xref: /openbmc/linux/drivers/hid/hid-steam.c (revision f21e49be)
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 	bool client_opened;
503 
504 	/*
505 	 * This function can be called several times in a row with the
506 	 * wireless adaptor, without steam_unregister() between them, because
507 	 * another client send a get_connection_status command, for example.
508 	 * The battery and serial number are set just once per device.
509 	 */
510 	if (!steam->serial_no[0]) {
511 		/*
512 		 * Unlikely, but getting the serial could fail, and it is not so
513 		 * important, so make up a serial number and go on.
514 		 */
515 		mutex_lock(&steam->mutex);
516 		if (steam_get_serial(steam) < 0)
517 			strlcpy(steam->serial_no, "XXXXXXXXXX",
518 					sizeof(steam->serial_no));
519 		mutex_unlock(&steam->mutex);
520 
521 		hid_info(steam->hdev, "Steam Controller '%s' connected",
522 				steam->serial_no);
523 
524 		/* ignore battery errors, we can live without it */
525 		if (steam->quirks & STEAM_QUIRK_WIRELESS)
526 			steam_battery_register(steam);
527 
528 		mutex_lock(&steam_devices_lock);
529 		if (list_empty(&steam->list))
530 			list_add(&steam->list, &steam_devices);
531 		mutex_unlock(&steam_devices_lock);
532 	}
533 
534 	mutex_lock(&steam->mutex);
535 	client_opened = steam->client_opened;
536 	if (!client_opened)
537 		steam_set_lizard_mode(steam, lizard_mode);
538 	mutex_unlock(&steam->mutex);
539 
540 	if (!client_opened)
541 		ret = steam_input_register(steam);
542 	else
543 		ret = 0;
544 
545 	return ret;
546 }
547 
548 static void steam_unregister(struct steam_device *steam)
549 {
550 	steam_battery_unregister(steam);
551 	steam_input_unregister(steam);
552 	if (steam->serial_no[0]) {
553 		hid_info(steam->hdev, "Steam Controller '%s' disconnected",
554 				steam->serial_no);
555 		mutex_lock(&steam_devices_lock);
556 		list_del_init(&steam->list);
557 		mutex_unlock(&steam_devices_lock);
558 		steam->serial_no[0] = 0;
559 	}
560 }
561 
562 static void steam_work_connect_cb(struct work_struct *work)
563 {
564 	struct steam_device *steam = container_of(work, struct steam_device,
565 							work_connect);
566 	unsigned long flags;
567 	bool connected;
568 	int ret;
569 
570 	spin_lock_irqsave(&steam->lock, flags);
571 	connected = steam->connected;
572 	spin_unlock_irqrestore(&steam->lock, flags);
573 
574 	if (connected) {
575 		ret = steam_register(steam);
576 		if (ret) {
577 			hid_err(steam->hdev,
578 				"%s:steam_register failed with error %d\n",
579 				__func__, ret);
580 		}
581 	} else {
582 		steam_unregister(steam);
583 	}
584 }
585 
586 static bool steam_is_valve_interface(struct hid_device *hdev)
587 {
588 	struct hid_report_enum *rep_enum;
589 
590 	/*
591 	 * The wired device creates 3 interfaces:
592 	 *  0: emulated mouse.
593 	 *  1: emulated keyboard.
594 	 *  2: the real game pad.
595 	 * The wireless device creates 5 interfaces:
596 	 *  0: emulated keyboard.
597 	 *  1-4: slots where up to 4 real game pads will be connected to.
598 	 * We know which one is the real gamepad interface because they are the
599 	 * only ones with a feature report.
600 	 */
601 	rep_enum = &hdev->report_enum[HID_FEATURE_REPORT];
602 	return !list_empty(&rep_enum->report_list);
603 }
604 
605 static int steam_client_ll_parse(struct hid_device *hdev)
606 {
607 	struct steam_device *steam = hdev->driver_data;
608 
609 	return hid_parse_report(hdev, steam->hdev->dev_rdesc,
610 			steam->hdev->dev_rsize);
611 }
612 
613 static int steam_client_ll_start(struct hid_device *hdev)
614 {
615 	return 0;
616 }
617 
618 static void steam_client_ll_stop(struct hid_device *hdev)
619 {
620 }
621 
622 static int steam_client_ll_open(struct hid_device *hdev)
623 {
624 	struct steam_device *steam = hdev->driver_data;
625 
626 	mutex_lock(&steam->mutex);
627 	steam->client_opened = true;
628 	mutex_unlock(&steam->mutex);
629 
630 	steam_input_unregister(steam);
631 
632 	return 0;
633 }
634 
635 static void steam_client_ll_close(struct hid_device *hdev)
636 {
637 	struct steam_device *steam = hdev->driver_data;
638 
639 	unsigned long flags;
640 	bool connected;
641 
642 	spin_lock_irqsave(&steam->lock, flags);
643 	connected = steam->connected;
644 	spin_unlock_irqrestore(&steam->lock, flags);
645 
646 	mutex_lock(&steam->mutex);
647 	steam->client_opened = false;
648 	if (connected)
649 		steam_set_lizard_mode(steam, lizard_mode);
650 	mutex_unlock(&steam->mutex);
651 
652 	if (connected)
653 		steam_input_register(steam);
654 }
655 
656 static int steam_client_ll_raw_request(struct hid_device *hdev,
657 				unsigned char reportnum, u8 *buf,
658 				size_t count, unsigned char report_type,
659 				int reqtype)
660 {
661 	struct steam_device *steam = hdev->driver_data;
662 
663 	return hid_hw_raw_request(steam->hdev, reportnum, buf, count,
664 			report_type, reqtype);
665 }
666 
667 static struct hid_ll_driver steam_client_ll_driver = {
668 	.parse = steam_client_ll_parse,
669 	.start = steam_client_ll_start,
670 	.stop = steam_client_ll_stop,
671 	.open = steam_client_ll_open,
672 	.close = steam_client_ll_close,
673 	.raw_request = steam_client_ll_raw_request,
674 };
675 
676 static struct hid_device *steam_create_client_hid(struct hid_device *hdev)
677 {
678 	struct hid_device *client_hdev;
679 
680 	client_hdev = hid_allocate_device();
681 	if (IS_ERR(client_hdev))
682 		return client_hdev;
683 
684 	client_hdev->ll_driver = &steam_client_ll_driver;
685 	client_hdev->dev.parent = hdev->dev.parent;
686 	client_hdev->bus = hdev->bus;
687 	client_hdev->vendor = hdev->vendor;
688 	client_hdev->product = hdev->product;
689 	client_hdev->version = hdev->version;
690 	client_hdev->type = hdev->type;
691 	client_hdev->country = hdev->country;
692 	strlcpy(client_hdev->name, hdev->name,
693 			sizeof(client_hdev->name));
694 	strlcpy(client_hdev->phys, hdev->phys,
695 			sizeof(client_hdev->phys));
696 	/*
697 	 * Since we use the same device info than the real interface to
698 	 * trick userspace, we will be calling steam_probe recursively.
699 	 * We need to recognize the client interface somehow.
700 	 */
701 	client_hdev->group = HID_GROUP_STEAM;
702 	return client_hdev;
703 }
704 
705 static int steam_probe(struct hid_device *hdev,
706 				const struct hid_device_id *id)
707 {
708 	struct steam_device *steam;
709 	int ret;
710 
711 	ret = hid_parse(hdev);
712 	if (ret) {
713 		hid_err(hdev,
714 			"%s:parse of hid interface failed\n", __func__);
715 		return ret;
716 	}
717 
718 	/*
719 	 * The virtual client_dev is only used for hidraw.
720 	 * Also avoid the recursive probe.
721 	 */
722 	if (hdev->group == HID_GROUP_STEAM)
723 		return hid_hw_start(hdev, HID_CONNECT_HIDRAW);
724 	/*
725 	 * The non-valve interfaces (mouse and keyboard emulation) are
726 	 * connected without changes.
727 	 */
728 	if (!steam_is_valve_interface(hdev))
729 		return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
730 
731 	steam = devm_kzalloc(&hdev->dev, sizeof(*steam), GFP_KERNEL);
732 	if (!steam) {
733 		ret = -ENOMEM;
734 		goto steam_alloc_fail;
735 	}
736 	steam->hdev = hdev;
737 	hid_set_drvdata(hdev, steam);
738 	spin_lock_init(&steam->lock);
739 	mutex_init(&steam->mutex);
740 	steam->quirks = id->driver_data;
741 	INIT_WORK(&steam->work_connect, steam_work_connect_cb);
742 	INIT_LIST_HEAD(&steam->list);
743 
744 	steam->client_hdev = steam_create_client_hid(hdev);
745 	if (IS_ERR(steam->client_hdev)) {
746 		ret = PTR_ERR(steam->client_hdev);
747 		goto client_hdev_fail;
748 	}
749 	steam->client_hdev->driver_data = steam;
750 
751 	/*
752 	 * With the real steam controller interface, do not connect hidraw.
753 	 * Instead, create the client_hid and connect that.
754 	 */
755 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_HIDRAW);
756 	if (ret)
757 		goto hid_hw_start_fail;
758 
759 	ret = hid_add_device(steam->client_hdev);
760 	if (ret)
761 		goto client_hdev_add_fail;
762 
763 	ret = hid_hw_open(hdev);
764 	if (ret) {
765 		hid_err(hdev,
766 			"%s:hid_hw_open\n",
767 			__func__);
768 		goto hid_hw_open_fail;
769 	}
770 
771 	if (steam->quirks & STEAM_QUIRK_WIRELESS) {
772 		hid_info(hdev, "Steam wireless receiver connected");
773 		/* If using a wireless adaptor ask for connection status */
774 		steam->connected = false;
775 		steam_request_conn_status(steam);
776 	} else {
777 		/* A wired connection is always present */
778 		steam->connected = true;
779 		ret = steam_register(steam);
780 		if (ret) {
781 			hid_err(hdev,
782 				"%s:steam_register failed with error %d\n",
783 				__func__, ret);
784 			goto input_register_fail;
785 		}
786 	}
787 
788 	return 0;
789 
790 input_register_fail:
791 hid_hw_open_fail:
792 client_hdev_add_fail:
793 	hid_hw_stop(hdev);
794 hid_hw_start_fail:
795 	hid_destroy_device(steam->client_hdev);
796 client_hdev_fail:
797 	cancel_work_sync(&steam->work_connect);
798 steam_alloc_fail:
799 	hid_err(hdev, "%s: failed with error %d\n",
800 			__func__, ret);
801 	return ret;
802 }
803 
804 static void steam_remove(struct hid_device *hdev)
805 {
806 	struct steam_device *steam = hid_get_drvdata(hdev);
807 
808 	if (!steam || hdev->group == HID_GROUP_STEAM) {
809 		hid_hw_stop(hdev);
810 		return;
811 	}
812 
813 	hid_destroy_device(steam->client_hdev);
814 	steam->client_opened = false;
815 	cancel_work_sync(&steam->work_connect);
816 	if (steam->quirks & STEAM_QUIRK_WIRELESS) {
817 		hid_info(hdev, "Steam wireless receiver disconnected");
818 	}
819 	hid_hw_close(hdev);
820 	hid_hw_stop(hdev);
821 	steam_unregister(steam);
822 }
823 
824 static void steam_do_connect_event(struct steam_device *steam, bool connected)
825 {
826 	unsigned long flags;
827 	bool changed;
828 
829 	spin_lock_irqsave(&steam->lock, flags);
830 	changed = steam->connected != connected;
831 	steam->connected = connected;
832 	spin_unlock_irqrestore(&steam->lock, flags);
833 
834 	if (changed && schedule_work(&steam->work_connect) == 0)
835 		dbg_hid("%s: connected=%d event already queued\n",
836 				__func__, connected);
837 }
838 
839 /*
840  * Some input data in the protocol has the opposite sign.
841  * Clamp the values to 32767..-32767 so that the range is
842  * symmetrical and can be negated safely.
843  */
844 static inline s16 steam_le16(u8 *data)
845 {
846 	s16 x = (s16) le16_to_cpup((__le16 *)data);
847 
848 	return x == -32768 ? -32767 : x;
849 }
850 
851 /*
852  * The size for this message payload is 60.
853  * The known values are:
854  *  (* values are not sent through wireless)
855  *  (* accelerator/gyro is disabled by default)
856  *  Offset| Type  | Mapped to |Meaning
857  * -------+-------+-----------+--------------------------
858  *  4-7   | u32   | --        | sequence number
859  *  8-10  | 24bit | see below | buttons
860  *  11    | u8    | ABS_HAT2Y | left trigger
861  *  12    | u8    | ABS_HAT2X | right trigger
862  *  13-15 | --    | --        | always 0
863  *  16-17 | s16   | ABS_X/ABS_HAT0X     | X value
864  *  18-19 | s16   | ABS_Y/ABS_HAT0Y     | Y value
865  *  20-21 | s16   | ABS_RX    | right-pad X value
866  *  22-23 | s16   | ABS_RY    | right-pad Y value
867  *  24-25 | s16   | --        | * left trigger
868  *  26-27 | s16   | --        | * right trigger
869  *  28-29 | s16   | --        | * accelerometer X value
870  *  30-31 | s16   | --        | * accelerometer Y value
871  *  32-33 | s16   | --        | * accelerometer Z value
872  *  34-35 | s16   | --        | gyro X value
873  *  36-36 | s16   | --        | gyro Y value
874  *  38-39 | s16   | --        | gyro Z value
875  *  40-41 | s16   | --        | quaternion W value
876  *  42-43 | s16   | --        | quaternion X value
877  *  44-45 | s16   | --        | quaternion Y value
878  *  46-47 | s16   | --        | quaternion Z value
879  *  48-49 | --    | --        | always 0
880  *  50-51 | s16   | --        | * left trigger (uncalibrated)
881  *  52-53 | s16   | --        | * right trigger (uncalibrated)
882  *  54-55 | s16   | --        | * joystick X value (uncalibrated)
883  *  56-57 | s16   | --        | * joystick Y value (uncalibrated)
884  *  58-59 | s16   | --        | * left-pad X value
885  *  60-61 | s16   | --        | * left-pad Y value
886  *  62-63 | u16   | --        | * battery voltage
887  *
888  * The buttons are:
889  *  Bit  | Mapped to  | Description
890  * ------+------------+--------------------------------
891  *  8.0  | BTN_TR2    | right trigger fully pressed
892  *  8.1  | BTN_TL2    | left trigger fully pressed
893  *  8.2  | BTN_TR     | right shoulder
894  *  8.3  | BTN_TL     | left shoulder
895  *  8.4  | BTN_Y      | button Y
896  *  8.5  | BTN_B      | button B
897  *  8.6  | BTN_X      | button X
898  *  8.7  | BTN_A      | button A
899  *  9.0  | BTN_DPAD_UP    | lef-pad up
900  *  9.1  | BTN_DPAD_RIGHT | lef-pad right
901  *  9.2  | BTN_DPAD_LEFT  | lef-pad left
902  *  9.3  | BTN_DPAD_DOWN  | lef-pad down
903  *  9.4  | BTN_SELECT | menu left
904  *  9.5  | BTN_MODE   | steam logo
905  *  9.6  | BTN_START  | menu right
906  *  9.7  | BTN_GEAR_DOWN | left back lever
907  * 10.0  | BTN_GEAR_UP   | right back lever
908  * 10.1  | --         | left-pad clicked
909  * 10.2  | BTN_THUMBR | right-pad clicked
910  * 10.3  | BTN_THUMB  | left-pad touched (but see explanation below)
911  * 10.4  | BTN_THUMB2 | right-pad touched
912  * 10.5  | --         | unknown
913  * 10.6  | BTN_THUMBL | joystick clicked
914  * 10.7  | --         | lpad_and_joy
915  */
916 
917 static void steam_do_input_event(struct steam_device *steam,
918 		struct input_dev *input, u8 *data)
919 {
920 	/* 24 bits of buttons */
921 	u8 b8, b9, b10;
922 	s16 x, y;
923 	bool lpad_touched, lpad_and_joy;
924 
925 	b8 = data[8];
926 	b9 = data[9];
927 	b10 = data[10];
928 
929 	input_report_abs(input, ABS_HAT2Y, data[11]);
930 	input_report_abs(input, ABS_HAT2X, data[12]);
931 
932 	/*
933 	 * These two bits tells how to interpret the values X and Y.
934 	 * lpad_and_joy tells that the joystick and the lpad are used at the
935 	 * same time.
936 	 * lpad_touched tells whether X/Y are to be read as lpad coord or
937 	 * joystick values.
938 	 * (lpad_touched || lpad_and_joy) tells if the lpad is really touched.
939 	 */
940 	lpad_touched = b10 & BIT(3);
941 	lpad_and_joy = b10 & BIT(7);
942 	x = steam_le16(data + 16);
943 	y = -steam_le16(data + 18);
944 
945 	input_report_abs(input, lpad_touched ? ABS_HAT0X : ABS_X, x);
946 	input_report_abs(input, lpad_touched ? ABS_HAT0Y : ABS_Y, y);
947 	/* Check if joystick is centered */
948 	if (lpad_touched && !lpad_and_joy) {
949 		input_report_abs(input, ABS_X, 0);
950 		input_report_abs(input, ABS_Y, 0);
951 	}
952 	/* Check if lpad is untouched */
953 	if (!(lpad_touched || lpad_and_joy)) {
954 		input_report_abs(input, ABS_HAT0X, 0);
955 		input_report_abs(input, ABS_HAT0Y, 0);
956 	}
957 
958 	input_report_abs(input, ABS_RX, steam_le16(data + 20));
959 	input_report_abs(input, ABS_RY, -steam_le16(data + 22));
960 
961 	input_event(input, EV_KEY, BTN_TR2, !!(b8 & BIT(0)));
962 	input_event(input, EV_KEY, BTN_TL2, !!(b8 & BIT(1)));
963 	input_event(input, EV_KEY, BTN_TR, !!(b8 & BIT(2)));
964 	input_event(input, EV_KEY, BTN_TL, !!(b8 & BIT(3)));
965 	input_event(input, EV_KEY, BTN_Y, !!(b8 & BIT(4)));
966 	input_event(input, EV_KEY, BTN_B, !!(b8 & BIT(5)));
967 	input_event(input, EV_KEY, BTN_X, !!(b8 & BIT(6)));
968 	input_event(input, EV_KEY, BTN_A, !!(b8 & BIT(7)));
969 	input_event(input, EV_KEY, BTN_SELECT, !!(b9 & BIT(4)));
970 	input_event(input, EV_KEY, BTN_MODE, !!(b9 & BIT(5)));
971 	input_event(input, EV_KEY, BTN_START, !!(b9 & BIT(6)));
972 	input_event(input, EV_KEY, BTN_GEAR_DOWN, !!(b9 & BIT(7)));
973 	input_event(input, EV_KEY, BTN_GEAR_UP, !!(b10 & BIT(0)));
974 	input_event(input, EV_KEY, BTN_THUMBR, !!(b10 & BIT(2)));
975 	input_event(input, EV_KEY, BTN_THUMBL, !!(b10 & BIT(6)));
976 	input_event(input, EV_KEY, BTN_THUMB, lpad_touched || lpad_and_joy);
977 	input_event(input, EV_KEY, BTN_THUMB2, !!(b10 & BIT(4)));
978 	input_event(input, EV_KEY, BTN_DPAD_UP, !!(b9 & BIT(0)));
979 	input_event(input, EV_KEY, BTN_DPAD_RIGHT, !!(b9 & BIT(1)));
980 	input_event(input, EV_KEY, BTN_DPAD_LEFT, !!(b9 & BIT(2)));
981 	input_event(input, EV_KEY, BTN_DPAD_DOWN, !!(b9 & BIT(3)));
982 
983 	input_sync(input);
984 }
985 
986 /*
987  * The size for this message payload is 11.
988  * The known values are:
989  *  Offset| Type  | Meaning
990  * -------+-------+---------------------------
991  *  4-7   | u32   | sequence number
992  *  8-11  | --    | always 0
993  *  12-13 | u16   | voltage (mV)
994  *  14    | u8    | battery percent
995  */
996 static void steam_do_battery_event(struct steam_device *steam,
997 		struct power_supply *battery, u8 *data)
998 {
999 	unsigned long flags;
1000 
1001 	s16 volts = steam_le16(data + 12);
1002 	u8 batt = data[14];
1003 
1004 	/* Creating the battery may have failed */
1005 	rcu_read_lock();
1006 	battery = rcu_dereference(steam->battery);
1007 	if (likely(battery)) {
1008 		spin_lock_irqsave(&steam->lock, flags);
1009 		steam->voltage = volts;
1010 		steam->battery_charge = batt;
1011 		spin_unlock_irqrestore(&steam->lock, flags);
1012 		power_supply_changed(battery);
1013 	}
1014 	rcu_read_unlock();
1015 }
1016 
1017 static int steam_raw_event(struct hid_device *hdev,
1018 			struct hid_report *report, u8 *data,
1019 			int size)
1020 {
1021 	struct steam_device *steam = hid_get_drvdata(hdev);
1022 	struct input_dev *input;
1023 	struct power_supply *battery;
1024 
1025 	if (!steam)
1026 		return 0;
1027 
1028 	if (steam->client_opened)
1029 		hid_input_report(steam->client_hdev, HID_FEATURE_REPORT,
1030 				data, size, 0);
1031 	/*
1032 	 * All messages are size=64, all values little-endian.
1033 	 * The format is:
1034 	 *  Offset| Meaning
1035 	 * -------+--------------------------------------------
1036 	 *  0-1   | always 0x01, 0x00, maybe protocol version?
1037 	 *  2     | type of message
1038 	 *  3     | length of the real payload (not checked)
1039 	 *  4-n   | payload data, depends on the type
1040 	 *
1041 	 * There are these known types of message:
1042 	 *  0x01: input data (60 bytes)
1043 	 *  0x03: wireless connect/disconnect (1 byte)
1044 	 *  0x04: battery status (11 bytes)
1045 	 */
1046 
1047 	if (size != 64 || data[0] != 1 || data[1] != 0)
1048 		return 0;
1049 
1050 	switch (data[2]) {
1051 	case STEAM_EV_INPUT_DATA:
1052 		if (steam->client_opened)
1053 			return 0;
1054 		rcu_read_lock();
1055 		input = rcu_dereference(steam->input);
1056 		if (likely(input))
1057 			steam_do_input_event(steam, input, data);
1058 		rcu_read_unlock();
1059 		break;
1060 	case STEAM_EV_CONNECT:
1061 		/*
1062 		 * The payload of this event is a single byte:
1063 		 *  0x01: disconnected.
1064 		 *  0x02: connected.
1065 		 */
1066 		switch (data[4]) {
1067 		case 0x01:
1068 			steam_do_connect_event(steam, false);
1069 			break;
1070 		case 0x02:
1071 			steam_do_connect_event(steam, true);
1072 			break;
1073 		}
1074 		break;
1075 	case STEAM_EV_BATTERY:
1076 		if (steam->quirks & STEAM_QUIRK_WIRELESS) {
1077 			rcu_read_lock();
1078 			battery = rcu_dereference(steam->battery);
1079 			if (likely(battery)) {
1080 				steam_do_battery_event(steam, battery, data);
1081 			} else {
1082 				dbg_hid(
1083 					"%s: battery data without connect event\n",
1084 					__func__);
1085 				steam_do_connect_event(steam, true);
1086 			}
1087 			rcu_read_unlock();
1088 		}
1089 		break;
1090 	}
1091 	return 0;
1092 }
1093 
1094 static int steam_param_set_lizard_mode(const char *val,
1095 					const struct kernel_param *kp)
1096 {
1097 	struct steam_device *steam;
1098 	int ret;
1099 
1100 	ret = param_set_bool(val, kp);
1101 	if (ret)
1102 		return ret;
1103 
1104 	mutex_lock(&steam_devices_lock);
1105 	list_for_each_entry(steam, &steam_devices, list) {
1106 		mutex_lock(&steam->mutex);
1107 		if (!steam->client_opened)
1108 			steam_set_lizard_mode(steam, lizard_mode);
1109 		mutex_unlock(&steam->mutex);
1110 	}
1111 	mutex_unlock(&steam_devices_lock);
1112 	return 0;
1113 }
1114 
1115 static const struct kernel_param_ops steam_lizard_mode_ops = {
1116 	.set	= steam_param_set_lizard_mode,
1117 	.get	= param_get_bool,
1118 };
1119 
1120 module_param_cb(lizard_mode, &steam_lizard_mode_ops, &lizard_mode, 0644);
1121 MODULE_PARM_DESC(lizard_mode,
1122 	"Enable mouse and keyboard emulation (lizard mode) when the gamepad is not in use");
1123 
1124 static const struct hid_device_id steam_controllers[] = {
1125 	{ /* Wired Steam Controller */
1126 	  HID_USB_DEVICE(USB_VENDOR_ID_VALVE,
1127 		USB_DEVICE_ID_STEAM_CONTROLLER)
1128 	},
1129 	{ /* Wireless Steam Controller */
1130 	  HID_USB_DEVICE(USB_VENDOR_ID_VALVE,
1131 		USB_DEVICE_ID_STEAM_CONTROLLER_WIRELESS),
1132 	  .driver_data = STEAM_QUIRK_WIRELESS
1133 	},
1134 	{}
1135 };
1136 
1137 MODULE_DEVICE_TABLE(hid, steam_controllers);
1138 
1139 static struct hid_driver steam_controller_driver = {
1140 	.name = "hid-steam",
1141 	.id_table = steam_controllers,
1142 	.probe = steam_probe,
1143 	.remove = steam_remove,
1144 	.raw_event = steam_raw_event,
1145 };
1146 
1147 module_hid_driver(steam_controller_driver);
1148