_unlock(&steam->mutex);
623 
624 	steam_input_unregister(steam);
625 
626 	return 0;
627 }
628 
629 static void steam_client_ll_close(struct hid_device *hdev)
630 {
631 	struct steam_device *steam = hdev->driver_data;
632 
633 	mutex_lock(&steam->mutex);
634 	steam->client_opened = false;
635 	mutex_unlock(&steam->mutex);
636 
637 	if (steam->connected) {
638 		steam_set_lizard_mode(steam, lizard_mode);
639 		steam_input_register(steam);
640 	}
641 }
642 
643 static int steam_client_ll_raw_request(struct hid_device *hdev,
644 				unsigned char reportnum, u8 *buf,
645 				size_t count, unsigned char report_type,
646 				int reqtype)
647 {
648 	struct steam_device *steam = hdev->driver_data;
649 
650 	return hid_hw_raw_request(steam->hdev, reportnum, buf, count,
651 			report_type, reqtype);
652 }
653 
654 static struct hid_ll_driver steam_client_ll_driver = {
655 	.parse = steam_client_ll_parse,
656 	.start = steam_client_ll_start,
657 	.stop = steam_client_ll_stop,
658 	.open = steam_client_ll_open,
659 	.close = steam_client_ll_close,
660 	.raw_request = steam_client_ll_raw_request,
661 };
662 
663 static struct hid_device *steam_create_client_hid(struct hid_device *hdev)
664 {
665 	struct hid_device *client_hdev;
666 
667 	client_hdev = hid_allocate_device();
668 	if (IS_ERR(client_hdev))
669 		return client_hdev;
670 
671 	client_hdev->ll_driver = &steam_client_ll_driver;
672 	client_hdev->dev.parent = hdev->dev.parent;
673 	client_hdev->bus = hdev->bus;
674 	client_hdev->vendor = hdev->vendor;
675 	client_hdev->product = hdev->product;
676 	client_hdev->version = hdev->version;
677 	client_hdev->type = hdev->type;
678 	client_hdev->country = hdev->country;
679 	strlcpy(client_hdev->name, hdev->name,
680 			sizeof(client_hdev->name));
681 	strlcpy(client_hdev->phys, hdev->phys,
682 			sizeof(client_hdev->phys));
683 	/*
684 	 * Since we use the same device info than the real interface to
685 	 * trick userspace, we will be calling steam_probe recursively.
686 	 * We need to recognize the client interface somehow.
687 	 */
688 	client_hdev->group = HID_GROUP_STEAM;
689 	return client_hdev;
690 }
691 
692 static int steam_probe(struct hid_device *hdev,
693 				const struct hid_device_id *id)
694 {
695 	struct steam_device *steam;
696 	int ret;
697 
698 	ret = hid_parse(hdev);
699 	if (ret) {
700 		hid_err(hdev,
701 			"%s:parse of hid interface failed\n", __func__);
702 		return ret;
703 	}
704 
705 	/*
706 	 * The virtual client_dev is only used for hidraw.
707 	 * Also avoid the recursive probe.
708 	 */
709 	if (hdev->group == HID_GROUP_STEAM)
710 		return hid_hw_start(hdev, HID_CONNECT_HIDRAW);
711 	/*
712 	 * The non-valve interfaces (mouse and keyboard emulation) are
713 	 * connected without changes.
714 	 */
715 	if (!steam_is_valve_interface(hdev))
716 		return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
717 
718 	steam = devm_kzalloc(&hdev->dev, sizeof(*steam), GFP_KERNEL);
719 	if (!steam) {
720 		ret = -ENOMEM;
721 		goto steam_alloc_fail;
722 	}
723 	steam->hdev = hdev;
724 	hid_set_drvdata(hdev, steam);
725 	spin_lock_init(&steam->lock);
726 	mutex_init(&steam->mutex);
727 	steam->quirks = id->driver_data;
728 	INIT_WORK(&steam->work_connect, steam_work_connect_cb);
729 
730 	steam->client_hdev = steam_create_client_hid(hdev);
731 	if (IS_ERR(steam->client_hdev)) {
732 		ret = PTR_ERR(steam->client_hdev);
733 		goto client_hdev_fail;
734 	}
735 	steam->client_hdev->driver_data = steam;
736 
737 	/*
738 	 * With the real steam controller interface, do not connect hidraw.
739 	 * Instead, create the client_hid and connect that.
740 	 */
741 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_HIDRAW);
742 	if (ret)
743 		goto hid_hw_start_fail;
744 
745 	ret = hid_add_device(steam->client_hdev);
746 	if (ret)
747 		goto client_hdev_add_fail;
748 
749 	ret = hid_hw_open(hdev);
750 	if (ret) {
751 		hid_err(hdev,
752 			"%s:hid_hw_open\n",
753 			__func__);
754 		goto hid_hw_open_fail;
755 	}
756 
757 	if (steam->quirks & STEAM_QUIRK_WIRELESS) {
758 		hid_info(hdev, "Steam wireless receiver connected");
759 		steam_request_conn_status(steam);
760 	} else {
761 		ret = steam_register(steam);
762 		if (ret) {
763 			hid_err(hdev,
764 				"%s:steam_register failed with error %d\n",
765 				__func__, ret);
766 			goto input_register_fail;
767 		}
768 	}
769 
770 	return 0;
771 
772 input_register_fail:
773 hid_hw_open_fail:
774 client_hdev_add_fail:
775 	hid_hw_stop(hdev);
776 hid_hw_start_fail:
777 	hid_destroy_device(steam->client_hdev);
778 client_hdev_fail:
779 	cancel_work_sync(&steam->work_connect);
780 steam_alloc_fail:
781 	hid_err(hdev, "%s: failed with error %d\n",
782 			__func__, ret);
783 	return ret;
784 }
785 
786 static void steam_remove(struct hid_device *hdev)
787 {
788 	struct steam_device *steam = hid_get_drvdata(hdev);
789 
790 	if (!steam || hdev->group == HID_GROUP_STEAM) {
791 		hid_hw_stop(hdev);
792 		return;
793 	}
794 
795 	hid_destroy_device(steam->client_hdev);
796 	steam->client_opened = false;
797 	cancel_work_sync(&steam->work_connect);
798 	if (steam->quirks & STEAM_QUIRK_WIRELESS) {
799 		hid_info(hdev, "Steam wireless receiver disconnected");
800 	}
801 	hid_hw_close(hdev);
802 	hid_hw_stop(hdev);
803 	steam_unregister(steam);
804 }
805 
806 static void steam_do_connect_event(struct steam_device *steam, bool connected)
807 {
808 	unsigned long flags;
809 	bool changed;
810 
811 	spin_lock_irqsave(&steam->lock, flags);
812 	changed = steam->connected != connected;
813 	steam->connected = connected;
814 	spin_unlock_irqrestore(&steam->lock, flags);
815 
816 	if (changed && schedule_work(&steam->work_connect) == 0)
817 		dbg_hid("%s: connected=%d event already queued\n",
818 				__func__, connected);
819 }
820 
821 /*
822  * Some input data in the protocol has the opposite sign.
823  * Clamp the values to 32767..-32767 so that the range is
824  * symmetrical and can be negated safely.
825  */
826 static inline s16 steam_le16(u8 *data)
827 {
828 	s16 x = (s16) le16_to_cpup((__le16 *)data);
829 
830 	return x == -32768 ? -32767 : x;
831 }
832 
833 /*
834  * The size for this message payload is 60.
835  * The known values are:
836  *  (* values are not sent through wireless)
837  *  (* accelerator/gyro is disabled by default)
838  *  Offset| Type  | Mapped to |Meaning
839  * -------+-------+-----------+--------------------------
840  *  4-7   | u32   | --        | sequence number
841  *  8-10  | 24bit | see below | buttons
842  *  11    | u8    | ABS_HAT2Y | left trigger
843  *  12    | u8    | ABS_HAT2X | right trigger
844  *  13-15 | --    | --        | always 0
845  *  16-17 | s16   | ABS_X/ABS_HAT0X     | X value
846  *  18-19 | s16   | ABS_Y/ABS_HAT0Y     | Y value
847  *  20-21 | s16   | ABS_RX    | right-pad X value
848  *  22-23 | s16   | ABS_RY    | right-pad Y value
849  *  24-25 | s16   | --        | * left trigger
850  *  26-27 | s16   | --        | * right trigger
851  *  28-29 | s16   | --        | * accelerometer X value
852  *  30-31 | s16   | --        | * accelerometer Y value
853  *  32-33 | s16   | --        | * accelerometer Z value
854  *  34-35 | s16   | --        | gyro X value
855  *  36-36 | s16   | --        | gyro Y value
856  *  38-39 | s16   | --        | gyro Z value
857  *  40-41 | s16   | --        | quaternion W value
858  *  42-43 | s16   | --        | quaternion X value
859  *  44-45 | s16   | --        | quaternion Y value
860  *  46-47 | s16   | --        | quaternion Z value
861  *  48-49 | --    | --        | always 0
862  *  50-51 | s16   | --        | * left trigger (uncalibrated)
863  *  52-53 | s16   | --        | * right trigger (uncalibrated)
864  *  54-55 | s16   | --        | * joystick X value (uncalibrated)
865  *  56-57 | s16   | --        | * joystick Y value (uncalibrated)
866  *  58-59 | s16   | --        | * left-pad X value
867  *  60-61 | s16   | --        | * left-pad Y value
868  *  62-63 | u16   | --        | * battery voltage
869  *
870  * The buttons are:
871  *  Bit  | Mapped to  | Description
872  * ------+------------+--------------------------------
873  *  8.0  | BTN_TR2    | right trigger fully pressed
874  *  8.1  | BTN_TL2    | left trigger fully pressed
875  *  8.2  | BTN_TR     | right shoulder
876  *  8.3  | BTN_TL     | left shoulder
877  *  8.4  | BTN_Y      | button Y
878  *  8.5  | BTN_B      | button B
879  *  8.6  | BTN_X      | button X
880  *  8.7  | BTN_A      | button A
881  *  9.0  | BTN_DPAD_UP    | lef-pad up
882  *  9.1  | BTN_DPAD_RIGHT | lef-pad right
883  *  9.2  | BTN_DPAD_LEFT  | lef-pad left
884  *  9.3  | BTN_DPAD_DOWN  | lef-pad down
885  *  9.4  | BTN_SELECT | menu left
886  *  9.5  | BTN_MODE   | steam logo
887  *  9.6  | BTN_START  | menu right
888  *  9.7  | BTN_GEAR_DOWN | left back lever
889  * 10.0  | BTN_GEAR_UP   | right back lever
890  * 10.1  | --         | left-pad clicked
891  * 10.2  | BTN_THUMBR | right-pad clicked
892  * 10.3  | BTN_THUMB  | left-pad touched (but see explanation below)
893  * 10.4  | BTN_THUMB2 | right-pad touched
894  * 10.5  | --         | unknown
895  * 10.6  | BTN_THUMBL | joystick clicked
896  * 10.7  | --         | lpad_and_joy
897  */
898 
899 static void steam_do_input_event(struct steam_device *steam,
900 		struct input_dev *input, u8 *data)
901 {
902 	/* 24 bits of buttons */
903 	u8 b8, b9, b10;
904 	s16 x, y;
905 	bool lpad_touched, lpad_and_joy;
906 
907 	b8 = data[8];
908 	b9 = data[9];
909 	b10 = data[10];
910 
911 	input_report_abs(input, ABS_HAT2Y, data[11]);
912 	input_report_abs(input, ABS_HAT2X, data[12]);
913 
914 	/*
915 	 * These two bits tells how to interpret the values X and Y.
916 	 * lpad_and_joy tells that the joystick and the lpad are used at the
917 	 * same time.
918 	 * lpad_touched tells whether X/Y are to be read as lpad coord or
919 	 * joystick values.
920 	 * (lpad_touched || lpad_and_joy) tells if the lpad is really touched.
921 	 */
922 	lpad_touched = b10 & BIT(3);
923 	lpad_and_joy = b10 & BIT(7);
924 	x = steam_le16(data + 16);
925 	y = -steam_le16(data + 18);
926 
927 	input_report_abs(input, lpad_touched ? ABS_HAT0X : ABS_X, x);
928 	input_report_abs(input, lpad_touched ? ABS_HAT0Y : ABS_Y, y);
929 	/* Check if joystick is centered */
930 	if (lpad_touched && !lpad_and_joy) {
931 		input_report_abs(input, ABS_X, 0);
932 		input_report_abs(input, ABS_Y, 0);
933 	}
934 	/* Check if lpad is untouched */
935 	if (!(lpad_touched || lpad_and_joy)) {
936 		input_report_abs(input, ABS_HAT0X, 0);
937 		input_report_abs(input, ABS_HAT0Y, 0);
938 	}
939 
940 	input_report_abs(input, ABS_RX, steam_le16(data + 20));
941 	input_report_abs(input, ABS_RY, -steam_le16(data + 22));
942 
943 	input_event(input, EV_KEY, BTN_TR2, !!(b8 & BIT(0)));
944 	input_event(input, EV_KEY, BTN_TL2, !!(b8 & BIT(1)));
945 	input_event(input, EV_KEY, BTN_TR, !!(b8 & BIT(2)));
946 	input_event(input, EV_KEY, BTN_TL, !!(b8 & BIT(3)));
947 	input_event(input, EV_KEY, BTN_Y, !!(b8 & BIT(4)));
948 	input_event(input, EV_KEY, BTN_B, !!(b8 & BIT(5)));
949 	input_event(input, EV_KEY, BTN_X, !!(b8 & BIT(6)));
950 	input_event(input, EV_KEY, BTN_A, !!(b8 & BIT(7)));
951 	input_event(input, EV_KEY, BTN_SELECT, !!(b9 & BIT(4)));
952 	input_event(input, EV_KEY, BTN_MODE, !!(b9 & BIT(5)));
953 	input_event(input, EV_KEY, BTN_START, !!(b9 & BIT(6)));
954 	input_event(input, EV_KEY, BTN_GEAR_DOWN, !!(b9 & BIT(7)));
955 	input_event(input, EV_KEY, BTN_GEAR_UP, !!(b10 & BIT(0)));
956 	input_event(input, EV_KEY, BTN_THUMBR, !!(b10 & BIT(2)));
957 	input_event(input, EV_KEY, BTN_THUMBL, !!(b10 & BIT(6)));
958 	input_event(input, EV_KEY, BTN_THUMB, lpad_touched || lpad_and_joy);
959 	input_event(input, EV_KEY, BTN_THUMB2, !!(b10 & BIT(4)));
960 	input_event(input, EV_KEY, BTN_DPAD_UP, !!(b9 & BIT(0)));
961 	input_event(input, EV_KEY, BTN_DPAD_RIGHT, !!(b9 & BIT(1)));
962 	input_event(input, EV_KEY, BTN_DPAD_LEFT, !!(b9 & BIT(2)));
963 	input_event(input, EV_KEY, BTN_DPAD_DOWN, !!(b9 & BIT(3)));
964 
965 	input_sync(input);
966 }
967 
968 /*
969  * The size for this message payload is 11.
970  * The known values are:
971  *  Offset| Type  | Meaning
972  * -------+-------+---------------------------
973  *  4-7   | u32   | sequence number
974  *  8-11  | --    | always 0
975  *  12-13 | u16   | voltage (mV)
976  *  14    | u8    | battery percent
977  */
978 static void steam_do_battery_event(struct steam_device *steam,
979 		struct power_supply *battery, u8 *data)
980 {
981 	unsigned long flags;
982 
983 	s16 volts = steam_le16(data + 12);
984 	u8 batt = data[14];
985 
986 	/* Creating the battery may have failed */
987 	rcu_read_lock();
988 	battery = rcu_dereference(steam->battery);
989 	if (likely(battery)) {
990 		spin_lock_irqsave(&steam->lock, flags);
991 		steam->voltage = volts;
992 		steam->battery_charge = batt;
993 		spin_unlock_irqrestore(&steam->lock, flags);
994 		power_supply_changed(battery);
995 	}
996 	rcu_read_unlock();
997 }
998 
999 static int steam_raw_event(struct hid_device *hdev,
1000 			struct hid_report *report, u8 *data,
1001 			int size)
1002 {
1003 	struct steam_device *steam = hid_get_drvdata(hdev);
1004 	struct input_dev *input;
1005 	struct power_supply *battery;
1006 
1007 	if (!steam)
1008 		return 0;
1009 
1010 	if (steam->client_opened)
1011 		hid_input_report(steam->client_hdev, HID_FEATURE_REPORT,
1012 				data, size, 0);
1013 	/*
1014 	 * All messages are size=64, all values little-endian.
1015 	 * The format is:
1016 	 *  Offset| Meaning
1017 	 * -------+--------------------------------------------
1018 	 *  0-1   | always 0x01, 0x00, maybe protocol version?
1019 	 *  2     | type of message
1020 	 *  3     | length of the real payload (not checked)
1021 	 *  4-n   | payload data, depends on the type
1022 	 *
1023 	 * There are these known types of message:
1024 	 *  0x01: input data (60 bytes)
1025 	 *  0x03: wireless connect/disconnect (1 byte)
1026 	 *  0x04: battery status (11 bytes)
1027 	 */
1028 
1029 	if (size != 64 || data[0] != 1 || data[1] != 0)
1030 		return 0;
1031 
1032 	switch (data[2]) {
1033 	case STEAM_EV_INPUT_DATA:
1034 		if (steam->client_opened)
1035 			return 0;
1036 		rcu_read_lock();
1037 		input = rcu_dereference(steam->input);
1038 		if (likely(input))
1039 			steam_do_input_event(steam, input, data);
1040 		rcu_read_unlock();
1041 		break;
1042 	case STEAM_EV_CONNECT:
1043 		/*
1044 		 * The payload of this event is a single byte:
1045 		 *  0x01: disconnected.
1046 		 *  0x02: connected.
1047 		 */
1048 		switch (data[4]) {
1049 		case 0x01:
1050 			steam_do_connect_event(steam, false);
1051 			break;
1052 		case 0x02:
1053 			steam_do_connect_event(steam, true);
1054 			break;
1055 		}
1056 		break;
1057 	case STEAM_EV_BATTERY:
1058 		if (steam->quirks & STEAM_QUIRK_WIRELESS) {
1059 			rcu_read_lock();
1060 			battery = rcu_dereference(steam->battery);
1061 			if (likely(battery)) {
1062 				steam_do_battery_event(steam, battery, data);
1063 			} else {
1064 				dbg_hid(
1065 					"%s: battery data without connect event\n",
1066 					__func__);
1067 				steam_do_connect_event(steam, true);
1068 			}
1069 			rcu_read_unlock();
1070 		}
1071 		break;
1072 	}
1073 	return 0;
1074 }
1075 
1076 static int steam_param_set_lizard_mode(const char *val,
1077 					const struct kernel_param *kp)
1078 {
1079 	struct steam_device *steam;
1080 	int ret;
1081 
1082 	ret = param_set_bool(val, kp);
1083 	if (ret)
1084 		return ret;
1085 
1086 	mutex_lock(&steam_devices_lock);
1087 	list_for_each_entry(steam, &steam_devices, list) {
1088 		mutex_lock(&steam->mutex);
1089 		if (!steam->client_opened)
1090 			steam_set_lizard_mode(steam, lizard_mode);
1091 		mutex_unlock(&steam->mutex);
1092 	}
1093 	mutex_unlock(&steam_devices_lock);
1094 	return 0;
1095 }
1096 
1097 static const struct kernel_param_ops steam_lizard_mode_ops = {
1098 	.set	= steam_param_set_lizard_mode,
1099 	.get	= param_get_bool,
1100 };
1101 
1102 module_param_cb(lizard_mode, &steam_lizard_mode_ops, &lizard_mode, 0644);
1103 MODULE_PARM_DESC(lizard_mode,
1104 	"Enable mouse and keyboard emulation (lizard mode) when the gamepad is not in use");
1105 
1106 static const struct hid_device_id steam_controllers[] = {
1107 	{ /* Wired Steam Controller */
1108 	  HID_USB_DEVICE(USB_VENDOR_ID_VALVE,
1109 		USB_DEVICE_ID_STEAM_CONTROLLER)
1110 	},
1111 	{ /* Wireless Steam Controller */
1112 	  HID_USB_DEVICE(USB_VENDOR_ID_VALVE,
1113 		USB_DEVICE_ID_STEAM_CONTROLLER_WIRELESS),
1114 	  .driver_data = STEAM_QUIRK_WIRELESS
1115 	},
1116 	{}
1117 };
1118 
1119 MODULE_DEVICE_TABLE(hid, steam_controllers);
1120 
1121 static struct hid_driver steam_controller_driver = {
1122 	.name = "hid-steam",
1123 	.id_table = steam_controllers,
1124 	.probe = steam_probe,
1125 	.remove = steam_remove,
1126 	.raw_event = steam_raw_event,
1127 };
1128 
1129 module_hid_driver(steam_controller_driver);
1130