[deliverable/linux.git] / drivers / usb / misc / appledisplay.c

/*
 * 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/slab.h>
#include <linux/usb.h>
#include <linux/backlight.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/atomic.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 const struct usb_device_id appledisplay_table[] = {
	{ APPLEDISPLAY_DEVICE(0x9218) },
	{ APPLEDISPLAY_DEVICE(0x9219) },
	{ APPLEDISPLAY_DEVICE(0x921c) },
	{ APPLEDISPLAY_DEVICE(0x921d) },
	{ APPLEDISPLAY_DEVICE(0x9236) },

	/* 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 */
	u8 *urbdata;			/* interrupt URB data buffer */
	u8 *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;
	struct device *dev = &pdata->udev->dev;
	unsigned long flags;
	int status = urb->status;
	int retval;

	switch (status) {
	case 0:
		/* success */
		break;
	case -EOVERFLOW:
		dev_err(dev,
			"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 */
		dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
			__func__, status);
		return;
	default:
		dev_dbg(dev, "%s - nonzero urb status received: %d/n",
			__func__, 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) {
		dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
			__func__, retval);
	}
}

static int appledisplay_bl_update_status(struct backlight_device *bd)
{
	struct appledisplay *pdata = bl_get_data(bd);
	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 = bl_get_data(bd);
	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 const struct backlight_ops appledisplay_bl_data = {
	.get_brightness	= appledisplay_bl_get_brightness,
	.update_status	= appledisplay_bl_update_status,
};

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

	retval = appledisplay_bl_get_brightness(pdata->bd);
	if (retval >= 0)
		pdata->bd->props.brightness = retval;

	/* 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 backlight_properties props;
	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) {
		dev_err(&iface->dev, "Could not find int-in endpoint\n");
		return -EIO;
	}

	/* allocate memory for our device state and initialize it */
	pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
	if (!pdata) {
		retval = -ENOMEM;
		dev_err(&iface->dev, "Out of memory\n");
		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;
		dev_err(&iface->dev,
			"Allocating buffer for control messages failed\n");
		goto error;
	}

	/* Allocate interrupt URB */
	pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!pdata->urb) {
		retval = -ENOMEM;
		dev_err(&iface->dev, "Allocating URB failed\n");
		goto error;
	}

	/* Allocate buffer for interrupt data */
	pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
		GFP_KERNEL, &pdata->urb->transfer_dma);
	if (!pdata->urbdata) {
		retval = -ENOMEM;
		dev_err(&iface->dev, "Allocating URB buffer failed\n");
		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;
		dev_err(&iface->dev, "Submitting URB failed\n");
		goto error;
	}

	/* Register backlight device */
	snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
		atomic_inc_return(&count_displays) - 1);
	memset(&props, 0, sizeof(struct backlight_properties));
	props.type = BACKLIGHT_RAW;
	props.max_brightness = 0xff;
	pdata->bd = backlight_device_register(bl_name, NULL, pdata,
					      &appledisplay_bl_data, &props);
	if (IS_ERR(pdata->bd)) {
		dev_err(&iface->dev, "Backlight registration failed\n");
		retval = PTR_ERR(pdata->bd);
		goto error;
	}

	/* Try to get brightness */
	brightness = appledisplay_bl_get_brightness(pdata->bd);

	if (brightness < 0) {
		retval = brightness;
		dev_err(&iface->dev,
			"Error while getting initial brightness: %d\n", retval);
		goto error;
	}

	/* Set brightness in backlight device */
	pdata->bd->props.brightness = brightness;

	/* 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_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
					pdata->urbdata, pdata->urb->transfer_dma);
			usb_free_urb(pdata->urb);
		}
		if (pdata->bd && !IS_ERR(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_free_coherent(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) {
		printk(KERN_ERR "appledisplay: 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);
Commit	Line	Data
069e8a65	1	/*
	2	* Apple Cinema Display driver
	3	*
	4	* Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
	5	*
	6	* Thanks to Caskey L. Dickson for his work with acdctl.
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	21	*/
	22
069e8a65	23	#include <linux/kernel.h>
	24	#include <linux/errno.h>
	25	#include <linux/init.h>
	26	#include <linux/module.h>
5a0e3ad6	27	#include <linux/slab.h>
069e8a65	28	#include <linux/usb.h>
	29	#include <linux/backlight.h>
	30	#include <linux/timer.h>
	31	#include <linux/workqueue.h>
60063497	32	#include <linux/atomic.h>
069e8a65	33
	34	#define APPLE_VENDOR_ID 0x05AC
	35
	36	#define USB_REQ_GET_REPORT 0x01
	37	#define USB_REQ_SET_REPORT 0x09
	38
	39	#define ACD_USB_TIMEOUT 250
	40
	41	#define ACD_USB_EDID 0x0302
	42	#define ACD_USB_BRIGHTNESS 0x0310
	43
	44	#define ACD_BTN_NONE 0
	45	#define ACD_BTN_BRIGHT_UP 3
	46	#define ACD_BTN_BRIGHT_DOWN 4
	47
	48	#define ACD_URB_BUFFER_LEN 2
	49	#define ACD_MSG_BUFFER_LEN 2
	50
	51	#define APPLEDISPLAY_DEVICE(prod) \
	52	.match_flags = USB_DEVICE_ID_MATCH_DEVICE \| \
	53	USB_DEVICE_ID_MATCH_INT_CLASS \| \
	54	USB_DEVICE_ID_MATCH_INT_PROTOCOL, \
	55	.idVendor = APPLE_VENDOR_ID, \
	56	.idProduct = (prod), \
	57	.bInterfaceClass = USB_CLASS_HID, \
	58	.bInterfaceProtocol = 0x00
	59
	60	/* table of devices that work with this driver */
33b9e162	61	static const struct usb_device_id appledisplay_table[] = {
069e8a65	62	{ APPLEDISPLAY_DEVICE(0x9218) },
069e8a65	63	{ APPLEDISPLAY_DEVICE(0x9219) },
4b372072	64	{ APPLEDISPLAY_DEVICE(0x921c) },
069e8a65	65	{ APPLEDISPLAY_DEVICE(0x921d) },
e7d3b6e2	66	{ APPLEDISPLAY_DEVICE(0x9236) },
069e8a65	67
	68	/* Terminating entry */
	69	{ }
	70	};
	71	MODULE_DEVICE_TABLE(usb, appledisplay_table);
	72
	73	/* Structure to hold all of our device specific stuff */
	74	struct appledisplay {
	75	struct usb_device udev; / usb device */
	76	struct urb urb; / usb request block */
	77	struct backlight_device bd; / backlight device */
37e9066b	78	u8 urbdata; / interrupt URB data buffer */
37e9066b	79	u8 msgdata; / control message data buffer */
069e8a65	80
6d5aefb8	81	struct delayed_work work;
069e8a65	82	int button_pressed;
	83	spinlock_t lock;
	84	};
	85
	86	static atomic_t count_displays = ATOMIC_INIT(0);
	87	static struct workqueue_struct *wq;
	88
7d12e780	89	static void appledisplay_complete(struct urb *urb)
069e8a65	90	{
069e8a65	91	struct appledisplay *pdata = urb->context;
0a3fd536	92	struct device *dev = &pdata->udev->dev;
069e8a65	93	unsigned long flags;
13f9782d	94	int status = urb->status;
069e8a65	95	int retval;
069e8a65	96
13f9782d	97	switch (status) {
069e8a65	98	case 0:
	99	/* success */
	100	break;
	101	case -EOVERFLOW:
0a3fd536 GKH	102	dev_err(dev,
0a3fd536 GKH	103	"OVERFLOW with data length %d, actual length is %d\n",
069e8a65	104	ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
	105	case -ECONNRESET:
	106	case -ENOENT:
	107	case -ESHUTDOWN:
	108	/* This urb is terminated, clean up */
0a3fd536	109	dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
441b62c1	110	__func__, status);
069e8a65	111	return;
069e8a65	112	default:
0a3fd536	113	dev_dbg(dev, "%s - nonzero urb status received: %d/n",
441b62c1	114	__func__, status);
069e8a65	115	goto exit;
	116	}
	117
	118	spin_lock_irqsave(&pdata->lock, flags);
	119
	120	switch(pdata->urbdata[1]) {
	121	case ACD_BTN_BRIGHT_UP:
	122	case ACD_BTN_BRIGHT_DOWN:
	123	pdata->button_pressed = 1;
6d5aefb8	124	queue_delayed_work(wq, &pdata->work, 0);
069e8a65	125	break;
	126	case ACD_BTN_NONE:
	127	default:
	128	pdata->button_pressed = 0;
	129	break;
	130	}
	131
	132	spin_unlock_irqrestore(&pdata->lock, flags);
	133
	134	exit:
	135	retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
	136	if (retval) {
0a3fd536	137	dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
441b62c1	138	__func__, retval);
069e8a65	139	}
	140	}
	141
	142	static int appledisplay_bl_update_status(struct backlight_device *bd)
	143	{
655bfd7a	144	struct appledisplay *pdata = bl_get_data(bd);
069e8a65	145	int retval;
	146
	147	pdata->msgdata[0] = 0x10;
599a52d1	148	pdata->msgdata[1] = bd->props.brightness;
069e8a65	149
	150	retval = usb_control_msg(
	151	pdata->udev,
	152	usb_sndctrlpipe(pdata->udev, 0),
	153	USB_REQ_SET_REPORT,
	154	USB_DIR_OUT \| USB_TYPE_CLASS \| USB_RECIP_INTERFACE,
	155	ACD_USB_BRIGHTNESS,
	156	0,
	157	pdata->msgdata, 2,
	158	ACD_USB_TIMEOUT);
	159
	160	return retval;
	161	}
	162
	163	static int appledisplay_bl_get_brightness(struct backlight_device *bd)
	164	{
655bfd7a	165	struct appledisplay *pdata = bl_get_data(bd);
069e8a65	166	int retval;
	167
	168	retval = usb_control_msg(
	169	pdata->udev,
	170	usb_rcvctrlpipe(pdata->udev, 0),
	171	USB_REQ_GET_REPORT,
	172	USB_DIR_IN \| USB_TYPE_CLASS \| USB_RECIP_INTERFACE,
	173	ACD_USB_BRIGHTNESS,
	174	0,
	175	pdata->msgdata, 2,
	176	ACD_USB_TIMEOUT);
	177
	178	if (retval < 0)
	179	return retval;
	180	else
	181	return pdata->msgdata[1];
	182	}
	183
cedf8a78	184	static const struct backlight_ops appledisplay_bl_data = {
069e8a65	185	.get_brightness = appledisplay_bl_get_brightness,
069e8a65	186	.update_status = appledisplay_bl_update_status,
069e8a65	187	};
069e8a65	188
6d5aefb8	189	static void appledisplay_work(struct work_struct *work)
069e8a65	190	{
6d5aefb8 DH	191	struct appledisplay *pdata =
6d5aefb8 DH	192	container_of(work, struct appledisplay, work.work);
069e8a65	193	int retval;
069e8a65	194
069e8a65	195	retval = appledisplay_bl_get_brightness(pdata->bd);
069e8a65	196	if (retval >= 0)
599a52d1	197	pdata->bd->props.brightness = retval;
069e8a65	198
	199	/* Poll again in about 125ms if there's still a button pressed */
	200	if (pdata->button_pressed)
	201	schedule_delayed_work(&pdata->work, HZ / 8);
	202	}
	203
	204	static int appledisplay_probe(struct usb_interface *iface,
	205	const struct usb_device_id *id)
	206	{
a19a6ee6	207	struct backlight_properties props;
069e8a65	208	struct appledisplay *pdata;
	209	struct usb_device *udev = interface_to_usbdev(iface);
	210	struct usb_host_interface *iface_desc;
	211	struct usb_endpoint_descriptor *endpoint;
	212	int int_in_endpointAddr = 0;
	213	int i, retval = -ENOMEM, brightness;
	214	char bl_name[20];
	215
	216	/* set up the endpoint information */
	217	/* use only the first interrupt-in endpoint */
	218	iface_desc = iface->cur_altsetting;
	219	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
	220	endpoint = &iface_desc->endpoint[i].desc;
16f96376	221	if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
069e8a65	222	/* we found an interrupt in endpoint */
	223	int_in_endpointAddr = endpoint->bEndpointAddress;
	224	break;
	225	}
	226	}
	227	if (!int_in_endpointAddr) {
fd3f1917	228	dev_err(&iface->dev, "Could not find int-in endpoint\n");
069e8a65	229	return -EIO;
	230	}
	231
	232	/* allocate memory for our device state and initialize it */
	233	pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
	234	if (!pdata) {
	235	retval = -ENOMEM;
fd3f1917	236	dev_err(&iface->dev, "Out of memory\n");
069e8a65	237	goto error;
	238	}
	239
	240	pdata->udev = udev;
	241
	242	spin_lock_init(&pdata->lock);
6d5aefb8	243	INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
069e8a65	244
	245	/* Allocate buffer for control messages */
	246	pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
	247	if (!pdata->msgdata) {
	248	retval = -ENOMEM;
fd3f1917 GKH	249	dev_err(&iface->dev,
fd3f1917 GKH	250	"Allocating buffer for control messages failed\n");
069e8a65	251	goto error;
	252	}
	253
	254	/* Allocate interrupt URB */
	255	pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
	256	if (!pdata->urb) {
	257	retval = -ENOMEM;
fd3f1917	258	dev_err(&iface->dev, "Allocating URB failed\n");
069e8a65	259	goto error;
	260	}
	261
	262	/* Allocate buffer for interrupt data */
997ea58e	263	pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
069e8a65	264	GFP_KERNEL, &pdata->urb->transfer_dma);
	265	if (!pdata->urbdata) {
	266	retval = -ENOMEM;
fd3f1917	267	dev_err(&iface->dev, "Allocating URB buffer failed\n");
069e8a65	268	goto error;
	269	}
	270
	271	/* Configure interrupt URB */
	272	usb_fill_int_urb(pdata->urb, udev,
	273	usb_rcvintpipe(udev, int_in_endpointAddr),
	274	pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
	275	pdata, 1);
	276	if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
	277	retval = -EIO;
fd3f1917	278	dev_err(&iface->dev, "Submitting URB failed\n");
069e8a65	279	goto error;
	280	}
	281
	282	/* Register backlight device */
	283	snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
	284	atomic_inc_return(&count_displays) - 1);
a19a6ee6	285	memset(&props, 0, sizeof(struct backlight_properties));
bb7ca747	286	props.type = BACKLIGHT_RAW;
a19a6ee6	287	props.max_brightness = 0xff;
81450b73	288	pdata->bd = backlight_device_register(bl_name, NULL, pdata,
a19a6ee6	289	&appledisplay_bl_data, &props);
069e8a65	290	if (IS_ERR(pdata->bd)) {
fd3f1917	291	dev_err(&iface->dev, "Backlight registration failed\n");
cedf8a78	292	retval = PTR_ERR(pdata->bd);
069e8a65	293	goto error;
	294	}
	295
	296	/* Try to get brightness */
069e8a65	297	brightness = appledisplay_bl_get_brightness(pdata->bd);
069e8a65	298
	299	if (brightness < 0) {
	300	retval = brightness;
fd3f1917 GKH	301	dev_err(&iface->dev,
fd3f1917 GKH	302	"Error while getting initial brightness: %d\n", retval);
069e8a65	303	goto error;
	304	}
	305
	306	/* Set brightness in backlight device */
599a52d1	307	pdata->bd->props.brightness = brightness;
069e8a65	308
	309	/* save our data pointer in the interface device */
	310	usb_set_intfdata(iface, pdata);
	311
	312	printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
	313
	314	return 0;
	315
	316	error:
	317	if (pdata) {
	318	if (pdata->urb) {
	319	usb_kill_urb(pdata->urb);
	320	if (pdata->urbdata)
997ea58e	321	usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
069e8a65	322	pdata->urbdata, pdata->urb->transfer_dma);
	323	usb_free_urb(pdata->urb);
	324	}
bedf0883	325	if (pdata->bd && !IS_ERR(pdata->bd))
069e8a65	326	backlight_device_unregister(pdata->bd);
	327	kfree(pdata->msgdata);
	328	}
	329	usb_set_intfdata(iface, NULL);
	330	kfree(pdata);
	331	return retval;
	332	}
	333
	334	static void appledisplay_disconnect(struct usb_interface *iface)
	335	{
	336	struct appledisplay *pdata = usb_get_intfdata(iface);
	337
	338	if (pdata) {
	339	usb_kill_urb(pdata->urb);
	340	cancel_delayed_work(&pdata->work);
	341	backlight_device_unregister(pdata->bd);
997ea58e	342	usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
069e8a65	343	pdata->urbdata, pdata->urb->transfer_dma);
	344	usb_free_urb(pdata->urb);
	345	kfree(pdata->msgdata);
	346	kfree(pdata);
	347	}
	348
	349	printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
	350	}
	351
	352	static struct usb_driver appledisplay_driver = {
	353	.name = "appledisplay",
	354	.probe = appledisplay_probe,
	355	.disconnect = appledisplay_disconnect,
	356	.id_table = appledisplay_table,
	357	};
	358
	359	static int __init appledisplay_init(void)
	360	{
	361	wq = create_singlethread_workqueue("appledisplay");
	362	if (!wq) {
fd3f1917	363	printk(KERN_ERR "appledisplay: Could not create work queue\n");
069e8a65	364	return -ENOMEM;
	365	}
	366
	367	return usb_register(&appledisplay_driver);
	368	}
	369
	370	static void __exit appledisplay_exit(void)
	371	{
	372	flush_workqueue(wq);
	373	destroy_workqueue(wq);
	374	usb_deregister(&appledisplay_driver);
	375	}
	376
	377	MODULE_AUTHOR("Michael Hanselmann");
	378	MODULE_DESCRIPTION("Apple Cinema Display driver");
	379	MODULE_LICENSE("GPL");
	380
	381	module_init(appledisplay_init);
	382	module_exit(appledisplay_exit);