xref: /openbmc/linux/drivers/input/mouse/bcm5974.c (revision fd589a8f)
1 /*
2  * Apple USB BCM5974 (Macbook Air and Penryn Macbook Pro) multitouch driver
3  *
4  * Copyright (C) 2008	   Henrik Rydberg (rydberg@euromail.se)
5  *
6  * The USB initialization and package decoding was made by
7  * Scott Shawcroft as part of the touchd user-space driver project:
8  * Copyright (C) 2008	   Scott Shawcroft (scott.shawcroft@gmail.com)
9  *
10  * The BCM5974 driver is based on the appletouch driver:
11  * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
12  * Copyright (C) 2005      Johannes Berg (johannes@sipsolutions.net)
13  * Copyright (C) 2005	   Stelian Pop (stelian@popies.net)
14  * Copyright (C) 2005	   Frank Arnold (frank@scirocco-5v-turbo.de)
15  * Copyright (C) 2005	   Peter Osterlund (petero2@telia.com)
16  * Copyright (C) 2005	   Michael Hanselmann (linux-kernel@hansmi.ch)
17  * Copyright (C) 2006	   Nicolas Boichat (nicolas@boichat.ch)
18  *
19  * This program is free software; you can redistribute it and/or modify
20  * it under the terms of the GNU General Public License as published by
21  * the Free Software Foundation; either version 2 of the License, or
22  * (at your option) any later version.
23  *
24  * This program is distributed in the hope that it will be useful,
25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
27  * GNU General Public License for more details.
28  *
29  * You should have received a copy of the GNU General Public License
30  * along with this program; if not, write to the Free Software
31  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
32  *
33  */
34 
35 #include <linux/kernel.h>
36 #include <linux/errno.h>
37 #include <linux/init.h>
38 #include <linux/slab.h>
39 #include <linux/module.h>
40 #include <linux/usb/input.h>
41 #include <linux/hid.h>
42 #include <linux/mutex.h>
43 
44 #define USB_VENDOR_ID_APPLE		0x05ac
45 
46 /* MacbookAir, aka wellspring */
47 #define USB_DEVICE_ID_APPLE_WELLSPRING_ANSI	0x0223
48 #define USB_DEVICE_ID_APPLE_WELLSPRING_ISO	0x0224
49 #define USB_DEVICE_ID_APPLE_WELLSPRING_JIS	0x0225
50 /* MacbookProPenryn, aka wellspring2 */
51 #define USB_DEVICE_ID_APPLE_WELLSPRING2_ANSI	0x0230
52 #define USB_DEVICE_ID_APPLE_WELLSPRING2_ISO	0x0231
53 #define USB_DEVICE_ID_APPLE_WELLSPRING2_JIS	0x0232
54 /* Macbook5,1 (unibody), aka wellspring3 */
55 #define USB_DEVICE_ID_APPLE_WELLSPRING3_ANSI	0x0236
56 #define USB_DEVICE_ID_APPLE_WELLSPRING3_ISO	0x0237
57 #define USB_DEVICE_ID_APPLE_WELLSPRING3_JIS	0x0238
58 
59 #define BCM5974_DEVICE(prod) {					\
60 	.match_flags = (USB_DEVICE_ID_MATCH_DEVICE |		\
61 			USB_DEVICE_ID_MATCH_INT_CLASS |		\
62 			USB_DEVICE_ID_MATCH_INT_PROTOCOL),	\
63 	.idVendor = USB_VENDOR_ID_APPLE,			\
64 	.idProduct = (prod),					\
65 	.bInterfaceClass = USB_INTERFACE_CLASS_HID,		\
66 	.bInterfaceProtocol = USB_INTERFACE_PROTOCOL_MOUSE	\
67 }
68 
69 /* table of devices that work with this driver */
70 static const struct usb_device_id bcm5974_table[] = {
71 	/* MacbookAir1.1 */
72 	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING_ANSI),
73 	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING_ISO),
74 	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING_JIS),
75 	/* MacbookProPenryn */
76 	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING2_ANSI),
77 	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING2_ISO),
78 	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING2_JIS),
79 	/* Macbook5,1 */
80 	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING3_ANSI),
81 	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING3_ISO),
82 	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING3_JIS),
83 	/* Terminating entry */
84 	{}
85 };
86 MODULE_DEVICE_TABLE(usb, bcm5974_table);
87 
88 MODULE_AUTHOR("Henrik Rydberg");
89 MODULE_DESCRIPTION("Apple USB BCM5974 multitouch driver");
90 MODULE_LICENSE("GPL");
91 
92 #define dprintk(level, format, a...)\
93 	{ if (debug >= level) printk(KERN_DEBUG format, ##a); }
94 
95 static int debug = 1;
96 module_param(debug, int, 0644);
97 MODULE_PARM_DESC(debug, "Activate debugging output");
98 
99 /* button data structure */
100 struct bt_data {
101 	u8 unknown1;		/* constant */
102 	u8 button;		/* left button */
103 	u8 rel_x;		/* relative x coordinate */
104 	u8 rel_y;		/* relative y coordinate */
105 };
106 
107 /* trackpad header types */
108 enum tp_type {
109 	TYPE1,			/* plain trackpad */
110 	TYPE2			/* button integrated in trackpad */
111 };
112 
113 /* trackpad finger data offsets, le16-aligned */
114 #define FINGER_TYPE1		(13 * sizeof(__le16))
115 #define FINGER_TYPE2		(15 * sizeof(__le16))
116 
117 /* trackpad button data offsets */
118 #define BUTTON_TYPE2		15
119 
120 /* list of device capability bits */
121 #define HAS_INTEGRATED_BUTTON	1
122 
123 /* trackpad finger structure, le16-aligned */
124 struct tp_finger {
125 	__le16 origin;		/* zero when switching track finger */
126 	__le16 abs_x;		/* absolute x coodinate */
127 	__le16 abs_y;		/* absolute y coodinate */
128 	__le16 rel_x;		/* relative x coodinate */
129 	__le16 rel_y;		/* relative y coodinate */
130 	__le16 size_major;	/* finger size, major axis? */
131 	__le16 size_minor;	/* finger size, minor axis? */
132 	__le16 orientation;	/* 16384 when point, else 15 bit angle */
133 	__le16 force_major;	/* trackpad force, major axis? */
134 	__le16 force_minor;	/* trackpad force, minor axis? */
135 	__le16 unused[3];	/* zeros */
136 	__le16 multi;		/* one finger: varies, more fingers: constant */
137 } __attribute__((packed,aligned(2)));
138 
139 /* trackpad finger data size, empirically at least ten fingers */
140 #define SIZEOF_FINGER		sizeof(struct tp_finger)
141 #define SIZEOF_ALL_FINGERS	(16 * SIZEOF_FINGER)
142 
143 /* device-specific parameters */
144 struct bcm5974_param {
145 	int dim;		/* logical dimension */
146 	int fuzz;		/* logical noise value */
147 	int devmin;		/* device minimum reading */
148 	int devmax;		/* device maximum reading */
149 };
150 
151 /* device-specific configuration */
152 struct bcm5974_config {
153 	int ansi, iso, jis;	/* the product id of this device */
154 	int caps;		/* device capability bitmask */
155 	int bt_ep;		/* the endpoint of the button interface */
156 	int bt_datalen;		/* data length of the button interface */
157 	int tp_ep;		/* the endpoint of the trackpad interface */
158 	enum tp_type tp_type;	/* type of trackpad interface */
159 	int tp_offset;		/* offset to trackpad finger data */
160 	int tp_datalen;		/* data length of the trackpad interface */
161 	struct bcm5974_param p;	/* finger pressure limits */
162 	struct bcm5974_param w;	/* finger width limits */
163 	struct bcm5974_param x;	/* horizontal limits */
164 	struct bcm5974_param y;	/* vertical limits */
165 };
166 
167 /* logical device structure */
168 struct bcm5974 {
169 	char phys[64];
170 	struct usb_device *udev;	/* usb device */
171 	struct usb_interface *intf;	/* our interface */
172 	struct input_dev *input;	/* input dev */
173 	struct bcm5974_config cfg;	/* device configuration */
174 	struct mutex pm_mutex;		/* serialize access to open/suspend */
175 	int opened;			/* 1: opened, 0: closed */
176 	struct urb *bt_urb;		/* button usb request block */
177 	struct bt_data *bt_data;	/* button transferred data */
178 	struct urb *tp_urb;		/* trackpad usb request block */
179 	u8 *tp_data;			/* trackpad transferred data */
180 	int fingers;			/* number of fingers on trackpad */
181 };
182 
183 /* logical dimensions */
184 #define DIM_PRESSURE	256		/* maximum finger pressure */
185 #define DIM_WIDTH	16		/* maximum finger width */
186 #define DIM_X		1280		/* maximum trackpad x value */
187 #define DIM_Y		800		/* maximum trackpad y value */
188 
189 /* logical signal quality */
190 #define SN_PRESSURE	45		/* pressure signal-to-noise ratio */
191 #define SN_WIDTH	100		/* width signal-to-noise ratio */
192 #define SN_COORD	250		/* coordinate signal-to-noise ratio */
193 
194 /* pressure thresholds */
195 #define PRESSURE_LOW	(2 * DIM_PRESSURE / SN_PRESSURE)
196 #define PRESSURE_HIGH	(3 * PRESSURE_LOW)
197 
198 /* device constants */
199 static const struct bcm5974_config bcm5974_config_table[] = {
200 	{
201 		USB_DEVICE_ID_APPLE_WELLSPRING_ANSI,
202 		USB_DEVICE_ID_APPLE_WELLSPRING_ISO,
203 		USB_DEVICE_ID_APPLE_WELLSPRING_JIS,
204 		0,
205 		0x84, sizeof(struct bt_data),
206 		0x81, TYPE1, FINGER_TYPE1, FINGER_TYPE1 + SIZEOF_ALL_FINGERS,
207 		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 256 },
208 		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
209 		{ DIM_X, DIM_X / SN_COORD, -4824, 5342 },
210 		{ DIM_Y, DIM_Y / SN_COORD, -172, 5820 }
211 	},
212 	{
213 		USB_DEVICE_ID_APPLE_WELLSPRING2_ANSI,
214 		USB_DEVICE_ID_APPLE_WELLSPRING2_ISO,
215 		USB_DEVICE_ID_APPLE_WELLSPRING2_JIS,
216 		0,
217 		0x84, sizeof(struct bt_data),
218 		0x81, TYPE1, FINGER_TYPE1, FINGER_TYPE1 + SIZEOF_ALL_FINGERS,
219 		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 256 },
220 		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
221 		{ DIM_X, DIM_X / SN_COORD, -4824, 4824 },
222 		{ DIM_Y, DIM_Y / SN_COORD, -172, 4290 }
223 	},
224 	{
225 		USB_DEVICE_ID_APPLE_WELLSPRING3_ANSI,
226 		USB_DEVICE_ID_APPLE_WELLSPRING3_ISO,
227 		USB_DEVICE_ID_APPLE_WELLSPRING3_JIS,
228 		HAS_INTEGRATED_BUTTON,
229 		0x84, sizeof(struct bt_data),
230 		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
231 		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
232 		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
233 		{ DIM_X, DIM_X / SN_COORD, -4460, 5166 },
234 		{ DIM_Y, DIM_Y / SN_COORD, -75, 6700 }
235 	},
236 	{}
237 };
238 
239 /* return the device-specific configuration by device */
240 static const struct bcm5974_config *bcm5974_get_config(struct usb_device *udev)
241 {
242 	u16 id = le16_to_cpu(udev->descriptor.idProduct);
243 	const struct bcm5974_config *cfg;
244 
245 	for (cfg = bcm5974_config_table; cfg->ansi; ++cfg)
246 		if (cfg->ansi == id || cfg->iso == id || cfg->jis == id)
247 			return cfg;
248 
249 	return bcm5974_config_table;
250 }
251 
252 /* convert 16-bit little endian to signed integer */
253 static inline int raw2int(__le16 x)
254 {
255 	return (signed short)le16_to_cpu(x);
256 }
257 
258 /* scale device data to logical dimensions (asserts devmin < devmax) */
259 static inline int int2scale(const struct bcm5974_param *p, int x)
260 {
261 	return x * p->dim / (p->devmax - p->devmin);
262 }
263 
264 /* all logical value ranges are [0,dim). */
265 static inline int int2bound(const struct bcm5974_param *p, int x)
266 {
267 	int s = int2scale(p, x);
268 
269 	return clamp_val(s, 0, p->dim - 1);
270 }
271 
272 /* setup which logical events to report */
273 static void setup_events_to_report(struct input_dev *input_dev,
274 				   const struct bcm5974_config *cfg)
275 {
276 	__set_bit(EV_ABS, input_dev->evbit);
277 
278 	input_set_abs_params(input_dev, ABS_PRESSURE,
279 				0, cfg->p.dim, cfg->p.fuzz, 0);
280 	input_set_abs_params(input_dev, ABS_TOOL_WIDTH,
281 				0, cfg->w.dim, cfg->w.fuzz, 0);
282 	input_set_abs_params(input_dev, ABS_X,
283 				0, cfg->x.dim, cfg->x.fuzz, 0);
284 	input_set_abs_params(input_dev, ABS_Y,
285 				0, cfg->y.dim, cfg->y.fuzz, 0);
286 
287 	__set_bit(EV_KEY, input_dev->evbit);
288 	__set_bit(BTN_TOUCH, input_dev->keybit);
289 	__set_bit(BTN_TOOL_FINGER, input_dev->keybit);
290 	__set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
291 	__set_bit(BTN_TOOL_TRIPLETAP, input_dev->keybit);
292 	__set_bit(BTN_TOOL_QUADTAP, input_dev->keybit);
293 	__set_bit(BTN_LEFT, input_dev->keybit);
294 }
295 
296 /* report button data as logical button state */
297 static int report_bt_state(struct bcm5974 *dev, int size)
298 {
299 	if (size != sizeof(struct bt_data))
300 		return -EIO;
301 
302 	dprintk(7,
303 		"bcm5974: button data: %x %x %x %x\n",
304 		dev->bt_data->unknown1, dev->bt_data->button,
305 		dev->bt_data->rel_x, dev->bt_data->rel_y);
306 
307 	input_report_key(dev->input, BTN_LEFT, dev->bt_data->button);
308 	input_sync(dev->input);
309 
310 	return 0;
311 }
312 
313 /* report trackpad data as logical trackpad state */
314 static int report_tp_state(struct bcm5974 *dev, int size)
315 {
316 	const struct bcm5974_config *c = &dev->cfg;
317 	const struct tp_finger *f;
318 	struct input_dev *input = dev->input;
319 	int raw_p, raw_w, raw_x, raw_y, raw_n;
320 	int ptest, origin, ibt = 0, nmin = 0, nmax = 0;
321 	int abs_p = 0, abs_w = 0, abs_x = 0, abs_y = 0;
322 
323 	if (size < c->tp_offset || (size - c->tp_offset) % SIZEOF_FINGER != 0)
324 		return -EIO;
325 
326 	/* finger data, le16-aligned */
327 	f = (const struct tp_finger *)(dev->tp_data + c->tp_offset);
328 	raw_n = (size - c->tp_offset) / SIZEOF_FINGER;
329 
330 	/* always track the first finger; when detached, start over */
331 	if (raw_n) {
332 		raw_p = raw2int(f->force_major);
333 		raw_w = raw2int(f->size_major);
334 		raw_x = raw2int(f->abs_x);
335 		raw_y = raw2int(f->abs_y);
336 
337 		dprintk(9,
338 			"bcm5974: "
339 			"raw: p: %+05d w: %+05d x: %+05d y: %+05d n: %d\n",
340 			raw_p, raw_w, raw_x, raw_y, raw_n);
341 
342 		ptest = int2bound(&c->p, raw_p);
343 		origin = raw2int(f->origin);
344 
345 		/* set the integrated button if applicable */
346 		if (c->tp_type == TYPE2)
347 			ibt = raw2int(dev->tp_data[BUTTON_TYPE2]);
348 
349 		/* while tracking finger still valid, count all fingers */
350 		if (ptest > PRESSURE_LOW && origin) {
351 			abs_p = ptest;
352 			abs_w = int2bound(&c->w, raw_w);
353 			abs_x = int2bound(&c->x, raw_x - c->x.devmin);
354 			abs_y = int2bound(&c->y, c->y.devmax - raw_y);
355 			while (raw_n--) {
356 				ptest = int2bound(&c->p,
357 						  raw2int(f->force_major));
358 				if (ptest > PRESSURE_LOW)
359 					nmax++;
360 				if (ptest > PRESSURE_HIGH)
361 					nmin++;
362 				f++;
363 			}
364 		}
365 	}
366 
367 	if (dev->fingers < nmin)
368 		dev->fingers = nmin;
369 	if (dev->fingers > nmax)
370 		dev->fingers = nmax;
371 
372 	input_report_key(input, BTN_TOUCH, dev->fingers > 0);
373 	input_report_key(input, BTN_TOOL_FINGER, dev->fingers == 1);
374 	input_report_key(input, BTN_TOOL_DOUBLETAP, dev->fingers == 2);
375 	input_report_key(input, BTN_TOOL_TRIPLETAP, dev->fingers == 3);
376 	input_report_key(input, BTN_TOOL_QUADTAP, dev->fingers > 3);
377 
378 	input_report_abs(input, ABS_PRESSURE, abs_p);
379 	input_report_abs(input, ABS_TOOL_WIDTH, abs_w);
380 
381 	if (abs_p) {
382 		input_report_abs(input, ABS_X, abs_x);
383 		input_report_abs(input, ABS_Y, abs_y);
384 
385 		dprintk(8,
386 			"bcm5974: abs: p: %+05d w: %+05d x: %+05d y: %+05d "
387 			"nmin: %d nmax: %d n: %d ibt: %d\n", abs_p, abs_w,
388 			abs_x, abs_y, nmin, nmax, dev->fingers, ibt);
389 
390 	}
391 
392 	/* type 2 reports button events via ibt only */
393 	if (c->tp_type == TYPE2)
394 		input_report_key(input, BTN_LEFT, ibt);
395 
396 	input_sync(input);
397 
398 	return 0;
399 }
400 
401 /* Wellspring initialization constants */
402 #define BCM5974_WELLSPRING_MODE_READ_REQUEST_ID		1
403 #define BCM5974_WELLSPRING_MODE_WRITE_REQUEST_ID	9
404 #define BCM5974_WELLSPRING_MODE_REQUEST_VALUE		0x300
405 #define BCM5974_WELLSPRING_MODE_REQUEST_INDEX		0
406 #define BCM5974_WELLSPRING_MODE_VENDOR_VALUE		0x01
407 #define BCM5974_WELLSPRING_MODE_NORMAL_VALUE		0x08
408 
409 static int bcm5974_wellspring_mode(struct bcm5974 *dev, bool on)
410 {
411 	char *data = kmalloc(8, GFP_KERNEL);
412 	int retval = 0, size;
413 
414 	if (!data) {
415 		err("bcm5974: out of memory");
416 		retval = -ENOMEM;
417 		goto out;
418 	}
419 
420 	/* read configuration */
421 	size = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
422 			BCM5974_WELLSPRING_MODE_READ_REQUEST_ID,
423 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
424 			BCM5974_WELLSPRING_MODE_REQUEST_VALUE,
425 			BCM5974_WELLSPRING_MODE_REQUEST_INDEX, data, 8, 5000);
426 
427 	if (size != 8) {
428 		err("bcm5974: could not read from device");
429 		retval = -EIO;
430 		goto out;
431 	}
432 
433 	/* apply the mode switch */
434 	data[0] = on ?
435 		BCM5974_WELLSPRING_MODE_VENDOR_VALUE :
436 		BCM5974_WELLSPRING_MODE_NORMAL_VALUE;
437 
438 	/* write configuration */
439 	size = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
440 			BCM5974_WELLSPRING_MODE_WRITE_REQUEST_ID,
441 			USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
442 			BCM5974_WELLSPRING_MODE_REQUEST_VALUE,
443 			BCM5974_WELLSPRING_MODE_REQUEST_INDEX, data, 8, 5000);
444 
445 	if (size != 8) {
446 		err("bcm5974: could not write to device");
447 		retval = -EIO;
448 		goto out;
449 	}
450 
451 	dprintk(2, "bcm5974: switched to %s mode.\n",
452 		on ? "wellspring" : "normal");
453 
454  out:
455 	kfree(data);
456 	return retval;
457 }
458 
459 static void bcm5974_irq_button(struct urb *urb)
460 {
461 	struct bcm5974 *dev = urb->context;
462 	int error;
463 
464 	switch (urb->status) {
465 	case 0:
466 		break;
467 	case -EOVERFLOW:
468 	case -ECONNRESET:
469 	case -ENOENT:
470 	case -ESHUTDOWN:
471 		dbg("bcm5974: button urb shutting down: %d", urb->status);
472 		return;
473 	default:
474 		dbg("bcm5974: button urb status: %d", urb->status);
475 		goto exit;
476 	}
477 
478 	if (report_bt_state(dev, dev->bt_urb->actual_length))
479 		dprintk(1, "bcm5974: bad button package, length: %d\n",
480 			dev->bt_urb->actual_length);
481 
482 exit:
483 	error = usb_submit_urb(dev->bt_urb, GFP_ATOMIC);
484 	if (error)
485 		err("bcm5974: button urb failed: %d", error);
486 }
487 
488 static void bcm5974_irq_trackpad(struct urb *urb)
489 {
490 	struct bcm5974 *dev = urb->context;
491 	int error;
492 
493 	switch (urb->status) {
494 	case 0:
495 		break;
496 	case -EOVERFLOW:
497 	case -ECONNRESET:
498 	case -ENOENT:
499 	case -ESHUTDOWN:
500 		dbg("bcm5974: trackpad urb shutting down: %d", urb->status);
501 		return;
502 	default:
503 		dbg("bcm5974: trackpad urb status: %d", urb->status);
504 		goto exit;
505 	}
506 
507 	/* control response ignored */
508 	if (dev->tp_urb->actual_length == 2)
509 		goto exit;
510 
511 	if (report_tp_state(dev, dev->tp_urb->actual_length))
512 		dprintk(1, "bcm5974: bad trackpad package, length: %d\n",
513 			dev->tp_urb->actual_length);
514 
515 exit:
516 	error = usb_submit_urb(dev->tp_urb, GFP_ATOMIC);
517 	if (error)
518 		err("bcm5974: trackpad urb failed: %d", error);
519 }
520 
521 /*
522  * The Wellspring trackpad, like many recent Apple trackpads, share
523  * the usb device with the keyboard. Since keyboards are usually
524  * handled by the HID system, the device ends up being handled by two
525  * modules. Setting up the device therefore becomes slightly
526  * complicated. To enable multitouch features, a mode switch is
527  * required, which is usually applied via the control interface of the
528  * device.  It can be argued where this switch should take place. In
529  * some drivers, like appletouch, the switch is made during
530  * probe. However, the hid module may also alter the state of the
531  * device, resulting in trackpad malfunction under certain
532  * circumstances. To get around this problem, there is at least one
533  * example that utilizes the USB_QUIRK_RESET_RESUME quirk in order to
534  * recieve a reset_resume request rather than the normal resume.
535  * Since the implementation of reset_resume is equal to mode switch
536  * plus start_traffic, it seems easier to always do the switch when
537  * starting traffic on the device.
538  */
539 static int bcm5974_start_traffic(struct bcm5974 *dev)
540 {
541 	if (bcm5974_wellspring_mode(dev, true)) {
542 		dprintk(1, "bcm5974: mode switch failed\n");
543 		goto error;
544 	}
545 
546 	if (usb_submit_urb(dev->bt_urb, GFP_KERNEL))
547 		goto error;
548 
549 	if (usb_submit_urb(dev->tp_urb, GFP_KERNEL))
550 		goto err_kill_bt;
551 
552 	return 0;
553 
554 err_kill_bt:
555 	usb_kill_urb(dev->bt_urb);
556 error:
557 	return -EIO;
558 }
559 
560 static void bcm5974_pause_traffic(struct bcm5974 *dev)
561 {
562 	usb_kill_urb(dev->tp_urb);
563 	usb_kill_urb(dev->bt_urb);
564 	bcm5974_wellspring_mode(dev, false);
565 }
566 
567 /*
568  * The code below implements open/close and manual suspend/resume.
569  * All functions may be called in random order.
570  *
571  * Opening a suspended device fails with EACCES - permission denied.
572  *
573  * Failing a resume leaves the device resumed but closed.
574  */
575 static int bcm5974_open(struct input_dev *input)
576 {
577 	struct bcm5974 *dev = input_get_drvdata(input);
578 	int error;
579 
580 	error = usb_autopm_get_interface(dev->intf);
581 	if (error)
582 		return error;
583 
584 	mutex_lock(&dev->pm_mutex);
585 
586 	error = bcm5974_start_traffic(dev);
587 	if (!error)
588 		dev->opened = 1;
589 
590 	mutex_unlock(&dev->pm_mutex);
591 
592 	if (error)
593 		usb_autopm_put_interface(dev->intf);
594 
595 	return error;
596 }
597 
598 static void bcm5974_close(struct input_dev *input)
599 {
600 	struct bcm5974 *dev = input_get_drvdata(input);
601 
602 	mutex_lock(&dev->pm_mutex);
603 
604 	bcm5974_pause_traffic(dev);
605 	dev->opened = 0;
606 
607 	mutex_unlock(&dev->pm_mutex);
608 
609 	usb_autopm_put_interface(dev->intf);
610 }
611 
612 static int bcm5974_suspend(struct usb_interface *iface, pm_message_t message)
613 {
614 	struct bcm5974 *dev = usb_get_intfdata(iface);
615 
616 	mutex_lock(&dev->pm_mutex);
617 
618 	if (dev->opened)
619 		bcm5974_pause_traffic(dev);
620 
621 	mutex_unlock(&dev->pm_mutex);
622 
623 	return 0;
624 }
625 
626 static int bcm5974_resume(struct usb_interface *iface)
627 {
628 	struct bcm5974 *dev = usb_get_intfdata(iface);
629 	int error = 0;
630 
631 	mutex_lock(&dev->pm_mutex);
632 
633 	if (dev->opened)
634 		error = bcm5974_start_traffic(dev);
635 
636 	mutex_unlock(&dev->pm_mutex);
637 
638 	return error;
639 }
640 
641 static int bcm5974_probe(struct usb_interface *iface,
642 			 const struct usb_device_id *id)
643 {
644 	struct usb_device *udev = interface_to_usbdev(iface);
645 	const struct bcm5974_config *cfg;
646 	struct bcm5974 *dev;
647 	struct input_dev *input_dev;
648 	int error = -ENOMEM;
649 
650 	/* find the product index */
651 	cfg = bcm5974_get_config(udev);
652 
653 	/* allocate memory for our device state and initialize it */
654 	dev = kzalloc(sizeof(struct bcm5974), GFP_KERNEL);
655 	input_dev = input_allocate_device();
656 	if (!dev || !input_dev) {
657 		err("bcm5974: out of memory");
658 		goto err_free_devs;
659 	}
660 
661 	dev->udev = udev;
662 	dev->intf = iface;
663 	dev->input = input_dev;
664 	dev->cfg = *cfg;
665 	mutex_init(&dev->pm_mutex);
666 
667 	/* setup urbs */
668 	dev->bt_urb = usb_alloc_urb(0, GFP_KERNEL);
669 	if (!dev->bt_urb)
670 		goto err_free_devs;
671 
672 	dev->tp_urb = usb_alloc_urb(0, GFP_KERNEL);
673 	if (!dev->tp_urb)
674 		goto err_free_bt_urb;
675 
676 	dev->bt_data = usb_buffer_alloc(dev->udev,
677 					dev->cfg.bt_datalen, GFP_KERNEL,
678 					&dev->bt_urb->transfer_dma);
679 	if (!dev->bt_data)
680 		goto err_free_urb;
681 
682 	dev->tp_data = usb_buffer_alloc(dev->udev,
683 					dev->cfg.tp_datalen, GFP_KERNEL,
684 					&dev->tp_urb->transfer_dma);
685 	if (!dev->tp_data)
686 		goto err_free_bt_buffer;
687 
688 	usb_fill_int_urb(dev->bt_urb, udev,
689 			 usb_rcvintpipe(udev, cfg->bt_ep),
690 			 dev->bt_data, dev->cfg.bt_datalen,
691 			 bcm5974_irq_button, dev, 1);
692 
693 	usb_fill_int_urb(dev->tp_urb, udev,
694 			 usb_rcvintpipe(udev, cfg->tp_ep),
695 			 dev->tp_data, dev->cfg.tp_datalen,
696 			 bcm5974_irq_trackpad, dev, 1);
697 
698 	/* create bcm5974 device */
699 	usb_make_path(udev, dev->phys, sizeof(dev->phys));
700 	strlcat(dev->phys, "/input0", sizeof(dev->phys));
701 
702 	input_dev->name = "bcm5974";
703 	input_dev->phys = dev->phys;
704 	usb_to_input_id(dev->udev, &input_dev->id);
705 	/* report driver capabilities via the version field */
706 	input_dev->id.version = cfg->caps;
707 	input_dev->dev.parent = &iface->dev;
708 
709 	input_set_drvdata(input_dev, dev);
710 
711 	input_dev->open = bcm5974_open;
712 	input_dev->close = bcm5974_close;
713 
714 	setup_events_to_report(input_dev, cfg);
715 
716 	error = input_register_device(dev->input);
717 	if (error)
718 		goto err_free_buffer;
719 
720 	/* save our data pointer in this interface device */
721 	usb_set_intfdata(iface, dev);
722 
723 	return 0;
724 
725 err_free_buffer:
726 	usb_buffer_free(dev->udev, dev->cfg.tp_datalen,
727 		dev->tp_data, dev->tp_urb->transfer_dma);
728 err_free_bt_buffer:
729 	usb_buffer_free(dev->udev, dev->cfg.bt_datalen,
730 		dev->bt_data, dev->bt_urb->transfer_dma);
731 err_free_urb:
732 	usb_free_urb(dev->tp_urb);
733 err_free_bt_urb:
734 	usb_free_urb(dev->bt_urb);
735 err_free_devs:
736 	usb_set_intfdata(iface, NULL);
737 	input_free_device(input_dev);
738 	kfree(dev);
739 	return error;
740 }
741 
742 static void bcm5974_disconnect(struct usb_interface *iface)
743 {
744 	struct bcm5974 *dev = usb_get_intfdata(iface);
745 
746 	usb_set_intfdata(iface, NULL);
747 
748 	input_unregister_device(dev->input);
749 	usb_buffer_free(dev->udev, dev->cfg.tp_datalen,
750 			dev->tp_data, dev->tp_urb->transfer_dma);
751 	usb_buffer_free(dev->udev, dev->cfg.bt_datalen,
752 			dev->bt_data, dev->bt_urb->transfer_dma);
753 	usb_free_urb(dev->tp_urb);
754 	usb_free_urb(dev->bt_urb);
755 	kfree(dev);
756 }
757 
758 static struct usb_driver bcm5974_driver = {
759 	.name			= "bcm5974",
760 	.probe			= bcm5974_probe,
761 	.disconnect		= bcm5974_disconnect,
762 	.suspend		= bcm5974_suspend,
763 	.resume			= bcm5974_resume,
764 	.reset_resume		= bcm5974_resume,
765 	.id_table		= bcm5974_table,
766 	.supports_autosuspend	= 1,
767 };
768 
769 static int __init bcm5974_init(void)
770 {
771 	return usb_register(&bcm5974_driver);
772 }
773 
774 static void __exit bcm5974_exit(void)
775 {
776 	usb_deregister(&bcm5974_driver);
777 }
778 
779 module_init(bcm5974_init);
780 module_exit(bcm5974_exit);
781 
782