summaryrefslogtreecommitdiffstats
path: root/drivers/usb/misc/appledisplay.c
blob: 416cde5893af83585a94bb3b787f6fc6b56bc93b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
/*
 * Apple Cinema Display driver
 *
 * Copyright (C) 2006  Michael Hanselmann (linux-kernel@hansmi.ch)
 *
 * Thanks to Caskey L. Dickson for his work with acdctl.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/backlight.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <asm/atomic.h>
#include <asm/semaphore.h>

#define APPLE_VENDOR_ID		0x05AC

#define USB_REQ_GET_REPORT	0x01
#define USB_REQ_SET_REPORT	0x09

#define ACD_USB_TIMEOUT		250

#define ACD_USB_EDID		0x0302
#define ACD_USB_BRIGHTNESS	0x0310

#define ACD_BTN_NONE		0
#define ACD_BTN_BRIGHT_UP	3
#define ACD_BTN_BRIGHT_DOWN	4

#define ACD_URB_BUFFER_LEN	2
#define ACD_MSG_BUFFER_LEN	2

#define APPLEDISPLAY_DEVICE(prod)				\
	.match_flags = USB_DEVICE_ID_MATCH_DEVICE |		\
		       USB_DEVICE_ID_MATCH_INT_CLASS |		\
		       USB_DEVICE_ID_MATCH_INT_PROTOCOL,	\
	.idVendor = APPLE_VENDOR_ID,				\
	.idProduct = (prod),					\
	.bInterfaceClass = USB_CLASS_HID,			\
	.bInterfaceProtocol = 0x00

/* table of devices that work with this driver */
static struct usb_device_id appledisplay_table [] = {
	{ APPLEDISPLAY_DEVICE(0x9218) },
	{ APPLEDISPLAY_DEVICE(0x9219) },
	{ APPLEDISPLAY_DEVICE(0x921d) },

	/* Terminating entry */
	{ }
};
MODULE_DEVICE_TABLE(usb, appledisplay_table);

/* Structure to hold all of our device specific stuff */
struct appledisplay {
	struct usb_device *udev;	/* usb device */
	struct urb *urb;		/* usb request block */
	struct backlight_device *bd;	/* backlight device */
	char *urbdata;			/* interrupt URB data buffer */
	char *msgdata;			/* control message data buffer */

	struct delayed_work work;
	int button_pressed;
	spinlock_t lock;
};

static atomic_t count_displays = ATOMIC_INIT(0);
static struct workqueue_struct *wq;

static void appledisplay_complete(struct urb *urb)
{
	struct appledisplay *pdata = urb->context;
	unsigned long flags;
	int retval;

	switch (urb->status) {
	case 0:
		/* success */
		break;
	case -EOVERFLOW:
		printk(KERN_ERR "appletouch: OVERFLOW with data "
			"length %d, actual length is %d\n",
			ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		/* This urb is terminated, clean up */
		dbg("%s - urb shutting down with status: %d",
			__FUNCTION__, urb->status);
		return;
	default:
		dbg("%s - nonzero urb status received: %d",
			__FUNCTION__, urb->status);
		goto exit;
	}

	spin_lock_irqsave(&pdata->lock, flags);

	switch(pdata->urbdata[1]) {
	case ACD_BTN_BRIGHT_UP:
	case ACD_BTN_BRIGHT_DOWN:
		pdata->button_pressed = 1;
		queue_delayed_work(wq, &pdata->work, 0);
		break;
	case ACD_BTN_NONE:
	default:
		pdata->button_pressed = 0;
		break;
	}

	spin_unlock_irqrestore(&pdata->lock, flags);

exit:
	retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
	if (retval) {
		err("%s - usb_submit_urb failed with result %d",
			__FUNCTION__, retval);
	}
}

static int appledisplay_bl_update_status(struct backlight_device *bd)
{
	struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
	int retval;

	pdata->msgdata[0] = 0x10;
	pdata->msgdata[1] = bd->props->brightness;

	retval = usb_control_msg(
		pdata->udev,
		usb_sndctrlpipe(pdata->udev, 0),
		USB_REQ_SET_REPORT,
		USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
		ACD_USB_BRIGHTNESS,
		0,
		pdata->msgdata, 2,
		ACD_USB_TIMEOUT);

	return retval;
}

static int appledisplay_bl_get_brightness(struct backlight_device *bd)
{
	struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
	int retval;

	retval = usb_control_msg(
		pdata->udev,
		usb_rcvctrlpipe(pdata->udev, 0),
		USB_REQ_GET_REPORT,
		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
		ACD_USB_BRIGHTNESS,
		0,
		pdata->msgdata, 2,
		ACD_USB_TIMEOUT);

	if (retval < 0)
		return retval;
	else
		return pdata->msgdata[1];
}

static struct backlight_properties appledisplay_bl_data = {
	.get_brightness	= appledisplay_bl_get_brightness,
	.update_status	= appledisplay_bl_update_status,
	.max_brightness	= 0xFF
};

static void appledisplay_work(struct work_struct *work)
{
	struct appledisplay *pdata =
		container_of(work, struct appledisplay, work.work);
	int retval;

	up(&pdata->bd->sem);
	retval = appledisplay_bl_get_brightness(pdata->bd);
	if (retval >= 0)
		pdata->bd->props->brightness = retval;
	down(&pdata->bd->sem);

	/* Poll again in about 125ms if there's still a button pressed */
	if (pdata->button_pressed)
		schedule_delayed_work(&pdata->work, HZ / 8);
}

static int appledisplay_probe(struct usb_interface *iface,
	const struct usb_device_id *id)
{
	struct appledisplay *pdata;
	struct usb_device *udev = interface_to_usbdev(iface);
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor *endpoint;
	int int_in_endpointAddr = 0;
	int i, retval = -ENOMEM, brightness;
	char bl_name[20];

	/* set up the endpoint information */
	/* use only the first interrupt-in endpoint */
	iface_desc = iface->cur_altsetting;
	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
		endpoint = &iface_desc->endpoint[i].desc;
		if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
			/* we found an interrupt in endpoint */
			int_in_endpointAddr = endpoint->bEndpointAddress;
			break;
		}
	}
	if (!int_in_endpointAddr) {
		err("Could not find int-in endpoint");
		return -EIO;
	}

	/* allocate memory for our device state and initialize it */
	pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
	if (!pdata) {
		retval = -ENOMEM;
		err("Out of memory");
		goto error;
	}

	pdata->udev = udev;

	spin_lock_init(&pdata->lock);
	INIT_DELAYED_WORK(&pdata->work, appledisplay_work);

	/* Allocate buffer for control messages */
	pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
	if (!pdata->msgdata) {
		retval = -ENOMEM;
		err("appledisplay: Allocating buffer for control messages "
			"failed");
		goto error;
	}

	/* Allocate interrupt URB */
	pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!pdata->urb) {
		retval = -ENOMEM;
		err("appledisplay: Allocating URB failed");
		goto error;
	}

	/* Allocate buffer for interrupt data */
	pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN,
		GFP_KERNEL, &pdata->urb->transfer_dma);
	if (!pdata->urbdata) {
		retval = -ENOMEM;
		err("appledisplay: Allocating URB buffer failed");
		goto error;
	}

	/* Configure interrupt URB */
	usb_fill_int_urb(pdata->urb, udev,
		usb_rcvintpipe(udev, int_in_endpointAddr),
		pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
		pdata, 1);
	if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
		retval = -EIO;
		err("appledisplay: Submitting URB failed");
		goto error;
	}

	/* Register backlight device */
	snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
		atomic_inc_return(&count_displays) - 1);
	pdata->bd = backlight_device_register(bl_name, NULL, pdata,
						&appledisplay_bl_data);
	if (IS_ERR(pdata->bd)) {
		err("appledisplay: Backlight registration failed");
		goto error;
	}

	/* Try to get brightness */
	up(&pdata->bd->sem);
	brightness = appledisplay_bl_get_brightness(pdata->bd);
	down(&pdata->bd->sem);

	if (brightness < 0) {
		retval = brightness;
		err("appledisplay: Error while getting initial brightness: %d", retval);
		goto error;
	}

	/* Set brightness in backlight device */
	up(&pdata->bd->sem);
	pdata->bd->props->brightness = brightness;
	down(&pdata->bd->sem);

	/* save our data pointer in the interface device */
	usb_set_intfdata(iface, pdata);

	printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");

	return 0;

error:
	if (pdata) {
		if (pdata->urb) {
			usb_kill_urb(pdata->urb);
			if (pdata->urbdata)
				usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
					pdata->urbdata, pdata->urb->transfer_dma);
			usb_free_urb(pdata->urb);
		}
		if (pdata->bd)
			backlight_device_unregister(pdata->bd);
		kfree(pdata->msgdata);
	}
	usb_set_intfdata(iface, NULL);
	kfree(pdata);
	return retval;
}

static void appledisplay_disconnect(struct usb_interface *iface)
{
	struct appledisplay *pdata = usb_get_intfdata(iface);

	if (pdata) {
		usb_kill_urb(pdata->urb);
		cancel_delayed_work(&pdata->work);
		backlight_device_unregister(pdata->bd);
		usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
			pdata->urbdata, pdata->urb->transfer_dma);
		usb_free_urb(pdata->urb);
		kfree(pdata->msgdata);
		kfree(pdata);
	}

	printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
}

static struct usb_driver appledisplay_driver = {
	.name		= "appledisplay",
	.probe		= appledisplay_probe,
	.disconnect	= appledisplay_disconnect,
	.id_table	= appledisplay_table,
};

static int __init appledisplay_init(void)
{
	wq = create_singlethread_workqueue("appledisplay");
	if (!wq) {
		err("Could not create work queue\n");
		return -ENOMEM;
	}

	return usb_register(&appledisplay_driver);
}

static void __exit appledisplay_exit(void)
{
	flush_workqueue(wq);
	destroy_workqueue(wq);
	usb_deregister(&appledisplay_driver);
}

MODULE_AUTHOR("Michael Hanselmann");
MODULE_DESCRIPTION("Apple Cinema Display driver");
MODULE_LICENSE("GPL");

module_init(appledisplay_init);
module_exit(appledisplay_exit);